Graph of polarimetric errors

Corrected Figure 7 of Paper I, showing the polarimetric errors for a stepped waveplate with 150◦ retardance (8-state modulation scheme), with dual-beam analysis, and 10 s integration. For this example, we adopted a non-optimal demodulation scheme consisting of simple additions and subtractions of individual modulated signals.

The Astrophysical Journal (Published 2012 September 4; submitting a "corrected" Figure 7 of Paper I) We analyze the generation of polarization cross-talk in Stokes polarimeters by atmospheric seeing, and its effects on the noise statistics of spectropolarimetric measurements for both single-beam and dual-beam instruments. We investigate the time evolution of seeing-induced correlations between different states of one modulation cycle and compare the response to these correlations of two popular polarization modulation schemes in a dual-beam system. Extension of the formalism to encompass an arbitrary number of modulation cycles enables us to compare our results with earlier work. Even though we discuss examples pertinent to solar physics, the general treatment of the subject and its fundamental results might be useful to a wider community.