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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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. Google Scholar

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 Google Scholar

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 Google Scholar

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. Google Scholar

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 Google Scholar

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 Google Scholar

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

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 Google Scholar

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. Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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

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 Google Scholar

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 Google Scholar

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 Google Scholar

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 Google Scholar

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

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 Google Scholar

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 Google Scholar

Professor Yang Du

Dr. Yingliang Luo

Dr. Wen-Zhe Yan

Professor Jin Au Kong