THE FANTASTIC GPS SYSTEM By Sean Callahan and George Martinez

WHAT IS IT? The Global Positioning System (GPS for short) is a system of satellites and relay stations that through measuring the delay of signals can triangulate the position of a receiver.

THE HISTORY OF THE GPS The Global Positioning System was first conceptualized by the department of defense, specifically the Navy, in It wasn’t until 1978 that the first satellite was launched for the program. In 1994 the program became fully operational. Its purpose was to overcome the restrictions of land-based radio navigation. With 24 satellites orbiting the earth, one could determine their location anywhere on the earth, regardless of mountainous terrain or rural location. The United States government owns and operates the program under the label of a natural resource. Initially only the military had access to the most accurate GPS services, but that was changed May 1 st 2000 when the restriction was abolished.

HOW IT WORKS The reason GPS works efficiently is because each of the 24 GPS satellites are equipped with an atomic clock that is synchronized with all of the other clocks. All of the satellites are regulated by ground control stations. The satellites are all constantly sending signals to one another and the ground control stations. Based off of the delay between sending and receiving signals, this information can then be used to calculate distance and with 3 or more satellites one can triangulate the position of a receiver that communicates to the satellites.

PRACTICAL APPLICATIONS Farming – because of the accuracy of GPS, farming equipment can now be fully automated with the vehicles equipped with receivers. The programing of the system can map out the farm, guide tractors, and even locate diseased patches of crops. With GPS, farming has become more efficient and economical. Search and rescue – With GPS receivers nowadays being as small as a cell phone, owning a receiver has become very popular with hikers and skiers. With this technology of their person, if they are in a dangerous situation or a emergency arises, their location can be very accurately deduced by the rescue team. This has allowed extremely fast response times that have saved lives. Aviation – Commercial flying is a multi-billion dollar business where efficiency is necessity. With GPS receivers equipped on a plane, it can determine the shortest route to its destination with great accuracy. This provides the shortest flight possible and helps control towers to very accurately determine the location of incoming planes. Automobile travel – with a GPS installed in an automobile, the need for paper maps and guesswork for how to get where you’re going is essentially eliminated. The GPS can determine your location and even your speed, and can calculate the best route for getting you to your destination and the time it will take to get there. Commercial Fishing – using GPS navigation, fisherman can now more accurately determine where to fish on the open sea. By recording their coordinates with the GPS systematically they can record patterns for areas where they are able to gather large numbers of fish. This data allows them to predict the typical movement over the year of the fish that they are trying to catch. By following these patterns, they are able to optimize their catch.

REFERENCES bitions/gps/revolution.html bitions/gps/revolution.html ducation/primers/gps/elements.html ducation/primers/gps/elements.html