===== Impact of error on orientation angles =====

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 --- //[[hivon@iap.fr|Eric Hivon]] 2017/10/18 10:22//


  * Scanning strategy generated with TOAST with the parameters (adapted from  [[:polarisation_sensitivity_maps | Ranajoy's post]]):
    * precession: 22 deg, 11.75hours
    * spin: 61 deg, 2mn
    * duration and sampling rate: 366 days, 85Hz

  * Focal plane simulation (with QuickPol: [[http://adsabs.harvard.edu/abs/2017A&A...598A..25H| Hivon, Mottet & Ponthieu, 2017, A&A 598, A25]] and {{quickpol:beams_quickpol.pdf|an introduction to QuickPol (PDF)}}): 
    * 8 Planck-like beams of FWHM = 7.68
      * nominal: 8 detectors rotated by (0,-90) or (-45,45deg) wrt the scan direction
      * MonteCarlo simulations: same as above with random error on each orientation angle \\ (Gaussian distribution of mean 0 and rms = 1deg)

  * CMB only, no noise, no foreground, no mask


In the plot below, are shown the leaked power spectra seen when auto-correlating the map obtained
when combining the 8 detectors, with either the nominal orientations or the MC error ones.
  * Green long dashes: nominal, 
  * colored shorter dashed: first 4 simulations, 
  * short gray dashes: next 6 simulations,
  * black dots: fraction of the input power spectrum.

{{quickpol:w_qp_pico_8d.png?800|}}





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