Orolia has developed an atomic clock that is small enough to fit into a UAV (writes Nick Flaherty).

The mRO-50 Ruggedized is a microwave optical double-resonance miniaturised rubidium oscillator. It provides a one-day holdover of less than 1 μs and a retrace of less than 1-10 in a 50.8 x 50.8 x 20 mm form factor that takes up only 51 cm3 of volume – about one-third the volume of standard rubidium oscillators – and consumes only 0.36 W of power, one-tenth of other timing systems.

With an operating temperature of -40 ºC to +80 ºC, it can provide accurate frequency and precise time synchronisation for mobile applications such as military radio pack systems in GNSS-degraded or denied environments including underwater and in uncrewed systems.