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2	<h3>BKG Ntrip Client (BNC) Version 2.7 Manual</h3>
3
4	<p>
5	The BKG Ntrip Client (BNC) is a program for simultaneously retrieving, decoding, converting and processing real-time GNSS data streams. It has been developed within the framework of the IAG sub-commission for Europe (EUREF) and the International GNSS Service (IGS). Although meant as a real-time tool, it comes with some Post Processing functionality. You may like to use it for data coming from NTRIP Broadcasters like
6	<u>http://www.euref-ip.net/home</u>,
7	<u>http://www.igs-ip.net/home</u>,
8	<u>http://products.igs-ip.net/home</u>, or
9	<u>http://mgex.igs-ip.net/home</u>.
10	</p>
11
12	<p>
13	BNC has been written under GNU General Public License (GPL). Source code is available from Subversion software archive <u>http://software.rtcm-ntrip.org/svn/trunk/BNC.</u> Binaries for BNC are available for Windows, 32-bit Linux, 64-bit Linux (compiled under -m32 32-bit compatibility mode), Solaris, and Mac systems. We used the MinGW Version 4.4.0 compiler to create the Windows binary. It is likely that BNC can be compiled on other systems where a GNU compiler and Qt Version 4.7.3 are installed. Please ensure that you have installed the latest version of BNC available from <u>http://igs.bkg.bund.de/ntrip/download</u> and feel free to send us your comments, suggestions or bug reports.
14	</p>
15
16	<p><b>Contents</b><br>
17	<a href=#purpose>1. Purpose</a><br>
18	<a href=#opthandling>2. Handling</a><br>
19	<a href=#optsettings>3. Settings</a><br>
20	<a href=#limits>4. Limitations</a><br>
21	<a href=#annex>5. Annex</a>
22	</p>
23
24	<p>
25	<b><a name="authors">Authors</b><br>
26	The BKG Ntrip Client (BNC) and its Qt graphic user interface has been developed for
27	</p>
28	<p>
29	Georg Weber<br>
30	Federal Agency for Cartography and Geodesy (BKG)<br>
31	Department of Geodesy<br>
32	Frankfurt, Germany<br>
33	[euref-ip@bkg.bund.de] or [igs-ip@bkg.bund.de]
34	</p>
35
36	<p>
37	BNC has been written by
38	</p>
39
40	<p>
41	Leos Mervart<br>
42	Czech Technical University (CTU)<br>
43	Department of Geodesy<br>
44	Prague, Czech Republic
45	</p>
46	<p>
47	BNC includes the following GNU GPL software components:
48	<ul>
49	<li> RTCM 2 decoder, written by Oliver Montenbruck, German Space Operations Center, DLR, Oberpfaffenhofen, Germany</li>
50	<li> RTCM 3 decoder for standard messages and a RTCM 3 encoder & decoder for SSR messages, both written for BKG by Dirk Stoecker, Alberding GmbH, Schoenefeld, Germany</li>
51	</ul>
52	</p>
53	</p>
54
55	<p>
56	<b>Acknowledgements</b><br>
57	Earlier versions of BNC's Help Contents have been proofread by Thomas Yan, University of New South Wales, Australia. He also provided pre-compiled builds of BNC for Mac systems.<br>
58	Scott Glazier, OmniSTAR Australia has been helpful in finding BNC's bugs.<br>
59	James Perlt, BKG, helped fixing bugs and redesigned BNC's main window.<br>
60	Andre Hauschild, German Space Operations Center, DLR, revised the RTCM Version 2 decoder.<br>
61	Zdenek Lukes, Czech Technical University Prague, Department of Geodesy, extended the RTCM Version 2 decoder to handle message types 3, 20, 21, and 22 and added loss of lock indicator.<br>
62	Jan Dousa, Geodetic Observatory Pecny, Czech Republic, provided a tool for drawing stream distribution maps and also helped with fixing bugs.<br>
63	Denis Laurichesse, Centre National d'Etudes Spatiales (CNES), suggested synchronizing observations and clock corrections to reduce high frequency noise in PPP solutions.
64	</p>
65
66	<p><a name="purpose"><h3>1. Purpose</h3></p>
67
68	<p> The purpose of BNC is to
69	<ul>
70	<li>retrieve real-time GNSS data streams available through NTRIP transport protocol,</li>
71	<li>retrieve real-time GNSS data streams via TCP directly from an IP address without using the NTRIP transport protocol,</li>
72	<li>retrieve real-time GNSS data streams from a local UDP or serial port without using the NTRIP transport protocol,</li>
73	<li>generate high-rate RINEX Observation and Navigation files to support near real-time GNSS Post Processing applications,</li>
74	<li>generate ephemeris and synchronized or unsynchronized observations epoch by epoch through an IP port to support real-time GNSS network engines,</li>
75	<li>generate clock and orbit corrections to Broadcast Ephemeris through an IP port to support real-time Precise Point Positioning on GNSS rovers,</li>
76	<li>generate synchronized or unsynchronized clock and orbit corrections to Broadcast Ephemeris epoch by epoch through an IP port to support the (outside) combination of such streams as coming simultaneously from various correction providers,</li>
77	<li>monitor the performance of a network of real-time GNSS data streams to generate advisory notes in case of outages or corrupted streams,</li>
78	<li>scan RTCM streams for incoming antenna information as well as message types and their repetition rates,</li>
79	<li>feed a stream into a GNSS receiver via serial communication link,</li>
80	<li>carry out a real-time Precise Point Positioning to determine a GNSS rover position,</li>
81	<li>simultaneously process several Broadcast Correction streams to produce, encode and upload combined Broadcast Corrections,</li>
82	<li>upload a Broadcast Ephemeris stream in RTCM Version 3 format,</li>
83	<li>read GNSS clocks and orbits in a plain ASCII format from an IP port - they can be produced by a real-time GNSS engine such as RTNet and should be referenced to the IGS Earth-Centered-Earth-Fixed (ECEF) reference system. BNC will then</li>
84	<ul>
85	<li>convert the IGS Earth-Centered-Earth-Fixed clocks and orbits into Broadcast Corrections with radial, along-track and cross-track components,</li>
86	<li>upload Broadcast Corrections as an RTCM Version 3 stream to an NTRIP Broadcaster,</li>
87	<li>refer the clock and orbit corrections to a specific reference system,</li>
88	<li>log the Broadcast Corrections as Clock RINEX files for further processing using other tools than BNC,</li>
89	<li>log the Broadcast Corrections as SP3 files for further processing using other tools than BNC,</li>
90	</ul>
91	<li>edit or concatenate RINEX files or check their quality.</li>
92	</ul>
93	</p>
94
95	<p>
96	BNC supports decoding the following GNSS stream formats and message types:
97	</p>
98	<p>
99	<ul>
100	<li>RTCM Version 2 message types for GPS and GLONASS observations, </li>
101	<li>RTCM Version 3 'conventional' message types for observations and Broadcast Ephemeris for GPS, GLONASS, SBAS and Galileo (coming soon: COMPASS and QZSS),</li>
102	<li>RTCM Version 3 'State Space Representation' (SSR) messages for GPS, GLONASS and Galileo,</li>
103	<li>Drafted RTCM Version 3 'Multiple Signal Messages' (MSM) and 'High Precision Multiple Signal Messages' (HP MSM),</li>
104	<li>RTNET, a plain ASCII format defined within BNC to receive orbits and clock from a serving GNSS engine.
105	</ul>
106	Furthermore, BNC allows to by-pass its decoding and conversion algorithms, leave whatever is received untouched and save it in files.
107	</p>
108
109	<p>
110	The first of the following figures shows a flow chart of BNC connected to a GNSS receiver providing observations via serial or TCP communication link for the purpose of Precise Point Positioning. The second figure shows the conversion of RTCM streams to RINEX files. The third figure shows a flow chart of BNC feeding a real-time GNSS engine which estimates precise orbits and clocks. BNC is used in this scenario to encode correctors to RTCM Version 3 and upload them to an NTRIP Broadcaster. The fourth figure shows BNC combining several Broadcast Correction streams to disseminate the combination product while saving results in SP3 and Clock RINEX files.
111	</p>
112	<p><img src="IMG/screenshot10.png"/></p>
113	<p><u>Figure 1:</u> Flowchart, BNC connected to a GNSS receiver for Precise Point Positioning.</p>
114
115	<p>
116	</p>
117	<p><img src="IMG/screenshot01.png"/></p>
118	<p><u>Figure 2:</u> Flowchart, BNC converting RTCM streams to RINEX batches.</p>
119
120	<p>
121	</p>
122	<p><img src="IMG/screenshot02.png"/></p>
123	<p><u>Figure 3:</u> Flowchart, BNC feeding a real-time GNSS engine and uploading encoded Broadcast Corrections.</p>
124
125	<p>
126	</p>
127	<p><img src="IMG/screenshot19.png"/></p>
128	<p><u>Figure 4:</u> Flowchart, BNC combining Broadcast Correction streams.</p>
129
130
131	<p><a name="opthandling"><h3>2. Handling</h3></p>
132	<p>
133	Although BNC is mainly a real-time tool to be operated online, it can be run offline
134	<ul>
135	<li>to simulate real-time observation situations for debugging purposes,</li>
136	<li>for Post Processing purposes.</li>
137	</ul>
138	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 or from command line.
139	</p>
140	<p>
141	Unless it runs offline, BNC
142	</p>
143	<ul>
144	<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>
145	<li>requires the clock of the host computer to be properly synchronized.</li>
146	<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>
147	</ul>
148	</p>
149
150	<p>
151	The main window of BNC shows a 'Top menu bar' section, a 'Settings' sections with tabs to set processing options, a 'Streams' section, a section for 'Log' tabs, and a 'Bottom menu bar' section, see figure below.
152	</p>
153	<p><img src="IMG/screenshot09.png"/></p>
154	<p><u>Figure 5:</u> Sections on BNC's main window.</p>
155
156	<p>
157	The usual handling of BNC is that you first select a number of streams ('Add Stream'). Any stream configured to BNC shows up on the 'Streams' canvas in the middle of BNC's main window. You then go through BNC's various configuration tabs to select a combination of input, processing and output options before you start the program ('Start'). Most configuration tabs are dedicated to a certain functionality of BNC. If the first option field on such a configuration tab is empty, the affected functionality is - apart from a few exceptions - deactivated.</p>
158
159	Records of BNC's activities are shown in the 'Log' tab. The bandwidth consumption per stream, the latency of incoming observations and a PPP time series for coordinates are shown in the 'Throughput', 'Latency' and 'PPP Plot' tabs of the main window.
160	</p>
161	<p>
162	As 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.bnc'.</p>
163	<p>
164	The default file name 'BNC.bnc' can be changed and the file contents can easily be edited. On graphical user interfaces it is possible to Drag & Drop a configuration file icon to start BNC (not on Mac systems). Some configuration options can be changed on-the-fly. See annexed 'Configuration Examples' for a complete set of configuration options. It is also possible to start and configure BNC via command line.
165	</p>
166	<p><a name="optsettings"><h3>3. Settings</h3></p>
167	<p>
168	This chapter describes how to set the BNC program options. It explains the top menu bar, the processing options, the 'Streams' and 'Log' sections, and the bottom menu bar.
169	</p>
170	<p>
171	<b>Top Menu Bar</b><br>
172	3.1. <a href=#topmenu>Top Menu Bar</a><br>
173	3.1.1 <a href=#file>File</a><br>
174	3.1.2 <a href=#help>Help</a><br><br>
175	<b>Settings Canvas</b><br>
176	3.2. <a href=#network>Network</a><br>
177	3.2.1 <a href=#proxy>Proxy</a><br>
178	3.2.2 <a href=#ssl>SSL</a><br>
179	3.3. <a href=#general>General</a><br>
180	3.3.1. <a href=#genlog>Logfile</a><br>
181	3.3.2. <a href=#genapp>Append Files</a><br>
182	3.3.3. <a href=#genconf>Reread Configuration</a><br>
183	3.3.4. <a href=#genstart>Auto Start</a><br>
184	3.3.5. <a href=#rawout>Raw Output File</a><br>
185	3.4. <a href=#rinex>RINEX Observations</a><br>
186	3.4.1. <a href=#rnxname>File Names</a><br>
187	3.4.2. <a href=#rnxdir>Directory</a><br>
188	3.4.3. <a href=#rnxinterval>File Interval</a><br>
189	3.4.4. <a href=#rnxsample>Sampling</a><br>
190	3.4.5. <a href=#rnxskl>Skeleton Extension</a><br>
191	3.4.6. <a href=#rnxscript>Script</a><br>
192	3.4.7. <a href=#rnxvers>Version</a><br>
193	3.5. <a href=#ephemeris>RINEX Ephemeris</a><br>
194	3.5.1. <a href=#ephdir>Directory</a><br>
195	3.5.2. <a href=#ephint>Interval</a><br>
196	3.5.3. <a href=#ephport>Port</a><br>
197	3.5.4. <a href=#ephvers>Version</a><br>
198	3.6. <a href=#reqc>RINEX Editing & QC</a><br>
199	3.6.1 <a href=#reqcact>Action</a><br>
200	3.6.2 <a href=#reqcedit>Set Edit Options</a><br>
201	3.6.3 <a href=#reqcinput>Input Files</a><br>
202	3.6.4 <a href=#reqcoutput>Output Files</a><br>
203	3.6.5 <a href=#reqccommand>Command Line, No Window</a><br>
204	3.7. <a href=#correct>Broadcast Corrections</a><br>
205	3.7.1. <a href=#corrdir>Directory, ASCII</a><br>
206	3.7.2. <a href=#corrint>Interval</a><br>
207	3.7.3. <a href=#corrport>Port</a><br>
208	3.7.4. <a href=#corrwait>Wait for Full Corr Epoch</a><br>
209	3.8. <a href=#syncout>Feed Engine</a><br>
210	3.8.1. <a href=#syncport>Port</a><br>
211	3.8.2. <a href=#syncwait>Wait for Full Obs Epoch</a><br>
212	3.8.3. <a href=#syncsample>Sampling</a><br>
213	3.8.4. <a href=#syncfile>File</a><br>
214	3.8.5. <a href=#syncuport>Port (unsynchronized)</a><br>
215	3.9. <a href=#serial>Serial Output</a><br>
216	3.9.1. <a href=#sermount>Mountpoint</a><br>
217	3.9.2. <a href=#serport>Port Name</a><br>
218	3.9.3. <a href=#serbaud>Baud Rate</a><br>
219	3.9.4. <a href=#serflow>Flow Control</a><br>
220	3.9.5. <a href=#serparity>Parity</a><br>
221	3.9.6. <a href=#serdata>Data Bits</a><br>
222	3.9.7. <a href=#serstop>Stop Bits</a><br>
223	3.9.8. <a href=#serauto>NMEA</a><br>
224	3.9.9. <a href=#serfile>File</a><br>
225	3.9.10. <a href=#serheight>Height</a><br>
226	3.10. <a href=#advnote>Outages</a><br>
227	3.10.1. <a href=#obsrate>Observation Rate</a><br>
228	3.10.2. <a href=#advfail>Failure Threshold</a><br>
229	3.10.3. <a href=#advreco>Recovery Threshold</a><br>
230	3.10.4. <a href=#advscript>Script</a><br>
231	3.11. <a href=#misc>Miscellaneous</a><br>
232	3.11.1. <a href=#miscmount>Mountpoint</a><br>
233	3.11.2. <a href=#miscperf>Log Latency</a><br>
234	3.11.3. <a href=#miscscan>Scan RTCM</a><br>
235	3.12. <a href=#pppclient>PPP Client</a><br>
236	3.12.1 <a href=#pppmode>Mode & Mountpoints</a><br>
237	3.12.1.1 <a href=#pppmodus>Mode</a><br>
238	3.12.1.2 <a href=#pppobsmount>Obs Mountpoint</a><br>
239	3.12.1.3 <a href=#pppcorrmount>Corr Mountpoint</a><br>
240	3.12.2 <a href=#pppxyz>Marker Coordinates</a><br>
241	3.11.3 <a href=#pppneu>Antenna Eccentricity</a><br>
242	3.12.4 <a href=#pppoutput>NMEA & Plot Output</a><br>
243	3.12.4.1 <a href=#pppnmeafile>NMEA File</a><br>
244	3.12.4.2 <a href=#pppnmeaport>NMEA Port</a><br>
245	3.12.4.3 <a href=#pppplot>PPP Plot</a><br>
246	3.12.5 <a href=#ppppost>Post Processing</a><br>
247	3.12.6 <a href=#ppprecant>Antennas</a><br>
248	3.12.6.1 <a href=#pppantex>ANTEX File</a><br>
249	3.12.6.2 <a href=#ppprecantenna>Antenna Name</a><br>
250	3.12.7 <a href=#pppbasics>Basics</a><br>
251	3.12.7.1 <a href=#pppphase>Use Phase Obs</a><br>
252	3.12.7.2 <a href=#ppptropo>Estimate Tropo</a><br>
253	3.12.7.3 <a href=#pppglo>Use GLONASS</a><br>
254	3.12.7.4 <a href=#pppgal>Use Galileo</a><br>
255	3.12.7.5 <a href=#pppsync>Sync Corr</a><br>
256	3.12.7.6 <a href=#pppaverage>Averaging</a><br>
257	3.12.7.7 <a href=#pppquick>Quick-Start</a><br>
258	3.12.7.8 <a href=#pppgap>Maximal Solution Gap</a><br>
259	3.12.8 <a href=#pppsigmas>Sigmas</a><br>
260	3.12.8.1 <a href=#pppsigc>Code</a><br>
261	3.12.8.2 <a href=#pppsigp>Phase</a><br>
262	3.12.8.3 <a href=#pppsigxyzi>XYZ Init</a><br>
263	3.12.8.4 <a href=#pppsigxyzn>XYZ White Noise</a><br>
264	3.12.8.5 <a href=#pppsigtrpi>Tropo Init</a><br>
265	3.12.8.6 <a href=#pppsigtrpn>Tropo White Noise</a><br>
266	3.13. <a href=#combi>Combine Corrections</a><br>
267	3.13.1 <a href=#combimounttab>Combine Corrections Table</a><br>
268	3.13.1.1 <a href=#combiadd>Add Row, Delete</a><br>
269	3.13.1.2 <a href=#combimethod>Method</a><br>
270	3.13.1.3 <a href=#combimax>Maximal Residuum</a><br>
271	3.13.1.4 <a href=#combismpl>Sampling</a><br>
272	3.14. <a href=#upclk>Upload Corrections</a><br>
273	3.14.1 <a href=#upadd>Add, Delete Row</a><br>
274	3.14.2 <a href=#uphost>Host, Port, Mountpoint, Password</a><br>
275	3.14.3 <a href=#upsystem>System</a><br>
276	3.14.4 <a href=#upcom>Center of Mass</a><br>
277	3.14.5 <a href=#upsp3>SP3 File</a><br>
278	3.14.6 <a href=#uprinex>RNX File</a><br>
279	3.14.7 <a href=#upinter>Interval</a><br>
280	3.14.8 <a href=#upclksmpl>Sampling</a><br>
281	3.14.8.1 <a href=#upclkorb>orbits</a><br>
282	3.14.8.2 <a href=#upclksp3>SP3</a><br>
283	3.14.8.3 <a href=#upclkrnx>RINEX </a><br>
284	3.14.9 <a href=#upcustom>Custom Trafo</a><br>
285	3.15. <a href=#upeph>Upload Ephemeris</a><br>
286	3.15.1 <a href=#brdcserver>Host & Port</a><br>
287	3.15.2 <a href=#brdcmount>Mountpoint & Password</a><br>
288	3.15.3 <a href=#brdcsmpl>Sampling</a><br><br>
289	<b>Streams Canvas</b><br>
290	3.16. <a href=#streams>Streams</a><br>
291	3.16.1 <a href=#streamedit>Edit Streams</a><br>
292	3.16.2 <a href=#streamdelete>Delete Stream</a><br>
293	3.16.3 <a href=#streamconf>Reconfigure Stream Selection On-the-fly</a><br><br>
294	<b>Logging Canvas</b><br>
295	3.17. <a href=#logs>Logging</a><br>
296	3.17.1 <a href=#logfile>Log</a><br>
297	3.17.2 <a href=#throughput>Throughput</a><br>
298	3.17.3 <a href=#latency>Latency</a><br>
299	3.17.4 <a href=#ppptab>PPP Plot</a><br><br>
300	<b>Bottom Menu Bar</b><br>
301	3.18. <a href=#bottom>Bottom Menu Bar</a><br>
302	4.18.1. <a href=#streamadd>Add Stream - Coming from Caster</a><br>
303	3.18.1.1 <a href=#streamhost>Caster Host and Port</a><br>
304	3.18.1.2 <a href=#streamtable>Casters Table</a><br>
305	3.18.1.3 <a href=#streamuser>User and Password</a><br>
306	3.18.1.4 <a href=#gettable>Get Table</a><br>
307	3.18.1.5 <a href=#ntripv>NTRIP Version</a><br>
308	3.18.1.6 <a href=#map>Map</a><br>
309	3.18.2 <a href=#streamip>Add Stream - Coming from TCP/IP Port</a><br>
310	3.18.3 <a href=#streamudp>Add Stream - Coming from UDP Port</a><br>
311	3.18.4 <a href=#streamser>Add Stream - Coming from Serial Port</a><br>
312	3.18.5 <a href=#start>Start</a><br>
313	3.18.6 <a href=#stop>Stop</a><br><br>
314	<b>Command Line</b><br>
315	3.19. <a href=#cmd>Command Line Options</a><br>
316	3.19.1. <a href=#nw>No Window Mode</a><br>
317	3.19.2. <a href=#post>File Mode</a><br>
318	3.19.3. <a href=#conffile>Configuration File</a><br>
319	3.19.4. <a href=#confopt>Configuration Options</a><br>
320	</p>
321
322	<p><a name="topmenu"><h4>3.1. Top Menu Bar</h4></p>
323	<p>
324	The 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.
325	</p>
326
327	<p><a name="file"><h4>3.1.1 File</h4></p>
328
329	<p>
330	The 'File' button lets you
331	<ul>
332	<li> select an appropriate font.<br>
333	Use smaller font size if the BNC main window exceeds the size of your screen.
334	</li>
335	<li> save selected options in configuration file.<br>
336	When using 'Save & Reread Configuration' while BNC is already processing data, some configuration options become immediately effective on-the-fly without interrupting uninvolved threads. See annexed section 'Configuration Examples' for a list of on-the-fly changeable configuration options.
337	</li>
338	<li> quit the BNC program.
339	</li>
340	</ul>
341	</p>
342
343	<p><a name="help"><h4>3.1.2 Help</h4></p>
344
345	<p>
346	The 'Help' button provides access to
347	<ul>
348	<li>
349	help contents.<br>
350	You may keep the 'Help Contents' window open while configuring BNC.
351	</li>
352	<li>
353	a 'Flow Chart' showing BNC linked to a real-time GNSS network engine such as RTNet.
354	</li>
355	<li>
356	general information about BNC.<br>
357	Close the 'About BNC' window to continue working with BNC.
358	</li>
359	</ul>
360	</p>
361	<p>
362	BNC 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 "?" button that users can click; click the relevant widget to pop up the help text.
363	</p>
364
365	<p><a name="network"><h4>3.2. Network</h4></p>
366	<p>
367	You may need to specify a proxy when running BNC in a protected network. You may also like to use the Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL) cryptographic protocols for secure NTRIP communication over the Internet.
368	</p>
369	<p><a name="proxy"><h4>3.2.1 Proxy - Usage in a protected LAN</h4></p>
370	<p>
371	If 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>
372	<p>
373	Note 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.
374	</p>
375
376	<p><a name="ssl"><h4>3.2.2 SSL - Transport Layer Security</h4></p>
377	<p>Communication with an NTRIP Broadcaster over SSL requires the exchange of client and/or server certificates. Specify the path to a directory where you save certificates on your system. You may like to check out <u>http://software.rtcm-ntrip.org/wiki/Certificates</u> for a list of known NTRIP Server certificates. You may also just try communication via SSL to check out whether this is supported by the involved NTRIP Broadcaster. </p>
378	<p>SSL communication may involve queries coming from the NTRIP Broadcaster. Tick 'Ignore SSL authorization errors' if you don't want to be bothered with this. Note that SSL communication is usually done over port 443.</p>
379
380	<p><a name="general"><h4>3.3. General</h4></p>
381	<p>
382	The following defines general settings for BNC's logfile, file handling, reconfiguration on-the-fly, and auto-start.
383	</p>
384
385	<p><a name="genlog"><h4>3.3.1 Logfile - optional</h4></p>
386	<p>
387	Records of BNC's activities are shown in the 'Log' tab on the bottom of the main window. These logs can be saved into a file when a valid path is specified in the 'Logfile (full path)' field. The logfile name will automatically be extended by a string '_YYMMDD' carrying the current date. This leads to series of daily logfiles when running BNC continuously for extended. Message logs cover the communication status between BNC and the NTRIP Broadcaster as well as problems that may occur in the communication link, stream availability, stream delay, stream conversion etc. All times are given in UTC. The default value for 'Logfile (full path)' is an empty option field, meaning that BNC logs will not be saved into a file.
