微波散射理論於地表散射之研究

以作者查詢圖書館館藏

、以作者查詢臺灣博碩士

、以作者查詢全國書目

、勘誤回報

、線上人數：50

、訪客IP：3.145.156.46

姓名

劉偉毅(Wei-Yi Liu) 查詢紙本館藏

畢業系所

電機工程學系

論文名稱

微波散射理論於地表散射之研究
(A Study of Electromagnetic Wave Scattering from Randomly Rough Surface)

相關論文

★ 小型化 GSM/GPRS 行動通訊模組之研究	★ 多載波調變信號之濾波器組、載波數估測與載波回復系統設計
★ 中華衛星一號數位電視直播實驗使用Ka頻段之系統效能分析與模擬	★ 利用小波轉換於影像之系統分析
★ 直接序列展頻系統利用平行干擾消除技術改善在多人使用干擾的分析與模擬	★ 在CDMA細胞組成的行動電話系統架構下使用中心化功率控制
★ 以地理資訊系統為架構的無線電波傳播損耗預測和干擾分析系統	★ LMDS系統受降雨衰減影響下通道使用效能之研究
★ 利用多模式分碼多重擷取技術以降區域多點分配服務系統中細胞間的干擾	★ 利用旋轉基地台的觀念來提出一個在LMDS上的新細胞式架構
★ 直接序列展頻系統利用平行干擾消除與編碼技術在M-ary正交調變下之干擾分析與模擬	★ 2.4GHz影像暨ＧＰＳ無線通訊系統之整合
★ 16QAM調變系統	★ LMDS通道在雨衰影響下的分析
★ OFDM技術應用於LMDS系統在時變通道模型下之效能評估	★ 中華衛星一號之Ka-Band數位直播實驗通道特性分析與改善

檔案

[Endnote RIS 格式]

[Bibtex 格式]

[相關文章]

[文章引用]

[完整記錄]

[館藏目錄]

[檢視]

[下載]

本電子論文使用權限為同意立即開放。
已達開放權限電子全文僅授權使用者為學術研究之目的，進行個人非營利性質之檢索、閱讀、列印。
請遵守中華民國著作權法之相關規定，切勿任意重製、散佈、改作、轉貼、播送，以免觸法。

摘要(中)

