1:24,000-scale Digital Line Graphs

Frequently anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How should this data set be cited?

   U.S. Geological Survey or another mapping agency in cooperation with USGS. , Unknown, 1:24,000-scale Digital Line Graphs: U.S. Geological Survey, Reston, Virginia.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -124.7333

   East_Bounding_Coordinate: -067.9500

   North_Bounding_Coordinate: 49.3833

   South_Bounding_Coordinate: 24.5333

3. What does it look like?

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 05-Jul-1980

   Ending_Date: present

   Currentness_Reference: publication date

5. What is the general form of this data set?

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

      Indirect_Spatial_Reference:

      
      
      For Public Land Survey System:
      
      U.S. Department of the Interior, Bureau of Land Management:
      
      U.S. Public Land Survey System
      
      For Boundaries:
      
      U.S. Department of Commerce, 1977, Countries, dependencies, areas
      of special sovereignty, and their principal administrative divisions.
      (Federal Information Processing Standard 10-3): Washington,D.C.,
      National Institute of Standards and Technology.
      U.S. 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, D. C.,
      National Institute of Standards and Technology.
      U.S. Department of Commerce,1990, Counties and equivalent
      entities of The United States, its possessions, and associated areas
      (Federal Information Processing Standard 6-4): Washington, D.C.
      National Institute of Standards and Technology.
      For Survey Control and Markers:
      U.S. 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, D. C.,
      National Institute of Standards and Technology.
      U.S. Department of Commerce,1990, Counties and equivalent
      entities of The United States, its possessions, and associated areas
      (Federal Information Processing Standard 6-4): Washington, D.C.
      National Institute of Standards and Technology.
      

      This is a Vector data set.

   2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator

      Universal_Transverse_Mercator:

      
      

      UTM_Zone_Number: 10-19

      
      

      Transverse_Mercator:

      
      

      Scale_Factor_at_Central_Meridian: .9996

      
      

      Longitude_of_Central_Meridian: -123 00 00

      
      

      Latitude_of_Projection_Origin: 0.0

      
      

      False_Easting: 500000

      
      

      False_Northing: 0.0

      
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.61 [0.635 for 1:25,000]
      Ordinates (y-coordinates) are specified to the nearest 0.61 [0.635 for 1:25,000]
      Planar coordinates are specified in meters

      The horizontal datum used is North American Datum 1927.
      The ellipsoid used is Clark 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.98.
      

      Vertical_Coordinate_System_Definition:

      
      

      Altitude_System_Definition:

      
      

      Altitude_Datum_Name: National Geodetic Vertical Datum of 1929

      
      

      Altitude_Resolution: 1

      
      

      Altitude_Distance_Units: feet or meters

      
      

      Altitude_Encoding_Method: attribute values

      
      

      Depth_System_Definition:

      
      

      Depth_Datum_Name: Mean lower low water

      
      

      Depth_Resolution: 1

      
      

      Depth_Distance_Units: meters or feet

      
      

      Depth_Encoding_Method: attribute values

      
      

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   
   DLG3 attribute codes are used to describe the physical and cultural
   characteristics of DLG node, line, and area elements. Attribute codes
   are used to reduce redundant information, provide enough reference
   information to support integration with larger data base, and describe
   the relationships between cartographic elements. Each DLG element
   has one or more attribute codes composed of a three digit major code
   and a four-digit minor code. For example, with the 1: 24,000-scale DLG
   data, the line attribute code 050 0412 has a major code (050), meaning
   hydrography, with a minor code (0412) meaning stream.
   

   Entity_and_Attribute_Detail_Citation:

   
   U.S. Department of the Interior, U.S. Geological Survey, 1987
   Digital Line Graphs from 1:24,000-Scale Maps--Data Users Guide 1;
   Reston, Virginia
   A hypertext extract is available at:
   URL: <http://edc.usgs.gov/glis/hyper/guide/usgs_dlg>
   Softcopies in ASCII, WordPerfect, and PostScript format are available at:
   URL: <ftp://mapping.usgs.gov/pub/ti/DLG/>
   U.S.Department of the Interior, U.S.Geological Survey, 1990,
   Standards for Digital Line Graphs, Reston, VA, 1994
   Softcopies in ASCII, WordPerfect, and PostScript format are available at:
   URL: <ftp://mapping.usgs.gov/pub/ti/DLG/>
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • U.S. Geological Survey or another mapping agency in cooperation with USGS.

2. Who also contributed to the data set?

3. To whom should users address questions about the data?

Why was the data set created?

DLG's depict information about geographic features on or near
the surface of the Earth, terrain, and political and administrative
units. These data were collected as part of the National Mapping
Program.

How was the data set created?

1. From what previous works were the data drawn?

   MAP1 (source 1 of 5)

   U.S. Geological Survey or another mapping agency in cooperation with USGS. , Unknown, The Topographic Map Names Data Base designation for the source quadrangle. : U.S. Geological Survey, Reston, Virginia.

