- Timestamp:
- Jan 19, 2007, 1:40:42 PM (18 years ago)
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trunk/BNC/bnchelp.html
r370 r373 13 13 <tr><td><b>History</b></td></tr> 14 14 <tr><td>Dec 1, 2006 </td><td>Version 1.0b </td><td>Binaries of first beta version published.</td></tr> 15 <tr><td>Jan 20, 2007 </td><td>Version 1.1b </td><td>Observables C2, S1, and S 1added, full VRS capability added, bug in RTCM2 decoder time tag solved, access to EUREF and IGS RINEX skeletons enabled.15 <tr><td>Jan 20, 2007 </td><td>Version 1.1b </td><td>Observables C2, S1, and S2 added, full VRS capability added, bug in RTCM2 decoder time tag solved, access to EUREF and IGS RINEX skeletons enabled. 16 16 </table> 17 17 </p> … … 103 103 <ul> 104 104 <li> 105 help contents.<br> 106 You may keep the 'Help Contents' window open while setting BNC options. 107 </li> 108 <li> 105 109 general information about BNC.<br> 106 110 Close the 'About BNC' window to continue with BNC. 107 111 </li> 108 <li>109 help contents.<br>110 You may keep the 'Help Contents' window open while setting BNC options.111 </li>112 112 </ul> 113 113 </p> … … 118 118 You may like to run BNC in a Local Area Network (LAN). LANs are often protected by a proxy server. 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 out the proxy server settings of your Internet browser or ask your network administrator.</p> 119 119 <p> 120 Note that IP streaming may generally be denied in a LAN. In such a case you need to ask for an appropriate modification of the security policy from your network administrator or for the installation of a TCP relay to involved NTRIP broadcasters. If that doesn't work, run BNC outside your LAN on a host that is connected to the Internet through an Internet Service Provider (ISP).120 Note that IP streaming may generally be denied in a LAN. In such a case you need to ask your network administrator for an appropriate modification of his security policy or for the installation of a TCP relay to involved NTRIP broadcasters. If that doesn't work out, run BNC outside your LAN on a host that is connected to the Internet through an Internet Service Provider (ISP). 121 121 </p> 122 122 123 123 <p><a name="output"><h4>B - 4. Synchronized Output</h4></p> 124 124 <p> 125 BNC lets you output synchronized observations epoch by epoch. This output is made available in a plain ASCII format and in a binary format. The output comprises the following observations if available where SNR is the signal-to-noise ratio S mapped to integer numbers 1 to 9:</p> 126 StatID, SVPRN, GPSWeek, GPSWeeks, C1, C2, P1, P2, L1, L2, S1, S2, SNR1, SNR2. 127 </p> 128 <p> 129 In case an observation is unavailable, its value is set to zero '0.000'. 125 BNC lets you output synchronized observations epoch by epoch. This output is made available in a plain ASCII format and in binary format. The output comprises the following observations if available:</p> 126 <p> 127 StatID, SVPRN, GPSWeek, GPSWeeks, C1, C2, P1, P2, L1, L2, S1, S2, SNR1, SNR2 128 </p> 129 <p> 130 Note that SNR stands for the signal-to-noise ratio S mapped to integer numbers 1 to 9. Note further that in case an observation is unavailable, its value is set to zero '0.000'. 130 131 </p> 131 132 <p><a name="wait"><h4>B - 4.1 Wait for Full Epoch - optional</h4></p> 132 133 <p> 133 When feeding a real-time GNSS engine waiting for input epoch by epoch, BNC ignores whatever is received later than 'Wait for full epoch' seconds. A value of 3 to 5 seconds could be an appropriate choice for that, depending on the latency of the incoming streams and the delay you wouldaccept for your real-time GNSS product. Default value for 'Wait for full epoch' is 1 second.134 When feeding a real-time GNSS engine waiting for input epoch by epoch, BNC ignores whatever is received later than 'Wait for full epoch' seconds. A value of 3 to 5 seconds could be an appropriate choice for that, depending on the latency of the incoming streams and the delay you can accept for your real-time GNSS product. Default value for 'Wait for full epoch' is 1 second. 134 135 </p> 135 136 <p> … … 223 224 <p><a name="rnxscript"><h4>B - 5.2 RINEX Script - optional</h4></p> 224 225 <p> 225 Whenever a RINEX file is saved, you may like to compress, copy or upload it immediately via FTP. For that you enter the full path of a script or batch file carrying out these operations. The RINEX file path will be passed to the script as a command line parameter (%1 on Windows systems, $1 on Unix/Linux systems). 226 Whenever a RINEX file is saved, you may like to compress, copy or upload it immediately via FTP. For that you enter the full path of a script or batch file which is then called to carry out these operations. The RINEX file path will be passed to the script as a command line parameter (%1 on Windows systems, $1 on Unix/Linux systems). 227 </p> 228 <p> 229 The triggering event for calling the script or batch file is the end of a RINEX file interval. If that is superposed by a stream outage, the triggering event is the stream reconnect. 