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Radio Frequency Interference (Rfi) Mapping for Radio Astronomy in Peninsular Malaysia

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RADIO FREQUENCY INTERFERENCE (RFI) MAPPING FOR RADIO ASTRONOMY IN PENINSULAR MALAYSIA ROSLAN UMAR FACULTY OF SCIENCE UNIVERSITY OF MALAYA KUALA LUMPUR 2014 RADIO FREQUENCY INTERFERENCE (RFI) MAPPING FOR RADIO ASTRONOMY IN PENINSULAR MALAYSIA ROSLAN UMAR THESIS SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PHYSICS FACULTY OF SCIENCE UNIVERSITY OF MALAYA KUALA LUMPUR 2014 UNIVERSITI MALAYA ORIGINAL LITERARY WORK DECLARATION Name of Candidate: Roslan b. Umar (I.C./Passport No.:800305115235) Registration/Matrix No.: SHC100045 Name of Degree: Doctor of Philosophy Title of Project Paper/Research Report/Dissertation/Thesis (“this Work”): Radio Frequency Interference (RFI) Mapping for Radio Astronomy In Peninsular Malaysia Field of Study: Radio Astronomy, I do solemnly and sincerely declare that: (1) I am the sole author/writer of this Work; (2) This work is original; (3) Any use of any work in which copyright exists was done by way of fair dealing and for permitted purposes and any excerpt or extract from, or reference to or reproduction of any copyright work has been disclosed expressly and sufficiently and the title of the Work and its authorship have been acknowledged in this Work; (4) I do not have any actual knowledge nor do I ought reasonably to know that the making of this work constitutes an infringement of any copyright work; (5) I hereby assign all and every rights in the copyright to this Work to the University of Malaya (“UM”), who henceforth shall be owner of the copyright in this Work and that any reproduction or use in any form or by any means whatsoever is prohibited without the written consent of UM having been first had and obtained; (6) I am fully aware that if in the course of making this Work I have infringed any copy- right whether intentionally or otherwise, I may be subject to legal action or any other action as may be determined by UM. Candidate’s Signature Date Subscribed and solemnly declared before, Witness’s Signature Date Name: Dr Zamri b. Zainal Abidin Designation: Supervisor Witness’s Signature Date Name: Prof. Dr. Zainol Abidin b. Ibrahim Designation: Co-Supervisor ii ABSTRACT Radio Frequency Interference (RFI) Mapping for Radio Astronomy In Peninsular Malaysia Radio astronomy observations are increasingly contaminated by human-made Radio Frequency Interferences (RFI). If these interferences are continuously present, they will be a major problem for radio astronomers in their observations. The purpose of this study is to create a radio interference intensity distribution map of Peninsular Malaysia using the RFI mapping technique. The Geographical Information System (GIS) was employed as a tool to carry out the mapping technique. A systematic procedure of decision analyses has been proposed by Drobne and Lisec, namely Multi Criteria Decision Analysis (MCDA), in order to process complex and various amounts of data obtained from different sources, and it offers many benefits, such as cost-effective, and efficient and rapid management. The proper decision-making process for selection of local RFI sites requires collection of information of various parameters. The factors that affect the selection process were decided and taken into account. In this study, the parameters involved are: the popula- tion density, the presence of telecommunication transmitters (e.g: mobile phone, radio and television), road networks, the rain effect and contour shielding. In this study, we found that the most suitable value for population density was below 150ppl km−1, for the contour effect, we found that type-V contours show the minimum effect of RFI and for road networks we found that 520 m is the minimum distance of RFI effects from vehicles. However, we did not see that the rain effect played an important role in low-frequency windows. This study will benefit radio astronomy research in Malaysia, especially in RFI profiling. iii ABSTRAK Kajian Pemetaan Interferen Radio Frekuensi (RFI) Untuk Radio Astronomi di Semenanjung Malaysia Pemerhatian radio astronomi semakin terbatas disebabkan oleh ganguan frekuensi radio (RFI) buatan manusia. Jika ganguan ini berterusan, ia bakal memberikan masalah besar kepada ahli astronomi radio dalam penyelidikan mereka. Tujuan kajian ini adalah untuk menyediakan sebuah peta taburan keamatan gangguan frekuensi radio bagi Se- menanjung Malaysia dengan menggunakan teknik pemetaan RFI. Sistem Maklumat Ge- ografi (GIS) digunakan sebagai alat dalam teknik pemetaan tersebut. Satu prosedur yang sistematik untuk menganalisis keputusan telah dicadangkan oleh Drobne dan Lisec, iaitu Analisis Keputusan Multi-kriteria (MCDA) untuk menyelesaikan masalah yang kom- pleks dengan pelbagai data yang