Patent ID: 6268922
Filing Date: 2001-07-31
Classification: G01C

Abstract:
A method for determining the fringe number for a fiber-optic gyro, the fiber-optic gyro comprising a light source feeding an interferometer wherein two light beams propagate in opposite directions, the interferometer feeding a detector, the detector output signal being a function of the fringe number and a plurality of controllable parameters, the method comprising the steps:(a) determining the values of the controllable parameters;(b) extracting the fringe number from the detector output signal utilizing the fringe visibility effect and the values of the controllable parameters, the detector output signal in the absence of the fringe visibility effect being proportional to (1+cos .theta.) where .theta. is the difference in phase of the two light beams, the fringe visibility effect being manifested by the cos .theta. term in the expression (1+cos .theta.) being multiplied by a power series in .theta. squared.