Digital Geodata Series
DGS98-7 County Topographic Base Map Images for New Jersey (1:100,000 scale)
N.J. Geological Survey DGS98-7 is a set of twenty-one (21) topographic base
map images of the counties in New Jersey. The colored images are derived
from U.S. Geological Survey 1:100,000-scale, 30 x 60 minute map series, digital
raster graphic (DRG) images covering the New Jersey region. The set of 8-bit
images preserves the 11-color format and 250 dots-per-inch resolution of
the source images. Each source image was processed to remove colored foreground
pixels extending beyond the boundary of a county. Most county images are
composed of pieces of several images that were manually joined along the
30 x 60 minute image boundaries. Each image was georegistered and rectified
to the 1983 North American Datum (state plane coordinate feet) using the
ARC/INFO Geographic Information System. At least four links corresponding
to 7-1/2 minute tics and other points along the image perimeter were used
for georegistration. The image files use an uncompressed tagged-image-file
format (TIFF). Each zip file contains a colored image having a
tif file name extension, and a corresponding world-reference
file having a tfw file name extension.
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