Details for Benchmark: AI7615
N 38° 51.567 W 077° 02.717 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In ARLINGTON county, VA View Original Datasheet
- DCA 00 05
- Marker Type:
- survey disk
- set into the top of a round concrete monument
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|Unknown by RICE (MONUMENTED)
|08/01/2000 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 2000 (RWA)
AT THE RONALD REAGAN WASHINGTON NATIONAL AIRPORT, AT BUILDING NO 12 AT NORTHWEST END OF AIRPORT AND MARK IS AT WEST SIDE OF BUILDING. 8.0 FEET (2.4 M) SOUTH OF A LIGHT POLE SUPPORTED BY A 10 FOOT (3.0 M) 10 INCH CONCRETE FOUNDATION, 10.8 FEET (3.3 M) WEST OF WEST SIDE OF BUILDING NO 12, 4.3 FEET (1.3 M) NORTHEAST OF A TREE, 22.0 FEET (6.7 M) EAST OF CENTERLINE OF BLACKTOP ROAD LEADING TO A PARKING LOT K. 2.0 FEET (0.6 M) ABOVE ROAD.
- 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 November 2000. No vertical observational check was made to the station.
- 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.