Passive distribution SAR (synthetic aperture radar) imaging process method based on double-stage multi-resolution reconstruction

Abstract

The invention relates to a passive distribution SAR imaging process method based on double-stage multi-resolution reconstruction and belongs to the technical field of SAR imaging signal processing methods. The method comprises the following steps of, firstly, performing filtering and modulation on target echo signals received by an airborne receiver, separating out the target echo signals from different radiation sources and modulating the target echo signals to a base band; secondly, processing various channel signals separated out in the first step through the Fourier reconstruction algorithm to obtain the coarse-resolution images of a target; thirdly, for the coarse-resolution images obtained in the second step, obtaining the high-definition image of the target in every coarse-definition pixel unit among the images through a sparse reconstruction method; lastly, obtaining the high-definition image of a whole scene through data screening and image splicing. The passive distribution SAR imaging process method based on the double-stage multi-resolution reconstruction can solves the grating lobe problem due to sparse sampling and meanwhile has higher computation efficiency compared with traditional sparse reconstruction methods.

Description

technical field [0001] The invention relates to a passive distributed SAR imaging processing method based on two-stage multi-resolution reconstruction, and belongs to the technical field of synthetic aperture radar (synthetic aperture radar, SAR for short) imaging signal processing methods. Background technique [0002] Passive radar is a radar that does not provide a radiation source itself, but uses external opportunistic radiation sources such as radio stations, television stations, and wireless communication base stations as illumination sources. Passive radar has the advantages of good concealment, strong anti-interference ability and low cost because it does not need a transmitter to provide an illumination source, and it is a research hotspot in the current radar field. For the commonly used external sources of opportunity illumination, the signals they provide usually have the characteristics of low carrier frequency and small bandwidth, which makes passive radar oft...

AI Technical Summary

Problems solved by technology

[0003] The invention proposes a passive distributed SAR imaging processing method based on two-stage multi-resolution reconstruction, which fully considers the data sampling characteristics of passive distributed synthetic aperture radar, and can solve sparse sampling through two-stage multi-resolution imaging. The resulting grating lobe problem, while having better computational efficiency than traditional sparse reconstruction methods

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