226 230 </p> 227 231 … … 238 242 <p><a name="rnxskeleton"><h4>B - 5.5 RINEX Skeleton Extension - optional</h4></p> 239 243 <p> 240 Whenever BNC generates a new RINEX file, it first tries to retrieve information needed for RINEX headers from so-called public RINEX header skeleton files which are derived from sitelogs. An 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 for a public RINEX header skeleton file concerning the EPN station Brussels.241 </p> 242 <p> 243 However, it may happen that public RINEX header skeleton files are not available, its contents is not up to date, or you need to have additional/optional records in the RINEX header. For that BNC allows to introduce personal skeleton files that contain the header records you would like to see. You may derive a personal RINEX header skeleton file from the information given in an up to date sitelog. A file in the 'RINEX directory' with the 'RINEX skeleton extension' is interpreted by BNC as a personal RINEX header skeleton file for the affected stream.244 Whenever BNC generates a new RINEX file, it first tries to retrieve information needed for RINEX headers from so-called public RINEX header skeleton files which are derived from sitelogs. An 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 for a public RINEX header skeleton file concerning the EPN station Brussels. 245 </p> 246 <p> 247 However, it may happen that public RINEX header skeleton files are not available, its contents is not up to date, or you need to have additional/optional records in the RINEX header. For that BNC allows to introduce personal skeleton files that contain the header records you would like to see. You may derive a personal RINEX header skeleton file from the information given in an up to date sitelog. A file in the 'RINEX directory' with the extension 'RINEX skeleton extension' is interpreted by BNC as a personal RINEX header skeleton file for the affected stream. 244 248 </p> 245 249 <p> … … 273 277 <li>They may contain any other optional complete header record as defined in the RINEX documentation.</li> 274 278 <li>They should then contain empty header records of type</li> 275 <br>- # / TYPES OF OBSERV ATIONS279 <br>- # / TYPES OF OBSERV 276 280 <br>- TIME OF FIRST OBS 277 281 <br>The existence of these empty records leads BNC to include such lines in the final RINEX file header together with an additional … … 289 293 <p><a name="rnxappend"><h4>B - 5.6 Append Files</h4></p> 290 294 <p> 291 When starting BNC, new RINEX files are created by default. Probably existing files will be overwritten. However, it may be desirable to append observations to already existing RINEX files following a restart of BNC after an intentional 'Stop', a system crash or a crash of BNC. Hit 'Append files' to continue with already existing files and thus save what has been recorded so far. Note that theoption 'Append files' also concerns the 'ASCII output file' and the 'Log' file.295 When starting BNC, new RINEX files are created by default. Probably existing files will be overwritten. However, it may be desirable to append observations to already existing RINEX files following a restart of BNC after an intentional 'Stop', a system crash or a crash of BNC. Hit 'Append files' to continue with already existing files and thus save what has been recorded so far. Note that option 'Append files' also concerns the 'ASCII output file' and the 'Log' file. 292 296 </p> 293 297 <p><a name="mountpoints"><h4>B - 6. Mountpoints</h4></p> … … 325 329 <p><a name="GetTable"><h4>B - 6.4 Get Table</h4></p> 326 330 <p> 327 Hit button 'Get Table' to download the source-table from the NTRIP broadcaster. Please pay attention to data fields 'format' and 'format-details'. Keep in mind that BNC can only decode and convert streams that come in RTCM 2.x, RTCM 3, or RTIGS formats. RTCM 2.x streams must contain message types 18 and 19 while RTCM 3 streams must contain GPS message types 1002 or 1004 and may contain GLONASS message types 1010 or 1012, see data field 'format-details' for available message types and their repetition rates in brackets. Select your streams line by line, use +Shift and +Ctrl when necessary. 328 </p> 331 Hit button 'Get Table' 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 2.x, RTCM 3, or RTIGS formats. RTCM 2.x streams must contain message types 18 and 19 while RTCM 3 streams must contain GPS message types 1002 or 1004 and may contain GLONASS message types 1010 or 1012, see data field 'format-details' for available message types and their repetition rates in brackets. Select your streams line by line, use +Shift and +Ctrl when necessary. 332 </p> 333 <p> 334 The contents of data field 'type' tells you whether a stream comes from a physical Reference Station (RS) or a Virtual Reference Station (VRS). 