Geoid Modeling with STAR*NET 8 or older using StarGeoid Utility

StarGeoid can be used to create .ght files and .vdf files to define geoid separation (N) and deflection from the vertical (eta and xi) for each station in your network.  Users in the United States and some international locations can use the National Geodetic Survey website to find ".bin" files which will be used as a source for StarGeoid.

*Note - StarGeoid is required for .GHT file creation for STAR*NET V7 and OLDER users.  STAR*NET V8 and NEWER  Users will not need to use this utility, they can place the .BIN file downloaded from the NGS directly into the mapping folder

*Note - StarGeoid is required to create .VDF Vertical Deflection files in ALL versions of the software, but this feature is limited to the United States because only NGS publishes the required source files.

*Note - For Vertical Deflections, make sure you download and use the "Hybrid Vertical Deflection Models" files, not the Geoid files. There are two .bin files for each zone listed as "Xi" and "Eta", you need both.

1. First you need to select the appropriate .bin file and download it from the website below:

http://www.ngs.noaa.gov/GEOID/

• StarGeoid will work with Geoid96 to Geoid 2018 files.
• When selecting your file, pick the "Little Endian Binary" version
• Take note of the Latitudinal and Longitudinal limits of the .Bin file you download, as your .ght file will have to fall inside those limits.
• If your work area includes more than one of the "panels" that the geoid is broken into you can download more than one .Bin file.

2. Save the file(s) in:

Windows Vista/7 or newer:

C:\ProgramData\MicroSurvey\StarNet\VX.X\Models

Windows XP or older:

C:\Documents and Settings\All Users\Application Data\MicroSurvey\StarNet\VX.X\Models

3. Run the StarGeoid utility (installed with STAR*NET)

4. Identify the input folder by browsing to the location you have saved your .bin file(s).

5. Identify the output folder by browsing to the above Models or a location of your choice and create a name for your GHT file.

6. Select the "USA" radio button in the Type section

7. Specify your region by entering the latitudes and longitudes to create a rectangle that covers your territory.

8. Once you have created a .GHT geoid file you can recycle the .bin file(s) to save space on your system.