Synthetic-aperture sonar motion compensation method under wide swath

Abstract

The invention relates to a synthetic-aperture sonar motion compensation method under a wide swath. In the method, after the sidesway motion error of a towed body can be preliminarily estimated by utilizing the phase center overlapping algorithm, the distance-direction uniform segmentation strategy can be adopted for segmentation motion compensation, so as to perform the wide swath imaging. The method comprises the following steps: 1) aiming at the backwave data under the wide swath, by utilizing the steps of the phase center overlapping algorithm and combining the depth from the towed body to the bottom, the corresponding sidesway error of the towed body is preliminarily estimated; 2) by utilizing the preliminarily estimated sidesway error and the combining the depth from the towed body to the bottom, the distance-direction non-uniform segmentation can be carried out on the backwave data; 3) for the backwave data after the non-uniform segmentation, the sidesway error corresponding to each segment can be estimated respectively by utilizing the steps of the phase center overlapping algorithm; 4) according to the sidesway error corresponding to each segment, the motion compensation can be carried out on the backwave data corresponding to the segments; 5) imagery processing is carried out on the backwave data after the motion compensation. The method provided in the invention has obvious motion compensation effect and small calculated amount and is suitable for real-time operation.

Description

technical field [0001] The invention belongs to the field of sonar signal processing, in particular to a synthetic aperture sonar motion compensation method under a large surveying zone. Background technique [0002] Synthetic Aperture Sonar (SAS) is an advanced high-resolution underwater acoustic imaging sonar. The nano-echoes are coherently processed to obtain high resolution in azimuth. [0003] In synthetic aperture sonar imaging, the towing body deviates from the ideal track due to the influence of waves, underwater currents, and towing systems, resulting in motion errors. These motion errors have a serious impact on the quality of SAS imaging. In order to obtain high-resolution Imaging results must be motion compensated. Motion compensation technology is one of the key technologies to be solved in synthetic aperture sonar. [0004] At present, motion compensation for synthetic aperture sonar is mainly divided into motion compensation based on inertial navigation sys...

AI Technical Summary

Problems solved by technology

The basic idea of ​​the phase center overlap algorithm is to use the redundant information of multiple receiving array elements to estimate the motion state of the sonar array. The traditional method is to use all the echo data to estimate and compensate the motion error. For large-scale mapping SAS motion error Due to the range-to-spatial variability, the compensation effect of this processing method on the near and far ends of the surveying zone is not satisfactory, and needs to be further improved

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