T-sheet #1453, COMMENCEMENT BAY, TACOMA

Transformation from North American Datum (NAD) to North American Datum of 1927 (NAD27)

Computations by Dave Snyder and Elizabeth Cassel

Station Data from: Patton, R.S., 1999. Datum Differences: Atlantic, Gulf, and Pacific Coast of the United States. U.S. Department of Commerce, U.S. Coast and Geodetic Survey, Washington, D.C. (Original publication: 1936).

Average of differences from all six stations

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Average converted to Decimal Degrees

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Avg Diff (sec) Avg Diff (Decimal Deg)
Latitude shift from NAD to NAD27 Seconds       -1.088
-0.000302129630
Latitude shift Standard Deviation (seconds)       0.001  
Latitude shift Standard Deviation (meters)       0.03  
Longitude shift from NAD to NAD27 Seconds      
-1.295
-0.000359583333
Longitude shift Standard Deviation (seconds)      
0.001
  
Longitude shift Standard Deviation (meters)      
0.02
  

Station Name PID NAD27 Deg min sec NAD sec Diff (sec)
WASH 2, 1921 29 47 16 12.572 13.66 -1.088
    122 29 3.034 4.328 -1.294
BOS, 1905 29 47 15 58.407 59.496 -1.089
    122 23 0.301 1.597 -1.296
SMELT, 1905 29 47 17 45.199 46.286 -1.087
    122 31 27.283 28.577 -1.294
DRON, 1905 29 47 17 59.729 60.816 -1.087
    122 26 27.217 28.511 -1.294
GULL, 1891 29 47 17 51.49 52.578 -1.088
    122 25 52.922 54.216 -1.294
BROWN, 1921 29 47 18 21.526 22.613 -1.087
    122 26 35.044 36.339 -1.295
   
arrow Latitude difference in seconds
arrow Longitude difference in seconds
   
  Determining the average shift in Latitude and Longitude from NAD to NAD27 datum. The average difference in Decimal Degrees is then applied to the tic coordinates.
Determining the average shift in Latitude and Longitude from NAD to NAD27 datum. The average difference in Decimal Degrees is then applied to the tic coordinates.