SGP/SIRS/C1 - Missing NIP data

The short_direct_normal (direct beam, NIP instrument) values are missing during this time 
range due a broken signal wire. Problem was corrected on 2/6/2013

The short_direct_normal data are not recoverable. However, it can be derived using the 
following relationship and applied to the good one minute data from the global and diffuse 
instruments (the SIRS instrument handbook describes this in detail):
short_direct_normal(derived) = (down_short_hemisp - down_short_diffuse_hemisp)/cos(zenith 
angle)

• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Shortwave direct normal irradiance, pyrheliometer, minima(short_direct_normal_min)
• Shortwave direct normal irradiance, pyrheliometer(short_direct_normal)

• Direct-beam normal solar irradiance(nip)