Phoenix Stonex S900 - Creating and Loading a Geoid Separation File for Survce

44



7 Creating and Loading a Geoid Separation File for SurvCE

7.1 Geoid File

GNSS receivers measure Ellipsoid Height; however, users typically need Orthometric Heights.

The Geoid Separation File (GSF) is a file organized as a grid of height differences. Field data collection tools like                   
SurvCE use the GSF file to derive an orthometric height at a Latitude - Longitude - Ellipsoid height from the ellipsoid.

It is very important that you survey with a GSF loaded for medium sized jobs (job extending over a linear distance of                     
1000 meters)

Every three to five years, the National Geodetic Survey (NGS) produces a new Geoid realization for the United States.                  
The most recent GEOID is Geoid12B.

7.2 Geoid Tools

Carlson SurvCE includes a Carlson XPort license number. You can download the latest XPort tool here:

http://www.carlsonsw.com/support/software-downloads/?product=SurvCE

Typically the XPortSetup tool is button number 1: