Frequency steering of spaceborne clocks based on XPNAV-1 observations

Abstract

Due to high stable rotations, timing of pulsars provides a natural tool to correct the frequency deviation of spaceborne atomic clocks. Based on processing the observational data about a year of Crab pulsar given by XPNAV-1 satellite, we study the possibility of correcting the frequency deviation of spaceborne atomic clocks using pulsar timing. According to the observational data in X-ray band and the timing model parameters from radio observations, the pre-fit timing residuals with a level of 67.66 µs are obtained. By fitting the slope of the timing residuals affected by the faked frequency-biased reference clock, we estimated successfully the relative frequency deviation of the reference clock. For a satellite clock with frequency deviation of the order about 10−12, a calibration accuracy with relative error of about 2% can be obtained from the Crab pulsar’s data for one year. The stability of the time scale based on Crab pulsar is about 10−12 for an interval of one year.