diperolehi daripada sumber-sumber yang berbeza dan sangat bermanfaat serta menawarkan kos yang efektif, cekap dan pengurusan yang pan- tas. Proses membuat keputusan untuk pemilihan ini memerlukan pengumpulan maklumat daripada pelbagai parameter. Faktor-faktor yang mempengaruhi proses pemilihan ini juga diambil kira. Dalam kajian ini, pelbagai faktor atau parameter yang terlibat antaranya adalah kepadatan penduduk, kewujudan pemancar telekomunikasi (seperti telefon bim- bit, radio, dan televisyen), rangkaian jalan, jumlah hujan, dan kontur. Hasil kajian men- dapati tahap ambang untuk kepadatan penduduk adalah dibawah 150ppl km−1, untuk kesan kontor pula hasil kajian menunjukan jenis-V memberikan kesan RFI yang mini- mum dan untuk factor rangkaian jalan pula, 520m adalah jarak minimum dari kesan RFI yang disebabkan oleh kenderaan. Walaubagaimanapun untuk kesan hujan tiada sebarang nilai yang boleh memberi kesan kepada gelombang radio pada frekuensi rendah. Ka- jian ini akan memberi manfaat kepada penyelidikan radio astronomi terutamanya dalam menghasilkan profil RFI di Semenanjung Malaysia. iv ACKNOWLEDGEMENTS In the name of Allah, the most gracious and the most merciful. I would like to thank all people around me for their support. First and foremost, I owe a great deal to my supervisor, Dr. Zamri Zainal Abidin, for his outstanding guidance and thoughtful ideas. Also to my co-supervisor Prof. Dr. Zainol Abidin Ibrahim for his help and advice. His enthusiasm in research and his relentless curiosity, have motivated and inspired me during those years that I had the opportunity to be his student. I would like to appreciate my true love, Dr. Nor Hazmin Sabri, the most understanding, patient and tolerant person for being by my side along this journey and always there to lend me her shoulder to rely on. I am thankful for having such wonderful kids, Muqri Wafa, Irdina Wafa, Rayhana Wafa and also the unforgotten deceased daughter, Syafiqatul Wafa for cheering up my life. Not to forget my helpful and caring parents, Umar and Eshah, for his/her unconditional love, patience and inspiration. An appreciation also goes to my mother-in-law, Naimah for her neverending du’a. I would also like to thank my whole family for their endless support. During the completion of this work, I had the privilege of working with many inspiring colleagues, in particular with Norsiah, Dr. Zety and Ferwani for their helpful discussions and endless assistance, Shaiful, Wan Zul, Khalaf and Zul for always being there for me, Aqma, Suzian, Jazeel and Nabila for their support; their contributions to this work is gratefully acknowledged. I had a very colorful life with them and have always enjoyed the friendly atmosphere of the group (Radio Cosmology Research Lab), and it was a privilege for me to work with such an outstanding group of people. The warmest gratitude goes to several parties; Universiti Sultan Zainal Abidin, Ministry of Higher Education, and University Malaya for their financial support (IPPP-PV025-2011A) and great help. Beyond these specific acknowledgments, I would like to thank all the people involved in this work whether directly or indirectly who gave their support until this work was successfully completed. v TABLE OF CONTENTS ORIGINAL LITERARY WORK DECLARATION ii ABSTRACT iii ACKNOWLEDGEMENTS v TABLE OF CONTENTS vi LIST OF FIGURES viii LIST OF TABLES x LIST OF APPENDICES xiii CHAPTER 1: INTRODUCTION 1 1.1 RFI Profile in Malaysia 3 1.1.1 The study area : The peninsular of Malaysia 4 1.2 Research Background 5 1.3 Problem Statement 9 1.4 Objectives of the Study 11 1.5 Research Significance 11 1.6 Thesis Organization 12 CHAPTER 2: LITERATURE REVIEW 14 2.1 L-Band Related Studies 14 2.2 Literature on Population Density 16 2.3 Past Studies of the Contour Effect 18 2.4 Road Network Related Studies 21 2.5 Past Studies on the Rain Effect 22 2.6 Research Conducted on Mapping Techniques 23 2.7 Summary 25 CHAPTER 3: RADIO ASTRONOMY AND RADIO FREQUENCY INTERFERENCES (RFI) 26 3.1 A Brief History of Radio Astronomy 27 3.2 The Role of Radio Astronomy 28 3.3 Observation Methods in Radio Astronomy 29 3.3.1 Radio continuum emission 30 3.3.2 Spectral line emission 31 3.4 Radio Frequency Interference (RFI) 31 3.5 RFI Sources 33 3.5.1 Spectrum management 35 vi 3.5.2 Radio interference free zones 35 3.6 Radio Frequency Allocation in Malaysia 38 CHAPTER 4: METHODOLOGY 39 4.1 Antenna Construction and Instrument Setup 40 4.2 Preliminary Study 43 4.2.1 Measurement procedure/protocol 46 4.3 The Predicted Radio Frequency Interference (RFI) Map 46 4.3.1 Geographical Information Systems (GIS) 48 4.3.2 Multi-Criteria Decision Analysis (MCDA) 49 4.3.3 Analytical Hierarchy Process (AHP) 50 4.3.4 Predicted RFI profile map 53 4.4 Observation and Data Analysis 60 4.4.1 Population density 62 4.4.2 The contour effect 63 4.4.3 The
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