Gps Satellite

Gps satellite

GPS History in Brief

The GPS satellite system for navigation was designed in the 1970s by the Department of Defense. Began as a global navigation system based on military land and air vehicles, with limited applicability to the civilian population. But today, things have changed - There are more GPS receivers used by civilians in the military!

Back in the 70s, the military used a variety of navigation systems such as LORAN (Acronym for Long Range Radio Navigation), VOR (VHF Omni-directional Radio acronym) and OMEGA, and felt the need for more aid to navigation accurate, which could be functional all day, all year and everywhere on earth, regardless of day or night or weather conditions. In the military needs were to navigate their planes, tanks and reliable staff. At that time, the U.S. Navy and Air Force were in search development of systems to meet those needs with programs such as Transit satellite system, satellite system Timation and Project 621B. The Department of Defense finally formed a Joint Program Office (JPO), which consolidated the progress to date in what is now known as the Global Positioning System (GPS).

The first GPS satellite was launched in 1974 and the GPS satellite constellation was declared fully operational in 1994. The satellites were / are designed and built by Rockwell International, Boeing and Lockheed Martin.

Although GPS was designed by the Department of Defense to the military, including some capabilities that could be useful in the civilian community. GPS satellites transmit coded signals that only the military has access a. The satellites also transmit signals not coded, which can be detected in both military and civilian GPS receivers. Civil signal known as the C / A code signal (thick) Acquisition.

A key parameter that describes the ability of GPS positioning accuracy, which in a nutshell, is the accuracy of the position of the user Gps Receiver calculates in GPS receiver. Gps System developers initially did not expect the civil signal to provide position accuracy comparable with those obtained by the signals military. However, the designers realized that civilian GPS receivers can use several newly developed algorithms that could improve accuracy of their position in the civilian GPS receivers dramatically. To limit the positional accuracy of civilian GPS receivers, implemented the demotions of the population civil GPS signal before being transmitted by GPS satellites. The degradation capacity is known as Selective Availability (SA). SA limited position accuracy GPS receivers in a ~ 50 meters. However, by late 1990, President Clinton had done for the benefit of GPS for civilian community, ordered the SA degradation removed. With the elimination of the SA, the doors opened for civilian users to use GPS to track the car for driving assistance, fleet management, ... ....

For a more comprehensive knowledge of GPS today, refer to these websites as www.gadgetknowledge.com/gps1.html

About the Author

Steve Kinder is a GPS industry veteran with extensive experience in the GPS receiver design and manufacturing. His latest hobby is to spread the knowledge of GPS to everybody through tutorials and websites (www.gadgetknowledge.com/gps1.html).

Not very often does a single system have such a large impact on the way we live. The Internet was revolutionary, so is GPS. Get to know GPS today and keep up with it before it permeates all over your lifestyle!