Satellite image pair data of TanDEM-X and TerraSAR-X sister radars of ESA in 2014.

Gamma software is used for preprocessing and interferometry (based on the 2014 TanDEM-X / TerraSAR-X radar satellite remote sensing data), and then the multi-functional DEM corrector software is used to repeatedly register and correct the DEM with reference to the 30 meter resolution SRTM data in 2000, so as to ensure that it has a unified elevation datum and minimum coordinate deviation with other DEM data in the region, and to make sure that it has the same elevation datum and minimum coordinate deviation with other DEM data in the area ICESat satellite laser altimetry data are used to evaluate the accuracy of the results.

By using the platform equipped with TerraSAR-X and TanDEM-X sensors, the complex data (including amplitude and phase information) of the same ground object are obtained at the same time to form an interference pair. After accurate registration, complex interferograms can be obtained by conjugate multiplication of complex images. Based on the geometric relationship among flight platform, beam view and baseline, the phase information in complex interferogram is unwrapped to obtain the ground elevation information. The absolute accuracy in the vertical direction is better than 10 m, and the relative accuracy is 4 m at & gt; 20% and 2 m at & lt; 20%.