The Effect of the Installation Angle of the Sky Quality Meter on the Night Sky Brightness and the Beginning of the Fajr Prayer Time
DOI:
https://doi.org/10.12928/irip.v3i2.2074Keywords:
Fajr prayer time, Light pollution, Night sky brightness, Sky Quality MeterAbstract
Measuring the brightness of the night sky and determining the start of Fajr prayer times can be done using SQM. Observations were made at OIF UMSU with coordinates 3o 34' 55.06" N and 98o 43' 17.09" E. The sky brightness was measured using three SQMs mounted facing the zenith, eastern horizon, and western horizon. The night sky brightness values for SQM directed to the zenith, eastern horizon, and western horizon are 18.23 mpsas, 15.82 mpsas, and 15.47 mpsas. The beginning of fajr prayer time produced by SQM is after the beginning of fajr prayer time obtained using the Accurate Times concerning the Sun's altitude 18o below the horizon. The difference obtained by SQM directed to the zenith, eastern horizon, and western horizon is 29.5 minutes, 36.7 minutes, and 39.5 minutes. In other words, the beginning of Fajr prayer time used in Indonesia is earlier than it should be.References
[2] S. Hideaki, “Research on Light Pollution by Using a Sky Quality Meter,†Young Sci. J., vol. 6, no. 13, pp. 23–24, 2013.
[3] L. Nurfarida, P. M. Yusup, and N. Komariah, “Tingkat Pengetahuan Masyarakat Sekitar Observatorium Bosscha Lembang mengenai Polusi Cahaya,†J. Kaji. Inf. dan Perpust., vol. 5, no. 1, pp. 13–22, Sep. 2017.
[4] A. Z. Kotarba, S. Chacewicz, and E. Żmudzka, “Night Sky Photometry Over Warsaw (Poland) Evaluated Simultaneously with Surface-Based and Satellite-Based Cloud Observations,†J. Quant. Spectrosc. Radiat. Transf., vol. 235, pp. 95–107, Sep. 2019.
[5] S. Bará, “Anthropogenic Disruption of the Night Sky Darkness in Urban and Rural Areas,†R. Soc. Open Sci., vol. 3, no. 10, pp. 1–14, Oct. 2016.
[6] P. Cinzano, “Night Sky Photometry with Sky Quality Meter,†ISTIL Internal Report. pp. 1–14, 2005.
[7] N. F. Ngadiman, N. N. M. Shariff, and Z. S. Hamidi, “Sensor Technology for Night Sky Brightness Measurements in Malaysia,†Int. J. Recent Technol. Eng., vol. 8, no. 6, pp. 198–202, Mar. 2020.
[8] Y. Pramudya and M. Arkanuddin, “The Sky Brightness Measurement during the 2016 Solar Eclipse in Ternate,†J. Phys. Conf. Ser., vol. 771, no. 1, pp. 2–6, Nov. 2016.
[9] F. F. R. S. Hamdani and L. A. H. Noor, “The Dawn Sky Brightness Observations in the Preliminary Shubuh Prayer Time Determination,†QIJIS (Qudus Int. J. Islam. Stud., vol. 6, no. 1, pp. 25–37, Jul. 2018.
[10] A. Bertolo, R. Binotto, S. Ortolani, and S. Sapienza, “Measurements of Night Sky Brightness in the Veneto Region of Italy: Sky Quality Meter Network Results and Differential Photometry by Digital Single Lens Reflex,†J. Imaging, vol. 5, no. 56, pp. 1–13, May 2019.
[11] A. Hänel et al., “Measuring Night Sky Brightness: Methods and Challenges,†J. Quant. Spectrosc. Radiat. Transf., vol. 205, pp. 278–290, Jan. 2018.
[12] J. Zamorano et al., “Testing Sky Brightness Models Against Radial Dependency: A Dense Two Dimensional Survey Around the City of Madrid, Spain,†J. Quant. Spectrosc. Radiat. Transf., vol. 181, pp. 52–66, Sep. 2016.
[13] A. Y. Raisal, Y. Pramudya, O. Okimustava, and M. Muchlas, “Pemanfaatan Metode Moving Average dalam Menentukan Awal Waktu Salat Subuh Menggunakan Sky Quality Meter (SQM),†Al-Marshad J. Astron. Islam dan Ilmu-Ilmu Berkaitan, vol. 5, no. 1, pp. 1–13, 2019.
[14] S. A. M. Nor and M. Z. Zainuddin, “Sky Brightness for Determination of Fajr and Isha Prayer by Using Sky Quality Meter,†Int. J. Sci. Eng. Res, vol. 3, no. 8, pp. 132–134, 2012.
[15] A. Y. Raisal, Y. Pramudya, O. Okimustava, and M. Muchlas, “The moon phases influence on the beginning of astronomical dawn determination in Yogyakarta,†Int. J. Sci. Appl. Sci. Conf. Ser., vol. 2, no. 1, p. 1, 2017.
[16] I. Plauchu-Frayn et al., “Night sky brightness at San Pedro Martir observatory,†Publ. Astron. Soc. Pacific, vol. 129, no. 973, pp. 1–13, 2017.
Downloads
Published
Issue
Section
License
Authors who publish in IRiP agree to the following terms: Authors retain copyright and grant the IRiP right of first publication with the work simultaneously licensed under a Creative Commons Attribution License (CC BY-SA 4.0) that allows others to share (copy and redistribute the material in any medium or format) and adapt (remix, transform, and build upon the material) the work for any purpose, even commercially with an acknowledgment of the work's authorship and initial publication in IRiP. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in IRiP. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).