Presentation on theme: "ICELAND 2013 GPS Processing"— Presentation transcript:
1ICELAND 2013 GPS Processing TU Delft GRS fieldworkHans van der Marel, TU Delft
2GPS Processing Strategy Three processing steps are foreseenData pre-processing (RINEXing & Q/C) of campaign dataIGS/EUREF Standards Ionosphere Free solutionBernese GPS Software (V5.0)Ionosphere free linear combinationAdditional XX IGS stations included (fiducial stations)IGS08(ITRF2008) Reference FrameEnabler for absolute Troposphere Delay estimationDownloaded from IGS Data CentersCampaign data stored in local (ORX) directoryAnalysis of the campaign solutions (time series)
3Motivation for Regional Network Network includes three types of stationsCampaign stations (1-3 days of occupation)Local permanent stations (continuous operation during campaign, but without good coordinates in ITRF)IGS/EPN stations with good station coordinates and velocities (!) in ITRF2008 (IGS08).The main goals of adding regional IGS/EPN stations areTo obtain the best possible site coordinates and position time series in a global reference frame (ITRF2008)To obtain estimates of the atmospheric delay (Zenith Tropospheric Delay) over the area of interestTo verify the stability of presumed stable reference points (local permanent stations)
4Bernese GPS Software 5.0Bernese software v5.0 developed by University of BerneStandard for IGS, EUREF and scientific campaign processingSemi-autonomous computation using Bernese processing engineStandard RNX2SNX script for Ionosphere free, Ambiguity Fixed, Double Differenced Network ProcessingWith some TU Delft additionsAutomatic FTP’ing of RINEX data and IGS orbitsAnalysis tools (Matlab)Wide experience (used at TU Delft since 1992)Latest version 5.0 including all modifications up to Oct 2012
5Main Steps involving the BSW5.0 Install the Bernese GPS software 5.0 (once)Install ActivePerlInstall BSW5.0 using the TU Delft installer fileSetup the Campaign (once)Select IGS/EPN station to include in processingPrepare campaign directories and campaign filesProcessing using the Bernese Processing Engine (BPE)Add campaign data (RINEX observation files) to ORX directoryUpdate station information file(s) for the new stations (only if there are new stations)Start the BPEThis step must be repeated every time there are new stations or data.
6Bernese Software BSW5.0 Desktop icons: Bernese 5.0 -> Start BSW5.0 GUIGPSDATA -> Campaign DirectoriesGPSDATA/ICELAND/STA <- campaign definition filesGPSDATA/ICELAND/ORX <- where to store campaign dataGPSUSER -> User files (scripts, program options, etc)Windows start menu(extra link to documentation)
7BSW 5.0 GUI The BSW50 has a very extensive help system Quit the GUI Used later to set session/computationdate for the BPEThe BSW50 has a veryextensive help systemQuit the GUI
8Add ICELAND Campaign 1 Edit list of campaigns Select active campaign Create new campaign32^Run creates the campaigndirectories(ignore warnings)
9ICELAND Campaign Directory GPSDATA/ICELAND/…Just created, except SAV…SAV you should create yourselfThree important subdirectories:ORX -> RINEX campaign dataSTA -> Station definition filesSAV -> Where results are saved- Others only hold temporary dataData file locations:GPSDATA/ICELAND/ORX (campaign data, RINEX observation files, no IGS data, copy yourself)GPSDATA/CACHE (IGS station, orbit and clock data, automatic download)
10Campaign Setup (manual task) Add new campaign (ICELAND) <- just doneSelect IGS/EPN fiducial sites (Network definition) <- nextData center selection for IGS/EPN data (ICELAND.FTP)Station Information File (ICELAND.STA)Station Abbreviations File (ICELAND.ABB)Plate Definition File (ICELAND.PLD)A-priori Coordinate Files (IGS08.CRD, IGS08.VEL, IGS08.FIX)IGS08 (ITRF2008) coordinates and velocities for IGS/EPN stations => used as constraints (min constraint, 3 dof, shift in XYZ)A-priori coordinates for campaign stations from Precise Point Positioning (PPP) and velocities from Nuvel-1A plate modelOcean Loading Parameter File (ICELAND.BLQ)
