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2<h3>BKG Ntrip Client (BNC) Version 2.8 Manual</h3>
3
4<p>
5The BKG Ntrip Client (BNC) is a program for simultaneously retrieving, decoding, converting and processing real-time GNSS data streams. It has been developed within the framework of the IAG sub-commission for Europe (EUREF) and the International GNSS Service (IGS). Although meant as a real-time tool, it comes with some Post Processing functionality. You may like to use it for data coming from NTRIP Broadcasters like
6<u>http://www.euref-ip.net/home</u>,
7<u>http://www.igs-ip.net/home</u>,
8<u>http://products.igs-ip.net/home</u>, or
9<u>http://mgex.igs-ip.net/home</u>.
10</p>
11
12<p>
13BNC has been written under GNU General Public License (GPL). Source code is available from Subversion software archive <u>http://software.rtcm-ntrip.org/svn/trunk/BNC.</u> Binaries for BNC are available for Windows, Linux, Solaris, and Mac OS X systems. We used the MinGW Version 4.4.0 compiler to create the Windows binary. It is likely that BNC can be compiled on other systems where a GNU compiler and Qt Version 4.7.3 are installed. Please ensure that you have installed the latest version of BNC available from <u>http://igs.bkg.bund.de/ntrip/download</u> and feel free to send us your comments, suggestions or bug reports.
14</p>
15
16<p><b>Contents</b><br>
17<a href="#purpose">1. Purpose</a><br>
18<a href="#opthandling">2. Handling</a><br>
19<a href="#optsettings">3. Settings</a><br>
20<a href="#limits">4. Limitations</a><br>
21<a href="#annex">5. Annex</a>
22</p>
23
24<p>
25<b><a name="authors">Authors</b><br>
26The BKG Ntrip Client (BNC) and its Qt graphic user interface has been developed for
27</p>
28<p>
29Federal Agency for Cartography and Geodesy (BKG)<br>
30Department of Geodesy<br>
31c/o Georg Weber<br>
32Frankfurt, Germany<br>
33[euref-ip@bkg.bund.de] or [igs-ip@bkg.bund.de]
34</p>
35
36<p>
37BNC has been written by
38</p>
39
40<p>
41Leos Mervart<br>
42Czech Technical University (CTU)<br>
43Department of Geodesy<br>
44Prague, Czech Republic
45</p>
46<p>
47BNC includes the following GNU GPL software components:
48<ul>
49<li> RTCM 2 decoder, written by Oliver Montenbruck, German Space Operations Center, DLR, Oberpfaffenhofen, Germany;</li>
50<li> RTCM 3 decoder for conventional and MSM observation messages and a RTCM 3 encoder & decoder for SSR messages, both written for BKG by Dirk Stoecker, Alberding GmbH, Schoenefeld, Germany.</li>
51</ul>
52</p>
53<p>
54Note that some figures presented in this documentation show screenshots from earlier versions of BNC. If so then there was either no relevant change in the presented contents or no change at all.
55</p>
56
57<p>
58<b>Acknowledgements</b><br>
59<ul>
60<li>
61Thomas Yan, Australian NSW Land and Property Information, proofread earlier versions of BNC's Help Contents. He also provides builds of BNC for Mac OS X systems.
62</li>
63<li>
64Scott Glazier, OmniSTAR Australia, has been helpful in finding BNC bugs.
65</li>
66<li>
67James Perlt, BKG, helped fixing bugs and redesigned BNC's main window.
68</li>
69<li>
70Andre Hauschild, German Space Operations Center, DLR, revised the RTCM Version 2 decoder.
71</li>
72<li>
73Zdenek Lukes, Czech Technical University Prague, Department of Geodesy, extended the RTCM Version 2 decoder to handle message types 3, 20, 21, and 22 and added the loss of lock indicator.
74</li>
75<li>
76Jan Dousa, Geodetic Observatory Pecny, Czech Republic, helped with fixing bugs.
77</li>
78<li>
79Denis Laurichesse, Centre National d'Etudes Spatiales (CNES), suggested synchronizing observations and clock corrections to reduce high frequency noise in PPP solutions.
80</li>
81<li>
82Lennard Huisman, Kadaster Netherlands, and Rolf Dach, Astronomical Institute University of Bern, assisted in handling satellite clocks in transformations from ITRF to regional reference frames.
83</li>
84</ul>
85</p>
86
87<p><a name="purpose"><h3>1. Purpose</h3></p>
88
89<p> The purpose of BNC is to
90<ul>
91<li>Retrieve real-time GNSS data streams available through NTRIP transport protocol;</li>
92<li>Retrieve real-time GNSS data streams via TCP directly from an IP address without using the NTRIP transport protocol;</li>
93<li>Retrieve real-time GNSS data streams from a local UDP or serial port without using the NTRIP transport protocol;</li>
94<li>Generate high-rate RINEX Observation and Navigation files to support near real-time GNSS Post Processing applications;</li>
95<li>Generate ephemeris and synchronized or unsynchronized observations epoch by epoch through an IP port to support real-time GNSS network engines;</li>
96<li>Generate orbit and clock corrections to Broadcast Ephemeris through an IP port to support real-time Precise Point Positioning on GNSS rovers;</li>
97<li>Generate synchronized or unsynchronized orbit and clock corrections to Broadcast Ephemeris epoch by epoch through an IP port to support the (outside) combination of such streams as coming simultaneously from various correction providers;</li>
98<li>Monitor the performance of a network of real-time GNSS data streams to generate advisory notes in case of outages or corrupted streams;</li>
99<li>Scan RTCM streams for incoming antenna information as well as observation types and message types and their repetition rates;</li>
100<li>Feed a stream into a GNSS receiver via serial communication link;</li>
101<li>Carry out real-time Precise Point Positioning to determine a GNSS rover position;</li>
102<li>Simultaneously process several Broadcast Correction streams to produce, encode and upload combined Broadcast Corrections;</li>
103<li>Upload a Broadcast Ephemeris stream in RTCM Version 3 format;</li>
104<li>Read GNSS orbits and clocks in a plain ASCII format from an IP port. They can be produced by a real-time GNSS engine such as RTNet and should be referenced to the IGS Earth-Centered-Earth-Fixed (ECEF) reference system. BNC will then</li>
105<ul>
106<li>Convert the IGS Earth-Centered-Earth-Fixed orbits and clocks into Broadcast Corrections with radial, along-track and cross-track components;</li>
107<li>Upload Broadcast Corrections as an RTCM Version 3 stream to an NTRIP Broadcaster;</li>
108<li>Refer the orbit and clock corrections to a specific reference system;</li>
109<li>Log the Broadcast Corrections as Clock RINEX files for further processing using other tools than BNC;</li>
110<li>Log the Broadcast Corrections as SP3 files for further processing using other tools than BNC;</li>
111</ul>
112<li>Edit or concatenate RINEX files or check their quality;</li>
113<li>Plot stream distribution map from NTRIP Broadcaster source-tables.</li>
114</ul>
115</p>
116
117<p>
118BNC supports decoding the following GNSS stream formats and message types:
119</p>
120<p>
121<ul>
122<li>RTCM Version 2 message types for GPS and GLONASS observations; </li>
123<li>RTCM Version 3 'conventional' message types for observations and Broadcast Ephemeris for GPS, GLONASS and Galileo (draft);</li>
124<li>RTCM Version 3 'State Space Representation' (SSR) messages for GPS and GLONASS;</li>
125<li>RTCM Version 3 'Multiple Signal Messages' (MSM) and 'High Precision Multiple Signal Messages' (HP MSM) including X-type observations for GPS, GLONASS and Galileo;</li>
126<li>RTNET, a plain ASCII format defined within BNC to receive orbits and clocks from a serving GNSS engine.
127</ul>
128</p>
129
130<p>
131Note that while BNC decodes RTCM's MSM and HP MSM messages for GPS, GLONASS and Galileo, the implemented decoding of
132<ul>
133<li>QZSS follows a JAXA proposal;</li>
134<li>BeiDou and SBAS follow an agreement between BKG, Alberding and DLR.</li>
135</ul>
136</p>
137
138<p>
139Note also that BNC allows to by-pass its decoding and conversion algorithms, leave whatever is received untouched and save it in files.
140</p>
141
142<p>
143The first of the following figures shows a flow chart of BNC connected to a GNSS receiver providing observations via serial or TCP communication link for the purpose of Precise Point Positioning. The second figure shows the conversion of RTCM streams to RINEX files. The third figure shows a flow chart of BNC feeding a real-time GNSS engine which estimates precise orbits and clocks. BNC is used in this scenario to encode correctors to RTCM Version 3 and upload them to an NTRIP Broadcaster. The fourth figure shows BNC combining several Broadcast Correction streams to disseminate the combination product while saving results in SP3 and Clock RINEX files.
144</p>
145<p><img src="IMG/screenshot10.png"/></p>
146<p><u>Figure 1:</u> Flowchart, BNC connected to a GNSS receiver for Precise Point Positioning.</p>
147
148<p>
149</p>
150<p><img src="IMG/screenshot01.png"/></p>
151<p><u>Figure 2:</u> Flowchart, BNC converting RTCM streams to RINEX batches.</p>
152
153<p>
154</p>
155<p><img src="IMG/screenshot02.png"/></p>
156<p><u>Figure 3:</u> Flowchart, BNC feeding a real-time GNSS engine and uploading encoded Broadcast Corrections.</p>
157
158<p>
159</p>
160<p><img src="IMG/screenshot19.png"/></p>
161<p><u>Figure 4:</u> Flowchart, BNC combining Broadcast Correction streams.</p>
162
163
164<p><a name="opthandling"><h3>2. Handling</h3></p>
165<p>
166Although BNC is mainly a real-time tool to be operated online, it can be run offline
167<ul>
168<li>To simulate real-time observation situations for debugging purposes;</li>
169<li>For Post Processing purposes.</li>
170</ul>
171Furthermore, apart from its regular window mode, BNC can be run as a batch/background job in a 'no window' mode using processing options from a previously saved configuration or from command line.
172</p>
173<p>
174Unless it runs offline, BNC
175</p>
176<ul>
177<li>Requires access to the Internet with a minimum of about 2 to 6 kbits/sec per stream depending on the stream format and the number of visible satellites. You need to make sure that the connection can sustain the required bandwidth;</li>
178<li>Requires the clock of the host computer to be properly synchronized;</li>
179<li>Has the capacity to retrieve hundreds of GNSS data streams simultaneously. Please be aware that such usage may incur a heavy load on the NTRIP Broadcaster side depending on the number of streams requested. We recommend limiting the number of streams where possible to avoid unnecessary workload.</li>
180</ul>
181</p>
182
183<p>
184The main window of BNC shows a 'Top menu bar' section, a 'Settings' sections with tabs to set processing options, a 'Streams' section, a section for 'Log' tabs, and a 'Bottom menu bar' section, see figure below.
185</p>
186<p><img src="IMG/screenshot09.png"/></p>
187<p><u>Figure 5:</u> Sections on BNC's main window.</p>
188
189<p>
190Running BNC in interactive mode requires graphics support. This is also
191required in batch mode when producing plots. Windows and Mac OS X systems always
192support graphics. However, when using BNC in batch mode on Linux systems for
193producing plots, you need to make sure that at least a virtual X-Server like
194'Xvfb' is installed and the '-display' command-line option is used.
195</p>
196
197<p>
198The usual handling of BNC is that you first select a number of streams ('Add Stream'). Any stream configured to BNC shows up on the 'Streams' canvas in the middle of BNC's main window. You then go through BNC's various configuration tabs to select a combination of input, processing and output options before you start the program ('Start'). Most configuration tabs are dedicated to a certain functionality of BNC. If the first option field on such a configuration tab is empty, the affected functionality is - apart from a few exceptions - deactivated.</p>
199
200Records of BNC's activities are shown in the 'Log' tab. The bandwidth consumption per stream, the latency of incoming observations and a PPP time series for coordinates are shown in the 'Throughput', 'Latency' and 'PPP Plot' tabs of the main window.
201</p>
202
203<p><a name="optconfig"><h3>2.1 Configuration Management</h3></p>
204<p>
205As a default, configuration files for running BNC on Unix/Linux/Mac OS X systems are saved in directory '${HOME}/.config/BKG'. On Windows systems, they are typically saved in directory 'C:/Documents and Settings/Username/.config/BKG'. The default configuration file name is 'BNC.bnc'.</p>
206<p>
207The default file name 'BNC.bnc' can be changed and the file contents can easily be edited. On graphical user interfaces it is possible to Drag &amp; Drop a configuration file icon to start BNC (not on Mac OS X systems). Some configuration options can be changed on-the-fly. See annexed 'Configuration Examples' for a complete set of configuration options. It is also possible to start and configure BNC via command line.
208</p>
209
210<p>
211BNC maintains configuration options at three different levels:
212</p>
213
214<ol type=b>
215<li>GUI, input fields level</li>
216<li>Active configuration level</li>
217<li>Configuration file, disk level</li>
218</ol>
219
220<p><img src="IMG/screenshot31.png"/></p>
221<p><u>Figure 6:</u> Management of configuration options in BNC:<br>
222&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Left: BNC in graphics mode where active configuration options are introduced through GUI input fields and finally saved on disk.<br>
223&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Middle: BNC in 'no window' mode where active configuration options are read from disk.<br>
224&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Right: BNC in 'no window' mode without configuration file where default configuration options can be replaced via command line options.</p>
225
226<p>
227Configuration options are usually specified using GUI input fields (1) after launching BNC. When hitting the 'Start' button, configuration options are transferred one level down to become BNC's active configuration (2) allowing the program to begin its operation. Pushing the 'Stop' button ends data processing so that the user can finally terminate BNC through 'File'->'Quit'->'Save Options' which saves processing options in a configuration file to disk (3). It is important to understand that:
228<ul>
229<li>Active configuration options (2) are independent from GUI input fields and configuration file contents.</li>
230<li>Hence changing configuration options at GUI level (1) while BNC is already processing data does not influence a running job.</li>
231<li>Editing configuration options at disk level (3) while BNC is already processing data does also not influence a running job. However, there are two exceptions which force BNC to update certain active options on-the-fly:</li>
232<ul>
233<li>Pushing the 'Save & Reread Configuration' button lets BNC immediately reread its configuration from disk.</li>
234<li>Specifying the 'Reread configuration' option lets BNC reread its configuration from disk at pre-defined intervals.</li>
235</ul>
236<li>A certain BNC configuration can be started in 'no window' mode from scratch without any configuration file if options for the active configuration level (2) are provided via command line.</li>
237</ul>
238</p>
239
240<p><a name="optsettings"><h3>3. Settings</h3></p>
241<p>
242This chapter describes how to set the BNC program options. It explains the top menu bar, the processing options, the 'Streams' and 'Log' sections, and the bottom menu bar.
243</p>
244<p>
245<b>Top Menu Bar</b><br>
2463.1. <a href=#topmenu>Top Menu Bar</a><br>
2473.1.1 <a href=#file>File</a><br>
2483.1.2 <a href=#help>Help</a><br><br>
249<b>Settings Canvas</b><br>
2503.2. <a href=#network>Network</a><br>
2513.2.1 <a href=#proxy>Proxy</a><br>
2523.2.2 <a href=#ssl>SSL</a><br>
2533.3. <a href=#general>General</a><br>
254&nbsp; &nbsp; &nbsp; 3.3.1. <a href=#genlog>Logfile</a><br>
255&nbsp; &nbsp; &nbsp; 3.3.2. <a href=#genapp>Append Files</a><br>
256&nbsp; &nbsp; &nbsp; 3.3.3. <a href=#genconf>Reread Configuration</a><br>
257&nbsp; &nbsp; &nbsp; 3.3.4. <a href=#genstart>Auto Start</a><br>
258&nbsp; &nbsp; &nbsp; 3.3.5. <a href=#rawout>Raw Output File</a><br>
2593.4. <a href=#rinex>RINEX Observations</a><br>
260&nbsp; &nbsp; &nbsp; 3.4.1. <a href=#rnxname>File Names</a><br>
261&nbsp; &nbsp; &nbsp; 3.4.2. <a href=#rnxdir>Directory</a><br>
262&nbsp; &nbsp; &nbsp; 3.4.3. <a href=#rnxinterval>File Interval</a><br>
263&nbsp; &nbsp; &nbsp; 3.4.4. <a href=#rnxsample>Sampling</a><br>
264&nbsp; &nbsp; &nbsp; 3.4.5. <a href=#rnxskl>Skeleton Extension</a><br>
265&nbsp; &nbsp; &nbsp; 3.4.6. <a href=#rnxscript>Script</a><br>
266&nbsp; &nbsp; &nbsp; 3.4.7. <a href=#rnxvers>Version</a><br>
2673.5. <a href=#ephemeris>RINEX Ephemeris</a><br>
268&nbsp; &nbsp; &nbsp; 3.5.1. <a href=#ephdir>Directory</a><br>
269&nbsp; &nbsp; &nbsp; 3.5.2. <a href=#ephint>Interval</a><br>
270&nbsp; &nbsp; &nbsp; 3.5.3. <a href=#ephport>Port</a><br>
271&nbsp; &nbsp; &nbsp; 3.5.4. <a href=#ephvers>Version</a><br>
2723.6. <a href=#reqc>RINEX Editing & QC</a><br>
273&nbsp; &nbsp; &nbsp; 3.6.1 <a href=#reqcact>Action</a><br>
274&nbsp; &nbsp; &nbsp; 3.6.2 <a href=#reqcedit>Set Edit Options</a><br>
275&nbsp; &nbsp; &nbsp; 3.6.3 <a href=#reqcinput>Input Files</a><br>
276&nbsp; &nbsp; &nbsp; 3.6.4 <a href=#reqcoutput>Output Files</a><br>
277&nbsp; &nbsp; &nbsp; 3.6.5 <a href=#reqcplots>Directory for Plots</a><br>
278&nbsp; &nbsp; &nbsp; 3.6.6 <a href=#reqccommand>Command Line, No Window</a><br>
2793.7. <a href=#correct>Broadcast Corrections</a><br>
280&nbsp; &nbsp; &nbsp; 3.7.1. <a href=#corrdir>Directory, ASCII</a><br>
281&nbsp; &nbsp; &nbsp; 3.7.2. <a href=#corrint>Interval</a><br>
282&nbsp; &nbsp; &nbsp; 3.7.3. <a href=#corrport>Port</a><br>
283&nbsp; &nbsp; &nbsp; 3.7.4. <a href=#corrwait>Wait for Full Corr Epoch</a><br>
2843.8. <a href=#syncout>Feed Engine</a><br>
285&nbsp; &nbsp; &nbsp; 3.8.1. <a href=#syncport>Port</a><br>
286&nbsp; &nbsp; &nbsp; 3.8.2. <a href=#syncwait>Wait for Full Obs Epoch</a><br>
287&nbsp; &nbsp; &nbsp; 3.8.3. <a href=#syncsample>Sampling</a><br>
288&nbsp; &nbsp; &nbsp; 3.8.4. <a href=#syncfile>File</a><br>
289&nbsp; &nbsp; &nbsp; 3.8.5. <a href=#syncuport>Port (unsynchronized)</a><br>
2903.9. <a href=#serial>Serial Output</a><br>
291&nbsp; &nbsp; &nbsp; 3.9.1. <a href=#sermount>Mountpoint</a><br>
292&nbsp; &nbsp; &nbsp; 3.9.2. <a href=#serport>Port Name</a><br>
293&nbsp; &nbsp; &nbsp; 3.9.3. <a href=#serbaud>Baud Rate</a><br>
294&nbsp; &nbsp; &nbsp; 3.9.4. <a href=#serflow>Flow Control</a><br>
295&nbsp; &nbsp; &nbsp; 3.9.5. <a href=#serparity>Parity</a><br>
296&nbsp; &nbsp; &nbsp; 3.9.6. <a href=#serdata>Data Bits</a><br>
297&nbsp; &nbsp; &nbsp; 3.9.7. <a href=#serstop>Stop Bits</a><br>
298&nbsp; &nbsp; &nbsp; 3.9.8. <a href=#serauto>NMEA</a><br>
299&nbsp; &nbsp; &nbsp; 3.9.9. <a href=#serfile>File</a><br>
300&nbsp; &nbsp; &nbsp; 3.9.10. <a href=#serheight>Height</a><br>
3013.10. <a href=#advnote>Outages</a><br>
302&nbsp; &nbsp; &nbsp; 3.10.1. <a href=#obsrate>Observation Rate</a><br>
303&nbsp; &nbsp; &nbsp; 3.10.2. <a href=#advfail>Failure Threshold</a><br>
304&nbsp; &nbsp; &nbsp; 3.10.3. <a href=#advreco>Recovery Threshold</a><br>
305&nbsp; &nbsp; &nbsp; 3.10.4. <a href=#advscript>Script</a><br>
3063.11. <a href=#misc>Miscellaneous</a><br>
307&nbsp; &nbsp; &nbsp; 3.11.1. <a href=#miscmount>Mountpoint</a><br>
308&nbsp; &nbsp; &nbsp; 3.11.2. <a href=#miscperf>Log Latency</a><br>
309&nbsp; &nbsp; &nbsp; 3.11.3. <a href=#miscscan>Scan RTCM</a><br>
3103.12. <a href=#pppclient>PPP Client</a><br>
311&nbsp; &nbsp; &nbsp; 3.12.1 <a href=#pppmode>Mode & Mountpoints</a><br>
312&nbsp; &nbsp; &nbsp; 3.12.1.1 <a href=#pppmodus>Mode</a><br>
313&nbsp; &nbsp; &nbsp; 3.12.1.2 <a href=#pppobsmount>Obs Mountpoint</a><br>
314&nbsp; &nbsp; &nbsp; 3.12.1.3 <a href=#pppcorrmount>Corr Mountpoint</a><br>
315&nbsp; &nbsp; &nbsp; 3.12.2 <a href=#pppxyz>Marker Coordinates</a><br>
316&nbsp; &nbsp; &nbsp; 3.11.3 <a href=#pppneu>Antenna Eccentricity</a><br>
317&nbsp; &nbsp; &nbsp; 3.12.4 <a href=#pppoutput>NMEA & Plot Output</a><br>
318&nbsp; &nbsp; &nbsp; 3.12.4.1 <a href=#pppnmeafile>NMEA File</a><br>
319&nbsp; &nbsp; &nbsp; 3.12.4.2 <a href=#pppnmeaport>NMEA Port</a><br>
320&nbsp; &nbsp; &nbsp; 3.12.4.3 <a href=#pppplot>PPP Plot</a><br>
321&nbsp; &nbsp; &nbsp; 3.12.5 <a href=#ppppost>Post Processing</a><br>
322&nbsp; &nbsp; &nbsp; 3.12.6 <a href=#ppprecant>Antennas</a><br>
323&nbsp; &nbsp; &nbsp; 3.12.6.1 <a href=#pppantex>ANTEX File</a><br>
324&nbsp; &nbsp; &nbsp; 3.12.6.2 <a href=#ppprecantenna>Antenna Name</a><br>
325&nbsp; &nbsp; &nbsp; 3.12.7 <a href=#pppbasics>Basics</a><br>
326&nbsp; &nbsp; &nbsp; 3.12.7.1 <a href=#pppphase>Use Phase Obs</a><br>
327&nbsp; &nbsp; &nbsp; 3.12.7.2 <a href=#ppptropo>Estimate Tropo</a><br>
328&nbsp; &nbsp; &nbsp; 3.12.7.3 <a href=#pppglo>Use GLONASS</a><br>
329&nbsp; &nbsp; &nbsp; 3.12.7.4 <a href=#pppgal>Use Galileo</a><br>
330&nbsp; &nbsp; &nbsp; 3.12.7.5 <a href=#pppsync>Sync Corr</a><br>
331&nbsp; &nbsp; &nbsp; 3.12.7.6 <a href=#pppaverage>Averaging</a><br>
332&nbsp; &nbsp; &nbsp; 3.12.7.7 <a href=#pppquick>Quick-Start</a><br>
333&nbsp; &nbsp; &nbsp; 3.12.7.8 <a href=#pppgap>Maximal Solution Gap</a><br>
334&nbsp; &nbsp; &nbsp; 3.12.7.9 <a href=#pppaudio>Audio Response</a><br>
335&nbsp; &nbsp; &nbsp; 3.12.8 <a href=#pppsigmas>Sigmas</a><br>
336&nbsp; &nbsp; &nbsp; 3.12.8.1 <a href=#pppsigc>Code</a><br>
337&nbsp; &nbsp; &nbsp; 3.12.8.2 <a href=#pppsigp>Phase</a><br>
338&nbsp; &nbsp; &nbsp; 3.12.8.3 <a href=#pppsigxyzi>XYZ Init</a><br>
339&nbsp; &nbsp; &nbsp; 3.12.8.4 <a href=#pppsigxyzn>XYZ White Noise</a><br>
340&nbsp; &nbsp; &nbsp; 3.12.8.5 <a href=#pppsigtrpi>Tropo Init</a><br>
341&nbsp; &nbsp; &nbsp; 3.12.8.6 <a href=#pppsigtrpn>Tropo White Noise</a><br>
3423.13. <a href=#combi>Combine Corrections</a><br>
343&nbsp; &nbsp; &nbsp; 3.13.1 <a href=#combimounttab>Combine Corrections Table</a><br>
344&nbsp; &nbsp; &nbsp; 3.13.1.1 <a href=#combiadd>Add Row, Delete</a><br>
345&nbsp; &nbsp; &nbsp; 3.13.1.2 <a href=#combimethod>Method</a><br>
346&nbsp; &nbsp; &nbsp; 3.13.1.3 <a href=#combimax>Maximal Residuum</a><br>
347&nbsp; &nbsp; &nbsp; 3.13.1.4 <a href=#combismpl>Sampling</a><br>
3483.14. <a href=#upclk>Upload Corrections</a><br>
349&nbsp; &nbsp; &nbsp; 3.14.1 <a href=#upadd>Add, Delete Row</a><br>
350&nbsp; &nbsp; &nbsp; 3.14.2 <a href=#uphost>Host, Port, Mountpoint, Password</a><br>
351&nbsp; &nbsp; &nbsp; 3.14.3 <a href=#upsystem>System</a><br>
352&nbsp; &nbsp; &nbsp; 3.14.4 <a href=#upcom>Center of Mass</a><br>
353&nbsp; &nbsp; &nbsp; 3.14.5 <a href=#upsp3>SP3 File</a><br>
354&nbsp; &nbsp; &nbsp; 3.14.6 <a href=#uprinex>RNX File</a><br>
355&nbsp; &nbsp; &nbsp; 3.14.7 <a href=#upinter>Interval</a><br>
356&nbsp; &nbsp; &nbsp; 3.14.8 <a href=#upclksmpl>Sampling</a><br>
357&nbsp; &nbsp; &nbsp; 3.14.8.1 <a href=#upclkorb>orbits</a><br>
358&nbsp; &nbsp; &nbsp; 3.14.8.2 <a href=#upclksp3>SP3</a><br>
359&nbsp; &nbsp; &nbsp; 3.14.8.3 <a href=#upclkrnx>RINEX </a><br>
360&nbsp; &nbsp; &nbsp; 3.14.9 <a href=#upcustom>Custom Trafo</a><br>
3613.15. <a href=#upeph>Upload Ephemeris</a><br>
362&nbsp; &nbsp; &nbsp; 3.15.1 <a href=#brdcserver>Host &amp; Port</a><br>
363&nbsp; &nbsp; &nbsp; 3.15.2 <a href=#brdcmount>Mountpoint &amp; Password</a><br>
364&nbsp; &nbsp; &nbsp; 3.15.3 <a href=#brdcsmpl>Sampling</a><br><br>
365<b>Streams Canvas</b><br>
3663.16. <a href=#streams>Streams</a><br>
367&nbsp; &nbsp; &nbsp; 3.16.1 <a href=#streamedit>Edit Streams</a><br>
368&nbsp; &nbsp; &nbsp; 3.16.2 <a href=#streamdelete>Delete Stream</a><br>
369&nbsp; &nbsp; &nbsp; 3.16.3 <a href=#streamconf>Reconfigure Stream Selection On-the-fly</a><br><br>
370<b>Logging Canvas</b><br>
3713.17. <a href=#logs>Logging</a><br>
372&nbsp; &nbsp; &nbsp; 3.17.1 <a href=#logfile>Log</a><br>
373&nbsp; &nbsp; &nbsp; 3.17.2 <a href=#throughput>Throughput</a><br>
374&nbsp; &nbsp; &nbsp; 3.17.3 <a href=#latency>Latency</a><br>
375&nbsp; &nbsp; &nbsp; 3.17.4 <a href=#ppptab>PPP Plot</a><br><br>
376<b>Bottom Menu Bar</b><br>
3773.18. <a href=#bottom>Bottom Menu Bar</a><br>
378&nbsp; &nbsp; &nbsp; 3.18.1. <a href=#streamadd>Add Stream</a><br>
379&nbsp; &nbsp; &nbsp; 3.18.1.1 <a href=#streamcaster>Add Stream - Coming from Caster</a><br>
380&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.18.1.1.1 <a href=#streamhost>Caster Host and Port</a><br>
381&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.18.1.1.2 <a href=#streamtable>Casters Table</a><br>
382&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.18.1.1.3 <a href=#streamuser>User and Password</a><br>
383&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.18.1.1.4 <a href=#gettable>Get Table</a><br>
384&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.18.1.1.5 <a href=#ntripv>NTRIP Version</a><br>
385&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.18.1.1.6 <a href=#castermap>Map</a><br>
386&nbsp; &nbsp; &nbsp; 3.18.1.2 <a href=#streamip>Add Stream - Coming from TCP/IP Port</a><br>
387&nbsp; &nbsp; &nbsp; 3.18.1.3 <a href=#streamudp>Add Stream - Coming from UDP Port</a><br>
388&nbsp; &nbsp; &nbsp; 3.18.1.4 <a href=#streamser>Add Stream - Coming from Serial Port</a><br>
389&nbsp; &nbsp; &nbsp; 3.18.2. <a href=#streamsdelete>Delete Stream</a><br>
390&nbsp; &nbsp; &nbsp; 3.18.3. <a href=#streamsmap>Map</a><br>
391&nbsp; &nbsp; &nbsp; 3.18.4 <a href=#start>Start</a><br>
392&nbsp; &nbsp; &nbsp; 3.18.5 <a href=#stop>Stop</a><br><br>
393<b>Command Line</b><br>
3943.19. <a href=#cmd>Command Line Options</a><br>
395&nbsp; &nbsp; &nbsp; 3.19.1. <a href=#nw>No Window Mode</a><br>
396&nbsp; &nbsp; &nbsp; 3.19.2. <a href=#post>File Mode</a><br>
397&nbsp; &nbsp; &nbsp; 3.19.3. <a href=#conffile>Configuration File</a><br>
398&nbsp; &nbsp; &nbsp; 3.19.4. <a href=#confopt>Configuration Options</a><br>
399</p>
400
401<p><a name="topmenu"><h4>3.1. Top Menu Bar</h4></p>
402<p>
403The top menu bar allows selecting a font for the BNC windows, save configured options, or quit the program execution. It also provides access to program documentation.
