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2<h3>BKG Ntrip Client (BNC) Version 2.1</h3>
3
4<p>
5The BKG Ntrip Client (BNC) is a program for simultaneously retrieving, decoding and converting real-time GNSS data streams from NTRIP broadcasters like <u>http://www.euref-ip.net/home</u> or <u>http://www.igs-ip.net/home</u>.
6</p>
7
8<p>
9BNC has been developed for the Federal Agency for Cartography and Geodesy (BKG) within the framework of EUREF's Real-time GNSS Project (EUREF-IP, IP for Internet Protocol) and the Real-Time IGS Pilot Project (RTIGS).
10</p>
11
12<p>
13BNC has been written under GNU General Public License (GPL). Binaries for BNC are available for Windows, 32-bit Linux, 64-bit Linux (compiled under -m32 32-bit compatibility mode), Solaris, and Mac systems. We used the MinGW Version 5.1.3 compiler to create the Windows binary. It is likely that BNC can be compiled on other systems where a GNU compiler and Qt Version 4.5.2 are installed.
14</p>
15
16<p>
17Please ensure that you have installed the latest version of BNC available from <u>http://igs.bkg.bund.de/ntrip/download</u>. We are continuously working on the program and would appreciate if you could send any comments, suggestions, or bug reports to [euref-ip@bkg.bund.de] or [igs-ip@bkg.bund.de].
18</p>
19
20<h3>Contents</h3>
21<p>
22<h4>
23<a href=#purpose>1. Purpose</a><br>
24<a href=#resources>2. Modes &amp; Resources</a><br>
25<a href=#options>3. Options</a><br>
26<a href=#limits>4. Limitations</a><br>
27<a href=#authors>5. Authors</a><br>
28<a href=#annex>6. Annex</a><br>
29</h4>
30</p>
31
32<p><a name="purpose"><h3>1. Purpose</h3></p>
33
34<p> The purpose of BNC is to
35
36<ul>
37<li>retrieve real-time GNSS data streams available through NTRIP transport protocol,</li>
38<li>retrieve real-time GNSS data streams via TCP directly from an IP address without using the NTRIP transport protocol, and/or</li>
39<li>retrieve real-time GNSS data streams from a local UDP or serial port without using the NTRIP transport protocol, and/or</li>
40<li>generate high-rate RINEX Observation and Navigation files to support near real-time GNSS post-processing applications, and/or</li>
41<li>generate ephemeris and synchronized or unsynchronized observations epoch by epoch through an IP port to support real-time GNSS network engines, and/or</li>
42<li>generate clock and orbit corrections to broadcast ephemeris through an IP port to support real-time Precise Point Positioning on GNSS rovers, and/or</li>
43<li>generate synchronized clock and orbit corrections to broadcast ephemeris epoch by epoch through an IP port to support the combination of such streams as coming simultaneously from various correction providers, and/or</li>
44<li>monitor the performance of a network of real-time GNSS data streams to generate advisory notes in case of outages or corrupted streams, and/or</li>
45<li>scan RTCM streams for incoming antenna information as well as message types and their repetition rates, and/or</li>
46<li>feed a stream into a GNSS receiver via serial communication link, and/or</li>
47<li>carry out a real-time Precise Point Positioning to determine a GNSS rover position.</li>
48</ul>
49</p>
50
51<p>
52BNC supports decoding the following GNSS data formats:
53</p>
54<p>
55<ul>
56<li>RTCM Version 2.x containing message types 18 and 19 or 20 and 21 together with 3 and 22 (GPS and GLONASS), </li>
57<li>RTCM Version 3.x containing message types 1002 (GPS, SBAS) or 1004 (GPS), 1010 or 1012 (GLONASS), 1019 or 1020 (broadcast ephemeris), 1057-1068 (premature State Space Representation messages for GPS and GLONASS)</li>
58<li>RTIGS containing GPS record types 200 (observations) and 300 (ephemeris).</li>
59</ul>
60BNC allows to by-pass its decoding and conversion algorithms, leave whatever is received untouched and save it in files.
61</p>
62
63<p>
64The first of the following figures shows a flow chart of BNC connected to a GNSS receiver via serial or TCP communication link for the pupose of Precise Point Positioning. The second figure shows the conversion of RTCM streams to RINEX batches. The third figure shows a flow chart of BNC feeding a real-time GNSS engine. The engine then estimates satellite orbit and clock correctors. The 'BKG Ntrip Server' (BNS) is used in this scenario to encode correctors to RTCMv3.
65</p>
66<p><img src="IMG/screenshot10.png"/></p>
67<p><u>Figure:</u> BNC connected to a GNSS receiver for Precise Point Positioning.</p>
68
69<p>
70</p>
71<p><img src="IMG/screenshot01.png"/></p>
72<p><u>Figure:</u> BNC converting RTCM streams to RINEX batches.</p>
73
74<p>
75</p>
76<p><img src="IMG/screenshot02.png"/></p>
77<p><u>Figuge:</u> BNC feeding a real-time GNSS engine.</p>
78
79
80<p><a name="resources"><h3>2. Modes &amp; Resources</h3></p>
81<p>
82Although BNC is a real-time tool to be operated in online mode, it can be run offline for post-processing of data made availabe from a single file. Furthermore, 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.
83</p>
84<p>
85Unless in offline mode, BNC
86</p>
87<ul>
88<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>
89<li>requires the clock of the host computer to be properly synchronized.</li>
90<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>
91</ul>
92</p>
93
94<p><a name="options"><h3>3. Options</h3></p>
95<p>
96This section describes BNC's top menu bar, its processing options, the 'Streams' and 'Log' sections, and the bottom menu bar, see figure below.
97</p>
98<p><img src="IMG/screenshot09.png"/></p>
99<p><u>Figure:</u> Sections on BNC's main window.</p>
100
101</p>
102<p>
103The 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'). Records of BNC's activities are shown in the 'Log' tab. The bandwidth consumption per stream, the latency of incoming observations and PPP time series for coordinate components are shown in the 'Throughput', 'Latency' and 'PPP Plot' tabs of the main window.
104</p>
105<p>
106As a default, configuration files for running BNC on Unix/Linux/Mac 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.ini'.</p>
107<p>
108The default file name 'BNC.ini' 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. Some configuration options can be changed on-the-fly. See annexed 'Configuration Example' for a complete set of configuration options.
109</p>
110<p>
1113.1. <a href=#topmenu>Top Menu Bar</a><br>
1123.1.1 <a href=#file>File</a><br>
1133.1.2 <a href=#help>Help</a><br>
1143.2. <a href=#proxy>Proxy</a><br>
1153.3. <a href=#general>General</a><br>
116&nbsp; &nbsp; &nbsp; 3.3.1. <a href=#genlog>Logfile</a><br>
117&nbsp; &nbsp; &nbsp; 3.3.2. <a href=#genapp>Append Files</a><br>
118&nbsp; &nbsp; &nbsp; 3.3.3. <a href=#genconf>Reread Configuration</a><br>
119&nbsp; &nbsp; &nbsp; 3.3.4. <a href=#genstart>Auto Start</a><br>
120&nbsp; &nbsp; &nbsp; 3.3.5. <a href=#rawout>Raw Output File</a><br>
1213.4. <a href=#rinex>RINEX Observations</a><br>
122&nbsp; &nbsp; &nbsp; 3.4.1. <a href=#rnxname>File Names</a><br>
123&nbsp; &nbsp; &nbsp; 3.4.2. <a href=#rnxdir>Directory</a><br>
124&nbsp; &nbsp; &nbsp; 3.4.3. <a href=#rnxinterval>File Interval</a><br>
125&nbsp; &nbsp; &nbsp; 3.4.4. <a href=#rnxsample>Sampling</a><br>
126&nbsp; &nbsp; &nbsp; 3.4.5. <a href=#rnxskl>Skeleton Extension</a><br>
127&nbsp; &nbsp; &nbsp; 3.4.6. <a href=#rnxscript>Script</a><br>
128&nbsp; &nbsp; &nbsp; 3.4.7. <a href=#rnxvers>Version</a><br>
1293.5. <a href=#ephemeris>RINEX Ephemeris</a><br>
130&nbsp; &nbsp; &nbsp; 3.5.1. <a href=#ephdir>Directory</a><br>
131&nbsp; &nbsp; &nbsp; 3.5.2. <a href=#ephint>Interval</a><br>
132&nbsp; &nbsp; &nbsp; 3.5.3. <a href=#ephport>Port</a><br>
133&nbsp; &nbsp; &nbsp; 3.5.4. <a href=#ephvers>Version</a><br>
1343.6. <a href=#correct>Broadcast Corrections</a><br>
135&nbsp; &nbsp; &nbsp; 3.6.1. <a href=#corrdir>Directory</a><br>
136&nbsp; &nbsp; &nbsp; 3.6.2. <a href=#corrint>Interval</a><br>
137&nbsp; &nbsp; &nbsp; 3.6.3. <a href=#corrport>Port</a><br>
138&nbsp; &nbsp; &nbsp; 3.6.4. <a href=#corrwait>Wait for Full Epoch</a><br>
1393.7. <a href=#syncout>Feed Engine</a><br>
140&nbsp; &nbsp; &nbsp; 3.7.1. <a href=#syncport>Port</a><br>
141&nbsp; &nbsp; &nbsp; 3.7.2. <a href=#syncwait>Wait for Full Epoch</a><br>
142&nbsp; &nbsp; &nbsp; 3.7.3. <a href=#syncsample>Sampling</a><br>
143&nbsp; &nbsp; &nbsp; 3.7.4. <a href=#syncfile>File</a><br>
144&nbsp; &nbsp; &nbsp; 3.7.5. <a href=#syncuport>Port (unsynchronized)</a><br>
1453.8. <a href=#serial>Serial Output</a><br>
146&nbsp; &nbsp; &nbsp; 3.8.1. <a href=#sermount>Mountpoint</a><br>
147&nbsp; &nbsp; &nbsp; 3.8.2. <a href=#serport>Port Name</a><br>
148&nbsp; &nbsp; &nbsp; 3.8.3. <a href=#serbaud>Baud Rate</a><br>
149&nbsp; &nbsp; &nbsp; 3.8.4. <a href=#serflow>Flow Control</a><br>
150&nbsp; &nbsp; &nbsp; 3.8.5. <a href=#serparity>Parity</a><br>
151&nbsp; &nbsp; &nbsp; 3.8.6. <a href=#serdata>Data Bits</a><br>
152&nbsp; &nbsp; &nbsp; 3.8.7. <a href=#serstop>Stop Bits</a><br>
153&nbsp; &nbsp; &nbsp; 3.8.8. <a href=#serauto>NMEA</a><br>
154&nbsp; &nbsp; &nbsp; 3.8.9. <a href=#serfile>File</a><br>
155&nbsp; &nbsp; &nbsp; 3.8.10. <a href=#serheight>Height</a><br>
1563.9. <a href=#advnote>Outages</a><br>
157&nbsp; &nbsp; &nbsp; 3.9.1. <a href=#obsrate>Observation Rate</a><br>
158&nbsp; &nbsp; &nbsp; 3.9.2. <a href=#advfail>Failure Threshold</a><br>
159&nbsp; &nbsp; &nbsp; 3.9.3. <a href=#advreco>Recovery Threshold</a><br>
160&nbsp; &nbsp; &nbsp; 3.9.4. <a href=#advscript>Script</a><br>
1613.10. <a href=#misc>Miscellaneous</a><br>
162&nbsp; &nbsp; &nbsp; 3.10.1. <a href=#miscmount>Mountpoint</a><br>
163&nbsp; &nbsp; &nbsp; 3.10.2. <a href=#miscperf>Log Latency</a><br>
164&nbsp; &nbsp; &nbsp; 3.10.3. <a href=#miscscan>Scan RTCM</a><br>
1653.11. <a href=#pppclient>PPP Client</a><br>
166&nbsp; &nbsp; &nbsp; 3.11.1 <a href=#pppmount>Mountpoint</a><br>
167&nbsp; &nbsp; &nbsp; 3.11.2 <a href=#pppopt>Options</a><br>
168&nbsp; &nbsp; &nbsp; 3.11.2.1 <a href=#pppstatic>Static</a><br>
169&nbsp; &nbsp; &nbsp; 3.11.2.2 <a href=#pppphase>Use Phase Obs</a><br>
170&nbsp; &nbsp; &nbsp; 3.11.2.3 <a href=#ppptropo>Estimate Tropo</a><br>
171&nbsp; &nbsp; &nbsp; 3.11.2.4 <a href=#pppglo>Use GLONASS</a><br>
172&nbsp; &nbsp; &nbsp; 3.11.3 <a href=#pppnmearef>Plot Origin</a><br>
