Details for Benchmark: AB9593
N 44° 31.583 W 073° 15.267 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In CHITTENDEN county, VT View Original Datasheet
- Marker Type:
- survey disk
- abutments and piers of large bridges
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1995 by VTAT (MONUMENTED)
|DESCRIBED BY VERMONT AGENCY OF TRANSPORTATION 1995 (CHR)
GENERAL LOCATION, COLCHESTER, VT. IN THE TOP OF THE ABUTMENT AT THE NORTHWEST CORNER OF THE VT ROUTE 127 BRIDGE OVER THE WINOOSKI RIVER (HEINEBURG BRIDGE). THE MARK IS 1.5 M (4.9 FT) SOUTH OF THE NORTH END OF THE ABUTMENT AND 0.25 M (0.82 FT) EAST OF THE WEST EDGE OF THE ABUTMENT. NOTE, MARK IS SUITABLE FOR GPS BUT HAS A VERY DIFFICULT TRIPOD SET-UP.
- 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 January 1997.
- 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.