Science.gov

Sample records for real-time holographic interferometry

  1. Real-time laser holographic Interferometry for aerodynamics

    NASA Technical Reports Server (NTRS)

    Lee, George

    1987-01-01

    Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil presssure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer.

  2. Real-time laser holographic interferometry for aerodynamics

    NASA Technical Reports Server (NTRS)

    Lee, George

    1987-01-01

    Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil pressure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer.

  3. Real-time trichromatic holographic interferometry: preliminary study

    NASA Astrophysics Data System (ADS)

    Albe, Felix; Bastide, Myriam; Desse, Jean-Michel; Tribillon, Jean-Louis H.

    1998-08-01

    In this paper we relate our preliminary experiments on real- time trichromatic holographic interferometry. For this purpose a CW `white' laser (argon and krypton of Coherent- Radiation, Spectrum model 70) is used. This laser produces about 10 wavelengths. A system consisting of birefringent plates and polarizers allows to select a trichromatic TEM00 triplet: blue line ((lambda) equals 476 nm, 100 mW), green line ((lambda) equals 514 nm, 100 mW) and red line ((lambda) equals 647 nm, 100 mW). In a first stage we recorded a trichromatic reflection hologram with a separate reference beam on a single-layer silver-halide panchromatic plate (PFG 03C). After processing, the hologram is put back into the original recording set-up, as in classical experiments on real-time monochromatic holographic interferometry. So we observe interference fringes between the 3 reconstructed waves and the 3 actual waves. The interference fringes of the phenomenon are observed on a screen and recorded by a video camera at 25 frames per second. A color video film of about 3 minutes of duration is presented. Some examples related to phase objects are presented (hot airflow from a candle, airflow from a hand). The actual results show the possibility of using this technique to study, in real time, aerodynamic wakes and mechanical deformation.

  4. Phase control during reconstruction of holographically recorded flow fields using real-time holographic interferometry

    NASA Astrophysics Data System (ADS)

    Burner, A. W.; Goad, W. K.

    1981-03-01

    A technique of phase control during reconstruction of holographic interferograms is demonstrated in which the recorded scene beam with disturbance present is made to interfere with the real-time scene beam after the disturbance is removed. The reference phase is adjusted during reconstruction by manipulating either the scene or reference beams. Comparisons are made between the present technique and the two-reference-beam and two-plate techniques, more commonly used for phase control during reconstruction of holographic interferograms for flow visualization.

  5. Application of real-time holographic interferometry in the nondestructive inspection of electronic parts and assemblies

    NASA Astrophysics Data System (ADS)

    Wood, Craig P.; Trolinger, James D.

    1991-01-01

    Nondestructive inspection by holographic interferometry (HI) is quickly gaining acceptance in the electronics industry as a sensitive and accurate method of locating manufacturing and assembly flaws in a wide range of electronics, from individual components to assembled modules. This paper describes the specific application of real-time HI in the nondestructive analysis of circuit board heat exchangers and multiple-layer printed wiring boards to locate areas of debonding and delamination. In the application of HI, the choice of a stressing method is often as important as the choice of a specific HI technique. Methods for component stressing include thermal, vibrational, and pressure-induced stressing methods, and these are described in detail. In addition, two techniques for sensitivity enhancement, phase shift interferometry and beam tilt correction, are discussed in detail.

  6. Visualization and Measurements of Sound Pressure Distribution of Ultrasonic Wave by Stroboscopic Real-Time Holographic Interferometry

    NASA Astrophysics Data System (ADS)

    Hisada, Shigeyoshi; Suzuki, Takahiro; Nakahara, Sumio; Fujita, Takeyoshi

    2002-05-01

    The sound pressure distribution of underwater ultrasonic waves is measured by real-time stroboscope holographic interferometry using bismuth silicon oxide single crystal. Stroboscopic sub-microsecond irradiation of laser light enables the recording of the stationary holographic interferogram of refractive index changes of water by ultrasonic waves for the frame time of a charge coupled device camera. The fringe order distribution is calculated from the interferogram by Fourier transform fringe analysis. The optical path differences caused by sound field along the optical path are converted into local field values of sound pressure, which is displayed as a gray scale distribution image. In the experiment, the sound pressure distributions of ultrasonic waves through rectangular and circular apertures are observed. They are compared with the theoretical sound pressure distribution. The sound pressure values obtained by a hydrophone show good agreement with the measured values obtained by this method. The converging and diverging sound pressure fields realized by an acoustic lens are measured.

  7. Real-time measurement of the average temperature profiles in liquid cooling using digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Guerrero-Mendez, Carlos; Anaya, Tonatiuh Saucedo; Araiza-Esquivel, M.; Balderas-Navarro, Raúl E.; Aranda-Espinoza, Said; López-Martínez, Alfonso; Olvera-Olvera, Carlos

    2016-12-01

    We present an alternative optical method to estimate the temperature during the cooling process of a liquid using digital holographic interferometry (DHI). We make use of phase variations that are linked to variations in the refractive index and the temperature property of a liquid. In DHI, a hologram is first recorded using an object beam scattered from a rectangular container with a liquid at a certain reference temperature. A second hologram is then recorded when the temperature is decreased slightly. A phase difference between the two holograms indicates a temperature variation, and it is possible to obtain the temperature value at each small point of the sensed optical field. The relative phase map between the two object states is obtained simply and quickly through Fourier-transform method. Our experimental results reveal that the temperature values measured using this method and those obtained with a thermometer are consistent. We additionally show that it is possible to analyze the heat-loss process of a liquid sample in dynamic events using DHI.

  8. Determination of mass diffusion coefficients of oxygenated fuel additives in air using digital real-time holographic interferometry

    NASA Astrophysics Data System (ADS)

    He, Maogang; Guo, Ying; Zhong, Qiu; Zhang, Ying

    2009-02-01

    In this work, an experimental system based on digital real-time holographic interferometry for measuring the mass diffusion coefficients of fluid is introduced. The method of processing interference fringe hologram is also introduced thoroughly. By uncertainties analysis and experimental verification, the accuracy of this system is validated. The experimental uncertainties in temperature and mass diffusion coefficient are estimated to be no greater than ± 0.16 K and ± 0.2 %, respectively. On this basis, the mass diffusion coefficients of three fuel additives, diethyl 1,6-hexanedioate (diethyl adipate, DEA), dimethyl carbonate (DMC) and diethyl carbonate (DEC) in air were measured at T = (278.15 to 338.15) K under atmospheric pressure, and polynomial was fitted by the experimental data.

  9. Comparative research and its significance of deformation measurements by technologies of laser real-time holographic interferometry and radar differential interferometry

    NASA Astrophysics Data System (ADS)

    Mao, Xian-Jin; Xu, Zhao-Young; Qian, Jia-Dong; Hu, Yi-Li; Yang, Run-Hai; Wang, Bin

    2006-05-01

    The principles and applications of laser real-time holographic interferometry (LRTHI) and radar differential interferometry (RDI) technologies are described in this paper, respectively. By using LRTHI, we can observe the deformation of samples under pressure in the lab and study the anomaly characteristics relating to different strain fields in different fracture-developing areas; while by using RDI, we can observe the landform and surface deformation. The results of deformation observed before and after the M S=7.9 Mani earthquake (Tibet) and M S=6.2 Shangyi-Zhangbei earthquake in China are obtained. It is pointed out that LRTHI and RDI are similar, which study the characteristics of anomalous deformation field by fringe variations for both of them. Therefore, the observation of deformation field in the seismogenic process, especially in the period impending an earthquake by RDI, and the comparative study in the lab by LRTHI are of great significance.

  10. Phase-shifting real-time holographic interferometry applied to load transmission evaluation in dried human skull.

    PubMed

    Gesualdi, Marcos R R; Mori, Matsuyoshi; Muramatsu, Mikiya; Liberti, Edson A; Munin, Egberto

    2007-08-01

    Phase-shifting real-time holography with photorefractive Bi(12)SiO(20) crystal as holographic recording medium applied to load transmission evaluation and tension dissipation on a dried human skull under loading is presented. The applied loading stands as a simulation of isolated contraction (SIC) of some masticatories muscles. The four-frames phase-shifting technique and the unwrapping branch-cut technique were used to obtain the phase map. The quantitative results show the feasibility of the employed system in the study of microdisplacements in the skull structure provided by SIC.

  11. Real-time preprocessing of holographic information

    NASA Astrophysics Data System (ADS)

    Schilling, Bradley W.; Poon, Ting-Chung

    1995-11-01

    Optical scanning holography (OSH) is a holographic recording technique that uses active optical heterodyne scanning to generate holographic information pertaining to an object. The holographic information manifests itself as an electrical signal suitable for real-time image reconstruction using a spatial light modulator. The electrical signal that carries the holographic information can also be digitized for computer storage and processing, allowing the image reconstruction to be performed numerically. In previous experiments with this technique, holographic information has been recorded using the interference pattern of a plane wave and a spherical wave of different temporal frequencies to scan an object. However, the proper manipulation of the pupil functions in the recording stage can result in real-time processing of the holographic edge extraction technique as an important example of real-time preprocessing of holographic information that utilizes alternate pupils in the OSH recording stage. We investigate the theory of holographic preprocessing using a spatial frequency-domain analysis based on the recording system's optical transfer function. The theory is reinforced through computer simulation.

  12. Intellectual property in holographic interferometry

    NASA Astrophysics Data System (ADS)

    Reingand, Nadya; Hunt, David

    2006-08-01

    This paper presents an overview of patents and patent applications on holographic interferometry, and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic interferometry were uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, Japanese Patent Office and Korean Patent Office for the time frame from 1971 through May 2006. The patent analysis unveils trends in patent temporal distribution, patent families formation, significant technological coverage within the market of system that employ holographic interferometry and other interesting insights.

  13. Real-time wideband holographic surveillance system

    DOEpatents

    Sheen, David M.; Collins, H. Dale; Hall, Thomas E.; McMakin, Douglas L.; Gribble, R. Parks; Severtsen, Ronald H.; Prince, James M.; Reid, Larry D.

    1996-01-01

    A wideband holographic surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply a three dimensional backward wave algorithm.

  14. Real-time holographic surveillance system

    DOEpatents

    Collins, H. Dale; McMakin, Douglas L.; Hall, Thomas E.; Gribble, R. Parks

    1995-01-01

    A holographic surveillance system including means for generating electromagnetic waves; means for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; means for receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; means for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and means for displaying the processed information to determine nature of the target. The means for processing the electrical signals includes means for converting analog signals to digital signals followed by a computer means to apply a backward wave algorithm.

  15. Real-time holographic surveillance system

    DOEpatents

    Collins, H.D.; McMakin, D.L.; Hall, T.E.; Gribble, R.P.

    1995-10-03

    A holographic surveillance system is disclosed including means for generating electromagnetic waves; means for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; means for receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; means for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and means for displaying the processed information to determine nature of the target. The means for processing the electrical signals includes means for converting analog signals to digital signals followed by a computer means to apply a backward wave algorithm. 21 figs.

  16. Real-time wideband holographic surveillance system

    DOEpatents

    Sheen, D.M.; Collins, H.D.; Hall, T.E.; McMakin, D.L.; Gribble, R.P.; Severtsen, R.H.; Prince, J.M.; Reid, L.D.

    1996-09-17

    A wideband holographic surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply a three dimensional backward wave algorithm. 28 figs.

  17. Real time processor for array speckle interferometry

    NASA Technical Reports Server (NTRS)

    Chin, Gordon; Florez, Jose; Borelli, Renan; Fong, Wai; Miko, Joseph; Trujillo, Carlos

    1989-01-01

    The authors are constructing a real-time processor to acquire image frames, perform array flat-fielding, execute a 64 x 64 element two-dimensional complex FFT (fast Fourier transform) and average the power spectrum, all within the 25 ms coherence time for speckles at near-IR (infrared) wavelength. The processor will be a compact unit controlled by a PC with real-time display and data storage capability. This will provide the ability to optimize observations and obtain results on the telescope rather than waiting several weeks before the data can be analyzed and viewed with offline methods. The image acquisition and processing, design criteria, and processor architecture are described.

  18. Real time processor for array speckle interferometry

    NASA Technical Reports Server (NTRS)

    Chin, Gordon; Florez, Jose; Borelli, Renan; Fong, Wai; Miko, Joseph; Trujillo, Carlos

    1989-01-01

    The authors are constructing a real-time processor to acquire image frames, perform array flat-fielding, execute a 64 x 64 element two-dimensional complex FFT (fast Fourier transform) and average the power spectrum, all within the 25 ms coherence time for speckles at near-IR (infrared) wavelength. The processor will be a compact unit controlled by a PC with real-time display and data storage capability. This will provide the ability to optimize observations and obtain results on the telescope rather than waiting several weeks before the data can be analyzed and viewed with offline methods. The image acquisition and processing, design criteria, and processor architecture are described.

  19. Real time moving scene holographic camera system

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1973-01-01

    A holographic motion picture camera system producing resolution of front surface detail is described. The system utilizes a beam of coherent light and means for dividing the beam into a reference beam for direct transmission to a conventional movie camera and two reflection signal beams for transmission to the movie camera by reflection from the front side of a moving scene. The system is arranged so that critical parts of the system are positioned on the foci of a pair of interrelated, mathematically derived ellipses. The camera has the theoretical capability of producing motion picture holograms of projectiles moving at speeds as high as 900,000 cm/sec (about 21,450 mph).

  20. Real-Time Holographic Image Correction Using Bacteriorhodopsin

    NASA Technical Reports Server (NTRS)

    Downie, John D.

    1994-01-01

    We present experimental results of one-way coherent imaging through a thin phase-aberrating medium using a holographic technique with bacteriorhodopsin as a real-time holographic material. Bacteriorhodopsin is well suited for the application when the aberration is time varying because of its real-time writing and erasing characteristics, sensitivity, and spatial resolution. We show results with final image resolution of greater than 20 line pairs/mm and high signal-to-noise ratio using a polarization-holography approach.

  1. Holograph and Interferometry.

    ERIC Educational Resources Information Center

    Altman, Thomas C.

    1992-01-01

    Describes a method to create holograms for use in different interferometry techniques. Students utilize these techniques in experiments to study the structural integrity of a clarinet reed and the effects of temperature on objects. (MDH)

  2. Holographic Interferometry The Twentieth Anniversary

    NASA Astrophysics Data System (ADS)

    Pryputniewicz, Ryszard J.

    1985-08-01

    Professor Ryszard Pryputniewicz of Worcester Polytechnic Institute has assembled a significant group of papers on the subject of holographic interferometry in celebration of the first twenty years of activity in this field. Several of these papers were received too late for inclusion in this issue but will be published as a group in the next issue of Optical Engineering. Taken together, these papers are an indication of the tremendous progress made during the twenty years of this field's existence.

  3. Diffusion in solids with holographic interferometry

    NASA Astrophysics Data System (ADS)

    Liu, Dingyu

    1996-12-01

    It is of great importance for the formation of p-n junction in semiconductors by penetrating some impurities through the depth near the surface, so it has long been paid attention to control the concentration distribution of impurities during the diffusion process. In recent years, ionic carburizing, and ion bombardment penetration etc. for the treatment of metal surface have also attracted by material sciences. It requires that the diffusion depth and the diffusion time of the impurities should be under precise control. Different methods, such as the method of radioisotopic detection and the method of chemical analysis have been adopted, however, the reports of different workers are very different, especially in the real time measurement, so, finding new method is never ending. In 1984, H. Fenichel have performed experiments on the solutions of table salt and sugar with the method of holographic interferometry. As for metals which are opaque for the visible light, but they become transparent by making them into a very thin film so that, in principle, the diffusion of atoms within a film is capable of measure by holographic interferometry. Alternatively, the electromagnetic waves within 1 - 70 micrometers wavelengths may be utilized, some materials, such as high purified germanium and silicon are good materials for infrared transmission. Some fluorides of alkaline-earth metals have high transmittance in the range of 1 - 8 micrometers , the concentration of impurities in the semiconductor and metal surface treatment are of 1015 - 1020 atoms per cubic cm, which is capable of detection.

  4. Real-time holographic pattern recognition with bacteriorhodopsin films

    NASA Astrophysics Data System (ADS)

    Hampp, Norbert A.; Thoma, Ralph; Braeuchle, Christoph R.; Oesterhelt, Dieter

    1993-03-01

    The biological photochrome bacteriorhodopsin (BR) has attractive photophysical properties which allow its use as the photoactive component for dynamic recording media for optical applications. Purple membrane (PM) patches, which contain BR in a two-dimensional crystalline lattice, are isolated from Halobacterium halobium. Polymeric films with embedded PM are well suited reversible media for holographic recording. In addition, artificial derivatives of BR with improved optical properties can be generated by genetic methods and isolated from the mutated halobacterial strains. The high reversibility (> 106 record/erase cycles), the fast timescale of its photoconversions (fs - ms), and the high resolution (> 5000 lines/mm) make these films suitable media for real-time holographic applications. A dual-axis joint-Fourier-transform correlator is described with two liquid crystal television screens as input devices and a BR-film as active holographic material in the Fourier plane. The experimental data presented demonstrate that this system is capable of processing two independent video signals in real-time with a signal-to-noise ratio of 45 dB. The polarization recording properties of BR-films offer an efficient method to separate the correlation signal from scattered light.

  5. Miniaturized holographic imaging system for real-time cellular detection

    NASA Astrophysics Data System (ADS)

    Song, Jun; Im, Hyungsoon; Liong, Monty; Fexon, Lioubov; Pivovarov, Misha; Weissleder, Ralph; Lee, Hakho

    2013-03-01

    We herein present a miniaturized holographic imaging system for high throughput cellular detection. The system consists of an imager chip with a microfluidic channel built on top. Clinical samples (e.g., blood) are introduced into the fluidic channel, and holographic images of cells are recorded by the imager chip. We then perform computational reconstruction of original cell images, retrieving both the intensity and phase information. For fast image reconstruction, we have implemented parallel computing software and utilized multicore GPU (graphics processing unit) chips. The resulting imaging system enabled high throughput cellular detection; up to 1000 cells/ μL could be imaged over a wide detection area (20 mm2), and cellular images could be reconstructed in real time (20 frames/sec). Furthermore, assays can be performed without extra dilution and washing steps, which significantly simplifies the diagnosis process. This cost-effective, real-time holographic imaging system can be used for target cell detection in point-of-care applications.

  6. 50 years of holographic interferometry

    NASA Astrophysics Data System (ADS)

    Stetson, Karl A.

    2015-01-01

    Fifty years ago, Robert L. Powell and I discovered holographic interferometry while working at the Radar Laboratory of the University of Michigan's Institute of Science and Technology. I have worked in this field for this entire time span, watched it grow from an unexplored technology to become a widespread industrial testing method, and I have contributed to these developments. In this paper, I will trace my history in this field from our discovery to my involvement in its theory and applications. I will conclude with a discussion of digital holography, which is currently replacing photographic holography for most research and industrial applications.

  7. Some applications of holographic interferometry in biomechanics

    NASA Astrophysics Data System (ADS)

    Ebbeni, Jean P. L.

    1992-03-01

    Holographic interferometry is well adapted for the determination of 2D strain fields in osseous structures. The knowledge of those strain fields is important for the understanding of structure behavior such as arthrosis.

  8. Real-time dynamic holographic image storage device

    NASA Technical Reports Server (NTRS)

    Lafleur, Sharon S. (Inventor); Montgomery, Raymond C. (Inventor)

    1990-01-01

    A real-time dynamic holographic image storage device uses four-wave mixing in a pair of photorefractive crystals. An oscillation is produced between the crystals which can be maintained indefinitely after the initial object beam is discontinued. The object beam produces an interference pattern in a first crystal to produce phase-conjugated object beam which is directed towards the second crystal. In the second crystal another interference pattern is created which produces a reconstructed object beam. The reconstructed object beam is directed back towards the first crystal. The interference patterns are produced by interaction of the object and phase-conjugated object beam with a read and write beam in each of the crystals. By manipulation of the ratio of the read and write beam intensities in at least one of the crystals, the phase-conjugate or reconstructed object beam output therefrom can be amplified to maintain stable oscillation between the two crystals.

  9. Method of vibration analysis using holographic interferometry and heterodyne optical detection

    NASA Technical Reports Server (NTRS)

    Vlad, V. I.; Maurer, J.; Popa, D.

    1974-01-01

    A method of studying thin plate vibrations with the aid of a laser beam is discussed. Through a suitable combination of time-average holographic interferometry, real-time holographic interferometry, and heterodyne optical detection, it is possible to obtain complete information on the vibration parameters of modes, amplitudes, frequencies, and phases. The method has the advantage of three dimensional global observation, noncontact, and high precision measurements.

  10. Large holographic displays for real-time applications

    NASA Astrophysics Data System (ADS)

    Schwerdtner, A.; Häussler, R.; Leister, N.

    2008-02-01

    Holography is generally accepted as the ultimate approach to display three-dimensional scenes or objects. Principally, the reconstruction of an object from a perfect hologram would appear indistinguishable from viewing the corresponding real-world object. Up to now two main obstacles have prevented large-screen Computer-Generated Holograms (CGH) from achieving a satisfactory laboratory prototype not to mention a marketable one. The reason is a small cell pitch CGH resulting in a huge number of hologram cells and a very high computational load for encoding the CGH. These seemingly inevitable technological hurdles for a long time have not been cleared limiting the use of holography to special applications, such as optical filtering, interference, beam forming, digital holography for capturing the 3-D shape of objects, and others. SeeReal Technologies has developed a new approach for real-time capable CGH using the socalled Tracked Viewing Windows technology to overcome these problems. The paper will show that today's state of the art reconfigurable Spatial Light Modulators (SLM), especially today's feasible LCD panels are suited for reconstructing large 3-D scenes which can be observed from large viewing angles. For this to achieve the original holographic concept of containing information from the entire scene in each part of the CGH has been abandoned. This substantially reduces the hologram resolution and thus the computational load by several orders of magnitude making thus real-time computation possible. A monochrome real-time prototype measuring 20 inches has been built and demonstrated at last year's SID conference and exhibition 2007 and at several other events.

  11. Polarization interferometry for real-time spectroscopic plasmonic sensing

    NASA Astrophysics Data System (ADS)

    Otto, Lauren M.; Mohr, Daniel A.; Johnson, Timothy W.; Oh, Sang-Hyun; Lindquist, Nathan C.

    2015-02-01

    We present quantitative, spectroscopic polarization interferometry phase measurements on plasmonic surfaces for sensing applications. By adding a liquid crystal variable wave plate in our beam path, we are able to measure phase shifts due to small refractive index changes on the sensor surface. By scanning in a quick sequence, our technique is extended to demonstrate real-time measurements. While this optical technique is applicable to different sensor geometries--e.g., nanoparticles, nanogratings, or nanoapertures--the plasmonic sensors we use here consist of an ultrasmooth gold layer with buried linear gratings. Using these devices and our phase measurement technique, we calculate a figure of merit that shows improvement over measuring only surface plasmon resonance shifts from a reflected intensity spectrum. To demonstrate the general-purpose versatility of our phase-resolved measurements, we also show numerical simulations with another common device architecture: periodic plasmonic slits. Since our technique inherently measures both the intensity and phase of the reflected or transmitted light simultaneously, quantitative sensor device characterization is possible.We present quantitative, spectroscopic polarization interferometry phase measurements on plasmonic surfaces for sensing applications. By adding a liquid crystal variable wave plate in our beam path, we are able to measure phase shifts due to small refractive index changes on the sensor surface. By scanning in a quick sequence, our technique is extended to demonstrate real-time measurements. While this optical technique is applicable to different sensor geometries--e.g., nanoparticles, nanogratings, or nanoapertures--the plasmonic sensors we use here consist of an ultrasmooth gold layer with buried linear gratings. Using these devices and our phase measurement technique, we calculate a figure of merit that shows improvement over measuring only surface plasmon resonance shifts from a reflected intensity

  12. Real-time shader rendering of holographic stereograms

    NASA Astrophysics Data System (ADS)

    Smithwick, Quinn Y. J.; Barabas, James; Smalley, Daniel E.; Bove, V. Michael, Jr.

    2009-02-01

    Horizontal-parallax-only holographic stereograms of nearly SDTV resolution (336 pixels by 440 lines by 96 views) of textured and normal-mapped models (500 polygons) are rendered at interactive rates (10 frames/second) on a single dual-head commodity graphics processor for use on MIT's third-generation electro-holographic display. The holographic fringe pattern is computed by a diffraction specific holographic stereogram algorithm designed for efficient parallelized vector implementation using OpenGL and Cg vertex/fragment shaders. The algorithm concentrates on lightfield reconstruction by holographic fringes rather than the computation of the interferometric process of creating the holographic fringes.

  13. Holographic interferometry with the compact arrowhead holographic setup.

    PubMed

    Ladera, Celso L

    2010-05-15

    A symmetric off-axis holographic setup, shaped as an arrowhead, which requires neither a collimator nor a beam splitter, is presented. It is applied to measure small perpendicular-to-surface displacements and deformations and the magnetostriction of a body by holographic interferometry. It offers advantages such as implicit fulfilment of several hologram recording conditions, possible use of short coherence length light sources, low-cost, and significant immunity against mechanical perturbations.

  14. Holographic interferometry: A user`s guide

    SciTech Connect

    Griggs, D.

    1993-10-01

    This manual describes the procedures and components necessary to produce a holographic interferogram of a flow field in the Sandia National Laboratories hypersonic wind tunnel. In contrast to classical interferometry, holographic interferometry records the amplitude and phase distribution of a lightwave passing through the flow field at some instant of time. This information can then be reconstructed outside the wind tunnel for visual analysis and digital processing, yielding precise characterizations of aerodynamic phenomena. The reconstruction and subsequent hologram image storage process is discussed, with particular attention paid to the digital image processor and the data reduction technique.

  15. Two color holographic interferometry for microgravity application

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.; Weber, David C.

    1995-01-01

    Holographic interferometry is a primary candidate for determining temperature and concentration in crystal growth experiments designed for space. The method measures refractive index changes within the fluid of an experimental test cell resulting from temperature and/or concentration changes. When the refractive index changes are caused by simultaneous temperature and concentration changes, the contributions of the two effects cannot be separated by single wavelength interferometry. By using two wavelengths, however, two independent interferograms can provide the additional independent equation required to determine the two unknowns. There is no other technique available that provides this type of information. The primary objectives of this effort were to experimentally verify the mathematical theory of two color holographic interferometry (TCHI) and to determine the practical value of this technique for space application. In the foregoing study, the theory of TCHI has been tested experimentally over a range of interest for materials processing in space where measurements of temperature and concentration in a solution are required. New techniques were developed and applied to stretch the limits beyond what could be done with existing procedures. The study resulted in the production of one of the most advanced, enhanced sensitivity holographic interferometers in existence. The interferometric measurements made at MSFC represent what is believed to be the most accurate holographic interferometric measurements made in a fluid to date. The tests have provided an understanding of the limitations of the technique in practical use.

  16. Realization of real-time interactive 3D image holographic display [Invited].

    PubMed

    Chen, Jhen-Si; Chu, Daping

    2016-01-20

    Realization of a 3D image holographic display supporting real-time interaction requires fast actions in data uploading, hologram calculation, and image projection. These three key elements will be reviewed and discussed, while algorithms of rapid hologram calculation will be presented with the corresponding results. Our vision of interactive holographic 3D displays will be discussed.

  17. Holographic diversity interferometry for optical storage.

    PubMed

    Okamoto, Atsushi; Kunori, Keisuke; Takabayashi, Masanori; Tomita, Akihisa; Sato, Kunihiro

    2011-07-04

    This study proposes holographic diversity interferometry (HDI), a system that combines information from spatially dispersed plural image sensors to reconstruct complex amplitude distributions of light signals. HDI can be used to generate four holographic interference fringes having different phases, thus enabling optical phase detection in a single measurement. Unlike conventional phase-shifting digital holography, this system does not require piezoelectric elements and phase shift arrays. In order to confirm the effectiveness of HDI, we generated optical signals having multilevel phases and amplitudes by using two SLMs and performed an experiment for detection and demodulation with HDI.

  18. Difference Holographic Interferometry Of Light-Bulbs At Direct Transillumination

    NASA Astrophysics Data System (ADS)

    Gyimesi, F.; Fuzessy, Z.

    1990-04-01

    Difference holographic interferometry makes the direct interferometric comparison of two objects possible by using holographic illuminations. In the present paper the case of phase objects is investigated at direct transillumination.

  19. A near-real-time full-parallax holographic display for remote operations

    NASA Technical Reports Server (NTRS)

    Iavecchia, Helene P.; Huff, Lloyd; Marzwell, Neville I.

    1991-01-01

    A near real-time, full parallax holographic display system was developed that has the potential to provide a 3-D display for remote handling operations in hazardous environments. The major components of the system consist of a stack of three spatial light modulators which serves as the object source of the hologram; a near real-time holographic recording material (such as thermoplastic and photopolymer); and an optical system for relaying SLM images to the holographic recording material and to the observer for viewing.

  20. Real-Time, Holographic, Dynamic Image-Storage Device

    NASA Technical Reports Server (NTRS)

    Montgomery, Raymond C.; Lafleur, Sharon S.

    1995-01-01

    Solid-state device developed for high-speed acquisition, dynamic storage, and amplification of three-dimensional holographic images. Holograms generated via four-wave mixing in two or more photorefractive crystals (or subelements of single crystal) to create single-crystal or multicrystal oscillator. Apparatus provides dynamic storage of holographic image of object after electronic shutter closed to turn off object beam. Provides capability to store, amplify, process, and transmit time-varying, two-dimensional, spatial information. Developments include sensors, actuators, and optical computers operating at speeds on order of speed of light. Potential in applications in which need for high-speed acquisition and storage of three-dimensional holographic images.

  1. Real-Time, Holographic, Dynamic Image-Storage Device

    NASA Technical Reports Server (NTRS)

    Montgomery, Raymond C.; Lafleur, Sharon S.

    1995-01-01

    Solid-state device developed for high-speed acquisition, dynamic storage, and amplification of three-dimensional holographic images. Holograms generated via four-wave mixing in two or more photorefractive crystals (or subelements of single crystal) to create single-crystal or multicrystal oscillator. Apparatus provides dynamic storage of holographic image of object after electronic shutter closed to turn off object beam. Provides capability to store, amplify, process, and transmit time-varying, two-dimensional, spatial information. Developments include sensors, actuators, and optical computers operating at speeds on order of speed of light. Potential in applications in which need for high-speed acquisition and storage of three-dimensional holographic images.

  2. Real-time wideband cylindrical holographic surveillance system

    DOEpatents

    Sheen, D.M.; McMakin, D.L.; Hall, T.E.; Severtsen, R.H.

    1999-01-12

    A wideband holographic cylindrical surveillance system is disclosed including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply Fast Fourier Transforms and obtain a three dimensional cylindrical image. 13 figs.

  3. Real-time wideband cylindrical holographic surveillance system

    DOEpatents

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.; Severtsen, Ronald H.

    1999-01-01

    A wideband holographic cylindrical surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply Fast Fourier Transforms and obtain a three dimensional cylindrical image.

  4. Holographic interferometry for security and forensic applications

    NASA Astrophysics Data System (ADS)

    Ambadiyil, Sajan; R. C., Sreelekshmi; Mahadevan Pillai, V. P.; Prabhu, Radhakrishna

    2016-10-01

    Security holograms having unique 3D images are one of the tools for enhancing the security for product and personnel authentication and anti-counterfeiting. Apart from the high technology that is required, the uniqueness of a 3D object presents a significant additional threshold for the counterfeiting of such security holograms. But, due to the development of 3D printing technology, the hurdles are disabled and allow the chances of counterfeiting. In order to overcome this, holographic interferometry is effectively utilized and the object is recorded twice before and after the state of random object change. At the time of reconstruction, two signal waves generated simultaneously interfere each other, resulting in a fringe modulation. This fringe modulation in 3D image hologram with respect to the random object change is exploited to generate a rigid and unique anticounterfeit feature. Though holographic interferometry techniques are being widely used for the non-destructive evaluation, the applicability of this technology for the security and forensic activity is less exploited. This paper describes our efforts to introduce holographic interferometry in 3D image holograms for security and forensic applications.

  5. Two color holographic interferometry for microgravity application

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.

    1993-01-01

    Holographic interferometry is a primary candidate for the measurement of temperature and concentration in various crystal growth experiments destined for space. The method measures refractive index changes in the experiment test cell. A refractive index change can be caused by concentration changes, temperature changes, or a combination of temperature and concentration changes. If the refractive index changes are caused by temperature and concentration changes occurring simultaneously in the experiment test cell, the contributions by the two effects cannot be separated by conventional measurement methods. By using two wavelengths, two independent interferograms can be produced from the reconstruction of the hologram. The two interferograms will be different due to dispersion properties of fluid materials. These differences provide the additional information that allows the separation of simultaneously occurring temperature and concentration gradients. There is no other technique available that can provide this type of information. The primary objectives of this effort are to experimentally verify the mathematical theory of two color holographic interferometry and to determine the practical value of this technique for space application. To achieve these objectives, the accuracy and sensitivity of the technique must be determined for geometry's and materials that are relevant to the Materials Processing in the Space program of NASA. This will be achieved through the use of a specially designed two-color holographic interferometry breadboard optical system. In addition to experiments to achieve the primary goals, the breadboard will also provide inputs to the design of an optimum space flight system.

  6. Real-time optical holographic tracking of multiple objects.

    PubMed

    Chao, T H; Liu, H K

    1989-01-15

    A coherent optical correlation technique for real-time simultaneous tracking of several different objects making independent movements is described, and experimental results are presented. An evaluation of this system compared with digital computing systems is made. The real-time processing capability is obtained through the use of a liquid crystal television spatial light modulator and a dichromated gelatin multifocus hololens. A coded reference beam is utilized in the separation of the output correlation plane associated with each input target so that independent tracking can be achieved.

  7. Real-time optical holographic tracking of multiple objects

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Liu, Hua-Kuang

    1989-01-01

    A coherent optical correlation technique for real-time simultaneous tracking of several different objects making independent movements is described, and experimental results are presented. An evaluation of this system compared with digital computing systems is made. The real-time processing capability is obtained through the use of a liquid crystal television spatial light modulator and a dichromated gelatin multifocus hololens. A coded reference beam is utilized in the separation of the output correlation plane associated with each input target so that independent tracking can be achieved.

  8. Real-time single analog output for quadrature phase interferometry

    NASA Astrophysics Data System (ADS)

    Barraud, C.; Garcia, L.; Cross, B.; Charlaix, E.

    2017-04-01

    We present a dynamic displacement sensor based on a quadrature phase interferometer, providing a real-time analog output of the differential displacement between two mobile surfaces. The sensor offers a sub-picometer resolution with a sensitivity essentially uniform over a distance range extending to several micrometers, and can be used to measure the amplitude and phase of very small oscillations in nano-mechanical testing. We demonstrate its use in nano-rheology, by studying the flow in nanometric liquid films at very small strain rates.

  9. A real time interferometry system for unsteady flow measurements

    NASA Technical Reports Server (NTRS)

    Brock, N. J.; Chandrasekhara, M. S.; Carr, L. W.

    1991-01-01

    A simple real-time interferometer system was developed for use in dynamic stall and other unsteady flow research at compressible flow speeds. A conventional schlieren system was modified to operate as a point diffraction interferometer. The implementation of this interferometer is discussed, and results of trials with different point diffractors are presented in this paper. The performance of the interferometer under various flow conditions was investigated. Results are presented which show the effects of the interferometer parameters such as pinhole size and pinhole-plate optical density on the performance of the system.

  10. The Compact and Inexpensive "Arrowhead" Setup for Holographic Interferometry

    ERIC Educational Resources Information Center

    Ladera, Celso L.; Donoso, Guillermo

    2011-01-01

    Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that…

  11. The Compact and Inexpensive "Arrowhead" Setup for Holographic Interferometry

    ERIC Educational Resources Information Center

    Ladera, Celso L.; Donoso, Guillermo

    2011-01-01

    Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that…

  12. Recording materials for holographic interferometry

    NASA Astrophysics Data System (ADS)

    Grichine, Mikhail V.; Skokov, Gleb R.; Ratcliffe, David B.; Kumonko, Petr I.; Sazonov, Yury A.

    1999-08-01

    We present a general review of our current recording materials suitable for laser interferometry applications. The review will cover fine-grain Silver-Halide materials sensitive to the red (PFG-01) and green (VRP-M) spectral ranges. These products have characteristics very similar to the old Agfa products 8E75 and 8E56. Additionally ultra-fine grain red-sensitive and panchromatic Silver-Halide materials will be covered as well as products based on dichromated gelatin. In each case detailed characteristics of each emulsion type will be presented and recommended processing schemes will be discussed in the context of both Pulsed and CW radiation sources. The choice of commercially available substrate and material dimensions will be mentioned.

  13. Real time study of development process in holographic emulsions

    NASA Astrophysics Data System (ADS)

    Fimia, A.; Blaya, S.; Carretero, L.; Madrigal, R. F.; Mallavia, R.

    2000-01-01

    In this paper we present the theoretical and experimental study using a real time technique for the measurement of the optical density when the emulsion is developing. Good agreement was observed between theory and experiment. We exposed an Agfa Gevaert 8E56HD emulsion with an Argon laser tuned at 514 nm and we measured the variation in optical density when the emulsion was put into the developer bath at 20°C. This method allows us to study the dynamics of different developers at different energy of storage. It also provides a way to optimize the composition of developers as a function of the chemical composition, temperature and other secondary factors as superadditivity and non-linear processes.

  14. Multi-channel holographic birfurcative neural network system for real-time adaptive EOS data analysis

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang; Diep, J.; Huang, K.

    1991-01-01

    Viewgraphs on multi-channel holographic bifurcative neural network system for real-time adaptive Earth Observing System (EOS) data analysis are presented. The objective is to research and develop an optical bifurcating neuromorphic pattern recognition system for making optical data array comparisons and to evaluate the use of the system for EOS data classification, reduction, analysis, and other applications.

  15. Multi-channel holographic birfurcative neural network system for real-time adaptive EOS data analysis

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang; Diep, J.; Huang, K.

    1991-01-01

    Viewgraphs on multi-channel holographic bifurcative neural network system for real-time adaptive Earth Observing System (EOS) data analysis are presented. The objective is to research and develop an optical bifurcating neuromorphic pattern recognition system for making optical data array comparisons and to evaluate the use of the system for EOS data classification, reduction, analysis, and other applications.

  16. The real-time display of interferometry data for Goldstone radar astronomy data acquisition

    NASA Technical Reports Server (NTRS)

    Howard, S. D.

    1994-01-01

    A method for visualizing radar interferometry data in real time has been developed for the Goldstone radar astronomy ranging data-acquisition system. The presentation is similar in appearance to a vector field display or data-based grid. This form was selected to facilitate the recognition of characteristic patterns of local variation in the phase and magnitude of complex elements in a two-dimensional data array. The design emphasized efficiency under the demands of real-time processing and remote monitoring. The interferometry 'phase-magnitude' presentation, as it has come to be called, has been used to monitor radar interferometry experiments on three targets, beginning with the asteroid 4179 Toutatis, and continuing with Mars and Mercury.

  17. Shell deformation studies using holographic interferometry

    NASA Technical Reports Server (NTRS)

    Parmerter, R. R.

    1974-01-01

    The buckling of shallow spherical shells under pressure has been the subject of many theoretical and experimental papers. Experimental data above the theoretical buckling load of Huang have given rise to speculation that shallow shell theory may not adequately predict the stability of nonsymmetric modes in higher-rise shells which are normally classified as shallow by the Reissner criterion. This article considers holographic interferometry as a noncontact, high-resolution method of measuring prebuckling deformations. Prebuckling deformations of a lambda = 9, h/b = 0.038 shell are Fourier-analyzed. Buckling is found to occur in an N = 5 mode as predicted by Huang's theory. The N = 4 mode was unusually stable, suggesting that even at this low value of h/b, stabilizing effects may be at work.

  18. Very high speed cw digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Pérez-López, Carlos; de La Torre-Ibarra, Manuel H.; Mendoza Santoyo, Fernando

    2006-10-01

    It is reported for the first time the use of a very high speed camera in digital holographic interferometry with an out of plane sensitivity setup. The image plane holograms of a spherical latex balloon illuminated by a cw laser were acquired at a rate of 4000 frames per second, representing a time spacing between holograms of 250 microseconds, for 512 × 512 pixels at 8 bits resolution. Two types of tests were accomplished for a proof of principle of the technique, one with no constrains on the object which meant random movements due to non controlled environmental air currents, and the other with specific controlled conditions on the object. Results presented correspond to a random sample of sequential digital holograms, chosen from a 1 second exposure, individually Fourier processed in order to perform the usual comparison by subtraction between consecutive pairs thus obtaining the phase map of the object out of plane displacement, shown as a movie.

  19. Modal analysis of musical instruments with holographic interferometry

    NASA Astrophysics Data System (ADS)

    Rossing, Thomas D.; Hampton, D. Scott

    1991-03-01

    Holographic interferometry is a useful technique for studying the vibrational modes of both separate vibrating elements and complete instruments. Spatial resolution is excellent and studies can be made at small amplitudes. Time-average holographic interferograms of handbells Chinese two-tone bells Caribbean steel drums snare drum shells cymbals and guitars are shown. 1 .

  20. Characterization of chromatic dispersion of optical filters by high-stability real-time spectral interferometry.

    PubMed

    Ogawa, Kensuke

    2006-09-10

    Chromatic dispersion of optical filters is characterized by what is believed to be novel broadband spectral interferometry, which is based on dual-wavelength heterodyne measurement of spectral phase. High phase stability is achieved by differential phase detection using two lasers for wavelength-swept probe and phase-tracking reference. The technique provides self-tracking interferometry by passive stabilization of optical phase and allows real-time measurement of spectral phase and group delay with a low phase drift of less than 0.04pi. A fiber Bragg grating and a thin-film filter are characterized by this method.

  1. Real-time three-dimensional counting and shape measurement of RBCs using digital holographic cytometry

    NASA Astrophysics Data System (ADS)

    Funamizu, Hideki; Sonoda, Kotaro; Goto, Ryoji; Aizu, Yoshihisa

    2017-04-01

    Digital holography is a useful technique for recording and reconstruction of the complex amplitude of an optical field. In this technique, an interference pattern of two waves is detected by an image sensor, and digital holograms are acquired in computer. The wavefront is reconstructed by a numerical calculation. In this study, we present the real-time threedimensional counting and shape measurement of RBCs using flow cytometry with digital holographic microscopy.

  2. Holographic multi-focus 3D two-photon polymerization with real-time calculated holograms.

    PubMed

    Vizsnyiczai, Gaszton; Kelemen, Lóránd; Ormos, Pál

    2014-10-06

    Two-photon polymerization enables the fabrication of micron sized structures with submicron resolution. Spatial light modulators (SLM) have already been used to create multiple polymerizing foci in the photoresist by holographic beam shaping, thus enabling the parallel fabrication of multiple microstructures. Here we demonstrate the parallel two-photon polymerization of single 3D microstructures by multiple holographically translated foci. Multiple foci were created by phase holograms, which were calculated real-time on an NVIDIA CUDA GPU, and displayed on an electronically addressed SLM. A 3D demonstrational structure was designed that is built up from a nested set of dodecahedron frames of decreasing size. Each individual microstructure was fabricated with the parallel and coordinated motion of 5 holographic foci. The reproducibility and the high uniformity of features of the microstructures were verified by scanning electron microscopy.

  3. Real-time digital holographic microscopy using the graphic processing unit.

    PubMed

    Shimobaba, Tomoyoshi; Sato, Yoshikuni; Miura, Junya; Takenouchi, Mai; Ito, Tomoyoshi

    2008-08-04

    Digital holographic microscopy (DHM) is a well-known powerful method allowing both the amplitude and phase of a specimen to be simultaneously observed. In order to obtain a reconstructed image from a hologram, numerous calculations for the Fresnel diffraction are required. The Fresnel diffraction can be accelerated by the FFT (Fast Fourier Transform) algorithm. However, real-time reconstruction from a hologram is difficult even if we use a recent central processing unit (CPU) to calculate the Fresnel diffraction by the FFT algorithm. In this paper, we describe a real-time DHM system using a graphic processing unit (GPU) with many stream processors, which allows use as a highly parallel processor. The computational speed of the Fresnel diffraction using the GPU is faster than that of recent CPUs. The real-time DHM system can obtain reconstructed images from holograms whose size is 512 x 512 grids in 24 frames per second.

  4. Speckle reference beam holographic and speckle photographic interferometry in non-destructive test systems

    NASA Technical Reports Server (NTRS)

    Liu, H. K.

    1976-01-01

    The techniques of speckle beam holographic interferometry and speckle photographic interferometry are described. In particular, their practical limitations and their applications to the existing holographic nondestructive test system are discussed.

  5. Laser Wakefield diagnostic using holographic longitudinal interferometry

    SciTech Connect

    Volfbeyn, P.; Esarey, E.; Leemans, W.P.

    1999-03-26

    We propose a diagnostic technique for wakefield measurement in plasma channels. A new technique for plasma channel creation, the Ignitor Heater scheme was proposed and experimentally tested in hydrogen and nitrogen previously. It makes use of two laser pulses. The Ignitor, an ultrashort (sub 100 fs) laser pulse, is brought to a line focus using a cylindrical lens to ionize the gas. The Heater pulse (160 ps long) is used to heat the existing spark via in-verse Bremsstrahlung. The hydrodynamic shock expansion creates a partially evacuated plasma channel with a density minimum on axis. Such a channel has properties of an optical waveguide. This technique allows creation of plasma channels in low atomic number gases, such as hydrogen, which is of importance for guiding of highly intense laser pulses. Laser pulses injected into such plasma channels produce a plasma wake that has a phase velocity close to the speed of light. A discussion of plasma wake measurements, using a Longitudinal Interferometry Wakefield Diagnostic Based on Time Domain Rayleigh Refractometry with Holographic Inversion, will be presented.

  6. Superior real-time holographic storage properties in doped potassium sodium strontium barium niobate crystal.

    PubMed

    Li, Y; Liu, S; Yang, M; Yang, K; Xu, K; Hou, F

    1997-02-15

    We demonstrate superior holographic storage performance in a cobalt doped potassium sodium strontium barium niobate (Co:KNSBN) crystal that possesses a fast response time of 1.4 ms, a large photorefractive sensitivity of 13 x 10(-3) cm(3) J(-1) under a total writing intensity of 1 W/cm(2) , and high spatial resolution of 45 line pairs/mm. Reconstructed images with high fidelity have been obtained in real-time holographic storage. The dynamic properties of the index grating, the dependence of response time on writing intensity, and the dark decay of diffraction signal with increased writing intensity indicate that two species and shallow traps exist in Co:KNSBN crystal.

  7. Multi-layer holographic bifurcative neural network system for real-time adaptive EOS data analysis

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang; Huang, K. S.; Diep, J.

    1993-01-01

    Optical data processing techniques have the inherent advantage of high data throughout, low weight and low power requirements. These features are particularly desirable for onboard spacecraft in-situ real-time data analysis and data compression applications. the proposed multi-layer optical holographic neural net pattern recognition technique will utilize the nonlinear photorefractive devices for real-time adaptive learning to classify input data content and recognize unexpected features. Information can be stored either in analog or digital form in a nonlinear photofractive device. The recording can be accomplished in time scales ranging from milliseconds to microseconds. When a system consisting of these devices is organized in a multi-layer structure, a feedforward neural net with bifurcating data classification capability is formed. The interdisciplinary research will involve the collaboration with top digital computer architecture experts at the University of Southern California.

  8. Multi-layer holographic bifurcative neural network system for real-time adaptive EOS data analysis

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang; Huang, K.; Diep, J.

    1992-01-01

    Optical data processing techniques have the inherent advantage of high data throughout, low weight and low power requirements. These features are particularly desirable for onboard spacecraft in-situ real-time data analysis and data compression applications. The proposed multi-layer optical holographic neural net pattern recognition technique will utilize the nonlinear photorefractive devices for real-time adaptive learning to classify input data content and recognize unexpected features. Information can be stored either in analog or digital form in a nonlinear photorefractive device. The recording can be accomplished in time scales ranging from milliseconds to microseconds. When a system consisting of these devices is organized in a multi-layer structure, a feed forward neural net with bifurcating data classification capability is formed. The interdisciplinary research will involve the collaboration with top digital computer architecture experts at the University of Southern California.

  9. Real-time differential refractometry without interferometry at a sensitivity level of 10-6

    NASA Astrophysics Data System (ADS)

    McClimans, Michael; Laplante, Charles; Bonner, David; Bali, Samir

    2006-09-01

    We present a refractometer based on the principle of total internal reflection that can sensitively record, in real time, the refractive index of fluids over a wide range of refractive indices. The device uses a divergent laser beam and a linear diode array, and has no mechanical or optical moving parts, enabling us to achieve the measurement of a refractive index at a sensitivity level of 10-6. Our refractometer does not rely on interferometry, thus enabling the device to be compact, portable, and inexpensive. To the best of our knowledge, this is the first time a noninterferometric device that performs real-time differential refractometry with a sensitivity of better than 10-5 has been demonstrated in the literature. We show that our experimental results agree very well with Fresnel theory. We establish a theoretical limit on the sensitivity of this class of refractometers.

  10. Determination of Young's modulus of silica aerogels using holographic interferometry

    NASA Astrophysics Data System (ADS)

    Chikode, Prashant P.; Sabale, Sandip R.; Vhatkar, Rajiv S.

    2016-05-01

    Digital holographic interferometry technique is used to determine elastic modulus of silica aerogels. Tetramethoxysilane precursor based Silica aerogels were prepared by the sol-gel process followed by supercritical methanol drying. The alcogels were prepared by keeping the molar ratio of tetramethoxysilane: methyltrimethoxysilane: H2O constant at 1:0.6:4 while the methanol / tetramethoxysilane molar ratio (M) was varied systematically from 12 to 18. Holograms of translucent aerogel samples have been successfully recorded using the digital holographic interferometry technique. Stimulated digital interferograms gives localization of interference fringes on the aerogel surface and these fringes are used to determine the surface deformation and Young's modulus (Y) of the aerogels.

  11. Holographic entropy and real-time dynamics of quarkonium dissociation in non-Abelian plasma

    SciTech Connect

    Iatrakis, Ioannis; Kharzeev, Dmitri E.

    2016-04-26

    The peak of the heavy quark pair entropy at the deconfinement transition, observed in lattice QCD, suggests that the transition is effectively driven by the increase of the entropy of bound states. The growth of the entropy with the interquark distance leads to the emergent entropic force that induces dissociation of quarkonium states. Since the quark-gluon plasma around the transition point is a strongly coupled system, we use the gauge-gravity duality to study the entropy of heavy quarkonium and the real-time dynamics of its dissociation. In particular, we employ the improved holographic QCD model as a dual description of large Nc Yang-Mills theory. Studying the dynamics of the fundamental string between the quarks placed on the boundary, we find that the entropy peaks at the transition point. We also study the real-time dynamics of the system by considering the holographic string falling in the black hole horizon where it equilibrates. As a result, in the vicinity of the deconfinement transition, the dissociation time is found to be less than a fermi, suggesting that the entropic destruction is the dominant dissociation mechanism in this temperature region.

  12. Holographic entropy and real-time dynamics of quarkonium dissociation in non-Abelian plasma

    DOE PAGES

    Iatrakis, Ioannis; Kharzeev, Dmitri E.

    2016-04-26

    The peak of the heavy quark pair entropy at the deconfinement transition, observed in lattice QCD, suggests that the transition is effectively driven by the increase of the entropy of bound states. The growth of the entropy with the interquark distance leads to the emergent entropic force that induces dissociation of quarkonium states. Since the quark-gluon plasma around the transition point is a strongly coupled system, we use the gauge-gravity duality to study the entropy of heavy quarkonium and the real-time dynamics of its dissociation. In particular, we employ the improved holographic QCD model as a dual description of largemore » Nc Yang-Mills theory. Studying the dynamics of the fundamental string between the quarks placed on the boundary, we find that the entropy peaks at the transition point. We also study the real-time dynamics of the system by considering the holographic string falling in the black hole horizon where it equilibrates. As a result, in the vicinity of the deconfinement transition, the dissociation time is found to be less than a fermi, suggesting that the entropic destruction is the dominant dissociation mechanism in this temperature region.« less

  13. Holographic entropy and real-time dynamics of quarkonium dissociation in non-Abelian plasma

    SciTech Connect

    Iatrakis, Ioannis; Kharzeev, Dmitri E.

    2016-04-26

    The peak of the heavy quark pair entropy at the deconfinement transition, observed in lattice QCD, suggests that the transition is effectively driven by the increase of the entropy of bound states. The growth of the entropy with the interquark distance leads to the emergent entropic force that induces dissociation of quarkonium states. Since the quark-gluon plasma around the transition point is a strongly coupled system, we use the gauge-gravity duality to study the entropy of heavy quarkonium and the real-time dynamics of its dissociation. In particular, we employ the improved holographic QCD model as a dual description of large Nc Yang-Mills theory. Studying the dynamics of the fundamental string between the quarks placed on the boundary, we find that the entropy peaks at the transition point. We also study the real-time dynamics of the system by considering the holographic string falling in the black hole horizon where it equilibrates. As a result, in the vicinity of the deconfinement transition, the dissociation time is found to be less than a fermi, suggesting that the entropic destruction is the dominant dissociation mechanism in this temperature region.

