The US Federal Aviation Administration has warned that GPS signals could be unavailable or unreliable on June 9, 21, 23, 28, and 30 across the west coast. The signals are most likely to be disturbed primarily around California, surrounding southwestern states. and the northern corner of Mexico. Although the disruptions will be more severe at higher altitudes, the signal could be scrambled as low as 15 meters (50 feet).
The FAA has advised pilots to avoid the areas at the mentioned times and instructed them to closely monitor their flight control systems.
According to the warning, the problem is something to do with “GPS Interference Testing." Other than that, the FAA remains quiet. The center point of the disturbances is the Naval Air Weapons Station China Lake in the Mojave Desert. This complex is the US Navy’s largest installation, which is dedicated to researching, developing, and testing the majority of their weaponry and armaments.