   Type_of_Source_Media: stable-base material

   Source_Scale_Denominator: 24000

   Source_Contribution: spatial and attribute information

   DOQ1 (source 2 of 5)

   U.S. Geological Survey or another mapping agency in cooperation with USGS. , Unknown, The Topographic Map Names Data Base designation for the DOQ : U.S. Geological Survey, Reston, Virginia.

   Type_of_Source_Media: magnetic tape

   Source_Scale_Denominator: 12000

   Source_Contribution:

   
   Provides locational and attribute information for
   photoidentifiable features during revision.
   

   DOQ2 (source 3 of 5)

   U.S. Geological Survey or another mapping agency in cooperation with USGS. , Unknown, The Topographic Map Names Data Base designation for the DOQ : U.S. Geological Survey, Reston, Virginia.

   Type_of_Source_Media: magnetic tape

   Source_Scale_Denominator: 12000

   Source_Contribution:

   
   Provides locational and attribute information for
   photoidentifiable features during revision.
   

   DOQ3 (source 4 of 5)

   U.S. Geological Survey or another mapping agency in cooperation with USGS. , Unknown, The Topographic Map Names Data Base designation for the DOQ : U.S. Geological Survey, Reston, Virginia.

   Type_of_Source_Media: magnetic tape

   Source_Scale_Denominator: 12000

   Source_Contribution:

   
   Provides locational and attribute information for
   photoidentifiable features during revision.
   

   DOQ4 (source 5 of 5)

   U.S. Geological Survey or another mapping agency in cooperation with USGS. , Unknown, The Topographic Map Names Data Base designation for the DOQ : U.S. Geological Survey, Reston, Virginia.

   Type_of_Source_Media: magnetic tape

   Source_Scale_Denominator: 12000

   Source_Contribution:

   
   Provides locational and attribute information for
   photoidentifiable features during revision.
   
   

2. How were the data generated, processed, and modified?

   Date: Unknown (process 1 of 3)

   
   For Digital Revision Status = Not digitally revised:
   This Digital Line Graph was digitized from the USGS source
   quadrangle, by either the National Mapping Division, one of
   their cooperators, or one of their contractors. The digital data
   were produced by one of the following methods:
   - scanning a stable-based copy of the graphic materials.
   The scanning process captured the digital data at a
   scanning resolution of at least 0.001 inches; the
   resulting raster data were vectorized and then attributed
   on an interactive editing station.
   - scanning the paper map. The scanning process captured
   the digital data at a scanning resolution of at least
   0.001 inches; the resulting raster data were vectorized
   and then attributed on an interactive editing station.
   - scanning a stable-based copy of the graphic materials.
   The resulting raster data were then manually digitized
   and attributed on an interactive editing station. The
   resolution of the digital data is at least 0.001 inches.
   - scanning the paper map. The resulting raster data were
   then manually digitized and attributed on an interactive
   editing station. The resolution of the digital data is
   at least 0.001 inches.
   - manually digitizing from a stable-based copy of the
   graphic material using a digitizing table to capture the
   digital data at a resolution of at least 0.001 inches;
   attribution was performed either as the data were
   digitized, or on an interactive edit station after the
   digitizing was completed.
   - manually digitizing from the paper map using a digitizing
   table to capture the digital data at a resolution of at
   least 0.001 inches; attribution was performed either as
   the data were digitized, or on an interactive edit
   station after the digitizing was completed.
   The determination of the DLG production method was based on
   various criteria, including feature density, feature
   symbology, and availability of production systems. Four
   control points corresponding to the four corners of the
   quadrangle were used for registration during data
   collection. An eight parameter projective transformation
   was performed on the coordinates used in the data collection
   and editing systems to register the digital data to the
   internal coordinates used in PROSYS, and a four parameter linear
   transformation was performed from the PROSYS internal coordinates
   to Universal Transverse Mercator (UTM) grid coordinates. The DLG
   data were checked for position by one or more of the following
   processes:
   - comparing plots of the digital data to the graphic source.
   - comparing the digital data to the digital raster scan.
   DLG data classification was checked by at least one of the
   following processes.
   - comparing plots of the digital data to the graphic source
   - comparing the digital data to the digital raster scan.
   

   Data sources used in this process:

   • MAP1

   Date: Unknown (process 2 of 3)

   
   For Digital Revision Status = Limited Update
   This file has undergone limited update digital revision.
   Limited update revision uses monoscopic imagery and limited
   ancillary source, with no field verification.
   

   Data sources used in this process:

   • DOQ1, DOQ2, DOQ3, DOQ4

   Date: Unknown (process 3 of 3)

   
   For Digital Revision Status = Standard Update
   This file has undergone standard update digital revision.
   Standard update revision uses stereoscopic imagery as
   needed, in addition to monoscopic imagery, with field
   verification.
   

   Data sources used in this process:

   • DOQ1, DOQ2, DOQ3, DOQ4

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?

