The High Frequency Instrument of Planck will map the entire sky in the millimeter and sub-millimeter domain from 100 to 857 GHz with unprecedented sensitivity to polarization ( \Delta P / T _ { \mbox { \tiny cmb } } \sim 4 \cdot 10 ^ { -6 } for P either Q or U and T _ { \mbox { \tiny cmb } } \simeq 2.7 K ) at 100 , 143 , 217 and 353 GHz .
It will lead to major improvements in our understanding of the Cosmic Microwave Background anisotropies and polarized foreground signals .
Planck will make high resolution measurements of the E -mode spectrum ( up to \ell \sim 1500 ) and will also play a prominent role in the search for the faint imprint of primordial gravitational waves on the CMB polarization . This paper addresses the effects of calibration of both temperature ( gain ) and polarization ( polarization efficiency and detector orientation ) on polarization measurements .
The specific requirements on the polarization parameters of the instrument are set and we report on their pre-flight measurement on HFI bolometers . We present a semi-analytical method that exactly accounts for the scanning strategy of the instrument as well as the combination of different detectors .
We use this method to propagate errors through to the CMB angular power spectra in the particular case of Planck-HFI , and to derive constraints on polarization parameters . We show that in order to limit the systematic error to 10 % of the cosmic variance of the E -mode power spectrum , uncertainties in gain , polarization efficiency and detector orientation must be below 0.15 % , 0.3 % and 1 ^ { \circ } respectively .
Pre-launch ground measurements reported in this paper already fulfill these requirements .