HOW THEY WORK : “How the (GPS) Global Positioning System Work”

Now days, we normally come across the acronym “GPS” in many aspects of our daily lives! This term in full stands for “Global Positioning System”. The GPS was developed by the United States of America (USA). During its inception, it was more or less a NASA (the US National Space Agency) thing. This evolved around the “Global Navigation Satellite System). It was intended to provide accurate and reliable positioning, navigation, and timing services to NASA in their space technology. These days, it has been released to civilian use worldwide though it remains an American system. In recent years, Europe has decided to develop its own parallel system that will be known as GALILEO (named after the historical Italian Astronomer). The GPS system comprises a number of satellites orbiting the earth; these satellites constantly relay information to planet earth. GPS is made up of three segments: Space, Control and User. The Space Segment is composed of 24 to 32 satellites in Medium Earth Orbit and also includes the boosters required to launch them into orbit. The Control Segment is composed of a Master Control Station, an Alternate Master Control Station, and a host of dedicated and shared Ground Antennas and Monitor Stations. The User Segment is composed of hundreds of thousands of U.S. and allied military users of the secure GPS Precise Positioning Service and tens of millions of civil, commercial and scientific users of the Standard Positioning Service. GPS satellites broadcast signals from space that GPS receivers use to provide three-dimensional location (latitude, longitude, and altitude) plus precise time. With this, one is able to know his coordinates in terms and Latitudes and longitudes (how Far East or west away from the Equator and how north or south away from GMT, plus how far or near the person is in proximity to the ground and sea level). To be precise, at the time or writing this article, I checked out my phone’s GPS and it said that, my location was S1⁰ 59.1611’ E30⁰ 6.3564’. GPS has become a commonly used navigation tool worldwide. In fact, so many large cities have had their entire road network maps embedded into GPS systems. Such GPS maps are used by motorists to manoeuvre their way in very big and confusing cities. All one has to do is plug in a location and the GPS handset will trace the physical location and lead you to the address. If you have ever used “Google Maps”, this is an example of what GPS maps look like. The only difference is that, the free “Google Maps” version will not give you the latest maps and may be inaccurate. Apart from the road maps, you are able to get useful tools for map-making, land surveying, commerce, scientific uses, tracking and surveillance. GPS is used in many applications including the scientific study of earthquakes and as a time synchronization source for cellular network protocols. By the way, when positioning communication devices like Cellular phone antennas, they use GPS to tell and position the antennas such that, they can point one (with exact accuracy) in the direction of another. In cases of land survey, you are able to capture the size and shape of a piece of land by simply moving around it as the GPS system maps the various points. GPS has become a basis of transportation systems worldwide, providing navigation for the Aviation industry, ground, and marine operations. A pilot is able to tell his exact location and make a decision of what direction to navigate his Aircraft or ship, thanks to GPS. There is a variety of very many more application to which GPS may effectively be put to. eddie@afrowebs.com