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.
...
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) | notes |
|---|---|---|---|---|---|---|
playa1 | 12/18 | west | 76.9 + 180 = 256.9 | 269.1 | 359.1 |
|
playa1 | 1/5 | " | 77.3+180 = 257.3 |
|
|
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abc2 | 12/16 | east | 249.5 - 180 = 69.5 | 81.7 | 171.7 |
|
abc2 | 1/4 | " | 80 |
|
| shot from the back (centered mast in claws), so hard to see; still thought it was okay |
hiland3 | 12/14 | east | 249.5 - 180 = 69.5 | 81.7 | 171.7 |
|
hiland3 | 12/20 | " | 253.5 - 180 = 73.5 | 85.7 | 175.7 |
|
hiland3 | 1/3 | " | 254.2 - 180 = 74.2 |
|
| shot from across the street |
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 | mast was not lowered between 12/16 and 12/19 |
wvally4 | 12/20 | " | 85.8 + 180 = 265.8 | 278.0 | 8.0 |
|
wvally4 | 1/3 | " | 80.8 +180 = 260.8 |
|
|
|
eslope5 | 12/15 | east | 248.7 - 180 = 68.7 | 80.9 | 170.9 |
|
eslope5 | 1/5 | " | 251.1 - 180 = 71.1 |
|
|
|
wslope6 | 12/13 | west | 77.8 + 180 = 257.8 | 270 | 0.0 |
|
wslope6 | 1/6 | " | 79.3 |
|
|
|
river7 | 12/13 | west | 85.5 + 180 = 265.5 | 277.7 | 7.7 |
|
Props
site | log date | pointing | prop azimuth, magnetic | prop az, true (mag+12.2) | notes |
|---|---|---|---|---|---|
playa1 | 11/20 | north |
| 1.0 |
|
playa1 | 12/18 | north | 171.7 + 180 = 351.7 | 3.9 |
|
playa1 | 1/6 | " | 174.2+180=354.2 | 6.4 |
|
wslope6 | 11/20 | north |
| 1.7 | should this have been -1.7, which agrees with 12/13? |
wslope6 | 12/13 | north | 346.1 | 358.3 |
|
wslope6 | 1/6 | " | 169.3+180=349.3 | 1.5 |
|