Identification_Information:
  Citation:
    Citation_Information:
      Originator: USGS
      Publication_Date:  19990611
      Title:  Valley Forge
      Geospatial_Data_Presentation_Form: map
      Publication_Information:
        Publication_Place: Reston, VA
        Publisher: U.S. Geological Survey
  Description:
    Abstract: 
      This Digital Raster Graphic (DRG) was produced by 
      down sampling, georeferencing, and conversion of 
      a 1000 dots-per-inch (dpi) composite image of 
      revised map separates to a standard, USGS GeoTIFF 
      DRG. This DRG includes collar information and 
      is georeferenced to the UTM grid.
    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.
    Supplemental_Information:
      The Product ID is 726840.
      The UTM x,y position of pixel 1,1 is
        456001.471050, 4442466.375587  
  Time_Period_of_Content:
    Time_Period_Information:
      Single_Date/Time:
        Calendar_Date:  19990611
    Currentness_Reference: Ground Condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency:
      Irregular
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate:  -75.500000
      East_Bounding_Coordinate:  -75.375000
      North_Bounding_Coordinate:  40.125000
      South_Bounding_Coordinate:  40.000000
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: None
      Theme_Keyword: digital raster graphic
      Theme_Keyword: DRG
      Theme_Keyword: new version DRG
    Place:
      Place_Keyword_Thesaurus:
        U.S. Department of Commerce, 1977, Countries,
        dependencies, areas of special sovereignty,
        and their principal administrative divisions
        (Federal Information Processing Standard 10-4):
        Washington, D.C., National Institute of Standards
        and Technology.
      Place_Keyword:  US
    Place:
      Place_Keyword_Thesaurus:
        Department of Commerce, 1987, Codes for the
        identification of the States,  the District of
        Columbia and the outlying  areas of  the United
        States, and associated  areas (Federal Information
        Processing Standard 5-2): Washington, D.C., National
        Institute of Standards and Technology.
      Place_Keyword:  PA
      Place_Keyword:  
      Place_Keyword:  
      Place_Keyword:  
  Access_Constraints: None
  Use_Constraints:
    Acknowledgment of the U.S. Geological Survey would
    be appreciated for products derived from these
    data.
  Data_Set_Credit:
    This DRG was produced by the U.S. Geological
    Survey. Please refer to the map collar in the image
    for cooperative agencies.
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report:
      The DRG is an 8-bit color image that uses a color
      palette to ensure uniform colors throughout a
      particular DRG series. All DRG's within a series
      must have the same red-green-blue (RGB) values.
      Attributes inherent in the symbology of the
      digital source remain the same in the DRG.
  Logical_Consistency_Report: Not applicable
  Completeness_Report:
    The DRG is a faithfully reproduced digital image
    of the revised source. Data completeness for DRG
    files reflects content of the digitally revised source.
    Features may have been eliminated or generalized
    during digital revision due to scale and
    legibility constraints. For information on
    collection and inclusion criteria, see  Standards
    for 1:24,000-Scale Digital Line Graphs and
    Quadrangle Maps, Parts 1-5 and 7-10, U.S. Geological
    Survey, National Mapping Program Technical Instructions,
    1996; Standards for 1:24,000-Scale Digital Line Graphs
    and Quadrangle Maps, Part 6, U.S. Geological
    Survey, National Mapping Program Technical
    Instructions, 1998; and Draft for Implementation
    of Standards for Revised Primary Series Quadrangle
    Maps, U.S. Geological Survey, National Mapping
    Program Technical Instructions, 1998.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:
        Although the datum of the source is retained, in
        order to be consistent with other USGS digital
        data, this image is cast on the UTM and may
        therefore be INCONSISTENT with the credit note on
        the image collar. DRG's meet the accuracy
        standards of the revised digital source
        only in the area of the DRG that falls within the
        neatline of the image, excluding insets. Overedge
        areas fall outside the transformation boundary
        area (map neatline). As a result, areas outside
        the neatline and beyond the control point extent
        can exhibit anomalies or discrepancies. These
        anomalies will also appear in the map inset area
        and in the map collar.
    Vertical_Positional_Accuracy:
      Vertical_Positional_Accuracy_Report: Refer to the
        DRG collar for information about vertical positional accuracy.
  Lineage:
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: USGS
          Publication_Date:  1998
          Title:  Valley Forge
          Geospatial_Data_Presentation_Form: 
            composite raster image of revised map separates
          Publication_Information:
            Publication_Place: Reston, VA
            Publisher: U.S. Geological Survey
      Source_Scale_Denominator:  24000
      Type_of_Source_Media: digital raster
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date:  1998
        Source_Currentness_Reference: Ground Condition
        Source_Citation_Abbreviation: RRI1
      Source_Contribution:
        Content and position
    Process_Step:
      Process_Description:
        The production procedures, instrumentation,
        hardware, and software used in the collection of
        new version DRG's may vary depending on systems
        used at the contract, cooperator or U.S. Geological
        Survey production site. The majority of DRG data sets
        are acquired through government partnerships and
        contracts. The process step describes, in general,
        the methods used at a typical USGS production site
        to produce DRG's derived from high resolution, 
        composite raster images of digitally revised map 
        separates.
  
        A de-screened, standard color palette, 8-bit, 1000 
        dpi, PackBits compressed Tagged Image File Format 
        (TIFF) raster image of composite map separates is 
        generated during the final stage of digital map revision.

