Photogrammetric rock art detection: assisting detection of rock art on lichen covered surfaces using photogrammetry and 3D-modelling software.
Erik Kjellman
Abstract This presentation aims to show how photogrammetry and simple 3D-modelling software techniques can aid in the detection of rock art in difficult natural conditions. The field of Rock art documentation has seen an increase in the use of digital recording methods, such as Reflectance Transformation Imaging (RTI) and digital photogrammetry. Detailed datasets means that new and novel methods for study are emerging and are making it possible to get better understanding and even making it possible to uncover previously unknown details in the rock art. In this paper, I will show how the knowledge about these methods would facilitate ad.hoc primary documentation of a newly discovered rock art site in northern Norway. The author discovered the rock art site at Gamnes, Sør-Varanger municipality, Norway, during an archaeological excavation. Due to the circumstances of the discovery in connection to the excavation, it became paramount to get high quality detailed documentation of the rock carvings at a minimum of time. Photogrammetry was used to document the rock art and generated good datasets for disseminating the findings. Identifying each of the pictographs was not easy. This was mostly due to difficult lighting conditions, but also because of heavy lichen growth on the rock surfaces. Manipulating the datasets gathered from the initial photogrammetry unveiled some parts of pictographs that were otherwise almost invisible. This discovery made it possible to get even better preliminary estimates of the rock art sites extent, and thus create a better basis for further work on the site.
