AIA/HMI Science Meeting, Monterey, Feb-2006

1
DEM Algorithms and Techniques
Various approaches to DEM analysis have a variety
of pros and cons, and some aspects have yet to be
fully investigated and understood.

• Examples
• Forward search versus direct inversion
  methods.
• Processing time how to impose constraints how
  to handle multiplicity of solutions
• - Selection of solution temperature range and
  temperature bins appropriate to instrument.
• Uniform grid vs optimized how to optimize how
  to set range over- vs under-determined
• A-priori constraints (eg, positivity,
  smoothness, etc).
• Decisions for data products how to impose
  (regularization, search constraints)
• Estimating uncertainties.
• Monte Carlo contribution of atomic physics does
  it affect choice of solution method
• Combining instrument data.
• Spectral vs imagers narrow- vs broadband
  cross-calibration

Should all of these aspects be explored? Can
community identify clear-cut decisions on some of
these issues? What other issues must be
recognized?
AIA/HMI Science Meeting, Monterey, Feb-2006
C3 Thermal Studies
2
DEM Science
New types of investigations in coronal physics
will be possible with SDO data and
state-of-the-art DEM techniques.

• Benefits of Thermal Maps
• Distinguish structures along LOS.
• Catch plasma evolving through temperature bins
• distinguish temperature changes vs plasma flows.
• Locations and magnitudes of heating and cooling.
• Topology and connectivity (and helicity?).
• - Relation to EVE irradiance.

What science does community hope to do with SDO
(and other) thermal maps? What new science can be
done with regular, whole-Sun, thermal maps?
AIA/HMI Science Meeting, Monterey, Feb-2006
C3 Thermal Studies