January 9, 2013
Following the SCP project, we tested each sonic in a zero-wind enclosure within the EOL temperature chamber, measuring wind component offsets and sonic temperature errors over the nominal range -30 C to 55 C.
The following table shows wind component offsets as okay if the u and v offsets are less than +/- 4 cm/s and the w offsets less than +/- 2 cm/s (between - 20 C and 30 C). If the zero wind offset exceed these thresholds, the table lists the temperature range of the over-limit offset and the largest amplitude of the offset. The plots of offsets versus temperature can then be examined to determine exact nature of the offset.
The sonic temperature corrections are listed as the slope and offset of a linear fit (between -20 C and 30 C), Tc = offset + slope*tc.sonic, where Tc is calculated from temperature, relative humidity, and pressure measured in the zero-wind enclosure.
Note that we have repeated the laboratory tests on SN0923 and SN0833 to determine the reproducibility of the results. The velocity component offsets agree within less than 2 cm/s and the temperature offsets agree within 0.06-0.10 C and the slopes agree within 0.2-0.3%, for an overall agreement of no worse than 0.1 C.
Location |
Sonic |
Owner |
Cal date |
u |
v |
w |
tc offset |
tc slope |
rms dev from |
|---|---|---|---|---|---|---|---|---|---|
Ah1 |
0923 |
UC Davis |
15aug12 |
ok |
7-23 C; -7.7 cm/s |
ok |
0.10 |
1.0223 |
0.07 |
repeat calibration |
0923 |
" |
" |
ok |
7-23 C; -7.7 cm/s |
ok |
0.04 |
1.0204 |
0.06 |
Ah2 ("glitching in high winds") |
0833 |
UC Davis |
29aug12 |
ok |
ok |
ok |
0.69 |
0.9971 |
0.08 |
repeat calibration |
0833 |
" |
" |
ok |
ok |
ok |
0.79 |
0.9938 |
0.08 |
Ah2 (after 10/19/12@10:15) |
0671 |
EOL |
|
|
|
|
|
|
|
Aph3 |
0743 |
RAL |
05jul12 |
|
|
|
|
|
|
A4 |
1120 |
EOL |
19jul12 |
|
|
|
|
|
|
Ah5 |
0732 |
RAL |
09jul12 |
|
|
|
|
|
|
Ah6 |
0800 |
EOL |
08dec11 |
|
|
|
|
|
|
A7 |
0673 |
EOL |
18jul12 |
|
|
|
|
|
|
Ap8 |
0176 |
UC Davis |
22aug12 |
ok |
ok |
ok |
0.50 |
1.0272 |
0.05 |
Ap9 |
1121 |
EOL |
08dec11 |
|
|
|
|
|
|
Ap10 |
0677 |
EOL |
17jul12 |
|
|
|
|
|
|
Ars11 |
0674 |
EOL |
13aug12 |
|
|
|
|
|
|
Ap12 |
0855 |
EOL |
12sep12 |
|
|
|
|
|
|
A13 |
0745 |
RAL |
09jul12 |
|
|
|
|
|
|
Ap14 |
1124 |
EOL |
19jul12 |
|
|
|
|
|
|
A15 |
1122 |
EOL |
08dec11 |
|
|
|
|
|
|
A16 |
0740 |
RAL |
28aug12 |
|
|
|
|
|
|
A17 |
0856 |
EOL |
31jan12 |
|
|
|
|
|
|
A18 |
0744 |
RAL |
06jul12 |
|
|
|
|
|
|
A19 (broken joint;removed 9/22/12) |
0672 |
EOL |
17jul12 |
NA |
NA |
NA |
NA |
NA |
|
A19 (installed 9/24/12) |
0178 |
UC Davis |
9sep12 |
ok |
ok |
ok |
0.72 |
1.0001 |
0.10 |
C.1m |
0200 |
UC Irvine |
27jun12 |
ok |
ok |
ok |
-0.04 |
1.0192 |
0.10 |
C.2m |
0197 |
UC Irvine |
03jul12 |
ok |
ok |
ok |
0.74 |
0.9900 |
0.07 |
M.05m |
1455 |
USFS (Massman) |
|
|
|
|
|
|
|
M.1m |
1117 |
EOL |
|
|
|
|
|
|
|
M.2m (until 9/27/12@15:03?) |
0538 |
EOL |
|
|
|
|
|
|
|
M.2m |
0536 |
EOL |
|
|
|
|
|
|
|
M.3m |
0540 |
EOL |
|
|
|
|
|
|
|
M.4m |
0738 |
RAL |
|
|
|
|
|
|
|
M.5m (until 9/27/12@15:03?) |
0671 |
EOL |
|
|
|
|
|
|
|
M.5m |
0537 |
EOL |
|
|
|
|
|
|
|
M.10m |
1119 |
EOL |
|
|
|
|
|
|
|
M.20m |
0741 |
RAL |
|
|
|
|
|
|
|