volume | PIER Journals

Abstract

The T-matrix approach is effective in analyzing electromagnetic scattering from finite scatterers. Yet for scatterers with extreme geometry, this approach may fail. One example is its inability to analyze scattering from dielectric cylinders with large aspect ratios. To deal with such difficulty, recently we proposed a method based on an extension of the T-matrix approach, where a long cylinder is hypothetically divided into a cluster of identical sub-cylinders, for each the T matrix can be numerically stably calculated. Special care was paid to fulfill the boundary conditions at the hypothetic surface of any two neighboring sub-cylinders. The resultant coupled equations are different from that of multi-scatterer theory. The model results were in good agreement with experiment data available in the literature. However, the validity region of the proposed method was not fully characterized. Now we have developed and validated a method of moment (MoM) code, and are in a position to carry on the task of characterizing the validity region. The proposed method is found to be applicable to dielectric cylinders of arbitrary length as long as the T matrix is attainable for the elementary sub-cylinder. The conditions for the T matrix to be numerically stably calculated in terms of the equivalent volumetric radius and relative dielectric constant are also empirically obtained.

1. Ulaby, F. T., K. Sarabandi, K. McDonald, M. Whitt, and M. C. Dobson, "Michigan microwave canopy scattering model," Int. J. Remote Sensing, Vol. 38, No. 7, 2097-2128, 2000. Google Scholar

2. Yueh, S. H., J. A. Kong, J. K. Jao, R. T. Shin, and T. L. Toan, "Branching model for vegetation," IEEE Trans. Geosci. Remote Sensing, Vol. 30, 390-402, 1992.
doi:10.1109/36.134088 Google Scholar

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

4. Du, Y., Y. Luo, W. Z. Yan, and J. A. Kong, "An electromagnetic scattering model for soybean canopy," Progress In Electromagnetics Research, Vol. 79, 209-223, 2008.
doi:10.2528/PIER07101603 Google Scholar

5. Ahmed, S. and Q. A. Naqvi, "Electromagnetic scattering from parallel perfect electromagnetic conductor cylinders of circular cross-sections using an iterative procedure," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 7, 987-1003, 2008.
doi:10.1163/156939308784150209 Google Scholar

6. Illahi, A., M. Afzaal, and Q. A. Naqvi, "Scattering of dipole field by a perfect electromagnetic conductor cylinder," Progress In Electromagnetics Research Letters, Vol. 4, 43-53, 2008.
doi:10.2528/PIERL08051601 Google Scholar

7. Mishra, M. and N. Gupta, "Application of quasi Monte Carlo integration technique in EM scattering from finite cylinders," Progress In Electromagnetics Research Letters, Vol. 9, 109-118, 2009.
doi:10.2528/PIERL09050806 Google Scholar

8. Valagiannopoulos, C. A., "Arbitrary currents on circular cylinder with inhomogeneous cladding and RCS optimization," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 5, 665-680, 2007.
doi:10.1163/156939307780667337 Google Scholar

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

10. Karam, M. A. and A. K. Fung, "Electromagnetic wave scattering from some vegetation samples," Int. J. Remote Sensing, Vol. 9, 1109-1134, 1988.
doi:10.1080/01431168808954918 Google Scholar

11. Waterman, P. C., "Matrix formulation of electromagnetic scattering," Proc. IEEE, Vol. 53, 805-811, 1956.

12. Mishchenko, M. I., L. D. Travis, and A. A. Lacis, Scattering, Absorption, and Emission of Light by Small Particles, Cambridge U. Press, 1985.

13. Mishchenko, M. I. and L. D. Travis, "T-matrix computations of light scattering by large spheroidal particles," Opt. Commun., Vol. 109, 16-21, 1994.
doi:10.1016/0030-4018(94)90731-5 Google Scholar

14. Mishchenko, M. I., L. D. Travis, and A. Macke, "Scattering of light by polydisperse, randomly oriented, finite circular cylinders," Appl. Opt., Vol. 35, 4927-4940, 1996.
doi:10.1364/AO.35.004927 Google Scholar

15. Mishchenko, M. I., L. D. Travis, and D. W. Mackowski, "T-matrix computations of light scattering by nonspherical particles: A review," J. Quant. Spectrosc. Radiat. Transfer, Vol. 55, 535-575, 1996.
doi:10.1016/0022-4073(96)00002-7 Google Scholar

16. Wielaard, D. J., M. I. Mishchenko, A. Macke, and B. E. Carlson, "Improved T-matrix computations for large, nonabsorbing and weakly absorbing nonspherical particles and comparison with geometrical optics approximation," Appl. Opt., Vol. 36, 4305-4313, 1997.
doi:10.1364/AO.36.004305 Google Scholar

17. Mishchenko, M. I., "Calculation of the amplitude matrix for a nonspherical particle in a fixed orientation," Appl. Opt., Vol. 39, 1026-1031, 2000.
doi:10.1364/AO.39.001026 Google Scholar

18. Barber, P. W., "Resonance electromagnetic absorption by non-spherical dielectric objects," IEEE Trans. Microwave Theory Tech., Vol. 25, 373-371, 1954.
doi:10.1109/TMTT.1977.1129106 Google Scholar

19. Yan, W.-Z., Y. Du, H. Wu, D. Liu, and B.-I. Wu, "EM scattering from a long dielectric circular cylinder," Progress In Electromagnetics Research, Vol. 85, 39-67, 2008.
doi:10.2528/PIER08081106 Google Scholar

20. Umashankar, K., A. Taflove, and S. M. Rao, "Electromagnetic scattering by arbitrary shaped three-dimensional homogeneous lossy dielectric objcts," IEEE Trans. Antennas Propagat., Vol. 34, 758-766, 1986.
doi:10.1109/TAP.1986.1143894 Google Scholar

21. Rao, S. M., D. R. Wilton, and A. W. Glisson, "Electromagnetic scattering by surfaces of arbitrary shape," IEEE Trans. Antennas Propagat., Vol. 30, 409-418, 1982.
doi:10.1109/TAP.1982.1142818 Google Scholar

22. Wang, L. F., J. A. Kong, K. H. Ding, T. Le Toan, F. Ribbes, and N. Floury, "Electromagnetic scattering model for rice canopy based on Monte Carlo simulation," Progress In Electromagnetics Research, Vol. 52, 153-171, 2005.
doi:10.2528/PIER04080601 Google Scholar

23. Arslan, A. N., J. Pulliainen, and M. Hallikainen, "Observations 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

24. Stein, S., "Addition theorems for spherical ware functions," Q. Appl. Math., Vol. 19, 15-24, 1961. Google Scholar

25. Tsang, L., J. A. Kong, and R. T. Shin, Theory of Microwave Remote Sensing, Wiley Interscience, 1985.

26. Xu, Y. L., "Electromagnetic scattering by an aggregate of spheres," Appl. Opt., Vol. 34, 4573-4588, 1995.
doi:10.1364/AO.34.004573 Google Scholar

27. Mishchenko, M. I., "Light scattering by size-shape distributions of randomly oriented axially symmetric particles of size comparable to a wavelength," Appl. Opt., Vol. 32, 4652-4666, 1993.
doi:10.1364/AO.32.004652 Google Scholar

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

Dr. Wen-Zhe Yan

Professor Yang Du

Dr. Zengyuan Li

Dr. Er-Xue Chen

Prof. Jian-Cheng Shi