http://204.108.4.16/d-tpp/0711/05932N31.PDF

This is an instructive read, not for the technical details, but for
the footnotes... Read their titles and notice well the dates of
publication as recent as 2 years ago...
This reinforces comments that I have made on here that GPS will not be
allowed to be the single source of navigation for commercial and
military purposes in the event of war or emergency...
LORAN C will continue to be the radio based source for maritime
navigation of last resort for the forseeable future (even though the
tankers will have GPS plotters on the bridge, and radar, and ADF)
In aviation, and especially military/cg aviation, Loran will continue
to be used - even if not heavily supported in the general aviation
market... Also, NDB, ILS, VOR, will continue to be supported...
Some folks are bright enough not to put the countries eggs all in one
basket...

denny