404</p>
405
406<p><a name="file"><h4>3.1.1 File</h4></p>
407
408<p>
409The 'File' button lets you
410<ul>
411<li> select an appropriate font.<br>
412Use smaller font size if the BNC main window exceeds the size of your screen.
413</li>
414<li> save selected options in configuration file.<br>
415When using 'Save &amp; Reread Configuration' while BNC is already processing data, some configuration options become immediately effective on-the-fly without interrupting uninvolved threads. See annexed section 'Configuration Examples' for a list of on-the-fly changeable configuration options.
416</li>
417<li> quit the BNC program.
418</li>
419</ul>
420</p>
421
422<p><a name="help"><h4>3.1.2 Help</h4></p>
423
424<p>
425The 'Help' button provides access to
426<ul>
427<li>
428help contents.<br>
429You may keep the 'Help Contents' window open while configuring BNC.
430</li>
431<li>
432a 'Flow Chart' showing BNC linked to a real-time GNSS network engine such as RTNet.
433</li>
434<li>
435general information about BNC.<br>
436Close the 'About BNC' window to continue working with BNC.
437</li>
438</ul>
439</p>
440<p>
441BNC comes with a help system providing online information about its functionality and usage. Short descriptions are available for any widget. Focus to the relevant widget and press Shift+F1 to request help information. A help text appears immediately; it disappears as soon as the user does something else. The dialogs on some operating systems may provide a &quot;?&quot; button that users can click; click the relevant widget to pop up the help text.
442</p>
443
444<p><a name="network"><h4>3.2. Network</h4></p>
445<p>
446You may need to specify a proxy when running BNC in a protected network. You may also like to use the Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL) cryptographic protocols for secure NTRIP communication over the Internet.
447</p>
448<p><a name="proxy"><h4>3.2.1 Proxy - Usage in a protected LAN</h4></p>
449<p>
450If you are running BNC within a protected Local Area Network (LAN), you might need to use a proxy server to access the Internet. Enter your proxy server IP and port number in case one is operated in front of BNC. If you don't know the IP and port of your proxy server, check the proxy server settings in your Internet browser or ask your network administrator.</p>
451<p>
452Note that IP streaming is often not allowed in a LAN. In this case you need to ask your network administrator for an appropriate modification of the local security policy or for the installation of a TCP relay to the NTRIP Broadcasters. If these are not possible, you might need to run BNC outside your LAN on a host that has unobstructed connection to the Internet.
453</p>
454
455<p><a name="ssl"><h4>3.2.2 SSL - Transport Layer Security</h4></p>
456<p>Communication with an NTRIP Broadcaster over SSL requires the exchange of client and/or server certificates. Specify the path to a directory where you save certificates on your system. You may like to check out <u>http://software.rtcm-ntrip.org/wiki/Certificates</u> for a list of known NTRIP Server certificates. You may also just try communication via SSL to check out whether this is supported by the involved NTRIP Broadcaster. </p>
457<p>SSL communication may involve queries coming from the NTRIP Broadcaster. Tick 'Ignore SSL authorization errors' if you don't want to be bothered with this. Note that SSL communication is usually done over port 443.</p>
458
459<p><a name="general"><h4>3.3. General</h4></p>
460<p>
461The following defines general settings for BNC's logfile, file handling, reconfiguration on-the-fly, and auto-start.
462</p>
463
464<p><a name="genlog"><h4>3.3.1 Logfile - optional</h4></p>
465<p>
466Records of BNC's activities are shown in the 'Log' tab on the bottom of the main window. These logs can be saved into a file when a valid path is specified in the 'Logfile (full path)' field. The logfile name will automatically be extended by a string '_YYMMDD' carrying the current date. This leads to series of daily logfiles when running BNC continuously for extended. Message logs cover the communication status between BNC and the NTRIP Broadcaster as well as problems that may occur in the communication link, stream availability, stream delay, stream conversion etc. All times are given in UTC. The default value for 'Logfile (full path)' is an empty option field, meaning that BNC logs will not be saved into a file.
467</p>
468
469<p><a name="genapp"><h4>3.3.2 Append Files - optional</h4></p>
470<p>
471When BNC is started, new files are created by default and any existing files with the same name will be overwritten. However, users might want to append existing files following a restart of BNC, a system crash or when BNC crashed. Tick 'Append files' to continue with existing files and keep what has been recorded so far. Note that option 'Append files' affects all types of files created by BNC.
472</p>
473
474<p><a name="genconf"><h4>3.3.3 Reread Configuration - optional</h4></p>
475<p>
476When operating BNC online in 'no window' mode (command line option -nw), some configuration options can nevertheless be changed on-the-fly without interrupting the running process. For that you force the program to reread parts of its configuration in pre-defined intervals from the disk. Select '1 min', '1 hour', or '1 day' to let BNC reread on-the-fly changeable configuration options every full minute, hour, or day. This lets in between edited options become effective without interrupting uninvolved threads. See annexed section 'Configuration Examples' for a configuration file example and a list of on-the-fly changeable options.
477</p>
478
479<p><a name="genstart"><h4>3.3.4 Auto Start - optional</h4></p>
480<p>
481You may like to auto-start BNC at startup time in window mode with pre-assigned configuration options. This may be required i.e. immediately after booting your system. Tick 'Auto start' to supersede the usage of the 'Start' button. Make sure that you maintain a link to BNC for that in your Autostart directory (Windows systems) or call BNC in a script below directory /etc/init.d (Unix/Linux/Mac OS X systems).
482</p>
483<p>
484 See BNC's command line option -nw for an auto-start of BNC in 'no window' mode.
485</p>
486
487<p><a name="rawout"><h4>3.3.5 Raw Output File - optional</h4></p>
488<p>
489BNC can save all data coming in through various streams in one daily file. The information is recorded in the specified 'Raw output file' in the received order and format. This feature allows a BNC user to run the PPP option offline with observations, Broadcast Corrections, and Broadcast Ephemeris being read from a previously saved file. It supports the offline repetition of a real-time situation for debugging purposes and it is not meant for Post Processing.
490</p>
491<p>
492Data will be saved in blocks in the received format separated by ASCII time stamps like (example):
493<pre>
4942010-08-03T18:05:28 RTCM3EPH RTCM_3 67
495</pre>
496</p>
497<p>
498This example block header tells you that 67 bytes were saved in the data block following this time stamp. The information in this block is encoded in RTCM Version 3 format, comes from mountpoint RTCM3EPH and was received at 18:05:29 UTC on 2010-08-03. BNC adds its own time stamps in order to allow the reconstruction of a recorded real-time situation.
499</p>
500<p>
501The default value for 'Raw output file' is an empty option field, meaning that BNC will not save all raw data into one single daily file.
502</p>
503
504<p><a name="rinex"><h4>3.4. RINEX Observations</h4></p>
505<p>
506Observations will be converted to RINEX if they come in either RTCM Version 2 or RTCM Version 3 format. Depending on the RINEX version and incoming RTCM message types, files generated by BNC may contain data from GPS, GLONASS, Galileo, SBAS, QZSS and BeiDou. In case an observation type is listed in the RINEX header but the corresponding observation is unavailable, its value is set to zero '0.000'. Note that the 'RINEX TYPE' field in the RINEX Version 3 Observation file header is always set to 'M(MIXED)' or 'Mixed' even if the file only contains data from one system.
507</p>
508<p>
509It is important to understand that converting RTCM streams to RINEX files requires a-priori information on observation types for specifying a complete RINEX header. Regarding the RINEX Version 2 file header, BNC simply introduces all observation types defined in the Version 2 standard and later reports "0.000" for all observations which are not received. However, following this approach is not possible for RINEX Version 3 files from RTCM Version 3 MSM streams because of the huge number of observation types which might in principle show up. The solution implemented in BNC is to start with RINEX Version 3 observation type records from skeleton files (see section 'Skeleton Extension') and switch to a default selection of observation types when such skeleton file is not available or it does not contain the required information. The 'Default selection of observation types specified' for a RINEX Version 3 file would be as follows:
510</p>
511<pre>
512C 12 C2 L2 D2 S2 C6 L6 D6 S6 C7 L7 D7 S7 SYS / # / OBS TYPES
513E 20 C1 L1 D1 S1 C5 L5 D5 S5 C6 L6 D6 S6 C7 SYS / # / OBS TYPES
514 L7 D7 S7 C8 L8 D8 S8 SYS / # / OBS TYPES
515G 20 C1C L1C D1C S1C C1P L1P D1P S1P C2C L2C D2C S2C C2P SYS / # / OBS TYPES
516 L2P D2P S2P C5 D5 L5 S5 SYS / # / OBS TYPES
517J 16 C1 L1 D1 S1 C2 L2 D2 S2 C5 L5 D5 S5 C6 SYS / # / OBS TYPES
518 D6 L6 S6 SYS / # / OBS TYPES
519R 16 C1C L1C D1C S1C C1P L1P D1P S1P C2C L2C D2C S2C C2P SYS / # / OBS TYPES
520 L2P D2P S2P SYS / # / OBS TYPES
521S 8 C1 L1 D1 S1 C5 L5 D5 S5 SYS / # / OBS TYPES
522</pre>
523
524<p>
525The screenshot below shows an example setup of BNC when converting streams to RINEX. Streams are coming from various NTRIP Broadcasters as well as from a serial communication link. Specifying a decoder string 'ZERO' means to not convert the affected stream contents but save its contents as received.
526</p>
527<p><img src="IMG/screenshot16.png"/></p>
528<p><u>Figure 7:</u> BNC translating incoming streams to 15 min RINEX Version 3 files.</p>
529
530
531<p><a name="rnxname"><h4>3.4.1 RINEX File Names</h4></p>
532<p>
533RINEX file names are derived by BNC from the first 4 characters of the corresponding stream's mountpoint (4Char Station ID). For example, data from mountpoints FRANKFURT and WETTZELL will have hourly RINEX Observation files named</p>
534<p>
535FRAN{ddd}{h}.{yy}O<br>
536WETT{ddd}{h}.{yy}O
537</p>
538<p>
539where 'ddd' is the day of year, 'h' is a letter which corresponds to an hour long UTC time block and 'yy' is the year.
540</p>
541<p>
542If there is more than one stream with identical 4Char Station ID (same first 4 characters for their mountpoints), the mountpoint strings are split into two sub-strings and both become part of the RINEX file name. For example, when simultaneously retrieving data from mountpoints FRANKFURT and FRANCE, their hourly RINEX Observation files are named as</p>
543<p>
544FRAN{ddd}{h}_KFURT.{yy}O<br>
545FRAN{ddd}{h}_CE.{yy}O.
546</p>
547<p>
548If several streams show exactly the same mountpoint name (example: BRUS0 from <u>www.euref-ip.net</u> and BRUS0 from <u>www.igs-ip.net</u>), BNC adds an integer number to the file name leading i.e. to hourly RINEX Observation files like</p>
549<p>
550BRUS{ddd}{h}_0.{yy}O<br>
551BRUS{ddd}{h}_1.{yy}O.
552</p>
553<p>
554Note that RINEX file names for all intervals less than 1 hour follow the file name convention for 15 minutes RINEX Observation files i.e.</p>
555<p>
556FRAN{ddd}{h}{mm}.{yy}O
557</p>
558<p>
559where 'mm' is the starting minute within the hour.
560</p>
561
562<p><a name="rnxdir"><h4>3.4.2 Directory - optional</h4></p>
563<p>
564Here you can specify the path to where the RINEX Observation files will be stored. If the specified directory does not exist, BNC will not create RINEX Observation files. Default value for 'Directory' is an empty option field, meaning that no RINEX Observation files will be written.
565</p>
566
567<p><a name="rnxinterval"><h4>3.4.3 File Interval - mandatory if 'Directory' is set</h4></p>
568<p>
569Select the length of the RINEX Observation file generated. The default value is 15 minutes.
570</p>
571
572<p><a name="rnxsample"><h4>3.4.4 Sampling - mandatory if 'Directory' is set </h4></p>
573<p>
574Select the RINEX Observation sampling interval in seconds. A value of zero '0' tells BNC to store all received epochs into RINEX. This is the default value.
575</p>
576
577<p><a name="rnxskl"><h4>3.4.5 Skeleton Extension - optional</h4></p>
578<p>
579Whenever BNC starts generating RINEX Observation files (and then once every day at midnight), it first tries to retrieve information needed for RINEX headers from so-called public RINEX header skeleton files which are derived from sitelogs. A HTTP link to a directory containing these skeleton files may be available through data field number 7 of the affected NET record in the source-table. See <u>http://www.epncb.oma.be:80/stations/log/skl/brus.skl</u> for an example of a public RINEX header skeleton file for the Brussels EPN station.
580</p>
581<p>
582However, sometimes public RINEX header skeleton files are not available, their contents is not up to date, or you need to put additional/optional records in the RINEX header. For that BNC allows using personal skeleton files that contain the header records you would like to include. You can derive a personal RINEX header skeleton file from the information given in an up to date sitelog. A file in the RINEX Observations 'Directory' with a 'Skeleton extension' suffix is interpreted by BNC as a personal RINEX header skeleton file for the corresponding stream.
583</p>
584<p>
585Examples for personal skeleton file name convention: RINEX Observation files for mountpoints WETTZELL, FRANKFURT and FRANCE (same 4Char Station ID), BRUS0 from <u>www.euref-ip.net</u> and BRUS0 from <u>www.igs-ip.net</u> (same 4Char Station ID, identical mountpoint stings) would accept personal skeleton files named</p>
586<p>
587WETT.skl<br>
588FRAN_KFURT.skl<br>
589FRAN_CE.skl<br>
590BRUS_0.skl<br>
591BRUS_1.skl</p>
592<p>
593if 'Skeleton extension' is set to 'skl'.
594</p>
595<p>
596Note the following regulations regarding personal RINEX header skeleton files:
597<ul>
598<li>If such a file exists in the 'RINEX directory', the corresponding public RINEX header skeleton file is ignored. The RINEX header is generated solely from the contents of the personal skeleton.</li>
599<li>Personal skeletons should contain a complete first header record of type
600<br>- &nbsp; RINEX VERSION / TYPE<br></li>
601<li>They should then contain an empty header record of type
602<br>- &nbsp; PGM / RUN BY / DATE<br>
603BNC will complete this line and include it in the RINEX file header.</li>
604<li>They should further contain complete header records of type
605<br>- &nbsp; MARKER NAME
606<br>- &nbsp; OBSERVER / AGENCY
607<br>- &nbsp; REC # / TYPE / VERS
608<br>- &nbsp; ANT # / TYPE
609<br>- &nbsp; APPROX POSITION XYZ
610<br>- &nbsp; ANTENNA: DELTA H/E/N
611<br>- &nbsp; WAVELENGTH FACT L1/2 (RINEX Version 2)</li>
612<br>- &nbsp; SYS / # / OBS TYPES (RINEX Version 3, will be ignored when writing Version 2 files)</li>
613<li>They may contain any other optional complete header record as defined in the RINEX documentation.</li>
614<li>They should also contain an empty header records of type
615<br>- &nbsp; # / TYPES OF OBSERV (only RINEX Version 2, will be ignored when writing RINEX Version 3 files)
616<br>BNC will include these lines in the final RINEX file header together with an additional
617<br>- &nbsp; COMMENT
618<br>line describing the source of the stream.</li>
619<li>They should finally contain an empty header record of type
620<br>- &nbsp; END OF HEADER (last record)</li>
621
622<li>They must not contain a header record of type
623<br>- &nbsp; TIME OF FIRST OBS</li>
624
625</ul>
626<p>
627If neither a public nor a personal RINEX header skeleton file is available for BNC, a default header will be used.
628</p>
629<p>
630The following is a skeleton example for a RINEX file:
631</p>
632<p>
633<pre>
634 OBSERVATION DATA M (Mixed) RINEX VERSION / TYPE
635DUND MARKER NAME
63650212M003 MARKER NUMBER
6374635120796 TRIMBLE NETR9 1.15 REC # / TYPE / VERS
63812626150 TRM41249.00 NONE ANT # / TYPE
639 -4388121.1700 726671.0500 -4556535.6300 APPROX POSITION XYZ
640 0.0020 0.0000 0.0000 ANTENNA: DELTA H/E/N
641GeoNet Reception GNS OBSERVER / AGENCY
642G 28 21C L1C D1C S1C C1W L1W D1W S1W C5X L5X D5X S5X C2W SYS / # / OBS TYPES
643 L2W D2W S2W C2X L2X D2X S2X SYS / # / OBS TYPES
644R 16 C1C L1C D1C S1C C1P L1P D1P S1P C2P L2P D2P S2P C2C SYS / # / OBS TYPES
645 L2C D2C S2C SYS / # / OBS TYPES
646S 12 C1C L1C D1C S1C C1W L1W D1W S1W C5I L5I D5I S5I SYS / # / OBS TYPES
647E 8 C1 L1 D1 S1 C5 L5 D5 S5 SYS / # / OBS TYPES
648C 4 C2I L2I D2I S2I SYS / # / OBS TYPES
649J 12 C1C L1C D1C S1C C2 L2 D2 S2 C5 L5 D5 S5 SYS / # / OBS TYPES
650PORTIONS OF THIS HEADER GENERATED BY BKG FROM COMMENT
651SITELOG dund_20070806.log COMMENT
652</pre>
653<p>
654
655<p><a name="rnxscript"><h4>3.4.6 Script - optional</h4></p>
656<p>
657Whenever a RINEX Observation file is saved, you might want to compress copy or upload it immediately via FTP. BNC allows you to execute a script/batch file to carry out these operations. To do that, specify the full path of the script/batch file here. BNC will pass the RINEX Observation file path to the script as a command line parameter (%1 on Windows systems, $1 on Unix/Linux/Mac OS X systems).
658</p>
659<p>
660The triggering event for calling the script or batch file is the end of a RINEX Observation file 'Interval'. If that is overridden by a stream outage, the triggering event is the stream reconnection.
661</p>
662<p>
663As an alternative to initiating file uploads through BNC, you may like to call an upload script or batch file through your crontable or Task Scheduler (independent from BNC) once every one or two minutes after the end of each RINEX file 'Interval'.
664</p>
665
666<p><a name="rnxvers"><h4>3.4.7 Version - optional</h4></p>
667<p>
668The default format for RINEX Observation files is RINEX Version 2.11. Select 'Version 3' if you would like to save observations in RINEX Version 3 format.
669</p>
670
671<p><a name="ephemeris"><h4>3.5. RINEX Ephemeris</h4></p>
672<p>
673Broadcast Ephemeris can be saved as RINEX Navigation files when received via RTCM Version 3 e.g. as message types 1019 (GPS) or 1020 (GLONASS) or 1045 (Galileo). The file name convention follows the details given in section 'RINEX File Names' except that the first four characters are 'BRDC' and the last character is
674</p>
675<ul>
676<li>'N' or 'G' for GPS or GLONASS ephemeris in two separate RINEX Version 2.11 Navigation files, or</li>
677<li>'P' for GPS plus GLONASS plus Galileo ephemeris saved together in one RINEX Version 3 Navigation file.
678</ul>
679
680<p>
681Note that streams dedicated to carry Broadcast Ephemeris messages in RTCM Version 3 format in high repetition rates are listed on <u>http://igs.bkg.bund.de/ntrip/ephemeris</u>.
682</p>
683
684<p><a name="ephdir"><h4>3.5.1 Directory - optional</h4></p>
685<p>
686Specify a path for saving Broadcast Ephemeris data as RINEX Navigation files. If the specified directory does not exist, BNC will not create RINEX Navigation files. Default value for Ephemeris 'Directory' is an empty option field, meaning that no RINEX Navigation files will be created.
687</p>
688
689<p><a name="ephint"><h4>3.5.2 Interval - mandatory if 'Directory' is set</h4></p>
690<p>
691Select the length of the RINEX Navigation file generated. The default value is 1 day.
692</p>
693
694<p><a name="ephport"><h4>3.5.3 Port - optional</h4></p>
695<p>
696BNC can output Broadcast Ephemeris in RINEX Version 3 format on your local host (IP 127.0.0.1) through an IP 'Port'. Specify an IP port number to activate this function. The default is an empty option field, meaning that no ASCII ephemeris output via IP port is generated.
697</p>
698<p>
699The source code for BNC comes with an example perl script 'test_tcpip_client.pl' that allows you to read BNC's ASCII ephemeris output from the IP port.
700</p>
701
702<p><a name="ephvers"><h4>3.5.4 Version - optional</h4></p>
703<p>
704Default format for RINEX Navigation files containing Broadcast Ephemeris is RINEX Version 2.11. Select 'Version 3' if you want to save the ephemeris in RINEX Version 3 format.
705</p>
706<p>
707Note that this does not concern the Broadcast Ephemeris output through IP port which is always in RINEX Version 3 format.
708</p>
709
710<p><a name="reqc"><h4>3.6. RINEX Editing & QC</h4></p>
711<p>
712Besides stream conversion from RTCM to RINEX, BNC allows editing RINEX files or concatenate their contents. RINEX Observation and Navigation files can be handled. BNC can also carry out a RINEX file quality check. In summary this functionality in BNC covers
713<ul>
714<li>Stream <u>T</u>ranslation</li>
715<li>File <u>E</u>diting and concatenation</li>
716<li>File <u>Q</b></u>uality <u>C</u>heck</li>
717<ul>
718<li>Multipath analysis sky plots (see Estey and Meertens 1999)</li>
719<li>Signal-to-Noise sky plots</li>
720<li>Satellite availability plots</li>
721<li>Satellite elevation plots</li>
722<li>PDOP plots</li>
723</ul>
724</ul>
725and hence follows UNAVCO's famous 'TEQC' program. The remarkable thing about BNC in this context is that it supports RINEX Version 3 under GNU General Public License.
726</p>
727
728<p><a name="reqcact"><h4>3.6.1 Action - optional</h4></p>
729<p>Select an action. Options are 'Edit/Concatenate' and 'Analyze'.
730<ul>
731<li>Select 'Edit/Concatenate' if you want to edit RINEX file contents according to options specified under 'Set Edit Options' or if you want to concatenate several RINEX files.</li>
732<li>Select 'Analyze' if you are interested in a quality check of your RINEX file contents.</li>
733</ul>
734</p>
735
736<p><a name="reqcedit"><h4>3.6.2 Set Edit Options - mandatory if 'Edit/Concatenate' is set</h4></p>
737<p>Once the 'Edit/Concatenate' action is selected, you have to 'Set Edit Options'. BNC lets you specify the RINEX version, sampling interval, begin and end of file, operator, comment lines, and marker, antenna, receiver details. Note that sampling, begin/end and marker/antenna/receiver specification are only meaningful for RINEX Observation files.
738</p>
739<p>
740When converting RINEX Version 2 to RINEX Version 3 Observation files, the tracking mode or channel information in the (last character out of the three characters) observation code is left blank if unknown. When converting RINEX Version 3 to RINEX Version 2 Observation files:
741<ul>
742<li>C1P in RINEX Version 3 is mapped to P1 in RINEX Version 2</li>
743<li>C2P in RINEX Version 3 is mapped to P2 in RINEX Version 2</li>
744<li>If several observations in RINEX Version 3 come with the same observation type and same band/frequency but different tracking modes, BNC uses only the one provided first for creating RINEX Version 2 while ignoring others.</li>
745</ul>
746</p>
747<p>Optionally you may specify a comment line text to be added to the emerging new RINEX file header. Any introduction of a newline through '\n' in this enforces the beginning of a further comment line. Comment line(s) will be added to the header immediately after the 'PGM / RUN BY / DATE' record. Default is an empty option field, meaning that no additional comment line will be added to the RINEX header.</p>
748
749<p>Specifying a 'RUN BY' string to be included in the emerging new RINEX file header is another option. Default is an empty option field meaning the operator's ID is automatically used as 'RUN BY' string.</p>
750<p>
751If you specify a 'New' but no 'Old' marker/antenna/receiver name, the corresponding data field in the emerging new RINEX Observation file will be filled accordingly. If you in addition specify an 'Old' marker/antenna/receiver name, the corresponding data field in the emerging new RINEX Observation file will only be filled accordingly where 'Old' specifications match existing file contents.
752</p>
753
754<p><img src="IMG/screenshot27.png"/></p>
755<p><u>Figure 8:</u> Example for 'RINEX Editing Options' window.</p>
756
757<p><a name="reqcinput"><h4>3.6.3 Input Files - mandatory if 'Action' is set</h4></p>
758<p>
759Specify full path to input RINEX Observation file(s), and<br>
760specify full path to input RINEX Navigation file(s).
761</p>
762<p>When specifying several input files BNC will concatenate their contents. Note that you may specify several RINEX Version 2 Navigation files for GPS and GLONASS.</p>
763
764<p><a name="reqcoutput"><h4>3.6.4 Output Files - mandatory if 'Action' is set</h4></p>
765<p>
766If 'Edit/Concatenate' is selected, specifying the a path to output RINEX Observation file(s) and specifying a full path to output RINEX Navigation file(s) is mandatory.</p>
767
768<p><img src="IMG/screenshot25.png"/></p>
769<p><u>Figure 9:</u> Example for RINEX file editing with BNC in Post Processing mode.</p>
770
771<p>
772If 'Analyze' is selected, specifying a 'Log' file to output analysis results is mandatory. The following is a RINEX quality check analysis logfile example:
773<pre>
774Analyze File
775------------
776File: cut02530.12o
777Marker name: CUT0
778Receiver: TRIMBLE NETR9
779Antenna: TRM59800.00 SCIS
780Start time: 2012-09-09 00:00:00.000
781End time: 2012-09-09 23:59:30.000
782Interval: 30
783# Sat.: 56
784# Obs.: 54159
785# Slips (file): 295
786# Slips (found): 52
787Mean MP1: 0.25382
788Mean MP2: 0.163092
789Mean SNR1: 4.83739
790Mean SNR2: 5.09455
791</pre>
792<p>
793
794<p><a name="reqcplots"><h4>3.6.5 Directory for Plots - optional if 'Action' is set</h4></p>
795<p>
796If 'Analyze' is selected, specifying the path to a directory where plot files will be saved is optional. File names will be composed from the RINEX input file name(s) plus suffix 'PNG' to indicate the plot file format in use. </p>
797
798<p><img src="IMG/screenshot29.png"/></p>
799<p><u>Figure 10:</u> Example for RINEX quality check graphics output with BNC. A multipath and a signal-to-noise ratio analysis are presented in terms of a sky plot.</p>
800
801<p><img src="IMG/screenshot30.png"/></p>
802<p><u>Figure 11:</u> Example for satellite availability, elevation and PDOP plots as a result of a RINEX quality check with BNC.</p>
803
804<p><a name="reqccommand"><h4>3.6.6 Command Line, No Window - optional</h4></p>
805<p>
806BNC applies options from the configuration file but allows updating every one of them on the command line while the contents of the configuration file remains unchanged, see section on 'Command Line Options'. The syntax for that looks as follows
807</p>
808<p>
809--key &lt;keyName&gt; &lt;keyValue&gt;
810</p>
811<p>
812where &lt;keyName&gt; stands for the name of an option contained in the configuration file and &lt;keyValue&gt; stands for the value you want to assign to it. This functionality may be helpful in the 'RINEX Editing & QC' context when running BNC on a routine basis for maintaining a RINEX file archive.
813</p>
814The following example for a Linux platform calls BNC in 'no window' mode with a local configuration file 'rnx.conf' for concatenating four 15min RINEX files from station TLSE residing in the local directory to produce an hourly RINEX Version 3 file with 30 seconds sampling interval:
815</p>
816<p>
817./bnc --nw --conf rnx.conf --key reqcAction Edit/Concatenate --key reqcObsFile "tlse119b00.12o,tlse119b15.12o,tlse119b30.12o,tlse119b45.12o" --key reqcOutObsFile tlse119b.12o --key reqcRnxVersion 3 --key reqcSampling 30
818</p>
819<p>
820You may use asterisk '*' and/or question mark '?' wildcard characters as shown with the following globbing command line option to specify a selection of files in a local directory:
821</p>
822<p>
823--key reqcObsFile "tlse*"<br>
824or:<br>
825--key reqcObsFile tlse\*
826</p>
827
828<p>The following Linux command line produces RINEX QC plots (see Estey and Meertens 1999) offline in 'no window' mode and saves them in directory '/home/user'. Introducing a dummy configuration file /dev/null makes sure that no configuration options previously saved on disc are used:</p>
829<p>
830/home/user/bnc --conf /dev/null --key reqcAction Analyze --key reqcObsFile CUT02070.12O --key reqcNavFile BRDC2070.12P --key reqcOutLogFile CUT0.txt --key reqcPlotDir /home/user --nw
831</p>
832<p></p>
833<p>The following Linux command line produces the same RINEX QC plots in interactive autoStart mode:</p>
834<p>
835/home/user/bnc --conf /dev/null --key reqcAction Analyze --key reqcObsFile CUT02070.12O --key reqcNavFile BRDC2070.12P --key reqcOutLogFile CUT0.txt --key --key startTab 4 --key autoStart 2
836</p>
837
838<p>
839The following is a list of available keynames for '<u>R</u>INEX <u>E</u>diting & <u>QC</u>' (short: REQC, pronounced 'rek') options and their meaning, cf. section 'Configuration Examples':
840</p>
841
842<table>
843<tr></tr>
844<tr><td><b>Keyname</b></td><td><b>Meaning</b></td></tr>
845<tr><td>reqcAction</td><td>RINEX Editing & QC action</td></tr>
846<tr><td>reqcObsFile</td><td>RINEX Observation input file(s)</td></tr>
847<tr><td>reqcNavFile</td><td>RINEX Navigation input files(s)</td></tr>
848<tr><td>reqcOutObsFile</td><td>RINEX Observation output file</td></tr>
849<tr><td>reqcPlotDir</td><td>RINEX QC plot directory</td></tr>
850<tr><td>reqcOutNavFile</td><td>RINEX Navigation output file</td></tr>
851<tr><td>reqcOutLogFile</td><td>Logfile</td></tr>
852<tr><td>reqcPlotDir</td><td>Plot file directory</td></tr>
853<tr><td>reqcRnxVersion</td><td>RINEX version of emerging new file</td></tr>
854<tr><td>reqcSampling</td><td>Sampling interval of emerging new RINEX file</td></tr>
855<tr><td>reqcStartDateTime</td><td>Begin of emerging new RINEX file</td></tr>
856<tr><td>reqcEndDateTime</td><td>End of emerging new RINEX file</td></tr>
857<tr><td>reqcRunBy</td><td>Operator name</td></tr>
858<tr><td>reqcComment</td><td>Additional comment lines</td></tr>
859<tr><td>reqcOldMarkerName</td><td>Old marker name</td></tr>
860<tr><td>reqcNewMarkerName</td><td>New marker name</td></tr>
861<tr><td>reqcOldAntennaName</td><td>Old antenna name</td></tr>
862<tr><td>reqcNewAntennaName</td><td>New antenna name</td></tr>
863<tr><td>reqcOldReceiverName</td><td>Old receiver name</td></tr>
864<tr><td>reqcNewReceiverName</td><td>New receiver name</td></tr>
865</table>
866
867<p><a name="correct"><h4>3.7. Broadcast Corrections</h4></p>
868<p>
869Differential GNSS and RTK operation using RTCM streams is currently based on corrections and/or raw measurements from single or multiple reference stations. This approach to differential positioning is using 'observation space' information. The representation with the RTCM standard can be called 'ObservationSpace Representation' (OSR).
870</p>
871<p>
872An alternative to the observation space approach is the so called 'sate space' approach. The principle here is to provide information on individual error sources. It can be called 'State Space Representation' (SSR). For a rover position, state space information concerning precise satellite clocks, orbits, ionosphere, troposphere et cetera can be converted into observation space and used to correct the rover observables for more accurate positioning. Alternatively the state information can directly be used in the rover's processing or adjustment model.
873</p>
874<p>
875RTCM has developed Version 3 messages to transport satellite orbit and clock corrections in real-time. The current set of SSR messages concerns:
876<ul>
877<li>Orbit corrections to Broadcast Ephemeris</li>
878<li>Clock corrections to Broadcast Ephemeris</li>
879<li>Code biases</li>
880<li>Combined orbit and clock corrections to Broadcast Ephemeris</li>
881<li>User Range Accuracy (URA)</li>
882<li>High-rate GPS clock corrections to Broadcast Ephemeris</li>
883</ul>
884<p>
885RTCM Version 3 streams carrying these messages may be used i.e. to support real-time Precise Point Positioning (PPP) applications.
886</p>
887<p>
888When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the conventional periodic relativistic effect. Chapter 10 of the IERS Conventions 2003 mentions that the conventional periodic relativistic correction to the satellite clock (to be added to the broadcast clock) is computed as dt = -2 (R * V) / c^2 where R * V is the scalar product of the satellite position and velocity and c is the speed of light. This can also be found in the GPS Interface Specification, IS-GPS-200, Revision D, 7 March 2006.
889</p>
890
891<p>
892Orbit corrections are provided in along-track, cross-track and radial components. These components are defined in the Earth-centered, Earth-fixed reference frame of the broadcast ephemerides. For an observer in this frame, the along-track component is aligned in both direction and sign with the velocity vector, the cross-track component is perpendicular to the plane defined by the satellite position and velocity vectors, and the radial direction is perpendicular to the along track and cross-track ones. The three components form a right-handed orthogonal system.
893</p>
894
895<p>
896After applying corrections, the satellite position and clock is referred to the 'ionospheric free' phase center of the antenna which is compatible with the broadcast orbit reference.
897</p>
898
899<p>
900The orbit and clock corrections do not include local effects (like Ocean Loading or Solid Earth Tides) or atmospheric effects (Ionosphere and/or troposphere). Depending on the accuracy of your application you should correct for such effects by other means. There is currently no RTCM SSR message for ionospheric state parameters. Such messages are needed for accurate single frequency applications. The development of Iono messages will be the next step in the schedule of the RTCM State Space Representation Working Group.
901</p>
902
903<p>
904Broadcast Corrections can be saved by BNC in files. The file name convention for Broadcast Correction files follows the convention for RINEX files except for the last character of the file name suffix which is set to &quot;C&quot;.
905</p>
906
907<p>
908Saved files contain blocks of records in plain ASCII format where - separate for each GNSS, message type, stream, and epoch - the begin of a block is indicated by a line like (examples):
909</p>
910<p>
911! Orbits/Clocks: 30 GPS 0 Glonass CLK11<br>
912or<br>
913! Orbits/Clocks: 0 GPS 19 Glonass CLK11
914<p>
915Such line informs you about the number of records (here 30 and 19) carrying GPS or GLONASS related parameters you should receive next.
916</p>
917<p>
918The first five parameters in each Broadcast Corrections record are:
919</p>
920<p>
921<ul>
922<li>RTCM Version 3 message type number</li>
923<li>SSR message update interval indicator</li>
924<ul>
925<li>0 = 1 sec</li>
926<li>1 = 2 sec</li>
927<li>2 = 5 sec</li>
928<li>3 = 10 sec</li>
929<li>4 = 15 sec</li>
930<li>5 = 30 sec</li>
931<li>6 = 60 sec</li>
932<li>7 = 120 sec</li>
933<li>8 = 240 sec</li>
934<li>9 = 300 sec</li>
935<li>10 = 600 sec</li>
936<li>11 = 900 sec</li>
937<li>12 = 1800 sec</li>
938<li>13 = 3600 sec</li>
939<li>14 = 7200 sec</li>
940<li>15 = 10800 sec</li>
941</ul>
942<li>GPS Week</li>
943<li>Second in GPS Week</li>
944<li>GNSS Indicator and Satellite Vehicle Pseudo Random Number</li>
945</ul>
946</p>
947<p>
948In case of RTCM message types 1057 or 1063 (see Annex) these parameters are followed by
949</p>
950<p>
951<ul>
952<li>IOD referring to Broadcast Ephemeris set</li>
953<li>Radial Component of Orbit Correction to Broadcast Ephemeris [m]</li>
954<li>Along-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
955<li>Cross-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
956<li>Velocity of Radial Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
957<li>Velocity of Along-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
958<li>Velocity of Cross-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
959<p>
960</ul>
961</p>
962<p>
963Undefined parameters would be set to zero &quot;0.000&quot;.<br>Example:
964<pre>
965...
9661057 0 1686 283200.0 G02 21 1.062 -0.791 1.070 -0.00025 -0.00031 -0.00005
9671057 0 1686 283200.0 G03 25 1.765 -2.438 -0.290 -0.00009 -0.00060 0.00028
9681057 0 1686 283200.0 G04 14 1.311 -0.862 0.334 0.00005 -0.00038 -0.00015
969
970...
9711063 0 1686 283200.0 R01 39 0.347 1.976 -1.418 0.00048 -0.00091 0.00008
9721063 0 1686 283200.0 R02 39 0.624 -2.092 -0.155 0.00005 -0.00054 0.00053
9731063 0 1686 283200.0 R03 39 0.113 5.655 -1.540 0.00003 -0.00079 -0.00003
9741063 0 1686 283200.0 R05 39 0.237 1.426 -1.282 0.00054 -0.00020 0.00027
975...
976</pre>
977<p>
978In case of RTCM message types 1058 or 1064 (see Annex) the first five parameters in each record are followed by
979</p>
980<ul>
981<li>IOD set to zero &quot;0&quot;</li>
982<li>C0 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
983<li>C1 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m/s]</li>
984<li>C2 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m/s**2]</li>
985</ul>
986Example:
987</p>
988<pre>
989...
9901058 0 1538 211151.0 G18 0 1.846 0.000 0.000
9911058 0 1538 211151.0 G16 0 0.376 0.000 0.000
9921058 0 1538 211151.0 G22 0 2.727 0.000 0.000
993...
9941064 0 1538 211151.0 R08 0 8.956 0.000 0.000
9951064 0 1538 211151.0 R07 0 14.457 0.000 0.000
9961064 0 1538 211151.0 R23 0 6.436 0.000 0.000
997...
998</pre>
999</p>
1000<p>
1001In case of RTCM message types 1060 or 1066 (see Annex) the first five parameters in each record are followed by
1002<p>
1003<ul>
1004<li>IOD referring to Broadcast Ephemeris set</li>
1005<li>C0 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
1006<li>Radial Component of Orbit Correction to Broadcast Ephemeris [m]</li>
1007<li>Along-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
1008<li>Cross-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
1009<li>C1 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
1010<li>Velocity of Radial Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
1011<li>Velocity of Along-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
1012<li>Velocity of Cross-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
1013<li>C2 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
1014</ul>
1015Example:
1016</p>
1017<pre>
1018...
10191060 0 1538 211610.0 G30 82 2.533 0.635 -0.359 -0.598 0.000 0.000 0.000 0.000 0.000
10201060 0 1538 211610.0 G31 5 -4.218 -0.208 0.022 0.002 0.000 0.000 0.000 0.000 0.000
10211060 0 1538 211610.0 G32 28 -2.326 0.977 -0.576 0.142 0.000 0.000 0.000 0.000 0.000
1022...
10231066 0 1538 211610.0 R22 27 1.585 2.024 2.615 -2.080 0.000 0.000 0.000 0.000 0.000
10241066 0 1538 211610.0 R23 27 6.277 2.853 4.181 1.304 0.000 0.000 0.000 0.000 0.000
10251066 0 1538 211610.0 R24 27 0.846 1.805 13.095 6.102 0.000 0.000 0.000 0.000 0.000
1026...
1027</pre>
1028</p>
1029<p>
1030In case of RTCM message types 1059 or 1065 (see Annex) the first five parameters in each record are followed by
1031<ul>
1032<li>Number of Code Biases</li>
1033<li>Indicator to specify the signal and tracking mode</li>
1034<li>Code Bias</li>
1035<li>Indicator to specify the signal and tracking mode</li>
1036<li>Code Bias</li>
1037<li>etc.</li>
1038</ul>
1039Example:
1040</p>
1041<pre>
1042...
10431059 0 1538 211151.0 G18 2 0 -0.010 11 -0.750
10441059 0 1538 211151.0 G16 2 0 -0.040 11 -0.430
10451059 0 1538 211151.0 G22 2 0 -0.630 11 -2.400
1046...
1047</pre>
1048
1049<p><a name="corrdir"><h4>3.7.1 Directory, ASCII - optional</h4></p>
1050<p>
1051Specify a directory for saving Broadcast Corrections in files. If the specified directory does not exist, BNC will not create Broadcast Correction files. Default value for Broadcast Corrections 'Directory' is an empty option field, meaning that no Broadcast Correction files will be created.
1052</p>
1053
1054<p><a name="corrint"><h4>3.7.2 Interval - mandatory if 'Directory, ASCII' is set</h4></p>
1055<p>
1056Select the length of the Broadcast Correction files. The default value is 1 day.
1057</p>
1058
1059<p><a name="corrport"><h4>3.7.3 Port - optional</h4></p>
1060<p>
1061BNC can output epoch by epoch synchronized Broadcast Corrections in ASCII format on your local host (IP 127.0.0.1) through an IP 'Port'. Specify an IP port number to activate this function. The default is an empty option field, meaning that no Broadcast Correction output via IP port is generated.
1062</p>
1063<p>
1064The output format equals the format used for saving Broadcast Corrections in a file with the exception that the Mountpoint is added at each line's end.
1065</p>
1066<p>
1067The following is an example output for streams from mountpoints RTCMSSR, CLK10 and CLK11:
1068<pre>
1069...
10701057 0 1538 211151.0 G18 1 0.034 0.011 -0.064 0.000 0.000 0.000 RTCMSSR
10711057 0 1538 211151.0 G16 33 -0.005 0.194 -0.091 0.000 0.000 0.000 RTCMSSR
10721057 0 1538 211151.0 G22 50 0.008 -0.082 -0.001 0.000 0.000 0.000 RTCMSSR
1073...
10741058 0 1538 211151.0 G18 0 1.846 0.000 RTCMSSR
10751058 0 1538 211151.0 G16 0 0.376 0.000 RTCMSSR
10761058 0 1538 211151.0 G22 0 2.727 0.000 RTCMSSR
1077...
10781059 0 1538 211151.0 G18 2 0 -0.010 11 -0.750 RTCMSSR
10791059 0 1538 211151.0 G16 2 0 -0.040 11 -0.430 RTCMSSR
10801059 0 1538 211151.0 G22 2 0 -0.630 11 -2.400 RTCMSSR
1081...
10821063 0 1538 211151.0 R09 111 -0.011 -0.014 0.005 0.0000 0.000 0.000 RTCMSSR
10831063 0 1538 211151.0 R10 43 0.000 -0.009 -0.002 0.0000 0.000 0.000 RTCMSSR
10841063 0 1538 211151.0 R21 75 -0.029 0.108 0.107 0.0000 0.000 0.000 RTCMSSR
1085...
10861064 0 1538 211151.0 R08 0 8.956 0.000 RTCMSSR
10871064 0 1538 211151.0 R07 0 14.457 0.000 RTCMSSR
10881064 0 1538 211151.0 R23 0 6.436 0.000 RTCMSSR
1089...
10901066 0 1538 211610.0 R24 27 0.846 1.805 13.095 6.102 0.000 0.000 0.000 0.000 0.000 CLK11
10911066 0 1538 211610.0 R23 27 6.277 2.853 4.181 1.304 0.000 0.000 0.000 0.000 0.000 CLK11
10921066 0 1538 211610.0 R22 27 1.585 2.024 2.615 -2.080 0.000 0.000 0.000 0.000 0.000 CLK11
1093...
10941060 0 1538 211610.0 G32 28 -2.326 0.977 -0.576 0.142 0.000 0.000 0.000 0.000 0.000 CLK10
10951060 0 1538 211610.0 G31 5 -4.218 -0.208 0.022 0.002 0.000 0.000 0.000 0.000 0.000 CLK10
10961060 0 1538 211610.0 G30 82 2.533 0.635 -0.359 -0.598 0.000 0.000 0.000 0.000 0.000 CLK10
1097...
1098</pre>
1099</p>
1100<p>
1101The source code for BNC comes with an example perl script 'test_tcpip_client.pl' that allows you to read BNC's Broadcast Corrections from the IP port.
1102</p>
1103
1104<p><a name="corrwait"><h4>3.7.4 Wait for Full Corr Epoch - mandatory if 'Port' is set</h4></p>
1105<p>
1106When feeding a real-time GNSS network engine (see 'Feed Engine') waiting epoch by epoch for synchronized Broadcast Corrections, or when you 'Combine Corrections' BNC drops (only concerning IP port output) whatever is received later than 'Wait for full corr epoch' seconds. A value of 2 to 5 seconds could be an appropriate choice for that, depending on the latency of the incoming Broadcast Corrections stream and the delay acceptable by your application. A message such as &quot;COCK1: Correction over aged by 5 sec&quot; shows up in BNC's logfile if 'Wait for full corr epoch' is exceeded.
1107</p>
1108<p>
1109Specifying a value of '0' means that BNC immediately outputs all incoming Broadcast Ephemeris Corrections and does not drop any of them for latency reasons.
1110</p>
1111
1112<p><a name="syncout"><h4>3.8. Feed Engine</h4></p>
1113<p>
1114BNC can generate synchronized or unsynchronized observations epoch by epoch from all stations and satellites to feed a real-time GNSS network engine. Observations can be streamed out through an IP port and/or saved in a local file. The output is always in plain ASCII format and comprises the following parameters:
1115</p>
1116<p>
1117StationID | GPSWeek | GPSWeekSec | PRN, G=GPS, R=GLO | SlotNumber (if GLO) | Band/Frequency & trackingMode | Code | Phase | Doppler | SNR | SlipCount | ....
1118</p>
1119<p>
1120In case an observation is not available, its value is set to zero '0.0'.
1121</p>
1122<p>Note on 'SlipCount':<br>
1123It is the current understanding of BNC's authors that different slip counts could be referred to different phase measurements (i.e. L1C and L1P). The 'loss-of-lock' flags in RINEX are an example for making such kind of information available per phase measurement. However, it looks like we do have only one slip count in RTCM Version 3 for all phase measurements. As it could be that a receiver generates different slip counts for different phase measurements, we output one slip count per phase measurement to a listening real-time GNSS network engine.
1124</p>
1125
1126<p>
1127The following is an output example for GPS and GLONASS:
1128<pre>
1129...
1130CUT07 1683 493688.0000000 G05 1C 24584925.242 129195234.317 3639.020 38.812 40 2P 24584927.676 100671636.233 0.0 22.812 -1 2X 24584927.336 100671611.239 0.0 39.500 -1
1131CUT07 1683 493688.0000000 G04 1C 22598643.968 118756563.731 -1589.277 42.625 40 2P 22598649.391 92537559.230 0.0 29.125 -1
1132CUT07 1683 493688.0000000 G02 1C 23290004.062 122389588.008 -445.992 46.375 -1 2P 23290003.567 95368508.986 0.0 29.188 -1
1133
1134CUT07 1683 493689.0000000 R16 -1 1C 19210052.313 102616872.230 364.063 53.375 42 1P 19210053.445 102616393.224 0.0 52.312 42 2P 19210057.785 79813218.557 0.0 50.188 -1
1135CUT07 1683 493689.0000000 R15 0 1C 20665491.149 110430900.266 -2839.875 49.188 -1 1P 20665491.695 110430900.278 0.0 47.625 -1 2P 20665497.559 85890714.522 0.0 48.000 -1
1136CUT07 1683 493689.0000000 R09 -2 1C 22028400.805 117630697.367 3584.840 47.625 -1 1P 22028401.586 117630607.367 0.0 45.688 -1 2P 22028406.746 91490549.182 0.0 41.625 -1
1137CUT07 1683 493689.0000000 R07 5 1C 24291127.360 130032400.255 4146.149 40.125 42 1P 24291128.492 130032400.259 0.0 39.312 42 2P 24291130.602 101136710.408 0.0 35.125 -1
1138CUT07 1683 493689.0000000 R05 1 1C 19740809.867 105526251.571 -921.679 54.125 42 1P 19740809.008 105526273.586 0.0 51.875 42 2P 19740814.051 82075815.588 0.0 50.812 -1
1139CUT07 1683 493689.0000000 R04 6 1C 23394651.125 125277095.951 -3385.191 40.875 42 1P 23394651.906 125277095.943 0.0 39.812 42 2P 23394658.125 97437771.004 0.0 39.000 -1
1140CUT07 1683 493689.0000000 G28 1C 25286905.648 132883677.970 4016.750 36.125 17 2P 25286911.715 103545663.916 0.0 14.812 11
1141CUT07 1683 493689.0000000 G23 1C 23018013.274 120961034.323 -1795.551 46.375 -1 2P 23018011.781 94255379.472 0.0 31.688 -1
1142CUT07 1683 493689.0000000 G20 1C 24055613.563 126413402.503 -3233.574 38.500 -1 2P 24055617.227 98504065.103 0.0 20.125 -1
1143CUT07 1683 493689.0000000 G16 1C 24846810.039 130571661.274 -2140.137 38.000 41 2P 24846811.477 101744166.486 0.0 18.625 -1
1144CUT07 1683 493689.0000000 G13 1C 21388182.664 112395102.592 -678.356 51.812 -1 2P 21388183.516 87580617.458 0.0 39.688 -1
1145CUT07 1683 493689.0000000 G10 1C 20656684.758 108551288.049 1726.191 52.875 -1 2P 20656687.016 84585420.340 0.0 42.625 -1
1146CUT07 1683 493689.0000000 G08 1C 20703057.860 108795261.566 1880.523 52.875 -1 2P 20703060.644 84775535.497 0.0 41.188 -1
1147CUT07 1683 493689.0000000 G07 1C 20200125.289 106152257.500 -603.082 53.312 41 2P 20200126.961 82716251.449 0.0 46.000 -1 2X 20200126.797 82716243.452 0.0 52.625 -1
1148CUT07 1683 493689.0000000 G05 1C 24584232.312 129191595.301 3639.047 38.875 41 2P 24584234.980 100668800.633 0.0 22.875 -1 2X 24584234.348 100668775.639 0.0 39.812 -1
1149CUT07 1683 493689.0000000 G04 1C 22598946.500 118758153.159 -1589.461 42.500 41 2P 22598951.570 92538797.744 0.0 29.125 -1
1150CUT07 1683 493689.0000000 G02 1C 23290088.758 122390034.211 -446.429 46.312 -1 2P 23290088.203 95368856.681 0.0 28.500 -1
1151
1152CUT07 1683 493690.0000000 R16 -1 1C 19209984.633 102616508.497 363.305 53.500 43 1P 19209985.180 102616029.506 0.0 51.812 43 2P 19209989.871 79812935.655 0.0 50.188 -1
1153CUT07 1683 493690.0000000 R15 0 1C 20666023.047 110433740.264 -2840.242 49.188 -1 1P 20666023.945 110433740.275 0.0 47.500 -1 2P 20666029.574 85892923.403 0.0 47.625 -1
1154CUT07 1683 493690.0000000 R09 -2 1C 22027730.398 117627112.720 3584.305 47.688 -1 1P 22027730.828 117627022.726 0.0 46.188 -1 2P 22027735.988 91487761.121 0.0 41.688 -1
1155...
1156</pre>
1157<p>
1158The source code for BNC comes with a perl script called 'test_tcpip_client.pl' that allows you to read BNC's (synchronized or unsynchronized) ASCII observation output from the IP port and print it on standard output.
1159</p>
1160<p>
1161Note that any socket connection of an application to BNC's synchronized or unsynchronized observations ports is recorded in the 'Log' tab on the bottom of the main window together with a connection counter, resulting in log records like 'New client connection on sync/usync port: # 1'.
1162</p>
1163
1164<p>
1165The following figure shows the screenshot of a BNC configuration where a number of streams is pulled from different NTRIP Broadcasters to feed a GNSS engine via IP port output.
1166</p>
1167<p><img src="IMG/screenshot12.png"/></p>
1168<p><u>Figure 12:</u> Synchronized BNC output via IP port to feed a GNSS real-time engine.</p>
1169
1170<p><a name="syncport"><h4>3.8.1 Port - optional</h4></p>
1171<p>
1172BNC can produce synchronized observations in ASCII format on your local host (IP 127.0.0.1) through an IP 'Port'. Synchronized means that BNC collects all observation data for any specific epoch which become available within a certain number of latency seconds (see 'Wait for Full Obs Epoch' option). It then - epoch by epoch - outputs whatever has been received. Specify an IP port number here to activate this function. The default is an empty option field, meaning that no binary synchronized output is generated.</p>
1173</p>
1174
1175<p><a name="syncwait"><h4>3.8.2 Wait for Full Obs Epoch - mandatory if 'Port' is set</h4></p>
1176<p>
1177When feeding a real-time GNSS network engine waiting for synchronized observations epoch by epoch, BNC drops whatever is received later than 'Wait for full obs epoch' seconds. A value of 3 to 5 seconds could be an appropriate choice for that, depending on the latency of the incoming streams and the delay acceptable for your real-time GNSS product. Default value for 'Wait for full obs epoch' is 5 seconds.
1178</p>
1179<p>
1180Note that 'Wait for full obs epoch' does not affect the RINEX Observation file content. Observations received later than 'Wait for full obs epoch' seconds will still be included in the RINEX Observation files.
1181</p>
1182
1183<p><a name="syncsample"><h4>3.8.3 Sampling - mandatory if 'File' or 'Port' is set</h4></p>
1184<p>
1185Select the synchronized observation output sampling interval in seconds. A value of zero '0' tells BNC to send/store all received epochs. This is the default value.
1186</p>
1187
1188<p><a name="syncfile"><h4>3.8.4 File - optional</h4></p>
1189<p>
1190Specify the full path to a 'File' where synchronized observations are saved in plain ASCII format. The default value is an empty option field, meaning that no ASCII output file is created.
1191</p>
1192<p>
1193Beware that the size of this file can rapidly increase depending on the number of incoming streams. This option is primarily meant for testing and evaluation.
1194</p>
1195
1196<p><a name="syncuport"><h4>3.8.5 Port (unsynchronized) - optional</h4></p>
1197<p>
1198BNC can produce unsynchronized observations from all configured streams in ASCII format on your local host (IP 127.0.0.1) through an IP 'Port'. Unsynchronized means that BNC immediately forwards any received observation to the port. Specify an IP port number here to activate this function. The default is an empty option field, meaning that no unsynchronized output is generated.</p>
1199<p>
1200
1201<p><a name="serial"><h4>3.9. Serial Output</h4></p>
1202<p>
1203You may use BNC to feed a serial connected device like a GNSS receiver. For that an incoming stream can be forwarded to a serial port. The following figure shows the screenshot of an example situation where BNC pulls a VRS stream from an NTRIP Broadcaster to feed a serial connected RTK rover.
1204</p>
1205<p><img src="IMG/screenshot11.png"/></p>
1206<p><u>Figure 13:</u> BNC pulling a VRS stream to feed a serial connected RTK rover.</p>
1207
1208<p><a name="sermount"><h4>3.9.1 Mountpoint - optional</h4></p>
1209<p>
1210Enter a 'Mountpoint' to forward its corresponding stream to a serial connected GNSS receiver.
1211</p>
1212<p>
1213When selecting one of the serial communication options listed below, make sure that you pick those configured to the serial connected receiver.
1214</p>
1215
1216<p><a name="serport"><h4>3.9.2 Port Name - mandatory if 'Mountpoint' is set</h4></p>
1217<p>
1218Enter the serial 'Port name' selected on your host for communication with the serial connected receiver. Valid port names are
1219</p>
1220<pre>
1221Windows: COM1, COM2
1222Linux: /dev/ttyS0, /dev/ttyS1
1223FreeBSD: /dev/ttyd0, /dev/ttyd1
1224Digital Unix: /dev/tty01, /dev/tty02
1225HP-UX: /dev/tty1p0, /dev/tty2p0
1226SGI/IRIX: /dev/ttyf1, /dev/ttyf2
1227SunOS/Solaris: /dev/ttya, /dev/ttyb
1228</pre>
1229<p>
1230Note that you must plug a serial cable in the port defined here before you start BNC.
1231</p>
1232
1233<p><a name="serbaud"><h4>3.9.3 Baud Rate - mandatory if 'Mountpoint' is set</h4></p>
1234<p>
1235Select a 'Baud rate' for the serial output link. Note that using a high baud rate is recommended.
1236</p>
1237
1238<p><a name="serflow"><h4>3.9.4 Flow Control - mandatory if 'Mountpoint' is set</h4></p>
1239<p>
1240Select a 'Flow control' for the serial output link. Note that your selection must equal the flow control configured to the serial connected device. Select 'OFF' if you don't know better.
1241</p>
1242
1243<p><a name="serparity"><h4>3.9.5 Parity - mandatory if 'Mountpoint' is set</h4></p>
1244<p>
1245Select the 'Parity' for the serial output link. Note that parity is often set to 'NONE'.
1246</p>
1247
1248<p><a name="serdata"><h4>3.9.6 Data Bits - mandatory if 'Mountpoint' is set</h4></p>
1249<p>
1250Select the number of 'Data bits' for the serial output link. Note that often '8' data bits are used.
1251</p>
1252
1253<p><a name="serstop"><h4>3.9.7 Stop Bits - mandatory if 'Mountpoint' is set</h4></p>
1254<p>
1255Select the number of 'Stop bits' for the serial output link. Note that often '1' stop bit is used.
1256</p>
1257
1258<p><a name="serauto"><h4>3.9.8 NMEA - mandatory for VRS streams</h4></p>
1259<p>
1260Select 'Auto' to automatically forward all NMEA-GGA messages coming from your serial connected GNSS receiver to the NTRIP Broadcaster and/or save them in a file.
1261</p>
1262<p>
1263Forwarding valid NMEA-GGA messages to the NTRIP Broadcaster is required for receiving 'Virtual Reference Station' (VRS) streams. Thus, in case your serial connected receiver is not capable to provide them, the alternative for VRS streams is a 'Manual' simulation of an initial NMEA-GGA message. Its content is based on the approximate (editable) latitude/longitude from the broadcaster's source-table and an approximate VRS height to be specified.
1264</p>
1265<p>
1266In summary: select 'Manual' only when handling a VRS stream and your serial connected GNSS receiver doesn't generate NMEA-GGA messages. Select 'Auto' otherwise.
1267</p>
1268
1269<p><a name="serfile"><h4>3.9.9 File - optional if 'Auto' NMEA is set</h4></p>
1270<p>Specify the full path to a file where NMEA messages coming from your serial connected receiver are saved.
1271</p>
1272<p><a name="serheight"><h4>3.9.10 Height - mandatory if 'Manual' NMEA is set</h4></p>
1273<p>
1274Specify an approximate 'Height' above mean sea level in meter for your VRS to simulate an initial NMEA-GGA message. Latitude and longitude for that (editable) are taken from the broadcaster's source-table.
1275</p>
1276<p>
1277This option concerns only 'Virtual Reference Stations' (VRS). Its setting is ignored in case of streams coming from physical reference stations.
