Preliminary Pointing Bias Calibration of ZY3-03 Laser Altimeter

ZiYuan3-03 (ZY3-03) satellite was launched on July 25, 2020, equipped with China’s second-generation laser altimeter for earth observation. In order to preliminarily evaluate the in-orbit performance of the ZY3-03 laser altimeter, the pointing bias calibration based on terrain matching method was adopted. Three tracks of laser data were employed for the ZY3-03 laser altimeter calibration test. Three groups of pointing parameters were obtained respectively, and the mean value of pointing is considered as the optimal calibration result. After calibration, ZY3-03 laser pointing accuracy is greatly improved by the method, and its pointing accuracy is approximately 12.7 arcsec. The first-track laser data on the Black Sea surface is used to evaluate the relative elevation accuracy of ZY3-03 laser altimeter after pointing bias calibration, which is improved from 0.33m to 0.19m after calibration. Meanwhile, the absolute elevation accuracy of ZY3-03 laser altimeter after pointing bias calibration is evaluated by the Ground Control Points (GCPs) measured by RTK (Real-Time Kinematic), which is better than 0.5m in the flat terrain.