Long before Global Positioning System (GPS) arrived, researchers worked hard to arrive at a feasible solution to aid travellers from getting lost. Earlier, travellers used to rely on elaborate maps to track and monitor the route to their destination. But today, GPS technology has ensured hassle – free trips and increased safety for vehicle owners. The figure below illustrates a GPS satellite in orbit.
GPS technology became a reality through the efforts of the American military, which established a satellite-based navigation system consisting of a network of 24 satellites orbiting the earth. GPS is also known as the NAVSTAR (Navigation System for Timing and Ranging).
GPS works all across the world and in all weather conditions, thus helping users track locations, objects, and even individuals! GPS technology can be used by any person if they have a GPS receiver.
This technique was initially developed for military applications. During 1980, the government decided to make it available for the civilian use as well. GPS has become an efficient tool in the field of scientific use, commerce, surveillance and tracking. GPS is used except in locations where it is difficult to detect the signal for example, underwater, subterranean location, inside the building and caves.
· Navigation – Used by navigators for orientation and precise velocity measurements.
· Geotagging – Map overlays can be created by applying location coordinates to photographs and other kind of documents.
· Surveying – Surveyors create maps and verify the boundaries of the property.
· Map-making – Used by civilians and military cartographers.
· Tectonics – Detect the direct false motion measurement in earthquakes.
· Geofencing – Vehicle, person or pet can be detected by using GPS vehicle tracking system, person tracking systems, and pet tracking systems.
· Navigation – Soldiers can find objectives in the dark and unknown regions with the help of GPS.
· Search and Rescue – Knowing the position of a downed pilot, its location can be traced out easily.
· Reconnaissance – Patrol movement can be handled.
· Target tracking – Military weapon systems use GPS to track air targets and potential ground before they are flagged as hostile.
· GPS carry a set of nuclear detonation detectors (such as optical sensor, dosimeter, electromagnetic pulse sensor, X-ray sensor) which is a part of United States Nuclear Detonation Detection System.
· Missile and projectile guidance – Targets military weapons such as cruise missiles, precision – guided munitions.
Structure of GPS
The GPS system comprises of three parts: Space segment, User segment and Control segment. The diagram of the structure of GPS is given below.
· Space segment – The satellites are the heart of the Global positioning system which helps to locate the position by broadcasting the signal used by the receiver. The signals are blocked when they travel through buildings, mountains, and people. To calculate the position, the signals of four satellites should be locked. You need to keep moving around to get clear reception.
· User segment – This segment includes military and civilian users. It comprises of a sensitive receiver which can detect signals (power of the signal to be less than a quadrillionth power of a light bulb) and a computer to convert the data into useful information. GPS receiver helps to locate your own position but disallows you being tracked by someone else.
· Control segment – This helps the entire system to work efficiently. It is essential that the transmission signals have to be updated and the satellites should be kept in their appropriate orbits.