CONTRAST OF CRESCENT MOON IMAGE WITH DSLR CAMERA: MEASUREMENT AND MODELING

• Main Author: Hasan Faadillah, M.
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71892
• Institution: Institut Teknologi Bandung

The observation of the hilal (young crescent moon) is identical to the determination of the beginning of the Hijri calendar. Currently, hilal observation is expanding to various interested groups using instruments that are easily obtained and widely available on the market. The use of portable telescopes and DSLR cameras is one configuration that is often chosen. The hilal observation is usually practiced at twilight, where the moon has similar brightness to the brightness of the background sky. Some theoretical models of the visibility of celestial objects at twilight, including the crescent moon, have been developed by several researchers. This provides an opportunity to study the contrast of crescent moon images, and test the models with more data. In this study, we present an alternative method of processing crescent images from DSLR cameras (in each of the Red, Green, and Blue channels) to measure the brightness of the moon and the brightness of the background sky. Both brightnesses are then used to determine the observed hilal contrast value (????????????????), with the definition of Sultan (2006). The observed contrast values (????????????????) and the theoretical model (???????????????? ) are fitted by finding the best parameter values in the theoretical model. The best parameter values are used to construct the crescent image contrast limit model.