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ANALYSIS AND MEASUREMENT OF ALIGNMENT AND TRACKING
METHOD OF EARTH STATION ANTENNA IN SATELLITE
COMMUNICATION SYSTEM
HO SHU MEI
This report is submitted in partial fulfilment of the requirements for the award
of Bachelor of Electronic Engineering (Telecommunication Electronics) With
Honours
Faculty of Electronic and Computer Engineering
Universiti Teknikal Malaysia Melaka
May 2011
ii
UNIVERSTI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek :
ANALYSIS AND MEASUREMENT OF ALIGNMENT
AND TRACKING METHOD OF EARTH STATION
ANTENNA IN SATELLITE COMMUNICATION SYSTEM Sesi
Pengajian : 1 0 / 1 1
Saya …………………………………………………………………………………………………..
(HURUF BESAR)
mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-
syarat kegunaan seperti berikut:
1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.
2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.
3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi
pengajian tinggi.
4. Sila tandakan ( √ ) :
SULIT*
*(Mengandungi maklumat yang berdarjah keselamatan atau
kepentingan Malaysia seperti yang termaktub di dalam AKTA
RAHSIA RASMI 1972)
TERHAD**
**(Mengandungi maklumat terhad yang telah ditentukan oleh
organisasi/badan di mana penyelidikan dijalankan)
TIDAK TERHAD
Disahkan oleh:
__________________________ ___________________________________ (TANDATANGAN PENULIS) (COP DAN TANDATANGAN PENYELIA)
Tarikh: ……………………….. Tarikh: ………………………..
iii
“I hereby declare that this report is the result of my own work except for quotes as
cited in the references”
Signature :…………………………..
Author :….……………………….
Date :…..………………………
iv
“I hereby declare that I have read this report and in my opinion this report is
sufficient in terms of the scope and quality for the award for Bachelor of Electronic
Engineering (Telecommunication Electronics) With Honours”
Signature :………………………………………….
Supervisor‟s Name :..………….……………………………..
Date :.…………………………………………
v
ACKNOWLEDGEMENT
First of all, I would like to thank my supervisor, Mr Chairulsyah bin
Abdul Wasli for teaching and guiding me during the project period. Many thanks
also to the FKEKK‟s lecturers for giving me a wonderful and cheerful time during
my four years of study in UTeM.
Next, I would to express my gratitude to Mr. Kamarulzaman, the
manager of Melaka Earth Satellite Station and En. Azizi, PASCA lab technician for
your time in explaining and guiding me in this project.
Lastly, I would like to thank my family and friends. Without your
support, I would not have completed this project smoothly.
vi
ABSTRACT
Communication satellites in the geostationary orbits possess daily
motion which causes the apparent position of the satellite to wander in the
sky as seen by the earth station. If uncompensated, it will cause a variation in
the performance of communication link. Therefore, the movement of the
satellite has to be tracked by the earth station antenna. This reports aims to
give an understanding of the satellite communication system and also the
requirements in the alignment and tracking method of the earth station. In this
report, we will explore the functions of communication system and its
subsystems. The parameters in the link budget and earth station configuration
will also be discussed. Other than that, the determination of the azimuth and
elevation angles and slant range will be done in order to point the earth
station to the satellite by using calculation and simulation method. Then, the
results will be analyzed and compared. To conclude, the alignment and
tracking is important to ensure reliable communication links between satellite
and earth station.
Key words: Satellite communication system, earth station antenna,
antenna alignment, antenna tracking
vii
ABSTRAK
Satelit komunikasi pada orbit geopegun mempunyai gerakan harian
yang menyebabkan kedudukan nyata satelit untuk berkeliaran di langit seperti
yang dilihat oleh stesen bumi. Jika tidak dikompensasi, ia akan menyebabkan
variasi dalam prestasi komunikasi. Oleh kerana itu, pergerakan satelit harus
dikesan oleh stesen bumi antena. Laporan ini bertujuan untuk memberikan
pemahaman tentang sistem komunikasi satelit dan juga faktor yang
memainkan peranan dalam kaedah penjajaran dan pengesanan yang
digunakan oleh stesen bumi. Dalam laporan ini, kita akan membincangkan
fungsi sistem komunikasi dan sub sistemnya. Parameter dalam „link budget‟
dan tatarajah stesen bumi juga akan dibincangkan. Selain itu, penentuan sudut
azimuth dan elevasi dan jarak satelit dari stesen bumi akan dilakukan untuk
menentukan titik stesen bumi ke satelit dengan menggunakan perhitungan
dan kaedah simulasi. Kemudian, hasilnya akan dianalisis dan dibandingkan.
