Propagation medium velocity measurement system

摘要

An apparatus measures an electromagnetic signal (e.g., light) propagation time delay that varies with system speed relative to its propagation medium. A one-way light propagation time measurement in the medium between two fixed points moving relative to the medium is used. The delay is compared with light propagating in a constant reference path that is independent of motion. A two-way system is also used, as well as increasing sensitivity through a light zigzag and fiber optic coil delay. The apparatus is a compact and extremely sensitive speedometer.

主权项

1. A method of measuring a velocity of an apparatus, said method comprising:
while said apparatus is at a reference velocity, transmitting a coherent electromagnetic beam via a first path completely within said apparatus to a first receiver, wherein a distance said beam travels via said first path is dependent on any velocity of said apparatus; while said apparatus is at said reference velocity, transmitting said beam via a second path completely within said apparatus to a second receiver, wherein a distance said beam travels via said second path is independent of any velocity of said apparatus; determining a reference phase difference at said receivers between said beam traveling via said first path at said reference velocity and said beam traveling via said second path at said reference velocity; while said apparatus is at said velocity, determining a velocity phase difference at said receivers between said beam traveling via said first path and said beam traveling via said second path; determining a total phase difference between said velocity phase difference and said reference phase difference; and calculating said velocity of said apparatus using at least said total phase difference, a frequency of said beam, and the speed of light.