The attached plots were made with our Splus function, plot.tilt, that does a linear least squares fit to find the plane of mean flow, and plots the wind vector elevation angle vs azimuth. The planar fit becomes a sine wave on the tilt plot.
From a long term plot of the sonic "diag" value, I chose two periods where the the values were consistently very small. plot.tilt discards 5 minute wind averages when "diag" is above 0.01, or more than 1% of the data has a non-zero CSAT3 diagnostic value.
date |
height (m) |
lean |
leanaz |
w offset (m/s) |
elevation residual rms (deg) |
offset residual rms (m/s) |
notes |
|---|---|---|---|---|---|---|---|
Mar 2011 |
2 |
4.1 |
-1.7 |
0.03 |
2.9 |
0.04 |
|
|
7 |
5.9 |
8.2 |
0.07 |
5.7 |
0.08 |
|
|
16 |
5.9 |
-0.2 |
-0.01 |
3.1 |
0.011 |
|
|
30 |
4.5 |
-2.1 |
0.02 |
2.7 |
0.014 |
|
|
43 |
4.3 |
-5.9 |
0.04 |
3 |
0.02 |
|
Aug 2011 |
2 |
5.6 |
-6.3 |
0.04 |
2.6 |
0.03 |
|
|
7 |
9.1 |
-1.4 |
0.06 |
7 |
0.09 |
large tilt |
|
16 |
5.9 |
4.6 |
-0.01 |
3.6 |
0.01 |
|
|
30 |
4.3 |
-0.9 |
0.00 |
3.6 |
0.01 |
|
|
43 |
4.4 |
-5.5 |
0.01 |
4.2 |
0.02 |
|
These tilts appear to be due to the slope of the terrain, slopeing down in the -u direction, in the direction that the sonic boom points. If the terrain was not sloping, these would be a "backwards" tilt, i.e. the booms not drooping from the tower but angling upward.
March 2011 |
|---|
| There are no images attached to this page. |
August 2011 |
|---|
| There are no images attached to this page. |
dpar(start="2011 2 21 00:25",end="2011 4 4 07:26",coords="instrument") dpar(hts=2) plot.tilt(flag="diag",ellim=10,spdmin=0.5)