GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.2 GNGTS 2024 constructon of the data matrix and the Voxler applicaton (Golden Sofware) for the graphic rendering. For the spatal interpolaton the Inverse Distance Weightng algorithm (Shepard, 1968) was applied, which uses a weighted average based on the distance of the points from the observaton point. Fig. 1 – Locaton of the ground penetratng radar profles. All GPR profles were carried out with an interdistance of 50 centmeters and acquired using the Georadar instrumentaton of IDS – Engineering dei Sistemi S.p.a. – RIS MF HI-MOD model, equipped with a 200/600 MHz dual frequency antenna. The investgaton depths were estmated considering an average electromagnetc wave propagaton velocity of 0.1 m/ns. This average value was obtained from the slopes of the refecton hyperbolas present in the data. Each profle has been processed to eliminate coherent and inconsistent noise present in the original data. Afer processing the data with RefexW sofware (Sandmeier, 2016) trying to eliminate both coherent and inconsistent noise, we proceeded with the analysis and interpretaton in relaton to the purposes envisaged by the study. For simplicity of graphic representaton of the processed data, it was chosen to display the interpretatve models of the investgated volume, in terms of normalized refected amplitude. For each of the four areas investgated (central nave, side nave, porton in front of the Jubè, external area) a 3D model was built, using a code implemented in Matlab for the constructon of the data matrix and the Voxler applicaton (Golden Sofware) for the graphic rendering. For the spatal interpolaton the Inverse Distance Weightng algorithm (Shepard, 1968) was applied, which uses a weighted average based on the distance of the points from the observaton point. The georadar survey carried out for a total of 54 profles identfed anomalies atributable to possible buried structures (fg. 2). In partcular, some anomalies are compatble with the presence of crypts/burials in the central nave in the area near the main altar and, at greater depth (about 3 m) an anomaly in the inital part of the nave, near the Jubé. The later is confrmed by another anomaly identfed at the same depth on the opposite side of the arches. Some anomalies have also been identfed in the side nave at a depth of approximately 2 m compatble with pre-existng architectural structures. As regards the external porton, the ground penetratng radar survey did