The study of periodic regularity of solar activity with data analysis method

In the paper, firstly different wavelet bases are selected to denoise the sunspot activity data through the wavelet transformation, then the EMD analysis method are taken to decompose these two sets of signals, subsequently the physical IMF period of each layer are obtained by using FFT transform. Through the comparisons between the obtained results and the public time-scale of solar activity, we select two proper sets of wavelet bases. At the same time, the above method are used to dispose the AP indexes to find 6 months, 1 year and 11 years' cycle and others. Experimental results indicate that it is effective in investigating the solar periodic activity regularity and the correlation among space environmental signal data.