1278</p>
1279
1280<p><a name="advnote"><h4>3.10. Outages</h4></p>
1281
1282<p>
1283At any time an incoming stream might become unavailable or corrupted. In such cases, it is important that the BNC operator and/or the stream providers become aware of the situation so that necessary measures can be taken to restore the stream. Furthermore, continuous attempts to decode a corrupted stream can generate unnecessary workload for BNC. Outages and corruptions are handled by BNC as follows:
1284</p>
1285<p>
1286<u>Stream outages:</u> BNC considers a connection to be broken when there are no incoming data detected for more than 20 seconds. When this occurs, BNC will attempt to reconnect at a decreasing rate. It will first try to reconnect with 1 second delay and again in 2 seconds if the previous attempt failed. If the attempt is still unsuccessful, it will try to reconnect within 4 seconds after the previous attempt and so on. The wait time doubles each time with a maximum wait time of 256 seconds.
1287</p>
1288<p>
1289<u>Stream corruption:</u> Not all bits chunk transfers to BNC's internal decoders return valid observations. Sometimes several chunks might be needed before the next observation can be properly decoded. BNC buffers all the outputs (both valid and invalid) from the decoder for a short time span (size derived from the expected 'Observation rate') and then determines whether a stream is valid or corrupted.
1290</p>
1291<p>
1292Outage and corruption events are reported in the 'Log' tab. They can also be passed on as parameters to a shell script or batch file to generate an advisory note to BNC operator or affected stream providers. This functionality lets users utilize BNC as a real-time performance monitor and alarm system for a network of GNSS reference stations.
1293</p>
1294
1295<p><a name="obsrate"><h4>3.10.1 Observation Rate - mandatory if 'Failure threshold', 'Recovery threshold' and 'Script' is set</h4></p>
1296<p>
1297BNC can collect all returns (success or failure) coming from a decoder within a certain short time span to then decide whether a stream has an outage or its content is corrupted. This procedure needs a rough a priory estimate of the expected observation rate of the incoming streams.</p><p>An empty option field (default) means that you don't want explicit information from BNC about stream outages and incoming streams that cannot be decoded.
1298</p>
1299
1300<p><a name="advfail"><h4>3.10.2 Failure Threshold - optional</h4></p>
1301<p>
1302Event 'Begin_Failure' will be reported if no data is received continuously for longer than the 'Failure threshold' time. Similarly, event 'Begin_Corrupted' will be reported when corrupted data is detected by the decoder continuously for longer than this 'Failure threshold' time. The default value is set to 15 minutes and is recommended so not to inundate user with too many event reports.
1303</p>
1304<p>
1305Note that specifying a value of zero '0' for the 'Failure threshold' will force BNC to report any stream failure immediately. Note also that for using this function you need to specify the 'Observation rate'.
1306</p>
1307
1308<p><a name="advreco"><h4>3.10.3 Recovery Threshold - optional</h4></p>
1309<p>
1310Once a 'Begin_Failure' or 'Begin_Corrupted' event has been reported, BNC will check for when the stream again becomes available or uncorrupted. Event 'End_Failure' or 'End_Corrupted' will be reported as soon as valid observations are again detected continuously throughout the 'Recovery threshold' time span. The default value is set to 5 minutes and is recommended so not to inundate users with too many event reports.
1311</p>
1312<p>
1313Note that specifying a value of zero '0' for the 'Recovery threshold' will force BNC to report any stream recovery immediately. Note also that for using this function you need to specify the 'Observation rate'.
1314</p>
1315
1316<p><a name="advscript"><h4>3.10.4 Script - optional </h4></p>
1317<p>
1318As mentioned previously, BNC can trigger a shell script or a batch file to be executed when one of the events described are reported. This script can be used to email an advisory note to network operator or stream providers. To enable this feature, specify the full path to the script or batch file in the 'Script' field. The affected stream's mountpoint and type of event reported ('Begin_Outage', 'End_Outage', 'Begin_Corrupted' or 'End_Corrupted') will then be passed on to the script as command line parameters (%1 and %2 on Windows systems or $1 and $2 on Unix/Linux/Mac OS X systems) together with date and time information.
1319</p>
1320<p>
1321Leave the 'Script' field empty if you do not wish to use this option. An invalid path will also disable this option.
1322</p>
1323<p>
1324Examples for command line parameter strings passed on to the advisory 'Script' are:
1325<pre>
1326FFMJ0 Begin_Outage 08-02-21 09:25:59
1327FFMJ0 End_Outage 08-02-21 11:36:02 Begin was 08-02-21 09:25:59
1328</pre>
1329</p>
1330<p>
1331Sample script for Unix/Linux/Mac OS X systems:
1332</p>
1333<pre>
1334#!/bin/bash
1335sleep $((60*RANDOM/32767))
1336cat | mail -s &quot;NABU: $1&quot; email@address &lt;&lt;!
1337Advisory Note to BNC User,
1338Please note the following advisory received from BNC.
1339Stream: $*
1340Regards, BNC
1341!
1342</pre>
1343</p>
1344<p>
1345Note the sleep command in this script which causes the system to wait for a random period of up to 60 seconds before sending the email. This should avoid overloading your mail server in case of a simultaneous failure of many streams.
1346</p>
1347
1348<p><a name="misc"><h4>3.11. Miscellaneous</h4></p>
1349<p>
1350This section describes several miscellaneous options which can be applied for a single stream (mountpoint) or for all configured streams.
1351</p>
1352
1353<p>
1354The following figure shows RTCM message numbers and observation types contained in stream 'CUT07' and the message latencies recorded every 2 seconds.
1355</p>
1356<p><img src="IMG/screenshot14.png"/></p>
1357<p><u>Figure 14:</u> RTCM message numbers, latencies and observation types.</p>
1358
1359
1360<p><a name="miscmount"><h4>3.11.1 Mountpoint - optional </h4></p>
1361<p>
1362Specify a mountpoint to apply one or several of the 'Miscellaneous' options to the corresponding stream. Enter 'ALL' if you want to apply these options to all configured streams. An empty option field (default) means that you don't want BNC to apply any of these options.
1363</p>
1364
1365<p><a name="miscperf"><h4>3.11.2 Log Latency - optional </h4></p>
1366<p>
1367 BNC can average latencies per stream over a certain period of GPS time, the 'Log latency' interval. Mean latencies are calculated from the individual latencies of one (first incoming) observation or Broadcast Correction per second. The mean latencies are then saved in BNC's logfile. Note that computing correct latencies requires the clock of the host computer to be properly synchronized. Note further that visualized latencies from the 'Latency' tab on the bottom of the main window represent individual latencies and not the mean latencies for the logfile.
1368</p>
1369<p>
1370<u>Latency:</u> Latency is defined in BNC by the following equation:
1371</p>
1372<pre>
1373 UTC time provided by BNC's host
1374 - GPS time of currently processed epoch
1375 + Leap seconds between UTC and GPS time
1376 --------------
1377 = Latency
1378</pre>
1379<p>
1380<u>Statistics:</u> BNC counts the number of GPS seconds covered by at least one observation. It also estimates an observation rate (independent from the a priory specified 'Observation rate') from all observations received throughout the first full 'Log latency' interval. Based on this rate, BNC estimates the number of data gaps when appearing in subsequent intervals.
1381</p>
1382<p>
1383Latencies of observations or corrections to Broadcast Ephemeris and statistical information can be recorded in the 'Log' tab at the end of each 'Log latency' interval. A typical output from a 1 hour 'Log latency' interval would be:
1384</p>
1385<pre>
138608-03-17 15:59:47 BRUS0: Mean latency 1.47 sec, min 0.66, max 3.02, rms 0.35, 3585 epochs, 15 gaps
1387</pre>
1388<p>
1389Select a 'Log latency' interval to activate this function or select the empty option field if you do not want BNC to log latencies and statistical information.
1390</p>
1391
1392
1393<p><a name="miscscan"><h4>3.11.3 Scan RTCM - optional</h4></p>
1394<p>
1395When configuring a GNSS receiver for RTCM stream generation, the firmware's setup interface may not provide details about RTCM message types observation types. As reliable information concerning stream contents should be available i.e. for NTRIP Broadcaster operators to maintain the broadcaster's source-table, BNC allows to scan RTCM streams for incoming message types and printout some of the contained meta-data. Contained observation types are also printed because such information is required a-priori to the conversion of RTCM Version 3 MSM streams to RINEX Version 3 files. The idea for this option arose from 'InspectRTCM', a comprehensive stream analyzing tool written by D. Stoecker.
1396</p>
1397<p>
1398Tick 'Scan RTCM' to scan RTCM Version 2 or 3 streams and log all contained
1399</p>
1400<ul>
1401<li>Numbers of incoming message types</li>
1402<li>Antenna Reference Point (ARP) coordinates</li>
1403<li>Antenna Phase Center (APC) coordinates</li>
1404<li>Antenna height above marker</li>
1405<li>Antenna descriptor.</li>
1406</ul>
1407In case of RTCM Version 3 MSM streams the output includes
1408<ul>
1409<li>RINEX Version 3 Observation Types</li>
1410</ul>
1411</p>
1412
1413<p>
1414Note that in RTCM Version 2 the message types 18 and 19 carry only the observables of one frequency. Hence it needs two type 18 and 19 messages per epoch to transport the observations from dual frequency receivers.
1415</p>
1416<p>
1417
1418<p>Logged time stamps refer to message reception time and allow understanding repetition rates. Enter 'ALL' if you want to log this information from all configured streams. Beware that the size of the logfile can rapidly increase depending on the number of incoming RTCM streams.
1419</p>
1420<p>This option is primarily meant for testing and evaluation. Use it to figure out what exactly is produced by a specific GNSS receiver's configuration. An empty option field (default) means that you don't want BNC to print the message type numbers and antenna information carried in RTCM streams.
1421</p>
1422
1423<p><a name="pppclient"><h4>3.12. PPP Client</h4></p>
1424<p>
1425BNC can derive coordinates for a rover position following the Precise Point Positioning (PPP) approach. It uses either code or code plus phase data in ionosphere free linear combinations P3 or L3. Besides pulling a stream of observations from a dual frequency receiver, this also
1426<ul>
1427<li>requires pulling in addition a stream carrying satellite orbit and clock corrections to Broadcast Ephemeris in the form of RTCM Version 3 'State Space Representation' (SSR) messages. Note that for BNC these Broadcast Corrections need to be referred to the satellite's Antenna Phase Center (APC). Streams providing such messages are listed on <u>http://igs.bkg.bund.de/ntrip/orbits</u>. Stream 'CLK11' on NTRIP Broadcaster 'products.igs-ip.net:2101' is an example.</li>
1428<li>may require pulling a stream carrying Broadcast Ephemeris available as RTCM Version 3 message types 1019, 1020, and 1045. This is a must only when the stream coming from the receiver does not contain Broadcast Ephemeris or provides them only at very low repetition rate. Streams providing such messages are listed on <u>http://igs.bkg.bund.de/ntrip/ephemeris</u>. Stream 'RTCM3EPH' on caster 'products.igs-ip.net:2101' is an example.</li>
1429</ul>
1430</p>
1431<p>
1432The following figure provides the screenshot of an example PPP session with BNC.
1433</p>
1434
1435<p><img src="IMG/screenshot03.png"/></p>
1436<p><u>Figure 15:</u> Precise Point Positioning with BNC, PPP Panel 1.</p>
1437
1438<p><img src="IMG/screenshot18.png"/></p>
1439<p><u>Figure 16:</u> Precise Point Positioning with BNC, PPP Panel 2.</p>
1440
1441<p>
1442PPP results are shown in the 'Log' tab on the bottom of BNC's main window. Depending on the processing options, the following values are shown about once per second (example):
1443<pre>
144410-09-08 09:14:06 FFMJ1 PPP 09:14:04.0 12 4053457.429 +- 2.323 617730.551 +- 1.630 4869395.266 +- 2.951
1445</pre>
1446</p>
1447<p>
1448The selected mountpoint in that is followed by a PPP time stamp in GPS Time, the number of processed satellites, and XYZ coordinates with their formal errors as derived from the implemented filter in [m]. The implemented algorithm includes outlier and cycle slip detection. The maximum for accepted residuals is hard coded to 10 meters for code observations and 10 centimeters for phase observations.
1449</p>
1450
1451<p>
1452More detailed PPP results are saved in BNC's logfile. Depending on the selected processing options you find
1453<ul>
1454<li>code and phase residuals for GPS and GLONASS and Galileo in [m], </li>
1455<li>receiver clock errors in [m], </li>
1456<li>a-priori and correction values of tropospheric zenith delay in [m],
1457<li>time offset between GPS time and Galileo time in [m],
1458<li>L3 biases, also known as 'floated ambiguities', given per satellite.
1459</ul>
1460These parameters are saved together with their standard deviation. The following is an example extract from a log file when BNC was in 'Single Point Positioning' (SPP) mode:
1461</p>
1462<p>
1463<pre>
146410-12-06 18:10:50 Single Point Positioning of Epoch 18:10:48.0
1465--------------------------------------------------------------
146618:10:48.0 RES G04 L3 0.0165 P3 -0.1250
146718:10:48.0 RES G11 L3 0.0150 P3 0.7904
146818:10:48.0 RES G13 L3 0.0533 P3 0.4854
146918:10:48.0 RES G17 L3 -0.0277 P3 1.2920
147018:10:48.0 RES G20 L3 -0.0860 P3 -0.1186
147118:10:48.0 RES G23 L3 0.0491 P3 -0.1052
147218:10:48.0 RES G31 L3 0.0095 P3 -3.2929
147318:10:48.0 RES G32 L3 0.0183 P3 -3.8800
147418:10:48.0 RES R05 L3 -0.0077
147518:10:48.0 RES R06 L3 0.0223
147618:10:48.0 RES R15 L3 -0.0020
147718:10:48.0 RES R16 L3 0.0156
147818:10:48.0 RES R20 L3 -0.0247
147918:10:48.0 RES R21 L3 0.0014
148018:10:48.0 RES R22 L3 -0.0072
148118:10:48.0 RES E52 L3 -0.0475 P3 -0.1628
148218:10:48.0 RES G04 L3 0.0166 P3 -0.1250
148318:10:48.0 RES G11 L3 0.0154 P3 0.7910
148418:10:48.0 RES G13 L3 0.0535 P3 0.4855
148518:10:48.0 RES G17 L3 -0.0272 P3 1.2925
148618:10:48.0 RES G20 L3 -0.0861 P3 -0.1188
148718:10:48.0 RES G23 L3 0.0489 P3 -0.1055
148818:10:48.0 RES G31 L3 0.0094 P3 -3.2930
148918:10:48.0 RES G32 L3 0.0183 P3 -3.8800
149018:10:48.0 RES R05 L3 -0.0079
149118:10:48.0 RES R06 L3 0.0223
149218:10:48.0 RES R15 L3 -0.0020
149318:10:48.0 RES R16 L3 0.0160
149418:10:48.0 RES R20 L3 -0.0242
149518:10:48.0 RES R21 L3 0.0016
149618:10:48.0 RES R22 L3 -0.0072
149718:10:48.0 RES E52 L3 -0.0474 P3 0.1385
1498
1499 clk = 64394.754 +- 0.045
1500 trp = 2.185 +0.391 +- 0.001
1501 offset = -415.400 +- 0.137
1502 amb G17 = 11.942 +- 0.045
1503 amb G23 = 248.892 +- 0.044
1504 amb G31 = 254.200 +- 0.045
1505 amb G11 = -12.098 +- 0.044
1506 amb G20 = -367.765 +- 0.044
1507 amb G04 = 259.588 +- 0.044
1508 amb E52 = 6.124 +- 0.130
1509 amb G32 = 201.496 +- 0.045
1510 amb G13 = -265.658 +- 0.044
1511 amb R22 = -106.246 +- 0.044
1512 amb R21 = -119.605 +- 0.045
1513 amb R06 = 41.328 +- 0.044
1514 amb R15 = 163.453 +- 0.044
1515 amb R20 = -532.746 +- 0.045
1516 amb R05 = -106.603 +- 0.044
1517 amb R16 = -107.830 +- 0.044
1518</pre>
1519</p>
1520
1521<p>
1522Note that for debugging or Post Processing purposes BNC's 'PPP' functionality option can also be used offline.
1523<ul>
1524<li>
1525<u>Debugging:</u> Apply the 'File Mode' 'Command Line' option for that to read a file containing synchronized observations, orbit and clock correctors, and Broadcast Ephemeris. Such a file must be generated before using BNC's 'Raw output file' option. Example:<br>
1526bnc.exe --conf c:\temp\PPP.bnc --file c:\temp\FFMJ1
1527</li>
1528<li>
1529<u>Post Processing:</u> Apply the 'Post Processing' option as described below.
1530</li>
1531</ul>
1532</p>
1533
1534<p>When using the PPP option, it is important to understand which effects are corrected by BNC.
1535</p>
1536<ul>
1537<li>BNC does correct for Solid Earth Tides and Phase Windup.</li>
1538<li>Satellite antenna phase center offsets are not corrected because applied orbit/clock corrections are referred to the satellite's antenna phase center.</li>
1539<li>Satellite antenna phase center variations are neglected because this is a small effect usually less than 2 centimeters.</li>
1540<li>Observations can be corrected for a Receiver Antenna Offset. Depending on whether or not this correction is applied, the estimated position is either that of the receiver's antenna phase center or that of the receiver's Antenna Reference Point.</li>
1541<li>Receiver antenna phase center variations are not included in the model. The bias caused by this neglect depends on the receiver antenna type. For most antennas it is smaller than a few centimeters.</li>
1542<li>Ocean and atmospheric loading is neglected. Atmospheric loading is pretty small. Ocean loading is usually also a small effect but may reach up to about 10 centimeters for coastal stations.</li>
1543<li>Rotational deformation due to polar motion (Polar Tides) is not corrected because this is a small effect usually less than 2 centimeters.</li>
1544</ul>
1545</p>
1546
1547<p><a name="pppmode"><h4>3.12.1 Mode & Mountpoints - optional</h4></p>
1548<p>
1549Specify the Point Positioning mode you want to apply and the mountpoints for observations and Broadcast Corrections.
1550</p>
1551
1552<p><a name="pppmodus"><h4>3.12.1.1 Mode - optional</h4></p>
1553<p>
1554Choose between plain Single Point Positioning (SPP) and Precise Point Positioning (PPP) in 'Realtime' or 'Post-Processing' mode. Options are 'Realtime-PPP', 'Realtime-SPP', and 'Post-Processing'.
1555</p>
1556
1557<p><a name="pppobsmount"><h4>3.12.1.2 Obs Mountpoint - optional</h4></p>
1558<p>
1559Specify an 'Observations Mountpoint' from the list of selected 'Streams' you are pulling if you want BNC to derive coordinates for the affected rover position through a Point Positioning solution.
1560</p>
1561
1562<p><a name="pppcorrmount"><h4>3.12.1.3 Corr Mountpoint - optional</h4></p>
1563<p>
1564Specify a Broadcast Ephemeris 'Corrections Mountpoint' from the list of selected 'Streams' you are pulling if you want BNC to correct your positioning solution accordingly.
1565</p>
1566
1567<p><a name="pppxyz"><h4>3.12.2 Marker Coordinates - optional</h4></p>
1568<p>
1569Enter the reference coordinate XYZ of the receiver's position in meters if known. This option makes only sense for static observations. Defaults are empty option fields, meaning that the antenna's XYZ position is unknown.
1570</p>
1571<p>
1572Once a XYZ coordinate is defined, the 'PPP' line in BNC's logfile is extended by North, East and Up displacements to (example):
1573</p>
1574<pre>
157510-08-09 06:01:56 FFMJ1 PPP 06:02:09.0 11 4053457.628 +- 2.639 617729.438 +- 1.180 4869396.447 +- 1.921 NEU -0.908 -0.571 1.629
1576</pre>
1577<p>
1578The parameters following the 'NEU' string provide North, East and Up components of the current coordinate displacement in meters.
1579</p>
1580
1581<p><a name="pppneu"><h4>3.12.3 Antenna Eccentricity - optional</h4></p>
1582<p>
1583You may like to specify North, East and Up components of an antenna eccentricity which is the difference between a nearby marker position and the antenna phase center. If you do so BNC will produce coordinates referring to the marker position and not referring to the antenna phase center.
1584</p>
1585
1586<p><a name="pppoutput"><h4>3.12.4 NMEA & Plot Output - optional</h4></p>
1587<p>
1588BNC allows to output results from Precise Point Positioning in NMEA format. It can also plot a time series of North, East and UP displacements.
1589</p>
1590
1591<p><a name="pppnmeafile"><h4>3.12.4.1 NMEA File - optional</h4></p>
1592<p>
1593The NMEA sentences generated about once per second are pairs of
1594<ul>
1595<li> GPGGA sentences which mainly carry the estimated latitude, longitude, and height values, plus</li>
1596<li> GPRMC sentences which mainly carry date and time information.</li>
1597</ul>
1598</p>
1599<p>
1600Specify the full path to a file where Point Positioning results are saved as NMEA messages. The default value for 'NMEA file' is an empty option field, meaning that BNC will not saved NMEA messages into a file.
1601</p>
1602<p>
1603Note that Tomoji Takasu has written a program called RTKPLOT for visualizing NMEA strings. It is available from <u>http://gpspp.sakura.ne.jp/rtklib/rtklib.htm</u> and compatible with the NMEA file and port output of BNC's 'PPP' client option.
1604</p>
1605
1606<p><a name="pppnmeaport"><h4>3.12.4.2 NMEA Port - optional</h4></p>
1607<p>
1608Specify the IP port number of a local port where Point Positioning results become available as NMEA messages. The default value for 'NMEA Port' is an empty option field, meaning that BNC does not provide NMEA messages vi IP port. Note that the NMEA file output and the NMEA IP port output are the same.
1609</p>
1610<p>
1611NASA's 'World Wind' software (see <u>http://worldwindcentral.com/wiki/NASA_World_Wind_Download</u>) can be used for real-time visualization of positions provided through BNC's NMEA IP output port. You need the 'GPS Tracker' plug-in available from <u>http://worldwindcentral.com/wiki/GPS_Tracker</u> for that. The 'Word Wind' map resolution is not meant for showing centimeter level details.
1612</p>
1613
1614<p><a name="pppplot"><h4>3.12.4.3 PPP Plot - optional</h4></p>
1615<p>
1616PPP time series of North (red), East (green) and Up (blue) displacements will be plotted in the 'PPP Plot' tab when this option is ticked. Values will be either referred to an XYZ reference coordinate (if specified) or referred to the first estimated XYZ coordinate. The sliding PPP time series window will cover the period of the latest 5 minutes.
1617</p>
1618<p>
1619Note that a PPP time series makes only sense for a stationary operated receiver.
1620</p>
1621
1622<p><a name="ppppost"><h4>3.12.5 Post Processing - optional</h4></p>
1623<p>When in 'Post-Processing' mode
1624<ul>
1625<li>specifying a RINEX Observation, a RINEX Navigation and a Broadcast Corrections file leads to a PPP solution.</li>
1626<li>specifying only a RINEX Observation and a RINEX Navigation file and no Broadcast Corrections file leads to a SPP solution.</li>
1627</ul>
1628</p>
1629<p>BNC accepts RINEX Version 2 as well as RINEX Version 3 Observation or Navigation file formats. Files carrying Broadcast Corrections must have the format produced by BNC through the 'Broadcast Corrections' tab.
1630<p>
1631Post Processing PPP results can be saved in a specific output file.
1632</p>
1633
1634<p><a name="ppprecant"><h4>3.12.6 Antennas - optional</h4></p>
1635<p>
1636BNC allows correcting observations for antenna phase center offsets and variations.
1637</p>
1638
1639<p><a name="pppantex"><h4>3.12.6.1 ANTEX File - optional</h4></p>
1640<p>
1641IGS provides a file containing absolute phase center corrections for GNSS satellite and receiver antennas in ANTEX format. Entering the full path to such an ANTEX file is required for correcting observations for antenna phase center offsets and variations. It allows you to specify the name of your receiver's antenna (as contained in the ANTEX file) to apply such corrections.
1642</p>
1643<p>
1644Default is an empty option field, meaning that you don't want to correct observations for antenna phase center offsets and variations.
1645</p>
1646
1647<p><a name="ppprecantenna"><h4>3.12.6.2 Receiver Antenna Name - optional if 'ANTEX File' is set</h4></p>
1648<p>
1649Specify the receiver's antenna name as defined in your ANTEX file. Observations will be corrected for the antenna phase center's offset which may result in a reduction of a few centimeters at max. Corrections for phase center variations are not yet applied by BNC. The specified name must consist of 20 characters. Add trailing blanks if the antenna name has less than 20 characters. Examples:
1650<pre>
1651'JPSREGANT_SD_E ' (no radome)
1652'LEIAT504 NONE' (no radome)
1653'LEIAR25.R3 LEIT' (radome)
1654</pre>
1655</p>
1656<p>
1657Default is an empty option field, meaning that you don't want to correct observations for antenna phase center offsets.
1658</p>
1659
1660<p><a name="pppbasics"><h4>3.12.7 Basics</h4></p>
1661<p>BNC allows using different Point Positioning processing options depending on the capability of the involved receiver and the application in mind. It also allows introducing specific sigmas for code and phase observations as well as for reference coordinates and troposphere estimates. You may also like to carry out your PPP solution in Quick-Start mode or enforce BNC to restart a solution if the length of an outage exceeds a certain threshold.
1662</p>
1663
1664<p><a name="pppphase"><h4>3.12.7.1 Use Phase Obs - optional</h4></p>
1665<p>
1666By default BNC applies a Point Positioning solution using an ionosphere free P3 linear combination of code observations. Tick 'Use phase obs' for an ionosphere free L3 linear combination of phase observations.
1667</p>
1668
1669<p><a name="ppptropo"><h4>3.12.7.2 Estimate Tropo - optional</h4></p>
1670<p>
1671BNC estimates the tropospheric delay according to equation
1672<pre>
1673T(z) = T_apr(z) + dT / cos(z)
1674</pre>
1675where T_apr is the a-priori tropospheric delay derived from Saastamoinen model.
1676</p>
1677<p>
1678By default BNC does not estimate troposphere parameters. Tick 'Estimate tropo' to estimate troposphere parameters together with the coordinates and save T_apr and dT/cos(z) in BNC's log file.
1679</p>
1680
1681<p><a name="pppglo"><h4>3.12.7.3 Use GLONASS - optional</h4></p>
1682<p>
1683By default BNC does not process GLONASS but only GPS observations when in Point Positioning mode. Tick 'Use GLONASS' to use GLONASS observations in addition to GPS (and Galileo if specified) for estimating coordinates in Point Positioning mode.
1684</p>
1685
1686<p><a name="pppgal"><h4>3.12.7.4 Use Galileo - optional</h4></p>
1687<p>
1688By default BNC does not process Galileo but only GPS observations when in Point Positioning mode. Tick 'Use Galileo' to use Galileo observations in addition to GPS (and GLONASS if specified) for estimating coordinates in Point Positioning mode.
1689</p>
1690
1691<p><a name="pppsync"><h4>3.12.7.5 Sync Corr - optional</h4></p>
1692<p>
1693Zero value (or empty field) means that BNC processes each epoch of data immediately after its arrival using satellite clock corrections available at that time. Non-zero value 'Sync Corr' means that the epochs of data are buffered and the processing of each epoch is postponed till the satellite clock corrections not older than 'Sync Corr' are available. Specifying a value of half the update rate of the clock corrections as 'Sync Corr' (i.e. 5 sec) may be appropriate. Note that this causes an additional delay of the PPP solutions in the amount of half of the update rate.
1694</p>
1695<p>
1696Using observations in sync with the corrections can avoid a possible high frequency noise of PPP solutions. Such noise could result from processing observations regardless of how late after a clock correction they were received. Note that applying the 'Sync Corr' option significantly reduces the PPP computation effort for BNC.
1697</p>
1698<p>
1699Default is an empty option field, meaning that you want BNC to process observations immediately after their arrival through applying the latest received clock correction.
1700</p>
1701
1702<p><a name="pppaverage"><h4>3.12.7.6 Averaging - optional if XYZ is set</h4></p>
1703<p>
1704Enter the length of a sliding time window in minutes. BNC will continuously output moving average values and their RMS as computed from those individual values obtained most recently throughout this period. RMS values presented for XYZ coordinates and tropospheric zenith path delays are bias reduced while RMS values for North/East/Up (NEU) displacements are not. Averaged values for XYZ coordinates and their RMS are marked with string &quot;AVE-XYZ&quot; in BNC's log file and 'Log' section while averaged values for NEU displacements and their RMS are marked with string &quot;AVE-NEU&quot; and averaged values for the tropospheric delays and their RMS are marked with string &quot;AVE-TRP&quot;. Example:
1705</p>
1706<pre>
170710-09-08 09:13:05 FFMJ1 AVE-XYZ 09:13:04.0 4053455.948 +- 0.284 617730.422 +- 0.504 4869397.692 +- 0.089
170810-09-08 09:13:05 FFMJ1 AVE-NEU 09:13:04.0 1.043 +- 0.179 0.640 +- 0.456 1.624 +- 0.331
170910-09-08 09:13:05 FFMJ1 AVE-TRP 09:13:04.0 2.336 +- 0.002
1710</pre>
1711<p>
1712Entering any positive value up to 1440 (24h mean value) is allowed. An empty option field (default) means that you don't want BNC to output moving average positions into the log file and the 'Log' section. Note that averaging positions makes only sense for a stationary receiver.
1713</p>
1714
1715<p><a name="pppquick"><h4>3.12.7.7 Quick-Start - optional if XYZ is set</h4></p>
1716<p>
1717Enter the length of a startup period in seconds for which you want to fix the PPP solution to a known XYZ coordinate. Constraining coordinates is done in BNC through setting the 'XYZ White Noise' temporarily to zero.
1718</p>
1719<p>
1720This so-called Quick-Start option allows the PPP solutions to rapidly converge after startup. It requires that the antenna remains unmoved on the know position throughout the defined period. A value of 60 is likely to be an appropriate choice for 'Quick-Start'. Default is an empty option field, meaning that you don't want BNC to start in 'Quick-Start' mode.
