Patent ID: 8422021

Claim:
A method comprising: inhibiting zero drift of an open loop interferometric fiber optic gyroscope by: reversing the polarity of a sinusoidal AC signal applied to a phase modulator of the open loop interferometric fiber optic gyroscope, according to a predetermined half-cycle time period, wherein the ratio of the cycle of polarity switching of the AC signal to the cycle of the AC signal is greater than 1000; and wherein reversing the polarity of the AC signal is controlled by a square wave signal; determining output rotation rates of the open loop interferometric fiber optic gyroscope in two adjacent half-cycles according to the output signal of a demodulation/amplifier circuit and the phase of the square wave signal; and calculating a final output rotation rate of the open loop interferometric fiber optic gyroscope in a cycle based on a difference between the determined output rotation rates of the open loop interferometric fiber optic gyroscope in the two adjacent half-cycles.