Drone makers race to build navigation that survives warzone jamming

GPS spoofing and jamming have become standard countermeasures on the battlefield in Ukraine, separating drones from their operators and rendering some guided munitions useless. US-made Excalibur artillery shells fell out of favour after initial successes because their GPS guidance was jammable. Even fibre-optic control wires have been countered by entangling lines strung across fields.