Spaceborne-airborne SAR interferometry based on BP algorithm

In this paper, an interferometric synthetic aperture radar (InSAR) technique based on spaceborne-airborne bistatic SAR interferometry (SA-BiInSAR) is presented, in which the transmitter and receivers are mounted on the spacecraft and aircraft respectively. Due to the separated transmitter and receivers, and also the common non-ideal trajectory of the airborne received platform, the conventional frequency-domain SAR imaging approaches, such as range-doppler algorithm and chirp scaling algorithm, are very difficult for SA-BiInSAR imaging processing directly. To obtain high-quality of SA-BiInSAR image formation and interferogram, in this paper a back-projection algorithm, based on time-domain coherent integration of target signals, is developed for SA-BiInSAR imaging and phase extraction in the case of non-ideal trajectory. In this scheme, the echoes of SA-BiInSAR master and slave channels are projected into the same imaging space, and the interferometric phase of SA-BiInSAR is derived utilizing the principle of BP algorithm. Simulation results demonstrate the performances of SA-BiInSAR, and verify the effectiveness of the presented BP algorithm for SA-BiInSAR image formation and phase extraction in the case of non-ideal trajectory.