A low frequency airborne GPR system for wide area geophysical surveys: The case study of Morocco Desert

The paper deals with development and validation of a VHF band airborne radar designed for subsurface exploration. The radar system is a pulsed one and transmits a chirp pulse at the central frequency of 165 MHz with 40 MHz bandwidth. A preliminary system validation has been performed by means of flight trials over Morocco desert in May 2018. An ad-hoc signal processing technique has been developed to produce focused images of the scene under investigation starting from raw and motion uncompensated data. In particular, the data processing technique is based on a microwave tomographic approach that has the novel feature to compensate the distortion effects produced by the non-rectilinear motion of the aircraft based on navigation data. The analysis and interpretation of the data is supported by comparison with electromagnetic simulations of the scene.