A registration method for multi-beam side-scan sonar images based on GPS positioning assistance

Abstract

The invention belongs to the field of acoustic image registration, and particularly relates to a multi-beam side-scan sonar image registration method based on GPS positioning assistance. The method comprises the steps as follows: multi-beam side-scan sonar data are read, and a reference image and a to-be-registered image are generated; GPS positioning assistance information of track points is recorded sequentially; feature points of the reference image and the to-be-registered image generated by the multi-beam side-scan sonar data are extracted respectively, and feature vectors are established; the feature points in the reference image and the to-be-registered image are matched; for a feature point in the reference point, a point with the smallest XOR sum value of Hamming distances of feature points in the to-be-registered image is found out and considered as a matching point; and according to the determined registration control point, a spatial alternation relationship is obtained, and registration is completed. According to the method, longitude and latitude coordinates of the feature points under a geodetic coordinate system are calculated, mistakenly matched points are effectively eliminated, and the optimized spatial alternation relationship is obtained, so that the registration is more accurate.

Description

technical field [0001] The invention belongs to the field of acoustic image registration, and in particular relates to a GPS positioning-assisted multi-beam side-scan sonar image registration method. Background technique [0002] As the marine economy has become an important engine for countries around the world to drive national economic development, marine development has become an important field to measure national development. In recent years, due to the continuous development of side-scan sonar technology, the stability of collected signals and the resolution and clarity of sonar image data have been improved, providing more favorable hardware support for marine surveying and mapping. Using the data collected by side-scan sonar to draw a seabed topographic map can help the laying of submarine cables, optical fibers and pipelines, oil well site surveys, anchor site selection, cross-sea bridge construction and other submarine projects to obtain preliminary topographic da...

AI Technical Summary

Problems solved by technology

However, during the registration process of multi-beam side-scan sonar images, because the gray distribution of sonar images is similar, after obtaining the feature vectors, the existing methods rely solely on the similarity measure, such as the literature 2011 by P.Vanish, Vardy.A , Walker.D, Dobre.O.A. published "Side-ScansonarimageregistrationforAUVnavigation." in 2011IEEEsymposiumonand2011WorkshoponScientificUseofSubmarineCablesandRelatedTechnolgies (SSC) on pages 1-7."Use the SIFT algorithm to extract the feature points of the sonar image, and then calculate the nearest and second nearest Euclidean distance of the feature vector The ratio is used to determine potential matching point pairs, and those whose ratio is less than a certain threshold are regarded as matching points. However, in this method, the selection of the threshold will affect the matching results, resulting in many false matching points, and often cannot obtain the best spatial transformation relationship. Images cannot be mosaicked. Therefore, it is of great significance for subsequent sonar image processing tasks to eliminate mismatching points during the registration process and find the best spatial transformation relationship.

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