HR: 1330h
AN: OS42A-0823    [PDF]
TI: Multibeam Bathymetry and Imagery Capabilities of the Newest UNOLS Research Vessel: R/V Kilo Moana (AGOR-26)
AU: * Appelgate, B
EM: tba@hawaii.edu
AF: SOEST - University of Hawaii, 1680 East-West Road, Honolulu, HI 96822
AU: Johnson, P
EM: paul@hawaii.edu
AF: SOEST - University of Hawaii, 1680 East-West Road, Honolulu, HI 96822
AU: Taylor, B
EM: taylorb@hawaii.edu
AF: SOEST - University of Hawaii, 1680 East-West Road, Honolulu, HI 96822
AU: Rolland, D
EM: drolland@jjma.com
AF: John J. McMullen Associates, Inc, 4300 King Street, Alexandria, VA 22302
AB: The R/V Kilo Moana is the newest vessel in the UNOLS fleet, owned by the Office of Naval Research and operated by the School of Ocean \& Earth Science \& Technology at the University of Hawaii. Kilo Moana is equipped with two separate multibeam mapping systems, one for shallow water (95kHz Simrad EM1002) and one for deep water (12 kHz Simrad EM120). Here we present results from sonar acceptance tests conducted during mission trials, and show examples of bathymetry and acoustic imagery collected during the first year of the ship's operation. This information can be used both as a performance baseline for Kilo Moana's mapping systems, and as a guideline for users who are planning future mapping surveys. Kilo Moana has a SWATH (Small Water Area, Twin Hull) hull design that offers two strong advantages for multibeam mapping. For their size, SWATH vessels are more stable than monohulls. Increased stability reduces bathymetry errors due to pitch/roll/yaw, and facilitates the acquisition of high quality acoustic imagery (backscatter), because backscatter characteristics are strongly dependent on the insonification direction. The SWATH design also reduces bubble sweepdown beneath the hull. These two characteristics (stability and lack of bubble sweepdown) enable Kilo Moana to conduct mapping operations at high speeds in high sea states, and here we show examples of performance in a variety of sea conditions. Results from initial shipboard acceptance tests indicate that each of Kilo Moana's multibeam system meets or exceeds performance targets. Tests were conducted in the Michelson Test Area (water depth 4900 m) and Key West Test Area (water depth 65 m). For the shallow water EM1002, the accuracy requirement for each of the system's 101 beams is 0.30% of water depth where the error is calculated as the standard deviation of a beam divided by the water depth. For the deep water EM120, the accuracy requirement for each of the system's 191 beams is 0.20% water depth. Kilo Moana multibeam performance has also be characterized by sea state, shaft RPM, and water depth, and results from these tests are presented here as both a means for evaluating the performance of the Kilo Moana multibeams, and as a guideline to assist users in planning multibeam mapping surveys. In addition to performance data, we present a series of examples from both deep and shallow water to demonstrate the capabilities of the sonar and the types of standard data products available to users of the vessel.
UR: http://www.soest.hawaii.edu/hmrg
DE: 0994 Instruments and techniques
DE: 3094 Instruments and techniques
DE: 4294 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting