Digital Orthophoto (DOQQ - quarter-quadrangle) for Virginia {2000}
Geological Survey (U.S.)
·
2000
Full Details
- Title
- Digital Orthophoto (DOQQ - quarter-quadrangle) for Virginia {2000}
- Description
- Orthophotos combine the image characteristics of a
photograph with the geometric qualities of a map. The
primary digital orthophotoquad (DOQ) is a 1-meter ground
resolution, quarter-quadrangle (3.75-minutes of latitude
by 3.75-minutes of longitude) image cast on the Universal
Transverse Mercator Projection (UTM) on the North
American Datum of 1983 (NAD83).The geographic extent of
the DOQ is equivalent to a quarter-quad plus The overedge
ranges a minimum of 50 meters to a maximum of 300 meters
beyond the extremes of the primary and secondary corner
points. The overedge is included to facilitate tonal
matching for mosaicking and for the placement of the NAD83
and secondary datum corner ticks. The normal orientation
of data is by lines (rows) and samples (columns). Each
line contains a series of pixels ordered from west to
east with the order of the lines from north to south.
The standard, archived digital orthophoto is formatted as
four ASCII header records, followed by a series of 8-bit
binary image data records. The radiometric image
brightness values are stored as 256 gray levels ranging
from 0 to 255. The metadata embedded in the digital
orthophoto contain a wide range of descriptive
information including format source information,
production instrumentation and dates, and data to assist
with displaying and georeferencing the image.
DOQ images are acquired as a part of the USGS' National Aerial Photography Program (NAPP).
Through NAPP imagery for each state is produced on a 7 year cycle.
These images are the NAPP III cycle which will run from 1997-2001
These DOQQ's are distributed through PASDA as GeoTIFF images as received from USGS.
- Creator
- Geological Survey (U.S.)
- Date Issued
- 2000
- Access Rights
- Public
- Format
- File
- Language
- English
- Date Added
- February 22, 2023
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