Dont throw out that "old " LORAN.
Seems the Euros (French) keep the Euro Loran system operating and are improving it in accuracy.
Loran C was 300 yards the new eLoran is accurate to 30, and is supposed to be compatable.
In the US a new G4 network is expected to wreck havoc on GPS signals with 4000 towers at 15KW each.
Still in review , but has been fast tracked , and the avation folks are in a panic.
IF the plan goes thru , it might mean tossing ALL existing accurate GPS units for units with better filters.The cheapo GPS will be less affected.
eLoran may be the replacement for GPS , the fight is on!