Experimental investigation of Digital Beamforming SAR Performance using a ground-based demonstrator

Digital beamforming (DBF) technique is a promising technique for future synthetic aperture radar (SAR). In this paper, we present the preliminary experiment and results. The measurements were accomplished by a ground-based DBF SAR system for a single target. The system is evaluated by mono-static SAR operation first. Comparing between DBF SAR and mono-static SAR images the channel imbalance effect is investigated. Since the experiment provides the SAR raw data containing the system response, from this raw data we estimate the linear phase error due to the channel imbalance and compensate it. The reconstructed DBF SAR images show that the minimum variation of the phase between the receive channel is crucial to obtain the theoretical improvement factor.