Details for Benchmark: EF1694
N 34° 30.789 W 087° 17.453 (NAD 83)
Coordinates may not be exact. Altitude is VERTCON and location is ADJUSTED. (more info)
- In LAWRENCE county, AL View Original Datasheet
- 40 2
- 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)
|01/01/1989 by ALHD (MONUMENTED)
|DESCRIBED BY ALABAMA HIGHWAY DEPARTMENT 1989
THE STATION IS LOCATED IN LAWRENCE COUNTY ON THE WEST RIGHT OF WAY OF ALA 157 IN THE NORTH SIDE OF MOULTON. TO REACH THE STATION FROM THE JUNCTION OF ALA 33 AND ALA 157, MILE POST 34.60 ON ALA 157, IN THE NORTH SIDE OF MOULTON, DRIVE SOUTH ON ALA 157 0.24 KM (0.15 MI) TO MILE POST 34.45 AND THE STATION ON THE RIGHT. THE STATION IS 1.25 M (4.10 FT) EAST - NORTHEAST OF A 1.22 M (4.00 FT) CHAIN LINK FENCE, 17.37 M (56.99 FT) SOUTH OF A SANITARY SEWER MANHOLE, 20.12 M (66.01 FT) SOUTH OF THE SOUTH END OF AN 18 INCH CONCRETE PIPE UNDER A DRIVEWAY, 20.33 M (66.70 FT) SOUTH - SOUTHEAST OF THE NORTHEAST CORNER OF A 1.22 M (4.00 FT) CHAIN LINK FENCE, 21.64 M (71.00 FT) WEST - SOUTHWEST OF THE CENTERLINE OF THE SOUTH BOUND LANES OF ALA 157, 22.46 M (73.69 FT) SOUTH OF THE SOUTH EDGE OF A CONCRETE DRIVEWAY, 1.24 M (4.07 FT) EAST OF A CARSONITE WITNESS POST, AND SET FLUSH WITH THE GROUND. STATION 40 - 1 1989 MAY BE USED AS AN AZIMUTH FOR THIS STATION.
|05/17/1990 by (GOOD)
RECOVERED IN GOOD CONDITION.
- The horizontal coordinates were established by GPS observations and adjusted by the National Geodetic Survey in December 1992.
- The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.)
- The X, Y, and Z were computed from the position and the ellipsoidal ht.
- The Laplace correction was computed from DEFLEC99 derived deflections.
- The ellipsoidal height was determined by GPS observations and is referenced to NAD 83.
- The geoid height was determined by GEOID99.