GPS Ratings

GPS (Global Positioning System) is a global navigation system. Its navigation is based on a satellite-based system. There is a network of around 18 to 24 satellites placed in the earth’s orbit. The characteristic feature is that it works in any part of the world and under any weather conditions present throughout the day. Use of GPS signals does not cost you anything; you must simply pay for the device itself.

This technology aids in space navigation as well as land navigation. We will deal with the land navigation concept briefly here. Although navigation has existed since medieval times, the constant evolution of technology has led to newer and better ways of navigating. One such technological revolution took shape in the form of GPS.

GPS satellites are constantly involved in the transmission of coded signals to users on earth. The receivers installed on the ground receive those coded signals and decode them to obtain the navigation-data and compute the receiver’s 3-D position as well as velocity. The navigation-data that is obtained can also be used in a series of value-added services such as tracking a child or a car. The main principle involved in global positioning is the capability to determine the position of a human or vehicle with precision. One such application that depends on the land navigation capabilities of GPS is car navigation. Train tracking and mobile oriented applications are also guided by this same navigation technology.

Let us briefly look into how train tracking is established. A GPS device is mounted on the train to constantly gauge its speed and position. This information proves useful to railway authorities so they can optimally allot tracks, efficiently schedule routes, re-route trains in case of obstruction in the tracks caused by natural calamities or mishaps, and detect collisions. The GPS transmitters keep transmitting the location details of a particular train in the form of coordinates such as position and velocity through a radio communication link to the CMS. A Geographic Info System at CMS has to monitor the locations of the various trains and make optimal decisions in route management. In addition to this, global positioning receivers provide information to the passengers in the train regarding the time that has elapsed since the train started from the previous station, distance and time to reach the next station, and the speed with which the train is moving. Thus GPS navigation is enabled. It’s quite the technological wonder indeed.