A Note on Saturation Seen in the MDI/SOHO Magnetograms
作者： Y. Liu , A. A. Norton , P. H. Scherrer
DOI: 10.1007/S11207-007-0296-5
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摘要: A type of saturation is sometimes seen in sunspot umbrae MDI/SOHO magnetograms. In this paper, we present the underlying cause such saturation. By using a set MDI circular polarization filtergrams taken during an line profile campaign observation, derive magnetograms two different approaches: on-board data processing and ground processing, respectively. The algorithms for are same, but former limited by 15-bit lookup table. Saturation clearly magnetogram from simulation, which comparable to observed one half hours before data. We analyze saturated pixels examine numerical calculation method. conclude that very low intensity leads depth spectral becomes problematic when treatment. This treatment values reason magnetogram. Although it possible occur combination strong magnetic field high velocity moves out effective sampling range, not observed.
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