volume | PIER Journals

Abstract

Extraction of vegetation water content and soil moisture from microwave observations requires development of a high fidelity scattering model. A number of factors associated with the vegetation canopy and with the underlying bare soil should be taken into account. In this paper,w e propose an electromagnetic scattering model for a soybean canopy which includes the coherent effect due to the soybean structure and takes advantage of recently advanced scattering models for rough surface. We also take care of some other issues, such as including curvature effect in studying the ground bounce scattering mechanisms,and using array theory with perturbation for characterizing the inter-plant structure to account for the prevailing agriculture practice of soybean. Good agreements are obtained between the model results and measurement data.

1. Tsang, L., J. A. Kong, and R. T. Shin, Theory of Microwave Remote Sensing, Wiley-In terscience, 1985.

2. Storvold, R., E. Malnes, Y. Larsen, K. A. Hogda, S. E. Hamran, K. Muller, and K. A. Langley, "SAR remote sensing of snow parameters in Norwegian areas — Current status and future perspective," J. of Electromagn. Waves and Appl., Vol. 20, No. 13, 1751-1759, 2006.
doi:10.1163/156939306779292192

3. Singh, D. and A. Kathpalia, "An efficient modeling with GA approach to retrieve soil texture,moisture and roughness from ERS-2 SAR data," Progress In Electromagnetics Research, Vol. 77, 121-136, 2007.
doi:10.2528/PIER07071803

4. Li, Z.-X., "Mo delling the passive microwave remote sensing of wet snow," Progress In Electromagnetics Research, Vol. 62, 143-164, 2006.
doi:10.2528/PIER05102402

5. Mudaliar, S., "On the application of the radiative transfer approach to scattering from a random medium layer with rough boundaries," J. of Electromagn. Waves and Appl., Vol. 20, No. 13, 1739-1749, 2006.
doi:10.1163/156939306779292246

6. Arslan, A. N., J. Pulliainen, and M. Hallikainen, "Observ ations of L-and C-band backscatter and a semi-empirical backscattering model approach from a forest-snow-ground system," Progress In Electromagnetics Research, Vol. 56, 263-281, 2006.
doi:10.2528/PIER05062701

7. Zhang, G., L. Tsang, and Z. Chen, "Collectiv e scattering effects of trees generated by stochastic Lindenmayer systems," Microwave Opt. Technol. Lett., Vol. 11, 107-111, 1995.
doi:10.1002/(SICI)1098-2760(19960205)11:2<107::AID-MOP18>3.0.CO;2-B

8. Yueh, S. H., J. A. Kong, J. K. Jao, R. T. Shin, and T. Le Toan, "Branc hing model for vegetation," IEEE Trans. Geosci. and Remote Sensing, Vol. 30, No. 2, 390-401, 1992.
doi:10.1109/36.134088

9. Lin, Y. C. and K. Sarabandi, "A Monte Carlo coherent scattering model for forest canopies using fractal generated trees," IEEE Trans. Geosci. Remote Sensing, Vol. 37, No. 1, 36-40, 1997.

10. Chiu, T. and K. Sarabandi, "Electromagnetic scattering from short branching vegetation," IEEE Trans. Geosci. and Remote Sensing, Vol. 38, No. 2, 911-925, 2000.
doi:10.1109/36.841974

11. Notarnicola, C. and F. Posa, "Inferring vegetation water content from C-and L-band SAR images," IEEE Trans. Geosci. and Remote Sensing, Vol. 45, No. 10, 3165-3171, 2007.
doi:10.1109/TGRS.2007.903698

12. Kong, J. A., Electromagnetic Wave Theory, EMW Publishing, 2005.

13. Ulaby, F. T., R. K. Moore, and A. K. Fung, Microwave Remote Sensing, Active and Passive, 1982.

14. Voronovich, A. G., "Small slope approximation in wave scattering by rough surface," Sov. Phys. JETP, Vol. 62, 65-70, 1985.

15. Winebrenner, D. and A. Ishimaru, "In vestigation of a surface field phase perturbation technique for scattering from rough surfaces," Radio Sci., Vol. 20, No. 4, 161-170, 1985.
doi:10.1029/RS020i002p00161

16. Milder, D. M., "An improved formalism for wave scattering from rough surfaces," J. Acoust. Soc. Am., Vol. 89, 529-541, 1991.
doi:10.1121/1.400377

17. Rodriguez, E. and Y. Kim, "A unified perturbation expansion for surface scattering," Radio Sci., Vol. 27, 79-93, 1992.
doi:10.1029/91RS02638

18. Rodriguez, E., Y. Kim, and S. L. Durden, "A numerical assessment of rough surface scattering theories: Horizontal polarization," Radio Sci., Vol. 27, No. 8, 497-513, 1992.
doi:10.1029/92RS00502

19. Bahar, E., "Radio wave propagation in stratified media with nonuniform boundaries and varying electromagnetic parameters: full wave analysis," Canad. J. Phys., Vol. 50, 3132-3142, 1972.

