urn:nasa:pds:context:instrument:el_leoncito.js2m15.torino_phot 1.0 1.10.0.0 Product_Context 2020-02-18 1.0 Initial export from OLAF urn:nasa:pds:context:telescope:el_leoncito.js2m15 instrument_to_telescope Scaltriti, F., V. Piirola, A. Cellino, E. Anderlucci, L. Corcione, G. Massone, F. Racioppi, and F. Porcu, The UBVRI photopolarimeter of the Torino Astronomical Observatory, Mem. Soc. Astron. It. 60, 243-246, 1989. Torino Photopolarimeter Polarimeter The Torino Photopolarimeter is capable of simultaneous polarimetric measurements in UBVRI colors, with four dichroic filters splitting the optical paths of the UBVRI components of white light in such a way as to feed five separate photomultipliers that measure each color simultaneously. A half-wave plate in front of a calcite block splits the incoming radiation into two components with polarization planes mutually orthogonal to each other. Rotation of the half-wave plate by steps of 22.5 degrees and corresponding measurements of the intensities of the two rays allow the observer to derive the values of the Stokes parameters and hence the value of the degree of linear polarization and the position angle.