Variable Sine Algorithmic Analysis (VSAA) is a new method of time-series analysis. It is designed for time series that have been produced by the action of a single frequency that varies in time. It is especially suitable for astronomical processes with variable periodicity.
Periodic and quasi-periodic phenomena in astronomy are handled almost uniquely with the Fourier Transform (FT) method. FT is very efficient in many cases where the phenomena present multi-periodic behaviour but the frequency and amplitude of each periodic component remain constant through time. On the other hand, FT is proved to be inadequate to analyze time-series produced by a single mechanism where frequency and amplitude are functions of time. For these cases, VSAA can provide a suitable tool for analysis.
In particular, VSAA can be applied to:
- Period variation analysis of close binaries
- Magnetic activity analysis in RS CVn-type binaries
- Asteroseismological analysis of the Blazhko effect in RR Lyrae-type variables
- Helioseismological study of the sunspot activity
The aim of our project is to develop a prototype TFA algorithm, (VSAA), incorporate it with certain other TFA methods in a single program, apply and distribute it freely to the scientific community.
If you are interested in details, here's a list of papers dealing with VSAA.