MULTI-TEMPORAL IMAGES AND 3D DENSE MODELS FOR ARCHAEOLOGICAL SITE MONITORING IN HIERAPOLIS OF PHRYGIA (TR)

The archaeological areas are one of the fields in which the contribution of image-base and range-based Geomatics techniques were employed since long time and are now getting popular (Hadjimitsis et al. 2009; Campana 2017). In recent times, Remotely Piloted Aircraft Systems (RPAS), together with Terrestrial Laser Scanning (TLS) survey systems become more and more interesting to be studied in excavations sites for monitoring purposes and solving high detail data and large scale and comprehensive mapping matters both from terrestrial and aerial point of view. 3D information derived from different acquisition campaign and different sensors too, belonging to the same spatial system, can be integrated and create a multi-temporal and multi-scale database (Remondino, Rizzi 2010; Kersten, Lindstaedt 2012; Moussa, Abdel-Wahab, Fritsch 2012; Chiabrando et al. 2016; Farella et al. 2016). The contribution of multi-sensor acquisitions, as it is known from increasing scientific experiences, offers by now to archaeological studies the possibility to obtain a multi-temporal view of the site with restricted time windows, but it is interesting considering also the possibility of a valuable integration and contribution of older image-based documentation, already stored in archives. In a complex archaeological area as the one of Hierapolis of Phrygia in Pamukkale (TR), a very interesting site investigated since several tens of years by the MAIER – Italian Archaeological Mission of Hierapolis, the impressive excavations have required extensive and accurate large-scale survey and documentation projects. This paper will also show the evolution over time of 3D survey methods. In particular, the presented experiences regarding the documentation campaigns by Politecnico di Torino and Geomatics group concern many multi-temporal datasets that have been acquired by different subsequent campaigns in 1997, 1998, 2007, 2012, 2015, by employing various sensors following the evolution of the acquisition techniques offers by geomatics in the archaeological field surveys