A Spaceborne SAR Echo Simulation and Imaging Method Based on Fixed Distance Delay

Abstract

A spaceborne SAR echo simulation and imaging method based on a fixed distance delay, which relates to the field of spaceborne SAR system development and testing; includes the following steps: Step 1, performing distance direction pulse compression on the delayed signal to obtain the pulse compressed signal the s 1 (t k ,t m ); Step 2, re-extract the echo signal s after pulse compression 2 (t' k ,t m ); Step 3, calculate the slant distance history R(t of the point target along the azimuth m ), for signal s 2 (t' k ,t m ) to perform phase precompensation to obtain the phase precompensation signal s 3 (t' k ,t m ); step 4, calculate the real slant distance history R of each grid point ij (t m ), through sinc interpolation and phase compensation to obtain the sub-images of each grid point. i ,y j ); The present invention solves the problem that the real slant distance delay of the echo signal cannot be simulated in the SAR load test process.

Description

technical field [0001] The invention relates to the field of development and testing of a spaceborne SAR system, in particular to a spaceborne SAR echo simulation and imaging method based on a fixed distance delay. Background technique [0002] Since the spaceborne synthetic aperture radar (SAR) is all-day, all-weather, unaffected by weather, has strong penetrability, and can obtain multi-band multi-polarization ground object information, it has received more and more attention. By upgrading the satellite orbit to a geosynchronous orbit, it can provide a larger observation range, higher time resolution, and realize multiple observations of the region within a day. With the improvement of the orbit, SAR satellites are affected by the rotation of the earth, and the synthetic aperture time is as long as thousands of seconds. During the synthetic aperture time, the distance of a single point target moves seriously, which brings great challenges to the test of SAR load. [0003]...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, provide a space-borne SAR echo simulation and imaging method based on fixed distance delay, and solve the problem that the real slant distance delay of the echo signal cannot be simulated in the SAR load test process

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