Distributed spaceborne InSAR DEM calibration

The residue error will be transferred to the elevation data during the acquirement of DEM data with distributed satellite SAR, which makes the accuracy fail to meet the need of system design. The systematic errors can be effectively reduced by the calibration method based on ground control points (GCPs), but inherent errors of control points will be transferred to the elevation data as well. Therefore, it is significant to determine the number of control points in a data take period and their layout in DEM calibration method. A method to forecast errors of DEM is proposed in this paper, and the formula of elevation data's standard deviation is deduced according to analysis of DEM calibration method and GCP location and accuracy. On basis of approaches mentioned above, the layout regulation of GCPs can be studied efficiently. The approaches are validated by digital simulation.