Additional fun fact: "[GPS receivers] being specially designed to employ anti-jam features (e.g. null steering antenna or electronically steerable antenna) to function in an environment of active or passive countermeasures" are MTCR category II dual-use missile related export-restricted components.
MTCR = Missile Technology Control Regime, an informal and voluntary partnership between 34 countries to prevent the proliferation of missile and unmanned aerial vehicle technology capable of carrying a 500 kg payload at least 300 km. https://en.wikipedia.org/wiki/Missile_Technology_Control_Reg...
http://www.mtcr.info/english/MTCR-April2011-Technical-Annex....
MTCR is also why GPS receivers will refuse to provide navigation information if you're flying too high or moving too fast.