Details for Benchmark: RD4281
N 45° 45.183 W 122° 30.983 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In CLARK county, WA View Original Datasheet
- Marker Type:
- bench mark disk
- set into the top of a prefabricated concrete post imbedded in the ground
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1990 by WA-011 (MONUMENTED)
|DESCRIBED BY CLARK COUNTY WASHINGTON 1990
ALONG THE CHELATCHIE PRAIRIE RAILROAD 2 MILES SOUTH OF THE CITY OF BATTLEGROUND, IN THE NORTHEAST CORNER OF THE CROSSING AT N.E. 181ST STREET (NEAR INTERSECTION OF 181ST ST AND N.E. 152ND AVE., NEAR CEDARS GOLF COURSE CLUBHOUSE), 17.5 FT (5.3 M) EAST OF CENTERLINE OF TRACKS, 48 FT (14.6 M) NORTH OF THE CENTERLINE OF 181ST ST, 45 FT (13.7 M) WEST OF CENTERLINE 152ND AVESET 2 1/2 IN DIAM DOMED BRASS DISK IN IRON PIPE CAST INTO TOP OF ROUND CONCRETE MONUMENT SET IN MASS OF CONCRETE. SET STEEL POST WITH SIGN BY THE POINT
- 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 April 1995.
- 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.