388	</p>
389
390	<p><a name="genapp"><h4>3.3.2 Append Files - optional</h4></p>
391	<p>
392	When 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.
393	</p>
394
395	<p><a name="genconf"><h4>3.3.3 Reread Configuration - optional</h4></p>
396	<p>
397	When operating BNC online in 'no window' mode (command line option -nw), some configuration options can nevertheless be changed on-the-fly without interrupting the running process. For that you force the program to reread parts of its configuration in pre-defined intervals from the disk. Select '1 min', '1 hour', or '1 day' to let BNC reread on-the-fly changeable configuration options every full minute, hour, or day. This lets in between edited options become effective without interrupting uninvolved threads. See annexed section 'Configuration Examples' for a configuration file example and a list of on-the-fly changeable options.
398	</p>
399
400	<p><a name="genstart"><h4>3.3.4 Auto Start - optional</h4></p>
401	<p>
402	You 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).
403	</p>
404	<p>
405	See BNC's command line option -nw for an auto-start of BNC in 'no window' mode.
406	</p>
407
408	<p><a name="rawout"><h4>3.3.5 Raw Output File - optional</h4></p>
409	<p>
410	BNC can save all data coming in through various streams in one daily file. The information is recorded in the specified 'Raw output file' in the received order and format. This feature allows a BNC user to run the PPP option offline with observations, Broadcast Corrections, and Broadcast Ephemeris being read from a previously saved file. It supports the offline repetition of a real-time situation for debugging purposes and it is not meant for Post Processing.
411	</p>
412	<p>
413	Data will be saved in blocks in the received format separated by ASCII time stamps like (example):
414	<pre>
415	2010-08-03T18:05:28 RTCM3EPH RTCM_3 67
416	</pre>
417	</p>
418	<p>
419	This example block header tells you that 67 bytes were saved in the data block following this time stamp. The information in this block is encoded in RTCM Version 3 format, comes from mountpoint RTCM3EPH and was received at 18:05:29 UTC on 2010-08-03. BNC adds its own time stamps in order to allow the reconstruction of a recorded real-time situation.
420	</p>
421	<p>
422	The default value for 'Raw output file' is an empty option field, meaning that BNC will not save all raw data into one single daily file.
423	</p>
424
425	<p><a name="rinex"><h4>3.4. RINEX Observations</h4></p>
426	<p>
427	Observations will be converted to RINEX if they come in either RTCM Version 2 or RTCM Version 3 format. Depending on the RINEX version and incoming RTCM message types, the files generated by BNC may contain data from GPS, GLONASS, Galileo and SBAS (coming soon: QZSS and COMPASS). In case an observation type is listed in the RINEX header but the corresponding observation is unavailable, its value is set to zero '0.000'. Note that the 'RINEX TYPE' field in the RINEX Version 3 Observation file header is always set to 'M(MIXED)' or 'Mixed' even if the file only contains data from one system.
428	</p>
429
430	<p>
431	The screenshot below shows an example setup of BNC when converting streams to RINEX. Streams are coming from various NTRIP Broadcasters as well as from a serial communication link. Specifying a decoder string 'ZERO' means to not convert the affected stream contents but save its contents as received.
432	</p>
433	<p><img src="IMG/screenshot16.png"/></p>
434	<p><u>Figure 6:</u> BNC translating incoming streams to 15 min RINEX Version 3 files.</p>
435
436	<p><a name="rnxname"><h4>3.4.1 RINEX File Names</h4></p>
437	<p>
438	RINEX 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>
439	<p>
440	FRAN{ddd}{h}.{yy}O<br>
441	WETT{ddd}{h}.{yy}O
442	</p>
443	<p>
444	where 'ddd' is the day of year, 'h' is a letter which corresponds to an hour long UTC time block and 'yy' is the year.
445	</p>
446	<p>
447	If there is more than one stream with identical 4Char Station ID (same first 4 characters for their mountpoints), the mountpoint strings are split into two sub-strings and both become part of the RINEX file name. For example, when simultaneously retrieving data from mountpoints FRANKFURT and FRANCE, their hourly RINEX Observation files are named as</p>
448	<p>
449	FRAN{ddd}{h}_KFURT.{yy}O<br>
450	FRAN{ddd}{h}_CE.{yy}O.
451	</p>
452	<p>
453	If 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>
454	<p>
455	BRUS{ddd}{h}_0.{yy}O<br>
456	BRUS{ddd}{h}_1.{yy}O.
457	</p>
458	<p>
459	Note 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>
460	<p>
461	FRAN{ddd}{h}{mm}.{yy}O
462	</p>
463	<p>
464	where 'mm' is the starting minute within the hour.
465	</p>
466
467	<p><a name="rnxdir"><h4>3.4.2 Directory - optional</h4></p>
468	<p>
469	Here 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.
470	</p>
471
472	<p><a name="rnxinterval"><h4>3.4.3 File Interval - mandatory if 'Directory' is set</h4></p>
473	<p>
474	Select the length of the RINEX Observation file generated. The default value is 15 minutes.
475	</p>
476
477	<p><a name="rnxsample"><h4>3.4.4 Sampling - mandatory if 'Directory' is set </h4></p>
478	<p>
479	Select 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.
480	</p>
481
482	<p><a name="rnxskl"><h4>3.4.5 Skeleton Extension - optional</h4></p>
483	<p>
484	Whenever 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 Version 2 header skeleton file for the Brussels EPN station.
485	</p>
486	<p>
487	However, 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.
488	</p>
489	<p>
490	Examples 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>
491	<p>
492	WETT.skl<br>
493	FRAN_KFURT.skl<br>
494	FRAN_CE.skl<br>
495	BRUS_0.skl<br>
496	BRUS_1.skl</p>
497	<p>
498	if 'Skeleton extension' is set to 'skl'.
499	</p>
500	<p>
501	Note the following regulations regarding personal RINEX header skeleton files:
502	<ul>
503	<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>
504	<li>Personal skeletons should contain a complete first header record of type
505	<br>-   RINEX VERSION / TYPE<br>
506	Note the small differences mentioned below with regards to RINEX Version 2 and RINEX Version 2 skeletons.</li>
507	<li>They should then contain an empty header record of type
508	<br>-   PGM / RUN BY / DATE<br>
509	BNC will complete this line and include it in the RINEX file header.</li>
510	<li>They should further contain complete header records of type
511	<br>-   MARKER NAME
512	<br>-   OBSERVER / AGENCY
513	<br>-   REC # / TYPE / VERS
514	<br>-   ANT # / TYPE
515	<br>-   APPROX POSITION XYZ
516	<br>-   ANTENNA: DELTA H/E/N
517	<br>-   WAVELENGTH FACT L1/2 (RINEX Version 2)</li>
518	<li>They may contain any other optional complete header record as defined in the RINEX documentation.</li>
519	<li>They should then contain empty header records of type
520	<br>-   # / TYPES OF OBSERV (RINEX Version 2)
521	<br>-   SYS/ # / OBS TYPES (RINEX Version 3)
522	<br>-   TIME OF FIRST OBS
523	<br>BNC will include these lines in the final RINEX file header together with an additional
524	<br>-   COMMENT
525	<br>line describing the source of the stream.</li>
526	<li>They should finally contain an empty header record of type
527	<br>-   END OF HEADER (last record)</li>
528	</ul>
529	<p>
530	If neither a public nor a personal RINEX header skeleton file is available for BNC, a default header will be used.
531	</p>
532	<p>
533	The following is a skeleton example for a RINEX Version 2 file:
534	</p>
535	<p>
536	<pre>
537	OBSERVATION DATA G (GPS) RINEX VERSION / TYPE
538	DUND MARKER NAME
539	50212M003 MARKER NUMBER
540	4635120796 TRIMBLE NETRS 1.15 REC # / TYPE / VERS
541	12626150 TRM41249.00 NONE ANT # / TYPE
542	-4388121.1700 726671.0500 -4556535.6300 APPROX POSITION XYZ
543	0.0020 0.0000 0.0000 ANTENNA: DELTA H/E/N
544	GeoNet Reception GNS OBSERVER / AGENCY
545	PORTIONS OF THIS HEADER GENERATED BY BKG FROM COMMENT
546	SITELOG dund_20070806.log COMMENT
547	</pre>
548	<p>
549
550	<p><a name="rnxscript"><h4>3.4.6 Script - optional</h4></p>
551	<p>
552	Whenever 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).
553	</p>
554	<p>
555	The 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.
556	</p>
557	<p>
558	As an alternative to initiating file uploads through BNC, you may like to call an upload script or batch file through your crontable or Task Scheduler (independent from BNC) once every one or two minutes after the end of each RINEX file 'Interval'.
559	</p>
560
561	<p><a name="rnxvers"><h4>3.4.7 Version - optional</h4></p>
562	<p>
563	The 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.
564	</p>
565
566	<p><a name="ephemeris"><h4>3.5. RINEX Ephemeris</h4></p>
567	<p>
568	Broadcast Ephemeris can be saved as RINEX Navigation files when received via RTCM Version 3 e.g. as message types 1019 (GPS) or 1020 (GLONASS) or 1045 (Galileo). The file name convention follows the details given in section 'RINEX File Names' except that the first four characters are 'BRDC' and the last character is
569	</p>
570	<ul>
571	<li>'N' or 'G' for GPS or GLONASS ephemeris in two separate RINEX Version 2.11 Navigation files, or</li>
572	<li>'P' for GPS plus GLONASS plus Galileo ephemeris saved together in one RINEX Version 3 Navigation file.
573	</ul>
574
575	<p>
576	Note that streams dedicated to carry Broadacst Ephemeris messages in RTCM Version 3 format in high repetition rates are listed on <u>http://igs.bkg.bund.de/ntrip/ephemeris</u>.
577	</p>
578
579	<p><a name="ephdir"><h4>3.5.1 Directory - optional</h4></p>
580	<p>
581	Specify a path for saving Broadcast Ephemeris data as RINEX Navigation files. If the specified directory does not exist, BNC will not create RINEX Navigation files. Default value for Ephemeris 'Directory' is an empty option field, meaning that no RINEX Navigation files will be created.
582	</p>
583
584	<p><a name="ephint"><h4>3.5.2 Interval - mandatory if 'Directory' is set</h4></p>
585	<p>
586	Select the length of the RINEX Navigation file generated. The default value is 1 day.
587	</p>
588
589	<p><a name="ephport"><h4>3.5.3 Port - optional</h4></p>
590	<p>
591	BNC can output Broadcast Ephemeris in RINEX Version 3 format on your local host (IP 127.0.0.1) through an IP 'Port'. Specify an IP port number to activate this function. The default is an empty option field, meaning that no ASCII ephemeris output via IP port is generated.
592	</p>
593	<p>
594	The source code for BNC comes with an example perl script 'test_tcpip_client.pl' that allows you to read BNC's ASCII ephemeris output from the IP port.
595	</p>
596
597	<p><a name="ephvers"><h4>3.5.4 Version - optional</h4></p>
598	<p>
599	Default 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.
600	</p>
601	<p>
602	Note that this does not concern the Broadcast Ephemeris output through IP port which is always in RINEX Version 3 format.
603	</p>
604
605	<p><a name="reqc"><h4>3.6. RINEX Editing & QC</h4></p>
606	<p>
607	Besides stream conversion from RTCM to RINEX, BNC allows editing RINEX files or concatenate their contents. RINEX Observation and Navigation files can be handled. BNC can also carry out a RINEX file quality check. In summary this functionality in BNC covers
608	<ul>
609	<li>Stream <u>T</u>ranslation</li>
610	<li>File <u>E</u>diting and concatenation</li>
611	<li>File <u>Q</b></u>uality <u>C</u>heck</li>
612	</ul>
613	and hence follows UNAVCO's famous 'TEQC' program. The remarkable thing about BNC in this context is that it supports RINEX Version 3 under GNU General Public License.
614
615	<p><a name="reqcact"><h4>3.6.1 Action - optional</h4></p>
616	<p>Select an action. Options are 'Edit/Concatenate' and 'Analyze'.
617	<ul>
618	<li>Select 'Edit/Concatenate' if you want to edit RINEX file contents according to options specified under 'Set Edit Options' or if you want to concatenate several RINEX files.</li>
619	<li>Select 'Analyze' if you are interested in a quality check of your RINEX file contents.</li>
620	</ul>
621	</p>
622
623	<p><a name="reqcedit"><h4>3.6.2 Set Edit Options - mandatory if 'Edit/Concatenate' is set</h4></p>
624	<p>Once the 'Edit/Concatenate' action is selected, you have to 'Set Edit Options'. BNC lets you specify the RINEX version, sampling interval, begin and end of file, operator, comment lines, and marker, antenna, receiver details. Note that sampling, begin/end and marker/antenna/receiver specification are only meaningful for RINEX Observation files.
625	</p>
626	<p>
627	When converting RINEX Version 2 to RINEX Version 3 Observation files, the tracking mode or channel information in the (last character out of the three characters) observation code is left blank if unknown. When converting RINEX Version 3 to RINEX Version 2 Observation files:
628	<ul>
629	<li>C1P in RINEX Version 3 is mapped to P1 in RINEX Version 2</li>
630	<li>C2P in RINEX Version 3 is mapped to P2 in RINEX Version 2</li>
631	<li>If several observations in RINEX Version 3 come with the same observation type and same band/frequency but different tracking modes, BNC uses only the one provided first for creating RINEX Version 2 while ignoring others.</li>
632	</ul>
633	</p>
634	<p>Optionally you may specify a comment line text to be added to the emerging new RINEX file header. Any introduction of a newline through '\n' in this enforces the beginning of a further comment line. Comment line(s) will be added to the header immediately after the 'PGM / RUN BY / DATE' record. Default is an empty option field, meaning that no additional comment line will be added to the RINEX header.</p>
635	<p>Specifying a 'RUN BY' string to be included in the emerging new RINEX file header is another option. Default is an empty option field meaning the operator's ID is automatically used as 'RUN BY' string.</p>
636	<p>
637	If you specify a 'New' but no 'Old' marker/antenna/receiver name, the corresponding data field in the emerging new RINEX Observation file will be filled accordingly. If you in addition specify an 'Old' marker/antenna/receiver name, the corresponding data field in the emerging new RINEX Observation file will only be filled accordingly where 'Old' specifications match existing file contents.
638	</p>
639
640	<p><img src="IMG/screenshot27.png"/></p>
641	<p><u>Figure 7:</u> Example for 'RINEX Editing Options' window.</p>
642
643	<p><a name="reqcinput"><h4>3.6.3 Input Files - mandatory if 'Action' is set</h4></p>
644	<p>
645	Specify full path to input RINEX Observation file(s), and<br>
646	specify full path to input RINEX Navigation file(s).
647	</p>
648	<p>When specifying several input files BNC will concatenate their contents.</p>
649
650	<p><a name="reqcoutput"><h4>3.6.4 Output Files - mandatory if 'Action' is set</h4></p>
651	<p>
652	If 'Edit/Concatenate' is selected, specifying the a path to output RINEX Observation file(s) and specifying a full path to output RINEX Navigation file(s) is mandatory.</p>
653
654	<p>
655	If 'Analyze' is selected, specifying logfile(s) to output analysis results is mandatory.<br>
656	</p>
657
658	<p><img src="IMG/screenshot25.png"/></p>
659	<p><u>Figure 7:</u> Example for RINEX file editing with BNC in Post Processing mode.</p>
660
661	<p><a name="reqccommand"><h4>3.6.5 Command Line, No Window - optional</h4></p>
662	<p>
663	BNC applies options from the configuration file but allows updating every one of them on the command line while the contents of the configuration file remains unchanged, see section on 'Command Line Options'. The syntax for that looks as follows
664	</p>
665	<p>
666	--key <keyName> <keyValue>
667	</p>
668	<p>
669	where <keyName> stands for the name of an option contained in the configuration file and <keyValue> stands for the value you want to assign to it. This functionality may be helpful in the 'RINEX Editing & QC' context when running BNC on a routine basis for maintaining a RINEX file archive.
670	</p>
671	The following example for a Linux platform calls BNC in 'no window' mode with a local configuration file 'rnx.conf' for concatenating four 15min RINEX files residing in the local directory to produce an hourly RINEX Version 3 file with 30 seconds sampling interval:
672	</p>
673	<p>
674	./bnc --nw --conf rnx.conf --key reqcAction Edit/Concatenate --key reqcObsFile "tlse119b00.12o,tlse119b15.12o,tlse119b30.12o,tlse119b45.12o" --key reqcOutObsFile tlse119b.12o --key reqcRnxVersion 3 --key reqcSampling 30
675	</p>
676	<p>
677	You may use asterisk '*' and/or question mark '?' wildcard characters as shown with the following globbing command line option to specify a selection of files in a local directory:
678	</p>
679	<p>
680	--key reqcObsFile "tlse*"<br>
681	or:<br>
682	--key reqcObsFile tlse\*
683	</p>
684
685	<p>
686	The following is a list of available keynames for '<u>R</u>INEX <u>E</u>diting & <u>QC</u>' (short: REQC, pronounced 'rek') options and their meaning, cf. section 'Configuration Examples':
687	</p>
688
689	<table>
690	<tr></tr>
691	<tr><td><b>Keyname</b></td><td><b>Meaning</b></td></tr>
692	<tr><td>reqcAction</td><td>RINEX Editing & QC action</td></tr>
693	<tr><td>reqcObsFile</td><td>RINEX Observation input file(s)</td></tr>
694	<tr><td>reqcNavFile</td><td>RINEX Navigation input files(s)</td></tr>
695	<tr><td>reqcOutObsFile</td><td>RINEX Observation output file</td></tr>
696	<tr><td>reqcOutNavFile</td><td>RINEX Navigation output file</td></tr>
697	<tr><td>reqcOutLogFile</td><td>Logfile</td></tr>
698	<tr><td>reqcRnxVersion</td><td>RINEX version of emerging new file</td></tr>
699	<tr><td>reqcSampling</td><td>Sampling interval of emerging new RINEX file</td></tr>
700	<tr><td>reqcStartDateTime</td><td>Begin of emerging new RINEX file</td></tr>
701	<tr><td>reqcEndDateTime</td><td>End of emerging new RINEX file</td></tr>
702	<tr><td>reqcRunBy</td><td>Operator name</td></tr>
703	<tr><td>reqcComment</td><td>Additional comment lines</td></tr>
704	<tr><td>reqcOldMarkerName</td><td>Old marker name</td></tr>
705	<tr><td>reqcNewMarkerName</td><td>New marker name</td></tr>
706	<tr><td>reqcOldAntennaName</td><td>Old antenna name</td></tr>
707	<tr><td>reqcNewAntennaName</td><td>New antenna name</td></tr>
708	<tr><td>reqcOldReceiverName</td><td>Old receiver name</td></tr>
709	<tr><td>reqcNewReceiverName</td><td>New receiver name</td></tr>
710	</table>
711
712	<p><a name="correct"><h4>3.7. Broadcast Corrections</h4></p>
713	<p>
714	Differential GNSS and RTK operation using RTCM streams is currently based on corrections and/or raw measurements from single or multiple reference stations. This approach to differential positioning is using 'observation space' information. The representation with the RTCM standard can be called 'ObservationSpace Representation' (OSR).
715	</p>
716	<p>
717	An alternative to the observation space approach is the so called 'sate space' approach. The principle here is to provide information on individual error sources. It can be called 'State Space Representation' (SSR). For a rover position, state space information concerning precise satellite clocks, orbits, ionosphere, troposphere et cetera can be converted into observation space and used to correct the rover observables for more accurate positioning. Alternatively the state information can directly be used in the rover's processing or adjustment model.
718	</p>
719	<p>
720	RTCM has developed Version 3 messages to transport satellite clock and orbit corrections in real-time. The current set of SSR messages concerns:
721	<ul>
722	<li>Orbit corrections to Broadcast Ephemeris</li>
723	<li>Clock corrections to Broadcast Ephemeris</li>
724	<li>Code biases</li>
725	<li>Combined orbit and clock corrections to Broadcast Ephemeris</li>
726	<li>User Range Accuracy (URA)</li>
727	<li>High-rate GPS clock corrections to Broadcast Ephemeris</li>
728	</ul>
729	<p>
730	RTCM Version 3 streams carrying these messages may be used i.e. to support real-time Precise Point Positioning (PPP) applications.
731	</p>
732	<p>
733	When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the conventional periodic relativistic effect. Chapter 10 of the IERS Conventions 2003 mentions that the conventional periodic relativistic correction to the satellite clock (to be added to the broadcast clock) is computed as dt = -2 (R * V) / c^2 where R * V is the scalar product of the satellite position and velocity and c is the speed of light. This can also be found in the GPS Interface Specification, IS-GPS-200, Revision D, 7 March 2006.
734	</p>
735
736	<p>
737	Orbit 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.
738	</p>
739
740	<p>
741	After 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.
742	</p>
743
744	<p>
745	The 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.
746	</p>
747
748	<p>
749	Broadcast 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 "C".
750	</p>
751
752	<p>
753	Saved files contain blocks of records in plain ASCII format where - separate for each GNSS, message type, stream, and epoch - the begin of a block is indicated by a line like (examples):
754	</p>
755	<p>
756	! Orbits/Clocks: 30 GPS 0 Glonass CLK11<br>
757	or<br>
758	! Orbits/Clocks: 0 GPS 19 Glonass CLK11
759	<p>
760	Such line informs you about the number of records (here 30 and 19) carrying GPS or GLONASS related parameters you should receive next.
761	</p>
762	<p>
763	The first five parameters in each Broadcast Corrections record are:
764	</p>
765	<p>
766	<ul>
767	<li>RTCM Version 3 message type number</li>
768	<li>SSR message update interval indicator</li>
769	<ul>
770	<li>0 = 1 sec</li>
771	<li>1 = 2 sec</li>
772	<li>2 = 5 sec</li>
773	<li>3 = 10 sec</li>
774	<li>4 = 15 sec</li>
775	<li>5 = 30 sec</li>
776	<li>6 = 60 sec</li>
777	<li>7 = 120 sec</li>
778	<li>8 = 240 sec</li>
779	<li>9 = 300 sec</li>
780	<li>10 = 600 sec</li>
781	<li>11 = 900 sec</li>
782	<li>12 = 1800 sec</li>
783	<li>13 = 3600 sec</li>
784	<li>14 = 7200 sec</li>
785	<li>15 = 10800 sec</li>
786	</ul>
787	<li>GPS Week</li>
788	<li>Second in GPS Week</li>
789	<li>GNSS Indicator and Satellite Vehicle Pseudo Random Number</li>
790	</ul>
791	</p>
792	<p>
793	In case of RTCM message types 1057 or 1063 (see Annex) these parameters are followed by
794	</p>
795	<p>
796	<ul>
797	<li>IOD referring to Broadcast Ephemeris set</li>
798	<li>Radial Component of Orbit Correction to Broadcast Ephemeris [m]</li>
799	<li>Along-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
800	<li>Cross-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
801	<li>Velocity of Radial Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
802	<li>Velocity of Along-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
803	<li>Velocity of Cross-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
804	<p>
805	</ul>
806	</p>
807	<p>
808	Undefined parameters would be set to zero "0.000".<br>Example:
809	<pre>
810	...
811	1057 0 1686 283200.0 G02 21 1.062 -0.791 1.070 -0.00025 -0.00031 -0.00005
812	1057 0 1686 283200.0 G03 25 1.765 -2.438 -0.290 -0.00009 -0.00060 0.00028
813	1057 0 1686 283200.0 G04 14 1.311 -0.862 0.334 0.00005 -0.00038 -0.00015
814
815	...
816	1063 0 1686 283200.0 R01 39 0.347 1.976 -1.418 0.00048 -0.00091 0.00008
817	1063 0 1686 283200.0 R02 39 0.624 -2.092 -0.155 0.00005 -0.00054 0.00053
818	1063 0 1686 283200.0 R03 39 0.113 5.655 -1.540 0.00003 -0.00079 -0.00003
819	1063 0 1686 283200.0 R05 39 0.237 1.426 -1.282 0.00054 -0.00020 0.00027
820	...
821	</pre>
822	<p>
823	In case of RTCM message types 1058 or 1064 (see Annex) the first five parameters in each record are followed by
824	</p>
825	<ul>
826	<li>IOD set to zero "0"</li>
827	<li>C0 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
828	<li>C1 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m/s]</li>
829	<li>C2 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m/s**2]</li>
830	</ul>
831	Example:
832	</p>
833	<pre>
834	...
835	1058 0 1538 211151.0 G18 0 1.846 0.000 0.000
836	1058 0 1538 211151.0 G16 0 0.376 0.000 0.000
837	1058 0 1538 211151.0 G22 0 2.727 0.000 0.000
838	...
839	1064 0 1538 211151.0 R08 0 8.956 0.000 0.000
840	1064 0 1538 211151.0 R07 0 14.457 0.000 0.000
841	1064 0 1538 211151.0 R23 0 6.436 0.000 0.000
842	...