Kesimpulannya, penyelarasan dan pengesanan adalah penting untuk
memastikan hubungan komunikasi handal antara satelit dan stesen bumi.
Kata kunci: Satelit komunikasi, stesen bumi antenna, kaedah penjajaran
antenna, kaedah pengesanan antena
viii
TABLE OF CONTENTS
CHAPTER TITLE PAGE
TITLE i
DECLARATION iii
ACKNOWLEDGEMENTS v
ABSTRACT vi
ABSTRAK vii
TABLE OF CONTENTS viii
LIST OF TABLES xiii
LIST OF FIGURES xv
LIST OF APPENDIXES xvii
I INTRODUCTION
1.1 INTRODUCTION 1
1.2 OBJECTIVES 2
1.3 SCOPE OF WORK 2
1.4 PROBLEM STATEMENTS 3
1.5 EXPECTED OUTCOMES 3
ix
1.6 METHODOLOGY 4
II LITERATURE REVIEW
2.1 INTRODUCTION TO A SATELLITE 5
COMMUNICATION SYSTEM
2.1.1 Configuration of A Satellite System 6
2.1.2 Communication Links 6
2.1.3 The Space Segment 7
2.1.4 The Ground Segment 8
2.2 SATELLITE ORBITS 9
2.2.1 Low Earth Orbit (LEO) 10
2.2.2 Medium Earth Orbit (MEO) 10
2.2.3 Highly-eccentric Orbit (HEO) 10
2.2.4 Geostationary Orbit (GEO) 11
2.3 FREQUENCY ALLOCATIONS 11
2.4 LINK BUDGET 12
2.4.1 Transmitter Power (P) 12
2.4.2 Antenna gain (G) 13
2.4.3 Equivalent Isotropically 13
Radiated Power (EIRP)
2.4.4 Illumination Level (W) 14
2.4.5 Free Space Path Loss (L) 14
2.4.6 Figure of Merit (G/Ts) 15
x
2.4.7 Carrier-to-Thermal Noise Ratio (C/T) 15
2.4.8 Carrier-to-Noise Density Ratio (C/No) 16
2.4.9 Carrier-to-Noise Ratio (C/N) 16
2.4.10 Examples of Link Budget 17
2.5 EARTH STATION ANTENNA 18
2.5.1 Configuration of Earth Station 19
2.5.2 Mountings to Permit Antenna Pointing 20
2.5.2.1 The X-Y mount 20
2.5.2.2 The AZ/EL mount 21
2.5.2.3 Polar mount 23
2.6 ALIGNMENT 24
2.6.1 Azimuth (A) and Elevation (h) Angles 25
2.6.2 Slant Range (S) 27
2.7 TRACKING 27
2.7.1 Fixed Antenna without Tracking 28
2.7.2 Programmed Tracking 29
2.7.3 Computed Tracking 29
2.7.4 Closed Loop Automatic Tracking 30
2.7.4.1 Sequential Amplitude Detection 30
2.7.4.1.1 Conical scanning 31
2.7.4.1.2 Step-by-step tracking 32
2.7.4.1.3 Electronic tracking 33
2.7.4.2 Monopulse Technique 33
2.7.5 Example of Tracking Process 34
xi
2.8 DISTANCE CALCULATION 35
2.8.1 Distance in One Dimension 36
2.8.2 Distance in Two Dimensions 36
2.8.3 Distance in Three Dimensions 37
2.8.3.1 Cartesian coordinate system 37
in three dimension
2.8.3.2 Geographic coordinate system 38
in three dimensional system
2.8.4 Distance between Earth Station and Satellite 39
2.8.5 Distance between Two Satellites in the 39
Same Orbit
III METHODOLOGY 40
3.1 FLOW CHART OF PROJECT 40
METHODOLOGY
3.2 ANIMATION 41
3.3 CALCULATION 42
3.4 SIMULATION 44
3.5 MEASUREMENT 45
IV RESULT AND ANALYSIS 47
4.1 CALCULATION RESULT 48
4.2 SIMULATION RESULT 48
4.3 MEASUREMENT RESULT 48
xiii
LIST OF TABLES
NO TITLE PAGE
2.1 Platform subsystems 7
2.2 INTELSAT Standard Earth Stations 8
2.3 The frequency allocations and its usage 11
2.4 Uplink budget for International TV 17
2.5 Downlink budget for International TV 18
2.6 The summary of tracking method 35
3.1 The latitudes and longitudes of the earth station and satellites 42
3.2 Satellite position according to DiSEqC positioner 45
4.1 The calculation result 47
4.2 The simulation result 48
4.3 The list of channels that can received in the 48
Asiasat 3S C-band 105.5E satellite
xiv
4.4 The list of channels that can be received in 51
Asiasat 2C 100.5E satellite
5.1 The comparison between calculation and simulation results 53
5.2 The comparison between the signals received from 54
Asiasat 3S 105.5E and Asiasat 2C 100.5E
xv
LIST OF FIGURES
NO TITLE PAGE
1.1 The flowchart of the project 4
2.1 Satellite communication system 6
2.2 The satellite orbits 9
2.3 The configuration of an earth station 19
2.4 10 meter diameter X-Y mount antenna 20
2.5 11 meter diameter AZ/EL mount antenna 21
2.6 97 foot diameter antenna using AZ/EL mount 22
