Step angles to reduce the north-finding error caused by rate random walk with fiber optic gyroscope

We study the relationship between the step angles and the accuracy of north finding with fiber optic gyroscopes. A north-finding method with optimized step angles is proposed to reduce the errors caused by rate random walk (RRW). Based on this method, the errors caused by both angle random walk and RRW are reduced by increasing the number of positions. For when the number of positions is even, we proposed a north-finding method with symmetric step angles that can reduce the error caused by RRW and is not affected by the azimuth angles. Experimental results show that, compared with the traditional north-finding method, the proposed methods with the optimized step angles and the symmetric step angles can reduce the north-finding errors by 67.5% and 62.5%, respectively. The method with symmetric step angles is not affected by the azimuth angles and can offer consistent high accuracy for any azimuth angles.