Timing Analysis for the Crab Pulsar Based on XPNAV-1 Satellite

In November 2016, China launched its first X-ray pulsar navigation satellite (XPNAV-1), in order to study the feasibility of using the regularly emitted X-ray signals from pulsars for spacecraft navigation. Over the past two years, a large amount of observations have been obtained by the XPNAV-1 satellites. The Crab pulsar (i.e. PSR0531+21) is its main observational source in which 3506627 s observations are made in 1251 orbits during 451 days. In order to study the X-ray pulsar observation performance of XPNAV-1 satellite in the past two years, those observations of Crab pulsar are processed fully. Each recovered pulse profile from daily observation have a mean similarity of 90.67% with the standard profile to be obtained from Rossi X-ray Timing Explorer (RXTE) satellite. The estimated pulse periods of Observation data of approximate to 3000 s is generally consistent with timing model of Fermi satellite and Crab ephemeris of Jodrell Bank Observatory (the mean errors of those two models are less than 10 ns). The observational results show that the pulsar data has been correctly received by the satellite, which is in good agreement with RXTE satellite and Jodrell Bank Observatory. Moreover, it is found that the X-ray detector on XPNAV-1 satellite has maintained a good technical status.