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There are lots of ways to get around the globe. Here are 9 of the most used navaids over the past 100 years.
Where would we be without GPS? Probably not going 'Direct To' many places. The first production GPS satellite was launched in 1989, and the 24th satellite was launched in 1994, making it a truly global system.
OMEGA, which became operational in 1971, was the first global radio navigation system. It enabled aircraft to navigate using very low-frequency radio signals around the world. There were 8 OMEGA transmitters placed around the globe. The OMEGA system was shut down in 1997 due to the widespread use of GPS, but one of its stations in La Moure, ND, was converted to a US Navy submarine communication station.
Loran-C, which gained popularity in the 1970s, used a network of land-based radio beacons to create a long-range and highly accurate navigation system. But its fate was sealed by GPS as well. While Loran-C is still operated, many stations around the world have been shut down, or are the process of being decommissioned.
Originally developed for rockets, INS systems started to show up in the 1940s, with the German V2 rocket housing one of the first successful systems. Completely self-contained, INS systems use a series of accelerometers and gyroscopes to determine their position. In the 1960s, INS reached widespread usage in civilian and military aircraft for worldwide navigation.
VORs were first used in the 1940s, and they're still one of the most common radio navigation systems in the US. VORs quickly took popularity over NDBs with their distinct advantages: 360 courses 'TO' and 'FROM' the station, greater accuracy, and less interference.
Decca was developed in the 1940s for ships, but was migrated for use by helicopters and other aircraft after WWII. Each Decca system used a 'chain' of 3 or 4 radio transmitters, achieving a range of up to 400NM in the day, and 250NM at night. But with limited range and range errors (especially at night), the final Decca chain was shut down in 2001.
It's the navaid every student pilot loves to hate, but it's still used across the US. NDBs reached widespread usage in the 1930s. NDBs can have an extremely long range, making them popular in remote areas, but their susceptibility to errors like night effect and shoreline effect makes them less reliable than other modern navigation aids.
It floats around in every aircraft, and it's got quite a history. The compass was invented in China sometime between 200BC and 100AD. Pitch limits and magnetic dip cause reliability problems, but in straight-and-level flight, the compass is still one of the most reliable means of telling which way is North.
It's one of the oldest forms of navigation, and one of the first navigation aids used by transport aircraft. Celestial navigators use a device called a sextant to determine the angle between a known star and the horizon. By using the angle, plus the time it was measured, you can calculate your position.
Believe it or not, the SR-71 used a computerized celestial navigation system as one of its primary means of navigating the globe. The system could lock onto as many as 11 stars at a time, even during the day, and could determine the jet's position with up to 300 feet of accuracy. That's not a bad thing to have when you're going Mach 3.
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