Navigation without GNSS
Position error: onboard configurations compared
The same flight replayed through four navigation configurations with the same sensor noise. IMU alone is clipped at 3 km.
Error against the filter's own uncertainty
Full system. Horizontal error against the filter's 1σ per axis; a consistent filter keeps 39% of the time inside 1σ, 86% inside 2σ and 99% inside 3σ.
Terrain, safety margins and energy
Altitude and terrain along the flight
Flown altitude against the true ground below the aircraft.
Height above ground
Battery
Energy remaining against the reserve that is never planned to be used.
Autonomy timeline
Mode changes and the decisions the UAV made without any link.