In March 2024, the plane carrying the British Minister of Defence hampered the GPS signal when it traveled near Kaliningrad, Russia on a journey between the UK and Poland. The British government later said that airplanes are never at risk, but obstruction cases are not uncommon in the area. In fact, various groups have noted that GPS obstruction has become common since the start of the Russian-Ukurein war.
For decades, the standard backup for this type of navigation failure has been inertial navigation, a way to track movement using accelerator meters and gyroscopes. However, these systems have their own weaknesses. Small errors increase over time, drifting the estimated location at just how many kilometers over a potentially long journey. This makes it unacceptable in many important applications.
What navigators desperately need is a new way that doesn’t rely on clogged satellite signals. Ideally, this system should be completely passive, unlike radar, to avoid revealing its own location.
Murat Muradoğlu and colleagues of Q-Ctrl, a quantum technology company currently in their office in Sydney, Australia, demonstrate exactly that technology. Their approach is to sense anomalies in the Earth’s magnetic field and compare them with known maps of the field to resolve their location. Additionally, quantum sensors are used for this process, allowing magnetic anomalies to be detected with much greater sensitivity than high-end inertial navigation systems.
The Q-CTRL system could be a passive, janshari and universally available navigation aid that could revolutionize how vehicles find their way in an environment where global navigation satellite systems are not available.
Landmark Advance
The concept behind Magnav is not new. The Earth’s magnetic field is not completely uniform. Overlapping the main field of up to 65,000 nanoteslas produced by the planet’s core is a small local variation known as magnetic anomalies. These anomalies usually range in sizes from 10 to 100 nanoteslus over several kilometers. They arise from the geological features within the Earth’s crust and are geographically different and stable over time.
These magnetic functions act as sign posts just as landmarks allow for visual navigation. If the vehicle has a sensitive magnetometer and has access to a map of these anomalies, its location can be determined by matching real-time magnetic field measurements to the map. Global magnetic anomaly maps already existed, compiled from decades of geophysical research.
However, it was difficult to translate this elegant concept into a practical system. First, the magnetic anomalies used for navigation are small compared to the main fields of the Earth, and can also be overwhelmed by the magnetic interference produced by the vehicle’s electronics and engines. Second, traditional magnetometers lack the sensitivity, stability, or small size required for deployment in mobile vehicles.
The entire process also requires sophisticated algorithms to filter the noise and then match the sensor data (often noisy, maps). In the past, this has forced the aircraft to perform complex “clover” operations to adjust the sensors.
Muradoğlu and Co tackled these challenges with a variety of hardware and software innovations. At the heart of their system is their own quantum magnetometer. This is a compact and lightweight package on the size of a Rubik’s Cube, measuring how external fields affect the spin of rubidium atoms.
This hardware is paired with a set of removal and map matching algorithms. Unlike traditional approaches that treat noise cancellation and map matching as separate steps, Q-CTRL software integrates them. For example, a physically driven model is used to learn the magnetic signature of a vehicle in real time to vary in payload and subtract platform noise from the desired signal.
To validate the system, the Q-CTRL team conducted extensive field trials. Aerial inspections included flying the Cessna 208B Grand Caravan for 6,700 km near Griffith, Australia. They tested a variety of configurations, including internally mounted sensors (high noise environments) and externally mounted sensors, comparing Magnav performance with strategic grade inertial navigation systems and GPS ground truth data.
They also evaluated the system in ground testing on a standard rental van driven through mixed terrain near Orange, New South Wales. This created even more severe noise and vibrational environments. “As far as we know, the successful ground-based test itself represents the world’s first demonstration,” the team says.
The results were convincing. Over numerous aerial tests, the quantum separation Magnav system consistently outperformed the inertial navigation system. “Our Magnav solution delivers excellent performance and offers a positioning error of about 46 x better (lower) than speed-assisted INS. The final final positioning accuracy achieved in flight trials is 22m or 0.006% of flight distance,” the researchers say.
In ground testing, the Magnav system achieved a final accuracy of 180 meters on the 18 km route, despite the magnetic noise within the van reaching 50 times the abnormal signal.
It’s an interesting job with important implications. Given the increasing vulnerabilities of GPS systems, much of the work has become an alternative form of navigation, but all have limitations. Camera-based terrain navigation and start trackers can fail when the weather is bad. Radar and rider are resilient options, but reveals location and beacon-based navigation systems based on mobile phone towers.
Q-Ctrl’s quantum magnuff could potentially leap these technologies. “Quantum-guaranteed Magnuff Solutions can outperform inertial navigation systems under a wide range of conditions,” says Muradoğlu and co.
Magnetic mapping
But it’s not a slam dunk yet. One challenge is to improve the resolution and coverage of public domain magnetic maps that usually have a resolution of several kilometers. That’s not enough for many applications. These maps need to be improved, especially at sea where magnetic anomalies tend to be smaller than on land. The key question is how accurately you can create a map.
Next is the issue of geomagnetic storms caused by solar activity. These storms can generate a field of war stars that this system depends on for navigation. Therefore, it may be necessary to integrate predictive models of geomagnetic activity for route planning.
Another factor is secretly developed military capabilities. “We recognize that secret demonstrations may exist. The danger is to abolish military systems that exceed Q-Ctrl. Other “unjummaable” quantum technologies, such as quantum inertial navigation, currently being tested by British technology company Infleqtion, could also compete.
All this work suggests that dawning is a new era of quantum-enabled navigation, which should protect future British defense ministers and others from harassment attacks. Of course, a new era of hacking, jamming and other evil activities cannot be far behind.
REF: Quantum-Asedured Magnetic Navigation achieves better positioning accuracy than strategic grade INS in airborne and ground field trials. arxiv.org/abs/2504.08167
