Sparse interferometric Stokes imaging under polarization constraint (Polarized SARA)

Understand

We develop a novel algorithm for sparse Stokes parameters imaging in radio interferometry under the polarization constraint.

• The latter is a physical non-linear relation between the Stokes parameters, imposing that the polarization intensity is a lower bound on the total intensity.
• To solve the joint inverse Stokes imaging problem including this bound, we leverage epigraphical projection techniques in convex optimization and design a primal-dual method offering a highly flexible and parallelizable structure.
• In addition, we propose to regularize each Stokes parameter map through an average sparsity prior in the context of a reweighted analysis approach (SARA).