Hello, I am plotting deeds in Somerset, NJ and without fail the bearings on these deeds are always off by about 5 degrees from the NAD83 foot NJ State plane. Does anyone know what is going on, and what the exact error is. My guess is that the surveyors who plotted these deeds used magnetic north instead of geodetic north and as such were off by a certain amount. What is happening, and what is the exact angle difference between these plotted deeds and the NJ State plane? Thanks.
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NAD83 Datum questions
- Thread starter cschear
- Start date
AI Overview
The magnetic declination in New Jersey varies by location, but generally ranges from about -7° to -12°. This means that magnetic north is 7 to 12 degrees west of true north in different parts of the state. According to magnetic-declination.com, the declination in Jersey is -7.41° (-7°24\'). In North Princeton, it's -12.15° (-12°9\'), according to a different search result. In Wildwood, it's -3.93° (-4°55\'), according to another search result. For Summit, it's -10.37° (-10°22\'), according to another search result.
from https://www.magnetic-declination.com/USA/Jersey/2818739.html#:~:text=Answer: -7.41° (-7°24')
The magnetic declination in New Jersey varies by location, but generally ranges from about -7° to -12°. This means that magnetic north is 7 to 12 degrees west of true north in different parts of the state. According to magnetic-declination.com, the declination in Jersey is -7.41° (-7°24\'). In North Princeton, it's -12.15° (-12°9\'), according to a different search result. In Wildwood, it's -3.93° (-4°55\'), according to another search result. For Summit, it's -10.37° (-10°22\'), according to another search result.
from https://www.magnetic-declination.com/USA/Jersey/2818739.html#:~:text=Answer: -7.41° (-7°24')
I don't believe it's related to magnetic north; that's not been used as a horizontal basis for survey documents such as plats.
The difference is likely because a different horizontal datum was used at the time of survey, possibly NAD27, or some local grid system.
The surveyor could probably explain the difference.
The difference is likely because a different horizontal datum was used at the time of survey, possibly NAD27, or some local grid system.
The surveyor could probably explain the difference.