A search for latent periodicities of irregular time series of total solar irradiance

In this paper we have analyzed the total solar irradiance signal obtained from Earth Radiation Budget Satellite. After denoising this signal using simple exponential smoothing we experimented with this filtered signal to study its nature. Fractal dimension analysis has been applied on it and the obtained value of fractal dimension demonstrates anti-persistent behaviour (short memory process) which may imply multi-periodic phenomenon. To sort out the possible periods with higher confidences we have applied Ferraz-Mello´s method of Date Compensated Discrete Fourier Transform as well as method of Periodogram which are very much useful for the present time series with uneven gaps. We have found certain periodicities from these two methods with confidence levels all higher than 95%.