Stereoscopy and tomography of coronal structures

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The solar corona is a low-density plasma intricately shaped by magnetic fields, displaying a variety of structures that range in size from the Sun’s diameter to the limits of angular resolution. Among these structures are polar plumes, which trace the open field lines extending from the Sun's surface into the heliosphere. Their 3D geometry, formation, and role in solar phenomena remain subjects of ongoing research. This dissertation introduces advanced mathematical techniques to detect and reconstruct the 3D structure of plumes, including: (i) a multiscale identification method utilizing Hough-wavelet analysis; (ii) tomography via filtered back projection that accounts for the Sun's differential rotation; and (iii) a conventional stereoscopic triangulation method. The study focuses on polar plumes observed in Solar Extreme Ultraviolet images from the STEREO/EUVI A and B, and SoHO/EIT telescopes. By analyzing the projected orientation of the plumes, the research characterizes the large-scale magnetic field, identifying the opening of the polar cap magnetic field and its inclination relative to the solar rotation axis. The 3D reconstructions enable an exploration of the plumes' cross-sectional shapes, their distribution over the polar cap, and potential associations with coronal jets.