On-orbit geometric calibration of satellite laser altimeter using ground-based IR detectors

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.