SGP/SIRS - SIRS E22 April 1999

Data quality is excellent at this site this month. Present daytime data is at 100%. Just 
over 98% of the present daytime data earn passing or low-level flags.  In the first week 
of the month low-level flags indicate that the DS is too high by the three-component test, 
or that the DD or NIP is too low. Heavy cloud cover on several occasions caused the DS 
and DD to fall below daytime empirical limits. On the afternoon of the 14th the NIP fell 
below daytime empirical limits for a short time. Shortly before noon on the 26th the DS 
signal was above daytime empirical limits. No problems note in the DIR, UIR or US signals.

• Downwelling longwave hemispheric irradiance, pyrgeometer(down_long_hemisp)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Upwelling shortwave hemispheric irradiance, pyranometer, minima(up_short_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Pyranometer, Standard
  Deviation(down_short_diffuse_hemisp_std)
• Downwelling shortwave hemispheric irradiance, pyranometer, maxima(down_short_hemisp_max)
• lon(lon)
• Time offset from base_time(time_offset)
• 10 meter Upwelling Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Downwelling Longwave Hemispheric Irradiance, Ventilated Pyrgeometer, Standard
  Deviation(down_long_hemisp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Standard Deviation(up_long_hemisp_std)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(down_long_hemisp_max)
• Upwelling longwave hemispheric irradiance, pyrgeometer, maxima(up_long_hemisp_max)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Downwelling shortwave diffuse hemispheric irradiance, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
  Standard Deviation(up_short_hemisp_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Pyrgeometer, Minima(down_short_diffuse_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Minima(down_short_hemisp_min)
• base time in epoch(base_time)
• North Latitude(lat)
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Shortwave direct normal irradiance, pyrheliometer(short_direct_normal)
• 25 meter Upwelling Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• -180.0 - +180.0(alt)
• Shortwave direct normal irradiance, pyrheliometer, minima(short_direct_normal_min)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer, Minima(down_long_hemisp_min)
• Battery voltage(vBatt)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)

• -180.0 - +180.0(alt)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• base time in epoch(base_time)
• Up-welling pyrgeometer case thermistor resistance(up_long_case_resist)
• Downwelling longwave hemispheric irradiance, pyrgeometer(down_long_hemisp)
• North Latitude(lat)
• Time offset from base_time(time_offset)
• 25 meter Upwelling Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Direct-beam normal solar irradiance(nip)
• lon(lon)
• Shaded pyranometer voltage(short_diffuse)
• 10 meter Upwelling Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Up-welling pyrgeometer dome thermistor resistance(up_long_dome_resist)
• Down-welling pyrgeometer dome thermistor resistance(down_long_dome_resist)
• Down-welling pyrgeometer case thermistor resistance(down_long_case_resist)