The introduction of the Iau 1980 nutation theory in the computation of the Earth Rotation Parameters by the Bureau International de l'Heure

Summary The status of nutation theory in the computation of the Earth Rotation Parameters from the different observational techniques is reviewed. The impact on the combined solution of the Bureau International de l'Heure is evaluated. In view of the improvement brought by the IAU 1980 Nutation Theory, its introduction in the BIH publications, without waiting for the adoption by the astronomical ephemerides (1984 Jan. 1) is decided.