SfM-photogrammetry for fast recording of archaeological features in remote areas

Digital documenting of archaeological evidence represents a crucial tool in the study, preservation, management, and promotion of archaeological sites in remote regions and in fragile landscapes. In fact, in marginal environment, the knowledge related to archaeological heritage can quickly disappear, especially when policies to protect cultural heritage are unreliable or lacking. In the last few decades, archaeological fieldwork has seen the increasing use of Structure-from-Motion (SfM) photogrammetric technique as a tool for mapping and recording archaeological evidence. This technique allows the creation of highly detailed 3D models of archaeological sites, monuments, and artefacts from sets of simple but accurately taken pictures, thus preserving the data for further research or (digital) cultural valorisation. Nowadays, low-cost/commercial off-the-shelf sensors (professional and semi-professional digital cameras and smartphones as well) are widely available and accessible by most of the users operating in cultural heritage documentation. This has made the acquisition of field pictures in archaeological research much more flexible and cost-effective. 3D models obtained from these pictures through photogrammetric commercial software can be scaled with a known-measure providing highly detailed models for archaeological purposes. This enhances the ability of archaeologists to record archaeological features during field surveys and rapidly obtain 3D models. This is especially useful in the case of archaeological surveys carried out in remote and barely accessible areas. In this paper, we present the results of the application of the above-mentioned methods during archaeological surveys in the Sultanate of Oman, where several archaeological features have been recorded through SfM photogrammetry using commercial devices and portable scale-bars. We demonstrate that this is a highly-flexible and fast process to record archaeological heritage in low-accessible or fragile contexts, where a 3D model (with centimetric precision) represents a valuable dataset for further in-lab analysis and cultural dissemination.