GPS Satellites Based Global Navigation System

GPS or Global Positioning System is a fully functional satellite based Global navigation system, which along with unequalled accuracy provides flexibility of positioning. It consists of 24 satellites placed into orbit U.S. Department of Defense. It provides three-dimensional positioning throughout the day. It is very useful for obtaining accurate data up to about100 meters for navigation. It is even used for mapping and geodetic positioning. GPS or Global Positioning System is very beneficial in GIS data collection, surveying, and mapping.

Initially GPS or Global Positioning System was not available for civilians .It was originally used for United States Department of Defense. In the 1980s, the government made the system available for civilians. The first GPS satellite was launched in 1978. GPS is functional in any weather conditions, anywhere in the world, 24 hours a day. GPS is officially named NAVSTAR GPS. The name NAVSTAR GPS was given by Mr. John Walsh. He played a very important role while deciding the budget for the GPS program. The satellite is managed by the United States Air Force 50th Space Wing.

GPS or Global Positioning System space segment which consists of 24 satellites revolves around the earth 12,000 miles at speeds of 7,000 miles an hour. It is powered by solar energy. During solar eclipse it uses backup batteries, which helps in consistent running in the event, when there's no solar power. Rocket boosters of small sizes are located on each satellite which helps them to fly in the correct path. A GPS signal contains three different bits of information — a pseudorandom code, ephemeris data and almanac data.

GPS or Global Positioning System is used by satellites and computers to compute positions anywhere on the earth. Basically it is based on satellite ranging. The approximate weight of GPS satellite is 2,000 pounds. There are no subscription fees or setup charges to use GPS. Even though GPS or Global Positioning System applies some of the most high-tech equipment but the principle behind it is very simple.

US Air Force GPS monitoring stations are present in Hawaii, Ascension Island, Diego Garcia, and Colorado Springs, Colorado. It also has monitor stations operated by the National Geospatial-Intelligence Agency. The requirement for positions of GPS Global Positioning System receiver is calculated by current time and the position of the satellite.

In order to measure the delay, the receiver compares the bit sequence received from the satellite. GPS Global Positioning System signals propagate at the speed of light. This represents an error of about 3 meters. On determining the users position, GPS unit can also calculate other important information like speed, track, sunrise, sunset etc. Global Positioning System