Azimuth Surveying Based On Fiber-Optic Gyroscope

Since the birth, the FOG has been put into application in many ways, especially in Strapdown Inertial Navigation System, for its many advantages such as simple structure, stability, quick- reaction higher reliability ,low cost, small volume and low weight . With many noises such as the noise of light-source and system and some inherent noise ,the stability of the FOG is not good. In order to improve the stability, the following has been done:After introducting the FOG's principle and the cause of the FOG's drift, we make use of the Allan variance method to separate the noise factors which affect the performance of the Optic gyro ,such as the angle random walk, bias instability, rate random walk, rate ramp, quantization noise, Markov noise and sinusoidal noise. In this paper, the random error model including the most common five noise as above.Second, the time series is adopted to analyze the drift data and it is concluded that(1) the FOG's drift is a non-stationary time series and includes random component and constant component, but it is a stationary time series as the temperature is stable;(2) the error model of the FOG's drift is expressed as ARMA(1,1).At last, by using the error model of FOG, kalman filtering is adopted in filtering the drift data. According to the simulation of the experiment data, the kalman filter achieves superior effect and has an important valuable in practical application.