利用卫星双向时间频率传递确定重力位差和高程差

Determination of the Geopotential and Orthometric Height Difference Based on the Two Way Satellite Time and Frequency Transfer Observations

根据广义相对论,两地之间的重力位差导致两地之间时钟的运行速率差或频率差。反之,通过比对两地之间高精度时钟的守时速率之差或频率差,则可确定两地之间的重力位差及海拔高程差。本文选取国际度量局(BIPM)发布的5个台站2013年4月1日至21日的卫星双向时频传递(TWSTFT)数据,采用卫星双向时间频率传递技术,并基于重力频移法确定两地之间重力位差和高程差。与EGM2008模型结果的比对结果表明,重力位差和高程差的标准差分别为129.2m^2·s^(-2)和13.2m。实验结果与目前守时台站所采用原子钟的稳定度10×10^(-15)量级基本一致。迅速发展的时频技术及原子钟(光钟)精度不断提高,为利用卫星双向时间频率传递确定重力位差和高程差提供了应用空间。

According to general relativity theory,the geopotential difference between two positions gives rise to a clock＇s running rate difference（time difference）or oscillation frequency difference.Inversely,the geopotential difference and height difference between these two positions can be determined by measuring the frequency or time difference between two clocks located at these two positions.Using the TWSTFT,two way satellite time and frequency transfer data sets at five timingkeeping stations released by the BIPM（Bureau International des Poids et Mesures）,we determined the geopotential difference and height difference between any two of the five stations based upon the gravity frequency shift method and TWSTFT technique.Compared with EGM2008 model results,the standard deviations of the geopotential and height differences are 129.2 m^2·s^（-2）and 13.2m,respectively.Our experimental results are consistent with the current stability level 10E^（-15） of the atomic clocks installed at the time-keeping stations.The quick development of time-frequency science,including highly precise atomic clocks or optical clocks,creates the potential for using the TWSTFT technique to determine geopotential and height difference,as well as enable its extensive application in various fields.