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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 procedure is to warm the chamber up to 55 C and then slowly decrease the temperature linearly to -30 C, followed by slowly increasing the temperature back to 55 C. The zero-wind enclosure holds two sonic heads on their sides (with the v-axis vertical) and electronics, one above the other and separated with a horizontal layer of rigid blue foam. On the cool-down cycle, the atmosphere around the top sonic is unstably stratified (cold enclosure lid above warmer the air) and that around the bottom sonic is stably stratified (cold enclosure bottom below warmer air). The opposite is true during the warm-up cycle. Both the wind component data and the sonic temperature data have significantly less variance when the air is stably stratified, and thus we use data from the bottom sonic during the cool-down cycle and data from the upper sonic during the warm-up cycle.
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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. Rudy also calculated the sonic temperature correction (again from -20 to 30 C) by interpolating the speed-of-sound temperatures of the hygrothermometers to the height of the sonic.
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.
SCP Site | EOL cal | Sonic | Owner | Cal date | u | v | w | tc offset | tc slope | rms dev | ||||||||
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Ah1 | 1/09/13 | 0923 | UC Davis (KT) | 15aug12 | ok | 7 - 23 C; | ok | 0.10 | 1.0223 | 0.07 | ||||||||
repeat calibration | 1/10/13 | 0923 | " | " | ok | 7 - 23 C; | ok | 0.04 | 1.0204 | 0.06 | ||||||||
Ah2 ("glitching in high winds") | 1/09/13 | 0833 | UC Davis (KT) | 29aug12 | ok | ok | ok | 0.69 | 0.9971 | 0.08 | ||||||||
repeat calibration | 1/10/13 | 0833 | " | " | ok | ok | ok | 0.79 | 0.9938 | 0.08 | ||||||||
Ah2 (after 10/19/12@10:15) | 2/04b/13 | 0671 | ISFS |
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| 28jun12 | ok | ok | ok | -0.13 | 1.0172 | 0.10 | |
Aph3 | 1/14/13 Aph3 | 0743 | RAL (Gochis) | 05jul12 | ok | ok | ok | 0.15 | 1.0206 | 0.11 | ||||||||
A4 | 2/06b/13 | 1120 | ISFS | 19jul12 |
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| ok | 23 - 30 C; | ok | -0.19 | 1.0193 | 0.06 | ||
Ah5 | 1/14/13 Ah5 | 0732 | RAL (Gochis) | 09jul12 | ok | ok | ok | 0.86 | 1.0004 | 0.11 | ||||||||
Ah6 | 2/07/13 | 0800 | ISFS | 08dec11 |
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| 19jun12 | ok | ok | ok | 0.08 | 1.0156 | 0.08 | |
A7 | 2/04/13 A7 | 0673 | ISFS | 18jul12 |
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| ok | ok | ok | 1.10 | 0.9979 | 0.09 | ||
Ap8 | 1/11/13 | Ap8 | 0176 | UC Davis (KT) | 22aug12 | ok | ok | ok | 0.50 | 1.0272 | 0.05 | |||||||
Ap9 | 2/05/13 | 1121 | ISFS | 08dec11 |
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| ok | ok | ok | -0.63 | 1.0137 | 0.10 | ||
Ap10 | 2/05/13 Ap10 | 0677 | ISFS | 17jul12 |
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| ok | ok | ok | 1.16 | 0.9995 | 0.10 | ||
Ars11 | 2/07b/12 Ars11 | 0674 | ISFS | 13aug12 |
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| ok | ok | ok | 0.96 | 0.9977 | 0.08 | ||
Ap12 | 2/01/13 | Ap12 | 0855 | ISFS | 12sep12 |
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| ok | ok | ok | 0.95 | 0.9975 | 0.11 | |
A13 | 1/31b/13 A13 | 0745 | RAL (Gochis) | 09jul12 |
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| ok | ok | ok | 1.21 | 0.9978 | 0.11 | ||
Ap14 | 2/06b/13 Ap14 | 1124 | ISFS | 19jul12 |
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| ok | ok | ok | 0.89 | 1.0048 | 0.08 | ||
A15 | 2/05b/13 | A15 | 1122 | ISFS | 08dec11 | ok | ok | ok | -0.44 |
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| 1.0161 | 0.07 | |||
A16 | 1/30/13 A16 | 0740 | RAL (Gochis) | 28aug12 | ok | ok | ok | -1.88 | 0.9979 | 0.9815 06 | ||||||||
A17 | 2/01/13 | 0856 | ISFS | 31jan12 |
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| ok | 19 - 30 C; | 29 - 30 C; | -0.62 | 1.0145 | 0.10 | ||
A18 | 1/15/13 A18 | 0744 | RAL (Gochis) | 05jul12 | ok | ok | ok | 0.41 | 1.0210 | 0.13 | ||||||||
repeat calibration | 2/07b/13 | 0744 | " | " | ok | ok | ok | 0.01 | 1.0227 | 0.06 | ||||||||
A19 (broken joint; |
| 0672 | ISFS | 17jul12 | NA | NA | NA | NA | NA | NA | ||||||||
A19 (installed 9/24/12) | 1/11/13 | 0178 | UC Davis (KT) | 9sep12 | ok | ok | ok | 0.72 | 1.0001 | 0.10 | ||||||||
C.1m | 1/07/13 | 0200 | UC Irvine (JRP) | 27jun12 | ok | ok | ok | -0.04 | 1.0192 | 0.10 | ||||||||
C.2m | 1/07/13 | 0197 | UC Irvine (JRP) | 03jul12 | ok | ok | ok | 0.74 | 0.9900 | 0.07 | ||||||||
M.05m | 1/15/13 | 1455 | USFS (WJM) | 29aug12 | ok | ok | ok | 0.66 | 1.0004 | 0.08 | ||||||||
M.1m | 2/07/13 | 1117 | ISFS |
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| 08dec11 | 29 - 30 C; | 16 - 27 C; | ok | 1.06 | 0.9976 | 0.10 | |||
M.2m (until 9/27/12@15:03?) |
| 0538 | ISFS | NA | NA | NA | NA | NA |
| NA | ||||||||
M.2m | 2/04b/13 | 0536 | ISFS |
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| 27jun12 | ok | ok | ok | 0.80 | 0.9993 | 0.08 | |||
M.3m | 2/01b/13 | 0540 | ISFS |
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| 28mar12 | 27 - 30 C; | ok | ok | -0.20 | 0.9930 | 0.15 | ||
repeat calibration | 2/08/13 | 0540 | " | " | 27 - 30 C; | ok | ok | -1.87 | 1.0125 | 0.09 | ||||||||
M.4m | 1/29/13 M.4m | 0738 | RAL (Gochis) | 8aug12 | ok | 29aug12 | 22 - 28 C; | 18 - 25 C; | ok | -0.46 26 | 1.0197 | 0.11 | ||||||
M.5m (until 9/27/12@15:03?) |
| 0671 | ISFS |
| NA | NA | NA | NA | NA | NA | ||||||||
M.5m | 2/06b/13 | 0537 | ISFS |
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| 21jun12 | ok | ok | ok | -0.19 | 1.0134 | 0.09 | |||
M.10m | 2/01b/13 | 1119 | ISFS |
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| 09aug12 | ok | ok | ok | -0.12 | 1.0137 | 0.16 | ||
repeat calibration | 2/08/13 | 1119 | " | " | ok | ok | ok | 1.22 | 0.9969 | 0.09 | ||||||||
M.20m | 1/31b/13 | 0741 | RAL (Gochis) |
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| 3jul12 | ok | ok | ok | -0.09 | 1.0199 | 0.09 |