NSA/SKYRAD/C1 - Direct and Diffuse incorrect

The short_direct_normal (NIP) instrument and cable were damaged by tracker rewind 
malfunction. Tracker and NIP replaced on 4/22 2200GMT but tracker not operational until 4/23 
1815GMT.  Thus, down_short_diffuse_hemisp (8-48) was not shaded 4/22 to 4/23.

Do not use 8-48 data from 4/22 to 4/23. NIP data is not recoverable during entire time but 
can be estimated using component sum for each 1 minute data: Direct = (global - 
diffuse)/cos(zenith angle)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• short_direct_normal_std
• down_short_diffuse_hemisp_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)

• inst_diffuse
• inst_direct_normal