volume | PIER Journals

Abstract

At wo-scale scattering model of the sea developed in terms of wind-generated stochastic processes of the surface-the elevation spectral density of the small-scale structure and the probability density of slopes of the large scale roughness-is combined with the Durden/Vesecky [1] wave height spectral model to analyze recent polarimetric measurements. Ad hoc parameter values are found for the wave model that allow the two-scale model to account for essentially all of the azimuthal features, amplitude and phase, appearing in all four Stokes parameters for the Jet Propulsion Laboratory (JPL) aircraft measurements at 19.35 and 37 GHz [2] and recent Naval Research Laboratory (NRL) aircraft measurements at 10.7 GHz. The excellent agreement provides support for the validation of the approximations of the two-scale model for the range of conditions encountered. The ad hoc parameters of the wave model are developed using the 19.35 and 37.0 GHz data and then tested with 10.7 GHz data. The twoscale model should be useful in studies dealing with simulations and retrievals of surface wind direction from satellite-based polarimetric measurements.

1. Durden, S. L. and J. F. Vesecky, "Aph ysical radar cross-section model for a wind-driven sea with swell," J. Ocean Engr., Vol. 10, No. 4, 445-451, 1985.
doi:10.1109/JOE.1985.1145133 Google Scholar

2. Yueh, S. H., "Modeling of wind direction signals in polarimetric sea surface brightness temperatures," IEEE Trans. Geosci. Remote Sensing, Vol. 35, No. 6, 1400-1418, 1997.
doi:10.1109/36.649793 Google Scholar

3. Yueh, S. H., W. J. Wilson, F. K. Li, W. B. Ricketts, and S. V. Nghiem, "Polarimetric brightness temperatures of sea surfaces measured with aircraft K- and Ka-band radiometers," IEEE Trans. Geosci. Remote Sensing, Vol. 33, No. 5, 1177-1187, 1997.
doi:10.1109/36.628785 Google Scholar

4. Chang, P. S., P. W. Gaiser, L. Li, and K. M. St. Germain, "Multi-frequency polarimetric microwave ocean wind direction retrievals," Proceedings of the International Geoscience and Remote Sensing Symposium, Singapore, 1997. Google Scholar

5. Yueh, S. H., W. J. Wilson, S. J. DiNardo, and F. K. Li, "Polarimetric microwave brightness signatures of ocean wind direction," IEEE Trans. Geosci. Remote Sensing, Vol. 37, No. 2, 949-959, 1999.
doi:10.1109/36.752213 Google Scholar

6. Wentz, F. J., "Measurement of oceanic wind vector using satellite microwave radiometers," IEEE Trans. Geosci. Remote Sensing, Vol. 30, No. 5, 960-972, 1992.
doi:10.1109/36.175331 Google Scholar

7. Meissner, T. and F. J. Wentz, "An updated analysis of the ocean surface wind direction signal in passive microwave brightness temperatures," submitted to IEEE Trans. Geosci. Remote Sensing, 2002. Google Scholar

8. Chang, P. S. and L. Li, "Ocean surface wind speed and direction retrievals from the SSM/I," IEEE Trans. Geosci. Remote Sensing, Vol. 36, No. 6, 1866-1871, 1998.
doi:10.1109/36.729357 Google Scholar

9. Wick, G. A., J. J. Bates, and C. C. Gottschall, "Observational evidence of a wind direction signal in SSM/I passive microwave data," IEEE Trans. Geosci. Remote Sensing, Vol. 38, No. 2, 823-837, 2000.
doi:10.1109/36.842011 Google Scholar

10. Piepmeier, J. R. and A. J. Gasiewski, "High-resolution passive polarimetric microwave mapping of the ocean surface wind vector fields," IEEE Trans. Geosci. Remote Sensing, Vol. 39, No. 3, 606-622, 2001.
doi:10.1109/36.911118 Google Scholar

