Sparse aperture ISAR self-focusing and lateral scaling method based on Bayesian learning

Abstract

The invention belongs to the field of radar signal processing, and particularly relates to a sparse aperture ISAR self-focusing and lateral scaling method based on Bayesian learning. The method comprises the following steps: firstly performing sparse prior modeling on an ISAR image by using a Laplace layered model, and performing sparse reconstruction on the ISAR image by using a variational Bayesian method, wherein during the reconstruction of the ISAR image, a modified Newton iterative method is used to simultaneously estimate a phase error and a target rotational speed to achieve self-focusing and lateral scaling of the ISAR under the sparse aperture condition. The invention obtains the beneficial effects that: due to the sparse aperture ISAR self-focusing and lateral scaling method based on Bayesian learning, the self-focusing and lateral scaling of the ISAR under the sparse aperture condition can be realized, and the ISAR image with good focusing effect, high resolution and exactlateral scaling can still be obtained under the condition of sparse radar echo data aperture caused by the factors such as low SNR, strong interference and insufficient effective aperture, which has important engineering application value and can provide theoretical support for the design of a compressed sensing radar.

Description

technical field [0001] The invention belongs to the field of radar signal processing, and in particular relates to a sparse aperture ISAR self-focusing and lateral calibration method based on Bayesian learning. Background technique [0002] Inverse synthetic aperture radar (ISAR) imaging technology can obtain high-resolution two-dimensional images of moving targets, thereby capturing the two-dimensional size and structural features of the target. It is an important technical means for space target recognition and has been used in space target detection, missile defense, aviation Control, radar astronomy and other fields have been widely used. [0003] In the field of radar imaging, a signal with complete pulses in the imaging interval is called a full-aperture signal, and if the echo signal has random or segmented pulses missing, it is called a sparse aperture signal. In the ISAR system, many factors can cause the echo signal aperture to be sparse: first, the low signal-to-...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is that under the condition of sparse aperture, the performance of ISAR self-focusing and lateral calibration decreases, resulting in the degradation of ISAR image quality, which is difficult to meet the actual needs of the project

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