Quick search algorithm of X-ray pulsar period based on unevenly spaced timing data

Abstract

Timing information of X-ray pulsar signal is of the vital significance for realizing the autonomous navigation of spacecraft in deep space. The accurate timing model (period and period derivation) is the foundation of achieving high-precision auto-navigation solutions. Because the data that the X-ray photons arrive at the detector are unevenly spaced, both χ2 evaluation method and Lomb algorithm are analyzed. The idea is brought forward that the initial value of pulsar period is gained using the χ2 evaluation method, then the result of period is refined by Lomb algorithm. Meanwhile, the Lomb algorithm is ameliorated by the idea of fast Fourier transform algorithm, the efficiency of operation is enhanced highly. Finally the exact pulsar period is estimated, and correct pulse profile is replicated using the measured timing data from the X-ray source simulation system which used to validate the algorithm.