GNGTS 2016 - Atti del 35° Convegno Nazionale

568 GNGTS 2016 S essione 3.2 yellow portions indicate the position of the cisterns. This method is more effective than the contour maps overlay method since it helps in better defining the position of the anomalies detected by the different methods in a more meaningful way. Quantitative data integration. Data Sum. The data sum integration method consists in adding together the normalized cell values of each dataset, to produce a new set of data containing all the anomalies detected by the methods employed, including those of large and small magnitude (Piro et al. , 2000). This process was carried out for each depth slice where the resulting datasets will contain the contribution of all the methods employed at different depths. More precisely this will give an indicator of the spatial distribution of the anomalous sources detected by at least one of the methods used. The results obtained show how both the GPR and ERT methods concur to give a complete image of the subsurface in the two sites (Figs. 1d and 2d). The maximum value of the integrated dataset corresponds to the areas where all methods recorded the maximum anomaly pattern, while the lowest values coincide with the points where no method recorded a variation in the measured parameter. As expected it can be seen from the results that the data sum enhances strong anomalies, yet also includes lower intensity anomalies that were not previously visible. Since this integration technique generates new datasets, it is also possible to generate a 3D model of the integrated data. Principal ComponentAnalysis. Principal components analysis (PCA) is a statistical procedure that transforms a number of correlated input datasets into output images that are uncorrelated. The first principal component usually accounts for most of the variance from all the output images and each successive component summarizes less and less of the total variation (Davis, 1986). The more the original variables are correlated, the more meaningful the new dataset will be and therefore the more information can be retrieved from the reclassification. The PCA was performed on the normalized depth slices for the two sites (Figs. 1e and 2e). In the first case (ancient Appian way) for most of the slices, this method gave good results; this is due to the fact that the GPR and ERT data for this site is highly correlated. References Accordi G., Carbone F., Civitelli G., Corda L., De Rita D., Esu D., Funiciello R., Kotsakis T., Mariotti G., Sposato A.; 1988: Note Illustrative alla Carta delle litofacies del Lazio – Abruzzo ed aree limitrofe . C.N.R – Progetto Finalizzato Geodinamica: sottoprogetto 4. Quad. Ric. Scient ., 114 , vol, 5, 223 p. Brizzolari E., Ermolli F., Orando L., Piro S., Versino L.; 1992: Integrated geophysical methods in archaeological surveys . Journal of Applied Geophysics 29 : 47-55. Campana S., Dabas M., Marasco L., Piro S., Zamuner D.; 2009: Integration of remote sensing, geophysical surveys and archaeological excavation for the study of a medieval mound (Tuscany-Italy) . Archaeological Prospection, Vol. 16 , n. 3, 167-176. Chiocchini M., Mancinelli A.; 1977: Microbiostratigrafia del Mesozoico in facies di piattaforma carbonatica dei Monti Aurunci (Lazio Meridionale) . Studi Geologici Camerti, 3 , 109-152. Davis J.C.; 1986: Statistics and Data Analysis in Geology . John Wiley & Sons. Funiciello R., Giordano G.; 2008: Note illustrative della carta geologica d’Italia alla scala 1:50000, Foglio 374 “Roma” . Servizio geologico d’Italia. Kucukdemirci M., Piro S., Ozer E., Baydemir N., Zamuner D.; 2015: An integrated geophysical survey at Aizanoi archaeological site (Turkey) . Proceedings of 11 th International Conference on Archaeological Prospection ICAP2015. Archaeologia Polona, Vol. 53 , 477-479. ISSN: 0066-5924. Kvamme L. K.; 2007: Integrating multiple geophysical datasets . Remote Sensing in Archaeology (Ed.s) Wiseman J and El-Baz F. , pp 345-374. Springer ISBN 978-0-387-44453-6. Piro S., Mauriello P., Cammarano F.; 2000: Quantitative integration of geophysical methods for archaeological prospection . Archaeological Prospection, 7 , 203-213. Piro S., Gabrielli R.; 2009: Multimethodological approach to investigate chamber tombs in the Sabine Necropolis at Colle del Forno (CNR, Rome, Italy) . Archaeological Prospection, Vol. 16 , n.2, pp. 111-124. Piro S., Papale E., Zamuner D.; 2016: Different integrated geophysical approaches to investigate archaeological sites in urban and suburban area. Geophysical Research Abstracts, Vol. 18, EGU General Assembly 2016.