USGS_DOQ_Not provided

USGS Digital Orthophoto Quadrangles

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  • Abstract
    A Digital Orthophoto Quadrangle (DOQ) is a computer-generated image of an aerial photograph in which the image displacement caused by terrain relief and camera tilt has been removed. The DOQ combines the image characteristics of the original photograph with the georeferenced qualities of a map. DOQs are black and white (B/W), natural color, or color-infrared (CIR) images with 1-meter ground resolution. The USGS produces three types of DOQs: 1. 3.75-minute (quarter-quad) DOQs cover an area measuring 3.75-minutes longitude by 3.75-minutes latitude. Most of the U.S. is currently available, and the remaining locations should be complete by 2004. Quarter-quad DOQs are available in both Native and GeoTIFF formats. Native format consists of an ASCII keyword header followed by a series of 8-bit binary image lines for B/W and 24-bit band-interleaved-by-pixel (BIP) for color. DOQs in native format are cast to the Universal Transverse Mercator (UTM) projection and referenced to either the North American Datum (NAD) of 1927 (NAD27) or the NAD of 1983 (NAD83). GeoTIFF format consists of a georeferenced Tagged Image File Format (TIFF), with all geographic referencing information embedded within the .tif file. DOQs in GeoTIFF format are cast to the UTM projection and referenced to NAD83. The average file size of a B/W quarter quad is 40-45 megabytes, and a color file is generally 140-150 megabytes. Quarter-quad DOQs are distributed via File Transfer Protocol (FTP) as uncompressed files. 2. 7.5-minute (full-quad) DOQs cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude. Full-quad DOQs are mostly available for Oregon, Washington, and Alaska. Limited coverage may also be available for other states. Full-quad DOQs are available in both Native and GeoTIFF formats. Native is formatted with an ASCII keyword header followed by a series of 8-bit binary image lines for B/W. DOQs in native format are cast to the UTM projection and referenced to either NAD27 or NAD83. GeoTIFF is a georeferenced Tagged Image File Format with referencing information embedded within the .tif file. DOQs in GeoTIFF format are cast to the UTM projection and referenced to NAD83. The average file size of a B/W full quad is 140-150 megabytes. Full-quad DOQs are distributed via FTP as uncompressed files. 3. Seamless DOQs are available for free download from the Seamless site. DOQs on this site are the most current version and are available for the conterminous U.S. [Summary provided by the USGS.]

Data Identification Fields:

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    Processing Level

    Not provided

    Quality
    Attribute_Accuracy: Attribute_Accuracy_Report: During photographic reproduction of the source photography, limited analog dodging is performed to improve image quality. Analog dodging consists of holding back light from certain areas of the sensitized photographic material to avoid overexposure. The diapositive is inspected to insure clarity and radiometric uniformity. Diapositive image brightness values are collected with a minimum of image quality manipulation. Image brightness values may deviate from brightness values of the original imagery due to image value interpolation during the scanning and rectification processes. Radiometry is verified by visually inspecting the DOQs to the original unrectified image to determine if the DOQ has the same image quality or better image quality than the original unrectified input image. Slight systematic and radiometric differences can be detected between adjacent DOQ files due primarily to differences in source photography capture dates and Sun angles of aerial photography along flight lines. These differences can be observed in an image's general lightness or darkness when compared to adjacent DOQ file coverages. Quantitative_Attribute_Accuracy_Assessment: Attribute_Accuracy_Value: 7.0 meters RMSE Attribute_Accuracy_Explanation: The DOQ root-mean-square-error (RMSE) is the square root of the average of the squared discrepancies. These discrepancies are the differences in coordinate (x and y) values derived by comparing the data being tested with values determined during aerotriangulation or by an independent survey of higher accuracy. Logical_Consistency_Report: All DOQ header data and image file sizes are validated by Tape Validation System (TVS) software prior to archiving in the Sales Data Base. This validation procedure assures correct physical format and field values for header record elements. Logical relationships between header record elements are tested. Completeness_Report: All DOQ images are visually inspected for completeness to ensure that no gaps or image misplacement exists in the image area or in overedge coverage. The DOQ images may be derived by mosaicking multiple images, in order to insure complete coverage. All DOQs are cloud free. Some clouds may, very infrequently, be encountered only in the overedge coverage. Source photography is leaf-off in deciduous vegetation regions. Void areas may exist, having a radiometric value of zero and appearing black. These voids are areas for which no photographic source is available or are the result of image transformation from other planimetric systems to the UTM projection. In the latter case, the void sliver areas are on the outside edges of the overedge area. The data set field content of each DOQ header record element is validated to assure completeness prior to archiving in the Sales Data Base. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The DOQ horizontal positional accuracy and the assurance of that accuracy depend, in part, on the accuracy of the data inputs to the rectification process. These inputs consist of the digital elevation model (DEM), aerotriangulation control and methods, the photo source camera calibration, scanner calibration, and aerial photographs that meet National Aerial Photography Program (NAPP) standards. Field control is acquired by third order class 1 or better survey methods sufficiently spaced to meet National Map Accuracy Standards for 1:12,000-scale products. Aerial cameras have current certification from the USGS, National Mapping Division, Optical Science Laboratory. Test calibration scans are performed on all source photography scanners. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The vertical accuracy of the verified USGS format DEM is equivalent to or better than a USGS level-1 or -2 DEM.
    Collection Progress