  14. An application of holographic interferometry for dynamic vibration analysis of a jet engine turbine compressor rotor

    NASA Astrophysics Data System (ADS)

    Fein, Howard

    2003-09-01

    Holographic Interferometry has been successfully employed to characterize the materials and behavior of diverse types of structures under dynamic stress. Specialized variations of this technology have also been applied to define dynamic and vibration related structural behavior. Such applications of holographic technique offer some of the most effective methods of modal and dynamic analysis available. Real-time dynamic testing of the modal and mechanical behavior of jet engine turbine, rotor, vane, and compressor structures has always required advanced instrumentation for data collection in either simulated flight operation test or computer-based modeling and simulations. Advanced optical holography techniques are alternate methods which result in actual full-field behavioral data in a noninvasive, noncontact environment. These methods offer significant insight in both the development and subsequent operational test and modeling of advanced jet engine turbine and compressor rotor structures and their integration with total vehicle system dynamics. Structures and materials can be analyzed with very low amplitude excitation and the resultant data can be used to adjust the accuracy of mathematically derived structural and behavioral models. Holographic Interferometry offers a powerful tool to aid in the developmental engineering of turbine rotor and compressor structures for high stress applications. Aircraft engine applications in particular most consider operational environments where extremes in vibration and impulsive as well as continuous mechanical stress can affect both operation and structural stability. These considerations present ideal requisites for analysis using advanced holographic methods in the initial design and test of turbine rotor components. Holographic techniques are nondestructive, real-time, and definitive in allowing the identification of vibrational modes, displacements, and motion geometries. Such information can be crucial to the

  15. Dynamic holographic interferometry by photorefractive crystals for quantitative deformation measurements.

    PubMed

    Pouet, B; Krishnaswamy, S

    1996-02-10

    A holographic interferometer that uses two-wave mixing in a photorefractive (Bi12SiO20) crystal under an applied ac field is described. The interferometer uses a repetitive sequence of separate record and readout times to obtain quasi real-time holographic interferograms of vibrating objects. It is shown that a good signal-to-noise ratio of the interferometer is obtained by turning off the object illumination and the applied ac field during readout of the hologram. The good signal-to-noise ratio of the resulting holographic interferograms enables phase measurement, which allows for quantitative deformation analysis.

  16. Flow field studies using holographic interferometry at Langley

    NASA Astrophysics Data System (ADS)

    Burner, A. W.; Snow, W. L.; Goad, W. K.; Helms, V. T.; Gooderum, P. B.

    1982-09-01

    Some of the uses of holographic interferometry at Langley Research Center both for flow visualization and for density field determinations are described and tests in cryogenic flows at the Langley 0.3-Meter Transonic Cryogenic Tunnel are discussed. Experimental and theoretical fringe shift data are compared.

  17. A demonstration of real-time connected element interferometry for spacecraft navigation

    NASA Technical Reports Server (NTRS)

    Edwards, C.; Rogstad, D.; Fort, D.; White, L.; Iijima, B.

    1992-01-01

    Connected element interferometry is a technique of observing a celestial radio source at two spatially separated antennas, and then interfering the received signals to extract the relative phase of the signal at the two antennas. The high precision of the resulting phase delay data type can provide an accurate determination of the angular position of the radio source relative to the baseline vector between the two stations. A connected element interferometer on a 21-km baseline between two antennas at the Deep Space Network's Goldstone, CA tracking complex is developed. Fiber optic links are used to transmit the data at 112 Mbit/sec to a common site for processing. A real-time correlator to process these data in real-time is implemented. The architecture of the system is described, and observational data is presented to characterize the potential performance of such a system. The real-time processing capability offers potential advantages in terms of increased reliability and improved delivery of navigational data for time-critical operations. Angular accuracies of 50-100 nrad are achievable on this baseline.

  18. Digital holographic microscopy real-time monitoring of cytoarchitectural alterations during simulated microgravity

    NASA Astrophysics Data System (ADS)

    Pache, Christophe; Kühn, Jonas; Westphal, Kriss; Toy, M. Fatih; Parent, Jérôme; Büchi, Oralea; Franco-Obregón, Alfredo; Depeursinge, Christian; Egli, Marcel

    2010-03-01

    Previous investigations on mammalian cells have shown that microgravity, either that experienced in space, or simulated on earth, causes severe cellular modifications that compromise tissue determination and function. The aim of this study is to investigate, in real time, the morphological changes undergone by cells experiencing simulated microgravity by using digital holographic microscopy (DHM). DHM analysis of living mouse myoblasts (C2C12) is undertaken under simulated microgravity with a random positioning machine. The DHM analysis reveals cytoskeletal alterations similar to those previously reported with conventional methods, and in agreement with conventional brightfield fluorescence microscopy a posteriori investigation. Indeed, DHM is shown to be able to noninvasively and quantitatively detect changes in actin reticular formation, as well as actin distribution, in living unstained samples. Such results were previously only obtainable with the use of labeled probes in conjunction with conventional fluorescence microscopy, with all the classically described limitations in terms of bias, bleaching, and temporal resolution.

  19. Real-time measurements of D/log-E curves in holographic emulsions: experimental results

    NASA Astrophysics Data System (ADS)

    Fimia, Antonio; Blaya-Escarre, Salvador; Carretero-Lopez, Luis; Madrigal, Roque F.; Mallavia, Ricardo M.

    1999-03-01

    The response curve D-Log E is the most important method to characterize photographic emulsions. In this work we present the experimental study using a real time technique that can be applied to the improvement of the holographic properties of emulsions. We have exposured an Agfa Gevaert 8E56HD emulsion with an Argon laser tuned at 514 nm. After it, we measured the transmittance curve when the emulsion was into the developer bath function of time at 20 degrees Celsius. This method gives us the possibility of study the dynamics of different developers as a function of the storage energy. It also provides a way to optimize the composition of developers function of the chemical composition, temperature and other secondary factors as superaditivity and non-linear processes.

  20. Cr(VI) and Fe(III) doped polymer systems as real-time holographic recording materials

    NASA Astrophysics Data System (ADS)

    Manivannan, Gurusamy; Changkakoti, Rupak; Lessard, Roger A.

    1992-12-01

    IL EXPERIMENTAL Cr(VI) [as (4)2271 and Fe(ffl) [as FeC1] doped Polyvinyl alcohol and Polyacrylic acid systems have been employed'' as real-time holographic recording materials. Holograms have been recorded in Dicbmmated Polyvinyl alcohol (DCPVA) Dichromated Polyacrylic acid (DCPAA) and Ferric chloride Polyvinyl alcohol (FePVA) films. Various chemical and physical parameters influencing the holographic performance have been optimized. L

  1. Real-time, auto-focusing digital holographic microscope using graphics processors

    NASA Astrophysics Data System (ADS)

    Doğar, Mert; İlhan, Hazar A.; Özcan, Meriç

    2013-08-01

    The most significant advantage of holographic imaging is that one does not need to do focusing alignment for the scene or objects while capturing their images. To focus on a particular object recorded in a digital hologram, a post-processing on the recorded image must be performed. This post-processing, so called the reconstruction, is essentially the calculation of wave propagation in free space. If the object's optical distance to the recording plane is not known a priori, focusing methods are used to estimate this distance. However, these operations can be quite time consuming as the hologram sizes increase. When there is a time constraint on these procedures and the image resolution is high, traditional central processing units (CPUs) can no longer satisfy the desired reconstruction speeds. Then, especially for real-time operations, additional hardware accelerators are required for reconstructing high resolution holograms. To this extend, today's commercial graphic cards offer a viable solution, as the holograms can be reconstructed tens of times faster with a graphics processing unit than with the state-of-the-art CPUs. Here we present an auto-focusing megapixel-resolution digital holographic microscope (DHM) that uses a graphics processing unit (GPU) as the calculation engine. The computational power of the GPU allows the DHM to work in real-time such that the reconstruction distance is estimated unsupervised, and the post-processing of the holograms are made completely transparent to the user. We compare DHM with GPU and CPU and present experimental results showing a maximum of 70 focused reconstructions per second (frps) with 1024 × 1024 pixel holograms.

  2. Real-time, auto-focusing digital holographic microscope using graphics processors.

    PubMed

    Doğar, Mert; İlhan, Hazar A; Özcan, Meriç

    2013-08-01

    The most significant advantage of holographic imaging is that one does not need to do focusing alignment for the scene or objects while capturing their images. To focus on a particular object recorded in a digital hologram, a post-processing on the recorded image must be performed. This post-processing, so called the reconstruction, is essentially the calculation of wave propagation in free space. If the object's optical distance to the recording plane is not known a priori, focusing methods are used to estimate this distance. However, these operations can be quite time consuming as the hologram sizes increase. When there is a time constraint on these procedures and the image resolution is high, traditional central processing units (CPUs) can no longer satisfy the desired reconstruction speeds. Then, especially for real-time operations, additional hardware accelerators are required for reconstructing high resolution holograms. To this extend, today's commercial graphic cards offer a viable solution, as the holograms can be reconstructed tens of times faster with a graphics processing unit than with the state-of-the-art CPUs. Here we present an auto-focusing megapixel-resolution digital holographic microscope (DHM) that uses a graphics processing unit (GPU) as the calculation engine. The computational power of the GPU allows the DHM to work in real-time such that the reconstruction distance is estimated unsupervised, and the post-processing of the holograms are made completely transparent to the user. We compare DHM with GPU and CPU and present experimental results showing a maximum of 70 focused reconstructions per second (frps) with 1024 × 1024 pixel holograms.

  3. Holographic data acquisition and display in real and quasi-real time: friendly for industrial inspections

    NASA Astrophysics Data System (ADS)

    Petrov, Valery; Lau, Bernhard

    1996-09-01

    Quick, reliable and inexpensive testing of products and components is needed in industry more often than not. Holography due to its intrinsic limitations and reasonably high costs yet is a method which is used comparatively rarely for industrial optical inspections. In the Laboratory of Technical Optics, Laser Technologies and Optoelectronics we produce holograms and interferograms on silver halide media in extremely unpromising conditions intentionally introduced to fit industrial ones. The main features of our processes are: (1) high speed of the whole process of data acquisition, storage and final presentation; (2) possibility to perform all these operations in strong daylight corresponding to industrial illumination levels or even exceeding recommended levels of illumination of industrial working places; (3) possibility to avoid any dark rooms; (4) high diffraction efficiency of holograms measured at the wavelength of recording, i.e. any wavelength shifts of holographic reconstruction are avoided for any types of holograms including reflection ones usually suffering from such shifts; (5) low costs due to low labor and equipment costs; and (6) easiness of performing quick checks in industrial environment. In our experiments we investigated various optical setups for recording holograms, double exposure and real time interferograms, in situ among them, and different types of holographic optical elements. We used different types of lasers: helium-neon (633 nm), argon (488 nm), semiconductor (675 and 685 nm), ruby (693 nm). Various silver halide media were used: Agfa Gevaert 8 E 75 HD films and plates, Russian PFG-03 and PFG-03 C (color).

  4. A Phase Locked High Speed Real-Time Interferometry System for Large Amplitude Unsteady Flows

    NASA Technical Reports Server (NTRS)

    Chandrasekhara, M. S.; Squires, D. D.; Wilder, M. C.; Carr, L. W.; Kutler, Paul (Technical Monitor)

    1994-01-01

    A high speed phase locked interferometry system has been designed and developed for real-time measurements of the dynamic stall flow over a pitching airfoil. Point diffraction interferograms of incipient flow separation over a sinusoidally oscillating airfoil have been obtained at rates of up to 20 KHz and for free stream Mach numbers of 0.3 and 0.45. The images were recorded on ASA 125 and ASA 400 film using a drum camera. Special electronic timing and synchronizing circuits were developed to trigger the laser light source from the camera, and to initiate acquisition of the interferogram sequence from any desired phase angle of oscillation. The airfoil instantaneous angle of attack data provided by an optical encoder was recorded via a FIFO and in EPROM into a microcomputer. The interferograms have been analyzed using software developed in-house to get quantitative flow density and pressure distributions.

  5. Holographic Interferometry--A Laboratory Experiment.

    ERIC Educational Resources Information Center

    de Frutos, A. M.; de la Rosa, M. I.

    1988-01-01

    Explains the problem of analyzing a phase object, separating the contribution due to thickness variations and that due to refractive index variations. Discusses the design of an interferometer and some applications. Provides diagrams and pictures of holographic images. (YP)

  6. Holographic Interferometry--A Laboratory Experiment.

    ERIC Educational Resources Information Center

    de Frutos, A. M.; de la Rosa, M. I.

    1988-01-01

    Explains the problem of analyzing a phase object, separating the contribution due to thickness variations and that due to refractive index variations. Discusses the design of an interferometer and some applications. Provides diagrams and pictures of holographic images. (YP)

  7. Quantitative three-dimensional holographic interferometry for flow field analysis

    NASA Astrophysics Data System (ADS)

    Holden, C. M. E.; Parker, S. C. J.; Bryanston-Cross, P. J.

    Holographic interferometry offers the potential for quantitative, wholefield analysis of three-dimensional compressible flows. The technique is non-intrusive, does not require the introduction of seeding particles, and records the entire flow information within the pulse duration of a Q-switched ruby laser (~30ns). At present, however, holographic interferometry is mainly used qualitatively due to the practical restrictions of data recording, acquisition and processing. To address the potential of holographic flow analysis a prototype multi-channel interferometer has been designed and preliminary wind tunnel results have been obtained. The proposed configuration uses specular illumination which, unlike comparable diffuse systems, does not suffer from fringe localisation and speckle noise. Beam collimation and steering through the flow field is achieved in a single operation by the use of holographic optical elements (HOEs). The resulting design is compact, light efficient, has aberration compensation, and the recorded data are conducive to both tomographic analysis and direct comparison to computational fluid dynamics (CFD) predictions. Holograms have been recorded of simple two-dimensional and axisymmetric compressible flows, to compare the accuracy of holographic density measurements with data from conventional pressure sensors and CFD codes. Data extraction from the holograms, and the elimination of rigid body motion, was achieved using digital Fourier transform fringe analysis. The introduction of phase errors by image processing has been investigated by analysing simulated fringe patterns generated from a combination of experimental amplitude information and computer generated phase data.

  8. Transonic rotor flow-measurement technique using holographic interferometry

    NASA Technical Reports Server (NTRS)

    Kittleson, John K.; Yu, Yung H.

    1987-01-01

    Holographic interferometry is used to record interferograms of the flow near a hovering transonic rotor blade. A pulsed ruby laser recorded 40 interferograms with a 2 ft dia. view field near the model rotor blade tip operating at a tip Mach number of 0.90. The experimental procedure is presented and example interferograms recorded in the rotor's tip path plane. In addition, a method currently being pursued to obtain quantitative flow information using computer assisted tomography (CAT) with the holographic interferogram data, is outlined.

  9. Status of holographic interferometry at University of Michigan

    NASA Technical Reports Server (NTRS)

    Vest, Charles

    1987-01-01

    Reflection holograms were taken of a jet of air injected traverse to a subsonic stream. The technique of reflection holograms allowed maximum viewing angle and minimum distance to the jet. Holographic interferometry is being used to measure the temperature distribution in a growing crystal. Computations of the temperatures are being made. A phase shift interferometer was used to study flows with very weak changes in refractive index, of the order of 1 shift. Tomographic techniques are being developed for strong refractive cases.

  10. Real-time holographic compensation of large optics for deployment in space

    NASA Astrophysics Data System (ADS)

    Guthals, Dennis M.; Sox, Daniel; Joswick, Michael D.; Rodney, Paul J.

    2000-11-01

    Large deployable space-based optical systems will likely require complex structure position controls in conjunction with an adaptive optic to maintain optical tolerances necessary for near diffraction-limited performance. A real- time holographic (RTH) compensation system can greatly reduce the requirements and complexity of the position control system and enable the use of novel or imperfect optical components for large mirror surfaces. A hologram of the distorted primary is recorded with a local beacon at 532 nm (approximately 100 nJ/exposure) on an optically addressed spatial light modulator and transferred as a phase grating to a ferroelectric liquid crystal layer. The hologram is played back with target light containing the same optical distortion. A corrected image is obtained in the conjugate diffracted order where the phase of the optical distortion is subtracted from the distorted image. We report recent test results and analysis of a RTH- compensated deformed mirror of 0.75 m diameter. The short exposure hologram is recorded at video frequencies (30 Hz) at bandwidths up to 5 kHz. Correction for tens of waves of static and dynamic optical distortions including mechanical and thermal warp, mechanical vibration, and air turbulence are shown for monochromatic (532 nm) and broadband (532 +/- 40 nm) illuminated targets. We also report on the generation of blazed gratings in electrically addressed spatial light modulators to achieve greatly enhanced diffraction efficiencies and to perform beam steering.

  11. Determination of use of a real time tone tracker to obtain same beam interferometry data

    NASA Technical Reports Server (NTRS)

    Nandi, S.; Border, J. S.; Folkner, W. M.

    1993-01-01

    The radio metric tracking technique known as Same-Beam Interferometry (SBI) has been shown to improve orbit determination accuracy for the Magellan and Pioneer 12 orbiter. Previous efforts to explore the technique were carried out by making open loop recordings of the carrier signals from the two spacecraft and extracting their phases through post processing. This paper reports on the use of a closed loop receiver to simultaneously measure the carrier signals from two spacecraft in order to produce SBI data in near real time. The Experiment Tone Tracker is a digital closed loop receiver installed in two of NASA's Deep Space Network stations which can simultaneously extract the phase of up to eight tones. The receivers were used in late September and October of 1992 to collect Doppler and SBI data from Pioneer 12 and Magellan. The demise of the Pionner 12 on October 8th during the start-up phase of our tests precluded the collection of an extensive set of SBI data, however two passes of SBI and several arcs of single spacecraft Doppler data were recorded. The SBI data were analyzed and determined to have statistical errors consistent with error models and similar to open loop data.

  12. Determination of use of a real time tone tracker to obtain same beam interferometry data

    NASA Technical Reports Server (NTRS)

    Nandi, S.; Border, J. S.; Folkner, W. M.

    1993-01-01

    The radio metric tracking technique known as Same-Beam Interferometry (SBI) has been shown to improve orbit determination accuracy for the Magellan and Pioneer 12 orbiter. Previous efforts to explore the technique were carried out by making open loop recordings of the carrier signals from the two spacecraft and extracting their phases through post processing. This paper reports on the use of a closed loop receiver to simultaneously measure the carrier signals from two spacecraft in order to produce SBI data in near real time. The Experiment Tone Tracker is a digital closed loop receiver installed in two of NASA's Deep Space Network stations which can simultaneously extract the phase of up to eight tones. The receivers were used in late September and October of 1992 to collect Doppler and SBI data from Pioneer 12 and Magellan. The demise of the Pionner 12 on October 8th during the start-up phase of our tests precluded the collection of an extensive set of SBI data, however two passes of SBI and several arcs of single spacecraft Doppler data were recorded. The SBI data were analyzed and determined to have statistical errors consistent with error models and similar to open loop data.

  13. Magnetostriction Measured by Holographic Interferometry with the Simple and Inexpensive "Arrowhead" Setup

    ERIC Educational Resources Information Center

    Ladera, Celso L.; Donoso, Guillermo; Contreras, Johnny H.

    2012-01-01

    Double-exposure holographic interferometry is applied to measure the "linear" or "longitudinal" magnetostriction constant of a soft-ferrite rod. This high-accuracy measurement is done indirectly, by measuring the small rotations of a lever in contact with the rod using double-exposure holographic interferometry implemented with a robust…

  14. Magnetostriction Measured by Holographic Interferometry with the Simple and Inexpensive "Arrowhead" Setup

    ERIC Educational Resources Information Center

    Ladera, Celso L.; Donoso, Guillermo; Contreras, Johnny H.

    2012-01-01

    Double-exposure holographic interferometry is applied to measure the "linear" or "longitudinal" magnetostriction constant of a soft-ferrite rod. This high-accuracy measurement is done indirectly, by measuring the small rotations of a lever in contact with the rod using double-exposure holographic interferometry implemented with a robust…

  15. Electronic speckle pattern interferometry and digital holographic interferometry with microbolometer arrays at 10.6 {mu}m

    SciTech Connect

    Vandenrijt, Jean-Francois; Georges, Marc P.

    2010-09-20

    Electronic speckle pattern interferometry and digital holographic interferometry are investigated at long infrared wavelengths. Using such wavelengths allows one to extend the measurement range and decrease the sensitivity of the techniques to external perturbations. We discuss the behavior of reflection by the object surfaces due to the long wavelength. We have developed different experimental configurations associating a CO2 laser emitting at 10.6{mu}m and microbolometer arrays. Phase-shifting in-plane and out-of-plane electronic speckle pattern interferometry and lensless digital holographic interferometry are demonstrated on rotation measurements of a solid object.

  16. Advances in pulsed holographic interferometry with photorefractive crystals

    NASA Astrophysics Data System (ADS)

    Georges, Marc P.; Pauliat, Gilles; Alexeenko, I.; Pedrini, Giancarlo; Lemaire, Philippe C.; Roosen, Gerald

    2004-06-01

    Photorefractive crystals offer many advantages over other classical holographic recording media. They allow fast in-situ processable holographic recording as well as indefinite reusability. Moreover high signal-to-noise ratio can be reached as well as high resolutions. We present the results obtained by pulsed holographic interferometry obtained with photorefractive crystals. First experiments showing the potentiality of photorefractive crystals for such applications will be reviewed. Some limitations were pointed out and led us to consider new developments under the frame of an European-funded project. The PHIFE European project (Pulsed Holographic Interferometer for the analysis of Fast Events) aims at developing a full field measurement system at a high repetition rate, based on a double-pulse YAG Q-switch laser. This device will be used for the analysis of vibrations and for aerodynamic studies. Different crystals are considered which are adapted to the fundamental line of the YAG (AsGa or CdTe crystals) or after frequency doubling at 532 nm (Bi12SiO20). Different crystal configurations and recording geometries are compared. Also different innovative phase quantification techniques are studied and take into account some special properties of the PRCs. We present the results obtained so far in the first development phases of the project.

  17. Butterflies' wings deformations using high speed digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Mendoza Santoyo, Fernando; Aguayo, Daniel D.; de La Torre-Ibarra, Manuel H.; Salas-Araiza, Manuel D.

    2011-08-01

    A variety of efforts in different scientific disciplines have tried to mimic the insect's in-flight complex system. The gained knowledge has been applied to improve the performance of different flying artifacts. In this research report it is presented a displacement measurement on butterflies' wings using the optical noninvasive Digital Holographic Interferometry technique with out of plane sensitivity, using a high power cw laser and a high speed CMOS camera to record the unrepeatable displacement movements on these organic tissues. A series of digital holographic interferograms were recorded and the experimental results for several butterflies during flapping events. The relative unwrapped phase maps micro-displacements over the whole wing surface are shown in a wire-mesh representation. The difference between flying modes is remarkably depicted among them.

  18. Insect wing deformation measurements using high speed digital holographic interferometry.

    PubMed

    Aguayo, Daniel D; Mendoza Santoyo, Fernando; De la Torre-I, Manuel H; Salas-Araiza, Manuel D; Caloca-Mendez, Cristian; Gutierrez Hernandez, David Asael

    2010-03-15

    An out-of-plane digital holographic interferometry system is used to detect and measure insect's wing micro deformations. The in-vivo phenomenon of the flapping is registered using a high power cw laser and a high speed camera. A series of digital holograms with the deformation encoded are obtained. Full field deformation maps are presented for an eastern tiger swallowtail butterfly (Pterourus multicaudata). Results show no uniform or symmetrical deformations between wings. These deformations are in the order of hundreds of nanometers over the entire surface. Out-of-plane deformation maps are presented using the unwrapped phase maps.

  19. Modelling of a holographic interferometry based calorimeter for radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Beigzadeh, A. M.; Vaziri, M. R. Rashidian; Ziaie, F.

    2017-08-01

    In this research work, a model for predicting the behaviour of holographic interferometry based calorimeters for radiation dosimetry is introduced. Using this technique for radiation dosimetry via measuring the variations of refractive index due to energy deposition of radiation has several considerable advantages such as extreme sensitivity and ability of working without normally used temperature sensors that disturb the radiation field. We have shown that the results of our model are in good agreement with the experiments performed by other researchers under the same conditions. This model also reveals that these types of calorimeters have the additional and considerable merits of transforming the dose distribution to a set of discernible interference fringes.

  20. Application Of Holographic Interferometry To Practical Vibration Study

    NASA Astrophysics Data System (ADS)

    Murata, M.; Kuroda, M.

    1983-10-01

    This paper describes a brief summary of applications of holographic interferometry to practical vibration study in Nagasaki Technical Institute of MHI. The applications of vibration mode measurement are concerned with steam turbine blades, compressor impeller, internal combustion engine, car body and car brake disk. The techniques of holography contained herein are (1) the time average method giving contour fringes of vibration amplitude,(2)the phase modulation method providing information on the relative phases of vibration, and(3)the double pulse method that offers the possibility of visualizing the vibration pattern of internal combustion engine in operating condition,and the transient vibration pattern of an object excited by impact force.

  1. Method of and apparatus for double-exposure holographic interferometry

    NASA Technical Reports Server (NTRS)

    Witherow, W. K. (Inventor)

    1984-01-01

    Double-exposure holographic interferometry is carried out using first and second lasers responsive to respective applied firing signals for producing respective pulsed output beams. An optical system is provided oriented such that the output beams of the lasers produce coinciding scene and reference beams. An initiator circuit generates and applies a firing signal to the first laser; and a timer/firing device responsive to the generation of a firing signal by the initiator circuit, generates and applies a firing signal to the second laser a predetermined period of time later.

  2. Development of real time digital holographic microscope for cell flow interactions using a High Performance Computing (HPC) cluster

    NASA Astrophysics Data System (ADS)

    Hojjati, Avesta; Molaei, Mehdi; Sheng, Jian

    2013-11-01

    Real-time imaging and analysis of 3D cell migration and locomotion is crucial to understand the underlying physics of cell environment interactions. In addition, such a microscopy would provide vital diagnostic capability in cell detection, particle sorting and drug screening with large throughput. However, 3D holographic imaging and subsequent analysis are computational intensive and up-to-date prohibitive for real-time applications. With the advances in high performance computing, we are developing a real-time digital holographic microscope (DHM) that includes an in-line DHM, a large format CCD camera, and a 24-node windows-based HPC cluster. The cluster is organized as the master-slave parallel computing paradigm with Message Passing Interface (MPI) as its communication protocol. The holograms are recorded, streamed and analyzed by the HPC cluster in real time, the 3D distributions and in focus images are rendered back on the data acquisition computer. The system will be applied to study marine protest interacting with oil droplets. Supports from GoMRI are acknowledged.

  3. Beam-modulation methods in quantitative and flow visualization holographic interferometry

    NASA Technical Reports Server (NTRS)

    Decker, A.

    1986-01-01

    This report discusses heterodyne holographic interferometry and time-average holography with a frequency shifted reference beam. Both methods will be used for the measurement and visualization of internal transonic flows, where the target facility is a flutter cascade. The background and experimental requirements for both methods are reviewed. Measurements using heterodyne holographic interferometry are presented. The performance of the laser required for time-average holography of time-varying transonic flows is discussed.

  4. High-speed digital holographic interferometry for vibration measurement

    SciTech Connect

    Pedrini, Giancarlo; Osten, Wolfgang; Gusev, Mikhail E

    2006-05-20

    A system based on digital holographic interferometry for the measurement of vibrations is presented. A high-power continuous laser(10 W) and a high-speed CCD camera are used. Hundreds of holograms of an object that has been subjected to dynamic deformation are recorded. The acquisition speed and the time of exposure of the detector are determined by the vibration frequency. Two methods are presented for triggering the camera in order to acquire at a given phase of the vibration. The phase of the wavefront is calculated from the recorded holograms by use of a two-dimensional digital Fourier-transform method. The deformation of the object is obtained from the phase. By combination of the deformations recorded at different times it is possible to reconstruct the vibration of the object.

  5. Digital holographic metrology based on multi-angle interferometry.

    PubMed

    Dong, Jun; Jiang, Chao; Jia, Shuhai

    2016-09-15

    We propose a multi-angle interferometry method for digital holographic metrology. In an application of three-dimensional (3D) reconstruction, the hologram corresponding to a different illumination angle is recorded as the illumination angle with a single wavelength tilted at regular intervals by an electronically controlled rotating stage. A Fourier-transform-based axial depth scanning algorithm formed by the reconstructed phase is used to obtain the height point by point over the whole field of view. Hence, the 3D reconstruction can be obtained effectively; even the object has large depth discontinuities resulting from the difficulty of the phase unwrapping. Due to a monochrome source only being used, the method is available for objects with wavelength-dependent reflectivity and those that are free of chromatic aberration caused by the different wavelengths.

  6. Visualization of thermal behavior of fluid by laser holographic interferometry

    SciTech Connect

    Kurosaki, Y.; Kashiwagi, T. Tokyo Univ. of Agriculture and Techonology, Koganei )

    1990-01-01

    Visualization of four phenomena associated with thermal and fluid flow fields effectively using laser holographic interferometry are reviewed: airflow in a narrow passage between louver arrays, steam absorption into an aqueous solution of LiBr, Marangoni convection effect of steam absorption into a solution with the addition of high molecular weight alcohol, and pressure distribution on a plate induced by air-jet impingement. The observation result obtained in the first case is useful for designing louvered fins used in a heat exchanger. In the second case, the mass diffusivity of water into a solution of LiBr is shown to be measurable. In the third case, the effect of Marangoni convection on steam absorption is both qualitatively and quantitatively elucidated. The last case is a new visualization method of fluctuating pressure on a wall that can be used to resolve eddy-motion behavior near a wall. 26 refs.

  7. Pulsed endoscopic digital holographic interferometry for investigation of hidden surfaces

    NASA Astrophysics Data System (ADS)

    Pedrini, Giancarlo; Alexeenko, I.; Tiziani, Hans J.

    2003-05-01

    Three systems based on digital holographic interferometry in combination with endoscopy are described. The three compact systems (using rigid, flexible endoscopes and miniaturized head) have been developed and used for the measurement of dynamical deformations on both mechanical and biological surfaces, where measurements need to be performed at "hidden" surfaces or inside more or less closed objects. A Q-switched pulsed laser is used. Two digital holograms of the test object, corresponding to the two laser pulses, are captured at separate video frames of the CCD-camera, transferred in a frame grabber and further processed in a PC. If during the interval between the two laser pulses (usually in the range of 5-600 μs) the object undergoes a vibration, a fringe pattern will result from the difference between the two holograms. This fringe pattern has the information needed to quantitatively evaluate the vibration.

  8. Real-time command, data, and control concepts from the instrument on the Space Interferometry Mission

    NASA Technical Reports Server (NTRS)

    Wette, M.

    2001-01-01

    The Space Interferometry Mission, slated to launch in 2008, will require simultaneous operation of tens of control loops running at kiloHertz rates. The task of designing a computer control system to run this complex, distributed system will require careful requirements analysis and design flow.

  9. Measurement Of The Deformation Of Rail Track Fastening Clips By Holographic Interferometry

    NASA Astrophysics Data System (ADS)

    Ennos, A. E.

    1985-01-01

    One method of attaching railway rails to the sleepers (ties) is to use spring steel clips, mounted on either side of the rail, that exert a downward force on the foot of the rail. In service these will flex with the passing of a train. Holographic interferometry has been used to measure quantitatively the manner in which the spring clips deform when the rail is given a displacement in a prescribed direction. The information can be used both to provide data on the bending and torsion of the clip, and as a means of testing the validity of finite element analysis calculations. Measurements on three different designs of commercial clip were carried out on a section of sleeper holding a short length of rail. A controlled upward displacement of the rail was achieved pneumatically by means of plastic pipes interposed between rail and concrete sleeper. Double exposure holograms were recorded on large photographic plates, allowing views of the fringe patterns from widely spaced directions. The three components of displacement at points along the length of the clip were calculated from fringe information taken from nine directions, using least squares fit to obtain increased accuracy. Rotations of the surface were calculated from the fringe directions and spacings. In addition to deformation measurements of the clip under service conditions, information on local yielding of the clip under increasing stress was also obtained by means of real-time interferometry, using an instant hologram camera.

  10. Design, construction, and performance of a real-time holographic refractometry prototype for liquid analysis.

    PubMed

    Barbosa, E A; Silva, D M; Preto, A O; Verzini, R

    2011-01-01

    The development and the performance of a portable holographic refractometer prototype for liquid measurement employing multimode diode lasers with emission centered at 662 nm as light sources is reported. Due to the multiwavelength character of the holographic recording, a synthetic wavelength was generated, and the diffracted wave intensity was thus modulated as a function of the optical path difference between the reference and the object beams. The transparent test cell containing the liquid was placed at the reference-beam arm of the optical setup, while the contour interferogram generated on the holographic image of a flat object was used for fringe counting. A change ΔL on the liquid column length is proportional to the Δp running fringes on the object image, and from this relation the refractive index of the test liquid was obtained. The holograms were recorded on a photorefractive Bi(12)TiO(20) crystal whether using a single multimode diode laser or by combining two diode lasers. In the latter configuration the synthetic wavelength can be varied in order to enhance the measurement sensitivity and∕or to allow the analysis of turbid liquids. The size of the whole prototype is 54 × 22 × 14 cm(3). The refractive indexes of ethanol∕water mixtures with different concentrations were measured, as well as the NaCl concentrations in aqueous solutions were determined upon comparison with an empirical curve. In both cases the results were compared with the ones obtained through an Abbe refractometer.

  11. Design, construction, and performance of a real-time holographic refractometry prototype for liquid analysis

    NASA Astrophysics Data System (ADS)

    Barbosa, E. A.; Silva, D. M.; Preto, A. O.; Verzini, R.

    2011-01-01

    The development and the performance of a portable holographic refractometer prototype for liquid measurement employing multimode diode lasers with emission centered at 662 nm as light sources is reported. Due to the multiwavelength character of the holographic recording, a synthetic wavelength was generated, and the diffracted wave intensity was thus modulated as a function of the optical path difference between the reference and the object beams. The transparent test cell containing the liquid was placed at the reference-beam arm of the optical setup, while the contour interferogram generated on the holographic image of a flat object was used for fringe counting. A change ΔL on the liquid column length is proportional to the Δp running fringes on the object image, and from this relation the refractive index of the test liquid was obtained. The holograms were recorded on a photorefractive Bi12TiO20 crystal whether using a single multimode diode laser or by combining two diode lasers. In the latter configuration the synthetic wavelength can be varied in order to enhance the measurement sensitivity and/or to allow the analysis of turbid liquids. The size of the whole prototype is 54 × 22 × 14 cm3. The refractive indexes of ethanol/water mixtures with different concentrations were measured, as well as the NaCl concentrations in aqueous solutions were determined upon comparison with an empirical curve. In both cases the results were compared with the ones obtained through an Abbe refractometer.

  12. Digital Holographic Interferometry of a Wide Spectral Range in the Systems of Nondestructive Testing of Dynamics of Micro- and Macrosystems

    NASA Astrophysics Data System (ADS)

    Alekseenko, I. V.; Gusev, M. E.

    2015-01-01

    Modern digital holographic interferometry is used to study the objects of various nature and various spatial scales. In this case, a wide spectral range of coherent electromagnetic radiation from long-wavelength infrared to deep ultraviolet is used. In this work, we present the results of studying dynamic processes in construction materials by the methods of digital holographic interferometry using radiation with a wavelength of up to 9.3 μm. The holographic method for testing of microelectromechanical structures is also considered. The method of digital holographic interferometry, which uses an automated holographic microscope, is proposed to study microscopic biological objects.

  13. Real-time, very-long-baseline interferometry based on the use of a communications satellite.

    PubMed

    Yen, J L; Kellermann, K I; Rayhrer, B; Broten, N W; Fort, D N; Knowles, S H; Waltman, W B; Swenson, G W

    1977-10-21

    The Hermes satellite, a joint Canadian-American program, has been used to provide a communication channel between radio telescopes in West Virginia and Ontario, for very-long-baseline interferometry (VLBI). This system makes possible instantaneous correlation of the data as well as a sensitivity substantially better than that of earlier VLBI systems, by virtue of a broader observational bandwidth. With the use of a geostationary communications satellite it is possible to eliminate the tape recorders and the most troublesome part of the postobservational data processing. A further possibility is the development of a phase-coherent interferometer.

  14. Real-time characterization of the neuronal response to osmotic shock by digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Gomariz, Maria; Garcia, Isabel; Soto-Sánchez, Cristina; Martínez-Navarrete, Gema; Fernández, Eduardo; Fimia, Antonio

    2015-05-01

    Digital holographic microscopy has numerous applications in biology for visualizing living cells and 3D tissues. This technique allows for the direct visualization of biological structures avoiding invasive and phototoxic procedures such as fixation and dying processing. In this study we have characterized the morphometry changes of neurons subject to osmolarity changes. For this purpose, we have measured the variations of the amplitude and the oscillation frequency of the plasmatic membrane, as well as the volume changes of the cells before the osmotic shock. There was a relation between the neural culture ageing and its behavioral changes. "Long-term" cultures that had not previously been studied were used to analyze the behavioral changes in aged cells.

  15. Real-time visualisation of deformation fields using speckle interferometry and temporal phase unwrapping

    NASA Astrophysics Data System (ADS)

    Coggrave, C. R.; Huntley, J. M.

    2004-04-01

    A real-time system for analysing data from speckle interferometers, and speckle shearing interferometers, has been developed. Interferograms are continuously recorded by a digital camera at a rate of 60 frames s -1 with temporal phase shifting carried out at the same rate. The images are analysed using a pipeline image processor. With a standard 4-frame phase-shifting algorithm (phase steps of π/2), wrapped phase maps are calculated and displayed at 15 frames s -1. These are unwrapped using a temporal phase unwrapping algorithm to provide a real-time colour-coded display of the relevant displacement component. Each camera pixel (or cluster of pixels) behaves in effect as an independent displacement sensor. The reference speckle interferogram is updated automatically at regular user-defined intervals, allowing arbitrarily large deformations to be measured and errors due to speckle decorrelation to be minimised. The system has been applied to the problem of detecting sub-surface delamination cracks in carbon fibre composite panels.

  16. Dichromated agar: a promising doped biocopolymer for real time holographic recording

    NASA Astrophysics Data System (ADS)

    Bolte, Michèle; Israëli, Yaël; Rivaton, Agnès; Lessard, Roger A.

    2006-09-01

    Agar is a natural polysaccharide which, when doped with dichromate ammonium, can be considered as a promising light sensitive material used for real time hologram recording. The volume transmission gratings were recorded with a Kypton laser at 413 nm and they were read in real-time with a He/Ne laser at 632.8 nm contrary to dichromated gelatin. The so obtained holograms formed were phase holograms due to a refraction index modulation. The optimisation of chemical and physical parameters was investigated in order to form high quality holograms. It was demonstrated the crucial role played by the remaining water in the final film on the value of the diffraction efficiency. In the optimal conditions, a maximum diffraction efficiency of 37 % was attained. Both on-off experiments and the storage of the exposed materials at room temperature and in the dark reveal that the holograms were stable. An attempt to rationalize the set of results in terms of chemical structure of the polymeric matrix and of its ability to stabilize chromium (V) is presented.

  17. Real-time one-point out-of-plane displacement measurement system using electronic speckle pattern interferometry

    NASA Astrophysics Data System (ADS)

    Xiong, Chen; Hu, Wenxin; Zhang, Ming; Miao, Hong

    2016-12-01

    We propose an electronic speckle pattern interferometry-based measurement method in which a hardware device in the reference arm is used to track the out-of-plane displacement in the objective arm. We developed a real-time one-point out-of-plane displacement measurement system, which uses a Michelson interferometer, a lead zirconate titanate (PZT) device, a charge-coupled device camera, and a tracking control system. The system works by checking the movement of carrier fringes, and the PZT is used to track the displacement. We also developed an efficient tracking algorithm based on direction judgment and correlation computation to determine whether the PZT is activated and the distance that the PZT is ordered to move. Our experimental results demonstrate the effectiveness of the system, and finally, we discuss the detailed mechanism of the system.

  18. Real-time optical detection of single human and bacterial viruses based on dark-field interferometry.

    PubMed

    Mitra, Anirban; Ignatovich, Filipp; Novotny, Lukas

    2012-01-15

    The rapid and sensitive detection and characterization of human viruses and bacteriophage is extremely important in a variety of fields, such as medical diagnostics, immunology and vaccine research, and environmental contamination and quality control. We introduce an optical detection scheme for real-time and label-free detection of human viruses and bacteriophage as small as ~24 nm in radius. Combining the advantages of heterodyne interferometry and dark-field microscopy, this label-free method enables us to detect and characterize various biological nanoparticles with unsurpassed sensitivity and selectivity. We demonstrate the high sensitivity and precision of the method by analyzing a mixture containing HIV virus and bacteriophage. The method also resolves the distribution of small nano-impurities (~20-30 nm) in clinically relevant virus samples.

  19. Diffusion dynamics of small molecules from mesoporous silicon films by real-time optical interferometry

    SciTech Connect

    Mares, Jeremy W.; Weiss, Sharon M.

    2011-09-20

    Time-dependent laser reflectometry measurements are presented as a means to rigorously characterize analyte diffusion dynamics of small molecules from mesoporous silicon (PSi) films for drug delivery and membrane physics applications. Calculations based on inclusion of a spatially and temporally dependent solute concentration profile in a one-dimensional Fickian diffusion flow model are performed to determine the diffusion coefficients for the selected prototypical polar species, sucrose (340 Da), exiting from PSi films. The diffusion properties of the molecules depend on both PSi pore size and film thickness. For films with average pore diameters between 10-30 nm and film thicknesses between 300-900 nm, the sucrose diffusion coefficient can be tuned between approximately 100 and 550 {mu}m{sup 2}/s. Extensions of the real-time measurement and modeling approach for determining the diffusivity of small molecules that strongly interact with and corrode the internal surfaces of PSi films are also discussed.

  20. Two detector, active digital holographic camera for 3D imaging and digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Żak, Jakub; Kujawińska, Małgorzata; Józwik, Michał

    2015-09-01

    In this paper we present the novel design and proof of concept of an active holographic camera consisting of two array detectors and Liquid Crystal on Silicon (LCOS) Spatial Light Modulator (SLM). The device allows sequential or simultaneous capture of two Fresnel holograms of 3D object/scene. The two detectors configuration provides an increased viewing angle of the camera, allows to capture two double exposure holograms with different sensitivity vectors and even facilitate capturing a synthetic aperture hologram for static objects. The LCOS SLM, located in a reference arm, serves as an active element, which enables phase shifting and proper pointing of reference beams towards both detectors in the configuration which allows miniaturization of the camera. The laboratory model of the camera has been tested for different modes of work namely for capture and reconstruction of 3D scene and for double exposure holographic interferometry applied for an engineering object under load. The future extension of the camera functionalities for Fourier holograms capture is discussed.

  1. Feasibility study of three-dimensional holographic interferometry for aerodynamics

    NASA Technical Reports Server (NTRS)

    Craig, J. E.

    1983-01-01

    Laser holographic interferometry was tried as a nonintrusive diagnostic tool for studying unsteady two dimensional flows. A NACA 0012 airfoil was tested, while undergoing dynamic stall, over a range of Mach numbers of 0.3 to 0.5, Reynolds number of 0.5 x 10 to the 6th power to 2 x 10 to the 6th power, and at reduced frequencies of 0.015 to 0.15. It was found that both quantitative and qualitative data could be obtained by the technique. Surface pressures on the airfoil can be measured to within 1% of those measured with orifices and pressure transducers when the flow is attached. Velocity profiles were measured near the wake region, and they compared very well with laser velocimeter data for attached flows. For separated flows with large scale vortices, densities can be measured, but pressures and velocities cannot be deduced with the assumption of constant pressure gradient in the normal direction. The sensitivity of the interferograms was good at a Mach number of 0.4 and a Reynolds number of 4 x 10 to the 6th power/ft; the sensitivity worsened at smaller Mach numbers and Reynolds numbers, and improved at larger ones.

  2. Digital holographic interferometry as a tool to obtain shapes

    NASA Astrophysics Data System (ADS)

    Uribe López, Ubaldo; Hernández-Montes, María. del Socorro; Muñoz-Solís, Silvino

    2015-08-01

    This work describes a new method to obtain shapes on surfaces based on digital holographic interferometry (DHI). Research has been reported with different methods, such as fringe projection. DHI, being a full-field technique, decreases the number of images to capture and the processing time, besides having a high resolution. Our proposed method consists in obtaining the shape of the object and a reference plane using an out-of-plane interferometer. The phase difference of the recorded holograms is achieved by means of the Fourier transform method. This resulting phase has a tilt produced by the angle of the object beam relative to the optical axis, which is removed by subtracting the phase difference from the reference plane. The method was tested in two cylinders, one with dimensions of 17.5x23.4mm reconstructed with a height sensitivity of 4.1mm, and another with two levels: one half with dimensions of 16.08x12.75mm, and the other half of 19.07x12.75mm; the result was a successfully reconstructed shape, with a height sensitivity of 2.7mm.

  3. Use of endoscopes in pulsed digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Pedrini, Giancarlo; Schedin, Staffan; Alexeenko, I.; Tiziani, Hans J.

    2001-10-01

    A system based on digital holographic interferometry in combination with an endoscope is described. A Q-switched pulsed laser is used. Two digital holograms of the test object, corresponding to the two laser pulse, are captured at separate video frames of the CCD-camera, transferred in a frame grabber and further processed in a PC. If during the interval between the two laser pulses the object undergoes a deformation, a fringe pattern will result from the difference between the two holograms. This fringe pattern has the information needed to quantitatively evaluate the amount of the deformation. A compact system has been developed to be used for many applications, both mechanical and biological, where measurements need to be performed at 'hidden' surfaces or inside more or less closed objects. The quality of the result obtained by using mechanical objects is usually better, this can be easily explained by the fact that a biological surface is much more complex, in particular some parts reflect well the light and some other absorb it. A comparison of different endoscopes as object image carrier in pulsed digital holography is presented.

  4. Pulsed digital holographic interferometry by using a flexible fiber endoscope

    NASA Astrophysics Data System (ADS)

    Pedrini, G.; Gusev, M.; Schedin, S.; Tiziani, H. J.

    2003-11-01

    A system based on digital holographic interferometry in combination with a flexible fiber endoscope is described. A Q-switched pulsed laser is used. Two digital holograms of the test object, corresponding to the two laser pulses, are captured at separate video frames of a CCD-camera, transferred in a frame grabber and further processed in a PC. If the object undergoes a deformation during the interval between the two laser pulses (usually in the range of 5-600 μs), a fringe pattern will result from the difference between the two holograms. This fringe pattern has the information needed to evaluate quantitatively the amount of the deformation. A compact system has been developed to be used for various applications, both mechanical and biological, where measurements need to be performed at "hidden" surfaces or inside more or less closed objects. The quality of the results obtained by using mechanical objects is usually better than for biological objects. This can be explained easily by the fact that a biological surface is much more complex, in particular some parts of the surface may reflect the light well whereas some other parts may absorb it. Experimental results are presented.

  5. Note: Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration.

    PubMed

    Brandi, F; Giammanco, F; Conti, F; Sylla, F; Lambert, G; Gizzi, L A

    2016-08-01

    The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 10(19) cm(-3) range well suited for LWFA.

  6. Note: Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration

    NASA Astrophysics Data System (ADS)

    Brandi, F.; Giammanco, F.; Conti, F.; Sylla, F.; Lambert, G.; Gizzi, L. A.

    2016-08-01

    The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 1019 cm-3 range well suited for LWFA.

  7. Note: Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration

    SciTech Connect

    Brandi, F.; Giammanco, F.; Conti, F.; Lambert, G.; Gizzi, L. A.

    2016-08-15

    The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 10{sup 19} cm{sup −3} range well suited for LWFA.

  8. Preliminary results of real-time in-vitro electronic speckle pattern interferometry (ESPI) measurements in otolaryngology

    NASA Astrophysics Data System (ADS)

    Conerty, Michelle D.; Castracane, James; Cacace, Anthony T.; Parnes, Steven M.; Gardner, Glendon M.; Miller, Mitchell B.

    1995-05-01

    Electronic Speckle Pattern Interferometry (ESPI) is a nondestructive optical evaluation technique that is capable of determining surface and subsurface integrity through the quantitative evaluation of static or vibratory motion. By utilizing state of the art developments in the areas of lasers, fiber optics and solid state detector technology, this technique has become applicable in medical research and diagnostics. Based on initial support from NIDCD and continued support from InterScience, Inc., we have been developing a range of instruments for improved diagnostic evaluation in otolaryngological applications based on the technique of ESPI. These compact fiber optic instruments are capable of making real time interferometric measurements of the target tissue. Ongoing development of image post- processing software is currently capable of extracting the desired quantitative results from the acquired interferometric images. The goal of the research is to develop a fully automated system in which the image processing and quantification will be performed in hardware in near real-time. Subsurface details of both the tympanic membrane and vocal cord dynamics could speed the diagnosis of otosclerosis, laryngeal tumors, and aid in the evaluation of surgical procedures.

  9. A real-time interferometer technique for compressible flow research

    NASA Technical Reports Server (NTRS)

    Bachalo, W. D.; Houser, M. J.

    1984-01-01

    Strengths and shortcomings in the application of interferometric techniques to transonic flow fields are examined and an improved method is elaborated. Such applications have demonstrated the value of interferometry in obtaining data for compressible flow research. With holographic techniques, interferometry may be applied in large scale facilities without the use of expensive optics or elaborate vibration isolation equipment. Results obtained using holographic interferometry and other methods demonstrate that reliable qualitative and quantitative data can be acquired. Nevertheless, the conventional method can be difficult to set up and apply, and it cannot produce real-time data. A new interferometry technique is investigated that promises to be easier to apply and can provide real-time information. This single-beam technique has the necessary insensitivity to vibration for large scale wind tunnel operations. Capabilities of the method and preliminary tests on some laboratory scale flow fluids are described.

  10. A real-time interferometer technique for compressible flow research

    NASA Technical Reports Server (NTRS)

    Bachalo, W. D.; Houser, M. J.

    1984-01-01

    Strengths and shortcomings in the application of interferometric techniques to transonic flow fields are examined and an improved method is elaborated. Such applications have demonstrated the value of interferometry in obtaining data for compressible flow research. With holographic techniques, interferometry may be applied in large scale facilities without the use of expensive optics or elaborate vibration isolation equipment. Results obtained using holographic interferometry and other methods demonstrate that reliable qualitative and quantitative data can be acquired. Nevertheless, the conventional method can be difficult to set up and apply, and it cannot produce real-time data. A new interferometry technique is investigated that promises to be easier to apply and can provide real-time information. This single-beam technique has the necessary insensitivity to vibration for large scale wind tunnel operations. Capabilities of the method and preliminary tests on some laboratory scale flow fluids are described.

  11. Applications of real-time holography

    NASA Astrophysics Data System (ADS)

    Feinberg, J.

    1985-01-01

    Holographic principles are discussed, with a description of the steps of hologram production and reconstruction and the materials used in storage of the images. Real-time holography applications, including photolithography, double-exposure interferometry, time-averaged holography, parallel optical processing, optical phase conjugation, beam steering, and moving holograms, are described in detail. In addition, current areas of active research and some experimental applications are discussed.

  12. TV-Holography and holographic interferometry: Industrial applications

    NASA Astrophysics Data System (ADS)

    Steinbichler, H.; Gehring, G.

    A detailed vibration analysis is vital for industry. However, in particular in the automotive industry, one is interested in the acoustical field or in the determination of strain and stress. The acoustical field can easily be measured by microphones or intensity microprobes; however, it is also important to understand by which vibration modes the noise is emanating. TV-Holography, also called electronic speckle interferometry (ESPI), and double or multipulse (three or four) holography are two famous techniques of holography (Marwitz H., Praxis der Holographie, Expert Verlag, 1990). In speckle interferometry two images of the speckle field at different times are recorded directly with a CCD camera and then subtracted from each other by an image processing system. The resulting interference fringes are available in real time. In double pulse holography a ruby laser is triggered such that the interesting object vibration is recorded by two consecutive laser pulses. The interference fringes can be evaluated at reconstruction time by the phase shift technique, if two reference beams are used. The multi-pulse method is very useful for the investigation of operational vibration modes or of transient processes like shock waves. The calculation of the acoustical field and frequency spectrum requires the knowledge of the contour for the generation of boundary elements. The contour data can be taken either from CAD or FEM data or by measurement with optical 3D measurement systems. The acoustical field is calculated by solving the Helmholtz integral. For experimental strain and stress analysis the 3D shape and the 3D displacement are also necessary. For acoustical prediction the component of the displacement, which is perpendicular to the surface, is determined. On the other hand, for strain/stress calculation the tangential components to the surface are used.

  13. Real-time optical fiber digital speckle pattern interferometry for industrial applications

    NASA Astrophysics Data System (ADS)

    Chan, Robert K.; Cheung, Y. M.; Lo, C. H.; Tam, T. K.

    1997-03-01

    There is current interest, especially in the industrial sector, to use the digital speckle pattern interferometry (DSPI) technique to measure surface stress. Indeed, many publications in the subject are evident of the growing interests in the field. However, to bring the technology to industrial use requires the integration of several emerging technologies, viz. optics, feedback control, electronics, imaging processing and digital signal processing. Due to the highly interdisciplinary nature of the technique, successful implementation and development require expertise in all of the fields. At Baptist University, under the funding of a major industrial grant, we are developing the technology for the industrial sector. Our system fully exploits optical fibers and diode lasers in the design to enable practical and rugged systems suited for industrial applications. Besides the development in optics, we have broken away from the reliance of a microcomputer PC platform for both image capture and processing, and have developed a digital signal processing array system that can handle simultaneous and independent image capture/processing with feedback control. The system, named CASPA for 'cascadable architecture signal processing array,' is a third generation development system that utilizes up to 7 digital signal processors has proved to be a very powerful system. With our CASPA we are now in a better position to developing novel optical measurement systems for industrial application that may require different measurement systems to operate concurrently and requiring information exchange between the systems. Applications in mind such as simultaneous in-plane and out-of-plane DSPI image capture/process, vibrational analysis with interactive DSPI and phase shifting control of optical systems are a few good examples of the potentials.

