Heritage site preservation with combined radiometric and geometric analysis of TLS data

Damage mapping is considered a critical stage in the correct diagnosis of the state of conservation of Cultural Heritage manifestations. The common approach generally implies a large user interaction to map the different pathological processes presented on 2D documents such as elevations or sections, among others. In contrast with this practice, the present paper proposes a semiautomatic 3D-methodology, with a minimum user interaction, able to accurately analyse both radiometric and geometric data recovered by a non-contact technology (Terrestrial Laser Scanning), allowing the extraction and quantification of a wide diversity of pathological processes from biological colonization to deformations. This approach is therefore a potential tool for the rapid and accurate diagnosis of Cultural Heritage. To confirm the applicability and potential offered by the proposed methodology, a highly affected historical masonry, the San Francisco Master Gate of the Almeida Fortress (Portugal), was evaluated by using the Faro Focus 3D 120 Laser Scanner. •A damage mapping methodology based on TLS data is applied in heritage assets.•The approach analyses both geometric and radiometric data recorder by TLS.•Radiometric analyses allow the detection of chemical and biological damages.•Geometric analyses allow the detection of physical damages.•The success of the radiometric analyses are based on the calibration of the TLS.