ephemeris time उदाहरण वाक्य
उदाहरण वाक्य
- The 1961 official reference put it this way : " The origin and rate of ephemeris time are defined to make the Sun's mean longitude agree with Newcomb's expression"
- Time : A major change introduced with the 1960 issue of " The Astronomical Ephemeris " was the use of ephemeris time in place of mean solar time for the major ephemeris tabulations.
- Its successor time scales, such as TDT, as well as the atomic time scale IAT ( TAI ), were designed with a relationship that " provides continuity with ephemeris time ".
- The ephemeris time of the 1952 standard leaves a continuing legacy, through its ephemeris second which became closely duplicated in the length of the current standard SI second ( see below : Redefinition of the second ).
- However, the International Astronomical Union meeting in Rome in 1952 had adopted the ephemeris time scale, on a proposal by Gerald Clemence defining the time unit in terms of the Earth s motion round the sun.
- The length of the SI second was calibrated on the basis of the second of ephemeris time and can now be seen to have a relationship with the mean solar day observed between 1750 and 1892, analysed by Simon Newcomb.
- Thus the new TDB, like T eph, is essentially a more refined continuation of the older ephemeris time ET and ( apart from the periodic fluctuations ) has the same mean rate as that established for ET in the 1950s.
- In 1976, however, the IAU resolved that the theoretical basis for ephemeris time was wholly non-relativistic, and therefore, beginning in 1984 ephemeris time would be replaced by two further time scales with allowance for relativistic corrections.
- In 1976, however, the IAU resolved that the theoretical basis for ephemeris time was wholly non-relativistic, and therefore, beginning in 1984 ephemeris time would be replaced by two further time scales with allowance for relativistic corrections.
- Previous to the 1960 change, the'Improved Lunar Ephemeris'had already been made available in terms of ephemeris time for the years 1952-1959 ( computed by Brown's theory with modifications recommended by Clemence ( 1948 ) ).