无人机载LiDAR测深系统进行海岸带测绘的可行性分析

Feasibility analysis of UAV-airborne LiDAR bathymetry system for coastal zone mapping

如何快速获取高精度、全覆盖的海岸带浅水地形数据一直是海洋测绘的难点之一。无人机载LiDAR测深是一种有效的海岸带水陆地形一体化测量技术,利用RIEGL VQ-840-G ALB系统在山东青岛海域开展了无人机载LiDAR测深实验。基于获得的青岛实测ALB数据,从海底点密度、最浅探测深度、最大探测深度、测深精度四个方面定量分析无人机载LiDAR测深系统的测量性能,并进一步分析了无人机载LiDAR测深系统对海岸带测绘的可行性。实验结果表明,该无人机载LiDAR测深青岛实验的水深点密度达603个/m^(2),最浅探测深度仅0.16 m,最大探测深度(基于平均海面)达6.14 m;通过与船载单波束测深数据和陆上RTK数据对比,水下测深精度为17.6 cm,陆上高程精度为5.2 cm,能够满足海岸带测绘的要求,相关成果可以为我国无人机载LiDAR测深技术研究与应用提供参考。

How to quickly obtain high-accuracy and full-coverage shallow water terrain data of coastal zones has always been one of the difficulties of surveying and mapping.UAV-airborne LiDAR bathymetry is an effective measurement technique for the integrated measurement of land and water terrain in coastal zones.By using the RIEGL VQ-840-G ALB system,the UAV-airborne LiDAR bathymetric experiment was carried out in the sea area of Qingdao,Shandong Province.Based on the obtained ALB data in Qingdao,the measurement performance of the UAV-ALB system was quantitatively analyzed from four aspects(bottom point density,minimum detection depth,maximum detection depth,and bathymetric accuracy).Then,the feasibility of the UAV-ALB for coastal zone mapping was further analyzed.The experimental results show that the bottom point density of this UAV-airborne LiDAR bathymetry reaches 603/m^(2),with the minimum detection depth of only 0.16 m and the maximum detection depth(based on the average seasurface)of 6.14 m.Through comparison with shipborne single beam sounding data and onshore RTK data,it is found that the underwater bathymetric accuracy is 17.6 cm and the onshore elevation accuracy is 5.2 cm.Meeting the requirements of coastal zone mapping,the proposed technique can provide some reference for the research and application of UAV-ALB technology in China.