Refraction error correction of Airborne LiDAR Bathymetry data considering sea surface waves
Refraction error correction of Airborne LiDAR Bathymetry data considering sea surface waves
复制标题
考虑海面波的机载LiDAR测深数据折射误差修正
DOI：
10.1016/j.jag.2021.102402
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发表时间：
2021
影响因子：
7.5
通讯作者：
Jie Li
中科院分区：
文献类型：
--
作者：
Wenxue Xu;Kai Guo;Yanxiong Liu;Ziwen Tian;Qiuhua Tang;Zhipeng Dong;Jie Li
机载光探测与测距（LiDAR）测深技术（ALB）在海陆综合测量方面具有无可比拟的优势，特别是在浅水区地形数据的获取方面。海面波浪是影响ALB数据质量的重要因素。本文提出了一种不需要对海底激光脉冲进行复杂的海面模拟，就能严格校正每个海底激光脉冲的海面波致折射误差的方法。该方法首先采用自适应邻域选择方法计算激光脉冲入海瞬间的正海表，然后构建考虑海表波的激光脉冲折射误差校正模型。根据斯涅尔定律，根据入射激光脉冲与波浪形海面法向量和实际折射光线之间的几何关系，建立距离条件方程、角度条件方程和共面条件方程，计算出经过折射误差校正后的海底各激光点坐标。实验结果表明，海面波浪对水下地形的三维点云坐标有显著影响。即使在风平浪静的海况下，海面波浪引起的海床点平面坐标位移误差也可达到米级，深度坐标位移误差也可超过0.2 m。平面坐标修正后的位移误差明显大于深度坐标修正后的位移误差，可以有效提高ALB数据的质量。
Airborne Light Detection And Ranging (LiDAR) Bathymetry (ALB) has an unparalleled advantage in integrated sea-land measurements, especially in the acquisition of topographic data in shallow water areas. Sea surface waves are an important factor affecting the quality of ALB data. This paper presents a method that strictly corrects the sea surface wave-induced refraction error for each seabed laser pulse without any complex modeling of the sea surface. In this method, an adaptive neighborhood selection method is first used to calculate the normal sea surface at the moment when a laser pulse enters the water, and then a laser pulse refraction error correction model considering sea surface waves is constructed. The distance condition equation, the angle condition equation and the coplanar condition equation are established based on Snell's law and the geometric relationship among the incident laser pulse, the normal vector of the wavy sea surface and the actual refracted ray in order to calculate the coordinates of each laser point at the seabed after refraction error correction. The experimental results show that sea surface waves have a significant impact on the three-dimensional point cloud coordinates of the underwater topography. Even in calm sea conditions, the plane coordinate displacement error of the seabed point caused by the sea surface waves may reach the meter level, and the depth coordinate displacement error can also exceed 0.2 m. The corrected displacement errors of the planimetric coordinates are significantly greater than the corrected displacement errors of the depth coordinates, which can effectively improve the quality of the ALB data.