GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 3.2 573 Fig. 3 – S. Giovanni in Laterano square. GPR time slices in the time window 112-118 ns (estimated depth 2.6 m) for 70 MHz antenna. Fig. 2 – S. Giovanni in Laterano square. GPR time slices in the time window 58-61 ns twt (estimated depth 2.4 m) for the 400 MHz antenna. site were collected alternatively in forward and reverse directions employing the GSSI cart system equipped with odometer. All radar reflections within the 90 ns for 400 MHz antenna and 195 ns for 70 MHz antenna (two-way-travel) time window were recorded digitally in the field as 16 bit data and 512 samples per radar scan. A nominal microwave velocity of about 10 cm/ns was determined from fitting hyperbolas to the raw field data. This was used in estimating a penetration depth from the GPR survey. Data processing and presentation. All the GPR data were processed in GPR-SLICE v7.0