  14. Application of holographic interferometry for analysis of the dynamic and modal characteristics of an advanced exotic metal airfoil structure

    NASA Astrophysics Data System (ADS)

    Fein, Howard

    1999-03-01

    Holographic Interferometry has been successfully employed to characterize the materials and behavior of diverse types of structures under stress. Specialized variations of this technology have also been applied to define dynamic and vibration related structural behavior. Such applications of holographic technique offer some of the most effective methods of modal and dynamic analysis available. Real-time dynamic testing of the modal and mechanical behavior of aerodynamic control and airfoil structures for advanced aircraft has always required advanced instrumentation for data collection in either actual flight test or wind-tunnel simulations. Advanced optical holography techniques are alternate methods which result in actual full-field behavioral data on the ground in a noninvasive environment. These methods offer significant insight in both the development and subsequent operational test and modeling of advanced exotic metal control structures and their integration with total vehicle system dynamics. Structures and materials can be analyzed with very low amplitude excitation and the resultant data can be used to adjust the accuracy mathematically derived structural and behavioral models. Holographic Interferometry offers a powerful tool to aid in the developmental engineering of exotic metal structures for high stress applications. Advanced Titanium alloy is a significant example of these sorts of materials which has found continually increased use in advanced aerodynamic, undersea, and other highly mobil platforms. Aircraft applications in particular must consider environments where extremes in vibration and impulsive mechanical stress can affect both operation and structural stability. These considerations present ideal requisites for analysis using advanced holographic methods in the initial design and test of structures made with such advanced materials. Holographic techniques are nondestructive, real- time, and definitive in allowing the identification of

  15. Digital holographic interferometry applied to the study of tympanic membrane displacements

    NASA Astrophysics Data System (ADS)

    Hernández-Montes, María del Socorro; Mendoza Santoyo, Fernando; Pérez López, Carlos; Muñoz Solís, Silvino; Esquivel, Jesús

    2011-06-01

    Quantitative studies of the mechanical properties of tympanic membrane (TM) are needed for better understanding of its role in detailed clinical evaluation, its research being of extreme importance because it is one of the most important structures of the middle ear. By finding the membrane's vibration patterns and quantifying the induced displacement it is possible to characterize and determine its physiological status. Digital holographic interferometry (DHI) has proved to be a reliable optical non-invasive and full-field-of-view technique for the investigation of different mechanical parameters of biological tissues, i.e., DHI has demonstrated an ability to detect displacement changes in quasi-real time and without the need to contact the sample's surface under study providing relevant information, such as clinical and mechanical sample properties. In this research fresh tympanic membrane specimens taken from post-mortem cats are subjected to acoustic stimuli in the audible frequency range producing resonant vibration patterns on the membrane, a feature that results in an ideal application for DHI. An important feature of this approach over other techniques previously used to study the tympanic membrane vibrations is that it only requires two images and less hardware to carry out the measurements, making of DHI a simpler and faster technique as compared to other proposed approaches. The results found show a very good agreement between the present and past measurements from previous research work, showing that DHI is a technique that no doubt will help to improve the understanding of the tympanic membrane's working mechanisms.

  16. Measurement of Three-dimensional Density Distributions by Holographic Interferometry and Computer Tomography

    NASA Technical Reports Server (NTRS)

    Vest, C. M.

    1982-01-01

    The use of holographic interferometry to measure two and threedimensional flows and the interpretation of multiple-view interferograms with computer tomography are discussed. Computational techniques developed for tomography are reviewed. Current research topics are outlined including the development of an automated fringe readout system, optimum reconstruction procedures for when an opaque test model is present in the field, and interferometry and tomography with strongly refracting fields and shocks.

  17. Quantitative measurement of displacement in photopolymer layers during holographic recording using phase shifting electronic speckle pattern interferometry

    NASA Astrophysics Data System (ADS)

    Moothanchery, Mohesh; Bavigadda, Viswanath; Upputuri, Paul Kumar; Pramanik, Manojit; Toal, Vincent; Naydenova, Izabela

    2016-03-01

    The aim of this study is to determine the displacement profile due to shrinkage in acrylamide-based photopolymer layer during holographic recording. Using phase shifting electronic speckle pattern interferometry the displacement at each pixel in the image of the object is measured by phase shifting technique so that a complete displacement profile of the object can be obtained. It was observed that the displacement profile is Gaussian and resembles to the profile of the recording beam. We observed an increase in shrinkage from 2 μm at 20 seconds of recording to 7.5 μm after 120 seconds of recording. The technique allows for real time measurement of the shrinkage profile.

  18. Holographic interferometry of oil films and droplets in water with a single-beam mirror-type scheme.

    PubMed

    Kukhtarev, Nickolai; Kukhtareva, Tatiana; Gallegos, Sonia C

    2011-03-01

    Application of single-beam reflective laser optical interferometry for oil films and droplets in water detection and characterization is discussed. Oil films can be detected by the appearance of characteristic interference patterns. Analytical expressions describing intensity distribution in these interference patterns allow determination of oil film thickness, size of oil droplets, and distance to the oil film from the observation plane. Results from these analyses indicate that oil spill aging and breakup can be monitored in real time by analyzing time-dependent holographic fringe patterns. Interferometric methods of oil spill detection and characterization can be automated using digital holography with three-dimensional reconstruction of the time-changing oil spill topography. In this effort, the interferometric methods were applied to samples from Chevron oil and British Petroleum MC252 oil obtained during the Deep Water Horizon oil spill in the Gulf of Mexico.

  19. Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

    NASA Technical Reports Server (NTRS)

    Decker, A. J.

    1984-01-01

    The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed.

  20. Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

    SciTech Connect

    Decker, A.J.

    1984-06-01

    The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed.

  1. Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

    NASA Technical Reports Server (NTRS)

    Decker, A. J.

    1984-01-01

    The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three-dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed. Previously announced in STAR as N84-21849

  2. Measurement of fluid properties using rapid-double-exposure and time-average holographic interferometry

    NASA Technical Reports Server (NTRS)

    Decker, A. J.

    1984-01-01

    The holographic recording of the time history of a flow feature in three dimensions is discussed. The use of diffuse illumination holographic interferometry or the three-dimensional visualization of flow features such as shock waves and turbulent eddies is described. The double-exposure and time-average methods are compared using the characteristic function and the results from a flow simulator. A time history requires a large hologram recording rate. Results of holographic cinematography of the shock waves in a flutter cascade are presented as an example. Future directions of this effort, including the availability and development of suitable lasers, are discussed. Previously announced in STAR as N84-21849

  3. Digital holographic microscopy long-term and real-time monitoring of cell division and changes under simulated zero gravity.

    PubMed

    Pan, Feng; Liu, Shuo; Wang, Zhe; Shang, Peng; Xiao, Wen

    2012-05-07

    The long-term and real-time monitoring the cell division and changes of osteoblasts under simulated zero gravity condition were succeed by combing a digital holographic microscopy (DHM) with a superconducting magnet (SM). The SM could generate different magnetic force fields in a cylindrical cavity, where the gravitational force of biological samples could be canceled at a special gravity position by a high magnetic force. Therefore the specimens were levitated and in a simulated zero gravity environment. The DHM was modified to fit with SM by using single mode optical fibers and a vertically-configured jig designed to hold specimens and integrate optical device in the magnet's bore. The results presented the first-phase images of living cells undergoing dynamic divisions and changes under simulated zero gravity environment for a period of 10 hours. The experiments demonstrated that the SM-compatible DHM setup could provide a highly efficient and versatile method for research on the effects of microgravity on biological samples.

  4. Real time observation of granular analogue rock material deformation in response to shocks via nonlinear laser interferometry

    NASA Astrophysics Data System (ADS)

    Walczak, Pierre; Mezzapesa, Francesco; Bouakline, Abderrahmane; Ambre, Julien; Bouissou, Stéphane; Barland, Stéphane

    2017-04-01

    Inelastic strain analysis of rock under stress is of first importance to build up adequate theory of inelastic deformation and failure of geomaterials. The latter is crucial to have a better understanding of natural processes such as landsliding or seismic fault activity. In laboratory experiments, a rock sample can be easily stressed and different methods are used to study the deformation as for exemple X-ray tomography, or digital image correlation. But during the compression process of the sample, these technique don't allow to access the 3-D strain tensor. We present a laboratory experiment in which we investigate the real time deformation of a granular rock material subjected to different mechanical perturbations. Our work provides a novel optical technique in the geoscientific context for studying the wave propagation and the fracture phenomenon. The experimental measurement of the sample deformation is performed by nonlinear laser interferometry. The principle is based on the so-called self-mixing technique : a beam emitted by a semiconductor laser diode is reinjected into the emitter after reflection on the sample surface. The self-mixing signal in the laser diode can be measured on an integrated photodiode or even more simply by measuring the voltage across the laser diode. In both cases, we have a compact device allowing to observe in real time the direction and amplitude of the motion of the sample surface with a resolution of the half-wavelength of the laser (1.3 micrometers) at microsecond time scales. In the experiment, our rock like sample which is actually made from a finely ground powder of TiO2 is submitted to a constant load. Then we have performed two different experiments in which we have applied either a uniaxial or a transversal mechanical perturbation. The surface displacement is measured by two self-mixing interferometers localized to each side of the sample. In the case of uniaxial perturbation, we have observed nonlinear compression waves

  5. Real-time, in-situ analysis of silver ions using nucleic acid probes modified silica microfiber interferometry.

    PubMed

    Yu, Bo; Huang, Yunyun; Zhou, Jun; Guo, Tuan; Guan, Bai-Ou

    2017-04-01

    A sensitive Ag(+) sensor based on nucleic acid probes modified silica microfiber interferometry is designed and developed. The probes on microfiber surface plays the part on catching Ag(+) as tentacles, while their conformation change from random coils to hairpins. It induces the fiber surface refractive index change, which is captured by the optical fiber and translated into a significant wavelength shift in the interferometric fringe. Such a combination enables an improved concentration sensitivity of 0.22nm/log M and limit of detection of 1.36 × 10(-9)M, taking the advantage of real-time and in-situ analysis. It shows good selectivity in the present of many other metal ions and offers potential to analysis in real matrix, especially in the environmental samples must be analyzed in a short time. This may provide insights into the preparation of sensing platforms for optical quantification of other small molecular, supplementing the existing tools. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Real-time holographic gratings recorded by He Ne laser in polymer films containing spirooxazine compounds pre-irradiated by UV light

    NASA Astrophysics Data System (ADS)

    Fu, Shencheng; Liu, Yichun; Lu, Zifeng; Dong, Lin; Hu, Weilin; Xie, Minggui

    2005-09-01

    Real-time holographic gratings were optically recorded with a pair of interferential He-Ne laser beams (632.8 nm) in poly(methylmethacrylate) (PMMA) film containing 6‧-piperidino-1,3,3-trimethylspiro[indolino-2,3‧-[3H]naphtha-[2,1-b][1,4]oxazine] (SO-1) pre-irradiated by ultraviolet light. The transformation from SO-1 to photomerocyanine (PMC) was studied in detail. PMC was observed in two forms. The holographic characteristics of the recorded gratings were dependent on the polarization direction of the recording beams. Reversible holograms were recorded in the medium by modulating UV light.

  7. Holographic optics

    SciTech Connect

    Cindrich, I

    1988-01-01

    These proceeding collect paper on holographic optics. Topics include: holographic helmet displays; optical performance of holographic kinoforms; lR, visible, UV and XUV Bragg holograms; diffractive optics; holographic laser-protective eyewear; interferometry; and hologon deflectors.

  8. Real-time heterodyne imaging interferometry: focal-plane amplitude and phase demodulation using a three-phase correlation image sensor.

    PubMed

    Kimachi, Akira

    2007-01-01

    A method of real-time heterodyne imaging interferometry using a three-phase correlation image sensor (3PCIS) is proposed. It simultaneously demodulates the amplitude and phase images of an incident interference pattern at an ordinary frame rate with good accuracy, thus overcoming the trade-off among measurement time, spatial resolution, and demodulation accuracy suffered in conventional interferometry. An experimental system is constructed with a 64x64 3PCIS camera operated at 30 frames/s and a two-frequency He-Ne laser with a beat frequency of 25 kHz. The results obtained for a scanning mirror and heated silicone oil confirm the proposed method.

  9. Experimental analysis of natural convection in square cavities heated from below with 2D-PIV and holographic interferometry techniques

    SciTech Connect

    Corvaro, F.; Paroncini, M.

    2007-07-15

    A numerical and experimental analysis was performed to study the natural convection heat transfer in a square cavity heated from below and cooled by the sidewalls. The enclosure was filled with air (Pr = 0.71) and a discrete heater was mounted on its lower surface; the effect of three different positions was evaluated. The air temperature distribution and the Nusselt numbers at different Rayleigh numbers on the heated strip were measured by an holographic interferometry thanks to the real-time and the double-exposure technique. The double-exposure technique was performed at steady-state and it was used to obtain the isothermal lines in the cavity at different Rayleigh numbers; while the real-time technique was used to control the presence of the plume oscillations and to determinate the achievement of the steady-state. A 2D particle image velocimetry (PIV) was utilized to measure the velocity fields at the same Rayleigh numbers. In particular we analysed the distribution of the velocity vectors and their modulus inside the cavity. The convective phenomenon was studied and the Nusselt numbers were presented as well as the Rayleigh numbers analysed. Moreover experimental and numerical correlations were determined for each position analysed to connect the Rayleigh numbers with the Nusselt numbers. Measured quantities were compared with the numerical results which were obtained with the finite volume code Fluent 6.2.16. (author)

  10. Experimental Aspects of Using Time-Averaged Holographic Interferometry to Detect Barely Visible Impact Damage in a Graphite/Epoxy Composite Plate,

    DTIC Science & Technology

    1987-08-25

    EXPERIMENTAL ASPECTS OF USING TIME-AVERAGED HOLOGRAPHIC INTERFEROMETRY TO DETECT BARELY VISIBLE IMPACT DAMAGE IN A GRAPHTEIEPOXY COMPOSITE PLATE (U) by...S.J. Rumble SUMMARY Time-averaged holographic interferometry has been used to detect barely visible impact damage in a graphiteiepoxy plate. Details...light. Double exposure holographic interferometry has also been used to detect barely visible impact damage . ’~ (C) COMMONWEALTH OF AUSTRALIA 1987 POSTAL

  11. Visualization of flows in a motored rotary combustion engine using holographic interferometry

    NASA Technical Reports Server (NTRS)

    Hicks, Yolanda R.; Schock, Harold J.; Craig, James E.; Umstatter, Holly L.; Lee, David Y.

    1986-01-01

    The use of holographic interferometry to view the small- and large-scale flow field structures in the combustion chamber of a motored Wankel engine assembly is described. In order that the flow patterns of interest could be observed, small quantities of helium were injected with the intake air. Variation of the air flow patterns with engine speed, helium flow rate, and rotor position are described. The air flow at two locations within the combustion chamber was examined using this technique.

  12. Holographic interferometry of transparent media with reflection from imbedded test objects

    NASA Technical Reports Server (NTRS)

    Prikryl, I.; Vest, C. M.

    1981-01-01

    In applying holographic interferometry, opaque objects blocking a portion of the optical beam used to form the interferogram give rise to incomplete data for standard computer tomography algorithms. An experimental technique for circumventing the problem of data blocked by opaque objects is presented. The missing data are completed by forming an interferogram using light backscattered from the opaque object, which is assumed to be diffuse. The problem of fringe localization is considered.

  13. Holographic interferometry of transparent media using light scattered by embedded test objects

    NASA Technical Reports Server (NTRS)

    Prikryl, I.; Vest, C. M.

    1982-01-01

    Fringe formation and localization in holographic interferometry of transparent media are discussed for configurations in which light enters the medium and is scattered back through it by an embedded diffuse object. Fringe order numbers are doubled, and the fringe localization region is translated and compressed by a factor of two. The results are applicable to tomographic reconstruction of aerodynamic density fields around opaque test objects.

  14. Holographic Interferometry and Image Analysis for Aerodynamic Testing

    DTIC Science & Technology

    1980-09-01

    tunnels, (2) development of automated image analysis techniques for reducing quantitative flow-field data from holographic interferograms, and (3...investigation and development of software for the application of digital image analysis to other photographic techniques used in wind tunnel testing.

  15. A dual plate thermoplastic recording device for holographic interferometry

    NASA Technical Reports Server (NTRS)

    Umstatter, Holly L.; Craig, James E.; Trolinger, James D.; Lee, George

    1986-01-01

    The development of a dual plate holographic interferometer using thermoplastic recording devices is described. The operational characteristics of the thermoplastic devices are investigated and optimized for fringe contrast and signal-to-noise ratio. The dual plate device was demonstrated in a transonic wind tunnel at NASA Ames Research Center. The interferograms derived from the thermoplastic device are compared with those derived from conventional photographic emulsions. The fringe contrast achieved with the optimized thermoplastic device is equivalent to the contrast achieved with conventional techniques.

  16. Holographic interferometry and tomography at Ames Research Center

    NASA Technical Reports Server (NTRS)

    Lee, G.

    1982-01-01

    A YAG laser holographic interferometer system and reconstruction laboratory for the Ames 2- by 2-Foot Transonic Wind Tunnel are discussed. This system provides dual plate and double pulse holography for quantitative and qualitative measurements, respectively. Interferometric measurements of two-dimensional airfoils and three-dimensional bodies of revolution for a tomography feasibility study were made. The two-dimensional work included supercritical airfoils, an oscillating airfoil undergoing dynamic stall, and a circulation control airfoil. The tomography experiments centered around hemispherical nose and tangent ogive models. In addition, the tomography work covered the development of a Fourier transform code for the retrieval of the three dimensional density distributions from the interferograms.

  17. Object tracking mask-based NLUT on GPUs for real-time generation of holographic videos of three-dimensional scenes.

    PubMed

    Kwon, M-W; Kim, S-C; Yoon, S-E; Ho, Y-S; Kim, E-S

    2015-02-09

    A new object tracking mask-based novel-look-up-table (OTM-NLUT) method is proposed and implemented on graphics-processing-units (GPUs) for real-time generation of holographic videos of three-dimensional (3-D) scenes. Since the proposed method is designed to be matched with software and memory structures of the GPU, the number of compute-unified-device-architecture (CUDA) kernel function calls and the computer-generated hologram (CGH) buffer size of the proposed method have been significantly reduced. It therefore results in a great increase of the computational speed of the proposed method and enables real-time generation of CGH patterns of 3-D scenes. Experimental results show that the proposed method can generate 31.1 frames of Fresnel CGH patterns with 1,920 × 1,080 pixels per second, on average, for three test 3-D video scenarios with 12,666 object points on three GPU boards of NVIDIA GTX TITAN, and confirm the feasibility of the proposed method in the practical application of electro-holographic 3-D displays.

  18. Digital three-color holographic interferometry for flow analysis.

    PubMed

    Desse, Jean-Michel; Picart, Pascal; Tankam, Patrice

    2008-04-14

    A digital three-color holographic interferometer was designed to analyze the variations in refractive index induced by a candle flame. Color holograms are generated and recorded with a three layer photodiode stack sensor allowing a simultaneous recording with a high spatial resolution. Phase maps are calculated using Fourier transform and spectral filtering is applied to eliminate parasitic diffraction orders. Then, the contribution along each color is obtained with the simultaneous three wavelength measurement. Results in the case of the candle flame are presented. Zero order fringe, meaning zero optical path difference, can be easily extracted from the experimental data, either by considering a modeled colored fringe pattern or the wrapped phases along the three wavelengths.

  19. Simultaneous two-wavelength holographic interferometry in a superorbital expansion tube facility.

    PubMed

    McIntyre, T J; Wegener, M J; Bishop, A I; Rubinsztein-Dunlop, H

    1997-11-01

    A new variation of holographic interferometry has been utilized to perform simultaneous two-wavelength measurements, allowing quantitative analysis of the heavy particle and electron densities in a superorbital facility. An air test gas accelerated to 12 km/s was passed over a cylindrical model, simulating reentry conditions encountered by a space vehicle on a superorbital mission. Laser beams with two different wavelengths have been overlapped, passed through the test section, and simultaneously recorded on a single holographic plate. Reconstruction of the hologram generated two separate interferograms at different angles from which the quantitative measurements were made. With this technique, a peak electron concentration of (5.5 +/- 0.5) x 10(23) m(-3) was found behind a bow shock on a cylinder.

  20. Application of digital phase-shift holographic interferometry to weak shock waves propagating at Mach 1.007

    NASA Astrophysics Data System (ADS)

    Mizukaki, Toshiharu

    2010-02-01

    Digital phase-shift holographic interferometry was applied to visualize weak shock waves and related phenomena quantitatively. This method of interferometry is an improved version of double-exposure holographic interferometry using digital image processing and a phase shift method. The obtained interferograms were analyzed using the Carré method. To evaluate the applicability of the interferometry to quantitatively visualize the phenomena, density profiles behind weak spherical shock waves generated with 500 μg of silver azide were examined. The results of the numerical analysis performed with the hydrocode AUTODYN were compared with those of the experiment. The Mach number of visualized shock waves was estimated to be 1.007 ± 0.001 at the pressure transducer near the test section. At the shock fronts, the density difference between the experimental and numerical results was within 0.3%.

  1. A holographic interferometry technique for measuring transonic flow near a rotor blade

    NASA Technical Reports Server (NTRS)

    Kittleson, J. K.

    1983-01-01

    A technique that uses holographic interferometry to record the first interferograms of the flow near a hovering transonic rotor blade is presented. A pulsed ruby laser is used to record interferograms of a 2 ft diam field of view near a rotor tip operating at a tip Mach number of 0.90. Several interferograms, recorded along planes perpendicular to the rotor's tip path plane at various azimuth angles around the flow, are presented. These interferograms yield quantitative information about shock structure and location, flow separation, and radiated noise that will help helicopter researchers understand the complexities of the flow around high speed rotor blades and thus improve performance and reduce noise.

  2. Flow-field measurements on an airfoil with an oscillating trailing-edge using holographic interferometry

    NASA Technical Reports Server (NTRS)

    Bachalo, W. D.

    1984-01-01

    Holographic interferometry data were acquired on an NACA 64A010 airfoil with an oscillating flap. The airfoil was installed in the Ames 11-Foot Transonic Wind Tunnel between splitter plates. Recordings were made at discrete phase angles of the oscillation. The interferometry results provided detailed flow visualization of the shock boundary-layer interaction and the separated flow. Quantitative results were extracted from the interferograms to produce pressure data. These results were compared to the surface pressures obtained with the surface pressure taps. Excellent agreement was found for low angles of incidence. At larger angles of incidence, the flow had greater three-dimensionality, and the results were not in good agreement in some regions of the flow field. Mach contours were traced for representative flow conditions. Wake profiles were also obtained using the assumption of constant pressure across the wake and the Crocco relationship.

  3. Real-time scaling of micro-objects by multiplexed holographic recording on photo-thermoplastic structure

    NASA Astrophysics Data System (ADS)

    Chirita, A.

    2010-06-01

    The processes of micro-object hologram real-time recording on a photo-thermo-plastic carrier based on a chalcogenide glassy semiconductor As-Se-S-Sn system were studied. The possibility to measure micro-object dimensions using an interference fringe pattern was shown. Double-exposure hologram recording by use of photo-induced structural transformation processes in a photo-semiconductor and photo-thermoplastic recording process was investigated.

  4. Stroboscopic holographic interferometry: measurements of vector components of a vibration.

    PubMed

    Hariharan, P; Oreb, B F; Freund, C H

    1987-09-15

    The interpretation of time-averaged holographic fringes recorded with a vibrating object presents problems when the direction of the motion is not known or when points on the object are moving in two or three dimensions. Measurements on additional holograms with properly chosen directions of the sensitivity vector are then required to evaluate the vibration amplitude. However, reduction of the data, even along a single line, is laborious and subject to errors. This paper describes a computerized system which uses stroboscopic illumination in conjunction with digital phase-shifting techniques to evaluate the magnitude and direction of the surface displacements at a uniformly spaced array of points covering the vibrating object. These values are used along with data on the shape of the object to calculate the in-plane and out-of-plane components of the vibration at these points. The operation of the system is illustrated with some results obtained with a compressor blade from a jet engine. Measurements of the surface displacements at different epochs of the vibration cycle permit a detailed analysis of complex vibrations.

  5. Real-time optical correlator using computer-generated holographic filter on a liquid crystal light valve

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Yu, Jeffrey

    1990-01-01

    Limitations associated with the binary phase-only filter often used in optical correlators are presently circumvented in the writing of complex-valued data on a gray-scale spatial light modulator through the use of a computer-generated hologram (CGH) algorithm. The CGH encodes complex-valued data into nonnegative real CGH data in such a way that it may be encoded in any of the available gray-scale spatial light modulators. A CdS liquid-crystal light valve is used for the complex-valued CGH encoding; computer simulations and experimental results are compared, and the use of such a CGH filter as the synapse hologram in a holographic optical neural net is discussed.

  6. Real-time optical correlator using computer-generated holographic filter on a liquid crystal light valve

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Yu, Jeffrey

    1990-01-01

    Limitations associated with the binary phase-only filter often used in optical correlators are presently circumvented in the writing of complex-valued data on a gray-scale spatial light modulator through the use of a computer-generated hologram (CGH) algorithm. The CGH encodes complex-valued data into nonnegative real CGH data in such a way that it may be encoded in any of the available gray-scale spatial light modulators. A CdS liquid-crystal light valve is used for the complex-valued CGH encoding; computer simulations and experimental results are compared, and the use of such a CGH filter as the synapse hologram in a holographic optical neural net is discussed.

  7. Real-time ultrawide-band group delay profile monitoring through low-noise incoherent temporal interferometry.

    PubMed

    Park, Yongwoo; Malacarne, Antonio; Azaña, José

    2011-02-28

    A simple, highly accurate measurement technique for real-time monitoring of the group delay (GD) profiles of photonic dispersive devices over ultra-broad spectral bandwidths (e.g. an entire communication wavelength band) is demonstrated. The technique is based on time-domain self-interference of an incoherent light pulse after linear propagation through the device under test, providing a measurement wavelength range as wide as the source spectral bandwidth. Significant enhancement in the signal-to-noise ratio of the self-interference signal has been observed by use of a relatively low-noise incoherent light source as compared with the theoretical estimate for a white-noise light source. This fact combined with the use of balanced photo-detection has allowed us to significantly reduce the number of profiles that need to be averaged to reach a targeted GD measurement accuracy, thus achieving reconstruction of the device GD profile in real time. We report highly-accurate monitoring of (i) the group-delay ripple (GDR) profile of a 10-m long chirped fiber Bragg grating over the full C band (~42 nm), and (ii) the group velocity dispersion (GVD) and dispersion slope (DS) profiles of a ~2-km long dispersion compensating fiber module over an ~72-nm wavelength range, both captured at a 15 frames/s video rate update, with demonstrated standard deviations in the captured GD profiles as low as ~1.6 ps.

  8. Deformation Studies and Elasticity Measurements of Hydrophobic Silica Aerogels using Double Exposure Holographic Interferometry

    NASA Astrophysics Data System (ADS)

    Chikode, Prashant; Sabale, Sandip; Chavan, Sugam

    2017-01-01

    Holographic interferometry is mainly used for the non-destructive testing of various materials and metals in industry, engineering and technological fields. This technique may used to study the elastic properties of materials. We have used the double exposure holographic interferometry (DEHI) to study the surface deformation and elastic constant such as Young's modulus of mechanically stressed aerogel samples. Efforts have been made in the past to use non-destructive techniques like sound velocity measurements through aerogels. Hydrophobic Silica aerogels were prepared by the sol-gel process followed by supercritical methanol drying. The molar ratio of tetramethoxysilane: methyltrimethoxysilane: H2O constant at 1.2:0.8:6 while the methanol / tetramethoxysilane molar ratio (M) was varied systematically from 14 to 20 to obtain hydrophobic silica aerogels. After applying the weights on the sample in grams, double exposure holograms of aerogel samples have been successfully recorded. Double exposure causes localization of interference fringes on the aerogel surface and these fringes are used to determine the surface deformation and elastic modulus of the aerogels and they are in good agreement with the experiments performed by using four point bending. University Grants Commission for Minor Research Project and Department of Science and Technology for FIST Program.

  9. Visual investigation on the heat dissipation process of a heat sink by using digital holographic interferometry

    SciTech Connect

    Wu, Bingjing; Zhao, Jianlin Wang, Jun; Di, Jianglei; Chen, Xin; Liu, Junjiang

    2013-11-21

    We present a method for visually and quantitatively investigating the heat dissipation process of plate-fin heat sinks by using digital holographic interferometry. A series of phase change maps reflecting the temperature distribution and variation trend of the air field surrounding heat sink during the heat dissipation process are numerically reconstructed based on double-exposure holographic interferometry. According to the phase unwrapping algorithm and the derived relationship between temperature and phase change of the detection beam, the full-field temperature distributions are quantitatively obtained with a reasonably high measurement accuracy. And then the impact of heat sink's channel width on the heat dissipation performance in the case of natural convection is analyzed. In addition, a comparison between simulation and experiment results is given to verify the reliability of this method. The experiment results certify the feasibility and validity of the presented method in full-field, dynamical, and quantitative measurement of the air field temperature distribution, which provides a basis for analyzing the heat dissipation performance of plate-fin heat sinks.

  10. Evaluation of double-exposure holographic interferometry for biomechanical measurements in vitro.

    PubMed

    Manley, M T; Ovryn, B; Stern, L S

    1987-01-01

    Double-exposure holographic interferometry is a nondestructive testing technique for measuring displacement and strain in a test object. A standard hologram contains three-dimensional information about an object. However, the holographic interferogram has additional information, as a series of interference bands overlaid on the three-dimensional image of the object contains information about object deformation. Interferograms were produced for intact cadaveric femora and cadaveric femora with implanted titanium alloy and cobalt-chromium alloy femoral components. A force was applied to the femoral head to simulate single leg stance, and changes in specimen deformation were observed as additional incremental loads were applied. We have observed that the femur behaves as a bending beam and that the holographic technique allows the position of maximal deflection to be identified and the magnitude of femoral displacement from the load axis to be determined at any point within the field of view. The effects of the modulus of the implanted stem on the bending characteristics of the composite structure were clearly seen in the interferograms. This communication presents a photographic analysis of the double exposure interferograms recorded, as well as a critique of the technique for biomechanical measurements in vitro.

  11. Real-time high-resolution vascular ultrasound using frequency domain interferometry with the ROI-division process.

    PubMed

    Taki, Hirofumi; Sakamoto, Takuya; Taki, Kousuke; Yamakawa, Makoto; Shiina, Tsuyoshi; Kudo, Motoi; Sato, Toru

    2013-01-01

    We have proposed a high-range-resolution ultrasound imaging method for human carotid artery using an adaptive beamforming technique based on frequency domain interferometry (FDI). The method assumes that the received signal consists of multiple echoes of targets and noise, where the waveform of each echo is similar to that of the reference signal. In this study, we examine the dependence of the echo waveform on the target depth, and investigate the proper measurement-range for the FDI imaging method using a reference signal. Furthermore, we propose a ROI-division process, where each sub-ROI has a proper measurement-range for the application of the FDI imaging method. Simulation and experimental results show the efficiency of the ROI-division process in improving the image quality of human carotid artery acquired using the FDI imaging method. We believe that the modified FDI imaging method with the ROI-division process has the potential to facilitate significant progress in the detection of vessel stenosis and in the assessment of cardiovascular disease risk.

  12. Evaluation of the holographic parameters by electrosynthesized CdXZn1-XS (X=0.3) thin films using double exposure digital holographic interferometry technique

    NASA Astrophysics Data System (ADS)

    Dhaygude, H. D.; Chikode, P. P.; Shinde, S. K.; Shinde, N. S.; Fulari, V. J.

    2017-02-01

    In this paper, we have reported the optical non destructive technique, which uses double exposure digital holographic interferometry (DEDHI) together with simple mathematical interpretation, which instantly situates to the thickness of thin films, deposited mass, stress to substrate and fringe width for different deposition times. Here, the stainless steel substrate was exposed for different intervals of time. It is observed that the fringe width, stress to substrate changes with changing the time of deposition. This effect is due to the increase in thickness of CdXZn1-XS (X=0.3) thin films. Thus, holographic studies show sensitivity to deposition time and concentrations of solution.

  13. The use of holographic interferometry for measurements of temperature in a rectangular heat pipe. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Marn, Jure

    1989-01-01

    Holographic interferometry is a nonintrusive method and as such possesses considerable advantages such as not disturbing the velocity and temperature field by creating obstacles which would alter the flow field. These optical methods have disadvantages as well. Holography, as one of the interferometry methods, retains the accuracy of older methods, and at the same time eliminates the system error of participating components. The holographic interferometry consists of comparing the objective beam with the reference beam and observing the difference in lengths of optical paths, which can be observed during the propagation of the light through a medium with locally varying refractive index. Thus, change in refractive index can be observed as a family of nonintersecting surfaces in space (wave fronts). The object of the investigation was a rectangular heat pipe. The goal was to measure temperatures in the heat pipe, which yields data for computer code or model assessment. The results were obtained by calculating the temperatures by means of finite fringes.

  14. Real-Time Detection and Tracking of Vital Signs with an Ambulatory Subject Using Millimeter-Wave Interferometry

    NASA Astrophysics Data System (ADS)

    Mikhelson, Ilya V.

    Finding a subject's heart rate from a distance without any contact is a difficult and very practical problem. This kind of technology would allow more comfortable patient monitoring in hospitals or in home settings. It would also allow another level of security screening, as a person's heart rate increases in stressful situations, such as when lying or hiding malicious intent. In addition, the fact that the heart rate is obtained remotely means that the subject would not have to know he/she is being monitored at all, adding to the efficacy of the measurement. Using millimeter-wave interferometry, a signal can be obtained that contains composite chest wall motion made up of component motions due to cardiac activity, respiration, and interference. To be of use, these components have to be separated from each other by signal processing. To do this, the quadrature and in-phase components of the received signal are analyzed to get a displacement waveform. After that, processing can be done on that waveform in either the time or frequency domains to find the individual heartbeats. The first method is to find the power spectrum of the displacement waveform and to look for peaks corresponding to heartbeats and respiration. Another approach is to examine the signal in the time domain using wavelets for multiresolution analysis. One more method involves studying the statistics of the wavelet-processed signal. The final method uses a heartbeat model along with probabilistic processing to find heartbeats. For any of the above methods to work, the millimeter-wave sensor has to be accurately pointed at the subject's chest. However, even small subject motions can render the rest of the gathered data useless as the antenna may have lost its aim. To combat this, a color and a depth camera are used with a servo-pan/tilt base. My program finds a face in the image and subsequently tracks that face through upcoming frames. The pan/tilt base adjusts the aim of the antenna depending on

  15. Remote Sensing and Characterization of Oil on Water Using Coherent Fringe Projection and Holographic in-Line Interferometry

    DTIC Science & Technology

    2013-03-01

    holography in material sci- ence and microbiology,” in New Directions in Holography and Speckle, H. J. Caulfield and C. S. Vikram, Eds., pp. 193–216...Moldova State University and received his MS degree in physics of semiconductors. Research interests: real-time holography , dynamic holography , holographic

  16. Comparative study for the nondestructive testing of advanced ceramic materials by infrared thermography and holographic interferometry

    NASA Astrophysics Data System (ADS)

    Sfarra, S.; Ibarra-Castanedo, C.; Bendada, A.; Maldague, X.; Ambrosini, D.; Paoletti, D.

    2010-05-01

    Advanced ceramic materials are increasingly employed in varied and new applications where improved electrical, mechanical and/or thermal properties are sought. For instance, in a manner similar to carbon or glass fiber reinforced plastics, ceramic matrix composites (CMCs) are designed to improve the naturally brittle characteristics of monolithic ceramics thanks to the inclusion of fibers. Among the main interests for advanced ceramics are the increase in the operation temperature of components, the elimination of the use of cooling fluids, and weight savings. In this paper, the capabilities of infrared thermography and holographic interferometry are investigated and compared for the nondestructive assessment of advanced ceramic materials using three experimental specimens: (1) a monolithic green ceramic tile with fabricated defects, (2) a CMC specimen (from production reject) with a porous alumina matrix reinforced with glass fibers, and (3) a sandwich structure consisting on a carbon fiber honeycomb core with a ceramic plate bonded in one side.

  17. An experimental investigation of circulation control flow fields using holographic interferometry

    NASA Technical Reports Server (NTRS)

    Bachalo, William D.

    1982-01-01

    Experiments are presented which were conducted on flow fields produced by a circulation control airfoil utilizing the Coanda effect at the trailing edge. The application of holographic interferometry to obtain both visualization and quantitative data on the flow field about a circulation control airfoil at transonic flow speed is covered. A brief description of the flow model and measurement techniques is given. The data reduction procedure, results, and interpretation are presented. The results have provided a good deal of information on the character of the flow field, particularly in the neighborhood of the trailing edge. As to the airfoil design, it is apparent that improved performance can be achieved if jet detachment is delayed. Another design improvement would involve the development of an optimum trailing-edge shape for the expected operating Mach and Reynolds number ranges.

  18. Digital holographic interferometry as an experimental instrumentation for measurements of macroscopic properties of polydomain ferroelectrics

    NASA Astrophysics Data System (ADS)

    Mokry, Pavel; Steiger, Kateřina; Psota, Pavel; Dolecek, Roman; Vojtisek, Petr; Ledl, Vit

    2015-01-01

    In this work, the theoretical study of macroscopic dielectric and optical properties of ferroelectric polydomain samples is presented. The role of average spontaneous polarization of the polydomain sample on the macroscopic dielectric response is analyzed. The measurement method of average spontaneous polarization using optical methods is suggested and analyzed. The presented analysis is focused on the computation of optical properties near ferroelectric domain walls. The computation of refractive index in the regions near neutral domain walls is presented. Since it is known that the refractive index depends on the configuration of the crystal lattice within a particular domain and on the internal and external electric fields, the obtained results will be used for a suggested method of 3D imaging of ferroelectric domain walls and internal electric fields using digital holographic interferometry.

  19. Study of heat dissipation process from heat sink using lensless Fourier transform digital holographic interferometry.

    PubMed

    Kumar, Varun; Shakher, Chandra

    2015-02-20

    This paper presents the results of experimental investigations about the heat dissipation process of plate fin heat sink using digital holographic interferometry. Visual inspection of reconstructed phase difference maps of the air field around the heat sink with and without electric power in the load resistor provides qualitative information about the variation of temperature and the heat dissipation process. Quantitative information about the temperature distribution is obtained from the relationship between the digitally reconstructed phase difference map of ambient air and heated air. Experimental results are presented for different current and voltage in the load resistor to investigate the heat dissipation process. The effect of fin spacing on the heat dissipation performance of the heat sink is also investigated in the case of natural heat convection. From experimental data, heat transfer parameters, such as local heat flux and convective heat transfer coefficients, are also calculated.

  20. Studies on electrodeposited silver sulphide thin films by double exposure holographic interferometry

    NASA Astrophysics Data System (ADS)

    Prabhune, V. B.; Shinde, N. S.; Fulari, V. J.

    2008-12-01

    Silver sulphide (Ag 2S) thin films have been deposited on to stainless steel and fluorine doped tin oxide (FTO) glass substrates by the electrodeposition process, in potentiostatic mode using silver nitrate (AgNO 3), sodium thiosulphate (Na 2S 2O 3) as a precursor sources and Ethylene Diamine Tetra Acetic Acid (EDTA) was used as a complexing agent. The deposition potential of the compound was investigated by cyclic voltammetry. The structural and optical properties of the deposited films have been studied using X-ray diffraction (XRD) and optical absorption techniques, respectively. XRD studies reveal that the films are polycrystalline with monoclinic crystal structure. Optical absorption study shows the presence of direct transition with bandgap energy 1.1 eV. The determination of thickness and stress of the Ag 2S thin films was carried out by Double Exposure Holographic Interferometry (DEHI) technique.

  1. Three-dimensional displacement measurement from phase signals embedded in a frame in digital holographic interferometry.

    PubMed

    Kulkarni, Rishikesh; Rastogi, Pramod

    2015-04-10

    A novel technique is proposed for the simultaneous measurement of all three components of displacement from a single recording of the interference field in digital holographic interferometry. The interference field is divided into a number of rectangular segments, and in each of these segments, the interference field is represented as a multicomponent low-order two-dimensional (2D) polynomial phase signal. 2D-product high-order ambiguity function based analysis is applied to obtain an accurate estimation of the 2D polynomial coefficients. These coefficients are further used to compute the interference phases. The simulation and experimental results show the robustness of the proposed method to noise and its effectiveness in multiple phase estimation.

  2. Synthetic aperture double exposure digital holographic interferometry for wide angle measurement and monitoring of mechanical displacements

    NASA Astrophysics Data System (ADS)

    Kujawinska, M.; Makowski, P.; Finke, G.; Zak, J.; Józwik, M.; Kozacki, T.

    2015-08-01

    A novel approach for wide angle registration and display of double exposure digital holograms of 3D objects under static or step-wise load is presented. The registration setup concept combines digital Fourier holography with synthetic aperture (SA) technique, which is equivalent to usage of a wide angle, spherically curved detector. The coherent object wavefields extracted from a pair of acquisitions collected in the synthetic aperture double exposure digital holographic interferometry scheme (SA DEDH) are utilized as the input for two different scenarios of investigation, which include (i) numerical determination of 2D phase difference fringes representing deformation of an object and (ii) physical displaying of a 3D image resulting from interference of two object (slightly different) wavefronts registered at the SA double exposure hologram. The capture and display processes are analyzed and implemented. The applicability of both numerical and experimental approach to SA DEDH for testing engineering objects is discussed.

  3. Time Dependent Holographic Interferometry and Finite-Element Analysis of Heat Transfer Within a Rectangular Enclosure

    DTIC Science & Technology

    1976-09-01

    I. INTRODUCTION- A. HOLOGRAPHIC INTERFEROMETRY The phenomenon of interference has had a considerable influence on the development of physics. Thomas...circulators were activated. The main factor(s) influencing this inability to acquire such live fringes, on film, was the necessary exclusion of the hologram... mooc ^30 •»-< * #00 + O00ɜ-tH Q(M I > •.-4(M-M- +30 ^f0*O I >o • -t-W-QOO 30 t^*Q(Mw O tO^ I o«o»-< •^ + 00 I fH (M(M3 -*>* (M +«o o fOOO *3Q • — » aoo

  4. Holographic interferometry of intact and radially incised human eye-bank corneas.

    PubMed

    Smolek, M K

    1994-05-01

    Many methods to measure corneal elasticity destroy the tissue and thereby produce erroneous results. Holographic interferometry, a highly precise nondestructive optical comparison technique, was used to evaluate corneal elasticity of intact eye-bank eyes. A double-pulse holographic interferometer operating at 632.8 nm was used to measure corneal deformation in 20 whole-globe eyes from donors 45 to 83 years of age for intraocular pressures from 16 mm Hg to 21 mm Hg. Stress was computed from LaPlace's law, and arc length strain was derived from z-axis distention of the central cornea. The stress-strain relationship in the normal physiological range of intraocular pressure was linear with a Young's elastic modulus of 1.03 gigapascals for the central cornea (r = 0.999). During interferometry of radial keratotomy of the cornea, interference fringe patterns developed in association with each incision as it was made. When four incisions were placed deep along each of the primary semimeridians, the fringe pattern developed as expected, based on current keratotomy models. When incisions were shallow (approximately 50% depth) and placed asymmetrically along the nasal, temporal, and superior semimeridians, the resulting surface strain was symmetrical about the central cornea, forming an annular pattern of interference fringes. These results indicate that when the cornea was stressed at physiological pressures as part of the intact whole globe, it was less elastic than excised corneal tissue tested by strip extensiometry. Radially incised corneas demonstrated strain patterns suggestive of inherent structural anisotropy with a possible inferior quadrant weakness.

  5. Digital holographic interferometry with CO2 lasers and diffuse illumination applied to large space reflector metrology [Invited].

    PubMed

    Georges, Marc P; Vandenrijt, Jean-François; Thizy, Cédric; Stockman, Yvan; Queeckers, Patrick; Dubois, Frank; Doyle, Dominic

    2013-01-01

    Digital holographic interferometry in the long-wave infrared domain has been developed by combining a CO(2) laser and a microbolometer array. The long wavelength allows large deformation measurements, which are of interest in the case of large space reflectors undergoing thermal changes when in orbit. We review holography at such wavelengths and present some specific aspects related to this spectral range on our measurements. For the design of our digital holographic interferometer, we studied the possibility of illuminating specular objects by a reflective diffuser. We discuss the development of the interferometer and the results obtained on a representative space reflector, first in the laboratory and then during vacuum cryogenic test.

  6. LED-based digital holographic microscopy with slightly off-axis interferometry

    NASA Astrophysics Data System (ADS)

    Guo, Rongli; Yao, Baoli; Min, Junwei; Zhou, Meiling; Yu, Xianghua; Lei, Ming; Yan, Shaohui; Yang, Yanlong; Dan, Dan

    2014-12-01

    An LED illuminated Linnik-type digital holographic microscope (DHM) for high-quality phase imaging is presented by the adoption of slightly off-axis two-step blind-phase-shifting interferometry (TB-PSI). Slightly off-axis interferometry lowers the requirement on the angle between the object and the reference waves as well as the requirement on the resolving power of the charge-coupled device (CCD) camera. In addition, the apparatus is cost-effective and offers ease of alignment. The phase-shifting DHM is simply implemented by mechanically moving the reference mirror while disposing of a precise phase modulator such as a piezoelectric transducer (PZT). The phase shift between the two interferograms is extracted by Fourier transformation analysis, and then the phase image is reconstructed. The performance of the TB-PSI used in the scheme is analyzed. The phase imaging for nanostructured specimens is conducted, and the results demonstrate the feasibility of the scheme. The phase noise is reduced by 73% when compared to the result obtained with coherent illumination.

  7. The Investigation of the Fundamental Limits of Heterodyne Holographic Interferometry with the Application of Imaging Laser Generated Lamb Waves

    DTIC Science & Technology

    1989-04-01

    study was conducted on the feasi- bility of using heterodyne holographic interferometry to detect and size surface breaking cracks in 718 inconel alloy...This information would include an accurate assessment of the integrity of the material along with the size and location of defects. However contact...example, from a manufacturing stand point, it would be advantageous to locate flaws and defects while a part was still at an elevated tem- perature

  8. Measurement of surface resistivity/conductivity of carbon steel in 5-20ppm of KGR-134 inhibited seawater by holographic interferometry techniques

    NASA Astrophysics Data System (ADS)

    Habib, K.

    2011-05-01

    Optical interferometry techniques were used for the first time to measure the surface resistivity/conductivity of carbon steel samples in blank seawater and in seawater with different concentrations of a corrosion inhibitor, without any physical contact. The measurement of the surface resistivity/conductivity of carbon steel samples was carried out in blank seawater and in seawater with a concentration range of 5-20ppm of KGR-134 corrosion inhibitor, at room temperature. In this investigation, the real-time holographic interferometry was carried out to measure the thickness of anodic dissolved layer or the total thickness, Utotal, of formed oxide layer of carbon steel samples during the alternating current (AC) impedance of the samples in blank seawater and in 5-20 ppm KGR-134 inhibited seawater, respectively. In other words, the surface resistivity/conductivity of carbon steel samples was determined simultaneously by holographic interferometry, an electromagnetic method, and by the Electrochemical Impedance (E.I) spectroscopy, an electronic method. In addition, a mathematical model was derived in order to correlate between the AC impedance (resistance) and to the surface (orthogonal) displacement of the surface of the samples in solutions. In other words, a proportionality constant (surface resistivity (ρ) or surface conductivity(σ)=1/[ surface resistivity (ρ)] between the determined AC impedance (by EIS technique) and the orthogonal displacement (by the optical interferometry techniques) was obtained. Consequently the values ρ and σ of the carbon steel samples in solutions were obtained. Also, the value of ρ from other source were used for comparison sake with the calculated values of this investigation. This study revealed that the oxide film of the carbon steel sample has been removed from the surface of the sample, in the blank seawater. Therefore, the corresponding value of the resistivity to such layer remained the same as the value of the resistivity

  9. Experimental characterization of the hygroscopic properties of wood during convective drying using digital holographic interferometry.

    PubMed

    Kumar, Manoj; Shakher, Chandra

    2016-02-10

    In this paper, an application of digital holography for the measurement of surface deformations and the strain field to understand the shrinkage behavior of wood during convective drying is presented. Moisture absorption and desorption induce the dimensional changes and deformations in wood that leads to failure of certain components made of wood. The knowledge of the dimensional changes in wood, deformations, strain distribution and their causes are important for the best utilization of wood. For the study, lensless Fourier transform digital holographic interferometry is used to measure moisture- induced deformation, strain distribution, and the coefficient of hygroscopic shrinkage in different samples of wood. The technique is highly sensitive and enables the observation of deformation and strain distribution during the variations of moisture content in the wood. The wet wood sample was exposed to convective drying, which leads to changes in the moisture content and the associated deformations. The deformation/strain in each step of drying process is used to evaluate the coefficient of hygroscopic shrinkage in different wood samples. The experiments were repeated for differently treated woods. The experimental results show that the strain and coefficient of hygroscopic shrinkage can be minimized if the wood is dried in the presence of the proper moisture content.

  10. Holographic interferometry as a method to detect welding failures on ribbed iron structures

    NASA Astrophysics Data System (ADS)

    Vincitorio, F. M.; Budini, N.; Mulone, C.; Freyre, C.; Spector, M.; López Díaz, A. J.; Ramil Rego, A.; Yañez Casal, A.

    2013-11-01

    Metallic structures made of ribbed iron bars (ADN-420) are of common use in sheds and supporting structures. Usually, trusses are constructed with many pieces of ribbed iron bars, combined together through a welding process. Although ribbed iron manufacturers do not recommend this type of structure it is still frequently used. The main weakness of these trusses is the welding point because ribbed iron is not a material suitable for welding. This work presents results obtained from an analysis of welding points between ribbed iron bars extracted from a collapsed truss, by means of conventional (optical) and digital holographic interferometry (HI and DHI, respectively). The experiments were divided in two different series of studies. The first series were performed by HI on metallographic samples while the second series were done by DHI on different welding points. These results were complemented by metallographic analysis made in an external laboratory. DHI indicated that the bars did not have important failures but evidenced defects in one of the welding points under analysis. This information together with metallographic results allowed inferring that the collapse was probably due to an error in the design of the structure, since the iron bars were out of standard compliance.

  11. Binary Diffusion Coefficient Data of Various Gas Systems Determined Using a Loschmidt Cell and Holographic Interferometry

    NASA Astrophysics Data System (ADS)

    Kugler, T.; Rausch, M. H.; Fröba, A. P.

    2015-11-01

    The paper reports on binary diffusion coefficient data for the gaseous systems argon-neon, krypton-helium, ammonia-helium, nitrous oxide-nitrogen, and propane-helium measured using a Loschmidt cell combined with holographic interferometry between (293.15 and 353.15) K as well as between (1 and 10) bar. The investigations on the noble gas systems aimed to validate the measurement apparatus by comparing the binary diffusion coefficients measured as a function of temperature and pressure with theoretical data. In previous studies, it was already shown that the raw concentration-dependent data measured with the applied setup are affected by systematic effects if pure gases are used prior to the diffusion process. Hence, the concentration-dependent measurement data were processed to obtain averaged binary diffusion coefficients at a mean mole fraction of 0.5. The data for the molecular gas systems complete literature data on little investigated systems of technical interest and point out the capabilities of the applied measurement apparatus. Further experimental data are reported for the systems argon-helium, krypton-argon, krypton-neon, xenon-helium, xenon-krypton, nitrous oxide-carbon dioxide, and propane-carbon dioxide at 293.15 K, 2 bar, and a mean mole fraction of 0.5.

  12. Grading of wooden plates for musical instrument making by means of holographic interferometry

    NASA Astrophysics Data System (ADS)

    Urgela, Stanislav

    1998-07-01

    Wood selection for musical instrument making is usually based on visual estimation and on manual mechanical and vibrational subjective testing. The method proposed uses TV holography and holographic interferometry with a double- pulsed laser to visualize the standing acoustic waves and the impact generated by transient waves as inspection testing tools. The theory of bending waves in orthotropic plates is used to interpret the experimental results. This enables us to estimate Young's moduli parallel to and perpendicular to the grain and the in-plane shear modulus in wood. The testing is nondestructive, so the expensive wooden plates can be used in production. Properly modified, the test can be applied to the judgement of any wooden and wooden composite plates. The 3D charts for a set of the physioacoustical characteristics--density, modulus of elasticity, and acoustic constant on the axes--are confirmed as a useful procedure that can help to provide more objective results in wood grading for materials selection in the design of musical instruments, mainly bowed string instruments and pianos.

