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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 221 deg and the downwind array is 40 deg.  Adding 90 and 270 degrees and the declination (13.7 deg) gives 324.7 degrees true for the upwind array and 323.7 deg true for the downwind array, which are close to the design value of 325 deg.  

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 = 349.7 deg true should be used with caution.

The tables list three or more independent measurements of sonic azimuth.  I measured each row at different times, requiring independent estimates of proper alignment of the datascope relative to the 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 remeasured the azimuths done prior to 7/11/08.

The cal_file entries are the value used for the sonic azimuth in the cal_files in order to give winds in a coordinate system with the sonic u component normal to the array (positive for winds blowing into the array sonics) and v parallel to the array:    use + 13.7 - (325-180) = use - 131.7

 Upwind Array Sonics

date

3u

4u

5u

6u

7u

8u

9u

10u

11u

7/6

133.6

136.5

133.3

134.3

135.3

NA

133.9

134.9

133.1

7/6

133.4

135.8

132.3

134.4

134.8

132.4

133.2

134.0

133.7

7/6

133.0

135.4

132.1

134.4

134.7

134.0

131.8

132.8

132.3

7/14

133.2

133.6

132.0

132.2

134.0

133.3

132.6

132.3

132.6

7/14

132.8

135.0

131.6

132.5

133.2

131.5

132.9

132.6

132.4

7/14

132.6

135.0

132.1

132.3

133.5

132.0

132.8

132.2

131.3

use

132.9

135.0

132.1

132.3

133.6

132.3

132.8

132.4

132.1

cal_file

  1.2

  3.3

  0.4

  0.6

   1.9

  0.6

   1.1

  0.7

  0.4

Profile tower Sonics

date

1.5m

3m

4m

5.5m

7m

8m

7/8

132.4

135.8

133.6

135.9

128.8

131.2

7/8

132.9

136.7

133.4

134.0

130.7

133.0

7/8

132.2

136.3

133.8

133.1

130.3

132.0

7/13

132.5

136.0

133.9

133.5

133.9

129.2

7/13

132.1

134.5

133.1

135.6

134.0

134.6

7/13

132.0

136.0

133.7

135.1

134.1

135.7

use

132.3

136.0

133.6

134.6

134.0

132.6

cal_file

   0.6

   4.3

    1.9

    2.9

    2.3

   0.9

Downwind Array, top sonics

date

3t

4t

5t

6t

7t

8t

9t

10t

11t

7/11

136.1

136.1

138.9

134.5

134.7

135.1

135.7

135.7

140.9

7/11

135.9

135.3

139.1

134.1

134.6

134.9

135.3

135.9

140.7

7/11

135.8

135.9

138.8

134.0

135.1

134.9

135.6

135.5

140.6

use

135.9

135.8

138.9

134.2

134.8

135.0

135.5

135.7

140.7

cal_file

   4.2

   4.1

   7.2

   2.5

   3.1

   3.3

  3.8

  4.0

  9.0

Downwind Array, bottom sonics

date

1b

2b

3b

4b

5b

6b

7b

8b

9b

10b

11b

12B

13B

7/12

136.3

131.8

134.3

133.8

136.3

130.9

134.5

135.8

134.4

134.5

138.5

136.8

137.0

7/12

136.3

130.8

134.4

134.1

136.0

131.8

134.0

136.3

135.2

135.1

138.6

136.6

136.7

7/13

136.1

131.5

135.1

134.2

136.4

131.6

134.1

136.1

134.8

135.3

138.7

136.5

136.9

use

136.2

131.4

134.6

134.0

136.2

131.4

134.2

136.1

134.8

135.0

138.6

136.6

136.9

cal_file

   4.5

  -0.3

   2.9

   2.3

  4.5

-0.3

   2.5

  4.4

   3.1

  3.3

   6.9

   4.9

  5.2