TWP/SKYRAD/C1 - Incorrect NIP data

Beginning 10/4/2013 the short_direct_normal datastream (NIP pyhrheliometer instrument) 
stopped reporting good values. Site ops found and repaired a bad signal cable on 11/12.

The short_direct_normal data is not directly recoverable.  It can be calculated by 
applying the following relationship for each data point:


During this time range the QCRAD VAP has properly flagged the bad data.

Use QCRAD data

• Shortwave direct normal irradiance, pyrheliometer(short_direct_normal)
• 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)