Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), National Centers for Coastal Ocean Sciences (NCCOS), Center for Coastal Monitoring and Assessment (CCMA), and Analytical Laboratories of Hawaii, 2012, Benthic Habitats of American Samoa Derived from Sonar and IKONOS Imagery, 2001-2012: NOAA's Ocean Service, National Centers for Coastal Ocean Science (NCCOS), Silver Spring, Maryland.This is part of the following larger work.
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, 2012, Shoreline to Shelf Edge Benthic Habitat Map of Tutuila, American Samoa Prepared by Visual Interpretation from Remote Sensing Imagery: NOAA's Ocean Service, National Centers for Coastal Ocean Science (NCCOS), 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 0.001024
Ordinates (y-coordinates) are specified to the nearest 0.001024
Planar coordinates are specified in meters
The horizontal datum used is D_North_American_1983_HARN.
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.
ESRI
Coordinates defining the features.
Incremental numeric field
Assigned during digitizing character field
Assigned during digitizing character field
Assigned during digitizing character field
Assigned during digitizing character field
| Range of values | |
|---|---|
| Minimum: | 10.03 |
| Maximum: | 200389160.20 |
| Units: | NA |
| Range of values | |
|---|---|
| Minimum: | 13.84 |
| Maximum: | 925134.59 |
| Units: | NA |
Matt Kendall, NOAA and Miles Anderson, Analytical Laboratories of Hawaii
301-713-3028 (voice)
301-713-4384 (FAX)
matt.kendall@noaa.gov
The National Ocean Service is digitally mapping biotic resources to support long-term monitoring programs and detect and predict change in U.S. coral reefs, and their associated habitats and biological communities.
Coyne, M.S., 2003, Classification Scheme for Benthic Habitats of the Pacific: NOAA's Ocean Service, National Centers for Coastal Ocean Science (NCCOS), Silver Spring, MD.Online Links:
Buja, Ken, 2003, Coral Reef Digitizing Extension: NOAA's Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Silver Spring, MD.Online Links:
Inc., Space Imaging , 2003, IKONOS Satellite Imagery: Space Imaging Inc., Thornton, CO.
Pacific Islands Benthic Habitat Mapping Center, 2006, Sonar imagery and derived products for Tutuila: PIBHMC, Honolulu, HI.Online Links:
Department of Marine and Wildlife Resources, American Samoa, 2010, Drop Camera Videos for Fisheries Assessment: Department of Marine and Wildlife Resources, American Samoa, Pago Pago, AS.
A first draft map was completed and features in the imagery where uncertainties existed, due to confusing or difficult to interpret signatures, were identified for ground validation. An ArcGIS point theme was generated with points positioned on the features of uncertain habitat type or along transects though gradients between habitat types. The GIS points were converted to GPS waypoints and were navigated to in the field using a Trimble GeoExplorer 3 GPS data logger.
A benthic habitat characterization was conducted at each site by drop camera, free diving, or where water depth and clarity permitted, by observation from the surface. GPS data were collected at each location and site ID, depth, habitat type, zone and the method used to make the assessment were recorded. A second draft of the map was generated incorporating these ground validation data.
The sonar and satellite based maps were edge matched primarily by clipping out any areas of overlap and retaining the sonar derived map. Polygon edges were merged where attributes matched and seams corrected for any inconsistencies.
Person who carried out this activity:
301-713-3028 (voice)
301-713-4388 (FAX)
To assess the thematic accuracy of the sonar portion of the maps, an independent field data set originally collected for a fishery assessment, was made available by scientists from the Department of Marine and Wildlife Resources in American Samoa (R. Tulafono, D. Ochavillo, M. Sabater, E. Simonsen, E. Schuster, T. Letalie). Each site consisted of GPS coordinates and several minutes of video data of the seafloor. Useable data were acquired for 77 points and compared to the attributes of the map polygons at each site to check thematic accuracy. A statistical analysis that generated a Tau statistic was preformed. The Tau statistic for the major classes exceeded 0.94 and for detailed classes exceeded 0.93. Overall thematic accuracy was established as 97.4% and 93.5% for the major and detailed structure classes respectively. A separate accuracy assessment was conducted for the shallow water-IKONOS based portion of the map that yielded similar results.
Horizontal accuracy of the benthic maps is inherited from the source imagery. For example, RMS from digitized output based on IKONOS was determined using the ESRI RMEer2 extension and shown to be <1m when conducted at 1:6000 scale.
Delineation of all habitat boundaries was conducted with the image scale at 1:6,000 for IKONOS and 1:10,000 for sonar. The minimum mapping unit (MMU) for identifying habitats or features was 1 acre.
All mapping was conducted from sonar and orthorectified IKONOS satellite imagery. IKONOS satellite imagery was corrected for atmospheric and water column effects, color balanced, pan sharpened and deglinted. During the digitizing process, image stretches and manipulating image contrast, brightness and color balance were performed in the ArcView Image Analysis Extension to enhance features in the processed imagery. Sonar imagery and derived datasets were downloaded from <http://www.soest.hawaii.edu/pibhmc/>.
Sonar based maps were edge matched to the IKONOS based maps and GIS topologic quality was established by executing ArcView extension routines that check for: overlapping polygons, multipart polygons, sliver polygons and void polygons. Additionally checks for adjacent polygons with the same habitat attributes were completed. All errors were identified 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
301-713-3028 (voice)
301-713-4384 (FAX)
matt.kendall@noaa.gov
Downloadable Data
The National Oceanic and Atmospheric Administration (NOAA) National Centers for Coastal Ocean Science (NCCOS) produced this data CD-ROM. NCCOS Biogeography Program does not guarantee the accuracy of the geographic features or attributes. Please see the metadata records for each data set for complete information on the source, limitations, and proper use.
| Data format: | Shapefile |
|---|---|
| Network links: |
<http://data.nodc.noaa.gov/coris/data/NOAA/nos/Tutuila_shore_to_shelf_edge/Tutuila_shore_to_shelf_edge.zip> |
Contact NOAA for distribution options (see Distributor). All maps of American Samoa prepared during this tenure are incorporated into this metadata summary.
301-713-3028 (voice)
301-713-4384 (FAX)
matt.kendall@noaa.gov