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IEEE Transactions on Antennas and Propagation
Volume 48 Number 8, August 2000

Table of Contents for this issue

Complete paper in PDF format

An Efficient Calculational Approach to Evaluation of Microwave Specific Attenuation

Le-Wei Li, Senior Member, IEEE Tat-Soon Yeo, Senior Member, IEEE Pang-Shyan Kooi, Member, IEEE and Mook-Seng Leong Senior Member, IEEE

Page 1220.

Abstract:

An efficient calculational approach using the scattering-radiation conversion is developed in this paper to evaluate the microwave attenuation by arbitrarily distorted raindrops. For this modified first-order approach,the perturbation technique and the spherical vector eigenfunction expansion method are employed. A method of obtaining the volumetric current distribution of the assumed source that generates the plane waves is developed in the paper and the current distribution of such a source is derived. The electromagnetic fields outside the distorted raindrop scatterers are formulated in terms of integrals consisting of a volumetric current distribution located at infinity and the dyadic Green's functions. To illustrate the validity of this approach,the spheroidal raindrop and the Pruppacher and Pitter (P-P) raindrop model of varying shapes are specifically investigated. Numerical results of the extinction cross sections and the specific attenuation due to the two models are obtained. While the former agrees well with the published results, the latter is in good agreement with the experimental specific attenuation data collected at 21.225 GHz in Singapore.

