Proceed as for a single pointing observation with AOT CAM01, but there are a few changes :
= one half of
the expected source flux.
exposures obtained with one polarizer.
and the formula in section
give the accuracy dP on the linear polarization ratio P, as a
function of the S/N ratio of the measurements, and of the expected
value of P.
stands for the total number of elementary
exposures taken on each polarizer during the observation. At each
passage of a polarizer in the beam, 12 exposures are taken.