LP360’s Adaptive TIN Ground Filter is designed to classify a ground surface from point data. There are multiple parameters within the filter, especially when using the Advanced Options. The following chart is a summary and general guidelines for setting the parameters.
|Seed Sample Distance||Grid size for initial seed surface.||Smaller is more aggressive, higher fidelity, but more false ground points in initial surface.|
|Advanced Option: Angular Threshold (degrees)||Maximum value at which a point will be added to the ground surface.||Higher is more aggressive; typical is 4 – 10°.|
|Advanced Option: Maximum Distance||Maximum height above surface at which a point will be added to the ground surface.||Higher is more aggressive; typical is 0.5 – 1.5 m.|
|Advanced Option: Direction/Edge Control||Turn on/off the algorithm for adding points along the edges of the triangles||You generally want this unchecked. Check this option when you do not want objects such as railroad cross-ties and street curbs included in the Destination class.|
|Iteration Control||Hard stop; no more points are added to surface after this point The process also stops automatically when no new points are added to the surface.||
Higher is more aggressive; typical is 4-10.
Classify Only Seed Points to get a feel for the initial surface being generated from the chosen Seed Sample Distance.