探討地表對微波散射的研究已有數十年之久。至今仍被公認正確而廣泛使用的理論模型有二，即克希荷夫模型KM (Kirchhoff Model)以及小擾動模型SPM (Small Perturbation Model)。但此二模型所能使用之範圍相當有限： KM 使用在地表起伏很大或頻率很高時；而SPM適用於地表輕微擾動的小尺度情形或頻率很低時。在此二模型適用的區域之外，便成為各方競相研究提出新模型與解決方案的地帶。
積分方程模型 IEM (Integral Equation Model)於1980年代被提出，並於1994年由Dr. A.K. Fung出版為 ’Microwave Scattering and Emission Models and Their Applications’一書。它包含了KM與SPM所適用的範圍，也適用於此二模型之間的區域。IEM這個模型和其它同為地表散射的模型相比，最大的優點是它的推導雖然開始於複雜的積分方程式，但結果卻結束於簡單的代數式。因為沒有其它模型存在多重積分難以計算的問題，而且仍有相當高的正確性，使得IEM模型在實際計算上實用性非常強，也因而受到廣泛的應用。
然而，IEM在發展的過程中，因為模型的推導相當複雜，因此有幾項近似與簡化存在於其中，這樣做法大幅降低了模型的複雜性，但也相對的降低了它的精確性與完整性，以致於IEM在某些情況如雙向散射(Bistatic Scattering)上的預測值不夠準確。若要使得它能更精確與完整，有幾個問題需要修正。其中之一是修正原來對格林函數(Green's Function)的波譜表示式所做的簡化。此問題在1997年所發表的論文中曾被探討過，且此模型亦被重新修正。不過在其推導過程中，雖然補償場(Complementary Field)的相位部分將舊有的簡化去除，並推導出新的表示式，然而只適用於多重散射(Multiple Scattering)，且在其補償場係數(Complementary Field Coefficient)，亦即振幅的部分仍採用舊的近似法來做，沒有配合相位一起處理。此補償場的問題之後被提出並加以修正，使得振幅配合相位均為修正後之表示式，但仍然只能用於多重散射，並沒有對單散射(Single Scattering)提出修正後適用的表示式。因此，IEM模型仍然不夠完整與精確。
本研究中，我們針對單散射(Single Scattering)去除了原先用於格林函數上的近似假設，使得補償場的振幅與相位由近似值回復到原先的精確值，再重新自散射場推導至平均散射功率以至於單散射散射係數(Single Scatter Scattering Coefficient)。新的IEM模型比之前要複雜許多，但仍舊維持簡單代數式的結果。研究中發現，地表粗糙程度大時，新舊兩模型的差異性並不大，說明了使用近似與否並不影響先前IEM對大尺度或高頻散射預測的準確性。就角度上來說，當入射角與散射角相近或相等時，有無使用近似的假設也沒有太大的差異，這解釋了以往IEM在例如背向散射(Back Scattering)上的應用可以相當準確的原因。但當入射角與散射角相差大，尤其是在地表粗糙程度小而散射微弱時，新舊模型的差異便相當可觀。新的IEM在雙向散射上的預測值其準確性大幅提高，在高頻區它可以和作為標準的KM符合，在低頻區它也能和作為標準的SPM一致;當應用在地表輻射率(Surface Emissivity)計算時，它也能提供較以往IEM有更近於電腦模擬的結果。本研究的結果使得IEM散射理論更完整而精確，提供此模型在雙向單散射(Bistatic Single Scattering)理論預測上一項重要的進展。

摘要(英)

In this dissertation, derivation of the new expressions within the framework of an IEM model is conducted. The simplifying assumptions used in the phase of the Green’s function and the complementary field coefficient are removed yielding a more complex model but still in algebraic form. Much effort was devoted to the solutions of the problems encountered after the removal was applied. The result shows that the assumption used in the past does not cause an appreciable difference when the incident and scattered angles are close to each other. This explains the accuracy of original IEM in backscattering scenario. However, for different incident and scatter angles there is a noticeable difference especially when the surface roughness is small and scattering is weak. For surfaces with large scale roughness the difference between the original IEM and the improved IEM is generally negligible. This proves that the application of the simplifying assumption is appropriate when the original IEM model is used in the high frequency region. Bistatically, the improved IEM model is in good agreement with the standard small perturbation model in the low frequency region and with the standard Kirchhoff model in the high frequency region. On the surface emission problem, the improvement shows the great influence from the correctness of the phase factor. The removal of the assumption has greatly improved the accuracy of the IEM model especially in bistatic prediction.

關鍵字(中)

★ 微波散射
★ 地表
★ 積分方程式

關鍵字(英)

