Details for Benchmark: MA1121
N 41° 28.383 W 079° 29.933 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In FOREST county, PA View Original Datasheet
- Marker Type:
- survey disk
- massive structures
- Probably hold position/elevation well.
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Documented History (by the NGS)
|Unknown by PADH (MONUMENTED)
|01/01/1935 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1935
AT HUNTER. AT HUNTER, FOREST COUNTY, ON U.S. HIGHWAY 62, ABOUT 740 FEET SOUTH OF THE CROSSING OF THE PENNSYLVANIA RAILROAD, AT THE 3-SPAN BRIDGE OVER THE ALLEGHENY RIVER, IN THE TOP OF THE NORTH CURBING AT THE WEST END OF THE NORTH ABUTMENT, 51 FEET NORTH OF THE WEST VERTICAL ON THE NORTHERNMOST PIER, 11 FEET WEST OF THE CENTER LINE OF THE HIGHWAY, 3 FEET SOUTH OF THE NORTH END OF HIGHWAY STATION 168+64, AND ABOUT 1 FOOT HIGHER THAN THE ROADWAY. A PENNSYLVANIA DEPARTMENT OF HIGHWAYS STANDARD DISK.
- 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.