Earlier quoted context omitted.
Back in the day GPS was intentionally offset so countries couldn't use it for weapons.. well except it's owner of course!
It seems like the intentional degradation didn't work as intended in the first place and the inaccuracy could be corrected with little effort - at least for someone who had the resources to use it for weapons systems, so it only affected civilian use cases. > Because SA affects every GPS receiver in a given area almost equally, a fixed station with an accurately known position can measure the SA error values and tran…
If you're a civilian doing surveying work, it was fine: you stick the base station at a known location, let it work for a few hours, and then you had high-precision GPS in that area. If you're a military power attacking someone on their own ground, it's not so useful. Even worse if you're at sea.