843	</pre>
844	</p>
845	<p>
846	In case of RTCM message types 1060 or 1066 (see Annex) the first five parameters in each record are followed by
847	<p>
848	<ul>
849	<li>IOD referring to Broadcast Ephemeris set</li>
850	<li>C0 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
851	<li>Radial Component of Orbit Correction to Broadcast Ephemeris [m]</li>
852	<li>Along-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
853	<li>Cross-track Component of Orbit Correction to Broadcast Ephemeris [m]</li>
854	<li>C1 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
855	<li>Velocity of Radial Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
856	<li>Velocity of Along-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
857	<li>Velocity of Cross-track Component of Orbit Correction to Broadcast Ephemeris [m/s]</li>
858	<li>C2 polynomial coefficient for Clock Correction to Broadcast Ephemeris [m]</li>
859	</ul>
860	Example:
861	</p>
862	<pre>
863	...
864	1060 0 1538 211610.0 G30 82 2.533 0.635 -0.359 -0.598 0.000 0.000 0.000 0.000 0.000
865	1060 0 1538 211610.0 G31 5 -4.218 -0.208 0.022 0.002 0.000 0.000 0.000 0.000 0.000
866	1060 0 1538 211610.0 G32 28 -2.326 0.977 -0.576 0.142 0.000 0.000 0.000 0.000 0.000
867	...
868	1066 0 1538 211610.0 R22 27 1.585 2.024 2.615 -2.080 0.000 0.000 0.000 0.000 0.000
869	1066 0 1538 211610.0 R23 27 6.277 2.853 4.181 1.304 0.000 0.000 0.000 0.000 0.000
870	1066 0 1538 211610.0 R24 27 0.846 1.805 13.095 6.102 0.000 0.000 0.000 0.000 0.000
871	...
872	</pre>
873	</p>
874	<p>
875	In case of RTCM message types 1059 or 1065 (see Annex) the first five parameters in each record are followed by
876	<ul>
877	<li>Number of Code Biases</li>
878	<li>Indicator to specify the signal and tracking mode</li>
879	<li>Code Bias</li>
880	<li>Indicator to specify the signal and tracking mode</li>
881	<li>Code Bias</li>
882	<li>etc.</li>
883	</ul>
884	Example:
885	</p>
886	<pre>
887	...
888	1059 0 1538 211151.0 G18 2 0 -0.010 11 -0.750
889	1059 0 1538 211151.0 G16 2 0 -0.040 11 -0.430
890	1059 0 1538 211151.0 G22 2 0 -0.630 11 -2.400
891	...
892	</pre>
893
894	<p><a name="corrdir"><h4>3.7.1 Directory, ASCII - optional</h4></p>
895	<p>
896	Specify 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.
897	</p>
898
899	<p><a name="corrint"><h4>3.7.2 Interval - mandatory if 'Directory, ASCII' is set</h4></p>
900	<p>
901	Select the length of the Broadcast Correction files. The default value is 1 day.
902	</p>
903
904	<p><a name="corrport"><h4>3.7.3 Port - optional</h4></p>
905	<p>
906	BNC 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.
907	</p>
908	<p>
909	The 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.
910	</p>
911	<p>
912	The following is an example output for streams from mountpoints RTCMSSR, CLK10 and CLK11:
913	<pre>
914	...
915	1057 0 1538 211151.0 G18 1 0.034 0.011 -0.064 0.000 0.000 0.000 RTCMSSR
916	1057 0 1538 211151.0 G16 33 -0.005 0.194 -0.091 0.000 0.000 0.000 RTCMSSR
917	1057 0 1538 211151.0 G22 50 0.008 -0.082 -0.001 0.000 0.000 0.000 RTCMSSR
918	...
919	1058 0 1538 211151.0 G18 0 1.846 0.000 RTCMSSR
920	1058 0 1538 211151.0 G16 0 0.376 0.000 RTCMSSR
921	1058 0 1538 211151.0 G22 0 2.727 0.000 RTCMSSR
922	...
923	1059 0 1538 211151.0 G18 2 0 -0.010 11 -0.750 RTCMSSR
924	1059 0 1538 211151.0 G16 2 0 -0.040 11 -0.430 RTCMSSR
925	1059 0 1538 211151.0 G22 2 0 -0.630 11 -2.400 RTCMSSR
926	...
927	1063 0 1538 211151.0 R09 111 -0.011 -0.014 0.005 0.0000 0.000 0.000 RTCMSSR
928	1063 0 1538 211151.0 R10 43 0.000 -0.009 -0.002 0.0000 0.000 0.000 RTCMSSR
929	1063 0 1538 211151.0 R21 75 -0.029 0.108 0.107 0.0000 0.000 0.000 RTCMSSR
930	...
931	1064 0 1538 211151.0 R08 0 8.956 0.000 RTCMSSR
932	1064 0 1538 211151.0 R07 0 14.457 0.000 RTCMSSR
933	1064 0 1538 211151.0 R23 0 6.436 0.000 RTCMSSR
934	...
935	1066 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
936	1066 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
937	1066 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
938	...
939	1060 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
940	1060 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
941	1060 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
942	...
943	</pre>
944	</p>
945	<p>
946	The source code for BNC comes with an example perl script 'test_tcpip_client.pl' that allows you to read BNC's Broadcast Corrections from the IP port.
947	</p>
948
949	<p><a name="corrwait"><h4>3.7.4 Wait for Full Corr Epoch - mandatory if 'Port' is set</h4></p>
950	<p>
951	When feeding a real-time GNSS network engine (see 'Feed Engine') waiting epoch by epoch for synchronized Broadcast Corrections, or when you 'Combine Corrections' BNC drops (only concerning IP port output) whatever is received later than 'Wait for full corr epoch' seconds. A value of 2 to 5 seconds could be an appropriate choice for that, depending on the latency of the incoming Broadcast Corrections stream and the delay acceptable by your application. A message such as "COCK1: Correction overaged by 5 sec" shows up in BNC's logfile if 'Wait for full corr epoch' is exceeded.
952	</p>
953	<p>
954	Specifying a value of '0' means that BNC immediately outputs all incoming Broadcast Ephemeris Corrections and does not drop any of them for latency reasons.
955	</p>
956
957	<p><a name="syncout"><h4>3.8. Feed Engine</h4></p>
958	<p>
959	BNC can generate synchronized or unsynchronized observations epoch by epoch from all stations and satellites to feed a real-time GNSS network engine. Observations can be streamed out through an IP port and/or saved in a local file. The output is always in plain ASCII format and comprises the following parameters:
960	</p>
961	<p>
962	StationID \| GPSWeek \| GPSWeekSec \| PRN, G=GPS, R=GLO \| SlotNumber (if GLO) \| Band/Frequency & trackingMode \| Code \| Phase \| Doppler \| SNR \| SlipCount \| ....
963	</p>
964	<p>
965	In case an observation is not available, its value is set to zero '0.000'.
966	</p>
967	<p>Note on 'SlipCount':<br>
968	It is the current understanding of BNC's authors that different slip counts could be referred to different phase measurements (i.e. L1C and L1P). The 'loss-of-lock' flags in RINEX are an example for making such kind of information available per phase measurement. However, it looks like we do have only one slip count in RTCM Version 3 for all phase measurements. As it could be that a receiver generates different slip counts for different phase measurements, we output one slip count per phase measurement to a listening real-time GNSS network engine.
969	</p>
970
971	<p>
972	The following is an output example for GPS and GLONASS:
973	<pre>
974	...
975	CUT07 1683 493688.0000000 G05 1C 24584925.242 129195234.317 3639.020 38.812 40 2P 24584927.676 100671636.233 0.0 22.812 -1 2X 24584927.336 100671611.239 0.0 39.500 -1
976	CUT07 1683 493688.0000000 G04 1C 22598643.968 118756563.731 -1589.277 42.625 40 2P 22598649.391 92537559.230 0.0 29.125 -1
977	CUT07 1683 493688.0000000 G02 1C 23290004.062 122389588.008 -445.992 46.375 -1 2P 23290003.567 95368508.986 0.0 29.188 -1
978
979	CUT07 1683 493689.0000000 R16 -1 1C 19210052.313 102616872.230 364.063 53.375 42 1P 19210053.445 102616393.224 0.0 52.312 42 2P 19210057.785 79813218.557 0.0 50.188 -1
980	CUT07 1683 493689.0000000 R15 0 1C 20665491.149 110430900.266 -2839.875 49.188 -1 1P 20665491.695 110430900.278 0.0 47.625 -1 2P 20665497.559 85890714.522 0.0 48.000 -1
981	CUT07 1683 493689.0000000 R09 -2 1C 22028400.805 117630697.367 3584.840 47.625 -1 1P 22028401.586 117630607.367 0.0 45.688 -1 2P 22028406.746 91490549.182 0.0 41.625 -1
982	CUT07 1683 493689.0000000 R07 5 1C 24291127.360 130032400.255 4146.149 40.125 42 1P 24291128.492 130032400.259 0.0 39.312 42 2P 24291130.602 101136710.408 0.0 35.125 -1
983	CUT07 1683 493689.0000000 R05 1 1C 19740809.867 105526251.571 -921.679 54.125 42 1P 19740809.008 105526273.586 0.0 51.875 42 2P 19740814.051 82075815.588 0.0 50.812 -1
984	CUT07 1683 493689.0000000 R04 6 1C 23394651.125 125277095.951 -3385.191 40.875 42 1P 23394651.906 125277095.943 0.0 39.812 42 2P 23394658.125 97437771.004 0.0 39.000 -1
985	CUT07 1683 493689.0000000 G28 1C 25286905.648 132883677.970 4016.750 36.125 17 2P 25286911.715 103545663.916 0.0 14.812 11
986	CUT07 1683 493689.0000000 G23 1C 23018013.274 120961034.323 -1795.551 46.375 -1 2P 23018011.781 94255379.472 0.0 31.688 -1
987	CUT07 1683 493689.0000000 G20 1C 24055613.563 126413402.503 -3233.574 38.500 -1 2P 24055617.227 98504065.103 0.0 20.125 -1
988	CUT07 1683 493689.0000000 G16 1C 24846810.039 130571661.274 -2140.137 38.000 41 2P 24846811.477 101744166.486 0.0 18.625 -1
989	CUT07 1683 493689.0000000 G13 1C 21388182.664 112395102.592 -678.356 51.812 -1 2P 21388183.516 87580617.458 0.0 39.688 -1
990	CUT07 1683 493689.0000000 G10 1C 20656684.758 108551288.049 1726.191 52.875 -1 2P 20656687.016 84585420.340 0.0 42.625 -1
991	CUT07 1683 493689.0000000 G08 1C 20703057.860 108795261.566 1880.523 52.875 -1 2P 20703060.644 84775535.497 0.0 41.188 -1
992	CUT07 1683 493689.0000000 G07 1C 20200125.289 106152257.500 -603.082 53.312 41 2P 20200126.961 82716251.449 0.0 46.000 -1 2X 20200126.797 82716243.452 0.0 52.625 -1
993	CUT07 1683 493689.0000000 G05 1C 24584232.312 129191595.301 3639.047 38.875 41 2P 24584234.980 100668800.633 0.0 22.875 -1 2X 24584234.348 100668775.639 0.0 39.812 -1
994	CUT07 1683 493689.0000000 G04 1C 22598946.500 118758153.159 -1589.461 42.500 41 2P 22598951.570 92538797.744 0.0 29.125 -1
995	CUT07 1683 493689.0000000 G02 1C 23290088.758 122390034.211 -446.429 46.312 -1 2P 23290088.203 95368856.681 0.0 28.500 -1
996
997	CUT07 1683 493690.0000000 R16 -1 1C 19209984.633 102616508.497 363.305 53.500 43 1P 19209985.180 102616029.506 0.0 51.812 43 2P 19209989.871 79812935.655 0.0 50.188 -1
998	CUT07 1683 493690.0000000 R15 0 1C 20666023.047 110433740.264 -2840.242 49.188 -1 1P 20666023.945 110433740.275 0.0 47.500 -1 2P 20666029.574 85892923.403 0.0 47.625 -1
999	CUT07 1683 493690.0000000 R09 -2 1C 22027730.398 117627112.720 3584.305 47.688 -1 1P 22027730.828 117627022.726 0.0 46.188 -1 2P 22027735.988 91487761.121 0.0 41.688 -1
1000	...
1001	</pre>
1002	<p>
1003	The source code for BNC comes with a perl script called 'test_tcpip_client.pl' that allows you to read BNC's (synchronized or unsynchronized) ASCII observation output from the IP port and print it on standard output.
1004	</p>
1005	<p>
1006	Note 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'.
1007	</p>
1008
1009	<p>
1010	The following figure shows the screenshot of a BNC configuration where a number of streams is pulled from different NTRIP Broadcasters to feed a GNSS engine via IP port output.
1011	</p>
1012	<p><img src="IMG/screenshot12.png"/></p>
1013	<p><u>Figure 8:</u> Synchronized BNC output via IP port to feed a GNSS real-time engine.</p>
1014
1015	<p><a name="syncport"><h4>3.8.1 Port - optional</h4></p>
1016	<p>
1017	BNC can produce synchronized observations in ASCII format on your local host (IP 127.0.0.1) through an IP 'Port'. Synchronized means that BNC collects all observation data for any specific epoch which become available within a certain number of latency seconds (see 'Wait for Full Obs Epoch' option). It then - epoch by epoch - outputs whatever has been received. Specify an IP port number here to activate this function. The default is an empty option field, meaning that no binary synchronized output is generated.</p>
1018	</p>
1019
1020	<p><a name="syncwait"><h4>3.8.2 Wait for Full Obs Epoch - mandatory if 'Port' is set</h4></p>
1021	<p>
1022	When feeding a real-time GNSS network engine waiting for synchronized observations epoch by epoch, BNC drops whatever is received later than 'Wait for full obs epoch' seconds. A value of 3 to 5 seconds could be an appropriate choice for that, depending on the latency of the incoming streams and the delay acceptable for your real-time GNSS product. Default value for 'Wait for full obs epoch' is 5 seconds.
1023	</p>
1024	<p>
1025	Note that 'Wait for full obs epoch' does not affect the RINEX Observation file content. Observations received later than 'Wait for full obs epoch' seconds will still be included in the RINEX Observation files.
1026	</p>
1027
1028	<p><a name="syncsample"><h4>3.8.3 Sampling - mandatory if 'File' or 'Port' is set</h4></p>
1029	<p>
1030	Select 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.
1031	</p>
1032
1033	<p><a name="syncfile"><h4>3.8.4 File - optional</h4></p>
1034	<p>
1035	Specify 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.
1036	</p>
1037	<p>
1038	Beware 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.
1039	</p>
1040
1041	<p><a name="syncuport"><h4>3.8.5 Port (unsynchronized) - optional</h4></p>
1042	<p>
1043	BNC can produce unsynchronized observations from all configured streams in ASCII format on your local host (IP 127.0.0.1) through an IP 'Port'. Unsynchronized means that BNC immediately forwards any received observation to the port. Specify an IP port number here to activate this function. The default is an empty option field, meaning that no unsynchronized output is generated.</p>
1044	<p>
1045
1046	<p><a name="serial"><h4>3.9. Serial Output</h4></p>
1047	<p>
1048	You may use BNC to feed a serial connected device like a GNSS receiver. For that an incoming stream can be forwarded to a serial port. The following figure shows the screenshot of an example situation where BNC pulls a VRS stream from an NTRIP Broadcaster to feed a serial connected RTK rover.
1049	</p>
1050	<p><img src="IMG/screenshot11.png"/></p>
1051	<p><u>Figure 9:</u> BNC pulling a VRS stream to feed a serial connected RTK rover.</p>
1052
1053	<p><a name="sermount"><h4>3.9.1 Mountpoint - optional</h4></p>
1054	<p>
1055	Enter a 'Mountpoint' to forward its corresponding stream to a serial connected GNSS receiver.
1056	</p>
1057	<p>
1058	When selecting one of the serial communication options listed below, make sure that you pick those configured to the serial connected receiver.
1059	</p>
1060
1061	<p><a name="serport"><h4>3.9.2 Port Name - mandatory if 'Mountpoint' is set</h4></p>
1062	<p>
1063	Enter the serial 'Port name' selected on your host for communication with the serial connected receiver. Valid port names are
1064	</p>
1065	<pre>
1066	Windows: COM1, COM2
1067	Linux: /dev/ttyS0, /dev/ttyS1
1068	FreeBSD: /dev/ttyd0, /dev/ttyd1
1069	Digital Unix: /dev/tty01, /dev/tty02
1070	HP-UX: /dev/tty1p0, /dev/tty2p0
1071	SGI/IRIX: /dev/ttyf1, /dev/ttyf2
1072	SunOS/Solaris: /dev/ttya, /dev/ttyb
1073	</pre>
1074	<p>
1075	Note that you must plug a serial cable in the port defined here before you start BNC.
1076	</p>
1077
1078	<p><a name="serbaud"><h4>3.9.3 Baud Rate - mandatory if 'Mountpoint' is set</h4></p>
1079	<p>
1080	Select a 'Baud rate' for the serial output link. Note that using a high baud rate is recommended.
1081	</p>
1082
1083	<p><a name="serflow"><h4>3.9.4 Flow Control - mandatory if 'Mountpoint' is set</h4></p>
1084	<p>
1085	Select 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.
1086	</p>
1087
1088	<p><a name="serparity"><h4>3.9.5 Parity - mandatory if 'Mountpoint' is set</h4></p>
1089	<p>
1090	Select the 'Parity' for the serial output link. Note that parity is often set to 'NONE'.
1091	</p>
1092
1093	<p><a name="serdata"><h4>3.9.6 Data Bits - mandatory if 'Mountpoint' is set</h4></p>
1094	<p>
1095	Select the number of 'Data bits' for the serial output link. Note that often '8' data bits are used.
1096	</p>
1097
1098	<p><a name="serstop"><h4>3.9.7 Stop Bits - mandatory if 'Mountpoint' is set</h4></p>
1099	<p>
1100	Select the number of 'Stop bits' for the serial output link. Note that often '1' stop bit is used.
1101	</p>
1102
1103	<p><a name="serauto"><h4>3.9.8 NMEA - mandatory for VRS streams</h4></p>
1104	<p>
1105	Select '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.
1106	</p>
1107	<p>
1108	Forwarding valid NMEA-GGA messages to the NTRIP Broadcaster is required for receiving 'Virtual Reference Station' (VRS) streams. Thus, in case your serial connected receiver is not capable to provide them, the alternative for VRS streams is a 'Manual' simulation of an initial NMEA-GGA message. Its content is based on the approximate (editable) latitude/longitude from the broadcaster's source-table and an approximate VRS height to be specified.
1109	</p>
1110	<p>
1111	In summary: select 'Manual' only when handling a VRS stream and your serial connected GNSS receiver doesn't generate NMEA-GGA messages. Select 'Auto' otherwise.
1112	</p>
1113
1114	<p><a name="serfile"><h4>3.9.9 File - optional if 'Auto' NMEA is set</h4></p>
1115	<p>Specify the full path to a file where NMEA messages coming from your serial connected receiver are saved.
1116	</p>
1117	<p><a name="serheight"><h4>3.9.10 Height - mandatory if 'Manual' NMEA is set</h4></p>
1118	<p>
1119	Specify 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.
1120	</p>
1121	<p>
1122	This option concerns only 'Virtual Reference Stations' (VRS). Its setting is ignored in case of streams coming from physical reference stations.
1123	</p>
1124
1125	<p><a name="advnote"><h4>3.10. Outages</h4></p>
1126
1127	<p>
1128	At any time an incoming stream might become unavailable or corrupted. In such cases, it is important that the BNC operator and/or the stream providers become aware of the situation so that necessary measures can be taken to restore the stream. Furthermore, continuous attempts to decode a corrupted stream can generate unnecessary workload for BNC. Outages and corruptions are handled by BNC as follows:
1129	</p>
1130	<p>
1131	<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.
1132	</p>
1133	<p>
1134	<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.
1135	</p>
1136	<p>
1137	Outage 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.
1138	</p>
1139
1140	<p><a name="obsrate"><h4>3.10.1 Observation Rate - mandatory if 'Failure threshold', 'Recovery threshold' and 'Script' is set</h4></p>
1141	<p>
1142	BNC can collect all returns (success or failure) coming from a decoder within a certain short time span to then decide whether a stream has an outage or its content is corrupted. This procedure needs a rough a priory estimate of the expected observation rate of the incoming streams.</p><p>An empty option field (default) means that you don't want explicit information from BNC about stream outages and incoming streams that cannot be decoded.
1143	</p>
1144
1145	<p><a name="advfail"><h4>3.10.2 Failure Threshold - optional</h4></p>
1146	<p>
1147	Event 'Begin_Failure' will be reported if no data is received continuously for longer than the 'Failure threshold' time. Similarly, event 'Begin_Corrupted' will be reported when corrupted data is detected by the decoder continuously for longer than this 'Failure threshold' time. The default value is set to 15 minutes and is recommended so not to inundate user with too many event reports.
1148	</p>
1149	<p>
1150	Note 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'.
1151	</p>
1152
1153	<p><a name="advreco"><h4>3.10.3 Recovery Threshold - optional</h4></p>
1154	<p>
1155	Once a 'Begin_Failure' or 'Begin_Corrupted' event has been reported, BNC will check for when the stream again becomes available or uncorrupted. Event 'End_Failure' or 'End_Corrupted' will be reported as soon as valid observations are again detected continuously throughout the 'Recovery threshold' time span. The default value is set to 5 minutes and is recommended so not to inundate users with too many event reports.
1156	</p>
1157	<p>
1158	Note 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'.
1159	</p>
1160
1161	<p><a name="advscript"><h4>3.10.4 Script - optional </h4></p>
1162	<p>
1163	As 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.
1164	</p>
1165	<p>
1166	Leave the 'Script' field empty if you do not wish to use this option. An invalid path will also disable this option.
1167	</p>
1168	<p>
1169	Examples for command line parameter strings passed on to the advisory 'Script' are:
1170	<pre>
1171	FFMJ0 Begin_Outage 08-02-21 09:25:59
1172	FFMJ0 End_Outage 08-02-21 11:36:02 Begin was 08-02-21 09:25:59
1173	</pre>
1174	</p>
1175	<p>
1176	Sample script for Unix/Linux/Mac systems:
1177	</p>
1178	<pre>
1179	#!/bin/bash
1180	sleep $((60*RANDOM/32767))
1181	cat \| mail -s "NABU: $1" email@address <<!
1182	Advisory Note to BNC User,
1183	Please note the following advisory received from BNC.
1184	Stream: $*
1185	Regards, BNC
1186	!
1187	</pre>
1188	</p>
1189	<p>
1190	Note 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.
1191	</p>
1192
1193	<p><a name="misc"><h4>3.11. Miscellaneous</h4></p>
1194	<p>
1195	This section describes several miscellaneous options which can be applied for a single stream (mountpoint) or for all configured streams.
1196	</p>
1197
1198	<p>
1199	The following figure shows RTCM message numbers contained in stream 'CONZ0' and the message latencies recorded every 10 seconds.
1200	</p>
1201	<p><img src="IMG/screenshot14.png"/></p>
1202	<p><u>Figure 10:</u> RTCM message numbers and latencies.</p>
1203
1204
1205	<p><a name="miscmount"><h4>3.11.1 Mountpoint - optional </h4></p>
1206	<p>
1207	Specify 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.
1208	</p>
1209
1210	<p><a name="miscperf"><h4>3.11.2 Log Latency - optional </h4></p>
1211	<p>
1212	BNC can average latencies per stream over a certain period of GPS time, the 'Log latency' interval. Mean latencies are calculated from the individual latencies of one (first incoming) observation or Broadcast Correction per second. The mean latencies are then saved in BNC's logfile. Note that computing correct latencies requires the clock of the host computer to be properly synchronized. Note further that visualized latencies from the 'Latency' tab on the bottom of the main window represent individual latencies and not the mean latencies for the logfile.
1213	</p>
1214	<p>
1215	<u>Latency:</u> Latency is defined in BNC by the following equation:
1216	</p>
1217	<pre>
1218	UTC time provided by BNC's host
1219	- GPS time of currently processed epoch
1220	+ Leap seconds between UTC and GPS time
1221	--------------
1222	= Latency
1223	</pre>
1224	<p>
1225	<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.
1226	</p>
1227	<p>
1228	Latencies 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:
1229	</p>
1230	<pre>
1231	08-03-17 15:59:47 BRUS0: Mean latency 1.47 sec, min 0.66, max 3.02, rms 0.35, 3585 epochs, 15 gaps
1232	</pre>
1233	<p>
1234	Select 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.
1235	</p>
1236
1237
1238	<p><a name="miscscan"><h4>3.11.3 Scan RTCM - optional</h4></p>
1239	<p>
1240	When configuring a GNSS receiver for RTCM stream generation, the firmware's 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.
1241	</p>
1242	<p>
1243	Tick 'Scan RTCM' to scan RTCM Version 2 or 3 streams and log all contained
1244	</p>
1245	<ul>
1246	<li>Numbers of incoming message types</li>
1247	<li>Antenna Reference Point (ARP) coordinates</li>
1248	<li>Antenna Phase Center (APC) coordinates</li>
1249	<li>Antenna height above marker</li>
1250	<li>Antenna descriptor.</li>
1251	</ul>
1252	</p>
1253
1254	<p>
1255	Note that in RTCM Version 2 the message types 18 and 19 carry only the observables of one frequency. Hence it needs two type 18 and 19 messages per epoch to transport the observations from dual frequency receivers.
