Single-beam Facilities

• Data from polarimeters or spectropolarimeters containing the following optical components can be processed:
  1. A fixed analyser and a rotating half-wave plate.
  2. Multiple fixed analysers.
  3. A single rotating analyser.

• Only linear polarization can be measured.

• Different target exposures can be rotated with respect to one another. That is, the linear mapping between corresponding positions in any two target exposures can include rotation, as well as magnification and a shift of origin (shear is not allowed).

• The transmission and efficiency of non-perfect analysers can be taken into account, if known values for these quantities are available.

• Estimates of the variance in the observed intensity images can be made if necessary. This is useful if your data does not have usable variance information associated with it. Variances on the reduced quantities (Stokes vectors, polarization vectors, etc.) can then be calculated on the basis of these estimated input variances.

• The observed intensity images must all have the same normalization. That is, the ``exposure times'' are all assumed to be equal.