225 meters after 19 hours without GPS

We validated our GNSS-denied navigation system on a 19.4-hour voyage in the Black Sea.

Using nothing but Ku-band Doppler shifts from a simulated 66-satellite constellation, the SR-UKF filter held position error to 225 meters, while the unaided inertial reference drifted 34.6 kilometers.

More sea trials are planned.