SGP/SIRS - SIRS E20 April 1999

Good data quality for this site this month. All data are present, and 92.5% of the present 
daytime data earn passing or low-level flags. Another 6.1% of the daytime data are 
flagged strange-but-true. Low-level flags in the early morning hours shortly after sunrise 
indicate that the DS is too low, or the NIP or DD too high by the three-component test. 
Low-level flags seen after noon in the second half of the month indicate that the DS is too 
high. The DS and DD are forced below daytime empirical limits by overcast skies on several 
occasions.  Moderate to serious flags shortly after noon on the 14th indicate that the 
DS signal is too high by the three-component test. On the 22nd at 1605 GMT the 10m tower 
was taken down for upgrade. The UIR and US signal fields will be filled with the data 
logger missing data flag, -99999, until the new tower is installed. Otherwise, data 
collection will continue as usual. No problems noted in DIR signal.

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

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