Details for Benchmark: LC0753
N 40° 48.883 W 088° 40.633 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In LIVINGSTON county, IL View Original Datasheet
- V 248
- Marker Type:
- bench mark disk
- massive structures
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1961 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1961
6 MI NE FROM CHENOA. ABOUT 6.0 MILES NORTHEAST ALONG U.S. HIGHWAY 66 FROM ITS JUNCTION WITH U.S. HIGHWAY 24 IN THE SOUTHWEST PART OF CHENOA, ABOUT 0.05 MILES SOUTHWEST OF THE JUNCTION OF A GRAVELED ROAD EAST AT GULF MOBILE AND OHIO RAIL ROAD MILE POST NO. 97, SET IN THE TOP OF THE NORTHWEST END OF A CONCRETE BACKWALL AT THE NORTHEAST END OF GULF MOBILE AND OHIO RAIL ROAD BRIDGE NO. 970, 5.5 FEET NORTHWEST OF THE NORTHWEST RAIL OF THE SOUTHBOUND TRACK, 99 FEET SOUTHEAST OF THE CENTER LINE OF THE NORTHBOUND LANE OF U.S. HIGHWAY 66, 72 FEET SOUTHWEST OF THE MILE POST NO. 97, 2 FEET ABOVE THE LEVEL OF THE HIGHWAY AND ABOUT LEVEL WITH THE RAILROAD TRACKS. NOTE-- THE MARK MAY ALSO BE REACHED FROM THE JUNCTION OF U.S. HIGHWAY 66 AND STATE HIGHWAY 116 IN THE SOUTHWEST EDGE OF PONTIAC BY GOING SOUTHWEST ALONG U.S. HIGHWAY 66 FOR 4.4 MILE.
- 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.