Abstract
In time-distance helioseismology wave travel times are measured from the cross-correlation between Doppler velocities recorded at any two locations on the solar surface. We compare two different methods to extract the travel times from the noisy cross-correlation functions. The first method consists of fitting a 5-parameter analytic function to the cross-correlation to obtain the phase travel time. The second method consists of linearizing the distance between the observed cross-correlation and a sliding reference cross-correlation (the only parameter is the travel time). We find that the one-parameter fits are more robust with respect to noise. Using SOHO data from the MDI Structure Program for the years 1996-2003, we study in detail the statistical properties of the noise associated with the travel-time measurements for the two different fitting methods.
Original language | English (US) |
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Pages (from-to) | 215-222 |
Number of pages | 8 |
Journal | Astronomische Nachrichten |
Volume | 328 |
Issue number | 3-4 |
DOIs | |
State | Published - Mar 2007 |
Keywords
- Methods: data analysis
- Sun: helioseismology
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science