The Method Of Time Delay Measurement Based On Sparse Representation For Pulsar Integrated Pulse Profile

Pulsar has wide application prospects and value in the navigation system of positioning,timing and attitude determination for the near Earth and interplanetary spacecraft of which radiation signal cycle is highly stable and not susceptible to interference.Thus,pulsar navigation has become a hot research field of space navigation.The time delay of integrated pulsar profile relative to standard profile is one of the important observations(referred as the time delay for integrated pulse profile)in pulsar navigation system,the accuracy of this observation directly affects the accuracy of the pulsar navigation system.For the above reasons,we study the measurement method of the time delay for integrated pulse profile in the pulsar navigation system,and propose a new method based on sparse representation(Sparse Representation,SR)to calculation the time delay for integrated pulse profile.This method builds a waveform-matched dictionary in accordance with standard pulse profile firstly.On the basis of the dictionary,first order sparse coefficient vector that contains the phase information of time delay is used to represent measurement pulse profile.Then,the time delay for integrated pulse profile is calculated by using of the sparse coefficient.On this basis,the experiments are carried with the data observed by Rossi X-ray Timing Explorer(RXTE).Compared with the measurement accuracy of FFT algorithm,the results show that SR algorithm can significantly reduce the impact of the signal-to-noise ratio of received pulse profile on the accuracy of the delay time.Even in the shorter observation period,the SR algorithm can still maintain the high measurement accuracy.If it is possible the higher phase bins of standard profile used to construct the redundant dictionary,the better the measurement accuracy of SR algorithm.