1721<p>
1722You may need to create your own reference coordinate through running BNC for an hour in normal mode before applying the 'Quick-Start' option. Don't forget to introduce a realistic sigma 'XYZ Ini' according to the coordinate's precision.
1723</p>
1724
1725<p><img src="IMG/screenshot17.png"/></p>
1726<p><u>Figure 17:</u> BNC in 'Quick-Start' mode (PPP, Panel 1)</p>
1727
1728<p><img src="IMG/screenshot22.png"/></p>
1729<p><u>Figure 18:</u> BNC in 'Quick-Start' mode (PPP, Panel 2)</p>
1730
1731<p><a name="pppgap"><h4>3.12.7.8 Maximal Solution Gap - optional if Quick-Start is set</h4></p>
1732<p>
1733Specify a 'Maximum Solution Gap' in seconds. Should the time span between two consecutive solutions exceed this limit, the algorithm returns into the 'Quick-Start' mode and fixes the introduced reference coordinate for the specified 'Quick-Start' period. A value of '60' seconds could be an appropriate choice.
1734</p>
1735<p>
1736This option makes only sense for a stationary operated receiver where solution convergence can be enforced because a good approximation for the rover position is known. Default is an empty option field, meaning that you don't want BNC to return into the 'Quick-Start' mode after failures caused i.e. by longer lasting outages.
1737</p>
1738
1739<p><a name="pppaudio"><h4>3.12.7.9 Audio Response - optional if Quick-Start is set</h4></p>
1740<p>
1741For natural hazard prediction and monitoring it may be appropriate to generate audio alerts. For that you can specify an 'Audio response' threshold in meters. A beep is produced by BNC whenever a horizontal PPP coordinate component differs by more than the threshold value from the specified marker coordinate.
1742</p>
1743<p>
1744Default is an empty option field, meaning that you don't want BNC to produce acoustic warning signals.
1745</p>
1746
1747<p><a name="pppsigmas"><h4>3.12.8 Sigmas</h4></p>
1748<p>
1749You may like to introduce specific sigmas for code and phase observations and for the estimation of troposphere parameters.
1750</p>
1751
1752<p><a name="pppsigc"><h4>3.12.8.1 Code - mandatory if 'Use Phase Obs' is set</h4></p>
1753<p>
1754When 'Use phase obs' is set in BNC, the PPP solution will be carried out using both, code and phase observations. A sigma of 10.0 m for code observations and a sigma of 0.02 m for phase observations (defaults) are used to combine both types of observations. As the convergence characteristic of a PPP solution can be influenced by the ratio of the sigmas for code and phase, you may like to introduce you own sigmas for code and phase observations which differ from the default values.
1755<ul>
1756<li>Introducing a smaller sigma (higher accuracy) for code observations or a larger sigma for phase observations leads to better results shortly after program start. However, it may take more time till you finally get the best possible solution.</li>
1757<li>Introducing a larger sigma (lower accuracy) for code observations or a smaller sigma for phase observations may lead to less accurate results shortly after program start and thus a prolonged period of convergence but could provide better positions in the long run.</li>
1758</ul>
1759</p>
1760<p>
1761Specify a sigma for code observations. Default is 10.0 m.
1762</p>
1763
1764<p><a name="pppsigp"><h4>3.12.8.2 Phase - mandatory if 'Use Phase Obs' is set</h4></p>
1765<p>
1766Specify a sigma for phase observations. Default is 0.02 m.
1767</p>
1768
1769<p><a name="pppsigxyzi"><h4>3.12.8.3 XYZ Init - mandatory</h4></p>
1770<p>
1771Enter a sigma in meters for the initial XYZ coordinate. A value of 100.0 (default) may be an appropriate choice. However, this value may be significantly smaller (i.e. 0.01) when starting for example from a station with known XZY position in Quick-Start mode.
1772</p>
1773
1774<p><a name="pppsigxyzn"><h4>3.12.8.4 XYZ White Noise - mandatory</h4></p>
1775<p>
1776Enter a sigma in meters for the 'White Noise' of estimated XYZ coordinate components. A value of 100.0 (default) may be appropriate when considering possible sudden movements of a rover.
1777</p>
1778
1779<p><a name="pppsigtrpi"><h4>3.12.8.5 Tropo Init - mandatory if 'Estimate tropo' is set</h4></p>
1780<p>
1781Enter a sigma in meters for the a-priory model based tropospheric delay estimation. A value of 0.1 (default) may be an appropriate choice.
1782</p>
1783
1784<p><a name="pppsigtrpn"><h4>3.12.8.6 Tropo White Noise - mandatory if 'Estimate tropo' is set</h4></p>
1785<p>
1786Enter a sigma in meters per second to describe the expected variation of the tropospheric effect. Supposing 1Hz observation data, a value of 3e-6 (default) would mean that the tropospheric effect may vary for 3600 * 3e-6 = 0.01 meters per hour.
1787</p>
1788
1789<p><a name="combi"><h4>3.13. Combine Corrections</h4></p>
1790<p>
1791BNC allows processing several orbit and clock correction streams in real-time to produce, encode, upload and save a combination of Broadcast Corrections from various providers. It is so far only the satellite clock corrections which are combined while orbit corrections in the combination product as well as the product update rates are just taken over from one of the incoming Broadcast Correction streams. Combining only clock corrections using a fixed orbit reference has the possibility to introduce some analysis inconsistencies. We may therefore eventually consider improvements on this approach. The clock combination can be based either on a plain 'Single-Epoch' or on a 'Kalman' Filter approach.
1792</p>
1793<p>
1794In the Kalman Filter approach satellite clocks estimated by individual Analyses Centers (ACs) are used as pseudo observations within the adjustment process. Each observation is modeled as a linear function (actually a simple sum) of three estimated parameters: AC specific offset, satellite specific offset common to all ACs, and the actual satellite clock correction which represents the result of the combination. These three parameter types differ in their statistical properties. The satellite clock offsets are assumed to be static parameters while AC specific and satellite specific offsets are stochastic parameters with appropriate white noise.
1795 The solution is regularized by a set of minimal constraints.
1796</p>
1797<p>
1798Removing the AC-dependent biases as well as possible is a major issue with clock combinations. Since they vary in time, it can be tricky to do this. Otherwise, there will be artificial jumps in the combined clock stream if one or more AC contributions drop out for certain epochs. Here the Kalman Filter approach is expected to do better than the Single-Epoch approach.
1799</p>
1800<p>
1801In view of IGS real-time products, the 'Combine Corrections' functionality has been integrated in BNC because
1802<ul>
1803<li>The software with its Graphic User Interface and wide range of supported Operating Systems represents a perfect platform to process many Broadcast Correction streams in parallel;</li>
1804<li>Outages of single AC product streams can be mitigated through merging several incoming streams into a combined product;</li>
1805<li>Generating a combination product from several AC products allows detecting and rejecting outliers;</li>
1806<li>A Combination Center (CC) can operate BNC to globally disseminate a combination product via NTRIP broadcast;</li>
1807<li>An individual AC could prefer to disseminate a stream combined from primary and backup IT resources to reduce outages;</li>
1808<li>It enables a BNC PPP user to follow his own preference in combining streams from individual ACs for Precise Point Positioning;</li>
1809<li>It allows an instantaneous quality control of the combination process not only in the time domain but also in the space domain; this can be done through direct application of the combined stream in a PPP solution even without prior upload to an NTRIP Broadcaster;</li>
1810<li>It provides the means to output SP3 and Clock RINEX files containing precise orbit and clock information for further processing using other tools than BNC.</li>
1811</ul>
1812</p>
1813<p>
1814Note that the combination process requires real-time access to Broadcast Ephemeris. So, in addition to the orbit and clock correction streams BNC must pull a stream carrying Broadcast Ephemeris in the form of RTCM Version 3 messages. Stream 'RTCM3EPH' on caster <u>products.igs-ip.net</u> is an example for that.
1815</p>
1816<p>
1817Note further that you need to tick the 'Use GLONASS' option which is part of the 'PPP (2)' panel in case you want to produce an GPS plus GLONASS combination.
1818</p>
1819<p>
1820A combination is carried out following a specified sampling interval. If incoming streams have different rates, only epochs that correspond to the sampling interval are used.
1821</p>
1822<p>
1823With respect to IGS, it is important to understand that a major effect in the combination of GNSS orbit and clock correction streams is the selection of ACs to include. It is likely that a combination product could be improved in accuracy by using only the best two or three ACs. However, with only a few ACs to depend on, the reliability of the combination product could suffer and the risk of total failures increases. So there is an important tradeoff here that must be considered when selecting streams for a combination. The major strength of a combination product is its reliability and stable median performance which can be much better than that of any single AC product.
1824</p>
1825<p>
1826This comment applies in situations where we have a limited number of solutions to combine and their quality varies significantly. The situation may be different when the total number of ACs is larger and the range of AC variation is smaller. In that case, a standard full combination is probably the best.
1827</p>
1828<p>
1829The following recursive algorithm is used to detect orbit outliers in the Kalman Filter combination when Broadcast Corrections are provided by several ACs:
1830<br>
1831Step 1: We don't produce a combination for a certain satellite if only one AC provides corrections for it.
1832<br>
1833Step 2: A mean satellite position is calculated as the average of positions from all ACs.
1834<br>
1835Step 3: For each AC and satellite the 3D distance between individual and mean satellite position is calculated.
1836<br>
1837Step 4: We find the greatest difference between AC specific and mean satellite positions.
1838<br>
1839Step 5: If that is less than a threshold, the conclusion is that we don't have an outlier and can proceed to the next epoch.
1840<br>
1841Step 6: If that is greater than a threshold, then corrections of the affiliated AC are ignored for the affected epoch and the outlier detection restarts with step 1.
1842</p>
1843<p>
1844Note that BNC can produce an internal PPP solution from combined Broadcast Corrections. For that you have to specify the keyword 'INTERNAL' as 'Corrections Mountpoint' in the PPP (1) panel.
1845</p>
1846<p>
1847The part of BNC which enables the combination of Broadcast Corrections is not intended for publication under GNU General Public License (GPL). However, pre-compiled BNC binaries which support the 'Combine Corrections' option are made available.
1848</p>
1849
1850<p><a name="combimounttab"><h4>3.13.1 Combine Corrections Table - optional</h4></p>
1851<p>
1852Hit the 'Add Row' button, double click on the 'Mountpoint' field, enter a Broadcast Corrections mountpoint from the 'Streams' section and hit Enter. Then double click on the 'AC Name' field to enter your choice of an abbreviation for the Analysis Center (AC) providing the stream. Finally, double click on the 'Weight' field to enter a weight to be applied to this stream in the combination. The stream processing can already be started with only one corrections stream configured for combination.
1853</p>
1854<p>
1855Note that an appropriate 'Wait for full corr epoch' value needs to be specified for the combination under the 'Broadcast Corrections' tab. To give an example: a value of 15 sec would make sense if the update rate of incoming clock corrections is 10 sec.
1856</p>
1857<p>
1858The sequence of entries in the 'Combine Corrections' table is not of importance. Note that the orbit information in the final combination stream is just copied from one of the incoming streams. The stream used for providing the orbits may vary over time: if the orbit providing stream has an outage then BNC switches to the next remaining stream for getting hold of the orbit information.</p>
1859<p>
1860Default is an empty 'Combine Corrections' table meaning that you don't want BNC to combine orbit and clock correction streams.
1861</p>
1862<p>
1863It is possible to specify only one Broadcast Ephemeris corrections stream in the 'Combine Corrections' table. Instead of combining corrections from several sources BNC will then merge the single corrections stream with Broadcast Ephemeris to save results in SP3 and/or Clock RINEX format when specified accordingly under the 'Upload Corrections' tab.
1864</p>
1865
1866<p><a name="combiadd"><h4>3.13.1.1 Add Row, Delete - optional</h4></p>
1867<p>
1868Hit 'Add Row' button to add another row to the 'Combine Corrections' table or hit the 'Delete' button to delete the highlighted row(s).
1869</p>
1870
1871<p>
1872The following screenshots describe an example setup of BNC when combining Broadcast Correction streams and uploading them to an NTRIP Broadcaster. Note that it requires specifying options under tabs 'Combine Corrections' and 'Upload Corrections'. The example uses the combination product to simultaneously carry out an 'INTERNAL' PPP solution in 'Quick-Start' mode which allows monitoring the quality of the combination product in the space domain.
1873</p>
1874
1875<br>
1876<p><img src="IMG/screenshot20.png"/></p>
1877<p><u>Figure 19:</u> BNC combining Broadcast Correction streams.</p>
1878<p><br></p>
1879<p><img src="IMG/screenshot21.png"/></p>
1880<p><u>Figure 20:</u> BNC uploading the combined Broadcast Corrections stream.</p>
1881<p></p>
1882<p><img src="IMG/screenshot23.png"/></p>
1883<p><u>Figure 21:</u> 'INTERNAL' PPP with BNC using combined Broadcast Corrections stream.</p>
1884
1885<p><a name="combimethod"><h4>3.13.1.2 Method - mandatory if 'Combine Corrections' table is populated</h4></p>
1886<p>
1887Select a clock combination method. Available options are Kalman 'Filter' and 'Single-Epoch. It is suggested to use the Kalman Filter approach in case the combined stream of Broadcast Corrections is intended for Precise Point Positioning.
1888</p>
1889
1890<p><a name="combimax"><h4>3.13.1.3 Maximal Residuum - mandatory if 'Combine Corrections' table is populated</h4></p>
1891
1892<p>BNC combines all incoming clocks according to specified weights. Individual clock estimates that differ by more than 'Maximal Residuum' meters from the average of all clocks will be ignored.<p>
1893</p>It is suggested to specify a value of about 0.2 m for the Kalman filter combination approach and a value of about 3.0 meters for the Single-Epoch combination approach.</p>
1894<p>Default is a 'Maximal Residuum' of 999.0 meters</p>
1895
1896<p><a name="combismpl"><h4>3.13.1.4 Sampling - mandatory if 'Combine Corrections' table is populated</h4></p>
1897<p>Specify a combination sampling interval. Orbit and clock corrections will be produced following that interval. A value of 10 sec may be an appropriate choice.</p>
1898
1899
1900<p><a name="upclk"><h4>3.14. Upload Corrections</h4></p>
1901<p>
1902BNC can upload streams carrying orbit and clock corrections to Broadcast Ephemeris in radial, along-track and cross-track components if they are<ol type=a>
1903<li>
1904either generated by BNC as a combination of several individual Broadcast Correction streams coming from an number of real-time Analysis Centers (ACs), see section 'Combine Corrections',</li>
1905<li>
1906or generated by BNC while the program receives an ASCII stream of precise satellite orbits and clocks via IP port from a connected real-time GNSS engine. Such a stream would be expected in a plain ASCII format and the associated 'decoder' string would have to be 'RTNET', see format description below. </li>
1907</ol>
1908The procedure taken by BNC to generate the orbit and clock corrections to Broadcast Ephemeris and upload them to an NTRIP Broadcaster is as follow:
1909<ul>
1910<li>Continuously receive up-to-date Broadcast Ephemeris carrying approximate orbits and clocks for all satellites. Read new Broadcast Ephemeris immediately whenever they become available. This information may come via a stream of RTCM messages generated from another BNC instance.</li>
1911</ul>
1912Then, epoch by epoch:
1913<ul>
1914<li>Continuously receive the best available orbit and clock estimates for all satellites in XYZ Earth-Centered-Earth-Fixed IGS08 reference system. Receive them every epoch in plain ASCII format as provided by a real-time GNSS engine such as RTNet or generate them following a combination approach. </li>
1915<li>Calculate XYZ coordinates from Broadcast Ephemeris orbits. </li>
1916<li>Calculate differences dX,dY,dZ between Broadcast Ephemeris and IGS08 orbits. </li>
1917<li>Transform these differences into radial, along-track and cross-track corrections to Broadcast Ephemeris orbits. </li>
1918<li>Calculate corrections to Broadcast Ephemeris clocks as differences between Broadcast Ephemeris clocks and IGS08 clocks. </li>
1919<li>Encode Broadcast Ephemeris orbit and clock corrections in RTCM Version 3 format. </li>
1920<li>Upload Broadcast Corrections stream to NTRIP Broadcaster. </li>
1921</ul>
1922<p>
1923The orbit and clock corrections to Broadcast Ephemeris are usually referred to the latest set of broadcast messages, which are generally also received in real-time by a GNSS rover. However, the use of the latest broadcast message is delayed for a period of 60 seconds, measured from the time of complete reception of ephemeris and clock parameters, in order to accommodate rover applications to obtain the same set of broadcast orbital and clock parameters. This procedure is recommended in the RTCM SSR standard.
1924</p>
1925</p>
1926Because the encoding process may put a significant load on the communication link between BNC and the real-time GNSS engine, it is recommended to run both programs on the same host. However, doing so is not compulsory.
1927</p>
1928<p>
1929The usual handling of BNC when uploading a stream with Broadcast Corrections is that you first specify Broadcast Ephemeris and Broadcast Correction streams. You then specify an NTRIP Broadcaster for stream upload before you start the program.
1930</p>
1931<p>
1932BNC requires GNSS orbits and clocks in the IGS Earth-Centered-Earth-Fixed (ECEF) reference system and in a specific ASCII format. The orbits and clocks must be referred to satellite Center of Mass (CoM) and must not contain the conventional periodic relativistic effect. They may be provided by a real-time GNSS engine such as RTNet. The sampling interval for data transmission should not exceed 15 sec. Note that otherwise tools involved in IP streaming such as NTRIP Broadcasters or NTRIP Clients may respond with a timeout.
1933</p>
1934
1935<p>
1936Below you find an example of precise orbits and clocks coming in ASCII format (which is named 'RTNET' in this document) from a real-time GNSS engine. Each epoch starts with an asterisk character followed by the time as year, month, day of month, hour, minute and second. Subsequent records provide the following set of parameters for each satellite:
1937</p>
1938
1939<p>
1940<ul>
1941<li>GNSS Indicator and Satellite Vehicle Pseudo Random Number</li>
1942<li>XYZ coordinates in Earth-Centered-Earth-Fixed system [km] at epoch T</li>
1943<li>Satellite clock error [microsecond]</li>
1944<li>Conventional periodic relativistic effect [microsecond]</li>
1945<li>DX,DY,DZ [m] in Earth-Centered-Earth-Fixed system for translation CoM-&gt;APC</li>
1946<li>Differential Code Bias P1C1 [m]</li>
1947<li>Differential Code Bias P1P2 [m]</li>
1948<li>Time increment dT [second]</li>
1949<li>XYZ coordinates in Earth-Centered-Earth-Fixed system [km] at epoch T+dT</li>
1950</ul>
1951</p>
1952Example for 'RTNET' stream format:
1953</p>
1954<p>
1955<pre>
1956...
1957PR22 24695.278546 4939.628474 -3498.468864 41.074663 0.000301 -2.458 0.059 0.259 0.000 0.369 60.0 24724.926665 4937.395818 -3285.525249
1958PR23 16644.528151 -4673.966731 -18755.727311 -381.408485 -0.000069 -1.484 0.958 1.597 0.000 -1.041 60.0 16794.540110 -4640.370673 -18629.931406
1959PR24 -835.564016 -11361.061950 -22837.329550 -67.978344 -0.000027 0.088 1.593 1.979 0.000 0.628 60.0 -654.746874 -11311.272410 -22867.926411
1960EOE
1961* 2012 4 13 18 5 20.00000000
1962PG01 -17662.477581 -4690.968816 19273.403670 247.562657 -0.001403 1.173 -0.094 -1.222 -0.081 -3.222 60.0 -17723.637492 -4824.411250 19184.308406
1963PG02 13499.913230 23158.540481 -1230.022763 386.539840 -0.009664 -0.392 -0.672 0.036 -0.007 1.778 60.0 13488.200264 23175.574718 -1044.681214
1964PG03 -16691.614702 -11720.144912 -17619.363518 35.472262 -0.007906 1.785 0.965 1.939 -0.171 -0.769 60.0 -16563.914187 -11742.834794 -17725.636699
1965...
1966PG32 -16198.232316 -3364.836652 20899.169198 -432.258718 -0.025811 1.728 0.075 -2.191 -0.370 -1.040 60.0 -16107.271625 -3493.294042 20951.654447
1967PR01 18574.288277 -17410.663026 -1754.600023 -178.990271 -0.000082 -1.469 2.095 0.024 0.000 0.188 60.0 18556.963974 -17406.362476 -1967.750384
1968PR02 8030.345235 -18665.480490 15430.035833 -298.816088 -0.000568 -0.516 2.171 -1.184 0.000 0.221 60.0 8114.572636 -18759.449343 15271.294411
1969PR03 -6108.423573 -9263.873363 23002.679850 -129.074986 0.000627 0.523 1.396 -2.019 0.000 1.568 60.0 -5976.535477 -9398.317054 22982.703956
1970...
1971PR24 -820.514575 -11356.881507 -22839.954618 -67.978328 -0.000026 0.087 1.593 1.979 0.000 0.628 60.0 -639.657024 -11307.160404 -22870.387083
1972EOE
1973* 2012 4 13 18 5 25.00000000
1974PG01 -17667.568396 -4702.119849 19266.035352 247.562677 -0.001403 1.173 -0.094 -1.222 -0.081 -3.222 60.0 -17728.740899 -4835.494883 19176.817383
1975PG02 13498.959815 23160.004885 -1214.580934 386.539856 -0.009647 -0.392 -0.672 0.035 -0.007 1.778 60.0 13487.197253 23176.941260 -1029.232392
1976PG03 -16680.999851 -11722.017340 -17628.269050 35.472285 -0.007882 1.783 0.966 1.940 -0.171 -0.769 60.0 -16553.240904 -11744.747432 -17734.434260
1977...
1978</pre>
1979</p>
1980<p>
1981Note that each end of an epoch in the incoming stream is indicated by an ASCII string 'EOE' (for End Of Epoch).
1982</p>
1983<p>
1984When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the conventional periodic relativistic effect. Chapter 10 of the IERS Conventions 2003 mentions that the conventional periodic relativistic correction to the satellite clock (to be added to the broadcast clock) is computed as dt = -2 (R * V) / c^2 where R *V is the scalar product of the satellite position and velocity and c is the speed of light. This can also be found in the GPS Interface Specification, IS-GPS-200, Revision D, 7 March 2006.
1985</p>
1986
1987<p><a name="upadd"><h4>3.14.1 Add, Delete Row - optional</h4></p>
1988<p>Hit 'Add Row' button to add another row to the stream 'Upload Table' or hit the 'Delete' button to delete the highlighted row(s).
1989</p>
1990<p>
1991Having an empty 'Upload Table' is default and means that you don't want BNC to upload orbit and clock correction streams to any NTRIP Broadcaster.
1992</p>
1993
1994<p><a name="uphost"><h4>3.14.2 Host, Port, Mountpoint, Password - mandatory if 'Upload Table' entries specified</h4></p>
1995
1996<p>Specify the domain name or IP number of an NTRIP Broadcaster for uploading the stream. Furthermore, specify the caster's listening IP port, an upload mountpoint and an upload password. Note that NTRIP Broadcasters are often configured to provide access on more than one port, usually port 80 and 2101. If you experience communication problems on port 80, you should try to use the alternative port(s).
1997</p>
1998<p>
1999BNC uploads a stream to the NNTRIP Broadcaster by referring to a dedicated mountpoint that has been set by its operator. Specify here the mountpoint based on the details you received for your stream from the operator. It is often a four character ID (capital letters) plus an integer number.</p>
2000<p>The stream upload may be protected through an upload 'Password'. Enter the password you received from the NTRIP Broadcaster operator along with the mountpoint(s).</p>
2001<p>
2002If 'Host', 'Port', 'Mountpoint' and 'Password' are set, the stream will be encoded in RTCM's 'State Space Representation' (SSR) messages and uploaded to the specified broadcaster following the NTRIP Version 1 transport protocol.
2003</p>
2004
2005<p><a name="upsystem"><h4>3.14.3 System - mandatory if 'Host' is set</h4></p>
2006<p>
2007BNC allows configuring several Broadcast Correction streams for upload so that they refer to different reference systems and different NTRIP Broadcasters. You may use this functionality for parallel support of a backup NTRIP Broadcaster or for simultaneous support of various regional reference systems. Available options for transforming orbit and clock corrections to specific target reference systems are
2008<p>
2009<ul>
2010<li>IGS08 which stands for the GNSS-based IGS realization of the International Terrestrial Reference Frame 2008 (ITRF2008), and</li>
2011<li>ETRF2000 which stands for the European Terrestrial Reference Frame 2000 adopted by EUREF, and</li>
2012<li>NAD83 which stands for the North American Datum 1983 as adopted for the U.S.A., and</li>
2013<li>GDA94 which stands for the Geodetic Datum Australia 1994 as adopted for Australia, and</li>
2014<li>SIRGAS2000 which stands for the Geodetic Datum adopted for Brazil, and</li>
2015<li>SIRGAS95 which stands for the Geodetic Datum adopted i.e. for Venezuela, and</li>
2016<li>'Custom' which allows a transformation of Broadcast Corrections from the IGS08 system to any other system through specifying up to 14 Helmert Transformation Parameters.</li>
2017</ul>
2018</p>
2019
2020<p>
2021Because a mathematically strict transformation to a regional reference system is not possible on the BNC server side when a scale factor is involved, the program follows an approximate solution. While <u>orbits</u> are transformed in full accordance with given equations, a transformed <u>clock</u> is derived through applying correction term
2022</p>
2023<pre>
2024dC = (s - 1) / s * &rho; / c
2025</pre>
2026<p>
2027where s is the transformation scale, c is the speed of light, and &rho; are the topocentric distance between an (approximate) center of the transformation's validity area and the satellite.
2028</p>
2029<p>
2030From a theoretical point of view this kind of approximation leads to inconsistencies between orbits and clocks and is therefore not allowed. However, it has been proved that resulting errors in Precise Point Positioning are on millimeter level for horizontal components and below the one centimeter for height components. The Australian GDA94 transformation with its comparatively large scale parameter is an exception in this as descrepancies may reach up to two centimeters.
2031</p>
2032
2033<p>
2034<u>IGS08:</u> As the orbits and clocks coming from real-time GNSS engine are expected to be in the IGS08 system, no transformation is carried out if this option is selected.
2035</p>
2036
2037<p>
2038<u>ETRF2000:</u> The formulas for the transformation 'ITRF2008-&gt;ETRF2000' are taken from 'Claude Boucher and Zuheir Altamimi 2008: Specifications for reference frame fixing in the analysis of EUREF GPS campaign', see <u>http://etrs89.ensg.ign.fr/memo-V8.pdf</u>. The following 14 Helmert Transformation Parameters were introduced:
2039</p>
2040<p>
2041<pre>
2042Translation in X at epoch To: 0.0521 m
2043Translation in Y at epoch To: 0.0493 m
2044Translation in Z at epoch To: -0.0585 m
2045Translation rate in X: 0.0001 m/y
2046Translation rate in Y: 0.0001 m/y
2047Translation rate in Z: -0.0018 m/y
2048Rotation in X at epoch To: 0.891 mas
2049Rotation in Y at epoch To: 5.390 mas
2050Rotation in Z at epoch To: -8.712 mas
2051Rotation rate in X: 0.081 mas/y
2052Rotation rate in Y: 0.490 mas/y
2053Rotation rate in Z: -0.792 mas/y
2054Scale at epoch To : 0.00000000134
2055Scale rate: 0.00000000008 /y
2056To: 2000.0
2057</pre>
2058</p>
2059
2060<p>
2061<u>NAD83:</u> Formulas for the transformation 'ITRF2005-&gt;NAD83' are taken from 'Chris Pearson, Robert McCaffrey, Julie L. Elliott, Richard Snay 2010: HTDP 3.0: Software for Coping with the Coordinate Changes Associated with Crustal Motion, Journal of Surveying Engineering'.
2062</p>
2063<p>
2064<pre>
2065Translation in X at epoch To: 0.9963 m
2066Translation in Y at epoch To: -1.9024 m
2067Translation in Z at epoch To: -0.5219 m
2068Translation rate in X: 0.0005 m/y
2069Translation rate in Y: -0.0006 m/y
2070Translation rate in Z: -0.0013 m/y
2071Rotation in X at epoch To: 25.915 mas
2072Rotation in Y at epoch To: 9.426 mas
2073Rotation in Z at epoch To: 11.599 mas
2074Rotation rate in X: 0.067 mas/y
2075Rotation rate in Y: -0.757 mas/y
2076Rotation rate in Z: -0.051 mas/y
2077Scale at epoch To : 0.00000000078
2078Scale rate: -0.00000000010 /y
2079To: 1997.0
2080</pre>
2081</p>
2082
2083<p>
2084<u>GDA94:</u> The formulas for the transformation 'ITRF2008-&gt;GDA94' are taken from 'John Dawson, Alex Woods 2010: ITRF to GDA94 coordinate transformations', Journal of Applied Geodesy, 4 (2010), 189-199, de Gruyter 2010. DOI 10.1515/JAG.2010.019'.
2085</p>
2086<p>
2087<pre>
2088Translation in X at epoch To: -0.08468 m
2089Translation in Y at epoch To: -0.09142 m
2090Translation in Z at epoch To: 0.03201 m
2091Translation rate in X: 0.00142 m/y
2092Translation rate in Y: 0.00134 m/y
2093Translation rate in Z: 0.00090 m/y
2094Rotation in X at epoch To: 0.4254 mas
2095Rotation in Y at epoch To: -2.2578 mas
2096Rotation in Z at epoch To: -2.4015 mas
2097Rotation rate in X: -1.5461 mas/y
2098Rotation rate in Y: -1.1820 mas/y
2099Rotation rate in Z: -1.1551 mas/y
2100Scale at epoch To : 0.000000009710
2101Scale rate: 0.000000000109 /y
2102To: 1994.0
2103</pre>
2104</p>
2105
2106<p>
2107<u>SIRGAS2000:</u> The formulas for the transformation 'ITRF2008-&gt;SIRGAS2000' were provided via personal communication from CGED-Coordenacao de Geodesia, IBGE/DGC - Diretoria de Geociencias, Brazil.</u>.
