Imaging method for inverse synthetic aperture radar of high-speed moving targets

Abstract

The invention discloses an imaging method for an inverse synthetic aperture radar of high-speed moving targets. Aimed at high-speed moving targets, the method firstly estimating target motion parameters by using a least square method and envelope alignment, then performing coherence processing on a dechirping echo signal by using the estimated motion parameters, eliminating phase error caused by the motion parameter estimation through a weighting feature vector self-focusing algorithm, and then correcting range migration by using wedge conversion, and finally obtaining an image result. An existing high-speed moving target imaging algorithm uses a dominant scatter method for self-focusing, and the weighting feature vector self-focusing algorithm used in the method has better focusing effect and anti-noise performance, so the method has better imaging effect.

Description

Technical field [0001] The invention belongs to the field of radar signal processing, in particular to an inverse synthetic aperture radar imaging method for high-speed moving targets. Background technique [0002] Inverse synthetic aperture radar is mainly used for the detection, tracking and imaging of non-cooperative targets (such as ballistic missiles, aircraft, satellites, etc.). When the speed of the target reaches a certain level, the traditional "stop-and-go" model may no longer be suitable for description If the precise radar echo of a moving target is still used to image the target using the imaging algorithm based on the “stop-and-go” model, problems such as poor image focus or even inability to focus may occur. At the same time, when the target is moving at a high speed, the radar and the The relative speed between the targets is very large, resulting in serious distance migration within the effective accumulation time, and also making the image difficult to focus. I...

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Problems solved by technology

[0003] Inverse synthetic aperture radar imaging method for high-speed moving targets (M.D.Xing, R.Wu, Z.Bao, "High resolution ISAR imaging of high speed moving targets", IEE Proceedings in Radar, Sonar and Navigation, 2005, vol.152, no. 2, pp.58-67.), the self-focusing algorithm needs to be used twice, so the quality of the self-focusing effect will have an important impact on the final imaging result. The original document uses the multi-point self-focusing method (Bao Zheng, Xing Mengdao, Wang Tong. Radar Imaging Technology [M]. Electronic Industry Press, 2005.pp.244-249.), there are two defects in this method: (1) The multi-point self-focusing method is in the process of noise processing It only uses its non-correlation to reduce its influence by accumulating, which is often less effective in the case of low SNR; (2) when calculating the phase correlation sequence, only the data information at the adjacent pulse time is used, resulting in The final estimated phase error is less accurate

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