A spaceborne SAR imaging processing method

Abstract

A spaceborne synthetic aperture radar imaging processing method, the method includes analyzing the traditional hyperbolic slant range model of spaceborne synthetic aperture radar imaging and analytically deriving the applicable boundary conditions to complete the algorithm selection; removing redundant sampling in the range direction of the original echo signal Data, through the compensation of the slant range model error and high-order phase error, the spaceborne SAR high-resolution high-squint data processing is realized, and a fully focused image is obtained. The method provided by the invention combines the high-resolution large squint processing signal model of the spaceborne SAR, analyzes the processing boundary conditions of the existing models and algorithms, and has certain references for the selection of the spaceborne SAR imaging processing algorithm. The compensation of range model error and high-order phase error realizes high-resolution high-squint data processing of spaceborne SAR, effectively solves the problems of severe coupling of two-dimensional spectrum and velocity space variation, reduces redundant sampling in range direction, and saves calculation requirements Resources and time have greatly promoted the application of spaceborne SAR to earth observation.

Description

technical field [0001] The present invention relates to the technical field of radar imaging, in particular to a spaceborne SAR imaging processing method. Background technique [0002] Spaceborne Synthetic Aperture Radar (SAR) is an active microwave remote sensing device with the characteristics of all-weather, all-weather, two-dimensional high-resolution, strong penetrability, multi-function, and multi-purpose. , disaster monitoring, battlefield reconnaissance, map surveying and mapping and other fields play an important role. Due to the large observation range of spaceborne SAR, it has become the mainstream means of earth observation. [0003] At present, most of the spaceborne SAR works under the conditions of frontal side view and small squint. In order to obtain fine ground SAR images more timely and flexibly, the high-resolution large squint mode of spaceborne SAR will be frequently used. However, high-resolution spaceborne SAR often corresponds to a longer synthetic...

AI Technical Summary

Problems solved by technology

However, high-resolution spaceborne SAR often corresponds to a longer synthetic aperture time, and the satellite trajectory is no longer equivalent to a straight line, which leads to the failure of the traditional oblique range model; moreover, a large oblique angle of view in the azimuth will introduce a large number of redundant sampling and Strong distance and azimuth coupling lead to a sharp increase in the amount of post-processing data and a decrease in the accuracy of traditional imaging processing algorithms

Therefore, traditional models and processing algorithms no longer meet the requirements of spaceborne SAR with high resolution, large squint, fast and high-precision image focusing, which will limit the application scenarios of spaceborne SAR

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