Sort out GAMIT learning materials

Sort out GAMIT learning materials

GAMIT10.4 installation (based on Ubuntu 10.04)

1. Install VMware and Ubuntu10.04 virtual machines;

2. Enter the terminal and enter sudo passwd root to create a password for the root user, and log on as the root user or press Enter;

3. system update and localization;

4. install gcc: # apt-get install gcc;

5. install csh: # apt-get install csh, change bash to csh, and restart;

6. install gfortran: # apt-get install gfortran;

7. install libx11-dev library support # apt-get install libx11-dev;

8. Change shall to bash, restart, and set the path:

Go back to the user root directory, open. bashrc, and add the following code at the end.

Export PATH = $ PATH:/opt/gamit/bin:/opt/gamit/com: /opt/gamit/kf/bin export setenv HELP_DIR =/opt/gamit/help/

9. Put the gamit installation package under the directory opt/gamit /.

Go to the directory: # cd/opt/gamit

10. modify the content of the install_software file: # gedit install_software, open the install_software file, and change "usr-name libX11.a" to "usr-name libX11.so" in the lower part of the file ". (Dynamic Shared Library)

11. Run install_software: #./install_software, enter Y twice as prompted, modify makefile. config, and modify a set of parameters in Makefile. config in/opt/gamit/libraries.

(1) MAXSIT 55, MAXSAT 32, MAXATM 25, and MAXEPC 5760

(2) # Specific to FC5 (F6, F7, F8)

Then, enter "Y" twice to complete the installation;

12. After installation, open the terminal and enter doy to check whether the program is correctly installed.

(Note: After the installation is completed under the root user, return to the user's end and cannot use it,

Reason: You need to modify the software permission (chmod 777 software name)

, Data preparation stage

(Personal understanding: this process can be prepared in windows first, and then copied to the linux project folder)

1. Standardization of observation documents:

1) The name of the o file in the observation file must be in lowercase, and the name of the o file in the observation file must be in uppercase.

2) Check the receiver type and antenna type in the observation file carefully and check whether there are corresponding types in ant. dat/rcvant. dat of GAMIT. Otherwise, update the files in tables.

3) antenna height and antenna measurement methods.

2. data files to be downloaded from the Internet

1) http://www.ngs.noaa.gov/CORS/Gpscal.html query observed 0-files file in the GPS week, the relationship between the day and UTC.

2) The navigation message file brdcdoyn.11n, the precise calendar *. sp3 file, and the IMG tracking station O-files data used. (Download autodoyn.11n from the navigation message file. Note: The file names must be changed to lowercase letters)

3. Some common table files

Dcb. dat: the pseudo-Range correction parameter statistical table of the code-related receiver. (an error occurs when the last part of the baseline processing is missing)

Antmod. dat: parameter file of the antenna phase center;

Rcvant. dat: Comparison Table of receiver and antenna names;

Guess_rcvant.dat: (if rcvant. if dat does not contain the receiver or antenna model in the rinex header file, it will be obtained from this file and you can modify it by yourself) (this file will be generated by yourself during processing and is generally useless without preparation) otl_FES2004.grid: Tide Correction file in GAMIT10.4, 696 M

Note: Earth's Solid Tide Correction and marine load Tide Correction (see the satellite navigation positioning new technology and high precision Data Processing Method "p7-p8)

Correction of the earth's solid tide: The gravity of the elastic earth caused by the disturbance of the earth's surface periodic fluctuations, known as the solid tide phenomenon. In relative GPS Positioning of less than 100KM, the influence of the solid tide of the two stations is almost the same, which can be offset during the difference process. Therefore, this correction is not considered.

Correction of ocean load tide: caused by the cyclical fluctuations of the ocean tide. Similar to the solid tide, but smaller than an order of magnitude. To be updated every week:

Ut1.: Earth Rotation Parameter; ln-s ***

Pole.: polar shift parameter; ln-s ***

To be updated every year:

Leap. sec: stopwatch;

Soltab.: Sun Calendar; ln-s ***

Luntab.: Moon star force; ln-s ***

Nutabl.: Zhang motion parameter table; ln-s ***

Gdetic. dat: Various coordinate system parameters;

Pmu. usno: ln-s ***

Grid. otc: ln-s *** (this seems to be a problem. This file is not in GAMIT10.4 )? Svs_exclude.dat: The satellite list needs to be removed. (if not, the system will prompt waring during processing, but it can also be calculated)

Vg_in: station coordinate speedometer;

Autcln. cmd: (Note: if not, csh btest1.bat cannot be processed normally in the last step of Data Processing.) important preparations should be made:

Sestbl: data processing parameter settings table;

Sittbl: test site constraints table;

Station.info: test site information table;

Lfile.: initial coordinate of the station (ball coordinate); (self-made)

, File preparation stage

1. File structure arrangement

Test: project directory, which includes:

1) tables/stores various table files;

2) storing the precise calendars *. sp3 file;

3) rinex/stores the observation data file * doyn.11;

4) brdc/stores the broadcast calendar file brdcdoy0.11n;

5) doy1/doy2 /?? /Stores the files and linked files for each period of time.

