Time-distance Helioseismology Technique Issues

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Time-distance Helioseismology Technique Issues

• T. L. Duvall Jr. (NASA/GSFC)

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Time-distance analysis

• Projection tracking
• Filtering (phase speed filtering other types)
• Cross correlation (includes mapping quadrants
  deep or surface focusing)
• peak bagging (Gabor wavelet fitting and the
  Gizon-Birch method)
• Inversion (somebody elses problem)

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Filtering

• Phase-speed filtering has a problem in areas
  like sunspots with oscillation amplitude
  spatially varying, travel time errors occur
  (Rajaguru et al. 2006)

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Cross correlation
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Cross correlation
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Fitting Gabor wavelet
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Fitting Gizon-Birch method