English to Romanian Tech/Engineering Aerospace / Aviation / Space

The system uses a ground station that provides a continuously rotating output and a fixed reference output. This is achieved by using an array of aerials that provide two modulated carriers. One of these is electronically rotated around and transmitted. The speed of rotation is 1800 rpm or 30 Hz. (The same frequency as the modulation). The two transmitted beams >change in phase relative to each other< depending on where you are to the beacon. For example an aircraft coming towards the beacon from due south, will receive two in phase signals. These become increasingly out of phase as we travel around the beacon.