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UNIVERSITI PUTRA MALAYSIA
HALID BIN AGIL
FK 2012 42
MITIGATION OF RAIN ATTENUATION IN EQUATORIAL REGION FOR MEASAT-2 AND MEASAT-3 USING ORBITAL DIVERSITY
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, Universiti Putra Malaysia,
in Fulfilment of the Requirements for the Master of Science
JULY 2012
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Abstract of thesis presented to the Senate of Universiti Putra Malaysia 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
By
HALID BIN AGIL
JULY 2012
Chairman : Harlisya binti Harun, PhD
Faculty : 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,
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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. The
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 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.
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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai
memenuhi keperluan untuk ijazah Master Sains
PELEGAAN REDAMAN HUJAN DI DALAM KAWASAN KHATULISTIWA
UNTUK MEASAT-2 DAN MEASAT-3 MENGGUNAKAN KEPELBAGAIAN
ORBIT
Oleh
HALID BIN AGIL
JULAI 2012
Pengerusi : Harlisya binti Harun, PhD
Fakulti : 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
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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. Keputusan simulasi telah diperolehi di dalam
berangka dan graf.
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.
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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.
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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 Universiti Putra Malaysia [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
Universiti Putra Malaysia
(Chairman)
Rizal bin Zahari, PhD
Senior Lecturer
Faculty of Engineering
Universiti Putra Malaysia
(Internal Examiner)
Faizal bin Mustapha, PhD
Associate Professor
Faculty of Engineering
Universiti Putra Malaysia
(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
Universiti Putra Malaysia
Date: 22 November 2012
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This thesis was submitted to the Senate of Universiti Putra Malaysia 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
Universiti Putra Malaysia
(Chairman)
Abd. Rahim bin Abu Talib, PhD
Associate Professor
Faculty of Engineering
Universiti Putra Malaysia
(Member)
Renuganth s/o Varatharajoo, PhD
Professor Dr.-Ing. Ir.
Faculty of Engineering
Universiti Putra Malaysia
(Member)
________________________________
BUJANG BIN KIM HUAT, PhD
Professor and Dean
School of Graduate Studies
Universiti Putra Malaysia
Date:
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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 Universiti Putra Malaysia or at
any other institution.
_________________________________
HALID BIN AGIL
Date: 20 July 2012
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TABLE OF CONTENTS
Page
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
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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
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