        1. The TIFF is initially re-sampled to 500 dpi and once
        again re-sampled to 250 dpi to create a TIFF file with 
        an output resolution of 2.4 meters (8.2 feet).

        2. The TIFF is georeferenced using UTM
        coordinates of the sixteen 2.5-minute grid ticks.
        Each tick is visited and assigned its respective 
        UTM coordinates which are stored in a ground control 
        file.  Geographic transformation software is then 
        used to produce a georeferenced TIFF.

        3. The TIFF image is converted to a GEOTIFF DRG.

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

        a. The color index values of each DRG are checked 
        to ensure that the RGB combinations are consistent 
        with the standardized color palette. 
 
        b. All DRG files are inspected to ensure that they 
        are geometrically consistent with normal map presentation.
  
        c. 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.

        d. Each DRG is checked for georeferencing accuracy
        by comparing  the book value of latitude and
        longitude tick marks with corresponding tick
        intersections in the DRG image.  

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

        f. Correct geographic transformation is verified on each  
        image by comparing absolute ground control values to the
        positions of well defined points, such as UTM grid
        ticks in the DRG image.  

        Current USGS DRG Standards, including product specifications 
        are available via the World Wide Web at:

        http://mapping.usgs.gov/standards  

        DRG Standards and specifications can also be obtained 
        from any of the regional USGS Earth Science Information
        Center (ESIC) offices or by telephone request at
        1 888 ASK USGS

      Process_Date:  19990611
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Raster
  Raster_Object_Information:
    Raster_Object_Type: Pixel
    Row_Count:  6742
    Column_Count:  5472
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Grid_Coordinate_System:
        Grid_Coordinate_System_Name: Universal Transverse Mercator
        Universal_Transverse_Mercator:
          UTM_Zone_Number:  18
          Transverse_Mercator:
            Scale_Factor_at_Central_Meridian: .9996
            Longitude_of_Central_Meridian:  -75.000
            Latitude_of_Projection_Origin: 0
            False_Easting: 500000
            False_Northing: 0
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: row and column
        Coordinate_Representation:
          Abscissa_Resolution:  2.438400
          Ordinate_Resolution:  -2.438400
        Planar_Distance_Units: Meters
    Geodetic_Model:
      Horizontal_Datum_Name:  North American Datum 1983
      Ellipsoid_Name:  GRS 1980
      Semi-major_Axis:  6378137
      Denominator_of_Flattening_Ratio:  298.257
Entity_and_Attribute_Information:
  Overview_Description:
    Entity_and_Attribute_Overview:
      Each raster entity or pixel contains a color index
      from 0 through 12 referencing a color palette of
      RGB values from 0 through 255 in which the
      standard colors used in the DRG are defined.

                      ----------------------
      		      USGS DRG Color Palette
                      ----------------------

       Digital Number    Color       Red     Green    Blue
       0                 Black        0        0        0
       1                 White        255      255      255
       2                 Blue         0        151      164
       3                 Red          203      0        23
       4                 Brown        131      66       37
       5                 Green        201      234      157
       6                 Purple       137      51       128
       7                 Yellow       255      234      0
       8                 Light Blue   167      226      226
       9                 Light Red    255      184      184
       10                Light Purple 218      179      214
       11                Light Grey   209      209      209
       12                Light Brown  207      164      142

    Entity_and_Attribute_Detail_Citation:
      Standards for Digital Raster Graphics, U.S. Geological
      Survey, National Mapping Program Technical Instructions,
      Reston, VA, 1997.
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization:
          Earth Science Information Center, U.S. Geological Survey
      Contact_Address:
        Address_Type: mailing address
        Address: 507 National Center
        City: Reston
        State_or_Province: VA
        Postal_Code: 20192
      Contact_Voice_Telephone: 1 888 ASK USGS
      Contact_Voice_Telephone: 1 888 275 8747
      Contact_Facsimile_Telephone: 703 648 5548
      Contact_Electronic_Mail_Address: esicmail@usgs.gov
      Hours_of_Service: 0800-1600 Monday through Friday
      Contact_Instructions:
        In addition to the ESIC at the address above,
        there are other ESIC offices throughout the country.
        A full list of these offices is at:
        http://mapping.usgs.gov/esic/
  Resource_Description: DRG
  Distribution_Liability:
    Although these data have been processed
    successfully on a computer system at the U.S.
    Geological Survey (USGS), no warranty expressed or
    implied is made by the USGS regarding the utility
    of the data on any other system, nor shall the act
    of distribution constitute any such warranty. The
    USGS 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: PackBit
      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
      are subject to change. Call 1 888 ASK USGS
      for current prices.
    Ordering_Instructions:
      For information about ordering DRG's on CD-R,
      contact any Earth Science Information Center
      office or call 1 888 ASK USGS. Sale of DRG's in
      fixed 1-degree blocks was discontinued on October
      1, 1998. Any combination of DRG data can now be
      purchased.
Metadata_Reference_Information:
  Metadata_Date:  19990611
  Metadata_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization:
          Earth Science Information Center, U.S. Geological
          Survey
      Contact_Address:
        Address_Type: Mailing Address
        Address: 1400 Independence Road
        City: Rolla
        State_or_Province: MO
        Postal_Code: 65401
      Contact_Voice_Telephone: 573 308 3500
      Contact_TDD/TTY_Telephone: 573 308 2716
      Contact_Facsimile_Telephone: 573 308 3615
      Contact_Electronic_Mail_Address:
        mcmcesic@usgs.gov
  Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
