“…The number r − 1 (= 2 in this case) describes the degrees of freedom of the power (which is chi-squared distributed), Neff is the effective number of data points, and Sω 2 is the weighted estimated variance of the time series. The last two are defined by Foster (1996b) as (13) (14) where ωα is given by (5) and V f , the weighted variation of the time series f(t), is computed via (15) Finally, the weighted wavelet transform (WWT) is defined by (16) where Vy, the weighted variation of the model function y(t), is calculated in a similar fashion as (15) through the expression (17) For fixed scale factor a and time shift τ, the WWT can be treated as a chi-square statistic with two degrees of freedom and expected value of one (Foster, 1996b;Haubold, 1998). It turns out, however, that the WWT in (16) still has a serious shortcoming: it is very sensitive to the effective number of data Neff, which leads to a shift of the WWT peaks to lower frequencies (at lower frequencies the window is wider, so that more data points can be sampled and Neff becomes larger).…”