3D survey and modelling of shipwrecks in different underwater environments

Experiments carried out by a combined team of the Ca' Foscari and IUAV Universities of Venice, on ancient shipwrecks with different characteristics in different environments (shallow water cargoes of marble stones and a deep water mound of amphoras), confirm the potential of three-dimensional surveys in documenting underwater archaeological sites. Multi-image photogrammetry is the principal and innovative technique used, but we have confirmed the necessity of accompanying this new system with a precise topographical net. This last aspect is particularly evident when it is necessary to solve the problem of the documentation of a multi-strata mound of amphoras, anchoring 3D models of each stratum as it is removed. Photogrammetric models must be processed with 3D software modelling to interpret the textured meshes and to construct polygonal models, selecting the important aspects of the objects, and eliminating the 'noise' of the point cloud. The 3D model can easily be used to reconstruct the original arrangement of the cargo, on which it is then possible to make various calculations and considerations of nautical engineering.