GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 3.2 567 a primary colour and the images are then combined to create colour mixes that span the full visual spectrum (Kvamme, 2007). In this case the GPR depth slices were represented by a red band and the ERT depth slices through a green band (Figs. 1c and 2c). In this case, the final images relative to different depths will be represented through various degrees of red and green, depending on the location and intensity of the anomalies; the yellow colour in the maps, will indicate the areas where strong anomalies were observed by both methods. This is clearly visible in the images obtained by the combination of the slices for the site of Fondi, where the Fig. 2 – Results for Santa Balbina’s site (Depth: 0.5 m). a) Normalized GPR and ERT data for a depth of 0.5 m. b) Contour map overlays: GPR data is represented as black contour lines; ERT data is represented as red contour lines. c) RGB colour composite: green indicates the GPR slice and red indicates ERT slice. d) Results for Data Sum. e) Results for Principal Component Analysis (1 st principal component).