Details for Benchmark: EM0146
N 34° 38.050 W 098° 38.583 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In COMANCHE county, OK View Original Datasheet
- P 37
- Marker Type:
- bench mark disk
- massive structures
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1934 by CGS (MONUMENTED)
|01/01/1963 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1963
7.5 MI E FROM INDIAHOMA. 7.5 MILES EAST ALONG THE ST. LOUIS-SAN FRANCISCO RAILWAY FROM THE STATION AT INDIAHOMA, COMANCHE COUNTY, 1/2 MILE WEST OF CACHE, AT MILEAGE 644.7, AT THE BRIDGE OVER CACHE CREEK, AND IN THE TOP OF THE SOUTHEAST END OF THE EAST CONCRETE PIER. A STANDARD DISK, STAMPED P 37 1934.
|01/01/1983 by LOCSUR (GOOD)
|RECOVERY NOTE BY LOCAL SURVEYOR (INDIVIDUAL OR FIRM) 1983
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.