Satellite-derived bathymetry for nearshore benthic habitats in Timor-Leste
Bathymetric data derived from multispectral, high-resolution (2 m) satellite imagery from DigitalGlobe’s WorldView-2 satellite to provide near complete coverage of nearshore terrain along the northern coastline of Timor-Leste, including the district of Oecusse to the west of mainland Timor-Leste and Atauro Island. Satellite images acquired by the NOAA Coral Reef Ecosystem Program (CREP) for the region are from Feb 9, 2010 to October 2, 2013. Methods used by CREP to estimate depths from the WorldView imagery were adapted from instructions developed by Kyle Hogrefe for using IKONOS imagery to derive seafloor elevations in optically clear water (Ehses and Rooney 2015).
Bathymetry values shallower than ~20 m were derived by gauging the relative attenuation of coastal, blue, green and yellow spectral radiance as a function of depth. A multiple linear regression analysis of coastal, blue, green and yellow band spectral values against in-situ depth determined the variables of y-intercept, coastal, blue, green and yellow slope values. The variables for each band were then used in a multivariate slope intercept equation to derive depth over the imagery. Variables and combinations of the bands were adjusted to improve the statistical accuracy and spatial coverage of the final derived bathymetry product. Digital image processing to derive depths was conducted with ENVI, and editing and integration was performed using Esri's ArcGIS.
The method assumes uniform water clarity but deviations from that condition made extraction difficult in water depths greater than 20 m. Results show that biotic material, or sediment in the water column skewed results shallower if the material has a high albedo and deeper if the material has a low albedo.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | non-public |
| contactPoint |
{
"fn": "DesRochers, Annette M",
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"hasEmail": "mailto:annette.desrochers@noaa.gov"
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|
| describedByType | application/octet-steam |
| description | Bathymetric data derived from multispectral, high-resolution (2 m) satellite imagery from DigitalGlobe’s WorldView-2 satellite to provide near complete coverage of nearshore terrain along the northern coastline of Timor-Leste, including the district of Oecusse to the west of mainland Timor-Leste and Atauro Island. Satellite images acquired by the NOAA Coral Reef Ecosystem Program (CREP) for the region are from Feb 9, 2010 to October 2, 2013. Methods used by CREP to estimate depths from the WorldView imagery were adapted from instructions developed by Kyle Hogrefe for using IKONOS imagery to derive seafloor elevations in optically clear water (Ehses and Rooney 2015). Bathymetry values shallower than ~20 m were derived by gauging the relative attenuation of coastal, blue, green and yellow spectral radiance as a function of depth. A multiple linear regression analysis of coastal, blue, green and yellow band spectral values against in-situ depth determined the variables of y-intercept, coastal, blue, green and yellow slope values. The variables for each band were then used in a multivariate slope intercept equation to derive depth over the imagery. Variables and combinations of the bands were adjusted to improve the statistical accuracy and spatial coverage of the final derived bathymetry product. Digital image processing to derive depths was conducted with ENVI, and editing and integration was performed using Esri's ArcGIS. The method assumes uniform water clarity but deviations from that condition made extraction difficult in water depths greater than 20 m. Results show that biotic material, or sediment in the water column skewed results shallower if the material has a high albedo and deeper if the material has a low albedo. |
| distribution |
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"description": "GeoTiff raster bathymetry data for nearshore waters of Timor Leste, derived from WorldView-2 satellite imagery. The bathymetry data are organized by region (north shore, Atauro Island, and Oecusse), and each region contains 1) the individual final bathymetry files (one geoTiff for each satellite image), 2) a projected (UTM_Zone_51S) bathymetry mosaic for the region, and 3) an unprojected (WGS84) mosaic for the region. The mosaics are also in geoTiff format. An ESRI layer file is included within each region's subfolder for ease of displaying the geoTiffs in ESRI's ArcGIS software. The symbology is based on the VALUE field.",
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|
| identifier | gov.noaa.nmfs.inport:46150 |
| issued | 2017-01-01T00:00:00.000+00:00 |
| keyword |
[
"Geographic Information > Bathymetry",
"EARTH SCIENCE > Biosphere > Aquatic Habitat > Benthic Habitat",
"EARTH SCIENCE > Biosphere > Aquatic Habitat > Coastal Habitat",
"EARTH SCIENCE > Biosphere > Aquatic Habitat > Reef Habitat",
"EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > GIS",
"EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Mapping",
"EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Mapping > Base map",
"EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Remote Sensing",
"EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Remote Sensing > Satellite (digital scans) > WorldView-2",
"EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Bathymetry",
"EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Water Depth",
"EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs",
"BATHYMETRY",
"water depth",
"GIS product",
"derived products",
"CORAL REEF STUDIES",
"Coral Triangle Initiative",
"US DOC; NOAA; NMFS; Pacific Islands Fisheries Science Center; Ecosystem Sciences Division; Coral Reef Ecosystem Program",
"COUNTRY/TERRITORY > Democratic Republic of Timor-Leste (East Timor) (09S126E0001)",
"OCEAN BASIN > Indian Ocean > Timor Sea > Democratic Republic of Timor-Leste (East Timor) (09S126E0001)",
"Indian Ocean",
"Timor Sea",
"SEA FLOOR",
"CRED",
"CREP",
"Coral Reef Ecosystem Division",
"Coral Reef Ecosystem Program",
"PIFSC",
"Pacific Islands Fisheries Science Center",
"Pseudobathymetry",
"USAID",
"United States Agency for International Development",
"derived depths",
"estimated depths",
"seafloor elevation",
"Atauro",
"Baucau",
"Bobonaro",
"Dili",
"Jaco",
"Lautem",
"Liquica",
"Manatuto",
"Oecusse",
"Timor",
"Timor-leste",
"Vila MPA",
"DOC/NOAA/NMFS/PIFSC > Pacific Islands Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Department of Commerce",
"Timor Leste"
]
|
| landingPage | https://www.fisheries.noaa.gov/inport/item/46150 |
| language |
[]
|
| license | https://creativecommons.org/publicdomain/zero/1.0/ |
| modified | 2017-01-01T00:00:00.000+00:00 |
| publisher |
{
"name": "Pacific Islands Fisheries Science Center",
"@type": "org:Organization"
}
|
| references |
[
"https://www.fisheries.noaa.gov/inportserve/waf/noaa/nmfs/pifsc/dmp/pdf/46150.pdf"
]
|
| rights | otherRestrictions, unclassified |
| spatial | 127.4,-9.4,124.0,-8.1 |
| temporal | 2010-02-09T00:00:00+00:00/2013-10-02T00:00:00+00:00 |
| title | Satellite-derived bathymetry for nearshore benthic habitats in Timor-Leste |
