GeoAnalysis S.A. has created a digital representation of the excavation as an indispensable part of the comprehensive, online-accessed platform of management and promotion of archaeological information produced under the Surgical Excavation project. For the implementation of this task an integrated system of digital recording was developed, oriented to the needs and particularities of an archaeological excavation.
This system is based on the company’s long experience in the documentation of cultural goods and the surveying of monuments and archaeological sites using modern methods, as well as on the advanced high-tech equipment it possesses. The particular objectives that were set and had to be met by the recording system are summarized in the following categories:
- Creation of material serving as a background for the interconnection of all information (base maps).
- Preparation of drawings and orthoimages to cover the needs of archaeologists during excavation.
- Immediate recording of the find spots and monitoring of the excavation progress in general, without the works being suspended.
- 3D documentation of findings and excavation areas, regardless of their size.
To achieve all these, a system of “tomographic documentation in time and space” or otherwise a 5D system was developed. The five dimensions that can be recorded by the system are the three dimensions of space, time and scale. In simple words, the excavation units were digitally documented in three dimensions at regular intervals to reflect the progress of the work, while the level of detail was adapted each time depending on the subject. For this purpose, the following means were used:
- Image capturing platforms for different scales (UAVs for aerial photography of archaeological sites or particular excavation areas and tripods for terrestrial shooting of individual trenches and findings).
- High-resolution sensors that record different parts of the spectrum (from DSLR cameras to hyperspectral and thermal sensors for recording and analysis of non-visible information).
- Computer Vision algorithms to create, in a short time, realistic three-dimensional models exclusively made of ordinary photos.
- Topographic instruments to offer the necessary measurements for the georeferencing of all data.
Eventually, the recording system is able to provide a range of products in two and three dimensions, corresponding to different levels of detail and different points in times.
2D products: orthophotos and small-scale orthomosaics that serve as base maps, large-scale orthomosaics for the study of specific trenches, and simple aerial panoramas or ordinary photos of findings taken from the ground. Moreover, multispectral and thermal orthomosaics, as well as mosaics of vegetation and temperature indices.
3D products: 3D models of findings of various dimensions, models of trenches or even whole excavation sites in different times and of multispectral image data.