Abstract: A method of determining polarization profiles of points in a scene from video frames using Stokes parameters. The method includes emitting scene light rays from points in a region in a scene, and emitting a correlator light ray from a correlator. The correlator includes a uniform light source, a second linear polarizer, and a fixed retarder. The method further includes substantially simultaneously transmitting the scene light rays and the correlator light ray through a color filter and a Stokes filter that includes a rotating retarder having angular positions ?, and a first linear polarizer having a transmission axis to a video camera having a video frame, projecting onto respective pixels in the video frame and recording as two-dimensional (2-D) arrays images corresponding to the scene light rays and the correlator light ray, and downloading the images into the computer system and storing the images into a memory in the computer system.

Abstract: A system for determining polarization profiles of points in a scene from video frames using Stokes parameters includes a scene having a region that emits scene light rays that correspond to the points in the scene, an optical chopper controller, a rotating Stokes filter wheel that includes five trigger holes, three rotating linear polarizers, a circular polarizer, and a reference screen, a color filter, a video camera having a video frame, and a computer system having a frame grabber apparatus. The scene light rays are transmitted through the Stokes filter and the color filter to the video camera.

Abstract: A system for determining polarization profiles of points in a scene from video frames using Stokes parameters includes a scene having a region that emits scene light rays that correspond to the points in the scene, a color filter, a Stokes filter that includes a rotating retarder having angular positions ?, and a first linear polarizer having a transmission axis, a correlator that emits a correlator light ray, and that comprises a uniform light source, a second linear polarizer, and a fixed retarder, a video camera having a video frame, and a computer system.

Abstract: A method for determining and displaying polarization profiles of points in a scene from a single imaging detector array, which utilizes a filter system comprised of a retarder, four linear polarizers, four lenses, a color filter, camera lens and CCD video camera. Light from points in a scene are transmitted through the system and exits with attenuated intensities unique for each wavelength of the light. A narrowband color filter selects the wavelength of interest. The four lenses in the system produce four images of the scene, which are recorded as a single CCD-image. The attenuated intensities in each of the four scene-images are used to calculate the Stokes parameters for selected points in the scene for the selected wavelength. A computer program separates the four scene-images in the CCD-image, crops, registers them and calculates the Stokes parameters for each point in the cropped scene.

Abstract: A method for obtaining spectral radiation data for points in a field of view utilizes a broad band variable filter to produce different intensity distributions on a photocell array. The array is in the focal plane of a camera and photocell locations correspond to points in the field of view. The variable filter has a sequence of optical train elements comprised of a first linear polarizer, a body of optically active material, a retarder and a second linear polarizer. A series of radiance measurements are taken at each photocell of the array and at least one of the optical train components is repositioned between measurements. For each photocell, a collection of photocell values is stored in a computer memory and is converted to a system of linear equations. Intensities for spectral components of light incident thereon are derived for each photocell. The method can be used to create a two-dimensional intensity map for the pixel array for each wavelength measured.

Abstract: A method for determining polarization profiles of individual wavelengths hin a polychromatic source utilizes a variable filter system comprised of a retarder and a linear polarizer. Polychromatic light from the source is transmitted through the system and exits therefrom with attenuated intensities unique for each wavelength of the light. The attenuated intensities are recorded by a spectroradiometer and used to calculate Stokes parameters for each wavelength. The inherent problem of the retarder introducing a different phase differential for each individual wavelength transmitted therethrough is solved by expressing the Stokes parameters explicitly as a function of wavelength. The primary purpose of the method is to obtain the four Stokes parameters for individual bands of wavelength within a polychromatic light beam.