Satellite-borne SAR imaging processing method

Abstract

The invention discloses a satellite-borne synthetic aperture radar imaging processing method. The method comprises steps of analyzing a conventional hyperbolic slant range model of satellite-borne synthetic aperture radar imaging, carrying out analysis and derivation of an applicable boundary condition, and completing algorithm type selection; removing distance direction redundant sampling data inan original echo signal, and realizing satellite-borne SAR high-resolution large squint data processing through compensation of a slant distance model error and a high-order phase error to obtain a complete focusing image. The method is advantaged in that a satellite-borne SAR high-resolution large squint processing signal model is combined, the processing boundary conditions of a model and an algorithm in the prior art are analyzed, certain reference is provided for model selection of a satellite-borne SAR imaging processing algorithm, besides, high-resolution and high-squint data processingof the satellite-borne SAR is realized through compensation of a slant distance model error and a high-order phase error. The method is advantaged in that problems of serious coupling and speed space-variant of the two-dimensional frequency spectrum are effectively solved, distance-direction redundant sampling is reduced, resources and the time required by operation are saved, and satellite-borneSAR earth observation application is greatly promoted.

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...

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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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