Digital Representation of Archaeological Sites. Recent Excavation at Alba Fucens

The use of digital technologies in the survey of archaeological sites arises some interesting methodological questions. This contribution aims to make analysis based on experience in performing in Alba Fucens, Latin colony of the fourth century BC, founded near the ancient lake Fucino for control important routes in the peninsula. The activity of documentation and analysis that the research center of Rieti Sapienza of Rome "Critevat" is in accordance with the Department of Human Sciences University of Foggia, concerns old and new excavations. The growing use of digital techniques, such as 3D laser scanner and photogrammetry, has as main consequence the tendency to objectify the data acquisition phase, shifting forward the time of interpretation and analysis. In the archaeological field, perhaps more than in other areas, this dichotomy is most accentuated. The representation makes more use of rendered three-dimensional models but are often difficult to manage, because they are still not standardized by the professionals or by the people who needs to acquire information for dissemination. The three-dimensional models often do not have the selection as a goal, but the "simple" repetition of a reality. The questions are: Are these models really objective? Is there a selection in the processing phase? The quality of a points-cloud where the real space is discretized into a number of discrete points depends on different resolutions, on the presence of voids, on photographic renderings which in turn depends on focus or exposure. We still think the automatic processes of continuous numerical surfaces and then of the mathematical (NURBS), which often use filters to reduce the "noise", based on algorithms developed for other applications. The paper plans to clarify the problems encountered in the experience of Alba Fucens and proposed some ideas arising from the comparison between surveyor and archaeologist.