11Fiducial site selection (1) To obtain the best possible site coordinates in ITRF2008 we should add as many as possible nearby IGS/EPN sitesThese are called fiducial sitesConflicting selection criteriaMore is better (averaging out of errors in fiducial coordinates and processing errors)Distances should be with 1000 km (otherwise no simultaneous observations, problems with ambiguity resolution, etc.). If necessary, we could add some other permanent stations to bridge the distance.Fiducial sites should have good coordinates -> not all permanent stations can be used (must be in ITRF).Only necessary for tectonic studies or studies which requires a well defined and stable reference frame (in absolute sense)
12Fiducial site selection (2) Useful linksWhat to watch out forUse (at least) the same fiducials as in campaigns of previous yearsCheck the station quality (using the web-links)IGS Reference frame sites are top of the line (used for definition of ITRF)Good tracking statisticsIf recent data is available (temporary outages, download problems)If the station has good coordinates in ITRF (several years of observations, check relevant EPN pages)Receiver and antenna type (stations with similar receiver and antenna types are a pro, good antenna calibrations are a must)
14Fiducial site selection for ICELAND Verify these yourself!Used by campaigns in previous year:HOFN (IGS reference frame site)REYK (data download problem)Other IGS sites (to be included):QAQ1 (IGS reference frame site)SCOR (IGS reference frame site)NYA1 (IGS reference frame site)TRO1 (IGS reference frame site)MORP (IGS reference frame site)Other EPN sites (candidates):ARGINo coordinates in ITRF2008, no velocities, not a fiducial, but could be used to bridge the distance with MORP
15Campaign Setup (manual task) Add new campaign (ICELAND) <- doneSelect IGS/EPN fiducial sites (Network definition) <- just doneData center selection for IGS/EPN data (ICELAND.FTP)Station Information File (ICELAND.STA)Station Abbreviations File (ICELAND.ABB)Plate Definition File (ICELAND.PLD)A-priori Coordinate Files (IGS08.CRD, IGS08.VEL, IGS08.FIX)IGS08 (ITRF2008) coordinates and velocities for IGS/EPN stations => used as constraints (min constraint, 3 dof, shift in XYZ)A-priori coordinates for campaign stations from Precise Point Positioning (PPP) and velocities from Nuvel-1A plate modelOcean Loading Parameter File (ICELAND.BLQ)We can now create the initial version of station definition files in the ICELAND/STA directory
16Campaign definition files IGS08.CRD, IGS08.VEL and IGS08.FIXDownload IGB08_R.CRD and IGB08_R.VEL from AIUB (ftp://ftp.unibe.ch/aiub/BSWUSER50/STA), extract required fiducials, and rename fiile to IGS08.CRD and IGS08.VELDownload ITRF2008.CRD and ITRF2008.VEL from AIUB [ibid], extract REYK coordinates and velocities, add to IGS08.CRD|VELCreate IGS08.FIX with the list of fiducial stations (REYK is the only non IGS reference frame station -> be alert later!)ICELAND.STA (Station information file)Download IGS.STA from AIUB [ibid] and extract only the fiducial stations we actually useICELAND.PLD (same as IGS08.VEL, just copy)ICELAND.FTPEach line contains first four character of file name (case sensitive) and the data center from where to download the data from
