Use GAMIT for batch baseline resolution

Use GAMIT for batch baseline resolution

1. File preparation

1.1 Control File

Run the sh_setup or sh_links.tables command to link all standard data table files to the project directory./tables folder.

Then, manually copy the following files from the tables folder in the GAMIT installation directory to the tables folder and configure the files as needed.

Process. defaults: Specifies your computing environment, internal and external data, track file, start time, sampling interval, and result archiving instructions.

Sites. defaults: Specifies the local site and the IMG site used to process the site data. To obtain the RINEX file from the IMG data center, use ftprnx in sites. defaults to specify the download site. Sh_gamit will call sh_get_rinex to download all the specified data from CDDIS, SOPAC, and UNAVCO to the/rinex directory.

Station.info: Make sure this file is new (from SOPAC) and contains all the IMG sites you need for the solution.

Apr file: sh_gamit requires two prior coordinate files under the tables file in the project directory: lfile. (update coordinates after calculation) and *. apr (fixed coordinates ). If the prior coordinates of the test site are not found in the L-file (or apr file) processed first, sh_gamit will call the sh_rx2apr script by default to calculate the pseudo-distance solution.

Sestbl. And sittbl.: edit these two files, set the appropriate parameter values, and complete your analysis.

Autcln. cmd: This file usually does not need to be edited unless abnormal data is encountered during processing, or the output of the ionic information needs to be set.

1.2 observation documents

Create a/rinex folder under the project directory, and copy the local data to it. You can also create a/rinex folder in process. specify the directory structure in the defaults file and automatically search for local and remote raw files and RINEX files. Other directories and files required by GAMIT are directly created by scripts.

2. Start processing

After completing the above operations, you have created two folders under the folder of the solution project: rinex and tables, and placed the observed data and table files respectively.

Now you can understand the batch processing. Run the cd command to return to the computing project folder and run the batch processing command:

Sh_gamit-expt $ expt-d $ year $ days> &! Sh_gamit.log

$ Expt indicates the task name, and $ year and $ days indicate the list of years and accumulated days. You can also use-s <start day> <end day> to specify the year/day list to process consecutive days, or use-r <days>, indicates a series of days before the current date.

When the sh_gamit script runs, it outputs each step to the screen. You can use "> &! Sh_gamit.log "to redirect the output to the file. You can combine the GAMIT. fatal file with the source code of sh_gamit to find the key and cause of failure.

3. Remarks

The following utilities are available for automatic batch processing: sh_make_rinex, sh_get_nav, sh_get_rinex,

Sh_get_orbits, sh_update_eop, sh_link_rinex, and sh_make_sky_gifs. The help information of these programs can be obtained directly by entering a program name without parameters.

If you do not need sh_rx2apr, you can set use_rxc = Y in process. defaults to apply the coordinates in the RINEX header file. This option can be used only when you are sure that the site coordinate value in the header file always exists and is accurate.

If ftp cannot obtain the required global RINEX file or track file from IG (usually SOPAC or CDDIS), The sh_gamit solution will also fail, GAMIT. fatal information usually tells you what file is missing.

When the resolution fails, you must avoid repeated failures. The easy way is to completely delete the day directory and delete the error records in the L-file and station.info files in the/tables directory.

If you are prompted that an error occurred while downloading the precise or broadcast calendar, it is usually because you have not installed the ftp program.

GAMIT reading: l

This article permanently updates the link address: