Use of Rayleigh-OFDR to Estimate the Bias Drift Induced by Quasi-Static and Homogeneous Temperature Variation of a Free-Standing Fiber-Gyro Coil

Abstract

The method of Rayleigh-Optical Frequency Domain Reflectometry (Rayleigh-OFDR) has been used to estimate, at the component level, the thermal bias drift due the elasto-optic effect into a 400m-long self-standing quadrupolar coil, under a temperature ramp ranging from -20°C to 80°C. This estimation is performed before integration of the sensing coil in a Fiber-Optic Gyroscope (FOG). A theoretical reminder of how a thermal perturbation is creating a spurious bias in the FOG rotation rate measurement is described. Then, we propose a new methodology to estimate the thermal bias drift of the sensing coil before its assembly. It is based upon Rayleigh-OFDR. Uncertainties are characterized to assess the performances of the Rayleigh-OFDR to characterize the thermal bias drift due to <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">elasto-optic</i> effect in a FOG.