Michael Lorrey writes:
> Well, I was under the impression that they were gonna remove the randomizer
> algorithm sometime soon, so civvies would get the same accuracy.
You don't need to remove anything differential GPS (DGPS) provides dm realtime accuracy, which is significantly better than you get without selective availability. I think European 'civvies were thinking aloud about a European GPS solution for civil uses.
Solid-state MEMS accelerometers have been built which resolve about a ug, while being remarkably shockproof.
Realtime heading information can be obtained from magnetic field sensors.
While each information itself is too unreliable, taken together the data can easily be used for 2d and 3d autonomous vehicle operation. The reason it's not done is not technological infeasibility but legal uncertainty.