| 摘要 |
A method and system for navigation comprising a plurality of transmitters (11, 13, 100, 102), pairs of which are excited from a common frequency source, and a receiver (18) responsive to and deployed within the wave fields (126, 108, 110, 128, 116, 132) created by the transmitters. The receiver (18) is provided with its initial coordinate position (R) and determines movement therefrom by detecting beat frequency cycles resulting from the relative movement between the receiver and the transmitters of a transmitter pair. The receiver (18) position change (S) is computed according to the beat frequency cycles detected. In a preferred embodiment, transmitter pairs are arranged generally perpendicularly to establish a coordinate system and transmitters of a transmitter pair radiate different frequencies that are precisely related to a common excitation frequency source. The receiver (18) detects the transmitted signals, compensates for the precise frequency relationship employed at each transmitter pair, and compares the signals from each transmitter pair to detect beat frequency cycles which are used to compute receiver position change. |
