shape and a uniform radiance distribution within the cross section of two plumes of different radii. Figure \[fig:cross\_sec\] shows the resulting radiance distributions from two different perspectives.

Finally, the axes of the five plumes were traced by repeating the procedure for each plume at eight different heights above the solar limb. Since in EUV images plumes are shaped as nearly straight lines, each plume axis was approximated by a linear function and plotted as a dotted line in Figure \[fig:euvi\_0407\]. The identification of the plumes for the second data set observed in June 2007 is similar and the results are overplotted on the corresponding EUVI A and B images shown in Figure \[fig:euvi\_0601\].

From these linear 2D plume positions in both EUVI images, we reconstruct the 3D plume locations based on epipolar geometry in the frame of the HEEQ coordinate system. The reconstructed plumes are straight lines in 3D. In order to obtain an error estimate, we here assume a maximal uncertainty of 3 Mm, corresponding to an positional error in the images of $4.3^{\prime\prime}$ in EUVI A and $4.0^{\prime\prime}$ in EUVI B, in the estimated plume position along the epipolar line due to the three-pixel smoothing as mentioned before. 