Calibration error model for multichannel spaceborne SAR systems based on Digital Beamforming

A new generation of spaceborne Synthetic Aperture Radar (SAR) systems based on multiple transmit/receive digital channels and provided with Digital Beamforming (DBF) capability is forthcoming. Whereas the technological feasibility and performance capability of these new SAR systems has been proved by a large number of studies in the last years, the identification and verification of an adequate calibration strategy is still required. In this paper a model of residual calibration error in multichannel spaceborne SAR systems based on DBF is provided with the aim to support the calibration performance prediction, the optimum design of calibration methods and the testing for scenarios in which sufficient real data are not available.