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    • Satellite-derived bathymetry for nearshore benthic habitats in Timor-Leste

    Metadata Updated: October 19, 2024

    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.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date October 3, 2024
    Metadata Created Date October 19, 2024
    Metadata Updated Date October 19, 2024
    Reference Date(s) 2017 (publication)
    Frequency Of Update notPlanned

    Metadata Source

    Harvested from NMFS PIFSC

    Other Data Resources

    Graphic Preview

    An example of the bathymetry data generated for Timor-Leste from WorldView-2 satellite imagery.

    Additional Metadata

    Resource Type Dataset
    Metadata Date October 3, 2024
    Metadata Created Date October 19, 2024
    Metadata Updated Date October 19, 2024
    Reference Date(s) 2017 (publication)
    Responsible Party (Point of Contact, Custodian)
    Contact Email
    Guid gov.noaa.nmfs.inport:46150
    Access Constraints Cite As: Pacific Islands Fisheries Science Center, [Date of Access]: Satellite-derived bathymetry for nearshore benthic habitats in Timor-Leste [Data Date Range], https://www.fisheries.noaa.gov/inport/item/46150., Access Constraints: None, Use Constraints: Please cite NOAA Coral Reef Ecosystem Program (CREP) when using the data. Example Coral Reef Ecosystem Program; Pacific Islands Fisheries Science Center (2017). Satellite-derived bathymetry for nearshore benthic habitats in Timor-Leste. NOAA's National Centers for Environmental Information. Dataset. https://www.fisheries.noaa.gov/inport/item/46150, Distribution Liability: While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
    Bbox East Long 127.4
    Bbox North Lat -8.1
    Bbox South Lat -9.4
    Bbox West Long 124
    Coupled Resource
    Frequency Of Update notPlanned
    Graphic Preview Description An example of the bathymetry data generated for Timor-Leste from WorldView-2 satellite imagery.
    Graphic Preview File https://www.coris.noaa.gov/activities/projects/timor-leste/images/bathymetry.jpg
    Graphic Preview Type JPG
    Harvest Object Id fc5d9af1-b1ef-4dc8-b193-7bfa5bc44e8a
    Harvest Source Id c0beac72-5f43-4455-8c33-1b345fbc2dfe
    Harvest Source Title NMFS PIFSC
    Licence NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose.
    Lineage Bathymetry data were derived for nearshore waters along the northern coastline of Timor-Leste, and the coastlines of Oecusse district and Atauro Island, from WorldView-2 satellite imagery following methods developed by Ehses and Rooney (2015).
    Metadata Language eng
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[124.0, -9.4], [127.4, -9.4], [127.4, -8.1], [124.0, -8.1], [124.0, -9.4]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 2010-02-09
    Temporal Extent End 2013-10-02

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