GCS model results (cf. Fig. 6) showing the heights of the reconstructed fronts ofCME1 (solid black) and CME2 (dashed red) as a function of their angular widths at five time steps according to the COR1 cadence. We defined the apex to cover an angle of 15° from the central axis, and the flanks to cover the angles larger than 15°. We note that the model results are symmetric, therefore only the half width is plotted.