1256	</p>
1257	<p>
1258
1259	<p>Logged time stamps refer to message reception time and allow understanding repetition rates. Enter 'ALL' if you want to log this information from all configured streams. Beware that the size of the logfile can rapidly increase depending on the number of incoming RTCM streams.
1260	</p>
1261	<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.
1262	</p>
1263
1264	<p><a name="pppclient"><h4>3.12. PPP Client</h4></p>
1265	<p>
1266	BNC 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
1267	<ul>
1268	<li>requires pulling in addition a stream carrying satellite orbit and clock corrections to Broadcast Ephemeris in the form of RTCM Version 3 'State Space Representation' (SSR) messages. Note that for BNC these Broadcast Corrections need to be referred to the satellite's Antenna Phase Center (APC). Streams providing such messages are listed on <u>http://igs.bkg.bund.de/ntrip/orbits</u>. Stream 'CLK11' on NTRIP Broadcaster 'products.igs-ip.net:2101' is an example.</li>
1269	<li>may require pulling a stream carrying Broadcast Ephemeris available as RTCM Version 3 message types 1019, 1020, and 1045. This is a must only when the stream coming from the receiver does not contain Broadcast Ephemeris or provides them only at very low repetition rate. Streams providing such messages are listed on <u>http://igs.bkg.bund.de/ntrip/ephemeris</u>. Stream 'RTCM3EPH' on caster 'products.igs-ip.net:2101' is an example.</li>
1270	</ul>
1271	</p>
1272	<p>
1273	The following figure provides the screenshot of an example PPP session with BNC.
1274	</p>
1275
1276	<p><img src="IMG/screenshot03.png"/></p>
1277	<p><u>Figure 11:</u> Precise Point Positioning with BNC, PPP Panel 1.</p>
1278
1279	<p><img src="IMG/screenshot18.png"/></p>
1280	<p><u>Figure 12:</u> Precise Point Positioning with BNC, PPP Panel 2.</p>
1281
1282	<p>
1283	PPP 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):
1284	<pre>
1285	10-09-08 09:14:06 FFMJ1 PPP 09:14:04.0 12 4053457.429 +- 2.323 617730.551 +- 1.630 4869395.266 +- 2.951
1286	</pre>
1287	</p>
1288	<p>
1289	The selected mountpoint in that is followed by a PPP time stamp in GPS Time, the number of processed satellites, and XYZ coordinates with their formal errors as derived from the implemented filter in [m]. The implemented algorithm includes outlier and cycle slip detection. The maximum for accepted residuals is hard coded to 10 meters for code observations and 10 centimeters for phase observations.
1290	</p>
1291
1292	<p>
1293	More detailed PPP results are saved in BNC's logfile. Depending on the selected processing options you find
1294	<ul>
1295	<li>code and phase residuals for GPS and GLONASS and Galileo in [m], </li>
1296	<li>receiver clock errors in [m], </li>
1297	<li>a-priori and correction values of tropospheric zenith delay in [m],
1298	<li>time offset between GPS time and Galileo time in [m],
1299	<li>L3 biases, also known as 'floated ambiguities', given per satellite.
1300	</ul>
1301	These parameters are saved together with their standard deviation. The following is an example extract from a log file when BNC was in 'Single Point Positioning' (SPP) mode:
1302	</p>
1303	<p>
1304	<pre>
1305	10-12-06 18:10:50 Single Point Positioning of Epoch 18:10:48.0
1306	--------------------------------------------------------------
1307	18:10:48.0 RES G04 L3 0.0165 P3 -0.1250
1308	18:10:48.0 RES G11 L3 0.0150 P3 0.7904
1309	18:10:48.0 RES G13 L3 0.0533 P3 0.4854
1310	18:10:48.0 RES G17 L3 -0.0277 P3 1.2920
1311	18:10:48.0 RES G20 L3 -0.0860 P3 -0.1186
1312	18:10:48.0 RES G23 L3 0.0491 P3 -0.1052
1313	18:10:48.0 RES G31 L3 0.0095 P3 -3.2929
1314	18:10:48.0 RES G32 L3 0.0183 P3 -3.8800
1315	18:10:48.0 RES R05 L3 -0.0077
1316	18:10:48.0 RES R06 L3 0.0223
1317	18:10:48.0 RES R15 L3 -0.0020
1318	18:10:48.0 RES R16 L3 0.0156
1319	18:10:48.0 RES R20 L3 -0.0247
1320	18:10:48.0 RES R21 L3 0.0014
1321	18:10:48.0 RES R22 L3 -0.0072
1322	18:10:48.0 RES E52 L3 -0.0475 P3 -0.1628
1323	18:10:48.0 RES G04 L3 0.0166 P3 -0.1250
1324	18:10:48.0 RES G11 L3 0.0154 P3 0.7910
1325	18:10:48.0 RES G13 L3 0.0535 P3 0.4855
1326	18:10:48.0 RES G17 L3 -0.0272 P3 1.2925
1327	18:10:48.0 RES G20 L3 -0.0861 P3 -0.1188
1328	18:10:48.0 RES G23 L3 0.0489 P3 -0.1055
1329	18:10:48.0 RES G31 L3 0.0094 P3 -3.2930
1330	18:10:48.0 RES G32 L3 0.0183 P3 -3.8800
1331	18:10:48.0 RES R05 L3 -0.0079
1332	18:10:48.0 RES R06 L3 0.0223
1333	18:10:48.0 RES R15 L3 -0.0020
1334	18:10:48.0 RES R16 L3 0.0160
1335	18:10:48.0 RES R20 L3 -0.0242
1336	18:10:48.0 RES R21 L3 0.0016
1337	18:10:48.0 RES R22 L3 -0.0072
1338	18:10:48.0 RES E52 L3 -0.0474 P3 0.1385
1339
1340	clk = 64394.754 +- 0.045
1341	trp = 2.185 +0.391 +- 0.001
1342	offset = -415.400 +- 0.137
1343	amb G17 = 11.942 +- 0.045
1344	amb G23 = 248.892 +- 0.044
1345	amb G31 = 254.200 +- 0.045
1346	amb G11 = -12.098 +- 0.044
1347	amb G20 = -367.765 +- 0.044
1348	amb G04 = 259.588 +- 0.044
1349	amb E52 = 6.124 +- 0.130
1350	amb G32 = 201.496 +- 0.045
1351	amb G13 = -265.658 +- 0.044
1352	amb R22 = -106.246 +- 0.044
1353	amb R21 = -119.605 +- 0.045
1354	amb R06 = 41.328 +- 0.044
1355	amb R15 = 163.453 +- 0.044
1356	amb R20 = -532.746 +- 0.045
1357	amb R05 = -106.603 +- 0.044
1358	amb R16 = -107.830 +- 0.044
1359	</pre>
1360	</p>
1361
1362	<p>
1363	Note that for debugging or Post Processing purposes BNC's 'PPP' functionality option can also be used offline.
1364	<ul>
1365	<li>
1366	<u>Debugging:</u> Apply the 'File Mode' 'Command Line' option for that to read a file containing synchronized observations, orbit and clock correctors, and Broadcast Ephemeris. Such a file must be generated before using BNC's 'Raw output file' option. Example:<br>
1367	bnc.exe --conf c:\temp\PPP.bnc --file c:\temp\FFMJ1
1368	</li>
1369	<li>
1370	<u>Post Processing:</u> Apply the 'Post Processing' option as described below.
1371	</li>
1372	</ul>
1373	</p>
1374
1375	<p>When using the PPP option, it is important to understand which effects are corrected by BNC.
1376	</p>
1377	<ul>
1378	<li>BNC does correct for Solid Earth Tides and Phase Windup.</li>
1379	<li>Satellite antenna phase center offsets are not corrected because applied orbit/clock corrections are referred to the satellite's antenna phase center.</li>
1380	<li>Satellite antenna phase center variations are neglected because this is a small effect usually less than 2 centimeters.</li>
1381	<li>Observations can be corrected for a Receiver Antenna Offset. Depending on whether or not this correction is applied, the estimated position is either that of the receiver's antenna phase center or that of the receiver's Antenna Reference Point.</li>
1382	<li>Receiver antenna phase center variations are not included in the model. The bias caused by this neglect depends on the receiver antenna type. For most antennas it is smaller than a few centimeters.</li>
1383	<li>Ocean and atmospheric loading is neglected. Atmospheric loading is pretty small. Ocean loading is usually also a small effect but may reach up to about 10 centimeters for coastal stations.</li>
1384	<li>Rotational deformation due to polar motion (Polar Tides) is not corrected because this is a small effect usually less than 2 centimeters.</li>
1385	</ul>
1386	</p>
1387
1388	<p><a name="pppmode"><h4>3.12.1 Mode & Mountpoints - optional</h4></p>
1389	<p>
1390	Specify the Point Positioning mode you want to apply and the mountpoints for observations and Broadcast Corrections.
1391	</p>
1392
1393	<p><a name="pppmodus"><h4>3.12.1.1 Mode - optional</h4></p>
1394	<p>
1395	Choose between plain Single Point Positioning (SPP) and Precise Point Positioning (PPP) in 'Realtime' or 'Post-Processing' mode. Options are 'Realtime-PPP', 'Realtime-SPP', and 'Post-Processing'.
1396	</p>
1397
1398	<p><a name="pppobsmount"><h4>3.12.1.2 Obs Mountpoint - optional</h4></p>
1399	<p>
1400	Specify an 'Observations Mountpoint' from the list of selected 'Streams' you are pulling if you want BNC to derive coordinates for the affected rover position through a Point Positioning solution.
1401	</p>
1402
1403	<p><a name="pppcorrmount"><h4>3.12.1.3 Corr Mountpoint - optional</h4></p>
1404	<p>
1405	Specify a Broadcast Ephemeris 'Corrections Mountpoint' from the list of selected 'Streams' you are pulling if you want BNC to correct your positioning solution accordingly.
1406	</p>
1407
1408	<p><a name="pppxyz"><h4>3.12.2 Marker Coordinates - optional</h4></p>
1409	<p>
1410	Enter the reference coordinate XYZ of the receiver's position in meters if known. This option makes only sense for static observations. Default are empty option fields, meaning that the antenna's XYZ position is unknown.
1411	</p>
1412	<p>
1413	Once a XYZ coordinate is defined, the 'PPP' line in BNC's logfile is extended by North, East and Up displacements to (example):
1414	</p>
1415	<pre>
1416	10-08-09 06:01:56 FFMJ1 PPP 06:02:09.0 11 4053457.628 +- 2.639 617729.438 +- 1.180 4869396.447 +- 1.921 NEU -0.908 -0.571 1.629
1417	</pre>
1418	<p>
1419	The parameters following the 'NEU' string provide North, East and Up components of the current coordinate displacement in meters.
1420	</p>
1421
1422	<p><a name="pppneu"><h4>3.12.3 Antenna Eccentricity - optional</h4></p>
1423	<p>
1424	You may like to specify North, East and Up components of an antenna eccentricity which is the difference between a nearby marker position and the antenna phase center. If you do so BNC will produce coordinates referring to the marker position and not referring to the antenna phase center.
1425	</p>
1426
1427	<p><a name="pppoutput"><h4>3.12.4 NMEA & Plot Output - optional</h4></p>
1428	<p>
1429	BNC allows to output results from Precise Point Positioning in NMEA format. It can also plot a time series of North, East and UP displacements.
1430	</p>
1431
1432	<p><a name="pppnmeafile"><h4>3.12.4.1 NMEA File - optional</h4></p>
1433	<p>
1434	The NMEA sentences generated about once per second are pairs of
1435	<ul>
1436	<li> GPGGA sentences which mainly carry the estimated latitude, longitude, and height values, plus</li>
1437	<li> GPRMC sentences which mainly carry date and time information.</li>
1438	</ul>
1439	</p>
1440	<p>
1441	Specify the full path to a file where Point Positioning results are saved as NMEA messages. The default value for 'NMEA file' is an empty option field, meaning that BNC will not saved NMEA messages into a file.
1442	</p>
1443	<p>
1444	Note that Tomoji Takasu has written a program called RTKPLOT for visualizing NMEA strings. It is available from <u>http://gpspp.sakura.ne.jp/rtklib/rtklib.htm</u> and compatible with the NMEA file and port output of BNC's 'PPP' client option.
1445	</p>
1446
1447	<p><a name="pppnmeaport"><h4>3.12.4.2 NMEA Port - optional</h4></p>
1448	<p>
1449	Specify the IP port number of a local port where Point Positioning results become available as NMEA messages. The default value for 'NMEA Port' is an empty option field, meaning that BNC does not provide NMEA messages vi IP port. Note that the NMEA file output and the NMEA IP port output are the same.
1450	</p>
1451	<p>
1452	NASA's 'World Wind' software (see <u>http://worldwindcentral.com/wiki/NASA_World_Wind_Download</u>) can be used for real-time visualization of positions provided through BNC's NMEA IP output port. You need the 'GPS Tracker' plug-in available from <u>http://worldwindcentral.com/wiki/GPS_Tracker</u> for that. The 'Word Wind' map resolution is not meant for showing centimeter level details.
1453	</p>
1454
1455	<p><a name="pppplot"><h4>3.12.4.3 PPP Plot - optional</h4></p>
1456	<p>
1457	PPP time series of North (red), East(green) and Up (blue) displacements will be plotted in the 'PPP Plot' tab when this option is ticked. Values will be either referred to an XYZ reference coordinate (if specified) or referred to the first estimated XYZ coordinate. The sliding PPP time series window will cover the period of the latest 5 minutes.
1458	</p>
1459	<p>
1460	Note that a PPP time series makes only sense for a stationary operated receiver.
1461	</p>
1462
1463	<p><a name="ppppost"><h4>3.12.5 Post Processing - optional</h4></p>
1464	<p>When in 'Post-Processing' mode
1465	<ul>
1466	<li>specifying a RINEX Observation, a RINEX Navigation and a Broadcast Corrections file leads to a PPP solution.</li>
1467	<li>specifying only a RINEX Observation and a RINEX Navigation file and no Broadcast Corrections file leads to a SPP solution.</li>
1468	</ul>
1469	</p>
1470	<p>BNC accepts RINEX Version 2 as well as RINEX Version 3 Observation or Navigation file formats. Files carrying Broadcast Corrections must have the format produced by BNC through the 'Broadcast Corrections' tab.
1471	<p>
1472	Post Processing PPP results can be saved in a specific output file.
1473	</p>
1474
1475	<p><a name="ppprecant"><h4>3.12.6 Antennas - optional</h4></p>
1476	<p>
1477	BNC allows correcting observations for antenna phase center offsets and variations.
1478	</p>
1479
1480	<p><a name="pppantex"><h4>3.12.6.1 ANTEX File - optional</h4></p>
1481	<p>
1482	IGS provides a file containing absolute phase center corrections for GNSS satellite and receiver antennas in ANTEX format. Entering the full path to such an ANTEX file is required for correcting observations for antenna phase center offsets and variations. It allows you to specify the name of your receiver's antenna (as contained in the ANTEX file) to apply such corrections.
1483	</p>
1484	<p>
1485	Default is an empty option field, meaning that you don't want to correct observations for antenna phase center offsets and variations.
1486	</p>
1487
1488	<p><a name="ppprecantenna"><h4>3.12.6.2 Receiver Antenna Name - optional if 'ANTEX File' is set</h4></p>
1489	<p>
1490	Specify the receiver's antenna name as defined in your ANTEX file. Observations will be corrected for the antenna phase center's offset which may result in a reduction of a few centimeters at max. Corrections for phase center variations are not yet applied by BNC. The specified name must consist of 20 characters. Add trailing blanks if the antenna name has less than 20 characters. Examples:
1491	<pre>
1492	'JPSREGANT_SD_E ' (no radome)
1493	'LEIAT504 NONE' (no radome)
1494	'LEIAR25.R3 LEIT' (radome)
1495	</pre>
1496	</p>
1497	<p>
1498	Default is an empty option field, meaning that you don't want to correct observations for antenna phase center offsets.
1499	</p>
1500
1501	<p><a name="pppbasics"><h4>3.12.7 Basics</h4></p>
1502	<p>BNC allows using different Point Positioning processing options depending on the capability of the involved receiver and the application in mind. It also allows introducing specific sigmas for code and phase observations as well as for reference coordinates and troposphere estimates. You may also like to carry out your PPP solution in Quick-Start mode or enforce BNC to restart a solution if the length of an outage exceeds a certain threshold.
1503	</p>
1504
1505	<p><a name="pppphase"><h4>3.12.7.1 Use Phase Obs - optional</h4></p>
1506	<p>
1507	By 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.
1508	</p>
1509
1510	<p><a name="ppptropo"><h4>3.12.7.2 Estimate Tropo - optional</h4></p>
1511	<p>
1512	BNC estimates the tropospheric delay according to equation
1513	<pre>
1514	T(z) = T_apr(z) + dT / cos(z)
1515	</pre>
1516	where T_apr is the a-priori tropospheric delay derived from Saastamoinen model.
1517	</p>
1518	<p>
1519	By default BNC does not estimate troposphere parameters. Tick 'Estimate tropo' to estimate troposphere parameters together with the coordinates and save T_apr and dT/cos(z) in BNC's log file.
1520	</p>
1521
1522	<p><a name="pppglo"><h4>3.12.7.3 Use GLONASS - optional</h4></p>
1523	<p>
1524	By default BNC does not process GLONASS but only GPS observations when in Point Positioning mode. Tick 'Use GLONASS' to use GLONASS observations in addition to GPS (and Galileo if specified) for estimating coordinates in Point Positioning mode.
1525	</p>
1526
1527	<p><a name="pppgal"><h4>3.12.7.4 Use Galileo - optional</h4></p>
1528	<p>
1529	By default BNC does not process Galileo but only GPS observations when in Point Positioning mode. Tick 'Use Galileo' to use Galileo observations in addition to GPS (and GLONASS if specified) for estimating coordinates in Point Positioning mode.
1530	</p>
1531
1532	<p><a name="pppsync"><h4>3.12.7.5 Sync Corr - optional</h4></p>
1533	<p>
1534	Zero value (or empty field) means that BNC processes each epoch of data immediately after its arrival using satellite clock corrections available at that time. Non-zero value 'Sync Corr' means that the epochs of data are buffered and the processing of each epoch is postponed till the satellite clock corrections not older than 'Sync Corr' are available. Specifying a value of half the update rate of the clock corrections as 'Sync Corr' (i.e. 5 sec) may be appropriate. Note that this causes an additional delay of the PPP solutions in the amount of half of the update rate.
1535	</p>
1536	<p>
1537	Using observations in sync with the corrections can avoid a possible high frequency noise of PPP solutions. Such noise could result from processing observations regardless of how late after a clock correction they were received. Note that applying the 'Sync Corr' option significantly reduces the PPP computation effort for BNC.
1538	</p>
1539	<p>
1540	Default is an empty option field, meaning that you want BNC to process observations immediately after their arrival through applying the latest received clock correction.
1541	</p>
1542
1543	<p><a name="pppaverage"><h4>3.12.7.6 Averaging - optional if XYZ is set</h4></p>
1544	<p>
1545	Enter the length of a sliding time window in minutes. BNC will continuously output moving average values and their RMS as computed from those individual values obtained most recently throughout this period. RMS values presented for XYZ coordinates and tropospheric zenit path delays are bias reduced while RMS values for North/East/Up (NEU) displacements are not. Averaged values for XYZ coordinates and their RMS are marked with string "AVE-XYZ" in BNC's log file and 'Log' section while averaged values for NEU displacements and their RMS are marked with string "AVE-NEU" and averaged values for the tropospheric delays and their RMS are marked with string "AVE-TRP". Example:
1546	</p>
1547	<pre>
1548	10-09-08 09:13:05 FFMJ1 AVE-XYZ 09:13:04.0 4053455.948 +- 0.284 617730.422 +- 0.504 4869397.692 +- 0.089
1549	10-09-08 09:13:05 FFMJ1 AVE-NEU 09:13:04.0 1.043 +- 0.179 0.640 +- 0.456 1.624 +- 0.331
1550	10-09-08 09:13:05 FFMJ1 AVE-TRP 09:13:04.0 2.336 +- 0.002
1551	</pre>
1552	<p>
1553	Entering any positive value up to 1440 (24h mean value) is allowed. An empty option field (default) means that you don't want BNC to output moving average positions into the log file and the 'Log' section. Note that averaging positions makes only sense for a stationary receiver.
1554	</p>
1555
1556	<p><a name="pppquick"><h4>3.12.7.7 Quick-Start - optional if XYZ is set</h4></p>
1557	<p>
1558	Enter the length of a startup period in seconds for which you want to fix the PPP solution to a known XYZ coordinate. Constraining coordinates is done in BNC through setting the 'XYZ White Noise' temporarily to zero.
1559	</p>
1560	<p>
1561	This so-called Quick-Start option allows the PPP solutions to rapidly converge after startup. It requires that the antenna remains unmoved on the know position throughout the defined period. A value of 60 is likely to be an appropriate choice for 'Quick-Start'. Default is an empty option field, meaning that you don't want BNC to start in 'Quick-Start' mode.
1562	<p>
1563	You may need to create your own reference coordinate through running BNC for an hour in normal mode before applying the 'Quick-Start' option. Don't forget to introduce a realistic sigma 'XYZ Ini' according to the coordinate's precision.
1564	</p>
1565
1566	<p><img src="IMG/screenshot17.png"/></p>
1567	<p><u>Figure 13:</u> BNC in 'Quick-Start' mode (PPP, Panel 1)</p>
1568
1569	<p><img src="IMG/screenshot22.png"/></p>
1570	<p><u>Figure 14:</u> BNC in 'Quick-Start' mode (PPP, Panel 2)</p>
1571
1572	<p><a name="pppgap"><h4>3.12.7.8 Maximal Solution Gap - optional if Quick-Start is set</h4></p>
1573	<p>
1574	Specify a 'Maximum Solution Gap' in seconds. Should the time span between two consecutive solutions exceed this limit, the algorithm returns into the 'Quick-Start' mode and fixes the introduced reference coordinate for the specified 'Quick-Start' period. A value of '60' seconds could be an appropriate choice.
1575	</p>
1576	<p>
1577	This option makes only sense for a stationary operated receiver where solution convergence can be enforced because a good approximation for the rover position is known. Default is an empty option field, meaning that you don't want BNC to return into the 'Quick-Start' mode after failures caused i.e. by longer lasting outages.
1578	</p>
1579
1580	<p><a name="pppsigmas"><h4>3.12.8 Sigmas</h4></p>
1581	<p>
1582	You may like to introduce specific sigmas for code and phase observations and for the estimation of troposphere parameters.
1583	</p>
1584
1585	<p><a name="pppsigc"><h4>3.12.8.1 Code - mandatory if 'Use Phase Obs' is set</h4></p>
1586	<p>
1587	When 'Use phase obs' is set in BNC, the PPP solution will be carried out using both, code and phase observations. A sigma of 10.0 m for code observations and a sigma of 0.02 m for phase observations (defaults) are used to combine both types of observations. As the convergence characteristic of a PPP solution can be influenced by the ratio of the sigmas for code and phase, you may like to introduce you own sigmas for code and phase observations which differ from the default values.
1588	<ul>
1589	<li>Introducing a smaller sigma (higher accuracy) for code observations or a larger sigma for phase observations leads to better results shortly after program start. However, it may take more time till you finally get the best possible solution.</li>
1590	<li>Introducing a larger sigma (lower accuracy) for code observations or a smaller sigma for phase observations may lead to less accurate results shortly after program start and thus a prolonged period of convergence but could provide better positions in the long run.</li>
1591	</ul>
1592	</p>
1593	<p>
1594	Specify a sigma for code observations. Default is 10.0 m.
1595	</p>
1596
1597	<p><a name="pppsigp"><h4>3.12.8.2 Phase - mandatory if 'Use Phase Obs' is set</h4></p>
1598	<p>
1599	Specify a sigma for phase observations. Default is 0.02 m.
1600	</p>
1601
1602	<p><a name="pppsigxyzi"><h4>3.12.8.3 XYZ Init - mandatory</h4></p>
1603	<p>
1604	Enter a sigma in meters for the initial XYZ coordinate. A value of 100.0 (default) may be an appropriate choice. However, this value may be significantly smaller (i.e. 0.01) when starting for example from a station with known XZY position in Quick-Start mode.
1605	</p>
1606
1607	<p><a name="pppsigxyzn"><h4>3.12.8.4 XYZ White Noise - mandatory</h4></p>
1608	<p>
1609	Enter a sigma in meters for the 'White Noise' of estimated XYZ coordinate components. A value of 100.0 (default) may be appropriate when considering possible sudden movements of a rover.
1610	</p>
1611
1612	<p><a name="pppsigtrpi"><h4>3.12.8.5 Tropo Init - mandatory if 'Estimate tropo' is set</h4></p>
1613	<p>
1614	Enter a sigma in meters for the a-priory model based tropospheric delay estimation. A value of 0.1 (default) may be an appropriate choice.