173&nbsp; &nbsp; &nbsp; 3.11.4 <a href=#pppnmeaout>NMEA</a><br>
174&nbsp; &nbsp; &nbsp; 3.11.4.1 <a href=#pppnmeafile>File</a><br>
175&nbsp; &nbsp; &nbsp; 3.11.4.2 <a href=#pppnmeaport>Port</a><br>
1763.12. <a href=#streams>Streams</a><br>
177&nbsp; &nbsp; &nbsp; 3.12.1 <a href=#streamedit>Edit Streams</a><br>
178&nbsp; &nbsp; &nbsp; 3.12.2 <a href=#streamdelete>Delete Stream</a><br>
179&nbsp; &nbsp; &nbsp; 3.12.3 <a href=#streamconf>Reconfigure Streams On-the-fly</a><br>
1803.13. <a href=#logs>Logging</a><br>
181&nbsp; &nbsp; &nbsp; 3.13.1 <a href=#logfile>Log</a><br>
182&nbsp; &nbsp; &nbsp; 3.13.2 <a href=#throughput>Throughput</a><br>
183&nbsp; &nbsp; &nbsp; 3.13.3 <a href=#latency>Latency</a><br>
184&nbsp; &nbsp; &nbsp; 3.13.4 <a href=#ppptab>PPP Plot</a><br>
1853.14. <a href=#bottom>Bottom Menu Bar</a><br>
186&nbsp; &nbsp; &nbsp; 3.14.1. <a href=#streamadd>Add Stream - Coming from Caster</a><br>
187&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.1 <a href=#streamhost>Caster Host and Port</a><br>
188&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.2 <a href=#streamtable>Casters Table</a><br>
189&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.3 <a href=#streamuser>User and Password</a><br>
190&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.4 <a href=#gettable>Get Table</a><br>
191&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.5 <a href=#ntripv>NTRIP Version</a><br>
192&nbsp; &nbsp; &nbsp; 3.14.2 <a href=#streamip>Add Stream - Coming from TCP/IP Port</a><br>
193&nbsp; &nbsp; &nbsp; 3.14.3 <a href=#streamudp>Add Stream - Coming from UDP Port</a><br>
194&nbsp; &nbsp; &nbsp; 3.14.4 <a href=#streamser>Add Stream - Coming from Serial Port</a><br>
195&nbsp; &nbsp; &nbsp; 3.14.5 <a href=#start>Start</a><br>
196&nbsp; &nbsp; &nbsp; 3.14.6 <a href=#stop>Stop</a><br>
1973.15. <a href=#cmd>Command Line Options</a><br>
198&nbsp; &nbsp; &nbsp; 3.15.1. <a href=#nw>No Window Mode</a><br>
199&nbsp; &nbsp; &nbsp; 3.15.2. <a href=#post>Offline Mode</a><br>
200&nbsp; &nbsp; &nbsp; 3.15.3. <a href=#conffile>Configuration File</a><br>
201</p>
202
203<p><a name="topmenu"><h4>3.1. Top Menu Bar</h4></p>
204<p>
205The top menu bar allows to select a font for the BNC windows, save configured options or quit the program execution. It also provides access to a program documentation.
206</p>
207
208<p><a name="file"><h4>3.1.1 File</h4></p>
209
210<p>
211The 'File' button lets you
212<ul>
213<li> select an appropriate font.<br>
214Use smaller font size if the BNC main window exceeds the size of your screen.
215</li>
216<li> save selected options in configuration file.<br>
217When 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 Example' for a list of on-the-fly changeable configuration options.
218</li>
219<li> quit the BNC program.
220</li>
221</ul>
222</p>
223
224<p><a name="help"><h4>3.1.2 Help</h4></p>
225
226<p>
227The 'Help' button provides access to
228<ul>
229<li>
230help contents.<br>
231You may keep the 'Help Contents' window open while configuring BNC.
232</li>
233<li>
234a 'Flow Chart' showing BNC linked to a real-time GNSS network engine such as RTNet.
235</li>
236<li>
237general information about BNC.<br>
238Close the 'About BNC' window to continue working with BNC.
239</li>
240</ul>
241</p>
242<p>
243BNC 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; they then click the relevant widget to pop up the help text.
244</p>
245
246<p><a name="proxy"><h4>3.2. Proxy - for usage in a protected LAN</h4></p>
247
248<p>
249If 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>
250<p>
251Note 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.
252</p>
253<p><a name="general"><h4>3.3. General</h4></p>
254<p>
255The following defines general settings for BNC's logfile, file handling, reconfiguration on-the-fly, and auto-start.
256</p>
257
258<p><a name="genlog"><h4>3.3.1 Logfile - optional</h4></p>
259<p>
260Records 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 saved into a file.
261</p>
262
263<p><a name="genapp"><h4>3.3.2 Append Files - optional</h4></p>
264<p>
265When 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.
266</p>
267
268<p><a name="genconf"><h4>3.3.3 Reread Configuration - optional</h4></p>
269<p>
270When 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 Example' for a configuration file example and a list of on-the-fly changeable options.
271</p>
272
273<p><a name="genstart"><h4>3.3.4 Auto Start - optional</h4></p>
274<p>
275You 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 systems).
276</p>
277<p>
278 See BNC's command line option -nw for an auto-start of BNC in 'no window' mode.
279</p>
280
281<p><a name="rawout"><h4>3.3.5 Raw Output File - optional</h4></p>
282<p>
283BNC can save all data coming in through various streams in the received order and format together in one single file. This is of importance i.e. when using the PPP option in offline mode where the contents of different streams carrying observations, orbit/clock correctors, and broadcast ephemeris are to be read from one file.
284</p>
285<p>
286The default value for 'Raw output file (full path)' is an empty option field, meaning that BNC will not save raw data into a file.
287</p>
288
289<p><a name="rinex"><h4>3.4. RINEX Observations</h4></p>
290<p>
291Observations will be converted to RINEX if they come in either RTCM Version 2.x, RTCM Version 3.x, or RTIGS format. BNC's RINEX Observation files generally contain C1, C2, P1, P2, L1, L2, S1, and S2 observations. In case an observation is unavailable, its value is set to zero '0.000'. Note that the 'RINEX TYPE' field in the RINEX Observation file header is always set to 'M(MIXED)' even if the file does not contain any GLONASS or SABAS data.
292</p>
293
294<p><a name="rnxname"><h4>3.4.1 RINEX File Names</h4></p>
295<p>
296RINEX 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>
297<p>
298FRAN{ddd}{h}.{yy}O<br>
299WETT{ddd}{h}.{yy}O
300</p>
301<p>
302where 'ddd' is the day of year, 'h' is a letter which corresponds to an hour long UTC time block and 'yy' is the year.
303</p>
304<p>
305If there are 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>
306<p>
307FRAN{ddd}{h}_KFURT.{yy}O<br>
308FRAN{ddd}{h}_CE.{yy}O.
309</p>
310<p>
311If 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>
312<p>
313BRUS{ddd}{h}_0.{yy}O<br>
314BRUS{ddd}{h}_1.{yy}O.
315</p>
316<p>
317Note 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>
318<p>
319FRAN{ddd}{h}{mm}.{yy}O
320</p>
321<p>
322where 'mm' is the starting minute within the hour.
323</p>
324
325<p><a name="rnxdir"><h4>3.4.2 Directory - optional</h4></p>
326<p>
327Here 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.
328</p>
329
330<p><a name="rnxinterval"><h4>3.4.3 File Interval - mandatory if 'Directory' is set</h4></p>
331<p>
332Select the length of the RINEX Observation file generated. The default value is 15 minutes.
333</p>
334
335<p><a name="rnxsample"><h4>3.4.4 Sampling - mandatory if 'Directory' is set </h4></p>
336<p>
337Select 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.
338</p>
339
340<p><a name="rnxskl"><h4>3.4.5 Skeleton Extension - optional</h4></p>
341<p>
342Whenever 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.
343</p>
344<p>
345However, sometimes public RINEX header skeleton files are not available, its 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.
346</p>
347<p>
348Examples 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>
349<p>
350WETT.skl<br>
351FRAN_KFURT.skl<br>
352FRAN_CE.skl<br>
353BRUS_0.skl<br>
354BRUS_1.skl</p>
355<p>
356if 'Skeleton extension' is set to 'skl'.
357</p>
358<p>
359Note the following regulations regarding personal RINEX header skeleton files:
360<ul>
361<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>
362<li>Personal skeletons should contain a complete first header record of type</li>
363<br>- &nbsp; RINEX VERSION / TYPE
364<li>They should then contain an empty header record of type</li>
365<br>- &nbsp; PGM / RUN BY / DATE
366<br>BNC will complete this line and include it in the actual RINEX file header.
367<li>They should further contain complete header records of type</li>
368<br>- &nbsp; MARKER NAME
369<br>- &nbsp; OBSERVER / AGENCY
370<br>- &nbsp; REC # / TYPE / VERS
371<br>- &nbsp; ANT # / TYPE
372<br>- &nbsp; APPROX POSITION XYZ
373<br>- &nbsp; ANTENNA: DELTA H/E/N
374<br>- &nbsp; WAVELENGTH FACT L1/2
375<li>They may contain any other optional complete header record as defined in the RINEX documentation.</li>
376<li>They should then contain empty header records of type</li>
377<br>- &nbsp; # / TYPES OF OBSERV
378<br>- &nbsp; TIME OF FIRST OBS
379<br>BNC will include these lines in the final RINEX file header together with an additional
380<br>- &nbsp; COMMENT
381<br>line describing the source of the stream.
382<li>They should finally contain an empty header record of type</li>
383<br>- &nbsp; END OF HEADER (last record)
384</ul>
385<p>
386If neither a public nor a personal RINEX header skeleton file is available for BNC, a default header will be used.
387</p>
388
389<p><a name="rnxscript"><h4>3.4.6 Script - optional</h4></p>
390<p>
391Whenever 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 systems).
392</p>
393<p>
394The 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.
395</p>
396<p>
397As 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 2 or 3 minutes after the end of each RINEX file 'Interval'.
398</p>
399
400<p><a name="rnxvers"><h4>3.4.7 Version - optional</h4></p>
401<p>
402The 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.
403</p>
404
405<p><a name="ephemeris"><h4>3.5. RINEX Ephemeris</h4></p>
406<p>
407Broadcast ephemeris can be saved as RINEX Navigation files when received via RTCM Version 3.x as message types 1019 (GPS) and 1020 (GLONASS) or via RTIGS records type 300. 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
408</p>
409<ul>
410<li>'N' or 'G' for GPS or GLONASS ephemeris in two separate RINEX Version 2.11 Navigation files, or</li>
411<li>'P' for GPS plus GLONASS ephemeris saved together in one RINEX Version 3 Navigation file.
412</ul>
413
414<p>
415Note that streams dedicated to carry Broadacst Ephemeris messages in RTCM v3 format in high repetition rates are listed on <u>http://igs.bkg.bund.de/ntrip/ephemeris</u>.
