SAR signal reconstruction from non-uniform displaced phase centre sampling

The displaced phase centre (DPC) technique enables a wide swath SAR with high azimuth resolution. In a classic DPC system, the PRF has to be chosen such that the SAR carrier moves just one half of its antenna length between subsequent radar pulses. Any deviation from this PRF results in a non-uniform sampling of the synthetic aperture. This paper shows that an unambiguous reconstruction of the SAR signal is also possible in case of such a non-optimum PRF. For this, an innovative reconstruction algorithm is derived, which enables a recovery of the unambiguous Doppler spectrum also in case of a non-uniform sampling of the synthetic aperture. This algorithm also has a great potential for multistatic satellite constellations as well as the dual receive antennas in Radarsat II and TerraSAR-X