INTRODUCTION Muslims around the world share the same fundamental practice of performing five prayers a day. The five prayers (fajr, zuhur, asar, maghrib, and isha) are speard around the 24 hours based on astronomical position of the sun. Prayers' times are determined using length of the shadow and start and end of twilight (light from sky when sun is below horizon especially in the evening) (Cooper, 1969) . Therefore, prayer times are not the same from one place to another depending on observers' longitude and latitude. Prayers are usually headed by call for prayer known as Athan. This study will employ GPS to help determine accurate prayer time while traveling across the world. Large number of civilian applications benefits from GPS signals. The ability to determine the receiver's location allows GPS receivers to perform as an aid to navigation. This study will add one more GPS civilian application that will help determining prayer time for Muslim travelers while onboard an airplane. The GPS receiver will be used to periodically determine the latitude, longitude and elevation of the location of the aircraft. It will communicate with the GPS and based on the time and location, it will update and display the upcoming prayer time. PURPOSE OF THE STUDY Large number of airplanes travels the world carrying Muslim onboard every day. Plains owned by Muslim countries provide direction for the Kaabah in Mecca, where Muslims should face while making prayers. However, none of which tells travelers when it is time to say prayers while traveling around the globe. Traveling Muslims usually estimate prayer times while onboard of an airplane based their best judgment. Computing appliances have been developed for businesses, students, games for all ages, and for the disabled (McMurtrey, McGaughey, & Downey, 2008). The same computing power can be used to design and develop applications can benefits from GPS signals, to provide a fully automated and accurate prayer time while in motion. Millions of traveling Muslims will benefit from this service. GLOBAL POSITIONING SYSTEM AND CIVILIAN APPLICATIONS The Global Positioning System GPS, while originally a military project has significant applications for both the military and the civilian industry. Concerning military applications, GPS allows accurate targeting of various military weapons such as precision-guided missiles. It is also used to navigate and coordinate the movement of troops and supplies. [FIGURE 1 OMITTED] GPS OVERVIEW The Global Positioning System (GPS) is a U.S. space-based radio navigation system based on a constellation of about 28 satellites (Diggelen & Abraham, 2001) orbiting the earth at altitudes of approximately 12,000 miles (McNamara, 2004). GPS was developed by the United States Department of Defense (DOD), for its tremendous application as a military locating utility. The system provides location and time information in all weather, day and night, anywhere in the world. GPS is made up of three parts: satellites orbiting the Earth; control and monitoring stations on Earth; and the GPS receivers owned by users (see figure 1). A satellite has three key pieces of hardware: 1) Computer that controls its flight among other functions; 2) A clock that keeps accurate time within three nanoseconds; and 3) A radio transmitter that sends signals to Earth. The signals broadcasted by the GPS satellites are picked up and identified by GPS receivers. Each GPS receiver then provides three-dimensional location (latitude, longitude, and altitude) plus the time. GPS has become a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, and scientific uses. GPS also provides a precise time reference which makes it perfect reference for prayer time. Many GPS receivers can relay position data to a PC or other device using the NMEA 0183 protocol (Mihai, 2004). …