Radiometric correction for multi-sector multi-beam echo sounder backscatter strength images considering multi-prior information

Seafloor observation based on multi-beam echo sounder (MBES) backscatter strength (BS) image has become increasingly important in guiding the management of marine ecosystems. However, the application has been limited by radiometric distortion. Currently, existing methods that rely on a single characteristic cannot reveal the intrinsic illumination and albedo components of BS images, resulting in poor radiometric correction performance. To this end, this paper proposes a correction method based on the variational Retinex framework that integrates multi-prior information to decompose an observed BS image into the separated seafloor albedo component and the acoustic illumination component. The albedo component corresponds to the radiometric distortion-free data. Firstly, we review the MBES BS observation model and analyze the multi-sector observation mode. Then, by modeling the angular response (AR) effect and incorporating weighted geomorphological smoothness and low-rank priors as beam pattern constraints, we model the acoustic illumination constraints; by introducing the weighted anisotropic total variation (WATV) as a geomorphology constraint and incorporating it with the sediment information term, we model the seafloor albedo constraints. By jointly considering these constraints, we build a decomposition model with well-structured priors in this paper. Both real and simulated experiments have verified the effectiveness of the proposed method.