Gps Background

GPS innovation is established partly on ground-based radio navigation systems that evolved in the early forties and these were employed in the Second World War. These systems were called LORAN and Decca Navigator and concentrated on learning about where the opposition was so that they can either assault or back out depending on the size of the army.

Further inspiration for modern Global Positioning System came up when Sputnik was launched by the Soviet Union in 1957. A team of scientists watched Sputnik’s radio transmissions and noticed that due to Doppler Effect, the frequency of the signal getting transmitted was high as the satellite came near and lower as it moved away. The Doppler shift is the alteration in frequency and wave length of a wave as it is seen by an observer moving relative to the source of the waves.

This team of scientists that was researching Sputnik’s radio transmissions shortly understood that as they knew their exact location on the Earth, they could pin point wherever the satellite was along its orbit by assessing the Doppler shift. This was groundbreaking and very interesting for the armed forces at the time.

The US Navy employed the first satellite navigation system known as Transit. It was first successfully tested in 1960 and was rather impressive for everybody in the armed services. When the Navy tried out Transit, they did so hoping for some rather specific results. Using a configuration of 5 satellites, they discovered that the arrangement could give a navigational fix roughly once per 60 minutes.

In 1967 the Navy created the Timation satellite which showed the ability to place precise clocks in space. This is a technology that the Global Positioning System or GPS relies on. In the seventies, the land-based Omega Navigation System, established on signal phase comparison, became the first global radio navigation system.

In February of 1978 the first experimental Block-I Global Positioning System satellite was launched into space and the evolution of modern GPS systems started. These original satellites were at first built by Rockwell International. Nowadays, the satellites we use for GPS are made by Lockheed Martin.

In 1983 Soviet interceptor aircraft shot down a civil airliner flight KAL 007 while it flew in bounded Soviet air space. This monstrous act killed all 269 people on board – every one of whom were civilians. Not long thenceforth, President Ronald Wilson Reagan declared that the Global Positioning System should be made available for civilian use as soon as it was completed. Due to this horrifying act on the part of the Soviets, development of the GPS system was intensified much more than it ever had been before and experiments started earnestly.

By mid eighties, 10 more experimental Block-I satellites had been launched into space to verify and validate the concept of Global Positioning System and in 1989; the first modernistic Block-II satellite was launched. By end of 1993, the GPS system accomplished initial functional capability and just a month afterward, a full constellation of twenty-four satellites were in orbit with fully functional capability announced by NAVSTAR in April of 1995.

A year later, President Clinton recognized the importance of Global Positioning System to civilian users in addition to military users which motivated him to issue a policy directing that GPS to be a dual-use system meaning civilian and military. He founded an Interagency Global Positioning System Executive Board that was accountable for managing GPS as an asset of the U.S.A