gps.gov стверджує наступне
Doesn't the government degrade civilian GPS accuracy?
No. During the 1990s, GPS employed a feature called Selective Availability that intentionally degraded civilian accuracy on a global basis.
In May 2000, at the direction of President Bill Clinton, the U.S. government ended its use of Selective Availability in order to make GPS more responsive to civil and commercial users worldwide.
The United States has no intent to ever use Selective Availability again.
пруф:
https://www.gps.gov/systems/gps/performance/accuracy/#difference