20. Bahar, E., "Radar scatter cross-sections for two-dimensional random rough surfaces: full wave solutions and comparisons with experiments," Waves Random Media, Vol. 6, No. 1, 1-23, 1996.
doi:10.1088/0959-7174/6/1/004

21. Fung, A. K. and N. C. Kuo, "Bac kscattering from multi-scale and exponentially correlated surfaces," J. of Electromagn. Waves and Appl., Vol. 20, No. 1, 3-11, 2006.
doi:10.1163/156939306775777378

22. Fung, A. K., Z. Q. Li, and K. S. Chen, "Bac kscattering from a randomly rough dielectric surface," IEEE Trans. Geosci. Remote Sensing, Vol. GE-30, No. 2, 356-369, 1992.
doi:10.1109/36.134085

23. Hsieh, C. Y., A. K. Fung, G. Nesti, A. Sieber, and P. Coppo, "A further study of the IEM surface scattering model," IEEE Trans. Geosci. Remote Sensing, Vol. 35, 901-909, 1997.
doi:10.1109/36.602532

24. Chen, K. S., T. D. Wu, L. Tsang, Q. Li, J. C. Shi, and A. K. Fung, "Emission of rough surfaces calculated by the integral equation method with comparison to three-dimensional moment method simulations," IEEE Trans. Geosci. Remote Sensing, Vol. GE-41, No. 1, 90-101, 2003.
doi:10.1109/TGRS.2002.807587

25. Alvarez-Perez, J., "An extension of the IEM/IEMM surface scattering model," Waves in Random Media, Vol. 11, 307-329, 2001.
doi:10.1088/0959-7174/11/3/308

26. Du, Y., J. A. Kong, W. Z. Yan, Z. Y. Wang, and L. Peng, "A statistical integral equation model for shadow-corrected EM scattering from a Gaussian rough surface," IEEE Trans. Antennas and Propag., Vol. 55, No. 6, 1843-1855, 2007.
doi:10.1109/TAP.2007.898503

27. Du, Y., "A new bistatic model for electromagnetic scattering from randomly rough surfaces," to appear in Waves in Random and Complex Media..

28. Chiu, T. and K. Sarabandi, "Electromagnetic scattering interaction between a dielectric cylinder and a slightly rough surface," IEEE Trans. Antennas Propagat., Vol. 47, 902-913, 1999.
doi:10.1109/8.774155

29. Davidson, M. W. J., T. L. Toan, F. Mattia, G. Satalino, T. Manninen, and M. Borgeaud, "On the characterization of agricultural soil roughness for radar remote sensing studies," IEEE Trans. Geosci. Remote Sensing, Vol. 38, No. 3, 630-640, 2000.
doi:10.1109/36.841993

30. De Roo, R. D., Y. Du, F. T. Ulaby, and M. C. A. Dobson, "Semi-empirical backscattering model at L-band and C-band for asoybean canopy with soil moisture inversion," IEEE Trans. Geosci. Remote Sensing, Vol. 39, No. 4, 864-872, 2001.
doi:10.1109/36.917912

31. Karam, M. A., A. K. Fung, and Y. M. M. Antar, "Electromagnetic wave scattering from some vegetation samples," IEEE Trans. Geosci. Remote Sensing, Vol. 26, 799-808, 1988.
doi:10.1109/36.7711

32. Rodriguez, E., "Bey ond the Kirchhoff approximation," Radio Sci., Vol. 26, 121-132, 1991.

33. Le Toan, T., F. Ribbes, N. Floury, L. Wang, J. A. Kong, T. Kurosu, and M. Fujita, "Rice crop monitoring using ERS-1 data: Experiment and modeling results," IEEE Trans. Geosci. Remote Sensing, Vol. 35, No. 1, 41-56, 1997.
doi:10.1109/36.551933

34. Chuah, H. T., S. Tjuatja, A. K. Fung, and J. W. Bredow, "Phase matrix for a dense discrete random medium: evaluation of volume scattering coefficient," IEEE Trans. Geosci. Remote Sensing, Vol. 34, No. 5, 1137-1143, 1996.
doi:10.1109/36.536529

Professor Yang Du

Dr. Yingliang Luo

Dr. Wen-Zhe Yan

Professor Jin Au Kong