Theoretical and experimental researches on the laser gyro fractal noise

A method of calculating fractal noise parameters by wavelet is developed. The signals of middle-and high-precision laser inertial navigation system (LINS) are decomposed for 7 times by dB10 wavelet. The 100 Hz data sampling frequency is employed in both systems. The parameters of fractal noise are estimated. The fractal exponent γ approximately equals 1 in high-precision laser gyro and about equals 2 in middle-precision laser gyro. The experiments further indicate that the noise in laser gyro signal is not angel random walk but bias instability and rate random walk. This conclusion is different from common paper. Two advices are presented in order to reduce the fractal noise. The laser output power and the technique for deposition should be improved during the laser gyro design and production. And good filter algorithm should be used in LINS when more laser gyros are applied. A new finite impulse response (FIR) filter example is introduced at last. It has three notches to decrease influence of three gyro jither at the same time.