Cross-domain navigation system and method for water-air cross-media vehicle

The invention discloses a cross-domain navigation system and method for a water-air cross-media vehicle. The system comprises a strapdown inertial navigation module, a Doppler velocimeter, an ultra-short baseline positioning module and a Beidou satellite navigation module which are mounted on an aircraft, wherein the strapdown inertial navigation module, the Doppler velocimeter and the ultra-short baseline positioning module are used for positioning and navigation when the aircraft is in an underwater environment; the strapdown inertial navigation module and the Beidou satellite navigation module are used for positioning and navigation when the aircraft is in a water surface-air environment; and the calculation module is used for receiving the first navigation data of the vehicle underwater and the second navigation data of the heading device in the water surface-air in the water-air cross-domain navigation process of the vehicle, processing the first navigation data and the second navigation data, and positi