11. Hollinger, J. P., "Passive microwave measurements of sea surface roughness," IEEE Trans. Geoscience Elect., Vol. 9, No. 3, 165-169, 1971.
doi:10.1109/TGE.1971.271489 Google Scholar

12. Stogryn, A. P., "The apparent temperature of the sea at microwave frequencies," IEEE Trans. Ant. Prop., Vol. 15, No. 2, 278-286, 1967.
doi:10.1109/TAP.1967.1138900 Google Scholar

13. Cox, C. S. and W. H. Munk, "Measurements of the roughness of the sea surface from photographs of the sun’s glitter," J. Opt. Soc. Am., Vol. 44, 838-850, 1954.
doi:10.1364/JOSA.44.000838 Google Scholar

14. Hollinger, J. P., "Passive microwave measurements of the sea surface," J. Geophys. Res., Vol. 75, No. 27, 5209-5213, 1970.
doi:10.1029/JC075i027p05209 Google Scholar

15. Semyonov, B. I., "Approximate computation of scattering of electromagnetic waves by rough surface contours," Radio Eng. Electron Phys., Vol. 11, 1179-1187, 1966. Google Scholar

16. Wu, S. T. and A. K. Fung, "A non-coherent model for microwave emissions and backscattering from the sea surface," J. Geophys. Res., Vol. 77, No. 30, 5917-5929, 1972.
doi:10.1029/JC077i030p05917 Google Scholar

17. Wentz, F. J., "At wo-scale scattering model for foam-free sea microwave brightness temperatures," J. Geophys. Res., Vol. 80, No. 24, 3441-3446, 1975.
doi:10.1029/JC080i024p03441 Google Scholar

18. Yueh, S. H., et al. "Polarimetric passive remote sensing of ocean wind vectors," Radio Sci., Vol. 29, No. 4, 799-814, 1994.
doi:10.1029/94RS00450 Google Scholar

19. Poe, G. A., K. M. St. Germain, and P. W. Gaiser, "Theory of polarimetric emission model of the sea at microwave frequencies,", Naval Research Laboratory Technical Memorandum Report, in press, 2002. Google Scholar

20. Stogryn, A. P., "A study of radiometric emission from a rough sea surface,", NASA Report CR-2088, Contract 1-10633, 1972. Google Scholar

21. Durden, S. L. and J. F. Vesecky, "An umerical study of the separation wavenumber in the two-scale scattering approximation," IEEE Trans. Geosci. Remote Sensing, Vol. 28, No. 2, 271-272, 1990.
doi:10.1109/36.46707 Google Scholar

22. Fung, A. K. and K. K. Lee, "A semi-empirical sea-spectrum model for scattering coefficient estimation," IEEE Ocean Engr., Vol. 7, No. 4, 166-176, 1982.
doi:10.1109/JOE.1982.1145535 Google Scholar

23. Donelan, M. A., W. J. Pierson, and Jr., "Radar scattering and equilibrium ranges and wind-generated waves with application to scatterometry," J. Geophys. Res., Vol. 92, No. C5, 4971-5029, 1987.
doi:10.1029/JC092iC05p04971 Google Scholar

24. Stogryn, A. P., "Equations for the permittivity of sea water,", Report to Naval Research Laboratory, Washington, D.C., Code 7223, Aug. 1997. Google Scholar

25. Yueh, S. H., W. J. Wilson, F. K. Li, W. B. Ricketts, and S. V. Nghiem, "Polarimetric measurements of sea surface brightness temperatures using an aircraft K-band radiometer," IEEE Trans. Geosci. Remote Sensing, Vol. 33, No. 1, 85-92, 1995.
doi:10.1109/36.368219 Google Scholar

26. Kunkee, D. B. and A. J. Gasiewski, "Simulation of passive microwave wind direction signatures over the ocean using an asymmetrices wave geometrical optics model," Radio Science, Vol. 32, No. 1, 59-78, Jan. 1997.
doi:10.1029/96RS02434 Google Scholar

Dr. Peter W. Gaiser