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Thursday, July 16, 2009

How Were GPS Systems Developed?


GPS Navigation Systems technology was originally developed by the United States Department of Defense and was meant for military use to keep track of enemies and know their position at all times. Tracking technology has been around for quite some time actually - since World War II to be exact.

Navigator GPS design is based partly on ground-based radio navigation systems developed in the early 1940's that were used in World War II. These systems were named LORAN and Decca Navigator and were focused on knowing where the enemy was so they could either attack or retreat depending on the size of the forces.

Additional inspiration for modern day GPS systems and GPS handhelds came when Sputnik was launched by the Soviet Union in 1957. A team of scientists monitored Sputnik's radio transmissions and discovered that because of the Doppler Effect, the frequency of the signal being transmitted was high as the satellite approached and lower as it moved away. The Doppler Effect is the change in frequency and wave length of a wave as it is perceived by an observer moving relative to the source of the waves.
This team of scientists that was observing Sputnik's radio transmissions soon realized that since they knew their exact location on the globe, they could pin point where the satellite was along its orbit by measuring the Doppler distortion. This was groundbreaking and very exciting for the military at the time. This technology is used in radar laser detectors too.

The United States Navy used the first satellite navigation system called Transit. It was first successfully test in 1960 and was quite mind-boggling for everyone in the military. When the Navy tested Transit, they did so hoping for some quite specific results. Using a constellation of five satellites, they found that the system could provide a navigational fix approximately once per hour. Today's GPS navigation systems like the Garmin Nuvi GPS use as many as twelve satellites to lock on for instant positioning fixes.

In 1967, the Navy developed the Timation satellite which proved the ability to place accurate clocks in space. This is a technology that the GPS navigation system relies on. In the 1970's, the ground-based Omega Navigation System, based on signal phase comparison, became the first world-wide radio navigation system. This was the foundation and building block of today's GPS Portables.

In February of 1978, the first experimental Block-I GPS satellite was launched into space and the development of modern-day GPS systems began. These original satellites were initially made by Rockwell International. Now, the satellites we use for GPS are manufactured by Lockheed Martin.

In 1983, Soviet interceptor aircraft shot down a civilian airliner flight KAL 007 as it flew in restricted Soviet airspace. This heinous act killed all 269 people on board - all of whom were civilians. Shortly thereafter, President Ronald Reagan announced that the GPS system would be made available for civilian use once it was completed. Because of this horrible act on the part of the Soviets, developed of the GPS navigation system was stepped up more than it ever had been before and experimentations began in earnest.

By 1985, ten more experimental Block-I satellites had been launched into space to validate the concept of GPS and in 1989; the first modern Block-II satellite was launched. By December of 1993, the GPS system achieve initial operational capability and just a month later, a complete constellation of 24 satellites were in orbit with full operational capability declared by NAVSTAR in April of 1995.

A year after that, President Bill Clinton realized the importance of GPS to civilian users as well as military users which prompted him to issue a policy directive that declared GPS to be a dual-use system meaning civilian as well as military. He established an Interagency GPS Executive Board that was responsible for managing GPS as an asset of the United States. With this came the commercial brands such as Garmin Nuvi GPS.

Plans began in earnest to improve upon the system for the everyday user of the navigation system. An announcement was made that the government was going to upgrade the GPS system with two new civilian signals that would lead towards enhanced user accuracy and reliability particularly with respect to aviation safety. Also, GPS handhelds would be made.

Since those early years, the GPS technology has evolved into something that the everyday public uses and uses with amazing accuracy and reliability. What began as a way to keep track of our enemies is now used to help guide us along the way during trips and excursions. Such companies as TomTom, Magellan and Garmin Nuvi GPS have made a business out of this.

In fact, the GPS system we have today has many applications including map making, land surveying, and commerce uses. Plus, because of the way a GPS can pinpoint times with amazing accuracy, scientists are able to use it in many applications including the study of earthquakes and the synchronization of telecommunications networks. Who knew that golfers would be able to use a GPS handheld to determine the distance to the flag.

New uses for GPS systems are constantly being discovered and the way that technology is always evolving, we are sure that even more new uses will come about for the GPS systems. They will probably always be finding new uses too as the system is constantly improved upon. Next time your on the highway, safely look over at the car next to you and see if it might contain a Garmin Nuvi GPS.

By Richard Alexander

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