Fast BP imaging method for parallel double-base spotlight mode SAR

Abstract

The invention relates to a fast BP imaging method for a parallel double-base spotlight mode SAR, comprising the following steps: acquiring full aperture echo data of the parallel double-base spotlightmode SAR; dividing the full aperture data into a plurality of non-overlapping subaperture data blocks, projecting the subaperture data after distance compression to a global rectangular coordinate system by using a double-base BP integration, and obtaining an initial resolution image of a first-stage subaperture; compressing the subaperture image spectrum by using a spectral compression function;performing azimuth multiple upsampling on compressed data; restoring the original signal form of the subaperture image by using the conjugated form of the spectral compression function; performing coherent superposition on the restored subaperture image to obtain a subaperture image with improved resolution; repeating the step S30 to S60 for the image with improved resolution until a full resolution image is obtained. Compared with an imaging algorithm, the fast BP imaging method for a parallel double-base spotlight mode SAR has the advantages that a high-quality image can be obtained, the calculation amount is greatly reduced, and the operation efficiency is further improved.

Description

technical field [0001] The invention belongs to the technical field of SAR imaging, and in particular relates to a limit protection device for an actuator. Background technique [0002] The bistatic Synthetic Aperture Radar (SAR) system has the advantages of convenient operation, long range, multiple receiving methods, rich information acquisition, good security and anti-interference, and is an important research direction in the field of radar imaging in recent years. . Parallel bistatic SAR transmitters and receivers are placed on different platforms, and they fly along parallel trajectories at a constant speed and straight line. Because this mode is relatively simple, it has been widely used. The bistatic SAR imaging method has carried out flight tests one after another, recorded relevant data and completed imaging processing, and achieved better focusing effects. [0003] Imaging algorithm is the core content of bistatic SAR. For parallel bistatic SAR, the azimuth sign...

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Problems solved by technology

[0005] In view of the problems and deficiencies in the prior art, the purpose of the present invention is to propose a new fast BP imaging algorithm on the basis of the parallel bistatic spotlight SAR mode and the FFBP imaging method to solve the problem of sub-image coherent accumulation. The contradiction between computational efficiency and imaging accuracy caused by two-dimensional interpolation enables the algorithm to greatly reduce the amount of computation and improve computational efficiency while reconstructing high-quality SAR images

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