Harmonic Analysis of IGS stations time series

Recent reprocessing of the IGS time series (e.g., due to absolute antenna phase centre variation) gives the opportunity to look into periodicities due to some geophysical or local effects (at the observation domain) or due to some mis- or un-modelled effects (at the residual domain). We do that by means of the Least Squares Spectral Analysis method. We first want to quantify periodicities in both time series and to qualify, if possible, these periodicities and to correlate to physical phenomena. Preliminary results are shown in this poster.