SMOS Validation Rehearsal Campaign Workshop, 18-19/11/2008, Noordwijkerhout, The Netherlands SMOS Validation Rehearsal Campaign Mediterranean flights C. Gabarró, M. Talone, J. Font SMOS Barcelona Expert Centre Pg. Marítim de la Barceloneta 37-49, Barcelona (Spain) URL:

SMOS Rehearsal Campaign 2 Flight from 18:20 to 21h (flight back on not analysed) Marseille Valencia Barcelona Buoy 3 Buoy 1-2 Mediterranean flights

SMOS Rehearsal Campaign 3 In situ data: oceanographic buoys  In situ data report and data files available through ESA Buoys 1-2: ICM specific deployment close to Casablanca oil platform Buoy 3: offshore permanent network (PE) Buoy 4: coastal permanent network (SMC)

SMOS Rehearsal Campaign 4  Closest data to overflight  19/04/08 20:20  Buoys 1-2   T = 10'  SSS = 38,09 -> m  SST = 14,50 ºC  WS = 4,16 m/s  SWH=0.7 m  Buoy 3   T=60'  SSS = 38,1 -> - 3 m  SST = 14,5 ºC  WS = 5,8 m/s In situ data: oceanographic buoys

SMOS Rehearsal Campaign 5 Δ Resolution = 1/16 º Time = 12h Marseille Valencia Barcelona Marseille Valencia Barcelona Mediterranean Forecasting System, Univ. Bologna (MOON) In situ conditions: numerical model

SMOS Rehearsal Campaign 6 Scatterometer winds provided by KNMI, Netherlands In situ conditions: Wind speed ASCATQuikSCAT ERS

SMOS Rehearsal Campaign 7 Only QuikSCAT covers the whole area of interest :  R = 25Km 18:18 h 19/04/2008 In situ conditions: Wind speed ASCATQuikSCAT ERS

SMOS Rehearsal Campaign 8 Flight from 18:20 to 21h Analysis by areas: 1 st: Casablanca buoys 2n: Marseille- Buoys Marseille Valencia Barcelona Buoy 3 Buoy 1-2 Analysis RFI - not used

SMOS Rehearsal Campaign 9 Simplified emissivity model  Klein & Swift for sea water dielectric constant  Linear fit of Hollinger measurements for wind effect  Linear approximation for the atmospheric and constant external sources contribution  Average of 0.1 s and points with RFI not used in average.

SMOS Rehearsal Campaign 10 Flight between buoys MFSTEP Between buoys

SMOS Rehearsal Campaign 11 EMIRAD beam center location Between buoys Horn = 0º Horn = 40º Roll Pitch

SMOS Rehearsal Campaign 12 T B measured and modelled, horn=0º Between buoys

SMOS Rehearsal Campaign 13 Between buoys T B measured and modelled, horn=40º

SMOS Rehearsal Campaign 14 Bias of 5 K -> Problem on calibration TY aft? Too simple model? T B measured - modelled Between buoys

SMOS Rehearsal Campaign 15 T B measured - modelled Between buoys Galatic noise corrected with gal maps + flat sea - error

SMOS Rehearsal Campaign 16 Small differences between models: Hollinger 1971 Gabarró 2004 Models comparison Between buoys Tb modelled using in situ SST, SSS, SWH, WS

SMOS Rehearsal Campaign 17 Flight from Marseille to buoys

SMOS Rehearsal Campaign 18 Only cleanest area used for analysis (3000 measurements) In situ data Marseille to buoys RFI percentages: H - aft = 12.66% V - aft = 4.33% H - nadir = 3.92% V - nadir = 1.40 %

SMOS Rehearsal Campaign 19 T B measured vs modelled Again bias on TY aft Marseille to buoys

SMOS Rehearsal Campaign 20 T B measured vs modelled Marseille to buoys Galatic noise corrected with gal maps + flat sea - error ?

SMOS Rehearsal Campaign 21 Theoretically: at surface reference frame, for θ  0 -> T H =T V T B measured for θ  0 Calibration problems? Only nadir horn used 0.5 K Marseille to buoys

SMOS Rehearsal Campaign 22 Conclusions – EMIRAD over sea  An important bias appears on the aft V channel antenna (~ 5 K) -> galactic noise???  Not accordance between T H & T V on θ  0 ( ~ 0.5 K)  Important RFI and noise are detected (near Valencia)  Measured T B variability fits with modeled variability  WE NEED TO USE A REALISTIC MODELING OF GALACTIC NOISE –> use a roughness model (not flat sea) -> review which output from TRAP to use.

SMOS Rehearsal Campaign 23 INTERFEROMETRIC RADIOMETER DATA – HUT 2D Flights over the Gulf of Finland August, 13th and 15th 2007

SMOS Rehearsal Campaign 24 HUT-2D Data Processing Two series of flights over the Gulf of Finland August, 13, 2007 (20 flights) August, 15, 2007 (22 flights)

SMOS Rehearsal Campaign 25 Approximations and Models Klein & Swift for the sea water dielectric constant Linear fit of Hollinger Measurements for Wind Effect Linear approximation for the Atmospheric Contribution Assuming Apparent Temperature = Brightness Temperature Ulaby F., Moore R., Fung A. - Microwave Remote Sensing Active and Passive - ed. Addison-Wesley Publishing Company HUT-2D Data Processing

SMOS Rehearsal Campaign 26 In-situ (vessel measured) SSS Nearest neighbour approximation along the ground-track for SSS and SST Nearest neighbour (in time and space) QuikSCAT data for Wind Speed [KNMI] 3.73 m/s 13/08/2007 at m/s 15/08/2007 at Direct measurements In-situ (vessel measured) SST Direct measurements

SMOS Rehearsal Campaign 27 Apparent Temperature at X-Pol Apparent Temperature at Y-Pol Second flight on August, 13

SMOS Rehearsal Campaign 28 Difference between Apparent Temperature and Modeled Brightness Temperature in the Earth reference frame The antenna pattern must be included in the processing to transform the apparent temperature in measured brightness temperature! Kainulainen, J., Rautiainen, K., Hallikainen, M., Takala, M - Radiometric performance of interferometric synthetic aperture radiometer HUT-2D IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2007.

SMOS Rehearsal Campaign 29 In order to make the SSS retrieval possible and reliable: Antenna pattern must be considered A previous selection of the measurements must be performed Better models for atmospheric and galactic contribution must be used

SMOS Barcelona Expert Centre (SMOS-BEC) Pg. Marítim de la Barceloneta 37-49, E Barcelona, SPAIN Tel. (+34) ; Fax. (+34) URL: