Polarization imaging can provide significant improvements in contrast in a number of target detection and discrimination applications. A multi-spectral imaging polarimeter has been constructed for the development of discrimination methods that exploit the polarization properties of a scene. The Stokes vector of a given scene is computed from a sequence of retardance measurements made with the instrument. A significant effort has been made to create a fast polarimeter which can make the necessary retardance measurements to produce a set of Stokes images in a minimum amount of time before the scene changes significantly, which shows up as errors in the resultant Stokes images. A number of wavebands spanning from 600 to 850 nm are considered to determine the dependence of polarization on the wavelength of light both emitted and reflected from various scene topologies. The retardance measurements are made using a rotating quarter-waveplate as opposed to using liquid crystal technology and benefits and drawbacks are discussed for this type of device. Extensive calibration of the instrument is performed to ensure the accuracy of the retardance measurements. This paper will discuss calibration methods, general operation, and results characterizing the polarization properties of numerous targets.
