By positioning itself as a technical support for DGAM, Iconem worked out the most innovative computing methods to assess the severity of damages suffered by ancient monuments destroyed in Palmyra and monitor the scientific work carried out by archaeologists. We can explain the work flow in 4 successive steps :
I - FIELD DATA ACQUISITION
The Iconem team followed DGAM archaeologists in Palmyra during the very first scientific mission in this place, just one week after liberation of Palmyra. This mission aimed to record the status of the antique site and of the museum, immediately after the liberation of the city, in order to provide experts and scientists with accurate documentation before any cleaning work. For that purpose, Iconem used a drone which took several thousands of aerial pictures, in order to record all the blocks of the site and survey each of them.
Figure 1. Drone shooting made in Palmyra in April 2016 by DGAM and ICONEM.
II - 3D RECONSTRUCTION PROCESSING
Aerial pictures taken under different angles are processed by a recent algorithm to generate a precise 3D model. Huge processing clusters are needed to reconstruct such broad and accurate models from thousands of pictures. The model thus obtained gives the shape and color of the real environment with high accuracy, in a photorealistic manner. We got high definition models for every destroyed monuments, and general survey of the whole area of Palmyra.
Figure 2. Temple of Bel: preliminary analysis of the blocks through the 3D model of the basted structure. Red blocks are regarded as in good condition, light red ones seem to be half broken, while white ones are in bad condition.
III - EARLIER DATA COLLECTION AND PROCESSING
3D model of existing structure is not such as to allow to make a clear evaluation of the actual damages on the antic site. It’s also essential to get 3D reconstruction of the monuments in their initial status before Daech’s destructions. To this end, we’ve worked on old surveys (from Robert Amy, an architect who has been working on the site in the early 1930s) and many photographs taken by people before the conflict. By processing and combining all this data sources together, we were able to reconstruct the temple of Bel and the monumental arch, stone by stone.
Figure 3. Temple of Bel: preliminary reconstruction of the temple of Bel before the explosion (in red), using old surveys and crowd sourced pictures overlapping the actual state of the temple (in white).
IV - THEORITICAL SIMULATION OF THE DYNAMICS OF THE EXPLOSION.
Using these models, Iconem processed theoretical simulation of the falling blocks of the monumental arch, during the explosion. By estimating the density and friction coefficient of the blocks, the computer processed the trajectory of every blocs after the blast. This simulation will help archaeologists and architects to find the original place of fallen blocks.
Figure 4. Arch: Schema of Theoretical simulation of the dynamics of the explosion with the falling blocks. This simulation will help experts to understand the explosion process and the disposition of fallen blocks.
The DGAM devoted ICONEM’s work in Palmyra a great article.