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arXiv · 2204.03732

A Model-based Technique for Ad Hoc Correction of Instrumental Polarization in Solar Spectropolarimetry

Sarah A. Jaeggli·Thomas A. Schad·Lucas A. Tarr·David M. Harrington
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Abstract

We present a new approach for correcting instrumental polarization by modeling the non-depolarizing effects of a complex series of optical elements to determine physically realizable Mueller matrices. Provided that the Mueller matrix of the optical system can be decomposed into a general elliptical diattenuator and general elliptical retarder, it is possible to model the cross-talk between both the polarized and unpolarized states of the Stokes vector and then use the acquired science observations to determine the best-fit free parameters. Here, we implement a minimization for solar spectropolarimetric measurements containing photospheric spectral lines sensitive to the Zeeman effect using physical constraints provided by polarized line and continuum formation. This model-based approach is able to provide an accurate correction even in the presence of large amounts of polarization cross-talk and conserves the physically meaningful magnitude of the Stokes vector, a significant improvement over previous ad hoc techniques.

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Sarah A. Jaeggli, Thomas A. Schad, Lucas A. Tarr, David M. Harrington. 2022-04-07. A Model-based Technique for Ad Hoc Correction of Instrumental Polarization in Solar Spectropolarimetry. https://doi.org/10.3847/1538-4357%2Fac6506

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