Data Reduction Frequently Asked Questions

I get an implausible polarimetric angle from my science products.

 

In pipeline versions prior to 0.26 the products of sph_zpl_modem_efficieny introduced a sign change in the Q and U frames created by sph_zpl_science_p1 and sph_zpl_science_p23. If you want to determine the polarization angle from those products you therefore have to use -Q and -U. This has been fixed since April 2018.