| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D000608.10 | TWP/MPL/C2 - Power Oscillation | twpmplC2.a1 |
| D000608.11 | TWP/C2/MPL Detector | twpmplC2.00, twpmplC2.a1, twpmplnor1campC2.c1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1 |
| D001113.2 | TWP/MPL/C2 - Nauru MPL Laser Diode accidentally off | twpmplC2.a1 |
| D020207.3 | TWP/MPL/C2 - Laser emission accidentally turned off | twpmplC2.00, twpmplC2.a1, twpmplnor1campC2.c1, twpmplcbh1scottC2.c0, twpmplcbh1scottC2.c1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1 |
| D030317.2 | TWP/MFRSR/C3 - Shadowband Misaligned | twpmfrsrC3.a0, twpmfrsrC3.b1 |
| D030922.1 | TWP/MPL/C2 - laser diode failure | twpmplC2.00, twpmplC2.a1, twpmplnor1campC2.c1, twpmplcbh1scottC2.c0, twpmplcbh1scottC2.c1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1 |
| D050106.2 | TWP/MFRSR/C3 - shadowband misalignment | twpmfrsrC3.a0, twpmfrsrC3.b1, twpmfrsrlangleyC3.c1, twpmfrsrlangplotC3.c1 |
| D050418.1 | TWP/MFRSR/C3 - Lightning strike/logger board | twpmfrsrC3.00, twpmfrsrC3.a0, twpmfrsrC3.b1, twpmfrsrlangleyC3.c1, twpmfrsrlangplotC3.c1 |
| D051028.4 | TWP/MPL/C2 - Reprocess: Global metadata error | twpmplC2.a1 |
| D051028.5 | TWP/MPL/C3 - Reprocess: Global metadata error | twpmplC3.a1 |
| D060621.1 | TWP/MPL/C3 - Missing data due to instrument removal | twpmplC3.00, twpmplC3.a1 |
| D060621.2 | TWP/MPL/C2 - Optical throughput unacceptable | twpmplC2.00, twpmplC2.a1 |
| D060621.3 | TWP/MPL/C2 - Detector on instrument failed. | twpmplC2.00, twpmplC2.a1 |
| D060621.4 | TWP/MPL/C2 - Missing data | twpmplC2.00, twpmplC2.a1 |
| D070515.3 | TWP/MPL/C2 - Reprocess: Incorrect longitude and altitude reported | twpmplC2.a1 |
| D080529.1 | TWP/MPL/C2 - Intermittent Double Pulse from laser | twpmplC2.a1 |
| D080529.2 | TWP/MPL/C3 - Intermittent Double Pulse from laser | twpmplC3.a1 |
| D080530.1 | TWP/MFRSR/C3 - Missing data | twpmfrsrC3.a0, twpmfrsrC3.b1 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/20/1998 | 0000 | 02/03/1999 | 0000 |
| Subject: | TWP/MPL/C2 - Power Oscillation |
| DataStreams: | twpmplC2.a1 |
| Description: | There is an oscillation that shows up in the reflected power and the power monitor. This oscillation shows up clearly whenever there is an absence of low (< ~5 km) clouds. Cloud return signals tend to be much larger than the level of this oscillation; however, it may introduce problems for studying aerosol distributions. The end date of this DQR is artificial in that this is as far as the QC went. |
| Measurements: | twpmplC2.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/03/1999 | 0000 | 04/20/1999 | 1200 |
| Subject: | TWP/C2/MPL Detector |
| DataStreams: | twpmplC2.00, twpmplC2.a1, twpmplnor1campC2.c1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1 |
| Description: | The MPL detector failed and was shut down. |
| Measurements: | twpmplC2.a1:
twpmplC2.00:
twpmplsmask1clothC2.c1:
twpmplcmask1clothC2.c1:
twpmplnor1campC2.c1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/11/2000 | 0010 | 11/13/2000 | 2200 |
| Subject: | TWP/MPL/C2 - Nauru MPL Laser Diode accidentally off |
| DataStreams: | twpmplC2.a1 |
| Description: | The emission from the laser diode supply was accidentally off. The Instrument Mentor, Connor Flynn, called Nauru directly and had them turn the laser emission back on. Backscatter and cloud base data during the period between 2000-11-11 00:00 GMT and 2000-11-13 22:00 GMT should be regarded as bad or incorrect while background light data and local temperature values are acceptable. |
| Measurements: | twpmplC2.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/11/2000 | 0000 | 11/13/2000 | 2200 |
| Subject: | TWP/MPL/C2 - Laser emission accidentally turned off |
