利用机载双激光测深反演近岸水体含沙量的方法

为解决利用机载激光测深(Airborne LiDAR bathymetry, ALB)波形数据估计水体含沙量(Suspended Sediment Concentration, SSC)难题,提出了一种利用ALB三维点云数据反演水体含沙量的新方法。首先,基于绿激光水面点和红外激光水面点计算绿激光水面穿透量;其次,利用实测水体含沙量及对应绿激光水面穿透量构建SSC经验模型;最后,基于构建的SSC经验模型实现了利用ALB三维点云的水体含沙量估计。实验验证了该方法的有效性,取得了优于20 mg/L的SSC反演精度,为水体含沙量信息的高精度、大区域面获取提供了一种新途径。

Retrieving Suspended Sediment Concentration by Using Water Surface Points of Infrared Laser and Green Laser in Airborne LiDAR Bathymetry

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.