Airborne interference synthetic aperture radar (SAR) shadow estimate and plane route design method

Abstract

The invention provides an airborne interference synthetic aperture radar (SAR) shadow estimate and plane route design method for resolving the problems of an airborne SAR low signal-to-noise ratio zone shadow estimate basis and a plane route design basis. The airborne interference SAR shadow estimate and plane route design method comprises the steps: step1, providing an initial plane route which can cover a measuring zone, and calculating a gradient angle, a radar part view angle, and a shadow length of each grid unit; step2, utilizing a backscattering coefficient model to calculate ground backscattering strength inside each grid unit under each ground covering condition; step3, calculating the low signal-to-noise ratio zone shadow estimate basis, distinguishing and marking whether the unit is low signal-to-noise ratio or not, and counting the proportion of the area in which the low signal-to-noise ratio shadow zone occupies the measuring zone; step4; judging and marking a geometry shadow and the low signal-to-noise ratio zone shadow in the plane route direction, and counting a proportion of the area in which the two shadows occupy the measuring zone; step 5, changing the initial plane route which is set in the step 1, repeating step1-step4, and selecting a plane route which is smallest in shadow proportion after the shadows are combined.

Description

technical field [0001] The invention belongs to the technical field of radar detection, and in particular relates to an airborne interferometric SAR shadow estimation and route design method. Background technique [0002] In interferometric synthetic aperture radar (Synthesis Aperture Radar: SAR) radar mapping applications, it is usually desired to reduce shadows, thereby reducing invalid data and improving the quality of interferometric SAR mapping data. Shadows are the main component of geometric distortion of interferometric SAR images. [0003] In traditional SAR shadow analysis, usually only the geometric relationship of radar imaging is considered, that is, under a certain radar viewing angle, the area that is not illuminated by the radar beam is called shadow (a part of geometric distortion). For the application of interferometric SAR mapping, not only traditional SAR shadows (or called geometric shadows) need to be considered, but also some areas with weak scattering...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the problem of airborne interferometric SAR shadow estimation in low signal-to-noise ratio area and route design basis, the present invention proposes an airborne interferometric SAR shadow estimation and route design method, which not only considers the shadow brought by radar imaging geometry, but also considers the For the shadows caused by low signal-to-noise ratio areas, with the help of the rough digital elevation model (Digital Elevation Model: DEM) and backscatter coefficient model known in the survey area, the proportion of shadow areas under different viewing angles is estimated, and on this basis, the quantitative Analyze the shadow reduction effect of combined routes in forward and reverse directions to complete the route design

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