UNIVERSITI PUTRA MALAYSIA

ARIS MUNAWAR

FK 2011 82

FOREIGN OBJECT DEBRIS DETECTION BASED ON CONTINUOUS WAVE FORWARD SCATTERING RADAR DOPPLER EFFECT

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TITLE PAGE

FOREIGN OBJECT DEBRIS DETECTION BASED ON CONTINUOUS

WAVE FORWARD SCATTERING RADAR DOPPLER EFFECT

By

ARIS MUNAWAR

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia,

in Fulfillment of the Requirements for the Degree of Master of Science

May 2011

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ABSTRACT

Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfillment of the requirement for the degree of Master of Science

FOREIGN OBJECT DEBRIS DETECTION BASED ON CONTINUOUS WAVE FORWARD SCATTERING RADAR DOPPLER EFFECT

By

ARIS MUNAWAR

May 2011

Chairman : Y.M. Raja Syamsul Azmir B. Raja Abdullah, PhD

Faculty : Engineering

Surveillance system has become necessity for many working areas such as civil,

military, defense, security, industry, flight, etc. This research concerns about the

using of radar to detect ground non-moving objects that become hazardous objects in

a specified environment. These kinds of objects are usually known as Foreign Object

Debris (FOD). Any unwanted objects lying on roads, bus ways, taxi ways, or the

airplane runways can be categorized as FOD. Especially for flight, FOD has become

a vital problem that can cause fatal damage or even an accident for an aircraft.

This study is specially aimed to detect and localize the existence of FOD in a covered

area using a special mode of bistatic radar system known as Forward Scattering

Radar (FSR). The method is by analyzing the Doppler signal extracted from the

received signal scattered by the target. The received signal comprises direct signal

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from the transmitter and scattered signal from the target, therefore by analyzing the

Doppler signal at the receiver could give the information about the existing of target.

This research is a development of the previous research which was Forward

Scattering Radar for moving ground target detection. The difference between current

research and the previous research is that in the previous research the Doppler shift is

caused by the moving target, while in the current research the Doppler shift is created

by intentionally moving the transmitter antenna.

A hardware setup and an experimental scenario have been chosen to carry out this

research. A transmitter antenna is set to move in an angular direction for scanning the

covered area, while in the other side a receiver is located to receive the transmitted

signal. An object – supposed to be the FOD – is then located between the transmitter

and the receiver. The transmitter antenna is fed into a continuous wave signal

generator and moved using a controlled stepper motor. While, the received signal at

the receiver will be passed through a receiving circuit to extract its Doppler signal.

A computer simulation in accordance with this experimental scenario is also

designed to confirm the analysis result of this research. Any parameters used in the

experimental will also be adopted in the computer simulation. An FSR formulation

will be applied to perform this simulation.

FOD detection will be performed both in time domain and frequency domain of the

Doppler signal. A subtraction and statistical correlation of several no-target Doppler

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and with-target Doppler signals will be performed in this case. Both theoretical and

experimental signals will be analyzed to confirm the result. The power – frequency

extraction will be done using standard Fourier Transform.

Analyses of FOD detection on time domain are done. Subtraction of with-target by

no-target Doppler signals results on scattered Doppler signal, and the existing of this

scattered Doppler signal has proven the existing of FOD. By performing cross

correlation between no-target and with-target Doppler signals, a line plot of

correlation coefficient is resulted. The average of correlation coefficient is

significantly different compared to the cross correlation between no-target Doppler

signals, and this is enough to conclude that the FOD does exist. While, analyses on

frequency domain of those signals give proportional results as on time domain

signals.

FOD localization will be performed using the time-frequency analysis of the

scattered Doppler signal. The existence of target will be represented by the existing

of zero Doppler at the time-frequency characteristic of the scattered Doppler signal.

FOD localization will be performed for both theoretical and experimental signal. An

optimized Hilbert – Huang transform will be used to analyze the time-frequency

properties of the signals. The elaboration about the Hilbert – Huang transform

optimization will be discussed.

