Two different approaches for georadar data processing: A case study in archaeological prospecting

This paper deals with the application of two different processing methods of the georadar data aimed at improving the results in the case of bad quality data. The georadar data are referred to two areas located in the Axum archaeological park (Ethiopia) and were acquired prior to the reinstallation of the returned Stele from Italy to the Ethiopian Government. In the area the schist formation is covered by an outcropping sandy silt formation about 6-8 m thick. The archaeological excavations, performed before the georadar data acquisition, revealed that tombs and catacombs were dug into the superficial layer. Because the complexity of the georadar data interpretation based on standard data processing, some of the collected measured data are also processed by an innovative microwave tomographic approach which permits to achieve clearer diagnostic results with respect to the classic radaristic techniques in 2D and 3D representation. We take into account the data acquired for the East stele 2 with 100 MHz antenna and in the parking area of the archaeological park with 200 MHz antenna. The data were acquired on profiles 1 m apart. Comparing the data processed with the two different approaches, we obtained an improvement of the vertical resolution and of the quality of image on time slices using the tomographic approach compared to the results obtained with the classic radar one.