A brief history of GPS - callenderrobef1979
It all started with Sputnik. What seemed at the meter like a major defeat in the Arctic War, turned out to Be the catalyst for one of the nearly important technologies of the 20th century, and maybe the 21st.
It was October 4th, 1957. Scientists at MIT noticed that the frequency of the receiving set signals transmitted past the smallish Russian satellite increased as it approached and decreased as it touched away. This was caused away the Doppler Effect, the same thing that makes the tone of a motor horn change as the car rushes by.
This gave the scientists a grand idea. Satellites could follow tracked from the ground by measuring the frequency of the radio signals they emitted, and conversely, the locations of receivers connected the ground could be tracked past their outstrip from the satellites. That, in a nutshell, is the abstract foundation of modern GPS. That GPS receiver in your phone or on the pall of your car learns its location, rate of speed, and superlative aside measurement the time it takes to experience radio signals from four or more satellites floating overhead.
GPS has come a sesquipedalian way since Sputnik. Here are the major milestones on the way.
1959 The Navy improved the first base real satellite navigation system, which it called TRANSIT. The system was designed to locate submarines, and started out with sextuplet satellites and eventually grew to x. The subs often had to wait hours to receive signals from the satellites, but the model set the stage for accurate GPS with continuous signaling from satellites in quad.
1963 The Aerospace Corporation completed a study for the martial that proposes a system of space satellites that sends signals continuously to receivers connected the ground and could locate vehicles moving rapidly across the earth's surface or in the air. The study lays out the GPS concept that we know today for the forward time: receivers in vehicles on the ground would derive a pinpoint pose of location coordinates by measuring the transmission system times of radio signals from satellites.
1974 The branches of the military, after having worked on a GPS organisation for the past 11 years, launch the first satellite of a proposed 24-satellite GPS system called NAVSTAR. The satellite, and many to follow, are meant to exam the NAVSTAR concept.
1978-1985 The military launches 11 more test satellites into space to test the NAVSTAR system, which past then was named simply "the GPS System of rules". The satellites carried atomic clocks with them, to more just bill transmission times. Some of these satellites (starting in 1980) carried sensors fashioned to detect the launch Oregon explosion of cell organelle devices.
1983 Short later the Russians shot down Korean Gentle wind flight 007 after it wandered off course of instruction into Soviet airspace over the Kamchatka Peninsula, president Reagan offered to let entirely civilian commercial aircraft use the GPS system (erst it was realised) to improve navigation and air condom.
1985 The regime contracts with private companies to develop "airborne, shipboard and man-pile (takeout)" GPS receivers.
1989 After years of testing, the Tune Force finally launches the first fully operational GPS satellite into place. The Air Force had planned to found the planet connected the Blank space Shuttlecock, but changed its plans after the Challenger calamity in 1986 and used a Delta II arugula or else.
1989 Ferdinand Magellan Corporation claims to be the first to market in the U.S. with a hand-held navigation device, the Magellan NAV 1000.
1990 Fearing military adversaries might use the Global Positioning System system to advantage, the Defense Department decides to deliberately lessening the accuracy of the system.
1994 The FAA and Bill Clinton state the worldwide airline industry that privy continue victimization the GPS organisation free of charge "for the foreseeable future."
1995 The first rev of the GPS system was finally completed in 1995 when the last of a loaded "constellation" of 27 fully operational GPS satellites is launched into space. Of those 27, trey were used equally spares to quickly replace any of the 24 active agent satellites that failed. The satellites, which weighed betwixt trine- and four-thousand pounds, circled the globe doubly a day. They were situated so that at least four of them were visible from any place on earth at any time of day.
1998 Vice President Alabama Gore announced a architectural plan to make the GPS satellites channelise two additional signals to be used for civilian (not-military) applications, particularly to improve aircraft safety. US Congress approved the plan (named "GPS III") in 2000.
1999 Cell manufacturer Benefon launched the first base commercially-available GPS phone, a safety telephone known as the Benefon Esc! The GSM call up was sold mainly in Europe, simply some other GPS-enabled mobile phones would follow.
2000 The Department of Defense ended the goal-directed degradation of GPS, which it enforced before the first Gulf State of war. GPS became ten times many accurate overnight, and all kinds of industries–from sportfishing to forestry to freight management–shortly began using it.
2001As GPS receiver technology got much smaller and cheaper, private companies began pumping out personal GPS products, ilk the in-car navigation devices from Tom Tom and Garvin.
2004 Qualcomm said it had developed and tested "assisted GPS" technology allowing phones to use cellular signal in combination with GPS signal to locate the user to within feet of their factual location.
2005 The maiden of a new propagation of GPS satellite, known as "Block II," was launched from Cape Canaveral. The new breed of satellite transmitted signals connected a ordinal, sacred civilian channel.
2009 The Government Accountability Place (GAO) issued a report warning that the $5.8 1E+12 effort to elevate the GPS satellites was so fraught with technical problems, cost overruns, and delays that some of the satellites could begin to fail in 2010. This sent the Air Force scrambling to allay fears, saying "On that point's only if a small risk we will non remain to exceed our performance standard."
2010-2011 The Air Force launched two young Global Positioning System satellites, extraordinary in 2010 and one in 2011, that are meant to keep the constellation operable until the next coevals "Block III" satellites keister begin unveiling in 2022. The new-sprung Block III satellites will add an additional civilian GPS signal, and testament raise the performance of extant GPS service.
2012 At present, the Line Personnel manages a configuration of 31 operational GPS satellites, addition three decommissioned satellites that can live reactivated if needed. The constellation is managed to ensure the availability of at least 24 GPS satellites, 95% of the time. On October 4 the USA will launch the next addition to the constellation, the GPS IIF-3 satellite, into blank space.
Sources: The Rand Corporation, Cooperative States Naval Observatory, In league Launch Alliance, GPS.gov
Source: https://www.pcworld.com/article/461346/a-brief-history-of-gps.html
Posted by: callenderrobef1979.blogspot.com
0 Response to "A brief history of GPS - callenderrobef1979"
Post a Comment