Details for Benchmark: AA5521
N 42° 16.850 W 083° 44.450 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In WASHTENAW county, MI 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)
|01/01/1993 by MI0150 (MONUMENTED)
|DESCRIBED BY CITY OF ANN ARBOR MICHIGAN 1993 (GD)
STATION 1011 IS LOCATED AT THE SOUTHWEST CORNER OF EAST HURON STREET AND SOUTH STATE STREET, SAID STATION BEING IN THE NORTHEAST 1/4 OF SECTION 29, ANN ARBOR TOWNSHIP, IN THE CITY OF ANN ARBOR, MICHIGAN. THE STATION IS LOCATED 1.1 FT (0.3 M) NORTH OF THE NORTH EDGE OF THE 5 FT (1.5 M) CONCRETE WALK ALONG THE SOUTH SIDE OF EAST HURON STREET AND 1.0 FT (0.3 M) WEST OF THE WEST EDGE OF THE 10 FT (3.0 M) CONCRETE WALK ALONG THE WEST SIDE OF SOUTH STATE STREET. SAID STATION IS A VERTICAL CONTROL MONUMENT AND IS DESCRIBED AS THE 1993 EDITION OF THE CITY OF ANN ARBOR BRASS DISC, WHICH IS SET IN CONCRETE PER DETAIL II AND IS FLUSH WITH THE GROUND. THIS POINT WAS SET BY THE CITY OF ANN ARBOR IN 1993.
- 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 August 1995.
- 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.