Eight complexity surfaces (mean depth, standard deviation of depth, curvature, plan curvature, profile curvature, rugosity, slope, and slope of slope) were stacked and exported to create one image with several different bands (each band representing a specific metric). This image was transformed into its first three principal components using the "Principal Components Analysis" (PCA) function in ENVI 4.6. The transformation reduced the dimensionality of the dataset by removing information that was redundant among the different bands. The resulting 2x2 meter resolution, three band PCA image only contains information that uniquely described the complexity and structure of the seafloor. Coral reef habitat types were delineated and classified from this PCA image. Acoustic imagery was acquired for the VICRNM on two separate missions onboard the NOAA ship, Nancy Foster. The first mission took place from 2/18/04 to 3/5/04. The second mission took place from 2/1/05 to 2/12/05. On both missions, seafloor depths between 14 to 55 m were mapped using a RESON SeaBat 8101 ER (240 kHz) MBES sensor. This pole-mounted system measured water depths across a 150 degree swath consisting of 101 individual 1.5 degree x 1.5 degree beams. The beams to the port and starboard of nadir (i.e., directly underneath the ship) overlapped adjacent survey lines by approximately 10 m. The vessel survey speed was between 5 and 8 kn. In 2004, the ship's location was determined by a Trimble DSM 132 DGPS system, which provided a RTCM differential data stream from the U.S. Coast Guard Continually Operating Reference Station (CORS) at Port Isabel, Puerto Rico. Gyro, heave, pitch and roll correctors were acquired using an Ixsea Octans gyrocompass. In 2005, the ship's positioning and orientation were determined by the Applanix POS/MV 320 V4, which is a GPS aided Inertial Motion Unit (IMU) providing measurements of roll, pitch and heading. The POS/MV obtained its positions from two dual frequency Trimble Zephyr GPS antennae. An auxiliary Trimble DSM 132 DGPS system provided a RTCM differential data stream from the U.S. Coast Guard CORS at Port Isabel, Puerto Rico. For both years, CTD (conductivity, temperature and depth) measurements were taken approximately every 4 hours using a Seabird Electronics SBE-19 to correct for the changing sound velocities in the water column. In 2004, raw data were logged in .xtf (extended triton format) using Triton ISIS software 6.2. In 2005, raw data were logged in .gsf (generic sensor format) using SAIC ISS 2000 software. Data from 2004 were referenced to the WGS84 UTM 20 N horizontal coordinate system, and data from 2005 were referenced to the NAD83 UTM 20 N horizontal coordinate system. Data from both projects were referenced to the Mean Lower Low Water (MLLW) vertical tidal coordinate system. The 2004 and 2005 MBES bathymetric data were both corrected for sensor offsets, latency, roll, pitch, yaw, static draft, the changing speed of sound in the water column and the influence of tides in CARIS Hips & Sips 5.3 and 5.4, respectively. The 2004 data was then binned to create a 1 x 1 m raster surface, and the 2005 data was binned to a create 2 x 2 m raster surface. After these final surfaces were created, the datum for the 2004 bathymetric surfaces was transformed from WGS84 to NAD83 using the "Project Raster" function in ArcGIS 9.1. The 2004 surface was transformed so that it would have the same datum as the 2005 surface. The 2004 bathymetric surface was then down sampled from 1 x 1 to 2 x 2 m using the "Resample" function in ArcGIS 9.1. The 2004 surface was resampled so it would have the same spatial resolution as the 2005 surface. Having the same coordinate systems and spatial resolutions, the final 2004 and 2005 bathymetry rasters were then merged using the Raster Calculator function "Merge" in ArcGIS's Spatial Analyst Extension to create a seamless bathymetry surface for the entire VICRNM area south of St. John. For a complete description of the data acquisition and processing parameters, please see the data acquisition and processing reports (DAPRs) for projects: NF-04-06-VI and NF-05-05-VI (Monaco & Rooney, 2004; Battista & Lazar, 2005).
This multibeam data was collected to support IOCM (Integrated Ocean and Coastal Mapping) initiatives as part of an ongoing NOAA scientific research mission to characterize coral reef habitats at depths down to 300 meters in the US Caribbean. The multibeam backscatter, multibeam bathymetry, and ground truth video footage collected during these missions was used to characterize sea floor features 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 seafloor mapping in the U.S. Virgin Islands.
Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: Mean lower low water Depth_Resolution: See Data Acquisition and Processing Report (DAPR) for project NF-04-06-VI and NF-05-05. Depth_Distance_Units: meters Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
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, N-SCI-1, SSMC 4, 9th Floor
Contact info is for CCMA general reception. Please ask for current Biogeography project manager for the Seafloor Characterization of the U.S. Caribbean Project
Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Center for Coastal Monitoring and Assessment (CCMA), Biogeography Branch NOAA - NMAO personnel and R/V NANCY FOSTER
While the project was conducted to meet IHO Order 1 or 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 GeoTIFF 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 GeoTIFF. Some positional shifts may have occurred between the original data points and the transformed grid.
See Data Acquisition and Processing Report (DAPR) for NF-04-06 and NF-05-05.
Original raw full resolution dataset.
Processed, cleaned, and corrected full resolution dataset. Sourced from raw XTF data.
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.
Downsampled ASCII text file containing XYZ values. XYZ = northing, easting, and depth in meters. Sourced from CARIS BASE surface.
For these two mapping projects, the Chief Scientists were NOAA/NOS/NCCOS/CCMA's Mark Monaco (2004) and Tim Battista (2005) and the Lead Hydrographers were NOAA/NOS/OCS/HSD/PHB's Sean Rooney (2004) and independent contractor Jay Lazar (2005). Data were collected aboard the NOAA ship Nancy Foster from 2/18/04 to 3/5/04 (project NF-04-06) and from 2/1/05 to 2/12/05 (project NF-05-05). For project number NF-04-06, multibeam data were 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 CORS beacon Isabel, Puerto Rico. For project NF-05-05, multibeam data were 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. For both NF-04-06-VI and NF-05-05-VI, data were 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). Process Dates: 200403, 200502,200502
SWMB data in XTF and GSF formats were converted and processed using CARIS HIPS v5.3 and v5.4 software, resulting in a CARIS HDCS format dataset with all correctors applied. Attitude and SWMB data were cleaned of fliers, and SWMB data were reviewed in subset mode by a NOAA contractor. Process_Date: 200403 - 200408, 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 (WGS84 UTM zone 20 for NF-04-06-VI and NAD83 UTM zone 20N for NF-05-05-VI). Process_Date: 200411, 200512
For project NF-04-06-VI, 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 WGS84 UTM zone 20. Next, the ArcToolbox 9 conversion tool "Feature to Raster" was used to convert the XY event into an ESRI Grid based on the depth field Z. For project NF-05-05, 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 WGS84 UTM zone 20N. Next, the ArcToolbox 9 conversion tool "Feature to Raster" was used to convert the XY event into an ESRI Grid based on the depth field Z. For NF-05-05-VI, the process was accomplished using an in-house Arc script which combined these functions and allowed bulk processing. Process_Date: 200411, 200512
The datum for the 2004 bathymetric surface was transformed from the WGS84 to NAD83 using the "Project Raster" function in ArcGIS 9.1, so that the bathymetric surfaces would have the same horizontal coordinate systems for both years. The 2004 bathymetric surface was then down sampled from 1 x 1 to 2 x 2 m using the "Resample" function in ArcGIS 9.1, so that the bathymetric surfaces would have the same spatial resolutions for both years. The final 2004 and 2005 bathymetry rasters were then merged using the Raster Calculator function "Merge" in ArcGIS's Spatial Analyst Extension to create a seamless bathymetry GeoTIFF for the entire VICRNM area.
Eight complexity surfaces (mean depth, standard deviation of depth, curvature, plan curvature, profile curvature, rugosity, slope, and slope of slope) were stacked and exported to create one image with several different bands (each band representing a specific metric). This image was transformed into its first three principal components using the "Principal Components Analysis" (PCA) function in ENVI 4.6. The transformation reduced the dimensionality of the dataset by removing information that was redundant among the different bands. This PCA image was used to delineate and classify the coral reef habitat types.
Contact info is for CCMA general reception. Please ask for current Biogeography project manager for the Seafloor Characterization of U.S. Caribbean.
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.
