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

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.