LORAN, an acronym for Long Range Navigation. Currently an obsolete terrestrial radio navigation system which enabled ships and aircraft to precisely determine their position and speed from low frequency radio signals transmitted by fixed land based radio beacons, using a dedicated receiver unit.
The final version of LORAN in North America was LORAN-C, which operated in the low frequency level of the radio spectrum from 90 to 110 kHz. Russia used a nearly identical system in the same frequency range, called CHAYKA. LORAN was in steep decline in the 90's and early part of the 21st Century with the satellite-based Global Positioning System being the preferred technology that eventually replaced.
However, there have been attempts to enhance and re-popularize LORAN, mainly to serve as a backup and land-based alternative to GPS and other satellite navigation systems. The current program has been phased out in the United States and Canada. The United States Coast Guard and Canadian Coast Guard ceased transmitting LORAN-C signals in early 2010. The other updated version of the navigation tool was E-Loran, primarily used in other parts of the globe. It was discontinued December 31, 2015 with international authorities leaving a few stations operating in the European sector...just in case.
Instruction of this type of navigation skill was a requirement until a few years ago and to this day the training charts used in USCG license examinations are full of these remnant lines.
Through the use of a Loran Linear Interpolator scale while plotting on a paper Mercator chart you could very accurately determine your position. Even on some of the GPS Multi-Function Displays there is evidence of E-LORAN input in the operating systems.
Why return to an old way of navigation? Maybe because it is terrestrial, not dependent on the premium cost and crowded space of satellites that orbit the Earth. Back-up systems are always critical to ensure accuracy regardless of the type vessel, aircraft, or vehicle you are operating. Are you absolutely sure your GPS is providing correct information all the time? Navigation is a vast arena of technology and utility. The return of LORAN will certainly help maintain a consistent environment and help reduce incidents that can develop with too little or inaccurate sensor input.