SGP/SIRS/E12 - Incorrect Times

The ntpd server (time adjustment) stopped working on Feb. 19th at 22:12:16 GMT, and the 
clock was corrected by -5600.177269 seconds
on March 10th at 22:47 GMT. The recorded times for observations are
off by amounts ranging from 0 seconds on Feb. 19th to 5600 seconds
on March 10th.

• Clear-sky Fit Coefficient b to Diffuse Irradiance to Total Irradiance Ratio
  (DFRb)(coef_clearsky_difratio_b)
• Clear-sky Fit Estimated Downwelling Summed Shortwave Irradiance
  (dirfluxdn_clearskyfit+diffluxdn_clearskyfit) (cssw)(sswfluxdn_clearskyfit)
• Time offset of tweaks from base_time(time_offset)
• Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cgsw)(gswfluxdn_clearskyfit)
• Clear-sky Fit Estimated Surface Albedo from Shortwave Irradiance Measurements
  (calb)(albedosw_clearskyfit)
• Clear-sky Fit Coefficient b to Global UVB Irradiance (UVBb)(coef_clearsky_guvb_b)
• Clear-sky Fit Coefficient a to Global minus Summed Shortwave Irradiance
  Difference (SCORa)(coef_clearsky_dsw_a)
• Clear-sky Fit Coefficient a to Albedo (Alba)(coef_clearsky_albedo_a)
• Measured Downwelling Global Shortwave Irradiance (gsw)(gswfluxdn_measured)
• Time Offset from base_time_LST(time_offset_LST)
• Difference: difswfluxdn_measured - difswfluxdn_clearskyfit (diffcg)(difswfluxdn_cloudeffect)
• Beginning Time of File (LST)(base_time_LST)
• Clear-sky Fit Estimated Downwelling Direct Shortwave Irradiance (cdir)(dirfluxdn_clearskyfit)
• Clear-sky Fit Estimated Downwelling Diffuse Field Shortwave Irradiance (cdif)(difswfluxdn_clearskyfit)
• Difference: sswfluxdn_measured - sswfluxdn_clearskyfit (sswfcg)(sswfluxdn_cloudeffect)
• Measured Downwelling Global UVB Irradiance (guvb)(guvbdn_measured)
• Clear-sky Fit Coefficient b to Albedo (Albb)(coef_clearsky_albedo_b)
• Site Identification(site)
• Ratio of Measured Downwelling Diffuse Shortwave Irradiance to Measured
  Downwelling Global Shortwave Irradiance (difr)(difratiodn_measured)
• Date (YYMMDD LST) for which the Coefficients are Applicable(coef_date)
• base time(base_time)
• Clear-sky Fit Coefficient b to Global minus Summed Shortwave Irradiance
  Difference (SCORb)(coef_clearsky_dsw_b)
• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)
• Measured Downwelling Summed Shortwave Irradiance
  (dirfluxdn_measured+diffluxdn_measured) (ssw)(sswfluxdn_measured)
• Measured Surface Albedo from Shortwave Irradiance Measurements (alb)(albedosw_measured)
• Ratio of Clear-sky Fit Estimated Downwelling Diffuse Shortwave Irradiance to
  Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cdifr)(difratiodn_clearskyfit)
• Clear-sky Detection Flag (clrf)(flag_clearsky_detection)
• Arithmetic Average Cosine of the Solar Zenith Angle Z (CosZ)(solar_cos_z)
• Arithmetic Average Distance from the Earth to the Sun (au)(sun_earth_distance)
• Daily Averaged Distance from the Earth to the Sun (auavg)(sun_earth_distance_dailyaverage)
• Clear-sky Fit Coefficient b to Global Shortwave Irradiance (CSWb)(coef_clearsky_gsw_b)
• Measured Downwelling Diffuse Shortwave Irradiance (dif)(difswfluxdn_measured)
• Clear-sky Fit Coefficient b to Summed Shortwave Irradiance (CSWb)(coef_clearsky_ssw_b)
• Clear-sky Fit Coefficient a to Summed Shortwave Irradiance (CSWa)(coef_clearsky_ssw_a)
• Clear-sky Fit Coefficient a to Global Shortwave Irradiance (CSWa)(coef_clearsky_gsw_a)
• Clear-sky Offset Coefficient c for Global minus Summed Shortwave Irradiance
  Difference (SCORc)(coef_clearsky_dsw_c)
• Difference: gswfluxdn_measured - gswfluxdn_clearskyfit (gswfcg)(gswfluxdn_cloudeffect)
• Clear-sky Fit Coefficient a to Diffuse Irradiance to Total Irradiance Ratio
  (DFRa)(coef_clearsky_difratio_a)
• Clear-sky Fit Estimated Downwelling Global UVB Irradiance (cguvb)(guvbdn_clearskyfit)
• Clear-sky Fit Coefficient a to Global UVB Irradiance (UVBa)(coef_clearsky_guvb_a)

