ozone radiometer at 142 ghz: calibration
DESCRIPTION
Yasmine Calisesi. Ozone Radiometer at 142 GHz: Calibration. The Stratospheric Ozone Monitoring Radiometer SOMORA. Developed by the IAP for MeteoSwiss Tuned to Ozone at 142.175 GHz Improved version of the GROMOS instrument Operated at the IAP since January 2000 Moved to Payerne in June 2002. - PowerPoint PPT PresentationTRANSCRIPT
Ozone Radiometer at 142 GHz:Calibration
Yasmine Calisesi
The Stratospheric Ozone Monitoring Radiometer SOMORA
●Developed by the IAP for MeteoSwiss●Tuned to Ozone at 142.175 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 MirrorHot Load
ColdLoad
Eccosorb CV-3
IF 7.1 Ghz
T = 310 K
T=77K
Fans PT 100HeatingElement
EccosorbCV-3
PT 100
PolystyreneWindow
SOMORA Hot Load
EccosorbCV-3
SOMORA Cold Load
Dewar Vessel
Packaging Foam Material
Liquid N2
InletGaz-phase N2 exhaust
ExpansionVesselP = 0.4 Bar
Total Power Calibration
coldcoldhotcoldhot
coldskysky TTT
PP
PPT
)(
,1
y
yTTT coldhotrec
0
0
PP
PPy
cold
hot
Temperature Definitions
● Physical Temperature● „Planck“ Brightness Temp.:
T :
TP :
)2
1ln(
1
2
3
Pc
hk
hTP
● In the RJ limit (hkT):
P ÷ T P can be replaced by T in RT model
RJP Tk
PcT :
2 2
2
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
● TRJ ≠ T
P Radiative transfer
computed in the units of P