| DataStreams: | twpmplC2.00, twpmplC2.a1, twpmplnor1campC2.c1, twpmplcbh1scottC2.c0, twpmplcbh1scottC2.c1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1 |
| Description: | Shortly after 00:00 GMT on 11/11/00, the MPL Energy Monitor value dropped abruptly to zero. At about 22:00 GMT on 11/13/00, the remote handset for the laser diode supply was used to turn the laser back on. |
| Measurements: | twpmplC2.a1:
twpmplC2.00:
twpmplsmask1clothC2.c1:
twpmplcmask1clothC2.c1:
twpmplcbh1scottC2.c1:
twpmplnor1campC2.c1:
twpmplcbh1scottC2.c0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 01/28/2003 | 0000 | 02/12/2003 | 2359 |
| Subject: | TWP/MFRSR/C3 - Shadowband Misaligned |
| DataStreams: | twpmfrsrC3.a0, twpmfrsrC3.b1 |
| Description: | The Shadowband was misaligned beginning as early as 1-28-2003. The banding was adjusted and the misalignment fixed on 2-12-2003. |
| Measurements: | twpmfrsrC3.a0:
twpmfrsrC3.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/20/2001 | 0000 | 01/07/2002 | 2359 |
| Subject: | TWP/MPL/C2 - laser diode failure |
| DataStreams: | twpmplC2.00, twpmplC2.a1, twpmplnor1campC2.c1, twpmplcbh1scottC2.c0, twpmplcbh1scottC2.c1, twpmplcmask1clothC2.c1, twpmplsmask1clothC2.c1 |
| Description: | On Nov 20, 2001, following a data gap of several hours the MPL energy monitor reading showed an abrupt decrease of about 60%. The laser energy continued to decrease to a reading of zero by Nov 23. Cloud detection is satisfactory through Nov 21, but is not satisfactory after this time until the laser diode was replaced on Jan 08, 2002. Data between the dates of 2001-11-22 and 2002-01-08 inclusive is not useful. |
| Measurements: | twpmplC2.a1:
twpmplC2.00:
twpmplsmask1clothC2.c1:
twpmplcmask1clothC2.c1:
twpmplcbh1scottC2.c1:
twpmplnor1campC2.c1:
twpmplcbh1scottC2.c0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/03/2004 | 0100 | 06/11/2004 | 0400 |
| Subject: | TWP/MFRSR/C3 - shadowband misalignment |
| DataStreams: | twpmfrsrC3.a0, twpmfrsrC3.b1, twpmfrsrlangleyC3.c1, twpmfrsrlangplotC3.c1 |
| Description: | During the time period specified, the shadowband was misaligned. Portions of the data have acceptable shading and can be used by experienced data users applying appropriate screening. |
| Measurements: | twpmfrsrC3.a0:
twpmfrsrlangleyC3.c1:
twpmfrsrC3.b1:
twpmfrsrlangplotC3.c1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/11/2005 | 0700 | 04/19/2005 | 0300 |
| Subject: | TWP/MFRSR/C3 - Lightning strike/logger board |
| DataStreams: | twpmfrsrC3.00, twpmfrsrC3.a0, twpmfrsrC3.b1, twpmfrsrlangleyC3.c1, twpmfrsrlangplotC3.c1 |
| Description: | On 11 April 2005 at approximately 07Z, the Darwin site experienced a lightning strike. This strike apparently destroyed the MFRSR logger board. After 11 April, 07Z, there was a short data gap followed by non-physical (roughly constant) values in all channels until the logger board was replaced at 03Z on 19 April 2005. After replacing the logger board, the instrument operated normally. |
| Measurements: | twpmfrsrC3.a0:
twpmfrsrlangleyC3.c1:
twpmfrsrC3.b1:
twpmfrsrC3.00:
twpmfrsrlangplotC3.c1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/06/1998 | 0538 | 07/08/2003 | 0731 |
| Subject: | TWP/MPL/C2 - Reprocess: Global metadata error |
| DataStreams: | twpmplC2.a1 |
| Description: | During the time period specified, the global metadata attribute "averaging_int" is reported as 30 seconds when the value for this attribute should be 60 seconds. |
| Measurements: | twpmplC2.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 08/08/2002 | 0041 | 07/22/2003 | 1447 |
| Subject: | TWP/MPL/C3 - Reprocess: Global metadata error |
| DataStreams: | twpmplC3.a1 |
| Description: | During the time period specified, the global metadata attribute "averaging_int" is reported as 30 seconds when the value for this attribute should be 60 seconds. |
