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Ricean Bias Correction in Linear Polarization Observation

  • Sohn, Bong-Won (Korea Astronomy Observatory, Yonsei University Observatory)
  • Received : 2011.11.15
  • Accepted : 2011.11.24
  • Published : 2011.12.15

Abstract

I developed an enhanced correction method for Ricean bias which occurs in linear polarization measurement. Two known methods for Ricean bias correction are reviewed. In low signal-to-noise area, the method based on the mode of the equation gives better representation of the fractional polarization. But a caution should be given that the accurate estimation of noise level, i.e. ${\sigma}$ of the polarized flux, is important. The maximum likelihood method is better choice for high signal-to-noise area. I suggest a hybrid method which uses the mode of the equation at the low signal-to-noise area and takes the maximum likelihood method at the high signal-to-noise area. A modified correction coefficient for the mode solution is proposed. The impact on the depolarization measure analysis is discussed.

Keywords

References

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