4.3 OTHER SOFTWARE PROGRAMS GLOBAL POSITIONING SYSTEM (GPS) In 2022, the was made up of 31 well-spaced satellites in orbit around the Earth. The satellites make it possible for people with ground receivers to their geographical location . The owner and operator of the GPS system is the US Department of Defense, but the system is made available for general use around the world. Global Positioning System (GPS) pinpoint 1 MORE The location accuracy varies, according to the equipment, from 10 to 100 metres. However, with militaryapproved equipment, the approximation can be reduced to 1 metre. 1 The Satellites In order to work properly, the GPS needs 24 satellites, each orbiting twice a day at an altitude of 12,550 miles, i.e. 20,200 km, above the Earth. However, in order to guarantee coverage during maintenance, there are 31 operational satellites in total. They are spaced in such a way as to that, from any point on Earth, four satellites will be above the horizon. Each satellite contains a computer, an atomic clock, and a radio. With an understanding of its own orbit and the help of the clock, the satellite continually its changing position in time. Moreover, each satellite checks its own sense of time and position with a ground station once a day and makes any minor corrections that may be necessary. ensure broadcasts The Receivers Any GPS receiver on the ground contains a computer that triangulates its own position by getting from three of the four satellites. The result of this is provided in the form of a geographic position expressed in longitude and latitude. If the receivers are also equipped with a display screen that shows maps, e.g. a smartphone or tablet, the position can be shown on a map. If a fourth satellite can be received, the receiver can also figure out the altitude as well as the geographical position. If the receiver is moving, it can also calculate the speed and direction and give estimated times of arrival at a specified destination. bearings triangulation Main Uses The main uses of GPS are in science. It provides data that has never been available before, as regards both quantity and accuracy. At the moment, it is being used to measure the movement of the arctic , the Earth’s tectonic plates, and volcanic activity. ice sheets However, as the cost has become relatively low, almost anyone can own a GPS receiver. Mobile GPS technology in smartphones enables end users to receive navigating instructions via a global positioning system process called . A built-in GPS receiver communicates with an array of satellites which provides navigation instructions. Smartphones can identify individual streets and places on maps and provide narrated tracking capability. trilateration