Investigations on the internal calibration of multi-channel SAR

A calibration scheme for future SAR systems utilizing digital beamforming, is suggested. These systems pose new challenges for the calibration, as the increased complexity of multi-channel SAR does not allow for the extrapolation of current calibration techniques. Further, depending on the operation mode, real-time error measurement and correction is unavoidable, which requires a reconsideration to current calibration approaches. On the other hand, the digital hardware already present in multi-channel SAR systems offer new possibilities for novel calibration such as on-board error correction and digital calibration. This paper presents a calibration scheme suitable for multi-channel digital beamforming SAR.