Details for Benchmark: MY0561
N 42° 21.417 W 071° 03.200 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In SUFFOLK county, MA View Original Datasheet
- Marker Type:
- bench mark disk
- light structures
- Mark of questionable or unknown stability.
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Documented History (by the NGS)
|Unknown by CGS (MONUMENTED)
|01/01/1947 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1947
AT BOSTON. A STANDARD DISK SET IN THE TOP OF A CONCRETE MONUMENT PROJECTING ABOUT 2.0 FEET ABOVE THE GROUND, LOCATED IN THE NORTHEAST SECTION OF FORT HILL SQUARE PARK, WHICH IS ON HIGH STREET AT THE INTERSECTION OF BATTERY MARCH AND OLIVER STREET, THE MONUMENT IS 9.0 FEET SOUTHEAST OF THE EDGE OF THE WALK LEADING FROM THE CENTER OF THE PARK TOWARDS BELCHER LANE, AND THE WORDS UNITED STATES COAST AND GEODETIC SURVEY BASIC BENCH MARK ARE INSCRIBED ON THE NORTHWEST SIDE OF THE MONUMENT.
- 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.