Imaging and Computing Seminar

Russell Hewett , Computer Science, UIUC

Numerical Methods for Solar Tomography in the STEREO Era

Despite its proximity, our collective understanding of the physical processes that drive the sun are incomplete. In particular, energetic and dynamic phenomena, such as active regions, solar flares, coronal mass ejections (CMEs), and solar wind, all of which contribute to geoeffective events collectively referred to as space weather, are not well understood. Knowledge of key physical parameters of the solar corona (or solar atmosphere), such as temperature and electron density, are critical to the understanding of the processes that drive coronal activity. This talk surveys new developments in key aspects of the mathematical and computational problems associated with the empirical estimation of these coronal parameters, including constrained methods for dynamic estimation, a phase field based level set method for tomography of CMEs from extremely limited points-of-view, and a scalable algorithm for constructing the tomographic projection matrices required for algebraic reconstruction methods.