Identification_Information:
  Citation:
    Citation_Information:
      Originator: Gaia Geo-Analytical in collaboration with
        Davey Jones Locker GIS Laboratory, Oregon State Universtiy for 
        Coral Reef Ecosystem Division, NOAA Pacific Islands Fisheries 
        Science Center, Pacific Islands Benthic Habitat Mapping Center
      Publication_Date: 20090818
      Title: Mosaic of gridded multibeam bathymetry and bathymetry derived from 
        multispectral IKONOS satellite imagery of Alamagan Island, Commonwealth of
        Northern Mariana Islands, USA
      Geospatial_Data_Presentation_Form: raster digital data
      Online_Linkage: http://www.soest.hawaii.edu/pibhmc/
      Online_Linkage: http://soest.hawaii.edu/pibhmc/pibhmc_cnmi_ala_bathy.htm
  Description:
    Abstract: Gridded multibeam bathymetry is integrated with bathymetry derived
      from multispectral IKONOS satellite data. Gridded (5 m cell size) multibeam
      bathymetry collected aboard NOAA Ship Hiialaka'i and R/V AHI. Bathymetry values
      shallower than 25 m were derived by gauging the reletive attenuation of blue and
      green spectral radiance as a function of depth. A multiple linear regression
      analysis of linearized blue and green band spectral values against depth
      determined the variables of y-intercept, blue slope and green slope values. 
      Variables then used in multivariate slope intercept formula to derive 
      depth. Variables were adjusted to improve the statistical accuracy and 
      spatial coverage of the final derived bathymetry product. Digital image 
      processing to derive depths conducted with the ENVI 4.5 software program 
      while data editing and integration was performed using ArcGIS 9.3.  This 
      dataset is for the shelf environment of Alamagan Island, Commonwealth of
      Northern Mariana Islands, USA.
    Purpose:
      The data were derived in support of NOAA Coral Reef Conservation 
      Program goals. Goal 1 is to map all U.S. Coral Reef Ecosystems.  
      This data set specifically addresses Objective 1 and 4: to develop 
      high-resolution benthic maps and to characterize priority deep 
      water reefs and associated habitats.  This integration of derived 
      bathymetry with multibeam sonar data provides a GIS layer with 
      expanded spatial coverage that may be used for benthic and essential 
      fish habitat characterization, and for the study of geologic features. 
      By combining the dataset with other bathymetry, backscatter, derivatives, 
      and in situ data, they collectively compose benthic habitat maps 
      designed to be used to understand and predict shallow depth (0m to 150m) 
      benthic habitats for organisms that inhabit coral reef ecosystems.
    Supplemental_Information:
      Gridded multibeam data were collected aboard the Hi'ialakai, a 218’ 
      United States National Oceanographic and Atmospheric Administration 
      (NOAA) research ship, and aboard the R/V AHI (Acoustic Habitat 
      Investigator), a 25’ survey launch owned and operated by the NOAA 
      Pacific Islands Fisheries Science Center in Honolulu, HI.  The 
      metadata for the bathymetry is documented in the product metadata, 
      alamagan_10m.txt
      http://www.soest.hawaii.edu/pibhmc/pibhmc_cnmi_ala.htm
      Original IKONOS imagery was purchased to support the Pacific Islands
      Geographic Information System (GIS) project and National Ocean Service's 
      (NOS) coral mapping activities. Orthographically corrected IKONOS Imagery 
      was provided by NOAA's National Centers for Coastal Ocean Science, Center 
      for Coastal Monitoring and Assessment. The metadata for this IKONOS 
      imagery is documented in the original product metadata, po_107146_metadata.txt
      and po_135475_metadata.txt.  http://www.soest.hawaii.edu/pibhmc/   

  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 20030331
        Ending_Date: 20070608
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: As needed
  Spatial_Domain: 
    Bounding_Coordinates:
      West_Bounding_Coordinate: 145.802157
      East_Bounding_Coordinate: 145.859205
      North_Bounding_Coordinate: 17.624929
      South_Bounding_Coordinate: 17.567343
  Keywords: 
    Theme: 
      Theme_Keyword_Thesaurus: CoRIS Theme Keyword Thesaurus 200806
      Theme_Keyword: EARTH SCIENCE > Oceans > Bathymetry/Seafloor 
         Topography > Bathymetry
    Theme: 
      Theme_Keyword_Thesaurus: CoRIS Theme Keyword Thesaurus 200806
      Theme_Keyword: EARTH SCIENCE > Oceans > Bathymetry/Seafloor 
         Topography > Water Depth
    Theme: 
      Theme_Keyword_Thesaurus: CoRIS Theme Keyword Thesaurus 200806
