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.

• null(Raw data stream - documentation not supported)

• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Instantaneous Case Temperature(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 Dome Temperature(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, 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, 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.

• null(Raw data stream - documentation not supported)

• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, 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, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)

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

• null(Raw data stream - documentation not supported)

• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, 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, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)

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

SGP/SIRS/E27 - Reprocessed: Longwave Calibration error

Modified pyrgeometer calibration procedures were implemented beginning in May 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 October 2006.

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

SGP/SIRS/E24 - Loose connections

The down_short_hemisp, down_long_hemisp_shaded & up_long_hemisp were reporting large 
negative values.  A loose ground wire was reconnected and the MUX was replaced.

• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_resist)
• Instantaneous Upwelling Pyrgeometer Thermopile(inst_up_long_hemisp_tp)
• Instantaneous Downwelling Hemispheric Shortwave, Unshaded Pyranometer Thermopile
  Voltage(inst_global)
• Instantaneous Upwelling Shortwave Hemispheric Irradiance, Pyranometer(inst_up_short_hemisp)
• Instantaneous Downwelling Pyrgeometer Thermopile Voltage, Shaded Pyrgeometer(inst_down_long_hemisp_shaded_tp)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer(inst_up_long_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 Dome Temperature(inst_up_long_dome_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_temp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Standard
  Deviation(down_long_hemisp_shaded_std)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_case_temp)
• Instantaneous Case Temperature(inst_up_long_case_temp)
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)