UNIVERSITI PUTRA MALAYSIA MITIGATION OF RAIN ATTENUATION IN EQUATORIAL REGION FOR MEASAT-2 AND MEASAT-3 USING ORBITAL DIVERSITY HALID BIN AGIL FK 2012 42
MITIGATION OF RAIN ATTENUATION IN EQUATORIAL REGION FOR MEASAT-2 AND MEASAT-3 USING ORBITAL DIVERSITY By HALID BIN AGIL Thesis Submitted to the School of Graduate Studies,, in Fulfilment of the Requirements for the Master of Science JULY 2012
Abstract of thesis presented to the Senate of in fulfilment of the requirement for the Master of Science MITIGATION OF RAIN ATTENUATION IN EQUATORIAL REGION FOR MEASAT-2 AND MEASAT-3 USING ORBITAL DIVERSITY Chairman Faculty By HALID BIN AGIL JULY 2012 : Harlisya binti Harun, PhD : Engineering Rain is the main contributor towards signal attenuation for satellites operating above 3 GHz, and its effect becomes significant at 10 GHz and above. This causes satellite signal to experience degradation, and to some extent, signal cut-off. A tropical area such as Malaysia faces heavy rainfall throughout the year, and thus the satellite s signal attenuation would occur frequently. This effect is undesirable for satellite services such as those provided by MEASAT satellites, as clients and customers demand for uninterrupted transmissions. Orbital diversity (OD) is seen to be a viable method to mitigate rain attenuation. It employs multiple satellites transmitting identical signal streams toward a mutual ground station. Although orbital diversity has been studied with great interest in regions such as Europe, there is little information of OD research in tropical regions, ii
particularly in Malaysia. Therefore, this thesis proposed an analysis of an OD system in Malaysian climate using MEASAT satellites. An OD simulation model has been setup using parameters from MEASAT-2, MEASAT-3, and MEASAT Satellite Control Centre in Pulau Langkawi. It involved a rain attenuation prediction for each satellite, based on the ITU-R recommended rain attenuation model, signal gain prediction, and diversity gain prediction. simulation model has been programmed in MATLAB environment. The results are obtained in numerical figures and graphs. The performance of the OD system is dependent upon the operating frequency and the satellite s elevation angle. The The simulation has shown that rain attenuation increases exponentially with the increase of frequency. Therefore, the signal gain decreases in an inverse exponential manner, particularly for individual signals of MEASAT-2 and MEASAT-3. Using signal combination, an OD signal can achieve a signal boost of up to 2.3 times the individual signal gain. With this significant finding, the OD is proposed to mitigate rain attenuation in Malaysia. iii
Abstrak tesis yang dikemukakan kepada Senat sebagai memenuhi keperluan untuk ijazah Master Sains PELEGAAN REDAMAN HUJAN DI DALAM KAWASAN KHATULISTIWA UNTUK MEASAT-2 DAN MEASAT-3 MENGGUNAKAN KEPELBAGAIAN ORBIT Pengerusi Fakulti Oleh HALID BIN AGIL JULAI 2012 : Harlisya binti Harun, PhD : Kejuruteraan Hujan adalah penyumbang utama kepada kemerosotan isyarat untuk satelit-satelit yang beroperasi melebihi frekuensi 3 GHz, dan kesannya menjadi ketara pada frekuensi 10 GHz dan ke atas. Ini menyebabkan kemerosotan pada isyarat satelit, dan pada tahap tertentu, isyarat tersebut akan terputus. Kawasan tropika seperti Malaysia mengalami taburan hujan lebat sepanjang tahun, dan ini menyebabkan kemerosotan pada isyarat satelit kerap berlaku. Ini memberikan kesan yang tidak diingini ke atas perkhidmatan-perkhidmatan satelit seperti yang dibekalkan oleh satelit-satelit MEASAT, kerana permintaan pelanggan adalah terhadap penghantaran tanpa gangguan. Kepelbagaian orbit (OD) adalah satu kaedah untuk melegakan redaman hujan. Ia menggunakan pelbagai satelit yang menghantar aliran-aliran isyarat yang serupa ke iv
arah satu stesen bumi bersama. Walaupun kaedah OD telah dikaji dengan minat yang mendalam di rantauan seperti di Eropah, hanya terdapat sedikit maklumat tentang penyelidikan OD di rantauan tropikal, terutamanya di Malaysia. Oleh sebab itu, tesis ini mencadangkan satu analisis sebuah sistem OD dalam iklim di Malaysia menggunakan satelit-satelit MEASAT. Satu model simulasi OD telah disediakan menggunakan parameter-parameter daripada MEASAT-2, MEASAT-3, dan Pusat Kawalan Satelit MEASAT di Pulau Langkawi. Ia melibatkan ramalan redaman dari hujan untuk setiap satelit, berdasarkan model redaman hujan yang disyorkan oleh ITU-R, ramalan gandaan isyarat, dan ramalan gandaan kepelbagaian. Model simulasi tersebut telah diprogram dalam persekitaran MATLAB. berangka dan graf. Keputusan simulasi telah diperolehi di dalam Prestasi OD bergantung kepada frekuensi operasi dan sudut dongakan. Simulasi telah menunjukkan bahawa redaman hujan meningkat secara eksponen dengan meningkatnya frekuensi. Oleh itu, gandaan isyarat berkurang secara eksponen songsang terutamanya untuk isyarat individu MEASAT-2 dan MEASAT-3. Dengan menggunakan kombinasi isyarat, suatu isyarat OD mampu mengalami peningkatan sehingga 2.3 kali ganda berbanding gandaan isyarat individu. Dengan penemuan penting ini, OD telah dicadangkan untuk melegakan redaman hujan di Malaysia. v
