Preliminary hard and soft bottom seafloor substrate map derived from an supervised classification of bathymetry derived from multispectral World View-2 satellite imagery of Ni'ihau Island, Territory of Main Hawaiian Islands, USA

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Frequently anticipated questions:


What does this data set describe?

Title:
Preliminary hard and soft bottom seafloor substrate map derived from an supervised classification of bathymetry derived from multispectral World View-2 satellite imagery of Ni'ihau Island, Territory of Main Hawaiian Islands, USA
Abstract:
Preliminary hard and soft seafloor substrate map derived from a supervised classification from multispectral World View-2 satellite imagery of Ni'ihau Island, Territory of Main Hawaiian Islands, USA. The dataset was derived using multipectral World View-2 satellite data. Limited groundtruthing data are available for Ni'ihau Island and therefore we are unable to evaluate the accuracy of the supervised classification seafloor substrate map.
Supplemental_Information:
Geographic Information System (GIS) projects and National Ocean Service's (NOS) coral mapping activities. Orthographically corrected World View-2 Imagery was provided by USGS, State of Hawaii and USDA. The metadata for this World View-2 imagery is documented in the original product metadata, 10JAN02213954-M3XM-052386144080_01_P001.(<http://www.soest.hawaii.edu/pibhmc/>)
  1. How should this data set be cited?

    Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), 20130404, Preliminary hard and soft bottom seafloor substrate map derived from an supervised classification of bathymetry derived from multispectral World View-2 satellite imagery of Ni'ihau Island, Territory of Main Hawaiian Islands, USA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -160.254655
    East_Bounding_Coordinate: -155.254655
    North_Bounding_Coordinate: 22.0298068
    South_Bounding_Coordinate: 17.0298068

  3. What does it look like?

    <http://www.soest.hawaii.edu/pibhmc/MHI_images/Niihau_WV2_hs_445.jpg> (JPEG, PDF)
    Hard and Soft Seafloor Substrate

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 13-Jun-2005
    Ending_Date: 15-Mar-2013
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Raster data set. It contains the following raster data types:

      • Dimensions 14420 x 9821 x 1, type Grid Cell

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 4
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -159
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000
      False_Northing: 0

      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 2
      Ordinates (y-coordinates) are specified to the nearest 2
      Planar coordinates are specified in meters

      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.

      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: mean lower low water
      Depth_Resolution: 0.01
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview: none
    Entity_and_Attribute_Detail_Citation: none


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    PIBHMC, CRED, PIFSC, NOAA, and JIMAR

  3. To whom should users address questions about the data?

    Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS)
    NOAA IRC
    Honolulu, HI 96818
    USA

    808 725-5360 (voice)
    nmfs.pic.credinfo@noaa.gov

    Contact_Instructions: e-mail preferred


Why was the data set created?

The hard and soft seafloor map is being used to improve sampling techniques for long-term ecosystem monitoring, to guide future ground-truthing operations and to identify coral-rich and species specific environments. This is a preliminary product and the methods used to generate the map are currently being evaluated for their accuracy.


How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: 10-Mar-2013 (process 1 of 1)
    Image preporcessing steps are described in the metadata file for WV-2 derived depths and can be found at www.soest.hawaii.edu/pibhmc. The pre-processed and de-glinted image was loaded into ENVI 4.8.software. Six different types of regions of interest (ROI's) were created in ENVI 4.8. The ROI's are classified as followed: 1. shallow soft/sand 2. medium deep soft/sand 3. deep soft/sand 4. shallow hard 5. medium deep hard 6. deep hard The Image classification was performed seperately on the multi-band image using three different methods. The MahalanobisDistance Classification, which is a direction sensitive distance classifier. J.A.Richards, 1999, Remote Sensing Digital Image Analysis, Springer-Verlag, Berlin, p. 240. The Maximum Likelihood Distance, which assumes that the statistics for each class in each band are normally distributed and the Minimum Distance, which uses the mean vectors for each class and calculates the distance from ech unknowkn pixel the the mean vector for ech class. More information about the MahalanobisDistance, Maximum LiklihoodDistance and the Minimum Distance algorithm can be found in the ENVI documentation available at <http://www.exelisvis.com/ProductsServices/ENVI/ENVI.aspx>. THe results of each of the three classifications were compiled into an ENVI standard image. The outputs were exported in a geotiff format and loaded in ArcGIS 10.1. All land and NoData values were removed using the Arc10.1 toolbox "extracting by mask" tool. The outputs were the same six classes as previously when creating the ROI's. THe results were reclassified using the Arc10.1 toolbox into "hard" and "soft" classes only.

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    Data are collected for resource management and research purposes and are tested for internal consistency; however, no effort is made to compare these data to external references or to other published data.

  2. How accurate are the geographic locations?

    Horizontal positioning system: GPS (SPS) Horizontal position accuracy: 25 meters

  3. How accurate are the heights or depths?

    1 m Range resolution of sonar ~1.25 cm Raw sounding resolution: Variable Vertical accuracy of gridded product: 1% of water depth

  4. Where are the gaps in the data? What is missing?

    Complete

  5. How consistent are the relationships among the observations, including topology?

    These data are believed to be logically consistent though no tests were performed


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:
These data are not to be used for navigation purposes. Please acknowledge the NOAA Pacific Islands Fisheries Science Center (PIFSC) Coral Reef Ecosystem Division (CRED) and the Pacific Islands Benthic Habitat Mapping Center (PIBHMC), and the Joint Institute for Marine and Atmospheric Research (JIMAR) and School of Ocean and Earth Science and Technology (SOEST), University of Hawaii as the sources of this information.

  1. Who distributes the data set? (Distributor 1 of 1)

    Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS)
    NOAA IRC
    Honolulu, HI 96818
    USA

    808 725-5360 (voice)
    nmfs.pic.credinfo@noaa.gov

    Contact_Instructions: e-mail preferred
  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    These data are not to be used for navigational purposes. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 12-Mar-2014
Metadata author:
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS)
NOAA IRC
Honolulu, HI 96818
USA

808 725-5360 (voice)
nmfs.pic.credinfo@noaa.gov

Contact_Instructions: e-mail preferred
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)


Generated by mp version 2.9.13 on Tue Jul 29 10:43:40 2014