416</p>
417
418<p><a name="ephdir"><h4>3.5.1 Directory - optional</h4></p>
419<p>
420Specify the 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.
421</p>
422
423<p><a name="ephint"><h4>3.5.2 Interval - mandatory if 'Directory' is set</h4></p>
424<p>
425Select the length of the RINEX Navigation file generated. The default value is 1 day.
426</p>
427
428<p><a name="ephport"><h4>3.5.3 Port - optional</h4></p>
429<p>
430BNC can output broadcast ephemeris in RINEX Version 3 ASCII format on your local host (IP 127.0.0.1) through an IP 'Port'. This function is introduced in order to support i.e. the 'BKG Ntrip Sate Space Server' (BNS) which transforms IGS clocks and orbits into corrections to broadcast ephemeris. 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.
431</p>
432<p>
433The source code for BNC comes with an example perl script 'test_bnc_eph.pl' that allows you to read BNC's ASCII ephemeris output from the IP port.
434</p>
435
436<p><a name="ephvers"><h4>3.5.4 Version - optional</h4></p>
437<p>
438Default 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.
439</p>
440<p>
441Note that this does not concern the broadcast ephemeris output through IP port which is always in RINEX Version 3 format.
442</p>
443
444<p><a name="correct"><h4>3.6. Broadcast Corrections</h4></p>
445<p>
446</p>
447RTCM is in the process of developing new Version 3 messages to transport satellite clock and orbit corrections in real-time. Based on the latest available proposal, the following premature so-called 'State Space Representation' (SSR) messages currently under discussion have been implemented in BNC:
448<ul>
449<li>Message type 1057: GPS orbit corrections to Broadcast Ephemeris</li>
450<li>Message type 1058: GPS clock corrections to Broadcast Ephemeris</li>
451<li>Message type 1059: GPS code biases</li>
452<li>Message type 1060: Combined orbit and clock corrections to GPS Broadcast Ephemeris</li>
453<li>Message type 1061: GPS User Range Accuracy (URA)</li>
454<li>Message type 1062: High-rate GPS clock corrections to Broadcast Ephemeris</li>
455<li>Message type 1063: GLONASS orbit corrections to Broadcast Ephemeris</li>
456<li>Message type 1064: GLONASS clock corrections to Broadcast Ephemeris</li>
457<li>Message type 1065: GLONASS code biases</li>
458<li>Message type 1066: Combined orbit and clock corrections to GLONASS Broadcast Ephemeris</li>
459<li>Message type 1067: GLONASS User Range Accuracy (URA)</li>
460<li>Message type 1068: High-rate GLONASS clock corrections to Broadcast Ephemeris</li>
461</ul>
462<p>
463RTCM Version 3 streams carrying these messages may be used i.e. to support real-time Precise Point Positioning (PPP) applications.
464</p>
465<p>
466When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may beimportant to understand that they are not corrected for the 2nd-order relativistic effect. The 2nd-order relativistic effect is a periodic time correction defined as -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.
467</p>
468
469<p>
470Orbit 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.
471</p>
472
473<p>
474After 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.
475</p>
476
477<p>
478The 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.
479</p>
480
481<p>
482Broadcast 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;.
483</p>
484
485<p>
486The saved files contain parameters in plain ASCII format. The first five parameters in each record are:
487</p>
488<p>
489<ul>
490<li>RTCMv3 message type number</li>
491<li>SSR message update interval indicator</li>
492<ul>
493<li>0 = 1 sec</li>
494<li>1 = 2 sec</li>
495<li>2 = 5 sec</li>
496<li>3 = 10 sec</li>
497<li>4 = 15 sec</li>
498<li>5 = 30 sec</li>
499<li>6 = 60 sec</li>
500<li>7 = 120 sec</li>
501<li>8 = 240 sec</li>
502<li>9 = 300 sec</li>
503<li>10 = 600 sec</li>
504<li>11 = 900 sec</li>
505<li>12 = 1800 sec</li>
506<li>13 = 3600 sec</li>
507<li>14 = 7200 sec</li>
508<li>15 = 10800 sec</li>
509</ul>
510<li>GPS Week</li>
511<li>Second in GPS Week</li>
512<li>GNSS Indicator and Satellite Vehicle Pseudo Random Number</li>
513</ul>
514</p>
515<p>
516In case of RTCM message types 1057 or 1063 these parameters are followed by
517</p>
518<p>
519<ul>
520<li>IOD referring to Broadcast Ephemeris set</li>
521<li>Radial Component of Orbit Correction to Broadcast Ephemeris [m]</li>
522<li>Along-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
523<li>Cross-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
524<li>Velocity of Radial Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
525<li>Velocity of Along-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
526<li>Velocity of Cross-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
527<p>
528</ul>
529</p>
530<p>
531Undefined parameters are set to zero &quot;0.000&quot;.<br>Example:
532<pre>
533...
5341057 0 1538 211151.0 G18 1 0.034 0.011 -0.064 0.000 0.000 0.000
5351057 0 1538 211151.0 G16 33 -0.005 0.194 -0.091 0.000 0.000 0.000
5361057 0 1538 211151.0 G22 50 0.008 -0.082 -0.001 0.000 0.000 0.000
537...
5381063 0 1538 211151.0 R09 111 -0.011 -0.014 0.005 0.000 0.000 0.000
5391063 0 1538 211151.0 R10 43 0.000 -0.009 -0.002 0.000 0.000 0.000
5401063 0 1538 211151.0 R21 75 -0.029 0.108 0.107 0.000 0.000 0.000
541...
542</pre>
543<p>
544In case of RTCM message types 1058 or 1064 the first five parameters are followed by
545</p>
546<ul>
547<li>IOD set to zero &quot;0&quot;</li>
548<li>C0 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
549<li>C1 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m/s]</li>
550<li>C2 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m/s**2]</li>
551</ul>
552Example:
553</p>
554<pre>
555...
5561058 0 1538 211151.0 G18 0 1.846 0.000 0.000
5571058 0 1538 211151.0 G16 0 0.376 0.000 0.000
5581058 0 1538 211151.0 G22 0 2.727 0.000 0.000
559...
5601064 0 1538 211151.0 R08 0 8.956 0.000 0.000
5611064 0 1538 211151.0 R07 0 14.457 0.000 0.000
5621064 0 1538 211151.0 R23 0 6.436 0.000 0.000
563...
564</pre>
565</p>
566<p>
567In case of RTCM message types 1060 or 1066 the first five parameters are followed by
568<p>
569<ul>
570<li>IOD referring to Broadcast Ephemeris set</li>
571<li>C0 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
572<li>Radial Component of Orbit Correction to Broadcast Ephemeris [m]</li>
573<li>Along-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
574<li>Cross-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
575<li>C1 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
576<li>Velocity of Radial Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
577<li>Velocity of Along-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
578<li>Velocity of Cross-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
579<li>C2 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
580</ul>
581Example:
582</p>
583<pre>
584...
5851060 0 1538 211610.0 G30 82 2.533 0.635 -0.359 -0.598 0.000 0.000 0.000 0.000 0.000
5861060 0 1538 211610.0 G31 5 -4.218 -0.208 0.022 0.002 0.000 0.000 0.000 0.000 0.000
5871060 0 1538 211610.0 G32 28 -2.326 0.977 -0.576 0.142 0.000 0.000 0.000 0.000 0.000
588...
5891066 0 1538 211610.0 R22 27 1.585 2.024 2.615 -2.080 0.000 0.000 0.000 0.000 0.000
5901066 0 1538 211610.0 R23 27 6.277 2.853 4.181 1.304 0.000 0.000 0.000 0.000 0.000
5911066 0 1538 211610.0 R24 27 0.846 1.805 13.095 6.102 0.000 0.000 0.000 0.000 0.000
592...
593</pre>
594</p>
595<p>
596In case of RTCM message types 1059 or 1065 the first five parameters are followed by
597<ul>
598<li>Number of Code Biases</li>
599<li>Indicator to specify the signal and tracking mode</li>
600<li>Code Bias</li>
601<li>Indicator to specify the signal and tracking mode</li>
602<li>Code Bias</li>
603<li>etc.</li>
604</ul>
605Example:
606</p>
607<pre>
608...
6091059 0 1538 211151.0 G18 2 0 -0.010 11 -0.750
6101059 0 1538 211151.0 G16 2 0 -0.040 11 -0.430
6111059 0 1538 211151.0 G22 2 0 -0.630 11 -2.400
612...
613</pre>
614
615<p><a name="corrdir"><h4>3.6.1 Directory - optional</h4></p>
616<p>
617Specify 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.
618</p>
619
620<p><a name="corrint"><h4>3.6.2 Interval - mandatory if 'Directory' is set</h4></p>
621<p>
622Select the length of the Broadcast Correction files. The default value is 1 day.
623</p>
624
625<p><a name="corrport"><h4>3.6.3 Port - optional</h4></p>
626<p>
627BNC 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.
628</p>
629<p>
630The 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.
631</p>
632<p>
633The following is an example output for streams from Mountpoints RTCMSSR, CLK10 and CLK11:
634<pre>
635...
6361057 0 1538 211151.0 G18 1 0.034 0.011 -0.064 0.000 0.000 0.000 RTCMSSR
6371057 0 1538 211151.0 G16 33 -0.005 0.194 -0.091 0.000 0.000 0.000 RTCMSSR
6381057 0 1538 211151.0 G22 50 0.008 -0.082 -0.001 0.000 0.000 0.000 RTCMSSR
6391058 0 1538 211151.0 G18 0 1.846 0.000 RTCMSSR
6401058 0 1538 211151.0 G16 0 0.376 0.000 RTCMSSR
6411058 0 1538 211151.0 G22 0 2.727 0.000 RTCMSSR
6421059 0 1538 211151.0 G18 2 0 -0.010 11 -0.750 RTCMSSR
6431059 0 1538 211151.0 G16 2 0 -0.040 11 -0.430 RTCMSSR
6441059 0 1538 211151.0 G22 2 0 -0.630 11 -2.400 RTCMSSR
6451063 0 1538 211151.0 R09 111 -0.011 -0.014 0.005 0.0000 0.000 0.000 RTCMSSR
6461063 0 1538 211151.0 R10 43 0.000 -0.009 -0.002 0.0000 0.000 0.000 RTCMSSR
6471063 0 1538 211151.0 R21 75 -0.029 0.108 0.107 0.0000 0.000 0.000 RTCMSSR
6481064 0 1538 211151.0 R08 0 8.956 0.000 RTCMSSR
6491064 0 1538 211151.0 R07 0 14.457 0.000 RTCMSSR
6501064 0 1538 211151.0 R23 0 6.436 0.000 RTCMSSR
6511066 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
6521066 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
6531066 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
6541060 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
6551060 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
6561060 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
657...
658</pre>
659</p>
660<p>
661The source code for BNC comes with an example perl script 'test_bnc_eph.pl' that allows you to read BNC's Broadcast Corrections from the IP port.
662</p>
663
664<p><a name="corrwait"><h4>3.6.4 Wait for Full Epoch - mandatory if 'Port' is set</h4></p>
665<p>
666When feeding a real-time GNSS network engine waiting epoch by epoch for synchronized Broadcast Corrections, BNC drops (only concerning IP port output) whatever is received later than 'Wait for full 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 overaged by 5 sec&quot; shows up in BNC's logfile if 'Wait for full epoch' is exceeded.
