NSA/GNDRAD/C2 - Incorrect calibration coefficients applied to upwelling(Gndrad)PIR

An insitu test comparing the Gndrad PIR and the Gndrad IRT at the NSA was performed from 6 
Jan 2005 to 12 Jan 2005.  The radiometer mentor requested the Eppley single calibration 
coefficient for the PIR replace the 4 coefficients method developed by NREL.  The Grndrad 
PIR compared closer to the Gndrad IRT during this period. However, the radiometer mentor 
believes the 4 coefficient PIR irradiance measurements remains superior to the single 
coefficient Eppley PIR measurement method.  Further questions should be directed to the 
radiometer instrument mentor.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Maxima(up_long_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Standard Deviation(up_long_hemisp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Minima(up_long_hemisp_min)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded standard deviation(pir1_sd)

NSA/GNDRAD/C2 - Reprocess: Longwave Calibration error

Modified pyrgeometer calibration procedures were implemented beginning in December 2003.  
These modified procedures introduced a calibration bias in the longwave data.  The 
previous procedures were re-implemented at all sites between December 2005 and February 2006 to 
restore proper calibrations.                                                             
                The data collected while the incorrect procedures were in place are 
being reprocessing to remove the calibration bias.  Note, this also affected standard 
deviation, maximum and minimum data fields.

• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)