Exploiting quantum physics could offer commercial aircraft an alternative to satellite-based navigation, by enhancing the accuracy of inertial systems while avoiding disruption and jamming.
Commercial flight trials, using a BAE Systems Avro RJ100 of UK engineering research specialist Qinetiq, have demonstrated the potential of quantum-based technology to achieve more resilient position, navigation and timing services.
Satellite navigation systems, which rely on constellations such as GPS and Galileo, provide flightpath accuracy and independence from ground-based equipment, allowing development of efficient routes and flexible approaches.
But the relatively weak satellite signals are vulnerable to interference. ICAO analysis revealed over 520 reported instances of jamming or suspected interference in the Middle East and North Africa region alone during 2022.
North Korea has previously been accused of GPS jamming and, more recently, disturbance to GPS navigation in the Baltic region led Estonian authorities to reinforce ground-based navigation systems.
The European Union Aviation Safety Agency held a workshop with IATA at the beginning of this year aimed at developing measures to address spoofing and jamming.
“We immediately need to ensure that pilots and crews can identify the risks and know how to react,” says EASA.
Its joint strategy with IATA centres on sharing of interference event data, procedural guidance from airframers, and the retention of a minimal network of conventional navaids for back-up.
Vulnerability of GPS could, however, also be countered with more accurate independent on-board navigation systems.
Aircraft avionics have evolved from using inertial navigation systems, based on accelerometers and mechanical gyroscopes, to inertial reference systems – employing laser-ring gyros – the information from which is typically fused with GPS to update flight-management computers.
But over the past two decades various aerospace research organisations including the US’s DARPA and NASA, and the European Space Agency, have been exploring the potential to base gyroscopes and accelerometers on atomic quantum effects – and develop a quantum positioning system, in order to achieve highly-accurate navigation.
Trapping and supercooling atoms with laser light – research which won the Nobel Prize for Physics in 1997 – reduces their thermal motion to a point where their quantum properties can be exploited.
Cold-atom interferometry allows analysis of modification – by gravity, inertia or other effects – of the atoms’ energy states. The creation of quantum gyroscopes and sensors are among the technological avenues opened by the research.
The recent UK commercial flight trials of a quantum-based navigation system – undertaken through a collaboration led by quantum technology firm Infleqtion – were carried out at the defence ministry’s Boscombe Down facility, with the final sortie on 9 May.
These tests demonstrated both a quantum system based on ultra-cold atoms, as well as a compact optical atomic clock, on board the RJ100.
Infleqtion has worked on the High-Bandwidth Inertial Atom Source & Sensor project – known as High-BIAS2 – aimed at validating cold-atom quantum gyroscopes, and demonstrating quantum sensor ability to stabilise aircraft guidance system orientation without satellite positioning signals.
“The cornerstone of modern [position, navigation and timing] technology is precision clocks. These ultra-accurate timekeepers are crucial for various applications,” adds Infleqtion. “And portable production of ultra-cold atoms is another key piece of the puzzle.”
It states that the technology will form part of a quantum inertial navigation system.
“Our recent trials mark a significant step forward in the development of quantum [position, navigation and timing] solutions,” says Infleqtion UK president Timothy Ballance. “The successful flight trials demonstrate the potential of quantum technology in overcoming navigation system challenges.”
Under its national quantum strategy programme, the UK government wants to “accelerate” quantum technologies for civil and military resilience. The strategy seeks to deploy quantum systems on aircraft by 2030.
