Data Management Plan

This image represents a 0.5 meter resolution backscatter mosaic of the southern shore of St. John, US Virgin Islands.NOAA's NOS/NCCOS/CCMA Biogeography Team and NOAA/NOS/OCS/HSD personnel, in collaboration with NOAA vessel Nancy Foster and territory, federal, and private sector partners, acquired multibeam bathymetry data in the US Virgin Islands from 2/18/04 to 3/5/04. Data was acquired with a pole-mounted Reson 8101 ER multibeam echosounder (240 kHz) and processed by a NOAA contractor using CARIS HIPS v5.4 software. Data has all correctors applied (attitude, sound velocity) and has been reduced to mean lower low water (MLLW) using final approved tides from NOAA COOPS. Data is in UTM zone 20 north, datum WGS84. The backscatter component of the bathymetry data were geometrically and radiometrically corrected using Geocoder 2.7 software.While the project was conducted to meet IHO Order 2 accuracy standards, there is a roll artifact (averaging 0.5m high) in the dataset that the user should take into consideration when performing any analysis.

Process Steps:

• 2004-01-01 00:00:00 - For this project, the Chief Scientist was NOAA/NOS/NCCOS/CCMA's Dr. Mark Monaco and the Lead Hydrographer was NOAA/NOS/OCS/HSD/PHB's Physical Scientist Sean Rooney. Data was collected aboard the NOAA ship Nancy Foster from 2/18/04 to 3/5/04, as project number NF-04-06-VI. Multibeam data was acquired in XTF format with a pole-mounted Reson 8101 ER multibeam echosounder (240 kHz), with options 033 and 040. Triton-Elics ISIS 6.20 software was used to interface with the Reson system. Line spacing for acquisition was typically three times the water depth, giving 100% bottom coverage, and data was retained out to 70 degrees from nadir. Heave, roll, pitch and heading correctors were collected using an Ixsea Octans gyrocompass and integrated motion sensor. Sound velocity profiles were acquired with a Seabird Electronics SeaCat SBE19 CTD profiler and processed using Velociwin 8.40 (NOS HSTP product), then concatenated. Positioning was obtained using a Trimble DSM212L GPS receiver with differential correctors from U.S. Coast Guard beacon Isabel, PR. Data was reduced to Mean Lower-Low Water (MLLW) using final approved tides from NOAA COOPS, based on National Water Level Observation Network (NWLON) primary tide stations at Charlotte Amalie, VI (9751639) and Lime Tree Bay, VI (9751401). (Citation: NF-04-06 Raw Multibeam Data)
• 2004-01-01 00:00:00 - SWMB data in GSF format were converted and processed using CARIS HIPS v5.3 and 5.4 software, resulting in a CARIS HDCS format dataset with all correctors applied. Attitude and SWMB data was cleaned of fliers, and SWMB data was reviewed in subset mode by a NOAA contractor. (Citation: NF-05-05 HDCS Processed Multibeam Data)
• 2006-01-01 00:00:00 - Acoustic backscatter mosaics are an important piece of information when characterizing surficial seafloor features and delineating benthic habitats. The multibeam backscatter data were corrected for geometric and radiometric distortions using Geocoder 2.7. In particular, the following corrections were applied when artifacts were evident: AVG Trend, TX Power and RX Gain, Area Correction, Spreading, Slant-Range and Extracted Beam Pattern. As no theoretical beam pattern for the Reson 8101 system exists, it was extracted from a mapped area that was flat and had a relatively uniform (sandy) substrate. Individual lines were also truncated based on ping number and/or angle of incidence where appropriate. The final mosaics were exported as geotiffs in WGS 1984 UTM Zone 20N. (Citation: saintJohn_0.5m_backscatter.tif)

Click on link from project page to NCEI archive and download zip file.; Click on link from project page to NCEI archive and download zip file.;