Details for Benchmark: JS4605
N 38° 46.167 W 121° 18.283 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In PLACER county, CA View Original Datasheet
- H 1446
- Marker Type:
- metal rod
- a metal rod driven into the ground
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1988 by NGS (MONUMENTED)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1988
2.5 KM (1.55 MI) NORTHERLY ALONG THE SOUTHERN PACIFIC RAILROAD FROM THE JUNCTION OF SIERRA BOULEVARD IN ROSEVILLE, A METAL ROD DRIVEN 1.4 METERS AND FLUSH WITH THE GROUND, 15.1 M (49.5 FT) NORTHEAST OF THE NEAR RAIL, 5.5 M (18.0 FT) SOUTHWEST OF THE CENTER OF A PAVED ROAD, 3.4 M (11.2 FT) SOUTH OF A UTILITY POLE WITH 2 GUY WIRES, 0.3 M (1.0 FT) NORTHEAST OF A WITNESS POST AND FENCE, AND 0.3 M (1.0 FT) BELOW THE LEVEL OF THE ROAD. NOTE--ACCESS TO THE DATUM POINT IS THROUGH A 5-INCH LOGO CAP.
- 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.