Details for Benchmark: LX3071
N 41° 33.800 W 072° 35.267 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In MIDDLESEX county, CT View Original Datasheet
- Marker Type:
- survey disk
- set into the top of a round concrete monument
- May hold, but of type commonly subject to surface motion.
Benchmarks may be on private property or in dangerous locations. Obey local laws. By using the services on Geocaching.com you agree to this disclaimer.
Documented History (by the NGS)
|01/01/1935 by CTGS (MONUMENTED)
|01/01/1986 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1986
4.8 KM (3.0 MI) SE FROM PORTLAND. 4.8 KM (3.0 MI) SOUTHEAST ALONG STATE HIGHWAY 66 FROM THE JUNCTION OF STATE HIGHWAY 17A IN PORTLAND TO THE MARK ON THE LEFT AND ACROSS THE HIGHWAY FROM POWER POLE NO. 459, ALSO 2.9 KM (1.8 MI) WEST ALONG STATE HIGHWAY 66 FROM THE JUNCTION OF STATE HIGHWAY 151 IN COBALT, 13.8 METERS (45.6 FT) NORTHEAST OF THE CENTERLINE OF THE HIGHWAY, 0.60 METER (2.0 FT) NORTHEAST OF A FENCELINE. THE MARK IS 0.91 METERS NW FROM A WITNESS POST THE MARK IS 11.8 M ABOVE HIGHWAY.
|12/02/1997 by USPSQD (GOOD)
|RECOVERY NOTE BY US POWER SQUADRON 1997
RECOVERED IN GOOD CONDITION.
- The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
- The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in June 1991.
- The geoid height was determined by GEOID99.
- The dynamic height is computed by dividing the NAVD 88 geopotential number by the normal gravity value computed on the Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 degrees latitude (g = 980.6199 gals.).
- The modeled gravity was interpolated from observed gravity values.