2108</p>
2109<p>
2110<pre>
2111Translation in X at epoch To: 0.0020 m
2112Translation in Y at epoch To: 0.0041 m
2113Translation in Z at epoch To: 0.0039 m
2114Translation rate in X: 0.0000 m/y
2115Translation rate in Y: 0.0000 m/y
2116Translation rate in Z: 0.0000 m/y
2117Rotation in X at epoch To: 0.170 mas
2118Rotation in Y at epoch To: -0.030 mas
2119Rotation in Z at epoch To: 0.070 mas
2120Rotation rate in X: 0.000 mas/y
2121Rotation rate in Y: 0.000 mas/y
2122Rotation rate in Z: 0.000 mas/y
2123Scale at epoch To : 0.000000000000
2124Scale rate: 0.000000000000 /y
2125To: 0000.0
2126</pre>
2127</p>
2128
2129<p>
2130<u>SIRGAS95:</u> The formulas for the transformation 'ITRF2005-&gt;SIRGAS95' were provided via personal communication from Gustavo Acuha, Laboratorio de Geodesia Fisica y Satelital at Zulia University (LGFS-LUZ), parameters based on values from Table 4.1 of "Terrestrial Reference Frames (April 10, 2009), Chapter 4" in http://tai.bipm.org/iers/convupdt/convupdt_c4.html.</u>.
2131</p>
2132<p>
2133<pre>
2134Translation in X at epoch To: 0.0077 m
2135Translation in Y at epoch To: 0.0058 m
2136Translation in Z at epoch To: -0.0138 m
2137Translation rate in X: 0.0000 m/y
2138Translation rate in Y: 0.0000 m/y
2139Translation rate in Z: 0.0000 m/y
2140Rotation in X at epoch To: 0.000 mas
2141Rotation in Y at epoch To: 0.000 mas
2142Rotation in Z at epoch To: -0.003 mas
2143Rotation rate in X: 0.000 mas/y
2144Rotation rate in Y: 0.000 mas/y
2145Rotation rate in Z: 0.000 mas/y
2146Scale at epoch To : 0.00000000157
2147Scale rate: -0.000000000000 /y
2148To: 1995.4
2149</pre>
2150</p>
2151
2152<p>
2153<u>Custom:</u> Feel free to specify your own 14 Helmert Transformation parameters for transformations from IGS08/ITRF2008 into your own target system.
2154</p>
2155
2156<p><a name="upcom"><h4>3.14.4 Center of Mass - optional</h4></p>
2157<p>
2158BNC allows to either referring Broadcast Corrections to the satellite's Center of Mass (CoM) or to the satellite's Antenna Phase Center (APC). By default corrections refer to APC. Tick 'Center of Mass' to refer uploaded corrections to CoM.
2159</p>
2160
2161<p><a name="upsp3"><h4>3.14.5 SP3 File - optional</h4></p>
2162<p>Specify a path for saving the generated orbit corrections as SP3 orbit files. If the specified directory does not exist, BNC will not create SP3 orbit files. The following is a path example for a Linux system:<br>/home/user/BNC${GPSWD}.sp3<br>Note that '${GPSWD}' produces the GPS Week and Day number in the file name.</p>
2163<p>
2164Default is an empty option field, meaning that you don't want BNC to save the uploaded stream contents in daily SP3 files.
2165</p>
2166<p>
2167As an SP3 file contents should be referred to the satellites Center of Mass (CoM) while Broadcast Corrections are referred to the satellites APC, an offset has to be applied which is available from an IGS ANTEX file (see section 'ANTEX File'). You should therefore specify the 'ANTEX File' path under tab 'PPP (2)' if you want to save the stream contents in SP3 format. If you don't specify an 'ANTEX File' path there, the SP3 file contents will be referred to the satellites APCs.
2168</p>
2169<p>
2170The file names for the daily SP3 files follow the convention for SP3 file names. The first three characters of each file name are set to 'BNC'. Note that clocks in the SP3 orbit files are not corrected for the conventional periodic relativistic effect.
2171</p>
2172<p>
2173In case the 'Combine Corrections' table contains only one Broadcast Corrections stream, BNC will merge that stream with Broadcast Ephemeris to save results in files specified here through SP3 and/or Clock RINEX file path. In such a case you have to define only the SP3 and Clock RINEX file path and no further option in the 'Upload Corrections' table.
2174</p>
2175
2176<p>
2177Note that BNC outputs a complete list of SP3 'Epoch Header Records' even if no 'Position and Clock Records' are available for certain epochs because of stream outages. Note further that the 'Number of Epochs' in the first SP3 header record may not be correct because that number is not available when the file is created. Depending on your processing software (e.g. Bernese GNSS Software, BSW) it could therefore be necessary to correct an incorrect 'Number of Epochs' in the file before you use in Post Processing.
2178</p>
2179
2180<p><a name="uprinex"><h4>3.14.6 RNX File - optional</h4></p>
2181<p>
2182The clock corrections generated by BNC for upload can be logged in Clock RINEX format. The file naming follows the RINEX convention.
2183</p>
2184<p>
2185Specify a path for saving the generated clock corrections as Clock RINEX files. If the specified directory does not exist, BNC will not create Clock RINEX files. The following is a path example for a Linux system:<br>/home/user/BNC${GPSWD}.clk<br>Note that '${GPSWD}' produces the GPS Week and Day number in the file name.
2186</p>
2187<p>
2188Note further that clocks in the Clock RINEX files are not corrected for the conventional periodic relativistic effect.
2189</p>
2190
2191<p><a name="upinter"><h4>3.14.7 Interval - mandatory if 'Upload Table' entries specified</h4></p>
2192<p>
2193Select the length of Clock RINEX files and SP3 Orbit files. The default value is 1 day.
2194</p>
2195
2196<p><a name="upclksmpl"><h4>3.14.8 Sampling - mandatory if 'Upload Table' entries specified</h4></p>
2197<p>BNC requires an orbit corrections sampling interval for the stream to be uploaded and sampling intervals for SP3 and Clock RINEX files. The outgoing stream's clock correction sampling interval follows that of incoming corrections and is therefore nothing to be specified here.</p>
2198
2199<p><a name="upclkorb"><h4>3.14.8.1 Orbits - mandatory if 'Upload Table' entries specified</h4></p>
2200<p>Select the stream's orbit correction sampling interval in seconds. A value of 60 sec may be appropriate.</p>
2201<p> A value of zero '0' tells BNC to upload all orbit correction samples coming in from the real-time GNSS engine along with the clock correction samples to produce combined orbit and clock corrections to Broadcast Ephemeris (1060 for GPS, 1066 for GLONASS).
2202</p>
2203
2204<p><a name="upclksp3"><h4>3.14.8.2 SP3 - mandatory if 'SP3 File' is specified</h4></p>
2205<p>Select the SP3 orbit file sampling interval in minutes. A value of 15 min may be appropriate. A value of zero '0' tells BNC to store all available samples into SP3 orbit files.</p>
2206
2207<p><a name="upclkrnx"><h4>3.14.8.3 RINEX - mandatory if 'RNX File' is specified</h4></p>
2208<p>Select the Clock RINEX file sampling interval in seconds. A value of 10 sec may be appropriate. A value of zero '0' tells BNC to store all available samples into Clock RINEX files.</p>
2209
2210<p><a name="upcustom"><h4>3.14.9 Custom Trafo - optional if 'Upload Table' entries specified</h4></p>
2211<p>Hit 'Custom Trafo' to specify your own 14 parameter Helmert Transformation instead of selecting a predefined transformation through 'System' button.</p>
2212
2213<p>
2214The following screenshot shows the encoding and uploading of a stream of precise orbits and clocks coming from a real-time engine in 'RTNET' ASCII format. The stream is uploaded to NTRIP Broadcaster 'products.igs-ip.net'. It is referred to APC and IGS08. Uploaded data are locally saved in SP3 and Clock RINEX format. The SSR Provider ID is set to 3. The SSR Solution ID is and the Issue of Data SSR are set to 1. Required Broadcast Ephemeris are received via stream 'RTCM3EPH'.
2215</p>
2216<p><img src="IMG/screenshot26.png"/></p>
2217<p><u>Figure 22:</u> Producing Broadcast Corrections from incoming precise orbits and clocks and uploading them to an NTRIP Broadcaster.</p>
2218
2219<p><a name="upeph"><h4>3.15. Upload Ephemeris</h4></p>
2220<p>
2221BNC can upload a stream carrying Broadcast Ephemeris in RTCM Version 3 format to an NTRIP Broadcaster.
2222</p>
2223
2224<p><a name="brdcserver"><h4>3.15.1 Host &amp; Port - optional</h4></p>
2225<p>
2226Specify the 'Host' IP name or number of an NTRIP Broadcaster to upload the stream. An empty option field means that you don't want to upload Broadcast Ephemeris.
2227</p>
2228<p>
2229Enter the NTRIP Broadcaster's IP 'Port' number for stream upload. Note that NTRIP Broadcasters are often configured to provide access on more than one port, usually
2230port 80 and 2101. If you experience communication problems on port 80, you should try to use the alternative port(s).
2231</p>
2232
2233<p><a name="brdcmount"><h4>3.15.2 Mountpoint &amp; Password - mandatory if 'Host' is set</h4></p>
2234<p>
2235BNC uploads a stream to the NTRIP Broadcaster by referring to a dedicated mountpoint that has been set by its operator. Specify the mountpoint based on the details you received for your stream from the operator. It is often a four character ID (capital letters) plus an integer number.</p>
2236<p>The stream upload may be protected through an upload 'Password'. Enter the password you received from the NTRIP Broadcaster operator along with the mountpoint.</p>
2237</p>
2238
2239<p><a name="brdcsmpl"><h4>3.15.3 Sampling - mandatory if 'Host' is set</h4></p>
2240Select the Broadcast Ephemeris repetition interval in seconds. Default is '5' meaning that a complete set of Broadcast Ephemeris is uploaded every 5 seconds.
2241</p>
2242
2243<p><img src="IMG/screenshot28.png"/></p>
2244<p><u>Figure 23:</u> Producing a Broadcast Ephemeris stream from navigation messages of globally distributed RTCM streams and uploading them in RTCM Version 3 format to an NTRIP Broadcaster.</p>
2245
2246<p><a name="streams"><h4>3.16. Streams</h4></p>
2247<p>
2248Each stream on an NTRIP Broadcaster (and consequently on BNC) is defined using a unique source ID called mountpoint. An NTRIP Client like BNC accesses the desired stream by referring to its mountpoint. Information about streams and their mountpoints is available through the source-table maintained by the NTRIP Broadcaster. Note that mountpoints could show up in BNC more than once when retrieving streams from several NTRIP Broadcasters.
2249</p>
2250
2251<p>
2252Streams selected for retrieval are listed under the 'Streams' canvas on BNC's main window. The list provides the following information either extracted from source-table(s) produced by the NTRIP Broadcasters or introduced by BNC's user:
2253</p>
2254<p>
2255<table>
2256<tr><td>'resource loader'&nbsp; </td><td>NTRIP Broadcaster URL and port, or<br>TCP/IP host and port, or<br>UDP port, or<br>Serial input port specification.</td></tr>
2257<tr><td>'mountpoint' &nbsp;</td><td>Mountpoint introduced by NTRIP Broadcaster, or<br>Mountpoint introduced by BNC's user.</td></tr>
2258<tr><td>'decoder' &nbsp;</td><td>Name of decoder used to handle the incoming stream content according to its format; editable.</td></tr>
2259<tr><td>'lat' &nbsp;</td><td>Approximate latitude of reference station, in degrees, north; editable if 'nmea' = 'yes'.</td></tr>
2260<tr><td>'long' &nbsp;</td><td>Approximate longitude of reference station, in degrees, east; editable if 'nmea' = 'yes'.</td></tr>
2261<tr><td>'nmea' &nbsp;</td><td>Indicates whether or not streaming needs to be initiated by BNC through sending NMEA-GGA message carrying position coordinates in 'lat' and 'long'.</td></tr>
2262<tr><td>'ntrip' &nbsp;</td><td>Selected NTRIP transport protocol version (1, 2, 2s, R, or U), or<br>'N' for TCP/IP streams without NTRIP, or<br>'UN' for UDP streams without NTRIP, or<br>'S' for serial input streams without NTRIP.</td></tr>
2263<tr><td>'bytes' &nbsp;</td><td>Number of bytes received.
2264</table>
2265</p>
2266
2267<p><a name="streamedit"><h4>3.16.1 Edit Streams</h4></p>
2268<ul>
2269<li>
2270BNC automatically allocates one of its internal decoders to a stream based on the stream's 'format' and 'format-details' as given in the source-table. However, there might be cases where you need to override the automatic selection due to incorrect source-table for example. BNC allows users to manually select the required decoder by editing the decoder string. Double click on the 'decoder' field, enter your preferred decoder and then hit Enter. The accepted decoder strings are 'RTCM_2.x', 'RTCM_3.x' and 'RTNET'.
2271</li>
2272<li>
2273In case you need to log the raw data as is, BNC allows users to by-pass its decoders and directly save the input in daily log files. To do this, specify the decoder string as 'ZERO'. The generated file names are created from the characters of the streams mountpoints plus two-digit numbers each for year, month, and day. Example: Setting the 'decoder' string for mountpoint WTZZ0 to 'ZERO' and running BNC on March 29, 2007 would save the raw data in a file named WTZZ0_070329.
2274</li>
2275<li>
2276BNC can also retrieve streams from virtual reference stations (VRS). To initiate these streams, an approximate rover position needs to be sent in NMEA format to the NTRIP Broadcaster. In return, a user-specific data stream is generated, typically by Network-RTK software. VRS streams are indicated by a 'yes' in the source-table as well as in the 'nmea' column on the 'Streams' canvas in BNC's main window. They are customized exactly to the latitude and longitude transmitted to the NTRIP Broadcaster via NMEA-GGA messages.
2277<br>If NMEA-GGA messages are not coming from a serial connected GNSS rover, BNC simulates them from the default latitude and longitude of the source-table as shown in the 'lat' and 'long' columns on the 'Streams' canvas. However, in most cases you would probably want to change these defaults according to your requirement. Double-click on 'lat' and 'long' fields, enter the values you wish to send and then hit Enter. The format is in positive north latitude degrees (e.g. for northern hemisphere: 52.436, for southern hemisphere: -24.567) and eastern longitude degrees (example: 358.872 or -1.128). Only streams with a 'yes' in their 'nmea' column can be edited. The position must preferably be a point within the VRS service area of the network. RINEX files generated from these streams will contain an additional COMMENT line in the header beginning with 'NMEA' showing the 'lat' and 'long' used.
2278<br>Note that when running BNC in a Local Area Network (LAN), NMEA strings may be blocked by a proxy server, firewall or virus scanner when not using the NTRIP Version 2 transport protocol..
2279</li>
2280</ul>
2281
2282<p><a name="streamdelete"><h4>3.16.2 Delete Stream</h4></p>
2283<p>
2284To remove a stream from the 'Streams' canvas in the main window, highlight it by clicking on it and hit the 'Delete Stream' button. You can also remove multiple streams simultaneously by highlighting them using +Shift and +Ctrl.</p>
2285
2286<p><a name="streamconf"><h4>3.16.3 Reconfigure Stream Selection On-the-fly</h4></p>
2287<p>
2288The streams selection can be changed on-the-fly without interrupting uninvolved threads in the running BNC process.
2289</p>
2290<p>
2291<u>Window mode:</u> Hit 'Save &amp; Reread Configuration' while BNC is in window mode and already processing data to let changes of your streams selection immediately become effective.
2292<p>
2293<u>No window mode:</u> When operating BNC online in 'no window' mode (command line option -nw), you force BNC to reread its 'mountPoints' configuration option from disk at pre-defined intervals. Select '1 min', '1 hour', or '1 day' as 'Reread configuration' option to reread the 'mountPoints' option every full minute, hour, or day. This lets a 'mountPoints' option edited in between in the configuration file become effective without terminating uninvolved threads. See annexed section 'Configuration Examples' for a configuration file example and a list of other on-the-fly changeable options.
2294</p>
2295
2296<p><a name="logs"><h4>3.17. Logging</h4></p>
2297<p>
2298A tabs section on the bottom of the main window provides online control of BNC's activities. Tabs are available to show the records saved in a logfile, for a plot to control the bandwidth consumption, for a plot showing stream latencies, and for time series plots of PPP results.
2299</p>
2300<p><a name="logfile"><h4>3.17.1 Log</h4></p>
2301<p>
2302Records of BNC's activities are shown in the 'Log' tab. They can be saved into a file when a valid path is specified in the 'Logfile (full path)' field.
2303</p>
2304
2305<p><a name="throughput"><h4>3.17.2 Throughput</h4></p>
2306<p>
2307The bandwidth consumption per stream is shown in the 'Throughput' tab in bits per second (bps) or kilo bits per second (kbps). The following figure shows an example for the bandwidth consumption of incoming streams.
2308</p>
2309
2310<p><img src="IMG/screenshot08.png"/></p>
2311<p><u>Figure 24:</u> Bandwidth consumption of incoming streams.</p>
2312
2313<p><a name="latency"><h4>3.17.3 Latency</h4></p>
2314<p>
2315The latency of observations in each incoming stream is shown in the 'Latency' tab in milliseconds or seconds. Streams not carrying observations (i.e. those providing only Broadcast Ephemeris messages) or having an outage are not considered here and shown in red color. Note that the calculation of correct latencies requires the clock of the host computer to be properly synchronized. The next figure shows an example for the latency of incoming streams.
2316</p>
2317
2318<p><img src="IMG/screenshot07.png"/></p>
2319<p><u>Figure 25:</u> Latency of incoming streams.</p>
2320
2321<p><a name="ppptab"><h4>3.17.4 PPP Plot</h4></p>
2322<p>
2323Precise Point Positioning time series of North (red), East (green) and Up (blue) coordinate components are shown in the 'PPP Plot' tab when a 'Origin' option is defined. Values are either referred to reference coordinates (if specified) or referred to the first estimated set of coordinate components. The time as given in format [hh:mm] refers to GPS Time. The sliding PPP time series window covers a period of 5 minutes. Note that it may take up to 30 seconds or more till the first PPP solutions becomes available. The following figure shows the screenshot of a PPP time series plot of North, East and Up coordinate components.
2324</p>
2325
2326<p><img src="IMG/screenshot13.png"/></p>
2327<p><u>Figure 26:</u> Time series plot of PPP session.</p>
2328
2329<p><a name="bottom"><h4>3.18. Bottom Menu Bar</h4></p>
2330<p>
2331The bottom menu bar allows to add or delete streams to BNC's configuration and to start or stop it. It also provides access to BNC's online help function. The 'Add Stream' button opens a window that allows user to select one of several input communication links, see figure below.
2332</p>
2333
2334<p><img src="IMG/screenshot06.png"/></p>
2335<p><u>Figure 27:</u> Steam input communication links.</p>
2336
2337<p><a name="streamadd"><h4>3.18.1 Add Stream</h4></p>
2338<p>
2339Button 'Add Stream' allows you to pull streams either from an NTRIP Broadcaster or from a TCP/IP port, a UPD port, or a serial port.
2340</p>
2341
2342<p><a name="streamcaster"><h4>3.18.1.1 Add Stream - Coming from Caster</h4></p>
2343
2344<p>
2345Button 'Add Stream' &gt; 'Coming from Caster' then opens a window that allows user to select data streams from an NTRIP Broadcaster according to their mountpoints and show a distribution map of offered streams.
2346</p>
2347
2348<p><a name="streamhost"><h4>3.18.1.1.1 Caster Host and Port - mandatory</h4></p>
2349<p>
2350Enter the NTRIP Broadcaster host IP and port number. Note that EUREF and IGS operate NTRIP Broadcasters at <u>http://www.euref-ip.net/home</u>, <u>http://www.igs-ip.net/home</u>, <u>http://www.products.igs-ip.net/home</u> and <u>http://mgex.igs-ip.net/home</u>.
2351</p>
2352
2353<p><a name="streamtable"><h4>3.18.1.1.2 Casters Table - optional</h4></p>
2354<p>
2355It may be that you are not sure about your NTRIP Broadcasters host and port number or you are interested in other broadcaster installations operated elsewhere. Hit 'Show' for a table of known broadcasters maintained at <u>www.rtcm-ntrip.org/home</u>. A window opens which allows selecting a broadcaster for stream retrieval, see figure below.
2356</p>
2357</p>
2358<p><img src="IMG/screenshot04.png"/></p>
2359
2360<p><u>Figure 28:</u> Casters table.</p>
2361
2362<p><a name="streamuser"><h4>3.18.1.1.3 User and Password - mandatory for protected streams</h4></p>
2363<p>
2364Some streams on NTRIP Broadcasters may be restricted. Enter a valid 'User' ID and 'Password' for access to protected streams. Accounts are usually provided per NTRIP Broadcaster through a registration procedure. Register through <u>http://igs.bkg.bund.de/ntrip/registeruser</u> for access to protected streams from EUREF and IGS.
2365</p>
2366
2367<p><a name="gettable"><h4>3.18.1.1.4 Get Table</h4></p>
2368<p>
2369Use the 'Get Table' button to download the source-table from the NTRIP Broadcaster. Pay attention to data fields 'format' and 'format-details'. Keep in mind that BNC can only decode and convert streams that come in RTCM Version 2, RTCM Version 3, or RTNET format. For access to observations, Broadcast Ephemeris and Broadcast Corrections in RTCM format streams must contain a selection of appropriate message types as listed in the Annex, cf. data field 'format-details' for available message types and their repetition rates in brackets. Note that in order to produce RINEX Navigation files RTCM Version 3 streams containing message types 1019 (GPS) and 1020 (GLONASS) and 1045 (Galileo) are required. Select your streams line by line, use +Shift and +Ctrl when necessary. The figure below provides an example source-table.
2370</p>
2371<p>
2372The contents of data field 'nmea' tells you whether a stream retrieval needs to be initiated by BNC through sending an NMEA-GGA message carrying approximate position coordinates (virtual reference station).
2373</p>
2374<p>
2375Hit 'OK' to return to the main window. If you wish you can click on 'Add Stream' and repeat the process again to retrieve streams from different casters.
2376</p>
2377<p><img src="IMG/screenshot05.png"/></p>
2378<p><u>Figure 29:</u> Broadcaster source-table.</p>
2379
2380<p><a name="ntripv"><h4>3.18.1.1.5 NTRIP Version - mandatory</h4></p>
2381<p>
2382Some limitations and deficiencies of the NTRIP Version 1 stream transport protocol are solved in NTRIP Version 2. Improvements mainly concern a full HTTP compatibility in view of requirements coming from proxy servers. Version 2 is backwards compatible to Version 1. Options implemented in BNC are:
2383</p>
2384<p>
2385&nbsp; 1:&nbsp; NTRIP Version 1, TCP/IP.<br>
2386&nbsp; 2:&nbsp; NTRIP Version 2 in TCP/IP mode.<br>
2387&nbsp; 2s:&nbsp; NTRIP Version 2 in TCP/IP mode via SSL.<br>
2388&nbsp; R:&nbsp; NTRIP Version 2 in RTSP/RTP mode.<br>
2389&nbsp; U:&nbsp; NTRIP Version 2 in UDP mode.
2390</p>
2391<p>
2392If NTRIP Version 2 is supported by the broadcaster:
2393</p>
2394<ul>
2395<li>Try using option '2' if your streams are otherwise blocked by a proxy server operated in front of BNC.</li>
2396<li>Option 'R' or 'U' may be selected if latency is more important than completeness for your application. Note that the latency reduction is likely to be in the order of 0.5 sec or less. Note further that options 'R' (RTSP/RTP mode) and 'U' (UDP mode) are not accepted by proxy servers and a mobile Internet Service Provider may not support it.</li>
2397</ul>
2398<p>
2399Select option '1' if you are not sure whether the broadcaster supports NTRIP Version 2.</li>
2400</p>
2401
2402<p><a name="castermap"><h4>3.18.1.1.6 Map - optional</h4></p>
2403<p>
2404Button 'Map' opens a window to show a distribution map of the caster's streams. You may like to zoom in or out using the mouse. Left button: draw a rectangle to zoom, right button: zoom out, middle button: zoom back.
2405</p>
2406
2407<p><img src="IMG/screenshot24.png"/></p>
2408<p><u>Figure 30:</u> Stream distribution map derived from NTRIP Broadcaster source-table.</p>
2409
2410<p><a name="streamip"><h4>3.18.1.2 Add Stream - Coming from TCP/IP Port</h4></p>
2411<p>
2412Button 'Add Stream' &gt; 'Coming from TCP/IP Port' allows to retrieve streams via TCP directly from an IP address without using the NTRIP transport protocol. For that you:
2413<ul>
2414<li>Enter the IP address of the stream providing host.</li>
2415<li>Enter the IP port number of the stream providing host.</li>
2416<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
2417<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTNET', and 'ZERO'.</li>
2418<li>Enter the approximate latitude of the stream providing rover in degrees. Example: 45.32.</li>
2419<li>Enter the approximate longitude of the stream providing rover in degrees. Example: -15.20.</li>
2420</ul>
2421</p>
2422<p>
2423Streams directly received from a TCP/IP port show up with an 'N' for 'No NTRIP' in the 'Streams' canvas on BNC's main window. Latitude and longitude are to be entered just for informal reasons.
2424<p>
2425</p>
2426Note that this option works only if no proxy server is involved in the communication link.
2427</p>
2428
2429<p><a name="streamudp"><h4>3.18.1.3 Add Stream - Coming from UDP Port</h4></p>
2430<p>
2431Button 'Add Stream' &gt; 'Coming from UDP Port' allows to pick up streams arriving directly at one of the local host's UDP ports without using the NTRIP transport protocol. For that you:
2432<ul>
2433<li>Enter the local port number where the UDP stream arrives.</li>
2434<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
2435<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTNET', and 'ZERO'.</li>
2436<li>Enter the approximate latitude of the stream providing rover in degrees. Example: 45.32.</li>
2437<li>Enter the approximate longitude of the stream providing rover in degrees. Example: -15.20.</li>
2438</ul>
2439</p>
2440<p>
2441Streams directly received at a UDP port show up with a 'UN' for 'UDP, No NTRIP' in the 'Streams' canvas section on BNC's main window. Latitude and longitude are to be entered just for informal reasons.
2442<p>
2443
2444<p><a name="streamser"><h4>3.18.1.4 Add Stream - Coming from Serial Port</h4></p>
2445<p>
2446Button 'Add Stream' &gt; 'Coming from Serial Port' allows to retrieve streams from a GNSS receiver via serial port without using the NTRIP transport protocol. For that you:
2447<ul>
2448<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
2449<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTNET', and 'ZERO'.</li>
2450<li>Enter the approximate latitude of the stream providing receiver in degrees. Example: 45.32.</li>
2451<li>Enter the approximate longitude of the stream providing receiver in degrees. Example: -15.20.</li>
2452<li>Enter the serial 'Port name' selected on your host for communication with the receiver. Valid port names are
2453<pre>
2454Windows: COM1, COM2
2455Linux: /dev/ttyS0, /dev/ttyS1
2456FreeBSD: /dev/ttyd0, /dev/ttyd1
2457Digital Unix: /dev/tty01, /dev/tty02
2458HP-UX: /dev/tty1p0, /dev/tty2p0
2459SGI/IRIX: /dev/ttyf1, /dev/ttyf2
2460SunOS/Solaris: /dev/ttya, /dev/ttyb
2461</pre>
2462</li>
2463<li>Select a 'Baud rate' for the serial input. Note that using a high baud rate is recommended.</li>
2464<li>Select the number of 'Data bits' for the serial input. Note that often '8' data bits are used.</li>
2465<li>Select the 'Parity' for the serial input. Note that parity is often set to 'NONE'.</li>
2466<li>Select the number of 'Stop bits' for the serial input. Note that often '1' stop bit is used.</li>
2467<li>Select a 'Flow control' for the serial link. Select 'OFF' if you don't know better.</li>
2468</ul>
2469</p>
2470<p>
2471When selecting one of the serial communication options listed above, make sure that you pick those configured to the serial connected GNSS receiver.
2472</p>
2473
2474<p>
2475Streams received from a serial connected GNSS receiver show up with an 'S' (for <u>S</u>erial Port, no NTRIP) in the 'Streams' canvas section on BNC's main window. Latitude and longitude are to be entered just for informal reasons.
2476<p>
2477
2478<p>
2479The following figure shows a BNC example setup for pulling a stream via serial port on a Linux operating system.
2480</p>
2481<p><img src="IMG/screenshot15.png"/></p>
2482<p><u>Figure 31:</u> BNC setup for pulling a stream via serial port.</p>
2483
2484<p><a name="streamsdelete"><h4>3.18.2 Delete Stream</h4></p>
2485<p>
2486Button 'Delete Stream' allows you to delete streams previously selected for retrieval as listed under the 'Streams' canvas on BNC's main window.
2487</p>
2488
2489<p><a name="streamsmap"><h4>3.18.3 Map</h4></p>
2490<p>
2491Button 'Map' opens a window to show a distribution map of the streams selected for retrieval as listed under the 'Streams' canvas. You may like to zoom in or out using the mouse. Left button: draw a rectangle to zoom, right button: zoom out, middle button: zoom back.
2492</p>
2493
2494<p><a name="start"><h4>3.18.4 Start</h4></p>
2495<p>
2496Hit 'Start' to start retrieving, decoding or converting GNSS data streams in real-time. Note that 'Start' generally forces BNC to begin with fresh RINEX which might overwrite existing files when necessary unless the option 'Append files' is ticked.
2497</p>
2498
2499<p><a name="stop"><h4>3.18.5 Stop</h4></p>
2500<p>
2501Hit the 'Stop' button in order to stop BNC.
2502</p>
2503
2504<p><a name="cmd"><h4>3.19. Command Line Options</h4></p>
2505<p>
2506Command line options are available to run BNC in 'no window' mode or let it read data offline from one or several files for debugging or Post Processing purposes. BNC will then use processing options from the involved configuration file. Note that the self-explaining contents of the configuration file can easily be edited. It is possible to introduce a specific configuration file name instead of using the default name 'BNC.bnc'.
