Calibration of the Bistatic TanDEM-X Interferometer

Abstract:
TanDEM-X is a high resolution radar interferometer in space with the mission to derive a global Digital Elevation Model (DEM) with previously unattained quality for a global coverage. During the commissioning phase and the first nine months of nominal operations the system showed its potential to obtain this goal. This paper addresses the main topics important in terms of the calibration of the bi-static interferometer formed by the two satellites, including the baseline calibration, the calibration of the radargrammetric phase band determination and finally the absolute height calibration of the interferograms. The baseline calibration is required to verify and calibrate the baseline which is the measured vector between the two satellites. By the appropriate calibration of the radargrammetry the DEM is hooked correctly into its height interval and the interferometric parameters determine the absolute height position of the DEM before DEM calibration and mosaicking.