Abstract: A new approach is presented for eliminating the effects of base motion disturbance on the accuracy of north finder mounted on a stationary carrier. The antisymmetric B-wavelet is used to process the original output signals of the north finder. The operation moment of the low frequency base motion disturbance is located in the time domain by observing the evolution of wavelet local modulus maxima across scales and the polluted data should be deserted. Preliminary simulation results based on field sampled signals indicate that this approach can effectively improve the performance of the north finder against base motion disturbance.