C-band space-borne synthetic aperture radar moving object imaging method

Abstract

The invention provides a C-band space-borne synthetic aperture radar moving object imaging method. The method comprises the following steps: receiving raw echo data, carrying out imaging processing onthe raw echo data through an SAR range migration imaging algorithm, extracting a defocused ROI complex image data matrix S0 comprising moving target information, and initializing equivalent motion parameters alpha and beta of a target in the azimuth direction and distance direction; constructing a focusing operator Gamma (.) by utilizing the equivalent motion parameters alpha and beta; establishing a compressed sensing sparse reconstruction model based on the ROI complex image data matrix S0 and the focusing operator Gamma (.), and reconstructing a model sparse solution X through a soft threshold iterative algorithm; establishing a minimum error model, and updating the equivalent motion parameters alpha and beta through the model sparse solution X; and when judging that equivalent motionparameters alpha and beta meet algorithm terminal conditions, outputting a sparse solution amplitude matrix |X|. The method can obtain a final two-dimensional amplitude image through the parameterizedsparse reconstruction technique, thereby effectively suppressing asymmetrical sidelobes due to higher-order motion of the target.

Description

technical field [0001] The invention relates to the field of radar signal processing, in particular to a C-band spaceborne synthetic aperture radar moving target imaging method. Background technique [0002] Synthetic Aperture Radar (SAR, Synthetic Aperture Radar) is a high-resolution imaging radar that can image target areas all-weather and all-time, and has been widely used in the field of remote sensing. Traditional SAR imaging algorithms are mainly used for imaging static scenes such as ground and sea. However, in practical applications, there are often moving targets in the observation scene, which makes the traditional SAR imaging algorithm no longer applicable. In the two-dimensional slant-range plane, the target motion can be decomposed into azimuth (SAR platform motion direction) motion component and range motion (SAR line-of-sight direction) motion component. Among them, the azimuth velocity component and the range acceleration component will cause the modulation...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problem in the prior art that the amount of observation matrix data required for imaging a SAR moving target is huge and the sidelobe effect caused by the actual high-order motion of the object cannot be dealt with, a C-band spaceborne synthetic aperture radar moving target is proposed Imaging methods, including:

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