The elevation values of raw laser data and trajectories are often provided as ellipsoidal height values. Usually, these values need to be transformed into orthometric values of a local height system.
For larger areas, the adjustment from ellipsoidal to orthometric height values can not be defined as one mathematical formula. Therefore, the elevation adjustment model needs to be defined by using local points for which the elevation difference between the height systems is known.
In TerraScan, the elevation adjustment can be performed for loaded points or for project blocks in batch mode. See Adjust to geoid command for loaded points, Adjust to geoid command for project blocks, and Adjust to geoid command for trajectories for more information.
See CueTip – Coordinate Reprojections, Datum Transformations and Geoid Adjustments in TerraScan for more information.