An Automatic Filtering Algorithm of Multi-beam Bathymetry Based on Bidirectional Cloth Simulation

  Objectives  To overcome the problem that the current bathymetric filtering methods require manual intervention and are difficult to implement technically, a bidirectional cloth simulation filtering (BCSF) algorithm is proposed and implemented in this paper.

  Methods  Firstly, the transfer iterative trend surface is established to eliminate the negative anomalies and guarantee the continuous expression of the seafloor topography. Then, the filtering surface is established to solve the over-filtering problem of convex and concave seafloor topographies based on the proposed BCSF correction model. Finally, to further improve the effectiveness of the filtering, adaptive distance threshold is optimized and estimated. To evaluate the performance of the proposed algorithm, the BCSF algorithm is applied to shallow water multibeam bathymetry data.

  Results  The experimental results show that the BCSF algorithm can avoid the over-filtering. The elimination rate of the proposed BCSF algorithm is better than that of the CSF (cloth simulation filtering) algorithm, which decreases from 12.87% to 0.76% for the whole study area and from 15.29% to 1.09% for local study area, respectively.

  Conclusions  Compared with the CUBE (combined uncertainty bathymetry estimation) algorithm, the BCSF algorithm is more easily to implement and can retain more terrain details. Consequently, the BCSF algorithm has strong robustness and application prospects for multibeam bathymetry data.