2. Four files to be prepared

1) station.info:

Record the site, site name, start time, end time, antenna height, antenna measurement method, receiver type, software and hardware version number, and antenna type of each site. Edit the settings in strict accordance with the given tracking site format. (Note: You need to upload the station.info file in the current directory and delete the content with the previous lines. Otherwise, the subsequent steps cannot be performed)

The procedure is as follows:

1. manual operations. The operations are aligned according to the corresponding file format. You can edit them from the sample format.

2. automatically extract information about the observation file and generate the station.info file.

Perform operations in the file directory of each time period:

Sh_upd_stnfo-files site1doy0. yyo site2doy0. yyo-orbt igsf-u-ref ../tables/station.info

After running the preceding command, important information is automatically extracted from the observation file 0-files to generate the station.info file.

My preparations for the station.info file (Wu Da Guo bofeng ):

1. Create the folder all_station in the rinex folder (store all points)

2. Copy the engineering observation file (o-files) to all_station, and the framework Network (o-files) to all_station.

3. Enter Terminal

Cd test/rinex/all_station

Sh_upd_stnfo-files *. 11o-ref station.info (this file is a soft link file, from ~ /Do not often update the table/station.info link to the specified folder, and there is only one header)

4. Check whether the station.info file is correct.

Gedit station.info

5. Copy the obtained station.info to the lfiles folder.

2) l-file:

Record the approximate coordinates of each test site: Gamit requires spherical coordinates, that is, l-file. Sort all o files together and run the following commands respectively:

Grep POSITION *. 11o> lfile. rnx

Rx2apr lfile. rnx 2011 250 (Note: average value is obtained based on x, y, and z in all o files, and the file name is lfile. rnx. apr)

Gapr_to_l lfile. rnx. apr lfile. "2011 250

My preparation for the l-file (Wu Da Guo bofeng ):

1. Create a folder named all_data in the rinex folder (store all vertices)

2. Go to the folder: cd test/rinex/all_data.

3. Extract POSITION

Grep POSITION *. 11o> lfile. xyz

4. Check whether the lfile. xyz file is correct.

-S ../tables/soltab.2011.J2000./soltab.

Ln-s ../tables/nutabl.2011./nutabl.

Ln-s ../tables/pole. usno./pole.

Ln-s ../tables/ut1.usno./ut1.

Ln-s ../tables/pmu. usno./pmu.

In addition, the Tide Correction file is also a file that is prone to errors. Take version 10.4 as an example. The default Tide Correction file name is otl. grid (this file is a corrupt file) (the file is otl. _ FES2004.grid before the link ). Make sure to check whether otl. grid is a real link. If there is a dead link, you need to manually link it. Command:

Ln-s ../tables/otl. _ FES2004.grid./otl. grid (I didn't use this file During computation. I will try it next time)

(Note: If the file already exists in the folder, you must delete the original file before linking the file, whether the link is successful or not .)

, Data processing stage

I. Batch Processing

1) run the makexp program to generate an input file

Sh_makexp-expt test-orbt igsf-yr 2011-doy 250-sess 99-srin-nav brdc2500.11n-apr lfile.-sinfo 15 00 00 5760

Or: Run makexp directly, and enter as prompted.

2) run the sh_sp3fit script to generate the initial number of tracks;

(An error occurred because the link of ut1. was not up-to-date .)

Sh_sp3fit-f igs15623.sp3-o igsf-d 2011 250-r BERNE-t-u

3) run the sh_check_sess script to check the satellite consistency;

Sh_check_sess-sess 250-type gfile-file gigsf1.250

4) run the makej program to generate the satellite clock difference file;

Makej brdc2500.11n jbrdc1.250

5) Run sh_check_sess to check satellite consistency;

Sh_check_sess-sess 250-type jfile-file jbrdc1.250

6) Run makex to generate X Files;

Makex test. makex. batch

7) run the fixdrv program to generate a batch file;

Fixdrv dtest1.250 (this step may cause an error, prompt

FATAL: 121202: 2337: 41.0 FIXDRV/armake: invalid T-file interval = 10 27 2012 10 27 2012 -- need either T-file or one X-file to run FIXDR modify fixdrv/armake. f file 2010 is 2099 or 9999) and run make-f Makefile in this directory to re-compile.

8) run the batch file generated by fixdrv.

Csh btest1.bat Delete GAMIT. FATAL and GAMTI. WARNING before running this command

Ii. gamit baseline processing result quality evaluation indicators: (test the q file)

A) The standard root-mean-square nrms calculation result is about 0.25. If nrms is greater than 0.5, the processing result is problematic (for example, weekly Skip is not fixed; the coordinates of the start point of the test station are incorrect ). If nrms is less than 0.5, the solution is considered successful; otherwise, the cause must be checked and processed again;

B) Check the baseline resolution accuracy of gamit. Generally, the relative precision is 10-8 ~ 10-9

C) check whether all test sites are involved in the calculation

Note: If you have any questions, you need to check them.

1. view the station.info file: REC #, ANT #, HtCod

The antennas of the IG tracking station are high to DHARP.

For field observation, you need to know the position of the antenna at that time.

2. view the sestbl File

1) height angle Elevation Cutoff (not 0 °, 15 ° according to specifications );

2) Choice of Observable: Select LC_help for the Long Baseline and L1 \ L2 Independent for the short baseline.

3) Other minor errors.

GAMIT reading: l

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