Details for Benchmark: JV0585
N 39° 15.983 W 076° 34.850 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In C OF BALTIMORE county, MD View Original Datasheet
- 857 4680 TIDAL 31
- Marker Type:
- tidal station disk
- light structures
- Mark of questionable or unknown stability.
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Documented History (by the NGS)
|01/01/1922 by CGS (MONUMENTED)
|01/01/1971 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1971
AT BALTIMORE. AT BALTIMORE, AT FORT MC HENRY, AT THE U.S. NAVAL RESERVE TRAINING CENTER, SET IN THE TOP OF THE GRANITE DOORSILL ON THE SOUTHWEST SIDE OF BUILDING FOUR, AT THE INTERSECTION OF HALSEY ROAD AND LEAHY STREET, 19 FEET NORTHEAST OF THE CENTER LINE OF THE STREET, 22 FEET NORTHWEST OF THE SOUTH CORNER OF THE BUILDING, AND ABOUT 2 FEET ABOVE THE LEVEL OF THE GROUND.
|01/01/1976 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1976
RECOVERED IN GOOD CONDITION.
|11/28/1995 by NOS (GOOD)
|RECOVERY NOTE BY NATIONAL OCEAN SERVICE 1995 (RFE)
THE BENCH MARK IS SET IN THE GRANITE DOORSILL ON THE SW SIDE OF THE US NAVAL RESERVE BOILER ROOM (BUILDING 4) LOCATED AT FORT MCHENRY, 13.6 M (44.6 FT) NORTH OF THE NW CORNER OF THE MAIN US NAVAL RESERVE BUILDING, 6.7 M (22.0 FT) NW OF THE SOUTH CORNER OF BUILDING 4, 5.5 M (18.0 FT) NNE OF THE ROAD CENTERLINE, 1.4 M (4.6 FT) NW OF THE EDGE OF THE TOP STEP, AND 1 M (3.3 FT) ABOVE GRADE.
- 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.
- This Tidal Bench Mark is designated as VM 433 by the Center for Operational Oceanographic Products and Services.
- 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.