2507</p>
2508
2509<p><a name="nw"><h4>3.19.1 No Window Mode - optional</h4></p>
2510<p>
2511Apart from its regular windows mode, BNC can be started on all systems as a batch job with command line option '-nw'. BNC will then run in 'no window' mode, using processing options from its configuration file on disk. Terminate BNC using Windows Task Manager when running it in 'no window' mode on Windows systems.
2512</p>
2513<p>
2514Example:<br><br>
2515bnc.exe -nw
2516</p>
2517<p>
2518It is obvious that BNC requires graphics support when started in interactive
2519mode. But, note that it also requires graphics support when producing plots in
2520batch mode (option -nw). Windows and Mac OS X systems always support graphics. For
2521producing plots in batch mode on Linux systems you must make sure that at
2522least a virtual X-Server such as 'Xvfb' is installed and the '-display' option
2523is used. The following is an example shell script to execute BNC in batch mode
2524for producing QC plots from RINEX files. It could be used via 'crontab':
2525</p>
2526<pre>
2527#!/bin/bash
2528
2529# Save string localhost
2530echo "localhost" > /home/user/hosts
2531
2532# Start virtual X-Server, save process ID
2533/usr/bin/Xvfb :29 -auth /home/user/hosts -screen 0 1280x1024x8 &
2534psID=`echo $!`
2535
2536# Run BNC application with defined display variable
2537/home/user/BNC/bnc --conf /dev/null --key reqcAction Analyze --key reqcObsFile ons12090.12o --key reqcNavFile brdc2090.12p --key reqcOutLogFile multi.txt --key reqcPlotDir /home/user --display localhost:29 --nw
2538
2539# BNC done, kill X-server process
2540kill $psID
2541</pre>
2542
2543<p><a name="post"><h4>3.19.2 File Mode - optional</h4></p>
2544<p>
2545Although BNC is primarily a real-time online tool, for debugging purposes it can be run offline to read data from a file previously saved through option 'Raw output file'. Enter the following command line option for that
2546</p>
2547<p>
2548--file &lt;<u>inputFileName</u>&gt;
2549</p>
2550
2551and specify the full path to an input file containing previously saved data. Example:<br><br>
2552./bnc --file /home/user/raw.output_110301
2553</p>
2554<p>
2555Note that when running BNC offline, it will use options for file saving, interval, sampling, PPP etc. from its configuration file.
2556</p>
2557<p>Note further that option '--file' forces BNC to appy the '-nw' option for running in 'no window' mode.
2558</p>
2559
2560<p><a name="conffile"><h4>3.19.3 Configuration File - optional</h4></p>
2561The default configuration file name is 'BNC.bnc'. You may change this name at startup time using the command line option '--conf &lt;<u>confFileName</u>&gt;'. This allows running several BNC jobs in parallel on the same host using different sets of configuration options. <u>confFileName</u> stands either for the full path to a configuration file or just for a file name. If you introduce only a filename, the corresponding file will be saved in the current working directory from where BNC is started.
2562</p>
2563<p>
2564Example:<br><br>
2565./bnc --conf MyConfig.bnc
2566</p>
2567<p>
2568This leads to a BNC job using configuration file 'MyConfig.bnc'. The configuration file will be saved in the current working directory.
2569</p>
2570
2571<p><a name="confopt"><h4>3.19.4 Configuration Options - optional</h4></p>
2572<p>
2573BNC applies options from the configuration file but allows updating every one of them on the command line while the contents of the configuration file remains unchanged. The command line syntax for that looks as follows
2574</p>
2575<p>
2576--key &lt;keyName&gt; &lt;keyValue&gt;
2577</p>
2578<p>
2579where &lt;keyName&gt; stands for the name of an option contained in the configuration file and &lt;keyValue&gt; stands for the value you want to assign to it. The following is a syntax example for a complete command line:
2580</p>
2581<p>
2582bnc --nw --conf &lt;confFileName&gt --key &lt;keyName1&gt; &lt;keyValue1&gt; --key &lt;keyName2&gt; &lt;keyValue2&gt; ...
2583</p>
2584<p>
2585Example:
2586</p>
2587<p>
2588./bnc --conf CONFIG.bnc --key proxyPort 8001 --key rnxIntr "1 day"
2589</p>
2590
2591<p><a name="limits"><h3>4. Limitations</h3></p>
2592<ul>
2593<li>
2594In Qt-based desktop environments (like KDE) on Unix/Linux platforms it may happen that you experience a crash of BNC at startup even when running the program in the background using the '-nw' option. This is a known bug most likely resulting from an incompatibility of Qt libraries in the environment and in BNC. Entering the command 'unset SESSION_MANAGER' before running BNC may help as a work-around.
2595</li>
2596
2597<li>
2598Using RTCM Version 3 to produce RINEX files, BNC will properly handle most message types. However, when handling message types 1001, 1003, 1009 and 1011 where the ambiguity field is not set, the output will be no valid RINEX. All values will be stored modulo 299792.458 (speed of light).
2599</li>
2600<li>
2601Using RTCM Version 2, BNC will only handle message types 18 and 19 or 20 and 21 together with position and the antenna offset information carried in types 3 and 22. Note that processing carrier phase corrections and pseudo-range corrections contained in message types 20 and 21 needs access to Broadcast Ephemeris. Hence, whenever dealing with message types 20 and 21, make sure that Broadcast Ephemeris become available for BNC through also retrieving at least one RTCM Version 3 stream carrying message types 1019 (GPS ephemeris) and 1020 (GLONASS ephemeris).
2602</li>
2603<li>
2604BNC's 'Get Table' function only shows the STR records of a source-table. You can use an Internet browser to download the full source-table contents of any NTRIP Broadcaster by simply entering its URL in the form of <u>http://host:port</u>. Data field number 8 in the NET records may provide information about where to register for an NTRIP Broadcaster account.
2605</li>
2606<li>
2607EUREF as well as IGS adhere to an open data policy. Streams are made available through NTRIP Broadcasters at <u>www.euref-ip.net</u>, <u>www.igs-ip.net</u> and <u>products.igs-ip.net</u> free of charge to anyone for any purpose. There is no indication up until now how many users will need to be supported simultaneously. The given situation may develop in such a way that it might become difficult to serve all registered users at the same times. In cases where limited resources on the NTRIP Broadcaster side (software restrictions, bandwidth limitation etc.) dictates, first priority in stream provision will be given to stream providers followed by re-broadcasting activities and real-time analysis centers while access to others might be temporarily denied.
2608</li>
2609<li>
2610Once BNC has been started, many of its configuration options cannot be changed as long as it is stopped. See chapter 'Reread Configuration' for on-the-fly configuration exceptions.
2611</li>
2612<li>
2613Drag and drop of configuration file is currently not supported on Mac OS X.
2614</li>
2615
2616</ul>
2617
2618<p><a name="annex"><h3>5. Annex</h3></p>
2619<p>
26205.1. <a href=#history>Revision History</a><br>
26215.2. <a href=#rtcm>RTCM</a><br>
2622&nbsp; &nbsp; &nbsp; 5.2.1 NTRIP <a href=#ntrip1>Version 1</a><br>
2623&nbsp; &nbsp; &nbsp; 5.2.2 NTRIP <a href=#ntrip2>Version 2</a><br>
2624&nbsp; &nbsp; &nbsp; 5.2.3 RTCM <a href=#rtcm2>Version 2</a><br>
2625&nbsp; &nbsp; &nbsp; 5.2.4 RTCM <a href=#rtcm3>Version 3</a><br>
26265.3. <a href=#config>Configuration Examples</a><br>
26275.4. <a href=#links>Further Reading</a>
2628</p>
2629
2630<p><a name=history><h4>5.1 Revision History</h3></p>
2631<table>
2632<tr></tr>
2633
2634<tr>
2635<td>Dec 2006 &nbsp;</td><td>Version 1.0b &nbsp;</td>
2636<td>[Add] First Beta Binaries published based on Qt 4.2.3.</td>
2637</tr>
2638
2639<tr>
2640<td>Jan 2007 &nbsp;</td><td>Version 1.1b &nbsp;</td>
2641<td>[Add] Observables C2, S1, and S2<br>[Add] Virtual reference station access<br>[Bug] RTCM2 decoder time tag fixed<br>[Mod] Small letters for public RINEX skeleton files<br>[Add] Online help through Shift+F1</td>
2642</tr>
2643
2644<tr>
2645<td>Apr 2007 &nbsp;</td><td>Version 1.2b &nbsp;</td>
2646<td>[Bug] Output only through IP port<br>[Bug] Method 'reconnecting' now thread-save<br> [Add] ZERO decoder added<br> [Mod] Download public RINEX skeletons once per day<br> [Mod] Upgrade to Qt Version 4.2.3<br> [Mod] Replace 'system' call for RINEX script by 'QProcess'<br> [Add] HTTP Host directive for skeleton file download<br> [Add] Percent encoding for user IDs and passwords<br> [Bug] Exit execution of calling thread for RTCM3 streams<br> [Bug] Signal-slot mechanism for threads</td>
2647</tr>
2648
2649<tr>
2650<td>May 2007 &nbsp;</td><td>Version 1.3 &nbsp;</td>
2651<td>[Add] Source code published.</td>
2652</tr>
2653
2654<tr>
2655<td>Jul 2007 &nbsp;</td><td>Version 1.4 &nbsp;</td>
2656<td>[Bug] Skip messages from proxy server<br> [Bug] Call RINEX script through 'nohup'</td>
2657</tr>
2658
2659<tr>
2660<td>Apr 2008 &nbsp;</td><td>Version 1.5 &nbsp;</td>
2661<td>[Add] Handle ephemeris from RTCM Version 3 streams<br> [Add] Upgrade to Qt Version 4.3.2<br> [Add] Optional RINEX v3 output<br> [Add] SBAS support<br> [Bug] RINEX skeleton download following stream outage<br> [Add] Handle ephemeris from RTIGS streams<br> [Add] Monitor stream failure/recovery and latency<br> [Mod] Redesign of main window<br> [Bug] Freezing of About window on Mac OS X<br> [Bug] Fixed problem with PRN 32 in RTCMv2 decoder<br> [Bug] Fix for Trimble 4000SSI receivers in RTCMv2 decoder<br> [Mod] Major revision of input buffer in RTCMv2 decoder</td>
2662</tr>
2663
2664<tr>
2665<td>Dec 2008 &nbsp;</td><td>Version 1.6 &nbsp;</td>
2666<td>[Mod] Fill blank columns in RINEXv3 with 0.000<br> [Add] RTCMv3 decoder for orbit and clock corrections<br>[Add] Check RTCMv3 streams for incoming message types<br> [Add] Decode RTCMv2 message types 3, 20, 21, and 22<br> [Add] Loss of lock and lock time indicator<br> [Bug] Rounding error in RTCMv3 decoder concerning GLONASS height<br> [Mod] Accept GLONASS in RTCMv3 when transmitted first<br> [Add] Leap second 1 January 2009<br> [Add] Offline mode, read data from file<br> [Add] Output antenna descriptor, coordinates and eccentricities from RTCMv3<br> [Add] Reconfiguration on-the-fly<br> [Mod] Binary output of synchronized observations<br> [Add] Binary output of unsynchronized observations<br> [Bug] Fixed problem with joined RTCMv3 blocks</td>
2667</tr>
2668
2669<tr>
2670<td>Dec 2008 &nbsp;</td><td>Version 1.6.1 &nbsp;</td>
2671<td>[Mod] HTTP GET when no proxy in front</td>
2672</tr>
2673
2674<tr>
2675<td>Nov 2009 &nbsp;</td><td>Version 1.7 &nbsp;</td>
2676<td>[Bug] RINEX Navigation file format<br> [Add] Upgrade to Qt Version 4.5.2<br> [Add] Support of NTRIP v2<br> [Add] Rover support via serial port<br> [Add] Show broadcaster table from www.rtcm-ntrip.org<br> [Add] Enable/disable tab widgets<br> [Add] User defined configuration file name<br> [Mod] Switch to configuration files in ini-Format<br> [Add] Daily logfile rotation<br> [Add] Read from TCP/IP port, by-pass NTRIP transport protocol<br> [Add] Save NMEA messages coming from rover<br> [Add] Auto start<br> [Add] Drag and drop ini files<br> [Add] Read from serial port, by-pass NTRIP transport protocol<br> [Mod] Update of SSR messages following RTCM 091-2009-SC104-542<br> [Add] Read from UPD port, by-pass NTRIP transport protocol<br> [Mod] Output format of Broadcast Corrections<br> [Add] Throughput plot<br> [Add] Latency plot</td>
2677</tr>
2678
2679<tr>
2680<td>Nov 2009 &nbsp;</td><td>Version 1.8 &nbsp;</td>
2681<td>[Mod] On-the-fly reconfiguration of latency and throughput plots</td>
2682</tr>
2683
2684<tr>
2685<td>Feb 2010 &nbsp;</td><td>Version 2.0 &nbsp;</td>
2686<td>[Mod] Change sign of Broadcast Corrections<br> [Add] Real-time PPP option</td>
2687</tr>
2688
2689<tr>
2690<td>Jun 2010 &nbsp;</td><td>Version 2.1 &nbsp;</td>
2691<td>[Bug] SSR GLONASS message generation<br> [Add] PPP in Post Processing mode<br> [Mod] Update of SSR messages following draft dated 2010-04-12<br> [Mod] Generating error message when observation epoch is wrong</td>
2692</tr>
2693
2694<tr>
2695<td>Jul 2010 &nbsp;</td><td>Version 2.2 &nbsp;</td>
2696<td>[Bug] GLONASS ephemeris time</td>
2697</tr>
2698
2699<tr>
2700<td>Aug 2010 &nbsp;</td><td>Version 2.3 &nbsp;</td>
2701<td>[Mod] Internal format for saving raw streams<br> [Bug] Outlier detection in GLONASS ambiguity resolution<br> [Mod] Format of PPP logs in logfile<br> [Bug] Complete acceleration terms for GLONASS ephemeris<br> [Bug] Handling ephemeris IOD's in PPP mode</td>
2702</tr>
2703
2704<tr>
2705<td>Dec 2010 &nbsp;</td><td>Version 2.4 &nbsp;</td>
2706<td>[Add] Output of averaged positions when in PPP mode<br> [Mod] Use always the latest received set of Broadcast Ephemeris<br> [Add] QuickStart PPP option<br> [Mod] Improvement of data sharing efficiency among different threads<br> [Mod] Design of PPP tab section<br> [Add] Sigmas for observations and parameters<br> [Add] Stream distribution map<br> [Bug] GPS Ephemeris in RINEX v3 format</td>
2707</tr>
2708
2709<tr>
2710<td>Feb 2011 &nbsp;</td><td>Version 2.5 &nbsp;</td>
2711<td>[Add] PPP option for sync of clock observations and corrections<br> [Add] Drafted RTCMv3 Galileo ephemeris messages 1045<br> [Add] Drafted RTCMv3 Multiple Signal Messages<br> [Add] Optional specification of sigmas for coordinates and troposphere in PPP<br> [Add] Include Galileo in SPP<br> [Add] Include Galileo observations in output via IP port<br> [Add] Include Galileo observations in output via RINEXv3 files<br> [Mod] Interface format for feeding a real-time engine with observations<br> [Add] Correct observations for antenna phase center offsets<br> [Add] Combine orbit/clock correction streams<br> [Add] Specify corrections mountpoint in PPP tab</td>
2712</tr>
2713
2714<tr>
2715<td>Apr 2011 &nbsp;</td><td>Version 2.6 &nbsp;</td>
2716<td>[Add] Complete integration of BNS in BNC<br> [Add] SP3 and Clock RINEX output<br> [Add] PPP in Post Processing Mode<br> [Add] Some RINEX editing & QC functionality<br> [Add] Threshold for orbit outliers in combination solution<br> [Add] Real-time engine becomes orbit/clock server instead of client<br> [Mod] 'EOE' added to orbit/clock stream from engine<br> [Add] Correction for antenna eccentricities<br> [Add] Quick start mode for PPP<br> [Mod] Design of format for feeding engine changed to follow RINEX v3<br> [Mod] Implementation of SSR message encoding modified according to standard<br> [Add] SSL/TLS Support of NTRIP Version 2<br> [Mod] Switch to Qt version 4.7.3<br> [Add] RINEX editing, concatenation and quality check<br> [Add] Reading all configuration options from command line<br> [Mod] RTCMv3 Galileo Broadcast Ephemeris message 1045<br> [Mod] Change default configuration file suffix from 'ini' to 'bnc'<br> [Add] Specific rates for orbits and clocks in streams and SP3/RNX files</td>
2717</tr>
2718
2719<tr>
2720<td>May 2012 &nbsp;</td><td>Version 2.6 &nbsp;</td>
2721<td>[Add] Version 2.6 published</td>
2722</tr>
2723
2724<tr>
2725<td>Sep 2012 &nbsp;</td><td>Version 2.7 &nbsp;</td>
2726<td>[Bug] Bug in L5 decoding fixed<br> [Bug] Bug in on-the-fly configuration fixed<br> [Add] Clock RINEX file header extended<br> [Add] Decoding/converting BeiDou and QZSS added<br> [Add] Work on RINEX v2 and v3 quality check started<br> [Mod] Source code completely re-arranged<br> [Add] QWT and QWTPOLAR graphics libraries added<br> [Add] RINEX QC through multipath analysis sky plot<br> [Add] RINEX QC through signal-to-noise sky plot<br> [Add] RINEX QC through satellite availability plot<br> [Add] RINEX QC through satellite elevation plot<br> [Add RINEX QC through PDOP plot<br> [Bug] Short periodic outages in PPP time series when operated when 'Sync Corr' set to zero<br> |Add] Log observation types contained in RTCM Version 3 MSM streams<br> [Add] Reading RINEX v3 observation type header records from RINEX skeleton files<br> [Add] Logfile for RINEX file editing and concatenation<br>[Add] Save PNG plot files on disk<br> [Mod] Plot stream distribution map from NTRIP Broadcaster source-table<br> [Add] Plot stream distribution map from selected sources<br> [Add] Version 2.7 published</td>
2727</tr>
2728
2729<tr>
2730<td>Feb 2013 &nbsp;</td><td>Version 2.8 &nbsp;</td>
2731<td>[Mod] Started work on new version in Sep 2012<br> [Bug] Epoch special event flag in RINEX concatenation<br> [Bug] Limit RINEX v2 records length to 80 characters<br> [Bug] SSR message update interval indicator<br> [Bug] Fixed SSR stream encoding and upload<br> [Add] Concatenate RINEX v3 navigation files containing Galileo ephemeris<br> [Mod] Plausibility check of GLONASS ephemeris<br> [Add] Correcting clocks for scale factor involved in transformation</td>
2732</tr>
2733
2734</table>
2735</p>
2736
2737<p><a name="rtcm"><h4>5.2. RTCM</h4></p>
2738
2739<p>
2740The Radio Technical Commission for Maritime Services (RTCM) is an international non-profit scientific, professional and educational organization. Special Committees provide a forum in which governmental and non-governmental members work together to develop technical standards and consensus recommendations in regard to issues of particular concern. RTCM is engaged in the development of international standards for maritime radionavigation and radiocommunication systems. The output documents and reports prepared by RTCM Committees are published as RTCM Recommended Standards. Topics concerning Differential Global Navigation Satellite Systems (DGNSS) are handled by the Special Committee SC 104.
2741<p>
2742Personal copies of RTCM Recommended Standards can be ordered through <u>http://www.rtcm.org/orderinfo.php</u>.
2743</p>
2744
2745<p><a name="ntrip1"><h4>5.2.1 NTRIP Version 1</h4></p>
2746
2747<p>
2748'Networked Transport of RTCM via Internet Protocol' Version 1.0 (NTRIP) stands for an application-level protocol streaming Global Navigation Satellite System (GNSS) data over the Internet. NTRIP is a generic, stateless protocol based on the Hypertext Transfer Protocol HTTP/1.1. The HTTP objects are enhanced to GNSS data streams.
2749</p>
2750
2751<p>
2752NTRIP Version 1 is an RTCM standard designed for disseminating differential correction data (e.g. in the RTCM-104 format) or other kinds of GNSS streaming data to stationary or mobile users over the Internet, allowing simultaneous PC, Laptop, PDA, or receiver connections to a broadcasting host. NTRIP supports wireless Internet access through Mobile IP Networks like GSM, GPRS, EDGE, or UMTS.
2753</p>
2754
2755<p>
2756NTRIP is implemented in three system software components: NTRIP Clients, NTRIP Servers and NTRIP Broadcasters. The NTRIP Broadcaster is the actual HTTP server program whereas NTRIP Client and NTRIP Server are acting as HTTP clients.
2757</p>
2758
2759<p>
2760NTRIP is an open none-proprietary protocol. Major characteristics of NTRIP's dissemination technique are:
2761<ul>
2762<li>Based on the popular HTTP streaming standard; comparatively easy to implement when having limited client and server platform resources available;</li>
2763<li>Application not limited to one particular plain or coded stream content; ability to distribute any kind of GNSS data;</li>
2764<li>Potential to support mass usage; disseminating hundreds of streams simultaneously for thousands of users possible when applying modified Internet Radio broadcasting software;</li>
2765<li>Considering security needs; stream providers and users don't necessarily get into contact, streams often not blocked by firewalls or proxy servers protecting Local Area Networks;</li>
2766<li>Enables streaming over mobile IP networks because of using TCP/IP.</li>
2767</ul>
2768</p>
2769
2770<p>
2771The NTRIP Broadcaster maintains a source-table containing information on available NTRIP streams, networks of NTRIP streams and NTRIP Broadcasters. The source-table is sent to an NTRIP Client on request. Source-table records are dedicated to one of the following: Data Streams (record type STR), Casters (record type CAS), or Networks of streams (record type NET).
2772</p>
2773
2774<p>
2775Source-table records of type STR contain the following data fields: 'mountpoint', 'identifier', 'format', 'format-details', 'carrier', 'nav-system', 'network', 'country', 'latitude', 'longitude', 'nmea', 'solution', 'generator', 'compr-encryp', 'authentication', 'fee', 'bitrate', 'misc'.
2776</p>
2777<p>
2778Source-table records of type NET contain the following data fields: 'identifiey', 'operator', 'authentication', 'fee', 'web-net', 'web-str', 'web-reg', 'misc'.
2779</p>
2780<p>
2781Source-table records of type CAS contain the following data fields: 'host', 'port', 'identifier', 'operator', 'nmea', 'country', 'latitude', 'longitude', 'misc'.
2782</p>
2783
2784<p><a name="ntrip2"><h4>5.2.2 NTRIP Version 2</h4></p>
2785
2786<p>
2787The major changes of NTRIP Version 2 compared to Version 1.0 are:
2788</p>
2789
2790<ul>
2791<li>Cleared and fixed design problems and HTTP protocol violations;</li>
2792<li>Replaced non standard directives;</li>
2793<li>Chunked transfer encoding;</li>
2794<li>Improvements in header records;</li>
2795<li>Source-table filtering;</li>
2796<li>RTSP communication.</li>
2797</ul>
2798
2799<p>NTRIP Version 2 allows to either communicate in TCP/IP mode or in RTSP/RTP mode or in UDP mode whereas Version 1 is limited to TCP/IP only. It furthermore allows using the Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL) cryptographic protocols for secure NTRIP communication over the Internet.
2800</p>
2801
2802<p><a name="rtcm2"><h4>5.2.3 RTCM Version 2</h4></p>
2803<p>
2804Transmitting GNSS carrier phase data can be done through RTCM Version 2 messages. Please note that only RTCM Version 2.2 and 2.3 streams may include GLONASS data. Messages that may be of interest here are:
2805</p>
2806
2807<ul>
2808<li>
2809Type 1 message is the range correction message and is the primary message in code-phase differential positioning (DGPS). It is computed in the base receiver by computing the error in the range measurement for each tracked SV.
2810</li>
2811<li>
2812Type 2 message is automatically generated when a new set of satellite ephemeris is downloaded to the base receiver. It is the computed difference between the old ephemeris and the new ephemeris. Type 2 messages are used when the base station is transmitting Type 1 messages.
2813</li>
2814<li>
2815Type 3 and 22 messages are the base station position and the antenna offset. Type 3 and 22 are used in RTK processing to perform antenna reduction.
2816</li>
2817<li>
2818Type 6 message is a null frame filler message that is provided for data links that require continuous transmission of data, even if there are no corrections to send. As many Type 6 messages are sent as required to fill in the gap between two correction messages (type 1). Message 6 is not sent in burst mode.
2819</li>
2820<li>
2821Type 9 message serves the same purpose as Type 1, but does not require a complete satellite set. As a result, Type 9 messages require a more stable clock than a station transmitting Type 1 's, because the satellite corrections have different time references.
2822</li>
2823<li>
2824Type 16 message is simply a text message entered by the user that is transmitted from the base station to the rover. It is used with code-phase differential.
2825</li>
2826<li>
2827Type 18 and 20 messages are RTK uncorrected carrier phase data and carrier phase corrections.
2828</li>
2829<li>
2830Type 19 and 21 messages are the uncorrected pseudo-range measurements and pseudo-range corrections used in RTK.
2831</li>
2832<li>
2833Type 23 message provides the information on the antenna type used on the reference station.
2834</li>
2835<li>
2836Type 24 message carries the coordinates of the installed antenna's ARP in the GNSS coordinate system coordinates.
2837</li>
2838</ul>
2839
2840<p><a name="rtcm3"><h4>5.2.4 RTCM Version 3</h4></p>
2841<p>
2842RTCM Version 3 has been developed as a more efficient alternative to RTCM Version 2. Service providers and vendors have asked for a standard that would be more efficient, easy to use, and more easily adaptable to new situations. The main complaint was that the Version 2 parity scheme was wasteful of bandwidth. Another complaint was that the parity is not independent from word to word. Still another was that even with so many bits devoted to parity, the actual integrity of the message was not as high as it should be. Plus, 30-bit words are awkward to handle. The Version 3 standard is intended to correct these weaknesses.
2843</p>
2844<p>
2845RTCM Version 3 defines a number of message types. Messages that may be of interest here are:
2846<ul>
2847<li>Type 1001, GPS L1 code and phase.</li>
2848<li>Type 1002, GPS L1 code and phase and ambiguities and carrier to noise ratio.</li>
2849<li>Type 1003, GPS L1 and L2 code and phase.</li>
2850<li>Type 1004, GPS L1 and L2 code and phase and ambiguities and carrier to noise ratio.</li>
2851<li>Type 1005, Station coordinates XYZ for antenna reference point.</li>
2852<li>Type 1006, Station coordinates XYZ for antenna reference point and antenna height.</li>
2853<li>Type 1007, Antenna descriptor and ID.</li>
2854<li>Type 1008, Antenna serial number.</li>
2855<li>Type 1009, GLONASS L1 code and phase.</li>
2856<li>Type 1010, GLONASS L1 code and phase and ambiguities and carrier to noise ratio.</li>
2857<li>Type 1011, GLONASS L1 and L2 code and phase.</li>
2858<li>Type 1012, GLONASS L1 and L2 code and phase and ambiguities and carrier to noise ratio.</li>
2859<li>Type 1013, Modified julian date, leap second, configured message types and interval.</li>
2860<li>Type 1014 and 1017, Network RTK (MAK) messages.</li>
2861<li>Type 1019, GPS ephemeris.</li>
2862<li>Type 1020, GLONASS ephemeris.</li>
2863<li>Type 4088 and 4095, Proprietary messages.
