Session H4: Local Helioseismology - Techniques
Tuesday, Valentine's Day, 2005
2:15-3:45 p.m.
Organizers: Deborah Haber & Tom Duvall

What problems do we face in making local helioseismology techniques more reliable in time for HMI?

one minute intro - Deborah

3:16 - 3:30  Time-Distance Inversions and Kernels for 3-D Ring Inversions - Aaron Birch

3:30 - 3:40  Time-Distance Analysis - Tom Duvall

3:40 - 3:50  Ring Analysis - Irene Gonzalez-Hernandez

3:50 - 4:00  Holography - Doug Braun

4:00 - 4:10  Progress in Direct Modelling - Martin Woodard

4:10 - 4:40  Discussion on Basic Problems Common to all - All

4:40 - 4:45  Wrap up - Deborah Haber

As a way of kick starting the discussion, please take a look at the list below
and see if any of these problems are ones that affect your research and if
there are any tests you can perform that will further our understanding of
how to address  them in time for HMI.  Which do you feel are most important?
What modelling might need to be carried out, or artificial data produced to
help us  address these issues?  What problems are missing from this list? If
you are one of the speakers and plan to address any of these issues please
let us know ahead of time.  If you are not one of the speakers, but have any
information on tests you have already run that you would like to present please
get the slides or files to me before Tues. at 3:15 when this session starts.

Possible problems for Ring and Time-Distance Analysis, but with possible broader implications

      1.  Foreshortening
      2.  Background noise
      3.  Spatially varying MTF effects (Instrumental FOV sensitivity)
      4.  Image distortions
      5.  Magnetic effects
      6.  Leaks (e.g., apodization effects on FFT)
      7.  Projection deficiencies (All projections are imperfect)
      8.  LOS effects (phase changes, distortion from center-to-limb effective height variations)
      9.  Carrington element errors
      10. Tracking choice
      11. Spectral line profile changes
      12. Crosstalk between observables
      13. Mode Asymmetry
      14. Temporal and Spatial filter sensitivity
      15. Why are there spatially varying frequencies or travel times across the disk?
      16. How should time-distance data cubes be filtered before analysis?