基于实测星载原子钟数据的脉冲星守时方法

Pulsar timing method based on measured spaceborne atomic clock data

关键词:  卫星导航  脉冲星  守时  星载原子钟  数据分析

Key words:  Satellite navigation  Pulsar  Timing  Spaceborne atomic clock  Data analysis

摘要:

利用脉冲星估计星载原子钟钟差是实现卫星自主守时的途径之一。为充分分析基于脉冲星的自主守时系统性能，利用实测的星载原子钟钟差数据和中子星内部组成探测器(neutron star interior composition explorer, NICER)的PSR B1937+21脉冲星的观测数据，对比分析了星载原子钟和脉冲星的误差特性。设计了脉冲星守时系统框架和星载原子钟钟差估计方法。以实测的星载原子钟钟差数据为基础，计算分析了脉冲星守时系统的性能。计算结果表明，若脉冲星的脉冲到达时间（time of arrival, TOA）解算精度为1 μs/30 d，则原子钟钟差估计精度可达到优于1 μs的水平，初步验证了脉冲星守时系统的可行性。

Abstract:

Using pulsars to estimate the clock deviation of spaceborne atomic clocks is one of the ways to achieve autonomous time keeping for satellites. In order to fully analyze the performance of pulsar-based timing systems, the error characteristics of spaceborne atomic clocks and pulsar are analyzed, using measured clock deviation data of the spaceborne atomic clock and observation data of PSR B1937+21 from neutron star interior composition explorer (NICER). Then, a pulsar timing system framework and a method for estimating the clock deviation of spaceborne atomic clocks is designed. Based on the measured clock deviation data of the spaceborne atomic clock, the performance of the pulsar timing system is simulated and analyzed. The simulation results show that if the accuracy of the pulse arrival time of a pulsar is 1 μs/30 d, the estimation accuracy of the atomic clock deviation can reach a level better than 1 μs, which preliminarily verifies the feasibility of the pulsar timing system.