NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Radio-quiet oceans and emergency navigation
From: Peter Monta
Date: 2013 Dec 14, 13:22 -0800
From: Peter Monta
Date: 2013 Dec 14, 13:22 -0800
Hi Frank,
... It's certainly true that you could pick up very distant AM stations, especially at night, but of course the fix accuracy falls off in direct proportion to distance.
Yes, and for FM stations, the propagation is not great (out to line of sight or a little beyond).
Maybe there are enough LF broadcasts (WWVB, DCF77, the Japanese one, etc.) to serve as a kind of ad-hoc low-precision Loran. If we assume the receiver can get pseudoranges to 100 us from the time code (optimistic but reasonable), then several of these might give 30km-ish positions. But this would require a specially built receiver (or software) and would have to be prepared in advance, not improvised.
Cheers,
Peter
Peter