    In Work

    Use Constraints
    There is no guarantee of warranty concerning the accuracy of these data. Users should be aware that temporal changes may have occurred since the data was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of their limitations. Acknowledgement of the originating agencies would be appreciated in products derived from these data. Any user who modifies the data set is obligated to describe the types of modifications they perform. User specifically agrees not to misrepresent the data set, nor to imply that changes made were approved or endorsed by the U.S. Geological Survey. Please refer to http://www.usgs.gov/privacy.html for the USGS disclaimer.
    Access Constraints

    None

Related URLs
    Science Keywords
    • EARTH SCIENCE
    • LAND SURFACE
    • TOPOGRAPHY
    • TERRAIN ELEVATION
    • DIGITAL ELEVATION/TERRAIN MODEL (DEM)
    • EARTH SCIENCE
    • BIOSPHERE
    • VEGETATION
    • VEGETATION COVER
    • EARTH SCIENCE
    • CRYOSPHERE
    • GLACIERS/ICE SHEETS
    • GLACIERS
    • EARTH SCIENCE
    • HUMAN DIMENSIONS
    • INFRASTRUCTURE
    • CULTURAL FEATURES
    • EARTH SCIENCE
    • TERRESTRIAL HYDROSPHERE
    • GLACIERS/ICE SHEETS
    • GLACIERS
    • EARTH SCIENCE
    • TERRESTRIAL HYDROSPHERE
    • SURFACE WATER
    • LAKES
    • EARTH SCIENCE
    • TERRESTRIAL HYDROSPHERE
    • SURFACE WATER
    • RIVERS/STREAMS
    • EARTH SCIENCE
    • LAND SURFACE
    • GEOMORPHIC LANDFORMS/PROCESSES
    • EARTH SCIENCE
    • LAND SURFACE
    • TOPOGRAPHY
    • TOPOGRAPHIC EFFECTS
    • EARTH SCIENCE
    • SPECTRAL/ENGINEERING
    • INFRARED WAVELENGTHS
    • INFRARED IMAGERY
    • EARTH SCIENCE
    • SPECTRAL/ENGINEERING
    • VISIBLE WAVELENGTHS
    • VISIBLE IMAGERY
    • EARTH SCIENCE
    • BIOSPHERE
    • AQUATIC ECOSYSTEMS
    • RIVERS/STREAM HABITAT
    • EARTH SCIENCE
    • BIOSPHERE
    • AQUATIC ECOSYSTEMS
    • LAKES
    • EARTH SCIENCE
    • BIOSPHERE
    • AQUATIC ECOSYSTEMS
    • MARINE HABITAT
Other Descriptive Keywords
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Ancillary Keywords
  • DOQ
  • DIGITAL IMAGE MAPS
  • DIGITAL ORTHOPHOTOQUADS
  • DOQQ
  • 7.5- x 7.5-MINUTE ORTHOPHOTOS
  • 2-METER ORTHOPHOTOS
  • QUARTER-QUADRANGLE ORTHOPHOTOS
  • RECTIFIED PHOTOGRAPHS
  • 1-METER ORTHOPHOTOS
  • 3.75- x 3.75-MINUTE ORTHOPHOTOS
  • AERIAL PHOTOGRAPHS
  • DIGITAL ORTHOPHOTOS
  • USGS/EROS
ISO Topic Categories
  • ELEVATION
  • IMAGERY/BASE MAPS/EARTH COVER
Additional Attributes
  • metadata.uuid
    STRING
    Not provided
    Resolution Range Begin Range End Unit of Measure Accuracy

  • metadata.extraction_date
    STRING
    Not provided
    Resolution Range Begin Range End Unit of Measure Accuracy

  • metadata.keyword_version
    FLOAT
    Not provided
    Resolution Range Begin Range End Unit of Measure Accuracy

Acquisition Information Fields:

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Platforms
  • DEM
    Instruments

Temporal Information Fields:

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Spatial Information Fields:

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    Coverage Type Zone Identifier Geometry Granule Representation
    HORIZONTAL CARTESIAN NO_SPATIAL
Location Keywords
    • CONTINENT
    • NORTH AMERICA
    • MEXICO
    • CONTINENT
    • NORTH AMERICA
    • CANADA
    • CONTINENT
    • NORTH AMERICA
    • UNITED STATES OF AMERICA

Data Centers

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  • USGS/EROS
    ORIGINATOR

    This data center does not have any addresses listed.

    This data center does not have any contact mechanisms listed.

  • DOI/USGS/EROS
    Multiple Roles

    ARCHIVER

    DISTRIBUTOR

    Earth Resources Observation and Science Center, U.S. Geological Survey, U.S. Department of the Interior

    This data center does not have any addresses listed.

    This data center does not have any contact mechanisms listed.

Data Contacts

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  • LTA REPRESENTATIVE
    Metadata Author
    LTA REPRESENTATIVE USGS EROS CENTER

    LTA Customer Services
    U.S. Geological Survey
    EROS Center
    Sioux Falls, South Dakota 57198-0001

    • Email
    • 605-594-6589
    • 605-594-6151, 800-252-4547
  • GEORGE
    Technical Contact
    GEORGE LEE

    U.S. Geological Survey
    National Mapping Division
    345 Middlefield Road, Mail Stop 531
    Menlo Park, CA 94025

    • Email
    • 650-329-4249
    • 650-329-4255
  • Data Center Contact
    EROS CENTER

    DOI/USGS/EROS

    LTA Customer Services
    U.S. Geological Survey
    EROS Center
    Sioux Falls, SD 57198-0001

    • Email
    • 605-594-6589
    • 605-594-6151, 800-252-4547

Collection Citations Fields:

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    Collection Citations
    • Digital Orthophoto Quadrangles

      Created by:

      Published by: U.S. Geological Survey

      Released: