Cross-link map

[TaiseiIwagaki]

Hello everyone. I'm Taisei, a master student working with Tomo.
I'm studying the systematic effect of the rotational instability of HWP on the polarization observation and using litebird_sim.
Does anyone know how to produce a cross-link map in litebird_sim? If there is no way to do that easily, I will construct the function or something to compute cross-link.

[ziotom78]

Hi Taisei, there is no facility to extract a cross-link map, but existing map-makers return the inverse of the 3×3 covariance matrix for each pixel in the map, so it should be trivial to do. For instance, the binner returns an object of type BinnerResult that contains the field invpp, which is an array of 3×3 matrices containing the inverse of the covariance matrix of each pixel in the map.

[TaiseiIwagaki]

Thank you, Maurizio. I will calculate by myself.