SGP/SIRS/E16 - Tracker Misaligned

Direct Normal Shortwave (NIP) values may be reduced by tracker
misalignment (tracker clock slow by 2 minutes 10 sec on 2/18/04).

Downwelling Diffuse (DD) values may be increased by the tracker
misalignment.

Error amounts can not be accurately quantified.

• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• 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 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/E16 - PSP Dome Contamination

Downwelling Shortwave (DS) values near 22:00 GMT during clear skys are
lower than expected due to contamination of pyranometer dome.  A dime-sized
spot of dirt was found on the southwest portion of the pyranometer dome. 
DS values for cloudy conditions during this period are also suspect, but
the amount of irradiance reduction are not significant.

• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)

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

SGP/SIRS/E16 - Ice storm

Data missing due to ice storm.

• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Battery Voltage(vBatt)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Instantaneous Dome Temperature(inst_up_long_dome_temp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• lon(lon)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_case_temp)
• base time(base_time)
• Instantaneous Case Temperature(inst_up_long_case_temp)
• lat(lat)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Standard
  Deviation(down_long_hemisp_shaded_std)
• Dummy altitude for Zeb(alt)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• Time offset of tweaks from base_time(time_offset)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_temp)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)

• Instantaneous Upwelling Shortwave Hemispheric Irradiance, Pyranometer(inst_up_short_hemisp)
• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)
• Instantaneous Downwelling Hemispheric Shortwave, Unshaded Pyranometer Thermopile
  Voltage(inst_global)
• Instantaneous Downwelling Pyrgeometer Thermopile Voltage, Shaded Pyrgeometer(inst_down_long_hemisp_shaded_tp)
• lon(lon)
• Instantaneous Upwelling Pyrgeometer Thermopile(inst_up_long_hemisp_tp)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_resist)
• lat(lat)
• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer(inst_up_long_dome_resist)
• Time offset of tweaks from base_time(time_offset)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer(inst_up_long_case_resist)
• Dummy altitude for Zeb(alt)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_case_resist)
• base time(base_time)

SGP/SIRS/E16 - 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 October 2006.

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

SGP/SIRS/E15 - NIP (short_direct_normal) failure

Short_direct_normal was spiking to large positive and negative values (+2000/-2000) with 
extended periods of missing data.  Repair of broken cable corrected the problem.

Data are not recoverable.  Suggest using remaining components (global hemispheric and 
global diffuse) to reconstruct direct normal data during this time period.   See SIRS 
instrument handbook for details on this process.

• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)

• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)