1 / 30

SMOS Validation Rehearsal Campaign Mediterranean flights

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) E-mail: cgabarro@icm.csic.es URL: www.smos-bec.icm.csic.es. Marseille. Barcelona. Buoy 3. Buoy 1-2. Valencia.

xenia
Download Presentation

SMOS Validation Rehearsal Campaign Mediterranean flights

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 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) E-mail: cgabarro@icm.csic.es URL: www.smos-bec.icm.csic.es

  2. Marseille Barcelona Buoy 3 Buoy 1-2 Valencia Mediterranean flights Flight 19-04-08 from 18:20 to 21h (flight back on 3-05-08 not analysed)

  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)

  4. In situ data: oceanographic buoys • Closest data to overflight • 19/04/08 20:20 • Buoys 1-2 • T = 10' • SSS = 38,09 -> - 0.6 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

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

  6. In situ conditions: Wind speed ASCAT QuikSCAT ERS Scatterometer winds 19-4-2008 provided by KNMI, Netherlands

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

  8. Analysis Flight 19-04-08 from 18:20 to 21h Marseille Analysis by areas: 1 st: Casablanca buoys 2n: Marseille- Buoys Barcelona Buoy 3 Buoy 1-2 Valencia RFI - not used

  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.

  10. Flight between buoys MFSTEP MFSTEP Between buoys

  11. EMIRAD beam center location Pitch Roll Between buoys Horn = 0º Horn = 40º

  12. TB measured and modelled, horn=0º Between buoys

  13. TB measured and modelled, horn=40º Between buoys

  14. TB measured - modelled Between buoys Bias of 5 K -> Problem on calibration TY aft? Too simple model?

  15. TB measured - modelled Galatic noise corrected with gal maps + flat sea - error Between buoys

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

  17. Flight from Marseille to buoys

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

  19. TB measured vs modelled Marseille to buoys Again bias on TY aft

  20. TB measured vs modelled Galatic noise corrected with gal maps + flat sea - error ? Marseille to buoys

  21. TB measured for θ0 Only nadir horn used Marseille to buoys 0.5 K Calibration problems? Theoretically: at surface reference frame, for θ 0 -> TH=TV

  22. Conclusions – EMIRAD over sea • An important bias appears on the aft V channel antenna (~ 5 K) -> galactic noise??? • Not accordance between TH & TV on θ0 (~ 0.5 K) • Important RFI and noise are detected (near Valencia) • Measured TB 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.

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

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

  25. HUT-2D Data Processing 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

  26. Direct measurements In-situ (vessel measured) SST Direct measurements 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 17.58 3.46 m/s 15/08/2007 at 17.06

  27. Second flight on August, 13 Apparent Temperature at X-Pol Apparent Temperature at Y-Pol

  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, 2007. IGARSS 2007.

  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

More Related