Abstract: An data channel system and method provide a composite signal having an overt, persistent signal channel and a non-persistent channel encoded onto a signal in the persistent channel by timing variation of the persistent channel signal.

Abstract: A method for carrying data on a live host signal, comprising the steps of: varying timing in a host signal in response to data to be encoded, wherein variations in timing are smaller than a sampling period for detection and capture of the digital signal receiving the live host signal; sensing pulse timing variations in the received live host signal by comparison to a reference signal; and determining information in the sensed timing variations.

Abstract: A method for carrying data on a live host signal, comprising the steps of: varying timing in a host signal in response to data to be encoded, wherein variations in timing are smaller than a sampling period for detection and capture of the digital signal receiving the live host signal; sensing pulse timing variations in the received live host signal by comparison to a reference signal; and determining information in the sensed timing variations.

Abstract: A non-retro-reflective imaging system and methods in which tilted image plane imaging is combined with selective Fourier filtering to substantially eliminate retro-reflection from the system. In certain examples, tilted image plane imaging is achieved using sliced source imaging. Through rotation of the image plane, the majority of incident light is reflected off-axis, rather than being retro-reflected. The Fourier filter is used to block incoming light from a particular angle that would otherwise be normally incident on the rotated image plane and retro-reflected. One example of a non-retro-reflective imaging system includes an optical element that focuses electromagnetic radiation onto a tilted image plane, an imaging sensor co-aligned with the tilted image plane, and a Fourier filter positioned in a Fourier plane of the optical element, a position of the Fourier filter in the Fourier plane determined by the tilt angle of the tilted image plane.

Abstract: Imaging systems and methods for simultaneous real and Fourier plane imaging. In one example, an imaging system includes at least one optical element configured to receive and focus incident electromagnetic radiation from a viewed scene, a first detector positioned at an image plane of the at least one optical element and configured to produce a first image of the viewed scene, and a second detector positioned at a Fourier plane of the at least one optical element and configured to produce a second image of the viewed scene, the first and second detectors configured to receive the electromagnetic radiation and produce the first and second images, respectively. The system may additionally include an optical component, such as a beamsplitter, for example, configured to divide and direct the incident electromagnetic radiation to the first and second detectors.

Abstract: A non-retro-reflective imaging system and methods in which tilted image plane imaging is combined with selective Fourier filtering to substantially eliminate retro-reflection from the system. In certain examples, tilted image plane imaging is achieved using sliced source imaging. Through rotation of the image plane, the majority of incident light is reflected off-axis, rather than being retro-reflected. The Fourier filter is used to block incoming light from a particular angle that would otherwise be normally incident on the rotated image plane and retro-reflected. One example of a non-retro-reflective imaging system includes an optical element that focuses electromagnetic radiation onto a tilted image plane, an imaging sensor co-aligned with the tilted image plane, and a Fourier filter positioned in a Fourier plane of the optical element, a position of the Fourier filter in the Fourier plane determined by the tilt angle of the tilted image plane.