At a recent event hosted by the European Space Agency, industry leaders Telespazio UK and Kongsberg Discovery presented the results of the VAUTAP project (‘VDES-R advanced user technologies for alternative PNT), a pioneering research initiative aimed at strengthening positioning, navigation, and timing (PNT) resilience at sea.
At the core of the initiative is the technical development and evaluation of VDES ranging mode, or VDES R-Mode, a nascent but promising technology that repurposes maritime communication signals from the very high frequency data exchange system (VDES) for navigation. Telespazio UK Project Manager Louise Mercy said, “By extracting precise timing and distance measurements from VDES shore-based transmissions, VDES R-Mode could function as a complementary terrestrial navigation source, critical when GNSS signals are degraded or denied.”
Today, Global Navigation Satellite Systems (GNSS) are the cornerstone of marine PNT. However, recent trials and operational incidents have highlighted GNSS signals’ acute vulnerable to both natural interference and human-induced threats, including jamming and spoofing. In a number of high-profile incidents, GNSS disruptions have led to dangerously inaccurate vessel positioning, often without triggering onboard alarms.
Exploring a new approach
The system-of-systems paradigm, cited increasingly by both academia and industry, calls for the integration of diverse and independent PNT sources. VDES, now operating on spectrum recently allocated by the International Telecommunication Union (ITU), is well-positioned to be a cornerstone in this strategy, not just as a communication backbone but as a PNT enabler.
VDES R-Mode currently sits at a relatively low technology readiness level (TRL), and many of the necessary technical standards are still in flux. With VAUTAP, the Telespazio-Kongsberg team, Mercy said, “is developing advanced waveforms, synchronization algorithms, and receiver technologies tailored to the unique propagation characteristics of VHF maritime signals.”
In addition to algorithmic innovation, the project has focused on practical engineering challenges, such as adapting existing maritime radio hardware to support dual-use – communication and navigation – functionality, and refining the timing stability of shore-based VDES transmitters to ensure centimeter-to-meter-level ranging precision.
As digitalization deepens across the maritime domain, from autonomous vessels to smart ports, the need for robust and resilient PNT solutions is becoming increasingly important. Funded under ESA’s NAVISP program, VAUTAP aligns with the broader goal of fostering emerging and cutting-edge PNT technologies across the European value chain.