2864</li>
2865</ul>
2866</p>
2867
2868<p>
2869The following is a proposed Galileo Navigation Message under discussion for standardization:
2870<ul>
2871<li>Type 1045, Galileo ephemeris.</li>
2872</ul>
2873</p>
2874
2875<p>
2876The following are so-called 'State Space Representation' (SSR) messages:
2877<ul>
2878<li>Type 1057, GPS orbit corrections to Broadcast Ephemeris</li>
2879<li>Type 1058, GPS clock corrections to Broadcast Ephemeris</li>
2880<li>Type 1059, GPS code biases</li>
2881<li>Type 1060, Combined orbit and clock corrections to GPS Broadcast Ephemeris</li>
2882<li>Type 1061, GPS User Range Accuracy (URA)</li>
2883<li>Type 1062, High-rate GPS clock corrections to Broadcast Ephemeris<br><br></li>
2884<li>Type 1063, GLONASS orbit corrections to Broadcast Ephemeris</li>
2885<li>Type 1064, GLONASS clock corrections to Broadcast Ephemeris</li>
2886<li>Type 1065, GLONASS code biases</li>
2887<li>Type 1066, Combined orbit and clock corrections to GLONASS Broadcast Ephemeris</li>
2888<li>Type 1067, GLONASS User Range Accuracy (URA)</li>
2889<li>Type 1068, High-rate GLONASS clock corrections to Broadcast Ephemeris</li>
2890</ul>
2891</p>
2892
2893<p>
2894The following are so-called 'Multiple Signal Messages' (MSM):
2895<ul>
2896<li>Type 1071, Compact GPS pseudo-ranges</li>
2897<li>Type 1072, Compact GPS carrier phases</li>
2898<li>Type 1073, Compact GPS pseudo-ranges and carrier phases</li>
2899<li>Type 1074, Full GPS pseudo-ranges and carrier phases plus signal strength</li>
2900<li>Type 1075, Full GPS pseudo-ranges, carrier phases, Doppler and signal strength</li>
2901<li>Type 1076, Full GPS pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2902<li>Type 1077, Full GPS pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)<br><br></li>
2903<li>Type 1081, Compact GLONASS pseudo-ranges</li>
2904<li>Type 1082, Compact GLONASS carrier phases</li>
2905<li>Type 1083, Compact GLONASS pseudo-ranges and carrier phases</li>
2906<li>Type 1084, Full GLONASS pseudo-ranges and carrier phases plus signal strength</li>
2907<li>Type 1085, Full GLONASS pseudo-ranges, carrier phases, Doppler and signal strength</li>
2908<li>Type 1086, Full GLONASS pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2909<li>Type 1087, Full GLONASS pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)<br><br></li>
2910<li>Type 1091, Compact Galileo pseudo-ranges</li>
2911<li>Type 1092, Compact Galileo carrier phases</li>
2912<li>Type 1093, Compact Galileo pseudo-ranges and carrier phases</li>
2913<li>Type 1094, Full Galileo pseudo-ranges and carrier phases plus signal strength</li>
2914<li>Type 1095, Full Galileo pseudo-ranges, carrier phases, Doppler and signal strength</li>
2915<li>Type 1096, Full Galileo pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2916<li>Type 1097, Full Galileo pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)</li>
2917</ul>
2918</p>
2919
2920<p>
2921The following are proposed 'Multiple Signal Messages' (MSM) under discussion for standardization:
2922<ul>
2923<li>Type 1101, Compact SBAS pseudo-ranges</li>
2924<li>Type 1102, Compact SBAS carrier phases</li>
2925<li>Type 1103, Compact SBAS pseudo-ranges and carrier phases</li>
2926<li>Type 1104, Full SBAS pseudo-ranges and carrier phases plus signal strength</li>
2927<li>Type 1105, Full SBAS pseudo-ranges, carrier phases, Doppler and signal strength</li>
2928<li>Type 1106, Full SBAS pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2929<li>Type 1107, Full SBAS pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)<br><br></li>
2930<li>Type 1111, Compact QZSS pseudo-ranges</li>
2931<li>Type 1112, Compact QZSS carrier phases</li>
2932<li>Type 1113, Compact QZSS pseudo-ranges and carrier phases</li>
2933<li>Type 1114, Full QZSS pseudo-ranges and carrier phases plus signal strength</li>
2934<li>Type 1115, Full QZSS pseudo-ranges, carrier phases, Doppler and signal strength</li>
2935<li>Type 1116, Full QZSS pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2936<li>Type 1117, Full QZSS pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)<br><br></li>
2937<li>Type 1121, Compact BeiDou pseudo-ranges</li>
2938<li>Type 1122, Compact BeiDou carrier phases</li>
2939<li>Type 1123, Compact BeiDou pseudo-ranges and carrier phases</li>
2940<li>Type 1124, Full BeiDou pseudo-ranges and carrier phases plus signal strength</li>
2941<li>Type 1125, Full BeiDou pseudo-ranges, carrier phases, Doppler and signal strength</li>
2942<li>Type 1126, Full BeiDou pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2943<li>Type 1127, Full BeiDou pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)</li>
2944</ul>
2945</p>
2946
2947<p><a name="config"><h4>5.3. Configuration Examples</h4></p>
2948
2949<p>
2950BNC comes with a number of configuration examples which can be used on all operating systems. Copy the complete directory 'Example_Configs' which comes with the software including sub-directories 'Input' and 'Output' to your disc. There are two ways to start BNC using one of the example configurations:
2951</p>
2952<ul>
2953<li>
2954On graphical systems (except for Mac systems) you may use the computer mouse to 'drag' a configuration file icon and 'drop' it on top of BNC's program icon.
2955</li>
2956<li>
2957On non-graphical systems you may start BNC using a command line with the following option for a configuration file (example for Windows systems):<br>
2958bnc.exe --conf &lt;configFileName&gt; --nw
2959</li>
2960</ul>
2961<p>
2962Although it's not a must, we suggest that you always create BNC configuration files with the file name extension '.bnc'.
2963</p>
2964
2965<p>
2966We furthermore suggest for convenience reasons that you configure your system to automatically start BNC when you double-click a file with the file name extension '.bnc'. The following describes what to do on Windows systems to associate the BNC program to such configuration files:
2967</p>
2968
2969<ol type=b>
2970<li>Right-click a file that has the extension '.bnc' and then click 'Open'. If the 'Open' command is not available, click 'Open With' or double-click the file.</li>
2971<li>Windows displays a dialog box that says that the system cannot open this file. The dialog box offers several options for selecting a program.</li>
2972<li>Click 'Select the program from a list', and then click 'OK'.</li>
2973<li>The 'Open With' dialog box is displayed. Click 'Browse', locate and then click the BNC program, and then click 'Open'.</li>
2974<li>Click to select the 'Always use the selected program to open this kind of file' check box.</li>
2975<li>Click 'OK'.</li>
2976</ol>
2977
2978<p>
2979Some of the presented example configuration files contain a user ID 'Example' with a password 'Configs' for accessing a few GNSS streams from public Ntrip Broadcasters. This generic account is arranged for convenience reasons only. Please be so kind as to replace the generic account details as well as the place holders 'User' and 'Pass' by the personal user ID and password you receive following an online registration through <u>http://register.rtcm-ntrip.org</u>.
2980</p>
2981
2982<p>
2983Note that the account for an Ntrip Broadcaster is usually limited to pulling a specified maximum number of streams at the same time. As running some of the example configurations requires pulling several streams, it is suggested to make sure that you don't exceed your account's limits.
2984</p>
2985
2986<p>
2987Make also sure that sub-directories 'Input' and 'Output' which are part of the example configurations exist on your system or adjust the affected example configuration options according to your needs.
2988</p>
2989
2990<p>
2991Some BNC options require antenna phase center variations as made available from IGS through so-called ANTEX files at <u>ftp://igs.org/pub/station/general</u>. An example ANTEX file 'igs08.atx' is part of the BNC package for convenience.
2992</p>
2993
2994<p>
2995The example configurations assume that no proxy protects your BNC host. Should a proxy be operated in front of BNC then you need to introduce its IP and port in the 'Network' tab.
2996</p>
2997
2998<p>
2999You should be able to run all configuration examples without changing their options. However, configurations 'Upload.bnc' and 'UploadPPP.bnc' are exceptions because they require an input stream from a connected network engine.
3000</p>
3001<ol type=b>
3002
3003<li>File 'RinexObs.bnc'<br>
3004The purpose of this configuration is showing how to convert RTCM streams to RINEX Observation files. The configuration pulls one stream from an Ntrip Broadcasters using Ntrip version 1 to generate a 15min 1Hz RINEX Version 3 Observation file. See http://igs.bkg.bund.de/ntrip/observations for observation stream resources.
3005</li><br>
3006
3007<li>File 'RinexEph.bnc'<br>
3008The purpose of this configuration is showing how to convert a RTCM stream carrying navigation messages to a RINEX Navigation files. The configuration pulls an RTCM Version 3 stream with Broadcast Ephemeris coming from the real-time EUREF and IGS networks. It saves hourly RINEX Version 3 Navigation files. See http://igs.bkg.bund.de/ntrip/ephemeris for further real-time Broadcast Ephemeris resources.
3009</li><br>
3010
3011<li>File 'SSR.bnc'<br>
3012The purpose of this configuration is to save Broadcast Corrections from RTCM SSR messages in a plain ASCII format as hourly files. See http://igs.bkg.bund.de/ntrip/orbits for further real-time IGS or EUREF orbit/clock products.
3013</li><br>
3014
3015<li>File 'RinexConcat.bnc'<br>
3016The purpose of this configuration is to concatenate RINEX Version 3 files to produce a concatenated file and edit the marker name in the file header. The sampling interval is set to 30 seconds. See section 'RINEX Editing & QC' in the documentation for examples on how to call BNC from command line in 'no window' mode for RINEX file editing, concatenation and quality checks.
3017</li><br>
3018
3019<li>File 'RinexQC.bnc'<br>
3020The purpose of this configuration is to check the quality of a RINEX Version 3 file through a multipath analysis. The results is saved in disk in terms of a plot in PNG format. See section 'RINEX Editing & QC' in the documentation for examples on how to call BNC from command line in 'no window' mode for RINEX file editing, concatenation and quality checks.
3021</li><br>
3022
3023<li>File 'RTK.bnc'<br>
3024The purpose of this configuration is to feed a serial connected receiver with observations from a reference station for conventional RTK. The stream is scanned for RTCM messages. Message type numbers and latencies of incoming observation are reported in BNC's logfile.
3025</li><br>
3026
3027<li>File 'FeedEngine.bnc'<br>
3028The purpose of this configuration is to feed a real-time GNSS engine with observations from a remote reference stations. The configuration pulls a single stream from an NTRIP Broadcasters. It would of course be possible to pull several streams from different casters. Incoming observations are decoded, synchronized and output through a local IP port and saved into a file. Failure and recovery thresholds are specified to inform about outages.
3029</li><br>
3030
3031<li>File 'PPP.bnc'<br>
3032The purpose of this configuration is Precise Point Positioning from observations of a rover receiver. The configuration reads RTCM Version 3 observations, a Broadcast Ephemeris stream and a stream with Broadcast Corrections. Positions are saved in the logfile.
3033</li><br>
3034
3035<li>File 'PPPQuickStart.bnc'<br>
3036The purpose of this configuration is Precise Point Positioning in Quick-Start mode from observations of a static receiver with precisely known position. The configuration reads RTCM Version 3 observations, Broadcast Corrections and a Broadcast Ephemeris stream. Positions are saved in NMEA format on disc. Positions are also output through IP port for real-time visualization with tools like RTKPLOT. Positions are also saved in the logfile.
3037</li><br>
3038
3039<li>File 'PPPPostProc.bnc'<br>
3040The purpose of this configuration is Precise Point Positioning in Post Processing mode. BNC reads a RINEX Observation and a RINEX Version 3 Navigation files and a Broadcast Corrections files. PPP processing options are set to support the Quick-Start mode. The output is saved in a specific Post Processing logfile and contains the coordinates derived over time following the implemented PPP filter algorithm.
3041</li><br>
3042
3043<li>File 'SPPQuickStartGal.bnc'<br>
3044The purpose of this configuration is Single Point Positioning in Quick-Start mode from observations of a static receiver with precisely known position. The configuration uses GPS, GLONASS and Galileo observations and a Broadcast Ephemeris stream.
3045</li><br>
3046
3047<li>File 'Sp3.bnc'<br>
3048The purpose of this configuration is to produce SP3 files from a Broadcast Ephemeris stream and a Broadcast Corrections stream. The Broadcast Corrections stream is formally introduced in BNC's 'Combine Corrections' table. Note that producing SP3 requires an ANTEX file because SP3 file contents should be referred to CoM.
3049</li><br>
3050
3051<li>File 'Sp3ETRF2000PPP.bnc'<br>
3052The purpose of this configuration is to produce SP3 files from a Broadcast Ephemeris stream and a stream carrying ETRF2000 Broadcast Corrections. The Broadcast Corrections stream is formally introduced in BNC's 'Combine Corrections' table. This leads to an SP3 file containing orbits referred also to ETRF2000. Pulling in addition observations from a reference station at precisely known ETRF2000 position allows comparing an 'INTERNAL' PPP solution with ETRF2000 reference coordinates.
3053</li><br>
3054
3055<li>File 'Upload.bnc'<br>
3056The purpose of this configuration is to upload orbits and clocks from a real-time GNSS engine to an NTRIP Broadcaster. For that the configuration reads precise orbits and clocks in RTNET format. It also reads a stream carrying Broadcast Ephemeris. BNC converts the orbits and clocks into Broadcast Corrections and encodes them in RTCM Version 3 SSR messages to upload them to an NTRIP Broadcaster. The Broadcast Corrections stream is referred to satellite Antenna Phase Center (APC) and IGS08. Orbits are saved on disk in SP3 format and clocks in Clock RINEX format.
3057</li><br>
3058
3059<li>File 'UploadPPP.bnc'<br>
3060This configuration equals the 'Upload.bnc' configuration. However, the Broadcast Corrections are in addition used for an 'INTERNAL' PPP solution based on observations from a static reference station with known precise coordinates. This allows a continuous quality check of the Broadcast Corrections through observing coordinate displacements.
3061</li><br>
3062
3063<li>File 'Combi.bnc'<br>
3064The purpose of this configuration is to pull several streams carrying Broadcast Corrections and a Broadcast Ephemeris stream from an NTRIP Broadcaster to produce a combined Broadcast Corrections stream. BNC encodes the combination product in RTCM Version 3 SSR messages and uploads that to an Ntrip Broadcaster. The Broadcast Corrections stream is not referred to satellite Center of Mass (CoM). It is referred to IGS08. Orbits are saved in SP3 format and clocks in Clock RINEX format.
3065</li><br>
3066
3067<li>File 'CombiPPP.bnc'<br>
3068This configuration equals the 'Combi.bnc' configuration. However, the combined Broadcast Corrections are in addition used for an 'INTERNAL' PPP solutions based on observations from a static reference station with known precise coordinates. This allows a continuous quality check of the combination product through observing coordinate displacements.
3069</li><br>
3070
3071<li>File 'UploadEph.bnc'<br>
3072The purpose of this configuration is to pull a number of streams from reference stations to get hold of contained Broadcast Ephemeris messages. These are encoded then in a RTCM Version 3 stream which only provides Broadcast Ephemeris with an update rate of 5 seconds.
3073</li>
3074
3075</ol>
3076</p>
3077
3078<p>
3079The following table's left column is a list options as contained in BNC's configuration files (default: BNC.bnc).
3080</p>
3081<table>
3082<tr></tr>
3083<tr><td><b>Option</b></td><td><b>Affiliation</b></td></tr>
3084<tr><td>[General]</td><td>Settings: Group</td></tr>
3085<tr><td>startTab=</td><td>Internal: Top tab index</td></tr>
3086<tr><td>statusTab=</td><td>Internal: Bottom tab index</td></tr>
3087<tr><td>font=</td><td>Internal: Used font</td></tr>
3088<tr><td>casterUrlList=</td><td>Internal: Visited URLs</td></tr>
3089<tr><td>mountPoints=</td><td>Add Streams: broadcaster:port/mountpoint</td></tr>
3090<tr><td>ntripVersion=</td><td>Add Stream: NTRIP Version</td></tr>
3091
3092<tr><td>proxyHost=</td><td>Network: Proxy host</td></tr>
3093<tr><td>proxyPort=</td><td>Network: Proxy port</td></tr>
3094<tr><td>sslCaCertPath=</td><td>Network: Path to SSL certificates</td></tr>
3095<tr><td>ignoreSslErrors=</td><td>Network: Ignore ssl authorization errors</td></tr>
3096
3097<tr><td>logFile=</td><td>General: Logfile (full path)</td></tr>
3098<tr><td>rnxAppend=</td><td>General: Append files</td></tr>
3099<tr><td>onTheFlyInterval=</td><td>General: Reread configuration</td></tr>
3100<tr><td>autoStart=</td><td>General: Auto start</td></tr>
3101<tr><td>rawOutFile=</td><td>General: Raw output file (full path)</td></tr>
3102
3103<tr><td>rnxPath=</td><td>RINEX Observations: Directory</td></tr>
3104<tr><td>rnxIntr=</td><td>RINEX Observations: Interval</td></tr>
3105<tr><td>rnxSample=</td><td>RINEX Observations: Sampling</td></tr>
3106<tr><td>rnxSkel=</td><td>RINEX Observations: Skeleton extension</td></tr>
3107<tr><td>rnxScript=</td><td>RINEX Observations: Uplod script</td></tr>
3108<tr><td>rnxV3=</td><td>RINEX Observation: Version 3</td></tr>
3109
3110<tr><td>ephPath=</td><td>RINEX Ephemeris: Directory</td></tr>
3111<tr><td>ephIntr=</td><td>RINEX Ephemeris: Interval</td></tr>
3112<tr><td>outEphPort=</td><td>RINEX Ephemeris: Port</td></tr>
3113<tr><td>ephV3=</td><td>RINEX Ephemeris: Version 3</td></tr>
3114
3115<tr><td>corrPath=</td><td>Broadcast Corrections: Directory, ASCII </td></tr>
3116<tr><td>corrIntr=</td><td>Broadcast Corrections: Interval</td></tr>
3117<tr><td>corrPort=</td><td>Broadcast Corrections: Port</td></tr>
3118<tr><td>corrTime=</td><td>Broadcast Corrections: Wait for full corr epoch</td></tr>
3119
3120<tr><td>outPort=</td><td>Feed Engine: Port</td></tr>
3121<tr><td>waitTime=</td><td>Feed Engine: Wait for full obs epoch</td></tr>
3122<tr><td>binSampl=</td><td>Feed Engine: Sampling</td></tr>
3123<tr><td>outFile=</td><td>Feed Engine: File (full path)</td></tr>
3124<tr><td>outUPort=</td><td>Feed Engine: Port (unsynchronized)</td></tr>
3125
3126<tr><td>serialMountPoint=</td><td>Serial Output: Mountpoint</td></tr>
3127<tr><td>serialPortName=</td><td>Serial Output: Port name</td></tr>
3128<tr><td>serialBaudRate=</td><td>Serial Output: Baud rate</td></tr>
3129<tr><td>serialFlowControl=</td><td>Serial Output: Flow control</td></tr>
3130<tr><td>serialDataBits=</td><td>Serial Output: Data bits</td></tr>
3131<tr><td>serialParity=</td><td>Serial Output: Parity</td></tr>
3132<tr><td>serialStopBits=</td><td>Serial Output: Stop bits</td></tr>
3133<tr><td>serialAutoNMEA=</td><td>Serial Output: NMEA</td></tr>
3134<tr><td>serialFileNMEA=</td><td>Serial Output: NMEA file name</td></tr>
3135<tr><td>serialHeightNMEA=</td><td>Serial Output: Height</td></tr>
3136
3137<tr><td>obsRate=</td><td>Outages: Observation rate</td></tr>
3138<tr><td>adviseFail=</td><td>Outages: Failure threshold</td></tr>
3139<tr><td>adviseReco=</td><td>Outages: Recovery threshold</td></tr>
3140<tr><td>adviseScript=</td><td>Outages: Script (full path)</td></tr>
3141
3142<tr><td>miscMount=</td><td>Miscellaneous: Mountpoint</td></tr>
3143<tr><td>perfIntr=</td><td>Miscellaneous: Log latency</td></tr>
3144<tr><td>scanRTCM=</td><td>Miscellaneous: Scan RTCM</td></tr>
3145
3146<tr><td>pppSPP=</td><td>PPP Client: PPP/SPP</td></tr>
3147<tr><td>pppMount=</td><td>PPP Client: Observations Mountpoint</td></tr>
3148<tr><td>pppCorrMount=</td><td>PPP Client: Corrections Mountpoint</td></tr>
3149<tr><td>pppRefCrdX=</td><td>PPP Client: X coordinate of plot origin</td></tr>
3150<tr><td>pppRefCrdY=</td><td>PPP Client: Y coordinate of plot origin</td></tr>
3151<tr><td>pppRefCrdZ=</td><td>PPP Client: Z coordinate of plot origin</td></tr>
3152<tr><td>pppRefdN=</td><td>PPP Client: North eccentricity</td></tr>
3153<tr><td>pppRefdE=</td><td>PPP Client: East eccentricity</td></tr>
3154<tr><td>pppRefdU=</td><td>PPP Client: Up eccentricity</td></tr>
3155<tr><td>nmeaFile=</td><td>PPP Client: NMEA outputfile</td></tr>
3156<tr><td>nmeaPort=</td><td>PPP Client: NMEA IP output port</td></tr>
3157<tr><td>pppPlotCoordinates=</td><td>PPP Client: Plot NEU time series</td></tr>
3158<tr><td>postObsFile=</td><td>PPP Client: Observations file</td></tr>
3159<tr><td>postNavFile=</td><td>PPP Client: Navigation file</td></tr>
3160<tr><td>postCorrFile=</td><td>PPP Client: Corrections file</td></tr>
3161<tr><td>postOutFile=</td><td>PPP Client: Output file</td></tr>
3162<tr><td>pppAntenna=</td><td>PPP Client: Antenna name</td></tr>
3163<tr><td>pppAntex=</td><td>PPP Client: Path to ANTEX file</td></tr>
3164<tr><td>pppUsePhase=</td><td>PPP Client: Use phase data </td></tr>
3165<tr><td>pppEstTropo=</td><td>PPP Client: Estimate troposphere</td></tr>
3166<tr><td>pppGLONASS=</td><td>PPP Client: Use GLONASS</td></tr>
3167<tr><td>pppGalileo=</td><td>PPP Client: Use Galileo</td></tr>
3168<tr><td>pppSync=</td><td>PPP Client: Sync observations and corrections</td></tr>
3169<tr><td>pppAverage=</td><td>PPP Client: Lenght of time window for moving average</td></tr>
3170<tr><td>pppQuickStart=</td><td>PPP Client: Quick-Start period</td></tr>
3171<tr><td>pppMaxSolGap=</td><td>PPP Client: Maximal Solution Gap</td></tr>
3172<tr><td>pppSigmaCode=</td><td>PPP Client: Sigma for Code observations</td></tr>
3173<tr><td>pppSigmaPhase=</td><td>PPP Client: Sigma for Phase observations</td></tr>
3174<tr><td>pppSigmaCrd0=</td><td>PPP Client: Sigma for initial XYZ coordinate</td></tr>
3175<tr><td>pppSigmaCrdP=</td><td>PPP Client: White noise for XYZ</td></tr>
3176<tr><td>pppSigmaTrp0=</td><td>PPP Client: Sigma for initial tropospheric delay</td></tr>
3177<tr><td>pppSigmaTrpP=</td><td>PPP Client: White noise for tropospheric delay</td></tr>
3178
3179<tr><td>reqcAction=</td><td>Reqc: Action</td></tr>
3180<tr><td>reqcObsFile=</td><td>Reqc: Observations file</td></tr>
3181<tr><td>reqcNavFile=</td><td>Reqc: Navigation file</td></tr>
3182<tr><td>reqcOutObsFile=</td><td>Reqc: Output observations file</td></tr>
3183<tr><td>reqcOutNavFile=</td><td>Reqc: Output navigation file</td></tr>
3184<tr><td>reqcPlotDir</td><td>Reqc: QC plots directory</td></tr>
3185<tr><td>reqcOutLogFile=</td><td>Reqc: Output logfile</td></tr>
3186<tr><td>reqcPlotDir=</td><td>Reqc: Plot file directory</td></tr>
3187<tr><td>reqcRnxVersion=</td><td>Reqc: RINEX version</td></tr>
3188<tr><td>reqcSampling=</td><td>Reqc: RINEX sampling</td></tr>
3189<tr><td>reqcStartDateTime=</td><td>Reqc: Start time</td></tr>
3190<tr><td>reqcEndDateTime=</td><td>Reqc: Stop time</td></tr>
3191<tr><td>reqcRunBy=</td><td>Reqc: Operators name</td></tr>
3192<tr><td>reqcComment=</td><td>Reqc: Additional comments</td></tr>
3193<tr><td>reqcOldMarkerName=</td><td>Reqc: Old marker</td></tr>
3194<tr><td>reqcNewMarkerName=</td><td>Reqc: New marker</td></tr>
3195<tr><td>reqcOldAntennaName=</td><td>Reqc: Old antenna</td></tr>
3196<tr><td>reqcNewAntennaName=</td><td>Reqc: New antenna</td></tr>
3197<tr><td>reqcOldReceiverName=</td><td>Reqc: Old receiver</td></tr>
3198<tr><td>reqcNewReceiverName=</td><td>Reqc: New receiver</td></tr>
3199
3200<tr><td>combineStreams=</td><td>Combination: List of correction streams</td></tr>
3201<tr><td>cmbMethod=Filter</td><td>Combination: Approach</td></tr>
3202<tr><td>cmbMaxres=</td><td>Combination: Clock outlier threshold</td></tr>
3203<tr><td>cmbSampl=</td><td>Combination: Orbit and clock sampling</td></tr>
3204
3205<tr><td>uploadIntr=</td><td>Upload Corrections: File interval</td></tr>
3206<tr><td>uploadMountpointsOut=</td><td>Upload Corrections: Upload streams</td></tr>
3207<tr><td>uploadSamplClkRnx=</td><td>Upload Corrections: Clock sampling</td></tr>
3208<tr><td>uploadSamplSp3=</td><td>Upload Corrections: Orbit sampling</td></tr>
3209<tr><td>uploadSamplRtcmEphCorr=</td><td>Upload Corrections: Orbit sampling</td></tr>
3210<tr><td>trafo_dx=</td><td>Upload Corrections: Translation X</td></tr>
3211<tr><td>trafo_dy=</td><td>Upload Corrections: Translation Y</td></tr>
3212<tr><td>trafo_dz=</td><td>Upload Corrections: Translation Z</td></tr>
3213<tr><td>trafo_dxr=</td><td>Upload Corrections: Translation change X</td></tr>
3214<tr><td>trafo_dyr=</td><td>Upload Corrections: Translation change Y</td></tr>
3215<tr><td>trafo_dzr=</td><td>Upload Corrections: Translation change Z</td></tr>
3216<tr><td>trafo_ox=</td><td>Upload Corrections: Rotation X</td></tr>
3217<tr><td>trafo_oy=</td><td>Upload Corrections: Rotation Y</td></tr>
3218<tr><td>trafo_oz=</td><td>Upload Corrections: Rotation Z</td></tr>
3219<tr><td>trafo_oxr=</td><td>Upload Corrections: Rotation change X</td></tr>
3220<tr><td>trafo_oyr=</td><td>Upload Corrections: Rotation change Y</td></tr>
3221<tr><td>trafo_ozr=</td><td>Upload Corrections: Rotation change Z</td></tr>
3222<tr><td>trafo_sc=</td><td>Upload Corrections: Scale</td></tr>
3223<tr><td>trafo_scr=</td><td>Upload Corrections: Scale change</td></tr>
3224<tr><td>trafo_t0=</td><td>Upload Corrections: Reference year</td></tr>
3225<tr><td>uploadEphHost=</td><td>Upload Ephemeris: Host</td></tr>
3226<tr><td>uploadEphPort=</td><td>Upload Ephemeris: Port</td></tr>
3227<tr><td>uploadEphMountpoint=</td><td>Upload Ephemeris: Moutpoint</td></tr>
3228<tr><td>uploadEphPassword=</td><td>Upload Ephemeris: Password</td></tr>
3229<tr><td>uploadEphSample=</td><td>Upload Ephemeris: Samplig</td></tr>
3230</table>
3231</p>
3232<p>
3233Note that the following configuration options saved on disk can be changed/edited on-the-fly while BNC is already processing data:
3234</p>
3235<p>
3236<ul>
3237<li>'mountPoints' to change the selection of streams to be processed, see section 'Streams';</li>
3238<li>'waitTime' to change the 'Wait for full obs epoch' option, see section 'Feed Engine';</li>
3239<li>'binSampl' to change the 'Sampling' option, see section 'Feed Engine'.</li>
3240</ul>
3241</p>
3242<p>
3243</p>
3244
3245<p><a name="links"><h4>5.4 Futher Reading</h3></p>
3246
3247<table>
3248<tr></tr>
3249<tr><td><b>Links</b></td></tr>
3250<tr><td>NTRIP &nbsp;</td><td><u>http://igs.bkg.bund.de/ntrip/index</u></td></tr>
3251<tr><td>EUREF-IP NTRIP Broadcaster &nbsp;</td><td><u>http://www.euref-ip.net/home</u></td></tr>
3252<tr><td>IGS-IP NTRIP Broadcaster &nbsp;</td><td><u>http://www.igs-ip.net/home</u></td></tr>
3253<tr><td>IGS products NTRIP Broadcaster &nbsp;</td><td><u>http://products.igs-ip.net/home</u></td></tr>
3254<tr><td>IGS M-GEX NTRIP Broadcaster &nbsp;</td><td><u>http://mgex.igs-ip.net/home</u></td></tr>
3255<tr><td>Distribution of IGS-IP streams &nbsp;</td><td><u>http://www.igs.oma.be/real_time/</u></td></tr>
3256<tr><td>Completeness and latency of IGS-IP data &nbsp;</td><td><u>http://www.igs.oma.be/highrate/</u></td></tr>
3257<tr><td>NTRIP Broadcaster overview &nbsp;</td><td><u>http://www.rtcm-ntrip.org/home</u></td></tr>
3258<tr><td>NTRIP Open Source software code &nbsp;</td><td><u>http://software.rtcm-ntrip.org</u></td></tr>
3259<tr><td>EUREF-IP Project &nbsp;</td><td><u>http://www.epncb.oma.be/euref_IP</u></td></tr>
3260<tr><td>Real-time IGS Pilot Project &nbsp;</td><td><u>http://www.rtigs.net/pilot</u></td></tr>
3261<tr><td>Radio Technical Commission<br>for Maritime Services &nbsp;</td><td><u>http://www.rtcm.org</u>
3262</table>
3263
3264<br>
3265<table>
3266<tr><td><b>Publications</b></td></tr>
3267
3268<tr><td>Weber, G., D. Dettmering, H. Gebhard and R. Kalafus </td><td>Networked Transport of RTCM via Internet Protocol (Ntrip), IP-Streaming for Real-Time GNSS Applications, ION GNSS 2005.</td></tr>
3269
3270<tr><td>Weber, G, L. Mervart, Z. Lukes, C. Rocken and J. Dousa </td><td>Real-time Clock and Orbit Corrections for Improved Point Positioning via NTRIP, ION GNSS 2007.</td></tr>
3271
3272<tr><td>Mervart, L., Z. Lukes, C. Rocken and T. Iwabuchi </td><td>Precise Point Positioning With Ambiguity Resolution in Real-Time, ION GNSS 2008.</td></tr>
3273
3274<tr><td>Weber, G. and L. Mervart </td><td>The BKG Ntrip Client (BNC), Report on EUREF Symposium 2007 in London, Mitteilungen des Bundesamtes fuer Kartographie und Geodaesie, Band 42, Frankfurt, 2009.</td></tr>
3275
3276<tr><td>Weber, G. and L. Mervart </td><td>Real-time Combination of GNSS Orbit and Clock Correction Streams Using a Kalman Filter Approach, ION GNSS 2010.</td></tr>
3277
3278<tr><td>Huisman, L., P. Teunissen and C. Hu </td><td>GNSS Precise Point Positioning in Regional Reference Frames Using Real-time Broadcast Corrections, Journal of Applied Geodesy, Vol. 6, pp15-23, 2012.</td></tr>
3279
3280<tr><td>Louis H. Estey and Charles M. Meertens</td><td>TEQC: The Multi-Purpose Toolkit for GPS/GLONASS Data, GPS Solutions, Vol. 3, No. 1, pp. 42-49, 1999.</td></tr>
3281
3282</table>
3283
3284
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