Abstract: In order to improve the efficiency of north finder, a gyro north finder model for arbitrary two-position north finding is presented. It can collect the signals in two places which are less different, reduce the rotation time of turntable, and save the whole north finding time to some extent. In order to further improve the north finding accuracy, a wavelet threshold de-noising method is introduced, and a new double- parameter adjustable threshold function is proposed. The function is simple and easy to calculate without segmental values. The north-seeking experiment in arbitrary two-position is conducted on the developed principle prototype. The results show that the north finding accuracy within 160 s is higher than 0.02°, the north-finding time is saved，and the new de-noising threshold function greatly improves the north finding accuracy.

Key words: control science and technology, north finder, arbitrary two-position, gyro drift, wavelet de-noising threshold, threshold function