Friday, October 29, 2010

Post Processing Static GPS Occupation Data With Topcon Tools

Topcon Tools software provides a powerful post-processing solution, network analysis and adjustment with an intuitive operator interface. In this post I will briefly cover the post processing procedures for for a Static GPS Occupation.

Before you begin verify that you have the proper access code, security dongle or server license and the PP module enabled. To verify this select “Licenses…” under the Tools Help pull-down menu.

Licenses Once the license and module has been verified you can begin by starting a new job:

NewJob Create new Job

A custom configuration for your project can be defined at this point if needed by selecting the Edit configuration button if desired.

Select the OK button to proceed.View menu

I personally like to activate both the Tabular View and the Occupation View prior to importing any raw GPS data by selecting them under the View pull-down Menu.

 

 

 

Next I will import the raw GPS static file by selecting Job>Import. Change The Format name to the desired data type. Topcon Tools can import various types of RINEX data, Sokkia PDC files and Topcon TPS files in their raw formats.

For this example I will import a TPS raw data file:

Import TPS

After import the log file will be graphically represented by a green bar in the Occupation View.

Occupation view1

The time represented at the bottom of the view is Greenwich Mean Time (GMT) by default. The time display can be set to local time in the Job Configuration> Display menu. 

A legend can be displayed for the Occupation View with a right click anywhere on the view and selecting Options… check the “Show Legend” box

OptionsShow

To display all of the recorded Satellite Vehicle (SV) observations expand the occupation by clicking the “+” node next to the occupation name:

Occupation View 2

Occupation View allows cutting a part of the satellite’s observations from a point’s occupations. To cut the satellite’s observations, select the desired satellites and time interval and right click any selected area, then click Disable on the pop-up menu.

Import CORS/IGS Data

Static data can be easily imported from the internet using Topcon Tools by selecting Import from Internet under the Job pull down menu: Import from internet1 

The center of project, begin and end times will be populated according to the existing observations in the job.

Improt from internet 2

The Advanced options can help further define the search criteria.

Advanced Options

Select “Search Points” to begin the internet search. Once a return has been generated for nearby stations select “Search Files>>” to locate the unique files for that station. An Ephemeris can also be downloaded for GPS and GLONASS  if checked.

Select “Import selected files” to complete the request. The status bar at the bottom of the page will display the progress.

The Import from Internet window can be closed by clicking the “X” in the upper right hand corner of the command bar.

All occupations should now be displayed  in Occupation View:

Occupation View 3

You should also have vectors displayed in Map View:

Map View Vectors

Importing Control Data Sheets

Now that the supporting station data has been imported you will have to import the data sheets to “fix” the position of each station and identify each as a controlling point. Topcon Tools makes it very easy to import NGS Data sheets that are downloaded from the web. To begin this process I will visit the National Geodetic Survey –Datasheet site at: http://www.ngs.noaa.gov/cgi-bin/datasheet.prl

Select DATASHEETS:

Datasheets

Select CORS SiteID: Select submit and save DATA SHEETS as an html only file.

In Tools select Job>Import. Change the format name to NGS Datasheet and browse for the saved file.

The file control point coordinates will merge with the downloaded static data.

Process vectors by selecting Process/ GPS+ Post Processing. Vectors meeting the set criteria will be green in color.

image

 

 

 

 

image