SGP/SIRS/E13 - Monthly Report

:Data quality this site-month is good. The offset for the Global PSP is about -7 W/m^2.
The dominant problem here is the daytime 3 component problem. Direct and Diffuse are
always too high and Global is too low. The problem occurs around the time that the
testing regime switches from twilight to daytime testing regimes or from daytime to
twilight. The flags occur in significant numbers on the 1st - 5th, 7th - 20th, 24th - 
28th,
30th, and 31st. The failures vary in magnitude and duration. The worst flags for a 
particular

respect to this problem. Global goes below daytime empirical limits on both the 5th and
6th for substantial periods of time. Diffuse
also goes below daytime empirical limits on the 6th in the afternoon. Upwelling Longwave
is
below empirical limits on the 24th. This may not be a problem, as many sites exhibited
the same problem on the same night. Exceptionally cold temperatures may be the cause.

:Applying the responsivity as a function of the zenith angle,
rather than the constant zenith angle will help with the 3 component failures.

• 10 meter Upwelling Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• 25 meter Upwelling Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Shortwave direct normal irradiance, pyrheliometer(short_direct_normal)
• Downwelling longwave hemispheric irradiance, shaded pyrgeometer(down_long_hemisp_shaded)