Details for Benchmark: LC1087
N 40° 10.283 W 089° 18.650 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In LOGAN county, IL View Original Datasheet
- F 220
- 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)
|01/01/1960 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1960
4.4 MI NE FROM LINCOLN. ABOUT 0.5 MILES NORTH ALONG NORTH MCLEAN STREET FROM THE POST OFFICE IN LINCOLN, THENCE 2.4 MILES EAST ALONG STATE HIGHWAY 10, THENCE 1.5 MILES NORTH ALONG A GRAVEL ROAD, AT A FENCE CORNER WEST OF THE ROAD, 23 FEET WEST OF THE CENTER LINE OF THE ROAD, 0.5 FEET EAST OF THE FENCE, 2 FEET SOUTH OF THE FENCE CORNER, 24 FEET NORTH OF A POWER POLE, 1.5 FEET NORTH OF A METAL WITNESS POST, ABOUT LEVEL WITH THE ROAD, AND SET IN THE TOP OF A CONCRETE POST PROJECTING 2 INCHES.
- 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.