SGP/SIRS - SIRS E25 April 1999

Data quality at this site is very good. All daytime data are present. Passing or low-level 
flags are assigned to 91.2% of the present daytime data. Another 5.8% of the data are 
labeled strange-but-true. Low- to mid-level flags in the late afternoon to early evening 
indicate that the DS is too low by the three-component test. Late in the month overcast 
skies drove the DS and DD signals below twilight or daytime empirical limits. Shortly after 
noon on the 14th a possible instance of cloud refraction is recorded in the DS. On the 
afternoon of the 19th the DS and DD signals fall into the physically impossible region of 
K-space. The DD signal is recorded as missing (-99999) by the data logger in a few 
short-lived instances (1-3 in duration minutes each) early in the afternoon of the 25th. Both 
the UIR and DIR signals continue to be noisy. No problems were noted in the US signal.

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

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