Todd Horton, post: 341080, member: 10231 wrote: Shift from US Survey Feet to International Feet is small in NJ because the coordinates at the zone origin are small (N=0m and E=150,000m). For contrast, see origin values for Virginia, Utah, Texas, Michigan, Nevada, and Colorado on page 64 of http://www.ngs.noaa.gov/PUBS_LIB/ManualNOSNGS5.pdf&apos ;">NOAA Manual NOS NGS 5.
For example, see http://www.ngs.noaa.gov/cgi-bin/ds_mark.prl?PidBox=KV6027&apos ;">point KV6027 in Trenton, NJ.
SPCS(2011): N 501,448.64 E 420,700.85 sFT
(12 inches/foot) / (39.37 inches/meter) = legal definition of US Survey Foot per NGS
0.3048 meter/foot = legal definition of International Foot501,448.64*(12/39.37-0.3048)=0.31 m
420,700.85*(12/39.37-0.3048)=0.26 mComputed shift between NAD83 realizations at KV6027:
1986 - 1996: 0.19 ft
1996 - 2007: 0.02 ft
2007 - 2011: 0.07 ft
Computed using http://www.ngs.noaa.gov/cgi-bin/spc_getpc.prl&apos ;">NGS Tools - Lat/Lon to SPCTodd
Isn't this because NJ has 1 zone? I had always heard real time anything in Nj was bad because of this.
I think the number of zones is nearly irrelevant.
The difference in coordinates of the two definitions of a foot depends on the distance from your location to the defined 0,0 point, which depends a lot on what they defined for the false northing and easting.
For most states the false northing and easting makes the 0,0 fall a state or two away from the actual zone, so multiplying that by the difference between foot diefinitions is large enough to be obvious in the coordinates.