17Campaign definition files (cont’) ICELAND.ABB (Station abbreviation file)Contains 4 and 2 letter abbreviations for the stationsCan be created automatically by the BSWBut it is also easy to do by handICELAND.BLQ (Ocean loading tables)Contains parameters to compute corrections for ocean loadingOcean tide model: FES2004 (NO correction for CMC)Parameters provided by Chalmers, Onsala (H.-G. Scherneck):Instead, we copied FES2004.BLQ from AIUB [ibid], and extracted the required fiducial stations, and renamed to ICELAND.BLQNow all files are ready for processing the ficucial data.IGS08.[CRD|VEL] and ICELAND.[STA|PLD|BLQ] have to be updated for campaign data
18IGS08.CRD, IGS08.VEL, IGS08.FIXYou may consider removing REYK from the IGS08.FIX file; this station is the only IGS non reference frame station (but leave it in IGS08.CRD and IGS08.VEL)
19ICELAND.STA Renaming of station names Receiver, antenna, antenna height information
20IGS Receiver/Antenna types IcelandStation name Receiver type Antenna type Dome AntHgt LocationHOFN 10204M LEICA GR LEIAR25.R LEIT Hoefn, IcelandREYK 10202M LEICA GR LEIAR25.R LEIT Reykjavik, IcelandMORP 13299S TRIMBLE NETR8 AOAD/M_T NONE Morpeth, United KingdoNYA M TRIMBLE NETR8 ASH SNOW Ny-Alesund, NorwayTRO M TRIMBLE NETR8 TRM SCIS Tromsoe, NorwayQAQ M ASHTECH UZ-12 ASH701945E_M SCIS Qaqortoq / JulianehaabSCOR 43006M ASHTECH UZ-12 ASH B SCIS Scoresbysund/Ittoqqoor(From ICELAND.STA)UK / NorwayGreenland
21ICELAND.FTP All data is available from BKGI (BKG IGS) data center In case you want to add for example ARGI (or other EUREF EPN site) use BKGE (BKG EUREF) as data centerOther possibilities are CDDIS, IGN, …We don’t use this for campaign data => these are just copied into the ICELAND/ORX directory
22All these files are available as in a zip file, just unzip this to the STA directory. Now everything is ready for processing fiducial stationsThis is what we will do next… using the BPELater we are going to add campaign data, but not yet!ICELAND.BLQ
23Two ways of processing with BSW50 The Bernese software consists of 60+ programs which have to be run in a particular order.Sometimes the same program has to be run twice, or even more, using different options and input dataThere are two ways to accomplish thisThrough the GUI and menu system; you run the individual programs. This offers the best flexibility, but it is also very labour intensive and not recommended for fist time users.You use the Bernese Processing Engine (BPE) using predefined settings and file naming conventions. The BPE runs the programs in a particular order.
24Bernese Processing (BPE engine) RNX2SNXA script (modified)IGS finial (rapid) orbits, clocks and ERPIGS RINEX data from various data centersIonosphere models, Differential Code Biases (DCB) and Satellite information (SATCRUX) files from University of BerneAbsolute antenna calibrations from IGS/EPN;Elevation Cut-off of 3 degreesElevation Dependent WeightingOcean loading parameters from Chalmers/TUDProcessing time 5-10 minutes/dayLet try it on our newly defined ICELAND campaign
25Starting the BPE 1 2 Set session/computation date Start BPE process Should be ICELANDSelected session/compute date
26Select session/computation date Various date options12check
27Start BPE Process (1)Press ^Next for the next panel
28Start BPE Process (2)Press ^Run to start the BPE. That’s all (for now)
29Here we go !!The BPE is running one program after the other, you can follow the progress here…
31What happened?Protocol files: look here for errors, especially the last file!!beforeafterFound!Temporary files (will be deleted when successful)Campaign directory before and after
