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  • 1. L-BAND R ADIOMETRIC M EASUREMENTS IN THE G ULF OF B ISCAY: SMOS AND CAROLS A. Martin1 , J. Boutin1 , D. Hauser2 , G. Reverdin1 , M. Pardé2 , M. Zribi2,3 , P. Fanise2,3 , X. Yin1 , J. Tenerelli6 , N. Reul5 1 LOCEAN-IPSL, Paris 2 LATMOS-IPSL, Paris 3 CESBIO, Toulouse 5 IFREMER, Plouzané 6 CLS, PlouzanéAdrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 1 / 25
  • 2. O BJECTIVESCAROLS — VALIDATION FOR SMOS ATR42 - SAFIRE Synergy between passive & active microwave data Comparison of SMOS and SMOS CAROLS data in the Gulf of Biscay Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 2 / 25
  • 3. SMOS AND CAROLS F LIGHT T RACKA IRBORNE C AMPAIGN N OVEMBER 2010 19 Nov. asc. 22 Nov. des. 25 Nov. des. 27 Nov. asc.ACQUISITION T IME :25 N OV. CAROLS: 18 to 23 UTC SMOS: 18:45 UTC November 25, 2010 — Gulf of Biscay Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 3 / 25
  • 4. SMOS AND CAROLS F LIGHT T RACKA IRBORNE C AMPAIGN N OVEMBER 2010 19 Nov. asc. 22 Nov. des. 25 Nov. des. 27 Nov. asc.ACQUISITION T IME :25 N OV. CAROLS: 18 to 23 UTC SMOS: 18:45 UTC November 25, 2010 — Gulf of Biscay Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 3 / 25
  • 5. O UTLINE1 A IRBORNE ACQUISITION Airborne Instruments Geophysical conditions L-band Brigthness Temperature2 SMOS Retrieved SSS Tb Analysis Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 4 / 25
  • 6. O UTLINES1 A IRBORNE ACQUISITION Airborne Instruments Geophysical conditions L-band Brigthness Temperature2 SMOS Retrieved SSS Tb Analysis Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 5 / 25
  • 7. A IRBORNE I NSTRUMENTS CAROLS L-band (21cm) radiometer STORM C-band (5.6cm) scatterometer Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 6 / 25
  • 8. CAROLSCAROLS Radiometer (derived from EMIRAD 2)[Zribi et al., 2011] Correlation radiometer with direct sampling Fully polarimetric (i.e 4 Stockes) Freq : - 3 dB @ 1401 MHz 1426 MHZ Sensitivity : 0.1 K for 1 s integration time CAROLS Antenna (300K target) Stability: better than 0.1K over 15 min Internal calibration : load and noise diode A large potter horn (HPBW 37.6◦ ) at 34◦ Cables with low loss and well monitored temperature CAROLS OMT Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 7 / 25
  • 9. CAROLSG ULF OF B ISCAY — 25 N OVEMBER 2010 Tb P ROCESSED AT LATMOS correction for cable attenuation and reflexion sorting out RFI (kurtosis method) T HIS W ORK Tb averaged on 1s keep incidence angles ∈ [33.3o ; 34.3o ] then averaged on ≈2 min centered on STORM measurements use V and H polarizations Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 8 / 25
  • 10. STORM — C- BAND S CATTEROMETER high wind speed low wind speed C-band radar (5.6 cm) antenna rotation (360˚/min) incidence range 5 to 35◦ σ 0 vs. incidence angleAdrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 9 / 25
  • 11. O UTLINES1 A IRBORNE ACQUISITION Airborne Instruments Geophysical conditions L-band Brigthness Temperature2 SMOS Retrieved SSS Tb Analysis Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 10 / 25
  • 12. G EOPHYSICAL C ONDITIONS in situ SSS STORM deduced Wind CAROLS L-band Speed (VV at 30◦ ) Brightness Temperature H-polSST = 12-15˚C Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 11 / 25
  • 13. O UTLINES1 A IRBORNE ACQUISITION Airborne Instruments Geophysical conditions L-band Brigthness Temperature2 SMOS Retrieved SSS Tb Analysis Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 12 / 25
  • 14. B RIGHTNESS T EMPERATURES S IMULATIONSTRAP: T ERRESTRIAL R ADIOMETRY A NALYSIS PACKAGE SOFWAREM ODELING L- BAND R ADIOMETER S IGNAL Sea Surface Emissivity for a flat surface [Klein and Swift, 1977] contribution of Roughness (two-scale model) [Dinnat et al., 2003] Atmospheric Emissivity and Absorption [Liebe et al., 1993] Modeling of SMOS Tbs Scattering of sky radiation by Sea Surface [Tenerelli et al., 2008] • Tb = Tbatm! + Rsea (Tbatm" + Tbsky) exp(-τatm) + Tbsea exp(-τatm) M ODELING CAROLS A NTENNA T EMPERATURE Atmosphere CAROLS antenna lobes geometry aircraft attitude Tbsea= (Tbflat+Tbrough) (1-F) + F Tbfoam Tbsea=esea SST 5 m/s ≈ 1K Ocean esea derived from SMOS Tbs after correcting for all other effects Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 13 / 25
