INTEGRATION OF LOW COST GEOMATIC TECNIQUES TO SUPPORT THE ARCHITECTONICAL PROJECT. THE PERLO CASTLE AREA SURVEY

In the high Tanaro Valley (Piedmont, Italy) the attestation of old pre-existence joined to the territory defence is possible to find numerous towers, castles, gouts and fortress. Today the most part of these cultural heritage are in ruin. Close to the municipality of Perlo few meters from the principal street, following a winding path is possible to arrive to a little hill; there the ruins of the old Castle of Perlo are hide from a rigorous vegetation. The old might of the fortress is lost today, is like an explosion of stone fragments swallow from the natural environment. The walls cut in some cases the hillok and the old towers are like rock spur. The requirement of the municipal administration to realize a preservation project for the historical area valorisation was the reason for begin complete survey of the Castle area. The only available metric information’s of the zone: the Piedmont Technical Cartography scale 1:10000 and the concerning aerial photograms, were not suitable in order to produce a project at an architectonical scale for the area. For these reasons, a complete survey campaign of the hillok and the ruins was performed in order to obtain large scale maps and architectonical drawings of the ruins and the terrain morphology. A traditional topographic approach with GPS and Total Station survey was followed for the hillok morphology definition. For the other parts (tower and walls ruins) simplify photogrammetric techniques with the employed of an Unmanned Aerial Vehicle (mini-helicopter) were followed. In particular the UAV was used in order to survey the towers, very high and not well measurable from the terrain. The paper present the utilized techniques, the survey operations, the results and the problems during the data acquisition. All the operations were focused to give operative support to the architectonical planning of the area. Finally the traditional graphic works (plans, facade and sections) and some example of 3D metrical views realized during the knowledge process for the Perlo castle are present.