Shrnutí

Popis

This georeferenced RGB image represents 1 meter resolution bathymetry of a sharply sloping swath of the St. John Shelf, a selected portion of seafloor south of St. John, USVI, derived from data collected in March and April 2010. This image is also vertically exaggerated by a factor of 1, and sun illuminated where the azimuth = 45 degrees and angle = 40 degrees. NOAA's NOS/NCCOS/CCMA Biogeography Branch, in collaboration with NOAA vessel Nancy Foster and territory, federal, and private sector partners, acquired multibeam bathymetry data south of St. Thomas and St. John, USVI, from 3/18/10 to 4/6/09. Data was acquired with a hull-mounted Kongsberg Simrad EM 1002 multibeam echosounder (95 kHz) for water depths greater than 75 meters, and with a moon pool flange-mounted Reson 7125 multibeam echosounder (dual frequecy, 200/400 kHz) for water depths of up to 75 meters. It was processed by a NOAA contractor using CARIS HIPS software. Data has all correctors applied (attitude, sound velocity) and has been reduced to mean lower low water (MLLW) using final approved tides and zoning from NOAA COOPS. Data is in UTM zone 20 north, datum NAD83. The processed CARIS data was used to generate a CARIS BASE surface based on CUBE, which was then pushed through the CARIS export tool "BASE Surface to Image" to create the final 8-bit GeoTIFF. The project was conducted to meet IHO Order 1 and 2 accuracy standards, dependant on the project area and depth. All users should individually evaluate the suitability of this data according to their own needs and standards.