GNSS jamming, spoofing, and the hard lessons from NATO exercises
During a NATO Task Force exercise in 2025, I watched a USV quietly lose its mind.
On the screen, our unmanned surface vehicle was suddenly “turn starboard 90 degrees and doing 50 knots” sideways. The track jumped inland. Position fixes wandered like a drunk reindeer in the archipelago. The hardware was fine. The environment was not.
We were sitting inside a live GNSS jamming and spoofing bubble.
For a manned ship, this is annoying but manageable. A human on the bridge says “this is garbage”, switches to radar, visual bearings and paper charts, and carries on. For an unmanned system, there is no salty navigator to shout at the GPS.
If your USV believes bad PNT, it does bad things.
That is the real problem.
The fragile keel: USVs built on weak PNT
Modern USVs are deeply GNSS-centric. Position, timing, comms pointing, collision avoidance, and route following. Much of it assumes that satellite navigation is “good enough, most of the time”.
In a real-world contested environment, that assumption quickly dies. Luckily, there was a skilled engineer (whose last name I cannot mention, as it is bad luck) who had the solution.
- Jamming makes you blind
- Spoofing makes you confidently wrong
For critical missions around naval exercises, offshore energy, or subsea infrastructure, that is not a nuisance. It is an operational risk.
And unlike a crewed vessel, the USV will happily:
- Track to a spoofed waypoint
- Violate a safety box
- Misalign a towed sensor
- Lose alignment with its AUV swarm
Simply because the math checked out on a compromised GNSS stream.
Navigating in the dark: sensor fusion or nothing
The path out of this trap is not a magical “GPS replacement”. It is ruthless redundancy.
For USVs, that means building a resilient PNT stack, not just “adding an INS”.
At minimum:
- Good IMU + INS for dead reckoning
- DVL or water-track speed, where the draft allows it
- Radar and EO/IR for shoreline, buoys, and traffic
- Multi-constellation + authenticated GNSS where available
With decent inertial quality and a DVL locked on the seabed, drift over tens of minutes becomes manageable. Sensor fusion algorithms can then do what they do best. They compare “what GNSS says” with “what the rest of physics says”.
If your Kalman filter sees a perfect satellite position disagreeing with inertial, DVL, and radar ranges, it does not need a PhD in electronic warfare. It just needs to vote GNSS off the island.
The key is architectural: Treat GNSS as one sensor among many, not the truth.
Design for failure: behavior when PNT goes bad
Resilient PNT is not only about sensors. It is also about what the USV does when things get weird.
For unmanned systems, I like to see three explicit modes:
- PNT Healthy — Normal operation. GNSS + fusion. All constraints green.
- PNT Degraded — GNSS flagged as suspect or lost. USV shifts to INS / DVL primary. Speed limits come down. Safety corridors widen. Autonomy level drops.
- PNT Lost / Corrupted — Pre-defined “lost nav” behavior. Slow to safe speed, hold last safe box using non-GNSS sensors, or return along a radar-matched corridor. No heroic improvisation.
These modes must be tested in anger. In a jammer. In a harbor full of multipath. In a fjord with poor DVL lock. If your USV only behaves well under perfect GNSS, it is not autonomous. It is domesticated.
From convenience to survivability
GNSS gave us a very comfortable decade. Cheap antennas. Easy integration. Pretty tracks. For manned shipping it will remain an amazing convenience.
For USVs operating near conflict zones, hybrid warfare, or critical underwater infrastructure, GNSS is no longer a convenience issue. It is a survivability issue.
The takeaway from this exercise was simple:
- The threat is real.
- The tech to handle it exists.
- The gap is in system design and in testing.
If your unmanned platform strategy does not include:
- A serious, fused PNT architecture
- Defined degraded-mode behaviors
- Regular exposure to jamming and spoofing environments
Then your shiny USV is only autonomous as long as nobody touches the satellites.
Strategic Ping: Do not ask “what GNSS do we have on the USV?” Ask “what happens when it lies?”
Call-To-Action
Please comment, repost, and discuss this important issue. I’m not a specialist in this, but I learned from colleagues who are experts.
We need to learn from each other and create best practices.
Originally published in the Strategic Pings ))) newsletter on LinkedIn on 2026-02-10. Subscribe there to get new editions first.