| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D060331.1 | NSA/AERI/C1 - Excessive Noise in C1 AERI data | nsaaerich1C1.b1, nsaaerisummaryC1.b1 |
| D061020.2 | NSA/AERI/C1 - Reprocessed: Failed temp sensor affected calibration | nsaaerich1C1.b1, nsaaerich2C1.b1, nsaaerisummaryC1.b1 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 09/30/2005 | 0000 | 07/01/2006 | 2359 |
| Subject: | NSA/AERI/C1 - Excessive Noise in C1 AERI data |
| DataStreams: | nsaaerich1C1.b1, nsaaerisummaryC1.b1 |
| Description: | Initially it was believed that the greater noise level in AERI C1 data was due to the extended range detector, which has lower sensitivity. However, when the S01 AERI was installed next to the C1 AERI and it stabilized on 9/30/2005, it was observed that the noise levels on the newly installed S01 AERI were much lower than for the C1 AERI. Therefore, the excessive noise of the C1 AERI is not due to the fundamental nature of the extended range detector but instead due to failure within the detector. The failure could be due to a poor D* value of too high a detector temperature. It could also be caused by optical alignment issues. In either case, the spectral radiance data have much more noise and that results in larger error bars when using the radiance data, especially long wave data as monitored by the LW_HBB_NEN flag. On 9/30/2005, the S01 AERI, which is next to the C1 AERI, came on-line and is producing low noise data. The S01 data should be used instead of the C1 data where low noise requirements are needed. On 6/26/2006, the S01 AERI went offline due to a laser failure. The C1 AERI was moved to the connex where data were within reasonable limits for an extended range detector. Beginning 20060701, the C1 data are the preferred AERI data set at the NSA Barrow location. |
| Measurements: | nsaaerisummaryC1.b1:
nsaaerich1C1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/18/2006 | 0000 | 11/22/2006 | 2359 |
| Subject: | NSA/AERI/C1 - Reprocessed: Failed temp sensor affected calibration |
| DataStreams: | nsaaerich1C1.b1, nsaaerich2C1.b1, nsaaerisummaryC1.b1 |
| Description: | On 18 Oct 2006, a thermistor that measures the temperature of the blackbody support structure failed, resulting in erroneously high values. This measurement, which is captured by the field "BBsupportStructureTemp", provides the temperature of the radiance that is reflected into the blackbody (i.e., captured by the field "calibrationAmbientTemp"), and thus the calibrated radiance (the field "mean_rad") was incorrect and outside the ARM specification that the AERI data should be absolutely calibrated to within 1% of the ambient radiance. The broken thermistor was fixed on 22 Nov 2006. Fortunately, since the emissivity of the blackbodies is so high, absolute accuracy of the calibrationAmbientTemp is not required but should be within a few degrees. The radiance data have been recalibrated using the ambient blackbody temperature (the field "calibrationCBBtemp") as a surrogate of the calibrationAmbientTemp. Historically, the calibrationAmbientTemp and calibrationCBBtemp measurements have been within 1-2 deg. As a result of this recalibration, the radiance data are now absolutely calibrated to better than 1%. |
| Measurements: | nsaaerich2C1.b1:
nsaaerisummaryC1.b1:
nsaaerich1C1.b1:
|