ACKNOWLEDGEMENTS Glory be to Allah, and all praises with Him. Glory be to Allah, The Greatest. I would like to thank my supervisor, Dr. Harlisya binti Harun and the members of the supervisory committee: Assoc. Prof. Dr. Abd. Rahim bin Abu Talib and Assoc. Prof. Dr-Ing. Ir. Renuganth s/o Varatharajoo for their guidance and support. I also greatly appreciated the financial support from the university through Graduate Research Assistant (GRA) and the Post-Graduate Scholarship Scheme. Special thanks to Mr. Mohd Azfar bin Roslan, Mr. Saffairus bin Salih, and all staffs from the Aerospace Engineering Department. Not forgetting Ms. Nurhaniza binti Mohamad and Ms. Zuliana binti Ismail for their contributions. Last but not least, many thanks to my family and my friends for their support. vi
I certify that a Thesis Examination Committee has met on 20 July 2012 to conduct the final examination of Halid bin Agil on his thesis entitled Mitigation of Rain Attenuation in Equatorial Region for MEASAT-2 and MEASAT-3 Using Orbital Diversity in accordance with the Universities and University College Act 1971 and the Constitution of the [P.U.(A) 106] 15 March 1998. The committee recommends that the student be awarded the Master of Science. Members of the Examination Committee were as follows: Mohd Ramly bin Mohd Ajir, PhD Associate Professor Lt. Col Faculty of Engineering (Chairman) Rizal bin Zahari, PhD Senior Lecturer Faculty of Engineering (Internal Examiner) Faizal bin Mustapha, PhD Associate Professor Faculty of Engineering (Internal Examiner) Norbahiah Misran, PhD Professor Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia (External Examiner) SEOW HENG FONG, PhD Professor and Deputy Dean School of Graduate Studies Date: 22 November 2012 vii
This thesis was submitted to the Senate of and has been accepted as fulfilment of the requirement for the Master of Science. Members of the Supervisory Committee were as follows: Harlisya binti Harun, PhD Senior Lecturer Faculty of Engineering (Chairman) Abd. Rahim bin Abu Talib, PhD Associate Professor Faculty of Engineering (Member) Renuganth s/o Varatharajoo, PhD Professor Dr.-Ing. Ir. Faculty of Engineering (Member) BUJANG BIN KIM HUAT, PhD Professor and Dean School of Graduate Studies Date: viii
DECLARATION I declare that the thesis is my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously, and is not concurrently, submitted for any other degree at or at any other institution. HALID BIN AGIL Date: 20 July 2012 ix
TABLE OF CONTENTS ABSTRACT ABSTRAK ACKNOWLEDGEMENTS APPROVAL DECLARATION LIST OF TABLES LIST OF FIGURES NOMENCLATURE CHAPTER 1. INTRODUCTION 1.1. Introduction 1.2. Research Motivation 1.3. Problem Statement 1.4. Research Objectives 1.5. Research Scope 1.6. Thesis Outline 2. LITERATURE REVIEW 2.1. Introduction 2.2. Climate in Malaysian Region 2.3. Seasonal Rainfall Variation in Peninsular Malaysia 2.4. Seasonal Rainfall Variation in Sabah and Sarawak 2.5. Rain Phenomenon 2.5.1. Types of Rain Effects 2.5.2. Characteristics of Rain Systems 2.5.3. Spatial Structure of Rain 2.5.4. Classical Description of Rain Attenuation 2.6. Rain Fade Mitigation 2.7. Orbital Diversity 2.8. Developments of Research in Orbital Diversity 3. METHODOLOGY 3.1. Introduction 3.2. Methodology Overview 3.3. Identification Phase 3.3.1. Satellites Selection Process 3.3.2. Ground Station Selection Process 3.3.3. Rain Attenuation Model Selection Process 3.3.4. OD Simulation Model Configuration 3.4. Rain Attenuation Simulation Phase 3.4.1. MATLAB Simulation 3.4.2. Attenuation Exceeded for 0.01 Percent of an Average Year x Page ii iv vi vii ix xii xiii xv 1 3 4 4 5 5 7 7 9 11 13 13 13 14 15 18 20 22 30 30 32 32 36 37 39 40 43 44
3.5. Signal Gain Simulation Phase 3.5.1. MATLAB Programming 3.5.2. Signal Gain 3.5.3. Combined Signal Gain using Maximal Ratio Combining 3.6. Diversity Gain Simulation Phase 4. RESULTS AND DISCUSSIONS 4.1. Introduction 4.2. Rain Attenuation Simulation 4.3. Signal Gain Simulation 4.4. Orbital Diversity Simulation 4.5. Parametric Study 4.5.1. Case 1 OD Signal Strength versus Attenuation Exceeded Probability 4.5.2. Case 2 - OD Signal Strength versus Maximum Signal Strength During Clear Sky Conditions 5. CONCLUSIONS AND RECOMMENDATIONS FOR FUTURE WORKS 5.1. Conclusions 5.2. Recommendations for Future Works REFERENCES APPENDIX A APPENDIX B APPENDIX C APPENDIX D BIODATA OF STUDENT LIST OF PUBLICATIONS 45 45 45 49 51 53 53 57 60 63 63 66 69 71 73 76 84 85 91 93 94 xi