I seem to recall the GPS sats have a dither error parttern
I seem to recall that the GPS sats enforce a randomly changing dither pattern for all non-military uses.
Receivers can then correct for the differ if a know position transmits its dither delta. int he UK this is done using the BBC radio masts
Are we saying the dither has now been disabled - or the correction is now so widespread that we just ignore it in conversation.
I recall that network rail in the UK is very keen to have accurate satellite positioning so that it can find its track side junction boxes. It appears that Network Rail keeps loosing them and then goes to the cost of sending out a search parties before the maintenance can take place..