667</p>
668
669<p><a name="syncout"><h4>3.7. Feed Engine</h4></p>
670<p>
671BNC can generate synchronized or unsynchronized observations epoch by epoch from all stations and satellites to feed a real-time GNSS network engine. The output can be produced in a binary format through an IP port and/or a plain ASCII format to save the observations in a local file. It comprises the following observations where available:</p>
672<p>
673StatID, SVPRN, GPSWeek, GPSWeeks, C1, C2, P1, P2, L1, L2, slip_cnt_L1, slip_cnt_L2, lock_timei_L1, lock_timei_L2, S1, S2, SNR1, SNR2
674</p>
675<p>
676Note that slip_cnt stands for the cumulative loss of continuity indicator, lock_timei for the lock time indicator, and SNR for the signal-to-noise ratio 'S' mapped to integer numbers 1 to 9. In case an observation is not available, its value is set to zero '0.000'. Loss of continuity indicator and lock time indicator are set to negative values if undefined.
677</p>
678
679<p>The binary output is a continuous stream in the following order:</p>
680<pre>
681begEpoch
682t_obsInternal
683t_obsInternal
684...
685t_obsInternal
686endEpoch
687begEpoch
688t_obsInternal
689...
690</pre>
691
692<p>The corresponding structures are defined as follow:</p>
693<pre>
694 const char begEpoch[] = &quot;BEGEPOCH&quot;;
695 const char endEpoch[] = &quot;ENDEPOCH&quot;;
696...
697...
698class t_obsInternal {
699 public:
700 int flags;
701 char StatID[20+1]; // Station ID
702 char satSys; // Satellite System ('G' or 'R')
703 int satNum; // Satellite Number (PRN for GPS NAVSTAR)
704 int slot; // Slot Number (for Glonass)
705 int GPSWeek; // Week of GPS-Time
706 double GPSWeeks; // Second of Week (GPS-Time)
707 double C1; // CA-code pseudorange (meters)
708 double C2; // CA-code pseudorange (meters)
709 double P1; // P1-code pseudorange (meters)
710 double P2; // P2-code pseudorange (meters)
711 double L1; // L1 carrier phase (cycles)
712 double L2; // L2 carrier phase (cycles)
713 int slip_cnt_L1; // L1 cumulative loss of continuity indicator (negative value = undefined)
714 int slip_cnt_L2; // L2 cumulative loss of continuity indicator (negative value = undefined)
715 int lock_timei_L1; // L1 last lock time indicator (negative value = undefined)
716 int lock_timei_L2; // L2 last lock time indicator (negative value = undefined)
717 double S1; // L1 signal-to noise ratio
718 double S2; // L2 signal-to noise ratio
719 int SNR1; // L1 signal-to noise ratio (mapped to integer)
720 int SNR2; // L2 signal-to noise ratio (mapped to integer)
721};
722</pre>
723
724<p>
725The source code for BNC comes with an example program called 'test_bnc_qt.cpp' that allows you to read BNC's (synchronized or unsynchronized) binary observation output from the IP port and print the observations in a plain ASCII format on standard output.
726</p>
727<p>
728Note 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'.
729</p>
730
731</p>
732The following figure shows the screenshot of a BNC configuration where a number if streams is pulled from different NTRIP broadcasters to feed a GNSS engine via IP port output.
733</p>
734<p><img src="IMG/screenshot12.png"/></p>
735<p><u>Figure:</u> Synchronized BNC output via IP port to feed a GNSS real-time engine.</p>
736
737<p><a name="syncport"><h4>3.7.1 Port - optional</h4></p>
738<p>
739BNC can produce synchronized observations in binary format on your local host (IP 127.0.0.1) through an IP 'Port'. Synchronized means that BNC collects all data for any specific epoch which become available within a certain number of latency seconds (see 'Wait for Full 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>
740<p>
741</p>
742
743<p><a name="syncwait"><h4>3.7.2 Wait for Full Epoch - mandatory if 'Port' is set</h4></p>
744<p>
745When feeding a real-time GNSS network engine waiting for synchronized input epoch by epoch, BNC drops whatever is received later than 'Wait for full 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 epoch' is 5 seconds.
746</p>
747<p>
748Note that 'Wait for full epoch' does not effect the RINEX Observation file content. Observations received later than 'Wait for full epoch' seconds will still be included in the RINEX Observation files.
749</p>
750
751<p><a name="syncsample"><h4>3.7.3 Sampling - mandatory if 'File' or 'Port' is set</h4></p>
752<p>
753Select 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.
754</p>
755
756<p><a name="syncfile"><h4>3.7.4 File - optional</h4></p>
757<p>
758Specifies 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.
759</p>
760<p>
761Beware 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.
762</p>
763
764<p><a name="syncuport"><h4>3.7.5 Port (unsynchronized) - optional</h4></p>
765<p>
766BNC can produce unsynchronized observations from all configured streams in binary 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 binary unsynchronized output is generated.</p>
767<p>
768
769<p><a name="serial"><h4>3.8. Serial Output</h4></p>
770<p>
771You may use BNC to feed a serial connected device like an GNSS receiver. For that one of the incoming streams 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 rover.
772</p>
773</p>
774<p><img src="IMG/screenshot11.png"/></p>
775<p><u>Figure:</u> BNC pulling a VRS to feed a serial connected rover.</p>
776
777<p><a name="sermount"><h4>3.8.1 Mountpoint - optional</h4></p>
778<p>
779Enter a 'Mountpoint' to forward its corresponding stream to a serial connected GNSS receiver.
780</p>
781<p>
782When selecting the serial communication options listed below, make sure that you pick those configured to the serial connected receiver.
783</p>
784
785<p><a name="serport"><h4>3.8.2 Port Name - mandatory if 'Mountpoint' is set</h4></p>
786<p>
787Enter the serial 'Port name' selected on your host for communication with the serial connected receiver. Valid port names are
788</p>
789<pre>
790Windows: COM1, COM2
791Linux: /dev/ttyS0, /dev/ttyS1
792FreeBSD: /dev/ttyd0, /dev/ttyd1
793Digital Unix: /dev/tty01, /dev/tty02
794HP-UX: /dev/tty1p0, /dev/tty2p0
795SGI/IRIX: /dev/ttyf1, /dev/ttyf2
796SunOS/Solaris: /dev/ttya, /dev/ttyb
797</pre>
798<p>
799Note that you must plug a serial cable in the port defined here before you start BNC.
800</p>
801
802<p><a name="serbaud"><h4>3.8.3 Baud Rate - mandatory if 'Mountpoint' is set</h4></p>
803<p>
804Select a 'Baud rate' for the serial output link. Note that using a high baud rate is recommended.
805</p>
806
807<p><a name="serflow"><h4>3.8.4 Flow Control - mandatory if 'Mountpoint' is set</h4></p>
808<p>
809Select 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.
810</p>
811
812<p><a name="serparity"><h4>3.8.5 Parity - mandatory if 'Mountpoint' is set</h4></p>
813<p>
814Select the 'Parity' for the serial output link. Note that parity is often set to 'NONE'.
815</p>
816
817<p><a name="serdata"><h4>3.8.6 Data Bits - mandatory if 'Mountpoint' is set</h4></p>
818<p>
819Select the number of 'Data bits' for the serial output link. Note that often '8' data bits are used.
820</p>
821
822<p><a name="serstop"><h4>3.8.7 Stop Bits - mandatory if 'Mountpoint' is set</h4></p>
823<p>
824Select the number of 'Stop bits' for the serial output link. Note that often '1' stop bit is used.
825</p>
826
827<p><a name="serauto"><h4>3.8.8 NMEA - mandatory for VRS streams</h4></p>
828<p>
829Select '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.
830</p>
831<p>
832Forwarding 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 contents is based on the approximate (editable) latitude/longitude from the broadcaster's source-table and an approximate VRS height to be specified.
833</p>
834<p>
835In summary: select 'Manual' only when handling a VRS stream and your serial connected GNSS receiver doesn't generate NMEA-GGA messages. Select 'Auto' otherwise.
836</p>
837
838<p><a name="serfile"><h4>3.8.9 File - optional if 'Auto' NMEA is set</h4></p>
839<p>Specify the full path to a file where NMEA messages coming from your serial connected receiver are saved.
840</p>
841<p><a name="serheight"><h4>3.8.10 Height - mandatory if 'Manual' NMEA is set</h4></p>
842<p>
843Specify 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.
844</p>
845<p>
846This option concerns only 'Virtual Reference Stations' (VRS). Its setting is ignored in case of streams coming from physical reference stations.
847</p>
848
849<p><a name="advnote"><h4>3.9. Outages</h4></p>
850
851<p>
852At various times, the 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 corrupted stream(s) can generate unnecessary workload for BNC. Outages and corruptions are handled by BNC as follows:
853</p>
854<p>
855<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.
856</p>
857<p>
858<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.
859</p>
860<p>
861Outage 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.
862</p>
863
864<p><a name="obsrate"><h4>3.9.1 Observation Rate - mandatory if 'Failure threshold', 'Recovery threshold', and 'Script' is set</h4></p>
865<p>
866BNC 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 an explicit information from BNC about stream outages and incoming streams that cannot be decoded.
867</p>
868
869<p><a name="advfail"><h4>3.9.2 Failure Threshold - optional</h4></p>
870<p>
871Event '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 innundate user with too many event reports.
872</p>
873<p>
874Note 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'.
875</p>
876
877<p><a name="advreco"><h4>3.9.3 Recovery Threshold - optional</h4></p>
878<p>
879Once 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 innundate users with too many event reports.
880</p>
881<p>
882Note 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'.
883</p>
884
885<p><a name="advscript"><h4>3.9.4 Script - optional </h4></p>
886<p>
887As 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 systems) together with date and time information.
888</p>
889<p>
890Leave the 'Script' field empty if you do not wish to use this option. An invalid path will also disable this option.
891</p>
892<p>
893Examples for command line parameter strings passed on to the advisory 'Script' are:
894<pre>
895FFMJ0 Begin_Outage 08-02-21 09:25:59
896FFMJ0 End_Outage 08-02-21 11:36:02 Begin was 08-02-21 09:25:59
897</pre>
898Sample script for Unix/Linux/Mac systems:
899<pre>
900#!/bin/bash
901sleep $((60*RANDOM/32767))
902cat | mail -s &quot;NABU: $1&quot; email@address &lt;&lt;!
903Advisory Note to BNC User,
904Please note the following advisory received from BNC.
905Stream: $*
906Regards, BNC
907!
908</pre>
909</p>
910<p>
911Note 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 avoids overloading your mail server in case of a simultaneous failure of many streams.
912</p>
913
914<p><a name="misc"><h4>3.10. Miscellaneous</h4></p>
915<p>
916This section describes a number of miscellaneous options which can be applied for a single stream (mountpoint) or for all configured streams.
917</p>
918
919<p><a name="miscmount"><h4>3.10.1 Mountpoint - optional </h4></p>
920<p>
921Specify 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.
922</p>
923
924<p><a name="miscperf"><h4>3.10.2 Log Latency - optional </h4></p>
925<p>
926 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 at most one (first incoming) observation or correction to Broadcast Ephemeris 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 the latencies available from the 'Latency' tab on the bottom of the main window represent individual latencies and not the mean latencies for the logfile.
927</p>
928<p>
929<u>Latency:</u> Latency is defined in BNC by the following equation:
930</p>
931<pre>
932 UTC time provided by BNC's host
933 - GPS time of currently processed epoch
934 + Leap seconds between UTC and GPS time
935 --------------
936 = Latency
937</pre>
938<p>
939<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.
940</p>
941<p>
942Latencies 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:
943</p>
944<pre>
94508-03-17 15:59:47 BRUS0: Mean latency 1.47 sec, min 0.66, max 3.02, rms 0.35, 3585 epochs, 15 gaps
946</pre>
947<p>
948Select 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.
949</p>
950
951
952<p><a name="miscscan"><h4>3.10.3 Scan RTCM - optional</h4></p>
953<p>
954When configuring a GNSS receiver for RTCM stream generation, the setup interface may not provide details about RTCM message 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. The idea for this option arose from 'InspectRTCM', a comprehensive stream analyzing tool written by D. Stoecker.
