时空参考系中的坐标和时间单位

The Unit of Coordinates and Time in Space-time Reference Systems

针对目前时空参考系中关于坐标和时间单位的一些模糊认识,回顾了国际单位制SI与计量基准的定义及其发展,分析了国际计量局(BIPM)对测量单位SI米和SI秒的新定义,得出了在原时的单位采用SI秒时,各种时空参考系中的坐标量(坐标时和空间坐标)的单位均可认为是SI秒的结论。同时通过分析,明确了目前太阳系历表中使用的天文单位系统在时空参考系中的使用方法。

Aiming at some fuzzy knowledge about the unit of coordinates and time in space-time reference systems,developments and definitions of SI unit and metrological datum are reviewed, new definitions with SI metric and SI second of the Bureau International des Poids et Mesures are analyzed in this paper.It is argued that the scaled time scales,the scaled spatial coordinates, should be considered as SI second,the TDB second and TT second are not exist,the relativity model and physical model used to correct observation quantity are only to contrast expediently each other.Along the same lines,the system of astronomical units is discussed in the relativistic framework,the application method of astronomical unit used in solar system ephemeris in spacetime reference systems is presented as well.