32What happened? We need more education on the BPE and PCF files first … When there is an error, look into the campaign directoryIn case of an error, no files are deleted in the campaign directory, so you will find all the program outputIn ICELAND/BPE you will also find the protocol filesThese are never deletedThese are the first place to look for diagnostic messagesStart with the last log-file: that is where the processing stoppedIn this case RNXGRA program is complaining about a file it cannot find. This is because we did not update the Process Control File (PCF) for the BPE: we’re using RNX2SNXA.PCF with it’s default settings (probably for the I2GPS example…).We need more education on the BPE and PCF files first …
33Process Control Files (PCF) GPSUSER contains the following subdirectoriesGPSUSER/PCF Process Control FilesGPSUSER/OPT Directories with pre-set program optionsGPSUSER/… (others are not relevant for the BPE now)The Process Control Files can be found in GPSUSER/PCFThe PCF we are using is RNX2SNXA.PCFCopy RNX2SNXA.PCF to ICELAND.PCF(so we can safely make changes)Open ICELAND.PCF in an editor
34ICELAND.PCF (1)After a lot of comments (explaining what is done) you find the following section linking SCRIPTS to OPT directories with the input parameters: You don’t need to change this part…PID SCRIPT OPT_DIR CAMPAIGN CPU P WAIT FOR....3** 8******* 8******* 8******* 8******* 1 3** 3** 3** 3** 3** 3** 3** 3** 3** 3**## Copy required files and create a priori CRD file#001 R2S_FTP R2S_GEN ANY002 COOVEL R2S_GEN ANY# Prepare pole, orbit, and clock information#101 POLUPD R2S_GEN ANY111 PRETAB R2S_GEN ANY112 ORBGEN R2S_GEN ANY(skipped)
35IGS means here final orbits (available after 13 days), may change this later into IGR for rapid orbits (one day delay)ICELAND.PCF (2)At the end of the file you find the following section:#VARIABLE DESCRIPTION DEFAULT8******* 40************************************** 16**************V_A A priori information APRV_B Orbit/ERP, DCB, ION information IGSV_C Preliminary (ambiguity-float) results P1_V_E Final (ambiguity-fixed) results F1_V_F Size-reduced NEQ information R1_V_MINUS Session range begin (for COMPAR)V_PLUS Session range endV_CLU Maximum number of files per clusterV_STAINF Station information file name I2GPSV_BLQINF Ocean loading correction file nameV_ABBINF Station name abbreviation file name I2GPSV_CRDREF A-priori/reference CRD/VEL/FIX filename IGS08V_PCV Absolute/relative PCV I08ICELANDICELANDIs blank, if you want ocean loading correctionsenter ICELAND here as wellWhy we got the error…
36Start BPE Process (again) Press ^Next to see next input panel
37Enter name of PCF file here. Use the ICELAND Enter name of PCF file here. Use the ICELAND.PCF created in the previous stepPress ^Next twice to see the 4th input panel
38Press ^Run from any of the BPE menu’s to start the BPE. Here you can make some last minute changes before starting the BPE (these are not saved in the PCF for future runs)IGS->IGR?Press ^Run from any of the BPE menu’s to start the BPE.If within 13 days, no finals are available, then use rapids (IGR)If you have no ocean loading, leave field blank (it won’t do corrections)Leave blank?
39Here we go again !!The BPE is running one program after the other, you can follow the progress here…… fingers crossed
41Where are the results? Protocol files before after Results saved in ICELAND/SAV directoryTemporary files deleted …Campaign directory before and after
42What are the results? Estimated Zenith Delays (troposphere) Bernese format [F1|P1]_yyddd0.TRPTroposphere SINEX F1_yyddd0.TROProtocol / Summary file (R2Syyddd0.PRC)ADDNEQ output ([F1|P1]_yyddd0.OUT)GPSEST output (ESTyyddd0.OUT)SINEX (Solution Independent Exchange) fileNormal equations file [R1|F1|P1_yyddd0.NEQCoordinate files [F1|P1}_yyddd0.CRDF1 Final Solution / P1 Provisional Solution
43Where are we now ? You have now successfully processed one day of data But only IGS stations were included…… this makes little sense.How do we add campaign data to the processing?This is up next.
