Changeset 6939 in ntrip


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Timestamp:
Jun 22, 2015, 4:06:33 PM (9 years ago)
Author:
weber
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Documentation completed

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  • trunk/BNC/src/bnchelp.html

    r6937 r6939  
    481481&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.3 <a href=#combimax>Maximal Residuum</a><br>
    482482&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.4 <a href=#combismpl>Sampling</a><br>
     483&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 3.14.1.5 <a href=#combiGLO>Use GLONASS</a><br>
    4834843.15. <a href=#upclk>Upload Corrections</a><br>
    484485&nbsp; &nbsp; &nbsp; 3.15.1 <a href=#upadd>Add, Delete Row</a><br>
     
    12311232</p>
    12321233
    1233 <p><a name="sp3exclude"><h4>3.7.2 Exclude Satellites - optional if 'Input SP3 Files' is set</h4></p>
     1234<p><a name="sp3exclude"><h4>3.7.2 Exclude Satellites - optional</h4></p>
    12341235<p>
    12351236You may want to exclude one or more satellites in your SP3 files from the comparison. Or you may like to exclude all satellites of a specific GNSS system from the comparison. The following are example strings to be entered for excluding satellites from the comparison.
     
    18481849</p>
    18491850
    1850 <p><a name="serauto"><h4>3.10.8 NMEA - mandatory for VRS streams</h4></p>
     1851<p><a name="serauto"><h4>3.10.8 NMEA - mandatory if 'Mountpoint' is set</h4></p>
    18511852<p>The 'NMEA' option supports the so-called 'Virtural Reference Station' (VRS) concept which requires the receiver to send approximate position information to the NTRIP Broadcaster. Select 'no' if you don't want BNC to forward or upload any NMEA message to the NTRIP broadcaster in support of VRS.
    18521853</p>
     
    18581859</p>
    18591860
    1860 <p><a name="serfile"><h4>3.10.9 File - optional if 'Auto' NMEA is set</h4></p>
     1861<p><a name="serfile"><h4>3.10.9 File - optional if 'NMEA' is set to 'Auto'</h4></p>
    18611862<p>Specify the full path to a file where NMEA messages coming from your serial connected receiver are saved. Default is an empty option field, meaning that no NMEA messages will be saved on disk.
    18621863</p>
    1863 <p><a name="serheight"><h4>3.10.10 Height - mandatory if 'Manual' NMEA is set</h4></p>
     1864<p><a name="serheight"><h4>3.10.10 Height - mandatory if 'NMEA' is set to 'Manual'</h4></p>
    18641865<p>
    18651866Specify an approximate 'Height' above mean sea level in meters for the reference station introduced through 'Mountpoint'. Together with the latitude and longitude from the NTRIP broadcaster sourcetable the height information is used to build GGA messages to be sent to the NTRIP broadcaster.
     
    18701871</p>
    18711872
    1872 <p><a name="sersampl"><h4>3.10.11 Sampling - mandatory if 'Manual' NMEA is set</h4></p>
     1873<p><a name="sersampl"><h4>3.10.11 Sampling - mandatory if 'NMEA' is set to 'Manual'</h4></p>
    18731874<p>
    18741875Select a sampling interval in seconds for manual generation and upload of NMEA GGA sentences.
     
    18921893</p>
    18931894
    1894 <p><a name="obsrate"><h4>3.11.1 Observation Rate - mandatory if 'Failure threshold', 'Recovery threshold' and 'Script' is set</h4></p>
     1895<p><a name="obsrate"><h4>3.11.1 Observation Rate - optional</h4></p>
    18951896<p>
    18961897BNC 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.
    18971898</p>
    18981899
    1899 <p><a name="advfail"><h4>3.11.2 Failure Threshold - optional</h4></p>
     1900<p><a name="advfail"><h4>3.11.2 Failure Threshold - mandatory if 'Observation rate' is set</h4></p>
    19001901<p>
    19011902Event '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.
     
    19051906</p>
    19061907
    1907 <p><a name="advreco"><h4>3.11.3 Recovery Threshold - optional</h4></p>
     1908<p><a name="advreco"><h4>3.11.3 Recovery Threshold - mandatory if 'Observation rate' is set</h4></p>
    19081909<p>
    19091910Once 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.
     
    19131914</p>
    19141915
    1915 <p><a name="advscript"><h4>3.11.4 Script - optional </h4></p>
     1916<p><a name="advscript"><h4>3.11.4 Script - optional if 'Observation rate' is set</h4></p>
    19161917<p>
    19171918As mentioned previously, BNC can trigger a shell script or a batch file to be executed when one of the events described are reported. This script can be used to email an advisory note to network operator or stream providers. To enable this feature, specify the full path to the script or batch file in the 'Script' field. The affected stream's mountpoint and type of event reported ('Begin_Outage', 'End_Outage', 'Begin_Corrupted' or 'End_Corrupted') will then be passed on to the script as command line parameters (%1 and %2 on Windows systems or $1 and $2 on Unix/Linux/Mac OS X systems) together with date and time information.
     
