comparison of theoretical total electron content …

COMPARISON OF THEORETICAL TOTAL ELECTRON CONTENT

(TEC) DURING DISTURBANCE

Roziana Binti Che Musa

Bachelor of Engineering with Honors

(Electronics & Telecommunications Engineering)

2009/2010

UNIVERSITI MALAYSIA SARAWAK

R13a

BORANG PENGESAHAN STATUS TESIS

Judul: COMPARISON THEORETICAL MODEL TOTAL ELECTRON CONTENT (TEC) DURING

DISTURBANCE

SESI PENGAJIAN: 2009/2010

Saya ROZIANA BINTI CHE MUSA

(HURUF BESAR)

mengaku membenarkan tesis * ini disimpan di Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak

dengan syarat-syarat kegunaan seperti berikut:

1. Tesis adalah hakmilik Universiti Malaysia Sarawak.

2. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat salinan untuk

tujuan pengajian sahaja.

3. Membuat pendigitan untuk membangunkan Pangkalan Data Kandungan Tempatan.

4. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat salinan tesis ini

sebagai bahan pertukaran antara institusi pengajian tinggi.

5. ** Sila tandakan ( ) di kotak yang berkenaan

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) (TANDATANGAN PENYELIA)

Alamat tetap: KAMPUNG PADANG

KIJANG, 17500 TANAH MERAH MDM.DAYANG AZRA BT AWANG MAT

Nama Penyelia

KELANTAN

Tarikh: Tarikh:

CATATAN * Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah, Sarjana dan Sarjana Muda.

** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi

berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai

SULIT dan TERHAD.

Final Year Project attached here:

Title : Comparison of Theoretical Total Electron Content (TEC) during

Disturbance

Student Name : ROZIANA BINTI CHE MUSA

Matric No : 17179

Is hereby read and approved by:

__________________________ _________________________

Mdm.Dayang Azra bt.Awang Mat Date

(Supervisor)

COMPARISON OF THEORETICAL TOTAL ELECTRON CONTENT

(TEC) DURING DISTURBANCE

ROZIANA BINTI CHE MUSA

Thesis is submitted to

Faculty of Engineering University Malaysia Sarawak

in Partial Fulfillment of the Requirements

for Degree of Bachelor of Engineering

with Honors (Electronics & Telecommunications) 2009/2010

ii

ACKNOWLEDGEMENT

I would like to express my sincere gratitude to my supervisor, Madam

Dayang Azra Awang Mat, for her patience, insight and guidance throughout this

research project.

My deepest gratitude goes to all my lecturers and friends for constant support,

encouragement and helps during completion this research project. Special thanks go

those who made their software available for this study and also to those who

provided the data used in this research effort.

To my beloved family members, thank you for unconditional support and

encouragement, which made an enormous contribution to this research by helping

me to continue onwards and persevere throughout my graduate studies.

iii

ABSTRAK

Lapisan ionosfera sangat penting bagi sistem komunikasi dan jumlah

kandungan elektron (Total Electron Content, TEC) memainkan peranan yang penting

dalam membuat kajian tentang peranan ‘ionospheric’. Projek ini melibatkan

perbandingan terhadap jumlah kandungan elektron (Total Electron Content, TEC)

menggunakan model secara teori dan data yang asal, semasa berlakunya gangguan

merujuk kepada keadaan tanpa gangguan dan keadaan dengan kehadiran gangguan di

kawasan khatulistiwa dan kawasan garis lintang tengah. Jumlah kandungan elektron

(Total Electron Content, TEC) ini dikesan dengan menggunakan dua model iaitu

International Reference Ionosphere 2001 secara versi tingkap (IRI-2001) dan

NeQuick menggunakan contoh pemacu slQu.exe. Kedua-dua model ini merupakan

model yang mengikut standard yang ditentukan oleh International

Telecommunication Union-Radio Sector (ITU-R). Data asal dalam format

IONospheric map exchange (IONEX) daripada Centre for Atmosphere

Determination (CODE) akan digunakan sebagai perbandingan. Keputusan

menunjukan nilai jumlah kandungan elektron di kawasan khatulistiwa lebih tinggi

berbanding dengan kawasan garis lintang tengah. Dicadangkn untuk pembaikan,

kedua-dua model teoritis (IRI-2001 dan NeQuick) harus memasukkan gangguan

“ionospheric” supaya kiraan jumlah kandungan elektron yang lebih tepat.

