Comment by crote

5 hours ago

GPS beacons would be stupidly expensive, as you'd need tens of thousands of them per city, and each one of them would need a very accurate atomic clock.

It would make far more sense (but still unviable) to go for Eurobalise-style RFID tags embedded in the road surface.

>you'd need tens of thousands of them per city

I was thinking more find a tall building and throw a single one there. Or maybe tallest 3.

As I understand it even a small number of extra satellites with line of sight can improve results a fair bit.

So aiming at low hanging fruit rather than blanket city

>very accurate atomic clock.

Indeed, but I'd think managing that on ground is easier than in space.