摘要
自由空间激光时频传递是未来空间高精度时频传递的重要技术发展方向。高精度的事件计时器是实现自由空间激光时频传递的关键核心设备,提出了组合确定性因素和随机因素的性能评估模型,通过测量精密频率源的时序数据得到不同事件计时器基于最小二乘的频率准确度、频率漂移率,表征频率稳定度的时域方差包括Allan方差、Modified Allan方差、Time方差和Hadamard方差,依据幂律谱模型分离出事件计时器测量数据的随机游走噪声、调频白噪声、调频闪烁噪声、调相白噪声和调相闪烁噪声五种随机噪声。对比分析了性能处于同一量级的两种典型高精度事件计时器A033和GT668的性能差异,在频率测量准确度上,A033事件计时器优于7×10^(-12),而GT668事件计时器优于3.1×10^(-12),频率漂移率A033为2.096×10^(-15),而GT668则是-1.071×10^(-15),短期(1 d)稳定性Allan标准差由7×10^(-12)变化到4×10^(-12);GT668在随机游走噪声曲线走势上更为稳定,调频闪烁噪声和调频白噪声没有明显差异。实验表明,通过文中性能分析方法可以对高精度事件计时器性能进行评估分析,对其准确性和可靠性进行判定,为高精度事件计时器的使用提供分析依据。
Objective Free-space laser time-frequency transmission technology has the advantages of high capacity,extensive coverage,long transmission distance,and high confidentiality.Its accuracy is expected to reach the standard quantum limit,making it an important technical development direction for space high-precision timefrequency transmission in the future.The precision of laser range directly affects the accuracy of laser time-frequency transmission,which is determined by the accuracy of measuring the pulse round-trip time interval.Compared with traditional time interval counting method,the measurement accuracy of event timing method has reached ps level,and it has become an essential measurement technology in high-repetition-rate laser ranging technology.In this research,an index evaluation model for the measurement performance of the event timer was established in order to provide a reference for the assessment of event timer in free-space laser time-frequency transmission with greater precision and longer distance.Methods The performance assessment model for event timers presented in this work mixes deterministic and random elements.Frequency stability(time-domain variance)and power-law spectral noise are random parameters,and frequency accuracy and frequency drift rate are deterministic ones.Time series from accurate frequency sources can be measured to obtain a number of indicators that describe the effectiveness of the event timer,such as those based on the minimum double-dimensional frequency accuracy and frequency drift rates,as well as time-dome differences that describe the stability of frequencies,such as Allan variance,Modified Allan variance,Time variance and Hadamard variance.The power law spectrum model contains five random noises,including random walk noise,frequency-modulated white noise,frequency-modulated flicker noise,phasemodulated white noise and phase-modulated flicker noise,which can be separated from the event timer measurement data.The measurement method was created using the performance as
作者
薛涵
张子昂
付靖祺
刁凌天
穆力纬
Xue Han;Zhang Ziang;Fu Jingqi;Diao Lingtian;Mu Liwei(Changchun Observatory of National Astronomical Observatories,Chinese Academy of Sciences,Changchun 130117,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《红外与激光工程》
EI
CSCD
北大核心
2023年第9期117-126,共10页
Infrared and Laser Engineering
基金
国家自然科学基金项目(12173059,11673082,11103047)
吉林省自然科学基金项目(20220101157JC)。
关键词
激光时频传递
事件计时器
时域方差
幂律谱噪声
laser time-frequency transmission
event timer
time-domain variance
power-law spectrum noise
