关键词: 水体含沙量, 机载激光测深, 红外激光, 绿激光, 水面穿透量, 三维点云数据, 水面不可靠问题

Abstract: High-precision estimation of sediment concentration in water can be achieved by using the waveform data of airborne LiDAR bathymetry (ALB). However, waveform data is difficult to be obtained and utilized. In view of this, a simple method to retrieve the sediment concentration using ALB 3D point cloud data is proposed. Firstly, the green laser water surface penetration is calculated based on the green laser water surface point and the infrared laser water surface point. Secondly, the empirical model of Suspended Sediment Concentration (SSC) is constructed by using the measured SSC and the corresponding green laser water surface penetration. Finally, the sediment content of the lower water body is obtained conveniently by the constructed SSC empirical model. Experimental results validate that the method is effective and has the inversion accuracy of SSC better than 20 mg/L. The proposed method provides a simple and fast approach to estimate SSC.

Key words: Suspended Sediment Concentration (SSC), Airborne LiDAR Bathymetry (ALB), IR laser, green laser, near water surface penetration(NWSP), 3D point cloud data, water surface uncertainty