Terrain signal photon-extraction algorithm for photon-counting LiDAR based on an adjustable length definition

A signal-extraction algorithm for photon-counting LiDAR is proposed to accurately measure mountainous terrain elevation during daylight. The algorithm exponentially scales distances among photons, employs the shortest path length between photons, and applies a maximum between-class variance method to extract the signals from dense connected point clouds. Simulated and advanced topographic altimeter system (ATLAS) data tests show the algorithm's accuracy surpassing 0.9 in high-relief areas during the day. This method utilizes global and local data consistencies to mitigate terrain fluctuations effects and accurately extract mountainous signals improving signal photon extractions in steep topography under varying background photon-counting rates.