2-D synthetic radargrams for archaeological investigation

Ground radar is being used in archaeological surveys with considerable success. The structures at excavated sites nevertheless often turn out to be different from those determined from raw radar profiles. The primary reason for these differences is the broadness of the microwave beam transmitted into the ground (see Fig. 1). Many radar antennas have significant response over a l20-degree looking angle, which means imaging of objects both directly below the antenna and off to the side. Although there are processing techniques able to eliminate some of the problems of surveying with a broad beam radar (e.g. migration), these techniques also have drawbacks. The raw, unprocessed radar data normally contain maximum information about the surveyed area. To take advantage of the information content of raw radar records in the interpretation of buried structures, we use forward modelling incorporating matching synthetic radargrams that include the entire directional response of the antenna, together with measured radargrams.