Governor Phil Murphy • Lt.Governor Sheila Oliver
  NJ Home | Services A to Z | Departments/Agencies | FAQs
NJGWS Home | DWSG Home | DEP Home  
New Jersey Geological and Water Survey
What's New at NJGS About NJGS NJGS Programs Publications Digital Geodata Environmental Education Links Contact NJGS

Digital Geodata Series
DGS98-4 A 30-Second State Plane Coordinate Grid for New Jersey



A 30-second grid covering New Jersey was generated using the ARC/INFO Geographic Information System (GIS). The grid was created and built as a tool for georegistering page size (8.5" x 11") field sheets using a GIS. The grid was generated as a geographic grid then projected to the 1983 North American Datum in State Plane Coordinate Feet. The grid was built solely as a line coverage and updated with line attributes indicating the value of each arc segment in degrees, minutes, and seconds (for example, 743000 equals 74 degrees, 30 minutes, and 00 seconds). A set of coordinate registration points (tics) covering New Jersey were generated at each latitudinal and longitudinal intersection point. Tic locations were compared to corresponding tics from the NJDEP 7-1/2' grid to check spatial accuracy. The comparison of 138 tic locations showed no spatial deviation between coverages to the nearest tenth of a foot.

 The 30-second coordinate interval provides a GIS basis for registering field sheets that use photoimagery near their maximum spatial resolution. About 64, 30-second tiles cover a quarterquad image (Figure 3). Figures 3, 4, and 5 shows the image resolution of a 30-second tile with respect to an orthoquarterquad image. Figure 4 shows that a 30-second tile fits on a 8.5" x 11" page at about the 1:10,000 scale. Figure 5 shows the quarterquad image near its maximum resolution at the 1:4000 scale (the NJDEP quarterquad images are reported to have a resolution of 5 feet to a pixel).

Figure 1, 1:2,000,000 scale
display of the 30-second grid

1:2,000,000 VIEW

Figure 2. 1:250,000-scale display of the 30-second grid.

1:250,000 VIEW

Figure 3. 1:80,000-scale display of one NJDEP quarter-quad image with the 30-second grid superimposed.

1:80,000 VIEW

Figure 4. 1:10,000 scale display of one 30-second tile with a NJDEP quarter-quad image superimposed.

1:10,000 VIEW

Figure 5. 1:4,000 scale display of a NJDEP quarter- quad image.

1:4,000 VIEW

NJGS HOME contact us privacy notice legal statement accessibility statement

Geological and Water Survey: Home | Directions | NJ-GeoWeb
Department: NJDEP Home | About DEP | Index by topic | Programs/Units | DEP Online
Statewide: NJHome | Services A to Z | Departments/Agencies | FAQ's

Copyright State of New Jersey, 1996-
Department of Environmental Protection
Geological and Water Survey
P. O. Box 420
Mail Code:29-01
Trenton, NJ 08625-0420

Phone: (609) 292-1185
FAX: (609) 633-1004