For centuries, explorers, as well as navigators, have started to develop a system to allow them to situate their location on the sphere with the accuracy to keep away from tragedy as well as to arrive at their destinations. In the year 1993, June 26, the U.S. Air Force was launched into orbit namely the 24th Navstar, completing a 24 satellite network is called the GPS or Global Positioning System. By using this system, one can discover the values of longitude, latitude, and also altitude values in a hundred feet distance. At present, this technology is used for different purposes like saving lives, assisting civilization in different ways & using this technology in multinational companies.
What is GPS?
The term GPS stands for Global Positioning System and it is one kind of satellite system used for global navigation by providing velocity, location as well as synchronization of time. At present, GPS is used in everywhere like Cars, Watches, Smartphones which assists in getting the location of where you want to go. This service is owned by the U.S and they provide different services to the operators like navigation, timing services & positioning.
This navigation system uses satellites, algorithms & a receiver to synchronize position, time, and velocity data for sea, land travel, and air. This satellite system includes a group of 24 satellites within 6 Earth-centered orbital planes, where each orbit plane is with 4 satellites that rotate at 13,000 miles above Earth & moves at a 14,000 km/h speed.
Whenever we need 3 satellites simply to generate a location on the surface of Earth, then a fourth satellite can be frequently used for validating the data from the remaining three satellites.The fourth satellite moves us into the 3rd dimension to measure the height of a device.
The four global navigation systems of the Global Positioning System (GPS) are GPS (US), Galileo (EU), GLONASS (Russia), and BeiDou (China). Also, there are two regional systems like NavIC (India) or IRNSS, and QZSS (Japan).
Segments or Elements of GPS
The GPS includes three segments like space, control, and user segment where these segments work together for providing the information of an exact location. These three segments can be developed, maintained, and operated by the US Air Force.
These three segments are discussed below.
The space segment of GPS mainly includes a group of satellites that transmits radio signals to the operators. A country like the US is committed to maintaining the accessibility of a minimum of 24 working GPS satellites. To make sure of this promise, the Air Force of the US has been flying 31 working GPS satellites for the past many years. When the satellite rotating around the earth, then the signals can be transmitted to operators based on the time as well as the position of the day.
This segment includes different stations based on earth, ground antenna as well as master control stations. The control activities mainly comprise tracking as well as monitoring and operating of satellites in space. There are different monitoring stations around the world like Asia, South America, North America, Australia, Europe, etc.
This segment includes a global network that is used to track the satellites, check their transmissions & to send data and commands to the constellation.
The present OCS or Operational Control Segment mainly includes a master control station, an alternate station, command as well as control antennas -11 and finally monitoring sites-16.
The user segment mainly includes different GPS receiver devices to get the signals from the satellites to use the transmitted data to measure the three-dimensional time as well as the position of the user.
How does GPS Work?
On the earth, there is a minimum of 4 GPS satellites will be available around the receiver. Every GPS satellite will send the data regarding its exact time as well as position to the receiver of the GPS receiver in a fixed time. This data can be transmitted toward the receiver in a signal form, after that the signal can be intercepted through the devices of the receiver.
These radio signals travel equal to the light speed. The distance among the satellite as well as a GPS receiver can be measured by discovering the dissimilarity between the time of the signal which was transmitted from the GPS satellite as well as the time of the signal received by the GPS receiver.
When the receiver of the device gets the signal from a minimum of three satellites, then the receiver locates its location through the trilateration procedure. The technique used in the GPS to work is “trilateration”, used to measure the exact location, altitude, and speed where trilateration gathers signals from different satellites to generate the location information. It is frequently wrong for triangulation because it is used to measure angles but not distances.
A GPS needs a minimum of 3 satellites to measure 2D position. In this case, the GPS receiver imagines that it is situated at the average level of the surface of the bodies of Earth. But, it needs a minimum of 4 satellites to discover receivers’ 3D positions like latitude, altitude & longitude.
GPS satellites provide different services like civilian services as well as military services. The civilian service is free to all the users around the world, whereas military service is accessible in the U.S. that is connected with armed forces & standard Government agencies.
Applications of a GPS
The application of GPS includes the following.
- Financial Services
- Social Activities
- Tracking of School Bus
- Road Transportation
- Tracking Locations
- Solo Travels and many more
The U.S is decided on a widespread upgrading program that includes the execution of a 2nd & 3rd civil signal on satellites. Here, the 2nd civil signal is used to enhance the exactness of the civilian service & provides support to some applications like protection of life. Further, the 3rd signal will improve the capability of civilians & it is mainly designed for applications of protection of life like aviation.