SAR (Synthetic Aperture Radar) target azimuth angle estimation method based on sparse description

Abstract

The invention discloses an SAR (Synthetic Aperture Radar) target azimuth angle estimation method based on sparse description, which mainly solves the problem of 180-degree indistinction caused when azimuth angle estimation is carried out in the prior art. The SAR target azimuth angle estimation method based on the sparse description is realized through the following steps of: (1) inputting training samples and test samples, intercepting a subimage which contains a target from the center of each of the training samples and the test samples, and carrying out histogram equalization on the intercepted subimage; (2) as for the training samples and the test samples, which are subjected to the histogram equalization, calculating the sparse description vectors of the test samples on a dictionary formed by all the training samples; (3) calculating the reconstruction error of the training sample which corresponds to each nonzero coefficient of the obtained sparse description vectors; and (4) selecting the azimuth angle of the training sample which corresponds to the nonzero coefficient with a minimum reconstruction error as an angle estimation for output. Compared with the prior art, the SAR target azimuth angle estimation method based on the sparse description, which is disclosed by the invention, has the advantages that 180-degree indistinction problem does not exist, the angle estimation accuracy is high and SAR target azimuth angle estimation and further SAR target recognition can be conducted.

Description

Technical field: [0001] The invention belongs to the technical field of image processing, relates to the estimation of SAR target azimuth angle, and can be used for SAR target recognition. Background technique: [0002] Synthetic Aperture Radar (SAR) has been widely used in civil and military fields because of its all-day and all-weather working ability, and the automatic target recognition of SAR images has attracted people's attention. Target azimuth estimation is an important step for automatic target recognition in SAR images. The template recognition method is to match and recognize the image of the target to be recognized with the image template of the known target at various azimuth angles. If the target azimuth angle can be estimated from the SAR image of the target to be recognized before recognition, the number of template matching and search time can be effectively reduced, and the accuracy and efficiency of target recognition can be improved. [0003] The exist...

AI Technical Summary

Problems solved by technology

[0004] When estimating the azimuth angle, the above methods only use the geometric structure characteristics of the target, and do not use the image information of the target. The angle estimation accuracy is low, and there is a 180° blur problem in the angle estimation result, which is not conducive to the real-time requirements of SAR target recognition.

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