Description: | DQR No: Platform: SGP BSRN C1.A1
(surface radiation station)
Subject: Bad radiation data on July 17
Date Submitted: July 7, 1995
Submitted By: John Augustine _X_ Instrument Mentor
for John Deluisi ___ EST Member
___ Science Team Member
___ Other
_____________________________
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Platform/Measurement:
What level data: (raw,a0,a1,b1,c1 etc): a1
What location was the data collected at: SGP
Period of time in question
Begin Date 7/16/95 Time 18:36 (GMT)
End Date 7/17/95 Time 23:59 (GMT)
Data should be labeled:
___ questionable ___ All data fields affected
___ incorrect _X_ Only some data fields affected
___ wrong calibration
___ others
Discussion of Problem:
After looking at the plots for solar direct, diffuse, and global
radiation, I believe that two problems are evident. The data on July 16
look normal for quasi-clear sky conditions until about 18:36 (UTC). The
rest of the day looks cloudy, i.e., the global and diffuse follow each
other, and the NIP signal is near 0, although noisy (i.e., the NIP signal
actually goes below 0 w m^-2 for two short periods between 2000 and 2100
UTC).
The diffuse and NIP data on July 17 are suspect. The NIP reads zero all
day. From sunrise to 17:55 (UTC), the diffuse and global track each
other to fairly high values (max 1000 W m^2). After the fuse was
replaced, at 17:55, the diffuse radiation drops to normal values (around
300 W m^2), and the global remains at high (normal) values. This
suggests that the blown fuse affected the shade disk mechanism for the
diffuse radiometer. However, the NIP remains at zero all day long.
According to the data on July 17, which suggests that it was a partly
cloudy day with no deep clouds, the NIP signal should be comparable to
the global reading. Therefore the NIP's erroneous signal was not corrected
after the fuse was replaced.
On July 18, all solar data look good, suggesting that the problem with
the NIP was corrected sometime before sunrise.
Other observations/measurements impacted by this problem:
Suggested corrections of the Problem: (e.g. change calibration
factor and recompute, flag data with this comment, etc.)
Flag data according to the above discussion. NIP and diffuse
measurement affected.
Data Processing Notes Date |