Details for Benchmark: AQ0253
N 29° 54.917 W 081° 18.333 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In ST JOHNS county, FL View Original Datasheet
- WEST END
- Marker Type:
- survey disk
- set into the top of a round concrete monument
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1948 by DOD (MONUMENTED)
|01/01/1970 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1970
1 MI E FROM ST AUGUSTINE. ABOUT 0.95 MILE EAST ALONG STATE HIGHWAY A 1 A FROM THE JUNCTION OF U.S. HIGHWAY 1 AT ST AUGUSTINE, 52 FEET SOUTH OF THE CENTER LINE OF THE HIGHWAY, 102 YARDS WEST OF THE WEST END OF THE LARGE BRIDGE OVER THE INTRACOASTAL WATERWAY, 30 1/2 FEET SOUTH OF A LARGE POWER LINE POLE WITH BRANCH LINES, 5 FEET SOUTHWEST OF THE GROUND END OF A GUY WIRE FOR THE POLE, 1.8 FEET SOUTH OF A WOODEN WITNESS POST, 2 FEET BELOW THE LEVEL OF THE HIGHWAY AND SET IN THE TOP OF A CONCRETE POST PROJECTING 5 INCHES ABOVE THE LEVEL OF THE GROUND.
|01/01/1989 by USPSQD (GOOD)
|RECOVERY NOTE BY US POWER SQUADRON 1989 (JD)
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.