A method to calibrate the on-board timing based on pulsar observation

Considering the on-board clock stability, the paper presents a method of timing calibration strategy based on the observation of pulsars, a natural celestial source, in order to improve the timing accuracy. A calibration model is established and the error factors are considered based on the characteristic of pulsars´ stable and periodical signals, and the pulsar timing residuals are caused by reference normal clock and pulsar itself, and the two influences are not correlative. Firstly, filters such as wavelet and HHT are implementing to data handling and error analysis, and then the paper investigated and developed a multiple-pulsar-observation method. Judging from the signals transmitted from different pulsars, the onboard timing residuals are determined by credibility weight of different pulsars´ observation different components. Finally this paper comes to the conclusion via simulations. The method allows separating the error from a single pulsar timing errors and the on-board time can be obtained by filtering the observation residuals of pulsars observed, extracting the filtering result of different pulsars, and then choosing the weight according to the stability of timing result denoted with timing variance.