From http://www.ngdc.noaa.gov/geomagmodels/struts/calcDeclination
, the magnetic declinations of the sites varied from 12 11' to 12 17' east. To correct the magnetic azimuths of the sonics and props we'll use a declination value of 12.2 degrees for all sites.
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The following are from logbook entries of the sonic azimuths.
Note that all measured azimuths are in degrees magnetic, with the declination set to 0 on the compass or datascope, to reduce untraceable mental mistakes.
site | log date | pointing | sonic boom azimuth, magnetic | boom azimuth, true (mag+12.2) | Vazimuth, true (boom+90) |
|---|---|---|---|---|---|
playa1 | 12/18 | west | 76.9 + 180 = 256.9 | 269.1 | 359.1 |
abc2 | 12/16 | east | 249.5 - 180 = 69.5 | 81.7 | 171.7 |
hiland3 | 12/14 | east | 249.5 - 180 = 69.5 | 81.7 | 171.7 |
wvally4 | 12/16 | west | 86.7 + 180 = 266.7 | 278.9 | 8.9 |
wvally4 | 12/19 | " | 80.3 + 180 = 260.3 | 272.5 | 2.5 |
eslope5 | 12/15 | east | 248.7 - 180 = 68.7 | 80.9 | 170.9 |
wslope6 | 12/13 | west | 77.8 + 180 = 257.8 | 270 | 0.0 |
river7 | 12/13 | west | 85.5 + 180 = 265.5 | 277.7 | 7.7 |
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