Details for Benchmark: HW3666
N 38° 39.671 W 078° 19.214 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is ADJUSTED. (more info)
- In RAPPAHANNOCK county, VA View Original Datasheet
- MARY AZ MK
- Marker Type:
- azimuth mark disk
- in a boulder
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1965 by CGS (MONUMENTED)
|05/18/1992 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1992
AT SKYLINE DRIVE AT THORNTON GAP,200 FT (61.0 M) NORTH OF US HIGHWAY 211, 180.0 FT (54.9 M) WEST OF ROAD LEADING TO THE SKYLINE DRIVE, 140.0 FT (42.7 M) EAST OF THE NORTHEAST CORNER OF THE BRIDGE OVER U.S. HIGHWAY 211 AND ON THE SKYLINE DRIVE AT THORNTON GAP, IN A LARGE BOULDER THAT PROJECTS 4 FEET (1.2 M).
|04/15/1998 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1998 (RWA)
FROM THE US211 AND US522 INTERSECTION IN SPERRYVILLE VIRGINIA, GO WEST ON US211 6.9 MI (11.02 KM) TO THE OFF RAMP TO SHENANDOAH NATIONAL PARK ENTRANCE. THE ROCK OUTCROPPING IS ON THE WEST SIDE OF THE ENTRANCE ROAD, IN A CLAER AREA. THE DISK IS SET IN THE LARGEST ROCK OUTCROPPING ON THE HIGHEST PART TOWARDS THE SOUTHWEST END. THE MARK IS A STANDARD NGS AZIMUTH MARK DISK STAMPED MARY AZ MK.
|10/02/1998 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1998 (RLA)
RECOVERED AS DESCRIBED.
|03/01/2000 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 2000 (RWA)
RECOVERED AS DESCRIBED.
- The horizontal coordinates were established by GPS observations and adjusted by the National Geodetic Survey in April 1999.
- The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in May 1999.
- The X, Y, and Z were computed from the position and the ellipsoidal ht.
- The Laplace correction was computed from DEFLEC99 derived deflections.
- The ellipsoidal height was determined by GPS observations and is referenced to NAD 83.
- 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.