Details for Benchmark: HY1469
N 38° 43.917 W 083° 00.550 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In SCIOTO county, OH View Original Datasheet
- X 78
- Marker Type:
- bench mark disk
- massive structures
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1935 by CGS (MONUMENTED)
|01/01/1948 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1948
AT PORTSMOUTH. AT PORTSMOUTH, SCIOTO COUNTY, ON U.S. HIGHWAY 52, 0.9 MILE WEST OF THE POST OFFICE, 47 YARDS WEST OF THE WEST END OF THE MINAMAX SERVICE STATION, AT A FOUR-SPAN BRIDGE OVER SCIOTO RIVER, IN THE TOP OF THE NORTH END OF THE CONCRETE WALL OF THE EAST ABUTMENT, ONE FOOT WEST OF THE PIPE RAIL FENCE, 17 FEET NORTH OF THE CENTERLINE OF THE HIGHWAY, AND ABOUT ONE FOOT ABOVE THE LEVEL OF THE ROADWAY. A STANDARD DISK, STAMPED X 78 1935.
- 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.