References

  1. A. F. Stevenson, "Solution of electromagnetic scattering problems as power series in the ratio (dimension of scatterer)/wavelength", J. Appl. Phys., vol. 24, pp.  1134-1142, 1953.
  2. A. F. Stevenson, "Electromagnetic scattering by an ellipsoid in the third approximation", J. Appl. Phys., vol. 24, pp.  1143-1151,  1953.
  3. T. Oguchi, "Attenuation of electromagnetic wave due to rain with distorted raindrops", J. Radio Res. Labs., vol. 7, pp.  467-485, 1960.
  4. T. Oguchi, "Attenuation of electromagnetic wave due to rain with distorted raindrops-Part II", J. Radio Res. Labs. , vol. 11, pp.  19-44, 1964.
  5. L. W. Li, P. S. Kooi, M. S. Leong, T. S. Yeo and M. Z. Gao, "Microwave attenuation by realistically distorted raindrops: Part I-Theory", IEEE Trans. Antennas Propagat., vol. 43, pp.  811-822, Aug.  1995.
  6. L. W. Li, P. S. Kooi, M. S. Leong, T. S. Yeo and M. Z. Gao, "Microwave attenuation by realistically distorted raindrops: Part II-Predictions", IEEE Trans. Antennas Propagat., vol. 43, pp.  823-828, Aug.  1995.
  7. J. A. Morrison and T. S. Chu, "Perturbation calculations of rain-induced differential attenuation and differential phase shift at microwave frequencies", Bell Syst. Tech. J., vol. 52, pp.  1907-1913, 1973.
  8. J. A. Morrison and M. J. Cross, "Scattering of a plane electromagnetic wave by axisymmetric raindrops", Bell Syst. Tech. J., vol. 53, pp.  955-1019, 1974.
  9. P. C. Waterman, "Matrix formulation of electromagnetic scattering", Proc. IEEE, vol. 53, pp.  805-812, 1965.
  10. P. C. Waterman, "Scattering by dielectric obstacles", Alta Freq., vol. 38, pp.  348-352, 1969.
  11. P. Barber and C. Yeh, "Scattering of electromagnetic waves by arbitrarily shaped dielectric bodies", Appl. Opt., vol. 14, pp.  2864 -2872, 1975.
  12. C. Warner and A. Hizal, "Scattering and depolarization of microwaves by spheroidal raindrops", Radio Sci., vol. 11, pp.  921-930, 1976.
  13. K. K. Mei, "Unimoment method of solving antenna and scattering problems", IEEE Trans. Antennas Propagat., vol. AP-22, pp.  760-766, Nov.  1974.
  14. S.-K. Chang and K. K. Mei, "Application of the unimoment method to electromagnetic scattering of dielectric cylinders", IEEE Trans. Antennas Propagat., vol.  AP-24, pp.  35-42, Jan.  1976.
  15. T. Oguchi, "Scattering from hydrometeors: A survey", Radio Sci., vol. 16, pp.  691-730, 1981.
  16. T. Oguchi, "Electromagnetic wave propagation and scattering in rain and other hydrometeors", Proc. IEEE, vol. 71, pp.  1029-1078,  Sept.  1983.
  17. R. L. Olsen, D. V. Rogers and D. B. Hodge, "The aRb relation in the calculation of rain attenuation", IEEE Trans. Antennas Propagat., vol. AP-26, pp.  318-329, Mar.  1978.
  18. D. M. A. Jones, "The shape of raindrops", J. Atmos. Sci., vol. 16, pp.  504-510, 1959.
  19. H. R. Pruppacher and K. V. Beard, "A wind tunnel investigation of the internal circulation and shape of water drops falling at terminal velocity in air", Quart. J. R. Met. Soc., vol. 96, pp.  247-256, 1970.
  20. L. W. Li, P. S. Kooi, M. S. Leong and T. S. Yeo, "On the simplified expression of realistic raindrop shapes", Microwave Opt. Technol. Lett., vol. 7, no. 4, pp.  201-205, March  1994.
  21. H. R. Pruppacher and R. L. Pitter, "A semi-empirical determination of the shape of cloud and rain drops", J. Atmos. Sci., vol. 28, pp.  86-94, 1971 .
  22. J. O. Laws and D. A. Parsons, "The relation of raindrop-size to intensity", Trans. Amer. Geophys. Union, vol. 24, pp.  452 -460, 1943.
  23. T. Oguchi, "Scattering properties of Pruppacher-and-Pitter form raindrops and cross polarization due to rain: Calculations at 11, 13, 19.3 and 34.8 GHz", Radio Sci., vol. 12, pp.  41-51, 1977.
  24. W. C. Chew, Waves and Fields in Inhomogeneous Media, New York: Van Nostrand Reinhold, 1990.
  25. C. T. Tai, Dyadic Green's Functions in Electromagnetic Theory, 2nd ed.   Piscataway, NJ: IEEE Press, 1994.
  26. M. Kerker, The Scattering of Light and Other Electromagnetic Radiation, New York: Academic, 1969.
  27. K. Shimizu, "Modification of the Rayleigh-Debye approximation", J. Opt. Soc. Amer. A, vol. 73, pp.  504-507, 1983.
  28. J. E. Gordon, "Simple method for approximating Mie scattering", J. Opt. Soc. Amer. A, vol. 75, pp.  156-159, 1985.
  29. A. R. Holt, N. K. Uzunoglu and B. G. Evans, "An integral equation solution to the scattering of electromagnetic radiation by dielectric spheroids and ellipsoids", IEEE Trans. Antennas Propagat., vol. AP-26, pp.  706-712, Sept.  1978.
  30. V. A. Erma, "An exact solution for the scattering of electromagnetic waves from conductors of arbitrary shape: I. Case of cylindrical symmetry", Phys. Rev., vol. 173, pp.  1243-1257, 1968.
  31. P. S. Ray, "Broadband complex refractive indices of ice and water", Appl. Opt., vol. 11, pp.  1836-1844, 1972.
  32. T. S. Yeo, P. S. Kooi and M. S. Leong, "Microwaves attenuation measurement in Singapore", in Proc. 1994 Asia-Pacific Microwave Conf., Tokyo, Japan,Dec. 1994, pp.  193- 196. 
  33. T. S. Yeo, P. S. Kooi and M. S. Leong, "A two-year measurement of rainfall attenuation of CW microwaves in Singapore", IEEE Trans. Antennas Propagat., vol. 41, pp.  709-712, June  1993.
  34. T. S. Yeo, P. S. Kooi, M. S. Leong and S. S. Ng, "Microwave attenuation due to rainfall at 21.225 GHz in the Singapore environment", Electron. Lett., vol. 26, pp.  1021-1022,  1990.
  35. L. W. Li, T. S. Yeo, P. S. Kooi and M. S. Leong, "Comment on raindrop size distribution model", IEEE Trans. Antennas Propagat., vol. 42, p.  1360, Sept.  1994.
  36. L. W. Li, P. S. Kooi, M. S. Leong and T. S. Yeo, "Electromagnetic dyadic Green's function in spherically multilayered media", IEEE Trans. Microwave Theory Tech., vol. 42, pp.  2302-2310, Dec.  1994.
  37. J. A. Stratton, Electromagnetic Theory, New York: McGraw-Hill, 1941.
  38. B. Friedman and J. Russek, "Addition theorems for spherical waves", Quart. Appl. Math., vol. 12, pp.  13-23, 1954.
  39. Seymour Stein, "Addition theorems for spherical wave functions", Quart. Appl. Math. , vol. 19, pp.  15-24, 1961.
  40. O. R. Cruzan, "Translational addition theorems for spherical vector wave functions", Quart. Appl. Math., vol. 20, pp.  33-40, 1962.