IFOG Technology for Gyrocompass Applications

Abstract : Interferometric fiber optic gyros (IFOGs) were fabricated and evaluated to demonstrate the feasibility of their use as rotation rate sensors within replacement gyrocompass systems. Bias repeatability of 0.008 deg/hr, input axis misalignment repeatability of 0.68 arcsec, scale factor repeatability of 4.5 ppm, and angle random walk of 0.0034 deg/hr were demonstrated. The measured gyro performance was included within system simulations to predict overall system performance for a series of gyrocompass scenarios. The results of the simulations showed that when mechanized with IFOGs similar to those tested, the performance specifications of the AN/WSN-2/2A gyrocompass can be achieved without the need for a vertical axis turntable for periodic self-calibration. IFOGs were shown to be a strong candidate for the rotation rate sensors within upgrades and future Navy gyrocompass systems.