Benthic Habitats of Guam 2001-2003, Derived From IKONOS Imagery

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Frequently anticipated questions:

What does this data set describe?

Title: Benthic Habitats of Guam 2001-2003, Derived From IKONOS Imagery
Abstract:
This project is a cooperative effort between the National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. The goal of the work was to map the coral reef habitats of American Samoa, Guam and the Common Wealth of the Northern Mariana Islands by visual interpretation and manual delineation of IKONOS satellite imagery. A two tiered habitat classification system was tested and implemented in this work. It integrates geomorphologic reef structure and biological cover into a single scheme and subsets each into detail. It also includes thirteen zones. Benthic features were mapped that covered an area of 104 square kilometers of which 32.9 were unconsolidated sediment and 71.6 were coral reef and hard bottom. Of the coral reef and hard bottom class, 35.6% is colonized by greater than 10% coral cover.
  1. How might this data set be cited?
    Miles Anderson, Analytical Laboratories of Hawaii, 2004, Benthic Habitats of Guam 2001-2003, Derived From IKONOS Imagery: Analytical Laboratories of Hawaii, Kailua, Hawaii.

    Online Links:

    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, 2004, Benthic Habitats of the Mariana Archipelago Prepared by Visual Interpretation from IKONOS satellite imagery procured by NOAA: NOAA's Ocean Service, National Centers for Coastal Ocean Science (NCCOS), Silver Spring, MD.

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: 144.599648
    East_Bounding_Coordinate: 144.972700
    North_Bounding_Coordinate: 13.669406
    South_Bounding_Coordinate: 13.222290
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2001
    Ending_Date: 2003Currentness_Reference: ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • G-polygon (1068)
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 55
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: 147.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.002048
      Ordinates (y-coordinates) are specified to the nearest 0.002048
      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 1/298.257222.
  7. How does the data set describe geographic features?
    guam_draft_map
    Shapefile attribute table (Source: None)
    FID
    Internal feature number. (Source: ESRI) ESRI
    Shape
    Feature geometry. (Source: ESRI) Coordinates defining the features.
    ID
    Value copied from UNIQUID field and used to run adjacency script for QA/QC (Source: NOAA mapping QA/QC standard)
    Formal codeset
    Codeset Name:Habitat description
    Codeset Source:Habitat classification scheme for the Pacific
    UNIQUEID
    4 digit numerical value representing a unique habitat combination of structure and cover attributes (Source: Habitat digitizing extension)
    Formal codeset
    Codeset Name:Habitat description
    Codeset Source:Habitat classification scheme for the Pacific
    POLYGONID
    Incremental value generated for QA/QC adjacency test (Source: ArcView script) Incremental numeric field
    AREA
    Area of polygon (Source: ArcView script)
    Range of values
    Minimum:23.621
    Maximum:543808930.37
    Units:NA
    PERIMETER
    Perimeter of polygon (Source: ArcView script)
    Range of values
    Minimum:18.442
    Maximum:343673.659
    Units:NA
    ACRES
    Area of polygon in acres (Source: ArcView script)
    Range of values
    Minimum:.006
    Maximum:134375.187
    Units:NA
    ISLAND
    Name of Island (Source: Manually assigned string) Manually assigned character field
    M_STRUCT
    Major reef structure (Source: Habitat digitizing extension) Assigned during digitizing character field
    D_STRUCT
    Detailed structure (Source: Habitat digitizing extension) Assigned during digitizing character field
    M_COVER
    Major biological cover (Source: Habitat classification scheme) Assigned during digitizing
    P_COVER
    Percent biological cover of major cover type (Source: Habitat classification scheme) Assigned during digitizing character field
    ZONE
    Geomorphologic zone (Source: Habitat classification scheme) Assigned during digitizing character field
    COVER_TYPE
    Concatenated field of major cover and percent cover used for legend fill (Source: ArcView script) Character field

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?
  3. To whom should users address questions about the data?
    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
    Biogeography Team Leader, Mapping Manager
    1305 East West Highway
    Silver Spring, MD

    301-713-3028 (voice)
    301-713-4388 (FAX)
    tim.battista@noaa.gov

Why was the data set created?

The National Ocean Service is conducting a map production effort to digitally map biotic resources and coordinate a long-term monitoring program that can detect and predict change in U.S. coral reefs, and their associated habitats and biological communities.

How was the data set created?

  1. From what previous works were the data drawn?
    Classification Scheme for Benthic Habitats of the Pacific (source 1 of 3)
    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.

    Type_of_Source_Media: Report
    Source_Contribution:
    This document identified the zone, structure and biological cover types attributed in the data set
    Habitat Digitizer (source 2 of 3)
    Buja, Ken, 2003, Coral Reef Digitizing Extension: NOAA's Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Silver Spring, MD.

