GPSurvey V2.35 - How to process GPS data (outline)

UNAVCO 10/9/00

1. PROJECT: Create New or Open existing project

2. LOAD data From DAT File: - CONFIG "interactive" or "quick edit/batch prompt"

3. PROCESS Baselines – ADD files to process

   In WAVE processor:

   • EDIT:

     – Station Position (check base station "fixed control" coordinates)
     – Occupations (check antenna heights)

   • PROCESS:

     – Setup (only to alter processing controls)
     – Baselines to start data processing

   • FILE:

     – Save results if satisfactory and Exit WAVE

4. VIEW Network Map

5. UTILITIES:

   Project Report to generate list of station coordinates and other output
   Coord Transformations to output continuous kinematic coordinates or transform coordinates

Outputting Continuous Kinematic Data Points From GPSurvey

1. UTILITIES – select COORD TRANSFORMATIONS

2. Set ASCII formats –

   From: Geographic
   To: Geographic (or other)

3. Set Coordinate Systems –

   From: Geographic WGS84
   To: Geographic WGS84 (or other)

4. Enter SSK File Coordinates: FILE-FROM-SSK FILE

5. Select files to output from selection (identify SSK files from network map)

6. Output to ASCII file: FILE-TO-ASCII FILE

7. Name the file and access it through a text editor

Using Precise Orbits in GPSurvey

Precise orbits are required to reduce orbit error when processing baselines over 100km and centimeter level errors are significant.

1. Connect to an online data center (such as http://sopac.ucsd.edu/cgi-bin/dbDataByDate.cgi) to access precise orbits.

2. (For SOPAC) select "products" and "data".

3. The orbit files are in the form: igsWWWWD.sp3. WWWW is the GPS week, D is the day of week.

4. In DOS, convert the files to EF18 format: "sp3ef18 *.sp *.e18"

5. Put the e18 files in the directory /gpsurvey/precise.

6. In Wave, select Process-Setup-Advanced Controls-Ephemeris-Precise before processing the data.