High-precision and quick algorithm for multibeam sounding coordinates considering the propagation surface

In order to solve the problem that the traditional algorithm for multibeam sounding coordinates ignores the significant impact of the difference in the position of the receiving and transmitting transducer on the deep-water sounding, and the new algorithm takes into account the difference in receiving and transmitting but low efficiency, this paper proposes a high-precision and quick algorithm for multibeam sounding coordinates that considers the propagation surface. First, based on the principle of multibeam measurement and sound ray propagation, a beam propagation surface model is proposed. Second, the beams in the sector are divided into interpolation nodes and points to be interpolated. For the former, a method based on iterative search and interpolation is proposed to avoid the establishment of a complete propagation surface. For the latter, using the interpolated node parameters, a method based on polynomial interpolation is proposed to obtain the single-way time, depression angle and azimuth angle of sound ray. Finally, all beam footprints are calculated. Experiments in shallow and medium-deep water areas show that the accuracy of the cross-line inspection method using this paper method is similar to that of Caris, and is better than the traditional algorithm. Compared with the results of Caris, the depth deviations of the same beam footprint in this paper are 0.35‰ depth and 0.11‰ depth, respectively, and the efficiency in this paper has increased by 8% and 35%, respectively.