Fiber-optic gyroscope（FOG） north seeker is a determining north system that utilizes the horizontal components of the earth rotation rate sensed by FOG when FOG is at rest relative to the earth.The angles between the base and the horizontal plate have great effect on the orientation accuracy.In order to detect the attitude angles（roll angle and pitch angle） of the carrier at the same time and compensate the outputs of the FOG

a high-precise angle sensor is developed

which adopts double axis quartz flexible accelerometer as detecting sensor.By making use of the outputs of the accelerometer at two directions with a phase difference of 180°

the tilt angles between the base and the horizontal plate can be accurately calculated and the constant offsets of the accelerometer are eliminated.The tilt angle sensor is easy to implement and has high measuring accuracy.