  • 15. B RIGHTNESS T EMPERATURES S IMULATIONSTRAP: T ERRESTRIAL R ADIOMETRY A NALYSIS PACKAGE SOFWAREM ODELING L- BAND R ADIOMETER S IGNAL Sea Surface Emissivity for a flat surface [Klein and Swift, 1977] contribution of Roughness (two-scale model) [Dinnat et al., 2003] Atmospheric Emissivity and Absorption [Liebe et al., 1993] Modeling of SMOS Tbs Scattering of sky radiation by Sea Surface [Tenerelli et al., 2008] • Tb = Tbatm! + Rsea (Tbatm" + Tbsky) exp(-τatm) + Tbsea exp(-τatm) M ODELING CAROLS A NTENNA T EMPERATURE Atmosphere CAROLS antenna lobes geometry aircraft attitude Tbsea= (Tbflat+Tbrough) (1-F) + F Tbfoam Tbsea=esea SST 5 m/s ≈ 1K Ocean esea derived from SMOS Tbs after correcting for all other effects Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 13 / 25
  • 16. B RIGHTNESS T EMPERATURE D EPENDENCE ON W IND Measure Tb (V and H-polarization) vs. Wind Speed Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 14 / 25
  • 17. B RIGHTNESS T EMPERATURE D EPENDENCE ON W IND Time biases on Tb around 0.5K Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 15 / 25
  • 18. B RIGHTNESS T EMPERATURE D EPENDENCE ON W INDS CATTERED G ALACTIC N OISE ALONG THE FLIGHT Modeled Scattered Galactic Noise Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 16 / 25
  • 19. B RIGHTNESS T EMPERATURE D EPENDENCE ON W INDS CATTERED G ALACTIC N OISE D EPENDENCY Scattered Galactic Noise Dependency Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 17 / 25
  • 20. B RIGHTNESS T EMPERATURE D EPENDENCE ON W INDA FTER REMOVING ALL MODELED DEPENDENCY δTb = Tbmeasured − Tbmodeled (WS = 5ms−1 ) δTb vs. Wind Speed Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 18 / 25
  • 21. O UTLINES1 A IRBORNE ACQUISITION Airborne Instruments Geophysical conditions L-band Brigthness Temperature2 SMOS Retrieved SSS Tb Analysis Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 19 / 25
  • 22. SMOS DATALast L1 (Roger Oliva pers. L2 RFI flags equal to 1 if:com.) and L2 processing 2 2 σrad + σmod(v500) std(Tbmeas−OTT − Tbmod ) > 1.2 N Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 20 / 25
  • 23. O UTLINES1 A IRBORNE ACQUISITION Airborne Instruments Geophysical conditions L-band Brigthness Temperature2 SMOS Retrieved SSS Tb Analysis Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 21 / 25
  • 24. SMOS S NAPSHOT AFFOV & EAFFOV H in the satellite frame V in the satellite frameAdrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 22 / 25
  • 25. SMOS S NAPSHOT AFFOV & EAFFOV H in the satellite frame V in the satellite frameAdrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 22 / 25
  • 26. SMOS — T B A NALYSIS EAFFOV EAFFOV Southest Block Northest BlockAdrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 23 / 25
  • 27. C ONCLUSIONS & P ERSPECTIVE C ONCLUSIONS High correlation between Brightness Temperature and scatterometer Wind Speed; SMOS data, highly polluted by RFI in the Gulf of Biscay for descending orbit. P ERSPECTIVE Analysis other flights of the November 2010 campaign; Looking at the ascending orbite in the Gulf of Biscay; Study the influence of Land contamination; Further validate the galactic scattering model using other CAROLS flights. Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 24 / 25
  • 28. Thanks for your attention
  • 29. Dinnat, E., Boutin, J., Caudal, G., and Etcheto, J. (2003). Issues concerning the sea emissivity modeling at L band for retrieving surface salinity. Radio Science, 38(4):8060. Klein, L. and Swift, C. (1977). An improved model for the dielectric constant of sea water at microwave frequencies. IEEE Journal of Oceanic Engineering, 2(1):104–111. Liebe, H., Hufford, G., and Cotton, M. (1993). Propagation modeling of moist air and suspended water/ice particles at frequencies below 1000 GHz. In AGARD, Atmospheric Propagation Effects Through Natural and Man-Made Obscurants for Visible to MM-Wave Radiation. (SEE N94-30495 08-32). Tenerelli, J., Reul, N., Mouche, A., and Chapron, B. (2008). Earth-viewing L-band radiometer sensing of sea surface scattered celestial sky radiation-Part I: General characteristics.Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 25 / 25
  • 30. IEEE Transactions on Geoscience and Remote Sensing, 46(3):659–674. Zribi, M., Parde, M., Boutin, J., Fanise, P., Hauser, D., Dechambre, M., Kerr, Y., Leduc-Leballeur, M., Reverdin, G., Skou, N., et al. (2011). CAROLS: A New Airborne L-Band Radiometer for Ocean Surface and Land Observations. Sensors, 11:719–742.Adrien MARTIN (LOCEAN-IPSL) SMOS & CAROLS IGARSS Vancouver 2011 25 / 25