Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Center for Coastal Monitoring and Assessment (CCMA), Biogeography Branch, 2009, Accuracy Assessment Sites (Mean Location) - Moderate-Depth Benthic Habitats of St. John, U.S. Virgin Islands (2009): NOAA's Ocean Service, National Centers for Coastal Ocean Science (NCCOS), Silver Spring, MD.
Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Monitoring and Assessment (CCMA), Biogeography Branch, 2009, Moderate-Depth Benthic Habitats of St. John, U.S. Virgin Islands: NOAA National Centers for Coastal Ocean Science, Silver Spring, MD.
This is a Vector data set. It contains the following vector data types (SDTS terminology):
Planar coordinates are encoded using Coordinate Pair
Abscissae (x-coordinates) are specified to the nearest 0.000001
Ordinates (y-coordinates) are specified to the nearest 0.000001
Planar coordinates are specified in meters
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
|Codeset Name:||Arbitrarily defined unique code|
|Codeset Source:||Specific to this field mission|
301-713-3028 x146 (voice)
The purpose of this survey data was to collect information on current habitat conditions at random locations throughout the mapping area. Locations were determined by an iterative, GIS-based, stratified random sampling technique to ensure that all bottom classifications would be assessed. This information was used to evaluate the thematic accuracy of the St. John moderate-depth benthic habitat map.
NOAA, 2009, GPS data.
The points in this thematic data layer were acquired by GPS data using a Trimble GeoXT receiver with a customized data dictionary designed to reflect the habitat classification scheme described in "Moderate-Depth Benthic Habitats of St. John, U.S. Virgin Islands" (Costa et al. 2009). All habitat determinations were made in the field by trained NOAA scientists, recorded in the GPS data logger and seamlessly transferred to ArcGIS shapefiles using Trimble Pathfinder Office software. Attributes are all expected to be correct.
The true positional accuracy of individual epics was determined to be within 1 m for 96% of the logged points. For each survey site, individual epics were averaged to generate a mean GPS point for each location.
299 field positions were occupied and habitat characterizations were conducted for accuracy assessment during this work. These data were plotted in concert with remotely sensed imagery to assess the benthic habitat classifications at random locations throughoout the map. Further analysis was conducted to calculate a suite of thematic accuracy assessment metrics and is described in Costaet al. (2009).
Data points with accompanying attribute information were collected with mapping-grade GPS receivers. The data were post processed for differential correction to the Continually Operating Reference System (CORS) station at St. Thomas, U.S. Virgin Islands (VITH). Site information was recorded in the field both in a data dictionary within the GPS receiver and on waterproof field sheets. A comparison between soft and hard copy data records were completed to ensure attribute collection consistency.
Furthermore, underwater video was recorded at each site to maintain a record of habitat condition. This video was reviewed by NOAA staff in the office to ensure correct habitat attribution was made in the field.
All errors were identified through these quality assurance techniques and corrected. This file is believed to be logically consistent.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints: Not for navigation.
The National Oceanic and Atmospheric Administration (NOAA) National Centers for Coastal Ocean Science (NCCOS) is publishing this data on their website. NCCOS Biogeography Branch does not guarantee the accuracy of the geographic features or attributes. Please see the written report and metadata records for each data set for complete information on the source, limitations, and proper use.
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