Decca run by who ?
AFAIK
In the beginning there was OBOE - a WWII German hyperbolic navigation system - you followed the phase interference pattern between two radio transmitters - each transmitting on a different multiple of a base frequency . The Time Difference patterns that the Phase patterns represent form hyperbole around the two transmitter masts. OBOE was set to 'read' a TD and output a warble when you were on it - with distinctive tones for being to the left or right - easy navigation until the Britts (DECCA Company) started interfering with it & 'bending' it so they missed. Over target was indicated by another 'beam' which crossed the navigation beam over the target. (See Arthur C Clarke's 'Glide Path')
Post war the DECCA Navigation Company was set up which LEASED Decca Navigators to end users (ships/aircraft/surveyors). The Decca Navigator Company used the lease money to make a profit and maintain all the Decca Transmitter chains around the world. Decca works with THREE frequencies (all multiples of some base frequency - 3f; 5f; 7f ). The base frequency gives the base accuracy. If I remember correctly it was some 100 metres or better at extreme range and approached 10 metres or better in the area between the three transmitters.
They also had HiFix Decca - which was accurate to better than 0.5m with in the coverage area (pilotage from Euro1 buoy to Europort first time I saw it used I was amazed as the Pilot wanted to know the mid point of the Decca Aerial - he then stood 'under' that point for the run in to Europort).
The Yanks refused to allow Decca to operate in the US as Decca's leasing model apparently broke some US law. However the Washington Chain (in Canada) was used by non US airlines going to Washington; and the East Canadian Chain was used for trans-Atlantic flights.
DECCA was a commercial organisation that built and maintained its transmitters and leased out its receivers. You could quite easily train OOWs in its accurate use.
Loran is/was moderately rubbish - its base frequency is around 100KHz- 400KHz range I think - pretty low so inherently inaccurate. But then it was designed to cover the mid ocean gaps between Decca Chains - so it didn't NEED to be accurate. Then there was OMEGA the benighted US attempt to use hyperbolic navigation on a global basis (f around 16KHz) and was a farce of Monty Python proportions
I had the pleasure of sailing with a Magnovox Sat Nav - the first commercial Sat Navs - serial number 00001 ! In the days before the 'cage' was established and you could wait 6 hours to get 'lock'
Biting the hand that feeds IT
