NSA/SKYRAD/C2 - IRT Grounding

Improper grounding of the IRT caused problems with other radiometer signals. The problem 
was corrected when the grounding of the data logger was changed.

• Sky Infra-Red Temperature Minima(sky_ir_temp_min)
• Sky Infra-Red Temperature(sky_ir_temp)
• Sky infrared temperature, standard deviation(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)