Fazili Anuar Md Yusuf

Bahagian Ukur dan Pemetaan,

Institut Tanah dan Ukur Negara, Behrang Ulu, 35950 Perak, Malaysia

Norziana Yusuf

Universiti Teknologi Malaysia, Faculty of Built Environment and Surveying, Department of Geoinformation, Johor Bahru, 81300 Johor Malaysia

Othman Zainon

Universiti Teknologi Malaysia, Faculty of Built Environment and Surveying, Department of Geoinformation, Johor Bahru, 81300 Johor Malaysia

Keywords: Time, Theodolite, Sky Quality Meter, Determining, Fajr

ABSTRACT

It is important for Muslims to determine the time of fajr prayer since it is one of the pillars. However, it is still challenging to start the fajr prayer due to the position of the sun that is below the horizon. To determine the time of Dhuhr, Asr and Maghrib prayer is easy since the object and shadow of the sun can be seen clearly. The position of the sun is determined by the solar angle. The value is positive (+) when the sun is positioned at the north of the celestial equator and negative (-) when it is at the south of the celestial equator. Fajr time is determined by the brightness level of the sky at the eastern horizon. Thus, this research conducted to ensure that the time to start and end at the astronomical twilight is the same theoretically. Astronomical twilight determines the start and the end of Fajr and Isha prayers time. The combination of theodolite and Sky Quality Meter (SQM) has been used to determine the sky’s brightness during dawn. The theodolite is used to establish the vertical angle of the instrument while the SQM is used to record the sky brightness data at the time of observation. Early research has been conducted at Balai Cerapan, Universiti Teknologi Malaysia. Finding has shown that the combination of theodolite and SQM has been the potential and can be used to observe the brightness level of the sky. The SQM readings were taken at 2 minutes intervals. The findings has shown that the darkest site reading can be detected at a value of less than 20 magnitud second in the morning. The SQM reading values are compared with the sun elevation value which is the condition to determine the start of the Fajr prayer.