      Theme_Keyword: EARTH SCIENCE > Biosphere > Zoology > Corals > 
         Reef Monitoring and Assessment > Remote Sensing > Satellite 
         (digital scans) > IKONOS
    Theme:
      Theme_Keyword_Thesaurus: None
      Theme_Keyword: Slope
      Theme_Keyword: Bathymetry
      Theme_Keyword: Multibeam sonar
    Place:
      Place_Keyword_Thesaurus: None
      Place_Keyword: Alamagan Island
      Place_Keyword: Commonwealth of Northern Mariana Islands
      Place_Keyword: United States of America
    Place: 
      Place_Keyword_Thesaurus: CoRIS Place Keywords by Ocean - Pacific Ocean
        April 2007 (without Great Barrier Reef)
      Place_Keyword: OCEAN BASIN > Pacific Ocean > Western Pacific Ocean >
        Alamagan Island > Alamagan Island (17N145E0002)
    Place: 
      Place_Keyword_Thesaurus: CoRIS Place Keywords by Country/Territory - 
        Pacific Ocean November 2007 (without Great Barrier Reef)
      Place_Keyword: COUNTRY/TERRITORY > Northern Mariana Islands > Alamagan Island 
        > Alamagan Island (17N145E0002)
      Place_Keyword: COUNTRY/TERRITORY > United States of America > Hawaii > 
        Honolulu (28N165W0001)
  Access_Constraints: None
  Use_Constraints: These data are not to be used for navigation 
      purposes. Please acknowledge NOAA Pacific Islands Fisheries 
      Science Center, the Joint Institute for Marine and 
      Atmospheric Research (JIMAR) University of Hawaii and Davey 
      Jones Locker GIS Laboratory Oregon State University as the 
      sources of this information.
  Point_of_Contact: 
    Contact_Information: 
      Contact_Organization_Primary: 
        Contact_Organization: Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), 
          Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS)
      Contact_Address: 
        Address_Type: mailing and physical
        Address: 1680 East-West Road POST 833
        City: Honolulu
        State_or_Province: HI
        Postal_Code: 96822
        Country: USA
      Contact_Voice_Telephone: 808-956-5239
      Contact_Electronic_Mail_Address: pibhmc@soest.hawaii.edu
      Contact_Instructions: e-mail preferred
  Browse_Graphic:
    Browse_Graphic_File_Name: ftp://ftp.soest.hawaii.edu/pibhmc/website/data/cnmi-guam/bathymetry/ala_bathymetry_mb&IKONOS_5m.pdf
    Browse_Graphic_File_Description: Gridded Bathymetry
    Browse_Graphic_File_Type: PDF
  Data_Set_Credit: NOAA PIFSC CRED, the Pacific Islands Benthic Habitat 
    Mapping Center and Davey Jones Locker GIS Laboratory 
    Oregon State University
  Native_Data_Set_Environment: ArcGIS ASCII file or ArcGIS Grid file, 
    bathymetry derived from 4x4m multispectral satellite imagery (IKONOS)
    using ENVI 4.5, multibeam and derived bathymetry were integrated using
    ArcGIS 9.3
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: 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.  
  Logical_Consistency_Report: These data are believed to be logically 
        consistent though no tests were performed
  Completeness_Report: Complete
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:
        Horizontal positioning system: GPS C/A
        Horizontal position accuracy: 25 meters
    Vertical_Positional_Accuracy:
      Vertical_Positional_Accuracy_Report: 
        Range resolution of sonar: varies with depth
        Raw sounding resolution: varies with depth
        Vertical accuracy of gridded sonar product: ~ 1% of water depth
        Vertical accuracy of derived bathymetry product: 5 meter range 
  Lineage:
    Process_Step:
      Process_Date: 20090814
      Process_Description:
        Multiple tools in ENVI 4.5 were used to complete the following
        processing steps: Data conversion from digital number to radiance,
        correction for atmosphere and water surface reflection, 
        linearization of spectral decay as function of depth, masking of 
        non-applicable values, and bathymetric derivation using variables
        from multiple linear regression analysis.  Multiple tools in 
        ArcGIS 9.3 were used for dataset integration and to extract values 
        for the multiple linear regression analysis and subsequent error 
        analyses.  The statisitcs program S-Plus was used for the multiple
        linear regression analysis to provide original variables for depth
        derivation.  The multivariate slope intercept formula used to 
        derive depth was Depth=Yint+(Mblue)(Xblue)+(Mgreen)(Xgreen). Eight derived
        products, four from the image alamagan_107146_msi_rat.pix (Ala146) and four from
        the image alamagan_135475_msi_rat.pix (Ala475), were integrated to expand spatial
        coverage.
