computes the height above or the distance in x/y from each point and its trajectory. The tool takes as input one (or many) LAS or LAZ files together with a trajectory file in the same projection that must have matching GPS time stamps. Switches like ‘-classify_below -0.4 7’  classify all points that are 40 centimeter or lower than the track (plus offset) as point class 7. Similarly ‘-classify_between -0.4 0.5 2’ classifies all points between 40 below and 50 centimeter above the track (plus offset) as point class 2. Option ‘-classify_below 37.5 25’ also exists.

Alternatively the tool can ‘-replace_z’ the original elevation value of each point with the computed height above the track. That means all points will have an elevation that equals their height above (or below) the track (plus offset). This “normalizes” the elevations of the points in respect to the recorded trajectory. Another possibility is to eliminate points with a particular height above or below the track with options ‘-drop_below 1.5’ or ‘-drop_above 6.8’.

Option ‘-classify_xy_range_between min max class’ classifies any point within the specified min/max range from the trajectory as specified. Similar, ‘-classify_xy_range_and_height_between min max min_h max_h class’ classifies any point within the specified min/max range from the trajectory as specified but only if their height is between min_h and max_h above (or below) the trajectory (plus offset). For more details see the README file.