By analyzing the ICESat-1 and ICESat-2 altimeter payloads, the similarities and differences in coordinate calculation methods between the multi-beam, single-photon system and the traditional single-beam, full-waveform system laser altimetric payloads, the similarities and differences between airborne and spaceborne LiDAR coordinate solving methods and processes are analyzed and compared, and the airborne LiDAR coordinate calculation methods and processes are established, and the independently developed airborne LiDAR is used for flight test and verification, which has reference significance for the later airborne and spaceborne laser altimer footprint geolocation calculation.