iv

ABSTRACT

The ionosphere layer is very important to the communication system and the

Total Electron Content (TEC) plays an important role in the study of ionospheric

behavior. This project involves the comparison of TEC simulated using theoretical

models and real data during the disturbances due to geomagnetic quiet and the

disturbed day at Equatorial region and Middle Latitude Region. Prediction of TEC is

carried out using two theoretical models which are International Reference

Ionosphere 2001(IRI-2001) PC using window version and NeQuick using the sample

driver’s slQu.exe. Both theoretical models are the standard model available from the

International Telecommunication Union-Radio Sector (ITU-R). The real data in the

form of IONospheric map Exchange (IONEX) from the Centre for Atmosphere

Determination (CODE) is used for comparison. Results show that the TEC values for

Equatorial Region is higher than the Middle Latitude region. It is recommended that

for undergo improvement, both theoretical models (IRI2001 and NeQuick) should

include ionospheric disturbance for more reliable TEC calculation.

v

LIST OF CONTENTS

Pages

Acknowledgement

Abstrak

Abstract

List of Contents

List of Tables

List of Figures

Abbreviation

ii

iii

iv

v

ix

x

xii

Chapter 1 INTRODUCTION

1.1 Chapter Introduction

1.2 Project Objectives

1.3 Problem Statement

1.4 Proposed Solution

1.5 Project Scope

1.6 Project Outline

1

3

4

4

5

5

Chapter 2 LITERATURE REVIEW


2.2 The Ionosphere

2.3 Ionosphere Science Standing

7

7

9

vi

2.4 Layers of Ionosphere

2.4.1 D-Layer

2.4.2 E-Layer

2.4.3 F-Layer

9

10

11

11

2.5 Geographical Variation

2.5.1 Equatorial Anomaly

2.5.2 Mid-Latitude Region

12

13

13

2.6 Electron Density Profile

2.7 Solar Activity

2.7.1 Solar Flux

2.7.2 Solar Flares

2.7.3 Sunspot Number (SNN)

14

15

15

16

16

2.8 Total Electron Content (TEC)

2.8.1 Calculation of Slant and Vertical TEC

17

18

2.9 Ionospheric Models

2.9.1 Chiu Ionospheric Model 1975

2.9.2 Bent Ionospheric Model 1972

2.9.3 SLIM Ionospheric Model 1985

2.9.4 FAIM Ionospheric Model 1989

2.9.5 International Reference Ionosphere (IRI)

19

19

20

20

21

21

2.10 NeQuick Model

2.10.1 NeQuick Electron Density Model Package

22

23

2.11 Ionspheric Disturbance

2.11.1 Sudden Disturbance (SID)

24

24

vii

2.11.2 Ionospheric Storms

2.11.3 Polar Cap Absorption (PCA)

2.11.4 Travelling Ionospheric Disturbance

(TIDs)

