Multibeam Imaging System for Submerged Archaeological Sites
The Lake Champlain Maritime Museum has undertaken innovative research in the non-invasive documentation of submerged archaeological sites. In recent years, handheld imaging sonars have been developed that provide near-visual quality information regardless of underwater conditions. The adaptation of existing imaging sonars for use on underwater sites will have widespread applicability to the nation’s thousands of submerged archaeological sites located in turbid waters that make detailed archaeological documentation impractical. LCMM has prototyped the feasibility and methodologies for this technology using a Blue View DF900-2250 Dual Frequency Miniature Multibeam Imaging System on sites in Lake Champlain. This research was undertaken with funding from the National Center for Preservation Technology and Training, grant number MT-2210-09-NC-02.
LCMM archaeologists tested the Blue View DF900-2250 on one test subject in shallow water. The system was then brought to a medium-depth shipwreck of known historic context and construction technique, Wreck GGG. Finally, the Blue View DF900-2250 was tested on the shallow-water wreck of the Champlain II, a nineteenth century steamboat. Each of these sites was in Lake Champlain. Safe diving techniques were practiced throughout all activities.
After multiple dives on one test subject and two shipwrecks, LCMM archaeologists have determined that the Blue View DF900-2250 Dual Frequency Miniature Multibeam Imaging System is not an effective tool to document the details of a shipwreck. However, it is an extremely useful system to provide a “big picture” image that could not be created by any other method at our disposal. Especially in low visibility environments, it also provided a safety mechanism by which we could immediately locate a separated diver.
The results of this study were published in our technical report: Assessment of Handheld High-Frequency Multibeam Sonar Imaging for the Study of Submerged Cultural Resources, Lake Champlain Maritime Museum 2011.