  13. Comparison of digital holographic interferometry and constant temperature anemometry for measurement of temperature field in fluid

    NASA Astrophysics Data System (ADS)

    Doleček, Roman; Psota, Pavel; Lédl, Vít.; Vít, Tomáś; Dančová, Petra; Kopecký, Václav

    2015-05-01

    The presented paper shows possibility of using digital holographic interferometry (DHI) for temperature field measurement in moving fluids. This method uses a modified Twymann-Green setup having double sensitivity instead of commonly used Mach-Zehnder type of interferometer in order to obtain sufficient phases change of the field. On the other hand this setup is not light efficient as Mach-Zehnder interferometer. For measurement of the fast periodical phenomenon is not necessary to use always the high speed camera. One can consider this field to coherent phenomenon. With employing one digital camera synchronized to periodic field and external triggered one can capture whole period of the phenomenon. However the projections form one viewing direction of asymmetrical temperature field maybe misguided. Hence for sufficient examination of the asymmetrical field one should capture a large number of the phenomenon's projections from different viewing directions. This projections are later used for 3D tomographic reconstruction of the whole temperature field and its time evolution. One of the commonly used method for temperature field measurement in moving fluids is hot wire method - constant temperature anemometry (CTA). In contrast to whole field measurement of DHI it is an invasive point temperature measurement method. One of the limiting factor of using CTA in moving fluids is frequency of temperature changes. This changes should not exceed 1 kHz. This limitation could be overcome by using of optical methods such as DHI. The results of temperature field measurement achieved by both method are compared in the paper.

  14. Comparison on different insects' wing displacements using high speed digital holographic interferometry.

    PubMed

    Aguayo, Daniel D; Santoyo, Fernando Mendoza; De la Torre-I, Manuel H; Salas-Araiza, Manuel D; Caloca-Mendez, Cristian

    2011-06-01

    In-flight insect wing motion behavior depends on a wide variety of conditions. They have a complex structural system and what seems to be a rather complicated motion. Researchers in many fields have endeavoured to study and reproduce these wing movements with the aim to apply the gained knowledge in their fields and for the benefit of avionic technological improvements and insect migration studies, among many other themes. The study of in-flight insect wing motion and its measurement is a relevant issue to understand and reproduce its functionality. Being capable of measuring the wing flapping using optical noninvasive methods adds scientific and technological value to the fundamental research in the area. Four different types of butterflies found widely in Mexico's forests are used to compare their wing flapping mechanisms. An out-of-plane digital holographic interferometry system is used to detect and measure its wingmicro deformations. Displacement changes from in vivo flapping wings are registered with a CMOS high speed camera yielding full field of view images depicting these insects' wing motion. The results have a resolution in the scale of hundreds of nanometers over the entire wing surface.

  15. Z-pinch equilibrium and instability analysis with digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Ross, M. P.; Shumlak, U.; Nelson, B. A.; Golingo, R. P.; Hughes, M. C.; Claveau, E. L.; Forbes, E. G.; Doty, S.; Kim, B.

    2016-10-01

    The ZaP-HD Flow Z-Pinch project provides a platform to explore how shear flow stabilized Z-pinches could scale to high-energy-density plasma and fusion reactor conditions. ZaP-HD generates shear stabilized, axisymmetric Z-pinches with stable lifetimes approaching 60 μs. The goal of the project is to increase the plasma density and temperature compared to the previous ZaP project by compressing the plasma to smaller radii ( 1 mm). Radial and axial plasma electron density structures are measured using digital holographic interferometry (DHI), which provides the necessary fine spatial resolution. ZaP-HD's DHI system uses a 2 ns Nd:YAG laser pulse with a second harmonic generator (λ = 532 nm) to produce holograms recorded by a Nikon D3200 digital camera. The holograms are numerically reconstructed with the Fresnel transform reconstruction method to obtain the phase shift caused by the interaction of the laser beam with the plasma. This provides a two-dimensional map of line-integrated electron density, which can be Abel inverted to determine the local number density. The DHI resolves line-integrated densities down to 3 ×1020 m-2 with spatial resolution near 10 μm. This work is supported by Grants from the US DoE and NNSA.

  16. Comparison on different insects' wing displacements using high speed digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Aguayo, Daniel D.; Santoyo, Fernando Mendoza; de La Torre-I, Manuel H.; Salas-Araiza, Manuel D.; Caloca-Mendez, Cristian

    2011-06-01

    In-flight insect wing motion behavior depends on a wide variety of conditions. They have a complex structural system and what seems to be a rather complicated motion. Researchers in many fields have endeavoured to study and reproduce these wing movements with the aim to apply the gained knowledge in their fields and for the benefit of avionic technological improvements and insect migration studies, among many other themes. The study of in-flight insect wing motion and its measurement is a relevant issue to understand and reproduce its functionality. Being capable of measuring the wing flapping using optical noninvasive methods adds scientific and technological value to the fundamental research in the area. Four different types of butterflies found widely in Mexico's forests are used to compare their wing flapping mechanisms. An out-of-plane digital holographic interferometry system is used to detect and measure its wingmicro deformations. Displacement changes from in vivo flapping wings are registered with a CMOS high speed camera yielding full field of view images depicting these insects' wing motion. The results have a resolution in the scale of hundreds of nanometers over the entire wing surface.

  17. Determination of curvature and twist of deformed object by digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Quan, C.; Chen, W.; Tay, C. J.

    2008-11-01

    This paper describes a feasibility study of digital holographic interferometry for the measurement of curvature and twist of a deformed object. Measurement of curvature and twist is an important aspect in experimental mechanics. Numerous methods have been proposed to determine the curvature and twist by using digital shearography. We proposed a novel method to determine curvature and twist based on digital holography (DH) and complex phasor (CP). In the conventional methods, phase difference between the first and second states is obtained directly by digital phase subtraction (DPS) and Fourier transform is then employed to extract phase maps. In this study, CP method is proposed to improve the quality of phase maps corresponding to second-order derivatives. Subsequently, sine/cosine transformation and short time Fourier transform (STFT) are employed to process the wrapped phase maps. An experiment is conducted on a clamped circular plate under a point load at centre. The experimental results show that the proposed method is valid and able to obtain high quality phase maps corresponding to curvature and twist of a deformed object.

  18. Surface strain-field determination of tympanic membrane using 3D-digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Hernandez-Montes, María del S.; Mendoza Santoyo, Fernando; Muñoz, Silvino; Perez, Carlos; de la Torre, Manuel; Flores, Mauricio; Alvarez, Luis

    2015-08-01

    In order to increase the understanding of soft tissues mechanical properties, 3D Digital Holographic Interferometry (3D-DHI) was used to quantify the strain-field on a cat tympanic membrane (TM) surface. The experiments were carried out applying a constant sound-stimuli pressure of 90 dB SPL (0.632 Pa) on the TM at 1.2 kHz. The technique allows the accurate acquisition of the micro-displacement data along the x, y and z directions, which is a must for a full characterization of the tissue mechanical behavior under load, and for the calculation of the strain-field in situ. The displacements repeatability in z direction shows a standard deviation of 0.062 μm at 95% confidence level. In order to realize the full 3D characterization correctly the contour of the TM surface was measured employing the optically non-contact two-illumination positions contouring method. The x, y and z displacements combined with the TM contour data allow the evaluation its strain-field by spatially differentiating the u(m,n), v(m,n), and w(m,n) deformation components. The accurate and correct determination of the TM strain-field leads to describing its elasticity, which is an important parameter needed to improve ear biomechanics studies, audition processes and TM mobility in both experimental measurements and theoretical analysis of ear functionality and its modeling.

  19. Z-pinch equilibrium and instability analysis with digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Ross, M. P.; Shumlak, U.; Nelson, B. A.; Golingo, R. P.; Hughes, M. C.; Claveau, E. L.; Weed, J. R.; Forbes, E. G.; Doty, S. A.; Kim, B.

    2015-11-01

    The ZaP-HD Flow Z-Pinch project generates flow shear stabilized Z-pinches, providing a platform to explore how such plasmas could scale to HEDP and fusion reactor conditions. To scale up the plasma's density and temperature, it must be compressed to a smaller size making measurements more difficult. Digital holographic interferometry (DHI) employing a pulsed Nd:YAG laser and consumer DSLR camera can spatially resolve the plasma's electron density. The Fresnel reconstruction method allows expedient numerical data reconstruction. Obtaining electron density radial profiles relies on applying an Abel inversion to convert measured line-integrated density, and the inversion process provides an independent measure of plasma symmetry. Entire Z-pinch equilibria (n, P, T, and B profiles) can be computed by applying physical models to the density data. Tracking the time evolution of pressure and density can reveal the presence of non-adiabatic heating mechanisms. Imaging the size scales of instabilities enables relative measures of viscosity at different positions and times. Error estimation of measured density profiles is presented along with observed asymmetric instabilities. This work is supported by grants from the U.S. Department of Energy and the U.S. National Nuclear Security Administration.

  20. Tympanic membrane contour measurement with two source positions in digital holographic interferometry.

    PubMed

    Solís, Silvino M; Hernández-Montes, María Del S; Santoyo, Fernando M

    2012-12-01

    The data acquisition from the shape of an object is a must to complete its quantitative displacement measurement analysis. Over the past years whole field of view optical non-invasive testing has been widely used in many areas, from industrial ones to, for instance, biomedical research topics. To measure the surface contour from the tympanic membrane (TM) of ex-vivo cats digital holographic interferometry (DHI) is used in combination with a two-illumination positions method: the shape is directly measured from the phase change between two source positions by means of a digital Fourier transform method. The TM shape data in conjunction with its displacement data renders a complete and accurate description of the TM deformation, a feature that no doubt will serve to better comprehend the hearing process. Acquiring knowledge from the tissue shape indicates a mechanical behavior and, indirectly, an alteration in the physiological structure due to middle ear diseases or damages in the tissue that can deteriorate sound transmission. The TM shape contour was successfully measured by using two source positions within DHI showing that the TM has a conical shape. Its maximum depth was found to be 2 mm, considering the umbo as the reference point with respect to the TM annulus plane, where the setup is arranged in such a manner that it is capable of measuring a height of up to 7 mm.

  1. Beam-splitting cube for fringe-projection, holographic, and shearographic interferometry.

    PubMed

    Shang, H M; Hung, M Y; Quan, C G; Tay, C J

    2001-11-01

    We describe a simple method in which the techniques of fringe-projection, holographic, and shearographic interferometry may be readily realized with a commercial beam-splitting cube, a laser source, and a beam expander. With the use of a computer algorithm, moiré fringes may be derived digitally from the fringes that are projected onto a reference surface and onto an object surface. Successful use of the beam-splitting cube for these optical methods is attributed to the refraction of the two split beams that exit from the two adjacent faces of the cube. By careful orientation of the cube, the two refracted light beams will converge and interfere, resulting in the formation of Young's interference fringes for the fringe-projection method. When the hypotenuse of the beam-splitting cube is placed nearly normal to an illuminated object, both the image and the mirror image of the object will be formed behind the cube where a camera is placed. This optical setup thus forms the basis for double-exposure holography when these two images are fully overlapped and for shearography when the images are slightly laterally displaced.

  2. Stress measurement of deposited SiO2 films on a silicon wafer using dimensional-stability holographic interferometry test

    NASA Astrophysics Data System (ADS)

    Dovgalenko, George E.; Haque, M. S.; Kniazkov, Anatoli; Onischenko, Yuri I.; Salamo, Gregory J.; Naseem, Hameed A.

    1997-11-01

    In quality control nondestructive techniques gain more and more importance. Holographic interferometry has the advantage of being very sensitive and can be used contactless for inspection of technical components. The interferogram contains fringes, whose pattern holds information about the surface deformation of a part subjected to the load. The load in case of deposited silicone oxide film is cased by stress produced different thermal expansion temperature coefficients film and silicone substrate. Change in stress in thin silicon dioxide films was observed using a high stability portable holographic interferometer using dimension stability test. Pattern recognition algorithm for synthesis of stress analyses map is reported. A stress relaxation phenomenon in this film thickness of 0.5 micrometers on Si wafer has been observed. Correlation of differential stress with initial flatness deviation of Si wafer has been discovered. The advantages of the proposed measuring technique and results are discussed.

  3. A scheme for recording a fast process at nanosecond scale by using digital holographic interferometry with continuous wave laser

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Zhao, Jianlin; Di, Jianglei; Jiang, Biqiang

    2015-04-01

    A scheme for recording fast process at nanosecond scale by using digital holographic interferometry with continuous wave (CW) laser is described and demonstrated experimentally, which employs delayed-time fibers and angular multiplexing technique and can realize the variable temporal resolution at nanosecond scale and different measured depths of object field at certain temporal resolution. The actual delay-time is controlled by two delayed-time fibers with different lengths. The object field information in two different states can be simultaneously recorded in a composite hologram. This scheme is also suitable for recording fast process at picosecond scale, by using an electro-optic modulator.

  4. Quantitative measurement of thermal lensing in diode-side-pumped Nd:YAG laser by use of digital holographic interferometry.

    PubMed

    Di, Jianglei; Yu, Yang; Wang, Zhaomin; Qu, Weijuan; Cheng, Chee Yuen; Zhao, Jianlin

    2016-12-12

    Thermal lensing in diode-side-pumped Nd:YAG laser has been measured quantitatively using digital holographic interferometry. A series of holograms, carrying the information of the laser rod under different pump currents, are recorded with a CCD and reconstructed numerically. The optical path difference induced by the thermal lensing and the corresponding evolution process under different currents are obtained accordingly. Further, the thermal lensing diopters, induced aberrations, and its Zernike coefficients are calculated. The proposed method can be applied in the thermal lensing measurement and the optimization design of a laser resonator.

  5. Measurement of natural convective heat transfer coefficient along the surface of a heated wire using digital holographic interferometry.

    PubMed

    Kumar, Varun; Kumar, Manoj; Shakher, Chandra

    2014-09-20

    In this paper, the local convective heat transfer coefficient (h) is measured along the surface of an electrically heated vertical wire using digital holographic interferometry (DHI). Experiments are conducted on wires of different diameters. The experimentally measured values are within the range as given in the literature. DHI is expected to provide a more accurate local convective heat transfer coefficient (h) as the value of the temperature gradient required for the calculation of "h" can be obtained more accurately than by other existing optical interferometric techniques without the use of a phase shifting technique. This is because in digital holography phase measurement accuracy is expected to be higher.

  6. Digital holographic interferometry: a novel optical calorimetry technique for radiation dosimetry.

    PubMed

    Cavan, Alicia; Meyer, Juergen

    2014-02-01

    To develop and demonstrate the proof-of-principle of a novel optical calorimetry method to determine radiation absorbed dose in a transparent medium. The calorimetric property of water is measured during irradiation by means of an interferometer, which detects temperature-induced changes in the refractive index that can be mathematically related to absorbed dose. The proposed method uses a technique called digital holographic interferometry (DHI), which comprises an optical laser interferometer setup and consecutive physical reconstruction of the recorded wave fronts by means of the Fresnel transform. This paper describes the conceptual framework and provides the mathematical basis for DHI dosimetry. Dose distributions from a high dose rate Brachytherapy source were measured by a prototype optical setup to demonstrate the feasibility of the approach. The developed DHI dosimeter successfully determined absorbed dose distributions in water in the region adjacent to a high dose rate Brachytherapy source. A temperature change of 0.0381 K across a distance of 6.8 mm near the source was measured, corresponding to a dose of 159.3 Gy. The standard deviation in a typical measurement set was ± 3.45 Gy (corresponding to an uncertainty in the temperature value of ± 8.3 × 10(-4) K). The relative dose fall off was in agreement with treatment planning system modeled data. First results with a prototype optical setup and a Brachytherapy source demonstrate the proof-of-principle of the approach. The prototype achieves high spatial resolution of approximately 3 × 10(-4) m. The general approach is fundamentally independent of the radiation type and energy. The sensitivity range determined indicates that the method is predominantly suitable for high dose rate applications. Further work is required to determine absolute dose in all three dimensions.

  7. Laser-ablation-induced refractive index fields studied using pulsed digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Amer, Eynas; Gren, Per; Sjödahl, Mikael

    2009-07-01

    Pulsed digital holographic interferometry has been used to investigate the plume and the shock wave generated in the ablation process of a Q-switched Nd-YAG ( λ=1064 nm and pulse duration=12 ns) laser pulse on a polycrystalline boron nitride (PCBN) target under atmospheric air pressure. A special setup based on two synchronised wavelengths from the same laser for simultaneous processing and measurement has been used. Digital holograms were recorded for different time delays using collimated laser light ( λ=532 nm) passed through the volume along the target. Numerical data of the integrated refractive index field were calculated and presented as phase maps showing the propagation of the shock wave and the plume generated by the process. Radon inversion has been used to estimate the 3D refractive index fields measured from the projections assuming rotational symmetry. The shock wave density has been calculated using the point explosion model and the shock wave condition equation and its behaviour with time at different power densities ranging from 1.4 to 9.1 GW/cm 2 is presented. Shock front densities have been calculated from the reconstructed refractive index fields using the Gladstone-Dale equation. A comparison of the shock front density calculated from the reconstructed data and that calculated using the point explosion model at different time delays has been done. The comparison shows quite good agreement between the model and the experimental data. Finally the reconstructed refractive index field has been used to estimate the electron number density distribution within the laser-induced plasma. The electron number density behaviour with distance from the target at different power densities and its behaviour with time are shown. The electron number densities are found to be in the order of 10 18 cm -3 and decay at a rate of 3×10 15 electrons/cm 3 ns.

  8. SU-E-T-196: Heat Diffusion Modeling for Digital Holographic Interferometry Dosimetry

    SciTech Connect

    Cavan, A; Meyer, J

    2014-06-01

    Purpose: We have previously demonstrated that with Digital Holographic Interferometry (DHI) 2D spatial calorimetric measurements of high dose rate radiation sources can be obtained. The impact of heat transfer must be considered when undertaking any form of calorimetric measurement, as the radiation induced temperature distributions are subject to degradation due to heat diffusion. Unaccounted for, this limits the accuracy of the approach especially for long delivery times. Methods: 3D modelling of the heat diffusion in water was undertaken, and two different approaches developed to account for this effect. The mathematical framework to describe heat diffusion in 3D was applied, with the differential equations solved numerically using an implicit method. The first approach involved the comparison of the DHI measurements to an independent dose model of the source. The model was forward modeled to account for the heat diffusion during irradiation, allowing a direct comparison to validate the measured results. The second approach involved the correction of the measured data directly, by comparing the temperature distribution of two instances and subtracting the effects of heat diffusion of the first distribution from the second instance. This required the use of the Abel transform to approximate the 3D dose distribution from the 2D DHI results, thus limiting the approach to radiation applications possessing cylindrical symmetry. Results: The first approach resulted in higher accuracy and was more straightforward, but has a major limitation in that the measured results are only able to be utilized in comparison with an independent dose model. The applicability of the second approach is affected by noise in the measurement data and introduces higher uncertainties, but results in higher usability of the final data. Conclusion: Both approaches were implemented, and if used in conjunction would provide the most utility for the interpretation and use of DHI measurements.

  9. Spatio-temporal experiments of volume elastic objects with high speed digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Pérez López, C.; Hernández Montes, M. S.; Mendoza Santoyo, F.; Gutiérrez Hernandez, D. A.

    2011-08-01

    The optical non-destructive digital holographic interferometry (DHI) technique has proven to be a powerful tool in measuring vibration phenomena with a spatial resolution ranging from a few hundreds of nanometers to tens of micrometers. With the aid of high speed digital cameras it is possible to achieve simultaneously spatial and temporal resolution, and thus capable of measuring the entire object mechanical oscillation trajectory from one to several cycles. It is important to mention that due to faster computers with large data storage capacity there is an increasing interest in applying numerical simulation methods to mimic different real life objects for example, in the field of modern elastic materials and biological systems. The complex algorithms involved cannot render significant results mainly due to the rather large number of variables. In order to test these numerical simulations some experiments using optical techniques have been designed and reported. This is very important for example in measurements of the dynamic elastic properties of materials. In this work we present some preliminary results from experiments that use DHI to measure vibrations of an elastic spherical object subject to a mechanical excitation that induces resonant vibration modes in its volume. We report on the spatial and temporal effects that by their nature have a non-linear mechanical response. The use of a high speed CMOS camera in DHI assures the measurement of this nonlinear behavior as a sum of linear effects that happen during very short time lapses and with very small displacement amplitudes. We conclude by stating that complex numerical models may be compared to results using DHI, thus proposing an alternative method to prove and verify the mathematical models vs. real measurements on volumetric elastic objects.

  10. Experimental research on thermocapillary migration of drops by using digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Zhang, Shuoting; Duan, Li; Kang, Qi

    2016-07-01

    The thermocapillary migration of drops in a rectangular cell, with a heated top wall and a cooled bottom wall, was investigated experimentally on the ground. The rectangular test cell was 70 mm high, with a horizontal cross section of 40 mm × 40 mm. In the present experiment, 30 cSt silicon oil was used as the continuous phase, and a water-ethanol mixture was used as the drop phase, respectively. The drops ranged in size from 1.87 to 6.94 mm in diameter and were injected into the continuous phase, where the temperature gradients ranged from 0.193 to 0.484 °C mm-1. In order to measure the temperature distribution of the liquid, a digital holographic interferometry was used, which was non-contact, full-field, and in-situ. The holograms were recorded, and then the corresponding wrapped phase distributions images were numerically reconstructed. The temperature distribution of the continuous phase liquid in the cell had been obtained following the unwrapping. Also, through an algebra layer analysis, the temperature distribution around the drop during the thermocapillary migration was obtained. As a result, the drop was colder than the continuous phase liquid, and a thermal wake existed behind the drop. The influence of convective transport on the drop migration was also investigated for the Marangoni number in the range of 7-174. With the increasing of the Marangoni number, the dimensionless interface temperature difference decreased, which was caused by the convective transport enhanced results in the drop thermocapillary migration velocity becoming decreased. The data were compared with previous space experiments to explain the phenomena of the drop migration. Finally, with the increasing Marangoni numbers, the length of the thermal wake region increased, and the thermal wake region became extended.

  11. Digital holographic interferometry: A novel optical calorimetry technique for radiation dosimetry

    SciTech Connect

    Cavan, Alicia; Meyer, Juergen

    2014-02-15

    Purpose: To develop and demonstrate the proof-of-principle of a novel optical calorimetry method to determine radiation absorbed dose in a transparent medium. Methods: The calorimetric property of water is measured during irradiation by means of an interferometer, which detects temperature-induced changes in the refractive index that can be mathematically related to absorbed dose. The proposed method uses a technique called digital holographic interferometry (DHI), which comprises an optical laser interferometer setup and consecutive physical reconstruction of the recorded wave fronts by means of the Fresnel transform. This paper describes the conceptual framework and provides the mathematical basis for DHI dosimetry. Dose distributions from a high dose rate Brachytherapy source were measured by a prototype optical setup to demonstrate the feasibility of the approach. Results: The developed DHI dosimeter successfully determined absorbed dose distributions in water in the region adjacent to a high dose rate Brachytherapy source. A temperature change of 0.0381 K across a distance of 6.8 mm near the source was measured, corresponding to a dose of 159.3 Gy. The standard deviation in a typical measurement set was ±3.45 Gy (corresponding to an uncertainty in the temperature value of ±8.3 × 10{sup −4} K). The relative dose fall off was in agreement with treatment planning system modeled data. Conclusions: First results with a prototype optical setup and a Brachytherapy source demonstrate the proof-of-principle of the approach. The prototype achieves high spatial resolution of approximately 3 × 10{sup −5} m. The general approach is fundamentally independent of the radiation type and energy. The sensitivity range determined indicates that the method is predominantly suitable for high dose rate applications. Further work is required to determine absolute dose in all three dimensions.

  12. Comparison of the results of refractometric measurements in the process of diffusion, obtained by means of the backgroundoriented schlieren method and the holographic interferometry method

    NASA Astrophysics Data System (ADS)

    Kraiskii, A. V.; Mironova, T. V.

    2015-08-01

    The results of the study of interdiffusion of two liquids, obtained using the holographic recording scheme with a nonstationary reference wave with the frequency linearly varying in space and time are compared with the results of correlation processing of digital photographs, made with a random background screen. The spatio-temporal behaviour of the signal in four basic representations ('space - temporal frequency', 'space - time', 'spatial frequency - temporal frequency' and 'spatial frequency - time') is found in the holographic experiment and calculated (in the appropriate coordinates) based on the background-oriented schlieren method. Practical coincidence of the results of the correlation analysis and the holographic double-exposure interferometry is demonstrated.

  13. Pulsed holographic interferometry: a technique for the detection of structural faults in aircraft structures and computerized recognition of records

    NASA Astrophysics Data System (ADS)

    Webster, John M.; Schmidt, Timothy E.; Mew, Jacqueline M.

    1998-03-01

    A method of application of pulsed holographic interferometry together with the associated hardware has been developed and applied as a non-destructive inspection (NDI) tool for application to aluminum aircraft fuselages such as those used in the present air transport fleet. A number of novel techniques are involved in the design features of the holographic camera and the method of excitation to obtain optimum conditions where any structural faults present can be made apparent. The holographic camera system has been designed to be small, portable and ruggedly designed so it is suitable for field operations in aircraft repair stations and hangars. The technique operates by the introduction of a selected single frequency vibration signal into the area undergoing test. The camera system has been designed to record both the relative and actual phase of the vibrationally induced into the structure of the fuselage undergoing excitation and NDI. Results are presented showing structural defects. A computerized technique is being developed for the analysis of the interferogram fringe maps an preliminary results are discussed.

  14. Comparison of the results of refractometric measurements in the process of diffusion, obtained by means of the backgroundoriented schlieren method and the holographic interferometry method

    SciTech Connect

    Kraiskii, A V; Mironova, T V

    2015-08-31

    The results of the study of interdiffusion of two liquids, obtained using the holographic recording scheme with a nonstationary reference wave with the frequency linearly varying in space and time are compared with the results of correlation processing of digital photographs, made with a random background screen. The spatio-temporal behaviour of the signal in four basic representations ('space – temporal frequency', 'space – time', 'spatial frequency – temporal frequency' and 'spatial frequency – time') is found in the holographic experiment and calculated (in the appropriate coordinates) based on the background-oriented schlieren method. Practical coincidence of the results of the correlation analysis and the holographic double-exposure interferometry is demonstrated. (interferometry)

  15. Digital holographic Michelson interferometer for nanometrology

    NASA Astrophysics Data System (ADS)

    Sevrygin, Alexander A.; Korotkov, V. I.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Yu.; Volkov, O. V.

    2014-11-01

    The paper considers the dynamic holographic interferometry schemes with amplification (multiplication) of holographic fringes and with correction for distortions, imposed by the interferometer scheme elements. The use of digital microscope and of the matrix light modulator with direct addressing provides the completely digital closed-loop performance of the overall system for real-time evaluation of nano-scale objects size. Considered schemes were verified in the laboratory experiment, using the Michelson micro-interferometer, equipped by the USB-microscope and digital holography stage, equipped by the Holoeye spatial light modulator.

  16. Phase unwrapping for large depth-of-field 3D laser holographic interferometry measurement of laterally discontinuous surfaces

    NASA Astrophysics Data System (ADS)

    Huang, Zhenhua; Shih, Albert J.; Ni, Jun

    2006-11-01

    A phase unwrapping method is developed to mathematically increase the depth-of-field for the 3D optical measurement of objects with laterally discontinuous surfaces, which contain disconnected high aspect ratio regions. This method is applied for laser holographic interferometry precision measurements. The phase wrap identification at boundary pixels, masking and recovery, dynamic segmentation and phase adjustment are developed to overcome the divergence problem in phase unwrapping of laterally discontinuous surfaces. An automotive automatic transmission valve body is applied as an example to demonstrate the developed method. Experimental results demonstrate that the proposed methods can efficiently unwrap the phase to increase the depth-of-field for laterally discontinuous surfaces. Effects of segment size and width of overlapped regions on the computational efficiency are investigated.

  17. On-line surveillance of a dynamic process by a moving system based on pulsed digital holographic interferometry.

    PubMed

    Pedrini, Giancarlo; Alexeenko, Igor; Osten, Wolfgang; Schnars, Ulf

    2006-02-10

    A method based on pulsed digital holographic interferometry for the measurement of dynamic deformations of a surface by using a moving system is presented. The measuring system may move with a speed of several meters per minute and can measure deformation of the surface with an accuracy of better than 50 nm. The deformation is obtained by comparison of the wavefronts recorded at different times with different laser pulses produced by a Nd:YAG laser. The effect due to the movement of the measuring system is compensated for by digital processing of the different holograms. The system is well suited for on-line surveillance of a dynamic process such as laser welding and friction stir welding. Experimental results are presented, and the advantages of the method are discussed.

  18. Preliminary investigation on monitoring transportation effects by full field methods: a digital holographic speckle pattern interferometry study on canvas paintings

    NASA Astrophysics Data System (ADS)

    Tsiranidou, Elsa; Bernikola, Eirini; Tornari, Vivi; Fankhauser, Thomas; Läuchli, Matthias; Palmbach, Cornelius; Bäschlin, Nathalie

    2011-06-01

    A preliminary investigation has taken place employing Digital Holographic Speckle Pattern Interferometry (DHSPI) in order to assess the effect of handling and transportation on canvas paintings. Canvas dummies were used on a series of measurements on a transport simulator which allows reproducible simulation of any transport logs in the laboratory. A number of cycles of controlled vibrations were applied on the samples and after each cycle a measurement with DHSPI was taken to monitor the behavior of the samples while increasing the vibration loading and also to record the conditions under which the first crack appears. The transport simulations in combination with DHSPI monitoring revealed the amplitude of oscillation where the first cracks appear on new canvas paintings and also the way these cracks grow. During the tests it was also feasible to locate areas at risk of future deterioration.

  19. Evaluation of the uncertainty of phase-difference measurements in (quasi-)Fourier transform digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Doval, Ángel F.; Trillo, Cristina; López Vázquez, José Carlos; Fernández, José L.

    2015-08-01

    Estimation of the uncertainty is an essential requisite for high-end measurement systems. In this communication we derive an expression to evaluate the standard uncertainty of the phase-difference measurements resulting from Fourier and quasi-Fourier transform digital holographic interferometry. We apply the law of propagation of uncertainty, as defined in the "Guide to the expression of uncertainty in measurement" (GUM), to the digital reconstruction of two holograms by Fourier transformation and to the subsequent calculation of the phase change between the holographic reconstructions. The resulting expression allows the evaluation of the uncertainty of the phase difference at every pixel in the reconstruction plane in terms of the measured hologram brightness values and their uncertainty at the whole of the pixels of the original digital holograms. This expression is simplified by assuming a linear dependence between the uncertainty and the local value of the original holograms; in that case, the local uncertainty of the phase difference can be evaluated from the local complex values of the reconstructed holograms. We assess the behavior of the method by comparing the predicted standard uncertainty with the sample variance obtained from experiments conducted under repeatability conditions, and found a good correlation between both quantities. This experimental procedure can be also used to calibrate the parameters of the linear function relating the uncertainty with the local value of the digital holograms, for a given set of operational conditions of the acquisition device.

  20. Fringe localization requirements for three-dimensional flow visualization of shock waves in diffuse-illumination double-pulse holographic interferometry

    NASA Astrophysics Data System (ADS)

    Decker, A. J.

    1982-04-01

    A theory of fringe localization in rapid-double-exposure, diffuse-illumination holographic interferometry was developed. The theory was then applied to compare holographic measurements with laser anemometer measurements of shock locations in a transonic axial-flow compressor rotor. The computed fringe localization error was found to agree well with the measured localization error. It is shown how the view orientation and the curvature and positional variation of the strength of a shock wave are used to determine the localization error and to minimize it. In particular, it is suggested that the view direction not deviate from tangency at the shock surface by more than 30 degrees.

  1. Fringe localization requirements for three-dimensional flow visualization of shock waves in diffuse-illumination double-pulse holographic interferometry

    NASA Technical Reports Server (NTRS)

    Decker, A. J.

    1982-01-01

    A theory of fringe localization in rapid-double-exposure, diffuse-illumination holographic interferometry was developed. The theory was then applied to compare holographic measurements with laser anemometer measurements of shock locations in a transonic axial-flow compressor rotor. The computed fringe localization error was found to agree well with the measured localization error. It is shown how the view orientation and the curvature and positional variation of the strength of a shock wave are used to determine the localization error and to minimize it. In particular, it is suggested that the view direction not deviate from tangency at the shock surface by more than 30 degrees.

  2. Comparison between holographic interferometry and high-speed videography techniques in the study of the reflection of plane shock waves

    NASA Astrophysics Data System (ADS)

    Barbosa, Filipe J.; Skews, Beric W.

    1997-05-01

    Double exposure holographic interferometry and high speed laser shadowgraph photography and videography are used to investigate the mutual reflection of two plane shock waves. Normally research on the transition from regular to Mach reflection is undertaken by allowing a plane shock wave to impinge on a wedge. However due to the boundary layer growth on the wedge, regular reflection persists at wedge angles higher than that allowed for by inviscid shock wave theory. Several bifurcated shock tubes have been constructed, wherein an initially planar shock wave is split symmetrically into two and then recombined at the trailing edge of a wedge. The plane of symmetry acts as an ideal rigid wall eliminating thermal and viscous boundary layer effects. The flow visualization system used needs to provide high resolution information on the shockwave, slipstream, triple point and vortex positions and angles. Initially shadowgraph and schlieren methods, with a Xenon light source, were used. These results, while proving useful, are not of a sufficient resolution to measure the Mach stem and slipstream lengths accurately enough in order to determine the transition point between regular and Mach reflection. To obtain the required image resolution a 2 joule double pulse ruby laser, with a 30 ns pulse duration, was used to make holographic interferograms. The combined advantages of holographic interferometry and the 30 ns pulse laser allows one to obtain much sharper definition, and more qualitative as well as quantitative information on the flow field. The disadvantages of this system are: the long time taken to develop holograms, the difficulty of aligning the pulse laser and the fact that only one image per test is obtained. Direct contact shadowgraphs were also obtained using the pulse ruby laser to help determine triple point trajectory angles. In order to provide further information a one million frames per second CCD camera, which can take up to 10 superimposed images, was

  3. Operating manual holographic interferometry system for 2 x 2 foot transonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Craig, J. E.

    1981-01-01

    A holographic interferometer system was installed in a 2X2 foot transonic wind tunnel. The system incorporates a modern, 10 pps, Nd:YAG pulsed laser which provides reliable operation and is easy to align. The spatial filtering requirements of the unstable resonator beam are described as well as the integration of the system into the existing Schieren system. A two plate holographic interferometer is used to reconstruct flow field data. For static wind tunnel models the single exposure holograms are recorded in the usual manner; however, for dynamic models such as oscillating airfoils, synchronous laser hologram recording is used.

  4. Real-time photothermoplastic 8-inch camera with an emphasis on the visualization of 3D digital data by holographic means

    NASA Astrophysics Data System (ADS)

    Cherkasov, Yuri A.; Alexandrova, Elena L.; Rumjantsev, Alexander G.; Smirnov, Mikhail V.

    1995-04-01

    The development and investigations of large-formate (8-inch) real-time photothermoplastic (PTP) camera are carried out. The PTP camera is applied for operative recording of 3D- images by means of compound and digital holography and visualization of these holograms as 3D-static images. The optimization of the recording regimes is fulfilled with use the model of the relief-phase PTP images thermodevelopment, proposed by authors. According with that model, the achievement of maximal value of deformation (diffraction efficiency) is based on the opportunity in increasing of charge contrast of electrostatic latent image formed early by the moment of the viscosity decreasing during the thermodevelopment process. It is achieved by means of the control of the thermodevelopment regime. Also, the opportunities of the increase of the camera size (to 14 inch), of the rising of photosensitivity value and the enlarging of its spectral range, of the creation of Benton holograms and of the increasing of the speed of response to 25 Hz are discussed.

  5. Evaluation of aero-optical effects in hypersonic flow using holographic interferometry

    NASA Astrophysics Data System (ADS)

    Azzazy, M.

    1991-01-01

    The aerooptical performance of a generic high endoatmospheric defense interceptor (HEDI) in a hypersonic tunnel is evaluated. The problem of a plane monochromatic wave incident on volume V of a turbulent medium is studied, and it is concluded that in order to evaluate the aerooptical effects on HEDI performance, it is imperative to measure phase fluctuations. A holographic optical system employed in the experiment is outlined, along with the test setup where the object beam travels through the wind-tunnel Schlieren window on the top of the tunnel, the splitter window on the bottom of the pylon, and the HEDI window before it is reflected back on itself through the same path to a steering mirror and on a holographic plate. The interferogram images are analyzed digitally to yield the fringe RMS and the phase correction function. It is noted that the fringe RMS influences the attenuation of the coherent beam, while the correlation length scale affects the circle of blur.

  6. Digital phase-stepping holographic interferometry in measuring 2-D density fields

    NASA Astrophysics Data System (ADS)

    Lanen, T. A. W. M.; Nebbeling, C.; van Ingen, J. L.

    1990-06-01

    This paper presents a holographic interferometer technique for measuring transparent (2-D or quasi 2-D) density fields. To be able to study the realization of such a field at a certain moment of time, the field is “frozen” on a holographic plate. During the reconstruction of the density field from the hologram the length of the path traversed by the reconstruction beam is diminished in equal steps by applying a computer controlled voltage to a piezo-electric crystal that translates a mirror. Four phase-stepped interferograms resulting from this pathlength variation are digitized and serve as input to an algorithm for computing the phase surface. The method is illustrated by measuring the basically 2-D density field existing around a heated horizontal cylinder in free convection.

  7. Separate recording of rationally related vibration frequencies using digital stroboscopic holographic interferometry

    SciTech Connect

    Alexeenko, Igor; Gusev, Michael; Gurevich, Vadim

    2009-06-20

    A method for separate recording of rationally related vibration frequencies is presented. To record and measure the mode shape of vibrations, a synchronized stroboscopic CCD camera is used. Synchronization and control of the camera acquisition for recording stroboscopic holographic sequence has been realized. The phase for different states of the object vibration is calculated using the Fourier-transform method. Experimental results are presented, and the advantages and disadvantages of the proposed method are discussed.

  8. Interferometry

    NASA Technical Reports Server (NTRS)

    Ridgway, Stephen; Wilson, Robert W.; Begelman, Mitchell C.; Bender, Peter; Burke, Bernard F.; Cornwell, Tim; Drever, Ronald; Dyck, H. Melvin; Johnston, Kenneth J.; Kibblewhite, Edward

    1991-01-01

    The following recommended programs are reviewed: (1) infrared and optical interferometry (a ground-based and space programs); (2) compensation for the atmosphere with adaptive optics (a program for development and implementation of adaptive optics); and (3) gravitational waves (high frequency gravitational wave sources (LIGO), low frequency gravitational wave sources (LAGOS), a gravitational wave observatory program, laser gravitational wave observatory in space, and technology development during the 1990's). Prospects for international collaboration and related issues are also discussed.

  9. Strain, curvature, and twist measurements in digital holographic interferometry using pseudo-Wigner-Ville distribution based method

    SciTech Connect

    Rajshekhar, G.; Gorthi, Sai Siva; Rastogi, Pramod

    2009-09-15

    Measurement of strain, curvature, and twist of a deformed object play an important role in deformation analysis. Strain depends on the first order displacement derivative, whereas curvature and twist are determined by second order displacement derivatives. This paper proposes a pseudo-Wigner-Ville distribution based method for measurement of strain, curvature, and twist in digital holographic interferometry where the object deformation or displacement is encoded as interference phase. In the proposed method, the phase derivative is estimated by peak detection of pseudo-Wigner-Ville distribution evaluated along each row/column of the reconstructed interference field. A complex exponential signal with unit amplitude and the phase derivative estimate as the argument is then generated and the pseudo-Wigner-Ville distribution along each row/column of this signal is evaluated. The curvature is estimated by using peak tracking strategy for the new distribution. For estimation of twist, the pseudo-Wigner-Ville distribution is evaluated along each column/row (i.e., in alternate direction with respect to the previous one) for the generated complex exponential signal and the corresponding peak detection gives the twist estimate.

  10. Simultaneous measurement of in-plane and out-of-plane displacement derivatives using dual-wavelength digital holographic interferometry.

    PubMed

    Rajshekhar, Gannavarpu; Gorthi, Sai Siva; Rastogi, Pramod

    2011-12-01

    The paper introduces a method for simultaneously measuring the in-plane and out-of-plane displacement derivatives of a deformed object in digital holographic interferometry. In the proposed method, lasers of different wavelengths are used to simultaneously illuminate the object along various directions such that a unique wavelength is used for a given direction. The holograms formed by multiple reference-object beam pairs of different wavelengths are recorded by a 3-color CCD camera with red, green, and blue channels. Each channel stores the hologram related to the corresponding wavelength and hence for the specific direction. The complex reconstructed interference field is obtained for each wavelength by numerical reconstruction and digital processing of the recorded holograms before and after deformation. Subsequently, the phase derivative is estimated for a given wavelength using two-dimensional pseudo Wigner-Ville distribution and the in-plane and out-of-plane components are obtained from the estimated phase derivatives using the sensitivity vectors of the optical configuration.

  11. Holographic interferometry with an injection seeded Nd:YAG laser and two reference beams

    SciTech Connect

    Decker, A.J. )

    1990-06-20

    The performance of twin injection seeded Nd:YAG lasers is compared with the performance of an argon-ion laser for recording dual-reference-beam holograms in AGFA 8E56 emulsion. Optical heterodyning is used to measure interference and the results are expressed in terms of heterodyning signal level and intensity signal to noise. The Nd:YAG laser system is to be used for optical inspections of structures for cracks, defects, gas leaks, and structural changes. Key words: holography, lasers, neodymium, heterodyning, Interferometry.

  12. Real-time visualization of Karman vortex street in water flow field by using digital holography.

    PubMed

    Sun, Weiwei; Zhao, Jianlin; Di, Jianglei; Wang, Qian; Wang, Le

    2009-10-26

    The Karman vortex street generated behind a circular cylinder in water flow field is displayed and analyzed in real time by means of digital holography. Using a modified Mach-Zehnder interferometer, a digital hologram of the flow field in still state and then a video of continuous digital holograms in flowing state are recorded at 14.6 frames per second by a CCD camera, respectively. A series of sequential phase maps of the flow field are numerically reconstructed from the holograms in different states above based on double-exposure holographic interferometry. By seriating these phase maps, the shape and evolution of Karman vortex street can be displayed in real time in the form of a movie. For comparison, numerical simulation of the Karman vortex street under the boundary conditions adopted in the experiment is also presented, and the consistent results indicate that the experimental observation of Karman vortex street by using digital holography is successful and feasible.

  13. Quantifying oil degradation processes by flow, microbes and dispersant using digital holographic interferometry and micro-bioassay

    NASA Astrophysics Data System (ADS)

    Sheng, Jian; Jalali, Maryam; Brock, Larry

    2016-11-01

    The unceasing demand of hydrocarbons has led and will lead to the future events of releasing crude into marine environment like Deep Horizon oil spill. The burning question to scientific community after the spill was the fate of oil spill especially with high concentration of dispersant. It is found that various physical processes such as wind, wave, turbulence, compounded with dispersants, break oil into suspension of micro-droplets. It is widely accepted that dispersant reduces interfacial tension and results in increased surface to volume ratio and subsequently improve biodegradation. Due to complexity of oil composition, key mechanisms differ substantially from well-studied laboratory system, especially in the presence of other environmental factors such as flow shear and microbes. To investigate these mechanisms at oil water interface qualitatively, we have developed a micro-bioassay consisting of microfluidics with a substrate printed with oil droplet array and a digital holographic interferometer (DHI). The degradation of micro-droplets is evaluated with the change of shape and volume measured in real time by DHI at a 2-minute interval over 100 hours. Time resolved experiments are performed to study effects of droplet size, dispersant concentrations, flow shear, and different bacteria species on the rate of degradation. The details on the rate and mechanisms will be provided in the talk.

  14. Displacement measurements over a square meter area using digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    De la Torre Ibarra, Manuel H.; Flores Moreno, J. Mauricio; Aguayo, Daniel D.; Hernández-Montes, María del Socorro; Pérez-López, Carlos; Mendoza-Santoyo, Fernando

    2014-09-01

    Current industrial demand for optical nondestructive testing includes the displacement analysis of large object areas. This paper reports on the use of a digital holographic interferometer to measure displacements over an area of 1.14 m2. The object under study is a framed working table covered with a Formica layer fixed to a granite bench, and it is observed and illuminated employing a high speed and high resolution camera and a continuous wave high output power laser, respectively. A stabilization procedure needs to be established as long illumination distances are required in order to retrieve the entire surface optical phase during a series of continuous deformations. As a proof of principle, two different tests are presented: the first involves a slow continuous loading process and the second a vibration condition. The wrapped phase and displacement maps are both displayed.

  15. Strain determination in bone sections with simultaneous 3D digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Alvarez, Araceli Sánchez; De la Torre Ibarra, Manuel H.; Santoyo, Fernando Mendoza; Anaya, Tonatiuh-Saucedo

    2014-06-01

    A 3D digital holographic interferometer was used to measure the surface strain components in two different bovine's bone sections. The applied force on the sample was induced by a precisely controlled lateral micro compression. The simultaneous acquisition capability of the system helps to record a fast sequence of images, each one containing three independent holograms that result in three orthogonal displacement components u, v and w from which the surface strain components ɛx, ɛy and γxy over the bone's field of view were calculated. This research study was carried out in two different bone sections: the cortical bone and the medullary cavity/yellow marrow section. The resulting strain concentrators are of great importance to better understand the mechanical response of complex biological structures such as this bovine femoral bone.

  16. Digital holographic interferometry employing Fresnel transform reconstruction for the study of flow shear stabilized Z-pinch plasmas.

    PubMed

    Ross, M P; Shumlak, U

    2016-10-01

    The ZaP-HD flow Z-pinch project provides a platform to explore how shear flow stabilized Z-pinches could scale to high-energy-density plasma (plasma with pressures exceeding 1 Mbar) and fusion reactor conditions. The Z-pinch is a linear plasma confinement geometry in which the plasma carries axial electric current and is confined by its self-induced magnetic field. ZaP-HD generates shear stabilized, axisymmetric Z-pinches with stable lifetimes approaching 60 μs. The goal of the project is to increase the plasma density and temperature compared to the previous ZaP project by compressing the plasma to smaller radii (≈1 mm). Radial and axial plasma electron density structure is measured using digital holographic interferometry (DHI), which provides the necessary fine spatial resolution. ZaP-HD's DHI system uses a 2 ns Nd:YAG laser pulse with a second harmonic generator (λ = 532 nm) to produce holograms recorded by a Nikon D3200 digital camera. The holograms are numerically reconstructed with the Fresnel transform reconstruction method to obtain the phase shift caused by the interaction of the laser beam with the plasma. This provides a two-dimensional map of line-integrated electron density, which can be Abel inverted to determine the local number density. The DHI resolves line-integrated densities down to 3 × 10(20) m(-2) with spatial resolution near 10 μm. This paper presents the first application of Fresnel transform reconstruction as an analysis technique for a plasma diagnostic, and it analyzes the method's accuracy through study of synthetic data. It then presents an Abel inversion procedure that utilizes data on both sides of a Z-pinch local number density profile to maximize profile symmetry. Error estimation and Abel inversion are applied to the measured data.

  17. Digital holographic interferometry employing Fresnel transform reconstruction for the study of flow shear stabilized Z-pinch plasmas

    NASA Astrophysics Data System (ADS)

    Ross, M. P.; Shumlak, U.

    2016-10-01

    The ZaP-HD flow Z-pinch project provides a platform to explore how shear flow stabilized Z-pinches could scale to high-energy-density plasma (plasma with pressures exceeding 1 Mbar) and fusion reactor conditions. The Z-pinch is a linear plasma confinement geometry in which the plasma carries axial electric current and is confined by its self-induced magnetic field. ZaP-HD generates shear stabilized, axisymmetric Z-pinches with stable lifetimes approaching 60 μs. The goal of the project is to increase the plasma density and temperature compared to the previous ZaP project by compressing the plasma to smaller radii (≈1 mm). Radial and axial plasma electron density structure is measured using digital holographic interferometry (DHI), which provides the necessary fine spatial resolution. ZaP-HD's DHI system uses a 2 ns Nd:YAG laser pulse with a second harmonic generator (λ = 532 nm) to produce holograms recorded by a Nikon D3200 digital camera. The holograms are numerically reconstructed with the Fresnel transform reconstruction method to obtain the phase shift caused by the interaction of the laser beam with the plasma. This provides a two-dimensional map of line-integrated electron density, which can be Abel inverted to determine the local number density. The DHI resolves line-integrated densities down to 3 × 1020 m-2 with spatial resolution near 10 μm. This paper presents the first application of Fresnel transform reconstruction as an analysis technique for a plasma diagnostic, and it analyzes the method's accuracy through study of synthetic data. It then presents an Abel inversion procedure that utilizes data on both sides of a Z-pinch local number density profile to maximize profile symmetry. Error estimation and Abel inversion are applied to the measured data.

  18. Optical phase analysis in drilled cortical porcine bones using digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Tavera R., César G.; De la Torre I., Manuel H.; Flores M., J. Mauricio; Luna H., Juan M.; Briones R., Manuel de J.; Mendoza S., Fernando

    2016-03-01

    A study in porcine femoral bones with and without the presence of cortical drilling is presented. An out of plane digital holographic interferometer is used to retrieve the optical phase during the controlled compression tests. These tests try to simulate physiological deformations in postmortem healthy bones and compare their mechanical response with those having a cortical hole. The cortical drilling technique is widely used in medical procedures to fix plaques and metallic frames to a bone recovering from a fracture. Several materials and drilling techniques are used for this purpose. In this work we analyze the superficial variations of the bone when different drilling diameters are used. By means of the optical phase it is possible to recover the superficial deformation of the tissue during a controlled deformation with high resolution. This information could give a better understand about the micro structural variations of the bone instead of a bulk response. As proof of principle, several tests were performed to register the modes and ranges of the displacements for compressive loads. From these tests notorious differences are observed between both groups of bones, having less structural stiffness the drilled ones as expected. However, the bone's characteristic to absorb and adjust itself due the load is also highly affected according to the number of holes. Results from different kind of samples (undrilled and drilled) are presented and discussed in this work.

  19. Measurement of parameters of simple lenses using digital holographic interferometry and a synthetic reference wave.

    PubMed

    Anand, Arun; Chhaniwal, Vani K

    2007-04-10

    The use of digital holographic intrerferometry in the testing of simple thin lenses is explored. Focal length, radius of curvature, and refractive index are the lens parameters that can be determined using this method. The digital holograms using the lens under test are recorded at various positions of the test lens using off-axis geometry. This is combined with a digitally computed plane wavefront to determine the curvature of the light beam emerging from the test lens. Focal length is the position of the test lens where a single fringe results. The radius of curvature of the test lens is also determined similarly using a long focal length lens to concentrate a collimated beam onto the test lens. The nonuniformities on the lens surface could also be found by using this method. The implementation of the method is shown by using computer simulations in the case of biconvex lenses. The method can be utilized to measure the parameters of plano-convex and concave lenses also.

  20. Digital holographic interferometry for characterizing deformable mirrors in aero-optics

    NASA Astrophysics Data System (ADS)

    Trolinger, James D.; Hess, Cecil F.; Razavi, Payam; Furlong, Cosme

    2016-08-01

    Measuring and understanding the transient behavior of a surface with high spatial and temporal resolution are required in many areas of science. This paper describes the development and application of a high-speed, high-dynamic range, digital holographic interferometer for high-speed surface contouring with fractional wavelength precision and high-spatial resolution. The specific application under investigation here is to characterize deformable mirrors (DM) employed in aero-optics. The developed instrument was shown capable of contouring a deformable mirror with extremely high-resolution at frequencies exceeding 40 kHz. We demonstrated two different procedures for characterizing the mechanical response of a surface to a wide variety of input forces, one that employs a high-speed digital camera and a second that employs a low-speed, low-cost digital camera. The latter is achieved by cycling the DM actuators with a step input, producing a transient that typically lasts up to a millisecond before reaching equilibrium. Recordings are made at increasing times after the DM initiation from zero to equilibrium to analyze the transient. Because the wave functions are stored and reconstructable, they can be compared with each other to produce contours including absolute, difference, and velocity. High-speed digital cameras recorded the wave functions during a single transient at rates exceeding 40 kHz. We concluded that either method is fully capable of characterizing a typical DM to the extent required by aero-optical engineers.

  1. CMOS and sCMOS imaging performance comparison by digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Flores-Moreno, Jorge Mauricio; De la Torre Ibarra, Manuel H.; del Socorro Hernández-Montes, María; Perez Lopez, Carlos; Santoyo, Fernando Mendoza

    2016-12-01

    We use a digital holographic interferometric setup to assess, as a proof of concept, two state-of-the-art sensors (CMOS and sCMOS cameras) that are widely used in nondestructive testing (NDT). This interferometric study is intended to evaluate the image quality recorded by any camera used in NDT. The assessing relies on the quantification of the optical phase information recovered by the cameras used for this study. For this, we calculate the signal-to-noise ratio, correlation coefficient, and quality index (Q-index) as main figures-of-merit. As far as we know, the Q-index has not been used for evaluation of the optical phase coming from image holograms. The CMOS and sCMOS sensors used record the same deformation event under the same experimental conditions. The experiment involves the inspection of a large sample (>1 m2 of area) which implies low illumination conditions for the imaging sensors. The retrieved CMOS optical phase shows artifacts that are not observed in the sCMOS. An analysis of these two groups of interferometric images is presented and discussed. The methodology set forth here can be applied to evaluate other sensors such as CCDs and EM-CCDs.

  2. Optical interferometry in fluid dynamics research

    NASA Technical Reports Server (NTRS)

    Bachalo, W. D.; Houser, M. J.

