[ChrisH]

I think you're talking about LORAN for LOng Range Navigation or some such. If you can pick up the signals, and get a good bearing on their origin, then it would work for an approximate location.

I'm not sure about how well the system would work for ground vehicles as clutter and reflections would be more of an issue. Basically it works by figuring out the bearing to a known radio transmitter location. Transmitters are distinguished by frequency. You would have many of the same problems as with GPS, but I doubt they'd try and spoof it or interfere with it other than the normal obstructions by mountains etc.

I would be most worried about getting a bearing on a echo. Better no signal than a wrong one, at least with no signal you know you can't rely on it.

I'm by no means an expert on this, I just know some of the general principles. Any pilots out there who want to comment?