SGP/SIRS - SIRS E24 April 1999

Data quality at this site is very good this month. Nearly all 99.6% of the daytime data is 
present. Passing or low-level flags are assigned to 93.5% of the present daytime data. 
High level flags seen in the first two days of the month indicate that the DD is above 
daytime empirical limits. A diurnal plot for the 1st shows that the suntracker has failed: 
the DD is tracking the DS, and the NIP signal is flat.  Low to mid-level flags observed 
from late morning to mid-afternoon late in the month indicate that the DS is too high by 
the three-component test. Alternatively, the flags may signal that the NIP or the DD is too 
low. The DS and DD were forced below daytime or twilight empirical limits by heavy cloud 
cover on a number of occasions. On the 27th at 1657 GMT the US and UIR signal fields are 
filled with the data logger value representing missing data -  -99999 as if the 
instruments were disconnected. The Operations Management Information Systems Instrument and 
Corrective Maintenance Report for this site indicate that the UIR and US were disconnected and 
the 10m tower taken down for upgrade on the 26th. No problems were noted in the DIR signal.

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

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