By analyzing two different Doppler signals of different target location, different zero

Doppler positions are identified. By relating the time position of zero Doppler with

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the angular velocity of transmitter antenna, the direction angle in which the target

was located could be calculated.

After all, this research will have contribution on introducing the theoretical and

experimental system design of FSR for non-moving object detection. Moreover, this

research also contributes on optimization of the existing well-known Hilbert-Huang

Transform, by removing the cyclic error.

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ABSTRAK

Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk ijazah Master Sains

PENGESANAN SERPIHAN OBJEK ASING BERDASARKAN KESAN DOPPLER FORWARD SCATTERING RADAR GELOMBANG

BERTERUSAN

By

ARIS MUNAWAR

Mei 2011

Pengerusi : Y.M Raja Syamsul Azmir B. Raja Abdullah, PhD

Fakulti : Kejuruteraan

Sistem pengawasan telah menjadi salah satu keperluan bagi kebanyakan bidang

pekerjaan, antaranya awam, ketenteraan, pertahanan, keselamatan, industri,

penerbangan dan sebagainya. Penyelidikan ini menitikberatkan tentang penggunaan

radar untuk mengesan objek tanah yang tidak bergerak, di mana ia akan menjadi

objek berbahaya dalam satu kawasan yang tertentu. Objek jenis ini biasanya dikenali

sebagai Foreign Object Debris (FOD). Mana-mana objek tidak diingini yang terletak

di jalan raya, jalan bas, jalan teksi, atau landasan kapal terbang boleh dikategorikan

sebagai FOD. Terutamanya untuk sesuatu penerbangan, FOD menjadi satu masalah

penting yang boleh menyebabkan kerosakan teruk atau kemalangan pesawat.

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Kajian ini mensasarkan untuk mengesan dan menempatkan FOD di kawasan tertutup

menggunakan cara khas sistem radar bistatic yang dikenali sebagai Forward

Scattering Radar (FSR). Menerusi kaedah ini, penganalisaan isyarat Doppler

diekstrak daripada isyarat yang diterima oleh sasaran. Isyarat yang diterima terdiri

daripada isyarat terus daripada pemancar dan isyarat yang diserak daripada sasaran.

Oleh itu, dengan menganalisis isyarat Doppler pada penerima boleh memberikan

maklumat berkenaan sasaran yang wujud.

Kajian ini merupakan satu perkembangan daripada penyelidikan sebelumnya iaitu

Forward Scattering Radar untuk mengesan sasaran yang bergerak di atas tanah.

Perbezaan diantara penyelidikan semasa dan penyelidikan sebelumnya adalah dalam

penyelidikan sebelumnya anjakan Doppler disebabkan oleh sasaran bergerak.

Manakala dalam penyelidikan semasa pula peralihan Doppler sengaja dicipta dengan

cara memindahkan antena pemancar.

Bagi menjalankan kajian ini, satu persediaan perkakasan dan senario eksperimen

telah ditentukan. Sebuah antena pemancar ditetapkan untuk bergerak ke arah sudut

tertentu untuk mengimbas kawasan tertutup. Sementara itu, pada bahagian lain pula

penerima diletakkan untuk menerima isyarat yang dihantar. Objek - sepatutnya FOD

- kemudian diletakkan di antara pemancar dan penerima. penjana Isyarat gelombang

berterusan dihantar kepada antenna penerima dan bergerak menggunakan stepper

motor terkawal. Manakala isyarat penerima dihantar menerusi litar penerima untuk

mengeluarkan isyarat Doppler itu.

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Satu simulasi komputer mengikut senario eksperimen ini juga direka untuk

mengesahkan hasil analisis kajian ini. Parameter yang sama akan diguna pakai untuk

simulasi komputer. Satu formula FSR akan diguna pakai untuk menjalankan simulasi

ini.

