Session 2: Solar, Planetary and Space Physics

Title: Improvement in Successive Approximations method and application on Ulysses energetic particle measurements near Jupiter
Author(s): Aggelis A., Anagnostopoulos G.C., Preka P. (Poster)

Successive Aproximations Method (SAM) is a recursive method for studying periodic phenomena in time series. Study of periodic phenomena with SAM is achieved by decomposing the observed time series into simpler sinusodial time series. The advantage of SAM compared to other methods (i.e. Fourier Analysis) is that it marks the location of each event on the time series, thus giving us the temporal / spatial/ intensity distributions of the events. SAM was not fully automated through computerized algorithms so far, thus requiring a lot of user decisions in order to produce results in large data sets. In this study we present an improvement on the automation of SAM and an application to the large data sets of HI-SCALE experiment during Ulysses Jupiter flyby. SAM supports previous findings (Anagnostopoulos et. al. 2001) about quasi-periodic (~20 / 40 /80 min) modulation of HI-SCALE energetic ion data in the outer high latitude dusk-side Jovian magnetosphere in February 1992.