Doppler hover

Doppler hover

The hovering of a helicopter, or a vertical takeoff and landing (VTOL) aircraft, over a point controlled by a Doppler coupler to an automatic flight control system. This makes it possible for a helicopter to hover at a point without reference to any outside visual reference.
References in periodicals archive ?
After working in the area for about an hour, we departed from our last Doppler hover and climbed toward 500 feet.
While established in a Doppler hover, the aircraft started to exhibit a one-per-revolution vertical vibration.
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