2.7 Wheel-and-track pedestal system 22
2.8 Polar mount geometry 23
2.9 The flow chart of antenna alignment process 24
2.10 Azimuth and elevation angles from 25
the earth station to the satellite
2.11 Spherical triangle showing satellite azimuth A 25
and earth station latitude
2.12 The slant range between the satellite and earth station 27
2.13 The types of tracking system 28
xvi
2.14 The movement of antenna in conical scanning 31
2.15 Possible step-tracking subsystems configuration 32
2.16 Tracking process of conical scanning 34
2.17 Distance in two dimensions 36
2.18 A three dimensional Cartesian coordinate system, with 37
origin O and axis lines X, Y and Z, oriented as shown
by the arrows
2.19 The geographic coordinate system 38
3.1 The flow chart on project methodology 40
3.2 Sequence of animation on earth station antenna tracking 41
3.3 Azimuth and elevation angles 42
3.4 Geometric relation between satellite range, earth station 43
elevation angle, central angle from earth‟s center
and nadir angle
3.5 Simulation using Satellite az-el Calculator 45
4.1 The measurement of channel 788, NOW 50
transmitted by Asiasat 3S satellite
4.2 The channel 788, NOW transmitted by Asiasat 3S 50
satellite visualized using PROMAX
4.3 The signal information channel 117, Jame-Jam 51
TV Ne obtained from the TV monitor
4.4 The measurements obtained for the channel 52
xvii
LIST OF APPENDIXES
NO TITLE PAGE
A The Standard Operating Procedure of Earth Station 58
Antenna
B The Standard Maintenance Procedure of Earth Station 63
Antenna
C Asiasat 3S 105.5E 67
D Asiasat 3S 105.5E Channel Guide 68
E Asiasat 2C 100.5E 77
F List of Channels for Asiasat 2C 100.5E 78
G DiSEqC 79
CHAPTER I
INTRODUCTION
This chapter consists of the outline of the project in terms of objectives, scope,
problem statement, expected outcomes and methodology. It aims to give the reader a
deeper understanding of the project.
1.1 INTRODUCTION
Earth station antenna is a main component in satellite communication system
and plays an important role in determining the quality of a signal. Antenna should be
aligned precisely on the ground with the satellite beforehand in order to establish and
maintain reliable and high quality two-way communication services at all time.
While the satellite is moving at a certain path, the antenna should also follow the
satellite movement. This action is called “antenna tracking”. There are several
methods in alignment and tracking which depend on the type of antenna and services.
This project will analyze the alignment and tracking method from the theoretical,
design, simulation and measurement aspect. The measurement presents azimuth and
elevation angle, power loss, signal-to-noise ratio, carrier-to-noise ratio and other
parameters that will be affected. Measurements will take place at FKEKK and Lendu
Earth Station. Other than that, an animation on how the alignment and tracking
method works will be done.
2
1.2 OBJECTIVE
The objectives of this project are:
To gain knowledge and skill in alignment and tracking system of earth station
antenna.
To prepare the SOP and SMP of FKEKK earth station antenna.
To be able to use FKEKK earth station antenna for student‟s experiment.
To foster close relation between UTeM and Telekom in satellite field.
1.3 SCOPES OF WORK
This project will discuss on:
Background of satellite communication system and earth station antenna.
Parameters involved in the alignment and tracking system of earth station
antenna.
Design for alignment and tracking system.
Implementation and simulation of the parameters involved in alignment and
tracking system.
Analysis and measurement of alignment and tracking of earth station antenna
at FKEKK and Lendu Earth Station.
