SGP/BRS/C1 - NIP sensor failure

Normal incidence values of downwelling shortwave radiation were
               reported as -9999 (missing).  The NIP instrument was damaged by
               lightning in the area near the time of failure.

Estimate missing direct component with (global - diffuse)*cosZ

• Instantaneous direct normal shortwave irradiance, pyrheliometer thermopile
  voltage(inst_direct_normal)

• (Raw data stream - documentation not supported)

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