To figure out their position on earth and navigate, people once depended on different ways that are quite unimaginable in this digital era. It must be astonishing for today’s generation to imagine that mariners relied on methods ranging from angular measurements to positioning of celestial bodies for calculating their location. Radionavigation was the first ever modern technique used in order to calculate the exact location.
GPS was initially prepared for military purpose, and then its service was extended to various fields. GPS has proved itself to be one among the smartest inventions ever made. Now GPS has found its way to even school buses for better service and safety.
The extent to which it is provides service to customers is indeed appreciable.
Read on through the remarkable evolution of GPS:
1957: SPUTNIK, the first man-made satellite was launched. William Guier and George Waeiffenbach, American Physicist monitored the emission of radio transmissions from Sputnik with the help of which they could locate its orbit and location.
1959: The first satellite navigation system was built by Navy, which was named TRANSIT. It was built in order to obtain the exact location of submarines. The system was introduced with six satellites which eventually grew to ten. The subs had to wait for hours to receive signals from satellites. The model paved way for the true GPS with continuous signalling from satellites in space.
1960: TRANSITwas successfully tested
1963: The Aerospace Corporation completed a study for the military that proposed a system of space satellites which sends signals continuously to receivers on the ground and could locate vehicles moving rapidly across the earth’s surface or in the air. The study laid out the GPS concept for the first time. Receivers in vehicles on the ground would derive a precise set of location coordinates by measuring the transmission times of radio signals from satellites.
1974: After having worked on GPS for past 11 years, the branches of military launched the first satellite called NAVSTAR.
1978-1985: In order to test the NAVSTAR System, military launched 11 more test satellites in to space, which was called “the GPS system”. To measure the transmission time, the satellites carried atomic clocks with them. Sensor design to detect the launch or detonation of nuclear devices was carried by some of the satellites starting from 1850.
1983: Korean Airflight 007 was shot down by Russians after it wandered in the Soviet airspace over the Kamchatka Peninsula. All 269 passengers and crew members were killed. In order to avoid similar situations in future, President Reagan ordered that all civilian commercials aircrafts must be equipped with GPS system. He believed that GPS could help in navigation and improve air safety to a great extent.
1985: Contracts for “airborne, shipboard and man-pack (portable)” GPS receivers were given to private companies by Government.
1989: The fully operational GPS satellite was launched by the Air Force after testing for years. After the Challenger disaster in 1986, the plan to launch the satellite on the Space Shuttle was changed. It was used in a Delta II rocket instead.
1990: Defence Department deliberately decreased the accuracy of the GPS system fearing that military adversaries might use GPS system for their advantage.
1994: With an eye on the future, FAA and Bill Clinton granted the worldwide airline industry to continue using the GPS system for free.
2000: The purposeful degradation of GPS which was implemented before the first Gulf War by the Defence Department was stopped. Overnight, GPS became ten times more accurate and powerful. Industries like fishing to forestry to freight management began to use it.
2001: Private companies began to introduce out personal GPS products as the GPS receiver technology got smaller and cheaper. In-car navigation devices from Tom Tom and Garvin were introduced.
2004: A new technology was introduced known as “assisted GPS”, which has been tested and developed. The new eminent technology allows phones to use cellular signal in combination with GPS signal in order to locate the user to within feet of their actual location.
2005: “Block II”, first new generation of GPS satellite was launched from Cape Canaveral. Signals were transmitted by the new breed on a second, dedicated civilian channel.
2009: The Government Accountability Office (GAO) issued a report warning that the $5.8 billion effort to upgrade the GPS satellites was so fraught with technical problems, cost overruns, and delays that some of the satellites could begin to fail in 2010.
2010-2011: Two new GPS satellites was launched by Air Force, one in 2010 and one in 2011 which are meant to keep the constellation operable, until the next generation “Block III” satellites get launched in 2014. An additional civilian GPS signal as well as enhanced performance compared to the GPS service is expected from new Block III satellites.
2012:Air Force manages a constellation of 31 operational GPS satellites, plus three decommissioned satellites that can be reactivated if needed, at present. The constellation ensures the availability of at least 24 GPS satellites, 95% of the time. The next addition to the constellation, the GPS IIF-3 satellite will be launched on October 4 by the Air Force in to the space.