    19931994<p><a name="miscscan"><h4>3.12.3 Scan RTCM - optional</h4></p>
    19941995<p>
    1995 When configuring a GNSS receiver for RTCM stream generation, the firmware's setup interface may not provide details about RTCM message types observation types. As reliable information concerning stream contents should be available i.e. for NTRIP Broadcaster operators to maintain the broadcaster's source-table, BNC allows to scan RTCM streams for incoming message types and printout some of the contained meta-data. Contained observation types are also printed because such information is required a-priori to the conversion of RTCM Version 3 MSM streams to RINEX Version 3 files. The idea for this option arose from 'InspectRTCM', a comprehensive stream analyzing tool written by D. Stoecker.
     1996When configuring a GNSS receiver for RTCM stream generation, the firmware's setup interface may not provide details about RTCM message types and observation types. As reliable information concerning stream contents should be available i.e. for NTRIP Broadcaster operators to maintain the broadcaster's source-table, BNC allows to scan RTCM streams for incoming message types and printout some of the contained meta-data. Contained observation types are also printed because such information is required a-priori for the conversion of RTCM Version 3 MSM streams to RINEX Version 3 files. The idea for this option arose from 'inspectRTCM', a comprehensive stream analyzing tool written by D. Stoecker.
    19961997</p>
    19971998<p>
     
    20052006<li>Antenna descriptor.</li>
    20062007</ul>
    2007 In case of RTCM Version 3 MSM streams the output includes
     2008In case of RTCM Version 3 streams the output includes
    20082009<ul>
    20092010<li>RINEX Version 3 Observation Types</li>
     
    24602461<p><a name="combi"><h4>3.14. Combine Corrections</h4></p>
    24612462<p>
    2462 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. All corrections must refer to satellite Antenna Phase Centers (APC). 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.
     2463BNC 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. All corrections must refer to satellite Antenna Phase Centers (APC). 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.
    24632464</p>
    24642465<p>
    24652466In 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.
    2466  The solution is regularized by a set of minimal constraints. After a change of one of the values 'SSR Provider ID', 'SSR Solution ID', or 'IOD SSR' the satellite clock offsets belonging to the corresponding analysis center are reset in adjustment.
     2467 The solution is regularized by a set of minimal constraints. After a change of one of the three values 'SSR Provider ID', 'SSR Solution ID', or 'IOD SSR', the satellite clock offsets belonging to the corresponding analysis center are reset in the adjustment.
    24672468</p>
    24682469<p>
     
    24852486Note 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.
    24862487</p>
    2487 <p>
    2488 Note further that you need to tick the 'Use GLONASS' option which is part of the 'PPP (2)' panel in case you want to produce an GPS plus GLONASS combination.
    2489 </p>
     2488
    24902489<p>
    24912490A 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.
     
    25132512</p>
    25142513<p>
    2515 Note that BNC can produce an internal PPP solution from combined Broadcast Corrections. For that you have to specify the keyword 'INTERNAL' as 'Corrections Mountpoint' in the PPP (1) panel.
     2514Note that BNC can produce an internal PPP solution from combined Broadcast Corrections. For that you have to specify the keyword 'INTERNAL' as 'Corrections' mountpoint in the PPP (1) panel.
    25162515</p>
    25172516<p>
     
    25212520<p><a name="combimounttab"><h4>3.14.1 Combine Corrections Table - optional</h4></p>
    25222521<p>
    2523 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 Antenna Phase Center (APC) related 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.
    2524 </p>
    2525 <p>
    2526 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.
     2522Hit 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 Antenna Phase Center (APC) related stream. Finally, double click on the 'Weight' field to enter a weight to be applied to this stream in the combination.
    25272523</p>
    25282524<p>
    25292525The 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>
    25302526<p>
     2527It 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. Note that in such a BNC application you must not pull more than one Broadcast Ephemeris corrections stream even if a second stream would provide the same corrections from a backup caster.
     2528</p>
     2529<p>
    25312530Default is an empty 'Combine Corrections' table meaning that you don't want BNC to combine orbit and clock correction streams.
    25322531</p>
    2533 <p>
    2534 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. Note that in such a BNC application you must not pull more than one Broadcast Ephemeris corrections stream even if a second stream would provide the same corrections from a backup caster.
    2535 </p>
    25362532
    25372533<p><a name="combiadd"><h4>3.14.1.1 Add Row, Delete - optional</h4></p>
     
    25412537
    25422538<p>
    2543 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.
     2539The following screenshots describe an example setup of BNC when combining Broadcast Correction streams and uploading them to an NTRIP Broadcaster. Note that this application requires specifying options under tabs 'Combine Corrections' and 'Upload Corrections'. The example uses the combination product to simultaneously carry out an 'INTERNAL' PPP solution which allows monitoring the quality of the combination product in the space domain.
    25442540</p>
    25452541
     
    25622558
    25632559<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>
    2564 </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>
     2560</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>
    25652561<p>Default is a 'Maximal Residuum' of 999.0 meters</p>
    25662562
     
    25682564<p>Specify a combination sampling interval. Orbit and clock corrections will be produced following that interval. A value of 10 sec may be an appropriate choice.</p>
    25692565
     2566<p><a name="combiGLO"><h4>3.14.1.5 Use GLONASS - optional</h4></p>
     2567<p>
     2568You may tick the 'Use GLONASS' option in case you want to produce an GPS plus GLONASS combination and both systems are supported by the Broadcast Correction streams participating in the combination.
     2569</p>
    25702570
    25712571<p><a name="upclk"><h4>3.15. Upload Corrections</h4></p>
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