[time-nuts] GPS vulnerability and e-Loran

[jimlux]

On 11/29/19 11:54 AM, Martin VE3OAT wrote:
> A nice "general reader" article about GPS vulnerabilities to jamming and 
> spoofing and the expected consequences, with a too-brief mention of 
> e-Loran, appears in the current issue of Scientific American ("GPS 
> Down", December 2019, pp 38-45).  Says e-Loran is unfunded and no one is 
> doing anything about it.  (What else is new?)
> 

Any "over the air" nav system has an inherent vulnerability to jamming 
and/or spoofing, especially a one-way system like GPS or Loran or Omega.

With improved constellation on board processing bandwidth, the need for 
a one way system is less important than it was back when Woodford and 
Nakamura wrote their system engineering report. Two way nav is tougher 
to spoof (assuming you have a good clock), and, depending on the system, 
tougher to jam.

A good clock, accelerometers, gyros, and celestial nav is tough to jam.