SGP/BRS/C1 - NIP sensor failure

Normal incidence values of downwelling shortwave radiation were
               reported as -9999 (missing).  The NIP instrument was damaged by
               lightning in the area near the time of failure.

• Shortwave Direct Normal Irradiance(short_direct_normal)
• Irradiance, shortwave, direct normal, pyrheliometer, mifkba(short_direct_normal_min)
• short_direct_normal_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)

SGP/BRS/C1 - low downwelling shortwave readings

Downwelling shortwave (DS) values frequently drop below -10 W/m^2 at night, and are 
consistently 20-40 W/m^2 less than the calculated downwelling shortwave during the day in 
clear-sky conditions. Corrective maintenance on 12/17/2004 corrected this offset.  It is not 
clear which CM action corrected the problem since the DS instrument cable was grounded to 
a new location and the DS ventilator fan was found in poor condition and was replaced.  
Either of these issues could have led to the problem observed in this instrument.

• Irradiance, shortwave, downwelling, hemispheric, pyranometer, mifkba(down_short_hemisp_min)
• down_short_hemisp_std
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)

SGP/BRS/C1 - Reprocessed: Longwave Calibration error

Modified pyrgeometer calibration procedures were implemented beginning in June 2004. 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 have been reprocessed to 
remove the calibration bias.  The reprocessed 60 second averaged data are based on 3 
instantaneous 20 second data records rather than on 60 1 second instantaneous data records. 
Still, these data are considered far superior to the originally processed data. The 
reprocessed data were archived in November 2006.

• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• Upwelling longwave hemispheric irradiance, pyrgeometer(up_long_hemisp)
• Upwelling longwave hemispheric net infrared(up_long_netir)
• Downwelling longwave hemispheric net infrared(down_long_netir)

SGP/BRS/C1 - Reprocess: Calibration error in Downwelling Longwave measurement

On 20031211 the Downwelling LW pyrgeometer was replaced but the calibrations were not 
updated.  Calibrations have been corrected in data beginning 20040615.

• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• down_long_hemisp_shaded_std
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• Downwelling longwave hemispheric net infrared(down_long_netir)