Identification_Information: Citation: Citation_Information: Originator: United States Geological Survey (USGS) Publication_Date: 19970422 Title: 1:24,000-scale Digital Raster Graphic Geospatial_Data_Presentation_Form: map Publication_Information: Publication_Place: Reston, VA Publisher: USGS Online_Linkage: 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. 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: The resolution and coodinates for the upper-left corner of the DRG can be found in the associated header file that has a .TFW extension. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 19970422 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: Irregular Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: East_Bounding_Coordinate: North_Bounding_Coordinate: South_Bounding_Coordinate: Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: digital raster graphic Theme_Keyword: DRG Theme_Keyword: topographic map Place: Place_Keyword_Thesaurus: Department of Commerce, 1977, Countries, Dependencies, Areas of Special Sovereignty, and their Principal Administrative Divisions (Federal Information Processing Standard 10-3): Washington, Department of Commerce, National Institute of Standards and Technology. Place_Keyword: US 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, Department of Commerce, National Institute of Standards and Technology. Place_Keyword: DE Place_Keyword_Thesaurus: Geographic Names Information System Place_Keyword: Delaware Place_Keyword: Place_Keyword: Access_Constraints: None Use_Constraints: Acknowledgment of the USGS would be appreciated in products derived from these data. Data_Set_Credit: This DRG was produced through an Innovative Partnership agreement between The Land Information Technology Company, Ltd., of Aurora, CO and the USGS. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The DRG is an 8-bit color image that employs a color palette to ensure uniform colors throughout a particular DRG series. All DRGs within a series must have the same RGB value. Logical_Consistency_Report: Not Applicable Completeness_Report: 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: 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. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Refer to the DRG collar for information about vertical positional accuracy. Lineage: Source_Information: Source_Citation_Abbreviation: map1 Source_Citation: Citation_Information: Originator: USGS Publication_Date: 1992 Title: Geospatial_Data_Presentation_Form: map Publication_Information: Publication_Place: Reston, VA Publisher: USGS Source_Scale_Denominator: 24000 Type_of_Source_Media: Paper Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1992 Source_Currentness_Reference: ground condition Source_Contribution: The source map is scanned to produce the DRG. Process_Step: Process_Description: The production procedures, instrumentation, hardware, and software used in the collection of standard DRG products vary depending on systems used at the contract, cooperator or USGS production sites. The majority of DRG data sets are acquired through government contract. The process step describes, in general, the process used in the production of standard DRG data sets. 1. Production of a DRG begins with the scanning of a paper 7.5-minute topographic map (map1) on a high-resolution scanner. Scanning resolutions range from 500 - 1000 dpi with the output file running between 160-300 mb. 2. Removal of screens (descreening) and color quantization to reduce the number of colors also takes place during the scanning phase. 3. The raw scan file is then transformed and georeferenced using UTM coordinates of the sixteen 2.5-minute grid ticks, which are obtained using the in-house produced program COORDAT and stored in a ground control file. Those sixteen 2.5-minute ticks are interactively visited and assigned their respective UTM coordinates. USGS program XSHAPES4 then performs a piecewise linear rubber sheet transformation. 4. An output resolution of 2.4 meters (8.2 feet) is chosen in order to resample the file to 250 dpi. 5. The image file is converted to a TIFF and further reduced by converting the file to a run length encoding Packbits compression (type 32773). 6. The color palette of the compressed DRG is then standardized by replacing the original RGB values assigned during the scanning process with standard RGB value combinations using the in-house produced TIFFREMAP program. 7. Prior to archiving, the DRG undergoes the following quality assurance procedures: a. The color index values of each DRG are checked to ensure 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. Selected DRGs are 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. Selected DRGs are checked for georeferencing accuracy by comparing the book value of latitude and longitude tick marks with corresponding tick intersections in the DRG image. e. Transformations are checked on selected DRGs by comparing the positions of well defined points, such as UTM grid intersections in the graphic product, with the corresponding image points in the DRG. USGS DRG production specifications are available on request from the National Mapping Division and Mid-Continent Mapping Center by contacting: Rolla-ESIC U.S. Geological Survey, 1400 Independence Rd., MS231, Rolla, MO 65401-2602 Phone: (573) 308-3500 Facsimile: (573) 308-3615 E-mail: World Wide Web: Source_Used_Citation_Abbreviation: map1 Process_Date: 19970422 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Pixel Row_Count: 6707 Column_Count: 5115 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: 0.9996 Longitude_of_Central_Meridian: -75.000 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000. False_Northing: 0.0 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 of 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 Entity_and_Attribute_Detail_Citation: Draft Standards for Digital Raster Graphic. 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: Virginia Postal_Code: 22092 Contact_Voice_Telephone: 1 800 USA MAPS Contact_Voice_Telephone: 1 703 648 6045 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 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 Format_Version_Number: 6.0 File_Decompression_Technique: Packbits, WinZip Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: DRG file and its metadata file Fees: Free Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: TIFF Format_Version_Number: 6.0 File_Decompression_Technique: Packbits Digital_Transfer_Option: Offline_Option: Offline_Media: CD-ROM Recording_Format: ISO 9660 Fees: For delivery on CD-ROM, the charge is $32 per CD-ROM Metadata_Reference_Information: Metadata_Date: 19970422 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Research Data Management Services Contact_Address: Address_Type: mailing address Address: University of Delaware City: Newark State_or_Province: Delaware Postal_Code: 19716 Contact_Voice_Telephone: 1 302 831 DATA Contact_Electronic_Mail_Address: Metadata_Standard_Name: Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: 19940608