Details for Benchmark: KV1492
N 40° 36.300 W 075° 27.967 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In LEHIGH county, PA View Original Datasheet
- Marker Type:
- chiseled square
- light structures
- Mark of questionable or unknown stability.
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Documented History (by the NGS)
|01/01/1881 by CGS (MONUMENTED)
|01/01/1932 by CGS (GOOD)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1932
AT ALLENTOWN. AT ALLENTOWN, LEHIGH COUNTY, AT THE CORNER OF NORTH FOURTH AND LINDEN STREETS, AT THE FRONT ENTRANCE TO THE JAIL, AND IN THE SILL OF A BASEMENT WINDOW ON THE SOUTH SIDE. A CHISELED SQUARE, FLANKED BY THE LETTERS I USC AND GS BM 1881.
|01/01/1934 by CGS (GOOD)
|RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1934
RECOVERED IN GOOD CONDITION.
|01/01/1987 by LOCSUR (MARK NOT FOUND)
|RECOVERY NOTE BY LOCAL SURVEYOR (INDIVIDUAL OR FIRM) 1987 (CT)
MARK NOT FOUND.
|12/11/1999 by USPSQD (MARK NOT FOUND)
|RECOVERY NOTE BY US POWER SQUADRON 1999
MARK NOT FOUND.
- 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.