This dataset contains a unified ESRI Grid with 2 meter cell size representing the bathymetry of selected portions of seafloor around St. Croix, St. Thomas, and St. John in the US Virgin Islands, derived from data collected in 2005. NOAA's NOS/NCCOS/CCMA Biogeography Team, in collaboration with NOAA vessel Nancy Foster and territory, federal, and private sector partners, acquired multibeam bathymetry data in the US Virgin Islands from 2/1/05 to 2/12/05. 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 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 swath angle. An ASCII XYZ file was exported from the BASE surface and opened in ESRI ArcMap 9 as an XY event. Then the ArcToolbox conversion tool 'Feature to Raster' was used to generate the final ESRI Grid. 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.
This multibeam data was collected as IOCM (Integrated Ocean and Coastal Mapping) project NF-05-05 during the second year of an ongoing NOAA scientific research mission in the US Caribbean to characterize nearshore coral reef habitats at depths down to 300 meters. The mission purpose is to better understand the resources within the surveyed reef habitats, and ultimately develop species utilization models linking physical habitats with biological information. The multibeam backscatter, multibeam bathymetry, and ground truth video footage collected during the 2005 mission will be used internally to characterize sea floor topography and to create benthic habitat maps, helping NOAA meet its mapping commitment to the US Coral Reef Task Force. The resulting publicly-distributed data is also a contribution to the greater scientific community interested in the USVI seafloor.
ground condition
Note: NOT TO BE USED FOR NAVIGATION. These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.
1305 East West Highway, SSMC4
Contact info is for CCMA general reception. Please ask for current Biogeography project manager for USVI.
Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Center for Coastal Monitoring and Assessment (CCMA), Biogeography Program NOAA - NMAO personnel and R/V NANCY FOSTER
While the project was conducted to meet IHO Order 1 and 2 accuracy standards, dependant on project area and depth, all users should independently analyze the dataset according to their own needs and standards to determine data usability.
This ESRI Grid is sourced from a gridded dataset. The original full-resolution multibeam data was used to create a downsampled uniform-resolution CARIS BASE (Bathymetry Associated with Statistical Error) surface grid with a best depth component. The downsampled grid nodes from that depth surface were then exported and used to generate the ESRI Grid. Some positional shifts may have occurred between the original data points and the transformed grid.
See Data Acquisition and Processing Report (DAPR) for NF-05-05.
Original raw full resolution dataset.
Processed, cleaned, and corrected full resolution dataset. Sourced from raw GSF data.
Downsampled CARIS BASE (Bathymetry Associated with Statistical Error) grid with best depth layer. Sourced from processed HDCS data.
Downsampled ASCII text file containing XYZ values. XYZ = northing, easting, and depth in meters. Sourced from CARIS BASE surface.
For this project, the Chief Scientist was NOAA/NOS/NCCOS/CCMA's Tim Battista and the Lead Hydrographer was independent contractor Jay Lazar. Data was collected aboard the NOAA ship Nancy Foster from 2/1/05 to 2/12/05, as project number NF-05-05-VI. Multibeam data was acquired in GSF format with a pole-mounted Reson 8101 ER multibeam echosounder (240 kHz), with options 033, 037, and 040. Reson backscatter snippet collection was enabled. SAIC ISS 2000 software was used to interface with the Reson system. Line spacing for acquisition was three times the water depth, and data was retained out to 60 or 70 degrees from nadir, depending on project area. Heave, roll, pitch and heading correctors were collected using an Applanix POS/MV Model 320 inertial measurement unit (IMU) and associated Trimble GPS antennas. Sound velocity profiles were acquired with a Seabird Electronics SeaCat SBE19P CTD profiler and processed using Seabird Seaterm software, then applied directly to the raw GSF data. Positioning was obtained using Northstar 941X GPS receivers with differential correctors from U.S. Coast Guard CORS beacon Isabel, Puerto Rico. 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).
Raw SWMB data in GSF (generic sensor format) format were converted and processed using CARIS HIPS v5.4 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. Process Date Range: 200502 - 200511
After being submitted to CCMA by the contractor, CARIS HIPS v5.4 was used to generate a CARIS BASE surface (similar to a DTM), based on weighted swath angle, from the processed HDCS data. Then CARIS export tool "BASE Surface to ASCII" was used to export a comma delimited ASCII XYZ file, with Easting, Northing, and Depth values, using ground position units (NAD83 UTM zone 20N).
The ASCII XYZ file was opened in ArcMap 9 and the 'Display XY Data' option was used to add the XY data as an event with spatial reference NAD83 UTM zone 20N. Finally, the ArcToolbox 9 conversion tool "Feature to Raster" was then used to convert the XY event into an ESRI Grid, based on the depth field Z. These steps were accomplished using an inhouse Arc script which combined these functions and allowed bulk processing.
Metadata imported.
These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials.