    1985-01-01

    Optical interferometry techniques have been applied to the investigation of transonic airfoil flow fields in large-scale wind tunnels. Holographic interferometry techniques were used in the study of two-dimensional symmetric NACA 64A010 and Douglas Aircraft Company DSMA671 supercritical airfoil performance in the NASA Ames 2 ft x 2 ft transonic wind tunnel. Quantitative data obtained from the interferograms were compared to the surface pressure data. The excellent agreement obtained verified the accuracy of the flow visualization and demonstrated the potential for acquiring quantitative scalar results. Measurements of the inviscid flow speed and the boundary layer and wake velocity profiles were extracted from the interferograms and compared to laser Doppler velocimeter measurements. These results were also in good agreement. A method for acquiring real-time interferometric data in large-scale facilities was developed. This method, based on the point diffraction interferometer, was successfully tested in the Ames 2 ft x 2 ft transonic wind tunnel. The holographic and real-time interferometry methods were applied to the investigations of circulation control airfoils utilizing the Coanda effect. These results revealed the details of the jet interaction with the trailing edge boundary layer and the other parameters affecting the lift augmentation.

  3. Optical interferometry in fluid dynamics research

    NASA Technical Reports Server (NTRS)

    Bachalo, W. D.; Houser, M. J.

    1987-01-01

    Optical interferometry techniques were applied to the investigation of transonic airfoil flow fields in large wind tunnels. Holographic interferometry techniques were used to study 2 dimensional symmetric NACA 64A010 and Douglas Aircraft Co. DSMA671 supercritical airfoil performance in the NASA Ames 2 x 2 ft transonic wind tunnel. Quantitative data obtained from the interferograms were compared to the surface pressure data. The agreement obtained verified the accuracy of the flow visualization and demonstrated the potential for acquiring quantitative scalar results. Measurements of the inviscid flow speed and the boundary layer and wake velocity profiles were extracted from the interferograms and compared to laser Doppler velocimeter measurements. These results were also in good agreement. A method for acquiring real time interferometric data in large scale facilities was developed. This method, based on the point diffraction interferometer, was successfully tested in the 2 x 2 ft transonic wind tunnel. The holographic and real time interferometry methods were applied to the investigations of circulation control airfoils utilizing the Coanda effect. These results reveals the details of the jet interacting with the trailing edge boundary layer and the other parameters affecting the lift augmentation.

  4. Optical interferometry in fluid dynamics research

    NASA Technical Reports Server (NTRS)

    Bachalo, W. D.; Houser, M. J.

    1985-01-01

    Optical interferometry techniques have been applied to the investigation of transonic airfoil flow fields in large-scale wind tunnels. Holographic interferometry techniques were used in the study of two-dimensional symmetric NACA 64A010 and Douglas Aircraft Company DSMA671 supercritical airfoil performance in the NASA Ames 2 ft x 2 ft transonic wind tunnel. Quantitative data obtained from the interferograms were compared to the surface pressure data. The excellent agreement obtained verified the accuracy of the flow visualization and demonstrated the potential for acquiring quantitative scalar results. Measurements of the inviscid flow speed and the boundary layer and wake velocity profiles were extracted from the interferograms and compared to laser Doppler velocimeter measurements. These results were also in good agreement. A method for acquiring real-time interferometric data in large-scale facilities was developed. This method, based on the point diffraction interferometer, was successfully tested in the Ames 2 ft x 2 ft transonic wind tunnel. The holographic and real-time interferometry methods were applied to the investigations of circulation control airfoils utilizing the Coanda effect. These results revealed the details of the jet interaction with the trailing edge boundary layer and the other parameters affecting the lift augmentation.

  5. Optical interferometry in fluid dynamics research

    NASA Astrophysics Data System (ADS)

    Bachalo, W. D.; Houser, M. J.

    1987-05-01

    Optical interferometry techniques were applied to the investigation of transonic airfoil flow fields in large wind tunnels. Holographic interferometry techniques were used to study 2 dimensional symmetric NACA 64A010 and Douglas Aircraft Co. DSMA671 supercritical airfoil performance in the NASA Ames 2 x 2 ft transonic wind tunnel. Quantitative data obtained from the interferograms were compared to the surface pressure data. The agreement obtained verified the accuracy of the flow visualization and demonstrated the potential for acquiring quantitative scalar results. Measurements of the inviscid flow speed and the boundary layer and wake velocity profiles were extracted from the interferograms and compared to laser Doppler velocimeter measurements. These results were also in good agreement. A method for acquiring real time interferometric data in large scale facilities was developed. This method, based on the point diffraction interferometer, was successfully tested in the 2 x 2 ft transonic wind tunnel. The holographic and real time interferometry methods were applied to the investigations of circulation control airfoils utilizing the Coanda effect. These results reveals the details of the jet interacting with the trailing edge boundary layer and the other parameters affecting the lift augmentation.

  6. Optical Interferometry In Fluid Dynamics Research

    NASA Astrophysics Data System (ADS)

    Bachalo, W. D.; Houser, M. J.

    1985-06-01

    Optical interferometry techniques have been applied to the investiga-tion of transonic airfoil flow fields in large-scale wind tunnels. Holographic interferometry techniques were used in the study of two-dimensional sym-metric NACA 64A010 and Douglas Aircraft Company DSMA671 supercritical airfoil performance in the NASA Ames 2 ft X2 ft transonic wind tunnel. Quan-titative data obtained from the interferograms were compared to the surface pressure data. The excellent agreement obtained verified the accuracy of the flow visualization and demonstrated the potential for acquiring quantitative scalar results. Measurements of the inviscid flow speed and the boundary layer and wake velocity profiles were extracted from the interferograms and com-pared to laser Doppler velocimeter measurements. These results were also in good agreement. A method for acquiring real-time interferometric data in large-scale facilities was developed. This method, based on the point diffraction interferometer, was successfully tested in the Ames 2 ft X2 ft transonic wind tunnel. The holographic and real-time interferometry methods were applied to the investigations of circulation control airfoils utilizing the Coanda effect. These results revealed the details of the jet interaction with the trailing edge boundary layer and the other parameters affecting the lift augmentation.

  7. Stabilization of an abutment under a rigidly fixed bridge by holographical-speckle interferometry*

    PubMed Central

    Zhang, Yan-zhen; Zhou, Yan-chun; Liu, Li; Lu, Yang; Hirofumi, Yatani

    2007-01-01

    Objective: There are no detailed reports of three-dimensional measurement of abutment teeth in mastication, because it is knotty to observe the rotation in chewing directly, and inexact to estimate indirectly. This work studies the three-dimensional stability of rigidly fixed bridge under the stresses of distributed loads and concentrated loads by optical method that gives the tip angle and rotation angle calculated directly based on measurement data. Methods: The specimen, taken from a 25-year-old male, was a left mandible without the second premolars and the first molars. As abutments, first premolar and second molar have complete periodontium. The specimen was soaked in formaldehyde solution. The bridge was fixed between two abutment teeth (first premolars and second molars), and the mandible was cemented in a steel box. The load was increased from 0 kg to 23 kg. Laser holographic technique was used to measure the three-dimensional bit shift of the dens, both buccolingual bit shift and mesiodistal bit shift, and determine tip angle and rotation angle. Results: The effects of stress distribution on the rigidly fixed bridge were evaluated, and stabilization of the bridge under the stresses of distributed loads and concentrated loads, respectively, were analyzed. The results showed that the tips of two abutments were very similar, and no distinct difference was observed between the distributed load and the concentrated load. However, the maximum rotation angle for the distributed load was two to four times as large as that for the concentrated load. In the experiment, the tip angle of the abutment teeth was no more than 0.65 degree, and the rotation angle was no more than 0.60 degree. All maximum angles occurred in the second molar. Conclusion: The fixed bridge is considered to be safe. In addition, a method for measuring the rotation angle was provided effectively. PMID:17565512

  8. Real Time Network Assessment

    DTIC Science & Technology

    2013-07-12

    Demonstrate a simple system Conduct a feasibility assessment of data storage, maintenance, and integration requirements Test a web-based data feed...Real Time Network Assessment Prototype We demonstrated the feasibility of linking near real time network analytics to mashups and web- based...combining similar concepts into single node) Stemmers Thesauri application Network position Statistical common patterns Pronoun identification

  9. Real-Time Gauge/Gravity Duality

    SciTech Connect

    Skenderis, Kostas; Rees, Balt C. van

    2008-08-22

    We present a general prescription for the holographic computation of real-time n-point functions in nontrivial states. In quantum field theory such real-time computations involve a choice of a time contour in the complex time plane. The holographic prescription amounts to 'filling in' this contour with bulk solutions: real segments of the contour are filled in with Lorentzian solutions while imaginary segments are filled in with Riemannian solutions and appropriate matching conditions are imposed at the corners of the contour. We illustrate the general discussion by computing the 2-point function of a scalar operator using this prescription and by showing that this leads to an unambiguous answer with the correct i{epsilon} insertions.

  10. Laser holographic detection of tiny thin tapes beneath a thick opaque composite structure

    NASA Technical Reports Server (NTRS)

    Liu, H.-K.; Kurtz, R. L.

    1974-01-01

    Real-time laser holographic interferometry technique has been applied successfully in the detection of 1mm x 1mm x 0.025mm duct tapes hidden beneath a 150mm x 150mm x 16mm ceramic-epoxy-fiberglass sandwiched structure. The experimental results clearly demonstrate future applicability of this technique in the optical nondestructive detection of debonds and flaws in such composite structures.

  11. Combination of temporal phase unwrapping and long-wave infrared digital holographic interferometry for metrology of mosaic detector under space simulated conditions

    NASA Astrophysics Data System (ADS)

    Vandenrijt, Jean-François; Thizy, Cédric; Beaumont, Florent; Garcia, José; Martin, Laurent; Fabron, Christophe; Prieto, Eric; Maciaszek, Thierry; Georges, Marc P.

    2015-08-01

    We present digital holographic interferometry (DHI) in the long-wave infrared for monitoring the deformation under cryogenic conditions of a segmented focal plane array to be used in a space mission. The long wavelength was chosen for its ability to allow measurement of displacements 20 times larger than DHI in the visible and which were foreseen with the test object under such temperature changes. The specimen consists of 4x4 mosaic of detectors assembled on a frame. It was required to assess the global deformation of the ensemble, the deformation of each detector, and piston movements of each of them with respect to their neighbors. For that reason we incorporated the temporal phase unwrapping by capturing a sufficiently high number of holograms between which the phase does not suffer strong variations. At last since the specimen exhibit specular reflectivity at that wavelength, it is illuminated through a reflective diffuser.

  12. Digital holographic interferometry in the long-wave infrared and temporal phase unwrapping for measuring large deformations and rigid body motions of segmented space detector in cryogenic test

    NASA Astrophysics Data System (ADS)

    Vandenrijt, Jean-François; Thizy, Cédric; Martin, Laurent; Beaumont, Florent; Garcia, José; Fabron, Christophe; Prieto, Éric; Maciaszek, Thierry; Georges, Marc P.

    2016-12-01

    We present digital holographic interferometry (DHI) in the long-wave infrared for monitoring the deformation under cryogenic conditions of a segmented focal plane array to be used in a space mission. The long wavelength was chosen for its ability to allow measurement of displacements 20 times larger than DHI in the visible, which were foreseen with the test object under large temperature variations. The latter is a mosaic of 4×4 detectors assembled on a frame. DHI was required to assess the global deformation of the assembly, the deformation of each detector, and out-of-plane movements of each of them with respect to their neighbors. For that reason, we incorporated the temporal phase unwrapping by capturing a sufficiently high number of holograms between which the phase does not undergo large variations. At last, since the specimen exhibits specular reflectivity at that wavelength, it is illuminated by means of a reflective diffuser.

  13. Real-time radiography

    SciTech Connect

    Bossi, R.H.; Oien, C.T.

    1981-02-26

    Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components.

  14. Real time obscuration monitoring

    NASA Astrophysics Data System (ADS)

    Agricola, Koos

    2016-09-01

    Recently a real time particle deposition monitoring system is developed. After discussions with optical system engineers a new feature has been added. This enables the real time monitoring of obscuration of exposed optical components by counting the deposited particles and sizing the obscuration area of each particle. This way the Particle Obscuration Rate (POR) can be determined. The POR can be used to determine the risk of product contamination during exposure. The particle size distribution gives information on the type of potential particle sources. The deposition moments will indicate when these sources were present.

  15. Deformation, strain and crack measurements using conjugate-wave holographic interferometry and its application to thermally stressed ceramic-coated metals

    NASA Astrophysics Data System (ADS)

    Gloeckner, Paul James

    The quantitative measurement of whole plane deformation fields has been approached by using methods such as moire interferometry, speckle interferometry and conventional holography. These methods have been used with success, but when isolation of deformation components is necessary and harsh environments exist some may not be practical. Conjugate Wave Holographic Interferometry (CWHI) is a non-contact method for measuring in-plane deformations on ordinary surfaces. By projecting the conjugate images from a hologram onto a deformed object, fringes can be observed that correlate to the object deformation. Its advantages include submicron resolution, whole field visualization, and isolation of individual in-plane components. Additionally, because CWHI is non-contacting it does not require special preparation of optically diffuse surfaces. Despite these apparent advantages, CWHI has not been widely used as an analysis tool. In this study, CWHI is used in conjunction with fringe skeletonizing and interpolation to obtain quantitative deformation and strain information for a simply supported beam. Additionally, the crack mouth opening displacement for a notched specimen was obtained. Experimentally obtained values agreed well with those predicted by theory. Furthermore, CWHI was applied to a ceramic thermal barrier coating subjected to localized 200°C heating at the surface and quantitative results for deformation and strain were obtained. An interesting phenomenon was observed during the crack measurements as well as the thermal loading study. Illumination of the object with a single conjugate image produced a dark spot at the crack, thus making it easily detectable. In the thermal loading study a dark spot was observed near the heated area in the ceramic layer. Several experiments were performed to identify the cause of the dark spot, but they were inconclusive.

  16. Interferometer real time control development for SIM

    NASA Astrophysics Data System (ADS)

    Bell, Charles E.

    2003-02-01

    Real Time Control (RTC) for the Space Interferometry Mission will build on the real time core interferometer control technology under development at JPL since the mid 1990s, with heritage from the ground based MKII and Palomar Testbed Interferometer projects developed in the late '80s and early '90s. The core software and electronics technology for SIM interferometer real time control is successfully operating on several SIM technology demonstration testbeds, including the Real-time Interferometer Control System Testbed, System Testbed-3, and the Microarcsecond Metrology testbed. This paper provides an overview of the architecture, design, integration, and test of the SIM flight interferometer real time control to meet challenging flight system requirements for the high processor throughput, low-latency interconnect, and precise synchronization to support microarcsecond-level astrometric measurements for greater than five years at 1 AU in Earth-trailing orbit. The electronics and software architecture of the interferometer real time control core and its adaptation to a flight design concept are described. Control loops for pointing and pathlength control within each of four flight interferometers and for coordination of control and data across interferometers are illustrated. The nature of onboard data processing to fit average downlink rates while retaining post-processed astrometric measurement precision and accuracy is also addressed. Interferometer flight software will be developed using a software simulation environment incorporating models of the metrology and starlight sensors and actuators to close the real time control loops. RTC flight software and instrument flight electronics will in turn be integrated utilizing the same simulation architecture for metrology and starlight component models to close real time control loops and verify RTC functionality and performance prior to delivery to flight interferometer system integration at Lockheed Martin

  17. Real-Time PCR

    NASA Astrophysics Data System (ADS)

    Evrard, A.; Boulle, N.; Lutfalla, G. S.

    Over the past few years there has been a considerable development of DNA amplification by polymerase chain reaction (PCR), and real-time PCR has now superseded conventional PCR techniques in many areas, e.g., the quantification of nucleic acids and genotyping. This new approach is based on the detection and quantification of a fluorescent signal proportional to the amount of amplicons generated by PCR. Real-time detection is achieved by coupling a thermocycler with a fluorimeter. This chapter discusses the general principles of quantitative real-time PCR, the different steps involved in implementing the technique, and some examples of applications in medicine. The polymerase chain reaction (PCR) provides a way of obtaining a large number of copies of a double-stranded DNA fragment of known sequence. This DNA amplification technique, developed in 1985 by K. Mullis (Cetus Corporation), saw a spectacular development over the space of a few years, revolutionising the methods used up to then in molecular biology. Indeed, PCR has many applications, such as the detection of small amounts of DNA, cloning, and quantitative analysis (assaying), each of which will be discussed further below.

  18. Real-time cosmology

    NASA Astrophysics Data System (ADS)

    Quercellini, Claudia; Amendola, Luca; Balbi, Amedeo; Cabella, Paolo; Quartin, Miguel

    2012-12-01

    In recent years, improved astrometric and spectroscopic techniques have opened the possibility of measuring the temporal change of radial and transverse position of sources in the sky over relatively short time intervals. This has made at least conceivable to establish a novel research domain, which we dub “real-time cosmology”. We review for the first time most of the work already done in this field, analysing the theoretical framework as well as some foreseeable observational strategies and their capability to constrain models. We first focus on real-time measurements of the overall redshift drift and angular separation shift in distant sources, which allows the observer to trace the background cosmic expansion and large scale anisotropy, respectively. We then examine the possibility of employing the same kind of observations to probe peculiar and proper accelerations in clustered systems, and therefore their gravitational potential. The last two sections are devoted to the future change of the cosmic microwave background on “short” time scales, as well as to the temporal shift of the temperature anisotropy power spectrum and maps. We conclude revisiting in this context the usefulness of upcoming experiments (like CODEX and Gaia) for real-time observations.

  19. Holographic Interferometry of Oil Films and Droplets in Water with a Single-Beam Mirror-Type Scheme

    DTIC Science & Technology

    2011-03-01

    patterns Inlerferometnr. methods of oil spill detection and characterization can be automated using digital holography with three-dimensional...holographic fringe patterns. Interferometric methods of oil spill detection and characterization can be automated using digital holography with three...reconstruction of the time-changing oil spill topography. In this effort, the interferometric methods were applied to samples from Chevron oil and British

  20. Real-Time Optical Correlator Based On GaAs

    NASA Technical Reports Server (NTRS)

    Liu, Tsuen-Hsi; Cheng, Li-Jen

    1992-01-01

    Apparatus performs correlation between input image and reference image in real time by means of degenerate four-wave mixing in photorefractive crystal, which serves as real-time holographic medium. Gallium arsenide chosen to be photorefractive material in this application because at frame rate and level of illumination used in experiments, offers adequate diffraction efficiency. Frame rates as high as 1,000 s to negative 1st power achievable.

  1. Real-Time Revolution?

    PubMed

    Berlin, Joey

    2016-03-01

    Austin Regional Clinic (ARC) physicians and officials know patient feedback is important, but getting patients to provide it can be a challenge. A pilot program of a new, real-time feedback system provided ARC patients a high-tech convenience previous attempts lacked and produced participation numbers dwarfing those past efforts. ARC's initial results with the system, in which patients answer five to seven questions on a computer tablet and can leave free-text comments, were so successful the clinic is already planning to expand it to all of its locations by the end of June.

  2. Real time Faraday spectrometer

    DOEpatents

    Smith, Jr., Tommy E.; Struve, Kenneth W.; Colella, Nicholas J.

    1991-01-01

    This invention uses a dipole magnet to bend the path of a charged particle beam. As the deflected particles exit the magnet, they are spatially dispersed in the bend-plane of the magnet according to their respective momenta and pass to a plurality of chambers having Faraday probes positioned therein. Both the current and energy distribution of the particles is then determined by the non-intersecting Faraday probes located along the chambers. The Faraday probes are magnetically isolated from each other by thin metal walls of the chambers, effectively providing real time current-versus-energy particle measurements.

  3. Experimental investigation of solid hydrogen pellet ablation in high-temperature plasmas using holographic interferometry and other diagnostics

    SciTech Connect

    Thomas, Jr., C. E.

    1981-03-01

    The technology currently most favored for the refueling of fusion reactors is the high-velocity injection of solid hydrogen pellets. Design details are presented for a holographic interferometer/shadowgraph used to study the microscopic characteristics of a solid hydrogen pellet ablating in an approx. 1-keV plasma. Experimental data are presented for two sets of experiments in which the interferometer/shadowgraph was used to study approx. 1-mm-diam solid hydrogen pellets injected into the Impurity Study Experiment (ISX-B) tokamak at Oak Ridge National Laboratory (ORNL) at velocities of 1000 m/s. In addition to the use of the holographic interferometer, the pellet ablation process is diagnosed by studying the emission of Balmer-alpha photons and by using the available tokamak diagnostics (Thomson scattering, microwave/far-infrared interferometer, pyroelectric radiometer, hard x-ray detector).

  4. Real-time optical tweezing

    NASA Astrophysics Data System (ADS)

    Rahman, Shah Mohammed Tamzidur

    In this thesis a new approach called ‘space-time-wavelength mapping’ has been developed for real-time electronic control of optical tweezers. The proposed technique enables precise control of optical signals in space, time, and frequency through time-domain dispersion and diffractive optics, which in turn enables generation of controlled radiation forces acting on small particles. In this study we show that 150 fs ultrafast optical pulses can be dispersed in time and space to achieve a 20 μm x 2 μm focused elliptical beam. The force field at the focal plane of the beam is dependent on local intensity gradients along the plane. The spatial intensity profile can be electronically controlled by assigning local power levels to each wavelength using time-domain RF modulation of dispersed pulses, and sending each wavelength, and hence the assigned power level, to a specific location in space through diffractive optics. We show that by choosing the appropriate RF waveform, one is able to create force fields for cell stretching and compression as well as multiple force hot-spots (of >200 pN force per pulse) for attractive and repulsive forces. A detailed theoretical model and simulation results from a proposed experimental setup are presented. This approach is significantly more advantageous in terms of flexibility and control, compared to conventional optical tweezers that require mechanical steering or holographic optical tweezers that produce undesired ‘ghost traps’. In addition, it is shown how the technique can also be extended to create tunable 2D force field distributions using a virtually-imaged phased-array (VIPA).

  5. Real time automated inspection

    DOEpatents

    Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.

    1985-05-21

    A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.

  6. Real time automated inspection

    DOEpatents

    Fant, Karl M.; Fundakowski, Richard A.; Levitt, Tod S.; Overland, John E.; Suresh, Bindinganavle R.; Ulrich, Franz W.

    1985-01-01

    A method and apparatus relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges are segmented out by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections.

  7. A Loschmidt cell combined with holographic interferometry for binary diffusion experiments in gas mixtures including first measurements on the argon-neon system

    NASA Astrophysics Data System (ADS)

    Buttig, D.; Vogel, E.; Bich, E.; Hassel, E.

    2011-10-01

    A new variant of the Loschmidt technique has been developed for measuring binary diffusion coefficients in gas mixtures in a temperature range from 10 to 80 °C and for pressures between 0.1 and 1 MPa. The two half cells of the thermostatted diffusion cell have a rectangular cross section and are fixed one upon the other. They can be connected and separated by means of a sliding plate provided with a pneumatically operated seal. The concentration in both half cells is determined simultaneously during the diffusion process using an optical system for holographic interferometry for each. The change in the refractive index results in an interference pattern which is recorded as a function of time. The concentrations of the diffusing components are derived by means of the Lorentz-Lorenz equation. The binary diffusion coefficients are calculated via the integrated ideal diffusion equation for the complete mole fraction range performing only a unique diffusion experiment. The performance of the apparatus is demonstrated on first measurements on the argon-neon system at 293.15 K. Separate refractive index measurements are carried out leading to values for the first refractivity virial coefficient of the pure gases with an estimated uncertainty of ±0.1%. This low uncertainty is required for the aimed uncertainty of ±0.5...1% for the diffusion measurements to determine the concentration and density dependences of the binary diffusion coefficient.

  8. Real time polarimetric dehazing.

    PubMed

    Mudge, Jason; Virgen, Miguel

    2013-03-20

    Remote sensing is a rich topic due to its utility in gathering detailed accurate information from locations that are not economically feasible traveling destinations or are physically inaccessible. However, poor visibility over long path lengths is problematic for a variety of reasons. Haze induced by light scatter is one cause for poor visibility and is the focus of this article. Image haze comes about as a result of light scattering off particles and into the imaging path causing a haziness to appear on the image. Image processing using polarimetric information of light scatter can be used to mitigate image haze. An imaging polarimeter which provides the Stokes values in real time combined with a "dehazing" algorithm can automate image haze removal for instant applications. Example uses are to improve visual display providing on-the-spot detection or imbedding in an active control loop to improve viewing and tracking while on a moving platform. In addition, removing haze in this manner allows the trade space for a system operational waveband to be opened up to bands which are object matched and not necessarily restricted by scatter effects.

  9. Vibration mode shapes visualization in industrial environment by real-time time-averaged phase-stepped electronic speckle pattern interferometry at 10.6 μm and shearography at 532 nm

    NASA Astrophysics Data System (ADS)

    Languy, Fabian; Vandenrijt, Jean-François; Thizy, Cédric; Rochet, Jonathan; Loffet, Christophe; Simon, Daniel; Georges, Marc P.

    2016-12-01

    We present our investigations on two interferometric methods suitable for industrial conditions dedicated to the visualization of vibration modes of aeronautic blades. First, we consider long-wave infrared (LWIR) electronic speckle pattern interferometry (ESPI). The use of long wavelength allows measuring larger amplitudes of vibrations compared with what can be achieved with visible light. Also longer wavelengths allow lower sensitivity to external perturbations. Second, shearography at 532 nm is used as an alternative to LWIR ESPI. Both methods are used in time-averaged mode with the use of phase-stepping. This allows transforming Bessel fringes, typical to time averaging, into phase values that provide higher contrast and improve the visualization of vibration mode shapes. Laboratory experimental results with both techniques allowed comparison of techniques, leading to selection of shearography. Finally a vibration test on electrodynamic shaker is performed in an industrial environment and mode shapes are obtained with good quality by shearography.

  10. Simplest holographic technique: unsurpassed features very friendly to practical applications

    NASA Astrophysics Data System (ADS)

    Petrov, Valery

    1996-12-01

    Holography and holographic interferometry in spite of their attractive features are rather rarely used for industrial inspections of products and components or in medical practice due to relative complexity, costs, lengthy multi- stage procedures, need of dark rooms and vibration insulation. But the most of these drawbacks might be avoided if momental holography on silver halide (SH) media is involved. Momental technique simplifies drastically the holographic process and ensures quasi real time or real time (in situ) bright reconstructions from holograms, real time or double exposure holographic interferograms. This technique permits the user to avoid dark rooms and to work with standard office or industrial illumination of 0.5 klx or even much more. Moreover, very bright holograms and holographic interferograms might be obtained also in the street in a diffused daylight or even under strong direct sunlight illumination. High quality off-axis and reflection holograms, interferograms, HOE were obtained utilizing ruby, semiconductor, He-Ne and Ar laser sources. Agfa-Gevaert 8 E 75 HD films and plates, Russian PFG-03 and PFG-03 C (color) plates were used as recording media. Different levels of external polychromatic illumination were applied to holograms and holographic interferograms during production. Extremely high levels (more than 50 klx) were also tested. Bright holographic reconstructions were obtained even in such unpromising environment. Photographic images from such holograms are presented. One of the holograms was momentally photoprocessed in the light of projector (a few klx) during presentation of this paper at the conference 'Holographic and Diffractive Techniques' in Berlin. Another unique feature of the technique: extremely long-term storage of holographic data on SH media in latent form is shown. It relates both to holograms recorded with cw lasers and to those recorded with pulsed laser sources. The latter case is the most interesting because it was

  11. Holographic Interferometry (HI), Infrared Vision and X-Ray Fluorescence (XRF) spectroscopy for the assessment of painted wooden statues: a new integrated approach

    NASA Astrophysics Data System (ADS)

    Sfarra, Stefano; Ibarra-Castanedo, Clemente; Ridolfi, Stefano; Cerichelli, Giorgio; Ambrosini, Dario; Paoletti, Domenica; Maldague, Xavier

    2014-06-01

    Wood has been routinely employed in decorative arts, as well as in sculptures and paintings (support) during the Middle Ages, because of its unique aesthetic virtues. It may safely be assumed that wood, as a material for monumental sculpture, was much more commonly employed in the mediaeval period than existing examples would seem to indicate (Bulletin of the metropolitan Museum of Art, 2013). Wood is easily obtainable; it could be carved and put in place with less difficulty than stone, it is chemically stable when dry, and its surface offers a compatible substrate for paint application. However, the use of wood is not without pitfalls, and requires an understanding of its anisotropic and hygroscopic nature. It is also dimensionally unstable and subject to deterioration by fungi and insects. Moisture-related dimensional changes are certainly among the most challenging problems in painting conservation. With the purpose of preventing important damages, the use of non-or microdestructive testing (NDT) techniques is undoubtedly of paramount interest for painted wooden statues of great value. This work has a threefold purpose: (1) to validate the effectiveness of an integrated approach using near-infrared (NIR) reflectography, square pulse thermography (SPT), and holographic interferometry (HI) techniques for discovering old repairs and/or inclusions of foreign materials in a wooden structure, (2) to confirm and approximately date the restoration carried out by x-ray fluorescence (XRF) spectroscopy and energy-dispersive x-ray spectroscopy (EDS) (that is assembled with a scanning electron microscopy—SEM) techniques, and (3) to combine into a multidisciplinary approach two quantitative NDT results coming from optical and thermographic methods. The subject of the present study was a statue named "Virgin with her Child" (XIV century), whose origins are mysterious and not properly documented.

  12. Holography and the virtual patient: the holographic medical image

    NASA Astrophysics Data System (ADS)

    Ko, Kathryn; Erickson, Ronald R.; Webster, John M.

    1996-12-01

    Practical holographic systems utilizing the pulsed laser are finding potential applications in medicine. Exploiting both the hologram's true 3D image and holographic interferometry these techniques enhance the physician's vision beyond the 2D radiological imaging of even the best CT and MRI. The authors describe the use of pulsed laser holography as applied to the morphological specialties: anatomy, pathology, and surgery. The authors report on the Holographic Brain Anatomy Atlas for medical education; pathologic documentation with holography, and the use of holographic interferometry in surgical planning. The techniques are outlined and a discussion on the interpretation of holographic interferometry with living subjects is provided.

  13. Tunable dichroic polarization beam splitter created by one-step holographic photoalignment using four-beam polarization interferometry

    NASA Astrophysics Data System (ADS)

    Kawai, Kotaro; Sakamoto, Moritsugu; Noda, Kohei; Sasaki, Tomoyuki; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2017-01-01

    A tunable dichroic polarization beam splitter (tunable DPBS) simultaneously performs the follow functions: 1. Separation of a polarized incident beam into multiple pairs of orthogonally polarized beams; 2. Separation of the propagation direction of two wavelength incident beams after passing through the tunable DPBS; and 3. Control of both advanced polarization and wavelength separation capabilities by varying the temperature of the tunable DPBS. This novel complex optical property is realized by diffraction phenomena using a designed three-dimensional periodic structure of aligned liquid crystals in the tunable DPBS, which was fabricated quickly with precision in a one-step photoalignment using four-beam polarization interferometry. In experiments, we demonstrated that these diffraction properties are obtained by entering polarized beams of wavelengths 532 nm and 633 nm onto the tunable DPBS. These diffraction properties are described using the Jones calculus in a polarization propagation analysis. Of significance is that the aligned liquid crystal structure needed to obtain these diffraction properties was proposed based on a theoretical analysis, and these properties were then demonstrated experimentally. The tunable DPBS can perform several functions of a number of optical elements such as wave plates, polarization beam splitter, dichroic beam splitter, and tunable wavelength filter. Therefore, the tunable DPBS can contribute to greater miniaturization, sophistication, and cost reduction of optical systems used widely in applications, such as optical measurements, communications, and information processing.

  14. Digital Holographic Logic

    NASA Technical Reports Server (NTRS)

    Preston, K., Jr.

    1972-01-01

    The characteristics of the holographic logic computer are discussed. The holographic operation is reviewed from the Fourier transform viewpoint, and the formation of holograms for use in performing digital logic are described. The operation of the computer with an experiment in which the binary identity function is calculated is discussed along with devices for achieving real-time performance. An application in pattern recognition using neighborhood logic is presented.

  15. Real-time sensing of optical alignment

    NASA Technical Reports Server (NTRS)

    Stier, Mark T.; Wissinger, Alan B.

    1988-01-01

    The Large Deployable Reflector and other future segmented optical systems may require autonomous, real-time alignment of their optical surfaces. Researchers have developed gratings located directly on a mirror surface to provide interferometric sensing of the location and figure of the mirror. The grating diffracts a small portion of the incident beam to a diffractive focus where the designed diagnostics can be performed. Mirrors with diffraction gratings were fabricated in two separate ways. The formation of a holographic grating over the entire surface of a mirror, thereby forming a Zone Plate Mirror (ZPM) is described. Researchers have also used computer-generated hologram (CGH) patches for alignment and figure sensing of mirrors. When appropriately illuminated, a grid of patches spread over a mirror segment will yield a grid of point images at a wavefront sensor, with the relative location of the points providing information on the figure and location of the mirror. A particular advantage of using the CGH approach is that the holographic patches can be computed, fabricated, and replicated on a mirror segment in a mass production 1-g clean room environment.

  16. Holographic optical trapping

    SciTech Connect

    Grier, David G.; Roichman, Yael

    2006-02-10

    Holographic optical tweezers use computer-generated holograms to create arbitrary three-dimensional configurations of single-beam optical traps that are useful for capturing, moving, and transforming mesoscopic objects. Through a combination of beam-splitting, mode-forming, and adaptive wavefront correction, holographic traps can exert precisely specified and characterized forces and torques on objects ranging in size from a few nanometers to hundreds of micrometers. Offering nanometer-scale spatial resolution and real-time reconfigurability, holographic optical traps provide unsurpassed access to the microscopic world and have found applications in fundamental research, manufacturing, and materials processing.

  17. Holographic optical trapping.

    PubMed

    Grier, David G; Roichman, Yael

    2006-02-10

    Holographic optical tweezers use computer-generated holograms to create arbitrary three-dimensional configurations of single-beam optical traps that are useful for capturing, moving, and transforming mesoscopic objects. Through a combination of beam-splitting, mode-forming, and adaptive wavefront correction, holographic traps can exert precisely specified and characterized forces and torques on objects ranging in size from a few nanometers to hundreds of micrometers. Offering nanometer-scale spatial resolution and real-time reconfigurability, holographic optical traps provide unsurpassed access to the microscopic world and have found applications in fundamental research, manufacturing, and materials processing.

  18. Real-time flutter identification

    NASA Technical Reports Server (NTRS)

    Roy, R.; Walker, R.

    1985-01-01

    The techniques and a FORTRAN 77 MOdal Parameter IDentification (MOPID) computer program developed for identification of the frequencies and damping ratios of multiple flutter modes in real time are documented. Physically meaningful model parameterization was combined with state of the art recursive identification techniques and applied to the problem of real time flutter mode monitoring. The performance of the algorithm in terms of convergence speed and parameter estimation error is demonstrated for several simulated data cases, and the results of actual flight data analysis from two different vehicles are presented. It is indicated that the algorithm is capable of real time monitoring of aircraft flutter characteristics with a high degree of reliability.

  19. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2006-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  20. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2007-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  1. Real Time Conference 2014 Overview

    NASA Astrophysics Data System (ADS)

    Nomachi, Masaharu

    2015-06-01

    This article presents an overview of the 19th Real Time Conference held last May 26-30, 2014, at the Nara Prefectural New Public Hall, Nara, Japan, organized by the Research Center for Nuclear Physics of the Osaka University. The program included many invited talks and oral sessions offering an extensive overview on the following topics: real-time system architectures, intelligent signal processing, fast data transfer links and networks, trigger systems, data acquisition, processing-farms, control, monitoring and test systems, emerging real-time technologies, new standards, real-time safety and security, and some feedback on experiences. In parallel to the oral and poster presentations, industrial exhibits by companies, workshops and short courses also ran through the week.

  2. Real Time Data System (RTDS)

    NASA Technical Reports Server (NTRS)

    Muratore, John F.

    1991-01-01

    Lessons learned from operational real time expert systems are examined. The basic system architecture is discussed. An expert system is any software that performs tasks to a standard that would normally require a human expert. An expert system implies knowledge contained in data rather than code. And an expert system implies the use of heuristics as well as algorithms. The 15 top lessons learned by the operation of a real time data system are presented.

  3. Real-time vision systems

    SciTech Connect

    Johnson, R.; Hernandez, J.E.; Lu, Shin-yee

    1994-11-15

    Many industrial and defence applications require an ability to make instantaneous decisions based on sensor input of a time varying process. Such systems are referred to as `real-time systems` because they process and act on data as it occurs in time. When a vision sensor is used in a real-time system, the processing demands can be quite substantial, with typical data rates of 10-20 million samples per second. A real-time Machine Vision Laboratory (MVL) was established in FY94 to extend our years of experience in developing computer vision algorithms to include the development and implementation of real-time vision systems. The laboratory is equipped with a variety of hardware components, including Datacube image acquisition and processing boards, a Sun workstation, and several different types of CCD cameras, including monochrome and color area cameras and analog and digital line-scan cameras. The equipment is reconfigurable for prototyping different applications. This facility has been used to support several programs at LLNL, including O Division`s Peacemaker and Deadeye Projects as well as the CRADA with the U.S. Textile Industry, CAFE (Computer Aided Fabric Inspection). To date, we have successfully demonstrated several real-time applications: bullet tracking, stereo tracking and ranging, and web inspection. This work has been documented in the ongoing development of a real-time software library.

  4. Holographic Characteristics of an Acrylamide/Bisacrylamide Photopolymer in 40 1000 µm Thick Layers

    NASA Astrophysics Data System (ADS)

    Ortuño, M.; Gallego, S.; García, C.; Pascual, I.; Neipp, C.; Beléndez, A.

    2005-01-01

    In this study we analyze the holographic behaviour of an acrylamide/bisacrylamide photopolymer in layers that range in thickness from 40 to 1000 µm. The photopolymer is composed of acrylamide as polymerizable monomer, N,N' methylene-bis-acrylamide as crosslinker, triethanolamine as radical generator, yellowish eosin as sensitizer and polyvinyl alcohol as binder. The composition and method of depositing the solution varies depending on the desired thickness of the final layer. For each thickness we analyze the holographic behaviour of the material during recording of unslanted diffraction gratings using a continuous argon laser (514 nm) at an intensity of 5 mW/cm2. The response of the material is monitored in real time with an He-Ne laser. The results obtained for the different parameters evaluated vary considerably depends on the layer thickness. Therefore, the different potential applications of the material (fabrication of holographic optical elements, use as recording material in holographic interferometry, or manufacture of holographic memories) depends on its thickness.

  5. HEVC real-time decoding

    NASA Astrophysics Data System (ADS)

    Bross, Benjamin; Alvarez-Mesa, Mauricio; George, Valeri; Chi, Chi Ching; Mayer, Tobias; Juurlink, Ben; Schierl, Thomas

    2013-09-01

    The new High Efficiency Video Coding Standard (HEVC) was finalized in January 2013. Compared to its predecessor H.264 / MPEG4-AVC, this new international standard is able to reduce the bitrate by 50% for the same subjective video quality. This paper investigates decoder optimizations that are needed to achieve HEVC real-time software decoding on a mobile processor. It is shown that HEVC real-time decoding up to high definition video is feasible using instruction extensions of the processor while decoding 4K ultra high definition video in real-time requires additional parallel processing. For parallel processing, a picture-level parallel approach has been chosen because it is generic and does not require bitstreams with special indication.

  6. Dependable Real-Time Systems

    DTIC Science & Technology

    1991-09-30

    and F. Wang, "On thle Competitiveness of On-Line Real-Time Task Sc~eduling," to appear. Proc. Icai - Time Systemns Symposium, Dec 1991. 6. Biyabaiii, S...Stankovic, and K. Ramrnamritham, "System Support for lRal-’Vi111C Al: A Spring Project Perspective," Workshop on Real-Time .A1, ICAI ., August 198!). 29...Informatics, Computer S,,iety ,f India , t,, aptpear. 41 . Shilh, C. and J. A. Stankovic, "Distributed Deadlock Detection in Ada IRuntinv En vi- ronments," TRI

  7. Biomechanical model produced from light-activated dental composite resins: a holographic analysis

    NASA Astrophysics Data System (ADS)

    Pantelić, Dejan; Vasiljević, Darko; Blažić, Larisa; Savić-Šević, Svetlana; Murić, Branka; Nikolić, Marko

    2013-11-01

    Light-activated dental composites, commonly applied in dentistry, can be used as excellent material for producing biomechanical models. They can be cast in almost any shape in an appropriate silicone mold and quickly solidified by irradiation with light in the blue part of the spectrum. In that way, it is possible to obtain any number of nearly identical casts. The models can be used to study the behavior of arbitrary structure under mechanical loads. To test the technique, a simple mechanical model of the tooth with a mesio-occluso-distal cavity was manufactured. Composite resin restoration was placed inside the cavity and light cured. Real-time holographic interferometry was used to analyze the contraction of the composite resin and its effect on the surrounding material. The results obtained in the holographic experiment were in good agreement with those obtained using the finite element method.

  8. Miniaturized low-cost digital holographic interferometer

    NASA Astrophysics Data System (ADS)

    Michalkiewicz, Aneta; Kujawinska, Małgorzata; Marc, Paweł; Jaroszewicz, Leszek R.

    2006-04-01

    Digital holography (DH) and digital holographic interferometry (DHI) are very useful, robust, full-field visualization and measurement techniques applied for small objects, especially in the field of bioengineering and microelements system testing. Nowadays CCD/CMOS detectors and microlasers allow to build miniaturized and compact digital holographic head. Various approaches to develop DH/DHI systems including a variety of optical and mechanical solutions have been made. The main recent requirements for holocamera design include compactness, insensitivity to vibrations environmental changes and with good quality of output data. Other requirement is the ability to build a low-cost and robust system for sensing applications. In our paper, we propose a design of miniaturized holo-camera head with fibre optics light delivery system and remote data read-out. The opto-mechanical architecture allows out-of-plane and shape measurements of diffuse and reflective surfaces. The possible data capture schemes and software for enhanced quality numerical reconstruction of complex objects are discussed and the optimized methodology is determined. Also real-time optoelectronic hologram reconstruction is demonstrated on the base of remote data delivery to liquid crystal on silicon spatial light modulator. The performance of the system is tested on the resolution amplitude test and master sphere, while engineering objects in the experiments are static and dynamic microelements.

  9. Real Time Conference 2016 Overview

    NASA Astrophysics Data System (ADS)

    Luchetta, Adriano

    2017-06-01

    This is a special issue of the IEEE Transactions on Nuclear Science containing papers from the invited, oral, and poster presentation of the 20th Real Time Conference (RT2016). The conference was held June 6-10, 2016, at Centro Congressi Padova “A. Luciani,” Padova, Italy, and was organized by Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA) and the Istituto Nazionale di Fisica Nucleare. The Real Time Conference is multidisciplinary and focuses on the latest developments in real-time techniques in high-energy physics, nuclear physics, astrophysics and astroparticle physics, nuclear fusion, medical physics, space instrumentation, nuclear power instrumentation, general radiation instrumentation, and real-time security and safety. Taking place every second year, it is sponsored by the Computer Application in Nuclear and Plasma Sciences technical committee of the IEEE Nuclear and Plasma Sciences Society. RT2016 attracted more than 240 registrants, with a large proportion of young researchers and engineers. It had an attendance of 67 students from many countries.

  10. Real Time Sonic Boom Display

    NASA Technical Reports Server (NTRS)

    Haering, Ed

    2014-01-01

    This presentation will provide general information about sonic boom mitigation technology to the public in order to supply information to potential partners and licensees. The technology is a combination of flight data, atmospheric data and terrain information implemented into a control room real time display for flight planning. This research is currently being performed and as such, any results and conclusions are ongoing.

  11. POSIX real-time extensions

    NASA Technical Reports Server (NTRS)

    Robbins, Henry H.

    1992-01-01

    POSIX is an evolving set of operating system interface standards, whose parts are in varying stages of production in a number of standards working groups. This presentation separates the real-time POSIX standards work in process from the rest and provides an overview of the purpose, status, dependencies, content, and project schedule of each.

  12. A Real Time Interferometry System for Unsteady Flow Measurements

    DTIC Science & Technology

    1991-10-01

    shown 4, that DCGI actually produces fringes is the reference wavefront resulting from the convolu- with greater contrast and intensity than PDI. How...During the work with DCGI , it was found were determined experimentally for the present appli- that laser pulses containing sufficient energy to ex...achieved with PD! 2 s. Hence, further develop- densities near 1 were used for the flow conditions of ment of DCGI for the facility was discontinued

  13. Novel Organic Polymer Films for Real-time Holographic Processing

    DTIC Science & Technology

    2007-11-02

    Because of the modelo In behavior of the arctangent function, the range is wrapped (ambiguous) beyond the so-called synthetic wavelength TB01JMF.DOC...photorefractive polymer with high optical gain and diffraction efficiency near 100%", Nature ’ill, pp . 497-500 (1994). 2 S. Ducharme, J.C. Scott, R.J. Tweig...W.E. Moerner, Phys. Rev. Lett., 66, pp . 1846-1849 (1991). 3 W.E. Moerner and S.M. Silence, "Polymeric Photorefractive Materials", Chem. Rev. 94, pp

  14. Combined Holographic Infrared Inspection Instrumentation

    DTIC Science & Technology

    1989-12-01

    wavefronts, an object beam and a refererce beam, cn a suitable recording material, such as a photog"".phic film . V, hen properly illuminated by the...methods for fringe control 14 and improved methods for processing holograms in place using better film methods and/or thermoplastic recording techniques...Inc. Holomatic 8000 phased-locked holographic interferometry system. The Holomatic 8000 records the reference hologram on 35mm holographic film which is

  15. [Real time 3D echocardiography

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Thomas, J. D.

    2001-01-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

  16. Real Time Data Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Silberberg, George G.

    1983-03-01

    By the early 1970s, classical photo-optical range instrumentation technology (as a means of gathering weapons' system performance data) had become a costly and inefficient process. Film costs were increasing due to soaring silver prices. Time required to process, read, and produce optical data was becoming unacceptable as a means of supporting weapon system development programs. NWC investigated the feasibility of utilizing Closed Circuit Television (CCTV) technology as an alternative solution for providing optical data. In 1978 a program entitled Metric Video (measurements from video images) was formulated at the Naval Weapons Center, China Lake, California. The purpose of this program was to provide timely data, to reduce the number of operating personnel, and to lower data acquisition costs. Some of the task elements for this program included a near real-time vector miss-distance system, a weapons scoring system, a velocity measuring system, a time-space position system, and a system to replace film cameras for gathering real-time engineering sequential data. These task elements and the development of special hardware and techniques to achieve real-time data will be discussed briefly in this paper.

  17. [Real time 3D echocardiography

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Thomas, J. D.

    2001-01-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

  18. Interactive real time flow simulations

    NASA Technical Reports Server (NTRS)

    Sadrehaghighi, I.; Tiwari, S. N.

    1990-01-01

    An interactive real time flow simulation technique is developed for an unsteady channel flow. A finite-volume algorithm in conjunction with a Runge-Kutta time stepping scheme was developed for two-dimensional Euler equations. A global time step was used to accelerate convergence of steady-state calculations. A raster image generation routine was developed for high speed image transmission which allows the user to have direct interaction with the solution development. In addition to theory and results, the hardware and software requirements are discussed.

  19. Real time infrared aerosol analyzer

    DOEpatents

    Johnson, Stanley A.; Reedy, Gerald T.; Kumar, Romesh

    1990-01-01

    Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

  20. Real-time flutter analysis

    NASA Technical Reports Server (NTRS)

    Walker, R.; Gupta, N.

    1984-01-01

    The important algorithm issues necessary to achieve a real time flutter monitoring system; namely, the guidelines for choosing appropriate model forms, reduction of the parameter convergence transient, handling multiple modes, the effect of over parameterization, and estimate accuracy predictions, both online and for experiment design are addressed. An approach for efficiently computing continuous-time flutter parameter Cramer-Rao estimate error bounds were developed. This enables a convincing comparison of theoretical and simulation results, as well as offline studies in preparation for a flight test. Theoretical predictions, simulation and flight test results from the NASA Drones for Aerodynamic and Structural Test (DAST) Program are compared.

  1. Real-time streamflow conditions

    USGS Publications Warehouse

    Graczyk, David J.; Gebert, Warren A.

    1996-01-01

    Would you like to know streamflow conditions before you go fishing in Wisconsin or in more distant locations? Real-time streamflow data throughout Wisconsin and the United States are available on the Internet from the U.S. Geological Survey. You can see if the stream you are interested in fishing is high due to recent rain or low because of an extended dry spell. Flow conditions at more than 100 stream-gaging stations located throughout Wisconsin can be viewed by accessing the Wisconsin District Home Page at: http://wwwdwimdn.er.usgs.gov

  2. Real-time pulmonary graphics.

    PubMed

    Mammel, Mark C; Donn, Steven M

    2015-06-01

    Real-time pulmonary graphics now enable clinicians to view lung mechanics and patient-ventilator interactions on a breath-to-breath basis. Displays of pressure, volume, and flow waveforms, pressure-volume and flow-volume loops, and trend screens enable clinicians to customize ventilator settings based on the underlying pathophysiology and responses of the individual patient. This article reviews the basic concepts of pulmonary graphics and demonstrates how they contribute to our understanding of respiratory physiology and the management of neonatal respiratory failure.

  3. Real-time tomographic holography for augmented reality

    PubMed Central

    Galeotti, John M.; Siegel, Mel; Stetten, George

    2011-01-01

    The concept and instantiation of Real-Time Tomographic Holography (RTTH) for augmented reality is presented. RTTH enables natural hand-eye coordination to guide invasive medical procedures without requiring tracking or a head-mounted device. It places a real-time virtual image of an object's cross-section into its actual location, without noticeable viewpoint dependence (e.g. parallax error). The virtual image is viewed through a flat narrow-band Holographic Optical Element with optical power that generates an in-situ virtual image (within 1 m of the HOE) from a small SLM display without obscuring a direct view of the physical world. Rigidly fixed upon a medical ultrasound probe, an RTTH device could show the scan in its actual location inside the patient, even as the probe was moved relative to the patient. PMID:20634827

  4. Real time analysis under EDS

    NASA Astrophysics Data System (ADS)

    Schneberk, D.

    1985-07-01

    The analysis component of the Enrichment Diagnostic System (EDS) developed for the Atomic Vapor Laser Isotope Separation Program (AVLIS) at Lawrence Livermore National Laboratory (LLNL) is described. Four different types of analysis are performed on data acquired through EDS: (1) absorption spectroscopy on laser-generated spectral lines, (2) mass spectrometer analysis, (3) general purpose waveform analysis, and (4) separation performance calculations. The information produced from this data includes: measures of particle density and velocity, partial pressures of residual gases, and overall measures of isotope enrichment. The analysis component supports a variety of real-time modeling tasks, a means for broadcasting data to other nodes, and a great degree of flexibility for tailoring computations to the exact needs of the process. A particular data base structure and program flow is common to all types of analysis. Key elements of the analysis component are: (1) a fast access data base which can configure all types of analysis, (2) a selected set of analysis routines, (3) a general purpose data manipulation and graphics package for the results of real time analysis.

  5. Real-time analysis keratometer

    NASA Technical Reports Server (NTRS)

    Adachi, Iwao P. (Inventor); Adachi, Yoshifumi (Inventor); Frazer, Robert E. (Inventor)

    1987-01-01

    A computer assisted keratometer in which a fiducial line pattern reticle illuminated by CW or pulsed laser light is projected on a corneal surface through lenses, a prismoidal beamsplitter quarterwave plate, and objective optics. The reticle surface is curved as a conjugate of an ideal corneal curvature. The fiducial image reflected from the cornea undergoes a polarization shift through the quarterwave plate and beamsplitter whereby the projected and reflected beams are separated and directed orthogonally. The reflected beam fiducial pattern forms a moire pattern with a replica of the first recticle. This moire pattern contains transverse aberration due to differences in curvature between the cornea and the ideal corneal curvature. The moire pattern is analyzed in real time by computer which displays either the CW moire pattern or a pulsed mode analysis of the transverse aberration of the cornea under observation, in real time. With the eye focused on a plurality of fixation points in succession, a survey of the entire corneal topography is made and a contour map or three dimensional plot of the cornea can be made as a computer readout in addition to corneal radius and refractive power analysis.

  6. Real time analysis under EDS

    SciTech Connect

    Schneberk, D.

    1985-07-01

    This paper describes the analysis component of the Enrichment Diagnostic System (EDS) developed for the Atomic Vapor Laser Isotope Separation Program (AVLIS) at Lawrence Livermore National Laboratory (LLNL). Four different types of analysis are performed on data acquired through EDS: (1) absorption spectroscopy on laser-generated spectral lines, (2) mass spectrometer analysis, (3) general purpose waveform analysis, and (4) separation performance calculations. The information produced from this data includes: measures of particle density and velocity, partial pressures of residual gases, and overall measures of isotope enrichment. The analysis component supports a variety of real-time modeling tasks, a means for broadcasting data to other nodes, and a great degree of flexibility for tailoring computations to the exact needs of the process. A particular data base structure and program flow is common to all types of analysis. Key elements of the analysis component are: (1) a fast access data base which can configure all types of analysis, (2) a selected set of analysis routines, (3) a general purpose data manipulation and graphics package for the results of real time analysis. Each of these components are described with an emphasis upon how each contributes to overall system capability. 3 figs.

