Interferometric synthetic aperture sonar complex image registration method based on piecewise curved surface fitting

Abstract

The invention relates to an interferometric synthetic aperture sonar complex image registration method based on piecewise curved surface fitting. The method comprises the steps that an effective control point is selected on a main image according to the principle of maximum correlation coefficient, and the azimuthal coordinates, the distance coordinates and the offset of the control point are recorded; the whole image is divided into multiple segments along the distance direction, polynomial curved surface fitting is performed for each segment through the least square method by using the coordinates and the offset of the control point in the segment so as to obtain the offset curved surface of each segment; the offset curved surfaces of all the segments are spliced into an entire offset curved surface; interpolation resampling is performed on an auxiliary image by using the offset so as to obtain the registered complex image; the main image and the registered auxiliary image are multiplied in a conjugated way, and the phase principal value is taken so as to obtain an interferometric phase image and complete the registration process. According to the method, piecewise curved surface fitting is closer to the real landform so that the distance space variation characteristics of the landform can be further reflected and the registration accuracy is high.

Description

technical field [0001] The invention relates to interferometric synthetic aperture sonar complex image registration, in particular to an interference synthetic aperture sonar complex image registration method based on segmented surface fitting. Background technique [0002] Due to the difference in spatial position between the two arrays used for imaging by the interferometric synthetic aperture sonar, the pixels at the same position in the main image and the auxiliary image after imaging do not correspond to the same echo point on the ground. image registration. Complex image registration is an extremely critical step in interferometric synthetic aperture sonar signal processing. High-precision complex image registration is the guarantee of obtaining high-quality interferometric phase maps, which is directly related to the accuracy of the final digital elevation model generated. The process of complex image registration mainly includes control point selection, surface fitt...

AI Technical Summary

Problems solved by technology

[0004]The purpose of this invention is to solve the problem of low registration accuracy of the traditional complex image registration method based on overall surface fitting, and propose a method based on segmented surface fitting A combined interferometric synthetic aperture sonar complex image registration method, which can have high registration accuracy for large scenes, especially terrain with obvious ups and downs

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