World War II tech eLoran deployed as GPS backup in the UK

[Mortblanc]

GPS will be around for a long time. The present system is getting upgrades for several more years before it will be replaced by a new system, the EU is placing their own system on line in a couple of years and the Chinese have a totally new network that will go into operation in 2020.

Keep in mind that all of these systems were placed as part of a military use network and civilian use is just a side benefit of the systems and not their primary function. Over here the defense department has control of what type, frequency and power a civilian gps unit can have, and there are several levels of the system. We can only access one frequency.

The ground based system that we have been discussing is only intended as a back up to GPS, not a replacement.