Details for Benchmark: HT2271
N 37° 43.767 W 122° 28.483 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In SAN FRANCISCO county, CA View Original Datasheet
- M 6 C OF SF
- Marker Type:
- survey disk
- light structures
- Mark of questionable or unknown stability.
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Documented History (by the NGS)
|01/01/1974 by CA3290 (MONUMENTED)
|01/01/1977 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1977
IN SAN FRANCISCO. AT SAN FRANCISCO, ON 19 TH AVE AT STONETOWN MALL, A DISK SET IN THE SIDEWALK IN THE CENTER OF A PAINTED WHITE CROSS, 10 FEET SOUTH OF THE STEPS LEADING TO THE MALL AT THE NORTH END, AND 5 FEET WEST OF THE WEST CURB OF 19 TH AVE.
- 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.