Details for Benchmark: MY2101
N 42° 15.567 W 071° 27.133 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In MIDDLESEX county, MA View Original Datasheet
- X 37
- Marker Type:
- bench mark disk
- massive structures
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1978 by NGS (MONUMENTED)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1978
0.8 MI EAST FROM ASHLAND. 0.8 MILE SOUTHEAST AND NORTHEAST ALONG MAIN STREET AND STATE HIGHWAY 135 FROM THE CROSSING OF THE RAILROAD TRACKS IN ASHLAND TO THE MARK ON THE LEFT, 2.45 MILES SOUTHWEST OF FRAMINGHAM, SET IN THE TOP OF THE NORTHWEST ABUTMENT OF HIGHWAY BRIDGE, 26.5 FEET EAST OF POWER POLE NUMBER 8, 24 FEET NORTHWEST OF THE CENTER LINE OF HIGHWAY, 2 FEET NORTHWEST OF A WIRE GUARDRAIL.
- 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.