DQR ID | Subject | Data Streams Affected |
---|---|---|
D050624.6 | NSA/VCEIL/C1 - Reprocess: Intermittent data and clock drift | nsavceil25kC1.b1 |
D051219.1 | NSA/VCEIL/C1 - poor sensitivity at low altitude | nsavceil25kC1.b1 |
D091210.1 | NSA/VCEIL/C1 - Degraded window | nsavceil25kC1.b1 |
D100125.2 | NSA/VCEIL/C1 - Missing data | nsavceil25kC1.b1 |
D100215.3 | NSA/VCEIL/C1/C2 - Reprocess: Incorrect serial_number and sum_backscatter fields | nsavceil25kC1.b1, nsavceil25kC2.b1 |
D100616.2 | NSA/VCEIL/C1 - Small gaps in data | nsavceil25kC1.b1 |
D100719.1 | NSA/VCEIL/C1 - Gaps in data | nsavceil25kC1.b1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
06/16/2005 | 0000 | 06/27/2005 | 2359 |
Subject: | NSA/VCEIL/C1 - Reprocess: Intermittent data and clock drift |
DataStreams: | nsavceil25kC1.b1 |
Description: | The available processed data for the NSA.C1 VCEIL for the time period indicated are incomplete. The raw data is largely complete but pre-processing is required before these data can be reprocessed to produce a complete netcdf data set. While awaiting the reprocessed data set, the intermittent data are available from the ARM Archive. Users should be aware that the data are additionally compromised by a clock drift of at least 10 minutes, though this likely has little affect on cloud detection results. The clock drift will not be addressed by the reprocessing. Note also, that the clock drift was corrected at the end of the DQR period, but it may have existed before the beginning of the DQR period. The data for this period should be used with caution. |
Measurements: | nsavceil25kC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/27/2005 | 1930 | 05/02/2006 | 0000 |
Subject: | NSA/VCEIL/C1 - poor sensitivity at low altitude |
DataStreams: | nsavceil25kC1.b1 |
Description: | The ceilometer has an internal amplifier that it sets to low or high depending on prevalant conditions. Normally, the gain is automatically set high during clear skies. It appears that during these times, a slight degradation in either the transmitter or receiver is being amplified and produces a "ripple" at low altitudes in the backscatter plot. Cloud base height detection is not affected. |
Measurements: | nsavceil25kC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/02/2006 | 0000 | 12/03/2009 | 2107 |
Subject: | NSA/VCEIL/C1 - Degraded window |
DataStreams: | nsavceil25kC1.b1 |
Description: | The ceilometer continuously gave warnings for window contamination because the window had deteriorated. Cloud base height detection did not appear to be significantly affected. The window conditioner was replaced on 8/11/09 but this did not clear the warning. The instrument was replaced. |
Measurements: | nsavceil25kC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
01/23/2010 | 0600 | 01/25/2010 | 2041 |
Subject: | NSA/VCEIL/C1 - Missing data |
DataStreams: | nsavceil25kC1.b1 |
Description: | Data are missing and unrecoverable. |
Measurements: | nsavceil25kC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/22/1999 | 0000 | 10/31/2009 | 2359 |
Subject: | NSA/VCEIL/C1/C2 - Reprocess: Incorrect serial_number and sum_backscatter fields |
DataStreams: | nsavceil25kC1.b1, nsavceil25kC2.b1 |
Description: | Attribute serial_number: In most cases, this field is not representative of the actual serial number of the instrument because the value did not change when an instrument changed locations or was replaced with a spare. Variable sum_backscatter: An out-of-range condition for the "sum of detected and normalized backscatter" was reported as 0 instead of missing (-9999). The valid range is 0 - 0.0999 /srad. This DQR also applies to a1 and b1 level data collected prior to the begin date. |
Measurements: | nsavceil25kC2.b1:
nsavceil25kC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/03/2009 | 2107 | 06/15/2010 | 2143 |
Subject: | NSA/VCEIL/C1 - Small gaps in data |
DataStreams: | nsavceil25kC1.b1 |
Description: | When the ceilometer was replaced, small gaps in the netCDF files occurred due to the presence of '?' characters in the backscatter and header records of the raw data that could not be ingested. It is unknown whether this was caused by a poor CPU board or incompatibilities with the computer configuration (hyper-threading). The problem was corrected when the instrument and computer were both replaced. During this period, approximately 3% of data are missing each hour due to this problem. |
Measurements: | nsavceil25kC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
06/15/2010 | 2159 | 06/17/2010 | 2201 |
Subject: | NSA/VCEIL/C1 - Gaps in data |
DataStreams: | nsavceil25kC1.b1 |
Description: | When the CT25K ceilometer was replaced with a new CL31, checksum errors began occurring at regular 6-min intervals and several things were done to diagnose the problem, including changing the serial cable and trying different computer types. It was finally corrected by replacing the computer with one in which hyperthreading was disabled by default in the BIOS. |
Measurements: | nsavceil25kC1.b1:
|