Research on establishing a joint time-scale of pulsar time and atomic time based on a wavelet analysis method

Abstract

ABSTRACT Pulsar time has different physical mechanisms from atomic time, and these two time-scales are complementary in terms of stability performance. The joint timekeeping of pulsar and atomic time is currently an important application direction. Our research utilizes a wavelet analysis method to perform multiscale analysis of time signals in both the time and frequency domains, and assigns corresponding weights to different frequency bands for synthesis, which solves the problem of balancing long- and short-term stability in unified weighted synthesis. In this paper, a joint time-scale APT (atomic pulsar time) is obtained by a fusion of pulsar ensemble time (EPT) and atomic time TA(NTSC) (AT) based on wavelet analysis. The results show that APT effectively integrates the stability advantages of both EPT and AT, and the short-term stability of APT at 0.4 yr is consistent with that of AT, reaching 5.6 × 10−15 as evaluated by σz variance. The stability of APT remains consistent with EPT after 3.2 yr, and the long-term stability at 13.1 yr is close to 1.3 × 10−16, perfectly retaining the excellent long-term stability characteristics of pulsar time. The root mean square of APT’s clock difference relative to TT(BIPM) is much lower than that of TA(NTSC). Moreover, we propose ways to improve the stability of APT through experimental comparisons. The results indicate that APT has the potential to serve as a reference for steering UTC(NTSC) in the future, improving the long-term timekeeping capability of local atomic time in China, thereby comprehensively improving the stability and reliability of China’s time reference.