Investigation of the variation of maximum usable frequency (MUF)‎ to ensure a good communications link between two locations

Other Title(s)

(MUF)‎ التحقيق في اختلاف التردد الأعلى القابل للاستخدام لضمان اتصالات جيدة بين موقعين

Dissertant

Muhammad, Muhammad Ujayl

Thesis advisor

al-Ubaydi, Najah Muhammad Rashid

Comitee Members

Abbud, Kamal Muhammad
al-Jabburi, Munim Hakim Khalaf
Karam, Nihad Ali

University

University of Baghdad

Faculty

College of Science

Department

Astronomy and Space Department

University Country

Iraq

Degree

Master

Degree Date

2011

English Abstract

In this research, an effort was made to investigate the dependence of the variation Maximum Usable Frequency (MUF) for F2-layer of the ionosphere with solar activity over different local time, different seasons and latitudes and comparison with predicted MUF using IRI-2007 model.

The database of observed MUFObs.

in mid-latitude region for four Japanese stations, Wakkanai (45.4° N 141.7° E), Kokubunji (35.7° N 139.5° E), Yamagawa (31.2° N 130.6° E) and Okinawa (26.3° N 127.8° E), at Asian sector, where used in this study.

The data which are received from selected stations are covered (424) months over the period (2000-2009), during a wide range of solar activity.

From data analysis, it was revealed that there is a good correlation between observed and predicted MUF all over the day, the month, all the years, and all the stations selected except 2002 there is a bad correlation especially in winter and day time.

The season variation, winter (January, February, November and December), summer (May, June, July and August) and equinox (March, April, September and October), the Summer season indicated the best agreement months due to the curved of Total Electron Content (TEC) fluctuates relatively little during those months.

For the yearly variation it is dependent on the 12- months average of the sunspot (R12), it shows that best agreement over ten years was in 2005 for four stations in terms of root mean square error (r.m.s.e) (an average r.m.s.e = 1.825535) this corresponding the low SSN (R12=29.78), but the year 2002 SSN (R12=104.09) and an average r.m.s.e (2.443448) has the worst correlation between predicted and observed values.

From these study one concludes that the Kokubunji station (35.7° N, 139.5° E), which is reveals best correlation between observed and predicted values, this station is one of the closest latitude for Iraq, this supports that the IRI model can be used successfully in the Iraqi cities (Baghdad 33.35°N, 44.38°E, Basrah 30.5°N, 47.78°E and Irbil 36.18° N, 44.52°E), during different phases of the solar activity from cycle 23 years (2001, 2003, 2005 and 2009).

In general we can conclude that the MUF is high in midday and low in the night, because the ionization due to X-ray and UV radiation from the Sun which increases the critical frequency foF2 and leads to increasing the MUF.

In winter the MUF values are higher than summer due to winter anomaly.

The variation between day and night MUF values are greater in winter than in summer because the ionization in summer remains after noon so the electron density is mostly high which leads to high foF2 then high MUF.

There is an inversely proportion between the observed and predicted MUF with latitude in Noontime (hour 12) and Sunset (18 LT), but there is no variation with latitude in Sunrise (06 LT).

Main Subjects

Astronomy

No. of Pages

138

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-603858