Abstract: The present disclosure relates to an optical alignment compensation system for a gas detection system, in particular, to an integrated alignment compensation system for an open-path gas sensing system. The optical alignment compensation system of the disclosure is able to compensate for unwanted drifts of a retroreflector. The optical alignment system comprises an array of transceiver pairs, wherein each transceiver pair is configured to transmit and receive light with an optical spectrum in an absorption region of a gas to be detected. Further, it comprises a retroreflector arranged at a nominal position and configured to reflect the light. Further, it comprises an optical element arranged and configured to direct the light from at least one of the transceiver pairs along an optical path through the gas to the retroreflector, to receive the light reflected by the retroreflector along the optical path, and to direct the reflected light to the respective transceiver pair.

Abstract: A method for determining a distance to a target comprises: receiving a bitstream of binary digits corresponding to a variation in time of a time-varying signal based on light transmitted by a light source being reflected by the target, wherein each binary digit in the bitstream is defined based on the time-varying signal at a time instance represented by the binary digit being above or below a threshold; comparing the bitstream of binary digits to a set of stored reference bitstreams of binary digits, wherein each reference bitstream represents a distance to the target, and determining the distance to the target based on selection of a reference bitstream in the set of stored reference bitstreams based on said comparing.

Abstract: A method for determining a distance to a target comprises: receiving a bitstream of binary digits corresponding to a time-varying signal based on light transmitted by a light source being reflected by the target, wherein each binary digit in the bitstream is defined based on the time-varying signal at a time instance represented by the binary digit being above or below a threshold; comparing the bitstream to a set of stored reference bitstreams, wherein the set comprises pairs comprising a first reference bitstream and a second reference bitstream representing a common distance to the target, wherein the first reference bitstream is phase-shifted in relation to the second reference bitstream; and determining the distance to the target based on selection of a pair of reference bitstreams based on said comparing.

Abstract: An imaging system as disclosed can include multiple bistatic radar sensors configured to transmit electromagnetic waves towards a surface of a target object and configured to measure the electromagnetic waves reflected from the surface of the target object. The imaging system includes a computing device that determines time of flight estimates based on the measured waves. The computing device can draw, within an image model for the target object, multiple candidate surface portions of the surface of the target object based on the TOF estimates and predetermined positions of the bistatic radar sensors. Further, the computing device can assign weights to the candidate surface portions. The computing device can determine points where the candidate surface portions meet with a predetermined probability based on the weights. The computing device is configured to define an estimated surface of the target object in the image model based on the determined points.

Abstract: A system for detecting object movement including a sensory network having at least one sensory device using modulated radar for detecting an object in proximity to the sensory network. The sensory network including a wireless transmission system and a base station having a computer processing system located remote from the sensory network and including a wireless transmission system to communicate with the sensory network. The base station having a computer readable program code for causing the computer processing system to analyze data received from the sensory network to determine motion characteristics of the object in proximity to the sensory network.

Abstract: An imaging system as disclosed can include multiple bistatic radar sensors configured to transmit electromagnetic waves towards a surface of a target object and configured to measure the electromagnetic waves reflected from the surface of the target object. The imaging system includes a computing device that determines time of flight estimates based on the measured waves. The computing device can draw, within an image model for the target object, multiple candidate surface portions of the surface of the target object based on the TOF estimates and predetermined positions of the bistatic radar sensors. Further, the computing device can assign weights to the candidate surface portions. The computing device can determine points where the candidate surface portions meet with a predetermined probability based on the weights. The computing device is configured to define an estimated surface of the target object in the image model based on the determined points.

Abstract: The invention provides a spatially-selective reflective structure for the detection of submillimeter electromagnetic waves and systems and methods incorporating spatially-selective reflective structures. One aspect of the invention provides a spatially-selective reflective structure including a partially-conducting slab and a modulating reflector disk adjacent to the partially-conducting slab. The modulating reflector disk includes a plurality of modulations. Another aspect of the invention provides a submillimeter imaging device including submillimeter wave optics, a spatially-selective reflective structure located in the focal plane of the submillimeter wave optics, a submillimeter wave receiver positioned to capture waves reflected from the spatially-selective reflective structure, and a motor configured to rotate the spatially-selective reflective structure.

