利用高精度时频信号测定重力位

Determining the gravity potential by high precision time-frequency signal

与传统测量方法相比,利用高精度时频信号测定重力位更加快捷,可实现陆地与岛屿之间的重力位差测定.进入21世纪以来,随着原子钟的精度不断提高,使得高精度时频信号测定重力位成为可能,相对论方法测定重力位逐渐成为全球研究热点,并取得了重要进展与成果.这里介绍了高精度时频信号测定重力位的基本原理,包括光纤电缆信号传递、激光时间传递、卫星双向时频传递、GNSS共视时频传递、GNSS载波相位时频传递、卫星频率信号传递和VLBI时频信号传递等测定重力位的方法和技术,并讨论了时频信号传递测定重力位的发展趋势.未来原子钟精度达到10量级时,有望在厘米级精度测定重力位和海拔高.

Compared with the traditional measurement method,the gravity potential difference between land and island can be precisely measured without difficulty using high-precision time-frequency signals.Since entering the 21st century,with the continuous improvement of the precision of atomic clocks,it has become prospective to measure the gravity potential by high-precision time-frequency signals.Using general relativity to determine gravity potential gradually became a global research focus and made significant progress and achievements.This paper introduces the basic principle of determining the gravity potential by high-precision time-frequency signals,which include the time-frequency transfer by optical fiber and cable links,laser time transfer,two-way satellite time-frequency transfer,GNSS common-view time-frequency transfer,GNSS carrier phase time-frequency transfer,frequency signals transfer between satellites and the ground stations,and VLBI time-frequency signal transfer,and other gravity potential determination methods and technologies.It discussed the trend of gravity potential measurement by time-frequency signal transmission.In the near future,it is expected to measure gravity potential and altitude with centimeter accuracy when the atomic clocks reach an accuracy level of 10.