Pengesanan kewujudan FOD akan dilakukan dalam domain masa dan domain

frekuensi Doppler. Sebuah operasi pengurangan dan korelasi statistik pada beberapa

isyarat Doppler dengan sasaran dan isyarat Doppler tanpa sasaran akan dilakukan.

Kedua-dua isyarat teori dan eksperimen akan dianalisis untuk mengesahkan

keputusan hasil. Pengekstrakan kuasa-frekuensi akan dilakukan menggunakan

standard Transformasi Fourier.

Analisis pengesanan FOD pada domain masa telah dilakukan. Pengurangan isyarat

Doppler dengan sasaran dan isyarat Doppler tanpa sasaran menghasilkan isyarat

Doppler terserak, dan kewujudan isyarat Doppler terserak ini membuktikan

kewujudan FOD. Dengan melaksanakan hubungan silang antara isyarat Doppler

dengan sasaran dan isyarat Doppler tanpa sasaran, satu pertalian garis dihasilkan.

Purata pertalian garis korelasi ini jauh berbeza berbanding hubungan silang antara

isyarat Doppler tanpa sasaran. Ini membuktikan kewujudan FOD. Sementara itu,

analisis isyarat pada domain frekuensi memberikan hasil yang berkadar langsung

seperti isyarat pada domain masa.

Lokasi FOD akan dilakukan menggunakan analisis frekuensi masa oleh isyarat

Doppler terserak. Kewujudan sasaran akan disahkan dengan kewujudan Doppler

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sifar pada ciri-ciri isyarat frekuensi masa Doppler terserak. Penempatan FOD akan

dilakukan untuk kedua-dua isyarat teori dan isyarat eksperimen. Pengubah optimum

Hilbert-Huang akan digunakan untuk menganalisis ciri-ciri isyarat frekuensi masa.

Penjelasan berkenaan pengoptimuman Transformasi Hilbert - Huang akan

dibincangkan.

Dengan menganalisis dua isyarat Doppler yang berlainan dan lokasi sasaran yang

berbeza, kedudukan sifar Doppler yang berbeza dikenal pasti. Dengan

menghubungkan kedudukan masa sifar Doppler dengan halaju sudut antena

pemancar, sudut arah di mana sasaran terletak boleh dikira.

Penyelidikan ini akan mempunyai sumbangan kepada memperkenalkan sistem teori

dan reka bentuk eksperimen FSR untuk mengesan objek tidak bergerak. Selain itu,

kajian ini juga menyumbang kepada pengoptimuman Transformasi Hilbert-Huang

sedia ada, dengan menghapuskan pusingan kesilapan.

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ACKNOWLEDGEMENTS

I would like to express profound gratitude to my supervisor, Dr. Raja Syamsul Azmir

Raja Abdullah for his invaluable support, encouragement, supervision and useful

suggestions throughout this research work. His moral support and continuous

guidance enabled me to complete my work successfully. I am also highly thankful to

Dr. M. Iqbal Saripan and Dr. Alyani Ismail for their valuable suggestions and

guidance throughout this thesis.

I wish to extend my warmest thanks to all those who have helped me with my work

in the Department of Computer and Communication System Engineering.

My sincere thanks also go to my friends who shared their love and experiences with

me. Finally, I thank my parents for their love and support throughout my life.

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APPROVAL

I certify that an Examination Committee met on …………….. to conduct the final examination of Aris Munawar on his Master of Science thesis entitled “Foreign Object Debris Detection Based On Forward Scattering Radar Doppler Effect Using Continuous Wave” in accordance with Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulations 1981. The committee recommends that the candidate be awarded the degree of Master of Science.

