星载激光测高仪回波信号仿真分析

摘要

为研究不同地形、地物对激光回波信号的变化状况和星载激光测高仪的实际测量精度等问题,文章采用计算机仿真技术建立了立体地物数字模型、激光脉冲数学模型和噪声信号模型;设计了针对光栅网格地形数据的激光回波近似算法,避免了三角面片的划分、面片间遮挡测试和消隐处理,简化了计算过程.对理想平面目标的激光回波仿真结果与理论结果一致.利用在Matlab环境下开发的仿真程序,对平面型、阶梯型和高斯起伏型3种典型地物模型进行了仿真实验,估算了星载激光测高仪对不同目标区域的实际测量精度.%In this paper, the computer simulation technology is used,to research the laser echo signals change in different terrains and the actual measurement accuracy of laser altimeter are researched. Three-dimensional digital models in the terrains and mathematical models of the laser pulse and noise signal are established. The laser echo approximation algorithm for grid terrain data is innovated, which can avoid the division of the triangular facets, the test of facet blocks and blanking processing to simplify the calculation process. The simulated results of laser echo for the ideal planar targets are identical with the theoretical results.The simulation program is developed and run in the Matlab environment. It can simulate the spaceborne laser altimeter echo signals in a variety of conditions, and the results can be applied in quantitative analysis and study. Three typical terrain models of plane, stairs and Gaussian Wave types are designed in simulation experiments, and the actual measurement accuracy of spaceborne laser altimeter for the different areas are estimated.