DQR ID | Subject | Data Streams Affected |
---|---|---|
D060327.4 | TWP/MPL/C1 - Intermittent Double Pulse from laser | twpmplC1.a1 |
D060522.1 | TWP/SMET/C1 - Upper wind sensor failure | twpsmet60sC1.b1 |
D060901.1 | TWP/MPL/C1 - Data dropouts | twpmplC1.a1, twpmplcmask1clothC1.c1, twpmplsmask1clothC1.c1 |
D061011.2 | TWP/SMET/C1 - Reprocess: Tipping bucket rain gauge added | twpsmet60sC1.b1 |
D070112.1 | TWP/MMCR/C1 - Reprocess: Height Error | twpmmcrmomC1.00, twpmmcrmomC1.b1, twpmmcrspecmomC1.a0 |
D070129.1 | TWP/MMCR/C1 - Error in recorded heights | twpmmcrmomC1.00, twpmmcrmomC1.b1, twpmmcrspecmomC1.a0 |
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:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/09/2006 | 0000 | 10/14/2006 | 0237 |
Subject: | TWP/SMET/C1 - Upper wind sensor failure |
DataStreams: | twpsmet60sC1.b1 |
Description: | The upper wind speed sensor was binding at low wind speeds. Comparison to the lower wind sensor showed that the upper sensor flat-lines for long periods of time. The upper anemometer was replaced. |
Measurements: | twpsmet60sC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/19/2006 | 1800 | 08/28/2006 | 0041 |
Subject: | TWP/MPL/C1 - Data dropouts |
DataStreams: | twpmplC1.a1, twpmplcmask1clothC1.c1, twpmplsmask1clothC1.c1 |
Description: | Data dropouts occurred during this period. Problem ended when MPL computer was rebooted. |
Measurements: | twpmplC1.a1:
twpmplsmask1clothC1.c1:
twpmplcmask1clothC1.c1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
10/09/1996 | 0000 | 10/17/2006 | 0000 |
Subject: | TWP/SMET/C1 - Reprocess: Tipping bucket rain gauge added |
DataStreams: | twpsmet60sC1.b1 |
Description: | A tipping bucket rain gauge was added to the TWP.C1 SMET suite of instruments on 20061017. Effective 20060926, two new variables (count and rain amount) were added to the end of the twpsmet60sC1.b1 datastream. Between 9/26 and 10/17, the data for these two variables are filled with zeros. Users should not use the data during this period as the zeros are not representative of the rain fall at the site. When reprocessing of this datastream occurs these variables will be added for the 19961009-20060926 and data from 19961009-20061017 will be filled with -9999 (missing). |
Measurements: | twpsmet60sC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
06/16/2006 | 0300 | 01/11/2007 | 1620 |
Subject: | TWP/MMCR/C1 - Reprocess: Height Error |
DataStreams: | twpmmcrmomC1.00, twpmmcrmomC1.b1, twpmmcrspecmomC1.a0 |
Description: | A timing error was found in the PIRAQ MMCR's. It resulted in recorded heights being too high for each radar mode by the following amounts: Mode 1: 24.8756 m too high Mode 2: 25.6249 m too high Mode 3: 33.1176 m too high Mode 4: 33.1176 m too high Range gate spacing was not affected. |
Measurements: | twpmmcrmomC1.b1:
twpmmcrspecmomC1.a0:
twpmmcrmomC1.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
06/16/2006 | 0300 | 11/28/2006 | 2359 |
Subject: | TWP/MMCR/C1 - Error in recorded heights |
DataStreams: | twpmmcrmomC1.00, twpmmcrmomC1.b1, twpmmcrspecmomC1.a0 |
Description: | An error in MMCR configuration resulted in a timing error. This caused erroneous height values (too large) to be recorded in the data files. |
Measurements: | twpmmcrmomC1.b1:
twpmmcrspecmomC1.a0:
twpmmcrmomC1.00:
|