太极计划时钟噪声传递的地面原理验证

Ground-based principle verification of clock noise transfer for the Taiji program

太极计划是中国科学院提出的空间引力波探测任务,其利用激光差分干涉的方法探测卫星间由引力波引起的pm级位移波动。为消除卫星间因时钟不同步而产生的测量误差,拟采用边带倍频时钟噪声传递方法进行星间时钟噪声测量与消除。本文讨论太极计划星间时钟噪声传递的需求、原理、方法,并设计实验进行原理验证。通过搭建电子学实验测试两个系统时钟噪声的极限值,确定实验相关参数,进一步通过光学实验验证边带倍频传递方案的原理。实验结果表明,本文提出的时钟噪声消除方案及相关参数合理可行,满足太极计划的应用需求。在0.05 Hz~1 Hz频段,星间时钟噪声的抑制效果优于2π×10^(−5)rad/Hz^(1/2),满足太极探路者的噪声需求。本文研究为未来太极计划的时钟噪声传递方案与参数设计奠定实验和理论基础。

The Taiji program is a space gravitational wave detection mission proposed by the Chinese Academy of Sciences,which uses laser differential interference to detect pm-level displacement fluctuations caused by gravitational waves between satellites.In order to eliminate the phase measurement error caused by the desynchronization of the clocks in satellites,the Taiji program intends to use the sideband multiplication transfer scheme to measure and eliminate inter-satellite clock noise.We discuss the requirements,principles,and methods of inter-satellite clock noise transmission of the Taiji program,and design experiments for the principle verification.By building an electronics experiment system,the limit value of the clock noise of the two systems was tested,the relevant parameters of the experiment were determined,and the principle of the sideband multiplication transfer scheme was verified by further optical experiments.The experimental results show that the clock noise cancellation scheme and related parameters proposed in this paper are reasonable and feasible,and are suitable for the needs of the Taiji program.Moreover,in the 0.05 Hz−1 Hz frequency band,the suppression effect of inter-satellite clock noise is better than 2π×10^(−5)rad/Hz^(1/2),which meets the noise requirements of the Taiji pathfinder and lays an experimental and theoretical foundation for the design of a clock noise transmission scheme and parameters of the Taiji program in the future.