DQR ID | Subject | Data Streams Affected |
---|---|---|
D020620.64 | TWP/C1 - Incorrect elevation reported in Manus Data | twpmplC1.a1, twpvceil25kC1.a1, twpvceil25kC1.b1 |
D040424.3 | TWP/MPL/C1 - SunShade timing problem | twpmplC1.00, twpmplC1.a1, twpmplcmask1clothC1.c1, twpmplsmask1clothC1.c1 |
D050718.1 | TWP/MPL/C1 - energy monitor spikes | twpmplC1.00, twpmplC1.a1 |
D051028.2 | TWP/MPL/C1 - Reprocess: Global metadata error | twpmplC1.a1 |
D060225.1 | TWP/MPL/C1 - Energy monitor values are erroneous | twpmplC1.00, twpmplC1.a1 |
D060327.4 | TWP/MPL/C1 - Intermittent Double Pulse from laser | twpmplC1.a1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
10/11/1996 | 0801 | 06/22/2000 | 2359 |
Subject: | TWP/C1 - Incorrect elevation reported in Manus Data |
DataStreams: | twpmplC1.a1, twpvceil25kC1.a1, twpvceil25kC1.b1 |
Description: | Bill Clements reports we have been using 6m MSL as the station elevation of Momote (Manus). This was based on information posted near the station barometer in the Momote Weather Service Office. It turns out that the official WMO station elevation for Momote is 4m MSL and the upper air elevation is 5m MSL. All Manus instruments except the sonde station are at 4m MSL. The sonde launching station is at 5m MSL. |
Measurements: | twpmplC1.a1:
twpvceil25kC1.a1:
twpvceil25kC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/14/2003 | 0000 | 02/17/2004 | 2359 |
Subject: | TWP/MPL/C1 - SunShade timing problem |
DataStreams: | twpmplC1.00, twpmplC1.a1, twpmplcmask1clothC1.c1, twpmplsmask1clothC1.c1 |
Description: | For an unknown reason, the sun shade was dropping for less then 10 minutes during the night at about 19:00 UTC between Dec 14, 2003 and Feb 17, 2004. Data taken during that ten minute interval is not looking at the sky and should be considered as though it were missing. This is a fairly small effect. Data users can simply average across the interval or block the records as "missing". |
Measurements: | twpmplC1.a1:
twpmplC1.00:
twpmplsmask1clothC1.c1:
twpmplcmask1clothC1.c1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/01/2005 | 0000 | 07/16/2005 | 2300 |
Subject: | TWP/MPL/C1 - energy monitor spikes |
DataStreams: | twpmplC1.00, twpmplC1.a1 |
Description: | The energy monitor spiked to abnormal values, from 2 up to 25 microjoules per pulse. At the beginning, it was only a few intermittent spikes, but the spikes became more frequent. Most of June does not show a spiky energy monitor. On June 28-30, July 1-10 a diurnal pattern shows up. On July 12-13 it abruptly goes away and returns July 14-16 for 24hrs. Then abruptly stops again 17-19. Except for the 12th, the last changes occurred at 00:00 UTC suggesting a piece of equipment is turning on and off. I do not know why a noisy energy monitor would have a day/night or 00:00UTC dependence. |
Measurements: | twpmplC1.a1:
twpmplC1.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/10/1999 | 0716 | 08/27/2002 | 2359 |
Subject: | TWP/MPL/C1 - Reprocess: Global metadata error |
DataStreams: | twpmplC1.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: | twpmplC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/11/2005 | 1200 | 02/25/2006 | 2300 |
Subject: | TWP/MPL/C1 - Energy monitor values are erroneous |
DataStreams: | twpmplC1.00, twpmplC1.a1 |
Description: | Energy monitor values should not be used to normalization the backscatter profiles. A problem with the energy monitor electronics forced the value to maximum. The problem was corrected. |
Measurements: | twpmplC1.a1:
twpmplC1.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
02/01/2005 | 0000 | 01/31/2007 | 0400 |
Subject: | TWP/MPL/C1 - Intermittent Double Pulse from laser |
DataStreams: | twpmplC1.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: | twpmplC1.a1:
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