DQRID : D090831.1
Start DateStart TimeEnd DateEnd Time Data Quality Metric
08/26/2009000010/23/20092359Suspect
08/26/2010000010/23/20102359Suspect
04/16/2009000004/18/20092359Suspect
03/01/2010000004/18/20102359Suspect
more
Subject:
GRW/SKYRAD/M1 - Daily brief instrument shading
DataStreams:grwskyrad20sM1.a0, grwskyrad60sM1.b1
Description:
Due to the persistent cloudy conditions at this site this shading of the NIP and PSP is 
rarely evident in the data. But from approximately 1745 to 1810 GMT from 8/26 to 10/23 and 
from 3/01 to 4/18 during the AMF deployment years 2009 and 2010, the NIP and PSP are 
shaded by the 10m met tower to the SE of the Skystand. 

Data review indicates that the NIP (short_direct_normal) and PSP (down_short_hemisp) are 
shaded by a single tower pole and possibly other tower mounted objects.  The data are not 
correctable but the azimuth and zenith windows to avoid are:
short_direct_normal (NIP instrument)
	     Zenith angle > 62 deg
  254 deg < Azimuth angle < 262 deg
primary obstruction at 255 deg Az

down_short_diffuse(PSP instrument)
	     Zenith angle > 59 deg
  246 deg < Azimuth angle < 257 deg
primary obstruction at 251.5 deg Az


Date ranges this problem will exist for are:
20090301-20090418 (pre-official deployment, data exist)
20090826-20091023
20100301-20100418
20100826-20101023

The QCrad VAP should flag bad data points via its QC logic.  Users should either exclude 
the data within the windows above or review data for outliers in these zenith, azimuth 
angles.
Suggestions: 
Measurements:grwskyrad20sM1.a0:
  • inst_global
  • inst_direct_normal
more
grwskyrad60sM1.b1:
  • short_direct_normal_std
  • short_direct_normal_max
  • short_direct_normal_min
  • down_short_hemisp_min
  • down_short_hemisp
  • down_short_hemisp_max
  • down_short_hemisp_std
  • short_direct_normal
more

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