Laurie Bauer, NOAA/NOS/NCCOS/CCMA Biogeography Branch, 2009, St. John Shallow Water Accuracy Assessment Transects: NOAA's Ocean Service, National Centers for Coastal Ocean Science (NCCOS), Silver Spring, MD.Online Links:
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 Program, 2009, 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 1/298.257224.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
Unknown
Unknown
| Range of values | |
|---|---|
| Minimum: | 2009 February 9 |
| Maximum: | 2009 February 20 |
| Range of values | |
|---|---|
| Minimum: | 06:00:00am |
| Maximum: | 06:00:00pm |
in meters
in meters
(301) 713-3028 x171 (voice)
(301) 713-4388 (FAX)
Tim.Battista@noaa.gov
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 benthic habitat map.
NOAA, 2009, GPS data.
Process Dates: 2008-2009
Person who carried out this activity:
(301) 713 - 3028 (voice)
At the start of every morning, the boat captain selected a general region to begin the day's work. Navigating to field locations was accomplished using a Garmin GPS 76 device with the uploaded GV site coordinates. The boat captain maneuvered the vessel to within 5 m of the target location and made every effort to maintain that location without jeopardizing crew and equipment safety. Once on site, NOAA scientists would simultaneously deploy a SeaViewer Sea-Drop 950 camera and begin logging a waypoint on a Trimble GeoXT GPS receiver.While the video camera was capturing bottom imagery, an observer viewed the video real-time on a Panasonic Toughbook aboard the survey vessel. They categorized each site according to the levels of the habitat classification scheme: major and detailed geomorphological structure, major biological cover, percent major biological cover and percent coral cover. Data was entered into a custom data dictionary generated in Trimble Pathfinder Office software and loaded onto the Trimble data logger.
Person who carried out this activity:
(301) 713 - 3028 (voice)
Person who carried out this activity:
(301) 713-3028 x171 (voice)
(301) 713-4388 (FAX)
Tim.Battista@noaa.gov
Person who carried out this activity:
(301) 713 - 3028 (voice)
The points in this data layer were acquired by GPS data using a Trimble GeoXT receiver. All data point characteristics were recorded in the GPS data logger automatically 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. However, it is estimated that horizontal accuracies may be 0 - 20m from the true position of the underwater camera assessment due to line "lay-back" during drift.
486 field positions were occupied and habitat characterizations were conducted for accuracy assessment during this work. A small subset of the accuracy assessment sites did not have transect information in this dataset, depending on the evaluation technique. Snorkel and visual inspection from distances did not allow for a GPS receiver to occupy the exact location, as a result, approximated GPS locations were used instead without the opportunity for transects with the underwater camera.
Data points 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).
All attribute information was recorded by the GPS receiver and stored directly in the raw GPS files. This automated process was assumed to be error free. 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.
301-713-3028 x171 (voice)
301-713-4384 (FAX)
tim.battista@noaa.gov
Downloadable Data
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.
Contact NOAA for distribution options (see Distributor).
301-713-3028 (voice)
301-713-4384 (FAX)