Measuring helioseismic travel times

M. Roth, Laurent Gizon, J. G. Beck

Research output: Contribution to journalArticle

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 languageEnglish (US)
Pages (from-to)215-222
Number of pages8
JournalAstronomische Nachrichten
Volume328
Issue number3-4
DOIs
StatePublished - Mar 1 2007

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cross correlation
travel time
travel
helioseismology
analytic functions
sliding
time measurement
measuring
method
parameter

Keywords

  • Methods: data analysis
  • Sun: helioseismology

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Measuring helioseismic travel times. / Roth, M.; Gizon, Laurent; Beck, J. G.

In: Astronomische Nachrichten, Vol. 328, No. 3-4, 01.03.2007, p. 215-222.

Research output: Contribution to journalArticle

Roth, M. ; Gizon, Laurent ; Beck, J. G. / Measuring helioseismic travel times. In: Astronomische Nachrichten. 2007 ; Vol. 328, No. 3-4. pp. 215-222.
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