Britain has scored a world-first with a series of test flights to demonstrate the core technologies of a future quantum navigation system that’s designed to foil one of the most potentially dangerous, yet not very widely publicized, threats that transportation faces: GPS jamming and spoofing.

Global Positioning Systems (GPS) have become so much a part of our lives with so many applications that it’s easy to take them for granted – that is, until you drive into a steep mountain valley or densely wooded forest and completely lose your satellite signal. That can be more than a little unnerving as the fuel gauge hovers around empty and you have no idea where the next gas station is.

It’s even worse for ships and especially aircraft because they don’t just face the possibility of an accidental signal outage but active jamming and spoofing. Jamming of GPS is identical to jamming radio or radar. It’s simply a matter of sending out a powerful transmission that can overwhelm and drown out the GPS signal. On the other hand, spoofing is far more dangerous. This means sending out false signals designed to fool a GPS device into thinking it’s somewhere else and traveling in the wrong direction.

This sounds like something out of a Bond thriller, but it’s a very real and very common threat. According to the European Business Aircraft Association, there were 49,605 incidents of civilian aircraft being the victims of spoofing in 2022 alone – often as the result of flying in the vicinity of conflict zones where spoofing is used to misdirect enemy warplanes and drones, though such incidents can happen anywhere.

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Once spoofed, the crew members are distracted. They lose situational awareness. They now have a much heavier workload as they cope with the emergency. The thing to remember is that spoofing isn’t just a matter of confusing an aircraft crew, air traffic controllers who rely on the aircraft’s transponder (which is now wrong) could also be affected, and may be of little use when contacted for confirmation of location.

Worse, the electronic flight bag that pilots depend on may be corrupted so the crew can’t trust its calculations of things like how much fuel is left. The plane’s course, speed, and altitude may be off too. The plane could even vanish from automatic tracking sites, increasing the chances of a fatal accident. The spoofing could also compromise takeoffs, as well as collision alarms and digital compasses, while autopilots could disconnect themselves.

One way to combat this is to add backup navigation like an inertial guidance system. This is essentially an electronic version of dead reckoning and is used by submarines all over the world by switching to gyrocompasses and accelerometers that automatically calculate the boat’s course and position to measure how it turns and accelerates along all three axes.

If you have a decent navigational fix to begin with, it’s a very useful tool, but it’s limited because over time errors will creep into the system until they accumulate and reinforce one another – which could result in the readout being off by miles. This is why submarines have to periodically rise close to the surface to get a fresh GPS position.

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Since aircraft move much faster than submarines, these errors can build up much faster. To get around this, British partners Infleqtion, BAE systems, QinetiQ, and UK Research and Innovation are working on creating a new version of dead reckoning using quantum mechanics.

Quantum navigation systems are based on what is called quantum sensing where, under cryogenic conditions, the movements of a single atom are tracked precisely by means of the peculiar properties of quantum mechanics, including quantum entanglement, quantum interference, and quantum state squeezing. Combined with atomic clocks and special software analysis to filter out interference, these can stand in for GPS for a considerable time.

According to the British government, the hope is that the new quantum-based Positioning, Navigation, and Timing (PNT) systems will be one part of a larger system to protect commercial flights against spoofing. The recent tests completed at the Ministry of Defence facility at Boscombe Down in Wiltshire recently demonstrated two quantum technologies: a compact Tiqker optical atomic clock and a tightly confined ultra-cold-atom-based quantum system. Both of these were installed on QinetiQ’s RJ100 Airborne Technology Demonstrator aircraft that has been fitted with a fighter plane nose. The PNT will eventually be integrated into a complete Quantum Inertial Navigation System (Q-INS).

“From passenger flights to shipping, we all depend on navigation systems that are accurate, safe and secure,” said UK Science Minister, Andrew Griffith. “The scientific research we are supporting here on quantum technology could well provide the resilience to protect our interests. The fact that this technology has flown for the first time in British skies, is further proof of the UK as one of the world leaders on quantum.”

Source: UK Government