Study on Technology of Orientation and North-Finding Based on Fiber Optic Gyroscope

North-finding system provides true north azimuth information to all kinds of ground-based equipment. A dynamic automatic north-finder based on the modulation output of fiber optic gyroscope (FOG) is presented in this paper. In this scheme, the sine output signal of the FOG was sampled and disposed, and then the real north of surveyed point on the surface of earth was calculated. The deviation caused by the platform base tilt was compensated by an accelerator, Allan standard deviation is used to analyze the random drift of FOG, and establish the random error mode of FOG. The FOG north-finding and laser collimation theodolite are assembled to achieve orientation and aiming integral, which lays foundation for switching to project application.