Q-CTRL navigates ship without GPS using quantum gravity sensing

Australian quantum technology firm Q-CTRL announced on August 27 the world's first open-water field demonstration of GPS-free quantum gravimetric navigation, successfully steering a 29-meter vessel through the Coral Sea without satellite signals.q-ctrl+1

Gravity as a Map

The company's Ironstone Opal platform achieved one nautical mile positioning accuracy over an 83-kilometer trajectory, outperforming standard navigation-grade inertial backups by more than ten times. The system works by detecting minute variations in Earth's gravitational field and matching them against pre-existing gravity maps — a technique Q-CTRL calls "GravNav".quantumcomputingreport+2

Unlike GPS, which relies on radio signals vulnerable to interference, the quantum gravimeter is entirely passive and emits no signal, making it immune to jamming and spoofing. The technology arrives amid a sharp rise in electronic warfare threats: approximately 978,000 GPS jamming and spoofing incidents were recorded globally in the first quarter of 2026, with 98 percent concentrated in the Middle East.q-ctrl+1

Software Over Hardware

Traditional cold-atom gravimeters require heavy motion-stabilization platforms and controlled environments. Q-CTRL's approach replaces much of that hardware with AI-powered software that stabilizes the quantum sensor under open-ocean conditions. In the Coral Sea trial, the instrument was installed in an unconditioned passenger cabin without gyroscopic stabilization rigs, operating autonomously and delivering comparable performance to gimbaled configurations.quantumcomputingreport+1

"The proliferation of GPS-jamming and spoofing instruments highlights that our adversaries are not waiting," said Michael J. Biercuk, Q-CTRL's CEO and founder. "Q-CTRL is proud to show again that quantum tech can transform real defense missions today".q-ctrl+1

Defense and Commercial Ambitions

The maritime demonstration builds on Q-CTRL's 2025 airborne MagNav trials, which used magnetic-field map matching and outperformed a high-end conventional GPS alternative by up to 100 times. Ironstone Opal was named one of TIME's Best Inventions of 2025 and became the first quantum navigation system to achieve safety-of-flight qualification under the RTCA DO-160 airworthiness standard.q-ctrl+2

Q-CTRL is working with DARPA, the U.S. Defense Innovation Unit, the Australian Department of Defence, the UK Royal Navy, and Lockheed Martin ↘ 1.92% on integration efforts. Lieutenant General Steve Sklenka noted that "adversarial investment in GPS jamming and spoofing capabilities has made assured positioning, navigation, and timing a warfighting necessity, not a convenience".q-ctrl+2