资源三号02星激光测高仪足印位置预报方法

摘要

On-orbit geometric calibration is an essential way to improve plane and elevation accuracy of laser altimeter data, and the laser footprint location prediction is a prerequisite for calibration based on land infrared detector.This paper builds a laser footprint location prediction model for China's first space-borne laser altimeter carried by ZY3-02, which refers to the satellite optical camera rigorous geometry imaging model.The model takes full account of the law of platform movement, and correlates laser emission center with ground footprint point.We get the precise predicted laser pointing by Pyramid terrain matching, ephemerisby acceleration prediction, and attitude by frequency analysis.The laser footprint location can be predicted.This laser footprint location prediction model were successfully applied in the calibration test of the laser altimeter on ZY3-02 satellite, and the maximum error between the predicted location and real footprint location obtained by triggered detectors is less than 150m, which proves the validity of the proposed model.The proposed method provides the precise point-to-point prediction from satellite to ground for Chinese remote sensing satellite, and offers a technological support for the space-borne laser altimeter calibration in future.%激光测高仪在轨几何检校是提高激光点平面和高程精度的必要途径,而激光足印地准确捕获是成功开展激光测高仪在轨几何检校的前提.本文针对资源三号02星搭载的我国首台激光测高仪的在轨几何检校试验需要,在参考光学遥感卫星成像几何模型的基础上,提出并构建了一套严密的激光足印位置预报模型.该模型充分顾及卫星平台在轨运行规律及激光与卫星相对几何关系,建立了激光发射点到地面足印的严密几何定位预报模型,通过金字塔地形匹配、基于加速度轨道预测以及频率域姿态分析分别获取预估的激光指向、轨道位置和姿态信息,实现地面激光足印的位置预报.该模型已应用于资源三号02星激光测高仪在轨几何检校试验中,预报的激光足印位置与探测器捕获到的实际位置的最大误差小于150m,充分验证了预报模型的正确性,实现了我国遥感卫星从天上到地面点对点的精确预报,为国产激光测高仪在轨几何检校提供了有力的技术支撑.