Video SAR (Synthetic Aperture Radar) imaging system and method based on adjustable transmitted waveform parameters

Abstract

The invention discloses a video SAR (Synthetic Aperture Radar) imaging system and method based on adjustable transmitted waveform parameters. The real-time position of a radar platform at each sampling point is measured by using a measurement and control module; the transmitted waveform generation module generates a baseband LFM signal; the transmitted waveform preprocessing module performs digital up-conversion and DA conversion on the baseband LFM signal; the radio frequency transmitting module mixes the intermediate frequency signal subjected to DA conversion with a variable local oscillator signal; the radio frequency receiving module receives echoes reflected by the observed scene; the received waveform preprocessing module performs AD sampling and digital down-conversion on the echo signal; and the inter-chip and in-chip parallel processing module of the multi-chip multi-core DSP carries out azimuth interpolation resampling and self-focusing algorithm processing. According to the method, the defect that image registration is needed during subsequent SAR video processing when each frame of SAR image is located in different coordinate systems after processing of a traditional PFA imaging algorithm is overcome, and better real-time performance is achieved during video SAR echo data processing.

Description

technical field [0001] The invention belongs to the technical field of radar, and further relates to a synthetic aperture radar (SAR) (Synthetic Aperture Radar) imaging system and method based on adjustable transmission waveform parameters in the technical field of radar signal processing. The invention can be used in an unmanned aerial vehicle-borne video SAR imaging system to process SAR echo data in real time to obtain the SAR video of the observed scene area. Background technique [0002] The UAV-borne SAR imaging system can continuously observe the observed scene area by adjusting the beam pointing in real time, and obtain high-resolution SAR video. The currently used video SAR imaging algorithms are mainly time-domain BPA (Back Projection Algorithm) imaging algorithm and frequency-domain PFA (Polar Format Algorithm) imaging algorithm. Scholars at home and abroad often use echo signals with fixed parameters when improving and optimizing these two algorithms. By doing a...

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Problems solved by technology

[0006] The purpose of the present invention is to address the deficiencies in the above-mentioned prior art, and propose a video SAR imaging system and method based on adjustable transmission waveform parameters, which is used to solve the problem of the large amount of algorithm computation and the post-processing problems of the prior art in video SAR real-time imaging. The problem that frame SAR images are located in different coordinate systems

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