# Polarization Calibration

Some part of the pulse emission is polarized, that is, the electric field part of the electromagnetic waves are all aligned with respect to one another. As the radiation is measured at the telescope, this polarization is altered as it passes through the signal path that measures it, and so we must correct for these alterations (“calibrate”) so that we know what the intrinsic emission at the pulsar looks like for the best possible arrival-time precision.