# Global Positioning System Essay

1521 Words7 Pages
Global Positioning System Wouldn’t it be great if you could be sure that you would never be lost again? That you would know exactly where you were at all times, whether at land, air, or sea. Well, that is possible with modern technology. More specifically, that is possible with the help of GPS, the Global Positioning System. GPS is a navigational tool that has recently become extremely popular because of it wide range of uses. Whether you are a fisherman or an avid traveler, you could find some use for GPS. And with GPS becoming more and more affordable, it won’t belong until everyone is using it. The Global Positioning System (GPS) was developed by the US Department of Defense in hopes of providing the military with a…show more content…
After taking a third measurement and a third sphere is imagined, the possible points are then narrowed down to only two. These are the two points in which all three spheres intersect. In most cases, one of the points can be immediately thrown out because it is an unreasonable answer. That leaves only the correct position. In order to measure the distance of the satellites, GPS receivers measure the time it takes for radio signals sent from the satellite to reach the base station on Earth. Once we have the precise time it takes we can plug that number into a simple equation and we have our answer. Speed of light * the precise time = Distance of the Satellite The speed of light is the easy part; it is 186,000 miles per hour. It is measuring the precise time that is so difficult. To solve this problem, something called the Pseudo Random Code (PRC) was developed. The PRC is a complicated sequence of “on” and “off” pulses that is given off by both the satellite and the base station. The PRC from both the satellite and the base station are played at the exact same time and are then compared. When played, the two PRCs will be slightly out of sync because one set of signals has to travel from the satellite in space. The time is measured on the basis of this sync ratio and the distance can then be calculated. The Global Positioning System (GPS) is used by an almost endless amount of people and professions. Although originally designed for