B-mode ultrasound imaging measurement and 3D reconstruction of submerged topography in sediment-laden flow

Abstract The accurate measurement and reconstruction of submerged topography in sediment-laden flow or muddy water is vital for the analysis of riverbed erosion and deposition. This paper describes a novel method of measuring and reconstructing submerged model topography by using B-mode ultrasound imaging technique to obtain video images. The distribution of gradient and grayscale in the image has a process of mutation. This mutation process is used to automatically track and extract the boundary lines of imaging topographies based on the continuity of topography in the horizontal direction. The extracted topographic lines are one pixel width and processed by wavelet denoising method with self-adaption. The last obtained topographic lines are used to reconstruct the original 3D submerged topography. Compared with the actual topography, the measuring error is within 0.5 mm and the reconstructing error is within 1.0 mm. This method is suitable for the reconstruction of all current model topographies. In particular, it has a strong penetrability for sediment-laden flow in movable-bed experiment.