激光测高卫星的回波波形是其核心数据之一, 回波波形的仿真分析对卫星指标论证及数据处理具有重要的参考价值。综合考虑地物反射率、发射波形和激光断面阵列(LPA)这3个因素对回波仿真结果的影响, 并进行对比实验, 探讨了最优的模拟仿真方法。实验中选择某研究区, 以冰、云和陆地高程卫星(ICESat)/地球科学激光测高系统(GLAS)数据作为验证数据, 通过相关系数对回波仿真精度进行评价。结果表明：在考虑实际地物反射率和发射波形后可以明显提高回波仿真的精度, 仿真结果的相关系数从0. 9337提高到0.9492; 由于LPA的像素空间分辨率较低, 故得到的仿真精度误差较大, 通过3次样条插值提高像素分辨率后可使仿真精度提高到0.9513。

The echo waveform is one of the core data from the laser altimetry satellite, and the simulation analysis of echo waveform has important reference value in parameters designing and data processing for the satellite. In this paper, the effects of three factors such as ground reflectivity, emission waveform and laser profile array (LPA) on the echo simulation results are considered, and the contrast experiment is conducted. The optimal simulation method is discussed. In the experiment, a certain research area is selected, and the data of ice, cloud and land elevation satellite (ICESat)/geo-science laser altimeter system (GLAS) is used as the verification data, and the echo simulation accuracy is evaluated by the correlation coefficients. The results show that the echo simulation accuracy can be significantly improved after the actual ground reflectivity and emission waveform are considered, and the correlation coefficient of the simulation results is improved from 0.9337 to 0.9492. Due to the low spatial resolution of the pixels in the LPA, there exists a large error in simulation accuracy. With the increase of pixel resolution by cubic spline interpolation, the simulation accuracy can be improved to 0.9513.