Patents by Inventor Grant Gerhart

Grant Gerhart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070263218
    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.
    Type: Application
    Filed: May 10, 2006
    Publication date: November 15, 2007
    Applicant: The United States of America as Represented by the Army
    Inventors: Grant Gerhart, Roy Matchko
  • Publication number: 20070252991
    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.
    Type: Application
    Filed: June 18, 2007
    Publication date: November 1, 2007
    Applicant: The United States of America as Represented by the Secretary of the Army
    Inventors: Grant Gerhart, Roy Matchko
  • Publication number: 20070041014
    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.
    Type: Application
    Filed: September 25, 2006
    Publication date: February 22, 2007
    Applicant: The United States of America as Represented by the Secretary of the Army
    Inventors: Grant Gerhart, Roy Matchko
  • Patent number: 7173698
    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 unique pseudo-color scheme that utilizes the Poincarè sphere is used for encoding and displaying polarization parameters.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: February 6, 2007
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Grant Gerhart, Roy Matchko
  • Publication number: 20050225761
    Abstract: A method and apparatus 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. The inherent problem of the retarder introducing a different phase differential for each individual wavelength transmitted through the optical element is solved by expressing the Stokes parameters explicitly as a function of wavelength.
    Type: Application
    Filed: April 13, 2004
    Publication date: October 13, 2005
    Applicant: The United States of America as Represented by the Secretary of the Army
    Inventors: Grant Gerhart, Roy Matchko