Precision 3-d Sub-bottom Imaging for Deep Water Archaeology.

Objectives:To develop a solid theoretical, technical and operational foundation for 3-d sub-bottom imaging. To characterize the existing sub-bottom profiler.To advance the technology of 3-d sub-bottom imaging with an improved transducer array.To educate students in preicison control of ocean vehicles, computer modeling of the seafloor, systems integration and field engineering.To apply the technology to new vehicles platforms (surface craft, ROVs, AUVs, etc.).To precisely model a burried, archaeologically significant shipwreck or settlement in very deep water.Methodology:Render existing data using volumetric techniques developed in other arenas.Model and characterize the existing sub-bottom profiler, transducer, and collection techniques.Develop model of high frequency narrow-bean sub-bottom profiling and imaging. Build on existing work in low-frequency sub-bottom profiling, parametric sonar, acoustic properties of sediments, and 3-d seismic techniques.Install array on JASON vehicle during 2001 archaeological field season in the Eastern Mediterranean.Conduct a full 3-d survey of Phoenician shipwrecks in this area.Process and render survey data.Design and fabricate a new acoustic array to improve array gain, swath-width, penetration depth, resolution, and survey speed.Characterize and test new array laboratory and shallow water settings.Install new array on JASON vehicle during 2002 field season in Eastern Mediterranean or Black Sea (or other site as available).Process and render survey data.Rationale:Archaeology is moving into deep water, and precision control and remote sensing are the key technologies to make it scientifically viable. This project aims to make precise three-dimensional maps (centimeter scale precision) of the top few meters of a local area of the seafloor and to render those maps volumetrically. This ability to precisely map below the seafloor in three dimensions is critical for understanding of buried shipwrecks and archaeological sites, but will also benefit other areas such as environmental assessment and monitoring and marine geology. Such data would allow archaeologists to record and replay a “virtual excavation” of a wreck site, that is a three-dimension model, removable in layers, all in a computer-without ever touching the wreck.