Details for Benchmark: HV2659
N 38° 45.700 W 077° 21.500 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In FAIRFAX county, VA View Original Datasheet
- A 120
- Marker Type:
- bench mark disk
- massive structures
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1935 by CGS (MONUMENTED)
|01/01/1941 by CGS (GOOD)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1941
2.2 MI SE FROM CLIFTON. 2.2 MILES SOUTHEAST ALONG SECONDARY STATE HIGHWAY 645 FROM THE SOUTHERN RAILWAY STATION AT CLIFTON, FAIRFAX COUNTY, AT A BRIDGE OVER WOLF RUN, IN THE TOP OF THE RETAINING WALL, 3 FEET WEST OF THE NORTHWEST CORNER OF THE BRIDGE, 12 FEET NORTH OF THE CENTER LINE OF THE HIGHWAY, AND LEVEL WITH THE HIGHWAY. A STANDARD DISK, STAMPED A 120 1935.
|01/01/1955 by CGS (MARK NOT FOUND)
|RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1955
MARK NOT FOUND.
|02/15/1997 by USPSQD (MARK NOT FOUND)
|RECOVERY NOTE BY US POWER SQUADRON 1997
MARK NOT FOUND.
- 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.