Application of Translation Invariant Discrete Wavelet Transform in Fiber Optic Gyro Signal Processing
Q Wang · 2007
In a FOG (Fiber Optic Gyro), there mainly exist white noises and fractal noises characterized by non-stationary, long-term dependence, self-similarity and 1/fγ spectrum density. It is difficult to eliminate all FOG noises by using traditional filtering methods. Wavelet analysis is effective in dealing with the FOG noises for its multi-resolution analysis. The FOG error characteristics and mathematic model were given, the characteristics of fractal noises were analyzed and fractal noises were generated in the wavelet transform method. FOG signals were acquired and filtered with many wavelet filtering methods in a lab environment. TIDWT (Translation Invariant Discrete Wavelet Transform) filter based on semi-soft threshold is effective in removing the noises existing in FOG proved by the simulation experiments, overcoming the big variance of hard threshold method and big biases of soft-threshold method.