Antennas for GPR systems

Antennas are a critical hardware component of a radar system, dictating its performance in terms of capability to detect targets. In this Chapter, a wide review on Ground-Penetrating Radar (GPR) antennas is given. Firstly, the gen- eral characteristics of GPR antennas are resumed and the requirements they have to satisfy are listed: these are somehow unique and very different than in conventional radar antennas, since GPR antennas operate in a strongly demand- ing environment, in close proximity to or at a limited distance from the natural or manmade investigated area. Subsequently, an overview on the most frequently used GPR antennas, for both pulsed and stepped-frequency radar systems, is pro- vided; recent studies concerning innovative solutions are presented and informa- tion on antenna arrays for GPR applications is included, as well. The Chapter continues with a census of commercial antennas of a number of GPR manufactur- ers, where the centre frequencies and general characteristics of the antennas avail- able on the market are schematically organised in tables. Aided by measurements and powerful computer modelling techniques, GPR antenna designers are increas- ingly able to predict and understand the performance of proposed design in real- istic electromagnetic environments: the Chapter includes two sections reviewing techniques for the experimental characterisation and numerical modelling of GPR antennas. Finally, conclusions are drawn and research perspectives in the field of GPR antennas are discussed.