Evaluation of multibeam sonar data collected by DOLPHIN

An evaluation of the performance of the Deep Ocean Logging Platform with Hydrographic Instrumentation and Navigation (DOLPHIN) Remotely Operated Vehicle (ROV) as a platform for collection of multibeam sonar data to produce bathymetry is presented. The DOLPHIN, equipped with an EM-100 echo sounder and NOAA´s ship WHITING, carrying a Hydrochart II sonar, surveyed the Norfolk Canyon, Virginia, from August 5 through August 7, 1992; the USNS LITTLEHALES conducted its survey of the same area from August 23 through 25, 1992 with a hull-mounted EM-100. The quality of the multibeam data collected by DOLPHIN is evaluated in terms of the rms noise in each beam, the presence of spurious noise and the frequency of dropouts suffered, and is compared to data from the ships. The frequency, amplitude and distribution of heave, roll and pitch are also investigated. Results indicate the DOLPHIN is a stable survey platform for multibeam data collection which introduces negligible noise to the system, and has very infrequent dropouts. Gridded bathymetry from the three platforms are compared and show good agreement, with the bathymetry produced by the ROV and its mother ship having the least rms difference