What is the full form of GPS
GPS: Global Positioning System
GPS stands for Global Positioning System. It is a satellite based navigation system which allows ground users to determine their exact location, velocity, and time 24 hours a day, in all weather conditions, all over the world. It is maintained and developed by the U.S. Department of Defense, and was basically designed to assist soldiers and military vehicles but after some decades it made accessible to anyone having a GPS receiver. It is widely used to track vehicles and follow the best route from one place to another place by Airlines, shipping firms, courier companies, drivers etc.
The first GPS was developed in the 1960s to assist the ships of US Navy in navigating the oceans more accurately. The first system started with five satellites which enabled ships to check their location once every hour.
Parts of GPS
It can be divided into three different segments which are as follows:
Space Segment: It refers to satellites. There are around 24 satellites distributed in six orbital planes.
Control Segment: It refers to stations on Earth developed to maintain and monitor the satellites.
User Segment: It refers to users that process the navigation signals received from the GPS satellites to calculate position and time.
Working of GPS
There are 24 satellites plus some spare satellites in orbit with a period of 12 hours (two orbits per day) at a height of about 11,500 miles. Satellites are placed such that four satellites will be above the horizon, from any point on Earth.
In order to receive the information GPS device will first establish a connection with 3 to 4 satellites. GPS satellite broadcast a message including location of the receiver. GPS receiver combines the message from different satellites to calculate the exact position using the process called triangulation.
GPS satellites require an unobstructed line of sight for the communication. Hence, this technology is not ideal for the indoor use. There some devices use nearby cell towers and public Wi-Fi signals. This technology is called LPS (Local Positioning System) and is a substitute of GPS.