Details for Benchmark: AI4402
N 39° 36.572 W 076° 36.008 (NAD 83)
Coordinates may not be exact. Altitude is GPS OBS and location is ADJUSTED. (more info)
- In BALTIMORE county, MD View Original Datasheet
- 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)
|01/01/1997 by MD-005 (MONUMENTED)
|DESCRIBED BY BALTIMORE COUNTY MARYLAND 1997 (WEH)
DESCRIBED BY BALTIMORE COUNTY SURVEY DIVISION 1997 (WEH) . STATION IS LOCATED ABOUT 3.7 MILES (6.0 KM) EAST NORTHEAST OF HEREFORD AND 6.5 MILES (10.5 KM) NORTH NORTHWEST OF JACKSONVILLE. TO REACH THE STATION FROM THE ROUTE 137 (MOUNT CARMEL ROAD) OVERPASS OF I83 AT EXIT 27, GO EAST ON ROUTE 137 FOR 0.5 MILES (0.8 KM) TO THE INTERSECTION WITH ROUTE 45 (YORK ROAD) . TURN RIGHT AND GO SOUTH ON ROUTE 45 FOR 0.1 MILES (0.2 KM) TO THE INTERSECTION WITH ROUTE 138 (MONKTON ROAD) .TURN LEFT AND GO EAST ON ROUTE 138 FOR 2.9 MILES (4.7 KM) TO THE BRIDGE OVER THE GUNPOWDER FALLS. CONTINUE EAST ON ROUTE 138 FOR 0.4 MILES (0.6 KM) TO A FORK. TAKE THE LEFT FORK WEST NORTHWEST ON ROUTE 138 (SHEPPERD ROAD) FOR 2.8 MILES (4.5 KM) TO A TEE INTERSECTION WITH TROYER ROAD. TURN LEFT AND GO NORTHWEST ON ROUTE 138 (TROYER ROAD) FOR 1.0 MILES (1.6 KM) TO THE INTERSECTION WITH MCCOMAS ROAD. TURN LEFT AND GO NORTHWEST 0.7 MILES (1.1 KM) TO THE INTERSECTION WITH WILSON ROAD. TURN LEFT AND GO WEST ON WILSON ROAD FOR 0.7 MILES (1.1 KM) TO THE STATION ON THE LEFT.STATION MARK IS SET IN THE TOP OF A 10 INCH DIAMETER CONCRETE MONUMENT. IT IS IN A GRASS STRIP BETWEEN THE PAVED ROAD AND A FENCED HORSE PASTURE. IT IS 15 FEET (4.6 M) NORTHEAST FROM A 6 INCH SQUARE WOOD FENCE POST, 5.50 FEET (1.68 M) NORTHWEST FROM A 4 INCH DIAMETER CIRCULAR WOOD FENCE POST, AND 15 FEET (4.6 M) SOUTH FROM THE CENTERLINE OF WILSON ROAD.
- The horizontal coordinates were established by GPS observations and adjusted by the National Geodetic Survey in March 2000.
- The orthometric height was determined by GPS observations and a high-resolution geoid model using precise GPS observation and processing techniques.
- 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.