NSA/GNDRAD/C1 - Reprocess: IRT insufficiently heated

IRT had insufficient heating to maintain an internal reference temperature above 0 degrees 
C. Measurements of surface temperature were over-estimated when instrument was below 
freezing.

Data will be reprocessed, but users can correct data using the following correction 
factor:

If T_reference < -5?C, then

  IRT_corrected = (IRT_original - 32.993K)/0.87238

where T_reference can be estimated with the ambient temperature (e.g. 
inst_up_long_hemisp_dome_temp or inst_up_long_dome_temp)

• Surface infra-red temperature(sfc_ir_temp)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Surface Infra-Red Temperature, Minima(sfc_ir_temp_min)
• Surface Infra-Red Temperature, Maxima(sfc_ir_temp_max)