Using StarGeoid Utility to Create VDF files

StarGeoid can be used to create  .vdf files to define deflection of 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 - For Vertical Deflections, make sure you download and use the "Hybrid Vertical Deflection Models" files and select the option for "little endian" format. There are two .bin files for each zone listed as "Xi" and "Eta", you need both.

 

1. Download Xi and Eta files for your region from:

https://geodesy.noaa.gov/GEOID/DEFLEC12B/DEFLEC12B_CONUS.shtml

• StarGeoid will work with Geoid96 to Geoid 2012B files.
• When selecting your file, pick the "Little Endian Binary" version
• 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.  If in doubt, download the largest available version (denoted by the name Grid #0).

2. Save the files in a convenient folder:

3. Run the StarGeoid utility from the Windows Start Button (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 a convenient folder.  It may be convenient to put your vdf file in the mapping folder at:

C:\ProgramData\MicroSurvey\StarNet\V##\Mapping

6. Select the "Vertical Deflections" radio button in the Extract section

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

8. Specify your region by entering the latitudes and longitudes to create a rectangle that covers your territory.  Note that because you are entering latitudes as West positive the eastern limit will be a smaller value than the western limit.

9. "Build Vertical Deflection File"

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

11. Once the vdf file is created, select both the vdf and the geoid file corresponding to the same model to complete your modeling settings: