儀器降落系統為一種在低能見度的條件下提供飛機垂直以及水平方向導引訊號的著陸引導系統。本研究探討導致馬祖北竿機場之左右定位輔助台導引訊號失準之訊號多路徑現象，由交通部民用航空局飛測小組執行北竿機場左右定位輔助台之飛測結果顯示該導引訊號於距跑道頭0~2海浬處航路中心線有明顯擺盪之狀況，並已超出CAT I規範之容忍範圍。該狀況將產生潛在之飛安問題，須予以改善。
本研究欲以儀降系統之訊號模擬軟體計算該左右定位輔助台訊號結構，並找出造成訊號產生多路徑反射之主因。運用由美國俄亥俄大學航電中心開發之助導航設備預測模型，可在短時間內獲解不同方位及面向之障礙物對於訊號的影響，並能有效節省時間以及投資於實際飛測的高成本。經由一連串模擬測試及結果分析，導致訊號多路徑行為之障礙物將被定義。解決左右定位輔助台訊號問題之可行方案將於本論文最後提出並討論。

Instrument Landing System (ILS) is a radio beam transmitter that provides both lateral and vertical guidance for approaching aircraft. This thesis studies the multipath effect which caused the structure roughness problem of the Localizer type Directional Aid (LDA) installed at Matsu Beigan Airport. The flight inspection taken by Civil Aeronautics Administration (CAA) in recent years show that the course structure doesn’t comply with the CAT I standard. This problem could seriously reduce the safety in the process of approaching and landing.
This thesis aim to find out the main reflector that cause the multipath effect of signal in space by using the ILS performance simulator. This numerical way not only calculate the course structure in a short period of time, but also save the vast cost from flight inspection. The Navigational Aid Performance Prediction Model (NPPM) from Avionic Engineering Center of Ohio University is used for predicting the performance of the localizer in this research. After a series of simulation and analysis, the main reflector of the multipath effect has been pointed out. Several solutions which may solve the problems of Beigan Airport 03 LDA are proposed and discussed in the end of this thesis.

[1] S. D. Courtney, " Determination of ILS Critical and Sensitive Areas: A Comparison of Flight Measurement versus Simulation Techniques" 15th International Flight Inspection Symposium, 2008.
[2] A. D. Yellu, "A Uniform Geometrical Theory of Diffraction Model of Very-High-Frequency Omni-Directional Range Systems for Improved Accuracy," Electronic Thesis , Ohio University, 2013.
[3] ICAO "ICAO ANNEX 10 - Aeronautical Telecommunications, Volume I - Radio Navigation Aids, Fifth edition", 1996.
[4] FAA "Pilot/Controller Glossary", Retrieved 2009.
[5] ICAO, "ICAO DOC8400 Amendment 28".
[6] D. Quinet, S. A. Odunaiya, "Analysis of ILS Receiver Output Data and Comparison to U.S. Flight Inspection Tolerances", IEEE/AIAA Digital Avionics Systems Conference, 2005.
[7] H. Demule, G. E. Berz, A. W. Bakken, "Evaluation, Design, Commissioning and Certification of a ±15° Reduced Coverage Localizer", 15th International Flight Inspection Symposium, 2008, Oklahoma City.
[8] Wikipedia contributors, "Flight inspection," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/wiki/Flight_inspection, accessed April 25, 2014.
[9] 張小千， "淺談儀器降落系統(ILS)飛測試程序"，"飛航電子65期" 台北: 飛航安全電子協會。
[10] FAA, "Flight Inspection Handbook, TI 8200.52", November 2007
[11] Antenna-Theory.com. 2009. "Log-Periodic Dipole Array Antenna" Available at: http://www.antenna-theory.com/. Accessed 6 May 2014.
[12] 李智傑， 2001， 電磁相容之對數偶極天線之研製。 碩士論文， 高雄： 國立中山大學電機工程研究所。
[13] M. Kayton, W. R. Fried, "Avionics Navigation Systems", 2nd ed. Wiley-Inter-Science, 1997.
[14] 吳勝國、宗建禮、高斌國， 2013, “「汰換清泉崗機場36跑道ILS/DME設備及新增南竿機場03跑道LDA/DME設備」工廠訓練出國報告書” 公務出國報告， 台北:交通部民用航空局飛航服務總台。
[15] A. Thain, J. P. Estienne, G. Peres, B. Spitz, L. Evain, "A rigorous simulator of ILS perturbations," Antennas and Propagation (EuCAP)”, 2010 Proceedings of the Fourth European Conference, April 2010.
[16] A. Alford, G. J. Adams, R. E. Parisi, "A Theoretical Investigation of the Effect of Deflections from Buildings on Localizer and Glide Path Course," Final Report, Contract AF33(038)-23700, for the Communication Navigation Lab., Wright Air Development Center, Wright-Patterson AFB, June 1955.
[17] G. G. Hollins, "Effect of United Airlines' Proposed Type B-747 Hngar on Localizer Courses at O'Hare International Airport," United Air Lines Contract 21147, December 29, 1967.
[18] R. W. Redlich, J. T. Gorman, "Disturbance of ILS Localizer Signals by Reflections from Large Hangers," IEEE Transactions on Aerospace and Electronic Systems, Vol. AES-5, No. 6, pp. 1001-1002, Nov. 1969.
[19] S. L. Shih, "LS Localizer Multipath Analysis," IEEE Transactions on Aerospace and Electronic Systems, Vol. AES-7, No. 1, pp. 54-60, Jan. 1971.
[20] G. Chin, J. Jordan, D. Kahn, S. Morin, "Instrument Landing System Performance Prediction," Microwave Symposium, 1975 IEEE-MTT-S International , pp. 346-348, May 12-14, 1975.
[21] F. Gong, F. Guo, Y. Ma, "Analysis of Electromagnetic Interference on Localizer Beam using in Parallel Runway," 2011 IEEE 4th International Symposium on Microwave, Antenna, Propagation, and EMC Technologies for Wireless Communications (MAPE), pp.562-565, Nov. 1-3, 2011.
[22] G. Greving, "Sophisticated numerical hybrid scattering analysis integrated into system simulations for navigation and radar applications," Asia-Pacific Conference Proceedings of Microwave Conference Proceedings, Vol.4, pp., 4-7 Dec. 2005.
[23] ENAC, "Assessment of ILS protection areas impact on large aircraft operations," Methodology, France: École nationale de l'aviation civile, 2006.
[24] K.F. Casey, "Electromagnetic shielding behavior of wire-mesh screens," IEEE Transactions on Electromagnetic Compatibility, vol.30, no.3, pp.298-306, Aug 1988.
[25] E. V. Jull, D. C. W. Hui, P. Facq, "Scattering by dual-blazed corrugated conducting strips and small reflection gratings," Journal of the Optical Society of America A, Vol. 2, pp.1049-1056, 1985.
[26] E.V. Jull and J.W. Heath "Conducting surface corrugations for multipath interference suppression," Electrical Engineers, Proceedings of the Institution of, Vol.125, no.12, 1978.
[27] E.V. Jull, G.R. Ebbeson, "The reduction of interference from large reflecting surfaces," IEEE Trans Ant Prop, pp.565, July 1977.
[28] A. Thain, J. P. Estienne, J. Robert, G. Peres, G. Cambon, L. Evain, B. Spitz, "A solution for ILS disturbance due to a building," Antennas and Propagation (EUCAP), 2012 6th European Conference on, pp.2392-2395, March 2012.
[29] AustralianFlying.com.au, "Wagga Wagga instrument landing system up and running," Available at: http://www.australianflying.com.au/news/wagga-wagga-instrument-landing-system-up-and-running, accessed May 6, 2014.
[30] Wikipedia contributors, "Double-sideband suppressed-carrier transmission," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/wiki/Double-sideband_suppressed-carrier_transmission, accessed May 23, 2014.