Tianlai Analysis Teleconference

→ US/Central
Peter Timbie (UW-Madison), Peter Timbie
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Minutes

 

21 cm Cosmology Workshop - Xuelei says it's unlikely there could be any visits from team members from China for an in-person meeting in the US in late summer b/c of the pandemic.  Reza and Olivier most likely could attend.

Low-z forecasts paper - Olivier and Reza will send a link by email to the Overleaf document in a few days.  Plan is to submit in mid-March.  Comments are welcome in the document:   define your own initials/color comment function in Overleaf.   Latest version has some updates related to the WIYN survey cross-correlation.  Some discussion about magnitude definitions (r vs R, for example).

Ground-pickup calculation - Albert will post extensive cdf file that he presented.   Contributions of ground emission to visibilities has right amplitude to account for the `correlated noise'.   In many cases phase matches well too. Works for some baselines, but not all.  Doesn't work for 'cross-polar' baselines HV/VH, but note that since this effect is coming from far sidelobes, the polarizations are not orthogonal and a non-zero contribution is expected.  Plan to continue discussion next week.   Some questions:

  • what is the effect of `blockage' by the telescopes?   Expect this to be significant because, by definition, maximum contribution comes from the ground along the baseline direction.
  • check orientation of feeds in CST files.  (Is phi = 0 parallel to feed dipole?)
  • check emissivity model for ground.  how deep do lambda ~ 0.4 m waves penetrate?

 

 

 

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