U.S. Geological Survey --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- 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: --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- Spatial_Data_Organization_Information Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 19896 Column_Count: 17296 --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- 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 --------------------------------------------------------------------------- Last modified: 2008-03-20