Effect of magnetic field on the performance of Fiber Optic Gyroscope

Abstract

Fiber Optic Gyroscope (FOG) is a rotation sensor which is used for control and navigation application of aircraft and missiles etc. Sensor coil is a critical element in FOG. The bias drift and scale factor stability of FOG depend on the sensor coil parameters. The environmental factors such as temperature, vibration, shock, magnetic interference etc. can affect the measured phase shift which is indistinguishable from Sagnac phase shift, resulting in degradation of FOG performance. In this paper, the performance of FOG in terms of bias variation due to the Earth’s magnetic field is analyzed for various sensor coil parameters. Commercially available Polarization Maintaining (PM) fiber from different manufacturers like Corning, Fujikura, Nufern and Fiber Core is considered for the analysis. It was found that the sensor coil having less beat length is less susceptible to the magnetic field and twisting of the fiber during sensor coil winding yields the degradation of gyro performance in the presence of Earth’s magnetic field.