SGP/BRS/C1 - Monthly Summary

Data quality this site-month is good. The offset in the Global PSP has been much improved, 
with an average nighttime offset of -4 W/m^2, since measures were taken on 17 DEC 2004 
to fix it. The Global PSP does not go below nighttime empirical limits all month. Global 
does fall below daytime empirical limits for significant time periods on the 2, 4, 5, 12, 
28, 30. There were still substantial 3 component flags 17 DEC 2004. The charcteristic 
three component failures are present through out the month, especially closer to the end of 
the month. The problem is about equally as bad in the morning as the evening.

The flags are usually high level yellow at their worst for any given day. Finally, there 
are the typical three component flags on the 29th as well, but these occur under cloudy 
skies. The data return to normal the next day and a cause for the problem cannot be 
determined.

• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Shortwave Direct Normal Irradiance, Pyrheliometer(short_direct_normal)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer(down_short_hemisp)

SGP/BRS/C1 - Reprocessed: Longwave Calibration error

Modified pyrgeometer calibration procedures were implemented beginning in June 2004. 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 November 2006.

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