Monitoring of the surface pattern of artistic and architectural artefacts by means of ultra close range photogrammetry

Today 3D technology and new digital instruments allow to represent the features of shape and colour of the objects in three dimensions, and constitute an useful tool for archaeological research, conservation and monitoring of Cultural Heritage assets. The ultra-close range photogrammetry approach, based on the same principles of classical photogrammetry, allows to generate a measurable3D model of small area, or artefacts of small size, by means of digital images. The technique, totally non-invasive, is currently used to assess the state of conservation and monitoring of objects and artefacts directly on-site. In the present work two examples of application of ultra-close range photogrammetry for assessing of state of conservation of surfaces of artistic and architectural interest are illustrated. The first case study regards the evaluation of cleaning treatments performed by chemical method and laser procedure on the detached fresco from the intrados of the Arco della Pesa in Sansepolcro (AR), Italy. The second case study regards the façade of Santa Croce in Lecce made by bioclastic limestone (Pietra di Lecce). In this case the effectiveness of consolidating treatments was controlled on several areas on the facade of Santa Croce in Lecce made by. The portability and the non-destructivity of such methodology (no-contact measurement method), suggest this methodology to be used, during the restoration works, for an easily and effective documentation method of the surface pattern, for control and monitoring of weathering processes of the intervention.