        The original MLR variables for Ala146 were Yint=15.1542, Mblue=-10.3798, and
        Mgreen=24.3859. The product derived from these variables (Ala146_DB) was mosaiced
        with three additional products derived using increasingly reduced Y-intercept values
        as follows: Yint=11.1542 (Ala146_DB4), Yint=7.1542 (Ala146_DB8), Yint=3.1542
        (Ala146_DB12). This was done to increase coverage in shallow areas. More information
        on this integration process is provided in the product error analysis, availble from
        PIBHMC upon request.
        The original MLR variables for Ala475 were Yint=12.0276, Mblue=-6.3664, and
        Mgreen=16.1327. The product derived from these variables (Ala475_DB) was mosaiced
        with three additional products derived using increasingly reduced Y-intercept values
        as follows: Yint=8.0276 (Ala475_DB4), Yint=4.0276 (Ala475_DB8), Yint=0.0276
        (Ala475_DB12). This was done to increase coverage in shallow areas. More information
        on this integration process is provided in the product error analysis, availble from
        PIBHMC upon request.
        The derived bathymetry from each image was in turn mosaiced prioritizing the data from
        Ala146 over Ala475.  Data with better statistical accuracy was given higher "priority"
        so that they replaced concurrent data with lower accuracy during the mosaic process.
        This mosaiced derived bathymetry product (Ala_DBall) was then resampled to a 5 meter
        grid and integrated with 5m resolution multibeam sonar data, with sonar data prioritized
        over the derived data, to create the final product (Ala_DBMB_5m). 
        A detailed description of all processing steps is available at: 
        http://dusk.geo.orst.edu/djl/theses/kyle/Cookbook_042108.pdf
        An error analysis of each derived bathymetry grid used is available upon request.
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Raster
  Raster_Object_Information:
    Raster_Object_Type: Grid Cell
    Row_Count: 1267
    Column_Count: 1203
    Vertical_Count: 1
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: row and column
        Coordinate_Representation:
          Abscissa_Resolution: 5.000000
          Ordinate_Resolution: 5.000000
        Planar_Distance_Units: meters
      Grid_Coordinate_System:
        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
    Geodetic_Model:
      Horizontal_Datum_Name: D_WGS_1984
      Ellipsoid_Name: WGS_1984
      Semi-major_Axis: 6378137.000000
      Denominator_of_Flattening_Ratio: 298.257224

Distribution_Information:
  Distributor:
    Contact_Information: 
      Contact_Organization_Primary: 
        Contact_Organization: Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), 
          Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS)
      Contact_Address: 
        Address_Type: mailing and physical
        Address: 1680 East-West Road POST 833
        City: Honolulu
        State_or_Province: HI
        Postal_Code: 96822
        Country: USA
      Contact_Voice_Telephone: 808-956-5239
      Contact_Electronic_Mail_Address: pibhmc@soest.hawaii.edu
      Contact_Instructions: e-mail preferred
  Resource_Description: Downloadable Data
  Distribution_Liability:
    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.
  Standard_Order_Process:
    Digital_Form: 
      Digital_Transfer_Information:
        Format_Name: Arc Grid
        Format_Information_Content: Arc Grid can be opened directly using 
              ArcMap or ArcCatalog.
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: http://www.soest.hawaii.edu/pibhmc
    Fees: None
Metadata_Reference_Information:
  Metadata_Date: 20090818
  Metadata_Contact:
    Contact_Information: 
      Contact_Organization_Primary: 
        Contact_Organization: Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), 
          Pacific Islands Fisheries Science Center (PIFSC), NOAA National Marine Fisheries Service (NMFS)
      Contact_Address: 
        Address_Type: mailing and physical
        Address: 1680 East-West Road POST 833
        City: Honolulu
        State_or_Province: HI
        Postal_Code: 96822
        Country: USA
      Contact_Voice_Telephone: 808-956-5239
      Contact_Electronic_Mail_Address: pibhmc@soest.hawaii.edu
      Contact_Instructions: e-mail preferred
  Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
  Metadata_Time_Convention: Universal Time
  Metadata_Access_Constraints: None
  Metadata_Use_Constraints: None