  7. Real-time image deblurring using four-wave mixing

    NASA Astrophysics Data System (ADS)

    Ja, Y. H.

    1983-09-01

    A real-time image deblurring method that uses four-wave mixing and is based on the deconvolution method developed by Stroke and others (Stroke and Zech, 1967; Stroke et al., 1969; Stroke and Halioua, 1970; and Stroke et al., 1977) is proposed. It is pointed out that the deconvolution method involves spatial filtering with a holographic deconvolution filter, where image division in the Fourier transform plane is performed. Since the deconvolution (division) filter is usually recorded on a negative photographic film by controlling gamma, the slope in the linear region of the Hurter-Driffield curve of the film, it is not possible to perform the operation in real time. With four-wave mixing, the recording of the hologram and the reconstruction of the image occur simultaneously and are almost in real time since the time-consuming processing of the film is not required. The general principle of image deblurring is outlined, and it is then shown how four-wave mixing in the nonlinear region can effect real-time image deblurring.

  8. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George; Stetson, Howard

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto- Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner-TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  9. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George I.; Stetson, Howard K.

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto-Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner- TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  10. Real-time flood forecasting

    USGS Publications Warehouse

    Lai, C.; Tsay, T.-K.; Chien, C.-H.; Wu, I.-L.

    2009-01-01

    Researchers at the Hydroinformatic Research and Development Team (HIRDT) of the National Taiwan University undertook a project to create a real time flood forecasting model, with an aim to predict the current in the Tamsui River Basin. The model was designed based on deterministic approach with mathematic modeling of complex phenomenon, and specific parameter values operated to produce a discrete result. The project also devised a rainfall-stage model that relates the rate of rainfall upland directly to the change of the state of river, and is further related to another typhoon-rainfall model. The geographic information system (GIS) data, based on precise contour model of the terrain, estimate the regions that were perilous to flooding. The HIRDT, in response to the project's progress, also devoted their application of a deterministic model to unsteady flow of thermodynamics to help predict river authorities issue timely warnings and take other emergency measures.

  11. Real-time extended dynamic range imaging in shearography

    SciTech Connect

    Groves, Roger M.; Pedrini, Giancarlo; Osten, Wolfgang

    2008-10-20

    Extended dynamic range (EDR) imaging is a postprocessing technique commonly associated with photography. Multiple images of a scene are recorded by the camera using different shutter settings and are merged into a single higher dynamic range image. Speckle interferometry and holography techniques require a well-modulated intensity signal to extract the phase information, and of these techniques shearography is most sensitive to different object surface reflectivities as it uses self-referencing from a sheared image. In this paper the authors demonstrate real-time EDR imaging in shearography and present experimental results from a difficult surface reflectivity sample: a wooden panel painting containing gold and dark earth color paint.

  12. Periodically driven holographic superconductor

    NASA Astrophysics Data System (ADS)

    Li, Wei-Jia; Tian, Yu; Zhang, Hongbao

    2013-07-01

    As a first step towards our holographic investigation of the far-from-equilibrium physics of periodically driven systems at strong coupling, we explore the real time dynamics of holographic superconductor driven by a monochromatically alternating electric field with various frequencies. As a result, our holographic superconductor is driven to the final oscillating state, where the condensate is suppressed and the oscillation frequency is controlled by twice of the driving frequency. In particular, in the large frequency limit, the three distinct channels towards the final steady state are found, namely under damped to superconducting phase, over damped to superconducting and normal phase, which can be captured essentially by the low lying spectrum of quasi-normal modes in the time averaged approximation, reminiscent of the effective field theory perspective.

  13. Clinical virology in real time.

    PubMed

    Niesters, Hubert G M

    2002-12-01

    The ability to detect nucleic acids has had and still has a major impact on diagnostics in clinical virology. Both quantitative and qualitative techniques, whether signal or target amplification based systems, are currently used routinely in most if not all virology laboratories. Technological improvements, from automated sample isolation to real time amplification technology, have given the ability to develop and introduce systems for most viruses of clinical interest, and to obtain clinical relevant information needed for optimal antiviral treatment options. Both polymerase chain reaction (PCR) and nucleic acid sequence-based amplification (NASBA) can currently be used together with real time detection to generate results in a short turn-around time and to determine whether variants relevant for antiviral resistance are present. These new technologies enable the introduction of an individual patient disease management concept. Within our clinical setting, we have introduced this e.g. for quantitative detection of Epstein-Barr Virus (EBV) in T-dell depleted allogeneic stem cell transplant patients. This enabled us to develop models for pre-emptive anti B-cell immunotherapy for EBV reactivation, thereby effectively reducing not the incidence of EBV-lymphoproliferative disease but the virus related mortality. Furthermore, additional clinically relevant viruses can now easily be detected simultaneously. It also becomes more feasible to introduce molecular testing for those viruses that can easily be detected using classical virological methods, like culture techniques or antigen detection. Prospective studies are needed to evaluate the clinical importance of the additional positive samples detected. It should however be made clear that a complete exchange of technologies is unlikely to occur, and that some complementary technologies should stay operational enabling the discovery of new viruses. The implementation of these molecular diagnostic technologies furthermore

  14. Mobile real time radiography system

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.

    1997-11-01

    A 450-keV Mobile Real Time Radiography (RTR) System was delivered to Los Alamos National Laboratory (LANL) in January 1996. It was purchased to inspect containers of radioactive waste produced at (LANL). Since its delivery it has been used to radiograph more than 600 drums of radioactive waste at various LANL sites. It has the capability of inspecting waste containers of various sizes from <1-gal. buckets up to standard waste boxes (SWB, dimensions 54.5 in. x 71 in. x 37 in.). It has three independent x-ray acquisition formats. The primary system used is a 12- in. image intensifier, the second is a 36-in. linear diode array (LDA) and the last is an open system. It is fully self contained with on board generator, HVAC, and a fire suppression system. It is on a 53-ft long x 8-ft. wide x 14-ft. high trailer that can be moved over any highway requiring only an easily obtainable overweight permit because it weights {approximately}38 tons. It was built to conform to industry standards for a cabinet system which does not require an exclusion zone. The fact that this unit is mobile has allowed us to operate where the waste is stored, rather than having to move the waste to a fixed facility.

  15. Real-Time Nonlinear Optical Information Processing.

    DTIC Science & Technology

    1979-06-01

    operations aree presented. One approach realizes the halftone method of nonlinear optical processing in real time by replacing the conventional...photographic recording medium with a real-time image transducer. In the second approach halftoning is eliminated and the real-time device is used directly

  16. Students Collecting Real time Data

    NASA Astrophysics Data System (ADS)

    Miller, P.

    2006-05-01

    Students Collecting Real-Time Data The Hawaiian Islands Humpback Whale National Marine Sanctuary has created opportunities for middle and high school students to become Student Researchers and to be involved in real-time marine data collection. It is important that we expose students to different fields of science and encourage them to enter scientific fields of study. The Humpback Whale Sanctuary has an education visitor center in Kihei, Maui. Located right on the beach, the site has become a living classroom facility. There is a traditional Hawaiian fishpond fronting the property. The fishpond wall is being restored, using traditional methods. The site has the incredible opportunity of incorporating Hawaiian cultural practices with scientific studies. The Sanctuary offers opportunities for students to get involved in monitoring and data collection studies. Invasive Seaweed Study: Students are collecting data on invasive seaweed for the University of Hawaii. They pull a large net through the shallow waters. Seaweed is sorted, identified and weighed. The invasive seaweeds are removed. The data is recorded and sent to UH. Remote controlled monitoring boats: The sanctuary has 6 boogie board sized remote controlled boats used to monitor reefs. Boats have a camera with lights on the underside. The boats have water quality monitoring devices and GPS units. The video from the underwater camera is transmitted via a wireless transmission. Students are able to monitor the fish, limu and invertebrate populations on the reef and collect water quality data via television monitors or computers. The boat can also pull a small plankton tow net. Data is being compiled into data bases. Artificial Reef Modules: The Sanctuary has a scientific permit from the state to build and deploy artificial reef modules. High school students are designing and building modules. These are deployed out in the Fishpond fronting the Sanctuary site and students are monitoring them on a weekly basis

  17. Holographic Interferometry based on photorefractive crystal to measure 3D thermo-elastic distortion of composite structures and comparison with finite element models

    NASA Astrophysics Data System (ADS)

    Thizy, C.; Eliot, F.; Ballhause, D.; Olympio, K. R.; Kluge, R.; Shannon, A.; Laduree, G.; Logut, D.; Georges, M. P.

    2013-04-01

    Thermo-elastic distortions of composite structures have been measured by a holographic camera using a BSO photorefractive crystal as the recording medium. The first test campaign (Phase 1) was performed on CFRP struts with titanium end-fittings glued to the tips of the strut. The samples were placed in a vacuum chamber. The holographic camera was located outside the chamber and configured with two illuminations to measure the relative out-of-plane and in-plane (in one direction) displacements. The second test campaign (Phase 2) was performed on a structure composed of a large Silicon Carbide base plate supported by 3 GFRP struts with glued Titanium end-fittings. Thermo-elastic distortions have been measured with the same holographic camera used in phase 1, but four illuminations, instead of two, have been used to provide the three components of displacement. This technique was specially developed and validated during the phase 2 in CSL laboratory. The system has been designed to measure an object size of typically 250x250 mm2; the measurement range is such that the sum of the largest relative displacements in the three measurement directions is maximum 20 μm. The validation of the four-illuminations technique led to measurement uncertainties of 120 nm for the relative in-plane and out-of-plane displacements, 230 nm for the absolute in-plane displacement and 400 nm for the absolute out-of-plane displacement. For both campaigns, the test results have been compared to the predictions obtained by finite element analyses and the correlation of these results was good.

  18. Real-Time Data Display

    NASA Technical Reports Server (NTRS)

    Pedings, Marc

    2007-01-01

    RT-Display is a MATLAB-based data acquisition environment designed to use a variety of commercial off-the-shelf (COTS) hardware to digitize analog signals to a standard data format usable by other post-acquisition data analysis tools. This software presents the acquired data in real time using a variety of signal-processing algorithms. The acquired data is stored in a standard Operator Interactive Signal Processing Software (OISPS) data-formatted file. RT-Display is primarily configured to use the Agilent VXI (or equivalent) data acquisition boards used in such systems as MIDDAS (Multi-channel Integrated Dynamic Data Acquisition System). The software is generalized and deployable in almost any testing environment, without limitations or proprietary configuration for a specific test program or project. With the Agilent hardware configured and in place, users can start the program and, in one step, immediately begin digitizing multiple channels of data. Once the acquisition is completed, data is converted into a common binary format that also can be translated to specific formats used by external analysis software, such as OISPS and PC-Signal (product of AI Signal Research Inc.). RT-Display at the time of this reporting was certified on Agilent hardware capable of acquisition up to 196,608 samples per second. Data signals are presented to the user on-screen simultaneously for 16 channels. Each channel can be viewed individually, with a maximum capability of 160 signal channels (depending on hardware configuration). Current signal presentations include: time data, fast Fourier transforms (FFT), and power spectral density plots (PSD). Additional processing algorithms can be easily incorporated into this environment.

  19. Holin triggering in real time.

    PubMed

    White, Rebecca; Chiba, Shinobu; Pang, Ting; Dewey, Jill S; Savva, Christos G; Holzenburg, Andreas; Pogliano, Kit; Young, Ry

    2011-01-11

    During λ infections, the holin S105 accumulates harmlessly in the membrane until, at an allele-specific time, suddenly triggering to form irregular holes of unprecedented size (>300 nm), releasing the endolysin from the cytoplasm, resulting in lysis within seconds. Here we used a functional S105-GFP chimera and real-time deconvolution fluorescence microscopy to show that the S105-GFP fusion accumulated in a uniformly distributed fashion, until suddenly, within 1 min, it formed aggregates, or rafts, at the time of lethal triggering. Moreover, the isogenic fusion to a nonlethal S105 mutant remained uniformly distributed, whereas a fusion to an early-lysing mutant showed early triggering and early raft formation. Protein accumulation rates of the WT, early, and nonlethal alleles were identical. Fluorescence recovery after photobleaching (FRAP) revealed that the nonlethal mutant and untriggered WT hybrids were highly mobile in the membrane, whereas the WT raft was essentially immobile. Finally, an antiholin allele, S105(ΔTMD1)-mcherryfp, in the product of which the S105 sequence deleted for the first transmembrane domain was fused to mCherryFP. This hybrid retained full antiholin activity, in that it blocked lethal hole formation by the S105-GFP fusion, accumulated uniformly throughout the host membrane and prevented the S105-GFP protein from forming rafts. These findings suggest that phage lysis occurs when the holin reaches a critical concentration and nucleates to form rafts, analogous to the initiation of purple membrane formation after the induction of bacteriorhodopsin in halobacteria. This model for holin function may be relevant for processes in mammalian cells, including the release of nonenveloped viruses and apoptosis.

  20. Holin triggering in real time

    PubMed Central

    White, Rebecca; Chiba, Shinobu; Pang, Ting; Dewey, Jill S.; Savva, Christos G.; Holzenburg, Andreas; Pogliano, Kit; Young, Ry

    2011-01-01

    During λ infections, the holin S105 accumulates harmlessly in the membrane until, at an allele-specific time, suddenly triggering to form irregular holes of unprecedented size (>300 nm), releasing the endolysin from the cytoplasm, resulting in lysis within seconds. Here we used a functional S105–GFP chimera and real-time deconvolution fluorescence microscopy to show that the S105–GFP fusion accumulated in a uniformly distributed fashion, until suddenly, within 1 min, it formed aggregates, or rafts, at the time of lethal triggering. Moreover, the isogenic fusion to a nonlethal S105 mutant remained uniformly distributed, whereas a fusion to an early-lysing mutant showed early triggering and early raft formation. Protein accumulation rates of the WT, early, and nonlethal alleles were identical. Fluorescence recovery after photobleaching (FRAP) revealed that the nonlethal mutant and untriggered WT hybrids were highly mobile in the membrane, whereas the WT raft was essentially immobile. Finally, an antiholin allele, S105ΔTMD1–mcherryfp, in the product of which the S105 sequence deleted for the first transmembrane domain was fused to mCherryFP. This hybrid retained full antiholin activity, in that it blocked lethal hole formation by the S105–GFP fusion, accumulated uniformly throughout the host membrane and prevented the S105–GFP protein from forming rafts. These findings suggest that phage lysis occurs when the holin reaches a critical concentration and nucleates to form rafts, analogous to the initiation of purple membrane formation after the induction of bacteriorhodopsin in halobacteria. This model for holin function may be relevant for processes in mammalian cells, including the release of nonenveloped viruses and apoptosis. PMID:21187415

  1. Dynamic digital speckle interferometry applied to optical diagnosis of gas-liquid phase change

    NASA Astrophysics Data System (ADS)

    Song, Yaozu; Zhang, Hongling; Zhang, Wei; Jiao, Tianfeng

    2001-11-01

    In this paper, a Dynamic Digital Speckle Interferometry (DDSI) applied to optical diagnosis of gas-liquid phase change is proposed. The basic principle and experimental system of the DDSI are presented. This technology of flow optical diagnosis has the following three main advantages. First, DDSI uses a CCD camera as record device of a specklegram and a microcomputer, which processes the specklegrams to obtain a speckle interferogram. Therefore, the DDSI does not need the photographic film and optical dark room that usually are needed for holographic interferometry and speckle photography. Second, in DDSI technique, the information of density field in flow is obtained by using a double exposure with and without flow variation respectively. As a result, it can automatically eliminate the effect of the density nonuniformity of the optical windows of test section on the density measurement (like holographic interferometry). Third, the DDSI can be used for dynamic visualization and real time measurement of continuous variation of density with time in flow (like M-Z interferometry). The gas-liquid phase change process of freon R13 is investigated experimentally. By means of the DDSI technique, both density distributions in gas phase and liquid phase of R13, which are located on two sides of gas-liquid interface respectively, can be measured when gas-liquid phase change occurs. It is also observed that the interface between gas-phase and liquid-phase has a thickness of the order of hundreds micrometers, when the temperature of R13 flow comes close to its critical temperature. The variation laws of the interface thickness with the temperature of R13 are discussed. The interface behaviors of movement, disappearance and renewal are presented. The investigations show that DDSI is very suitable for the optical diagnosis of gas-liquid phase change in mini or micro scale. It provides an effective method for experimental investigations on heat transfer and flow in mini or micro

  2. The goldstone real-time connected element interferometer

    NASA Technical Reports Server (NTRS)

    Edwards, C., Jr.; Rogstad, D.; Fort, D.; White, L.; Iijima, B.

    1992-01-01

    Connected element interferometry (CEI) is a technique of observing a celestial radio source at two spatially separated antennas and then interfering the received signals to extract the relative phase of the signal at the two antennas. The high precision of the resulting phase delay data type can provide an accurate determination of the angular position of the radio source relative to the baseline vector between the two stations. This article describes a recently developed connected element interferometer on a 21-km baseline between two antennas at the Deep Space Network's Goldstone, California, tracking complex. Fiber-optic links are used to transmit the data to a common site for processing. The system incorporates a real-time correlator to process these data in real time. The architecture of the system is described, and observational data are presented to characterize the potential performance of such a system. The real-time processing capability offers potential advantages in terms of increased reliability and improved delivery of navigational data for time-critical operations. Angular accuracies of 50-100 nrad are achievable on this baseline.

  3. Research in Distributed Real-Time Systems

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.

    1997-01-01

    This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

  4. Large-memory real-time multichannel multiplexed pattern recognition

    NASA Astrophysics Data System (ADS)

    Gregory, D. A.; Liu, H. K.

    1984-12-01

    The principle and experimental design of a real-time multichannel multiplexed optical pattern recognition system via use of a 25-focus dichromated gelatin holographic lens (hololens) are described. Each of the 25 foci of the hololens may have a storage and matched filtering capability approaching that of a single-lens correlator. If the space-bandwidth product of an input image is limited, as is true in most practical cases, the 25-focus hololens system has 25 times the capability of a single lens. Experimental results have shown that the interfilter noise is not serious. The system has already demonstrated the storage and recognition of over 70 matched filters - which is a larger capacity than any optical pattern recognition system reported to date.

  5. Real-time human face recognition system with high parallelism

    NASA Astrophysics Data System (ADS)

    Feng, Wenyi; He, Qingsheng; Yan, Yingbai; Jin, Guofan; Wu, Minxian

    1999-10-01

    Volume holographic associative storage in a photorefractive crystal provides an inherent mechanism to develop a multichannel correlation system for real-time human face recognition with high parallelism. Wavelet transform is introduced to improve parallelism and discrimination of the system. Parameters of the system are optimized for maximum parallelism under limitation of hardware in this paper. Two factors mainly relative to parallelism of the system, dynamic scanning scope of the reference beam and angle interval of the 2D scanning setup, are analyzed. In our experiments, correlation outputs between an input human face and hundreds of face templates are obtained instantly in parallel. It can be recognized by simply identifying position of the correlation peak with highest intensity. Invariance of the system for human face recognition is also studied. A novel method to recognize an input human face of any rotation angle is proposed and testified by experiments.

  6. Large-memory real-time multichannel multiplexed pattern recognition

    NASA Technical Reports Server (NTRS)

    Gregory, D. A.; Liu, H. K.

    1984-01-01

    The principle and experimental design of a real-time multichannel multiplexed optical pattern recognition system via use of a 25-focus dichromated gelatin holographic lens (hololens) are described. Each of the 25 foci of the hololens may have a storage and matched filtering capability approaching that of a single-lens correlator. If the space-bandwidth product of an input image is limited, as is true in most practical cases, the 25-focus hololens system has 25 times the capability of a single lens. Experimental results have shown that the interfilter noise is not serious. The system has already demonstrated the storage and recognition of over 70 matched filters - which is a larger capacity than any optical pattern recognition system reported to date.

  7. Large-memory real-time multichannel multiplexed pattern recognition

    NASA Technical Reports Server (NTRS)

    Gregory, D. A.; Liu, H. K.

    1984-01-01

    The principle and experimental design of a real-time multichannel multiplexed optical pattern recognition system via use of a 25-focus dichromated gelatin holographic lens (hololens) are described. Each of the 25 foci of the hololens may have a storage and matched filtering capability approaching that of a single-lens correlator. If the space-bandwidth product of an input image is limited, as is true in most practical cases, the 25-focus hololens system has 25 times the capability of a single lens. Experimental results have shown that the interfilter noise is not serious. The system has already demonstrated the storage and recognition of over 70 matched filters - which is a larger capacity than any optical pattern recognition system reported to date.

  8. Accurate phase-shifting digital interferometry.

    PubMed

    Atlan, M; Gross, M; Absil, E

    2007-06-01

    In phase-shifting interferometry experiments, the accuracy of the phase shift is a major issue. Many experimental and data analyses are done to cancel phase-shift errors inherent to the modulation techniques used. We propose to remove most of the phase-shift error by recourse to a frequency-shifting method. This approach can be applied to both holography and interferometry. We validate the idea with a holographic experiment.

  9. Real time programming environment for Windows

    SciTech Connect

    LaBelle, D.R.

    1998-04-01

    This document provides a description of the Real Time Programming Environment (RTProE). RTProE tools allow a programmer to create soft real time projects under general, multi-purpose operating systems. The basic features necessary for real time applications are provided by RTProE, leaving the programmer free to concentrate efforts on his specific project. The current version supports Microsoft Windows{trademark} 95 and NT. The tasks of real time synchronization and communication with other programs are handled by RTProE. RTProE includes a generic method for connecting a graphical user interface (GUI) to allow real time control and interaction with the programmer`s product. Topics covered in this paper include real time performance issues, portability, details of shared memory management, code scheduling, application control, Operating System specific concerns and the use of Computer Aided Software Engineering (CASE) tools. The development of RTProE is an important step in the expansion of the real time programming community. The financial costs associated with using the system are minimal. All source code for RTProE has been made publicly available. Any person with access to a personal computer, Windows 95 or NT, and C or FORTRAN compilers can quickly enter the world of real time modeling and simulation.

  10. Evaluation of intrusive mechanics of the type "segmented arch" on a macerated human skull using the laser reflection technique and holographic interferometry.

    PubMed

    Dermaut, L R; Vanden Bulcke, M M

    1986-03-01

    Twelve different systems of intrusion, based on the principle of the "segmented arch," were evaluated on a macerated human skull. The number of teeth involved in the anterior unit and the location of the application points of intrusive force were considered to be variables. Initial displacements of the anterior teeth after loading were registered by means of the laser reflection technique and double exposure holographic recordings. An attempt was made to define "this" intrusive system, achieving the most genuine intrusion (for definition, see text) without flaring of the teeth. When two central incisors were incorporated in the sectional wire, strong torque forces appeared, especially when the intrusive forces seized more distally. When four or six anterior teeth were pinned in the sectional wire, tooth movement seemed to be under better control. When the six front teeth were incorporated in the sectional wire, the center of resistance (for definition, see text) was located more to the distal side of the canines. It seemed more difficult, however, to define the center of resistance of the four incisors; it was situated approximately distal to the lateral incisors. In some of the intrusive systems, the teeth underwent independent mesial or distal rotations. This was easily observed with the laser measuring techniques used.

  11. Real Time Superresolution by Means of an Ultrasonic Light Diffractor and TV System.

    PubMed

    Sato, T; Ueda, M; Ikeda, T

    1974-06-01

    The change of angle and the shift of frequency of light by an ultrasonic light diffractor are used for real time realization of a holographic superresolution system. A TV system and an electrical filter are used to pick up the desired image hologram from the superposed, images, which are obtained by a number of object-beam lights and reference beams. For two-dimensional as well as one-dimensional objects, images superresolved three to five times are displayed on a TV monitor in real time.

  12. One-shot dual-wavelength in-line digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    León-Rodríguez, Miguel; Rodríguez-Vera, Ramón; Rayas, Juan A.; Flores-Moreno, J. M.

    2013-07-01

    In this work, we propose a dual-wavelength in-line digital holographic microscopy (DHM) configuration in order to eliminate the conjugate image and reach the maximum resolution of CCD. By using this configuration, two holograms are acquired in one shot. Our method is based not only on the recordings of two holograms at slightly different planes, but also on the diffraction patterns formed with two wavelengths. With this experimental setup, we are able to analyze fast dynamic processes at the microscopic scale in real time. Theoretical evaluation, computer simulations and experimental results validate our proposal. The experimental results are obtained using a phase-amplitude object and compared with those calculated from the well-established phase-shifting interferometry technique. As far as we know, in-axis configuration with a single exposure has not been used in DHM, as we present in this paper.

  13. The ALMA Real Time Control System

    NASA Astrophysics Data System (ADS)

    Kern, Jeffrey S.; Juerges, Thomas A.; Marson, Ralph G.

    2009-01-01

    The Atacama Large Millimeter Array (ALMA) is a revolutionary millimeter and submillimeter array being developed on the Atacama plateau of northern Chile. An international partnership lead by NRAO, ESO, and NAOJ this powerful and flexible telescope will provide unprecedented observations of this relatively unexplored frequency range. The control subsystem for the Atacama Large Millimeter Array must coordinate the monitor and control of at least sixty six antennas (in four different styles), two correlators, and all of the ancillary equipment (samplers, local oscillators, front ends, etc.). This equipment will be spread over tens of kilometers and operated remotely. Operation of the array requires a robust, scalable, and maintainable real time control system. The real time control system is responsible for monitoring and control of any devices where there are fixed deadlines. Examples in the ALMA context are antenna pointing and fringe tracking. Traditionally the real time portion of a large software system is an intricate and error prone portion of the software. As a result the real time portion is very expensive in terms of effort expended both during construction and during maintenance phases of a project. The ALMA real time control system uses a Linux based real time operating system to interact with the hardware and the CORBA based ALMA Common Software to communicate in the distributed computing environment. Mixing the requirements of real time computing and the non-deterministic CORBA middleware has produced an interesting design. We discuss the architecture, design, and implementation of the ALMA real time control system. Highlight some lessons learned along the way, and justify our assertion that this should be the last large scale real time control system in radio astronomy.

  14. Real-time medical applications and telecommunications.

    PubMed

    Stravs, M

    1999-01-01

    Telecommunications play an important role in telemedicine. Many forms of telecommunication services based on different telecommunication technologies are developed for various needs. The paper deals with complex real-time applications which demand high telecommunication requirements. At the beginning, medical applications are categorised and real-time applications qualified as multimedia applications. Requirements for multimedia elements are listed separately. Later on, short introduction of related telecommunication protocols is given. Real-time medical applications can show their ability in case of guaranteed quality of services delivered by telecommunication network as it is explained in the end.

  15. Achieving real-time performance in FIESTA

    NASA Technical Reports Server (NTRS)

    Wilkinson, William; Happell, Nadine; Miksell, Steve; Quillin, Robert; Carlisle, Candace

    1988-01-01

    The Fault Isolation Expert System for TDRSS Applications (FIESTA) is targeted for operation in a real-time online environment. Initial stages of the prototype development concentrated on acquisition and representation of the knowledge necessary to isolate faults in the TDRSS Network. Recent efforts focused on achieving real-time performance including: a discussion of the meaning of FIESTA real-time requirements, determination of performance levels (benchmarking) and techniques for optimization. Optimization techniques presented include redesign of critical relations, filtering of redundant data and optimization of patterns used in rules. Results are summarized.

  16. Real Time Computer Graphics From Body Motion

    NASA Astrophysics Data System (ADS)

    Fisher, Scott; Marion, Ann

    1983-10-01

    This paper focuses on the recent emergence and development of real, time, computer-aided body tracking technologies and their use in combination with various computer graphics imaging techniques. The convergence of these, technologies in our research results, in an interactive display environment. in which multipde, representations of a given body motion can be displayed in real time. Specific reference, to entertainment applications is described in the development of a real time, interactive stage set in which dancers can 'draw' with their bodies as they move, through the space. of the stage or manipulate virtual elements of the set with their gestures.

  17. Real time sensor for therapeutic radiation delivery

    DOEpatents

    Bliss, M.; Craig, R.A.; Reeder, P.L.

    1998-01-06

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body. 14 figs.

  18. Real-time monitoring of landslides

    USGS Publications Warehouse

    Reid, Mark E.; LaHusen, Richard G.; Baum, Rex L.; Kean, Jason W.; Schulz, William H.; Highland, Lynn M.

    2012-01-01

    Landslides cause fatalities and property damage throughout the Nation. To reduce the impact from hazardous landslides, the U.S. Geological Survey develops and uses real-time and near-real-time landslide monitoring systems. Monitoring can detect when hillslopes are primed for sliding and can provide early indications of rapid, catastrophic movement. Continuous information from up-to-the-minute or real-time monitoring provides prompt notification of landslide activity, advances our understanding of landslide behavior, and enables more effective engineering and planning efforts.

  19. Real time sensor for therapeutic radiation delivery

    DOEpatents

    Bliss, Mary; Craig, Richard A.; Reeder, Paul L.

    1998-01-01

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body.

  20. Achieving real-time performance in FIESTA

    NASA Technical Reports Server (NTRS)

    Wilkinson, William; Happell, Nadine; Miksell, Steve; Quillin, Robert; Carlisle, Candace

    1988-01-01

    The Fault Isolation Expert System for TDRSS Applications (FIESTA) is targeted for operation in a real-time online environment. Initial stages of the prototype development concentrated on acquisition and representation of the knowledge necessary to isolate faults in the TDRSS Network. Recent efforts focused on achieving real-time performance including: a discussion of the meaning of FIESTA real-time requirements, determination of performance levels (benchmarking) and techniques for optimization. Optimization techniques presented include redesign of critical relations, filtering of redundant data and optimization of patterns used in rules. Results are summarized.

  1. Automated Digital Analysis Of Holographic Interferograms Of Pure Translations

    NASA Astrophysics Data System (ADS)

    Choudry, A.; Frankena, H. J.; van Beek, J. W.

    1983-10-01

    Holographic interferometry is a versatile technique for non-tactile measurement of changes in a wide variety of physical variables such as temperature, strain, position etc. It has a great potential for becoming an important metrologic technique in industrial applications. For holographic interferometry to become more attractive for industrial practice the problem of quantitative analysis of the patterns and thereby eliciting reliable values of the relevant parameters has to be addressed. In an attempt to calibrate the technique of holographic interferometry and ascertain the reliability of the subsequent digital analysis, we have chosen precisely known translations as a basis. Holographic interferograms taken from these are analysed manually and by digital techniques specially developed for such patterns. The results are promising enough to indicate the feasibility of automated digital analysis for determining translations within an acceptable accuracy. Some details of the evaluation techniques, along with a brief discussion of the preliminary results are presented.

  2. Digital holographic setups for phase object measurements in micro and macro scale

    NASA Astrophysics Data System (ADS)

    Lédl, Vít; Psota, Pavel; Doleček, Roman; Vít, Tomáš

    2015-05-01

    The measurement of properties of so called phase objects is being solved for more than one Century starting probably with schlieren technique 1. Classical interferometry served as a great measurement tool for several decades and was replaced by holographic interferometry, which disposes with many benefits when compared to classical interferometry. Holographic interferometry undergone an enormous development in last decade when digital holography has been established as a standard technique and most of the drawbacks were solved. The paper deals with scope of the huge applicability of digital holographic interferometry in heat and mass transfer measurement from micro to macro scale and from simple 2D measurement up to complex tomographic techniques. Recently the very complex experimental setups are under development in our labs combining many techniques leading to digital holographic micro tomography methods.

  3. Real-Time Ada Problem Study

    DTIC Science & Technology

    1989-03-24

    define this set of problems. The authors were chosen because of their proven expertise in real-time development with Ada. They could enrich the results of...for Real-Time Embedded Systems". LabTek Corporation, the author , had proven expertise in embedded system design utilizing Motorola MC680XO- based...processors. The second report is entitledSoftware Enineering Problems Using Ada in Computers Integral to Weapons Systems. Its author , Sonicraft, had

  4. Real-time scheduling using minimum search

    NASA Technical Reports Server (NTRS)

    Tadepalli, Prasad; Joshi, Varad

    1992-01-01

    In this paper we consider a simple model of real-time scheduling. We present a real-time scheduling system called RTS which is based on Korf's Minimin algorithm. Experimental results show that the schedule quality initially improves with the amount of look-ahead search and tapers off quickly. So it sppears that reasonably good schedules can be produced with a relatively shallow search.

  5. Real-time interferometric synthetic aperture microscopy

    PubMed Central

    Ralston, Tyler S.; Marks, Daniel L.; Carney, P. Scott; Boppart, Stephen A.

    2010-01-01

    An interferometric synthetic aperture microscopy (ISAM) system design with real-time 2D cross-sectional processing is described in detail. The system can acquire, process, and display the ISAM reconstructed images at frame rates of 2.25 frames per second for 512 × 1024 pixel images. This system provides quantitatively meaningful structural information from previously indistinguishable scattering intensities and provides proof of feasibility for future real-time ISAM systems. PMID:18542337

  6. The LAA real-time benchmarks

    SciTech Connect

    Block, R.K.; Krischer, W.; Lone, S.

    1989-04-01

    In the context of the LAA detector development program a subgroup Real Time Data Processing has tackled the problem of intelligent triggering. The main goal of this group is to show how fast digital devices, implemented as custom-made or commercial processors, can execute some basic algorithms, and how they can be embedded in the data flow between detector readout components and fully programmable commercial processors, which are expected to be the final data processing filter in real time.

  7. Real Time Cockpit Resource Management (CRM) Training

    DTIC Science & Technology

    2010-10-01

    i AFRL-RH-AZ-TR-2011-0005 Real Time Cockpit Resource Management ( CRM ) Training David Kaiser Jeffery Eberhart Chris Butler Gregg...Resource Management ( CRM ) Training 5a. CONTRACT NUMBER FA8650-08-C-6848 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kaiser, David...283 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39-18 Real Time Cockpit Resource Management ( CRM ) Training 4 Table of

  8. Computer-generated real-time digital holography: first time use in clinical medical imaging.

    PubMed

    Bruckheimer, Elchanan; Rotschild, Carmel; Dagan, Tamir; Amir, Gabriel; Kaufman, Aviad; Gelman, Shaul; Birk, Einat

    2016-08-01

    Assessment of the feasibility of creating real-time interactive 3D digital holograms in a standard catheterization laboratory. 3D medical images are typically displayed and interacted with on 2D screens limiting their usefulness. A digital computer-generated real-time holographic display of patient's 3D data could provide a spatially accurate image with all the depth cues and afford interaction within the image. We performed a feasibility study of creating real-time interactive 3D digital holograms with a purpose-built prototype using intraprocedural data from 3D rotational angiography and live 3D transesophageal echocardiography. The primary objective was to demonstrate that all the anatomical landmarks identified on standard imaging can be similarly identified using dynamic and static holographic images. The secondary objective was to demonstrate the usability of interactions with the image. Parameters were assessed by a rating scale. Eight patients were enrolled of whom five underwent transcatheter ASD closure using 3DTEE and three patients were evaluated by 3D rotational angiography. In all cases dynamic real-time and static 3D holograms were created in standard cath lab conditions. Four individual observers identified all anatomical landmarks on the holographic display independently from the 2D display. Interactions with the hologram including marking, cropping and rotation were performed. There were no adverse events. This study demonstrates, for the first time, the feasibility of generating high quality, clinically relevant, 3D real-time colour dynamic holograms in a standard clinical setting with real patient volumetric data. The impact of computer-generated holography needs to be evaluated in controlled clinical trials. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  9. Analysis of real-time vibration data

    USGS Publications Warehouse

    Safak, E.

    2005-01-01

    In recent years, a few structures have been instrumented to provide continuous vibration data in real time, recording not only large-amplitude motions generated by extreme loads, but also small-amplitude motions generated by ambient loads. The main objective in continuous recording is to track any changes in structural characteristics, and to detect damage after an extreme event, such as an earthquake or explosion. The Fourier-based spectral analysis methods have been the primary tool to analyze vibration data from structures. In general, such methods do not work well for real-time data, because real-time data are mainly composed of ambient vibrations with very low amplitudes and signal-to-noise ratios. The long duration, linearity, and the stationarity of ambient data, however, allow us to utilize statistical signal processing tools, which can compensate for the adverse effects of low amplitudes and high noise. The analysis of real-time data requires tools and techniques that can be applied in real-time; i.e., data are processed and analyzed while being acquired. This paper presents some of the basic tools and techniques for processing and analyzing real-time vibration data. The topics discussed include utilization of running time windows, tracking mean and mean-square values, filtering, system identification, and damage detection.

  10. Composite materials inspection. [ultrasonic vibration holographic NDT

    NASA Technical Reports Server (NTRS)

    Erf, R. K.

    1974-01-01

    Investigation of the application requirements, advantages, and limitations of nondestructive testing by a technique of ultrasonic-vibration holographic-interferometry readout used in a production control facility for the inspection of a single product such as composite compressor blades. It is shown that, for the detection and characterization of disbonds in composite material structures, this technique may represent the most inclusive test method.

  11. REAL TIME SYSTEM OPERATIONS 2006-2007

    SciTech Connect

    Eto, Joseph H.; Parashar, Manu; Lewis, Nancy Jo

    2008-08-15

    The Real Time System Operations (RTSO) 2006-2007 project focused on two parallel technical tasks: (1) Real-Time Applications of Phasors for Monitoring, Alarming and Control; and (2) Real-Time Voltage Security Assessment (RTVSA) Prototype Tool. The overall goal of the phasor applications project was to accelerate adoption and foster greater use of new, more accurate, time-synchronized phasor measurements by conducting research and prototyping applications on California ISO's phasor platform - Real-Time Dynamics Monitoring System (RTDMS) -- that provide previously unavailable information on the dynamic stability of the grid. Feasibility assessment studies were conducted on potential application of this technology for small-signal stability monitoring, validating/improving existing stability nomograms, conducting frequency response analysis, and obtaining real-time sensitivity information on key metrics to assess grid stress. Based on study findings, prototype applications for real-time visualization and alarming, small-signal stability monitoring, measurement based sensitivity analysis and frequency response assessment were developed, factory- and field-tested at the California ISO and at BPA. The goal of the RTVSA project was to provide California ISO with a prototype voltage security assessment tool that runs in real time within California ISO?s new reliability and congestion management system. CERTS conducted a technical assessment of appropriate algorithms, developed a prototype incorporating state-of-art algorithms (such as the continuation power flow, direct method, boundary orbiting method, and hyperplanes) into a framework most suitable for an operations environment. Based on study findings, a functional specification was prepared, which the California ISO has since used to procure a production-quality tool that is now a part of a suite of advanced computational tools that is used by California ISO for reliability and congestion management.

  12. Holographic characterization of protein aggregates

    NASA Astrophysics Data System (ADS)

    Wang, Chen; Zhong, Xiao; Ruffner, David; Stutt, Alexandra; Philips, Laura; Ward, Michael; Grier, David

    Holographic characterization directly measures the size distribution of subvisible protein aggregates in suspension and offers insights into their morphology. Based on holographic video microscopy, this analytical technique records and interprets holograms of individual aggregates in protein solutions as they flow down a microfluidic channel, without requiring labeling or other exceptional sample preparation. The hologram of an individual protein aggregate is analyzed in real time with the Lorenz-Mie theory of light scattering to measure that aggregate's size and optical properties. Detecting, counting and characterizing subvisible aggregates proceeds fast enough for time-resolved studies, and lends itself to tracking trends in protein aggregation arising from changing environmental factors. No other analytical technique provides such a wealth of particle-resolved characterization data in situ. Holographic characterization promises accelerated development of therapeutic protein formulations, improved process control during manufacturing, and streamlined quality assurance during storage and at the point of use. Mrsec and MRI program of the NSF, Spheryx Inc.

  13. Hard Real-Time: C++ Versus RTSJ

    NASA Technical Reports Server (NTRS)

    Dvorak, Daniel L.; Reinholtz, William K.

    2004-01-01

    In the domain of hard real-time systems, which language is better: C++ or the Real-Time Specification for Java (RTSJ)? Although ordinary Java provides a more productive programming environment than C++ due to its automatic memory management, that benefit does not apply to RTSJ when using NoHeapRealtimeThread and non-heap memory areas. As a result, RTSJ programmers must manage non-heap memory explicitly. While that's not a deterrent for veteran real-time programmers-where explicit memory management is common-the lack of certain language features in RTSJ (and Java) makes that manual memory management harder to accomplish safely than in C++. This paper illustrates the problem for practitioners in the context of moving data and managing memory in a real-time producer/consumer pattern. The relative ease of implementation and safety of the C++ programming model suggests that RTSJ has a struggle ahead in the domain of hard real-time applications, despite its other attractive features.

  14. Visualization of Real-Time Data

    NASA Technical Reports Server (NTRS)

    Stansifer, Ryan; Engrand, Peter

    1996-01-01

    In this project we explored various approaches to presenting real-time data from the numerous systems monitored on the space shuttle to computer users. We examined the approach that several projects at the Kennedy Space Center (KSC) used to accomplish this. We undertook to build a prototype system to demonstrate that the Internet and the Java programming language could be used to present the real-time data conveniently. Several Java programs were developed that presented real-time data in different forms including one form that emulated the display screens of the PC GOAL system which is familiar to many at KSC. Also, we developed several communications programs to supply the data continuously. Furthermore, a framework was created using the World Wide Web (WWW) to organize the collection and presentation of the real-time data. We believe our demonstration project shows the great flexibility of the approach. We had no particular use of the data in mind, instead we wanted the most general and the least complex framework possible. People who wish to view data need only know how to use a WWW browser and the address (the URL). People wanting to build WWW documents containing real-time data need only know the values of a few parameters, they do not need to program in Java or any other language. These are stunning advantages over more monolithic systems.

  15. Personnel real time dosimetry in interventional radiology.

    PubMed

    Servoli, L; Bissi, L; Fabiani, S; Magalotti, D; Placidi, P; Scorzoni, A; Calandra, A; Cicioni, R; Chiocchini, S; Dipilato, A C; Forini, N; Paolucci, M; Di Lorenzo, R; Cappotto, F P; Scarpignato, M; Maselli, A; Pentiricci, A

    2016-12-01

    Interventional radiology and hemodynamic procedures have rapidly grown in number in the past decade, increasing the importance of personnel dosimetry not only for patients but also for medical staff. The optimization of the absorbed dose during operations is one of the goals that fostered the development of real-time dosimetric systems. Indeed, introducing proper procedure optimization, like correlating dose rate measurements with medical staff position inside the operating room, the absorbed dose could be reduced. Real-time dose measurements would greatly facilitate this task through real-time monitoring and automatic data recording. Besides real-time dose monitoring could allow automatic data recording. In this work, we will describe the calibration and validation of a wireless real-time prototype dosimeter based on a new sensor device (CMOS imager). The validation measurement campaign in clinical conditions has demonstrated the prototype capability of measuring dose-rates with a frequency in the range of few Hz, and an uncertainty smaller than 10%. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  16. Real-time Enhanced Vision System

    NASA Technical Reports Server (NTRS)

    Hines, Glenn D.; Rahman, Zia-Ur; Jobson, Daniel J.; Woodell, Glenn A.; Harrah, Steven D.

    2005-01-01

    Flying in poor visibility conditions, such as rain, snow, fog or haze, is inherently dangerous. However these conditions can occur at nearly any location, so inevitably pilots must successfully navigate through them. At NASA Langley Research Center (LaRC), under support of the Aviation Safety and Security Program Office and the Systems Engineering Directorate, we are developing an Enhanced Vision System (EVS) that combines image enhancement and synthetic vision elements to assist pilots flying through adverse weather conditions. This system uses a combination of forward-looking infrared and visible sensors for data acquisition. A core function of the system is to enhance and fuse the sensor data in order to increase the information content and quality of the captured imagery. These operations must be performed in real-time for the pilot to use while flying. For image enhancement, we are using the LaRC patented Retinex algorithm since it performs exceptionally well for improving low-contrast range imagery typically seen during poor visibility conditions. In general, real-time operation of the Retinex requires specialized hardware. To date, we have successfully implemented a single-sensor real-time version of the Retinex on several different Digital Signal Processor (DSP) platforms. In this paper we give an overview of the EVS and its performance requirements for real-time enhancement and fusion and we discuss our current real-time Retinex implementations on DSPs.

  17. Characterization of real-time computers

    NASA Technical Reports Server (NTRS)

    Shin, K. G.; Krishna, C. M.

    1984-01-01

    A real-time system consists of a computer controller and controlled processes. Despite the synergistic relationship between these two components, they have been traditionally designed and analyzed independently of and separately from each other; namely, computer controllers by computer scientists/engineers and controlled processes by control scientists. As a remedy for this problem, in this report real-time computers are characterized by performance measures based on computer controller response time that are: (1) congruent to the real-time applications, (2) able to offer an objective comparison of rival computer systems, and (3) experimentally measurable/determinable. These measures, unlike others, provide the real-time computer controller with a natural link to controlled processes. In order to demonstrate their utility and power, these measures are first determined for example controlled processes on the basis of control performance functionals. They are then used for two important real-time multiprocessor design applications - the number-power tradeoff and fault-masking and synchronization.

  18. Real-time electron density measurements from Cotton-Mouton effect in JET machine

    SciTech Connect

    Brombin, M.; Boboc, A.; Zabeo, L.

    2008-10-15

    Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.

  19. Real-time electron density measurements from Cotton-Mouton effect in JET machine.

    PubMed

    Brombin, M; Boboc, A; Zabeo, L; Murari, A

    2008-10-01

    Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.

  20. Real-Time Visualization of Tissue Ischemia

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory H. (Inventor); Chrien, Thomas D. (Inventor); Eastwood, Michael L. (Inventor)

    2000-01-01

    A real-time display of tissue ischemia which comprises three CCD video cameras, each with a narrow bandwidth filter at the correct wavelength is discussed. The cameras simultaneously view an area of tissue suspected of having ischemic areas through beamsplitters. The output from each camera is adjusted to give the correct signal intensity for combining with, the others into an image for display. If necessary a digital signal processor (DSP) can implement algorithms for image enhancement prior to display. Current DSP engines are fast enough to give real-time display. Measurement at three, wavelengths, combined into a real-time Red-Green-Blue (RGB) video display with a digital signal processing (DSP) board to implement image algorithms, provides direct visualization of ischemic areas.

  1. Real-time inspection by submarine images

    NASA Astrophysics Data System (ADS)

    Tascini, Guido; Zingaretti, Primo; Conte, Giuseppe

    1996-10-01

    A real-time application of computer vision concerning tracking and inspection of a submarine pipeline is described. The objective is to develop automatic procedures for supporting human operators in the real-time analysis of images acquired by means of cameras mounted on underwater remotely operated vehicles (ROV) Implementation of such procedures gives rise to a human-machine system for underwater pipeline inspection that can automatically detect and signal the presence of the pipe, of its structural or accessory elements, and of dangerous or alien objects in its neighborhood. The possibility of modifying the image acquisition rate in the simulations performed on video- recorded images is used to prove that the system performs all necessary processing with an acceptable robustness working in real-time up to a speed of about 2.5 kn, widely greater than that the actual ROVs and the security features allow.

  2. Network protocols for real-time applications

    NASA Technical Reports Server (NTRS)

    Johnson, Marjory J.

    1987-01-01

    The Fiber Distributed Data Interface (FDDI) and the SAE AE-9B High Speed Ring Bus (HSRB) are emerging standards for high-performance token ring local area networks. FDDI was designed to be a general-purpose high-performance network. HSRB was designed specifically for military real-time applications. A workshop was conducted at NASA Ames Research Center in January, 1987 to compare and contrast these protocols with respect to their ability to support real-time applications. This report summarizes workshop presentations and includes an independent comparison of the two protocols. A conclusion reached at the workshop was that current protocols for the upper layers of the Open Systems Interconnection (OSI) network model are inadequate for real-time applications.

  3. Continuous, real time microwave plasma element sensor

    DOEpatents

    Woskov, P.P.; Smatlak, D.L.; Cohn, D.R.; Wittle, J.K.; Titus, C.H.; Surma, J.E.

    1995-12-26

    Microwave-induced plasma is described for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. 3 figs.

  4. Continuous, real time microwave plasma element sensor

    DOEpatents

    Woskov, Paul P.; Smatlak, Donna L.; Cohn, Daniel R.; Wittle, J. Kenneth; Titus, Charles H.; Surma, Jeffrey E.

    1995-01-01

    Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury.

  5. Real-time, high frequency QRS electrocardiograph

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T. (Inventor); DePalma, Jude L. (Inventor); Moradi, Saeed (Inventor)

    2006-01-01

    Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as RAZs. RAZs are displayed as go, no-go signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

  6. Machine vision for real time orbital operations

    NASA Technical Reports Server (NTRS)

    Vinz, Frank L.

    1988-01-01

    Machine vision for automation and robotic operation of Space Station era systems has the potential for increasing the efficiency of orbital servicing, repair, assembly and docking tasks. A machine vision research project is described in which a TV camera is used for inputing visual data to a computer so that image processing may be achieved for real time control of these orbital operations. A technique has resulted from this research which reduces computer memory requirements and greatly increases typical computational speed such that it has the potential for development into a real time orbital machine vision system. This technique is called AI BOSS (Analysis of Images by Box Scan and Syntax).

  7. Automated real-time software development

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Walker, Carrie K.; Turkovich, John J.

    1993-01-01

    A Computer-Aided Software Engineering (CASE) system has been developed at the Charles Stark Draper Laboratory (CSDL) under the direction of the NASA Langley Research Center. The CSDL CASE tool provides an automated method of generating source code and hard copy documentation from functional application engineering specifications. The goal is to significantly reduce the cost of developing and maintaining real-time scientific and engineering software while increasing system reliability. This paper describes CSDL CASE and discusses demonstrations that used the tool to automatically generate real-time application code.

  8. Axial Tomography from Digitized Real Time Radiography

    DOE R&D Accomplishments Database

    Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  9. Software Package For Real-Time Graphics

    NASA Technical Reports Server (NTRS)

    Malone, Jacqueline C.; Moore, Archie L.

    1991-01-01

    Software package for master graphics interactive console (MAGIC) at Western Aeronautical Test Range (WATR) of NASA Ames Research Center provides general-purpose graphical display system for real-time and post-real-time analysis of data. Written in C language and intended for use on workstation of interactive raster imaging system (IRIS) equipped with level-V Unix operating system. Enables flight researchers to create their own displays on basis of individual requirements. Applicable to monitoring of complicated processes in chemical industry.

  10. Real-Time, Interactive Sonic Boom Display

    NASA Technical Reports Server (NTRS)

    Haering, Jr., Edward A. (Inventor); Plotkin, Kenneth J. (Inventor)

    2012-01-01

    The present invention is an improved real-time, interactive sonic boom display for aircraft. By using physical properties obtained via various sensors and databases, the invention determines, in real-time, sonic boom impacts locations and intensities for aircraft traveling at supersonic speeds. The information is provided to a pilot via a display that lists a selectable set of maneuvers available to the pilot to mitigate sonic boom issues. Upon selection of a maneuver, the information as to the result of the maneuver is displayed and the pilot may proceed with making the maneuver, or provide new data to the system in order to calculate a different maneuver.

  11. Imaging of living cells in real time

    NASA Astrophysics Data System (ADS)

    Tychinsky, Vladimir P.; Koufal, Georgy E.; Perevedentseva, Elena V.; Vyshenskaia, Tatiana V.; Nikandrov, Serguei L.

    1996-12-01

    Parameters of intrinsic cell motility is one of the cell activity characteristics which can be measured in real-time. For evaluation of certain organelles velocity we propose to use high sensitivity of computer-aided phase microscope airyscan to local phase changes connected with refractive index. This method is based on periodical scanning of cell profile in direction perpendicular to organelles movement. Analysis of the obtained 2-dimensional time-coordinate matrix allows us to define organelle velocity in quasi-real time and areas of cell activity. The experiments with onion cells confirm the method applicability for cell activity investigation.

  12. Robotic real-time radiographic inspection system

    SciTech Connect

    McNair, J.

    1987-01-01

    A computer-controlled real-time radiographic system with remote robotic material handling has been developed and installed at the US Army's Yuma Proving Ground. This system is used for the nondestructive examination of a variety of munition types tested at the proving ground. This paper describes the system and its capabilities. The system consists of an overhead robot for material handling, a five-axis manipulator for positioning the item being inspected, and the real-time radiographic image acquisition and analysis equipment. The system is fully automated and uses a single minicomputer as the system controller.

  13. Real-time elastography of the prostate.

    PubMed

    Junker, D; De Zordo, T; Quentin, M; Ladurner, M; Bektic, J; Horniger, W; Jaschke, W; Aigner, F

    2014-01-01

    Palpation of organs is one of the oldest clinical examination techniques, for instance, if you think of the palpation of the breast or the digital rectal examination of the prostate, where hard palpable regions are suspicious for cancer. This is the basic principle of real-time elastography, an ultrasound technique, which is able to visualise tissue elasticity. Since prostate cancer features an increased stiffness due to the higher cell and vessel density than the normal surrounding tissue, real-time elastography has been used for several years for prostate cancer detection. This review introduces the different techniques of ultrasound elastography and furthermore summarises its limitations and potentials.

  14. Real-Time Elastography of the Prostate

    PubMed Central

    Junker, D.; De Zordo, T.; Quentin, M.; Ladurner, M.; Bektic, J.; Horniger, W.; Jaschke, W.; Aigner, F.

