Hyperbolic Navigation

[Golden Rivet]

Anyone know which,if any, of the following hyperbolic nav systems are still used/operational.

Decca
Loran C
Omega.

Thanks

GR

[reynoldsno1]

Loran is still operational - mainly N. American coverage

[End_of_Descent]

Omega has been shut down as of Sept 30 1997. See http://tycho.usno.navy.mil/omega.html

E_o_D

[twistedenginestarter]

The advent of GPS navigation satellites slowly made the service superfluous. During 1999, the GLA announced the final shutdown of the service at midnight March 31, 2000 following over 50 years of successful operation. The occasion was marked earlier that week by a farewell conference at Church House in London where users and pioneers of the system met to review the development of the technology and their experience of its benefits.

During its lifetime, the name Decca became a piece of nautical terminology that epitomized security and dependability. At its peak there were chains in all of the principal shipping areas of the world and an estimated 200,000 Decca users in Europe alone. By measuring the differences in signals received from transmitters along many of the world's coastlines, mariners and aviators were able to establish their positions with a degree of accuracy and consistency previously considered impossible.

Speaking at the farewell conference, Stephen Clark, director for Racal-Tracs, said: "It is always sad when something good, that so many people had worked so hard to create, comes to an end. Decca Navigator was a huge success in its day but life moves on. Satellite positioning is with us now and happily Racal has not lost its lead. The company has built on its long experience to create the next generation of positioning technology." Continuing, Stephen Clark said: "Racal was the first company to offer a commercial Differential GPS (DGPS) service and the rest of the world followed us.

Despite the free availability of GPS positioning, the withdrawal of the Decca service is still regretted by some sectors of the maritime industry. Most notably, fishermen valued Decca’s ability to guide them back to fishing spots at sea with a degree of precision that is only available now through the more advanced Differential GPS services. Other sectors of the maritime community regret the loss of a positioning service that is totally independent of satellites. The demise of Decca Navigator did not greatly affect the aeronautical community because aircraft installations were less common than those of VOR/DME, the internationally accepted system for position finding.

The shutdown of the British chain also affected many parts of Ireland, however the Irish Chain 7D, which was operated by Bord Iascaigh Mhara, provided coverage for the West and South Coasts of Ireland, until it too shut down on May 19th 2000. Norway closed down their five Decca chains and back on January 17, 1997. The Japanese Decca chains are expected to close by the end of year 2000.