335 </p> 329 336 <p> 330 337 Hit 'OK' to return to the main window. You may like to 'Add Mountpoints' from another NTRIP broadcaster when necessary. … … 341 348 </li> 342 349 <li> 343 BNC allows to retrieve streams from Virtual Reference Stations. Whether a stream comes from a physical Reference Station (RS) or a Virtual Reference Station (VRS) is indicated in column 'type' under 'Mountpoints' as well as in column 'type' of the affected source-table. For retrieving a VRS stream, an approximate rover position is required to be send in NMEA format to the NTRIP broadcaster. In return, an individual user-specific data stream is generated, usually by a network RTK software. This stream is tailored exactly to the latitude and longitude shown in the 'lat' and 'long' columns under 'Mountpoints'. Default values for 'lat' and 'long' are taken from the source-table. You may change these values (first double-click, then edit fields 'lat' and/or 'long', then hit Enter) according to your needs. The position has to be introduced in northern latitude degrees (example for northern hemisphere: 52.436, example for eastern hemisphere: -24.567) and eastern longitude degrees (example: 358.872 or -1.128). Editing the 'lat' and 'long' values under 'Mountpoints' is only possible for VRS streams. The position must point to a location within the service area of the affected RTK network. RINEX files generated from VRS streams contain an additional COMMENT line in the header mentioning the 'lat' and 'long' values introduced. Note that when running BNC in a Local Area Network (LAN), NMEA strings may be blocked by a proxy server, firewall or virus scanner. 350 BNC allows to retrieve streams from Virtual Reference Stations. Whether a stream comes from a physical Reference Station (RS) or a Virtual Reference Station (VRS) is indicated in column 'type' under 'Mountpoints' as well as in column 'type' of the affected source-table. For retrieving a VRS stream, an approximate rover position is required to be send in NMEA format to the NTRIP broadcaster. In return, an individual user-specific data stream is generated, usually by a network RTK software. This stream is tailored exactly to the latitude and longitude shown in the 'lat' and 'long' columns under 'Mountpoints'. 351 <br><br>Default values for 'lat' and 'long' are taken from the source-table. You may change these values (first double-click, then edit fields 'lat' and/or 'long', then hit Enter) according to your needs. The position has to be introduced in northern latitude degrees (example for northern hemisphere: 52.436, example for eastern hemisphere: -24.567) and eastern longitude degrees (example: 358.872 or -1.128). Editing the 'lat' and 'long' values under 'Mountpoints' is only possible for VRS streams. The position must point to a location within the service area of the affected RTK network. RINEX files generated from VRS streams contain an additional COMMENT line in the header mentioning the 'lat' and 'long' values introduced. 352 <br><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. 344 353 </li> 345 354 </ul> … … 362 371 <p><a name="nw"><h4>B - 10. No Window - optional</h4></p> 363 372 <p> 364 You can use BNC on all systems in batch mode with the command line option -nw. BNC then runs in 'no window' mode, reading options from the configuration file ${HOME}/.config/BKG/BNC_NTRIP_Client.conf (Unix/Linux) or from the register BKC_NTRIP_Client (Windows).373 You can use BNC on all systems in batch mode with the command line option '-nw'. BNC then runs in 'no window' mode, reading options from the configuration file ${HOME}/.config/BKG/BNC_NTRIP_Client.conf (Unix/Linux) or from the register BKC_NTRIP_Client (Windows). 365 374 </p> 366 375 <p> … … 371 380 <ul> 372 381 <li> 373 The connection to an NTRIP broadcaster may possibly break or a stream requested may be temporarily unavailable. Furthermore, a connection is interpreted by BNC to be broken if no data is coming in for a period of 20 seconds. When this happens, a reconnect is being attempted with decreasing frequency. BNC first tries to reconnect with ~1 second delay, if unsuccessful, tries again in ~2 seconds from the last attempt, if still unsuccessful tries with ~4 seconds from the last attempt etc. Each attempt doubles the delay from the previous attempt. The maximum delay between attempts is limited to ~128 seconds. The reconnection process is documented in the 'Log' file .382 The connection to an NTRIP broadcaster may possibly break or a stream requested may be temporarily unavailable. Furthermore, a connection is interpreted by BNC to be broken if no data is coming in for a period of 20 seconds. When this happens, a reconnect is being attempted with decreasing frequency. BNC first tries to reconnect with ~1 second delay, if unsuccessful, tries again in ~2 seconds from the last attempt, if still unsuccessful tries with ~4 seconds from the last attempt etc. Each attempt doubles the delay from the previous attempt. The maximum delay between attempts is limited to ~128 seconds. The reconnection process is documented in the 'Log' file/section. 