Study On the Conversion and Teaching of Time Scales in Space Positioning and Navigation

With some time scales discussed,classification of time scales is concluded,and translation theories between them are introduced.Differences in different time scales and translation between UTC(Universal Time Coordinate) and ST(Sidereal time) based on different IAU(The International Astronomical Union) Precession-Nutation Models are analyzed by real count data.The results show that leap seconds are not uniform distribution in time and Earth's rotation is slower and slower. We also get the conclusion that differences in Dynamics time are small,TCB(Barycentric Coordinate Time) is excepted,difference between Dynamics time and TAI(International Atomic Time) is not lager than 1 minute.IAU94 Precession-Nutation Models have more difference with IAU2000 Precession-Nutation Models and IAU2006(10-6rad) Precession-Nutation Models in translation of UTC and ST.The software and calculation process of this paper will provide the necessary reference for the theory and experiment teaching of related courses.