Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity

Wireless radio in the HF band still uses the ionospheric layer as the main medium for communication. Critical frequencies are important parameters of the ionosphere. Due to the activities of the sun, the critical frequency varies diurnally, following the pattern of day and night. The critical fre...

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Main Author:	Abdullah, Sabirin
Format:	Thesis
Language:	English English English
Published:	2011
Subjects:	HC94-1085 By region or country
Online Access:	http://eprints.uthm.edu.my/2951/1/24p%20SABIRIN%20ABDULLAH.pdf http://eprints.uthm.edu.my/2951/2/SABIRIN%20ABDULLAH%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/2951/3/SABIRIN%20ABDULLAH%20WATERMARK.pdf
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id	my-uthm-ep.2951
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spelling	my-uthm-ep.29512021-11-02T00:54:21Z Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity 2011-06 Abdullah, Sabirin HC94-1085 By region or country Wireless radio in the HF band still uses the ionospheric layer as the main medium for communication. Critical frequencies are important parameters of the ionosphere. Due to the activities of the sun, the critical frequency varies diurnally, following the pattern of day and night. The critical frequency for the Parit Raja station is determined using an ionosonde at latitude 1° 52' N and longitude 103° 48' E which is close to the geomagnetic equator at geographic latitude 5° N. This work analyses the dependence of the critical frequency during the solar minimum of Solar Cycle 23. The median critical frequency value is used to develop a model using regression and polynomial approaches because it is more accurate than using average values. From the observations, the critical frequency observed in 2005 is the highest, corresponding to a higher sunspot number of between 11 and 192. In contrast, the critical frequency is lower in 2007 due to the decrease in the sunspot number of between 11 to 63. The general trend of the daily critical frequency is 6.8 MHz to 12.0 MHz from 00:00 to 17:30 UTC and decreasing to 7.0 MHz from 18:00 to 23:00 UTC. The average value of the critical frequency for 2005 to 2007 is 7.5 MHz, with a minimum of 1.8 MHz and a maximum of 11.0 MHz. In addition, the daily observed virtual height for the F-layer is 200 to 480 km except during the months of January, February, November and December, during which it is much higher up to 550 km. The Parit Raja model showed good agreement for the 3rd degree polynomial fitted between the measured values. This model can be used as a reference ionospheric profile over southern Malaysia. 2011-06 Thesis http://eprints.uthm.edu.my/2951/ http://eprints.uthm.edu.my/2951/1/24p%20SABIRIN%20ABDULLAH.pdf text en public http://eprints.uthm.edu.my/2951/2/SABIRIN%20ABDULLAH%20COPYRIGHT%20DECLARATION.pdf text en staffonly http://eprints.uthm.edu.my/2951/3/SABIRIN%20ABDULLAH%20WATERMARK.pdf text en validuser mphil masters Universiti Tun Hussein Malaysia Fakulti Kejuruteraan Elektrik dan Elektronik
institution	Universiti Tun Hussein Onn Malaysia
collection	UTHM Institutional Repository
language	English English English
topic	HC94-1085 By region or country
spellingShingle	HC94-1085 By region or country Abdullah, Sabirin Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity
description	Wireless radio in the HF band still uses the ionospheric layer as the main medium for communication. Critical frequencies are important parameters of the ionosphere. Due to the activities of the sun, the critical frequency varies diurnally, following the pattern of day and night. The critical frequency for the Parit Raja station is determined using an ionosonde at latitude 1° 52' N and longitude 103° 48' E which is close to the geomagnetic equator at geographic latitude 5° N. This work analyses the dependence of the critical frequency during the solar minimum of Solar Cycle 23. The median critical frequency value is used to develop a model using regression and polynomial approaches because it is more accurate than using average values. From the observations, the critical frequency observed in 2005 is the highest, corresponding to a higher sunspot number of between 11 and 192. In contrast, the critical frequency is lower in 2007 due to the decrease in the sunspot number of between 11 to 63. The general trend of the daily critical frequency is 6.8 MHz to 12.0 MHz from 00:00 to 17:30 UTC and decreasing to 7.0 MHz from 18:00 to 23:00 UTC. The average value of the critical frequency for 2005 to 2007 is 7.5 MHz, with a minimum of 1.8 MHz and a maximum of 11.0 MHz. In addition, the daily observed virtual height for the F-layer is 200 to 480 km except during the months of January, February, November and December, during which it is much higher up to 550 km. The Parit Raja model showed good agreement for the 3rd degree polynomial fitted between the measured values. This model can be used as a reference ionospheric profile over southern Malaysia.
format	Thesis
qualification_name	Master of Philosophy (M.Phil.)
qualification_level	Master's degree
author	Abdullah, Sabirin
author_facet	Abdullah, Sabirin
author_sort	Abdullah, Sabirin
title	Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity
title_short	Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity
title_full	Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity
title_fullStr	Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity
title_full_unstemmed	Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity
title_sort	observations of f-region critical frequency variation over batu pahat, malaysia during low solar activity
granting_institution	Universiti Tun Hussein Malaysia
granting_department	Fakulti Kejuruteraan Elektrik dan Elektronik
publishDate	2011
url	http://eprints.uthm.edu.my/2951/1/24p%20SABIRIN%20ABDULLAH.pdf http://eprints.uthm.edu.my/2951/2/SABIRIN%20ABDULLAH%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/2951/3/SABIRIN%20ABDULLAH%20WATERMARK.pdf
_version_	1747831000266702848

Observations of f-region critical frequency variation over Batu Pahat, Malaysia during low solar activity

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