U.S. Geological Survey

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Metadata for DRG250

 Table of Contents

Identification_Information
     Abstract
     Purpose
     Supplemental Information
Data_Quality_Information
Spatial_Data_Organization_Information
Entity_and_Attribute_Information
     Detailed Description
     Overview
Distribution_Information
Metadata_Reference_Section

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Identification_Information

Citation_Information
    Originator: Musser, Jonathan W.
    Publication_Date: 1997
    Title: Digital Raster Graphic of Georgia, 1:250,000 Scale
    Edition: 1.0
             1.1 Datum change from 1927 to 1983 (North American Datum of 1983)
                 Data Re-projected using North American Datum (NAD83) - September 2000
    Series_Information
        Series_Name: Digital Data Series
    Publication_Information
        Publication_Place: Atlanta, GA
        Publisher: U.S. Geological Survey
    Online_Linkage: http://csat.er.usgs.gov/statewide/layers/drg250.html
    Scale_Denominator: 250000

Description
    Abstract
    The Digital Raster Graphic (DRG) is a raster image of a scanned USGS
    topographic map including the collar information, georeferenced to the UTM
    grid.  This dataset contains the 1:250,000 DRGs for the entire state of
    Georgia edgematched into one continuous layer.

    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 DLG data.  DRGs can also be merged with other
    digital data, e.g. DEMs or DOQs, to produce a hybrid digital file.

Supplemental_Information
    Procedures_Used
    1. A coverage of 1:250,000 quadrangles was projected into the two UTM zones
    in the state, 16 and 17.
    2. These two coverages were then clipped by the outline of Georgia.
    3. All of the 1:250,000 DRGs that contain a part of Georgia were converted
    from TIF format into Grid format using the commands IMAGEGRID.
    4. These grids were then clipped by the appropriate quadrangle boundary
    in the appropriate zone by using the function SELECTPOLYGON().
    5. The clipped grids were all projected into an Albers projection with
    standard parallels of 29 degrees 30 minutes, and 45 degrees 30 minutes,
    a central meridian of -83 degrees 30 minutes, and a latitude of origin
    of 23 degrees.
    6. The albers grids were then combined into one statewide grid using the
    function MERGE().
    7. The resulting statewide grid was then documented.

    Revisions
    1.0 Original work
    1.1 Datum change from 1927 to 1983 (North American Datum of 1983)

    Reviews_Applied
    1. The dataset was checked for completeness and for the proper projection
    and spatial extent.

    2. Colleague review October 31, 1996 by Jack Alhadeff and Diane Burgoon.
    Digital data was reviewed with respect to positional accuracy, contextual
    accuracy, attribute accuracy, topological consistency, and metadata
    content.

    a) Fix Horizontal Positional Accuracy Report wording. Done.
    b) Fix central meridian. Document AML problem. Done.
    c) Attribute misunderstandings. Done.

    3. Approved by District Chief, TIm Hale, on November 3, 1997.

    Related_Spatial_and_Tabular_Data_Sets
    The file "drg250.clr" is the colormap file used for displaying in Arc/Info.

    Other_References_Cited
    ______,1996, Digital Raster Graphic Metadata, U.S. Geological Survey,
    Reston, VA.

    Notes
    Since the DRG quadrangle boundaries are contained in the original datasets,
    the boundaries still appear in the combined statewide version.

Time_Period_of_Content
    Single_Date/Time
    Calendar_Date: 1975
    Currentness_Reference
    Ground Condition

Status
    Progress: Completed. Approved for distribution by District Chief.
    Maintenance_and_Update_Frequency
    None planned

Spatial_Domain
    Bounding_Coordinates
    West_Bounding_Coordinate: -85.60520007
    East_Bounding_Coordinate: -80.63823341
    North_Bounding_Coordinate: 34.98452504
    South_Bounding_Coordinate: 30.33161047

Keywords
    Theme
        Theme_Keyword_Thesaurus: None
        Theme_Keyword:  Digital Raster Graphic DRG 1:250000
    Place
        Place_Keyword_Thesaurus: None
        Place_Keyword:  State of Georgia
    Stratum
        Stratum_Keyword_Thesaurus: None
        Stratum_Keyword:
    Temporal
        Temporal_Keyword_Thesaurus: None
        Temporal_Keyword:

Access_Constraints
n/a

Use_Constraints
This dataset is of 1:250,000 scale, so that when used at other scales, the
features can be very large.

