基于精细地形的星载激光测高仪回波波形仿真

Waveform Simulation of Spaceborne Laser Altimeter Echo Based on Fine Terrain

针对当前我国星载激光测高仪地面载荷性能分析和在轨检校等迫切需求,本文从星载激光测高仪在轨工作环境出发,对激光全链路工作原理进行深入研究,设计了一套基于精细地形的星载激光测高仪回波全链路仿真方法与流程,并详细推导了星载激光测高仪的回波仿真模型;通过精细化地形实现激光分束处理,完成高精度回波仿真.以目前全球唯一具备回波记录的对地观测激光测高仪GLAS为试验对象,利用高精度机载点云精细地形数据,选取平坦和山地地形试验区域进行全链路回波波形仿真与试验分析.结果表明:平坦地形区域仿真波形与真实波形相似度达到0.985,山地地形区域仿真波形与真实波形相似度为0.921.本文方法能实现两类典型地形的星载激光回波波形高精度仿真.

For the performance analysis of the domestic spaceborne laser altimeter in the laboratory and in-orbit calibration technology improvement,the principle of laser waveform full-link simulation was studied in detail,and a full-link simulation method with the fine terrain and flow were designed by considering the in-orbit working environment of the spaceborne laser altimeter,as well as its echo simulation model of was deduced in detail.Then high-precision echo simulation was performed by laser beam splitting based on fine terrain.The Geoscience Laser Altimeter System(GLAS)is used for testing,and the high-precision airborne Lidar point cloud data is used to simulate the waveform of GLAS in flat and mountain terrains.The results show that the simulated waveform are used compared with the real data from GLAS,then the similarity between the simulation waveform and the real waveform is 0.985 in the flat terrain,as well as 0.921 in the mountain terrain.The proposed method and model can achieves high accuracy simulation of the spaceborne laser waveform for the flat areas.