    2014-01-01

    Palpation of organs is one of the oldest clinical examination techniques, for instance, if you think of the palpation of the breast or the digital rectal examination of the prostate, where hard palpable regions are suspicious for cancer. This is the basic principle of real-time elastography, an ultrasound technique, which is able to visualise tissue elasticity. Since prostate cancer features an increased stiffness due to the higher cell and vessel density than the normal surrounding tissue, real-time elastography has been used for several years for prostate cancer detection. This review introduces the different techniques of ultrasound elastography and furthermore summarises its limitations and potentials. PMID:24967334

  15. Quantitative Real-Time PCR: Recent Advances.

    PubMed

    Singh, Charanjeet; Roy-Chowdhuri, Sinchita

    2016-01-01

    Quantitative real-time polymerase chain reaction is a technique for simultaneous amplification and product quantification of a target DNA as the process takes place in real time in a "closed-tube" system. Although this technique can provide an absolute quantification of the initial template copy number, quantification relative to a control sample or second sequence is typically adequate. The quantification process employs melting curve analysis and/or fluorescent detection systems and can provide amplification and genotyping in a relatively short time. Here we describe the properties and uses of various fluorescent detection systems used for quantification.

  16. Software Package For Real-Time Graphics

    NASA Technical Reports Server (NTRS)

    Malone, Jacqueline C.; Moore, Archie L.

    1991-01-01

    Software package for master graphics interactive console (MAGIC) at Western Aeronautical Test Range (WATR) of NASA Ames Research Center provides general-purpose graphical display system for real-time and post-real-time analysis of data. Written in C language and intended for use on workstation of interactive raster imaging system (IRIS) equipped with level-V Unix operating system. Enables flight researchers to create their own displays on basis of individual requirements. Applicable to monitoring of complicated processes in chemical industry.

  17. Machine vision for real time orbital operations

    NASA Technical Reports Server (NTRS)

    Vinz, Frank L.

    1988-01-01

    Machine vision for automation and robotic operation of Space Station era systems has the potential for increasing the efficiency of orbital servicing, repair, assembly and docking tasks. A machine vision research project is described in which a TV camera is used for inputing visual data to a computer so that image processing may be achieved for real time control of these orbital operations. A technique has resulted from this research which reduces computer memory requirements and greatly increases typical computational speed such that it has the potential for development into a real time orbital machine vision system. This technique is called AI BOSS (Analysis of Images by Box Scan and Syntax).

  18. Real-time Shakemap implementation in Austria

    NASA Astrophysics Data System (ADS)

    Weginger, Stefan; Jia, Yan; Papi Isaba, Maria; Horn, Nikolaus

    2017-04-01

    ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes. They are automatically generated within a few minutes after occurrence of an earthquake. We tested and included the USGS ShakeMap 4.0 (experimental code) based on python in the Antelope real-time system with local modified GMPE and Site Effects based on the conditions in Austria. The ShakeMaps are provided in terms of Intensity, PGA, PGV and PSA. Future presentation of ShakeMap contour lines and Ground Motion Parameter with interactive maps and data exchange over Web-Services are shown.

  19. Mobile waste inspection real time radiography system

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.; Rael, C.; Martinez, F.; Mendez, J.

    1995-10-01

    The 450-KeV Mobile Real Time Radiography System was designed and purchased to inspect containers of radioactive waste produced at Los Alamos National Laboratory (LANL). The Mobile Real Time Radiography System has the capability of inspecting waste containers of various sizes from 5-gal. buckets to standard waste boxes (SWB, dimensions 54.5 in. x 71 in. x 37 in.). The fact that this unit is mobile makes it an attractive alternative to the costly road closures associated with moving waste from the waste generator to storage or disposal facilities.

  20. Real-time ISEE data system

    NASA Technical Reports Server (NTRS)

    Tsurutani, B. T.; Baker, D. N.

    1979-01-01

    A real-time ISEE data system directed toward predicting geomagnetic substorms and storms is discussed. Such a system may allow up to 60+ minutes advance warning of magnetospheric substorms and up to 30 minute warnings of geomagnetic storms (and other disturbances) induced by high-speed streams and solar flares. The proposed system utilizes existing capabilities of several agencies (NASA, NOAA, USAF), and thereby minimizes costs. This same concept may be applicable to data from other spacecraft, and other NASA centers; thus, each individual experimenter can receive quick-look data in real time at his or her base institution.

  1. Axial tomography from digitized real time radiography

    SciTech Connect

    Zolnay, A.S.; McDonald, W.M.; Doupont, P.A.; McKinney, R.L.; Lee, M.M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  2. Real-Time Occupancy Change Analyzer

    SciTech Connect

    2005-03-30

    The Real-Time Occupancy Change Analyzer (ROCA) produces an occupancy grid map of an environment around the robot, scans the environment to generate a current obstacle map relative to a current robot position, and converts the current obstacle map to a current occupancy grid map. Changes in the occupancy grid can be reported in real time to support a number of tracking capabilities. The benefit of ROCA is that rather than only providing a vector to the detected change, it provides the actual x,y position of the change.

  3. Beam shaping for holographic techniques

    NASA Astrophysics Data System (ADS)

    Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

    2014-09-01

    Uniform intensity of laser radiation is very important in holographic and interferometry technologies, therefore transformation of typical Gaussian distribution of a TEM00 laser to flat-top (top hat) is an actual technical task, it is solved by applying beam shaping optics. Holography and interferometry have specific requirements to a uniform laser beam, most important of them are flatness of phase front and extended depth of field. There are different refractive and diffractive beam shaping approaches used in laser industrial and scientific applications, but only few of them are capable to fulfil the optimum conditions for beam quality demanding holography and interferometry. We suggest applying refractive field mapping beam shapers piShaper, which operational principle presumes almost lossless transformation of Gaussian to flat-top beam with flatness of output wavefront, conserving of beam consistency, providing collimated low divergent output beam, high transmittance, extended depth of field, negligible wave aberration, and achromatic design provides capability to work with several lasers with different wavelengths simultaneously. This approach is used in SLM-based technologies of Computer Generated Holography, Dot-Matrix mastering of security holograms, holographic data storage, holographic projection, lithography, interferometric recording of Volume Bragg Gratings. High optical quality of resulting flat-top beam allows applying additional optical components to vary beam size and shape, thus adapting an optical system to requirements of a particular application. This paper will describe design basics of refractive beam shapers and optical layouts of their applying in holographic systems. Examples of real implementations and experimental results will be presented as well.

  4. Real-time distributed multimedia systems

    SciTech Connect

    Rahurkar, S.S.; Bourbakis, N.G.

    1996-12-31

    This paper presents a survey on distributed multimedia systems and discusses real-time issues. In particular, different subsystems are reviewed that impact on multimedia networking, the networking for multimedia, the networked multimedia systems, and the leading edge research and developments efforts and issues in networking.

  5. REAL TIME CONTROL OF URBAN DRAINAGE NETWORKS

    EPA Science Inventory

    Real-time control (RTC) is a custom-designed, computer-assisted management technology for a specific sewerage network to meet the operational objectives of its collection/conveyance system. RTC can operate in several modes, including a mode that is activated during a wet weather ...

  6. REAL TIME CONTROL OF URBAN DRAINAGE NETWORKS

    EPA Science Inventory

    Real-time control (RTC) is a custom-designed, computer-assisted management technology for a specific sewerage network to meet the operational objectives of its collection/conveyance system. RTC can operate in several modes, including a mode that is activated during a wet weather ...

  7. Real Time Grid Reliability Management 2005

    SciTech Connect

    Eto, Joe; Eto, Joe; Lesieutre, Bernard; Lewis, Nancy Jo; Parashar, Manu

    2008-07-07

    The increased need to manage California?s electricity grid in real time is a result of the ongoing transition from a system operated by vertically-integrated utilities serving native loads to one operated by an independent system operator supporting competitive energy markets. During this transition period, the traditional approach to reliability management -- construction of new transmission lines -- has not been pursued due to unresolved issues related to the financing and recovery of transmission project costs. In the absence of investments in new transmission infrastructure, the best strategy for managing reliability is to equip system operators with better real-time information about actual operating margins so that they can better understand and manage the risk of operating closer to the edge. A companion strategy is to address known deficiencies in offline modeling tools that are needed to ground the use of improved real-time tools. This project: (1) developed and conducted first-ever demonstrations of two prototype real-time software tools for voltage security assessment and phasor monitoring; and (2) prepared a scoping study on improving load and generator response models. Additional funding through two separate subsequent work authorizations has already been provided to build upon the work initiated in this project.

  8. Feedback as Real-Time Constructions

    ERIC Educational Resources Information Center

    Keiding, Tina Bering; Qvortrup, Ane

    2014-01-01

    This article offers a re-description of feedback and the significance of time in feedback constructions based on systems theory. It describes feedback as internal, real-time constructions in a learning system. From this perspective, feedback is neither immediate nor delayed, but occurs in the very moment it takes place. This article argues for a…

  9. The Power of Real-Time PCR

    ERIC Educational Resources Information Center

    Valasek, Mark A.; Repa, Joyce J.

    2005-01-01

    In recent years, real-time polymerase chain reaction (PCR) has emerged as a robust and widely used methodology for biological investigation because it can detect and quantify very small amounts of specific nucleic acid sequences. As a research tool, a major application of this technology is the rapid and accurate assessment of changes in gene…

  10. The Power of Real-Time PCR

    ERIC Educational Resources Information Center

    Valasek, Mark A.; Repa, Joyce J.

    2005-01-01

    In recent years, real-time polymerase chain reaction (PCR) has emerged as a robust and widely used methodology for biological investigation because it can detect and quantify very small amounts of specific nucleic acid sequences. As a research tool, a major application of this technology is the rapid and accurate assessment of changes in gene…

  11. Real-time analysis of telemetry data

    NASA Technical Reports Server (NTRS)

    Kao, Simon A.; Laffey, Thomas J.; Schmidt, James L.; Read, Jackson Y.; Dunham, Larry L.

    1987-01-01

    This paper descibes a knowledge-based system for performing real-time monitoring and analysis of telemetry data from the NASA Hubble Space Telescope (HST). In order to handle asynchronous inputs and perform in real time the system consists of three or more separate processes, which run concurrently and communicate via a message passing scheme. The data management process gathers, compresses, and scales the incoming telemetry data befoe sending it to the other tasks. The inferencing process uses the incoming data to perform a real-time analysis of the state and health of the Space Telescope. The I/O process receives telemetry monitors from the data management process, updates its graphical displays in real time, and acts as the interface to the console operator. The three processes may run on the same or different computers. This system is currently under development and is being used to monitor testcases produced by the Bass Telemetry System in the Hardware/Software Integration Facility at Lockheed Missile and Space Co. in Sunnyvale, California.

  12. Feedback as Real-Time Constructions

    ERIC Educational Resources Information Center

    Keiding, Tina Bering; Qvortrup, Ane

    2014-01-01

    This article offers a re-description of feedback and the significance of time in feedback constructions based on systems theory. It describes feedback as internal, real-time constructions in a learning system. From this perspective, feedback is neither immediate nor delayed, but occurs in the very moment it takes place. This article argues for a…

  13. Quantitative real-time imaging of glutathione

    USDA-ARS?s Scientific Manuscript database

    Glutathione plays many important roles in biological processes; however, the dynamic changes of glutathione concentrations in living cells remain largely unknown. Here, we report a reversible reaction-based fluorescent probe—designated as RealThiol (RT)—that can quantitatively monitor the real-time ...

  14. Real-time Metadata Capture Implementations

    NASA Astrophysics Data System (ADS)

    Chayes, D. N.; Arko, R. A.

    2002-12-01

    The current rate of data acquisition in the ocean sciences precludes the manual generation of appropriate metadata after the fact. Recognizing this fact, we have begun to implement methods for creating metadata and inserting them into relational databases in real-time. We have also created web-based tools for watchstanders and maintenance personnel to enter logbook data in real-time. Several examples will be addressed in this poster. Enhancements to the Hudson Interactive River Observatory (HIRO) real-time data logging system have been made that create metadata records and insert them (as SQL transactions over a secure wireless TCP/IP connection) into a relational database in real-time. These records document the start and stop time of individual data files, of sensor-specific data streams and of the logging system as a whole. An interactive watchstanders logbook has been developed and used on the R/V Maurice Ewing to create and log metadata records associated with upgrades to the Hydrosweep DS2 multibeam system. A similar version of this tool is being used to capture the maintenance and update records associated with the HRIO system.

  15. Real-Time Operating System/360

    NASA Technical Reports Server (NTRS)

    Hoffman, R. L.; Kopp, R. S.; Mueller, H. H.; Pollan, W. D.; Van Sant, B. W.; Weiler, P. W.

    1969-01-01

    RTOS has a cost savings advantage for real-time applications, such as those with random inputs requiring a flexible data routing facility, display systems simplified by a device independent interface language, and complex applications needing added storage protection and data queuing.

  16. Real-time optoacoustic monitoring during thermotherapy

    NASA Astrophysics Data System (ADS)

    Esenaliev, Rinat O.; Larina, Irina V.; Larin, Kirill V.; Motamedi, Massoud

    2000-05-01

    Optoacoustic monitoring of tissue optical properties and speed of sound in real time can provide fast and accurate feedback information during thermotherapy performed with various heating or cooling agents. Amplitude and temporal characteristics of optoacoustic pressure waves are dependent on tissue properties. Detection and measurement of the optoacoustic waves may be used to monitor the extent of tissue hyperthermia, coagulation, or freezing with high resolution and contrast. We studied real-time optoacoustic monitoring of thermal coagulation induced by conductive heating and laser radiation and cryoablation with liquid nitrogen. Q-switched Nd:YAG laser pulses were used as probing radiation to induce optoacoustic waves in tissues. Dramatic changes in optoacoustic signal parameters were detected during tissue freezing and coagulation due to sharp changes in tissue properties. The dimensions of thermally- induced lesions were measured in real time with the optoacoustic technique. Our studies demonstrated that the laser optoacoustic technique is capable of real-time monitoring of tissue coagulation and freezing front with submillimeter spatial resolution. This may allow accurate thermal ablation or cryotherapy of malignant and benign lesions with minimal damage to normal tissues.

  17. OPAD-EDIFIS Real-Time Processing

    NASA Technical Reports Server (NTRS)

    Katsinis, Constantine

    1997-01-01

    The Optical Plume Anomaly Detection (OPAD) detects engine hardware degradation of flight vehicles through identification and quantification of elemental species found in the plume by analyzing the plume emission spectra in a real-time mode. Real-time performance of OPAD relies on extensive software which must report metal amounts in the plume faster than once every 0.5 sec. OPAD software previously written by NASA scientists performed most necessary functions at speeds which were far below what is needed for real-time operation. The research presented in this report improved the execution speed of the software by optimizing the code without changing the algorithms and converting it into a parallelized form which is executed in a shared-memory multiprocessor system. The resulting code was subjected to extensive timing analysis. The report also provides suggestions for further performance improvement by (1) identifying areas of algorithm optimization, (2) recommending commercially available multiprocessor architectures and operating systems to support real-time execution and (3) presenting an initial study of fault-tolerance requirements.

  18. Tradeoffs for real-time hyperspectral analysis

    NASA Astrophysics Data System (ADS)

    Winter, Edwin M.; Schlangen, Michael J.; Hill, Anthony B.; Simi, Christopher G.; Winter, Michael E.

    2002-08-01

    There has been considerable interest in the application of real-time processing techniques to the problem of hyperspectral scene analysis. Recent satellite and aircraft systems can produce data at a rate far faster than the data can be analyzed by interactive computer procedures. Automated and fast procedures for preparing the data for analyst inspection are required for even laboratory use of the large quantities of data. In addition, there are several real-time applications where the data must be processed as it is being acquired. A typical application is a computing system on-board an airplane for operator analysis of the scene as the hyperspectral sensor collects data. In this paper the possible tradeoffs fore rapid analysis are discussed, including choice of algorithm, possible dimensionality reduction, and reduced display level. A real time anomaly detection processing system based on the N- FINDR algorithm has been designed and implemented for the Night Vision Imaging Spectrometer (NVIS). The N-FINDR algorithm is a linear unmixing based algorithm that automatically finds spectral endmembers. The algorithm works by inflating a simplex inside the data, beginning with a random set of pixels. Once these endmember spectra have been found, the image cube can be unmixed using a least-squares approach into a map of fractional abundances of each endmember material in each pixel. In addition to the N-FINDR algorithm, the real-time processing system performs calibration, bad pixel removal, and display of selected fraction planes. The real-time processor is implemented in a commercial Pentium IV computer.

  19. Algorithms for Real-Time Processing

    DTIC Science & Technology

    2003-04-01

    algorithm has been mapped on an application specific prototyping platform which contains four VLSI CORDIC ASICs and some FPGAs (Field Programmable Gate... makes less critical the implementation of a VLSI based systolic array. A practical application of systolic processing for classical ground based or ship...interferometry (ATI) - SAR to detect moving targets [ 18]. It can be shown that this approach offers a considerable computational advantage; FPGA technology has

  20. VLBI real-time analysis by Kalman Filtering

    NASA Astrophysics Data System (ADS)

    Karbon, Maria; Soja, Benedikt; Nilson, Tobias; Heinkelmann, Robert; Liu, Li; Lu, Ciuxian; Xu, Minghui; Raposo-Pulido, Virginia; Mora-Diaz, Julian; Schuh, Harald

    2014-05-01

    Geodetic Very Long Baseline Interferometry (VLBI) is one of the primary space geodetic techniques. It provides the full set of Earth Orientation Parameter (EOP) and is unique for observing long term Universal Time (UT1) and precession/nutation. Currently the VLBI products are delivered with a delay of about two weeks from the moment of the observation. However, the need for near-real time estimates of the parameters is increasing, e.g. for satellite based navigation and positioning or for enabling precise tracking of interplanetary spacecraft. The goal is thus to reduce the time span between observation and the final result to less than one day. This can be archived by replacing the classical least squares method with an adaptive Kalman filter. We have developed a Kalman filter for VLBI data analysis. This method has the advantage that it is simultaneously possible to estimate stationary parameters, e.g. station positions, and to model the highly variable stochastic behavior of non-stationary parameters like clocks or atmospheric parameters. The filter is able to perform without any human interaction, making it a completely autonomous tool. In this work we describe the filter and discuss its application for EOP determination and prediction. We discuss the implementation of the stochastic models to statistically account for unpredictable changes in EOP. Furthermore, additional data like results from other techniques can be included to improve the performance. For example, atmospheric angular momentum calculated from numerical weather models can be introduced to supplement the short-term prediction of UT1 and polar motion. This Kalman filter will be extended and embedded in the newly developed Vienna VLBI Software (VieVS) as a completely autonomous tool enabling the VLBI analysis in near real-time and providing all the parameters of interest with the highest possible accuracy.

  1. ALMA Correlator Real-Time Data Processor

    NASA Astrophysics Data System (ADS)

    Pisano, J.; Amestica, R.; Perez, J.

    2005-10-01

    The design of a real-time Linux application utilizing Real-Time Application Interface (RTAI) to process real-time data from the radio astronomy correlator for the Atacama Large Millimeter Array (ALMA) is described. The correlator is a custom-built digital signal processor which computes the cross-correlation function of two digitized signal streams. ALMA will have 64 antennas with 2080 signal streams each with a sample rate of 4 giga-samples per second. The correlator's aggregate data output will be 1 gigabyte per second. The software is defined by hard deadlines with high input and processing data rates, while requiring interfaces to non real-time external computers. The designed computer system - the Correlator Data Processor or CDP, consists of a cluster of 17 SMP computers, 16 of which are compute nodes plus a master controller node all running real-time Linux kernels. Each compute node uses an RTAI kernel module to interface to a 32-bit parallel interface which accepts raw data at 64 megabytes per second in 1 megabyte chunks every 16 milliseconds. These data are transferred to tasks running on multiple CPUs in hard real-time using RTAI's LXRT facility to perform quantization corrections, data windowing, FFTs, and phase corrections for a processing rate of approximately 1 GFLOPS. Highly accurate timing signals are distributed to all seventeen computer nodes in order to synchronize them to other time-dependent devices in the observatory array. RTAI kernel tasks interface to the timing signals providing sub-millisecond timing resolution. The CDP interfaces, via the master node, to other computer systems on an external intra-net for command and control, data storage, and further data (image) processing. The master node accesses these external systems utilizing ALMA Common Software (ACS), a CORBA-based client-server software infrastructure providing logging, monitoring, data delivery, and intra-computer function invocation. The software is being developed in tandem

  2. Real-Time Seismology in Portugal

    NASA Astrophysics Data System (ADS)

    Custodio, S.; Marreiros, C.; Carvalho, S.; Vales, D.; Lima, V.; Carrilho, F.

    2012-12-01

    Portugal is located next to the plate boundary between Eurasia (Iberia) and Africa (Nubia). The country has been repeatedly affected by some of the largest earthquakes, both onshore and offshore, in the historical European record, including the largest historical European earthquake, the great Lisbon earthquake of 1755 (~M8.5). The Portuguese territory has suffered directly the consequences of strong ground shaking (collapse of buildings, etc) and also some of the most destructive consequences of earthquakes (e.g. tsunamis, fires, etc). However, the rate of tectonic deformation in the Portuguese territory is low (the Eurasian-African plates converge at a rate of ~ 5 mm/yr), which results in long recurrence intervals between earthquakes. This low to moderate rate of seismic activity has two major negative effects: 1) it is difficult to study the regional seismo-tectonics with traditional passive methods; 2) the population is little aware of earthquake risk and unprepared to react in case of disaster. In this scenario, real-time seismology is key to monitoring earthquake crisis in real-time, providing early warnings about potentially destructive events, and assisting in the channeling of recovery efforts in case of disaster. In this paper we will present the real-time algorithms implemented at Instituto de Meteorologia (IM), the institution responsible for seismic monitoring in Portugal. In particular, we will focus on the following aspects: 1) Data collection and real-time transmission to the headquarters. Broadband seismological stations are owned and operated by five different institutions. The last years have witnessed an effort for integration, and presently most data arrives at IM lab in real-time. 2) Earthquake location and local magnitude determination. Data is automatically analyzed in order to obtain a first earthquake hypocenter and ML. While this process is mostly automatic, it still requires the revision by an operator, who is available 24h. 3

  3. Industrial applications of holographic and speckle measuring techniques; Proceedings of the Meeting, The Hague, Netherlands, Mar. 12, 13, 1991

    SciTech Connect

    Jueptner, W.P.

    1991-01-01

    The present meeeting on industrial applications of holographic and speckle measuring techniques discusses applications of holographic interferometry, electro-optical holography, and new methods of interferometry. Attention is given to strategies for unwrapping noisy interferograms in phase-sampling interferometry, a spatial-carrier phase-shifting technique of fringe pattern analysis, synthetic wavelength interferometry for the extension of the dynamic range, and a universal interferometer with a synthesized reference wave. Topics addressed include industrial applications of self-diffraction phenomena in holography on photorefractive crystals, holographic soundfield visualization for nondestructive testing of hot surfaces, and determination of the adhesive load by holographic interferometry using the results of FEM calculations. Also discussed are plate vibrations by moire holography, fringe quality in pulsed TV-holography, and computerized vibration analysis of hot objects.

  4. Real-time retrieval of precipitable water vapor from GPS and BeiDou observations

    NASA Astrophysics Data System (ADS)

    Lu, Cuixian; Li, Xingxing; Nilsson, Tobias; Ning, Tong; Heinkelmann, Robert; Ge, Maorong; Glaser, Susanne; Schuh, Harald

    2015-09-01

    The rapid development of the Chinese BeiDou Navigation Satellite System (BDS) brings a promising prospect for the real-time retrieval of zenith tropospheric delays (ZTD) and precipitable water vapor (PWV), which is of great benefit for supporting the time-critical meteorological applications such as nowcasting or severe weather event monitoring. In this study, we develop a real-time ZTD/PWV processing method based on Global Positioning System (GPS) and BDS observations. The performance of ZTD and PWV derived from BDS observations using real-time precise point positioning (PPP) technique is carefully investigated. The contribution of combining BDS and GPS for ZTD/PWV retrieving is evaluated as well. GPS and BDS observations of a half-year period for 40 globally distributed stations from the International GNSS Service Multi-GNSS Experiment and BeiDou Experiment Tracking Network are processed. The results show that the real-time BDS-only ZTD series agree well with the GPS-only ZTD series in general: the RMS values are about 11-16 mm (about 2-3 mm in PWV). Furthermore, the real-time ZTD derived from GPS-only, BDS-only, and GPS/BDS combined solutions are compared with those derived from the Very Long Baseline Interferometry. The comparisons show that the BDS can contribute to real-time meteorological applications, slightly less accurately than GPS. More accurate and reliable water vapor estimates, about 1.3-1.8 mm in PWV, can be obtained if the BDS observations are combined with the GPS observations in the real-time PPP data processing. The PWV comparisons with radiosondes further confirm the performance of BDS-derived real-time PWV and the benefit of adding BDS to standard GPS processing.

  5. AMON: Transition to real-time operations

    NASA Astrophysics Data System (ADS)

    Cowen, D. F.; Keivani, A.; Tešić, G.

    2016-04-01

    The Astrophysical Multimessenger Observatory Network (AMON) will link the world's leading high-energy neutrino, cosmic-ray, gamma-ray and gravitational wave observatories by performing real-time coincidence searches for multimessenger sources from observatories' subthreshold data streams. The resulting coincidences will be distributed to interested parties in the form of electronic alerts for real-time follow-up observation. We will present the science case, design elements, current and projected partner observatories, status of the AMON project, and an initial AMON-enabled analysis. The prototype of the AMON server has been online since August 2014 and processing archival data. Currently, we are deploying new high-uptime servers and will be ready to start issuing alerts as early as winter 2015/16.

  6. Real-time imaging of quantum entanglement.

    PubMed

    Fickler, Robert; Krenn, Mario; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton

    2013-01-01

    Quantum Entanglement is widely regarded as one of the most prominent features of quantum mechanics and quantum information science. Although, photonic entanglement is routinely studied in many experiments nowadays, its signature has been out of the grasp for real-time imaging. Here we show that modern technology, namely triggered intensified charge coupled device (ICCD) cameras are fast and sensitive enough to image in real-time the effect of the measurement of one photon on its entangled partner. To quantitatively verify the non-classicality of the measurements we determine the detected photon number and error margin from the registered intensity image within a certain region. Additionally, the use of the ICCD camera allows us to demonstrate the high flexibility of the setup in creating any desired spatial-mode entanglement, which suggests as well that visual imaging in quantum optics not only provides a better intuitive understanding of entanglement but will improve applications of quantum science.

  7. System Equivalent for Real Time Digital Simulator

    NASA Astrophysics Data System (ADS)

    Lin, Xi

    2011-07-01

    The purpose of this research is to develop a method of making system equivalents for the Real Time Digital Simulator (RTDS), which should enhance its capability of simulating large power systems. The proposed equivalent combines a Frequency Dependent Network Equivalent (FDNE) for the high frequency electromagnetic transients and a Transient Stability Analysis (TSA) type simulation block for the electromechanical transients. The frequency dependent characteristic for FDNE is obtained by curve-fitting frequency domain admittance characteristics using the Vector Fitting method. An approach for approximating the frequency dependent characteristic of large power networks from readily available typical power-flow data is also introduced. A new scheme of incorporating TSA solution in RTDS is proposed. This report shows how the TSA algorithm can be adapted to a real time platform. The validity of this method is confirmed with examples, including the study of a multi in-feed HVDC system based network.

  8. Real Time Radiation Monitoring Using Nanotechnology

    NASA Technical Reports Server (NTRS)

    Li, Jing (Inventor); Wilkins, Richard T. (Inventor); Hanratty, James J. (Inventor); Lu, Yijiang (Inventor)

    2016-01-01

    System and method for monitoring receipt and estimating flux value, in real time, of incident radiation, using two or more nanostructures (NSs) and associated terminals to provide closed electrical paths and to measure one or more electrical property change values .DELTA.EPV, associated with irradiated NSs, during a sequence of irradiation time intervals. Effects of irradiation, without healing and with healing, of the NSs, are separately modeled for first order and second order healing. Change values.DELTA.EPV are related to flux, to cumulative dose received by NSs, and to radiation and healing effectivity parameters and/or.mu., associated with the NS material and to the flux. Flux and/or dose are estimated in real time, based on EPV change values, using measured .DELTA.EPV values. Threshold dose for specified changes of biological origin (usually undesired) can be estimated. Effects of time-dependent radiation flux are analyzed in pre-healing and healing regimes.

  9. Real Time Radiation Exposure And Health Risks

    NASA Technical Reports Server (NTRS)

    Hu, Shaowen; Barzilla, Janet E.; Semones, Edward J.

    2015-01-01

    Radiation from solar particle events (SPEs) poses a serious threat to future manned missions outside of low Earth orbit (LEO). Accurate characterization of the radiation environment in the inner heliosphere and timely monitoring the health risks to crew are essential steps to ensure the safety of future Mars missions. In this project we plan to develop an approach that can use the particle data from multiple satellites and perform near real-time simulations of radiation exposure and health risks for various exposure scenarios. Time-course profiles of dose rates will be calculated with HZETRN and PDOSE from the energy spectrum and compositions of the particles archived from satellites, and will be validated from recent radiation exposure measurements in space. Real-time estimation of radiation risks will be investigated using ARRBOD. This cross discipline integrated approach can improve risk mitigation by providing critical information for risk assessment and medical guidance to crew during SPEs.

  10. Real-time remote scientific model validation

    NASA Technical Reports Server (NTRS)

    Frainier, Richard; Groleau, Nicolas

    1994-01-01

    This paper describes flight results from the use of a CLIPS-based validation facility to compare analyzed data from a space life sciences (SLS) experiment to an investigator's preflight model. The comparison, performed in real-time, either confirms or refutes the model and its predictions. This result then becomes the basis for continuing or modifying the investigator's experiment protocol. Typically, neither the astronaut crew in Spacelab nor the ground-based investigator team are able to react to their experiment data in real time. This facility, part of a larger science advisor system called Principal Investigator in a Box, was flown on the space shuttle in October, 1993. The software system aided the conduct of a human vestibular physiology experiment and was able to outperform humans in the tasks of data integrity assurance, data analysis, and scientific model validation. Of twelve preflight hypotheses associated with investigator's model, seven were confirmed and five were rejected or compromised.

  11. Real time gamma-ray signature identifier

    DOEpatents

    Rowland, Mark [Alamo, CA; Gosnell, Tom B [Moraga, CA; Ham, Cheryl [Livermore, CA; Perkins, Dwight [Livermore, CA; Wong, James [Dublin, CA

    2012-05-15

    A real time gamma-ray signature/source identification method and system using principal components analysis (PCA) for transforming and substantially reducing one or more comprehensive spectral libraries of nuclear materials types and configurations into a corresponding concise representation/signature(s) representing and indexing each individual predetermined spectrum in principal component (PC) space, wherein an unknown gamma-ray signature may be compared against the representative signature to find a match or at least characterize the unknown signature from among all the entries in the library with a single regression or simple projection into the PC space, so as to substantially reduce processing time and computing resources and enable real-time characterization and/or identification.

  12. Real-time photo-magnetic imaging

    PubMed Central

    Nouizi, Farouk; Erkol, Hakan; Luk, Alex; Unlu, Mehmet B.; Gulsen, Gultekin

    2016-01-01

    We previously introduced a new high resolution diffuse optical imaging modality termed, photo-magnetic imaging (PMI). PMI irradiates the object under investigation with near-infrared light and monitors the variations of temperature using magnetic resonance thermometry (MRT). In this paper, we present a real-time PMI image reconstruction algorithm that uses analytic methods to solve the forward problem and assemble the Jacobian matrix much faster. The new algorithm is validated using real MRT measured temperature maps. In fact, it accelerates the reconstruction process by more than 250 times compared to a single iteration of the FEM-based algorithm, which opens the possibility for the real-time PMI. PMID:27867701

  13. The Real-Time Data Distribution Service

    NASA Astrophysics Data System (ADS)

    Corsaro, A.; Karoui, R.; Richard-Foy, M.

    2011-08-01

    A large class of Aerospace applications, such as, very large telescopes, shuttle launch systems, ground satellite systems, etc., are characterised by the need of distributing very large volumes of data in real-time. Some of this applications, especially those involved in the control of telescopes mirrors or launch systems require that the system predictability is maintained in face of partial failure and overload.The Data Distribution Service of Real-Time Systems (DDS) is an Object Management Group standard that was introduced in 2004 to address the needs of applications requiring high performance and determinism. Since its inception, implementation of this standard have been adopted in different domains, such as Aerospace, Defence, Capital Market, and SCADA. This paper introduces the key features of DDS, provides some performance characterisation of OpenSplice DDS, an Open Source DDS implementation, and concludes by providing a use case to Aerospace where DDS is applied to overcome APEX ARINC653 communication system limitations.

  14. Visualizations for Real-time Pricing Demonstration

    SciTech Connect

    Marinovici, Maria C.; Hammerstrom, Janelle L.; Widergren, Steven E.; Dayley, Greg K.

    2014-10-13

    In this paper, the visualization tools created for monitoring the operations of a real-time pricing demonstration system that runs at a distribution feeder level are presented. The information these tools provide gives insights into demand behavior from automated price responsive devices, distribution feeder characteristics, impact of weather on system’s development, and other significant dynamics. Given the large number of devices that bid into a feeder-level real-time electricity market, new techniques are explored to summarize the present state of the system and contrast that with previous trends as well as future projections. To better understand the system behavior and correctly inform decision-making procedures, effective visualization of the data is imperative.

  15. Real-Time Imaging of Quantum Entanglement

    PubMed Central

    Fickler, Robert; Krenn, Mario; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton

    2013-01-01

    Quantum Entanglement is widely regarded as one of the most prominent features of quantum mechanics and quantum information science. Although, photonic entanglement is routinely studied in many experiments nowadays, its signature has been out of the grasp for real-time imaging. Here we show that modern technology, namely triggered intensified charge coupled device (ICCD) cameras are fast and sensitive enough to image in real-time the effect of the measurement of one photon on its entangled partner. To quantitatively verify the non-classicality of the measurements we determine the detected photon number and error margin from the registered intensity image within a certain region. Additionally, the use of the ICCD camera allows us to demonstrate the high flexibility of the setup in creating any desired spatial-mode entanglement, which suggests as well that visual imaging in quantum optics not only provides a better intuitive understanding of entanglement but will improve applications of quantum science. PMID:23715056

  16. Distributed Real-Time Computing with Harness

    SciTech Connect

    Di Saverio, Emanuele; Cesati, Marco; Di Biagio, Christian; Pennella, Guido; Engelmann, Christian

    2007-01-01

    Modern parallel and distributed computing solutions are often built onto a ''middleware'' software layer providing a higher and common level of service between computational nodes. Harness is an adaptable, plugin-based middleware framework for parallel and distributed computing. This paper reports recent research and development results of using Harness for real-time distributed computing applications in the context of an industrial environment with the needs to perform several safety critical tasks. The presented work exploits the modular architecture of Harness in conjunction with a lightweight threaded implementation to resolve several real-time issues by adding three new Harness plug-ins to provide a prioritized lightweight execution environment, low latency communication facilities, and local timestamped event logging.

  17. Real-Time Dynamics of String Breaking

    NASA Astrophysics Data System (ADS)

    Hebenstreit, F.; Berges, J.; Gelfand, D.

    2013-11-01

    We study the real-time dynamics of string breaking in quantum electrodynamics in one spatial dimension. A two-stage process with a clear separation of time and energy scales for the fermion-antifermion pair creation and subsequent charge separation leading to the screening of external charges is found. Going away from the traditional setup of external static charges, we establish the phenomenon of multiple string breaking by considering dynamical charges flying apart.

  18. Nonlinear Real-Time Optical Signal Processing.

    DTIC Science & Technology

    1984-10-01

    DTIC ELECTE I B IIMAGE PROCESSING INSTITUTE 84 11 26 107 UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When Dota Entered), REPORT DOCUMENTATION...30, 1984 N NONLINEAR REAL-TIME OPTICAL SIGNAL PROCESSING i E~ A.A. Sawchuk, Principal Investigator T.C. Strand and A.R. Tanguay. Jr. October 1, 1984...RDepartment of Electrical Engineering Image Processing institute University of Southern California University Park-MC 0272 Los Angeles, California

  19. Real time computer controlled weld skate

    NASA Technical Reports Server (NTRS)

    Wall, W. A., Jr.

    1977-01-01

    A real time, adaptive control, automatic welding system was developed. This system utilizes the general case geometrical relationships between a weldment and a weld skate to precisely maintain constant weld speed and torch angle along a contoured workplace. The system is compatible with the gas tungsten arc weld process or can be adapted to other weld processes. Heli-arc cutting and machine tool routing operations are possible applications.

  20. Nonlinear Real-Time Optical Signal Processing.

    DTIC Science & Technology

    1981-06-30

    bandwidth and space-bandwidth products. Real-time homonorphic and loga- rithmic filtering by halftone nonlinear processing has been achieved. A...Page ABSTRACT 1 1. RESEARCH OBJECTIVES AND PROGRESS 3 I-- 1.1 Introduction and Project overview 3 1.2 Halftone Processing 9 1.3 Direct Nonlinear...time homomorphic and logarithmic filtering by halftone nonlinear processing has been achieved. A detailed analysis of degradation due to the finite gamma

  1. Real-Time X-Ray Inspection

    NASA Technical Reports Server (NTRS)

    Bulthuis, Ronald V.

    1988-01-01

    X-ray imaging instrument adapted to continuous scanning. Modern version of fluoroscope enables rapid x-ray inspection of parts. Developed for detection of buckling in insulated ducts. Uses radiation from radioactive gadolinium or thallium source. Instrument weighs only 6 1/2 lb. Quickly scanned by hand along duct surface, providing real-time image. Based on Lixiscope, developed at Goddard Space Flight Center.

  2. Real-Time Ocean Modeling Systems

    DTIC Science & Technology

    2013-10-22

    2002 2. REPORT TYPE 3. DATES COVERED (From - To) Journal Article 4 . TITLE AND SUBTITLE Real-time 16iebaf Modeling Systems \\&&»A 5a...Director NCST E.O. Hartwig, 7000 Public Affairs (Unclassified/ Unlimited Only), Code 7n30 4 Division, Code Author, Code HQ-NRL 5511/6 (Rev. 12-93...according to the routing in Section 4 . 1. NRL Reports Submit the diskette (if available), manuscript, typed double-spaced, complete with tables

  3. Real-time radiographic inspection facility

    NASA Technical Reports Server (NTRS)

    Roberts, E., Jr.

    1977-01-01

    A real time radiographic inspection facility has been developed for nondestructive evaluation applications. It consists of an X-ray source, an X-ray sensitive television imaging system, an electronic analog image processing system, and a digital image processing system. The digital image processing system is composed of a computer with the necessary software to drive the overall facility. Descriptions are given of the design strategy, the facility's components, and its current capabilities.

  4. Neural Network Retinal Model Real Time Implementation

    DTIC Science & Technology

    1992-09-02

    addresses the specific needs of vision processing. The goal of this SBIR Phase I project has been to take a significant neural network vision...application and to map it onto dedicated hardware for real time implementation. The neural network was already demonstrated using software simulation on a...general purpose computer. During Phase 1, HNC took a neural network model of the retina and, using HNC’s Vision Processor (ViP) prototype hardware

  5. Real-time RGBD SLAM system

    NASA Astrophysics Data System (ADS)

    Czupryński, BłaŻej; Strupczewski, Adam

    2015-09-01

    A real-time tracking and mapping SLAM system is presented. The developed system uses input from an RGBD sensor and tracks the camera pose from frame to frame. The tracking is based on matched feature points and is performed with respect to selected keyframes. The system is robust and scalable, as an arbitrary number of keyframes can be chosen for visualization and tracking depending on the desired accuracy and speed. The presented system is also a good platform for further research.

  6. Thermal imaging with real time picture presentation.

    PubMed

    Borg, S B

    1968-09-01

    The accomplishment of thermal imaging with real-time picture presentation represents a significant advance in nondestructive testing. Described here is the AGA Thermovision, capable of producing such imaging. Operating principles, basic features, and recording techniques are reviewed, and a survey is made of the range of applications. Examples include electrical power distribution elements, a turbine blade, and a missile model in a wind tunnel.

  7. Applications of Non-Crystalline Materials — C. REAL TIME OPTICAL RECORDING ON THIN FILMS OF AMORPHOUS SEMICONDUCTORS

    NASA Astrophysics Data System (ADS)

    Mitkova, Maria

    The following sections are included: * Introduction * Amorphous Semiconductors as Optical Storage Medium * Principles and Results on Real-time Optical Recording * Digital optical recording * Digital optical recording due to ablation of the films by illumination with light * Digital optical recording due to coagulation of an island film * Digital optical recording due to phase transition * Digital optical recording due to photoinduced surface deposition of metallic silver * Principles of holographic recording * Recording and readout * Classification of the holograms * Diffraction efficiency * Results in holographic recording on chalcogenide glasses * Future Trends * Acknowledgments * References

  8. Real-time optical image processing techniques

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang

    1988-01-01

    Nonlinear real-time optical processing on spatial pulse frequency modulation has been pursued through the analysis, design, and fabrication of pulse frequency modulated halftone screens and the modification of micro-channel spatial light modulators (MSLMs). Micro-channel spatial light modulators are modified via the Fabry-Perot method to achieve the high gamma operation required for non-linear operation. Real-time nonlinear processing was performed using the halftone screen and MSLM. The experiments showed the effectiveness of the thresholding and also showed the needs of higher SBP for image processing. The Hughes LCLV has been characterized and found to yield high gamma (about 1.7) when operated in low frequency and low bias mode. Cascading of two LCLVs should also provide enough gamma for nonlinear processing. In this case, the SBP of the LCLV is sufficient but the uniformity of the LCLV needs improvement. These include image correlation, computer generation of holograms, pseudo-color image encoding for image enhancement, and associative-retrieval in neural processing. The discovery of the only known optical method for dynamic range compression of an input image in real-time by using GaAs photorefractive crystals is reported. Finally, a new architecture for non-linear multiple sensory, neural processing has been suggested.

  9. Software Analyzes Complex Systems in Real Time

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Expert system software programs, also known as knowledge-based systems, are computer programs that emulate the knowledge and analytical skills of one or more human experts, related to a specific subject. SHINE (Spacecraft Health Inference Engine) is one such program, a software inference engine (expert system) designed by NASA for the purpose of monitoring, analyzing, and diagnosing both real-time and non-real-time systems. It was developed to meet many of the Agency s demanding and rigorous artificial intelligence goals for current and future needs. NASA developed the sophisticated and reusable software based on the experience and requirements of its Jet Propulsion Laboratory s (JPL) Artificial Intelligence Research Group in developing expert systems for space flight operations specifically, the diagnosis of spacecraft health. It was designed to be efficient enough to operate in demanding real time and in limited hardware environments, and to be utilized by non-expert systems applications written in conventional programming languages. The technology is currently used in several ongoing NASA applications, including the Mars Exploration Rovers and the Spacecraft Health Automatic Reasoning Pilot (SHARP) program for the diagnosis of telecommunication anomalies during the Neptune Voyager Encounter. It is also finding applications outside of the Space Agency.

  10. Real-time earthquake data feasible

    NASA Astrophysics Data System (ADS)

    Bush, Susan

    Scientists agree that early warning devices and monitoring of both Hurricane Hugo and the Mt. Pinatubo volcanic eruption saved thousands of lives. What would it take to develop this sort of early warning and monitoring system for earthquake activity?Not all that much, claims a panel assigned to study the feasibility, costs, and technology needed to establish a real-time earthquake monitoring (RTEM) system. The panel, drafted by the National Academy of Science's Committee on Seismology, has presented its findings in Real-Time Earthquake Monitoring. The recently released report states that “present technology is entirely capable of recording and processing data so as to provide real-time information, enabling people to mitigate somewhat the earthquake disaster.” RTEM systems would consist of two parts—an early warning system that would give a few seconds warning before severe shaking, and immediate postquake information within minutes of the quake that would give actual measurements of the magnitude. At this time, however, this type of warning system has not been addressed at the national level for the United States and is not included in the National Earthquake Hazard Reduction Program, according to the report.

  11. Real-time Interactive Tree Animation.

    PubMed

    Quigley, Ed; Yu, Yue; Huang, Jingwei; Lin, Winnie; Fedkiw, Ronald

    2017-01-30

    We present a novel method for posing and animating botanical tree models interactively in real time. Unlike other state of the art methods which tend to produce trees that are overly flexible, bending and deforming as if they were underwater plants, our approach allows for arbitrarily high stiffness while still maintaining real-time frame rates without spurious artifacts, even on quite large trees with over ten thousand branches. This is accomplished by using an articulated rigid body model with as-stiff-as-desired rotational springs in conjunction with our newly proposed simulation technique, which is motivated both by position based dynamics and the typical O(N) algorithms for articulated rigid bodies. The efficiency of our algorithm allows us to pose and animate trees with millions of branches or alternatively simulate a small forest comprised of many highly detailed trees. Even using only a single CPU core, we can simulate ten thousand branches in real time while still maintaining quite crisp user interactivity. This has allowed us to incorporate our framework into a commodity game engine to run interactively even on a low-budget tablet. We show that our method is amenable to the incorporation of a large variety of desirable effects such as wind, leaves, fictitious forces, collisions, fracture, etc.

  12. Real-time optical image processing techniques

    NASA Astrophysics Data System (ADS)

    Liu, Hua-Kuang

    1988-10-01

    Nonlinear real-time optical processing on spatial pulse frequency modulation has been pursued through the analysis, design, and fabrication of pulse frequency modulated halftone screens and the modification of micro-channel spatial light modulators (MSLMs). Micro-channel spatial light modulators are modified via the Fabry-Perot method to achieve the high gamma operation required for non-linear operation. Real-time nonlinear processing was performed using the halftone screen and MSLM. The experiments showed the effectiveness of the thresholding and also showed the needs of higher SBP for image processing. The Hughes LCLV has been characterized and found to yield high gamma (about 1.7) when operated in low frequency and low bias mode. Cascading of two LCLVs should also provide enough gamma for nonlinear processing. In this case, the SBP of the LCLV is sufficient but the uniformity of the LCLV needs improvement. These include image correlation, computer generation of holograms, pseudo-color image encoding for image enhancement, and associative-retrieval in neural processing. The discovery of the only known optical method for dynamic range compression of an input image in real-time by using GaAs photorefractive crystals is reported. Finally, a new architecture for non-linear multiple sensory, neural processing has been suggested.

  13. Real-time speckle photography: a breakthrough

    NASA Astrophysics Data System (ADS)

    Petrov, Valery

    1996-12-01

    Speckle photography for small displacements can be carried out rather easily. It is a well established method. Unfortunately problems arise when specklegrams must be obtained in real time. Silver halide media infer lengthy multi-stage photoprocessing of specklegrams. Real time speckle photography utilizing non-silver media can be implemented but the techniques involved are rather complicated. Extremely simple and inexpensive approaches to speckle photography are introduced here. They combine positive features of speckle photography and momental holography. This permits the user to produce quasi real time specklegrams within a few seconds. High quality speckle photographs were obtained with different laser sources on high resolution silver halide media: Russian PFG-03, PFG-03 C (color), Agfa-Gevaert 8E 75 HD films and plates. Very good specklegrams were obtained also in lighted environment. Hybrid holospecklegrams i.e. holograms and speckle photographs of the same object were obtained simultaneously on the same media. Such holospecklegrams were also produced within fa few seconds. Quite unexpectedly good specklegrams were recorded even in water. Photographs of momentally produced specklegrams are given.

  14. The IGS Real-Time Service

    NASA Astrophysics Data System (ADS)

    Caissy, Mark; Agrotis, Loukis; Weber, Georg; Fisher, Steven

    2013-04-01

    The IGS Real-Time Service (RTS) is being rolled out in 2013 following the successful completion of the IGS Real-Time Pilot Project. The RTS has recently completed beta testing and is now operating at the level of initial operating capability. The service will reach full operating capability by the end of 2013. RTS products include GNSS data streams and GNSS orbit and clock correction streams. These products are available in real-time in accordance with the IGS open-data policy using RTCM standard formats and the NTRIP transportation protocol. The RTS is key to IGS's support of the GGOS Natural Hazards theme. Of particular importance in this context is the high degree of redundancy that is build into the RTS in order to reliably support public-good scientific applications commonly associated with natural hazards; for example, precise-point positioning applications requiring high accuracy and low latency related to earthquakes and tsunamis . This presentation will illustrate the data gathering through product generation to user distribution design of the RTS, highlighting built-in robustness at various stages. The presentation will also present an assessment of the performance of the service to date.

  15. Real-time monitoring system for microfluidics

    NASA Astrophysics Data System (ADS)

    Sapuppo, F.; Cantelli, G.; Fortuna, L.; Arena, P.; Bucolo, M.

    2007-05-01

    A new non-invasive real-time system for the monitoring and control of microfluidodynamic phenomena is proposed. The general purpose design of such system is suitable for in vitro and in vivo experimental setup and therefore for microfluidic application in the biomedical field such as lab-on-chip and for research studies in the field of microcirculation. The system consists of an ad hoc optical setup for image magnification providing images suitable for image acquisition and processing. The optic system was designed and developed using discrete opto-mechanic components mounted on a breadboard in order to provide an optic path accessible at any point where the information needs to be acquired. The optic sensing, acquisition, and processing were performed using an integrated vision system based on the Cellular Nonlinear Networks (CNNs) analogic technology called Focal Plane Processor (FPP, Eye-RIS, Anafocus) and inserted in the optic path. Ad hoc algorithms were implemented for the real-time analysis and extraction of fluido-dynamic parameters in micro-channels. They were tested on images recorded during in vivo microcirculation experiments on hamsters and then they were applied on images optically acquired and processed in real-time during in vitro experiments on a continuous microfluidic device (serpentine mixer, ThinXXS) with a two-phase fluid.

  16. Holographic Skyrmions

    NASA Astrophysics Data System (ADS)

    Sutcliffe, Paul

    2015-06-01

    Skyrmions are topological solitons that describe baryons within a nonlinear theory of pions. In holographic QCD, baryons correspond to topological solitons in a bulk theory with an extra spatial dimension. Thus, the three-dimensional Skyrmion lifts to a four-dimensional holographic Skyrmion in the bulk. We begin this review with a description of the simplest example of this correspondence, where the holographic Skyrmion is exactly the self-dual Yang-Mills instanton in flat space. This places an old result of Atiyah and Manton within a holographic framework and reveals that the associated Skyrme model extends the nonlinear pion theory to include an infinite tower of vector mesons, with specific couplings for a BPS theory. We then describe the more complicated curved space version that arises from the string theory construction of Sakai and Sugimoto. The basic concepts remain the same but the technical difficulty increases as the holographic Skyrmion is a curved space version of the Yang-Mills instanton, so self-duality and integrability are lost. Finally, we turn to a low-dimensional analog of holographic Skyrmions, where aspects such as multi-baryons and finite baryon density are amenable to both numerical computation and an approximate analytic treatment.

  17. Holographic Skyrmions

    NASA Astrophysics Data System (ADS)

    Sutcliffe, Paul M.

    Skyrmions are topological solitons that describe baryons within a nonlinear theory of pions. In holographic QCD, baryons correspond to topological solitons in a bulk theory with an extra spatial dimension: thus the three-dimensional Skyrmion lifts to a four-dimensional holographic Skyrmion in the bulk. We begin this review with a description of the simplest example of this correspondence, where the holographic Skyrmion is exactly the self-dual Yang-Mills instanton in flat space. This places an old result of Atiyah and Manton within a holographic framework and reveals that the associated Skyrme model extends the nonlinear pion theory to include an infinite tower of vector mesons, with specific couplings for a BPS theory. We then describe the more complicated curved space version that arises from the string theory construction of Sakai and Sugimoto. The basic concepts remain the same but the technical difficulty increases as the holographic Skyrmion is a curved space version of the Yang-Mills instanton, so self-duality and integrability are lost. Finally, we turn to a low-dimensional analogue of holographic Skyrmions, where aspects such as multi-baryons and finite baryon density are amenable to both numerical computation and an approximate analytic treatment.

  18. Mining the Optical Sky in Real Time

    NASA Astrophysics Data System (ADS)

    Vestrand, W. T.

    2002-05-01

    While it has been known for centuries that the optical sky is variable, monitoring the sky for optical transients with durations of less than a day is a rich area of research that remains largely unexplored. The fact that spectacular optical transients exist was clearly demonstrated by the detection of an optical flash associated with a Gamma Ray Burst at redshift z=1.6. However, the depth and breath of optical sky monitoring is so incomplete that this cosmological optical transient, which reached the astounding apparent magnitude of 9, would have been missed but for the real-time position provided by a high-energy satellite. Since there are many reasons to suspect the existence of rapid optical transients that cannot be found through sky monitoring by high-energy satellites, we need all-sky optical monitoring systems that can locate rapid transients in real time. We discuss how with existing technology it is possible to construct robotic telescope systems for monitoring all of the optical sky that can autonomously locate celestial optical transients with timescales as short as a fraction of a minute. The data from such a monitoring system could also be used to recognize important variations of known sources. Real-time alerts from such an optical all-sky monitoring system would enable otherwise impossible observations with more powerful, narrow-field telescopes that more deeply probe the physics of the rapidly varying sources. As an example of this new type of sky monitoring system, we discuss the RAPTOR telescope system at Los Alamos National Laboratory that is designed to identify and make follow-up observations of optical transients in real time. The system is composed of two arrays of telescopes, separated by 38 kilometers, that stereoscopically monitor a field of about 1500 square degrees for transients down to about 12th magnitude in 30 seconds. Each array also contains a sensitive, higher resolution "fovea" telescope, capable of imaging at a faster cadence

  19. Deformation measurements of surface mount assembly under power cycling using optical interferometry

    NASA Astrophysics Data System (ADS)

    Leung, Kang M.; Wang, W. N.