| Measurements: | twpmplC3.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/23/2003 | 0000 | 03/03/2005 | 0000 |
| Subject: | TWP/MPL/C3 - Missing data due to instrument removal |
| DataStreams: | twpmplC3.00, twpmplC3.a1 |
| Description: | The instrument was removed from this site to replace a failed instrument at TWP-C2 Nauru. |
| Measurements: | twpmplC3.00:
twpmplC3.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/01/2003 | 0000 | 11/12/2004 | 1900 |
| Subject: | TWP/MPL/C2 - Optical throughput unacceptable |
| DataStreams: | twpmplC2.00, twpmplC2.a1 |
| Description: | The optical throughput of the MPL at Nauru is below an acceptable level. Despite an extended stay to address the problem in Feb 2003, the problem was unresolved. An additional repair was attempted in July 2003 with no significant success. Several optical components were replaced and the system was repeatedly re-aligned. The system appears to have been properly collimated as the shape of the signal is appropriate for both near and far range. The magnitude of the signal was simply too low. This signal decrease was apparent in ambient background values as well as from atmospheric signal, so the impact on data quality was not as severe as might otherwise be the case. The MPL was still capable of detecting high altitude cirrus (day and night) but the sensitivity was reduced. |
| Measurements: | twpmplC2.a1:
twpmplC2.00:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/12/2004 | 1900 | 12/14/2004 | 2330 |
| Subject: | TWP/MPL/C2 - Detector on instrument failed. |
| DataStreams: | twpmplC2.00, twpmplC2.a1 |
| Description: | The detector on the MPL failed. The result are zeros for the detector counts data. |
| Measurements: | twpmplC2.a1:
twpmplC2.00:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/14/2004 | 2330 | 02/01/2005 | 2130 |
| Subject: | TWP/MPL/C2 - Missing data |
| DataStreams: | twpmplC2.00, twpmplC2.a1 |
| Description: | The MPL was turned off due to a dead detector. |
| Measurements: | twpmplC2.a1:
twpmplC2.00:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/06/1998 | 0000 | 12/01/2000 | 2359 |
| Subject: | TWP/MPL/C2 - Reprocess: Incorrect longitude and altitude reported |
| DataStreams: | twpmplC2.a1 |
| Description: | The longitude of the MPL instrument is reported as -166.916. The correct longitude is +166.916. The altitude of the MPL instrument is reported as 7.2. The correct altitude is 7.1 M. These data will be reprocessed at a low priority. |
| Measurements: | twpmplC2.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/01/2005 | 0000 | 11/27/2006 | 0500 |
| Subject: | TWP/MPL/C2 - Intermittent Double Pulse from laser |
| DataStreams: | twpmplC2.a1 |
| Description: | When Spectra Physics discontinued support for their laser diode power supply, an alternative was need to extend the usefulness of the Spectra Physics laser head inside the MPLs. The solution was to use a Coherent laser diode. Unfortunately, the Coherent diode lasers do not have the exact same characteristics as the Spectra Physics diode lasers. As a result, the output of the Spectra Physics laser head sometimes produces a second pulse close in time but lower in intensity from the first main pulse. This is known as ?double pulsing?. Not all of the Spectra Physics/Coherent combination systems produce a double pulse and the systems that do produce a double pulse do not always exhibit this behavior. It can be identified by a second peak at ~.2km. At first glance the signal in the data will resemble a low aerosol or cloud layer. When the double pulse is weak, the atmospheric signal will obscure the double pulse signal. At the ARM sites with a sunshade such as TWP and AMF, the double