Virtual Surveyor can help you align your photogrammetry outputs with your elevation datum

The proper elevation datum needs to be set up in your photogrammetry process. That is the processing step before you start working in Virtual Surveyor. Most of the time, your image processing software only exports Ellipsoidal height unless you use GCPs or adjust the 3D model to a global or local geoid model.

Virtual Surveyor provides a quick and easy way to adjust your data to local heights. 

Adjust Your Terrain Elevation

  1. Import the survey dataset.
  2. Select the Elevation Terrain file in the Project View layers and go to the TOOLS tab.
  3. Set the offset Z value in the Offset group.
  4. Press Enter.
  5. The Elevation Terrain is moved up or down according to the offset value.

Tips and Tricks

  • Objects (points, polylines, surfaces...) initially placed on the terrain do not follow the offset terrain. 
    • The best practice is to first offset the terrain and then perform your survey.
  • You can remove the offset by entering a zero value as the Offset Z. 
    • The terrain reverts to its originally uploaded state.
  • Refer to the site supervisor to determine the offset value between ellipsoidal height and local height. 
    • You can also use the geoid height value if you want to offset from ellipsoidal height to geoidal height. 
    • Refer to your national geographic institute to know more about the geoid height values.