Natural SciencesAstronomyGeophysicsOptical AstronomyOpticsSolar AstronomyFourier OpticsSolar Active RegionsSolar Magnetic FieldsSolar ObservationsSolar PolarimetrySolar RadiationDiffraction-limited ImagingImaging PolarimetryOptical Transfer Function EstimationSmall-scale Magnetic FieldsSolar ImagingSolar MagnetogramsSolar System PolarimetrySpeckle Phenomena
The combination of a polarimeter with real-time frame selection and differential speckle imaging results in diffraction-limited magnetograms that provide new insight into the morphology of solar small-scale magnetic fields. The method to record diffraction limited narrow-band filtergrams of solar features is based on two cameras taking simultaneous short exposure images through a broad-band and a narrow-band filter, respectively. Speckle imaging reconstructs the image in the broad-band channel. This reconstruction determines the instantaneous optical transfer function (OTF) for each individual broad-band exposure