An ensemble pulsar timescale derived from the traditional Wiener filtration still contains some high level noise.To improve this situation we developed a Wiener filtration algorithm of the ensemble pulsar timescale based on a power-law model of power spectrum for pulsars.Our algorithm has three strengths:(1)mitigating spectral leakage between frequency bins for Fourier techniques;(2)using a power-law model for power spectrum;(3)signal realization in original residuals of data set by the power-law model.According to improved algorithm we constructed an ensemble pulsar timescale EPT-TAI using timing data with respect to International Atomic Time(TAI)about 16 yr time span of ten pulsars from International Pulsar Timing Array second data release(version A).The results show that EPT-TAI detected correctly the differences TT(BIPM2015)-TAI between terrestrial time TT(BIPM2015)and TAI.Fractional frequency stability σz analysis shows that EPT-TAI does not indicate red noise for 16 yr time interval,and fractional frequency stability for 8 yr and longer time intervals is slightly better than that of TT(BIPM2015)-TAI.Stability for short time intervals of TT(BIPM2015)-TAI is better than that of EPT-TAI,but TT(BIPM2015)-TAI shows red noise for longer time intervals.Using the same algorithm we also derived an ensemble pulsar timescale EPT-TT(BIPM2015)with respect to TT(BIPM2015).The fractional frequency stability curve of EPT-TT(BIPM2015)shows similar characteristics as that of EPT-TAI but with slightly lower values.

Ting-Gao Yang;Ming-Lei Tong;Yu-Ping Gao

National Time Service Center,Chinese Academy of Sciences,Xi'an 710600,China;Key Laboratory of Time and Frequency Primary Standards,Chinese Academy of Sciences,Xi'an 710600,China;University of Chinese Academy of Sciences,Beijing 100049,China

天文和天体物理学研究

[1]Ting-Gao Yang;Ming-Lei Tong;Yu-Ping Gao-.Wiener Filtration Algorithm of an Ensemble Pulsar Timescale Based on a Power-law Model of Pulsar Power Spectrum)[J].天文和天体物理学研究,2022(10):121-132

Pulsar,Timescale,pulsars,BIPM2015

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