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

• Measured Surface Albedo from Shortwave Irradiance Measurements (alb)(albedosw_measured)
• Time offset of tweaks from base_time(time_offset)
• Measured Downwelling Global UVB Irradiance (guvb)(guvbdn_measured)
• Number of 1-minute Cloud Fraction Estimates in the 15-minute Interval (Ncf)(nsamples_cloudfraction)
• Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cgsw)(gswfluxdn_clearskyfit)
• Difference: sswfluxdn_measured - sswfluxdn_clearskyfit (sswfcg)(sswfluxdn_cloudeffect)
• Time Offset from base_time_LST(time_offset_LST)
• Difference: gswfluxdn_measured - gswfluxdn_clearskyfit (gswfcg)(gswfluxdn_cloudeffect)
• Clear-sky Fit Estimated Downwelling Summed Shortwave Irradiance
  (dirfluxdn_clearskyfit+diffluxdn_clearskyfit) (cssw)(sswfluxdn_clearskyfit)
• Ratio of Measured minus Clear-sky Fit Estimated Downwelling Diffuse Shortwave
  Irradiance to Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance
  (di(difcloudeffect_normalized)
• Measured Downwelling Diffuse Shortwave Irradiance (dif)(difswfluxdn_measured)
• Beginning Time of File (LST)(base_time_LST)
• Clear-sky Fit Estimated Surface Albedo from Shortwave Irradiance Measurements
  (calb)(albedosw_clearskyfit)
• Number of 1-minute Measured Downwelling Summed Shortwave Irradiances in the
  15-minute Interval (Nssw)(nsamples_sswfluxdn_measured)
• Average over the interval of the standard deviation of difratiodn_measured
  computed using a 3-5 sample window centered at each 1-min sample(difratiodn_measured_stdev)
• Fractional Sky Cover(cloudfraction)
• Arithmetic Average Cosine of the Solar Zenith Angle Z (CosZ)(solar_cos_z)
• Measured Downwelling Global Shortwave Irradiance (gsw)(gswfluxdn_measured)
• Clear-sky Fit Estimated Downwelling Direct Shortwave Irradiance (cdir)(dirfluxdn_clearskyfit)
• Site Identification(site)
• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)
• Measured Downwelling Summed Shortwave Irradiance
  (dirfluxdn_measured+diffluxdn_measured) (ssw)(sswfluxdn_measured)
• Ratio of Measured Downwelling Diffuse Shortwave Irradiance to Measured
  Downwelling Global Shortwave Irradiance (difr)(difratiodn_measured)
• Clear-sky Fit Estimated Downwelling Global UVB Irradiance (cguvb)(guvbdn_clearskyfit)
• Arithmetic Average Distance from the Earth to the Sun (au)(sun_earth_distance)
• Difference: difswfluxdn_measured - difswfluxdn_clearskyfit (diffcg)(difswfluxdn_cloudeffect)
• Ratio of Clear-sky Fit Estimated Downwelling Diffuse Shortwave Irradiance to
  Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cdifr)(difratiodn_clearskyfit)
• Number of 1-minute Clear-sky Detections in the 15-minute Interval (Nclr)(nsamples_clearsky_detection)
• Clear-sky Fit Estimated Downwelling Diffuse Field Shortwave Irradiance (cdif)(difswfluxdn_clearskyfit)
• Number of 1-minute Clear-sky Fit Downwelling Global Shortwave Irradiance
  Estimates in the 15-minute Interval (Ncsw)(nsamples_gswfluxdn_clearskyfit)
• base time(base_time)

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

• null(Raw data stream - documentation not supported)

SGP/SIRS/E12 - 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.

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