Point_of_Contact: See Data_Set_Credit
The U. S. Geological Survey, National Mapping Division was responsible for
the original scanning and production of the DRGs that make up this dataset.

Security_Information
    Security_Classification_System: None
    Security_Classification:  UNCLASSIFIED
    Security_Handling_Description: None

Native_Data_Set_Environment: dgux UNIX, ARC/INFO version 7.0.4

Cross_Reference
    Originator:
    Publication_Date: 1996
    Publication_Time:
    Title: Digital Raster Graphic
    Edition:
    Geospatial_Data_Presentation_Form:
    Series_Information
        Series_Name:
        Issue_Identification:
    Publication_Information
        Publication_Place: Reston, VA
        Publisher: U. S. Geological Survey
    Other_Citation_Details:
    Online_Linkage: http://mcmcweb.cr.usgs.gov/gdc/
    Larger_Work_Citation:

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Data_Quality_Information

Attribute_Accuracy
    Attribute_Accuracy_Report: See Logical_Consistency_Report: Not applicable for raster data.

Completeness_Report
(From the original National Mapping Division metadata)
The DRG is a faithfully reproduced digital image of the original source map.
Some differences may be detected between the source graphic used and the DRG
due to the RGB values assigned that particular color.  The intent is to
recreate those colors as near as possible.  Data completeness for DRG files
reflect 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 U.S. Geological
Survey, 1994, Standards for 1:24,000-Scale Digital Line Graphs and Quadrangle
Maps: National Mapping Program Technical Instructions and U.S. Geological
Survey, 1994, Standards for Digital Line Graphs:  National Mapping Program
Technical Instructions.

Positional_Accuracy
    Horizontal_Positional_Accuracy
        Horizontal_Positional_Accuracy_Report:
        (From the original National Mapping Division metadata)
        While the datum of the published map is retained to be consistent with other
        USGS digital data, this image is cast on the UTM and may be INCONSISTENT with
        the credit note on the image collar.

        Quantitative_Horizontal_Positional_Accuracy_Assessment:
            Horizontal_Positional_Accuracy_Value: 60 meters
            Horizontal_Positional_Accuracy_Explanation:  Resolution as reported

    Vertical_Positional_Accuracy
        Vertical_Positional_Accuracy_Report:
        Refer to the collar of the original DRGs, or the original 1:250,000 paper
        maps for information about vertical positional accuracy

Lineage: See Cloud_Cover
n/a

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Spatial_Data_Organization_Information

Direct_Spatial_Reference_Method: Raster

    Raster_Object_Information:
    Raster_Object_Type:  Grid Cell
    Row_Count:  19896
    Column_Count:  17296

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Spatial_Reference_Information

Horizontal_Coordinate_System_Definition
    Planar
        Map_Projection:
        Map_Projection_Name:  ALBERS
        Longitude_of_Central_Meridian: -83.5
        Latitude_of_Projection_Origin: 23
        Latitude_of_First_Standard_Parallel: 29.5
        Latitude_of_Second_Standard_Parallel: 45.5
        False_Easting:  0.00000
        False_Northing:  0.00000
    Geodetic Model
        Horizontal_Datum_Name: North American Datum of 1983 (NAD83)
        Ellipsoid_Name:  GRS 80
        Semi-major_Axis: 6,378,206.4
        Denominator_of_Flattening: 294.98

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Entity_and_Attribute_Information

