GAMIT Processing for Modern Geodetic Methods (Page. 1 of 3)
by Andrew Newman
NEXT RUNNING GAMIT: Determining loosely constrained GPS positions
Please refer to the Introduction, GAMIT, and GLOBK manuals (local version) for details of processing.
A few words about the data and network:
- These data are from 3-campaigns that I performed across the Socorro Magma Body in 2002, 2003 and 2004.
- The network was established to identify transient deformation across the region.
- In years 2002 and 2003, 9 campaign sites were used. Going west to east they are LDRN, LINO and CLIF along a line
in the Northwest, followed by SLVR, SVRK (ROCK), VVRS, BOWL, PRTC and YES along a line to the south.
- In year 2004, an additional 4 sites were added, to identify possible increased deformation along a portion of the network. These
stations were named CORK, KELL, PRID, and PAS1. With the last station reoccupying a continuous site for the
duration of the campaign near the PASSCAL instrument
center at New Mexico Tech. Thus far, these stations have only been measured during one campaign, so we will only be able
to constrain their location, and not deformation rate.
- Additionally, a continuous site, SC01, in the southern part of the network, just north of PAS1 was running, and can be used
to additionally constrain deformation and reduce overall error.
- Depending on year, campaign sites were occupied between 2 to 4 days, continuously.
Specific initializations:
Data Conversion and initial Quality Control:
- If you haven't already done so, please copy over data from TEST directory. Go to the new directory and create
a subdirectory called 'rinex'.
% cp -a ~anewman/MGM/TEST/Socorro2002 .
% cd Socorro2002
- Lets also clean up the directory structure a bit
% mkdir RAW
% mv *dat *eph *ion *mes RAW
- IMPORTANT: Should check to make sure that none of the campaign station IDs overlap
with continuous stations. It turns out that my station ROCK was previously used,
thus I need to a different name for this site. I chose to create a
symbolic link for temporary station SVRK (for SeVilleta RocK).
% cd RAW
% for file in ROCK* # run on all rock files
do
tail=`echo $file | cut -c 5-` # create a variable 'tail' with the last part of the file names
ln -s $file SVRK$tail # create a symbolic link for the new name
done
Create a directory for RINEX data called 'rinex':
% mkdir ~/MGM/Socorro2002/rinex
% cd ~/MGM/Socorro2002/rinex
TEQC:
Look at the TEQC GPS preprocessing manual for details on using the program and for deciphering output.
- We will use 'teqc' to create Navigation (.nav) and RINEX (.YYo) files. RINEX is the standard GPS format for geodesy.
% teqc -tr d -week 2002:323 +nav BOWL3230.nav ../RAW/BOWL3230.dat > BOWL3230.02o
# ^ ^ ^ ^ ^
# | | | | |
# convert | create navigation | output file
# | file |
# | input dat
# tell it when file
# data is from
Doing this for every file gets a little time consuming, particularly if you are re-processing a lot
of old data. Thus it is better to use a shell script to automate this process.
Please read over the script in /usr/local/geophysics/bin/run_teqc.
# run without arguements to get usage.
% run_teqc
Usage: /usr/local/geophysics/bin/run_teqc YEAR 'GPS.dat_files'
runs teqc on the 'GPS.dat files' listed as the 2nd and later arguements
YEAR is the year of the occupation... all other information is pulled from
the file name.
# run again correctly this time.
% run_teqc 2002 ../RAW/*.dat
- We can now remove the newly created ROCK* files since the SVRK files are
the same. We will also need to individually replace all occurrence of the word
ROCK within the filesSVRK*.
% cd ~/MGM/Socorro2002/rinex/ # make sure you are in the correct directory
% rm ROCK* # remove any residual ROCK* files
% gunzip * # uncompress all compressed files in directory (*.gz *.Z)
% for file in SVRK* # run on all SVRK* files
do
sed 's/ROCK/SVRK/g' $file > $$.tmp # replace text 'ROCK' with 'SVRK' within $file and put it in $$.tmp
mv $$.tmp $file # replace $file with $$.tmp
done
- Once complete, check to see if all necessary files are in the current directory.
(9 stations X 2day X 10files = 180 files). Number depends on whether you created additional files (e.g. lfiles.*).
% ls
% ls -1 | wc # gives first output number is equal to the number
# of files in current directory
GAMIT preprocessing:
Official GAMIT website and manual is here.
