Variable Bandwidth Filtering Algorithm for Multi-beam Seafloor Echo and Its Implementation on FPGA

In multi-beam bathymetric sonar, noise is one of the most important disadvantageous factors that restrict the estimation precision. Fixed bandwidth filter is currently widely used to suppress noise in sonar systems. On the measuring swath, the impact of noise varies with the beam angle. Considering this issue, an algorithm of variable bandwidth filter is proposed and its parameters are given in the paper. Compared with traditional method, this algorithm can not only improve the SNR but also have less computation and the structure is suitable for fast realization on FPGA. The realization structure of the algorithm is given and the engineering possibility is proved by computer simulation. The processing results of experimental data on lake prove the effectiveness of the proposed algorithm.