Array 1 sonic azimuths

Started to measure the sonic azimuths with the datascope.  Set declination = 0.

 Array orientations

Sighting along the PAM masts, the orientation of the upwind array is 39.6 deg and the downwind array is 39.2 deg.  Adding 270 degrees and the declination (13.7 deg) gives 323.3 degrees true for the upwind array and 322.9 deg true for the downwind array, which is close to the design value of 325 deg.  Note that the datascope had the wrong declination (but don't know what value was used for the site survey), 13.4 degrees rather than  13.7 degrees, which may account for 0.3 degrees of the differences of 1.7 and 2.1 degrees.

Note that the tripods for the second upwind array are already set up roughly N of the profile tower.  The data scope gives an angle of 156 deg magnetic from the leg of  the SW tripod to the profile sonics, so the profile winds from directions greater than 156+180 + 13.7 = 7.7 deg true should be used with caution.

Tables list three independent measurements of sonic azimuth.  I measured each row at different times, requiring independent estimates of proper alignment of datascope relative to sonic, which is the biggest source of uncertainty.  I found that the sun angle is much better for visibility of the sonics at 7 am than at 10 am, so I reshot the azimuths done prior to 7/11/08

 Upwind Array Sonics

Profile tower Sonics

Downwind Array, top sonics

Downwind Array, bottom sonics