POINT_SOURCE_POL

Dual-beam spectropolarimetry data can be reduced using the POINT_SOURCE_POL recipe. This recipe reduces data using the steps in Sections , , and . The data can be taken in any order between waveplate positions, but corresponding object-sky pairs for a given waveplate position must be observed together. Spectrum extraction is done such that separate E and O beam spectra are created for each waveplate position. After a cycle of eight observations has done, corresponding to one object-sky pair at each of the 0-, 45-, 22.5-, and 67.5-degree waveplate angles, the pipeline calculates the I, Q, and U Stokes parameters, from which the percentage polarization, polarization intensity, and polarization angle spectra are calculated.