Origins, Operation, and Global Navigation Networks

With a click of a button on your phone, you can find where you are in the world with near-pinpoint accuracy. A magic-like thing that has recently come into reality is not a miracle, but the most common system used today for navigation and much more. This is the Global Positioning System which is known as GPS. The global positioning system (GPS) – originally known as Navstar GPS – was a project by the US Department of Defense, with its first satellite launched in 1978. Today, GPS is still operated by the US Space Force but is free for civilian use worldwide. GPS is a global navigation satellite system (GNSS). There are altogether four global GNSS systems developed by several countries such as US, Russia, EU, and China. In addition, there are two regional systems from Japan and India. The GPS is composed of three main parts – space segment, control segment, and user segment. The space segment comprises 31 operational satellites that send data signals to Earth. The control segment includes the people and computers in all the continents that monitor and control the satellites. The user segment is the GPS receiver on Earth. Basically, most receivers contain three components –an antenna that receives the signal and, in some cases, has antijamming potential, a receiver-processor unit that converts the radio signal to a functional navigation solution, and a control/display unit that displays the positioning information. Some GPS receivers are accurate enough to pinpoint their location within one centimeter (0.4 inches). GPS receivers provide location in latitude, longitude, and altitude. They provide accurate time as well. As of 2022, a series of 31 GPS satellites fly in circular orbits at an altitude of 10,900 nautical miles (20,200 km) and with a period of 12 hours for a full orbit of Earth, constantly sending out radio signals. The orbits are slanted to the earth’s equator by 55 degrees to ensure coverage of Polar Regions. With its main functions of locating, navigating, tracking and mapping, GPS is categorized into three, depending on users and purpose: personal, commercial and military. The personal GPS is the most common type of receiver used around the world. It eases and simplifies our daily routines, for example, finding paths or a nearest shop, tracking a stolen phone, etc. Surveyors, scientists, weather forecasters, pilots, drivers, boat captains, and those who work in mining and agriculture, are just some of the people who use GPS on a daily basis. The commercial GPS is used by companies and businesses, especially delivery companies. GPS tracking enables businesses to offer better customer service by providing accurate delivery or service (ETA or estimated time of arrival), ensuring timely responses to customer needs, and improving their overall service quality. The military GPS navigates, guides, tracks and monitors forces, enemy troops, military assets, and missiles. The military GPS usually helps the army to pinpoint locations for air raids and military operations. As a geographical tool, GPS is used for mapping, physical geography and human geography by accurately locating and illustrating the Earth’s physical features, and changes and patterns in the Earth’s environment. Moreover, it is valuable for emergency cases to track the emergency personnel and to get timely aid during tough periods, and in disaster relief efforts as early warning for earthquakes. Concerning health and fitness, wearable technology like smart watches tracks your physical activity like running. Similarly, GPS tracking is useful in live games such as Pokémon Go. Though there are occasional obstacles - namely gravity, Earth’s atmosphere, trees, buildings, and other structures to getting a clear GPS signal, technologies have improved anti jamming capabilities and reduced attenuation, too. GPS also needs no connection to the internet, cellular data, Wi-Fi, or Bluetooth radio. This applies to both Android and iOS devices. Some types of GPS tracker are with/ without SIM cards. Due to its versatility, GPS is more and more popular around the world; it works 24/7 regardless of weather and location, and without subscription fees or setup charges except the need to replace batteries frequently. As a result, GPS has become an essential tool for a wide range of applications for our increasingly connected world, and the prospect of it appears to be virtually infinite; with thriving technological fantasies.