Polynomial Approximations for the Correction Delta T = E.T. U.T. in the Period 18001975
Abstract
Polynomial approximations for the empirical difference between Ephemeris and Universal Time are discussed in order to provide simple arithmetic means for computing purposes. The entire period 1972.61978.5 can be covered by a 12th degree polynomial with a mean error of less than one second. All coefficients are significant values well above the 3 sigma level of the mean coefficient errors. Coefficients, mean errors, and maximal residuals for polynomials of degree 8 to 16 are given as well as leastsquares solutions fitting lowdegree expressions to some smaller time intervals.
 Publication:

Acta Astronomica
 Pub Date:
 1979
 Bibcode:
 1979AcA....29..101S
 Keywords:

 Ephemeris Time;
 Error Correcting Devices;
 Polynomials;
 Universal Time;
 Approximation;
 Least Squares Method;
 Long Term Effects;
 Tables (Data);
 Astronomy