Pre-estimate Relative Intensity Noise subtraction performance of FOG by using signal cross-correlation

A method of pre-estimate Relative Intensity Noise (RIN) subtraction performance in Interference Fiber Optic Gyroscope (IFOG) is introduced. Experiment shows that the noise subtraction result depends on the cross-correlation coefficient between FOG's output and coupler's free port signal. The variance of the noise would rise when cross-correlation coefficient is lower then 0.5 and reduce to 17.16% with crosscorrelation coefficient 0.91. Estimating the cross-correlation coefficient before noise subtraction can avoid the situation that the noise increase after noise subtraction, and finally enhance the reliability of noise subtraction.