Polarimetric subsurface SAR imaging outcome of theoretical development and CARABAS III tests

This is a preliminary report on theoretical and experimental results regarding SAR imaging of buried targets. The work has been motivated by the CARABAS III radar development ongoing at Saab. The radar operates in the two bands with centre frequencies 55 and 220 MHz and with a bandwidth equal to the centre frequency. The radar design went partly parallel with a theoretical modelling work for subsurface targets. Theory predicted that the best options for discriminating the weak subsurface returns from surface returns was to use of shallow depression angles and polarimetry. However in this case returns will be very weak and radar operation must be short range. The radar is designed to comply with these requirements and performing our first dedicated subsurface detection experiments in the autumn 2013, the results obtained vividly support the theoretical predictions made.