High-Accuracy Dynamic North-Finding Method Based on Dual-Polarization Fiber-Optic Angular Accelerometer

North-finding technology is an autonomous orientation technique used to determine the true north direction of carrier platforms, and it holds significant application value in fields such as seismic exploration and aerospace. In this work, we propose, for the first time to the best of our knowledge, a high-accuracy dynamic north-finding method based on a dual-polarization fiber-optic angular accelerometer (DP-FOAA). The angular accelerometer exhibits high sensitivity and a flat response across a broad frequency band. With an enclosed fiber coil area of 12.4 m2, it achieves a sensitivity of 2.7 × 10-⁷ rad/s²/(Hz)1/2within the frequency range of 0.01 - 100 Hz. A north-finding system was stablished using this angular accelerometer integrated with a high-precision turntable. The novel north-finding method based on the DP-FOAA, together with its effective suppression of turntable vibration noise, has significantly enhanced the accuracy of dynamic north finding. The experimental results show that the north-finding accuracy of this system is better than 52 arcsec, with a total north-finding time of 18 s. Compared to a fiber-optic gyroscope with the same fiber coil, its measurement accuracy is improved by 3.2 times. This research provides a feasible approach for the development of novel high-speed, high-accuracy north finders, thereby advancing their technological progress.