Frequency stability analysis of pulsar‐aided clocks

Abstract

This paper discusses the use of a pulsar signal in clock calibration. The analysis method is presented from the perspective of filtering theory, where Hadamard variance is used to analyze the frequency stability of both the stand-alone and the pulsar-aided clock systems. The aided clock is constructed using a steady state Kalman filter and accounts for the fractional power spectral density of the pulsar timing noise. The results of this simplified analysis indicate that the frequency stability of the aided clock has noticeable improvement at large averaging time due to the suppression of the random walk frequency noise in the stand-alone clock.