Purpose
The intention of the IHSP Phase-One project is to gather as much digital video information on the shipwrecks now resting in the southern end of Lake Michigan by the use of remote sensing.

Remote Sensing Survey
An established method of obtaining the current condition of a wreck site can be easily accomplished by the use of an underwater camera system that is towed beneath a support vessel. These systems use cameras capable of capturing sharp images in very low-light level conditions that can then be turned into high quality composite prints. This technique is often referred to as a 'photomosaic'.

Weather and water conditions permitting, a small, lightweight multi-camera system can be quickly deployed above a wreck site to capture all of the overhead images needed to complete the intended photomosaic survey. There are very few limitations encountered when using this type of system as opposed to using dive teams to accomplish the same results. The key advantage to using a towed camera system for an overhead survey is that of time and effort saved.

The Nautical Archaeology Group has designed and built its own unit and has successfully tested it during the 2007 season. It is officially called TowCam One.

Photomosaic
A photomosaic is the end result of a technique commonly used for this type of overhead imaging work. Individual frames are copied from the digital video by computer and assembled one at a time in the order required to produce a master layout of the entire site.

The photomosaic process is an involved one and can be rather time consuming to complete. However, the end results justify the means. The final composite can then be printed out to scale and measurements taken directly from the final print.

Using this type of camera system is by no means a fool-proof survey method. It does however produce excellent results in a very short period of time. The photomosaic becomes just one tool of many that can be used to complete a project.

Phase-One Wreck Sites
The Nautical Archaeology Group has selected the following 10 shipwrecks to perform a remote sensing survey on using TowCam One. The Phase One wrecks all belong to a larger group located along the west side of the southern end of Lake Michigan.

National Archives and Records Administration - Chicago
As each new wreck site survey is completed an enlarged copy print will be submitted to the National Archives and Records Administration - Great Lakes Region, for public research and permanent storage. Their facility is open to the public and located in Chicago, Illinois USA.

At the end of each new IHSP phase, a copy of the NAG project report will also be submitted to the Archives for the record.

Click here for more about TowCam One.