Digital
raster graphic (DRG)
Digital raster graphic (DRG) is a scanned image of a
U.S.
Geological Survey (USGS) topographic map which are
produced by private organizations through an innovative
partnership with the USGS. The scanned image can include all
map collar information, or may be ordered without the collar
information (clipped to the neat line). The image inside the
map neat line is georeferenced to the surface of the Earth.
The DRG can be used to collect, review, and revise other
digital data, especially digital line graphs (DLG). DRG's
are "rough" representations of USGS maps, and are a low-cost
alternative to electronic versions of USGS maps. When
the DRG is combined with other digital products, such
as digital orthophoto quadrangles (DOQ) or digital elevation
models (DEM), the resulting image provides additional
visual detail for the extraction and revision of base
cartographic information.
DRG
SPECIFICATIONS
1:24000
250 DPI (Dots per Inch)
16 color table (4 BIT)
Can be ordered with or without collar information
HTSI can Deliver DRG'S
in the following projections:
UNIVERSAL TRANVERSE MECATOR , NAD 83, NAD 27 OR WGS 84 Meters
TRANSVERSE MECATOR
- SPECIFIC STATE ZONE; NAD 83 feet or meters; NAD 27
feet or meters; WGS 84 feet or meters
State
Plane, NAD 27 NAD 83 OR WGS84, METERS OR FEET
LAT\LON
NAD 83 OR NAD 27 OR WGS84
Lambert
Conformal Conic - SPECIFIC STATE ZONE NAD 83 METERS OR FEET
: NAD 27 METERS OR FEET : WGS84 METERS OR FEET
IMAGE FORMATS
TIF- ARCINFO TFW
TIF -MAPINFO TAB
TIF - GEOTIFF (GEOGRAPHIC)
TIF - GEOTIFF (PROJECTED)
TIF - DRG (FGD)
TIF - TIF 6.0
HTM - HTML FORMAT
TIF - TIF 4.0
BMP - Windows Bitmap Format
JPG - JPEG Format (JPW)
SDW - MR SID Compressed