Detailed_Description
    Entity_Type
    Entity_Type_Label: DRG250.VAT
    Entity_Type_Definition: Grid Attribute Table
    Entity_Type_Definition_Source: U. S. Geological Survey
    Attribute:
        Attribute_Label: -
        Attribute_Definition: Grid Attribute Table
        Attribute_Definition_Source: U. S. Geological Survey
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: -
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:
    Attribute:
        Attribute_Label: VALUE
        Attribute_Definition: Internal feature number for GRIDs
        Attribute_Definition_Source: Computed
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: Integer
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:
    Attribute:
        Attribute_Label: COUNT
        Attribute_Definition: Number of GRID cells of a VALUE
        Attribute_Definition_Source: Computed
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: Integer
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:
    Entity_Type
    Entity_Type_Label: DRG250.STA
    Entity_Type_Definition: Statistics table
    Entity_Type_Definition_Source: GRID
    Attribute:
        Attribute_Label: -
        Attribute_Definition: Statistics table
        Attribute_Definition_Source: GRID
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: -
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:
    Attribute:
        Attribute_Label: MIN
        Attribute_Definition: Minimum GRID cell VALUE
        Attribute_Definition_Source: Computed
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: Real number
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:
    Attribute:
        Attribute_Label: MAX
        Attribute_Definition: Maximum GRID cell VALUE
        Attribute_Definition_Source: Computed
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: Real number
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:
    Attribute:
        Attribute_Label: MEAN
        Attribute_Definition: Mean GRID cell VALUE
        Attribute_Definition_Source: Computed
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: Real number
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:
    Attribute:
        Attribute_Label: STDV
        Attribute_Definition: Standard Deviation of GRID cell VALUEs
        Attribute_Definition_Source: Computed
        Attribute_Domain_Values
            Enumerated_Domain
                Enumerated_Domain_Value: Positive real number
                Enumerated_Domain_Value_Definition
                Enumerated_Domain_Value_Definition_Source:

 Overview_Description
    Entity_and_Attribute_Overview
    Each grid cell 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.  A colormap file containing
    this information can be used to display the DRG in Arc/Info using the
    command GRIDPAINT.

    Note: These values represent the color value of the cell in the RGB
    color model.  They have no other significant attribute value.

    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: Not Available

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Distribution_Information

Distributor
    Contact_Person_Primary
        Contact_Person: Jonathan W. Musser
        Contact_Organization: U.S. Geological Survey
    Contact_Position: Hydrologist

    Contact_Address
        Address_Type: mailing address
        Address: U.S. Geological Survey
                 3039 Amwiler Road
                 Suite 130
        City: Atlanta
        State_or_Province: GA
        Postal_Code: 30360-2824
        Country: USA

    Contact_Facsimile_Telephone: 770-903-9199
    Contact_Electronic_Mail_Address: jwmusser@usgs.gov

Standard_Order_Process
    Digital_Form
        Digital_Transfer_Information
        Format_Name: ARC/INFO GRID Format
        File_Decompression_Technique: gzip & tar
        Digital_Transfer_Option
        Online_Option
        Computer_Contact_Information
        Network_Address
        Network_Resource_Name: http://csat.er.usgs.gov/statewide/layers/drg250.html

Distributor
    Contact_Person_Primary
        Contact_Person: Jonathan W. Musser
        Contact_Organization: U.S. Geological Survey
    Contact_Position: Hydrologist

    Contact_Address
        Address_Type: mailing address
        Address: U.S. Geological Survey
                 3039 Amwiler Road
                 Suite 130
        City: Atlanta
        State_or_Province: GA
        Postal_Code: 30360-2824
        Country: USA

    Contact_Facsimile_Telephone: 770-903-9199
    Contact_Electronic_Mail_Address: jwmusser@usgs.gov

Standard_Order_Process
    Digital_Form
        Digital_Transfer_Information
        Format_Name: tif, tagged image format
        File_Decompression_Technique: packed bits compression used
        Digital_Transfer_Option
        Online_Option
        Computer_Contact_Information
        Network_Address
        Network_Resource_Name: http://csat.gatech.edu/statewide/layers/drg250.html

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Metadata_Reference_Section

Metadata_Date: 19980114
Metadata_Contact: nybunek
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version:  19940608
Metadata_Time_Convention:  Local Time
Metadata_Security_Information:
    Metadata_Security_Classification_System:  None
    Metadata_Security_Classification:  UNCLASSIFIED
    Metadata_Security_Handling_Description:  None

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Last modified: 2008-03-20