This course covers imaging polarimeters from an instrumentation-design point of view. Basic polarization elements for the visible, mid-wave infrared, and long-wave infrared are described in terms of Mueller matrices and the Poincaré sphere. Polarization parameters such as the degree of polarization (DOP), the degree of linear polarization (DOLP) and the degree of circular polarization (DOCP) are explained in an imaging context. Emphasis is on imaging systems designed to detect polarized light in a 2-D image format. System concepts are discussed using a Stokes-parameter (s0,s1,s2,s3) image. Imaging-polarimeter systems design, pixel registration, and signal to noise ratios are explored. Temporal artifacts, characterization and calibration techniques are defined.