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polarisation_sensitivity_maps

Polarisation sensitivity

Some preliminary scan parameters discussed in the "Imager" telecon 28/08/2017.

In particular Kris plotted some hitcount maps and polarisation angle maps for the following configuration

  • alpha = 22
  • beta = 73
  • T_precession = 11.751 hours
  • T_spin = 121 s

The following illustrates the general scan strategy employed. This is the case for CORE and LiteBIRD too. scan_params.pdf. (Ignore the instrument design at the origin)

I performed a scan using 36 detectors for a period of $4$ years using the same scanning strategy as Kris. The detectors are spread in 9 rows, each row having an ideal configuration (0, 90, 45, 135 degrees). Each row is separated by ~9' towards increasing beta. The map is then rescaled for 144 detectors.

I took as an example the Band #10 at 107.5 GHz. This has a beam of 7.91'. As a rule of thumb I took the number of samples along the scan direction as 4 per FWHM. This gives me a scan frequency of ~85Hz.

Band #10 quotes a raw sensitivity of 46 muK/sqrt(Hz). To have a comparison with results for CORE I assumed a white noise of 40 muK/sqrt(Hz). These maps can be easily rescaled for the appropriate noise.

polarisation_sensitivity_maps.txt · Last modified: 2017/08/30 10:50 by banerji