SGP/SIRS/E27 - Instrument problem, Shadowband Misalignment

Downwelling and Upwelling longwave values are somewhat noisy due to noisy PIR (pygeometer) 
case and dome thermistor measurements on both the upwelling and downwelling PIRs. This 
problem dates back to the beginning of the SIRS E27 data stream.

• 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(up_long_hemisp)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer(inst_up_long_case_temp)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Standard
  Deviation(down_long_hemisp_shaded_std)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer(inst_up_long_dome_temp)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_case_temp)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Standard Deviation(up_long_hemisp_std)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Minima(up_long_hemisp_min)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Minima(down_long_hemisp_shaded_min)

• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_resist)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_case_resist)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer(inst_up_long_case_resist)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer(inst_up_long_dome_resist)

SGP/SIRS/E27 - Tracker Misalignment

Suntracker failed at this facility. The suntracker was reset on
                  9/17, but this only temporarily fixed the problem and the tracker 
                  began failing again 9/18.  Tracker was reset and realigned on 
                  10/15/03 17:30GMT and has been operating properly since.

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

• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrheliometer(short_direct_normal)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Standard Deviation(down_short_diffuse_hemisp_std)

• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)
• Instantaneous Direct Normal Shortwave Irradiance, Pyrheliometer Thermopile
  Voltage(inst_direct_normal)

SGP/SIRS/E27 - incorrect tracking

The solar tracker at E27 was not functioning properly.  The problem affected tracker 
mounted instruments: downwelling diffuse 8-48 and direct normal pyrheliometer NIP.  

After tracker adjustment on 4/14/2004 1700GMT the tracker stopped tracking properly during 
afternoon hours.  Attempts to correct tracker operation throughout the failure period 
resulted in variations on incorrect tracker operation.  No replacement tracker was available.

After adjustment on 9/15/2004 the tracker problem was resolved.  It is unclear what, other 
than typical az and zen tracker software changes by field techs, corrected the problem.  
This problem period corresponds to the first time range specified (4/14 to 9/15). 

On 10/27/2004 a replacement tracker was installed at E27.  Technical difficulties kept 
tracker out of service until 11/05/2004. The replacement tracker at E27 was put into serice 
by the field techs on 11/05/2004 1830GMT.  The tracker has been tracking correctly since 
this time.  This problem period corresponds to the second time range (10/27 to 11/05).

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

• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrheliometer(short_direct_normal)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Standard Deviation(down_short_diffuse_hemisp_std)

• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)
• Instantaneous Direct Normal Shortwave Irradiance, Pyrheliometer Thermopile
  Voltage(inst_direct_normal)

SGP/SIRS/E27 - 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 Longwave Hemispheric Net Infrared(up_long_netir)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)