374 383 </li> 375 384 <li> … … 383 392 </li> 384 393 <li> 385 As a consequence of the current implementation of the RTIGS format and transport protocol, streams coming in that format containonly GPS data.394 Streams coming in RTIGS format carry only GPS data. 386 395 </li> 387 396 <li> … … 389 398 </li> 390 399 <li> 391 EUREF as well as IGS follow an open data policy. Streams are made available through NTRIP broadcasters at <u>www.euref-ip.net</u> and <u>www.igs-ip.net</u> free of charge to anyone for any purpose. Up to now it is not clear how many users will have to be supported simultaneously. The given situation may develop in a way that becomes difficult to serve all registered users at all times. In case limited dissemination resources on the NTRIP broadcaster side (software restrictions, bandwidth limitation etc.) make it necessary, first priority in stream provision will be given to stream providers, re-broadcasting activities, and real-time analysis centers while access for others might be temporarily denied.400 EUREF as well as IGS follow an open data policy. Streams are made available through NTRIP broadcasters at <u>www.euref-ip.net</u> and <u>www.igs-ip.net</u> free of charge to anyone for any purpose. Up to now it is not clear how many users will have to be supported simultaneously. The given situation may develop in a way that it becomes difficult to serve all registered users at all times. In case limited dissemination resources on the NTRIP broadcaster side (software restrictions, bandwidth limitation etc.) make it necessary, first priority in stream provision will be given to stream providers, re-broadcasting activities, and real-time analysis centers while access for others might be temporarily denied. 392 401 </li> 393 402 <li> … … 424 433 <tr><td>NTRIP broadcaster overview </td><td><u>http://www.rtcm-ntrip.org/home</u></td></tr> 425 434 <tr><td>EUREF-IP Pilot Project </td><td><u>http://www.epncb.oma.be/euref_IP</u></td></tr> 426 <tr><td>Real-Time IGS Working Group </td><td><u>http://igscb.jpl.nasa.gov/projects/rtwg/index.html</u> 435 <tr><td>EUREF-IP Pilot Project </td><td><u>http://www.epncb.oma.be/euref_IP</u></td></tr> 436 <tr><td>Radio Technical Commission<br>for Maritime Services </td><td><u>http://www.rtcm.org</u> 427 437 </table> 428 438 <br> … … 552 562 <p><a name="rtigs"><h4>F - 3. RTIGS</h4></p> 553 563 <p> 554 RTIGS stands for a data format and transport protocol for GPS observations (no GLONASS). It was defined by the Real-Time IGS Working Group (RTIGS WG). Its definition is based on the SOC format. Every RTIGS record has one of the following numbers:564 RTIGS stands for a data format and transport protocol for GPS observations. It was defined by the Real-Time IGS Working Group (RTIGS WG). Its definition is based on the SOC format. Every RTIGS record has one of the following numbers: 555 565 </p> 556 566 <p> … … 605 615 <p><a name="soc"><h4>F - 3.1 SOC</h4></p> 606 616 <p> 607 The SOC format has been designed in July 1999 by the Jet Propulsion Laboratory (JPL) and the California Institute of Technology (CalTech) to transport 1Hz GPS data (no GLONASS)with minimal bandwidth over the open Internet. SOC follows the 'little-endian' byte order meaning that the low-order byte of a number is stored in memory at the lowest address, and the high-order byte at the highest address. Because the transport layer is UDP, the format does not include sync bits, a checksum, or cyclic redundancy checksum (CRC). SOC allows to transport the GPS observable CA, P1, P2, L1, and L2, efficiently compressed down to 14 bytes with 1 mm range resolution and 0.02 mm phase resolution. SOC contains epochs for cycle slips, a stand-alone time-tag per epoch, a minimum representation of the receiver's clock solution, 3 SNR numbers, a unique site id, a modulo 12 hour sequence number and flags for receiver type and GPS health. SOC's simple structure comprises an 8 byte header, a 9 byte overhead for timetag, number of gps, etc., plus 21 data bytes per gps.617 The SOC format has been designed in July 1999 by the Jet Propulsion Laboratory (JPL) and the California Institute of Technology (CalTech) to transport 1Hz GPS data with minimal bandwidth over the open Internet. SOC follows the 'little-endian' byte order meaning that the low-order byte of a number is stored in memory at the lowest address, and the high-order byte at the highest address. Because the transport layer is UDP, the format does not include sync bits, a checksum, or cyclic redundancy checksum (CRC). SOC allows to transport the GPS observable CA, P1, P2, L1, and L2, efficiently compressed down to 14 bytes with 1 mm range resolution and 0.02 mm phase resolution. SOC contains epochs for cycle slips, a stand-alone time-tag per epoch, a minimum representation of the receiver's clock solution, 3 SNR numbers, a unique site id, a modulo 12 hour sequence number and flags for receiver type and GPS health. SOC's simple structure comprises an 8 byte header, a 9 byte overhead for timetag, number of gps, etc., plus 21 data bytes per gps. 608 618 </p> 609 619 <p>
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