Members of the Examination Committee are as follows:

Chairman, PhD Professor Faculty of Engineering Universiti Putra Malaysia (Chairman)

Examiner 1, PhD Professor Faculty of Engineering Universiti Putra Malaysia (Internal Examiner)

Examiner 2, PhD Professor Faculty of Engineering Universiti Putra Malaysia (Internal Examiner)

External Examiner, PhD Professor Faculty of ……………… Universiti ………………. (External Examiner)

_________________________ Bujang Kim Huat, Ph.D Professor and Deputy Dean School of Graduate Studies Universiti Putra Malaysia Date:

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This thesis was submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfillment of the requirements for the degree of Master of Science. The members of the Supervisory Committee were as follows:

Y.M Raja Syamsul Azmir Raja Abdullah, PhD Senior Lecturer Faculty of Engineering Universiti Putra Malaysia (Chairman)

M. Iqbal Saripan, PhD Senior Lecturer Faculty of Engineering Universiti Putra Malaysia (Member)

Alyani Ismail, PhD Senior Lecturer Faculty of Engineering Universiti Putra Malaysia (Member)

_________________________________ HASANAH MOHD GHAZALI, 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 institutions.

_______________________________ ARIS MUNAWAR

Date: 3 May 2011

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TABLE OF CONTENTS

Page TITLE PAGE i ABSTRACT ii ABSTRAK vi ACKNOWLEDGEMENTS x APPROVAL xi DECLARATION xiii LIST OF TABLES xvi LIST OF FIGURES xvii LIST OF ABBREVIATIONS xxi CHAPTER

1 INTRODUCTION 1 1.1 Background 1 1.2 Problem Statements and Motivations 4 1.3 Aim and Objectives 5 1.4 Scope of Study 6 1.5 Methodology 7 1.6 Thesis Organization 8

2 LITERATURE REVIEW 9

2.1 Introduction 9 2.2 Foreign Object Debris 9 2.3 FOD Detection Technologies 10

2.3.1 XSight System Ltd – FODetect® 11 2.3.2 QinetiQ – Tarsier® 12 2.3.3 Trex Enterprises – FODFinder® 12 2.3.4 Stratech System Ltd – iFerret™ 13

2.4 Principles of Forward Scattering Radar 14 2.4.1 Basic Radar System 14 2.4.2 Bistatic Radar 16 2.4.3 Forward Scattering Radar 17 2.4.4 FSR for Ground Target Detection 18

2.5 Time – Frequency Extraction 19 2.5.1 Short Time Fourier Transform 19 2.5.2 Discrete Wavelet Transform 20 2.5.3 Continuous Wavelet Transform 21 2.5.4 Pseudo Wigner Distribution 23 2.5.5 Hilbert – Huang Transform 24

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3 FORWARD SCATTERING RADAR FOR NON-MOVING

TARGET DETECTION 24 3.1 Introduction 25 3.2 The System Design 26 3.3 System Components 27

3.3.1 Signal Source 27 3.3.2 Scanning Part 28 3.3.3 Receiving Circuit 30 3.3.4 Signal Processing 35

3.4 Theoretical Design 35 3.4.1 Transmitted Signal 35 3.4.2 Received Signal 36 3.4.3 Doppler Signal 50

3.5 Hilbert – Huang Transform Optimization 53 3.5.1 Introduction 53 3.5.2 Standard Time-Frequency Extraction Algorithm 56 3.5.3 Optimization Algorithm 58

4 RESULT AND ANALYSIS 63

4.1 Target Detection and Localization Algorithm 63 4.2 Simulation vs. Experimentation Result 66

4.2.1 Simulation Properties 66 4.2.2 Experiment Properties 80 4.2.3 Theoretical vs. Experimental Doppler Signal 84

4.3 Target Detection 84 4.3.1 Target Detection on Theoretical Doppler Signal 85 4.3.2 Target Detection on Experimental Doppler Signal 94

4.4 Target Localization 106 4.4.1 Theoretical Analysis 106 4.4.2 Experimental Analysis 126

5 CONCLUSIONS AND FUTURE WORKS 133

5.1 Conclusions 134 5.2 Research Contributions 137 5.3 Recommendations and Future Works 137

REFERENCES 139 APPENDIX 1 142 BIODATA OF STUDENT 144 LIST OF PUBLICATIONS 145