Description: | DQR No: Platform: sgpsondeB4
Subject: Jump in pressure value B4 sounding 970420.2030
Date Submitted: 4/24/97
Submitted By: Barry Lesht _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
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509-375-6898 or via email at dqr@arm.gov.
Platform/Measurement: sgpsondewrpnb4/ (alt, asc, press)
What level data: (raw,a0,a1,b1,c1 etc): all
What location was the data collected at: SGP/BF4
Period of time in question
Begin Date 4/20/97 Time 20:30 (GMT)
End Date Time (GMT)
Data should be labeled:
___ questionable _X_ All data fields affected
_X_ incorrect ___ Only some data fields affected
___ wrong calibration
___ others
Discussion of Problem:
The first pressure value reported by the radiosonde (t = 2 sec) is
925.7. The surface pressure value was 933.7 hPa. This difference
is somewhat greater than the expected (normal) change and may mean that
either the pressure sensor was jarred during launch or the system
mis-identified the actual launch start time. Further clarification requires
analysis of the raw data which will take some time. The altitude values
for this sounding will be incorrect. The ascent rate values during the
first 30 seconds also will be wrong. Because the system will reject
samples with out of bound ascent rates (i.e., during the first 30 seconds),
the temperature and rh values also will be incorrect (result of
interpolation). Relative height values after 30 seconds should be okay.
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. |