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Digital Raster Graphic (DRG), Anchorage B-8 NE

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: USGS

Publication_Date: 19971017

Title: Digital Raster Graphic (DRG), Anchorage B-8 NE

Geospatial_Data_Presentation_Form:
map

Publication_Information:
Publication_Place: Reston, VA

Publisher:
USGS

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. DRG's can also be merged with other digital data, e.g. DEM's or DOQ's, to produce a hybrid digital file.

Supplemental_Information:
348669.284284204826, 6822509.579474327150

Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 19971017

Currentness_Reference:
"Ground Condition"

Status:
Progress: Complete

Maintenance_and_Update_Frequency:
"Irregular"

Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -149.812500

East_Bounding_Coordinate: -149.625000

North_Bounding_Coordinate: 61.500000

South_Bounding_Coordinate:
61.375000

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: AK

Place_Keyword:

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 DRG's 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:
Citation_Information:
Originator: USGS

Publication_Date: 1993

Title: Anchorage B-8 NE

Geospatial_Data_Presentation_Form:
map

Publication_Information:
Publication_Place: Reston, VA

Publisher: USGS

Source_Scale_Denominator: 25000

Type_of_Source_Media: "paper"

Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1993

Source_Currentness_Reference: "ground condition"

Source_Citation_Abbreviation: map1
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 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 with 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, 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 to mcmcesic@usgs.gov World Wide Web: http://mcmcweb.er.usgs.gov/drg/

Source_Used_Citation_Abbreviation:
map1

Process_Date:
19971017


Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:
Raster_Object_Type: Pixel

Row_Count: 6778

Column_Count:
4960


Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator

Universal_Transverse_Mercator:
UTM_Zone_Number: 6

Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.9996

Longitude_of_Central_Meridian: -147.000

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: 2.540000000000

Ordinate_Resolution: -2.540000000000

Planar_Distance_Units:
"meters"

Geodetic_Model:
Horizontal_Datum_Name: North American Datum 1927

Ellipsoid_Name: Clarke 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 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:
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

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

Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <URL:http://agdcftp1.wr.usgs.gov/pub/usgs/drg/data/l61149d6.tif.gz>
Online_Computer_and_Operating_System:
Data General AViiON 6220 system running DG/UX version 5.4R3.10 (UNIX)
Offline_Option:
Offline_Media: "CD-ROM"

Recording_Format:
"ISO 9660"; DRG image files with corresponding metadata files.

Fees:
For delivery on CD-ROM, the charge is $32 per CD-ROM


Metadata_Reference_Information:
Metadata_Date: 19971017

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


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Page Last Modified: Monday, 28-Jan-2013 09:14:39 AKST