Optimised polarimeter configurations for measuring the Stokes parameters   of the Cosmic Microwave Background Radiation
  We present configurations of polarimeters which measure the three linear Stokes parameters of the Cosmic Microwave Background Radiation with a nearly diagonal error matrix, independent of the global orientation of the polarimeters in the focal plane. These configurations also provide the smallest possible error box volume. 
F. Couchot, J. Delabrouille, J. Kaplan, and B. Revenu