All of these posts prove the need for a position backup source when the world switches to airborne surveillance (ADS-B). By design, ADS-B is GPS based, and with loss of signal an FMS with inertial will provide a reasonable position for some time, but there will have to be a backup.
Looks like Loran E is getting the nod…..
“JPDO Study Endorses eLoran as Best Satnav Backup
A satellite navigation backup study commissioned by the JPDO has given
eLoran "the highest overall preference rating...particularly in the U.S."
Not yet publicly released, the 180-page document was prepared by ITT's
advanced engineering and sciences division and assessed seven candidates
against a series of essential requirements. The candidates include
DME/DME/INS; GNSS/INS; eLoran; VOR; "hardened" GNSS; terrain mapping; and multilateration. Leading requirements were the ability to support RNP values of 2.0, 1.0 and 0.3, for en route, terminal and nonprecision approach
respectively, plus technical readiness by 2015 to 2025 and complete
independence from satnav. The ability of eLoran to continue beyond INS
coasting limits following satnav loss was also noted. The report concluded,
"eLoran scored significantly highest for the general aviation segment, and
eLoran integration into GNSS/eLoran FMS systems for general aviation and
certain air carrier segments appears to be a viable and capable solution."