USA As Represented by Secretary of the Navy

Other

John F Reintjes

John E Tucker

Mark Bashkansky

Paul L Howard

Lawrence L Tankersley

David G Cooper

James L Dexter

Michael D Duncan

Rita Mahon

Ronald W Waynant

Thomas J Manuccia, Jr

Raymond C Elton

Robert H Dixon

Samuel Park

Thomas M McKenna

Martin Chamberlain

Joseph E Landry

Sølve J Fjerdingstad

Thomas L McClelland

A method for using a single-pixel camera to reconstruct images of objects obscured by fog or other dynamic scattering media. A pseudo-random phase or intensity pattern is imposed on illumination beams directed at a target. The beam with the imposed pattern forms a pseudo random pattern on the target. Information regarding the pattern imposed on each pulse is entered into a data processor/controller. The illumination beams with the pseudo random patterns are reflected off the target, collected by receiving optics and a bucket detector and converted into electronic signals fed into the data processor/controller. The data processor/controller applies a high-pass filter to remove slower signal variations produced by dynamic changes in the scattering medium over time. The filtered bucket values are then used together with their corresponding speckle patterns to generate the images using any appropriate reconstruction algorithm such as CGI or CSI.

Single-pixel imaging through dynamic scattering media

A method and system for separating multicomponent fluids into components having different buoyancies. A flow shaping member has a helical channel that imparts a helical motion to the fluid, and a separation chamber for separating the moving fluid into a helically moving heavier flow portion and a more buoyant portion along the central axis. A flow receiving member has a first collection horn with a mouth arranged to collect the higher buoyancy fluid and direct the fluid to an outlet. At least one other fluid passageway for carrying lower buoyancy fluid has an inlet surrounding of the collection horn, and directs the fluid to a separate outlet at an end of the separator. Additional collection horns can be arranged concentrically around the first collection horn to collect intermediate buoyancy flows. Cascaded fluid separators can concentrate the higher buoyancy fluid or the denser fluid.

Cascaded axial fluid separator methods and systems

A system and method for maintaining the face of an optical window at a desired axial position with respect to the face of a high pressure housing, suitable for use in a high pressure optical flow cell for a real time optical particle monitoring system. The window fits within a mounting hole that extends through the pressure housing. The window has a smaller-diameter cylindrical end portion extending to the high pressure side and an opposite larger-diameter cylindrical end portion, with a shoulder between the cylindrical end portions. A threaded retaining member axially compresses a gasket, o-ring, or other compliant sealing member between the shoulder of the optical window and a corresponding shoulder in the mounting hole, creating a static seal and maintaining the high pressure face of the optical window at a desired position over a wide range of temperatures and pressures.

High pressure housing and optical viewing system

A high pressure optical flow cell system suitable for use in a real time optical particle monitoring system. The system is modular, with at least two housings joined together with removable mechanical attachment devices. Inlet and outlet passageways introduce and remove high pressure fluid into a flow cavity located between adjacent housing faces. An o-ring or other compliant member seal is provided between the faces to prevent leaks of the high pressure fluid. At least one optical window is provided with a substantially planar face flush with the flow cavity surface. An optical assembly maintains the face of the optical window flush with the flow cavity surface over a wide range of temperatures and pressures. A system and method for maintaining the face of the optical window flush with the flow cavity surface over a wide range of temperatures and pressures.

Method and apparatus for stabilizing the thickness of an optical channel for extended pressure environments

A flow separation system for separating multicomponent fluids into components having different buoyancies. The system can deaerate fluids, and segregate solid particles into a channel for removal or real time particle analysis. The system can have, positioned axially within a housing, a cup shaped first member having an axial passageway and a concave inner surface, a second member with a surface that forms a gap with the first member, the gap directing the flow into at least one helical channel. The flow exits the helical channel into a separation chamber positioned between the second member and a third member and separates into spinning heavier flow portion and a more buoyant portion that is driven toward the central axis. The third member has central fluid passageway that collects the higher buoyancy fluid and least one other fluid passageway for carrying lower buoyancy fluid, with an inlet positioned radially outward of the central fluid passageway.

Method and apparatus for separation of components of differing buoyancy mixed into a flowing fluid

An optical fluid monitoring system for imaging debris and other particles in a flowing fluid. The system can have multiple sensors (camera and viewing port) connected to a single, remotely located, laser and computer. The system can also include multiple lasers, viewing ports and cameras to be located at different locations in a flow, with each sensor being configured to image a different particle size range. The system can simultaneously image fluid flows on different pieces of equipment. Optical sensors can be arranged on parallel flow conduits, with each sensor configured to image a different particle size range.

Parallel multisensor optical particle sensors for flowing fluid systems

An optical fluid monitoring system for imaging debris and other particles in a flowing fluid. The system can have multiple sensors (camera and viewing port) connected to a single, remotely located, laser and computer. The system can also include multiple lasers, viewing ports and cameras to be located at different locations in a flow, with each sensor being configured to image a different particle size range. The system can simultaneously image fluid flows on different pieces of equipment.

Remote multisensor optical particle monitor for flowing fluid systems

A method and system for particle entrained fluid sampling, capable of sampling a high pressure and/or high flow rate fluid flow system using a pressure intensifier for applying pressure or suction to the fluid sample in the fluid sampling system operatively connected to a sample extractor and a sample analysis device. The pressure intensifier for applying pressure or suction is adjustable to provide control over the sample flow in the fluid sampling system. The fluid sampling system of the present invention may be particularly applicable to monitoring the condition of hydraulic and lubrication systems.

