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 0.33 m to 0.19 m 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 0.5 m in the flat terrain.

基于资源三号03星影像的立体测图精度评价

为探索资源三号03星影像立体测图精度及其新增的激光测高数据能否有助于提高无地面控制的测图精度,本文研究基于资源三号03星立体影像,开展了不同地形类别数字表面模型(Dig⁃ital Surface Model,DSM)、数字高程模型(Digital Elevation Model,DEM)、数字正射影像(Digital Or⁃thophoto Map,DOM)、数字线划图(Digital Line Graphic,DLG)(简称“4D”)产品精度评价及其与资源三号01星、02星影像的对比分析,以及03星影像复合RPC立体模型的精度评价。结果表明,基于资源三号03星影像测制的1∶50000“4D”产品的平面位置和高程精度均满足1∶50000丘陵地、山地、高山地精度要求;DSM、DEM、DOM(简称“3D”)产品精度与02星影像相差不大,但优于01星影像。利用加入激光测高数据复合RPC文件恢复的立体模型精度明显高于利用原始RPC自由网平差参数恢复的立体模型精度。