YOUNG LUNAR CRESCENT VISIBILITY PREDICTION ON TELESCOPIC–BASED VISUAL OBSERVATION (original) (raw)
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The aim of this research is to present a new criterion for earliest crescent visibility based on the brightness difference between the young crescent and its background sky at sunset. In this work, 141 and 52 of lunar crescent observations from Malaysia and Iran respectively has been studied and analyzed. The data collected consisted of visible and non-visible observation data (naked eye and optically aided). The results indicated that the Moon’s percentage illumination (or Moon’s phase) must be >= 0.52 % ± 0.10 % and >= 0.39 % ± 0.10 % for Malaysia and Iran respectively. The average sky brightness during sunset measured was 6.80 ± 1.13 magnitude/arcsecond^2
Sains Malaysiana
Many astronomers have studied lunar crescent visibility throughout history. Its importance is unquestionable, especially in determining the local Islamic calendar and the dates of important Islamic events. Different criteria have been used to predict the possible visibility of the crescent moon during the sighting process. However, so far, the visibility models used are based on linear statistical theory, whereas the useful variables in this study are in the circular unit. Hence, in this paper, we propose new visibility tests using the circular regression model, which will split the data into three visibility categories; visible to the unaided eye, may need optical aid and not visible. We formulate the procedure to separate the categories using the residuals of the fitted circular regression model. We apply the model on 254 observations collected at Baitul Hilal Teluk Kemang Malaysia, starting from March 2000 to date. We show that the visibility test developed based on elongation of the moon (dependent variable) and altitude of the moon (independent variable) gives the smallest misclassification rate. From the statistical analysis, we propose the elongation of the moon 7.28°, altitude of the moon of 3.33° and arc of vision of 3.74 at sunset as the new crescent visibility criteria. The new criteria have a significant impact on improving the chance of observing the crescent moon and in producing a more accurate Islamic calendar in Malaysia.
Application of Scientific Approach to Determine Lunar Crescent’s Visibility
Middle-East Journal of Scientific Research, 2012
Abstract: The visibility of lunar crescent has been explained in Islamic Law (fiqh) by previous scholars. Until today, the explanations which were nuance in qualitative sense are still provide vacuum and need to be studied critically with different method particularly in quantitative approach. Therefore, this paper will present the application of scientific approach using sky illumination measurement to explain lunar crescent's visibility. The approach combines computational and observational technique will help fiqh in ...
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Academia Letters, 2021
We observe the first visibility of the lunar crescent on the western horizon shortly after sunset, and it is the beginning of the month in the Islamic calendar. There are numerous techniques for predicting the day of the first sight of the Moon, but our interest is in the physical method, which began with the investigations of Samaha, Assad, and Mikhail (1969) and Bruin (1977). To predict when we will observe the first crescent Moon, we need: 1. The topocentric altitude of the Moon; azimuth difference between the centers of the Sun and the Moon (DZ); Sun depression (d); Earth-Moon distance and topocentric phase angle (or selenocentric angle between the observer's position and the center of the Sun). 2. The luminance of the Moon without atmospheric absorption for the phase angle; (we understand luminance as the luminous flux per unit of the luminous area perpendicular to the observation direction and per unit of solid angle). 3. The atmospheric extinction coefficient for the place of observation, which determines the luminance of the Moon Bm at the surface of the Earth. 4. The twilight sky luminance Bs, as a function of d and DZ. 5. The threshold contrast or the threshold illuminance for viewing the Moon in the twilight sky; (we define the contrast by C = Bm/Bs, and the illuminance is the luminous flux that reaches the observer per unit area normal to the observation direction). Photometric measurements of the Moon at large phase angle are difficult since its observation has to be made at a low altitude above the horizon and therefore, is highly affected by atmospheric attenuation; also, the observation has to be done with twilight light, therefore the Moon's own illumination is added to the illumination of the sky, and finally, it must be added
Predicting new crescent moon visibility applying machine learning algorithms
Scientific Reports, 2023
The world's population is projected to grow 32% in the coming years, and the number of Muslims is expected to grow by 70%-from 1.8 billion in 2015 to about 3 billion in 2060. Hijri is the Islamic calendar, also known as the lunar Hijri calendar, which consists of 12 lunar months, and it is tied to the Moon phases where a new crescent Moon marks the beginning of each month. Muslims use the Hijri calendar to determine important dates and religious events such as Ramadan, Haj, Muharram, etc. Till today, there is no consensus on deciding on the beginning of Ramadan month within the Muslim community. This is mainly due to the imprecise observations of the new crescent Moon in different locations. Artificial intelligence and its sub-field machine learning have shown great success in their application in several fields. In this paper, we propose the use of machine learning algorithms to help in determining the start of Ramadan month by predicting the visibility of the new crescent Moon. The results obtained from our experiments have shown very good accurate prediction and evaluation performance. The Random Forest and Support Vector Machine classifiers have provided promising results compared to other classifiers considered in this study in predicting the visibility of the new Moon. Islam is considered the second religion in the world. Hijri is the Islamic calendar, also known as the lunar Hijri calendar. This is because each month starts in the Hijri calendar when the new crescent Moon is