955</p>
956<p>
957Tick 'Scan RTCM' to scan RTCM Version 2.x or 3.x streams and log all contained
958</p>
959<ul>
960<li>numbers of incoming message types</li>
961<li>Antenna Reference Point (ARP) coordinates</li>
962<li>Antenna Phase Center (APC) coordinates</li>
963<li>antenna height above marker</li>
964<li>antenna descriptor.</li>
965</ul>
966</p>
967
968<p>
969Note that in RTCM Version 2.x 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.
970</p>
971<p>
972
973<p>Logged time stamps refer to message reception time and allow to understand 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.
974</p>
975<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.
976</p>
977
978<p><a name="pppclient"><h4>3.11. PPP Client</h4></p>
979<p>
980BNC 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 requires pulling in addition
981<ul>
982<li>a stream carrying satellite orbit and clock corrections to Broadcast Ephemeris in the form of 'State Space Representation' (SSR) messages as proposed by RTCM (i.e. premature message type 1060). Note that for BNC these correctors 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 www.igs-ip.net:2101/CLK11 is an example.</li>
983<li>a stream carrying Broadcast Ephemeris available as RTCM Version 3 message types 1019 and 1020. This is a must when the stream coming from the receiver does not contain Broadcast Ephemeris or provides them only at low repetition rate. Streams providing such messages are listed on <u>http://igs.bkg.bund.de/ntrip/ephemeris</u>. Stream www.igs-ip.net:2101/RTCM3EPH is an example.</li>
984</ul>
985</p>
986<p>
987The following figure provides the screenshot of an example PPP session with BNC.
988</p>
989<p><img src="IMG/screenshot03.png"/></p>
990<p><u>Figure:</u> Precise Point Positioning (PPP) with BNC.</p>
991
992<p>
993PPP 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):
994<pre>
99509-12-15 22:30:39 PPP CAS10 22:30:44.0 9 -901775.887 +- 0.058 2409382.427 +- 0.046 -5816746.721 +- 0.087
996</pre>
997</p>
998<p>
999The 'PPP' string in that is followed by the selected mounpoint, 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 an 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.
1000</p>
1001
1002<p>
1003More detailed PPP results are saved in BNC's logfile. Depending on the selected processing options you find
1004<ul>
1005<li>code and phase residuals for GPS and GLONASS in [m], </li>
1006<li>receiver clock errors in [m], </li>
1007<li>a-priori and correction values of tropospheric zenith delay in [m],
1008<li>L3 biases, also known as 'floated ambiguities', given per satellite.
1009</ul>
1010These parameters are saved together with their standard deviation. Example extract from a log file:
1011<pre>
101210-01-07 15:18:02
1013residuals code 0.778 -0.608 -1.269 1.697
1014residuals phase 0.002 0.001 -0.002 -0.002
1015residuals glo -0.000 0.000 0.001
1016
1017 clk = 112578.741 +- 9.345
1018 trp = 2.339 +0.000 +- 0.010
1019 amb G11 = -1.762 +- 3.590
1020 amb G19 = -18.195 +- 5.386
1021 amb G23 = 1.316 +- 4.843
1022 amb G32 = 9.299 +- 3.920
1023 amb R01 = -146.297 +- 4.568
1024 amb R02 = -146.738 +- 15.037
1025 amb R17 = -156.881 +- 13.671
1026</pre>
1027</p>
1028
1029<p>
1030Note that BNC's 'PPP Client' option can also be used in 'Offline Mode'. Apply the 'Offline Mode' command line options for that to read a file containing synchronized observations, orbit and clock corretors, and broadcast ephemeris. Such a file can be generated using BNC's 'Raw Output File' option. The first five characters of the file name read in 'Offline Mode' must then be the same as the specified PPP 'Mounpoint': If you produce a 'Raw Output File' named 'FFMJ1' then the PPP 'Mountpoint' needs to be also specified as 'FFMJ1' and the command line to execute BNC on a Windows system in 'Offline Mode' could look like:
1031</p>
1032
1033<p>
1034bnc.exe --conf c:\temp\BNC.ppp --file c:\temp\FFMJ1 --date 2010-03-27 --time 06:58:00 --format RTCM_3
1035</p>
1036
1037<p><a name="pppmount"><h4>3.11.1 Mountpoint - optional</h4></p>
1038<p>
1039Specify a mountpoint if you want BNC to derive coordinates for the affected rover position through a Point Positioning solution.
1040</p>
1041<p>
1042Furthermore, specify the Point Positioning method you want to apply. Options are
1043<ul>
1044<li> Precise Point Positioning (PPP, default), and </li>
1045<li> Single Point Positioning (SPP).</li>
1046</ul>
1047Note that a plain SPP solution does not require to pull a stream carrying Broadcast Ephemeris Corrections. It only needs Broadcast Ephemeris.
1048</p>
1049
1050<p><a name="pppopt"><h4>3.11.2 Options</h4></p>
1051BNC allows to use different Point Positioning processing options depending on the capability of the involved receiver and the application in mind.
1052</p>
1053
1054<p><a name="pppstatic"><h4>3.11.2.1 Static - optional</h4></p>
1055<p>
1056By default BNC considers the rover as mobile. It means that the rover coordinates are estimated as stochastic parameters with white noise 100 meters per epoch. Tick 'Static' in a static observation situation to adapt appropriate filter characteristics for that.
1057</p>
1058
1059<p><a name="pppphase"><h4>3.11.2.2 Use Phase Obs - optional</h4></p>
1060<p>
1061By 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.
1062</p>
1063
1064<p><a name="ppptropo"><h4>3.11.2.3 Estimate Tropo - optional</h4></p>
1065<p>
1066BNC estimates the tropospheric delay according to equation
1067<pre>
1068T(z) = T_apr(z) + dT / cos(z)
1069</pre>
1070where T_apr is the a-priori tropospheric delay derived from Saastamoinen model.
1071</p>
1072<p>
1073By default BNC does not estimate troposphere parameters. Tick 'Estimate tropo' to estimate troposphere parameters together with the coordinates and save T_apr and dT in BNC's log file.
1074</p>
1075
1076<p><a name="pppglo"><h4>3.11.2.4 Use GLONASS - optional</h4></p>
1077<p>
1078By default BNC does not process GLONASS observations when in Point Positioning mode. Tick 'Use GLONASS' to use GPS and GLONASS observations for estimating coordinates in Point Positioning mode.
1079</p>
1080
1081<p><a name="pppnmearef"><h4>3.11.3 Plot Origin - optional</h4></p>
1082<p>
1083Select an origin for North/East/Up time series plots of derived coordinates in the 'PPP Plot' tab. Note that this makes only sense for a stationary receiver. Available options are
1084<ul>
1085<li>'No plot', meaning that BNC not plot a time series of estimated position.
1086<li>'Start position', meaning that BNC will refer time series plots to the first estimated position.
1087</li>
1088<li>'X Y Z', meaning the known reference coordinate components for the receiver's position.
1089</li>
1090</ul>
1091Default is the selection of an empty option field meaning that no PPP time series will be plotted in the "PPP Plot' tab..
1092</p>
1093<p>
1094If option 'X Y Z' is selected, the following line (example) is recorded in BNC's logfile
1095</p>
1096<pre>
109710-03-12 09:25:25 FFMJ1: NEU 09:25:24.0 8 -0.042 -0.084 0.026
1098</pre>
1099<p>
1100The 'NEU' string in that is followed by a PPP time stamp in GPS Time, the number of processed satellites, and the Nort, East and Up value of the current displacement in meter.
1101</p>
1102
1103<p><a name="pppnmeaout"><h4>3.11.4 NMEA</h4></p>
1104<p>
1105BNC allows to output results from Point Positioning in NMEA format. The NMEA messages generated are
1106<ul>
1107<li> one leading GPRMC message which carries only date and time information, plus</li>
1108<li> about once per second a GPGGA message which mainly carries the estimated latitude, longitude, and height values.</li>
1109</ul>
1110</p>
1111
1112<p><a name="pppnmeafile"><h4>3.11.4.1 File - optional</h4></p>
1113<p>
1114Specify the full path to a file where Point Positioning results are saved as NMEA messages. The generated NMEA file begins with a single GPRMC message which carries only date and time information. The default value for 'File (full path)' is an empty option field, meaning that BNC will not saved NMEA messages into a file.
1115</p>
1116
1117<p><a name="pppnmeaport"><h4>3.11.4.2 Port - optional</h4></p>
1118<p>
1119Specify the IP port number of a local port where Point Positioning results become available as NMEA messages. The default value for 'Port' is an empty option field, meaning that BNC does not provide NMEA messsages vi IP port. Note that the NMEA file output and the NMEA IP port output are the same.
1120</p>
1121
1122<p><a name="streams"><h4>3.12. Streams</h4></p>
1123<p>
1124Each stream on an NTRIP broadcaster (and consequently on BNC) is defined using a unique source ID called mountpoint. An NTRIP client like BNC access the desired data 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.
1125</p>
1126
1127<p>
1128Streams selected for retrieval are listed under the 'Streams' canvas section 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:
1129</p>
1130<p>
1131<table>
1132<tr><td>'resource loader'&nbsp; </td><td>NTRIP broadcaster URL and port, or<br>TCP/IP host and port, or<br>Serial input port specification.</td></tr>
1133<tr><td>'mountpoint' &nbsp;</td><td>Mountpoint introduced by NTRIP broadcaster, or<br>Mountpoint introduced by BNC's user.</td></tr>
1134<tr><td>'decoder' &nbsp;</td><td>Type of decoder used to handle the incoming stream content according to its format; editable.</td></tr>
1135<tr><td>'lat' &nbsp;</td><td>Approximate latitude of reference station, in degrees, north; editable if 'nmea' = 'yes'.</td></tr>
1136<tr><td>'long' &nbsp;</td><td>Approximate longitude of reference station, in degrees, east; editable if 'nmea' = 'yes'.</td></tr>
1137<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>
1138<tr><td>'ntrip' &nbsp;</td><td>Selected NTRIP transport protocol version (1, 2, 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>
1139<tr><td>'bytes' &nbsp;</td><td>Number of bytes received.
1140</table>
1141</p>
1142
1143<p><a name="streamedit"><h4>3.12.1 Edit Streams</h4></p>
1144<ul>
1145<li>
1146BNC 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 'RTIGS'.
1147</li>
1148<li>
1149In 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.
1150</li>
1151<li>
1152BNC 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 a 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.
1153<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.
1154<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.
1155</li>
1156</ul>
1157
1158<p><a name="streamdelete"><h4>3.12.2 Delete Stream</h4></p>
1159<p>
1160To 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>
1161
1162<p><a name="streamconf"><h4>3.12.3 Reconfigure Streams On-the-fly</h4></p>
1163<p>
1164The streams selection can be changed on-the-fly without interrupting uninvolved threads in the running BNC process.
1165</p>
1166<p>
1167<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.
1168<p>
1169<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 Example' for a configuration file example and a list of other on-the-fly changeable options.
1170</p>
1171
1172<p><a name="logs"><h4>3.13. Logging</h4></p>
1173<p>
1174A 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 consumtion, for a plot showing stream latencies, and for time series plots of PPP results.
1175</p>
1176<p><a name="logfile"><h4>3.13.1 Log</h4></p>
1177<p>
1178Records 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.
1179</p>
1180
1181<p><a name="throughput"><h4>3.13.2 Throughput</h4></p>
1182<p>
1183The 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 the bandwidth comsumption of incoming streams.
1184</p>
1185
1186<p>
1187</p>
1188<p><img src="IMG/screenshot08.png"/></p>
1189<p><u>Figure:</u> Bandwidth consumption of incoming streams.</p>
1190
1191<p><a name="latency"><h4>3.13.3 Latency</h4></p>
1192<p>
1193The 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 read color. Note that the calculation of correct latencies requires the clock of the host computer to be properly synchronized. The next figure shows the latency of incoming streams.
