一种面向森林区域的全波形激光雷达数据全链路仿真方法

A Full-link Simulation Method of Full-waveform LiDAR Data in Forest Area

星载全波形激光雷达森林回波仿真,普遍使用的“混合几何光学辐射传输模型”,在建立目标场景时输入参数多而复杂,难以获取,且多依赖经验公式。针对上述问题,文章利用机载激光雷达点云数据,提取目标区域森林植被特征参数及地面高程参数,实现目标场景输入参数去经验式获取,并追踪传感器发射脉冲、脉冲光束与地面物体交互作用、接收回波全过程,建立包括传感器模型、目标植被模型、回波模型在内的激光雷达全链路仿真模型,为跨区域快速建模提供依据。对实验区域采集的机载激光雷达点云数据进行仿真得到模拟全波形激光雷达森林回波波形,并将模拟波形与机载激光雷达点云数据直接生成的拟大光斑波形进行比较;再将模拟波形与对应区域的GLAS波形进行对比分析,二者相关系数高于0.80,验证了模型的有效性。

At present,the hybrid geometric optical radiation transmission model is widely used to simulate forest echo by satellite-borne full-waveform LiDAR.As the input parameters are numerous and complex,difficult to obtain,certain multi-dependence empirical formula is often adopted.In view of the above problems,the point cloud data of airborne LiDAR are used to extract both forest vegetation characteristic parameters and ground elevation parameters in the target area.The target scene input parameters are acquired de-empirically,and the whole process is tracked from sensor pulse emission to echo receiving and pulse beam interaction with ground objects.The whole-link simulation models of LiDAR are established including sensor model,target vegetation model and echo model,thus providing basis for fast modeling across regions.The experimental area is simulated and compared with that of the airborne LiDAR point cloud data.And then,comparing the GLAS waveform in the corresponding area with the analog one,the correlation coefficient is higher than 0.80,and the validity of the model is verified.