Method and apparatus for fluid sampling

A method for in situ sampling and monitoring of a fluid flowing in a flow path, whereby the fluid is to be directed to a chamber a first valve may provide a connection between an inlet to the chamber and the flow path and a second valve may provide a connection between an outlet from the chamber and the flow path, comprising the following steps: a) opening the first valve and the second valve to let the incoming fluid flow through the inlet to the chamber and from the chamber through the outlet into the continuation of the fluid path, thereby allowing fluid to circulate through the chamber for a certain time, b) trapping the fluid in the chamber by closing the second valve and thereafter closing the first valve, c) opening a valvefor reducing pressure, to obtain a pressure in the chamber suitable for monitoring the fluid, d) opening an access valveand leading the fluid trapped in the chamber into a monitor system wherein the fluid is analyzed, and thereby providing the data representing the fluid characteristics, e) providing exit for the fluid analyzed through a further fluid path possibly to a low pressure section of the system.

In situ sampling and monitoring a fluid

A method and apparatus for reducing speckle due to MSL, without any loss of resolution, by averaging over different angles of the incident light at low input resolution, while collecting the backscattered light at a full resolution of a lens is described. The present invention allows discrimination against the speckle due to coherent MSL.

Method and apparatus for reducing speckle in optical coherence tomography images

A method and apparatus for real-time monitoring of particulates in a fluid. The fluid is illuminated, and an image formed of the interior of the fluid. The image is then detected, and processed to determine the size, shape, etc. of particulates within the fluid.

Real time suspended particle monitor

A scanning system for scanning in first and second dimensions a desired surface topology of a sample, the scanning device comprising: a light source for producing a collimated light beam; a first scanning device responsive to the collimated light beam from the light source for producing a first scanned beam in a first dimension with a constant optical path length; and a second scanning device coupled between the first scanning device and the sample for focusing and scanning the first scanned beam in a second dimension onto the surface region of the sample to cause the collimated light beam to scan the surface topology of the sample with a constant optical path length in each of the first and second dimensions of the desired topology of the sample. In a second embodiment of the invention, a beam of light is focused by a first lens before a scanner and the scanner is rotated. Second and third lenses arranged in a 4-f combination are used to image rotated focal spots along a spherical convex surface of a sample while the optical path length stays constant. Slow scanning in other dimensions can be performed by mechanical means.

Rapid, high-resolution scanning of flat and curved regions for gated

An optical scheme for in situ identification of particulates in fluid such s engine oil, in which a portion of the fluid flow is tapped, fed via a conduit to a pair of optically transparent opposed plates, imaged through the plates, and the fluid returned to the main flow. Imaging is preferably done with a laser and photodetector array, and the output fed to a computer for image processing. Separation between the plates ensures that all the oil therebetween will be in the imaging system's near field. Preferably, the computer counts the number of particles in the oil, and classifies their shape, by scanning the image until it hits an object (i.e. hits an opaque pixel), using known chain code to trace the object's outline, determining the object's aspect ratio, and repeating for each object in the image. One embodiment uses a planar rotary member which is scalloped about its periphery. The scallops act to push oil continuously against an outer casing. The casing has a light source for directing coherent light at the rotary member, which is made reflective. As the rotary member moves in the casing, it carries fluid with it, and packs the fluid against the casing. The gap between the light source and the rotary member then constitutes the passageway which is imaged.

Fluid sampler utilizing optical near-field imaging

An apparatus for imaging through scattering materials produces a broadband laser reference beam and a correlated Stokes illumination beam. The broadband reference beam has a preselected Raman pump wavelength and the Stokes illumination beam has a preselected Stokes wavelength. The Stokes illumination beam is transmitted into the scattering material to obtain a Stokes signal beam having a first image carrying component and a first nonimage component. A relative delay is produced between the reference beam and the Stokes signal beam. The delayed reference beam and the delayed Stokes signal beam are polarized. The polarized reference beam and the polarized Stokes signal beam are combined to produce a combined beam having a Stokes component and a reference component, the Stokes component having a second image carrying component and a second nonimage component, so that the second image carrying component and the reference component are mutually correlated, and so that the polarization state of the Stokes component differs from the polarization state of the reference component. A Stimulated Raman amplifier responsive to the combined beam produces an amplified signal beam having a third image carrying component with polarization state perpendicular to the polarization state of the Stokes component and having a third nonimage component with polarization state parallel to the polarization state of the Stokes component. The third image carrying component is separated from the rest of the amplified signal beam with the use of a polarizer and is later detected.

Time gated imaging through scattering material using polarization and

A method and apparatus for imaging an object that is part of, embedded in or viewed through a scattering medium is provided. A first broadband beam generator, such as a broadband pulse laser, provides a first broadband beam. A second broadband beam generator, such as a Raman Stokes generator disposed to receive the first broadband beam, generates a second broadband beam capable of correlation with the first broadband beam. A coherent anti-Stokes Raman scattering material is disposed to receive the second broadband beam after dispersion in the scattering medium. A variable delay path also illuminates the coherent anti-Stokes Raman scattering material with the first broadband beam. The coherent anti-Stokes Raman scattering material produces an anti-Stokes beam which contains an extracted image of an object in the scattering medium, which image is recorded on a photodetector.

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Alexandria, VA, United States of America

John F Reintjes