SGP/SIRS/E20 - Downwelling Shortwave PSP Damaged by Lightning

The PSP was damaged by a lightning strike on 8/04/05 (22:10 GMT).  Data from other 
radiometers are good after this event.  

The PSP, NIP and shaded 8-48 were replaced 8/17/05 and the system returned to service at 
18:40 GMT.

Downwelling Shortwave (DS) data from the unshaded PSP during this period is reported as 
0.0 W/sq m.  The DS can be computed from available Direct Normal (NIP), Downwelling Diffuse 
(DD), and the computed Solar Zenith Angle (SZA) using the following equation:

    DS = NIP * Cos(SZA) + DD

Estimated uncertainties of the computed values are actually lower than those of the 
measured DS  (+/- 3% or 4% vs. +/- 5% to 10% respectively, depending on SZA).

• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer(down_short_hemisp)

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

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

SGP/SIRS/E20 - Instrument noise problem

Afer recovery from lightening strike the upwelling longwave SIRS Eppley PIR (UIR) has had 
noise on both dome and case thermistor measurements.  On 4/12/2006 techs replaced 
defective j-panel at base of tower.

• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Minima(up_long_hemisp_min)
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Maxima(up_long_hemisp_max)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer(inst_up_long_case_temp)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer(inst_up_long_dome_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Standard Deviation(up_long_hemisp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)

• Instantaneous Upwelling Pyrgeometer Thermopile Voltage, Pyrgeometer(inst_up_long_hemisp_tp)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer(inst_up_long_dome_resist)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer(inst_up_long_case_resist)

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

SGP/SIRS/E20 - Reprocessed: Longwave Calibration error

Modified pyrgeometer calibration procedures were implemented beginning in July 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 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.

• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)