Наскальные рисунки местонахождения Идрисовская II. Методы цифрового картографирования и документирования

Abstract

Petroglyphs at Idrisovskaya II are located on the left (Western) bank of the Yuryuzan River in Salavatsky District, the Republic of Bashkortostan. The Petroglyphs at Idrisovskaya II are hardly preserved. Therefore, the 1900s researchers faced significant challenges in defining and copying these images. In 2022-2023 a team of authors undertook to study Idrisovskaya II location to mainly adapt the method of comprehensive mapping and record creation for the location of petroglyphs specifically for the Southern Urals conditions. The approach to the record creation was in the first place based reflection relations between heterogeneous data that describe particular surfaces with paintings on them and their landscape context. Mapping of the landscape context and surfaces with petroglyphs was made with 3D modelling and a wide use with satellite geodesic technologies. The outcomes of the landscape context mapping of the petroglyphs location allowed to precisely determine coordinates of the surface and, as a consequence, to guarantee further rediscovery of the images, including non-figurative ones. At the same time, the site mapping results allowed re-indexation of the petroglyph-bearing surfaces. Records of the painted surfaces were also made using 3D modelling. It allowed to correctly reproduce the geometry of the images and avoid angle distortions, Such distortions are unavoidable in photography. Furthermore, 3D modelling allows to avoid damage to the images which often happens due to contact copying methods. Traces of mineral paints were determined through conversion of 3D model bitmap rendering with the decorrelation stretch algorithm. The study used 3 to 5 renders calculated with different methods. The extracted pixels were joined; the obtained image was assigned the pigment colour determined by the active sensor (spectral colorimeter) and classified with according to the Munsell scale. The data obtained in this manner were applied to the 3D model colourless render to form an image. This image s compatible with polygraphic and electronic publication. A complex of above-mentioned inter-related methods and techniques for mapping, record creation, systematization, data analysis and reproduction allow to create a complete digital image of the location of petroglyphs and to obtain the new data of the drawings. Further this digital image becomes the foundation both for publication of the petroglyphs and for comparative research of petroglyphs in different locations based on the reliable basic data.