Multi-beam sounding sonar water body imaging beamforming algorithm

Abstract

A multi-beam sounding sonar water body imaging beamforming algorithm relates to the field of signal processing. The multi-beam sounding sonar water body imaging beamforming algorithm mainly comprises:compensating for the propagation loss of the acoustic wave according to a time gain curve in each detection sampling time, and obtaining a background noise level of the current detected water area after time averaging; performing near-field focusing beamforming on the signal and estimating the number of sources under the current snapshot sequence number according to the current background noise level; performing covariance matrix estimation on a signal vector with a snapshot number of 1, and obtaining a new pseudo covariance matrix by reconstructing the data covariance matrix after the forward and backward smoothness; performing singular value decomposition on the pseudo-covariance matrix, using conventional beamforming output results and an array manifold to construct a spatial spectralfunction, and obtaining a multi-beam sounding sonar water body imaging result. The algorithm can be widely applied to the multi-beam sounding sonar water body imaging function, can effectively suppress the background noise of the multi-beam sounding sonar water body imaging, and can improve the sonar imaging quality.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to a multi-beam sounding sonar water body imaging beamforming algorithm. Background technique [0002] With the gradual deepening of human development of marine resources, the demand for detection of underwater targets is increasing, and various underwater acoustic detection instruments have been widely used. Multi-beam sounding sonar has become one of the mainstream marine resource detection equipment. . With the development of multi-beam bathymetry technology, the original detection function only for underwater terrain can no longer meet people's needs. Multi-beam bathymetry sonar has gradually developed water body imaging, underwater terrain and landform integrated measurement, multi-beam shallow strata New functions such as profile detection. Among them, the multi-beam water body imaging function can effectively detect fish schools and floating small targets in the water body,...

AI Technical Summary

Problems solved by technology

At present, beamforming methods for multi-beam bathymetric sonar are mainly divided into three types: the first is the conventional beamforming algorithm, which has a simple structure and good stability, but is limited by the Rayleigh limit, the beam width is large, and the main side lobe Relatively low, imaging resolution is not high

Windowing the output of conventional beamforming can effectively suppress the sidelobe level, but it will cause the main lobe of the beam to broaden; the second method is based on the signal subspace class, such as the multi-signal subspace algorithm such as the MUSIC algorithm, which is characterized by the ability to obtain Narrower beam width, high main-side lobe ratio, but this method needs to accurately estimate the number of sources, once the number of targets is not estimated accurately, it will cause inaccurate signal subspace estimation, resulting in collapse of beamforming results

The third is the subspace rotation method, such as the signal parameter estimation rotation invariant technology ESPRIT, which is also a characteristic structure algorithm, which can give asymptotically unbiased signal parameter estimation, but this method does not obtain the beam through traversal Form an image, but directly estimate the angle parameter of the target, so this method is not suitable for application in the field of multi-beam water body imaging

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