Details for Benchmark: BU1471
N 31° 01.367 W 087° 31.367 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In ESCAMBIA county, AL View Original Datasheet
- Y 409
- Marker Type:
- bench mark 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)
|01/01/1955 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1955
1.8 MI W FROM ATMORE. 1.8 MILES WEST ALONG THE LOUISVILLE AND NASHVILLE RAILROAD FROM THE STATION AT ATMORE, ABOUT 0.35 MILE WEST OF MILE POST 623, AND 1.0 MILE EAST OF BRIDGE OVER BRUSHY CREEK, AT CROSSING OF A ROAD LEADING NORTH TO A FARM HOUSE, 47 FEET NORTH OF NORTH RAIL, 72 FEET NORTHWEST OF CENTER OF CROSSING, 1 FOOT SOUTH OF A FENCE LINE, 41 1/2 FEET WEST OF A FENCE CORNER, 53 FEET WEST OF CENTER LINE OF ROAD, 34 FEET NORTHWEST OF TELEPHONE POLE NO. 14F, 108 1/2 FEET NORTH-NORTHWEST AND ACROSS TRACK FROM TELEPHONE POLE NO. 5255, 2 FEET WEST OF A WHITE WOODEN WITNESS POST, ABOUT 1 FOOT BELOW LEVEL OF TRACK AND SET IN THE TOP OF A CONCRETE POST PROJECTING 3 INCHES.
- 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.