Searching for Resonances in the Presence of Cycle Variations
Abstract
The identification of new weak resonances against a broadband background of convection noise is favoured by the analysis of longer time-series. The signal to noise ratio is always improved by more data but particularly so where the coherence time approaches or exceeds the length of the series. On the other hand it is well known that the frequencies of solar p-mode oscillations vary as a function of the solar cycle. Many workers have made quantitative studies of this effect as a function of activity frequency and degree. Such variations tend to reduce the efficiency of many of the classical methods of searching for signals in the presence of noise. The development of search techniques which take into account the known or predicted cycle variation can improve the detectability of certain low-frequency modes. If as some theorists have suggested there exist activity cycle variations for solar g-mode frequencies then such methods would be particularly applicable.
- Publication:
-
IAU Joint Discussion
- Pub Date:
- 2003
- Bibcode:
- 2003IAUJD..12E..47G