- Before we start processing with GAMIT, we need to create a link called 'gg' to GAMIT from your base
directory. This will only need to be done once.
% ln -s $GAMIT ~/gg
Tables:
Table updates: tables/lfile.Adding Campaign SitesDetermining useful continuous sites
Table updates: tables/sites.defaults
Table updates: tables/station.info
- We now need to make sure to create a proper table/station.info file.
- You can use the following command to get station.info information, only for the continuous sites,
from SOPAC (Southern California GPS processing center). This
will create a file called test.info for the individual station that you can put into your station.info file.
% wget "http://sopac.ucsd.edu/cgi-bin/procInputMetadata.cgi?site=gode&date=20021107&format=station_info" -O test.info
We can automate this for all the stations.
% cd ~/MGM/Socorro2002
% YYYYMMDD=20021107 # DOY 311
% for stat in `awk '$1!~"#"{print $1}' ./tables/sites.defaults | cut -c -4`
do
echo $stat $YYYYMMDD
wget "http://sopac.ucsd.edu/cgi-bin/procInputMetadata.cgi?site=${stat}&date=${YYYYMMDD}&format=station_info" -O test.info
cat test.info >> all.info
done
# edit this file to remove excessive junk
% mv all.info ./tables/station.info
- Alternatively, we can pull information for most, if not all of the continuous stations from ~/gg/tables/station.info.sopac.newfmt
or ~/gg/tables/station.info.
- Important: We will additionally need to put in the information for the campaign sites. This information
should come form the hand-written site logs during the occupations.
See my station.info to get the pertinent campaign site information.
*SITE Station Name Session Start Session Stop Ant Ht HtCod Ant N Ant E Receiver Type Vers SwVer Receiver SN Antenna Type Dome Antenna SN
PIE1 pie10000 2002 302 00 30 00 9999 999 00 00 00 0.0610 DHPAB 0.0000 0.0000 ROGUE SNR-8000 3.2.32.11 3.20 -------------------- AOAD/M_T NONE -------------------
MDO1 mdo10000 2002 240 00 00 00 2004 342 00 00 00 0.0610 DHPAB 0.0000 0.0000 ROGUE SNR-8000 3.2.32.11 3.20 -------------------- AOAD/M_T JPLA -------------------
AMC2 amc20000 2002 184 00 21 00 9999 999 00 00 00 0.0000 DHPAB 0.0000 0.0000 ASHTECH Z-XII3 IL01-1D04-MCF-12MX 9.90 -------------------- AOAD/M_T NONE -------------------
NLIB nlib0000 1999 243 00 00 00 2005 105 00 00 00 0.0610 DHPAB 0.0000 0.0000 ROGUE SNR-8000 0.5 0.50 -------------------- AOAD/M_T JPLA -------------------
GODE gode0000 2002 123 00 00 00 2006 101 00 00 00 0.0614 DHPAB 0.0000 0.0000 AOA SNR-8000 ACT 3.3.32.5 3.30 -------------------- AOAD/M_T JPLA -------------------
SC01 sc010000 2001 227 00 00 00 2005 318 00 00 00 0.0000 DHPAB 0.0000 0.0000 TRIMBLE 4700 1.37 1.37 -------------------- TRM29659.00 SCIT -------------------
BOWL BOWL0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14628--------------- AOAD/M_T NONE 62099--------------
CLIF CLIF0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14628--------------- AOAD/M_T NONE 73539--------------
LDRN LDRN0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14629--------------- AOAD/M_T NONE 185528-------------
LINO LINO0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14633--------------- AOAD/M_T NONE 62099--------------
PRTC PRTC0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14633--------------- AOAD/M_T NONE 185528-------------
SLVR SLVR0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14628--------------- AOAD/M_T NONE 185528-------------
SVRK SVRK0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14629--------------- AOAD/M_T NONE 73539--------------
VVRS VVRS0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14633--------------- AOAD/M_T NONE 62099--------------
YESO YESO0000 2002 001 00 00 00 9999 999 00 00 00 0.5000 DHPAB 0.0000 0.0000 TRIMBLE 4000SSI 7.19 / 3.04 7.19 14629--------------- AOAD/M_T NONE 73539--------------
The specific information for this file, particularly the receiver and antenna types are crucial. Please check over the file
~/gg/tables/rcvant.dat for details about the different antenna and receiver types.
Additional information can be found in the GAMIT manual(local version).
NEXT RUNNING GAMIT: Determining loosely constrained GPS positions
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