Abstract: The X ray pulsar with weak signal buried in strong noise leads to the low signal to noise ratio of folded pulse profiles in short time, both estimation accuracy and efficiency are affected. A denoising method for X ray pulsar is proposed in the paper. By preprocessing and folding the pulse profiles, and the measured data are employed for Daubechies wavelet, the SNR of pulse profile is improved. The RXTE data are used for verification and the simulation results show the method proposed can eliminate the noise from equipments and space environment, thus shorting the observing time and improving the efficiency of X ray pulsar navigation without reducing the accuracy of TOA. 

Key words: X ray pulsar signal, Daubechies wavelet, Denoising, Time of arrival, Epoch folding