Compression perception multilayer ISAR imaging method based on BP optimization

Abstract

The invention belongs to the field of a radar imaging technology, and discloses a compression perception multilayer ISAR imaging method based on BP optimization, for mainly solving the problems of noise sensitivity, high single-layer compression perception optimization time complexity and difficult sparse control parameters by use of conventional ISAR imaging. The specific realization process is as follows: preprocessing original echo data; determining an orientation resolution step factor sigma; initializing an encoding matrix M1 and a decoding matrix W2; performing training by use of a BP algorithm to optimize an encoding process and a decoding process; reconstructing an ISAR image by use of a compression perception theory; performing reverse Fourier transformation on orientation, and inputting obtained echoes into a next layer, and carrying out the training by use of the same principle; and outputting a high-resolution ISAR image at a final layer. According to the invention, the convergence speed is fast, high-resolution imaging can be realized under the conditions of a low signal-to-noise ratio and a small echo quantity, and the method can be applied to classification and identification of ISAR image objects.

Description

technical field [0001] The invention belongs to the field of radar imaging, in particular to a method related to ISAR imaging, which can be applied to the classification and identification of targets. Background technique [0002] Compared with other remote sensing technologies, inverse synthetic aperture radar (ISAR) imaging has the advantages of all-weather and all-weather imaging of long-distance moving targets, so it is widely used in military and civilian fields to classify and identify targets. In order to improve the ability to classify and recognize targets, ISAR images need to have very high resolution to extract the scattering characteristics and geometric features of the target. The resolution in the range direction depends on the bandwidth of the radar transmission signal, and the resolution in the azimuth direction is limited by the coherent accumulation angle of the target. In order to improve the azimuth resolution, the azimuth coherent accumulation time must...

AI Technical Summary

Problems solved by technology

However, this algorithm needs to be optimized by using optimization algorithms such as Newton's method and conjugate gradient, and needs to solve the Hessian matrix, which increases the time complexity of the algorithm.

When the signal-to-noise ratio of the echo is low, the ISAR image cannot achieve better focus, and false points will appear near strong scattering points, and the quality of the image will decrease

And sparse control parameters affect the imaging effect to a large extent, and artificially setting parameters reduces the robustness of the algorithm

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