Key points are not available for this paper at this time.
A large set of high-quality chromospheric activity index data of sufficient temporal extent to allow quantitative characterization of stellar cycles now exists thanks to the work, begun two decades ago, by Olin Wilson. In this paper the authors discuss the methods which can be used in analyzing the 18 yr records of Ca II H and K index data. It is shown that derivation of accurate periods and characterization of cycle morphology (ratio of rise to decay time) is possible, but that the background noise, especially the growth and decay of activity, is an important and troublesome factor to consider.
Gilliland et al. (Sun,) studied this question.