Active and Passive 3D survey merging. The case study of the water chanel system in Al Habis castle, Jordan

This research project is funded by the Italian Ministry of Education, University and Research and the Ministry of Foreign Affairs and has developed as a joint project between the University of Urbino, CNRS, UMR 694-MAP of Marseille and the CNR, ITABC of Rome. The aim of the work is the development of an integrated system of automated topography applied to the remains of the Crusaders' castle of al-Habis at the western boundary of the archaeological area of Petra. In particular, the monumental site of Petra is located on the left rim of the Rift Valley, in central-southern Jordan. The only visible part of the architectonic heritage consists of tombs and temples dated to the Nabataean period and sculptures within the rock walls. Past inspections carried out in the field have highlighted the key role played by rainwater flowing down the facades of the monuments and causing their advanced deterioration. Today, this drainage system is no longer operational, as it has been blocked by both the accumulation of debris and collapses caused by landslides and earthquakes. One of the main objectives of the architectural and patrimonial survey is to provide a precise documentation of the status quo of the surveyed objects (monuments, buildings, archaeological objects and sites) in order to preserve and protect them, to study and restore the monuments and to present them to the people. Complex objects, not planar or with ornaments and decoration, require the highdensity and the high-resolution of the spatial data. The laser scanning techniques and close range photogrammetry can offer two complementary sets of instruments and technologies able to answer to the specific requirements of architectural and archaeological survey. The results of this operation is an extremely detailed and measurable 3-D model of the channels that can be used both for classification and study purposes as well as for virtual tests and simulations on the waters flow. The creation of this detailed model allowed us to extract information on sections along the course of a channel and revealed the degree of deterioration of the side walls of the water channel.