Etude de la couronne solaire en 3D et de son évolution avec SOHO ...

tel-00089354, version 1 - 17 Aug 2006
304 F. PORTIER-FOZZANI ET AL.
Figure 12. For r1 given at 10 Mm, minimal variation obtained for φ1 from −90 to −80 deg, φ2 from
−200 to −190 deg: minimum deviation correspond to φ1 ∼−81 deg and φ2 ∼−197 deg.
Figure 13. For r1 given at 9 Mm, measurement of the minimum variation for φ1 from −90 up to
−80 deg, φ2 from −200 up to −190 deg.
The uncertainty calculation is given by the sum of all uncertainties for each of
the parameters. With 30 points, a previous calculation (in the main text) shows that
the most discernible difference between the sampled loop and the model is an error
of 0.2 pixels. If s1 is the solution and s2 can be a solution if Error(Norm(s2 −s1)) ≤
0.2 pixels. Then for all fixed parameters except 2, this cooresponds numerically
to ∼ 4.7 deg (Portier–Fozzani, 1999). Numerical simulations for the uncertainties
is used because even if the torus is a correct analytical function, a line over
a torus is not a simple function and the error cannot be easily derived.