    Online Links:

    Type_of_Source_Media: computer program
    Source_Contribution:
    This ArcView extension was used to digitize and attribute benthic zones, structure and biological cover of this map.
    IKONOS imagery (source 3 of 3)
    Inc., Space Imaging, 2003, IKONOS Satellite Imagery: Space Imaging Inc., Thornton, CO.

    Other_Citation_Details:
    This imagery was obtained at a 4 m pixel resolution, corrected for water column and atmospheric effects, deglinted and Pan sharpened.
    Type_of_Source_Media: CD-ROM
    Source_Contribution: Used to identify and digitize benthic habitats for Guam.
  2. How were the data generated, processed, and modified?
    Date: 2004 (process 1 of 1)
    IKONOS images used in this habitat product were observed in 2001 through 2003. Benthic habitat maps were digitized by delineating habitat boundaries from georeferenced orthorectified IKONOS satellite imagery loaded into ArcView 3.3 GIS software with the Image Analysis and NOAA Coral Reef Habitat Digitizing extensions both activated. Digitizing was conducted using heads-up on computer screen methods with the minimum mapping unit (MMU) set to 1 acre and the image scale at 1:6,000. All IKONOS imagery was processed by NOS prior to map production. The imagery was corrected for atmospheric and water column effects, pan sharpened and deglinted. During the digitizing process, images were stretched and contrast, brightness and color balance were modified using the Arc View Image Analysis Extension to enhance features in the processed imagery. 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 future ground validation effort. An ArcView GIS 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 using Trimble Pathfinder Software 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 snorkeling, 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. Person who carried out this activity:
    Dr. Miles Anderson
    Analytical Laboratories of Hawaii, LLC
    Researcher
    1320 Aalapapa Dr.
    Kailua, HI
    USA

    (808) 262-2417 (voice)
    (808) 262-7027 (FAX)
    miles@interpac.net
  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?
    A statistically robust field data set was collected to assess the thematic accuracy of the map products. A random stratified sampling method was implemented to select field sites to conduct this test. Each site was navigated to using a Trimble Geo Explorer 3 GPS data logger, and positional data was acquired. A total of 1,113 GPS waypoints were occupied and benthic characterizations conducted for the purpose of accuracy assessment. Areas that were obscured by cloud cover or where other environmental conditions such as glint of turbidity prevented visual interpretation of the benthic habitats were assigned an attribute of "unknown". Field observations that fell in polygons designated "unknown" were not included in the statistical analysis. During this survey, 5 of the 1,113 field observations were excluded for this reason and 1,108 observations were used in the accuracy assessment. A statistical analysis that generated a Tau statistic was preformed. The Tau statistic for the major classes exceeded 0.85 and for detailed classes exceeded 0.75. Overall thematic accuracy was established as 98.7% and 92.6% for the major structure and cover classes and 87.8% and 80.9% for the detailed classes respectively for the entire Mariana Archipelago.
  2. How accurate are the geographic locations?
    RMS from digitized output was determined using the ESRI RMEer2 extension and shown to be less than 1m when conducted at 1:6000 scale.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    NOAA supplied georeferenced imagery to Analytical Laboratories of Hawaii through BAE Systems Spectral Solutions. Delineation of all habitat boundaries was conducted with the image scale at 1:6,000. This ensures that the level of detail produced by the photo interpreter is uniform throughout the project. Also, NOAA has shown from similar mapping efforts in the Caribbean and Florida Keys, that little additional information is gained from having the image at a smaller scale and the labor intensity increased significantly. The minimum mapping unit (MMU) for identifying habitats or features was 1 acre. The software utilized in this project was designed to alert the photo interpreter each time a polygon was drawn smaller than the MMU. When this occurred the photo interpreter has the choice whether to include the polygon in the data set. Only in areas where local coral reef managers expressed interest in specific map classes or in Marine Protected Areas were polygons of smaller then the MMU allowed.
  5. How consistent are the relationships among the observations, including topology?
    All mapping was conducted from orthorectified IKONOS satellite imagery provided by NOS prior to map production. 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. 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.

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: Not for navigation
  1. Who distributes the data set? (Distributor 1 of 1)
    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
    Biogeography Team Leader, Mapping Manager
    1305 East West Highway
    Silver Spring, MD

    301-713-3028 (voice)
    301-713-4388 (FAX)
    tim.battista@noaa.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    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. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA can not assume liability for and 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?
  5. Is there some other way to get the data?
    Contact NOAA for distribution options (see Distributor).

Who wrote the metadata?

Dates:
Last modified: 15-Dec-2024
Metadata author:
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
Biogeography Team Leader, Mapping Manager
1305 East West Highway
Silver Spring, MD

301-713-3028 (voice)
301-713-4388 (FAX)
tim.battista@noaa.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Generated by mp version 2.9.44 on Fri Dec 20 22:09:37 2024