Abstract: One aspect of the invention provides a spatially-selective disk including a plurality of holes arranged such that a matrix having a plurality of rows, each row having elements corresponding to a fraction of a pixel in a viewing window projected onto the disk that is backed by a hole at a distinct rotational position of the disk, has linearly independent rows. Another aspect of the invention provides a spectrometry device including: a disk having one or more holes; a motor configured to rotate the disk; one or more beam-shaping optics arranged to map one or more spectral components of radiation of interest onto a plurality of locations on the disk; and a receiver positioned to capture the one or more spectral components passing through the one or more holes as the disk is rotated.

Abstract: The invention provides a spatially-selective reflective structure for the detection of submillimeter electromagnetic waves and systems and methods incorporating spatially-selective reflective structures. One aspect of the invention provides a spatially-selective reflective structure including a partially-conducting slab and a modulating reflector disk adjacent to the partially-conducting slab. The modulating reflector disk includes a plurality of modulations. Another aspect of the invention provides a submillimeter imaging device including submillimeter wave optics, a spatially-selective reflective structure located in the focal plane of the submillimeter wave optics, a submillimeter wave receiver positioned to capture waves reflected from the spatially-selective reflective structure, and a motor configured to rotate the spatially-selective reflective structure.

Abstract: A system for detecting object movement including a sensory network having at least one sensory device using modulated radar for detecting an object in proximity to the sensory network. The sensory network including a wireless transmission system and a base station having a computer processing system located remote from the sensory network and including a wireless transmission system to communicate with the sensory network. The base station having a computer readable program code for causing the computer processing system to analyze data received from the sensory network to determine motion characteristics of the object in proximity to the sensory network.

Abstract: The invention provides a spatially-selective reflective structure for the detection of submillimeter electromagnetic waves and systems and methods incorporating spatially-selective reflective structures. One aspect of the invention provides a spatially-selective reflective structure including a partially-conducting slab and a modulating reflector disk adjacent to the partially-conducting slab. The modulating reflector disk includes a plurality of modulations. Another aspect of the invention provides a submillimeter imaging device including submillimeter wave optics, a spatially-selective reflective structure located in the focal plane of the submillimeter wave optics, a submillimeter wave receiver positioned to capture waves reflected from the spatially-selective reflective structure, and a motor configured to rotate the spatially-selective reflective structure.

Abstract: One aspect of the invention provides a spatially-selective disk including a plurality of holes arranged such that a matrix having a plurality of rows, each row having elements corresponding to a fraction of a pixel in a viewing window projected onto the disk that is backed by a hole at a distinct rotational position of the disk, has linearly independent rows. Another aspect of the invention provides a spectrometry device including: a disk having one or more holes; a motor configured to rotate the disk; one or more beam-shaping optics arranged to map one or more spectral components of radiation of interest onto a plurality of locations on the disk; and a receiver positioned to capture the one or more spectral components passing through the one or more holes as the disk is rotated.

Abstract: The invention provides a spatially-selective reflective structure for the detection of submillimeter electromagnetic waves and systems and methods incorporating spatially-selective reflective structures. One aspect of the invention provides a spatially-selective reflective structure including a partially-conducting slab and a modulating reflector disk adjacent to the partially-conducting slab. The modulating reflector disk includes a plurality of modulations. Another aspect of the invention provides a submillimeter imaging device including submillimeter wave optics, a spatially-selective reflective structure located in the focal plane of the submillimeter wave optics, a submillimeter wave receiver positioned to capture waves reflected from the spatially-selective reflective structure, and a motor configured to rotate the spatially-selective reflective structure.