While celebrating the Galileo milestone, the conference focused on addressing today’s GNSS vulnerabilities and moving toward a more assured PNT.
When the Institute of Navigation (ION) brought GNSS+ back to the U.S. East Coast in September, Baltimore was the backdrop for a conference concerned with spectrum conflict and the next generation of navigation infrastructure. With two packed days on the exhibit floor, ION GNSS+ 2025 mixed technical research tracks, commercial updates and policy conversations in a way that underscored how central resilient PNT has become to everything from aviation and space to smartphones and autonomous vehicles.
At the center of the week was a historically minded plenary, “Galileo—A Journey of 30 Years,” delivered by two people who have progressed alongside Europe’s GNSS: Marco Falcone of the European Space Agency (ESA) and Jérémie Godet of the European Commission (EC). Rather than simply a programmatic update, the session walked the audience through three decades of political debates, technical challenges and engineering breakthroughs that turned a fragile concept into a fully global system delivering meter-level open-service accuracy, 20 cm high-accuracy service and near real-time
Medium-altitude Earth Orbit Search and Rescue (MEOSAR) performance.
Their framing—“climbing a mountain” with a summit that always reveals a higher peak—fit neatly with the rest of the conference, where almost every track grappled with how to move GNSS beyond “good signals in clear sky” toward assured PNT in contested and cluttered environments.
Galileo as Case Study in Engineering and Governance
Falcone and Godet started in the 1990s, when GPS was declaring Initial Operational Capability (IOC) and GLONASS was operational—and Europe, as they reminded the room, had no navigation system at all. Early ESA and national studies converged on a two-step GNSS1/GNSS2 concept, but nothing could really move without three ingredients: a name, a clear ambition and political backing. The name “Galileo” and the civilian-focused, GPS-interoperable vision appeared in a 1999 European Commission communication, paired with an insistence on European strategic autonomy even as the system was designed to mesh tightly with GPS.
Getting from PowerPoint to space required political heavy lifting. Godet paid tribute to Loyola de Palacio, the Spanish Transport Commissioner he called the “real mother” of Galileo, who pushed the program through an initially hostile Transport Council asking why Europe needed its own GNSS when GPS was “free of charge.” Her approach of systematically addressing each member state’s objections on cost, NATO security and duplication set a tone the program would repeat for decades.
The governance upheaval around 2007 to 2010 will have sounded familiar to many in the room: An over-ambitious PPP model collapsed when private concessionaires balked at taking real risk, forcing a mid-course pivot to full public funding and a more classical ESA–EU division of labor. From there, the talk traced the first “Galileo-only” position fix, the Soyuz launch anomaly that stranded two satellites in eccentric orbits, and the 2016–2017 clock failures traced back to a 50-cent feed-through component. Each episode was treated as evidence that large, safety-critical systems live or die on the ability to change operations quickly without breaking legacy services.
The most sobering moment came with the 2019 ground-segment incident that corrupted the navigation message and forced a week-long service interruption.The independent inquiry and subsequent redesign—shorter restart times, a “navigation extending mode” that allows graceful degradation for up to a week and a full pre-operational chain shadowing major software release—mapped directly onto themes running through multiple ION tracks on continuity and graceful degradation.
More recently, the war in Ukraine and the loss of Soyuz access to Kourou triggered another round of improvisation: Ten built satellites went into long-term storage while Brussels and Washington negotiated the security framework that ultimately allowed launches 12 and 13 on SpaceX Falcon 9 from Cape Canaveral. That experience, Falcone stressed, compressed their launch campaign tempo and forced leaner processes, lessons now being taken back into Europe as Galileo returns to Ariane 6 for launch 14.
In its forward-looking portion, the plenary jumped from Galileo Second Generation—reprogrammable, fully flexible payloads with electric propulsion and inter-satellite links—to low-Earth-orbit (LEO) PNT “pathfinders” as a future third GNSS layer, and then out to Moonlight and Mars comm/nav architectures being co-defined with NASA and the Japan Aerospace Exploration Agency (JAXA). Taken together, these plans cast Galileo not as a finished system, but as the medium Earth orbit (MEO) backbone of a multi-layer, multi-orbit PNT ecosystem. Their closing “recipe” for success—political will, technical excellence, user-driven evolution, industrial strength and international cooperation—could just as easily have served as the conference’s motto.
Themes from the Program
Resilience, AI and multi-layer PNT were strongly reflected in the conference’s technical program and tutorials. Short courses on GNSS jamming and spoofing with LEO constellations as a fallback, signals of opportunity (SoO), ionospheric effects and space applications all picked up on aspects of the resilience story: interference is now assumed, and LEO, SoO and environmental monitoring are no longer niche topics but central planks.
On the research side, tracks opened with sessions on navigation security and authentication, AI-driven positioning and robust navigation using GNSS, setting the tone for a week that treated jamming and spoofing as operational realities. Papers covered space-based RFI detection, spoofing detection assisted by specific force inputs, RAIM-like anti-spoofing methods and multi-modal signal classification for challenging environments.
Artificial intelligence and modern estimation methods were everywhere: factor-graph optimization in tightly coupled GNSS/INS, hybrid physics-informed neural networks and deep learning for interference suppression, ionospheric scintillation prediction and context-aware positioning for low-cost receivers in urban canyons. Sessions on smartphones and wearables, autonomous land and sea-based applications and indoor positioning underlined how far GNSS+ has moved beyond its aviation-first focus into mass-market, edge-compute and robotics domains.
Alternative and complementary PNT got full track treatment: atmospheric effects on GNSS and LEO PNT, non-optical and optical approaches for GNSS-denied navigation, geomagnetic and tunnel positioning, and advanced processing of terrestrial and non-terrestrial SoO all pointed to a consensus that “GNSS alone” is no longer a serious design assumption for critical applications. At the same time, classic augmentation work remains vigorous, with papers on global Satellite-Based Augmentation System (SBAS) architectures, Dual-Frequency Multi-Constellation (DFMC) integrity, ionospheric monitoring for GBAS and the modernization of network RTK services to ride out the looming solar maximum.
LEO PNT, referenced in the Galileo plenary as “GNSS3,” was one of the week’s hot topics, with dedicated sessions on LEO satellites for PNT, integrating LEO for enhanced positioning and atmospheric impacts on LEO-based systems. The technical content there dovetailed with Godet and Falcone’s vision of a future where MEO GNSS provides the timing backbone while LEO constellations add power, bandwidth and geometry for robustness and fast convergence.
On the Show Floor: A Dynamic Ecosystem
Those themes carried over into the exhibit hall, where the evening reception “30 Years of Galileo” gave the anniversary a more informal stage amid booths from ESA, DLR, receiver and simulator vendors, timing specialists and the Resilient Navigation and Timing Foundation. Hardware testbeds for spoofing and jamming, compact multi-band GNSS antennas, MEMS inertial units, timing oscillators and real-time PPP-RTK correction services sat alongside new-space LEO PNT players such as Xona.
GNSS is no longer a fragile, single-system asset but a set of global constellations, terrestrial backups and emerging LEO and lunar layers that must be engineered, governed and funded as a whole. The story Falcone and Godet told of difficult political choices, technical challenges turned into features and decades-long continuity of expertise, is now being replayed at new altitudes and in new orbits. For a community gathered in Baltimore to talk about the next 30 years of PNT, that combination of learning from the past and ambition for the future was exactly the signal they came to hear.
