不同函数拟合水体后向散射波形对激光测深精度的影响

为了提高激光测深数据处理结果的精度，在原有的激光测深回波信号拟合方法的基础上，结合信号形成的物理过程，提出使用指数函数模拟激光测深水体后向散射回波成分的方法。利用Wa-LiD（Water LiDAR）工具生成了多组模拟数据集以对比和检验提出的新方法。对于每个可探测回波，海面回波和海底回波均使用高斯函数进行拟合，水体后向散射波形分别使用三角形、四边形、指数函数进行拟合。实验结果显示，指数函数测深误差统计量明显优于三角形和四边形拟合方法，且更适用于拟合不同水质和水深条件下水体后向散射回波信号。同时检验了体积散射函数取180°时数值对测深回波信号探测结果的影响。

The Impact of Different Fitting Functions for Water Backscatter Waveforms on the Accuracy of Laser Sounding

Considering the physical process of laser sounding echo signal formation, a fitting method using exponential function to simulate water column contribution in Lidar waveforms is proposed on the basis of the existing Lidar waveforms fitting method. In order to compare and test the new method, pluralities of sets of simulated data sets are generated for further analyses. For each detectable echoes, the sea surface echoes and the seabed echoes are fitted by Gauss function, and the backscattering echoes are fitted by triangle, quadrilateral and exponential function. The results show significantly more accurate laser sounding estimates for the use of exponential function method compared with the use of a triangular function or a quadrilateral function to fit the column contribution. Moreover, exponential function is more suitable for fitting water column contribution in Lidar waveforms of different water quality and water depth. Meanwhile, the paper examines the impact of the volume scattering function at 180° on laser sounding estimates.