Details for Benchmark: JS0769
N 38° 50.167 W 121° 10.983 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In PLACER county, CA View Original Datasheet
- J 566
- Marker Type:
- bench mark 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)
|01/01/1938 by CGS (MONUMENTED)
|01/01/1969 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1969
8.4 MI NE FROM ROSEVILLE. 8.4 MILES NORTHEAST ALONG THE SOUTHERN PACIFIC COMPANY RAILROAD FROM THE STATION AT ROSEVILLE, 0.1 MILE WEST OF THE CROSSING OF A PRIVATE ROAD, 99 1/2 FEET EAST AND ACROSS THE TRACK FROM MILEPOLE 115, 78 FEET SOUTH AND ACROSS THE TRACK FROM THE FIRST POLE NORTHEAST OF THE MILEPOLE, 28.1 FEET SOUTHEAST OF THE SOUTHEAST RAIL OF THE WESTBOUND TRACK, 58 1/2 FEET SOUTHWEST OF THE CENTER OF THE SOUTHWEST END OF A RAILROAD CULVERT, 3.0 FEET NORTHWEST OF A FENCE, 1.1 FEET SOUTHWEST OF A WITNESS POST, ABOUT 3 FEET LOWER THAN THE TRACK, AND SET IN THE TOP OF A CONCRETE POST 0.2 FOOT UNDERGROUND.
|06/09/1989 by USPSQD (GOOD)
|RECOVERY NOTE BY US POWER SQUADRON 1989 (EH)
RECOVERED IN GOOD CONDITION.
- 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. WARNING-Repeat measurements at this control monument indicate possible vertical movement.
- 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.