1615	</p>
1616
1617	<p><a name="pppsigtrpn"><h4>3.12.8.6 Tropo White Noise - mandatory if 'Estimate tropo' is set</h4></p>
1618	<p>
1619	Enter a sigma in meters per second to describe the expected variation of the tropospheric effect. Supposing 1Hz observation data, a value of 3e-6 (default) would mean that the tropospheric effect may vary for 3600 * 3e-6 = 0.01 meters per hour.
1620	</p>
1621
1622	<p><a name="combi"><h4>3.13. Combine Corrections</h4></p>
1623	<p>
1624	BNC allows processing several orbit and clock correction streams in real-time to produce, encode, upload and save a combination of Broadcast Corrections from various providers. It is so far only the satellite clock corrections which are combined while orbit corrections in the combination product as well as the product update rates are just taken over from one of the incoming Broadcast Correction streams. Combining only clock corrections using a fixed orbit reference has the possibility to introduce some analysis inconsistencies. We may therefore eventually consider improvements on this approach. The clock combination can be based either on a plain 'Single-Epoch' or on a 'Kalman' Filter approach.
1625	</p>
1626	<p>
1627	In the Kalman Filter approach satellite clocks estimated by individual Analyses Centers (ACs) are used as pseudo observations within the adjustment process. Each observation is modeled as a linear function (actually a simple sum) of three estimated parameters: AC specific offset, satellite specific offset common to all ACs, and the actual satellite clock correction which represents the result of the combination. These three parameter types differ in their statistical properties. The satellite clock offsets are assumed to be static parameters while AC specific and satellite specific offsets are stochastic parameters with appropriate white noise.
1628	The solution is regularized by a set of minimal constraints.
1629	</p>
1630	<p>
1631	Removing the AC-dependent biases as well as possible is a major issue with clock combinations. Since they vary in time, it can be tricky to do this. Otherwise, there will be artificial jumps in the combined clock stream if one or more AC contributions drop out for certain epochs. Here the Kalman Filter approach is expected to do better than the Single-Epoch approach.
1632	</p>
1633	<p>
1634	In view of IGS real-time products, the 'Combine Corrections' functionality has been integrated in BNC because
1635	<ul>
1636	<li>the software with its Graphic User Interface and wide range of supported Operating Systems represents a perfect platform to process many Broadcast Correction streams in parallel;</li>
1637	<li>outages of single AC product streams can be mitigated through merging several incoming streams into a combined product;</li>
1638	<li>generating a combination product from several AC products allows detecting and rejecting outliers;</li>
1639	<li>a Combination Center (CC) can operate BNC to globally disseminate a combination product via NTRIP broadcast;</li>
1640	<li>an individual AC could prefer to disseminate a stream combined from primary and backup IT resources to reduce outages;</li>
1641	<li>it enables a BNC PPP user to follow his own preference in combining streams from individual ACs for Precise Point Positioning;</li>
1642	<li>it allows an instantaneous quality control of the combination process not only in the time domain but also in the space domain; this can be done through direct application of the combined stream in a PPP solution even without prior upload to an NTRIP Broadcaster;</li>
1643	<li>it provides the means to output SP3 and Clock RINEX files containing precise orbit and clock information for further processing using other tools than BNC.</li>
1644	</ul>
1645	</p>
1646	<p>
1647	Note that the combination process requires real-time access to Broadcast Ephemeris. So, in addition to the orbit and clock correction streams BNC must pull a stream carrying Broadcast Ephemeris in the form of RTCM Version 3 messages. Stream 'RTCM3EPH' on caster <u>products.igs-ip.net</u> is an example for that.
1648	</p>
1649	<p>
1650	Note further that you need to tick the 'Use GLONASS' option which is part ot the 'PPP (2)' panel in case you want to produce an GPS plus GLONASS combination.
1651	</p>
1652	<p>
1653	A combination is carried out following a specified sampling interval. If incoming streams have different rates, only epochs that correspond to the sampling interval are used.
1654	</p>
1655	<p>
1656	With respect to IGS, it is important to understand that a major effect in the combination of GNSS orbit and clock correction streams is the selection of ACs to include. It is likely that a combination product could be improved in accuracy by using only the best two or three ACs. However, with only a few ACs to depend on, the reliability of the combination product could suffer and the risk of total failures increases. So there is an important tradeoff here that must be considered when selecting streams for a combination. The major strength of a combination product is its reliability and stable median performance which can be much better than that of any single AC product.
1657	</p>
1658	<p>
1659	This comment applies in situations where we have a limited number of solutions to combine and their quality varies significantly. The situation may be different when the total number of ACs is larger and the range of AC variation is smaller. In that case, a standard full combination is probably the best.
1660	</p>
1661	<p>
1662	The following recursive algorithm is used to detect orbit outliers in the Kalman Filter combination when Broadcast Corrections are provided by several ACs:
1663	<br>
1664	Step 1: We don't produce a combination for a certain satellite if only one AC provides corrections for it.
1665	<br>
1666	Step 2: A mean satellite position is calculated as the average of positions from all ACs.
1667	<br>
1668	Step 3: For each AC and satellite the 3D distance between individual and mean satellite position is calculated.
1669	<br>
1670	Step 4: We find the greatest difference between AC specific and mean satellite positions.
1671	<br>
1672	Step 5: If that is less than a threshold, the conclusion is that we don't have an outlier and can proceed to the next epoch.
1673	<br>
1674	Step 6: If that is greater than a threshold, then corrections of the affiliated AC are ignored for the affected epoch and the outlier detection restarts with step 1.
1675	</p>
1676	<p>
1677	Note that BNC can produce an internal PPP solution from combined Broadcast Corrections. For that you have to specify the keyword 'INTERNAL' as 'Corrections Mounpoint' in the PPP (1) panel.
1678	</p>
1679	<p>
1680	The part of BNC which enables the combination of Broadcast Corrections is not intended for publication under GNU General Public License (GPL). However, pre-compiled BNC binaries which support the 'Combine Corrections' option are made available.
1681	</p>
1682
1683	<p><a name="combimounttab"><h4>3.13.1 Combine Corrections Table - optional</h4></p>
1684	<p>
1685	Hit the 'Add Row' button, double click on the 'Mountpoint' field, enter a Broadcast Corrections mountpoint from the 'Streams' section and hit Enter. Then double click on the 'AC Name' field to enter your choice of an abbreviation for the Analysis Center (AC) providing the stream. Finally, double click on the 'Weight' field to enter a weight to be applied to this stream in the combination. The stream processing can already be started with only one corrections stream configured for combination.
1686	</p>
1687	<p>
1688	Note that an appropriate 'Wait for full corr epoch' value needs to be specified for the combination under the 'Broadcast Corrections' tab. To give an example: a value of 15 sec would make sense if the update rate of incoming clock corrections is 10 sec.
1689	</p>
1690	<p>
1691	The sequence of entries in the 'Combine Corrections' table is not of importance. Note that the orbit information in the final combination stream is just copied from one of the incoming streams. The stream used for providing the orbits may vary over time: if the orbit providing stream has an outage then BNC switches to the next remaining stream for getting hold of the orbit information.</p>
1692	<p>
1693	Default is an empty 'Combine Corrections' table meaning that you don't want BNC to combine orbit and clock correction streams.
1694	</p>
1695	<p>
1696	It is possible to specify only one Broadcast Ephemeris corrections stream in the 'Combine Corrections' table. Instead of combining corrections from several sources BNC will then merge the single corrections stream with Broadcast Ephemeris to save results in SP3 and/or Clock RINEX format when specified accordingly under the 'Upload Corrections' tab.
1697	</p>
1698
1699	<p><a name="combiadd"><h4>3.13.1.1 Add Row, Delete - optional</h4></p>
1700	<p>
1701	Hit 'Add Row' button to add another row to the 'Combine Corrections' table or hit the 'Delete' button to delete the highlighted row(s).
1702	</p>
1703
1704	<p>
1705	The following screenshots describe an example setup of BNC when combining Broadcast Correction streams and uploading them to an NTRIP Broadcaster. Note that it requires specifying options under tabs 'Combine Corrections' and 'Upload Corrections'. The example uses the combination product to simultaneously carry out an 'INTERNAL' PPP solution in 'Quick-Start' mode which allows monitoring the quality of the combination product in the space domain.
1706	</p>
1707
1708	<br>
1709	<p><img src="IMG/screenshot20.png"/></p>
1710	<p><u>Figure 15:</u> BNC combining Broadcast Correction streams.</p>
1711	<p></p>
1712	<p><img src="IMG/screenshot21.png"/></p>
1713	<p><u>Figure 16:</u> BNC uploading the combined Broadcast Corrections stream.</p>
1714	<p></p>
1715	<p><img src="IMG/screenshot23.png"/></p>
1716	<p><u>Figure 17:</u> 'INTERNAL' PPP with BNC using combined Broadcast Corrections stream.</p>
1717
1718	<p><a name="combimethod"><h4>3.13.1.2 Method - mandatory if 'Combine Corrections' table is populated</h4></p>
1719	<p>
1720	Select a clock combination method. Available options are Kalman 'Filter' and 'Single-Epoch. It is suggested to use the Kalman Filter approach in case the combined stream of Broadcast Corrections is intended for Precise Point Positioning.
1721	</p>
1722
1723	<p><a name="combimax"><h4>3.13.1.3 Maximal Residuum - mandatory if 'Combine Corrections' table is populated</h4></p>
1724
1725	<p>BNC combines all incoming clocks according to specified weights. Individual clock estimates that differ by more than 'Maximal Residuum' meters from the average of all clocks will be ignored.<p>
1726	</p>It is suggested to specify a value of about 0.2 m for the Kalman filter combination approach and a value of about 3.0 meters for the Single-Epoch combination approach.</p>
1727	<p>Default is a 'Maximal Residuum' of 999.0 meters</p>
1728
1729	<p><a name="combismpl"><h4>3.13.1.4 Sampling - mandatory if 'Combine Corrections' table is populated</h4></p>
1730	<p>Specify a combination sampling interval. Clock and orbit corrections will be produced following that interval. A value of 10 sec may be an appropriate choice.</p>
1731
1732
1733	<p><a name="upclk"><h4>3.14. Upload Corrections</h4></p>
1734	<p>
1735	BNC can upload streams carrying orbit and clock corrections to Broadcast Ephemeris in radial, along-track and cross-track components if they are<ol type=a>
1736	<li>
1737	either generated by BNC as a combination of several individual Broadcast Correction streams coming from an number of real-time Analysis Centers (ACs), see section 'Combine Corrections',</li>
1738	<li>
1739	or generated by BNC while the program receives an ASCII stream of precise satellite orbits and clocks via IP port from a connected real-time GNSS engine. Such a stream would be expected in a plain ASCII format and the associated 'decoder' string would have to be 'RTNET', see format description below. </li>
1740	</ol>
1741	The procedure taken by BNC to generate the clock and orbit corrections to Broadcast Ephemeris and upload them to an NTRIP Broadcaster is as follow:
1742	<ul>
1743	<li>Continuously receive up-to-date Broadcast Ephemeris carrying approximate orbits and clocks for all satellites. Read new Broadcast Ephemeris immediately whenever they become available. This information may come via a stream of RTCM messages generated from another BNC instance.</li>
1744	</ul>
1745	Then, epoch by epoch:
1746	<ul>
1747	<li>Continuously receive the best available clock and orbit estimates for all satellites in XYZ Earth-Centered-Earth-Fixed IGS08 reference system. Receive them every epoch in plain ASCII format as provided by a real-time GNSS engine such as RTNet or generate them following a combination approach. </li>
1748	<li>Calculate XYZ coordinates from Broadcast Ephemeris orbits. </li>
1749	<li>Calculate differences dX,dY,dZ between Broadcast Ephemeris and IGS08 orbits. </li>
1750	<li>Transform these differences into radial, along-track and cross-track corrections to Broadcast Ephemeris orbits. </li>
1751	<li>Calculate corrections to Broadcast Ephemeris clocks as differences between Broadcast Ephemeris clocks and IGS08 clocks. </li>
1752	<li>Encode Broadcast Ephemeris clock and orbit corrections in RTCM Version 3 format. </li>
1753	<li>Upload Broadcast Corrections stream to NTRIP Broadcaster. </li>
1754	</ul>
1755	<p>
1756	The orbit and clock corrections to Broadcast Ephemeris are usually referred to the latest set of broadcast messages, which are generally also received in real-time by a GNSS rover. However, the use of the latest broadcast message is delayed for a period of 60 seconds, measured from the time of complete reception of ephemeris and clock parameters, in order to accommodate rover applications to obtain the same set of broadcast orbital and clock parameters. This procedure is recommended in the RTCM SSR standard.
1757	</p>
1758	</p>
1759	Because the encoding process may put a significant load on the communication link between BNC and the real-time GNSS engine, it is recommended to run both programs on the same host. However, doing so is not compulsory.
1760	</p>
1761	<p>
1762	The usual handling of BNC when uploading a stream with Broadcast Corrections is that you first specify Broadcast Ephemeris and Broadcast Correction streams. You then specify an NTRIP Broadcaster for stream upload before you start the program.
1763	</p>
1764	<p>
1765	BNC requires GNSS clocks and orbits in the IGS Earth-Centered-Earth-Fixed (ECEF) reference system and in a specific ASCII format. The clocks and orbits must be referred to satellite Center of Mass (CoM) and must not contain the conventional periodic relativistic effect. They may be provided by a real-time GNSS engine such as RTNet. The sampling interval for data transmission should not exceed 15 sec. Note that otherwise tools involved in IP streaming such as NTRIP Broadcasters or NTRIP Clients may respond with a timeout.
1766	</p>
1767
1768	<p>
1769	Below you find an example of precise clocks and orbits coming in ASCII format (which is named 'RTNET' in this document) from a real-time GNSS engine. Each epoch starts with an asterisk character followed by the time as year, month, day of month, hour, minute and second. Subsequent records provide the following set of parameters for each satellite:
1770	</p>
1771
1772	<p>
1773	<ul>
1774	<li>GNSS Indicator and Satellite Vehicle Pseudo Random Number</li>
1775	<li>XYZ coordinates in Earth-Centered-Earth-Fixed system [km] at epoch T</li>
1776	<li>Satellite clock error [microsecond]</li>
1777	<li>Conventional periodic relativistic effect [microsecond]</li>
1778	<li>DX,DY,DZ [m] in Earth-Centered-Earth-Fixed system for translation CoM->APC</li>
1779	<li>Differential Code Bias P1C1 [m]</li>
1780	<li>Differential Code Bias P1P2 [m]</li>
1781	<li>Time increment dT [second]</li>
1782	<li>XYZ coordinates in Earth-Centered-Earth-Fixed system [km] at epoch T+dT</li>
1783	</ul>
1784	</p>
1785	Example for 'RTNET' stream format:
1786	</p>
1787	<p>
1788	<pre>
1789	...
1790	PR22 24695.278546 4939.628474 -3498.468864 41.074663 0.000301 -2.458 0.059 0.259 0.000 0.369 60.0 24724.926665 4937.395818 -3285.525249
1791	PR23 16644.528151 -4673.966731 -18755.727311 -381.408485 -0.000069 -1.484 0.958 1.597 0.000 -1.041 60.0 16794.540110 -4640.370673 -18629.931406
1792	PR24 -835.564016 -11361.061950 -22837.329550 -67.978344 -0.000027 0.088 1.593 1.979 0.000 0.628 60.0 -654.746874 -11311.272410 -22867.926411
1793	EOE
1794	* 2012 4 13 18 5 20.00000000
1795	PG01 -17662.477581 -4690.968816 19273.403670 247.562657 -0.001403 1.173 -0.094 -1.222 -0.081 -3.222 60.0 -17723.637492 -4824.411250 19184.308406
1796	PG02 13499.913230 23158.540481 -1230.022763 386.539840 -0.009664 -0.392 -0.672 0.036 -0.007 1.778 60.0 13488.200264 23175.574718 -1044.681214
1797	PG03 -16691.614702 -11720.144912 -17619.363518 35.472262 -0.007906 1.785 0.965 1.939 -0.171 -0.769 60.0 -16563.914187 -11742.834794 -17725.636699
1798	...
1799	PG32 -16198.232316 -3364.836652 20899.169198 -432.258718 -0.025811 1.728 0.075 -2.191 -0.370 -1.040 60.0 -16107.271625 -3493.294042 20951.654447
1800	PR01 18574.288277 -17410.663026 -1754.600023 -178.990271 -0.000082 -1.469 2.095 0.024 0.000 0.188 60.0 18556.963974 -17406.362476 -1967.750384
1801	PR02 8030.345235 -18665.480490 15430.035833 -298.816088 -0.000568 -0.516 2.171 -1.184 0.000 0.221 60.0 8114.572636 -18759.449343 15271.294411
1802	PR03 -6108.423573 -9263.873363 23002.679850 -129.074986 0.000627 0.523 1.396 -2.019 0.000 1.568 60.0 -5976.535477 -9398.317054 22982.703956
1803	...
1804	PR24 -820.514575 -11356.881507 -22839.954618 -67.978328 -0.000026 0.087 1.593 1.979 0.000 0.628 60.0 -639.657024 -11307.160404 -22870.387083
1805	EOE
1806	* 2012 4 13 18 5 25.00000000
1807	PG01 -17667.568396 -4702.119849 19266.035352 247.562677 -0.001403 1.173 -0.094 -1.222 -0.081 -3.222 60.0 -17728.740899 -4835.494883 19176.817383
1808	PG02 13498.959815 23160.004885 -1214.580934 386.539856 -0.009647 -0.392 -0.672 0.035 -0.007 1.778 60.0 13487.197253 23176.941260 -1029.232392
1809	PG03 -16680.999851 -11722.017340 -17628.269050 35.472285 -0.007882 1.783 0.966 1.940 -0.171 -0.769 60.0 -16553.240904 -11744.747432 -17734.434260
1810	...
1811	</pre>
1812	</p>
1813	<p>
1814	Note that each end of an epoch in the incoming stream is indicated by an ASCII string 'EOE' (for End Of Epoch).
1815	</p>
1816	<p>
1817	When using clocks from Broadcast Ephemeris (with or without applied corrections) or clocks from SP3 files, it may be important to understand that they are not corrected for the conventional periodic relativistic effect. Chapter 10 of the IERS Conventions 2003 mentions that the conventional periodic relativistic correction to the satellite clock (to be added to the broadcast clock) is computed as dt = -2 (R * V) / c^2 where R *V is the scalar product of the satellite position and velocity and c is the speed of light. This can also be found in the GPS Interface Specification, IS-GPS-200, Revision D, 7 March 2006.
1818	</p>
1819
1820	<p><a name="upadd"><h4>3.14.1 Add, Delete Row - optional</h4></p>
1821	<p>Hit 'Add Row' button to add another row to the stream 'Upload Table' or hit the 'Delete' button to delete the highlighted row(s).
1822	</p>
1823	<p>
1824	Having an empty 'Upload Table' is default and means that you don't want BNC to upload orbit and clock correction streams to any NTRIP Broadcaster.
1825	</p>
1826
1827	<p><a name="uphost"><h4>3.14.2 Host, Port, Mountpoint, Password - mandatory if 'Upload Table' entries specified</h4></p>
1828
1829	<p>Specify the domain name or IP number of an NTRIP Broadcaster for uploading the stream. Furthermore, specify the caster's listening IP port, an upload mountpoint and an upload password. Note that NTRIP Broadcasters are often configured to provide access on more than one port, usually port 80 and 2101. If you experience communication problems on port 80, you should try to use the alternative port(s).
1830	</p>
1831	<p>
1832	BNC uploads a stream to the NNTRIP Broadcaster by referring to a dedicated mountpoint that has been set by its operator. Specify here the mountpoint based on the details you received for your stream from the operator. It is often a four character ID (capital letters) plus an integer number.</p>
1833	<p>The stream upload may be protected through an upload 'Password'. Enter the password you received from the NTRIP Broadcaster operator along with the mountpoint(s).</p>
1834	<p>
1835	If 'Host', 'Port', 'Mountpoint' and 'Password' are set, the stream will be encoded in RTCM's 'State Space Representation' (SSR) messages and uploaded to the specified broadcaster following the NTRIP Version 1 transport protocol.
1836	</p>
1837
1838	<p><a name="upsystem"><h4>3.14.3 System - mandatory if 'Host' is set</h4></p>
1839	<p>
1840	BNC allows to configure several Broadcast Correction streams for upload so that they refer to different reference systems and different NTRIP Broadcasters. You may use this functionality for parallel support of a backup NTRIP Broadcaster or for simultaneous support of several reference systems. Available options for referring clock and orbit corrections to specific target reference systems are
1841	<p>
1842	<ul>
1843	<li>IGS08 which stands for the GNSS-based IGS realization of the International Terrestrial Reference Frame 2008 (ITRF2008), and</li>
1844	<li>ETRF2000 which stands for the European Terrestrial Reference Frame 2000 adopted by EUREF, and</li>
1845	<li>NAD83 which stands for the North American Datum 1983 as adopted for the U.S.A., and</li>
1846	<li>GDA94 which stands for the Geodetic Datum Australia 1994 as adopted for Australia, and</li>
1847	<li>SIRGAS2000 which stands for the Geodetic Datum adopted for Brazil, and</li>
1848	<li>SIRGAS95 which stands for the Geodetic Datum adopted i.e. for Venezuela, and</li>
1849	<li>'Custom' which allows a transformation of Broadcast Corrections from the IGS08 system to any other system through specifying up to 14 Helmert Transformation Parameters.</li>
1850	</ul>
1851	</p>
1852
1853	<p>
1854	BNC only transforms the original IGS08 <u>orbits</u> in the Broadcast Corrections stream to a target reference system while leaving the clocks unchanged. From a theoretical point of view this leads to inconsistencies between orbits and clocks and is therefore not allowed. However, it has been shown by Huisman et al. 2012 that as long as involved scale parameters are small enough, this way of transforming corrections stream contents only leads to height biases less than about one centimeter. With regards to the systems listed above, the approach has therefore been implemented in BNC for practical reasons.
1855	</p>
1856	<p>
1857	The transformation to <u>GDA94 is an exception</u> in this because it involves a ten times higher scale parameter compared to the other transformations. Note that hence the resulting height biases for a BNC-transformed GDA94 corrections stream can increase up to about 10 centimeters.
1858	</p>
1859
1860	<p>
1861	<u>IGS08:</u> As the clocks and orbits coming from real-time GNSS engine are expected to be in the IGS08 system, no transformation is carried out if this option is selected.
1862	</p>
1863
1864	<p>
1865	<u>ETRF2000:</u> The formulas for the transformation 'ITRF2005->ETRF2000' are taken from 'Claude Boucher and Zuheir Altamimi 2008: Specifications for reference frame fixing in the analysis of EUREF GPS campaign', see <u>http://etrs89.ensg.ign.fr/memo-V8.pdf</u>. The following 14 Helmert Transformation Parameters were introduced:
1866	</p>
1867	<p>
1868	<pre>
1869	Translation in X at epoch To: 0.0521 m
1870	Translation in Y at epoch To: 0.0493 m
1871	Translation in Z at epoch To: -0.0585 m
1872	Translation rate in X: 0.0001 m/y
1873	Translation rate in Y: 0.0001 m/y
1874	Translation rate in Z: -0.0018 m/y
1875	Rotation in X at epoch To: 0.891 mas
1876	Rotation in Y at epoch To: 5.390 mas
1877	Rotation in Z at epoch To: -8.712 mas
1878	Rotation rate in X: 0.081 mas/y
1879	Rotation rate in Y: 0.490 mas/y
1880	Rotation rate in Z: -0.792 mas/y
1881	Scale at epoch To : 0.00000000134
1882	Scale rate: 0.00000000008 /y
1883	To: 2000.0
1884	</pre>
1885	</p>
1886
1887	<p>
1888	<u>NAD83:</u> Formulas for the transformation 'ITRF2005->NAD83' are taken from 'Chris Pearson, Robert McCaffrey, Julie L. Elliott, Richard Snay 2010: HTDP 3.0: Software for Coping with the Coordinate Changes Associated with Crustal Motion, Journal of Surveying Engineering'.
1889	</p>
1890	<p>
1891	<pre>
1892	Translation in X at epoch To: 0.9963 m
1893	Translation in Y at epoch To: -1.9024 m
1894	Translation in Z at epoch To: -0.5219 m
1895	Translation rate in X: 0.0005 m/y
1896	Translation rate in Y: -0.0006 m/y
1897	Translation rate in Z: -0.0013 m/y
1898	Rotation in X at epoch To: 25.915 mas
1899	Rotation in Y at epoch To: 9.426 mas
1900	Rotation in Z at epoch To: 11.599 mas
1901	Rotation rate in X: 0.067 mas/y
1902	Rotation rate in Y: -0.757 mas/y
1903	Rotation rate in Z: -0.051 mas/y
1904	Scale at epoch To : 0.00000000078
1905	Scale rate: -0.00000000010 /y
1906	To: 1997.0
1907	</pre>
1908	</p>
1909
1910	<p>
1911	<u>GDA94:</u> The formulas for the transformation 'ITRF2000->GDA94' are taken from 'John Dawson, Alex Woods 2010: ITRF to GDA94 coordinate transformations', Journal of Applied Geodesy, 4 (2010), 189¿199, de Gruyter 2010. DOI 10.1515/JAG.2010.019'.
