SGP/SIRS/E9 - Unknown -failed PSP ventilator fan

Downwelling shortwave hemispheric (DSH) readings appear to have a slight to moderate 
negative offset from derived DSH values.  At night, this negative offset causes qc flags 
(since values are below the minimum threshold of -10 W/m^2).  Differences between derived and 
actual DSH values are sometimes on the order of 50 W/m^2 due to this offset. 
The offset was discovered to be due to a failed ventilator fan which is used to clear the 
dome of the PSP, the instrument which measures the DSH.  The ventilator likely seized or 
was intermittent and heated the PSP base giving an erroneous DSH reading.  Field techs 
replaced the fan on 01/25/2005 1745GMT.  The DSH has been reading normally since that time.

Disregard this data.

• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling shortwave hemispheric irradiance, pyranometer, maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Minima(down_short_hemisp_min)

• Instantaneous Downwelling Hemispheric Shortwave, Pyranometer Thermopile Voltage(inst_global)

• (Raw data stream - documentation not supported)