光纤陀螺中分形噪声的参数估计和去除

光纤陀螺零漂信号中主要存在分形噪声和高斯白噪声,采用传统的时间序列分析法很难去除这类混合噪声.基于小波分析,提出一种分步估计加性白噪声强度和分形随机过程参数的新方法.先通过拟合自相关函数,估计出白噪声的强度;再在小波变换域估计分形噪声参数,并选取适当软阈值对测量值滤波.实验结果表明该估计和降噪方法有效地去除了光纤陀螺中的混合噪声,且不需要噪声的先验知识,具有很好的适应性. 

Parameter estimation and elimination to fractal noise of fiber optic gyro

There are Gauss white noise and fractal noise in drift of fiber-optic gyro.It is difficult to eliminate this mixed noise using traditional time series analysis method.Based on wavelet analysis,a new parameter estimation approach step by step for fractal stochastic processes and added white noise was proposed.On the basis of the fit for autocorrelation function,the power of white noise was estimated.Then the parameters of fractal noise were estimated in wavelet transform.The suitable threshold was selected to filter fractal noise and white noise of measurements.This estimation and denoising method is effective for this mixed noise in fiber optic gyro which can be proven by experiment results.Further more,a prior knowledge of noise is not needed,which means it is suitable in most situations.