The difference is that a portable Loran station & power supply can be built for VERY low cost compared to a GPS satellite. It take a LONG time to get a new bird on orbit but almost no time to move a portable Loran system from a bunker up and in operation.

The quick talk specifically talked to "hardened" chip any they are finding that even hardened chip can not withstand a strong (man made) EMP. The talk also taled about the EPIRB satellite system that is in work. Sure sounds sweet.

Greg