1912	</p>
1913	<p>
1914	<pre>
1915	Translation in X at epoch To: -0.07973 m
1916	Translation in Y at epoch To: -0.00686 m
1917	Translation in Z at epoch To: 0.03803 m
1918	Translation rate in X: 0.00225 m/y
1919	Translation rate in Y: -0.00062 m/y
1920	Translation rate in Z: -0.00056 m/y
1921	Rotation in X at epoch To: 0.0351 mas
1922	Rotation in Y at epoch To: -2.1211 mas
1923	Rotation in Z at epoch To: -2.1411 mas
1924	Rotation rate in X: -1.4707 mas/y
1925	Rotation rate in Y: -1.1443 mas/y
1926	Rotation rate in Z: -1.1701 mas/y
1927	Scale at epoch To : 0.000000006636
1928	Scale rate: 0.000000000294 /y
1929	To: 1994.0
1930	</pre>
1931	</p>
1932
1933	<p>
1934	<u>SIRGAS2000:</u> The formulas for the transformation 'ITRF2005->SIRGAS2000' were provided via personal communication from CGED-Coordenacao de Geodesia, IBGE/DGC - Diretoria de Geociencias, Brazil.</u>.
1935	</p>
1936	<p>
1937	<pre>
1938	Translation in X at epoch To: -0.0051 m
1939	Translation in Y at epoch To: -0.0065 m
1940	Translation in Z at epoch To: -0.0099 m
1941	Translation rate in X: 0.0000 m/y
1942	Translation rate in Y: 0.0000 m/y
1943	Translation rate in Z: 0.0000 m/y
1944	Rotation in X at epoch To: 0.150 mas
1945	Rotation in Y at epoch To: 0.020 mas
1946	Rotation in Z at epoch To: 0.021 mas
1947	Rotation rate in X: 0.000 mas/y
1948	Rotation rate in Y: 0.000 mas/y
1949	Rotation rate in Z: 0.000 mas/y
1950	Scale at epoch To : 0.000000000000
1951	Scale rate: -0.000000000000 /y
1952	To: 2000.0
1953	</pre>
1954	</p>
1955
1956	<p>
1957	<u>SIRGAS95:</u> The formulas for the transformation 'ITRF2005->SIRGAS95' were provided via personal communication from Gustavo Acuha, Laboratorio de Geodesia Fisica y Satelital at Zulia University (LGFS-LUZ), parameters based on values from Table 4.1 of "Terrestrial Reference Frames (April 10, 2009), Chapter 4" in http://tai.bipm.org/iers/convupdt/convupdt_c4.html.</u>.
1958	</p>
1959	<p>
1960	<pre>
1961	Translation in X at epoch To: 0.0077 m
1962	Translation in Y at epoch To: 0.0058 m
1963	Translation in Z at epoch To: -0.0138 m
1964	Translation rate in X: 0.0000 m/y
1965	Translation rate in Y: 0.0000 m/y
1966	Translation rate in Z: 0.0000 m/y
1967	Rotation in X at epoch To: 0.000 mas
1968	Rotation in Y at epoch To: 0.000 mas
1969	Rotation in Z at epoch To: -0.003 mas
1970	Rotation rate in X: 0.000 mas/y
1971	Rotation rate in Y: 0.000 mas/y
1972	Rotation rate in Z: 0.000 mas/y
1973	Scale at epoch To : 0.00000000157
1974	Scale rate: -0.000000000000 /y
1975	To: 1995.4
1976	</pre>
1977	</p>
1978
1979	<p>
1980	<u>Custom:</u> The default numbers shown as examples are those for a transformation from ITRF2005 to ETRF2000'.
1981	</p>
1982
1983	<p><a name="upcom"><h4>3.14.4 Center of Mass - optional</h4></p>
1984	<p>
1985	BNC allows to either refer Broadcast Corrections to the satellite's Center of Mass (CoM) or to the satellite's Antenna Phase Center (APC). By default corrections refer to APC. Tick 'Center of Mass' to refer uploaded corrections to CoM.
1986	</p>
1987
1988	<p><a name="upsp3"><h4>3.14.5 SP3 File - optional</h4></p>
1989	<p>Specify a path for saving the generated orbit corrections as SP3 orbit files. If the specified directory does not exist, BNC will not create SP3 orbit files. The following is a path example for a Linux system:<br>/home/user/BNC${GPSWD}.sp3<br>Note that '${GPSWD}' produces the GPS Week and Day number in the file name.</p>
1990	<p>
1991	Default is an empty option field, meaning that you don't want BNC to save the uploaded stream contents in daily SP3 files.
1992	</p>
1993	<p>
1994	As an SP3 file contents should be referred to the satellites Center of Mass (CoM) while Broadcast Corrections are referred to the satellites APC, an offset has to be applied which is available from an IGS ANTEX file (see section 'ANTEX File'). You should therefore specify the 'ANTEX File' path under tab 'PPP (2)' if you want to save the stream contents in SP3 format. If you don't specify an 'ANTEX File' path there, the SP3 file contents will be referred to the satellites APCs.
1995	</p>
1996	<p>
1997	The file names for the daily SP3 files follow the convention for SP3 file names. The first three characters of each file name are set to 'BNC'. Note that clocks in the SP3 orbit files are not corrected for the conventional periodic relativistic effect.
1998	</p>
1999	<p>
2000	In case the 'Combine Corrections' table contains only one Broadcast Corrections stream, BNC will merge that stream with Broadcast Ephemeris to save results in files specified here through SP3 and/or Clock RINEX file path. In such a case you have to define only the SP3 and Clock RINEX file path and no further option in the 'Upload Corrections' table.
2001	</p>
2002
2003	<p><a name="uprinex"><h4>3.14.6 RNX File - optional</h4></p>
2004	<p>
2005	The clock corrections generated by BNC for upload can be logged in Clock RINEX format. The file naming follows the RINEX convention.
2006	</p>
2007	<p>
2008	Specify a path for saving the generated clock corrections as Clock RINEX files. If the specified directory does not exist, BNC will not create Clock RINEX files. The following is a path example for a Linux system:<br>/home/user/BNC${GPSWD}.clk<br>Note that '${GPSWD}' produces the GPS Week and Day number in the file name.
2009	</p>
2010	<p>
2011	Note further that clocks in the Clock RINEX files are not corrected for the conventional periodic relativistic effect.
2012	</p>
2013
2014	<p><a name="upinter"><h4>3.14.7 Interval - mandatory if 'Upload Table' entries specified</h4></p>
2015	<p>
2016	Select the length of Clock RINEX files and SP3 Orbit files. The default value is 1 day.
2017	</p>
2018
2019	<p><a name="upclksmpl"><h4>3.14.8 Sampling - mandatory if 'Upload Table' entries specified</h4></p>
2020	<p>BNC requires an orbit corrections sampling interval for the stream to be uploaded and sampling intervals for SP3 and Clock RINEX files. The outgoing stream's clock correction sampling interval follows that of incoming corrections and is therefore nothing to be specified here.</p>
2021
2022	<p><a name="upclkorb"><h4>3.14.8.1 Orbits - mandatory if 'Upload Table' entries specified</h4></p>
2023	<p>Select the stream's orbit correction sampling interval in seconds. A value of 60 sec may be appropriate.</p>
2024	<p> A value of zero '0' tells BNC to upload all orbit correction samples coming in from the real-time GNSS engine along with the clock correction samples to produce combined orbit and clock corrections to Broadcast Ephemeris (1060 for GPS, 1066 for GLONASS).
2025	</p>
2026
2027	<p><a name="upclksp3"><h4>3.14.8.2 SP3 - mandatory if 'SP3 File' is specified</h4></p>
2028	<p>Select the SP3 orbit file sampling interval in minutes. A value of 15 min may be appropriate. A value of zero '0' tells BNC to store all available samples into SP3 orbit files.</p>
2029
2030	<p><a name="upclkrnx"><h4>3.14.8.3 RINEX - mandatory if 'RNX File' is specified</h4></p>
2031	<p>Select the Clock RINEX file sampling interval in seconds. A value of 10 sec may be appropriate. A value of zero '0' tells BNC to store all available samples into Clock RINEX files.</p>
2032
2033	<p><a name="upcustom"><h4>3.14.9 Custom Trafo - optional if 'Upload Table' entries specified</h4></p>
2034	<p>Hit 'Custom Trafo' to specify your own 14 parameter Helmert Transformation instead of selecting a predefined transformation through 'System' button.</p>
2035
2036	<p>
2037	The following screenshot shows the encoding and uploading of a stream of precise orbits and clocks coming from a real-time engine in 'RTNET' ASCII format. The stream is uploaded to NTRIP Broadcaster 'products.igs-ip.net'. It is referred to APC and IGS08. Uploaded data are locally saved in SP3 and Clock RINEX format. The SSR Provider ID is set to 3. The SSR Solution ID is and the Issue of Data SSR are set to 1. Required Broadcast Ephemeris are received via stream 'RTCM3EPH'.
2038	</p>
2039	<p><img src="IMG/screenshot26.png"/></p>
2040	<p><u>Figure 18:</u> Producing Broadcast Corrections from incoming precise orbits and clocks and uploading them to an NTRIP Broadcaster.</p>
2041
2042	<p><a name="upeph"><h4>3.15. Upload Ephemeris</h4></p>
2043	<p>
2044	BNC can upload a stream carrying Broadcast Ephemeris in RTCM Version 3 format to an NTRIP Broadcaster.
2045	</p>
2046
2047	<p><a name="brdcserver"><h4>3.15.1 Host & Port - optional</h4></p>
2048	<p>
2049	Specify the 'Host' IP name or number of an NTRIP Broadcaster to upload the stream. An empty option field means that you don't want to upload Broadcast Ephemeris.
2050	</p>
2051	<p>
2052	Enter the NTRIP Broadcaster's IP 'Port' number for stream upload. Note that NTRIP Broadcasters are often configured to provide access on more than one port, usually
2053	port 80 and 2101. If you experience communication problems on port 80, you should try to use the alternative port(s).
2054	</p>
2055
2056	<p><a name="brdcmount"><h4>3.15.2 Mountpoint & Password - mandatory if 'Host' is set</h4></p>
2057	<p>
2058	BNC uploads a stream to the NTRIP Broadcaster by referring to a dedicated mountpoint that has been set by its operator. Specify the mountpoint based on the details you received for your stream from the operator. It is often a four character ID (capital letters) plus an integer number.</p>
2059	<p>The stream upload may be protected through an upload 'Password'. Enter the password you received from the NTRIP Broadcaster operator along with the mountpoint.</p>
2060	</p>
2061
2062	<p><a name="brdcsmpl"><h4>3.15.3 Sampling - mandatory if 'Host' is set</h4></p>
2063	Select the Broadcast Ephemeris repetition interval in seconds. Defaut is '5' meaning that a complete set of Broadcast Ephemeris is uploaded every 5 seconds.
2064	</p>
2065
2066	<p><img src="IMG/screenshot28.png"/></p>
2067	<p><u>Figure 28:</u> Producing a Broadcast Ephemeris stream from navigation messages of globally distributed RTCM streams and uploading them in RTCM Version 3 format to an NTRIP Broadcaster.</p>
2068
2069	<p><a name="streams"><h4>3.16. Streams</h4></p>
2070	<p>
2071	Each 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 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.
2072	</p>
2073
2074	<p>
2075	Streams selected for retrieval are listed under the 'Streams' canvas on BNC's main window. The list provides the following information either extracted from source-table(s) produced by the NTRIP Broadcasters or introduced by BNC's user:
2076	</p>
2077	<p>
2078	<table>
2079	<tr><td>'resource loader'  </td><td>NTRIP Broadcaster URL and port, or<br>TCP/IP host and port, or<br>UDP port, or<br>Serial input port specification.</td></tr>
2080	<tr><td>'mountpoint'  </td><td>Mountpoint introduced by NTRIP Broadcaster, or<br>Mountpoint introduced by BNC's user.</td></tr>
2081	<tr><td>'decoder'  </td><td>Name of decoder used to handle the incoming stream content according to its format; editable.</td></tr>
2082	<tr><td>'lat'  </td><td>Approximate latitude of reference station, in degrees, north; editable if 'nmea' = 'yes'.</td></tr>
2083	<tr><td>'long'  </td><td>Approximate longitude of reference station, in degrees, east; editable if 'nmea' = 'yes'.</td></tr>
2084	<tr><td>'nmea'  </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>
2085	<tr><td>'ntrip'  </td><td>Selected NTRIP transport protocol version (1, 2, 2s, R, or U), or<br>'N' for TCP/IP streams without NTRIP, or<br>'UN' for UDP streams without NTRIP, or<br>'S' for serial input streams without NTRIP.</td></tr>
2086	<tr><td>'bytes'  </td><td>Number of bytes received.
2087	</table>
2088	</p>
2089
2090	<p><a name="streamedit"><h4>3.16.1 Edit Streams</h4></p>
2091	<ul>
2092	<li>
2093	BNC automatically allocates one of its internal decoders to a stream based on the stream's 'format' and 'format-details' as given in the source-table. However, there might be cases where you need to override the automatic selection due to incorrect source-table for example. BNC allows users to manually select the required decoder by editing the decoder string. Double click on the 'decoder' field, enter your preferred decoder and then hit Enter. The accepted decoder strings are 'RTCM_2.x', 'RTCM_3.x' and 'RTNET'.
2094	</li>
2095	<li>
2096	In 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.
2097	</li>
2098	<li>
2099	BNC can also retrieve streams from virtual reference stations (VRS). To initiate these streams, an approximate rover position needs to be sent in NMEA format to the NTRIP Broadcaster. In return, a user-specific data stream is generated, typically by Network-RTK software. VRS streams are indicated by a 'yes' in the source-table as well as in the 'nmea' column on the 'Streams' canvas in BNC's main window. They are customized exactly to the latitude and longitude transmitted to the NTRIP Broadcaster via NMEA-GGA messages.
2100	<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.
2101	<br>Note that when running BNC in a Local Area Network (LAN), NMEA strings may be blocked by a proxy server, firewall or virus scanner when not using the NTRIP Version 2 transport protocol..
2102	</li>
2103	</ul>
2104
2105	<p><a name="streamdelete"><h4>3.16.2 Delete Stream</h4></p>
2106	<p>
2107	To 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>
2108
2109	<p><a name="streamconf"><h4>3.16.3 Reconfigure Stream Selection On-the-fly</h4></p>
2110	<p>
2111	The streams selection can be changed on-the-fly without interrupting uninvolved threads in the running BNC process.
2112	</p>
2113	<p>
2114	<u>Window mode:</u> Hit 'Save & Reread Configuration' while BNC is in window mode and already processing data to let changes of your streams selection immediately become effective.
2115	<p>
2116	<u>No window mode:</u> When operating BNC online in 'no window' mode (command line option -nw), you force BNC to reread its 'mountPoints' configuration option from disk at pre-defined intervals. Select '1 min', '1 hour', or '1 day' as 'Reread configuration' option to reread the 'mountPoints' option every full minute, hour, or day. This lets a 'mountPoints' option edited in between in the configuration file become effective without terminating uninvolved threads. See annexed section 'Configuration Examples' for a configuration file example and a list of other on-the-fly changeable options.
2117	</p>
2118
2119	<p><a name="logs"><h4>3.17. Logging</h4></p>
2120	<p>
2121	A tabs section on the bottom of the main window provides online control of BNC's activities. Tabs are available to show the records saved in a logfile, for a plot to control the bandwidth consumption, for a plot showing stream latencies, and for time series plots of PPP results.
2122	</p>
2123	<p><a name="logfile"><h4>3.17.1 Log</h4></p>
2124	<p>
2125	Records 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.
2126	</p>
2127
2128	<p><a name="throughput"><h4>3.17.2 Throughput</h4></p>
2129	<p>
2130	The bandwidth consumption per stream is shown in the 'Throughput' tab in bits per second (bps) or kilo bits per second (kbps). The following figure shows an example for the bandwidth comsumption of incoming streams.
2131	</p>
2132
2133	<p><img src="IMG/screenshot08.png"/></p>
2134	<p><u>Figure 19:</u> Bandwidth consumption of incoming streams.</p>
2135
2136	<p><a name="latency"><h4>3.17.3 Latency</h4></p>
2137	<p>
2138	The latency of observations in each incoming stream is shown in the 'Latency' tab in milliseconds or seconds. Streams not carrying observations (i.e. those providing only Broadcast Ephemeris messages) or having an outage are not considered here and shown in red color. Note that the calculation of correct latencies requires the clock of the host computer to be properly synchronized. The next figure shows an example for the latency of incoming streams.
2139	</p>
2140
2141	<p><img src="IMG/screenshot07.png"/></p>
2142	<p><u>Figure 20:</u> Latency of incoming streams.</p>
2143
2144	<p><a name="ppptab"><h4>3.17.4 PPP Plot</h4></p>
2145	<p>
2146	Precise Point Positioning time series of North (red), East (green) and Up (blue) coordinate components are shown in the 'PPP Plot' tab when a 'Origin' option is defined. Values are either referred to reference coordinates (if specified) or referred to the first estimated set of coordinate components. The time as given in format [hh:mm] refers to GPS Time. The sliding PPP time series window covers a period of 5 minutes. Note that it may take up to 30 seconds or more till the first PPP solutions becomes available. The following figure shows the screenshot of a PPP time series plot of North, East and Up coordinate components.
2147	</p>
2148
2149	<p><img src="IMG/screenshot13.png"/></p>
2150	<p><u>Figure 21:</u> Time series plot of PPP session.</p>
2151
2152	<p><a name="bottom"><h4>3.18. Bottom Menu Bar</h4></p>
2153	<p>
2154	The bottom menu bar allows to add or delete streams to BNC's configuration and to start or stop it. It also provides access to BNC's online help function. The 'Add Stream' button opens a window that allows user to select one of several input communication links, see figure below.
2155	</p>
2156
2157	<p><img src="IMG/screenshot06.png"/></p>
2158	<p><u>Figure 22:</u> Steam input communication links.</p>
2159
2160	<p><a name="streamadd"><h4>3.18.1 Add Stream - Coming from Caster</h4></p>
2161
2162	<p>
2163	Button 'Add Stream' > 'Coming from Caster' then opens a window that allows user to select data streams from an NTRIP Broadcaster according to their mountpoints and show a distribution map of offered streams.
2164	</p>
2165
2166	<p><a name="streamhost"><h4>3.18.1.1 Caster Host and Port - mandatory</h4></p>
2167	<p>
2168	Enter the NTRIP Broadcaster host IP and port number. Note that EUREF and IGS operate NTRIP Broadcasters at <u>http://www.euref-ip.net/home</u>, <u>http://www.igs-ip.net/home</u>, <u>http://www.products.igs-ip.net/home</u> and <u>http://mgex.igs-ip.net/home</u>.
2169	</p>
2170
2171	<p><a name="streamtable"><h4>3.18.1.2 Casters Table - optional</h4></p>
2172	<p>
2173	It 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.
2174	</p>
2175	</p>
2176	<p><img src="IMG/screenshot04.png"/></p>
2177
2178	<p><u>Figure 23:</u> Casters table.</p>
2179
2180	<p><a name="streamuser"><h4>3.18.1.3 User and Password - mandatory for protected streams</h4></p>
2181	<p>
2182	Some streams on NTRIP Broadcasters may be restricted. Enter a valid 'User' ID and 'Password' for access to protected streams. Accounts are usually provided per NTRIP Broadcaster through a registration procedure. Register through <u>http://igs.bkg.bund.de/ntrip/registeruser</u> for access to protected streams from EUREF and IGS.
2183	</p>
2184
2185	<p><a name="gettable"><h4>3.18.1.4 Get Table</h4></p>
2186	<p>
2187	Use the 'Get Table' button to download the source-table from the NTRIP Broadcaster. Pay attention to data fields 'format' and 'format-details'. Keep in mind that BNC can only decode and convert streams that come in RTCM Version 2, RTCM Version 3, or RTNET format. For access to observations, Broadcast Ephemeris and Broadcast Corrections in RTCM format streams must contain a selection of appropriate message types as listed in the Annex, cf. data field 'format-details' for available message types and their repetition rates in brackets. Note that in order to produce RINEX Navigation files RTCM Version 3 streams containing message types 1019 (GPS) and 1020 (GLONASS) and 1045 (Galileo) are required. Select your streams line by line, use +Shift and +Ctrl when necessary. The figure below provides an example source-table.
2188	</p>
2189	<p>
2190	The 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).
2191	</p>
2192	<p>
2193	Hit '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.
2194	</p>
2195	<p><img src="IMG/screenshot05.png"/></p>
2196	<p><u>Figure 24:</u> Broadcaster source-table.</p>
2197
2198	<p>Button 'Map' leads to the presentation of a map showing the distribution of streams offered through the downloaded source-table.</p>
2199
2200	<p><a name="ntripv"><h4>3.18.1.5 NTRIP Version - mandatory</h4></p>
2201	<p>
2202	Some 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:
2203	</p>
2204	<p>
2205	1:  NTRIP Version 1, TCP/IP.<br>
2206	2:  NTRIP Version 2 in TCP/IP mode.<br>
2207	2s:  NTRIP Version 2 in TCP/IP mode via SSL.<br>
2208	R:  NTRIP Version 2 in RTSP/RTP mode.<br>
2209	U:  NTRIP Version 2 in UDP mode.
2210	</p>
2211	<p>
2212	If NTRIP Version 2 is supported by the broadcaster:
2213	</p>
2214	<ul>
2215	<li>Try using option '2' if your streams are otherwise blocked by a proxy server operated in front of BNC.</li>
2216	<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>
2217	</ul>
2218	<p>
2219	Select option '1' if you are not sure whether the broadcaster supports NTRIP Version 2.</li>
2220	</p>
2221
2222	<p><a name="map"><h4>3.18.1.6 Map - optional</h4></p>
2223	<p>
2224	Button 'Map' opens a window to show a distribution map of the caster's streams. You may like to zoom in or out using option 'Zoom +' or 'Zoom -'. You may also like to 'Clean' or 'Reset' a map or let it 'Fit' exactly to the current size of the window. Option 'Close' shuts the window.
2225	</p>
2226	<p><img src="IMG/screenshot24.png"/></p>
2227	<p><u>Figure 25:</u> Stream distribution map derived from NTRIP Broadcaster source-table.</p>
2228
2229	<p><a name="streamip"><h4>3.18.2 Add Stream - Coming from TCP/IP Port</h4></p>
2230	<p>
2231	Button 'Add Stream' > '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:
2232	<ul>
2233	<li>Enter the IP address of the stream providing host.</li>
2234	<li>Enter the IP port number of the stream providing host.</li>
2235	<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
2236	<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTNET', and 'ZERO'.</li>
2237	<li>Enter the approximate latitude of the stream providing rover in degrees. Example: 45.32.</li>
2238	<li>Enter the approximate longitude of the stream providing rover in degrees. Example: -15.20.</li>
2239	</ul>
2240	</p>
2241	<p>
2242	Streams directly received from a TCP/IP port show up with an 'N' for 'No NTRIP' in the 'Streams' canvas on BNC's main window. Latitude and longitude are to be entered just for informal reasons.
2243	<p>
2244	</p>
2245	Note that this option works only if no proxy server is involved in the communication link.
2246	</p>
2247
2248	<p><a name="streamudp"><h4>3.18.3 Add Stream - Coming from UDP Port</h4></p>
2249	<p>
2250	Button 'Add Stream' > '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:
2251	<ul>
2252	<li>Enter the local port number where the UDP stream arrives.</li>
2253	<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
2254	<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTNET', and 'ZERO'.</li>
2255	<li>Enter the approximate latitude of the stream providing rover in degrees. Example: 45.32.</li>
2256	<li>Enter the approximate longitude of the stream providing rover in degrees. Example: -15.20.</li>
2257	</ul>
2258	</p>
2259	<p>
2260	Streams 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.
2261	<p>
2262
2263	<p><a name="streamser"><h4>3.18.4 Add Stream - Coming from Serial Port</h4></p>
2264	<p>
2265	Button 'Add Stream' > 'Coming from Serial Port' allows to retrieve streams from a GNSS receiver via serial port without using the NTRIP transport protocol. For that you:
2266	<ul>
2267	<li>Specify a mountpoint. Recommended is a 4-character station ID. Example: FFMJ</li>
2268	<li>Specify the stream format. Available options are 'RTCM_2', 'RTCM_3', 'RTNET', and 'ZERO'.</li>
2269	<li>Enter the approximate latitude of the stream providing receiver in degrees. Example: 45.32.</li>
2270	<li>Enter the approximate longitude of the stream providing receiver in degrees. Example: -15.20.</li>
2271	<li>Enter the serial 'Port name' selected on your host for communication with the receiver. Valid port names are
2272	<pre>
2273	Windows: COM1, COM2
2274	Linux: /dev/ttyS0, /dev/ttyS1
2275	FreeBSD: /dev/ttyd0, /dev/ttyd1
2276	Digital Unix: /dev/tty01, /dev/tty02
2277	HP-UX: /dev/tty1p0, /dev/tty2p0
2278	SGI/IRIX: /dev/ttyf1, /dev/ttyf2
2279	SunOS/Solaris: /dev/ttya, /dev/ttyb
2280	</pre>
2281	</li>
2282	<li>Select a 'Baud rate' for the serial input. Note that using a high baud rate is recommended.</li>
2283	<li>Select the number of 'Data bits' for the serial input. Note that often '8' data bits are used.</li>
2284	<li>Select the 'Parity' for the serial input. Note that parity is often set to 'NONE'.</li>
2285	<li>Select the number of 'Stop bits' for the serial input. Note that often '1' stop bit is used.</li>
2286	<li>Select a 'Flow control' for the serial link. Select 'OFF' if you don't know better.</li>
2287	</ul>
2288	</p>
2289	<p>
2290	When selecting one of the serial communication options listed above, make sure that you pick those configured to the serial connected GNSS receiver.
