NavList:

There's an article on recent solar activity on the S&T website. I spotted on intriguing paragraph:

Even then, there were significant consequences. “The agricultural industry . . . had a half billion dollar impact,” Murtagh says. Farmers rely on high-precision GPS for seed planting, tilling, and irrigation. “That weekend in May, they could not do it because of the inaccuracy of the GPS.” During extreme space weather events, changes in the ionosphere, a layer in Earth’s atmosphere, affect the signals that travel between ground and space.

It's an interesting thought... Perhaps one of the oldest practices of civilization itself --planting seeds in straight rows-- has become dependent, arguably by accident, on satellite navigation! I suppose there are folks right now trying to sell ground-based backups. It seems it would be relatively easy to implement a local eLORAN-like system that could replace the satellite signals and provide a backup during solar storms and intentional jamming.

Frank Reed