Expression for Greenwich Sidereal Time based on the IAU2000A precession-nutation model Expression ensuring continuity of UT1 on 1st January 2003 -------------------------------------------------------------------------------------------------------------- GST = Theta(UT1) + polynomial part + DeltaPsi*cos(epsilon_A) + non-polynomial part -------------------------------------------------------------------------------------------------------------- Theta(UT1) = 2*Pi*(0.7790572732640 + 1.00273781191135448.T_u) where T_u = Julian UT1 date - 2451545.0, and UT1 = UTC + (UT1 - UTC) -------------------------------------------------------------------------------------------------------------- Polynomial part (unit arcsecond) 0''.014506 + 4612''.15739966t + 1''.39667721t^2 - 0''.00009344t^3 + 0''.00001882t^4 -------------------------------------------------------------------------------------------------------------- DeltaPsi*cos(epsilon_A) = classical expression for the equation of the equinoxes -------------------------------------------------------------------------------------------------------------- Non-polynomial part (unit microarcsecond) (ARG being for various combination of the fundamental arguments of the nutation theory) Sum_i[C_{s,0})_i * sin(ARG) + C_{c,0})_i * cos(ARG)] + Sum_i[C_{s,1})_i * t * sin(ARG) + C_{c,1})_i * cos(ARG)] * t] The Table below provides the values for C_{s,j})_i and C_{c,j})_i Cutoff (0.1 microarcsecond and periods less than 500 years) The expressions for the fundamental arguments appearing in columns 4 to 8 (luni-solar part) and in columns 6 to 17 (planetary part) are those of the IERS Conventions 2000 -------------------------------------------------------------------------------------------------------------- i C_{s,j})_i C_{c,j})_i l l' F D Om L_Me L_Ve L_E L_Ma L_J L_Sa L_U L_Ne p_A -------------------------------------------------------------------------------------------------------------- j = 0 Nb of terms = 33 1 2640.96 -0.39 0 0 0 0 1 0 0 0 0 0 0 0 0 0 2 63.52 -0.02 0 0 0 0 2 0 0 0 0 0 0 0 0 0 3 11.75 0.01 0 0 2 -2 3 0 0 0 0 0 0 0 0 0 4 11.21 0.01 0 0 2 -2 1 0 0 0 0 0 0 0 0 0 5 -4.55 0.00 0 0 2 -2 2 0 0 0 0 0 0 0 0 0 6 2.02 0.00 0 0 2 0 3 0 0 0 0 0 0 0 0 0 7 1.98 0.00 0 0 2 0 1 0 0 0 0 0 0 0 0 0 8 -1.72 0.00 0 0 0 0 3 0 0 0 0 0 0 0 0 0 9 -1.41 -0.01 0 1 0 0 1 0 0 0 0 0 0 0 0 0 10 -1.26 -0.01 0 1 0 0 -1 0 0 0 0 0 0 0 0 0 11 -0.63 0.00 1 0 0 0 -1 0 0 0 0 0 0 0 0 0 12 -0.63 0.00 1 0 0 0 1 0 0 0 0 0 0 0 0 0 13 0.46 0.00 0 1 2 -2 3 0 0 0 0 0 0 0 0 0 14 0.45 0.00 0 1 2 -2 1 0 0 0 0 0 0 0 0 0 15 0.36 0.00 0 0 4 -4 4 0 0 0 0 0 0 0 0 0 16 -0.24 -0.12 0 0 1 -1 1 0 -8 12 0 0 0 0 0 0 17 0.32 0.00 0 0 2 0 0 0 0 0 0 0 0 0 0 0 18 0.28 0.00 0 0 2 0 2 0 0 0 0 0 0 0 0 0 19 0.27 0.00 1 0 2 0 3 0 0 0 0 0 0 0 0 0 20 0.26 0.00 1 0 2 0 1 0 0 0 0 0 0 0 0 0 21 -0.21 0.00 0 0 2 -2 0 0 0 0 0 0 0 0 0 0 22 0.19 0.00 0 1 -2 2 -3 0 0 0 0 0 0 0 0 0 23 0.18 0.00 0 1 -2 2 -1 0 0 0 0 0 0 0 0 0 24 -0.10 0.05 0 0 0 0 0 0 8 -13 0 0 0 0 0 -1 25 0.15 0.00 0 0 0 2 0 0 0 0 0 0 0 0 0 0 26 -0.14 0.00 2 0 -2 0 -1 0 0 0 0 0 0 0 0 0 27 0.14 0.00 1 0 0 -2 1 0 0 0 0 0 0 0 0 0 28 -0.14 0.00 0 1 2 -2 2 0 0 0 0 0 0 0 0 0 29 0.14 0.00 1 0 0 -2 -1 0 0 0 0 0 0 0 0 0 30 0.13 0.00 0 0 4 -2 4 0 0 0 0 0 0 0 0 0 31 -0.11 0.00 0 0 2 -2 4 0 0 0 0 0 0 0 0 0 32 0.11 0.00 1 0 -2 0 -3 0 0 0 0 0 0 0 0 0 33 0.11 0.00 1 0 -2 0 -1 0 0 0 0 0 0 0 0 0 j = 1 Nb of terms = 1 34 -0.87 0.00 0 0 0 0 1 0 0 0 0 0 0 0 0 0