Global Positioning System (GPS)
The United States Department of Defense designed the Global Positioning System (GPS) for the first time in 1978 and today, it has evolved to become an important navigational tool employed in map designing, navigation and land surveying among others. It is estimated that the approximate annual outlay of the United States government is 750 million US dollars for the maintenance and upkeep of the system. In spite of the exorbitant costs involved, GPS services are available to all residents, free of cost.
Defining GPS and its mode of functioning
Although the name of Global Positioning System is familiar to almost all of us, its exact features and functions might not be clear to all. It is nothing but a group of satellites, which convey signals to receivers, from which the direction, position, and speed of the receiver can be easily gauged.
At present, more than two dozen satellites revolve round the earth. The three main sections of the GPS are those pertaining to the space, the control and the users.
The space segment GPS satellites are those which transmits signals to receivers to find the various parameters of the receiver like location, direction etc. These satellites are equally dispersed along the six orbital planes, with their centers on the earth. Every satellite completes two full orbits each day and crosses the same point on earth once every day.
Keeping an eye of these flight paths is done by the control segment; and the various stations based in Colorado, Kwaialein, Hawaii, Ascension Island, and Diego Garcia do the tracking. The navigational updates given from these locations offer the time and space weather data to these GPS satellites.
The user segments receive the system signals transmitted in various formats using an antenna. The number of channels of the GPS receivers denotes the number of satellites transmitting signals to them. The contemporary receivers are capable of receiving anything from five to twenty-five channels at a time. Most of the receivers have the capabilities to transmit signals to personal computers and cars.
What are the uses of the Global Positioning System?
The GPS is made use of in many practical applications such as in nuclear detonation detectors and for targeting weapons in military. It is also widely used in airplanes, cars, and boats apart from adventure sports like hiking and biking, as a navigational tool.
In addition, GPS information is also widely employed in many activities like mapping, land surveying, tracking, archeology, emergency services, weather prediction, and skydiving apart from catering to the specific navigational needs of the visually impaired users.
Global Positioning System technology has indeed come a long way since its origin, way back in 1978 with the launch of the first experimental satellite and will remain an important navigational tool for many future generations to come.