Details for Benchmark: AB4821
N 40° 59.040 W 102° 46.117 (NAD 83)
Coordinates may not be exact. Altitude is GPS OBS and location is ADJUSTED. (more info)
- In LOGAN county, CO View Original Datasheet
- 7 D
- 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)
|01/01/1949 by USGS (MONUMENTED)
|01/01/1995 by CODOT (GOOD)
|DESCRIBED BY COLORADO DEPARTMENT OF TRANSPORTATION 1995
STATION IS LOCATED ABOUT 10 MILES (16.1 KM) NORTH NORTHEAST OF CROOK, IN THE SW 1/4 OF SEC. 30, T. 12 N., R. 48 W. TO REACH FROM THE INTERSECTION OF SH 138 AND COUNTY ROAD 65, GO NORTH ON COUNTY ROAD 65 FOR ABOUT 8 MILES, (12.9 KM) TO THE STATION ON THE RIGHT (EAST) . STATION MARK IS A BRASS DISK SET IN A CONCRETE MONUMENT, 0.1 MILES (0.2 KM) NORTH OF COUNTY ROAD 65 AND COUNTY ROAD 76, 39 FT (11.9 M) EAST OF THE CENTER OF COUNTY ROAD 65, 52 FT (15.8 M) SOUTH OF A PRIVATE ROAD LEADING EAST TO A FARM HOUSE, 5.4 FT (1.6 M) WEST OF A FIBERGLASS WITNESS POST (NOAA) .
- The horizontal coordinates were established by GPS observations and adjusted by the National Geodetic Survey in July 1996.
- The orthometric height was determined by GPS observations and a high-resolution geoid model.
- The X, Y, and Z were computed from the position and the ellipsoidal ht.
- The Laplace correction was computed from DEFLEC99 derived deflections.
- The ellipsoidal height was determined by GPS observations and is referenced to NAD 83.
- The geoid height was determined by GEOID99.