We’ve been struggling to get our elevations from the Lidar to match up with our known ground control elevations. When processing, we know that we’re supposed to enter the ellipsoidal height of our base station to the phase centre of the receiver. Normally our controllers are loaded with Geoid models as we do a lot of terrestrial surveying and only recently started with Lidar and Rock.
Our control points have been set with rovers that have geoid models embedded so I’m thinking that our issue has been that when we grab the exact location of our base and determine height to phase centre, we are referencing the Orthometric Height rather than the Ellipsoidal Height as we are told to do. Most people have the opposite problem and need to load a geoid model to get decent ground elevations. My theory is that we should be setting our base station point using no geoid model applied and that way it should provide us with ellipsoidal height instead of orthometric. Orthometric heights are from ground to the geoid and we want to avoid this all together for our data processing. We seem to be getting a 2-3 foot bust in the vertical.
Has anyone had this issue? We are using Trimble TSC3 and R8 Receiver.