first sighted after the birth of a new Moon. Although almost all countries in the world use the Gregorian calendar for easy communication, The Hijri calendar is used by Muslim countries and Muslims, in general, across the world when it comes to religious events. Ramadan is among the holy months for Muslims. Deciding on the start of Ramadan has always been a challenging mission, and as a result, not all Muslims start Ramadan synchronously. The main reason is due to the reliance on individuals' observations of the new crescent Moon which depends on several factors that affect the final results, such as the tools used for Moon observation, sky status whether clear or cloudy, the location from where the observation is conducted, the proficiency of the observers, etc. Furthermore, with technological advancement, there are controversial opinions on whether to use the eye sighting of the new crescent Moon or astronomical calculation methods. The problem becomes even more serious given the number of Muslims worldwide who, each time Ramadan approaches, wait for the announcement of the first day of Ramadan. The latter is the ninth month in the Hijri calendar, and during this month, Muslim fast from before Sunrise till Sunset. Additionally, there is a need for a consensus on that day among all Muslims in the world. According to 1 and 2 , and as indicated in Fig. 1 3 , there are about 50 countries in the world where the majority of the population is Muslim. There are approximately 30 Muslim-populated countries around the world, with more than 90% of the population of Islam. In 20 other countries, 50% to 80% of Muslim populations live in the country. In 26 countries, Islam is a national religion under the state constitution 4. Each year and at the end of the eighth month (Sha'ban), Muslims across the world put lots of effort and utilize different instruments such as telescopes and binoculars, astronomy, or the naked-eyes, to observe the visibility of the new crescent Moon in order to confirm the start of the holy month of Ramadan. Most of the time, it is difficult to predict the start of the month in advance, resulting in a division between Muslims fasting on different dates. The new crescent Moon has always been a matter of attention since the early decades of Islamic astronomers. Predicting the visibility of the birth of the new Moon from a given location on earth is still a challenging problem for many astronomers and mathematicians 5. In the second half of the first century 2,6 , The priest and astronomer of Babylon developed sophisticated numerical algorithms to predict the motion of the Moon, such as the times of synodic phases and the first visibility of the new crescent Moon above the western horizon just after the Sunset 5. Later, multiple religious scholars developed more precise methods that are now refined 5 .
The Impact of Light Pollution on Islamic New Moon (hilal) Observation
International Journal of Sustainable Lighting
Muslims has differentiated between new moon and Islamic new moon (hilal). The determination of first day of months based on visibility of Islamic new moon (hilal) i.e. sightings of the first sliver of the waxing moon marking the start of each month. One major issue that has affected hilal visibility for many years is misdirected, excessive and obtrusive artificial light. The objective of this research is to study the impact of light pollution on the visibility of hilal. The data were taken using Sky Quality Meter (SQM) which records the visual magnitudes per square arcsecond (mpsas) to measure sky limiting magnitude. Result showed that reading between 16-22 mpsas, the chances to witness hilal is high. Any lower than 16mpsas, the hilal is not visible. The main result of this research is to find out a vital parameter of hilal observations which leads to propose a new criterion i.e. sky limiting magnitude.
Predicting the Visibility of the First Crescent
KIET Journal of Computing and Information Sciences, 2018
This study presents an application of machine learning to predict whether the first crescent of the lunar month will be visible to naked eye on a given date. The study presents a dataset of successful and unsuccessful attempts to find the first crescent at the start of the lunar month. Previously, this problem was solved by analytically deriving the equations for visibility parameter(s) and manually fixing threshold values. However, we applied supervised machine learning on the independent variables of the problem, and the system learnt about the criteria of classification. The system gives precision of 0.88 and recall of 0.87 and hence it treats both false positives and false negatives equally well.
The Extended Crescent Visibility Criterion
2017
Crescent visibility has been a concern for determining the start of any lunar month. Various criteria have been offered by the astronomers since the Babylonians. The indigenous criterion proposed in this paper uses the two reliable parameters, altitude and crescent width, and makes it possible to estimate the visibility for any phase of the Moon, not just limited to thin crescents. Though very simple, the algorithm presented here produces rather consistent results. Various visibility graphs are included. In addition is introduced a tool for demonstration.
Islamic Historical Review on Middle Age Lunar Crescent Visibility Criterion
Journal of Al-Tamaddun
Middle Age lunar crescent visibility criterion is criterion that was produced during 8th until 17th century. This includes al-Khawarizmi lunar crescent visibility criterion in 8th century until al-Lathiqi lunar crescent visibility criterion in 17th century. Numbers of review on mathematics and astronomy during the Middle Age, however the number of review that specifically written for Middle Age lunar crescent visibility criterion limited, with majority of review is written to study the historical of Middle Age science, astronomy, mathematics and geography as a whole, and not converge on lunar crescent visibility criterion. . Therefore, this article aimed to provide a review on Middle Age lunar crescent visibility criterion. The review is conducted using literature analysis, snowball literature search and specific inclusion and exclusion criteria. The review is performed based on 13 works on lunar crescent visibility criterion that pass the selection criteria. The review found out th...