Details for Benchmark: TT2259
N 63° 04.883 W 146° 41.017 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In county, AK View Original Datasheet
- E 123
- Marker Type:
- bench mark disk
- copper-clad steel rod
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1965 by CGS (MONUMENTED)
|01/01/1967 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1967
30.75 MI E FROM SUSITNA BRIDGE. 30.75 MILES EAST ALONG STATE HIGHWAY 8 AND THE DENALI HIGHWAY FROM THE WEST END OF THE BRIDGE OVER THE SUSITNA RIVER, AT THE SOUTHWEST END OF A CURVE, ON THE CREST OF A SMALL KNOLL, 0.3 MILE NORTHEAST OF MILEPOST 49, 36 FEET SOUTHEAST OF THE CENTER OF THE HIGHWAY, 2 FEET SOUTHEAST OF A METAL WITNESS POST, ABOUT 3 FEET HIGHER THAN THE HIGHWAY, A DISK CLAMPED TO THE TOP OF A 5/8-INCH COPPER COATED ROD THAT IS DRIVEN TO A DEPTH OF 20 FEET AND ENCASED IN A 5-INCH ORANGEBURG PIPE WHICH PROJECTS 0.5 FEET.
- 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.