The bistatic aspect of the TanDEM-X mission

In addition to the promising and well known features in the field of monostatic interferometry and polarimetry, TanDEM-X can also be used for bistatic purposes. In this Helix orbit concept one TerraSAR-X satellite (TSX) serves as transmitter whereas the reflected signal is received by the transmitter as well as by an almost identical satellite (TDX), which has a similar orbit as the first one. This paper focuses the bistatic possibilities and restrictions of this space borne formation. In the bistatic mode of TanDEM-X it is possible to receive the echoes simultaneously by the two receiving sensors. From this it follows that there is no temporal decorrelation. For having an idea of how this configuration works in the bistatic mode and how the bistatic raw data looks like, we simulated realistic orbit data. Using zero Doppler steering we generated raw data which was processed by the bistatic processing approach of our institute. Another basic issue of the paper is the bistatic parameter estimation for this special configuration.