What would it take to attack or disrupt the GPS system over a wide area?

Question

What would it take to attack or disrupt the GPS system? In other words, how feasible or likely is it for the GPS system and its network of satellites to be disrupted across a large area such as an entire state or country?

I understand that GPS jamming might be possible from the ground, but I suspect it would be quite localized and apparently newer devices are more resilient to this.

If conflict was to arise between two countries, what is stopping the country that controls some of the GPS satellites from blacking out or jamming an entire region. And perhaps more of a political question – would the effort required actually pay off in any significant advantage or bargaining power?

Answer 1

Traditionally as GPS was an american military system, it was intended to be possible to disable it in times of war, by removing the unencrypted civilian signals. Also in the earlier days Selective Availability could be used to render it inaccurate.

However the situation is different now as there are multiple systems controlled by different countries, GLONASS from Russia, BeiDou from China and Galileo under development from the EU.

As such disabling by switching off the signal is unlikely to affect all the available services, which would make country-wide jamming problematic.

As to more localised jamming that's perfectly possible as the signal for GPS type systems is pretty weak and all that's theoretically needed is a transmitter which swamps the signal in an area. On a small scale there's evidence to suggest that truckers use these to disable employer tracking of their movements.

Answer 2

A correct antenna or drone used as an electromagnetic weapon may totally kill any electromagnetic equipment (computer, radar, emitter…) :

• American electromagnetic weapon
• Russian electromagnetic weapon

The technology to target satelittes exists. These waepons might be used toward mobile phones antennas, mobile phones network satelittes and of course toward GPS satelittes. A few other countries have the technology level to disrupt a full mobile phone network or a full GPS network, either directly or through bounces against the ionized upper layers of the atmosphere.