Details for Benchmark: JV3255
N 39° 55.250 W 077° 39.733 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In FRANKLIN county, PA View Original Datasheet
- R 3
- Marker Type:
- bench mark disk
- in rock outcrop
- Most reliable and expected to hold position/elevation well.
Benchmarks may be on private property or in dangerous locations. Obey local laws. By using the services on Geocaching.com you agree to this disclaimer.
Documented History (by the NGS)
|01/01/1931 by CGS (MONUMENTED)
|01/01/1942 by CGS (GOOD)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1942
1.2 MI S FROM CHAMBERSBURG. 1.2 MILES SOUTH ALONG THE PENNSYLVANIA RAILROAD FROM THE STATION AT CHAMBERSBURG, FRANKLIN COUNTY, AT THE OVERHEAD CROSSING OF THE WESTERN MARYLAND RAILWAY (BRIDGE 52.86), IN THE ROCK LEDGE WHICH IS PART OF THE BASE OF THE EAST WALL OF THE BRIDGE, 8.7 FEET NORTH OF THE SOUTH END OF THE WALL, AND LEVEL WITH THE P.R.R. TRACK. A STANDARD DISK, STAMPED 623.509 R 3 1931.
|01/01/1979 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1979
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.
- 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.