Correction method for updating DEM (digital elevation model) by aid of ground based SAR (synthetic aperture radar)

Abstract

The invention relates to a correction method for updating a DEM (digital elevation model) by the aid of ground based SAR (synthetic aperture radar). The correction method includes computing an amplitude image of the SAR according to received complex-domain echo data of the ground based SAR; extracting corner reflector points of the ground based SAR image; registering the ground based SAR image and an optical image; acquiring ground based SAR image data received by two antenna sensors; respectively correcting phases of the two images; computing coherence of interference patterns of two antennas; unwrapping the phases; computing path difference of corrected slope distance signals and reducing inaccurate measurement errors of base line components B<h> and B<v> of the sensors; completing final elevation calibration work by the aid of ground elevation control points; three-dimensionally superimposing and displaying the ground based SAR image, the optical image and the updated DEM. The correction method has the advantages that approximation is omitted in processing procedures, the optical image and the ground based SAR image can be registered, the DEM can be updated in correction procedures, accordingly, the multi-source data can be precisely corrected, and excellent three-dimensional processing result displaying effects can be realized.

Description

technical field [0001] The invention relates to a DEM update and correction technology, in particular to a ground-based SAR update DEM correction method. Background technique [0002] The use of ground-based SAR ((Ground Based Synthetic Aperture Radar, GB-SAR) is an important means for regional, all-weather, all-weather, fixed-point continuous deformation monitoring. The deformation of the ground-based SAR interferometry can be used to update the DEM (Digital Elevation Model Digital Elevation Model), and can realize the accurate correction of ground-based SAR amplitude map, deformation map, and optical image in the real three-dimensional coordinate system. The correction method of SAR updating DEM can use the deformation of SAR to update DEM. Ground-based SAR can Obtain images before and after deformation by repeated observation, and obtain deformation information of the target after interference processing to realize close-range deformation monitoring. However, due to the i...

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Problems solved by technology

[0005] Aiming at the inability to obtain topographic information from echo signals in the prior art and the inability to make DEM, the technical problem to be solved by the present invention is to provide a ground-based SAR update that can realize the registration of optical and ground-based SAR, and the processing process is not approximate. Calibration method of DEM

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