    1996-09-01

    The reliability of solder joints has been regarded as one of the most critical problems in surface mount technology because of large stress developed at the joints due to thermal expansion mismatch between components and the substrate in operation. uNderstanding the deformation modes of surface mount assemblies and obtaining stress and strain values of joints allow the designer to predict the fatigue life of the solder joints. This study is directed toward a comprehensive evaluation of thermomechanical behavior through 3D deformation measurements of a typical surface mount assembly having gull-wing leads soldered on a printed circuit board by means of laser interferometric techniques. In this paper we describe the application of real-time holographic interferometry and Moire interferometry to measure the 3D formation of the device under power cycling. By combining the measured results of the out-of-plane and the in-plane displacements, together with the temperature distribution of the assembly, the stress distributions of the leads and solder joints were evaluated. It was estimated that the mechanical stress will exceed the yield stress of solder material when the PQFP assembly operates at the rated temperature of 75 degrees C. Then, the deformation of solder joints might change from elastic to plastic.

  20. The measurement of 3-D asymmetric temperature field by using real time laser interferometric tomography

    NASA Astrophysics Data System (ADS)

    Wang, Dezhong; Zhuang, Tiange

    2001-09-01

    A real time nondestructive temperature measurement technique based on laser holographic interference tomography technique is presented. An He-Ne laser is used as light source, and a CCD video camera is used to grab the interferogram. This laser holographic tomography technique is applied to the measurement of the temperature fields generated by two heated rods. Since data error is inevitable in engineering measurement, it is necessary to study the reconstruction techniques for reconstructing the temperature field. Three techniques including convolution back projection (CBP), algebra reconstruction technique (ART) and simultaneous iterative reconstruction technique (SIRT) are studied. Based on the reconstruction techniques and experimental situation, ART is used to reconstruct the asymmetric temperature fields. The thermocouples are used to measure the temperatures of the two heated rods. Comparing the reconstructed result with the measured temperature value, a satisfactory result is obtained.

  1. Detection of deoxynivalenol using biolayer interferometry

    USDA-ARS?s Scientific Manuscript database

    Biolayer interferometry allows for the real time monitoring of the interactions between molecules without the need for reagents with enzymatic, fluorescent, or radioactive labels. The technology is based upon the changes in interference pattern of light reflected from the surface of an optical fiber...

  2. Acting to gain information: Real-time reasoning meets real-time perception

    NASA Technical Reports Server (NTRS)

    Rosenschein, Stan

    1994-01-01

    Recent advances in intelligent reactive systems suggest new approaches to the problem of deriving task-relevant information from perceptual systems in real time. The author will describe work in progress aimed at coupling intelligent control mechanisms to real-time perception systems, with special emphasis on frame rate visual measurement systems. A model for integrated reasoning and perception will be discussed, and recent progress in applying these ideas to problems of sensor utilization for efficient recognition and tracking will be described.

  3. Acting to gain information: Real-time reasoning meets real-time perception

    NASA Technical Reports Server (NTRS)

    Rosenschein, Stan

    1994-01-01

    Recent advances in intelligent reactive systems suggest new approaches to the problem of deriving task-relevant information from perceptual systems in real time. The author will describe work in progress aimed at coupling intelligent control mechanisms to real-time perception systems, with special emphasis on frame rate visual measurement systems. A model for integrated reasoning and perception will be discussed, and recent progress in applying these ideas to problems of sensor utilization for efficient recognition and tracking will be described.

  4. Pulsed holographic interferometry in predictive tire testing

    NASA Astrophysics Data System (ADS)

    Wesolowski, Piotr J.; Woisetschlaeger, Jakob

    1995-06-01

    This paper presents several examples of tire vibration analysis under different loads, inflation pressures, and excitation modes. Several consecutive structural resonant modes were also analysed in the frequency range 190-260 Hz to search for their contribution to a phenomenon called the first resonant frequency of the tire cavity as well as to experimentally determine their contribution to the tire noise spectrum. A Lumonics HLS-2 ruby laser system was used in double exposure mode during the experiments. The capability to precisely map a 3D displacement vector field is shown through utilization of an image processing system and a simple fringe order tracking procedure. The examples supplied demonstrate that HI can provide very accurate experimental measurement of mode amplitudes to precisely tune FEA tire models under arbitrary boundary condition. This experimental technique can also be used to measure responses of some 'exotic' materials built into a tire for which the computer models cannot be easily established. The unique capabilities of HI were also applied to studies of the surface shock wave propagation in the tire carcass and sidewall. Several examples of different dynamic response of the tire due to changing experimental conditions are presented.

  5. Holographic interferometry at Wright Aeronautical Laboratories

    NASA Technical Reports Server (NTRS)

    Roquemore, Mel

    1987-01-01

    The optical diagnostics requirements and plans for the Aero Propulsion Lab. are described. This laboratory is performing work in combustion as related to aero propulsion systems. They would like to use holography and other types of optical instrumentation for combustion diagnostics and flow visualization. A movie of a laser light sheet flow visualization of a combustor in operation was shown. This movie showed extremely clear examples of vortical and unsteady flow, and it would be of interest to use image analysis to quantify such data.

  6. Digital Holographic Interferometry for Airborne Particle Characterization

    DTIC Science & Technology

    2015-03-19

    with this support includes, e.g., UV and visible diode-pumped Nd:YLF Q-switch lasers from Photonics Industries, an optics table, optical elements with...research program at MSU, three graduate and five undergraduate students were supported, nine peer-reviewed journal articles were published, and 20...supported, nine peer-reviewed journal articles were published, and 20 presentations at professional meetings were given. Several major research

  7. Interferometry concepts

    NASA Astrophysics Data System (ADS)

    Millour, F.

    2014-09-01

    This paper serves as an introduction to the current book. It provides the basic notions of long-baseline optical/infrared interferometry prior to reading all the subsequent chapters, and is not an extended introduction to the field.

  8. Holographic Optical Data Storage

    NASA Technical Reports Server (NTRS)

    Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)

    2000-01-01

    Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising

  9. The application of holography as a real-time three-dimensional motion picture camera

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.

    1973-01-01

    A historical introduction to holography is presented, as well as a basic description of sideband holography for stationary objects. A brief theoretical development of both time-dependent and time-independent holography is also provided, along with an analytical and intuitive discussion of a unique holographic arrangement which allows the resolution of front surface detail from an object moving at high speeds. As an application of such a system, a real-time three-dimensional motion picture camera system is discussed and the results of a recent demonstration of the world's first true three-dimensional motion picture are given.

  10. Golographic interferometry of physical processes

    NASA Astrophysics Data System (ADS)

    Ostrovskaya, G. V.

    2016-06-01

    This paper is devoted to the contribution of Yuri Ostrovsky to holographic interferometry, one of the fundamental scientific and practical applications of holography. The title of this paper is the same as the title of his doctoral thesis that he defended in 1974, and, as it seems to me, reflects most of the specific features of the majority of his scientific publications, viz., an inseparable link of the methods developed by him with the results obtained with the help of these methods in a wide range of investigations of physical processes and phenomena.

  11. Exploring Earthquakes in Real-Time

    NASA Astrophysics Data System (ADS)

    Bravo, T. K.; Kafka, A. L.; Coleman, B.; Taber, J. J.

    2013-12-01

    Earthquakes capture the attention of students and inspire them to explore the Earth. Adding the ability to view and explore recordings of significant and newsworthy earthquakes in real-time makes the subject even more compelling. To address this opportunity, the Incorporated Research Institutions for Seismology (IRIS), in collaboration with Moravian College, developed ';jAmaSeis', a cross-platform application that enables students to access real-time earthquake waveform data. Students can watch as the seismic waves are recorded on their computer, and can be among the first to analyze the data from an earthquake. jAmaSeis facilitates student centered investigations of seismological concepts using either a low-cost educational seismograph or streamed data from other educational seismographs or from any seismic station that sends data to the IRIS Data Management System. After an earthquake, students can analyze the seismograms to determine characteristics of earthquakes such as time of occurrence, distance from the epicenter to the station, magnitude, and location. The software has been designed to provide graphical clues to guide students in the analysis and assist in their interpretations. Since jAmaSeis can simultaneously record up to three stations from anywhere on the planet, there are numerous opportunities for student driven investigations. For example, students can explore differences in the seismograms from different distances from an earthquake and compare waveforms from different azimuthal directions. Students can simultaneously monitor seismicity at a tectonic plate boundary and in the middle of the plate regardless of their school location. This can help students discover for themselves the ideas underlying seismic wave propagation, regional earthquake hazards, magnitude-frequency relationships, and the details of plate tectonics. The real-time nature of the data keeps the investigations dynamic, and offers students countless opportunities to explore.

  12. Real-time structured light depth extraction

    NASA Astrophysics Data System (ADS)

    Keller, Kurtis; Ackerman, Jeremy D.

    2000-03-01

    Gathering depth data using structured light has been a procedure for many different environments and uses. Many of these system are utilized instead of laser line scanning because of their quickness. However, to utilize depth extraction for some applications, in our case laparoscopic surgery, the depth extraction must be in real time. We have developed an apparatus that speeds up the raw image display and grabbing in structured light depth extraction from 30 frames per second to 60 and 180 frames per second. This results in an updated depth and texture map of about 15 times per second versus about 3. This increased update rate allows for real time depth extraction for use in augmented medical/surgical applications. Our miniature, fist-sized projector utilizes an internal ferro-reflective LCD display that is illuminated with cold light from a flex light pipe. The miniature projector, attachable to a laparoscope, displays inverted pairs of structured light into the body where these images are then viewed by a high-speed camera set slightly off axis from the projector that grabs images synchronously. The images from the camera are ported to a graphics-processing card where six frames are worked on simultaneously to extract depth and create mapped textures from these images. This information is then sent to the host computer with 3D coordinate information of the projector/camera and the associated textures. The surgeon is then able to view body images in real time from different locations without physically moving the laparoscope imager/projector, thereby, reducing the trauma of moving laparoscopes in the patient.

  13. Real-time failure control (SAFD)

    NASA Technical Reports Server (NTRS)

    Panossian, Hagop V.; Kemp, Victoria R.; Eckerling, Sherry J.

    1990-01-01

    The Real Time Failure Control program involves development of a failure detection algorithm, referred as System for Failure and Anomaly Detection (SAFD), for the Space Shuttle Main Engine (SSME). This failure detection approach is signal-based and it entails monitoring SSME measurement signals based on predetermined and computed mean values and standard deviations. Twenty four engine measurements are included in the algorithm and provisions are made to add more parameters if needed. Six major sections of research are presented: (1) SAFD algorithm development; (2) SAFD simulations; (3) Digital Transient Model failure simulation; (4) closed-loop simulation; (5) SAFD current limitations; and (6) enhancements planned for.

  14. Real-Time Ada Demonstration Project

    DTIC Science & Technology

    1989-05-31

    CENER OR OFTAREENGINEERING ADVANCED SOFTWARE TECHNOLOGY Subject: Final Report - Real-Time Ada Demonstration Proj e-t- --.-. SEP 0 1989 D SEA)~ CIN...C02 0921I 6))00 I 31 MAY 1989 *:i ’C O~ 0"ed ~ 842 190 ?’ 45 DEMONSTRATION PROJECT FINAL REPORT PREPARED FOR: U.S. Army HQ CECOM Center for Software ...Engineering Advanced Software Technology Fort Monmouth, NJ 07703-5000 Accession For NTIS G1A&I DTIC TAB PREPARED BY: unannou:1r2d E LabTek Corporation

  15. Systems Analyze Water Quality in Real Time

    NASA Technical Reports Server (NTRS)

    2010-01-01

    A water analyzer developed under Small Business Innovation Research (SBIR) contracts with Kennedy Space Center now monitors treatment processes at water and wastewater facilities around the world. Originally designed to provide real-time detection of nutrient levels in hydroponic solutions for growing plants in space, the ChemScan analyzer, produced by ASA Analytics Inc., of Waukesha, Wisconsin, utilizes spectrometry and chemometric algorithms to automatically analyze multiple parameters in the water treatment process with little need for maintenance, calibration, or operator intervention. The company has experienced a compound annual growth rate of 40 percent over its 15-year history as a direct result of the technology's success.

  16. CUDA-based real time surgery simulation.

    PubMed

    Liu, Youquan; De, Suvranu

    2008-01-01

    In this paper we present a general software platform that enables real time surgery simulation on the newly available compute unified device architecture (CUDA)from NVIDIA. CUDA-enabled GPUs harness the power of 128 processors which allow data parallel computations. Compared to the previous GPGPU, it is significantly more flexible with a C language interface. We report implementation of both collision detection and consequent deformation computation algorithms. Our test results indicate that the CUDA enables a twenty times speedup for collision detection and about fifteen times speedup for deformation computation on an Intel Core 2 Quad 2.66 GHz machine with GeForce 8800 GTX.

  17. Real-Time Reed-Solomon Decoder

    NASA Technical Reports Server (NTRS)

    Maki, Gary K.; Cameron, Kelly B.; Owsley, Patrick A.

    1994-01-01

    Generic Reed-Solomon decoder fast enough to correct errors in real time in practical applications designed to be implemented in fewer and smaller very-large-scale integrated, VLSI, circuit chips. Configured to operate in pipelined manner. One outstanding aspect of decoder design is that Euclid multiplier and divider modules contain Galoisfield multipliers configured as combinational-logic cells. Operates at speeds greater than older multipliers. Cellular configuration highly regular and requires little interconnection area, making it ideal for implementation in extraordinarily dense VLSI circuitry. Flight electronics single chip version of this technology implemented and available.

  18. Real-time teleteaching in medical physics

    PubMed Central

    Woo, M; Ng, KH

    2008-01-01

    Medical physics is a relatively small professional community, usually with a scarcity of expertise that could greatly benefit students entering the field. However, the reach of the profession can span great geographical distances, making the training of students a difficult task. In addition to the requirement of training new students, the evolving field of medical physics, with its many emerging advanced techniques and technologies, could benefit greatly from ongoing continuing education as well as consultation with experts. Many continuing education courses and workshops are constantly being offered, including many web-based study courses and virtual libraries. However, one mode of education and communication that has not been widely used is the real-time interactive process. Video-based conferencing systems do exist, but these usually require a substantial amount of effort and cost to set up. The authors have been working on promoting the ever-expanding capability of the Internet to facilitate the education of medical physics to students entering the field. A pilot project has been carried out for six years and reported previously. The project is a collaboration between the Department of Medical Physics at the Toronto Odette Cancer Centre in Canada and the Department of Biomedical Imaging at the University of Malaya in Malaysia. Since 2001, medical physics graduate students at the University of Malaya have been taught by lecturers from Toronto every year, using the Internet as the main tool of communication. The pilot study explored the different methods that can be used to provide real-time interactive remote education, and delivered traditional classroom lectures as well as hands-on workshops. Another similar project was started in 2007 to offer real-time teaching to a class of medical physics students at Wuhan University in Hubei, China. There are new challenges as well as new opportunities associated with this project. By building an inventory of tools and

  19. Low cost real time interactive analysis system

    NASA Technical Reports Server (NTRS)

    Stetina, F.

    1988-01-01

    Efforts continue to develop a low cost real time interactive analysis system for the reception of satellite data. A multi-purpose ingest hardware software frame formatter was demonstrated for GOES and TIROS data and work is proceeding on extending the capability to receive GMS data. A similar system was proposed as an archival and analysis system for use with INSAT data and studies are underway to modify the system to receive the planned SeaWiFS (ocean color) data. This system was proposed as the core of a number of international programs in support of U.S. AID activities. Systems delivered or nearing final testing are listed.

  20. Real-time teleteaching in medical physics.

    PubMed

    Woo, M; Ng, Kh

    2008-01-01

    Medical physics is a relatively small professional community, usually with a scarcity of expertise that could greatly benefit students entering the field. However, the reach of the profession can span great geographical distances, making the training of students a difficult task. In addition to the requirement of training new students, the evolving field of medical physics, with its many emerging advanced techniques and technologies, could benefit greatly from ongoing continuing education as well as consultation with experts.Many continuing education courses and workshops are constantly being offered, including many web-based study courses and virtual libraries. However, one mode of education and communication that has not been widely used is the real-time interactive process. Video-based conferencing systems do exist, but these usually require a substantial amount of effort and cost to set up.The authors have been working on promoting the ever-expanding capability of the Internet to facilitate the education of medical physics to students entering the field. A pilot project has been carried out for six years and reported previously. The project is a collaboration between the Department of Medical Physics at the Toronto Odette Cancer Centre in Canada and the Department of Biomedical Imaging at the University of Malaya in Malaysia. Since 2001, medical physics graduate students at the University of Malaya have been taught by lecturers from Toronto every year, using the Internet as the main tool of communication.The pilot study explored the different methods that can be used to provide real-time interactive remote education, and delivered traditional classroom lectures as well as hands-on workshops.Another similar project was started in 2007 to offer real-time teaching to a class of medical physics students at Wuhan University in Hubei, China. There are new challenges as well as new opportunities associated with this project. By building an inventory of tools and

  1. High energy real-time imaging studies

    SciTech Connect

    Haskins, J.J.; Dolan, K.W.; Perkins, D.E.; Rikard, D.; Schneberk, D.J.

    1993-04-01

    Performance characteristics of high energy real-time radiography (RTR) systems were optimized by interchanging components and varying optical coupling methods. Phosphor screens, fiber optic scintillation plates, monolithic high density glass scintillation plates, mirror coatings, different cameras and integration times were studied. X-ray sources were 4- and 9-MeV linear accelerators. High density monolithic glass, high resolution and wide dynamic range CCD cameras, and special focusing and fixturing methods have provided significantly improved spatial resolution and contrast for our high energy real-rime imaging. RTR systems with improved performance characteristics and proper translational/rotational staging were adapted for computed tomography applications.

  2. Real-Time Surface Traffic Adviser

    NASA Technical Reports Server (NTRS)

    Glass, Brian J. (Inventor); Spirkovska, Liljana (Inventor); McDermott, William J. (Inventor); Reisman, Ronald J. (Inventor); Gibson, James (Inventor); Iverson, David L. (Inventor)

    2001-01-01

    A real-time data management system which uses data generated at different rates by multiple heterogeneous incompatible data sources are presented. In one embodiment, the invention is as an airport surface traffic data management system (traffic adviser) that electronically interconnects air traffic control, airline, and airport operations user communities to facilitate information sharing and improve taxi queuing. The system uses an expert system to fuse dam from a variety of airline, airport operations, ramp control, and air traffic control sources, in order to establish, predict, and update reference data values for every aircraft surface operation.

  3. Real-time video image processing

    NASA Astrophysics Data System (ADS)

    Smedley, Kirk G.; Yool, Stephen R.

    1990-11-01

    Lockheed has designed and implemented a prototype real-time Video Enhancement Workbench (VEW) using commercial offtheshelf hardware and custom software. The hardware components include a Sun workstation Aspex PIPE image processor time base corrector VCR video camera and realtime disk subsystem. A cornprehensive set of image processing functions can be invoked by the analyst at any time during processing enabling interactive enhancement and exploitation of video sequences. Processed images can be transmitted and stored within the system in digital or video form. VEW also provides image output to a laser printer and to Interleaf technical publishing software.

  4. Object detection in real-time

    NASA Astrophysics Data System (ADS)

    Solder, Ulrich; Graefe, Volker

    1991-03-01

    An algorithm working on monocular gray-scale image sequences for object detection combined with a road tracker is presented. This algorithm appropriate for the real-time demands of an autonomous car driving with speeds over 40 km/h may be used for triggering obstacle avoidance maneuvers such as coming to a safe stop automatically in front of an obstacle or following another car. Moving and static objects have been detected in real-world experiments on various types of roads even under unfavorable weather conditions. . Morgenthaler and

  5. Real-time optical fiber dosimeter probe

    NASA Astrophysics Data System (ADS)

    Croteau, André; Caron, Serge; Rink, Alexandra; Jaffray, David; Mermut, Ozzy

    2011-03-01

    There is a pressing need for a passive optical fiber dosimeter probe for use in real-time monitoring of radiation dose delivered to clinical radiation therapy patients. An optical fiber probe using radiochromic material has been designed and fabricated based on a thin film of the radiochromic material on a dielectric mirror. Measurements of the net optical density vs. time before, during, and after irradiation at a rate of 500cGy/minute to a total dose of 5 Gy were performed. Net optical densities increased from 0.2 to 2.0 for radiochromic thin film thicknesses of 2 to 20 μm, respectively.

  6. [Development of real-time CT fluoroscopy].

    PubMed

    Katada, K; Anno, H; Takeshita, G; Ogura, Y; Koga, S; Ida, Y; Nonomura, K; Kanno, T; Ohashi, A; Sata, S

    1994-10-25

    A new CT system that permits real-time monitoring of CT images was developed. Phantom and volunteer studies revealed that the images were displayed at a rate of six per second with a delay time of 0.83 second with clinically sufficient resolution (256 x 256) using the newly developed fast image processor and partial-reconstruction algorithm. The clinical trial of stereotactic aspiration of intracerebral hematoma was successful. The initial trial with CT fluoroscopy revealed potential usefulness of the system in biopsy and other CT-guided interventions.

  7. Real time analysis of voiced sounds

    NASA Technical Reports Server (NTRS)

    Hong, J. P. (Inventor)

    1976-01-01

    A power spectrum analysis of the harmonic content of a voiced sound signal is conducted in real time by phase-lock-loop tracking of the fundamental frequency, (f sub 0) of the signal and successive harmonics (h sub 1 through h sub n) of the fundamental frequency. The analysis also includes measuring the quadrature power and phase of each frequency tracked, differentiating the power measurements of the harmonics in adjacent pairs, and analyzing successive differentials to determine peak power points in the power spectrum for display or use in analysis of voiced sound, such as for voice recognition.

  8. Optical aberration correction by real-time holography in liquid crystals.

    PubMed

    Karaguleff, C; Clark, G L

    1990-07-15

    We present results of experiments that use nematic-phase liquid crystal as a real-time holographic recording medium. Plane-wave gratings were written with as little as 10 mJ/cm(2) of incident write-beam energy from a pulsed Nd:YAG laser, and diffraction efficiencies greater than 25% were measured at 633 nm. Grating decay times were observed to fall within two distinct time regimes: a rapid-decay time of 60 to 100 microsec and a slower-decay time of 6 to 30 msec. The rapid-decay regime was used to demonstrate real-time correction of severely aberrated images by degenerate four-wave mixing.

  9. The use of correlation interferometry for analysis of phase inhomogeneous environments and surfaces

    NASA Astrophysics Data System (ADS)

    Derzhypolska, L.; Gnatovskiy, O.; Negriyko, A.

    2015-12-01

    In the paper investigated are optically inhomogeneous objects using holographic interferometry, speckle-interferometry and optical correlation. A non-interferometricshift of interference fringes is observed. Shown is that the shift is related to the statistical distribution that describes the optical inhomogeneity of the objects of study.

  10. Real Time Simulation of Power Grid Disruptions

    SciTech Connect

    Chinthavali, Supriya; Dimitrovski, Aleksandar D; Fernandez, Steven J; Groer, Christopher S; Nutaro, James J; Olama, Mohammed M; Omitaomu, Olufemi A; Shankar, Mallikarjun; Spafford, Kyle L; Vacaliuc, Bogdan

    2012-11-01

    DOE-OE and DOE-SC workshops (Reference 1-3) identified the key power grid problem that requires insight addressable by the next generation of exascale computing is coupling of real-time data streams (1-2 TB per hour) as the streams are ingested to dynamic models. These models would then identify predicted disruptions in time (2-4 seconds) to trigger the smart grid s self healing functions. This project attempted to establish the feasibility of this approach and defined the scientific issues, and demonstrated example solutions to important smart grid simulation problems. These objectives were accomplished by 1) using the existing frequency recorders on the national grid to establish a representative and scalable real-time data stream; 2) invoking ORNL signature identification algorithms; 3) modeling dynamically a representative region of the Eastern interconnect using an institutional cluster, measuring the scalability and computational benchmarks for a national capability; and 4) constructing a prototype simulation for the system s concept of smart grid deployment. The delivered ORNL enduring capability included: 1) data processing and simulation metrics to design a national capability justifying exascale applications; 2) Software and intellectual property built around the example solutions; 3) demonstrated dynamic models to design few second self-healing.

  11. Real-time PCR in microfluidic devices

    NASA Astrophysics Data System (ADS)

    Becker, Holger; Hlawatsch, Nadine; Klemm, Richard; Moche, Christian; Hansen-Hagge, Thomas; Gärtner, Claudia

    2014-03-01

    A central method in a standard biochemical laboratory is represented by the polymerase chain reaction (PCR), therefore many attempts have been performed so far to implement this technique in lab-on-a-chip (LOC) devices. PCR is an ideal candidate for miniaturization because of a reduction of assay time and decreased costs for expensive bio-chemicals. In case of the "classical" PCR, detection is done by identification of DNA fragments electrophoretically separated in agarose gels. This method is meanwhile frequently replaced by the so-called Real-Time-PCR because here the exponential increase of amplificates can be observed directly by measurement of DNA interacting fluorescent dyes. Two main methods for on-chip PCRs are available: traditional "batch" PCR in chambers on a chip using thermal cycling, requiring about 30 minutes for a typical PCR protocol and continuous-flow PCR, where the liquid is guided over stationary temperature zones. In the latter case, the PCR protocol can be as fast as 5 minutes. In the presented work, a proof of concept is demonstrated for a real-time-detection of PCR products in microfluidic systems.

  12. Real-Time Flight Envelope Monitoring System

    NASA Technical Reports Server (NTRS)

    Kerho, Michael; Bragg, Michael B.; Ansell, Phillip J.

    2012-01-01

    The objective of this effort was to show that real-time aircraft control-surface hinge-moment information could be used to provide a robust and reliable prediction of vehicle performance and control authority degradation. For a given airfoil section with a control surface -- be it a wing with an aileron, rudder, or elevator -- the control-surface hinge moment is sensitive to the aerodynamic characteristics of the section. As a result, changes in the aerodynamics of the section due to angle-of-attack or environmental effects such as icing, heavy rain, surface contaminants, bird strikes, or battle damage will affect the control surface hinge moment. These changes include both the magnitude of the hinge moment and its sign in a time-averaged sense, and the variation of the hinge moment with time. The current program attempts to take the real-time hinge moment information from the aircraft control surfaces and develop a system to predict aircraft envelope boundaries across a range of conditions, alerting the flight crew to reductions in aircraft controllability and flight boundaries.

  13. Real-time sensor data validation

    NASA Technical Reports Server (NTRS)

    Bickmore, Timothy W.

    1994-01-01

    This report describes the status of an on-going effort to develop software capable of detecting sensor failures on rocket engines in real time. This software could be used in a rocket engine controller to prevent the erroneous shutdown of an engine due to sensor failures which would otherwise be interpreted as engine failures by the control software. The approach taken combines analytical redundancy with Bayesian belief networks to provide a solution which has well defined real-time characteristics and well-defined error rates. Analytical redundancy is a technique in which a sensor's value is predicted by using values from other sensors and known or empirically derived mathematical relations. A set of sensors and a set of relations among them form a network of cross-checks which can be used to periodically validate all of the sensors in the network. Bayesian belief networks provide a method of determining if each of the sensors in the network is valid, given the results of the cross-checks. This approach has been successfully demonstrated on the Technology Test Bed Engine at the NASA Marshall Space Flight Center. Current efforts are focused on extending the system to provide a validation capability for 100 sensors on the Space Shuttle Main Engine.

  14. REal-time COsmic Ray Database (RECORD)

    NASA Astrophysics Data System (ADS)

    Usoskin, I.; Kozlov, Valery; Ksenofontov, Leonid, Kudela, Karel; Starodubtsev, Sergei; Turpanov, Alexey; Yanke, Victor

    2003-07-01

    In this paper we present a first distributed REal-time COsmic Ray Database (RECORD). The aim of the project is to develop a unified database with data from different neutron monitors collected together, in unified format and to provide a user with several commonly used data access methods. The database contains not only original cosmic ray data but also auxiliary data necessary for scientific data analysis. Currently the database includes Lomn.Stit, Moscow, Oulu; Tixie Bay, Yakutsk stations. The main database server is located in IKFIA SB RAS (Yakutsk) but there will be several mirrors of the database. The database and all its mirrors are up dated on the nearly real-time (1 hour) basis. The data access software includes WWW-interface, Perl scripts and C library, which may be linked to a user program. Most of frequently used functions are implemented to make it operable to users without SQL language knowledge. A draft of the data representation standard is suggested, based on common practice of neutron monitor community. The database engine is freely distributed open-sourced PostgreSQL server coupled with a set of replication to ols developed at Bio engineering division of the IRCCS E.Medea, Italy.

  15. An efficient real time superresolution ASIC system

    NASA Astrophysics Data System (ADS)

    Reddy, Dikpal; Yue, Zhanfeng; Topiwala, Pankaj

    2008-04-01

    Superresolution of images is an important step in many applications like target recognition where the input images are often grainy and of low quality due to bandwidth constraints. In this paper, we present a real-time superresolution application implemented in ASIC/FPGA hardware, and capable of 30 fps of superresolution by 16X in total pixels. Consecutive frames from the video sequence are grouped and the registered values between them are used to fill the pixels in the higher resolution image. The registration between consecutive frames is evaluated using the algorithm proposed by Schaum et al. The pixels are filled by averaging a fixed number of frames associated with the smallest error distances. The number of frames (the number of nearest neighbors) is a user defined parameter whereas the weights in the averaging process are decided by inverting the corresponding smallest error distances. Wiener filter is used to post process the image. Different input parameters, such as size of input image, enlarging factor and the number of nearest neighbors, can be tuned conveniently by the user. We use a maximum word size of 32 bits to implement the algorithm in Matlab Simulink as well as the hardware, which gives us a fine balance between the number of bits and performance. The algorithm performs with real time speed with very impressive superresolution results.

  16. Neutron monitor database in real time

    NASA Astrophysics Data System (ADS)

    Kozlov, Valery; Kudela, Karel; Starodubtsev, Sergei; Turpanov, Alexey; Usoskin, Ilya; Yanke, Victor

    2003-09-01

    A first distributed Real Time Cosmic Ray Database using measurements of several neutron monitors is presented. The aim of the project is to develop a unified database with data from different neutron monitors collected together, in unified format and to provide a user with several commonly used data access methods. The database contains original cosmic ray as well as all housekeeping and technical data necessary for scientific data analysis. Currently the database includes Lomnicky Stit, Moscow, Oulu, Tixie Bay, Yakutsk stations and it is opened for other neutron monitors. The main database server is located in IKFIA SB RAS (Yakutsk) but there will be several mirrors of the database. The datbase and all its mirrors are updated on the nearly real-time (1 hour) basis. The data access software includes WWW-interface, Perl scipts and C library, which may be linked to a user program. Most of frequently used functions are implemented to make it operable to users without SQL language knowledge. A draft of the data representation standard is suggested, based on common practice of neutron monitor community. The database engine is freely distributed open-sourced PostgreSQL server coupled with a set of replication tools developed at Bioengineering division of the IRCCS E. Medea, Italy.

  17. Real-time design with peer tasks

    NASA Technical Reports Server (NTRS)

    Goforth, Andre; Howes, Norman R.; Wood, Jonathan D.; Barnes, Michael J.

    1995-01-01

    We introduce a real-time design methodology for large scale, distributed, parallel architecture, real-time systems (LDPARTS), as an alternative to those methods using rate or dead-line monotonic analysis. In our method the fundamental units of prioritization, work items, are domain specific objects with timing requirements (deadlines) found in user's specification. A work item consists of a collection of tasks of equal priority. Current scheduling theories are applied with artifact deadlines introduced by the designer whereas our method schedules work items to meet user's specification deadlines (sometimes called end-to-end deadlines). Our method supports these scheduling properties. Work item scheduling is based on domain specific importance instead of task level urgency and still meets as many user specification deadlines as can be met by scheduling tasks with respect to urgency. Second, the minimum (closest) on-line deadline that can be guaranteed for a work item of highest importance, scheduled at run time, is approximately the inverse of the throughput, measured in work items per second. Third, throughput is not degraded during overload and instead of resorting to task shedding during overload, the designer can specify which work items to shed. We prove these properties in a mathematical model.

  18. Real-time applications of neural nets

    SciTech Connect

    Spencer, J.E.

    1989-05-01

    Producing, accelerating and colliding very high power, low emittance beams for long periods is a formidable problem in real-time control. As energy has grown exponentially in time so has the complexity of the machines and their control systems. Similar growth rates have occurred in many areas, e.g., improved integrated circuits have been paid for with comparable increases in complexity. However, in this case, reliability, capability and cost have improved due to reduced size, high production and increased integration which allow various kinds of feedback. In contrast, most large complex systems (LCS) are perceived to lack such possibilities because only one copy is made. Neural nets, as a metaphor for LCS, suggest ways to circumvent such limitations. It is argued that they are logically equivalent to multi-loop feedback/forward control of faulty systems. While complimentary to AI, they mesh nicely with characteristics desired for real-time systems. Such issues are considered, examples given and possibilities discussed. 21 refs., 6 figs.

  19. Real-time applications of neural nets

    SciTech Connect

    Spencer, J.E. )

    1989-10-01

    Producing, accelerating and colliding very high power, low emittance beams for long periods is a formidable problem in real-time control. As energy has grown exponentially in time so has the complexity of the machines and their control systems. Similar growth rates have occurred in many areas e.g. improved integrated circuits have been paid for with comparable increases in complexity. However, in this case, reliability, capability and cost have improved due to reduced size, high production and increased integration which allow various kinds of feedback. In contrast, most large complex systems (LCS) are perceived to lack such possibilities because only one copy is made. Neural nets, as a metaphor for LCS, suggest ways to circumvent such limitations. It is argued that they are logically equivalent to multi-loop feedback/forward control of faulty systems. While complimentary to AI, they mesh nicely with characteristics desired for real-time systems. In this paper, such issues are considered, examples given and possibilities discussed.

  20. Machine learning for real time remote detection

    NASA Astrophysics Data System (ADS)

    Labbé, Benjamin; Fournier, Jérôme; Henaff, Gilles; Bascle, Bénédicte; Canu, Stéphane

    2010-10-01

    Infrared systems are key to providing enhanced capability to military forces such as automatic control of threats and prevention from air, naval and ground attacks. Key requirements for such a system to produce operational benefits are real-time processing as well as high efficiency in terms of detection and false alarm rate. These are serious issues since the system must deal with a large number of objects and categories to be recognized (small vehicles, armored vehicles, planes, buildings, etc.). Statistical learning based algorithms are promising candidates to meet these requirements when using selected discriminant features and real-time implementation. This paper proposes a new decision architecture benefiting from recent advances in machine learning by using an effective method for level set estimation. While building decision function, the proposed approach performs variable selection based on a discriminative criterion. Moreover, the use of level set makes it possible to manage rejection of unknown or ambiguous objects thus preserving the false alarm rate. Experimental evidences reported on real world infrared images demonstrate the validity of our approach.

  1. Real-time protein kinase assay.

    PubMed

    Sun, Hongye; Low, Karen E; Woo, Sam; Noble, Richard L; Graham, Ronald J; Connaughton, Sonia S; Gee, Melissa A; Lee, Linda G

    2005-04-01

    We report a novel, real-time fluorogenic kinase assay. The peptide substrates are synthesized with a fluorescent dye and a hydrocarbon tail. The substrate self-assembles into micelles, increasing the local concentration of the dye and quenching its fluorescence. Upon phosphorylation, the fluorescence intensity increases 4-6-fold due to micelle reorganization. Both dynamic light scattering data and cryoelectron microscope images show that the size and the shape of the phosphopeptide micelles are significantly different from micelles of substrate peptide. The system provides a robust fluorescence increase in a real-time protein kinase assay. Unlike other fluorogenic systems, the fluorophore may be distant from the serine, threonine, or tyrosine that is phosphorylated. Assays for several kinases, including PKA, PKC, p38, MAPKAP K2, akt, Erk1, and src-family kinases, have been developed. IC(50) values of inhibitors for PKC betaII determined with this technology are consistent with published values. The utility of this assay to high-throughput screening was demonstrated with Sigma's LOPAC library, a collection of 640 compounds with known biological activities, and satisfactory results were obtained.

  2. NSTX power supply real time controller

    SciTech Connect

    Neumeyer, C.; Hatcher, R.; Marsala, R.; Ramakrishnan, S.

    2000-01-06

    The NSTX is a new national facility for the study of plasma confinement, heating, and current drive in a low aspect ratio, spherical torus (ST) configuration. The ST configuration is an alternate magnetic confinement concept which is characterized by high beta (ratio plasma pressure to magnetic field pressure) and low toroidal field compared to conventional tokamaks, and could provide a pathway to the realization of a practical fusion power source. The NSTX depends on a real time, high speed, synchronous, and deterministic control system acting on a system of thyristor rectifier power supplies to (1) establish the initial magnetic field configuration; (2) initiate plasma within the vacuum vessel; (3) inductively drive plasma current; and (4) control plasma position and shape. For the initial ``day 0'' 1st plasma operations (Feb. 1999), the system was limited to closed loop proportional-integral current control of the power supplies based on preprogrammed reference waveforms. For the ``day 1'' phase of operations beginning Sept. 1999 the loop has been closed on plasma current and position. This paper focuses on the Power Supply Real Time Controller (PSRTC).

  3. Reconfigurable real-time distributed processing network

    NASA Astrophysics Data System (ADS)

    Page, S. F.; Seely, R. D.; Hickman, D.

    2011-06-01

    This paper describes a novel real-time image and signal processing network, RONINTM, which facilitates the rapid design and deployment of systems providing advanced geospatial surveillance and situational awareness capability. RONINTM is a distributed software architecture consisting of multiple agents or nodes, which can be configured to implement a variety of state-of-the-art computer vision and signal processing algorithms. The nodes operate in an asynchronous fashion and can run on a variety of hardware platforms, thus providing a great deal of scalability and flexibility. Complex algorithmic configuration chains can be assembled using an intuitive graphical interface in a plug-and- play manner. RONINTM has been successfully exploited for a number of applications, ranging from remote event detection to complex multiple-camera real-time 3D object reconstruction. This paper describes the motivation behind the creation of the network, the core design features, and presents details of an example application. Finally, the on-going development of the network is discussed, which is focussed on dynamic network reconfiguration. This allows to the network to automatically adapt itself to node or communications failure by intelligently re-routing network communications and through adaptive resource management.

  4. Image denoising for real-time MRI.

    PubMed

    Klosowski, Jakob; Frahm, Jens

    2017-03-01

    To develop an image noise filter suitable for MRI in real time (acquisition and display), which preserves small isolated details and efficiently removes background noise without introducing blur, smearing, or patch artifacts. The proposed method extends the nonlocal means algorithm to adapt the influence of the original pixel value according to a simple measure for patch regularity. Detail preservation is improved by a compactly supported weighting kernel that closely approximates the commonly used exponential weight, while an oracle step ensures efficient background noise removal. Denoising experiments were conducted on real-time images of healthy subjects reconstructed by regularized nonlinear inversion from radial acquisitions with pronounced undersampling. The filter leads to a signal-to-noise ratio (SNR) improvement of at least 60% without noticeable artifacts or loss of detail. The method visually compares to more complex state-of-the-art filters as the block-matching three-dimensional filter and in certain cases better matches the underlying noise model. Acceleration of the computation to more than 100 complex frames per second using graphics processing units is straightforward. The sensitivity of nonlocal means to small details can be significantly increased by the simple strategies presented here, which allows partial restoration of SNR in iteratively reconstructed images without introducing a noticeable time delay or image artifacts. Magn Reson Med 77:1340-1352, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  5. Real-time Raman sensing without spectrometer

    NASA Astrophysics Data System (ADS)

    Kim, Min Ju; Kim, Sungho; Yang, Timothy K.; Kumar, Dinesh; Bae, Sung Chul

    2015-03-01

    Raman spectroscopy has been a powerful tool in various fields of science and technology ranging from analytical chemistry to biomedical imaging. In spite of unique features, Raman spectroscopy has also some limitations. Among them are weak Raman signal compared to strong fluorescence and relatively complicated setup with expensive and bulky spectrometer. In order to increase the sensitivity of Raman technique, many clever attempts have been made and some of them were very successful including CARS, SRS, and so on. However, these still requires expensive and more complicated setup. In this work, we have attempted to build a real-time compact Raman sensor without spectrometer. Conventional spectrometer was replaced with a narrow-band optical filter and alternatively modulated two lasers with slightly different wavelengths. At one laser, Raman signal from a target molecule was transmitted through the optical filter. At the other laser, this signal was blocked by the optical filter and could not be detected by photon detector. The alternative modulation of two lasers will modulate the Raman signal from a target molecule at the same modulation frequency. This modulated weak Raman signal was amplified by a lock-in amplifier. The advantages of this setup include compactness, low cost, real-time monitoring, and so on. We have tested the sensitivity of this setup and we found that it doesn't have enough sensitivity to detect single molecule-level, but it is still good enough to monitor the change of major chemical composition in the sample.

  6. Real-time animation of complex hairstyles.

    PubMed

    Volino, Pascal; Magnenat-Thalmann, Nadia

    2006-01-01

    True real-time animation of complex hairstyles on animated characters is the goal of this work, and the challenge is to build a mechanical model of the hairstyle which is sufficiently fast for real-time performance while preserving the particular behavior of the hair medium and maintaining sufficient versatility for simulating any kind of complex hairstyles. Rather than building a complex mechanical model directly related to the structure of the hair strands, we take advantage of a volume free-form deformation scheme. We detail the construction of an efficient lattice mechanical deformation model which represents the volume behavior of the hair strands. The lattice is deformed as a particle system using state-of-the-art numerical methods, and animates the hairs using quadratic B-Spline interpolation. The hairstyle reacts to the body skin through collisions with a metaball-based approximation. The model is highly scalable and allows hairstyles of any complexity to be simulated in any rendering context with the appropriate trade off between accuracy and computation speed, fitting the need of Level-of-Detail optimization schemes.

  7. Real-Time and Near Real-Time Data for Space Weather Applications and Services

    NASA Astrophysics Data System (ADS)

    Singer, H. J.; Balch, C. C.; Biesecker, D. A.; Matsuo, T.; Onsager, T. G.

    2015-12-01

    Space weather can be defined as conditions in the vicinity of Earth and in the interplanetary environment that are caused primarily by solar processes and influenced by conditions on Earth and its atmosphere. Examples of space weather are the conditions that result from geomagnetic storms, solar particle events, and bursts of intense solar flare radiation. These conditions can have impacts on modern-day technologies such as GPS or electric power grids and on human activities such as astronauts living on the International Space Station or explorers traveling to the moon or Mars. While the ultimate space weather goal is accurate prediction of future space weather conditions, for many applications and services, we rely on real-time and near-real time observations and model results for the specification of current conditions. In this presentation, we will describe the space weather system and the need for real-time and near-real time data that drive the system, characterize conditions in the space environment, and are used by models for assimilation and validation. Currently available data will be assessed and a vision for future needs will be given. The challenges for establishing real-time data requirements, as well as acquiring, processing, and disseminating the data will be described, including national and international collaborations. In addition to describing how the data are used for official government products, we will also give examples of how these data are used by both the public and private sector for new applications that serve the public.

  8. Holographic telescope

    NASA Astrophysics Data System (ADS)

    Odhner, Jefferson E.

    2016-07-01

    Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases replace conventional optical elements that work on the principal of refraction. An HOE can be thinner, lighter, can have more functionality, and can be lower cost than conventional optics. An HOE can serve as a beam splitter, spectral filter, mirror, and lens all at the same time. For a single wavelength system, an HOE can be an ideal solution but they have not been widely accepted for multispectral systems because they suffer from severe chromatic aberration. A refractive optical system also suffers from chromatic aberration but it is generally not as severe. To color correct a conventional refractive optical system, a flint glass and a crown glass are placed together such that the color dispersion of the flint and the crown cancel each other out making an achromatic lens (achromat) and the wavelengths all focus to the same point. The color dispersion of refractive lenses and holographic lenses are opposite from each other. In a diffractive optical system, long wavelengths focus closer (remember for HOEs: RBM "red bends more") than nominal focus while shorter wavelengths focus further out. In a refractive optical system, it is just the opposite. For this reason, diffractives can be incorporated into a refractive system to do the color correction and often cut down on the number of optical elements used [1.]. Color correction can also be achieved with an all-diffractive system by combining a holographic optical element with its conjugate. In this way the color dispersion of the first holographic optical element can be cancelled by the color dispersion of the second holographic optic. It is this technique that will be exploited in this paper to design a telescope made entirely of holographic optical elements. This telescope could be more portable (for field operations) the same technique could be used to make optics light enough for incorporation into a UAV.

  9. In-line real time air monitor

    DOEpatents

    Wise, Marcus B.; Thompson, Cyril V.

    1998-01-01

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds.

  10. In-line real time air monitor

    DOEpatents

    Wise, M.B.; Thompson, C.V.

    1998-07-14

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds. 3 figs.

  11. Real-time, face recognition technology

    SciTech Connect

    Brady, S.

    1995-11-01

    The Institute for Scientific Computing Research (ISCR) at Lawrence Livermore National Laboratory recently developed the real-time, face recognition technology KEN. KEN uses novel imaging devices such as silicon retinas developed at Caltech or off-the-shelf CCD cameras to acquire images of a face and to compare them to a database of known faces in a robust fashion. The KEN-Online project makes that recognition technology accessible through the World Wide Web (WWW), an internet service that has recently seen explosive growth. A WWW client can submit face images, add them to the database of known faces and submit other pictures that the system tries to recognize. KEN-Online serves to evaluate the recognition technology and grow a large face database. KEN-Online includes the use of public domain tools such as mSQL for its name-database and perl scripts to assist the uploading of images.

  12. A Flexible Real-Time Architecture

    SciTech Connect

    WICKSTROM,GREGORY L.

    2000-08-17

    Assuring hard real-time characteristics of I/O associated with embedded software is often a difficult task. Input-Output related statements are often intermixed with the computational code, resulting in I/O timing that is dependent on the execution path and computational load. One way to mitigate this problem is through the use of interrupts. However, the non-determinism that is introduced by interrupt driven I/O may be so difficult to analyze that it is prohibited in some high consequence systems. This paper describes a balanced hardware/software solution to obtain consistent interrupt-free I/O timing, and results in software that is much more amenable to analysis.

  13. Real time speech formant analyzer and display

    DOEpatents

    Holland, George E.; Struve, Walter S.; Homer, John F.

    1987-01-01

    A speech analyzer for interpretation of sound includes a sound input which converts the sound into a signal representing the sound. The signal is passed through a plurality of frequency pass filters to derive a plurality of frequency formants. These formants are converted to voltage signals by frequency-to-voltage converters and then are prepared for visual display in continuous real time. Parameters from the inputted sound are also derived and displayed. The display may then be interpreted by the user. The preferred embodiment includes a microprocessor which is interfaced with a television set for displaying of the sound formants. The microprocessor software enables the sound analyzer to present a variety of display modes for interpretive and therapeutic used by the user.

  14. Real time speech formant analyzer and display

    DOEpatents

    Holland, G.E.; Struve, W.S.; Homer, J.F.

    1987-02-03

    A speech analyzer for interpretation of sound includes a sound input which converts the sound into a signal representing the sound. The signal is passed through a plurality of frequency pass filters to derive a plurality of frequency formants. These formants are converted to voltage signals by frequency-to-voltage converters and then are prepared for visual display in continuous real time. Parameters from the inputted sound are also derived and displayed. The display may then be interpreted by the user. The preferred embodiment includes a microprocessor which is interfaced with a television set for displaying of the sound formants. The microprocessor software enables the sound analyzer to present a variety of display modes for interpretive and therapeutic used by the user. 19 figs.

  15. PCs stir reliability, real-time concerns

    SciTech Connect

    Strothman, J.

    1994-11-01

    While pre-Christmas price wars regularly boost personal computer sales this time of year, price cuts alone won`t cause process control systems designers to open their wallets and buy PCs. User studies and user feedback to process control equipment suppliers show several other issues continue to rank higher than price including: (1) Hardware and software reliability; (2) easy-to-use user interfaces; (3) ability to do multitasking; (4) need for real-time updates. These and several other non-price issues - including open versus proprietary systems, slower scan rates from PCs compared to programmable controllers, and assurances that the PC will work in an industrial environment - scored high in a study authored earlier this year by Jesse Yoder, owner of Idea Network, Clinton, NJ. The report, titled {open_quotes}The World Market for Process Control Equipment,{close_quotes} was written for FIND/SVP, a New York City market research firm.

  16. Near real-time traffic routing

    NASA Technical Reports Server (NTRS)

    Yang, Chaowei (Inventor); Cao, Ying (Inventor); Xie, Jibo (Inventor); Zhou, Bin (Inventor)

    2012-01-01

    A near real-time physical transportation network routing system comprising: a traffic simulation computing grid and a dynamic traffic routing service computing grid. The traffic simulator produces traffic network travel time predictions for a physical transportation network using a traffic simulation model and common input data. The physical transportation network is divided into a multiple sections. Each section has a primary zone and a buffer zone. The traffic simulation computing grid includes multiple of traffic simulation computing nodes. The common input data includes static network characteristics, an origin-destination data table, dynamic traffic information data and historical traffic data. The dynamic traffic routing service computing grid includes multiple dynamic traffic routing computing nodes and generates traffic route(s) using the traffic network travel time predictions.

  17. Real-time monitoring of swimming performance.

    PubMed

    Delgado-Gonzalo, R; Lemkaddem, A; Renevey, Ph; Calvo, E Muntane; Lemay, M; Cox, K; Ashby, D; Willardson, J; Bertschi, M

    2016-08-01

    This article presents the performance results of a novel algorithm for swimming analysis in real-time within a low-power wrist-worn device. The estimated parameters are: lap count, stroke count, time in lap, total swimming time, pace/speed per lap, total swam distance, and swimming efficiency (SWOLF). In addition, several swimming styles are automatically detected. Results were obtained using a database composed of 13 different swimmers spanning 646 laps and 858.78 min of total swam time. The final precision achieved in lap detection ranges between 99.7% and 100%, and the classification of the different swimming styles reached a sensitivity and specificity above 98%. We demonstrate that a swimmers performance can be fully analyzed with the smart bracelet containing the novel algorithm. The presented algorithm has been licensed to ICON Health & Fitness Inc. for their line of wearables under the brand iFit.

  18. Cerebral Autoregulation Real-Time Monitoring

    PubMed Central

    Tsalach, Adi; Ratner, Eliahu; Lokshin, Stas; Silman, Zmira; Breskin, Ilan; Budin, Nahum; Kamar, Moshe

    2016-01-01

    Cerebral autoregulation is a mechanism which maintains constant cerebral blood flow (CBF) despite changes in mean arterial pressure (MAP). Assessing whether this mechanism is intact or impaired and determining its boundaries is important in many clinical settings, where primary or secondary injuries to the brain may occur. Herein we describe the development of a new ultrasound tagged near infra red light monitor which tracks CBF trends, in parallel, it continuously measures blood pressure and correlates them to produce a real time autoregulation index. Its performance is validated in both in-vitro experiment and a pre-clinical case study. Results suggest that using such a tool, autoregulation boundaries as well as its impairment or functioning can be identified and assessed. It may therefore assist in individualized MAP management to ensure adequate organ perfusion and reduce the risk of postoperative complications, and might play an important role in patient care. PMID:27571474

  19. REAL TIME DATA FOR REMEDIATION ACTIVITIES [11505

    SciTech Connect

    BROCK CT

    2011-01-13

    Health physicists from the CH2M HILL Plateau Remediation Company collaborated with Berkeley Nucleonics Corporation to modify the SAM 940 isotope identifier instrument to be used for nuclear waste remediation. These modifications coupled with existing capabilities of the SAM 940 have proven to be invaluable during remediation activities, reducing disposal costs by allowing swift remediation of targeted areas that have been identified as having isotopes of concern (IOC), and eliminating multiple visits to sites by declaring an excavation site clear of IOCs before demobilizing from the site. These advantages are enabled by accumulating spectral data for specific isotopes that is nearly 100 percent free of false positives, which are filtered out in 'real time.'

  20. Terrestrial Real-Time Volcano Monitoring

    NASA Astrophysics Data System (ADS)

    Franke, M.

    2013-12-01

    As volcano monitoring involves more and different sensors from seismic to GPS receivers, from video and thermal cameras to multi-parameter probes measuring temperature, ph values and humidity in the ground and the air, it becomes important to design real-time networks that integrate and leverage the multitude of available parameters. In order to do so some simple principles need to be observed: a) a common time base for all measurements, b) a packetized general data communication protocol for acquisition and distribution, c) an open and well documented interface to the data permitting standard and emerging innovative processing, and d) an intuitive visualization platform for scientists and civil defense personnel. Although mentioned as simple principles, the list above does not necessarily lead to obvious solutions or integrated systems, which is, however, required to take advantage of the available data. Only once the different data streams are put into context to each other in terms of time and location can a broader view be obtained and additional information extracted. The presentation is a summary of currently available technologies and how they can achieve the goal of an integrated real-time volcano monitoring system. A common time base are standard for seismic and GPS networks. In different projects we extended this to video feeds and time-lapse photography. Other probes have been integrated with vault interface enclosures (VIE) as used in the Transportable Array (TA) of the USArray. The VIE can accommodate the sensors employed in volcano monitoring. The TA has shown that Antelope is a versatile and robust middleware. It provides the required packetized general communication protocol that is independent from the actual physical communication link leaving the network design to adopt appropriate and possible hybrid solutions. This applies for the data acquisition and the data/information dissemination providing both a much needed collaboration platform, as