**1. Introduction**

In recent years, LiDAR (Light Detection and Ranging) has been developing rapidly as a new generation of precise earth observation technology. The satellite-based LiDAR system uses satellite as the platform and photon-counting LiDAR as the main payload to detect global surface 3D information around the clock, precisely determine laser point positions in near real time, and simultaneously collect 3D point clouds (active SLAM) in the mission region, as shown in **Figure 1**, providing a new and efficient means to rapidly implement global 3D information mapping (including:

high-precision laser control points, 3D digital surface model (DSM), and digital elevation model (DEM)).

Compared with the existing or developing optical or microwave remote sensing mapping satellites, it has the advantages of high accuracy of observation data and fast information acquisition efficiency. First, the elevation accuracy is improved by 5–10 times; second, the data processing is highly automated; and third, the overall acquisition cost is significantly reduced. The development of satellite-based LiDAR measurement means can effectively improve the overall geometric accuracy of earth observation, provide basic 3D topographic data support for the comprehensive application of various types of remote sensing satellite images; fill in the gaps of geospatial information in the polar regions; and provide high-precision 3D frame information support for precise location services [1–8].

The rapid development of satellite-based LiDAR measurement technology has brought a new breakthrough in the field of satellite-based earth observation, and the significant advantages of all-day, high-precision and high-efficiency will definitely lead the future development direction of aerospace remote sensing and mapping technology [5].
