3D geometric survey of cultural heritage by UAV in inaccessible coastal or shallow aquatic environments

Abstract

Cultural heritage in coastal or shallow aquatic environments is often located in areaswhere access is difficult or where accurate survey and documentation may notalways be possible with terrestrial or aquatic equipment. The combination of photo-grammetry and unmanned aerial vehicles (UAVs) generates a range of possibilitiesacross multiple sectors, including history, ethnography and cultural heritage studies.Additionally, these methods can be used to prospect new archaeological sites. Thisarticle presents three case studies that use UAV techniques and Structure fromMotion and Multiview Stereo (SfM-MVS) photogrammetry to conduct topographicand geometric registrations of archaeological, historical and ethnographic sites (someof which are classified as cultural heritage sites). These examples are located incoastal or shallow aquatic environments that are difficult to survey with traditionalmethods. The results show that it is possible to carry out detailed geometric registra-tion and heritage prospection over large coastal or shallow aquatic environmentsusing a low-cost UAV. Furthermore, the results of this work show great advantagesin terms of cost and quality, even in cases where the seabed is below a shallow watercolumn. Other particularities of SfM-MVS application in aquatic environments arediscussed. From an interdisciplinary perspective, this methodology will offer newpossibilities for the study, restoration and conservation of archaeological, historicaland ethnographic monuments