We have developed a seafloor geodesy system for this environment based on an anchored spar buoy topped by high precision GPS. Orientation of the buoy is measured using a digital compass (3D attitude) that provides heading, pitch and roll information. The combined orientation and GPS tracking data are use to recover the three-dimensional position of the seafloor marker (anchor). A test system has been deployed in Tampa Bay, Florida, for nearly one year, and has weathered several major storms without incident. Even in the presence of strong tidal currents which can deflect the buoy several meters from vertical, daily repeatability in the corrected three component position estimates is 1-2 cm or better.
System Design