★ Integral Equation
★ Microwave Scattering

論文目次

CHAPTER
1
Introduction………………………………………………………………………………………1
1.1 Background……………………………………………………………………………………1
1.2 Objectives……………………………………………………………………………………3
2
The Integral Equation Model…………………………………………………………………4
2.1 Tangential Surface Fields on a Dielectric Interface……………………………4
2.2 Far-Zone Scattered Fields………………………………………………………………12
2.3 The Simplifying Assumptions for the IEM Model……………………………………16
3
A New Expression for the Single Scattering in the IEM Model………………………19
3.1 The Scattered Field Coefficients……………………………………………………21
3.1.1 The Kirchhoff Field Coefficient …………………………………………………21
3.1.2 The Complementary Field Coefficient ……………………………………………24
3.2 Derivation of the Scattering Coefficients…………………………………………39
3.2.1 Derivation of the Cross Term Scattering Coefficient…………………………39
3.2.2 Derivation of the Complementary Term Scattering Coefficient………………51
3.3 Expression for the Single Scatter Scattering Coefficients……………………75
4
Bistatic Scattering Properties of the IEM Model………………………………………79
4.1 Angular Behavior of the Model..………………………………………………………79
4.2 Azimuthal Angular Behavior of the Model……………………………………………106
4.3 Frequency Behavior of the Model…………………………..…………………………112
5 Emission from Rough Surfaces Based on the IEM Model ……………………………117
6 Conclusions …………………………………………………………………………………132
APPENDIX
A
Introduction……………………………………………………………………………………134
A.1 Derivation of the C Coefficients……………………………………………………134
A.2 Evaluation of Surface Slopes in C Coefficients…………………………………138
A.3 Expressions of C Coefficients in Terms of u,v and q.....................145
B
The Ensemble Averages………………………………………………………………………150
B.1 Ensemble Average of Two Random Variables…………………………………………150
B.2 Ensemble Average of Three Random Variables………………………………………156
B.3 Ensemble Average of Four Random Variables………………………………………172
BIBLIOGRAPHY……………………………………………………………………………………202

