高精度在轨几何定标是星载激光测高仪有效应用的基础, 在参考国外 冰、云和陆地高程卫星(Ice, cloud and land Elevation Satellite, ICESat)卫星搭载的地球科学激光测高系统(Geo-science Laser Altimeter System, GLAS)几何定标的基础上, 提出了一种基于地面红外探测器的星载激光测高仪几何定标方法。采用资源三号02星上搭载的国内首台试验性对地观测激光测高仪的真实数据开展了实验验证。实验结果表明: 地面红外探测器能有效捕捉到激光测高仪对地发射的激光信号, 几何定标方法能有效消除指向角的系统误差项, 标定后平面绝对精度可提高到15.0 m左右, 而华北某地高精度地形数据验证表明其绝对高程精度可提高到1.09 m, 少量点高程误差小于0.5 m。虽然精度水平离国外GLAS还有一定差距, 但相关结论能为后续国产激光测高卫星的优化设计、数据处理与应用提供参考。

High precision on-orbit geometric calibration is an indispensible step for space-borne laser altimeter, and which is the foundation for effective application. Considering the geometric calibration method of foreign Geo-science Laser Altimeter System(GLAS) loaded on Ice cloud and land Elevation Satellite(ICESat), an algorithm of satellite laser altimeter geometric calibration was proposed, which used the ground infrared detectors to capture the laser signal transmitted from the satellite. Experiment was carried out using ZY3-02 satellite, which was equipped with domestic first laser altimeter for earth observation. The result shows that the ground infrared detectors can effectively capture the laser signal transmitted from the satellite, the geometric calibration method can eliminate the pointing angle systematic error and improve the height accuracy of laser footprint dramatically. After geometric calibration, the absolute planimetry accuracy can be improved to 15.0 m, and the vertical accuracy is about 1.09 m and a small amount of points even better than 0.5 m according to the experimental region of North China using high accuracy DEM as referenced dataset. Although the disparity of accuracy is clear compared with GLAS, the conclusion can provide a reference for the optimization design, data processing and application of the subsequent domestic laser altimetry satellite.