Identification_Information:
  Citation:
    Citation_Information:
      Originator: U.S. Geological Survey
      Publication_Date: 19991001
      Title: Shackleton Glacier
      Geospatial_Data_Presentation_Form: Raster Data
      Publication_Information:
        Publication_Place: Rolla, MO
        Publisher: U.S. Geological Survey

  Description:
    Abstract:
      This non-standard Digital Raster Graphic (DRG) Product was
      produced by scanning, color mapping, georeferencing,
      and GeoTIFF conversion of a USGS Antarctic map.
      This DRG product includes collar information and is
      georeferenced to the Polar Stereogrphic (PS) projection.
    Purpose:
      A DRG is useful as a source or background layer in a GIS,
      as a means to perform quality assurance on other digital products, and
      as a source for the collection and revision of vector data. DRG's can also
      be merged with other digital data, for example, DEM's or DOQ's, to
      provide additional visual information for the extraction and revision of
      base cartographic information.  This specific product was made for use in
      studies by the National Science Foundation (NSF).
    Supplemental_Information:
      The Product ID is 840752. 

      The x,y coordinate position of pixel 1,1 is based on a
      specific PS projection and has a x,y
      position of -113803.0, 678368.0.

  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 1960
        Ending_Date: 1964
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: irregular
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -165.000000
      East_Bounding_Coordinate: -180.000000
      North_Bounding_Coordinate: -84.000000
      South_Bounding_Coordinate: -85.000000
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: Antarctica DRG's
      Theme_Keyword: Digital Raster Graphic
      Theme_Keyword: Digital Antarctic Map
      Theme_Keyword: DRG
      Theme_Keyword: topographic map
      Theme_Keyword: special version DRG
    Place:
      Place_Keyword_Thesaurus:
        United States Board on Geographic Names, U.S. Geological Survey,
        1995, Geographic Names of the Antarctic, 2nd edition, Reston, VA
      Place_Keyword: Antarctica
      Place_Keyword:
        Shackleton Glacier


  Access_Constraints: none

  Use_Constraints:
    Acknowledgment of the USGS would be appreciated in products derived from
    these data.

  Point_of_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: USGS Antarctic Resource Center
      Contact_Address:
        Address_Type: mailing address
        Address: 515 National Center
        Address: 12201 Sunrise Valley Drive
        City: Reston
        State_or_Province: VA
        Postal_Code: 20192
      Contact_Voice_Telephone: 703 648-6010
      Contact_Facsimile_Telephone: 703 648-5080
      Contact_Electronic_Mail_Address: usarc@usgs.gov

  Data_Set_Credit:
    This DRG was produced by the U.S. Geological Survey in cooperation with the
    National Science Foundation. Please refer to the map collar in the image for
    cooperative agencies.

Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report:
      The Antarctic DRG is an 8-bit color image that may have up to 255 colors
      to represent features present on the Antarctic map.  Attributes inherent in
      the symbology of the source remain the same in the DRG.  Positional
      accuracy of individual pixels should generally be within three pixels(one
      pixel represents 25.4 meters on the DRG) of calculated position.
  Logical_Consistency_Report: not applicable
  Completeness_Report:
    This DRG is a faithfully reproduced digital image of the revised source
    map. Some differences may be detected between the source graphic used
    and the DRG due to the RGB values assigned to that particular color. The
    intent is to recreate those colors as closely as possible. Data
    completeness for DRG files reflects content of the source graphic.
    Features may have been eliminated or generalized on the source graphic
    due to scale and legibility constraints. For information on collection and
    inclusion criteria, see Topographic Mapping Methods For Antarctica by
    Geo. D. Whitmore and Rupert Southard, Jr., August 1964.

  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:
        The original datum of the published map is assumed to be Camp
        Area Astro.  A datum shift to WGS-84 has been applied to the
        image.  The image is cast on the PS projection with a standard
        parallel at 80.23333 degrees South latitude, which
        may be INCONSISTENT with map collar information.  A special
        coordinate system has been generated specifically for this map.
        The longitude of origin for this map's reference system is the center
        of the map.  The latitude of origin is 90 degrees south latitude.

  Lineage:
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: U.S. Geological Survey
          Publication_Date: 1967
          Title: Shackleton Glacier
          Geospatial_Data_Presentation_Form: map
          Publication_Information:
            Publication_Place: Reston, VA
            Publisher: U.S. Geological Survey

      Source_Scale_Denominator: 250000
      Type_of_Source_Media: paper
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Range_of_Dates/Times:
            Beginning_Date: 1960
            Ending_Date: 1964
        Source_Currentness_Reference: ground condition
      Source_Citation_Abbreviation: map1
      Source_Contribution: spatial and attribute information
    Process_Step:
      Process_Description:
        The following describes procedures, instrumentation, hardware,
        and software used in the production of this non-standard Antarctic
        DRG. The process steps describe, in general, the method used at
        Mid-Continent Mapping Center to produce special version DRG's
        derived from scanning, georeferencing, and GeoTIFF conversion
        of an Antarctic USGS topographic map.

        1. Production of this Antarctic DRG begins with the scanning of an
        Antarctic map (map1) on a high-resolution scanner. Scanning
        resolution is 500 dpi with the output file size of 20-150 mb.  The
        color palette of the compressed DRG may be slightly modified to
        improve overall appearance.

        2.  The raw scan file is converted to TIFF format and the file size is
        reduced by converting the file to a PackBits compressed image.

        3. The image is down sampled to produce a 250 dpi TIFF with an
        output resolution of 25.4 meters (83.3 feet).

        4.   An ASCII file of geographic coordinates is generated for all
        latitude/longitude grid intersections on the map.  The geographic
        coordinates are then converted to meter coordinates, specific to the
        quad, using the parameters listed below:

        Projection: Polar Stereographic (PS)
        Datum: Camp Area Astro
        Spheroid: International 1909
        Standard Parallel: 80.23333 degrees South Latitude
        Latitude of Origin: 90 degrees South
        Longitude of Origin: Center of map 172.5 West Longitude

        5.  The meter coordinate system is then correlated to corresponding
        x,y points on the image file.

        6.  The entire image file(.tif) is projected using the meter
        coordinates as control.

        7.  The image is then reprojected using a WGS-84 Datum.

        8.  The WGS-84 file is ouput in Packbits compressed TIFF format
        with GeoTIFF tags populated.

        9.  A world file(.tfw) is generated.

        10.  Prior to archiving the DRG undergoes the following quality
        quality assurance procedures:

        a. All DRG files are inspected to ensure that they are
        geometrically consistent with normal map presentation.

        b. Each DRG is checked to ensure that data elements in
        the DRG metadata file correspond to the map collar information
        and to the information in the associated image file.

        c. Each DRG is checked for georeferencing accuracy by
        comparing the calculated values for latitude and longitude
        intersections with corresponding intersections in the DRG image.

        d.  GeoTIFF header records in each DRG are checked for
        completeness and accuracy.

        e. Correct geographic transformation is verified on each image
        by comparing absolute ground control values to the positions
        of well defined points such as latitude/longitude intersections in
        the DRG image.

      Process_Date: 19991001

Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: raster
  Raster_Object_Information:
    Raster_Object_Type: pixel
    Row_Count: 6469
    Column_Count: 9118
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Map_Projection:
        Map_Projection_Name: Polar Stereographic
        Polar Stereographic:
          Standard_Parallel: -80.2333
          Longitude_of_Central_Meridian: -172.5
          Latitude_of_Projection_Origin: -90.0
          False_Easting: 0
          False_Northing: 0
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: row and column
        Coordinate_Representation:
          Abscissa_Resolution: 25.4
          Ordinate_Resolution: 25.4
        Planar_Distance_Units: meters
    Geodetic_Model:
      Horizontal_Datum_Name: WGS-84
      Ellipsoid_Name: WGS-84
      Semi-major_Axis: 6378137.0
      Denominator_of_Flattening_Ratio: 298.3

Entity_and_Attribute_Information:
  Overview_Description:
    Entity_and_Attribute_Overview:
      Each raster entity or pixel contains a possible color index from 0 through
      255 referencing a color palette of RGB values from 0 through 255.  Due to
      the complexity of the DRG imagery no standard colors have been assigned
      to represent map features.
    Entity_and_Attribute_Detail_Citation: Noted in this metadata file.
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: Customer Services, U.S. Geological Survey

      Contact_Address:
        Address_Type: mailing address
        Address: EROS Data Center
        City: Sioux Falls
        State_or_Province: SD
        Postal_Code: 57198
      Contact_Voice_Telephone: 1 800 252 4547
      Contact_Voice_Telephone: 1 605 594 6151
      Contact_TDD/TTY_Telephone: 1 605 594 6933
      Contact_Facsimile_Telephone: 1 605-594-6589 (24 hours)
      Contact_Electronic_Mail_Address:
        custserv@edcmail.cr.usgs.gov (24 hours)
        On-Line Inquiry Form
      Hours_of_Service: 0800-1600 CT Monday-Friday

  Distribution_Liability:
    Although these data have been processed successfully on a computer system
    at the USGS, no warranty expressed or implied is made by the USGS
    regarding the use of the data on any other system, nor does the act of
    distribution constitute any such warranty. The U.S. Geological Survey
    will warrant the delivery of this product in computer-readable format
    and will offer appropriate adjustment of credit when the product is
    determined unreadable by correctly adjusted computer input peripherals,
    or when the physical medium is delivered in damaged condition.  Requests
    for adjustment of credit must be made within 90 days from the date of
    this shipment from the ordering site.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: TIFF, GeoTIFF
        Format_Version_Number: 6.0, 0.2
        File_Decompression_Technique: PackBits
      Digital_Transfer_Option:
        Offline_Option:
          Offline_Media: Compact Disc-Recordable (CD-R)
          Recording_Format:
            ISO 9660: DRG image files with
            corresponding world files and metadata files

    Fees:
      The online copy of the data set (when available electronically) can be
      accessed without charge. Fees for DRG's distributed on CD-R are subject
      to change. Call 1 800 252 4547 for current prices.
    Ordering_Instructions:
      For information about ordering DRG's on CD-R, contact EROS Data
      Center at 1 800 252 4547.

Metadata_Reference_Information:
  Metadata_Date: 19991001
  Metadata_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: Customer Services, U.S. Geological Survey

      Contact_Address:
        Address_Type: mailing address
        Address: EROS Data Center
        City: Sioux Falls
        State_or_Province: SD
        Postal_Code: 57198
      Contact_Voice_Telephone: 1 800 252 4547
      Contact_Voice_Telephone: 1 605 594 6151
      Contact_TDD/TTY_Telephone: 1 605 594 6933
      Contact_Facsimile_Telephone: 1 605-594-6589
      Contact_Electronic_Mail_Address:
        custserv@edcmail.cr.usgs.gov (24 hours)
        On-Line Inquiry Form

  Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