2291	</p>
2292
2293	<p>
2294	Streams 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.
2295	<p>
2296
2297	<p>
2298	The following figure shows a BNC example setup for pulling a stream via serial port on a Linux operating system.
2299	</p>
2300	<p><img src="IMG/screenshot15.png"/></p>
2301	<p><u>Figure 26:</u> BNC setup for pulling a stream via serial port.</p>
2302
2303	<p><a name="start"><h4>3.18.5 Start</h4></p>
2304	<p>
2305	Hit 'Start' to start retrieving, decoding or converting GNSS data streams in real-time. Note that 'Start' generally forces BNC to begin with fresh RINEX which might overwrite existing files when necessary unless the option 'Append files' is ticked.
2306	</p>
2307
2308	<p><a name="stop"><h4>3.18.6 Stop</h4></p>
2309	<p>
2310	Hit the 'Stop' button in order to stop BNC.
2311	</p>
2312
2313	<p><a name="cmd"><h4>3.19. Command Line Options</h4></p>
2314	<p>
2315	Command line options are available to run BNC in 'no window' mode or let it read data offline from one or several files for debugging or Post Processing purposes. BNC will then use processing options from the involved configuration file. Note that the self-explaining contents of the configuration file can easily be edited. It is possible to introduce a specific configuration file name instead of using the default name 'BNC.bnc'.
2316	</p>
2317
2318	<p><a name="nw"><h4>3.19.1 No Window Mode - optional</h4></p>
2319	<p>
2320	Apart from its regular windows mode, BNC can be started on all systems as a batch job with command line option '-nw'. BNC will then run in 'no window' mode, using processing options from its configuration file on disk. Terminate BNC using Windows Task Manager when running it in 'no window' mode on Windows systems.
2321	</p>
2322	<p>
2323	Example:<br><br>
2324	bnc.exe -nw
2325	</p>
2326
2327	<p><a name="post"><h4>3.19.2 File Mode - optional</h4></p>
2328	<p>
2329	Although BNC is primarily a real-time online tool, for debugging purposes it can be run offline to read data from a file previously saved through option 'Raw output file'. Enter the following command line option for that
2330	</p>
2331	<p>
2332	--file <<u>inputFileName</u>>
2333	</p>
2334
2335	and specify the full path to an input file containing previously saved data. Example:<br><br>
2336	./bnc --file /home/user/raw.output_110301
2337	</p>
2338	<p>
2339	Note that when running BNC offline, it will use options for file saving, interval, sampling, PPP etc. from its configuration file.
2340	</p>
2341	<p>Note further that option '--file' forces BNC to appy the '-nw' option for running in 'no window' mode.
2342	</p>
2343
2344	<p><a name="conffile"><h4>3.19.3 Configuration File - optional</h4></p>
2345	The default configuration file name is 'BNC.bnc'. You may change this name at startup time using the command line option '--conf <<u>confFileName</u>>'. This allows running several BNC jobs in parallel on the same host using different sets of configuration options. <u>confFileName</u> stands either for the full path to a configuration file or just for a file name. If you introduce only a filename, the corresponding file will be saved in the current working directory from where BNC is started.
2346	</p>
2347	<p>
2348	Example:<br><br>
2349	./bnc --conf MyConfig.bnc
2350	</p>
2351	<p>
2352	This leads to a BNC job using configuration file 'MyConfig.bnc'. The configuration file will be saved in the current working directory.
2353	</p>
2354
2355	<p><a name="confopt"><h4>3.19.4 Configuration Options - optional</h4></p>
2356	<p>
2357	BNC applies options from the configuration file but allows updating every one of them on the command line while the contents of the configuration file remains unchanged. The command line syntax for that looks as follows
2358	</p>
2359	<p>
2360	--key <keyName> <keyValue>
2361	</p>
2362	<p>
2363	where <keyName> stands for the name of an option contained in the configuration file and <keyValue> stands for the value you want to assign to it. The following is a syntax example for a complete command line:
2364	</p>
2365	<p>
2366	bnc --nw --conf <confFileName&gt --key <keyName1> <keyValue1> --key <keyName2> <keyValue2> ...
2367	</p>
2368	<p>
2369	Example:
2370	</p>
2371	<p>
2372	./bnc --conf CONFIG.bnc --key proxyPort 8001 --key rnxIntr "1 day"
2373	</p>
2374
2375	<p><a name="limits"><h3>4. Limitations</h3></p>
2376	<ul>
2377	<li>
2378	In 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.
2379	</li>
2380
2381	<li>Observations from COMPASS and QZSS are so far not supported.</li>
2382	<li>
2383	Using RTCM Version 3 to produce RINEX files, BNC will properly handle most message types. However, when handling message types 1001, 1003, 1009 and 1011 where the ambiguity field is not set, the output will be no valid RINEX. All values will be stored modulo 299792.458 (speed of light).
2384	</li>
2385	<li>
2386	Using RTCM Version 2, BNC will only handle message types 18 and 19 or 20 and 21 together with position and the antenna offset information carried in types 3 and 22. Note that processing carrier phase corrections and pseudo-range corrections contained in message types 20 and 21 needs access to Broadcast Ephemeris. Hence, whenever dealing with message types 20 and 21, make sure that Broadcast Ephemeris become available for BNC through also retrieving at least one RTCM Version 3 stream carrying message types 1019 (GPS ephemeris) and 1020 (GLONASS ephemeris).
2387	</li>
2388	<li>
2389	BNC'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.
2390	</li>
2391	<li>
2392	EUREF as well as IGS adhere to an open data policy. Streams are made available through NTRIP Broadcasters at <u>www.euref-ip.net</u>, <u>www.igs-ip.net</u> and <u>products.igs-ip.net</u> free of charge to anyone for any purpose. There is no indication up until now how many users will need to be supported simultaneously. The given situation may develop in such a way that it might become difficult to serve all registered users at the same times. In cases where limited resources on the NTRIP Broadcaster side (software restrictions, bandwidth limitation etc.) dictates, first priority in stream provision will be given to stream providers followed by re-broadcasting activities and real-time analysis centers while access to others might be temporarily denied.
2393	</li>
2394	<li>
2395	Once 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.
2396	</li>
2397	</ul>
2398
2399	<p><a name="annex"><h3>5. Annex</h3></p>
2400	<p>
2401	5.1. <a href=#history>Revision History</a><br>
2402	5.2. <a href=#rtcm>RTCM</a><br>
2403	5.2.1 NTRIP <a href=#ntrip1>Version 1</a><br>
2404	5.2.2 NTRIP <a href=#ntrip2>Version 2</a><br>
2405	5.2.3 RTCM <a href=#rtcm2>Version 2</a><br>
2406	5.2.4 RTCM <a href=#rtcm3>Version 3</a><br>
2407	5.3. <a href=#config>Configuration Examples</a><br>
2408	5.4. <a href=#links>Further Reading</a>
2409	</p>
2410
2411	<p><a name=history><h4>5.1 Revision History</h3></p>
2412	<table>
2413	<tr></tr>
2414
2415	<tr>
2416	<td>Dec 2006  </td><td>Version 1.0b  </td>
2417	<td>[Add] First Beta Binaries published based on Qt 4.2.3.</td>
2418	</tr>
2419
2420	<tr>
2421	<td>Jan 2007  </td><td>Version 1.1b  </td>
2422	<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>
2423	</tr>
2424
2425	<tr>
2426	<td>Apr 2007  </td><td>Version 1.2b  </td>
2427	<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>
2428	</tr>
2429
2430	<tr>
2431	<td>May 2007  </td><td>Version 1.3  </td>
2432	<td>[Add] Source code published.</td>
2433	</tr>
2434
2435	<tr>
2436	<td>Jul 2007  </td><td>Version 1.4  </td>
2437	<td>[Bug] Skip messages from proxy server<br> [Bug] Call RINEX script through 'nohup'</td>
2438	</tr>
2439
2440	<tr>
2441	<td>Apr 2008  </td><td>Version 1.5  </td>
2442	<td>[Add] Handle ephemeris from RTCM Version 3 streams<br> [Add] Upgrade to Qt Version 4.3.2<br> [Add] Optional RINEX v3 output<br> [Add] SBAS support<br> [Bug] RINEX skeleton download following stream outage<br> [Add] Handle ephemeris from RTIGS streams<br> [Add] Monitor stream failure/recovery and latency<br> [Mod] Redesign of main window<br> [Bug] Freezing of About window on Mac 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>
2443	</tr>
2444
2445	<tr>
2446	<td>Dec 2008  </td><td>Version 1.6  </td>
2447	<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 eccentricities from RTCMv3<br> [Add] Reconfiguration on-the-fly<br> [Mod] Binary output of synchronized observations<br> [Add] Binary output of unsynchronized observations<br> [Bug] Fixed problem with joined RTCMv3 blocks</td>
2448	</tr>
2449
2450	<tr>
2451	<td>Dec 2008  </td><td>Version 1.6.1  </td>
2452	<td>[Mod] HTTP GET when no proxy in front</td>
2453	</tr>
2454
2455	<tr>
2456	<td>Nov 2009  </td><td>Version 1.7  </td>
2457	<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>
2458	</tr>
2459
2460	<tr>
2461	<td>Nov 2009  </td><td>Version 1.8  </td>
2462	<td>[Mod] On-the-fly reconfiguration of latency and throughput plots</td>
2463	</tr>
2464
2465	<tr>
2466	<td>Feb 2010  </td><td>Version 2.0  </td>
2467	<td>[Mod] Change sign of Broadcast Corrections<br> [Add] Real-time PPP option</td>
2468	</tr>
2469
2470	<tr>
2471	<td>Jun 2010  </td><td>Version 2.1  </td>
2472	<td>[Bug] SSR GLONASS message generation<br> [Add] PPP in Post Processing mode<br> [Mod] Update of SSR messages following draft dated 2010-04-12<br> [Mod] Generating error message when observation epoch is wrong</td>
2473	</tr>
2474
2475	<tr>
2476	<td>Jul 2010  </td><td>Version 2.2  </td>
2477	<td>[Bug] GLONASS ephemeris time</td>
2478	</tr>
2479
2480	<tr>
2481	<td>Aug 2010  </td><td>Version 2.3  </td>
2482	<td>[Mod] Internal format for saving raw streams<br> [Bug] Outlier detection in GLONASS ambiguity resolution<br> [Mod] Format of PPP logs in logfile<br> [Bug] Complete acceleration terms for GLONASS ephemeris<br> [Bug] Handling ephemeris IOD's in PPP mode</td>
2483	</tr>
2484
2485	<tr>
2486	<td>Dec 2010  </td><td>Version 2.4  </td>
2487	<td>[Add] Output of averaged positions when in PPP mode<br> [Mod] Use always the latest received set of Broadcast Ephemeris<br> [Add] QuickStart PPP option<br> [Mod] Improvement of data sharing efficiency among different threads<br> [Mod] Design of PPP tab section<br> [Add] Sigmas for observations and parameters<br> [Add] Stream distribution map<br> [Bug] GPS Ephemeris in RINEX v3 format</td>
2488	</tr>
2489
2490	<tr>
2491	<td>Feb 2011  </td><td>Version 2.5  </td>
2492	<td>[Add] PPP option for sync of clock observations and corrections<br> [Add] Drafted RTCMv3 Galileo ephemeris messages 1045<br> [Add] Drafted RTCMv3 Multiple Signal Messages<br> [Add] Optional specification of sigmas for coordinates and troposphere in PPP<br> [Add] Include Galileo in SPP<br> [Add] Include Galileo observations in output via IP port<br> [Add] Include Galileo observations in output via RINEXv3 files<br> [Mod] Interface format for feeding a real-time engine with observations<br> [Add] Correct observations for antenna phase center offsets<br> [Add] Combine orbit/clock correction streams<br> [Add] Specify corrections mountpoint in PPP tab</td>
2493	</tr>
2494
2495	<tr>
2496	<td>Apr 2011  </td><td>Version 2.6  </td>
2497	<td>[Add] Complete integration of BNS in BNC<br> [Add] SP3 and Clock RINEX output<br> [Add] PPP in Post Processing Mode<br> [Add] Some RINEX editing & QC functionality<br> [Add] Threshold for orbit outliers in combination solution<br> [Add] Real-time engine becomes orbit/clock server instead of client<br> [Mod] 'EOE' added to orbit/clock stream from engine<br> [Add] Correction for antenna eccentricities<br> [Add] Quick start mode for PPP<br> [Mod] Design of format for feeding engine changed to follow RINEX v3<br> [Mod] Implementation of SSR message encoding modified according to standard<br> [Add] SSL/TLS Support of NTRIP Version 2<br> [Mod] Switch to Qt version 4.7.3<br> [Add] RINEX editing, concatenation and quality check<br> [Add] Reading all configuration options from command line<br> [Mod] RTCMv3 Galileo Broadcast Ephemeris message 1045<br> [Mod] Change default configuration file suffix from 'ini' to 'bnc'<br> [Add] Specific rates for orbits and clocks in streams and SP3/RNX files</td>
2498	</tr>
2499
2500	<tr>
2501	<td>May 2012  </td><td>Version 2.6  </td>
2502	<td>[ADD] Version 2.6 published</td>
2503	</tr>
2504
2505	<tr>
2506	<td>Jul 2012  </td><td>Version 2.7  </td>
2507	<td>[Bug] Bug in L5 decoding fixed<br> [Bug] Bug in on-the-fly configuration fixed<br> [Add] Clock RINEX file header extended<br> [Add] Decoding/converting COMPASS and QZSS added<br> [Add] Work on RINEX quality check started</td>
2508	</tr>
2509
2510	</table>
2511	</p>
2512
2513	<p><a name="rtcm"><h4>5.2. RTCM</h4></p>
2514
2515	<p>
2516	The 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.
2517	<p>
2518	Personal copies of RTCM Recommended Standards can be ordered through <u>http://www.rtcm.org/orderinfo.php</u>.
2519	</p>
2520
2521	<p><a name="ntrip1"><h4>5.2.1 NTRIP Version 1</h4></p>
2522
2523	<p>
2524	'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.
2525	</p>
2526
2527	<p>
2528	NTRIP Version 1 is an RTCM standard designed for disseminating differential correction data (e.g. in the RTCM-104 format) or other kinds of GNSS streaming data to stationary or mobile users over the Internet, allowing simultaneous PC, Laptop, PDA, or receiver connections to a broadcasting host. NTRIP supports wireless Internet access through Mobile IP Networks like GSM, GPRS, EDGE, or UMTS.
2529	</p>
2530
2531	<p>
2532	NTRIP 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.
2533	</p>
2534
2535	<p>
2536	NTRIP is an open none-proprietary protocol. Major characteristics of NTRIP's dissemination technique are:
2537	<ul>
2538	<li>Based on the popular HTTP streaming standard; comparatively easy to implement when having limited client and server platform resources available.</li>
2539	<li>Application not limited to one particular plain or coded stream content; ability to distribute any kind of GNSS data.</li>
2540	<li>Potential to support mass usage; disseminating hundreds of streams simultaneously for thousands of users possible when applying modified Internet Radio broadcasting software.</li>
2541	<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>
2542	<li>Enables streaming over mobile IP networks because of using TCP/IP.</li>
2543	</ul>
2544	</p>
2545
2546	<p>
2547	The 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).
2548	</p>
2549
2550	<p>
2551	Source-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'.
2552	</p>
2553	<p>
2554	Source-table records of type NET contain the following data fields: 'identifiey', 'operator', 'authentication', 'fee', 'web-net', 'web-str', 'web-reg', 'misc'.
2555	</p>
2556	<p>
2557	Source-table records of type CAS contain the following data fields: 'host', 'port', 'identifier', 'operator', 'nmea', 'country', 'latitude', 'longitude', 'misc'.
2558	</p>
2559
2560	<p><a name="ntrip2"><h4>5.2.2 NTRIP Version 2</h4></p>
2561
2562	<p>
2563	The major changes of NTRIP Version 2 compared to Version 1.0 are:
2564	</p>
2565
2566	<ul>
2567	<li>cleared and fixed design problems and HTTP protocol violations;</li>
2568	<li>replaced non standard directives;</li>
2569	<li>chunked transfer encoding;</li>
2570	<li>improvements in header records;</li>
2571	<li>source-table filtering;</li>
2572	<li>RTSP communication.</li>
2573	</ul>
2574
2575	<p>NTRIP Version 2 allows to either communicate in TCP/IP mode or in RTSP/RTP mode or in UDP mode whereas Version 1 is limited to TCP/IP only. It furthermore allows using the Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL) cryptographic protocols for secure NTRIP communication over the Internet.
2576	</p>
2577
2578	<p><a name="rtcm2"><h4>5.2.3 RTCM Version 2</h4></p>
2579	<p>
2580	Transmitting GNSS carrier phase data can be done through RTCM Version 2 messages. Please note that only RTCM Version 2.2 and 2.3 streams may include GLONASS data. Messages that may be of interest here are:
2581	</p>
2582
2583	<ul>
2584	<li>
2585	Type 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.
2586	</li>
2587	<li>
2588	Type 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.
2589	</li>
2590	<li>
2591	Type 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.
2592	</li>
2593	<li>
2594	Type 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.
2595	</li>
2596	<li>
2597	Type 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.
2598	</li>
2599	<li>
2600	Type 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.
2601	</li>
2602	<li>
2603	Type 18 and 20 messages are RTK uncorrected carrier phase data and carrier phase corrections.
2604	</li>
2605	<li>
2606	Type 19 and 21 messages are the uncorrected pseudo-range measurements and pseudo-range corrections used in RTK.
2607	</li>
2608	<li>
2609	Type 23 message provides the information on the antenna type used on the reference station.
2610	</li>
2611	<li>
2612	Type 24 message carries the coordinates of the installed antenna's ARP in the GNSS coordinate system coordinates.
2613	</li>
2614	</ul>
2615
2616	<p><a name="rtcm3"><h4>5.2.4 RTCM Version 3</h4></p>
2617	<p>
2618	RTCM Version 3 has been developed as a more efficient alternative to RTCM Version 2. Service providers and vendors have asked for a standard that would be more efficient, easy to use, and more easily adaptable to new situations. The main complaint was that the Version 2 parity scheme was wasteful of bandwidth. Another complaint was that the parity is not independent from word to word. Still another was that even with so many bits devoted to parity, the actual integrity of the message was not as high as it should be. Plus, 30-bit words are awkward to handle. The Version 3 standard is intended to correct these weaknesses.
2619	</p>
2620	<p>
2621	RTCM Version 3 defines a number of message types. Messages that may be of interest here are:
2622	<ul>
2623	<li>Type 1001, GPS L1 code and phase.</li>
2624	<li>Type 1002, GPS L1 code and phase and ambiguities and carrier to noise ratio.</li>
2625	<li>Type 1003, GPS L1 and L2 code and phase.</li>
2626	<li>Type 1004, GPS L1 and L2 code and phase and ambiguities and carrier to noise ratio.</li>
2627	<li>Type 1005, Station coordinates XYZ for antenna reference point.</li>
2628	<li>Type 1006, Station coordinates XYZ for antenna reference point and antenna height.</li>
2629	<li>Type 1007, Antenna descriptor and ID.</li>
2630	<li>Type 1008, Antenna serial number.</li>
2631	<li>Type 1009, GLONASS L1 code and phase.</li>
2632	<li>Type 1010, GLONASS L1 code and phase and ambiguities and carrier to noise ratio.</li>
2633	<li>Type 1011, GLONASS L1 and L2 code and phase.</li>
2634	<li>Type 1012, GLONASS L1 and L2 code and phase and ambiguities and carrier to noise ratio.</li>
2635	<li>Type 1013, Modified julian date, leap second, configured message types and interval.</li>
2636	<li>Type 1014 and 1017, Network RTK (MAK) messages (under development).</li>
2637	<li>Type 1019, GPS ephemeris.</li>
2638	<li>Type 1020, GLONASS ephemeris.</li>
2639	<li>Type 4088 and 4095, Proprietary messages (under development).
2640	</li>
2641	</ul>
2642	</p>
2643
2644	<p>
2645	The following are so-called 'State Space Representation' (SSR) messages:
2646	<ul>
2647	<li>Type 1057, GPS orbit corrections to Broadcast Ephemeris</li>
2648	<li>Type 1058, GPS clock corrections to Broadcast Ephemeris</li>
2649	<li>Type 1059, GPS code biases</li>
2650	<li>Type 1060, Combined orbit and clock corrections to GPS Broadcast Ephemeris</li>
2651	<li>Type 1061, GPS User Range Accuracy (URA)</li>
2652	<li>Type 1062, High-rate GPS clock corrections to Broadcast Ephemeris</li>
2653	<li>Type 1063, GLONASS orbit corrections to Broadcast Ephemeris</li>
2654	<li>Type 1064, GLONASS clock corrections to Broadcast Ephemeris</li>
2655	<li>Type 1065, GLONASS code biases</li>
2656	<li>Type 1066, Combined orbit and clock corrections to GLONASS Broadcast Ephemeris</li>
2657	<li>Type 1067, GLONASS User Range Accuracy (URA)</li>
2658	<li>Type 1068, High-rate GLONASS clock corrections to Broadcast Ephemeris</li>
2659	</ul>
2660	</p>
2661
2662	<p>
2663	The following are proposed 'Multiple Signal Messages' (MSM) under discussion for standardization:
2664	<ul>
2665	<li>Type 1045, Galileo ephemeris.</li>
2666	<li>Type 1071, Compact GPS pseudo-ranges</li>
2667	<li>Type 1072, Compact GPS carrier phases</li>
2668	<li>Type 1073, Compact GPS pseudo-ranges and carrier phases</li>
2669	<li>Type 1074, Full GPS pseudo-ranges and carrier phases plus signal strength</li>
2670	<li>Type 1075, Full GPS pseudo-ranges, carrier phases, Doppler and signal strength</li>
2671	<li>Type 1076, Full GPS pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2672	<li>Type 1077, Full GPS pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)<br></li>
2673	<li>Type 1081, Compact GLONASS pseudo-ranges</li>
2674	<li>Type 1082, Compact GLONASS carrier phases</li>
2675	<li>Type 1083, Compact GLONASS pseudo-ranges and carrier phases</li>
2676	<li>Type 1084, Full GLONASS pseudo-ranges and carrier phases plus signal strength</li>
2677	<li>Type 1085, Full GLONASS pseudo-ranges, carrier phases, Doppler and signal strength</li>
2678	<li>Type 1086, Full GLONASS pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2679	<li>Type 1087, Full GLONASS pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)<br></li>
2680	<li>Type 1091, Compact Galileo pseudo-ranges</li>
2681	<li>Type 1092, Compact Galileo carrier phases</li>
2682	<li>Type 1093, Compact Galileo pseudo-ranges and carrier phases</li>
2683	<li>Type 1094, Full Galileo pseudo-ranges and carrier phases plus signal strength</li>
2684	<li>Type 1095, Full Galileo pseudo-ranges, carrier phases, Doppler and signal strength</li>
2685	<li>Type 1096, Full Galileo pseudo-ranges and carrier phases plus signal strength (high resolution)</li>
2686	<li>Type 1097, Full Galileo pseudo-ranges, carrier phases, Doppler and signal strength (high resolution)<br></li>
2687	</ul>
2688	</p>
2689
2690	<p><a name="config"><h4>5.3. Configuration Examples</h4></p>
2691
2692	<p>BNC comes with a number of configuration examples which can be used on all operating systems. There are two ways to start BNC using one of these files:
2693	<ul>
2694	<li> On graphical systems you may use the computer mouse to 'drag' a configuration file icon and 'drop' it on top of BNC's program icon.
2695	</li>
2696	<li> On non-graphical systems you may start BNC using a command line with the following option for a configuration file (example for Windows systems):<br>bnc.exe --conf <configFileName>
2697	</li>
2698	</ul>
2699	Presented example configuration files contain a user ID 'user' and a password 'pass' for accessing streams from various Ntrip Broadcasters. Replace these account details by a the personal user ID and password you receive following an online registration through <u>http://register.rtcm-ntrip.org</u>.
