DQRID : D100325.1
Start DateStart TimeEnd DateEnd Time Data Quality Metric
08/18/2009162503/16/20101518Suspect
more
Subject:
SGP/SIRS/E9 - Downwelling SW sensor alignment/level
DataStreams:sgpsirs20sE9.a0, sgpsirsE9.b1
Description:
On clear days, the down_short_hemisp data (PSP instrument) exhibit asymmetry in its daily 
output curve especially when compared to derived downwelling shortwave.  Ops corrected 
the problem by re-leveling the PSP on 3/16/2010. The issue may likely be due to a slowly 
sinking platform at this site or inadvertent loosening of instrument hold down screws.  

Problem may have developed slowly over the last year.  Corrections are not easily 
quantifiable.  Suggest using derived downwelling shortwave which is not dependent on the PSP 
instrument:

derived DS = down_short_diffuse + short_direct_normal * cos(zenith angle)
Suggestions: 
Measurements:sgpsirsE9.b1:
  • down_short_hemisp
  • down_short_hemisp_max
  • down_short_hemisp_std
  • down_short_hemisp_min
more
sgpsirs20sE9.a0:
  • inst_global
more

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