Abstract: Regarding applications of low-precision and medium-precision fiber-optic gyroscope (FOG), we present a fast north-seeking algorithm based on wavelet transform. The proposed method imports continuous slow-speed rotation, changes static measurements into dynamic measurements under the leveling condition. Measurement noise is suppressed, and the useful information of FOG output is kept with wavelet transform filtering. Consequently the influence of FOG’s low-frequency random drifting is reduced. Thus the FOG can find the geographical north fast and accurately. Experimental results show that the method can effectively reduce the time needed to seek north and errors in repetitive north-seeking, and improve direction accuracy. The method is expected to have theoretical and practical values.

Key words: fiber-optic gyroscope (FOG), automated north-seeking, inertia measure, wavelet transform