alt Hacker NewsSeems like we'd need a modern version that's less susceptible to jamming, otherwise aren't we just replacing one jammable service with another?
Replies
azernik • yesterday at 8:40 PM
Being much closer to the receiver and tied into terrestrial power grids, ground-based beacons can transmit at higher powers than GNSS signals and be received at much higher powers.
Received GNSS power is on the order of -130dBm (10e-16 W) - you can jam that with a 1W terrestrial source for hundreds of meters around. Way more if you're willing to scale the power from car USB power levels to bigger grid-connected supplies.
LORAN, from my quick googling, looks to be about 6-7 orders of magnitude higher received power.
There are two types of GPS jamming.
There's GPS jamming by the military, mostly in war zones. This seldom effects airliners because they steer clear of active war zones.
Then there's GPS jamming by delivery drivers who don't want their boss watching over their shoulder all the time. When the article mentions jammers as small as a cellphone and costing less than $100, those are sold to drivers.
Delivery drivers don't jam LORAN or VOR, though - so it's not jammed by the second type.