Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 19941121 Title: MONTGOMERY NORTH Geospatial_Data_Presentation_Form: "map" Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey 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 QC/QA other digital products, and as a source for the collection and revision of Digital Line Graph (DLG) data. DRG's can also be merged with other digital data, e.g. digital elevation models or digital orthophotos, to produce a hybrid digital file. Supplemental_Information: The UTM meter coordinates of pixel 1,1 are: x = 557855.845041 y = 3596665.161424 Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1958 Currentness_Reference: "Ground Condition" Status: Progress: "Complete" Maintenance_and_Update_Frequency: "Irregular" Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -86.375 East_Bounding_Coordinate: -86.250 North_Bounding_Coordinate: 32.500 South_Bounding_Coordinate: 32.375 Keywords: Theme: Theme_Keyword_Thesaurus: "None" Theme_Keyword: digital raster graph 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: AL Access_Constraints: "None" Use_Constraints: Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data. Data_Set_Credit: Not Applicable Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The DRG is an 8-bit color image which employs a color palette to ensure uniform colors throughout a particular DRG series. That is to say, if a color is defined as having a particular RGB value, for all DRG's within that series, the RGB value is the same. Logical_Consistency_Report: Not Applicable Completeness_Report: The Digital Raster Graphic (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 digital raster graphic 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/inclusion criteria, see NMD Product Standards for DLG and Quadrangle Maps, published as the Technical Instructions. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: While the datum of the published map 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. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Refer to the DRG collar for information about vertical positional accuracy. Lineage: Source_Information: Source_Citation: Source_Citation_Abbreviation: map1 8.1 ORIGINATOR: U.S. Geological Survey *8.2 PUBLICATION DATE: 1982 *8.4 TITLE: MONTGOMERY NORTH, ALA. *8.6 GEOSPATIAL DATA PRESENTATION FORM: "map" --Publication Information-- 8.8.1 PUBLICATION PLACE: Reston, VA 8.8.2 PUBLISHER: U.S.Geological Survey Source_Scale_Denominator: 24000 Type_of_Source_Media: "paper" Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 1981 Source_Currentness_Reference: "ground condition" Source_Contribution: The source map is scanned to produce the digital raster graphic. Process_Step: Process_Description: The production procedures, instrumentation, hardware and software used in the collection of standard U.S. Geological Survey (USGS) Digital Raster Graphic (DRG) products vary depending on systems used at the contract, cooperator or National Mapping Division (NMD) production sites. The majority of DRG datasets are acquired through government contract. The process step describes, in general, the process used in the production of standard USGS DRG datasets. 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 16 2.5-minute grid ticks which are obtained using the in-house produced program COORDAT and stored in a ground control file. Those 16, 2.5-minute ticks are interactively visited and assigned their respective UTM coordinate. USGS program XSHAPES4 then performs a piecewise linear rubber sheet transformation. 4. An output resolution of 2.4 meters (7.9 feet) is chosen in order to resample the file to 250 dots per inch (dpi). 5. The image file is converted to a Tagged Image File Format (TIFF), and further reduced by converting the file to a run length encoding PackBit 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 archival 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 DRG's 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 DRG's are checked for georeferencing accuracy by comparing the book value of latitude and longitude tick marks to corresponding tick intersections in the DRG image. e. Transformations are checked on selected DRG's by comparing the positions of well defined points such as UTM grid intersections in the graphic product to the corresponding image points in the DRG. Source_Used_Citation_Abbreviation: map1 Process_Date: 19941121 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: "Raster" Raster_Object_Information: Raster_Object_Type: "Pixel" Row_Count: 5854 Column_Count: 7109 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: "Universal Transverse Mercator" Universal_Transverse_Mercator: UTM_Zone_Number: 16 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 *4.1.2.1.2.2 LONGITUDE AT CENTRAL MERIDIAN: -87.000 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: 2.4 Ordinate_Resolution: -2.4 Planar_Distance_Units: "meters" Geodetic_Model: Horizontal_Datum_Name: "North American Datum of 1927" Ellipsoid_Name: "Clark 1866" Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.98 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: Each raster entity or pixel contains a color index from 0 through 11 referencing a color palette of RGB values from O through 255 in which the standard colors used in the DRG are defined. Index R G B 0 0 0 0 Black 1 255 255 255 White 2 60 80 240 Blue 3 240 20 20 Red 4 144 66 45 Brown 5 210 240 170 Light Green 6 150 115 56 Light Brown 7 200 20 160 Purple 8 190 225 225 Light Blue 9 255 160 255 Light Purple 10 255 190 190 Light Red ll 200 200 200 Grey 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 U.S. Geological Survey, 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 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 Format_Version_Number: 5.0 File_Decompression_Technique: PackBit Digital_Transfer_Option: Offline_Option: Offline_Media: "CD-ROM" Recording_Format: "ISO 9660"; Digital raster graphic image files with corresponding metadata files. Fees: This CD-ROM is being offered in limited quantity, free of charge to the public, as a sampler of the new DRG product being produced by the U.S. Geological Survey. Future deliveries of production DRG's on CD-ROM will cost $32 per disc. Metadata_Reference_Information: Metadata_Date: 19941121 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: "mailing address" Address: 590 National Center City: Reston State_or_Province: Virginia Postal_Code: 22092 Contact_Voice_Telephone: 1 703 648 4533 Contact_Electronic_Mail_Address: Copies of this publication are available from anonymous File Transfer Protocol (anonymous FTP); ftp://fgdc.er.usgs.gov/ Metadata_Standard_Name: "Content Standards for Digital Geospatial Metadata" Metadata_Standard_Version: 19940608