In grating measurement system

the Moiré signal is subdivided for enhancing accuracy of grating sensor

but the white Gaussian noises and impulsive noises is main cause of impacting accuracy.Generally

median and average filtering is used for denoising

nevertheless

they can be only applied in static signal and can not be applied in dynamic Moiré signal.A value of current signal is predicted by polynomial finite impulse response（FIR） predictors according to many previous samples.The output of the hybrid filter is the median of prediction value and the actual signal value in the middle of filter window.The method is proved to be effective by the simulation experimental.