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.