Errors of Airborne Bathymetry LiDAR Detection Caused by Ocean Waves and Dimension-Based Laser Incidence Correction
Errors of Airborne Bathymetry LiDAR Detection Caused by Ocean Waves and Dimension-Based Laser Incidence Correction
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DOI：
10.3390/rs13091750
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发表时间：
2021-05-01
期刊：
影响因子：
5
通讯作者：
Wu, Anlei
中科院分区：
文献类型：
--
作者：
Guo, Kai;Li, Qingquan;Wu, Anlei
海浪是影响机载激光测深（ALB）系统精度的重要环境因素。由于区域水面起伏的随机性，激光在大气-水面的传播方向会发生变化，对ALB系统的水下地形测量结果产生影响，特别是对于小发散角的激光系统。然而，自然海面随时间变化迅速，ALB扫描得到的海面点云不均匀会导致激光传播方向的不确定性，因此，基于分波表面特征的自适应校正方法是提高ALB系统精度和适用性的关键。针对表面波引起的空间位置偏差和水下激光足迹的位置修正问题，采用基于维数的自适应方法对激光入射角进行修正。仿真实验和对不同ALB系统实测数据的分析表明，该方法能有效抑制海浪的影响。此外，反演的海面倾角变化结果与地面风浪再分析产品一致。基于该策略中的激光水下传播模型，定量分析了表面波对激光测深的影响，可指导特定水深和动态海洋条件下ALB系统的作业选择和数据处理。
Ocean waves are a vital environmental factor that affects the accuracy of airborne laser bathymetry (ALB) systems. As the regional water surface undulates with randomness, the laser propagation direction through the air-water surface will change and impact the underwater topographic result from the ALB system, especially for the small laser divergence system. However, the natural ocean surface changes rapidly over time, and uneven ocean surface point clouds from ALB scanning will cause an uncertain estimation of the laser propagation direction; therefore, a self-adaptive correction method based on the characteristics of the partial wave surface is key to improving the accuracy and applicability of the ALB system. In this paper, we focused on the issues of spatial position deviation caused by surface waves and position correction of the underwater laser footprint, and the dimension-based adaptive method is applied to attempt to correct the laser incidence angle. Simulation experiments and analysis of the actual measurement data from different ALB systems verified that the method can effectively suppress the influence of ocean waves. Furthermore, the inversion result of sea surface inclination changes is consistent with the surface wind wave reanalysis products. Based on the laser underwater propagation model in the strategy, we also quantitatively analyzed the influence of surface waves on laser bathymetry, which can guide the operation selection and data processing of the ALB system at specific water depths and under dynamic ocean conditions.