A homogeneous z-term series of astrometric latitude observations (January 5, 1962-December 31, 1981)

Optical astrometric data for 1962-1982 has been reduced in order to redetermine the earth rotation parameters. A homogeneous series of z-terms of latitude observations has also been obtained. A total of 1461 z-terms at five-day intervals in the 20 years are given in this paper. The typical precisions of the z-terms are of the order of + or - 0.014 arcsec for the first five years and from + or - 0.008 arecsec to + or - 0.005 arcsec for the following years.