资源三号02星对地激光测高系统几何检校及验证

星载激光测高仪安装误差、激光指向和激光测距误差等导致最终激光测高精度不高，对激光器进行在轨几何检校可以有效提升激光测高精度。针对资源三号02星（ZY3-02）激光测高仪的工作模式，以裸露地表的航天飞机雷达地形测绘任务（shuttle radar topography mission，SRTM）数字高程模型（digital elevation model，DEM）数据约束同轨激光测距值，通过逼近地形起伏趋势线实现了卫星激光器出射方向的初始检校，实验证明不同轨激光指向的相对检校精度在20 m以内。利用地面铺设激光靶标的方法对星载激光测高系统进行几何精检校，并通过外业测量验证了ZY3-02激光器在平坦区域的测高精度优于0.5 m。

Geometric Calibration and Validation of ZY3-02 Satellite Laser Altimeter System

The location accuracy of space-borne laser altimeters suffers from installation errors. Calibration could improve the positioning and height accuracy effectively based on the operation data of satellite in orbit. A novel calibration method is put forward for ZiYuan-3 (02) satellite (ZY3-02) laser altimeter that without waveform. In this approach, the error in the laser distance and positioning calibration is indicated by the terrain matching method. A test area with an exposed surface constrains the orbit laser ranging using SRTM-DEM data, and the initial calibration of the direction of the starter is obtained by approximating the terrain fluctuation trend line. The test results were verified; the relative pointing precision of different orbits data was 20 meters. A series of laser reflectors operated on the ground determine the surface radiometric intensity of the laser footprint. The calibration parameters compensate the laser positioning model; the height accuracy of the ZY3-02 satellite laser altimeter was 0.5 meter on a flat surface.