1194</p>
1195
1196<p>
1197</p>
1198<p><img src="IMG/screenshot07.png"/></p>
1199<p><u>Figure:</u> Latency of incoming streams.</p>
1200
1201<p><a name="ppptab"><h4>3.13.4 PPP Plot</h4></p>
1202<p>
1203Precise Point Positioning time series of North (red), East (green) and Up (blue) coordinate components are shown in the 'PPP Plot' tab when a 'Plot 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 coordiate components.
1204</p>
1205
1206<p>
1207</p>
1208<p><img src="IMG/screenshot13.png"/></p>
1209<p><u>Figure:</u> Time series plot of PPP session.</p>
1210
1211<p><a name="bottom"><h4>3.14. Bottom Menu Bar</h4></p>
1212<p>
1213The 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.
1214</p>
1215
1216<p><a name="streamadd"><h4>3.14.1 Add Stream - Coming from Caster</h4></p>
1217
1218<p>
1219Button 'Add Stream' opens a window that allows user to select one of several input communication links, see figure below.
1220</p>
1221<p><img src="IMG/screenshot06.png"/></p>
1222<p><u>Figure:</u> Steam input communication links.</p>
1223
1224<p>
1225Button '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.
1226</p>
1227
1228<p><a name="streamhost"><h4>3.14.1.1 Caster Host and Port - mandatory</h4></p>
1229<p>
1230Enter 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> and <u>http://www.igs-ip.net/home</u>.
1231</p>
1232
1233<p><a name="streamtable"><h4>3.14.1.2 Casters Table - optional</h4></p>
1234<p>
1235It may be that your 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 to select a broadcaster for stream retrieval, see figure below.
1236</p>
1237</p>
1238<p><img src="IMG/screenshot04.png"/></p>
1239<p><u>Figure:</u> Casters table.</p>
1240
1241<p><a name="streamuser"><h4>3.14.1.3 User and Password - mandatory for protected streams</h4></p>
1242<p>
1243Some 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 on <u>www.euref-ip.net</u> and <u>www.igs-ip.net</u>.
1244</p>
1245
1246<p><a name="gettable"><h4>3.14.1.4 Get Table</h4></p>
1247<p>
1248Use 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.x, RTCM Version 3.x, or RTIGS format. RTCM Version 2.x streams must contain message types 18 and 19 or 20 and 21 while RTCM Version 3.x streams must contain GPS or SBAS message types 1002 or 1004 and may contain GLONASS message types 1010 or 1012, see 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.x streams containing message types 1019 (GPS) and 1020 (GLONASS) are required. Select your streams line by line, use +Shift and +Ctrl when necessary. The figure below provides an example source-table.
1249</p>
1250<p>
1251The 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).
1252</p>
1253<p>
1254Hit '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.
1255</p>
1256</p>
1257</p>
1258<p><img src="IMG/screenshot05.png"/></p>
1259<p><u>Figure:</u> Broadcaster source-table.</p>
1260
1261<p><a name="ntripv"><h4>3.14.1.5 NTRIP Version - mandatory</h4></p>
1262<p>
1263Some 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:
1264</p>
1265<p>
1266&nbsp; 1:&nbsp; NTRIP version 1, TCP/IP.<br>
1267&nbsp; 2:&nbsp; NTRIP version 2 in TCP/IP mode.<br>
1268&nbsp; R:&nbsp; NTRIP version 2 in RTSP/RTP mode.<br>
1269&nbsp; U:&nbsp; NTRIP version 2 in UDP mode.
1270</p>
1271<p>
1272If NTRIP version 2 is supported by the broadcaster:
1273</p>
1274<ul>
1275<li>Try using option '2' if your streams are otherwise blocked by a proxy server operated in front of BNC.</li>
1276<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>
1277</ul>
1278<p>
1279Select option '1' if you are not sure whether the broadcaster supports NTRIP version 2.</li>
1280</p>
1281
1282<p><a name="streamip"><h4>3.14.2 Add Stream - Coming from TCP/IP Port</h4></p>
1283<p>
1284Button '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:
1285<ul>
1286<li>Enter the IP address of the stream providing host.</li>
1287<li>Enter the IP port number of the stream providing host.</li>
1288<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
1289<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTIGS', and 'ZERO'.</li>
1290<li>Enter the approximate latitude of the stream providing rover in degrees. Example: 45.32.</li>
1291<li>Enter the approximate longitude of the stream providing rover in degrees. Example: -15.20.</li>
1292</ul>
1293</p>
1294<p>
1295Streams directly received from a TCP/IP port show up with an 'N' for 'No NTRIP' in the 'Streams' canvas section on BNC's main window . Latitude and longitude are to be entered just for informal reasons.
1296<p>
1297</p>
1298Note that this option works only if no proxy server is involved in the communication link.
1299</p>
1300
1301<p><a name="streamudp"><h4>3.14.3 Add Stream - Coming from UDP Port</h4></p>
1302<p>
1303Button '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:
1304<ul>
1305<li>Enter the local port number where the UDP stream arrives.</li>
1306<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
1307<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTIGS', and 'ZERO'.</li>
1308<li>Enter the approximate latitude of the stream providing rover in degrees. Example: 45.32.</li>
1309<li>Enter the approximate longitude of the stream providing rover in degrees. Example: -15.20.</li>
1310</ul>
1311</p>
1312<p>
1313Streams 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.
1314<p>
1315
1316<p><a name="streamser"><h4>3.14.4 Add Stream - Coming from Serial Port</h4></p>
1317<p>
1318Button '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:
1319<ul>
1320<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
1321<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTIGS', and 'ZERO'.</li>
1322<li>Enter the approximate latitude of the stream providing receiver in degrees. Example: 45.32.</li>
1323<li>Enter the approximate longitude of the stream providing receiver in degrees. Example: -15.20.</li>
1324<li>Enter the serial 'Port name' selected on your host for communication with the receiver. Valid port names are
1325<pre>
1326Windows: COM1, COM2
1327Linux: /dev/ttyS0, /dev/ttyS1
1328FreeBSD: /dev/ttyd0, /dev/ttyd1
1329Digital Unix: /dev/tty01, /dev/tty02
1330HP-UX: /dev/tty1p0, /dev/tty2p0
1331SGI/IRIX: /dev/ttyf1, /dev/ttyf2
1332SunOS/Solaris: /dev/ttya, /dev/ttyb
1333</pre>
1334</li>
1335<li>Select a 'Baud rate' for the serial input. Note that using a high baud rate is recommended.</li>
1336<li>Select the number of 'Data bits' for the serial input. Note that often '8' data bits are used.</li>
1337<li>Select the 'Parity' for the serial input. Note that parity is often set to 'NONE'.</li>
1338<li>Select the number of 'Stop bits' for the serial input. Note that often '1' stop bit is used.</li>
1339<li>Select a 'Flow control' for the serial link. Select 'OFF' if you don't know better.</li>
1340</ul>
1341</p>
1342<p>
1343When selecting the serial communication options listed above, make sure that you pick those configured to the serial connected GNSS receiver.
1344</p>
1345
1346<p>
1347Streams 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.
1348<p>
1349
1350<p><a name="start"><h4>3.14.5 Start</h4></p>
1351<p>
1352Hit 'Start' to start retrieving, decoding, and 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.
1353</p>
1354
1355<p><a name="stop"><h4>3.14.6 Stop</h4></p>
1356<p>
1357Hit the 'Stop' button in order to stop BNC.
1358</p>
1359
1360<p><a name="cmd"><h4>3.15. Command Line Options</h4></p>
1361<p>
1362Command line options are available to run BNC in 'no window' mode or let it read data from a file in offline mode. BNC will then use processing options from the 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.ini'.
1363</p>
1364
1365<p><a name="nw"><h4>3.15.1 No Window Mode - optional</h4></p>
1366<p>
1367Apart from its regular windows mode, BNC can be started on all systems as a background/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.
1368</p>
1369<p>
1370Example:<br><br>
1371bnc.exe -nw
1372</p>
1373
1374<p><a name="post"><h4>3.15.2 Offline Mode - optional</h4></p>
1375<p>
1376Although BNC is primarily a real-time online tool, it can be run in offline mode to read data from a file for post-processing purposes. Enter the following four command line options for that:
1377</p>
1378<p>
1379<ul>
1380<li>'--file &#060;<u>inputFileName</u>&#062;' to enter the full path to an input file containing data in RTCM Version 2.x, or Version 3.x, or RTIGS/SOC format.</li>
1381<li>'--format &#060;<u>format</u>&#062;' to enter one of the file format describing strings 'RTCM_2', 'RTCM_3' or 'RTIGS'.</li>
1382<li>'--date YYYY-MM-DD' to enter a date for the first epoch.</li>
1383<li>'--time HH:MM:SS' to enter a time for the first epoch.</li>
1384</ul>
1385<p>
1386Example:<br><br>
1387./bnc --file FFMJ.dat --format RTCM_3 --date 2008-10-27 --time 23:12:56
1388</p>
1389<p>
1390Note that it is necessary to define a date and time for the first epoch because RTCM streams do not contain complete time stamps as needed i.e. for RINEX files or for PPP in post-processing mode. Note further that when running BNC in offline mode, it will use options for file saving, interval, sampling etc. from its configuration file.
1391</p>
1392
1393<p><a name="conffile"><h4>3.15.3 Configuration File - optional</h4></p>
1394The default configuration file name is 'BNC.ini'. You may change this name at startup time using the command line option '--conf &#060;<u>confFileName</u>&#062;'. This allows to run 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.
1395</p>
1396<p>
1397Example:<br><br>
1398./bnc --conf MyConfig.ini
1399</p>
1400<p>
1401This leads to a BNC job using configuration file 'MyConfig.ini'. The configuration file will be saved in the current working directory.
1402</p>
1403
1404<p><a name="limits"><h3>4. Limitations</h3></p>
1405<ul>
1406<li>
1407In 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.
1408</li>
1409<li>
1410Currently BNC only handles GPS, SBAS and GLONASS data. Galileo is not yet supported.
1411</li>
1412<li>
1413BNC currently will only handle C1, C2, P1, P2, L1, L2, S1, and S2 observations as well as the cumulative loss of continuity and lock time indicators. Which observables and indicators are available on a particular stream will depend on the setup of source receiver and the data format used. RTCM Version 2.x streams do not carry signal-to-noise ratio 'S' values while RTCM Version 3.x streams can only transport one code observable per frequency. Note that signal-to-noise ratios 'S' are also logged mapped to integer numbers 1 to 9.
1414</li>
1415<li>
1416Using RTCM Version 3.x, BNC will properly handle message types 1002, 1004, 1010, and 1012. Note that 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).
1417</li>
1418Concerning the RTCM Version 3.x premature message types 1057-1068 (see RTCM document 091-2009-SC104-542 'Version 3 Proposed Messages â&#8364;&#8220; Set 10'), a final decision is not yet made. Note the what's implemented in BNC is just a temporary solutions.
1419<li>
1420Using RTCM Version 2.x, 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.x stream carrying message types 1019 (GPS ephemeris) and 1020 (GLONASS ephemeris).
1421</li>
1422<li>
1423Streams coming in RTIGS format carry only GPS data.
1424</li>
1425<li>
1426BNC'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.
1427</li>
1428<li>
1429EUREF as well as IGS adhere to an open data policy. Streams are made available through NTRIP broadcasters at <u>www.euref-ip.net</u> and <u>www.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.
1430</li>
1431<li>
1432We experienced a limitation of the Standard Version of Microsoft Windows related to socket communication where sockets are not always handled properly. Since BNC makes intensive use of communication through sockets, we recommend to use the Server Version of Microsoft Windows when running BNC continuously for extended on a Windows platform.
