Improvement of the Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Inversion Code

A spectral line inversion code, Very Fast Inversion of the Stokes Vector (VFISV), has been used since May 2010 to infer solar atmospheric parameters from spectropolarimetric observations taken by Helioseismic and Magnetic Imager (HMI) aboard Solar Dynamics Observatory (SDO). The magnetic filling factor, fraction surface with a resolution element occupied field, is set have constant value one in current version VFISV. This report describes an improved strategy for data observed HMI field strengths intermediate values areas spatially not fully resolved. VFISV code modified enable profiles two different components: non-magnetic. In this scheme, both components share except strength, inclination, azimuth. order determine whether new useful, we evaluate inferred inverted component (the original inversion) version) using Bayesian analysis. pixels (e.g. plages), provides statistically significant vector. Not only does fitting profile improve, but inference line-of-sight velocity are obtained uniquely. also proven be effective mitigating anomalous hemispheric bias east-west moderate regions.