DQRID : D000705.3
Start DateStart TimeEnd DateEnd Time Data Quality Metric
04/28/1998000012/31/19982359Does not affect quality
more
Subject:
TWP/SKYRAD/C1 - Shaded vs. unshaded radiometer comparison
DataStreams:twpskyrad60sC1.b1, twpskyrad20sC1.a1
Description:
The daily average difference between the shaded and unshaded PIRs
reversed on 19980428.  Previous to then, the unshaded PIR was typically
about 2 Wm-2 less than the shaded PIR.  Since the 28th, the unshaded
PIR has been averaging about 4-5 Wm-2 greater than the shaded PIR.
This latter difference worsened for the period 5/25 to 5/31, when the
daily average difference increased to between 8-10 Wm-2.    The
disagreement is typically greater at night, reaching differences of
greater than 12 Wm-2 during the period 5/25-5/31.  The cause for the
switch in sign of the difference can most likely be attributed to
instrument replacement, however the (in general) larger absolute
disagreement after Apr 28th indicates a possible calibration problem.
The cause of the large discrepancies from 5/25 to 5/31 is unknown.

I noticed that the daylight differences increased slightly, with an
attendant slight decrease in the night differences. This daylight
difference is on the order of an additional 1 Wm-2.

Note: the unshaded PIR is incorrectly named "shaded2" during this
time period.  This is covered in a separate DQR.
Suggestions: 
Measurements:twpskyrad60sC1.b1:
  • down_long_hemisp_shaded1_min
  • down_long_hemisp_shaded2_min
  • down_long_hemisp_shaded1_max
  • down_long_hemisp_shaded1_std
  • down_long_hemisp_shaded2_max
  • down_long_hemisp_shaded2_std
  • down_long_hemisp_shaded1
  • down_long_hemisp_shaded2
more
twpskyrad20sC1.a1:
  • inst_down_long_shaded2_case_resist
  • inst_down_long_shaded1_dome_resist
  • inst_down_long_shaded1_case_resist
  • inst_down_long_shaded2_dome_resist
  • inst_down_long_hemisp_shaded2_tp
  • inst_down_long_hemisp_shaded1_tp
more

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