United States of America As Represented by the Administrator of Nasa

Other

Washington University

Paul M Danehy

Christopher J Wohl, Jr

Adrian Andrew Dorrington

Daniel Bivolaru

Pacita I Tiemsin

Jason E Danley

Brian S Thurow

John W Connell

Kent A Watson

Christopher J Peters

Thomas W Jones

W Keith Belvin

Richard S Pappa

Brian K Perkins

Timothy W Fahringer

Joseph W Lee

William Hutchins

Jennifer A Inman

Andrew D Cutler

Methods, systems, and apparatuses for a hyperspectral plenoptic camera. A hyperspectral plenoptic camera may be configured with a filter in the aperture plane of the camera. The filter may selectively transmit radiated wavelengths to a microlens array, which may focus and transmit the wavelengths to an image sensor based on, e.g., the location and intensity of the wavelengths. One or more lenses and/or an iris may be configured to collect, focus, and/or transmit wavelengths to and from the filter. The filter may be located between two lenses, and the distance between the two lenses may be based on a diameter of an aperture of the plenoptic camera.

Hyperspectral plenoptic camera

According to certain examples, a head-mounted apparatus includes a safety eyewear component and an optical display coupled to the safety eyewear component. The safety eyewear component is configured to be worn of a head of an operator and to block transmission of a laser light therethrough. The optical display is configured to receive data associated with the laser light and to display a visual representation of the laser light in a field of view of the operator. In other examples, an apparatus includes a display, a sensor, at least one processor and at least one memory storing computer-readable instructions that, when executed by the at least one processor, cause the apparatus to receive, from the sensor, data associated with a laser light, process the data, and provide an image to the display, such as a representation of the laser light.

Optical head-mounted displays for laser safety eyewear

Various embodiments provide dye-doped polystyrene microspheres generated using dispersion polymerization. Polystyrene microspheres may be doped with fluorescent dyes, such as xanthene derivatives including Kiton Red 620 (KR620), using dispersion polymerization. Certain functionalities, such as sodium styrene sulfonate, may be used to shift the equilibrium distribution of dye molecules to favor incorporation of the dye into the particles. Polyelectrolyte materials, such as poly(diallyldimethyl ammnonium chloride), PolyDADMAC, may be used to electrostatically trap and bind dye molecules within the particles. A buffer may be used to stabilize the pH change of the solution during dye-doped polystyrene microsphere generation and the buffer may be selected depending on the pKa of the dye being incorporated. The various embodiments may provide dye-doped polystyrene microspheres, such as KR620-doped polystyrene microspheres that are non-toxic and non-carcinogenic. These non-toxic and non-carcinogenic dye-doped polystyrene microspheres may be suitable for use in wind tunnel testing.

Dye doped polymer microparticles

Methods and systems are disclosed for deriving quantitative measurements of an imaged material using plenoptic imaging. In one or more embodiments, image data is generated by a plenoptic camera having a filter configured to transmit a plurality of different spectra in different regions of the filter. A set of plenoptic image data is produced by determining respective sets of pixels in the image data corresponding to the different regions of the filter and determining light intensities of the plurality of different spectra for respective super-pixel groups of the pixels in the image data. One or more additional quantitative measurements of an imaged material are then derived from a comparison of the determined light intensities of two or more of the plurality of different spectra.

Methods and systems for processing plenoptic images

Various embodiments provide dye-doped polystyrene microspheres generated using dispersion polymerization. Polystyrene microspheres may be doped with fluorescent dyes, such as xanthene derivatives including kiton red 620 (KR620), using dispersion polymerization. Certain functionalities, such as sodium styrene sulfonate, may be used to shift the equilibrium distribution of dye molecules to favor incorporation of the dye into the particles. Polyelectrolyte materials, such as poly(diallyldimethyl ammonium chloride), PolyDADMAC, may be used to electrostatically trap and bind dye molecules within the particles. A buffer may be used to stabilize the pH change of the solution during dye-doped polystyrene microsphere generation and the buffer may be selected depending on the pKa of the dye being incorporated. The various embodiments may provide dye-doped polystyrene microspheres, such as KR620-doped polystyrene microspheres that are non-toxic and non-carcinogenic. These non-toxic and non-carcinogenic dye-doped polystyrene microspheres may be suitable for use in wind tunnel testing.

Method of making dye-doped polystyre microparticles

An optical device with a light source and a detector is provided. A digital micromirror device positioned between the detector and the light source may deflect light beams projected from the light source. An aperture in front of the detector may block an incoming light beam from the detector when the incoming light beam is incident on the detector outside of a passable incident range and including an aperture opening configured to pass the incoming light beam to the detector when the incoming light beam is incident on the detector within a passable incident range. The digital micromirror device may rotate between a first position causing the light beam to pass through the aperture opening and a second position causing the light beam to be blocked by the aperture. The optical device may be configured to operate as a shutter, chopper, modulator and/or deflector.

Rapid optical shutter, chopper, modulator and deflector

A system that simultaneously measures the translational temperature, bulk velocity, and density in gases by collecting, referencing, and analyzing nanosecond time-scale Rayleigh scattered light from molecules is described. A narrow-band pulsed laser source is used to probe two largely separated measurement locations, one of which is used for reference. The elastically scattered photons containing information from both measurement locations are collected at the same time and analyzed spectrally using a planar Fabry-Perot interferometer. A practical means of referencing the measurement of velocity using the laser frequency, and the density and temperature using the information from the reference measurement location maintained at constant properties is provided.

Spatially-and temporally-resolved multi-parameter interferometric rayleigh scattering system and method

A light scatter sensor includes a sensor body in which are positioned a plurality of optical fibers. The sensor body includes a surface, in one end of each of the optical fibers terminates at the surface of the sensor body. One of the optical fibers is an illumination fiber for emitting light. A plurality of second optical fibers are collection fibers for collecting scattered light signals. A light sensor processor is connected to the collection fibers to detect the scattered light signals.

Micro-LiDAR velocity, temperature, density, concentration sensor

A photogrammetric system uses an array of spaced-apart targets coupled to a structure. Each target exhibits fluorescence when exposed to a broad beam of illumination. A photogrammetric imaging system located remotely with respect to the structure detects and processes the fluorescence (but not the illumination wavelength) to measure the shape of a structure.

Photogrammetric system and method used in the characterization of a structure

A method and apparatus for performing simultaneous multi-point measurements of multiple velocity components in a gas flow is described. Pulses of laser light are directed to a measurement region of unseeded gas to produce Rayleigh or Mie scattered light in a plurality of directions. The Rayleigh or Mie scattered light is collected from multiple directions and combined in a single collimated light beam. The Rayleigh or Mie scattered light is then mixed together with a reference laser light before it is passed through a single planar Fabry-Perot interferometer for spectral analysis. At the output of the interferometer, a high-sensitivity CCD camera images the interference fringe pattern. This pattern contains the spectral and spatial information from both the Rayleigh scattered light and the reference laser light. Interferogram processing software extracts and analyzes spectral profiles to determine the velocity components of the gas flow at multiple points in the measurement region. The Rayleigh light rejected by the interferometer is recirculated to increase the accuracy and the applicability of the method for measurements at high temperatures without requiring an increase in the laser energy.

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Newport News, VA, United States of America

Paul M Danehy