1433</li>
1434<li>
1435The source code provided by NRCan for decoding RTIGS streams is 32-bit dependent. Hence the BNC executable generated for 64-bit Linux systems would only run when compiled using the -m32 compiler option.
1436</li>
1437<li>
1438Once 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.
1439</li>
1440<br>
1441</ul>
1442<p><a name="authors"><h3>5. Authors</h3></p>
1443<p>
1444The BKG Ntrip Client (BNC) Qt Graphic User Interface (GUI) has been developed for the Federal Agency for Cartography and Geodesy (BKG) by Leos Mervart, Czech Technical University Prague, Department of Geodesy. BNC includes the following GNU GPL software components:
1445<ul>
1446<li> RTCM 2.x decoder, written by Oliver Montenbruck, German Space Operations Center, DLR, Oberpfaffenhofen</li>
1447<li> RTCM 3.x decoder, written for BKG by Dirk Stoecker, Alberding GmbH, Schoenefeld</li>
1448<li> RTIGS decoder, written by Ken MacLeod, Natural Resources, Canada.</li>
1449</ul>
1450</p>
1451<p>
1452Georg Weber<br>
1453Federal Agency for Cartography and Geodesy (BKG)<br>
1454Frankfurt, Germany<br>
1455[euref-ip@bkg.bund.de] or [igs-ip@bkg.bund.de]
1456</p>
1457<p>
1458<b>Acknowledgements</b><br>
1459BNC's Help Contents has been proofread by Thomas Yan, University of New South Wales, Australia.<br>
1460Scott Glazier, OmniSTAR Australia, included the decoding of broadcast ephemeris from RTIGS streams and has been helpful in finding BNC's bugs.<br>
1461James Perlt, BKG, helped fixing bugs and redesigned BNC's main window.<br>
1462Andre Hauschild, German Space Operations Center, DLR, revised the RTCMv2 decoder.<br>
1463Zdenek Lukes, Czech Technical University Prague, Department of Geodesy, extended the RTCMv2 decoder to handle message types 3, 20, 21, and 22 and added loss of lock indicator.<br>
1464</p>
1465
1466<p><a name="annex"><h3>6. Annex</h3></p>
1467<p>
14686.1. <a href=#history>Revision History</a><br>
14696.2. <a href=#rtcm>RTCM</a><br>
1470&nbsp; &nbsp; &nbsp; 6.2.1 NTRIP <a href=#ntrip1>Version 1</a><br>
1471&nbsp; &nbsp; &nbsp; 6.2.2 NTRIP <a href=#ntrip2>Version 2</a><br>
1472&nbsp; &nbsp; &nbsp; 6.2.3 RTCM <a href=#rtcm2>Version 2.x</a><br>
1473&nbsp; &nbsp; &nbsp; 6.2.4 RTCM <a href=#rtcm3>Version 3.x</a><br>
14746.3. <a href=#rtigs>RTIGS</a><br>
1475&nbsp; &nbsp; &nbsp; 6.3.1 <a href=#soc>SOC</a><br>
14766.4. <a href=#config>Configuration Example</a><br>
14776.5. <a href=#links>Links</a><br>
1478</p>
1479
1480<p><a name=history><h3>6.1 Revision History</h3></p>
1481<table>
1482<tr></tr>
1483
1484<tr>
1485<td>Dec 2006 &nbsp;</td><td>Version 1.0b &nbsp;</td>
1486<td>[Add] First Beta Binaries published based on Qt 4.2.3.</td>
1487</tr>
1488
1489<tr>
1490<td>Jan 2007 &nbsp;</td><td>Version 1.1b &nbsp;</td>
1491<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>
1492</tr>
1493
1494<tr>
1495<td>Apr 2007 &nbsp;</td><td>Version 1.2b &nbsp;</td>
1496<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>
1497</tr>
1498
1499<tr>
1500<td>May 2007 &nbsp;</td><td>Version 1.3 &nbsp;</td>
1501<td>[Add] Source code published.</td>
1502</tr>
1503
1504<tr>
1505<td>Jul 2007 &nbsp;</td><td>Version 1.4 &nbsp;</td>
1506<td>[Bug] Skip messages from proxy server<br> [Bug] Call RINEX script through 'nohup'</td>
1507</tr>
1508
1509<tr>
1510<td>Apr 2008 &nbsp;</td><td>Version 1.5 &nbsp;</td>
1511<td>[Add] Handle ephemeris from RTCM Version 3.x 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 systems<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>
1512</tr>
1513
1514<tr>
1515<td>Dec 2008 &nbsp;</td><td>Version 1.6 &nbsp;</td>
1516<td>[Mod] Fill blanc columns in RINEXv3 with 0.000<br> [Add] RTCMv3 decoder for clock and orbit 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 excentricities from RTCMv3<br> [Add] Reconfiguration on-the-fly<br> [Mod] Binary ouput of synchronized observations<br> [Add] Binary output of unsynchronized observations<br> [Bug] Fixed problem with joined RTCMv3 blocks</td>
1517</tr>
1518
1519<tr>
1520<td>Dec 2008 &nbsp;</td><td>Version 1.6.1 &nbsp;</td>
1521<td>[Mod] HTTP GET when no proxy in front</td>
1522</tr>
1523
1524<tr>
1525<td>Nov 2009 &nbsp;</td><td>Version 1.7 &nbsp;</td>
1526<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>
1527</tr>
1528
1529<tr>
1530<td>Nov 2009 &nbsp;</td><td>Version 1.8 &nbsp;</td>
1531<td>[Mod] On-the-fly reconfiguration of latency and throughput plots</td>
1532</tr>
1533
1534<tr>
1535<td>Feb 2010 &nbsp;</td><td>Version 2.0 &nbsp;</td>
1536<td>[Mod] Change sign of Broadcast Ephemeris correctors<br> [Add] Real-time PPP option</td>
1537</tr>
1538
1539<tr>
1540<td>April 2010 &nbsp;</td><td>Version 2.1 &nbsp;</td>
1541<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</td>
1542</tr>
1543
1544</table>
1545</p>
1546
1547<p><a name="rtcm"><h4>6.2. RTCM</h4></p>
1548
1549<p>
1550The 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.
1551<p>
1552Personal copies of RTCM Recommended Standards can be ordered through <u>http://www.rtcm.org/orderinfo.php</u>.
1553</p>
1554
1555<p><a name="ntrip1"><h4>6.2.1 NTRIP Version 1</h4></p>
1556
1557<p>
1558'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.
1559</p>
1560
1561<p>
1562NTRIP Version 1.0 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.
1563</p>
1564
1565<p>
1566NTRIP 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.
1567</p>
1568
1569<p>
1570NTRIP is an open none-proprietary protocol. Major characteristics of NTRIP's dissemination technique are:
1571<ul>
1572<li>Based on the popular HTTP streaming standard; comparatively easy to implement when having limited client and server platform resources available.</li>
1573<li>Application not limited to one particular plain or coded stream content; ability to distribute any kind of GNSS data.</li>
1574<li>Potential to support mass usage; disseminating hundreds of streams simultaneously for thousands of users possible when applying modified Internet Radio broadcasting software.</li>
1575<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>
1576<li>Enables streaming over mobile IP networks because of using TCP/IP.</li>
1577</ul>
1578</p>
1579
1580<p>
1581The 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).
1582</p>
1583
1584<p>
1585Source-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'.
1586</p>
1587<p>
1588Source-table records of type NET contain the following data fields: 'identifiey', 'operator', 'authentication', 'fee', 'web-net', 'web-str', 'web-reg', 'misc'.
1589</p>
1590<p>
1591Source-table records of type CAS contain the following data fields: 'host', 'port', 'identifier', 'operator', 'nmea', 'country', 'latitude', 'longitude', 'misc'.
1592</p>
1593
1594<p><a name="ntrip2"><h4>6.2.1 NTRIP Version 2</h4></p>
1595
1596<p>
1597The major changes of NTRIP version 2.0 compared to version 1.0 are:
1598</p>
1599
1600<ul>
1601<li>cleared and fixed design problems and HTTP protocol violations;</li>
1602<li>replaced non standard directives;</li>
1603<li>chunked transfer encoding;</li>
1604<li>improvements in header records;</li>
1605<li>source-table filtering; and</li>
1606<li>RTSP communication.</li>
1607</ul>
1608
1609<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.
1610</p>
1611
1612<p><a name="rtcm2"><h4>6.2.3 RTCM Version 2.x</h4></p>
1613<p>
1614Transmitting GNSS carrier phase data can be done through RTCM Version 2.x messages. Please note that only RTCM Version 2.2 and 2.3 streams may include GLONASS data. Messages that may be of some interest here are:
1615</p>
1616
1617<ul>
1618<li>
1619Type 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.
1620</li>
1621<li>
1622Type 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.
1623</li>
1624<li>
1625Type 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.
1626</li>
1627<li>
1628Type 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.
1629</li>
1630<li>
1631Type 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.
1632</li>
1633<li>
1634Type 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.
1635</li>
1636<li>
1637Type 18 and 20 messages are RTK uncorrected carrier phase data and carrier phase corrections.
1638</li>
1639<li>
1640Type 19 and 21 messages are the uncorrected pseudo-range measurements and pseudo-range corrections used in RTK.
1641</li>
1642<li>
1643Type 23 message provides the information on the antenna type used on the reference station.
1644</li>
1645<li>
1646Type 24 message carries the coordinates of the installed antenna's ARP in the GNSS coordinate system coordinates.
1647</li>
1648</ul>
1649
1650<p><a name="rtcm3"><h4>6.2.4 RTCM Version 3.x</h4></p>
1651<p>
1652RTCM Version 3.x has been developed as a more efficient alternative to RTCM Version 2.x. 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.x standard is intended to correct these weaknesses.
1653</p>
1654<p>
1655RTCM Version 3.x defines a number of message types. Messages that may be of interest here are:
1656</p>
1657<ul>
1658<li>Type 1001, GPS L1 code and phase.</li>
1659<li>Type 1002, GPS L1 code and phase and ambiguities and carrier to noise ratio.</li>
1660<li>Type 1003, GPS L1 and L2 code and phase.</li>
1661<li>Type 1004, GPS L1 and L2 code and phase and ambiguities and carrier to noise ratio.</li>
1662<li>Type 1005, Station coordinates XZY for antenna reference point.</li>
1663<li>Type 1006, Station coordinates XYZ for antenna reference point and antenna height.</li>
1664<li>Type 1007, Antenna descriptor and ID.</li>
1665<li>Type 1008, Antenna serial number.</li>
1666<li>Type 1009, GLONASS L1 code and phase.</li>
1667<li>Type 1010, GLONASS L1 code and phase and ambiguities and carrier to noise ratio.</li>
1668<li>Type 1011, GLONASS L1 and L2 code and phase.</li>
1669<li>Type 1012, GLONASS L1 and L2 code and phase and ambiguities and carrier to noise ratio.</li>
1670<li>Type 1013, Modified julian date, leap second, configured message types and interval.</li>
1671<li>Type 1014 and 1017, Network RTK (MAK) messages (under development).</li>
1672<li>Type 1019, GPS ephemeris.</li>
1673<li>Type 1020, GLONASS ephemeris.</li>
1674<li>Type 4088 and 4095, Proprietary messages (under development).
