摘要 |
In a phase comparison radio navigation system in which phase-locked signals are radiated from spaced stations to be compared in phase in a receiver, the receiver has a separate phase memory oscillator for each received signal, the phase memory oscillators operating at the same frequencies (apart from differences due to Doppler shifts) and being locked to their respective signals from the transmitting stations and display units are provided each with selector means enabling any display unit to effect phase comparison between any pair of outputs from the memory oscillators. |