Survey results of ORCA in the Gulf of Mexico

The Oceanographic Remote Controlled Automaton (ORCA) is a diesel-powered semi-submersible designed to survey water depths from 10 to 300 m. The ORCA is currently outfitted with a Simrad EM-950, a 95-kHz multibeam system. ORCA field trials were conducted with the EM-950 in February, 1995, off the coast of Pensacola, FL where bathymetry was collected over a previously surveyed National Oceanic and Atmospheric Administration (NOAA) site. The NOAA data were collected by the Whiting with the Hydrochart II, a 36-kHz multibeam system. The USNS Pathfinder also collected data at the site with a Simrad EM-121, a 12-kHz multibeam system. Data sets are compared and evaluated for noise, bias and consistency. Results are presented and interpreted in terms of standards for hydrographic surveys.