Photo interpretation and geographic information systems for dolmen identification in Portugal: The case study of Mora and Arraiolos

Aerial archaeology use vertical aerial photography and satellite images, allowing the identification of archaeological sites, both isolated or in agglomeration, since aerial images capture large scales of the territory. These images combined with Geographic Information Systems are powerful tools in Archaeology. This work, through the integration of photo interpretation techniques over aerial and satellites images available in Google Earth and BING, is presented as a non-intrusive prospecting method. This method was used to analyse standard features of dolmens in Alentejo Central, more specifically between Mora and Arraiolos municipalities (South Portugal). The analysis of these images permitted the perception of the dolmens size, colour, texture, structure and distribution pattern, allowing to find key criteria to photo interpreter already referenced archaeological sites more accurately, as well as to prospect potential new dolmens.