OMEGA HYPERBOLIC NAVIGATION by Bv79aD6

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									OMEGA HYPERBOLIC
   NAVIGATION
OMEGA was the first truly global
 radio navigation system for aircraft,
 operated by the United States in
 cooperation with six partner nations.
Argentina
            Norway
Liberia
            France
Japan
            Australia
  HISTORY
Developed by the United States Navy
 for military aviation users

Was approved for full implementation
 in 1968
Initially, the system was to be used for
 navigating nuclear bombers across the
 North Pole to Russia

Later  it was found useful for
 submarines
 John Alvin Pierce, the "Father of Omega," first proposed the use
  of continuous wave modulation of VLF signals for navigation
  purposes in the 1940's.
RADUX

  - measuring the phase difference of
  radio signals to compute a location
  solution
 After experimenting with various frequencies, he settled on a
  phase stable, 10 kHz transmission in the 1950's.




                 "OMEGA"

                              - last letter of the Greek alphabet
 1950’s       Ambiguity errors

          Inertial Navigation System (INS)
          Transistor

  1963
          Omega Implementation Committee (OIC)
             charged with designing the new
             navaid and, on the basis of their
             experiments, took the decisions
             about how Omega would work - the
             choice of frequencies, location of
             transmitters, power levels, etc.
Due to the high cost of constructing VLF
antennas (Omega antenna towers were
more than 1,200 feet in height), the first
experimental transmissions were actually
existing VLF communications stations that
were modified for Omega transmissions
 Omega stations used very
 extensive antennas in order to
 transmit their extremely low
 frequencies. Specifically, they
 used grounded or insulated
 guyed masts with umbrella
 antennas, or wire-spans across
 fjords. Some Omega antennas
 were the tallest constructions
 on the continent where they
 stood or still stand.
 1968

        the U.S. Navy authorized full scale
         implementation of the Omega System

  1971
        transferred from the U.S.Navy to the
         U.S. Coast Guard
        Omega Navigation System Operations
         Detail (ONSOD)
1983
   Omega achieved full eight station
    implementation in 1983 and was used
    by several airlines flying long range
    routes over water as well as by military
    forces
             OPERATION
 Each Omega station transmitted a very low frequency signal
  which consisted of a pattern of four tones unique to the
  station that was repeated every ten seconds. Because of this
  and radio navigation principles, an accurate fix of the
  receiver's position could be calculated. OMEGA employed
  hyperbolic radio navigation techniques and the chain
  operated in the VLF portion of the spectrum between 10 to
  14 kHz.
 By receiving signals from three stations, an Omega receiver
  could locate a position to within 4 nautical miles using the
  principle of phase comparison of signals.
OMEGA STATIONS
 Trelew, Argentina - tallest construction in South America. On June 23, 1998 it was demolished after
     the OMEGA service was shut down.

      Woodside, Victoria, Australia This mast is the highest construction in the
       southern hemisphere. Since the shutdown of OMEGA it is used as a transmitter
       for orders to submarines at 13 kHz
 Due to the success of the Global Positioning System the use
  of Omega declined during the 1990s, to a point where the
  cost of operating Omega could no longer be justified.
  Omega was permanently terminated on September 30,
  1997 and all stations ceased operation.

 Some of the stations, such as the LaMoure station, are now
  used for submarine communications.

								
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