2700	</p>
2701	<p>
2702	Note that the account for an Ntrip Broadcaster is usually limited to pulling a certain maximum number of streams at the same time. As running some of the example configurations requires pulling several streams, it is suggested to make sure that you don't exceed your account's limits.
2703	</p>
2704	<p>
2705	Make also sure that directories which are part of the example configurations exist on your system or adjust the affected configuration options according to your needs.
2706	</p>
2707	<p>
2708	Some BNC options require antenna phase center variations as made available from IGS through so-called ANTEX files at <u>ftp://igs.org/pub/station/general</u>. An example ANTEX file is also part of the BNC package for convenience.
2709	</p>
2710	<p>
2711	The example configurations assume that no proxy protects your BNC host. Should a proxy be operated in front of BNC then you need to introduce its IP and port in the 'Network' tab.
2712	</p>
2713
2714	<ol type=b>
2715	<li>File 'RinexObs.bnc'<br>
2716	The purpose of this configuration is to convert RTCM streams to RINEX Observation files. The configuration pulls streams from several Ntrip Broadcasters using different Ntrip versions and generate 15min 1Hz RINEX Version 3 Observation files. See <u>http://igs.bkg.bund.de/ntrip/observations</u> for observation stream resources.
2717	</li>
2718	<br>
2719	<li>File 'RinexEph.bnc'<br>
2720	The purpose of this configuration is to convert RTCM streams to RINEX Navigation files. The configuration pulls an RTCM Version 3 stream carrying Broadcast Ephemeris coming from the real-time EUREF and IGS network. It saves hourly RINEX Version 3 Navigation files. See <u>http://igs.bkg.bund.de/ntrip/ephemeris</u> for further real-time Broadcast Ephemeris resources.
2721	</li>
2722	<br>
2723	<li>File 'SSR.bnc'<br>
2724	The purpose of this configuration is to save Broadcast Corrections from RTCM SSR messages in a plain ASCII format as hourly files. See <u>http://igs.bkg.bund.de/ntrip/orbits</u> for further real-time IGS or EUREF orbit/clock products.
2725	</li>
2726	<br>
2727	<li>File 'RinexConcat.bnc'<br>
2728	The purpose of this configuration is to concatenate RINEX Version 3 files to produce a concatenated file and edit the marker name in the file header. The sampling interval is set to 30 seconds. See section 'RINEX Editing & QC' in the documentation for examples on how to call BNC from command line in 'no window' mode for RINEX file editing, concatenation and quality checks.
2729	</li>
2730	<br>
2731	<li>File 'RTK.bnc'<br>
2732	The purpose of this configuration is to feed a serial connected receiver with observations from a reference station for conventional RTK. The stream is scanned for RTCM messages. Message type numbers and latencies of incoming observation are reported in BNC's logfile.
2733	</li>
2734	<br>
2735	<li>File 'FeedEngine.bnc'<br>
2736	The purpose of this configuration is to feed a real-time GNSS engine with observations from a number of remote reference stations. The configuration pulls streams provided in various formats from different Ntrip Broadcasters. Incoming observations are decoded, synchronized and output through a local IP port and saved into a file. Failure and recovery thresholds are specified to inform about outages.
2737	</li>
2738	<br>
2739	<li>File 'PPP.bnc'<br>
2740	The purpose of this configuration is Precise Point Positioning from observations of a rover receiver. The configuration reads RTCM Version 3 observations, a stream of Broadcast Corrections and a Broadcast Ephemeris stream. Positions are saved in the logfile.
2741	</li>
2742	<br>
2743	<li>File 'QuickStartPPP.bnc'<br>
2744	The purpose of this configuration is Precise Point Positioning in Quick-Start mode from observations of a static receiver with precisely known position. The configuration reads RTCM Version 3 observations, Broadcast Corrections and a Broadcast Ephemeris stream. Positions are saved in NMEA format on disc. Positions are also output through IP port for real-time visualization with tools like RTKPLOT.
2745	</li>
2746	<br>
2747	<li>File 'PPPPostProc.bnc'<br>
2748	The purpose of this configuration is Precise Point Positioning in Post Processing mode. BNC reads a RINEX Observation and a RINEX Version 3 Navigation files and a Broadcast Corrections files. PPP processing options are set to support the Quick-Start mode. The output is saved in a specific Post Processing logfile and contains the coordinates derived over time following the implemented PPP filter algorithm.
2749	</li>
2750	<br>
2751	<li>File 'SPPQuickStartGal.bnc'<br>
2752	The purpose of this configuration is Single Point Positioning in Quick-Start mode from observations of a static receiver with precisely known position. The configuration uses GPS, GLONASS and Galileo observations and a Broadcast Ephemeris stream.
2753	</li>
2754	<br>
2755	<li>File 'Sp3.bnc'<br>
2756	The purpose of this configuration is to produce SP3 files from a Broadcast Ephemeris stream and a Broadcast Corrections stream. Note that this requires an ANTEX file because SP3 file contents should be referred to CoM.
2757	</li>
2758	<br>
2759	<li>File 'Sp3ETRF2000PPP.bnc'<br>
2760	The purpose of this configuration is to produce SP3 files from a Broadcast Ephemeris stream and a stream carrying ETRF2000 Broadcast Corrections. The Broadcast Corrections stream is formally introduced in BNC's 'Combine Corrections' table. This leads to an SP3 file containing orbits referred also to ETRF2000. Pulling in addition observations from a reference station at precisely known ETRF2000 position allows to compare an 'INTERNAL' PPP solution with ETRF2000 reference coordinates.
2761	</li>
2762	<br>
2763	<li>File 'Upload.bnc'<br>
2764	The purpose of this configuration is to upload orbits and clocks from a real-time GNSS engine to an Ntrip Broadcaster. For that the configuration reads precise orbits and clocks in RTNET format. It also reads a stream carrying Broadcast Ephemeris. BNC converts the orbits and clocks into Broadcast Corrections and encodes them in RTCM Version 3 SSR messages to uploads them to an Ntrip Broadcaster. The Broadcast Corrections stream is referred to satellite Antenna Phase Center (APC) and IGS08. Orbits are saved on disk in SP3 format and clocks in Clock RINEX format.
2765	</li>
2766	<br>
2767	<li>File 'UploadPPP.bnc'<br>
2768	This configuration equals the 'Upload.bnc' configuration. However, the Broadcast Corrections are in addition used for an 'INTERNAL' PPP solution based on observations from a static reference station with known precise coordinates. This allows a continuous quality check of the Broadcast Corrections through observing coordinate displacements.
2769	</li>
2770	<br>
2771	<li>File 'Combi.bnc'<br>
2772	The purpose of this configuration is to pull several streams carrying Broadcast Corrections and a Broadcast Ephemeris stream from an Ntrip Broadcaster to produce a combined Broadcast Corrections stream. BNC encodes the combination product in RTCM Version 3 SSR messages and uploads that to an Ntrip Broadcaster. The Broadcast Corrections stream is not referred to satellite Center of Mass (CoM). It is referred to IGS08. Orbits are saved in SP3 format and clocks in Clock RINEX format.
2773	</li>
2774	<br>
2775	<li>File 'CombiPPP.bnc'<br>
2776	This configuration equals the 'Combi.bnc' configuration. However, the combined Broadcast Corrections are in addition used for an 'INTERNAL' PPP solutions based on observations from a static reference station with known precise coordinates. This allows a continuous quality check of the combination product through observing coordinate displacements.
2777	</li>
2778	<br>
2779	<li>File 'UploadEph.bnc'<br>
2780	The purpose of this configuration is to pull a number of streams from reference stations to get hold of contained Broadcast Ephemeris messages. These are encoded then in a RTCM Version 3 stream which only provides Broadcast Ephemeris with an update rate of 5 seconds.
2781	</li>
2782	</ol>
2783	</p>
2784
2785	<p>
2786	The following table's left column is a list options as contained in BNC's configuration files (default: BNC.bnc).
2787	</p>
2788	<table>
2789	<tr></tr>
2790	<tr><td><b>Option</b></td><td><b>Affiliation</b></td></tr>
2791	<tr><td>[General]</td><td>Settings: Group</td></tr>
2792	<tr><td>startTab=</td><td>Internal: Top tab index</td></tr>
2793	<tr><td>statusTab=</td><td>Internal: Bottom tab index</td></tr>
2794	<tr><td>font=</td><td>Internal: Used font</td></tr>
2795	<tr><td>casterUrlList=</td><td>Internal: Visited URLs</td></tr>
2796	<tr><td>mountPoints=</td><td>Add Streams: broadcaster:port/mountpoint</td></tr>
2797	<tr><td>ntripVersion=</td><td>Add Stream: NTRIP Version</td></tr>
2798
2799	<tr><td>proxyHost=</td><td>Network: Proxy host</td></tr>
2800	<tr><td>proxyPort=</td><td>Network: Proxy port</td></tr>
2801	<tr><td>sslCaCertPath=</td><td>Network: Path to SSL certificates</td></tr>
2802	<tr><td>ignoreSslErrors=0</td><td>Network: Ignore ssl authorization errors</td></tr>
2803
2804	<tr><td>logFile=</td><td>General: Logfile (full path)</td></tr>
2805	<tr><td>rnxAppend=</td><td>General: Append files</td></tr>
2806	<tr><td>onTheFlyInterval=</td><td>General: Reread configuration</td></tr>
2807	<tr><td>autoStart=</td><td>General: Auto start</td></tr>
2808	<tr><td>rawOutFile=</td><td>General: Raw output file (full path)</td></tr>
2809
2810	<tr><td>rnxPath=</td><td>RINEX Observations: Directory</td></tr>
2811	<tr><td>rnxIntr=</td><td>RINEX Observations: Interval</td></tr>
2812	<tr><td>rnxSample=</td><td>RINEX Observations: Sampling</td></tr>
2813	<tr><td>rnxSkel=</td><td>RINEX Observations: Skeleton extension</td></tr>
2814	<tr><td>rnxScript=</td><td>RINEX Observations: Uplod script</td></tr>
2815	<tr><td>rnxV3=</td><td>RINEX Observation: Version 3</td></tr>
2816
2817	<tr><td>ephPath=</td><td>RINEX Ephemeris: Directory</td></tr>
2818	<tr><td>ephIntr=</td><td>RINEX Ephemeris: Interval</td></tr>
2819	<tr><td>outEphPort=</td><td>RINEX Ephemeris: Port</td></tr>
2820	<tr><td>ephV3=</td><td>RINEX Ephemeris: Version 3</td></tr>
2821
2822	<tr><td>corrPath=</td><td>Broadcast Corrections: Directory, ASCII </td></tr>
2823	<tr><td>corrIntr=</td><td>Broadcast Corrections: Interval</td></tr>
2824	<tr><td>corrPort=</td><td>Broadcast Corrections: Port</td></tr>
2825	<tr><td>corrTime=</td><td>Broadcast Corrections: Wait for full corr epoch</td></tr>
2826
2827	<tr><td>outPort=</td><td>Feed Engine: Port</td></tr>
2828	<tr><td>waitTime=</td><td>Feed Engine: Wait for full obs epoch</td></tr>
2829	<tr><td>binSampl=</td><td>Feed Engine: Sampling</td></tr>
2830	<tr><td>outFile=</td><td>Feed Engine: File (full path)</td></tr>
2831	<tr><td>outUPort=</td><td>Feed Engine: Port (unsynchronized)</td></tr>
2832
2833	<tr><td>serialMountPoint=</td><td>Serial Output: Mountpoint</td></tr>
2834	<tr><td>serialPortName=</td><td>Serial Output: Port name</td></tr>
2835	<tr><td>serialBaudRate=</td><td>Serial Output: Baud rate</td></tr>
2836	<tr><td>serialFlowControl=</td><td>Serial Output: Flow control</td></tr>
2837	<tr><td>serialDataBits=</td><td>Serial Output: Data bits</td></tr>
2838	<tr><td>serialParity=</td><td>Serial Output: Parity</td></tr>
2839	<tr><td>serialStopBits=</td><td>Serial Output: Stop bits</td></tr>
2840	<tr><td>serialAutoNMEA=</td><td>Serial Output: NMEA</td></tr>
2841	<tr><td>serialFileNMEA=</td><td>Serial Output: NMEA file name</td></tr>
2842	<tr><td>serialHeightNMEA=</td><td>Serial Output: Height</td></tr>
2843
2844	<tr><td>obsRate=</td><td>Outages: Observation rate</td></tr>
2845	<tr><td>adviseFail=</td><td>Outages: Failure threshold</td></tr>
2846	<tr><td>adviseReco=</td><td>Outages: Recovery threshold</td></tr>
2847	<tr><td>adviseScript=</td><td>Outages: Script (full path)</td></tr>
2848
2849	<tr><td>miscMount=</td><td>Miscellaneous: Mountpoint</td></tr>
2850	<tr><td>perfIntr=</td><td>Miscellaneous: Log latency</td></tr>
2851	<tr><td>scanRTCM=</td><td>Miscellaneous: Scan RTCM</td></tr>
2852
2853	<tr><td>pppSPP=</td><td>PPP Client: PPP/SPP</td></tr>
2854	<tr><td>pppMount=</td><td>PPP Client: Observations Mountpoint</td></tr>
2855	<tr><td>pppCorrMount=</td><td>PPP Client: Corrections Mountpoint</td></tr>
2856	<tr><td>pppRefCrdX=</td><td>PPP Client: X coordinate of plot origin</td></tr>
2857	<tr><td>pppRefCrdY=</td><td>PPP Client: Y coordinate of plot origin</td></tr>
2858	<tr><td>pppRefCrdZ=</td><td>PPP Client: Z coordinate of plot origin</td></tr>
2859	<tr><td>pppRefdN=</td><td>PPP Client: North eccentricity</td></tr>
2860	<tr><td>pppRefdE=</td><td>PPP Client: East eccentricity</td></tr>
2861	<tr><td>pppRefdU=</td><td>PPP Client: Up eccentricity</td></tr>
2862	<tr><td>nmeaFile=</td><td>PPP Client: NMEA outputfile</td></tr>
2863	<tr><td>nmeaPort=</td><td>PPP Client: NMEA IP output port</td></tr>
2864	<tr><td>pppPlotCoordinates=0</td><td>PPP Client: Plot NEU time series</td></tr>
2865	<tr><td>postObsFile=</td><td>PPP Client: Observations file</td></tr>
2866	<tr><td>postNavFile=</td><td>PPP Client: Navigation file</td></tr>
2867	<tr><td>postCorrFile=</td><td>PPP Client: Corrections file</td></tr>
2868	<tr><td>postOutFile=</td><td>PPP Client: Output file</td></tr>
2869	<tr><td>pppAntenna=</td><td>PPP Client: Antenna name</td></tr>
2870	<tr><td>pppAntex=</td><td>PPP Client: Path to ANTEX file</td></tr>
2871	<tr><td>pppApplySatAnt=</td><td>PPP Client: Apply sat antenna phase center Offset</td></tr>
2872	<tr><td>pppUsePhase=</td><td>PPP Client: Use phase data </td></tr>
2873	<tr><td>pppEstTropo=</td><td>PPP Client: Estimate troposphere</td></tr>
2874	<tr><td>pppGLONASS=</td><td>PPP Client: Use GLONASS</td></tr>
2875	<tr><td>pppGalileo=</td><td>PPP Client: Use Galileo</td></tr>
2876	<tr><td>pppSync=</td><td>PPP Client: Sync observations and corrections</td></tr>
2877	<tr><td>pppAverage=</td><td>PPP Client: Lenght of time window for moving average</td></tr>
2878	<tr><td>pppQuickStart=200</td><td>PPP Client: Quick-Start period</td></tr>
2879	<tr><td>pppMaxSolGap=</td><td>PPP Client: Maximal Solution Gap</td></tr>
2880	<tr><td>pppSigmaCode=</td><td>PPP Client: Sigma for Code observations</td></tr>
2881	<tr><td>pppSigmaPhase=</td><td>PPP Client: Sigma for Phase observations</td></tr>
2882	<tr><td>pppSigmaCrd0=</td><td>PPP Client: Sigma for initial XYZ coordinate</td></tr>
2883	<tr><td>pppSigmaCrdP=</td><td>PPP Client: White noise for XYZ</td></tr>
2884	<tr><td>pppSigmaTrp0=</td><td>PPP Client: Sigma for initial tropospheric delay</td></tr>
2885	<tr><td>pppSigmaTrpP=</td><td>PPP Client: White noise for tropospheric delay</td></tr>
2886
2887	<tr><td>reqcAction=</td><td>Reqc: Action</td></tr>
2888	<tr><td>reqcObsFile=</td><td>Reqc: Observations file</td></tr>
2889	<tr><td>reqcNavFile=</td><td>Reqc: Navigation file</td></tr>
2890	<tr><td>reqcOutObsFile=</td><td>Reqc: Output observations file</td></tr>
2891	<tr><td>reqcOutNavFile=</td><td>Reqc: Output navigation file</td></tr>
2892	<tr><td>reqcOutLogFile=</td><td>Reqc: Output logfile</td></tr>
2893	<tr><td>reqcRnxVersion=</td><td>Reqc: RINEX version</td></tr>
2894	<tr><td>reqcSampling=</td><td>Reqc: RINEX sampling</td></tr>
2895	<tr><td>reqcStartDateTime=</td><td>Reqc: Start time</td></tr>
2896	<tr><td>reqcEndDateTime=</td><td>Reqc: Stop time</td></tr>
2897	<tr><td>reqcRunBy=</td><td>Reqc: Operators name</td></tr>
2898	<tr><td>reqcComment=</td><td>Reqc: Additional comments</td></tr>
2899	<tr><td>reqcOldMarkerName=</td><td>Reqc: Old marker</td></tr>
2900	<tr><td>reqcNewMarkerName=</td><td>Reqc: New marker</td></tr>
2901	<tr><td>reqcOldAntennaName=</td><td>Reqc: Old antenna</td></tr>
2902	<tr><td>reqcNewAntennaName=</td><td>Reqc: New antenna</td></tr>
2903	<tr><td>reqcOldReceiverName=</td><td>Reqc: Old receiver</td></tr>
2904	<tr><td>reqcNewReceiverName=</td><td>Reqc: New receiver</td></tr>
2905
2906	<tr><td>combineStreams=</td><td>Combination: List of correction streams</td></tr>
2907	<tr><td>cmbMethod=Filter</td><td>Combination: Approach</td></tr>
2908	<tr><td>cmbMaxres=</td><td>Combination: Clock outlier threshold</td></tr>
2909	<tr><td>cmbSampl=</td><td>Combination: Orbit and clock sampling</td></tr>
2910
2911	<tr><td>uploadIntr=</td><td>Upload Corrections: File interval</td></tr>
2912	<tr><td>uploadMountpointsOut=</td><td>Upload Corrections: Upload streams</td></tr>
2913	<tr><td>uploadSamplClkRnx=</td><td>Upload Corrections: Clock sampling</td></tr>
2914	<tr><td>uploadSamplSp3=</td><td>Upload Corrections: Orbit sampling</td></tr>
2915	<tr><td>uploadSamplRtcmEphCorr=</td><td>Upload Corrections: Orbit sampling</td></tr>
2916	<tr><td>trafo_dx=</td><td>Upload Corrections: Translation X</td></tr>
2917	<tr><td>trafo_dy=</td><td>Upload Corrections: Translation Y</td></tr>
2918	<tr><td>trafo_dz=</td><td>Upload Corrections: Translation Z</td></tr>
2919	<tr><td>trafo_dxr=</td><td>Upload Corrections: Translation change X</td></tr>
2920	<tr><td>trafo_dyr=</td><td>Upload Corrections: Translation change Y</td></tr>
2921	<tr><td>trafo_dzr=</td><td>Upload Corrections: Translation change Z</td></tr>
2922	<tr><td>trafo_ox=</td><td>Upload Corrections: Rotation X</td></tr>
2923	<tr><td>trafo_oy=</td><td>Upload Corrections: Rotation Y</td></tr>
2924	<tr><td>trafo_oz=</td><td>Upload Corrections: Rotation Z</td></tr>
2925	<tr><td>trafo_oxr=</td><td>Upload Corrections: Rotation change X</td></tr>
2926	<tr><td>trafo_oyr=</td><td>Upload Corrections: Rotation change Y</td></tr>
2927	<tr><td>trafo_ozr=</td><td>Upload Corrections: Rotation change Z</td></tr>
2928	<tr><td>trafo_sc=</td><td>Upload Corrections: Scale</td></tr>
2929	<tr><td>trafo_scr=</td><td>Upload Corrections: Scale change</td></tr>
2930	<tr><td>trafo_t0=</td><td>Upload Corrections: Reference year</td></tr>
2931	<tr><td>uploadEphHost=</td><td>Upload Ephemeris: Host</td></tr>
2932	<tr><td>uploadEphPort=</td><td>Upload Ephemeris: Port</td></tr>
2933	<tr><td>uploadEphMountpoint=</td><td>Upload Ephemeris: Moutpoint</td></tr>
2934	<tr><td>uploadEphPassword=</td><td>Upload Ephemeris: Password</td></tr>
2935	<tr><td>uploadEphSample=</td><td>Upload Ephemeris: Samplig</td></tr>
2936	</table>
2937	</p>
2938	<p>
2939	Note that the following configuration options saved on disk can be changed/edited on-the-fly while BNC is already processing data:
2940	</p>
2941	<p>
2942	<ul>
2943	<li>'mountPoints' to change the selection of streams to be processed, see section 'Streams',</li>
2944	<li>'waitTime' to change the 'Wait for full obs epoch' option, see section 'Feed Engine', and</li>
2945	<li>'binSampl' to change the 'Sampling' option, see section 'Feed Engine'.</li>
2946	</ul>
2947	</p>
2948	<p>
2949	</p>
2950
2951	<p><a name="links"><h4>5.4 Futher Reading</h3></p>
2952
2953	<table>
2954	<tr></tr>
2955	<tr><td><b>Links</b></td></tr>
2956	<tr><td>NTRIP  </td><td><u>http://igs.bkg.bund.de/ntrip/index</u></td></tr>
2957	<tr><td>EUREF-IP NTRIP Broadcaster  </td><td><u>http://www.euref-ip.net/home</u></td></tr>
2958	<tr><td>IGS-IP NTRIP Broadcaster  </td><td><u>http://www.igs-ip.net/home</u></td></tr>
2959	<tr><td>IGS products NTRIP Broadcaster  </td><td><u>http://products.igs-ip.net/home</u></td></tr>
2960	<tr><td>IGS M-GEX NTRIP Broadcaster  </td><td><u>http://mgex.igs-ip.net/home</u></td></tr>
2961	<tr><td>Distribution of IGS-IP streams  </td><td><u>http://www.igs.oma.be/real_time/</u></td></tr>
2962	<tr><td>Completeness and latency of IGS-IP data  </td><td><u>http://www.igs.oma.be/highrate/</u></td></tr>
2963	<tr><td>NTRIP Broadcaster overview  </td><td><u>http://www.rtcm-ntrip.org/home</u></td></tr>
2964	<tr><td>NTRIP Open Source software code  </td><td><u>http://software.rtcm-ntrip.org</u></td></tr>
2965	<tr><td>EUREF-IP Project  </td><td><u>http://www.epncb.oma.be/euref_IP</u></td></tr>
2966	<tr><td>Real-time IGS Pilot Project  </td><td><u>http://www.rtigs.net/pilot</u></td></tr>
2967	<tr><td>Radio Technical Commission<br>for Maritime Services  </td><td><u>http://www.rtcm.org</u>
2968	</table>
2969
2970	<br>
2971	<table>
2972	<tr><td><b>Publications</b></td></tr>
2973
2974	<tr><td>Weber, G., D. Dettmering, H. Gebhard and R. Kalafus </td><td>Networked Transport of RTCM via Internet Protocol (Ntrip), IP-Streaming for Real-Time GNSS Applications, ION GNSS 2005.</td></tr>
2975
2976	<tr><td>Weber, G, L. Mervart, Z. Lukes, C. Rocken and J. Dousa </td><td>Real-time Clock and Orbit Corrections for Improved Point Positioning via NTRIP, ION GNSS 2007.</td></tr>
2977
2978	<tr><td>Mervart, L., Z. Lukes, C. Rocken and T. Iwabuchi </td><td>Precise Point Positioning With Ambiguity Resolution in Real-Time, ION GNSS 2008.</td></tr>
2979
2980	<tr><td>Weber, G. and L. Mervart </td><td>The BKG Ntrip Client (BNC), Report on EUREF Symposium 2007 in London, Mitteilungen des Bundesamtes fuer Kartographie und Geodaesie, Band 42, Frankfurt, 2009.</td></tr>
2981
2982	<tr><td>Weber, G. and L. Mervart </td><td>Real-time Combination of GNSS Orbit and Clock Correction Streams Using a Kalman Filter Approach, ION GNSS 2010.</td></tr>
2983
2984	<tr><td>Huisman, L., P. Teunissen and C. Hu </td><td>GNSS Precise Point Positioning in Regional Reference Frames Using Real-time Broadcast Corrections, Journal of Applied Geodesy, Vol. 6, pp15-23, 2012.</td></tr>
2985
2986	</table>
2987
2988

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