pulse can be seen when the sunshade closes during solar noon. When the sunshade closes, the MPL does not see atmospheric signal so the second pulse is evident. At SGP, a daily window cleaning is part of the routine. During this time the double pulse can be seen. Without a sunshade or window cleaning it is impossible to say definitively if double pulse is present. The first system to produce a double pulse was MPL s/n 008 located at TWP ? C2 Nauru in February 2005. The second system was MPL s/n 004 located at SGP in August 2005. The potential for the other systems to produce a double pulse is high. However, as of March 2006, the MPLs at NSA, TWP ? C1, TWP ? C3 and AMF have not recorded data with the double pulse artifact. The ARM program is in the process of replacing all the MPLs with a newer model. After the new MPLs are deployed the double pulse problem should not be an issue. The old systems will be relegated as spares. The double pulse problem will return if an old system is needed to replace a failed new system. |
| Measurements: | twpmplC2.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/01/2005 | 0000 | 08/24/2006 | 2359 |
| Subject: | TWP/MPL/C3 - Intermittent Double Pulse from laser |
| DataStreams: | twpmplC3.a1 |
| Description: | When Spectra Physics discontinued support for their laser diode power supply, an alternative was need to extend the usefulness of the Spectra Physics laser head inside the MPLs. The solution was to use a Coherent laser diode. Unfortunately, the Coherent diode lasers do not have the exact same characteristics as the Spectra Physics diode lasers. As a result, the output of the Spectra Physics laser head sometimes produces a second pulse close in time but lower in intensity from the first main pulse. This is known as ?double pulsing?. Not all of the Spectra Physics/Coherent combination systems produce a double pulse and the systems that do produce a double pulse do not always exhibit this behavior. It can be identified by a second peak at ~.2km. At first glance the signal in the data will resemble a low aerosol or cloud layer. When the double pulse is weak, the atmospheric signal will obscure the double pulse signal. At the ARM sites with a sunshade such as TWP and AMF, the double pulse can be seen when the sunshade closes during solar noon. When the sunshade closes, the MPL does not see atmospheric signal so the second pulse is evident. At SGP, a daily window cleaning is part of the routine. During this time the double pulse can be seen. Without a sunshade or window cleaning it is impossible to say definitively if double pulse is present. The first system to produce a double pulse was MPL s/n 008 located at TWP ? C2 Nauru in February 2005. The second system was MPL s/n 004 located at SGP in August 2005. The potential for the other systems to produce a double pulse is high. However, as of March 2006, the MPLs at NSA, TWP ? C1, TWP ? C3 and AMF have not recorded data with the double pulse artifact. The ARM program is in the process of replacing all the MPLs with a newer model. After the new MPLs are deployed the double pulse problem should not be an issue. The old systems will be relegated as spares. The double pulse problem will return if an old system is needed to replace a failed new system. |
| Measurements: | twpmplC3.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 03/19/2002 | 0202 | 03/22/2002 | 0215 |
| 05/21/2004 | 0617 | 05/25/2004 | 0002 |
| 05/25/2004 | 0213 | 05/28/2004 | 0502 |
| 04/23/2006 | 2302 | 04/26/2006 | 0002 |
| 11/28/2007 | 1602 | 12/08/2007 | 0502 |
| Subject: | TWP/MFRSR/C3 - Missing data |
| DataStreams: | twpmfrsrC3.a0, twpmfrsrC3.b1 |
| Description: | Data are missing and unrecoverable. |
| Measurements: | twpmfrsrC3.a0:
twpmfrsrC3.b1:
|