NSA/GNDRAD/C1 - Frosting/Condensation

The GNDRAD PIR and IRT comparison was showing the IRT 2-4 W/m^2 greater than the PIR.  
Suspected snow or frost on the instrument(s).  Corrective maintenance performed 10/15/04 at 
21:30 UT.  Optics of both instruments were cleaned.  Upwelling longwave measurement 
agreement restored (+/- 5 W/^2).

Although the relative performance (agreement) of the two instruments improved after 
corrective maintenance (+/- 2 W/m^2), no correction is suggested because the agreement remains 
with the estimated measurement uncertainty of +/- 4 W/m^2 (IRT) and +/-10 W/m^2 (Inverted 
PIR)

• up_long_hemisp_min
• net_std
• up_long_hemisp
• sfc_ir_temp
• sfc_ir_temp_min
• up_long_hemisp_std
• up_long_hemisp_max
• sfc_ir_temp_std
• sfc_ir_temp_max

• Raw data stream - documentation not supported

• pir1_voltage
• pir1_dome_therm
• inst_up_long_case_resist
• inst_up_long_hemisp_tp
• pir1_case_therm
• inst_up_long_dome_resist