Details for Benchmark: AC7987
N 44° 53.422 W 097° 04.566 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is ADJUSTED. (more info)
- In CODINGTON county, SD View Original Datasheet
- A 467
- Marker Type:
- metal rod
- stainless steel rod in sleve
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1995 by NGS (MONUMENTED)
|06/12/1996 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1996 (DFC)
THE STATION IS LOCATED ABOUT 7.0 MI (11.3 KM) WEST OF KRAZENBURG, 6.6 MI (10.6 KM) SOUTH-SOUTHEAST OF RAUVILLE, AND 2.0 MI (3.2 KM) EAST OF WATERTOWN, ON U.S. HIGHWAY 212. OWNERSHIP--THE STATE OF SOUTH DAKOTA. TO REACH THE STATION FROM THE JUNCTION OF INTERSTATE HIGHWAY 29 AND U.S. HIGHWAY 212, ABOUT 3.0 MI (4.8 KM) EAST OF WATERTOWN, GO WEST ON U.S. HIGHWAY 212 FOR 0.95 MI (1.53 KM) TO A DRIVEWAY AND THE STATION ON THE RIGHT. THE STATION IS 115.5 FT (35.2 M) NORTH OF THE HIGHWAY CENTERLINE, 26.5 FT (8.1 M) WEST OF A SIGN (ELMIRA 33-350), 20.5 FT (6.2 M) NORTHWEST OF THE NORTHWEST CORNER OF A CULVERT UNDER THE DRIVEWAY, AND 1.0 FT (0.3 M) SOUTH OF A WITNESS POST AND A FENCE. NOTE--ACCESS TO THE DATUM POINT IS THROUGH A 5-INCH LOGO CAP.
|10/11/1996 by CHANCE (GOOD)
|RECOVERY NOTE BY JE CHANCE AND ASSOCIATES 1996 (LH)
1.5 KM (0.95 MI) WESTERLY ALONG U.S. HIGHWAY 212 FROM THE JUNCTION OF INTERSTATE HIGHWAY 29 IN WATERTOWN (EXIT 177), 348.0 M (1141.7 FT) WEST OF MILEPOST 379, 31.9 M (104.7 FT) NORTH OF THE CENTERLINE OF THE WESTBOUND LANES OF THE HIGHWAY, 10.1 M (33.1 FT) NORTHWEST OF THE CENTER OF A DRIVEWAY, 6.0 M (19.7 FT) WEST OF THE CENTER OF A FIELD ENTRANCE AND GATE, 0.4 M (1.3 FT) BELOW THE LEVEL OF THE HIGHWAY, AND 0.3 M (1.0 FT) SOUTH OF A WITNESS POST AND FENCE. NOTE--ACCESS TO THE DATUM POINT IS THROUGH A 5-INCH LOGO CAP. THE SLEEVE DEPTH DOES NOT MEET THE SPECIFICATIONS FOR A CLASS A MARK.
- The horizontal coordinates were established by GPS observations and adjusted by the National Geodetic Survey in April 1997. This is a SPECIAL STATUS position. See SPECIAL STATUS under the DATUM ITEM on the data sheet items page.
- The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in July 1998.
- 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.