SGP/IRT/E13 - Reprocess: Sky temperature bias

Measurements of sky temperature, especially those <250K,, were positively biased compared 
with AERI because there was no compensation for the effect of the emissivity and 
temperature of the gold mirror. The problem was corrected by changing the IRT emissivity from 
1.000 to 0.987, adding an RTD and transmitter electronics to measure the temperature of the 
mirror, and changing the ambient temperature measurement for internal reference to 
external mirror temperature.

Use sky temperature measurements less than 230K with caution. Biases as large as 30K have 
been observed when the actual temperature, as measured by AERI, is less than 210 K.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)