Ozone Radiometer at 142 GHz: Calibration Yasmine Calisesi
The Stratospheric Ozone Monitoring Radiometer SOMORA ● Developed by the IAP for MeteoSwiss ● Tuned to Ozone at GHz ● Improved version of the GROMOS instrument ● Operated at the IAP since January 2000 ● Moved to Payerne in June 2002
Somora location in Payerne
SOMORA Quasi-Optics Rotating Planar Mirror Hot Load Cold Load Eccosorb CV-3 IF 7.1 Ghz T = 310 K T=77K
Fans PT 100 Heating Element Eccosorb CV-3 PT 100 Polystyrene Window SOMORA Hot Load
Eccosorb CV-3 SOMORA Cold Load Dewar Vessel Packaging Foam Material
Liquid N 2 Inlet Gaz-phase N 2 exhaust Expansion Vessel P = 0.4 Bar
Total Power Calibration
Temperature Definitions ● Physical Temperature ● „Planck“ Brightness Temp.: ● In the RJ limit (h kT): P ÷ T P can be replaced by T in RT model
Example: Planck and RJ emission curves at various frequencies Brightness Temperature [K]
Conclusions : ● SOMORA: Total power radiometer ● P ÷ T in considered T range Total power calibration formula can be used ● T RJ ≠ T P Radiative transfer computed in the units of P