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Chinese Physics B 2021年第8期30卷 260-268页

作者： Hui-Jian Liang Shi-Guang Wang Yu Bai Si-Chen Sun Li-Jun Wang Department of Electronic Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua UniversityBeijing 100084China Department of Precision Instruments Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China

We demonstrate a novel and stable frequency transfer scheme over ground-to-satellite link based on real-time carrier-phase detection and *** performed a zero-baseline measurement with the designed system,an uninterrupted frequency standard signal is recovered in the reception station without additional post-correction of delay error caused in the route,which is because the phase error of the entire route is tracked and compensated continuously in *** achieve this goal,we employed two carriers in the system and the differential signal is transferred in order to eliminate the instability results from the local oscillator at the satellite transponder as well as the common-mode noise induced in the transfer route and microwave *** stability of 3×10^(-16) with an integration time of 1 day was achieved and the time fluctuation during one day was measured to be about±20 *** sources and possible solutions are *** zero-baseline method shows a promising result for real-time satellite-based time and frequency transfer and deserves further research to find whether it works between long-baseline stations.

关键词： frequency transfer ground-to-satellite link carrier-phase compensation

Determination of the orthometric height difference based on optical fiber frequency transfer technique

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Geodesy and Geodynamics 2021年第6期12卷 405-412页

作者： Anh The Hoang Ziyu Shen Wen Bin Shen Chenghui Cai Wei Xu An Ning Yifan Wu School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China School of Resource Environmental Science and EngineeringHubei University of Science and TechnologyXianningHubeiChina School of Agriculture and Natural Resource Vinh UniversityVinh City 460000Viet Nam State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China Guangxi Key Laboratory of Spatial Information and Geomatics Guilin 541006China

The development of remote frequency transfer techniques,especially the appearance of optical clocks with unprecedented stability,has prompted geoscientists to study their applications in *** remote frequency transfer technique,by frequency comparison of two optical clocks at two points P and Q connected by optical fibers,one can measure the signal’s frequency shift between them,and the geopotential difference between them can be determined based on the gravity frequency shift *** the orthometric height of P,the orthometric height of Q can be *** the present stability of the optical clock has achieved 1×10^(-18) or better and comparing the frequency transfer via optical fiber provides stability at 10^(-19) level,the optical clock network enables determining the orthometric height at *** study provides a formulation to determine the height diffe rence at one-centimeter level between two points on the ground based on the optical fiber frequency transfer technique.

关键词： Optical fiber frequency transfer(OFFT) Optical fiber frequency transfer Geopotential

Fiber-based joint time and frequency dissemination via star-shaped commercial telecommunication network

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Chinese Physics B 2017年第8期26卷 96-101页

作者：袁一博王波王力军 State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China

A fiber-based, star-shaped joint time and frequency dissemination scheme is demonstrated. By working in cooperation with the existing commercial telecommunication network. Our scheme enables the frequency, time, and digital data networks to be integrated together and could represent an ideal option of interconnection among scientific *** compensation functions of the time and frequency transfer scheme are set at the client nodes. The complexity of the central node is thus reduced, and future expansion by the addition of further branches will be accomplished more *** a performance test in which the ambient temperature fluctuation is 30℃/day, timing signal dissemination stability is achieved to be approximately ±50 ps along 25-km-long fiber spools. After calibration, a timing signal synchronization accuracy of 100 ps is also realized. The proposed scheme offers an option of the construction of large-scale fiber-based frequency and time transfer networks.

关键词： time synchronization telecommunication network frequency transfer star-shaped network

Portable Atmospheric transfer of Microwave Signal Using Diode Laser with Timing Fluctuation Suppression

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ZTE Communications 2018年第4期16卷 52-56页

作者： CHEN Shijun BAI Qingsong CHEN Dawei SUN Fuyu HOU Dong ZTE Corporation Shenzhen 518057China University of Electronic Science and Technology of China Chengdu 611731China

We demonstrate an atmospheric transfer of microwave signal over a 120 m outdoor free-space link using a compact diode laser with a timing fluctuation suppression *** fluctuation and Allan Deviation are both measured to characterize the instability of transferred frequency incurred during the transfer *** transferring a 100 MHz microwave signal within 4500 s,the total root-mean-square(RMS)timing fluctuation was measured to be about 6 ps,with a fractional frequency instability on the order of 1×10-12 at 1 s,and order of 7×10-15 at 1000 *** portable atmospheric frequency transfer scheme with timing fluctuation suppression can be used to distribute an atomic clock-based frequency over a free-space link.

关键词： atmospheric communication frequency transfer diode laser timing fluctuation suppression