圆扫描式机载激光测深系统定位模型与仿真分析

Positioning Model and Simulation of Conical Scanning Airborne Laser Bathymetry System

基于海岸带测绘成像雷达(CZMIL)圆扫描式机载激光测深系统的内部结构,推导了激光光线在棱镜、大气、海水中的方向矢量,并针对激光、扫描仪、光学棱镜之间的安置误差纠正激光方向向量,结合全球定位系统和惯性导航系统提供的位置姿态数据,推导出成图坐标系中的激光脚点定位模型。从直线与平面交会的数学原理出发,模拟激光光线与海面的交会过程,继而根据折射原理解算激光光线在水中的方向矢量,最终根据激光光线与水中的直线方程和海底面数学方程模拟激光脚点的位置。探讨了存在视准轴偏角时飞机姿态和航高发生较大变化对点云分布的影响,对圆扫描式机载激光测深系统误差的检校及点云位置的纠正有着实际的意义。

Based on the internal structure of the circular scanning airborne laser bathymetry system coastal zone mapping and imaging lidar （CZMIL）, the vector equations of laser in the prism, atmosphere and water are deduced and rectified to remove the mounting error of the prism, scanner and laser. With the vector equations and the attitude and location data provided by global position system/inertial navigation system, the laser point positioning model is deduced in the mapping coordinates. The intersection of laser line and sea surface is simulated depending on the mathematical principles of line and plane intersection. Combined with the direction vector of laser line in the water got by the refraction principle and the sea floor plane mathematical equation, the location of the laser points are simulated. Finally the influences of the plane attitude and height on the point clouds distribution are discussed deeply when the boresight misalignments are existed, which are meaningful to the calibration of system error and the correction of point clouds location for the circular scanning airborne laser bathymetry system.