   Unknown

2. How accurate are the geographic locations?

   For Digital Revision Status = Not revised:

3. How accurate are the heights or depths?

   
   For Hypsography, Hydrography and Survey Control and
   Markers Only:
   For Digital Revision Status = Not revised:
   

4. Where are the gaps in the data? What is missing?

   
   For Digital Revision Status = Not revised
   Data completeness reflects the content of the source quadrangle.
   Features may have been eliminated or generalized on the source
   graphic, due to scale and legibility constraints.
   For Digital Revision Status = Limited Update
   This file has undergone limited update digital revision. The
   file contains only (1) those features that are photoidentifiable
   on monoscopic source, supplemented with limited ancillary source,
   and (2) those features, present on the original source quadrangle,
   that can not be reliably photoidentified but that are not
   considered particularly prone to change.
   For Digital Revision Status = Standard Update
   This file has undergone standard update digital revision. The
   data completeness of this file meets NMD standards for feature
   content.
   

5. How consistent are the relationships among the observations, including topology?

   
   Topological requirements include: lines must begin and end at
   nodes, lines must connect to each other at nodes, lines do not
   extend through nodes, left and right areas are defined for each
   line element and are consistent throughout the file, and the
   lines representing the limits of the file (neatline) are free of
   gaps.
   The tests of logical consistency were performed by the USGS
   PROSYS program. The neatline was generated by connecting the
   four corners of the digital file, as established during initialization
   of the digital file. All data outside the enclosed region were ignored
   and all data crossing these geographically straight lines were clipped at
   the neatline. Data within a specified tolerance of the neatline
   were snapped to the neatline. Neatline straightening aligned the
   digitized edges of the digital data with the generated neatline,
   that is, with the longitude/latitude lines in geographic
   coordinates. All internal areas were tested for closure using
   PROSYS.
   

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None

Use_Constraints:

None. Acknowledgement of the U.S. Geological Survey would
be appreciated in products derived from these data.

1. Who distributes the data set? (Distributor 1 of 1)
   Earth Science Information Center, U.S.Geological Survey
   507 National Center
   Reston, Virginia 20192
   

   1-888-ASK-USGS (voice)
   

   Hours_of_Service: 0800-1600

   Contact_Instructions:

   
   In addition to the address above there are other ESIC offices
   throughout the country. A full list of these offices is at:
   URL:<http://mapping.usgs.gov/esic/esic_index.html>
   

2. What's the catalog number I need to order this data set?

   1:24,000-scale digital line graphs

3. What legal disclaimers am I supposed to read?

   
   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 day from the date
   of this shipment from the ordering site.
   

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	SDTS Topological Vector Profile
     Network links:	URL: <http://edc.usgs.gov/doc/edchome/ndcdb/dlg_large/states.html> URL: <ftp://edcftp.cr.usgs.gov/pub/data/DLG_LARGE/>
     Media you can order:	CD-ROM (format ISO 9660) Note: This CD-ROM can be used with all computer operating systems that support CD-ROM as a logical storage device. All text files on the disc are in ASCII format. Data files are in ASCII or binary format.

     Data format:

     DLG Optional

     Media you can order:

     CD-ROM (format ISO 9660) Note: This CD-ROM can be used with all computer operating systems that support CD-ROM as a logical storage device. All text files on the disc are in ASCII format. Data files are in ASCII or binary format. Cartridge (Density 3480 megabytes) (format ASCII; available unlabelled or with ANSI- standard labels; available block sizes are multiples of 144 characters ranging from 8064 to 32720 characters. ) Cassette (Density 8-mm High (4.5Gb) gigabytes) (format ASCII; available unlabelled or with ANSI- standard labels; available block sizes are multiples of 144 characters ranging from 8064 to 32720 characters. ) Cassette (Density 8-mm Low (2.3Gb) gigabytes) (format ASCII; available unlabelled or with ANSI- standard labels; available block sizes are multiples of 144 characters ranging from 8064 to 32720 characters. )

   • Cost to order the data:

     The online copy of the data set (when available electronically) may be accessed without charge. For cartridge, cassette, and CD-ROM the costs are available at: URL: <http://edc.usgs.gov/glis/hyper/order_info/prices#DLG_LARGE>

   • Special instructions:

     
     All nonstandard quadrangles with neatlines that extend beyond the
     standard unit size to accommodate overedge boundaries are collected
     as multiples of the standard unit size. Data covering a 7.5- by 8.5-
     minute quadrangle area would be sold as two 7.5-minute units.
     Each 7.5-minute unit is distributed as 1 7.5-minute cell, except in
     high-density areas, where the 7.5-minute cells may be divided into 2 or
     more cells.
     The transportation category of data includes major transportation systems
     collected in three separate overlays labeled: (1) Roads and Trails, (2) Railroads,
     and (3) Pipelines, Transmission Lines, and Miscellaneous Transportation Features.
     Although collected separately, the three files are distributed as a single unit.
     Orders for the transportation category for a given area will include all
     three files.
     Dataset searching and ordering capabilities are available through the
     Global Land Information System (GLIS) at:
     URL: <http://edc.usgs.gov/webglis>
     

Who wrote the metadata?

Dates:

Last modified: Jan-1990

Metadata author:

U.S. Geological Survey
508 National Center
Reston, Virginia 20192

1 703 648 4543 (voice)

Metadata standard:

Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)