脉冲星钟模型保持方法和脉冲星时自主保持精度是决定脉冲星时应用精度的关键。根据地球时TT发布的特点以及脉冲星自转稳定特点,提出基于滑动累积窗口的脉冲星钟模型保持方法。首先利用IPTA第2批发布的2颗脉冲星观测数据开展钟模型保持...脉冲星钟模型保持方法和脉冲星时自主保持精度是决定脉冲星时应用精度的关键。根据地球时TT发布的特点以及脉冲星自转稳定特点,提出基于滑动累积窗口的脉冲星钟模型保持方法。首先利用IPTA第2批发布的2颗脉冲星观测数据开展钟模型保持精度分析,在13年以上的时间窗口内2颗源的自转频率测量值相对于平均值波动幅度在10^(-13)Hz之内,且随着时间窗口累积增加钟参数测量精度单调提高;其次,利用观测数据分析钟模型在滑动预报下的脉冲星时自主保持精度和稳定度,J0437-4715在13.58年内自主保持的脉冲星时与TT(BIPM15)偏差的RMS(root mean square)为0.454μs,长期(13.58年)稳定度为1.77×10^(-15),J1713+0747在17.46年内保持的脉冲星时与TT(BIPM15)偏差为2.471μs,长期(17.46年)稳定度为6.62×10^(-17),相对于最佳保持脉冲星时的精度分别降低24%和0.16%,但提升了短期(<1年)稳定度,长期稳定度略有恶化。展开更多
In this paper,we investigate the statistical signal-processing algorithm to measure the instant local clock jump from the timing data of multiple pulsars.Our algorithm is based on the framework of Bayesian statistics....In this paper,we investigate the statistical signal-processing algorithm to measure the instant local clock jump from the timing data of multiple pulsars.Our algorithm is based on the framework of Bayesian statistics.In order to make the Bayesian algorithm applicable with limited computational resources,we dedicated our efforts to the analytic marginalization of irrelevant parameters.We found that the widely used parameter for pulsar timing systematics,the"Efac"parameter,can be analytically marginalized.This reduces the Gaussian likelihood to a function very similar to the Student’s t-distribution.Our iterative method to solve the maximum likelihood estimator is also explained in the paper.Using pulsar timing data from the Yunnan Kunming 40-m radio telescope,we demonstrate the application of the method,where 80-ns level precision for the clock jump can be achieved.Such a precision is comparable to that of current commercial time transferring service using satellites.We expect that the current method could help developing the autonomous pulsar time scale.展开更多
文摘脉冲星钟模型保持方法和脉冲星时自主保持精度是决定脉冲星时应用精度的关键。根据地球时TT发布的特点以及脉冲星自转稳定特点,提出基于滑动累积窗口的脉冲星钟模型保持方法。首先利用IPTA第2批发布的2颗脉冲星观测数据开展钟模型保持精度分析,在13年以上的时间窗口内2颗源的自转频率测量值相对于平均值波动幅度在10^(-13)Hz之内,且随着时间窗口累积增加钟参数测量精度单调提高;其次,利用观测数据分析钟模型在滑动预报下的脉冲星时自主保持精度和稳定度,J0437-4715在13.58年内自主保持的脉冲星时与TT(BIPM15)偏差的RMS(root mean square)为0.454μs,长期(13.58年)稳定度为1.77×10^(-15),J1713+0747在17.46年内保持的脉冲星时与TT(BIPM15)偏差为2.471μs,长期(17.46年)稳定度为6.62×10^(-17),相对于最佳保持脉冲星时的精度分别降低24%和0.16%,但提升了短期(<1年)稳定度,长期稳定度略有恶化。
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB23010200)the National Natural Science Foundation of China(Grant Nos.U15311243,and 11690024)+1 种基金the National Basic Research Program of China(Grant No.2015CB857101)the funding from Tian Shan Chuang Xin Tuan Dui and the Max-Planck Partner Group
文摘In this paper,we investigate the statistical signal-processing algorithm to measure the instant local clock jump from the timing data of multiple pulsars.Our algorithm is based on the framework of Bayesian statistics.In order to make the Bayesian algorithm applicable with limited computational resources,we dedicated our efforts to the analytic marginalization of irrelevant parameters.We found that the widely used parameter for pulsar timing systematics,the"Efac"parameter,can be analytically marginalized.This reduces the Gaussian likelihood to a function very similar to the Student’s t-distribution.Our iterative method to solve the maximum likelihood estimator is also explained in the paper.Using pulsar timing data from the Yunnan Kunming 40-m radio telescope,we demonstrate the application of the method,where 80-ns level precision for the clock jump can be achieved.Such a precision is comparable to that of current commercial time transferring service using satellites.We expect that the current method could help developing the autonomous pulsar time scale.
