Start Date | Start Time | End Date | End Time | Data Quality Metric |
---|---|---|---|---|
10/09/1996 | 1943 | 12/09/1998 | 0000 | Does not affect quality |
Subject: | TWP/GNDRAD/C1 - Incorrect dome calibration factor |
DataStreams: | twpgndrad60sC1.b1, twpgndrad60sC1.a1, twpgndrad20sC1.a1 |
Description: | The Manus GNDRAD PIR had an incorrect dome factor since installation. The following is an estimate by Chris Cornwall of the magnitude of the effect of this calibration error. The magnitude of this error is smaller than the calibration accuracy. "Processed the instantaneous data from ARCS2 (10, 30 and 50 seconds after the minute) using 4.32 as the dome factor, and also using 4.00 as the dome factor, as it should have been. The difference between the calculated irradiance results was negligible, as was expected with an instrument operating in the downward-facing direction. Over the three days from 11/06/98 to 11/08/98, the error between the two signals averaged 0.09%. Overnight values were much lower than this, daytime values peaked at 0.42%. The statistics for these error signals were as follows: average error 0.000895 standard dev 0.001119 max error 0.004242 min error -0.00064 We should change ARCS1 so it is using the correct value for the groundrad pir dome coefficient (4.0 instead of 4.32), and we may want to include a DQR stating these findings, although they are much smaller than the overall uncertainty of the PIR itself." |
Suggestions: | Be aware the data contains a very small calibration error. |
Measurements: | twpgndrad20sC1.a1: more
twpgndrad60sC1.b1: more twpgndrad60sC1.a1: more |