1675</li>
1676</ul>
1677
1678<p><a name="rtigs"><h4>6.3. RTIGS</h4></p>
1679<p>
1680RTIGS stands for a data format and transport protocol for GPS observations. It was defined by the Real-Time IGS Working Group (RTIGS WG). Its definition is based on the SOC format. Every RTIGS record has one of the following numbers:
1681</p>
1682<p>
1683Station record number 100<br>
1684Observation record (O_T) number 200<br>
1685Ephemeris record (E_T) number 300<br>
1686Meteorological record (M_T) number 400
1687</p>
1688<p>
1689Every station has one of the following unique numbers:
1690</p>
1691<p>
16921-99 reserved for JPL<br>
1693100-199 reserved for NRCan<br>
1694200-299 reserved for NGS<br>
1695300-399 reserved for ESOC<br>
1696400-499 reserved for GFZ<br>
1697500-599 reserved for BKG<br>
1698600-699 reserved for GEOSCIENCE AUS<br>
1699700-799 others<br>
1700etc
1701</p>
1702<p>
1703The number of bytes in each real time message includes the header as well as the data content, but NOT the pointer.
1704</p>
1705<p>
1706For example:
1707</p>
1708<ul>
1709<li>A station message is output once per hour and is 20 bytes.</li>
1710<li>An observation message is output once per second. The header is 12 bytes long and the SOC data is 21 bytes per PRN. So a typical RTIGSO_T message will be 390 bytes if 8 sats are being tracked.</li>
1711<li>An ephemeris message is output when the ephemeris is decoded by the GPS receiver. The time in the ephemeris header is the collected time. Only one ephemeris can be bundled in a RTIGSE_T message.<br>
1712A RTIGSE_T message contains one eph. The message consists of 12 header bytes and 72 ephemeris bytes, for a total of 84 bytes.</li>
1713<li>The RTIGSM_T (met) message should be issued once every 15 minutes. A basic met message consists of a 12 byte header and 3 longs (temp, press and relative humidity) for a total of 24 bytes.</li>
1714</ul>
1715<p>
1716All records are related to a station configuration indicated by the Issue of Data Station (IODS). The IODS will enable the user to identify the equipment and software that was used to derive the observation data.
1717</p>
1718<p>
1719Each record header contains the GPS Time in seconds which flows continuously from 6 Jan-1980 onwards.
1720</p>
1721<p>
1722The data payload of each record consists of observations. The structures indicate a pointer to data but in fact the broadcast messages do not contain the pointer, only the data. Users will have to manage the data and the pointer is shown in order to illustrate where the data is located in the message and one possible data management option.
1723</p>
1724<p>
1725All record data are in network byte order (Big Endian), i.e. IA32 users have to swap bytes.
1726</p>
1727<p>
1728Visit <u>http://igscb.jpl.nasa.gov/mail/igs-rtwg/2004/msg00001.html</u> for further details.
1729</p>
1730
1731<p><a name="soc"><h4>6.3.1 SOC</h4></p>
1732<p>
1733The SOC format has been designed in July 1999 by the Jet Propulsion Laboratory (JPL) and the California Institute of Technology (CalTech) to transport 1Hz GPS data with minimal bandwidth over the open Internet. SOC follows the 'little-endian' byte order meaning that the low-order byte of a number is stored in memory at the lowest address, and the high-order byte at the highest address. Because the transport layer is UDP, the format does not include sync bits, a checksum, or cyclic redundancy checksum (CRC). SOC allows to transport the GPS observable CA, P1, P2, L1, and L2, efficiently compressed down to 14 bytes with 1 mm range resolution and 0.02 mm phase resolution. SOC contains epochs for cycle slips, a stand-alone time-tag per epoch, a minimum representation of the receiver's clock solution, 3 SNR numbers, a unique site id, a modulo 12 hour sequence number and flags for receiver type and GPS health. SOC's simple structure comprises an 8 byte header, a 9 byte overhead for timetag, number of gps, etc., plus 21 data bytes per gps.
1734</p>
1735<p>
1736Visit <u>http://gipsy.jpl.nasa.gov/igdg/papers/SOC_FORMAT.ppt</u> for further details.
1737</p>
1738<p>
1739</p>
1740<p><a name="config"><h4>6.4. Configuration Example</h4></p>
1741<p>
1742The following table's left column is an example for the contents of a configuration file 'BNC.ini'. It enables the retrieval of stream ACOR0 form www.euref-ip.net for the generation of 15 min RINEX files. RINEX files are uploaded to an archive using script 'up2archive' :
1743</p>
1744<table>
1745<tr></tr>
1746<tr><td><b>Option</b></td><td><b>Affiliation</b></td></tr>
1747<tr><td>[General]</td><td>Settings: Group</td></tr>
1748<tr><td>adviseFail=15</td><td>Outages: Failure threshold</td></tr>
1749<tr><td>adviseReco=5</td><td>Outages: Recovery threshold</td></tr>
1750<tr><td>adviseScript=</td><td>Outages: Script (full path)</td></tr>
1751<tr><td>autoStart=0</td><td>General: Auto start</td></tr>
1752<tr><td>binSample=0</td><td>Feed Engine: Sampling</td></tr>
1753<tr><td>casterUrlList=http://user:pass@euref-ip:2101</td><td>Internal memory: Visited URLs</td></tr>
1754<tr><td>corrIntr=1 day</td><td>Broadcast Corrections: Interval</td></tr>
1755<tr><td>corrPath=</td><td>Broadcast Corrections: Directory </td></tr>
1756<tr><td>corrPort=</td><td>Broadcast Corrections: Port</td></tr>
1757<tr><td>corrTime=5</td><td>Broadcast Corrections: Wait for full epoch</td></tr>
1758<tr><td>ephIntr=15 min</td><td>RINEX Ephemeris: Interval</td></tr>
1759<tr><td>ephPath=</td><td>RINEX Ephemeris: Directory</td></tr>
1760<tr><td>ephV3=0</td><td>RINEX Ephemeris: Version 3</td></tr>
1761<tr><td>font=</td><td>Internal memory: Used font</td></tr>
1762<tr><td>logFile=/home/weber/bnc.log</td><td>General: Logfile (full path)</td></tr>
1763<tr><td>rawOutFile=</td><td>General: Raw output file (full path)</td></tr>
1764<tr><td>miscMount=</td><td>Miscellaneous: Mountpoint</td></tr>
1765<tr><td>mountPoints=//user:pass@www.euref-ip.net:2101<br>/ACOR0 RTCM_2.3 43.36 351.60 no 1</td><td>Streams: broadcaster:port/mountpoint</td></tr>
1766<tr><td>ntripVersion=1</td><td>Add Stream: NTRIP Version</td></tr>
1767<tr><td>obsRate=</td><td>Outages: Observation rate</td></tr>
1768<tr><td>onTheFlyInterval=1 day</td><td>General: Reread configuration</td></tr>
1769<tr><td>outEphPort=</td><td>RINEX Ephemeris: Port</td></tr>
1770<tr><td>outFile=</td><td>Feed Engine: File (full path)</td></tr>
1771<tr><td>outPort=</td><td>Feed Engine: Port</td></tr>
1772<tr><td>outUPort=</td><td>Feed Engine: Port (unsynchronized)</td></tr>
1773<tr><td>perfIntr=</td><td>Miscellaneous: Log latency</td></tr>
1774<tr><td>proxyHost=</td><td>Proxy: Proxy host</td></tr>
1775<tr><td>proxyPort=</td><td>Proxy: Proxy port</td></tr>
1776<tr><td>rnxAppend=2</td><td>General: Append files</td></tr>
1777<tr><td>rnxIntr=15 min</td><td>RINEX Observations: Interval</td></tr>
1778<tr><td>rnxPath=/home/user/rinex</td><td>RINEX Observations: Directory</td></tr>
1779<tr><td>rnxSample=0</td><td>RINEX Observations: Sampling</td></tr>
1780<tr><td>rnxScript=/home/user/rinex/up2archive</td><td>RINEX Observations: Script (full path)</td></tr>
1781<tr><td>rnxSkel=</td><td>RINEX Observations: Skeleton extension</td></tr>
1782<tr><td>rnxV3=0</td><td>RINEX Observation: Version 3</td></tr>
1783<tr><td>scanRTCM=0</td><td>Miscellaneous: Scan RTCM</td></tr>
1784<tr><td>serialAutoNMEA=Auto</td><td>Serial Output: NMEA</td></tr>
1785<tr><td>serialBaudRate=9600</td><td>Serial Output: Baud rate</td></tr>
1786<tr><td>serialDataBits=8</td><td>Serial Output: Data bits</td></tr>
1787<tr><td>serialHeightNMEA=</td><td>Serial Output: Height</td></tr>
1788<tr><td>serialMountPoint=</td><td>Serial Output: Mountpoint</td></tr>
1789<tr><td>serialParity=NONE</td><td>Serial Output: Parity</td></tr>
1790<tr><td>serialPortName=</td><td>Serial Output: Port name</td></tr>
1791<tr><td>serialStopBits=1</td><td>Serial Output: Stop bits</td></tr>
1792<tr><td>startTab=0</td><td>Internal memory: Top tab index</td></tr>
1793<tr><td>statusTab=0</td><td>Internal memory: Bottom tab index</td></tr>
1794<tr><td>waitTime=5</td><td>Feed Engine: Wait for full epoch</td></tr>
1795<tr><td>pppMount=</td><td>PPP Client: Mountpoint</td></tr>
1796<tr><td>pppSPP=</td><td>PPP Client: PPP/SPP</td></tr>
1797<tr><td>pppStatic=0</td><td>PPP Client: Static mode</td></tr>
1798<tr><td>pppUsePhase=0</td><td>PPP Client: Use phase data </td></tr>
1799<tr><td>pppEstTropo=0</td><td>PPP Client: Estimate troposphere</td></tr>
1800<tr><td>pppGLONASS=0</td><td>PPP Client: Use GLONASS</td></tr>
1801<tr><td>pppOrigin=</td><td>PPP Client: Origin of time series plot</td></tr>
1802<tr><td>pppRefCrdX=</td><td>PPP Client: X coordinate of plot origin</td></tr>
1803<tr><td>pppRefCrdY=</td><td>PPP Client: Y coordinate of plot origin</td></tr>
1804<tr><td>pppRefCrdZ=</td><td>PPP Client: Z coordinate of plot origin</td></tr>
1805<tr><td>nmeaFile=</td><td>PPP Client: NMEA outputfile</td></tr>
1806<tr><td>nmeaPort=</td><td>PPP Client: NMEA IP output port</td></tr>
1807</table>
1808</p>
1809<p>
1810Note that the following configuration options saved on disk can be changed/edited on-the-fly while BNC is already processing data:
1811</p>
1812<p>
1813<ul>
1814<li>'mountPoints' to change the selection of streams to be processed, see section 'Streams',</li>
1815<li>'waitTime' to change the 'Wait for full epoch' option, see section 'Feed Engine', and</li>
1816<li>'binSampl' to change the 'Sampling' option, see section 'Feed Engine'.</li>
1817</ul>
1818</p>
1819
1820<p><a name="links"><h3>6.5 Links</h3></p>
1821<table>
1822<tr></tr>
1823<tr><td>NTRIP &nbsp;</td><td><u>http://igs.bkg.bund.de/ntrip/about</u></td></tr>
1824<tr><td>EUREF-IP NTRIP broadcaster &nbsp;</td><td><u>http://www.euref-ip.net/home</u></td></tr>
1825<tr><td>IGS-IP NTRIP broadcaster &nbsp;</td><td><u>http://www.igs-ip.net/home</u></td></tr>
1826<tr><td>NTRIP broadcaster overview &nbsp;</td><td><u>http://www.rtcm-ntrip.org/home</u></td></tr>
1827<tr><td>EUREF-IP Project &nbsp;</td><td><u>http://www.epncb.oma.be/euref_IP</u></td></tr>
1828<tr><td>Real-time IGS Pilot Project &nbsp;</td><td><u>http://www.rtigs.net/pilot</u></td></tr>
1829<tr><td>Radio Technical Commission<br>for Maritime Services &nbsp;</td><td><u>http://www.rtcm.org</u>
1830</table>
1831
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