2.11.5 Earthquake Disturbance

24

25

25

26

Chapter 3 METHODOLOGY


3.2 International Reference Ionosphere (IRI) and

NeQuick Model

3.3 Stage involved in the Analysis

3.4 Calculation TEC using IRI

3.5 Calculation TEC using NeQuick Model

3.6 Calculation TEC from IONEX TEC Maps

27

27

29

30

33

34

Chapter 4 RESULT AND DISCUSSIONS


4.2 Results and Discussions on Equatorial Region

4.2.1 Simualtion Results on 15th

August 2007

4.2.2 Simulation Results on 16th

August 2007


August 2007


August 2007


August 2007


August 2007

4.2.7 Comparison Between Quiet day and

36

36

36

37

38

39

40

41

42

viii

Disturbed Day

4.3 Results and Discussions on Middle Latitude

Region


March 2007

4.3.2 Simulation Results on 21st March 2007

4.3.3 Simulation Results on 22nd

March 2007

4.3.4 Simulation Results on 23rd

March 2007


March 2007


March 2007

4.3.7 Comparison Between Quiet Day and

Disturbance Day

4.4 Comparison of TEC value between Equatorial

Region and Middle Latitude Region

45

45

46

47

48

49

49

50

53

Chapter 5 CONCLUSION AND RECOMMENDATION

5.1 Conclusion

5.2 Recommendations

55

56

REFERENCE 58

APPENDIX Appendix A

Appendix B

Appendix C

Appendix D

58

64

70

78

ix

LIST OF TABLES

Tables Page

3.1 The Output of NeQuick at 15th

August 2007 on 2-UT 34

4.1 TEC values in Max, Min and Mean 43



x

LIST OF FIGURES

Figures Page

2.1 Atmospheric Layers 7

2.2 A Simplified View of the Layers in the Ionosphere

Over the Period of a Day

10

2.3 Structure of the Ionosphere World Map 11

2.4 Ionosphere Electron Density Profile 13

2.5 Total Electron Content World Map 18

3.1 Stage Involved in the Analysis 29

3.2(a) Command Window for IRI-2001 30

3.2(b) Command Window for IRI-2001 31

3.3 Result IRI-2001 on 2-UT 31

3.4 Command Window for slQu.exe 32

4.1 Result on the 15th

August 2007 36


August 2007 37


August 2007 38


August 2007 39


August 2007 40


August 2007 41

4.7 Results on 15th

August 2007 until 20th

August 2007

based on IONEX data

42

xi

4.8 Results on 20th

March 2007 44

4.9 Results on 21st March 2007 45

4.10 Results on 22nd

March 2007 46

4.11 Results on 23rd

March 2007 47

4.12 Results on 24th

March 2007 48


March 2007 49


March 2007 until 25th

March 2007

based on IONEX data

50

4.15 Comparison TECU between Equatorial Region and

Middle Latitude Region.

53

xii

ABBREVIATIONS

AGWs Atmospheric Gravity Waves

CCMC Community Coordinated Modeling Center

CCIR International Radio Consultative Committee

CODE Centre for Atmospheric Determination

COSPAR Committee on Space Research

DGR Di Giovanni and Radicella

EDP Electron Density Profile

EGNOS European Geostationary Navigation Overlay Service

ESA European Space Agency

EUV Extreme Ultraviolet

FAIM Fully Analytical Ionospheric Model

GPS Global Positioning System

H Hydrogen

He Helium

HF High frequencies

ICTP International Centre for Theoretical Physics

IONEX IONospheric map Exchange

IRI International Reference Ionosphere

ISIS International Satellites for Ionospheric Studies

ITUR International Telecommunication Union

LSTIDs Large Scale Travelling Ionospheric Disturbances

xiii

MSTIDs Medium Scale Travelling Ionospheric Disturbances

N2 Nitrogen

NOAA National Oceanic and Atmosphere Administration

NSSDC National Space Science Data Center

O Oxygen

PCA Polar Cab Absorption

PWs Planetary Waves

SLIM The Semi-Empirical Low-Latitude Ionospheric Model

SID Sudden Ionospheric Disturbance

SSN Solar Sunspot Number

SSTIDs Small Scale Travelling Ionospheric Disturbances

TEC Total Electron Content

TID Travelling Ionospheric Disturbance

URSI International Union of Radio Science

UV Ultra Violet

WAAS Wide Area Augmentation System

1

CHAPTER 1

INTRODUCTION


The ionosphere is another atmospheric layer, where represents less than 0.1%

of the total electron mass of the earth’s atmosphere [1] .The ionosphere regions are

broken down into four major layers which are C, D, E and F-layers. Each layers has

different approximate height range where C-layer (40-50 km), D-layer (50-90 km),

E-layer (90-140 km) and F-layer (140-500 km). The solar wind strongly influences

the structure of the ionosphere [2].

From the layers mention above there are a lot of benefit which is their

characteristic can influence the reflection of radio wave signal due by the electron

content of the layers which is different either during daytime or nighttime. Actually

the plasma of ionized gas of the upper atmosphere by solar radiation and high energy

particles from the Sun is about 60 km to 1000 km above the earth’s surface. The

ionized electrons concentrations is depending to the height above earth’s surface,

location, time of delay, season and amount of solar activity. To determine the state of

the ionospheric activities the electron density plays the main important physical in

2

ionosphere. It is also important for predicting space weather and disturbance due to

geomagnetic and solar flares [3].

There are many disturbance influences by ionosphere due the solar activity

such as Sudden Ionospheric Disturbance (SID), Ionospheric Storms, Polar cab

absorption (PCA), Travelling Ionospheric Disturbance (TID) and Earthquake. This

project focuses on the earthquake disturbance, where the earthquake occurs when the

rock underground suddenly breaks along a fault because the suddenly release of

energy can causes the seismic waves that make the ground shake [4].

Total electron content (TEC) is an important parameter for the ionosphere of

the Earth. TEC is the total number of electrons in a cylinder centered on the line of

sight between the two points, with units of electron per square meter, where 1016

electron/m2 equal to 1 TEC unit and measured in TECU and commonly in the range

between 1015

and 1018.

Generally TEC is minimal during midnight and is maximal

around local noon [5].