44Step 1: Conversion to RINEX We use Trimble’s “Convert to Rinex” to convert T01 into RINEX.There are a couple of issues to pay attention to:Marker name field : change s/n into the 4 letter codeMarker number field: leave/make blankReceiver type: change “R7” into “TRIMBLE R7”, change “5700” into “TRIMBLE 5700” (if you don’t do this the s/w will not recognize the receiverAntenna offset: enter the antenna height (to ARP) you measuredAntenna serial number: enter the serial number of the antennaAfter conversion you have to rename the RINEX filesChange s/n into 4 letter code, e.g o -> KVIH OUse all uppercase letters (not kvih o but KVIH O)Copy/move RINEX observation files to GPSDATA/ICELAND/ORX
45Step 2: Update campaign files (1) When there are new stations we have to update the campaign definition files IGS08.CRD, IGS08.VEL, ICELAND.STA, ICELAND.ABB and ICELAND.BLQ.We could do this all by hand (using an editor) and results from e.g. a PPP run with NRCAN’s web-service.We can also do this by doing PPP (Precise Point Positioning) run using the BPE in the BSW50:Open the BPE (after selecting a date) and select in the 2nd panel the PPPA Process Control FileIn the 4th panel you leave the STAINFO and BLQ input fields blank. Also check whether to use IGS (final) or IGR (rapid) products.Press ^Run to start the BPE.The BPE will now process all RINEX observation files (in ORX) for the selected day using the PPPA.PCF.
46Step 2: Update campaign files (2) When the BPE/PPPA has finished, it has:Created IGS08_U.CRD and IGS08_U.VEL in the STA directoryUpdated ICELAND.ABB in the STA directoryCreate a SINEX file PPP_____.SNX in the SOL directorySaved other output in the SAV/… directoriesIGS08_U.CRD is an update of IGS08.CRD whereby coordinates for new stations have been added (only for stations which did not exist previously). IGS08_U.VEL contains the new stations with zero velocities : we will be using zero velocities for all campaign stations, resulting in coordinates at the epoch of measurement!If you are happy with the IGS08_U.[CRD|VEL] updates you use these to replace the IGS08.[CRD|VEL] that is used in the RNX2SNXA processing.
47Step 2: Update campaign files (3) The BPE/PPPA script has also updated the abbreviation tables in ICELAND.ABB (STA directory). No action is needed here.Next we have to update the ICELAND.STA information fileWe left the STAINFO field blank in the BPE/PPPA, so that the RINEX file was not checked against the station information fileThis is not allowed for the BPE/RNX2SNXA script; the STAINFO file is an essential step in checking the RINEX filesA easy way to update the ICELAND.STA file isIn the Bernese GUI, select conversion > sinex to station informationSelect the SINEX file PPP_____.SNX created by the BPE/PPPA run, select an output file (e.g. UPDATE.STA) and enter a title, then enter ^Run.This will extract information from the SINEX file.
48Step 2: Update campaign files (4) Now you can merge the output of UPDATE.STA with ICELAND.STA.When doing this:Check that the collected information is correct, if necessary correct the information. Doing this now will save you a lot of work later.Change the start and end times for the stationsThe final item on the list is to update the Ocean Loading tables in ICELAND.BLQ.Open ICELAND.BLQ in an editor, copy the a block for one of the campaign stations, and rename the station nameThe ocean loading effect is the same for all campaign stations(You could also decide to do without ocean loading corrections in the BPE/RNX2SNXA by leaving the entry for BLQ files blank)
49Step 3: Run the BPE/RNX2SNXA Now you restart the network processing including the campaign data.A few point to pay attention to:Check that you are using the ICELAND.PCF (which is our tailored version of RNX2SNXA.PCF)Decide if you will be using final IGS products (IGS) or rapid products (IGR). Final products are only available after 13 days; rapid products will only remains available for a few days after finals.If you have a BLQ file no not leave the BLQ field blank (you won’t have ocean loading corrections then…)Check the protocol files that the stations have actually been included and that the processing results are ok.Don’t loose your patience, things may not go directly your way…Good luck!
50Further reading README.TXT that came with the Windows installer Has some good hints on setting up a new campaign, and the steps needed to include new stationsThe on-line help system available from the GUIThis is an excellent source of information (one mouse click away)The Bernese manual (pdf)Has lots and lots of information, available from BERN50 directory. Contains also very good information on GPS (and Glonass) in general.