Comparison between the theoretical, simulation and measurement results of
the alignment and tracking system.
3
1.4 PROBLEM STATEMENT
Earth station consists of an antenna sub-system with an associated tracking
system, transmitting and receiving section. This type of antenna can be seen in
FKEKK, UTeM whereby it is used for television broadcasting. However, the
Standard of Operating Procedure (SOP) and Standard of Maintenance Procedure
(SMP) are not available for the antenna in UTeM. It will be a problem to realign and
operate the antenna if crisis occurs such as the antenna‟s system break down.
Moreover, there is not much study in satellite topic related at UTeM at this time. In
other words, there is not much relation of UTeM with leading telecommunication
company such as Telekom in terms of satellite studies at current time.
1.5 EXPECTED OUTCOMES
At the end of the project, the expected results will be as the following:
Animation on alignment and tracking system of earth station antenna.
Analysis of alignment and tracking of the satellite using FKEKK earth station
antenna.
Develop the SOP and SMP for FKEKK earth station antenna.
Simulation of antenna alignment and tracking system.
Conference technical paper.
4
1.6 METHODOLOGY
Figure 1.1: The flowchart of the project
Start
Project Title Registration
Background Study
Submit Proposal
Literature Review
Calculations for Alignment
and Tracking System
Is there an
error in
calculations?
Implementation and Simulation of
Alignment and Tracking System
of Earth Station Antenna
A
No
Yes
A
Is there an
error in
simulation?
Measurement of Alignment and
Tracking Method at FKEKK and
Lendu Earth Station
Performance Analysis and
Comparison
Animation of Alignment and
Tracking System
Report Writing
Seminar PSM
Submit Report
End
Yes
No
5
CHAPTER II
LITERATURE REVIEW
This chapter is devoted to the studies on satellite communication system and
its orbit. The allocation of frequency band based on space radio communication
services is also discussed. This chapter will also sees into the link budget,
organization of earth station and the characteristics of the antenna. In the last part,
the alignment and tracking system will be examined.
2.1 INTRODUCTION TO A SATELLITE COMMUNICATION SYSTEM
A communication satellite is an orbiting artificial earth satellite that receives
communication signal from a transmitting ground station, amplifies and then
transmits it back to the earth for reception by one or more receiving ground stations.
In the mid-1960s, the commercial satellite communications industry has
started and in less than 50 years, has progressed from an alternative technology to
mainstream transmission technology. Today‟s communication satellites offer
extensive capabilities in applications involving data, voice and video, with services
provided to fixed, broadcast, mobile, personal communications and private network
users.[1]
6
2.1.1 Configuration of A Satellite Communication System
Figure 2.1 gives an overview on the satellite communication system and its
interfacing with terrestrial entities. The system is consists of space segment, control
segment and ground segment.
Figure 2.1: Satellite communication system
2.1.2 Communication Links
A link between a transmitting terminal and a receiving terminal consists of a
radio or optical modulated carrier. The types of link are the uplinks from the earth
stations to the satellites, downlinks from the satellites to the earth stations and the
intersatellite links between the satellites. Uplinks and downlinks consist of radio
frequency modulated carriers, while intersatellite links can be either radio frequency
or optical. Carriers are modulated by baseband signals conveying information for
communication purposes.
7
The link performance can be measured by the ratio of the received carrier
power to the noise power spectral density, C/No ratio (Hz). This ratio will determine
the quality of service of connection between the end terminals in baseband signal-to-
noise power ratio, S/N or bit error rate (BER). [1]
2.1.3 The Space Segment
The space segment contains one or several active and spare satellites
organized in a constellation and the satellite consists of the payload and the platform.
In the payload, there are the receiving and transmitting antennas and all the
electronic equipment which supports the transmission of the carriers. The two types
of payload organization are transparent and regenerative. The platform consists of all
the subsystems which permit the payload to operate. The Table 2.1 below lists these
subsystems and indicates their respective main functions and characteristics: [1]
Table 2.1: Platform subsystems
Subsystem Principal Functions Characteristics
Attitude and orbit control
(AOCS)
Attitude stabilisation
and orbit determination
Accuracy
Propulsion Provision of velocity
increments
Specific impulse, mass
of propellant
Electric power supply Provision of electrical
energy
Power, voltage stability
Telemetry, tracking and
command (TTC)
Exchange of
housekeeping
information
Number of channels,
security of
communications
Thermal control Temperature
maintenance
Dissipation capability
Structure Equipment support Rigidity, lightness