> just in a degraded form that wasn't very useful Differential GPS was already in widespread use in many counties by 2000, which made "selective ability" poin

> just in a degraded form that wasn't very useful Differential GPS was already in widespread use in many counties by 2000, which made "selective ability" pointless at it provided automatic corrections to the 'degraded' GPS signal. https://en.wikipedia.org/wiki/Differential_GNSS https://en.wikipedia.org/wiki/Differential_GNSS