The main aim of this project is to do simulation during the ionospheric

disturbance using two theoretical models which are International Reference

Ionosphere (IRI-2001) and NeQuick-ITUR. The result from that models were

calculated and compared with the real data in the form of IONospheric map

Exchange (IONEX).

3

1.2 Project Objectives

This project concentrates on the following objectives:

I. To analyze total electron content (TEC) using models on different

selected period.

In this project the ionosphere models such as International Reference

Ionosphere (IRI-2001) windows version and NeQuick-ITUR are used to

predict the value of TEC during the normal quiet day and the disturbed

time.

II. To compare the result with the actual data called IONospheric map

Exchange (IONEX).

The simulation from the two models above was compared with the actual

data in format of IONEX. These data was downloaded from the Centre

for Atmospheric Determination (CODE) website. Then, the results were

compared to the solar sunspot number (SSN), R12.

III. To simulate the result during normal and disturbance time.

During normal time and disturbance time, the values of TEC are different.

The values of TEC was calculated and simulated on the day before the

4

disturbance time and the result was compared with the result during the

disturbance time.

IV. To analyze advantages and disadvantages of the models as a

reference during the ionospheric disturbance.

1.3 Problem Statement

The main expected problem that will be encountered in this project is come

from the calculation of IONEX data. The data produced by the Centre for

Atmospheric Determination (CODE) not accurate latitude and longitude with the

latitude and longitude in study which is LAT1 is 87.5 until LAT2 is -87.5 with

DLAT are -2.5. While the LON1/LON2/DLON is -180 and 180.

1.4 Proposes Solution

The solution accurate latitude and longitude can be solved by using the

interpolating processes between the two latitude and longitude. The other solution

can be used which is by introduces appropriate software programming to extract the

values of the TEC.

5

1.5 Project Scope

This project involves the simulation and analysis from the different models

such as International Reference Ionosphere (IRI-2001) using PC windows version

and NeQuick- ITUR, these models were used to calculate and compare the

theoretical total electron content (TEC) with the real value in the format of IONEX.

The simulation and analysis was done during the ionospheric disturbance at places

located in the middle latitude region comparing to the equatorial region.

1.6 Project Outline

Chapter 1 briefly introduces ionosphere layer, TEC, ionosperic disturbances,

aim of the project, project scope and objective.

Chapter 2 is explains, summarizes and reviews the overall studies and

researches which are related to the project. In this chapter the ionosphere layers,

ionospheric models, electron density, electron content (TEC), ionospheric

disturbance also are discussed.

Chapter 3 describes the method that is used in this project. In this project the

ionospheric models are used IRI-2001 and NeQuick-ITUR for predicting the value of

TEC during the quiet normal days. Then the predicted data are compared with actual

6

data in the format of IONEX reference to solar flux number, F10.7 or sunspot number,

R12.

Chapter 4 consists of the results, analysis and discussion. This chapter

exhibits the results and data obtain from the IRI and NeQuick simulation process.

The results are compared with the real data from the IONEX. It also examines

whether the simulation results fulfill the predicted or expected results as mention in

the early part of the project.

Chapter 5 concludes the overall finding of the project. In addition, further

works which can are implemented or future improvement of the project will be

discussed.

7

CHAPTER 2

LITERATURE REVIEW


This chapter is explained, summarizes and reviews the overall studies and

researches which are related to the project. In this chapter the ionosphere’s layers,

electron density, sunspot number (SSN), R12, Total Electron Content (TEC),

ionospheric models and ionospheric disturbance were discussed.

2.2 The Ionosphere

The Earth’s atmosphere is divided into several altitude regions, where is

defined by the neutral temperature gradients. The lowest region in the Earth’s

atmosphere is the troposphere with 10 km distance from the surface and containing

about 75% of the total mass of the atmosphere. The upper atmosphere and the

ionosphere are important because they are absorbing the dangerous solar radiation

before it reaches the surface. As shows as figure 2.1, from 60 to 1000 km is the

region of the atmosphere where sufficient number of ions and free electrons is are

exist to effect the propagation of radio waves [6].

8

Figure 2.1: Atmospheric Layers [6].

The earth’s ionosphere strongly ionised at approximately 90 km. The

electrons release the gas molecules and resulting in ions. The plasma is containing

the number of positive ions and the negative particles, which is the most common

state of the universe. Below the 200 km is represent by the molecular oxygen (O2)

and nitrogen (N2), while above the 200 km is represent by the atomic oxygen (O) and

above the 600 km altitude is referring to hydrogen (H) and Helium (He). The

ionosphere can carry electrical currents as well as reflect, deflect and scatter radio

waves. [7].

comparison of theoretical total electron content …

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