參考文獻

Beckmann, P. and A. Spizzichino, The Scattering of Electromagnetic Waves from Rough Surfaces, Pergamon Press, Oxford, 1963.
Beckmann, P., "Scattering by composite rough surfaces," Proc. IEEE, vol. 53, no. 8, pp. 1012-1015, 1965
Brown, G. S., "Backscattering from a Gaussian-distributed perfectly conducting rough surface," IEEE Trans. Ant. and Prop, vol. AP-26, no. 3, pp. 472-482, May 1978
Chen, K. S., and A. K. Fung, "A comparison of backscattering models for rough surfaces," IEEE Trans. Geosci. Remote Sensing, vol.33, no. 1, Jan, pp. 195-200, 1995.
Chen, K. S., T. D. Wu, M. K. Tsay and A. K. Fung, “A note on the multiple scattering in an IEM model,” IEEE Trans. Geosci. Remote Sensing, vol. 38, no. 1, Jan. 2000.
Chen, K. S., T. D. Wu, Q. Li, L. Tsang, and J. C. Shi, “Scattering and Emission from Rough Surfaces Based on Integral Equation Method,” IEEE Trans. Geosci. Remote Sensing, 2002, in press.
Chen, M. F., K. S. Chen and A. K. Fung, "A study of the validity of the Integral Equation Model by moment method simulation: cylindrical case," Remote Sensing of Environment, Vol. 29, pp. 217-228, 1989.
Chen, M. F. and S. Y. Bai, "Computer simulation of wave scattering from a dielectric random surface in two dimensions: cylindrical case," J. Electromagnetic Waves and Applications, Vol. 4, no. 10, pp.963-982, 1990.
Fung, A. K., Microwave Scattering and Emission Models and Their Applications, Artech House, Norwood, MA, 1994.
Fung, A. K., and G. W. Pan, “An Integral Equation Method for Rough Surface Scattering,” Proceedings of the International Symposium on Multiple Scattering of Wave in Random Media and Random Surface, held at the Pennsylvania State University from 1 July to 1 August 1985 (Pennsylvania State University Press), pp. 701-714, 1986.
Fung, A. K. and H. J. Eom, "Note on the Kirchhoff rough surface solution in backscattering," Radio Sci., vol. 16, no. 3, pp. 299-302, 1981
Fung, A. K. and K. S. Chen, "A validation of the IEM surface scattering model," Proc. IGARSS95, pp.933-935, 1995
Fung, A. K., M. R. Shah, and S. Tjuatja, "Numerical simulation of scattering from three-dimensional randomly rough surfaces, " IEEE Trans. Geosci. Remote Sensing, vol.32, no. 5, pp. 986-994, 1994.
Fung, A. K., W. Y. Liu, K. S. Chen and M. K. Tsay, “An Improved IEM Model for Bistatic Scattering,” Journal of Electromagnetic Wave and Applications, vol. 16, no.5, pp. 689-702, May 2002.
Fung, A. K., Z. Li, and K. S. Chen, "Backscattering from a randomly rough dielectric surface," IEEE Trans. Geosci. Remote Sensing, vol. 30, pp. 356-369, 1992.
Fung, A. K., W. Y. Liu, K. S. Chen, “A Comparison Between IEM-based Surface Bistatic Scattering Models,” IGARSS, 2002.
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, no. 4, pp. 901-909, May 1997.
Jose, A.-P., “An extension of the IEM/IEMM surface scattering model,” Waves in Random Media, vol. 11, no. 3, pp. 307-329, July 2001.
Li, Q., C. H. Chan, and L. Tsang, “Monte-Carlo Simulations of Wave Scattering from Lossy Dielectric Random Rough Surfaces Using the Physics-Based Two-Grid Method and Canonical Grid Method,” IEEE Trans. Antennas Propagat., vol. 47, no. 4, pp. 752-763, Apr. 1999.
Li, Q., L. Tsang, K. Pak, and C. H. Chan, “Bistatic Scattering and Emissivities of Random Rough Dielectric Lossy Surfaces with the Physics-Based Two-Grid Method in Conjunction with the Sparse-Matrix Canonical Grid Method,” IEEE Trans. Antennas Propagat., vol. 48, iss. 1, pp. 1-11, Jan. 2000.
Liu, W. Y., A. K. Fung, K. S. Chen and M. K. Tsay, “Another Surface Scattering Model for Bistatic Scattering,” IGARSS, 2001.
Macelloni, G.; Nesti, G.; Pampaloni, P.; Sigismondi, S.; Tarchi, D.; Lolli, S. ”Experimental validation of surface scattering and emission models,” IEEE Trans. Geosci. Remote Sensing, vol. 38, iss. 1, Part 2, pp. 459 -469, Jan. 2000.
Poggio, A. J. and E. K. Miller, “Integral equation solution of three dimensional scattering problems,” Computer Techniques for Electromagnetics, Pergamon, New York, Ch. 4, 1973.
Shi, J. C., J. Wang, A. Y. Hsu, P. E. O’Neill, and E. T. Engman, “Estimation of bare surface soil moisture and surface roughness parameter using L-band SAR image data,” IEEE Trans. Geosci. Remote Sensing, vol. 35, pp. 1254-1266, Sept. 1992.
Sancer, M. I., "An analysis of the vector Kirchhoff equations and the associated boundary-line change," Radio Sci., vol. 3, pp. 141-144, 1968.
Tsang, L., J.A. Kong, and R.T. Shin, Theory of Microwave Remote Sensing, New York: Wiley, 1985
Tsay, M. K., W. Y. Liu, T. D. Wu and K. S. Chen, “A Re-Examination of the IEM Model for Microwave Scattering from Random Rough Boundary,” Journal of the Chinese Institute of Engineers, in press, 2002.
Ulaby, F. T., R. K. Moore, and A. K. Fung, Microwave Remote Sensing, Active and Passive, vol. I, MA: Addison-Wesley, 1981.
Ulaby, F. T., R. K. Moore, and A. K. Fung, Microwave Remote Sensing, Active and Passive, vol. II, MA: Addison-Wesley, 1982.
Valenzuela, G. R., "Scattering of electromagnetic waves from a tilted slightly rough surfaces," Radio Sci., vol. 3, pp.1057-1066, 1968
Wu, S. T., and A. K. Fung, "A Noncoherent Model for Microwave Emissions and Backscattering from the Sea Surface," J. Geophys. Res., 77, pp. 5917-5929, 1972
Wu, T. D., K. S. Chen, J. C. Shi and A. K. Fung, “A Transition Model for the Reflection Coefficient in Surface Scattering,” IEEE Trans. Geosci. Remote Sensing, vol. 39, no. 9, pp. 2040-2050, Sept. 2001.

指導教授

蔡木金、陳錕山
(Mu-King Tsay、Kun-Shan Chen)

審核日期

2002-10-14

推文