UPGRADE – Underwater photogrammetry and archaeological data enhancement

Underwater archaeology requires the identification of sites of interest, followed by accurate geo-referenced mapping of selected target areas. The maps obtained play a key role in the documentation and preservation of archaeological sites and allow for better planning of further excavations and interventions. After surveying the ocean floor on a large scale (using e.g. A side scan sonar or magnetometer), observations at closer ranges were traditionally done by human divers. Over the past decade, however, with the growing challenge of reaching deeper sites,human divers are being complemented with or replaced by Remotely Operated Vehicles (ROVs). These ROVs are equipped with sonar and vision equipment and even tools to sample the seabed and manipulate artefacts.

Regardless of how data are acquired, the crucial problem of overlaying the different data sets so as to generate composites of the archaeological site at both large and small scales has not been satisfactorily resolved yet. Therefore the new UPGRADE project is bringing together experts in underwater archaeology to develop a software suite for the integration and fusion of acoustical, optical and platform navigation data. These tools should make the whole process largely automatic, and facilitate the construction of georeferenced 3D maps of underwater archaeological areas.

UPGRADE - NEWTONNo off-the-shelf tools are available for the these purposes. Several issues have not been yet convincingly addressed in the scientific literature and no efficient software tools are available to solve them. Currently, accurate navigation of underwater platforms still resorts to prohibitively expensive inertial sensor suites. Another issue is the automated processing of underwater images for photogrammetric purpose and the estimation of the camera parameters. Finally, there’s a need for integration of Digital Terrain Models (DTM) at different resolution scale, associated with the corresponding navigation data, with 3-D information from photogrammetric data. These DTM+photogrammetry models should be compatible with data with archaeologically oriented metadata and 3-D Virtual/Augmented reality systems.

The ultimate goal is to facilitate safer, faster, and far more efficient ways of performing archaeological surveys. Both Autonomous Underwater Vehicles (AUVs) and Remotely Operated Vehicles (ROVs) will be used as platforms to collect data. In particular, AUVs are used for performing preliminary, large scale acoustic surveys and exploration, while ROVs are used for collecting close distance data of a photogrammetric nature. By controlling at the same time the vehicle motion and the data acquisition process, one can correlate data coming from different sensors, The results (2D and 3D) will be produced using different software and formalisms in order to reach several goals: sharing data and information on-line through the internet, or allow for an in-depth, off-line investigation

The efficacy of the tools developed will be evaluated in simulation and through a series of tests at sea in controlled conditions, over a known and documented archaeological site. The use of the software itself will be demonstrated, oriented toward underwater archaeologists Other visitors will be able to see the final output of the system in a 3D environment. They can experience virtual navigation on the mapped archaeological site, using for instance VRML, complemented with movies of the experimental work.

At the same time, the UPGRADE partners will define a set of best practice recommendations. For the latter, a study of the system performance with respect to accuracy, precision and resolution of the various data sets will be performed.