NSA/MFR10M/C1 - Instrument rotated skyward to check calibration

For purposes of checking the calibration stability, the GNDMFR at the NSA Barrow was 
turned upside down for two days (19990413-19990414).  So instead of looking at the ground, 
this instrument was pointed toward the zenith. 

When the GNDMFR was turned outside down and compared with the MFRSR data, very good 
agreement between the two data streams was observed.  This indicates that both instruments' 
calibrations are remaining stable.

Do not use data on these days

• Fields flagged by callang: 0 = No Flag ,(callang_flags)
• 3 meter upwelling narrowband hemispheric irradiance, filter 3, offset corrected(up_hemisp_narrowband_filter3)
• 3 meter upwelling narrowband hemispheric irradiance, filter 2, offset corrected(up_hemisp_narrowband_filter2)
• 10 meter upwelling narrowband hemispheric irradiance, filter 1(up_hemisp_narrowband_filter1)
• Cosine solar zenith angle(cosine_solar_zenith_angle)
• 3 meter upwelling broadband hemispheric irradiance(up_hemisp_broadband)
• 10 meter Narrowband Upwelling Hemispheric Irradiance, Filter 6(up_hemisp_narrowband_filter6)
• 25 meter upwelling narrowband hemispheric irradiance, filter 5, offset corrected(up_hemisp_narrowband_filter5)
• 3 meter upwelling narrowband hemispheric irradiance, filter 4(up_hemisp_narrowband_filter4)

• 10 meter Narrowband Upwelling Hemispheric Irradiance, Filter 6(up_hemisp_narrowband_filter6)
• 3 meter upwelling narrowband hemispheric irradiance, filter 4(up_hemisp_narrowband_filter4)
• 25 meter upwelling narrowband hemispheric irradiance, filter 5, offset corrected(up_hemisp_narrowband_filter5)
• 3 meter upwelling broadband hemispheric irradiance(up_hemisp_broadband)
• 3 meter upwelling narrowband hemispheric irradiance, filter 2, offset corrected(up_hemisp_narrowband_filter2)
• 3 meter upwelling narrowband hemispheric irradiance, filter 3, offset corrected(up_hemisp_narrowband_filter3)
• 10 meter upwelling narrowband hemispheric irradiance, filter 1(up_hemisp_narrowband_filter1)
• Fields flagged by callang: 0 = No Flag ,(callang_flags)