An Improved Forward-Looking Sonar 3D Visualization Scheme of Underwater Objects

This paper presents an improved scheme for forward-looking sonar (FLS) visualization, including an echo acquisition method, a global threshold based on local outlier factor and a reconstruction method. Based on the model of line target in the shallow water, the paper presents an echo acquisition method with impulse response convolution and ray tracing, and considering the reverberation. Then, a transform matrix is presented for the coordinate transformation to obtain the point cloud. After that, the paper presents the global threshold based on local outlier factor (LOF) method to solving the problem of noise sensitivity in the global thresholding. Finally, the paper presents a novel reconstruction method, including the coarse step via random sample consensus (RANSC) and the refined step via Power crust. Both simulation and experimental results show that the scheme in this paper produced superior result compared with the state-of the art.