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Sample records for future wide-field optical

  1. The DESI Wide Field Corrector Optics

    SciTech Connect

    Doel, Peter; Sholl, Michael J.; Liang, Ming; Brooks, David; Flaugher, Brenna; Gutierrez, Gaston; Kent, Stephen; Lampton, Michael; Miller, Timothy; Sprayberry, David

    2014-01-01

    The Dark Energy Spectroscopic instrument (DESI) is a 5000 fiber multi-object spectrometer system under development for installation on the National Optical Astronomy Observatory (NOAO) Kitt Peak 4m telescope (the Mayall telescope). DESI is designed to perform a 14,000˚ (square) galaxy and Quasi-Stellar Object (QSO) redshift survey to improve estimates of the dark energy equation of state. The survey design imposes numerous constraints on a prime focus corrector design, including field of view, geometrical blur, stability, fiber injection efficiency, zenith angle, mass and cost. The DESI baseline wide-field optical design described herein provides a 3.2˚ diameter field of view with six 0.8- 1.14m diameter lenses and an integral atmospheric dispersion compensator.

  2. Adaptive wide-field optical tomography

    NASA Astrophysics Data System (ADS)

    Venugopal, Vivek; Intes, Xavier

    2013-03-01

    We describe a wide-field optical tomography technique, which allows the measurement-guided optimization of illumination patterns for enhanced reconstruction performances. The iterative optimization of the excitation pattern aims at reducing the dynamic range in photons transmitted through biological tissue. It increases the number of measurements collected with high photon counts resulting in a dataset with improved tomographic information. Herein, this imaging technique is applied to time-resolved fluorescence molecular tomography for preclinical studies. First, the merit of this approach is tested by in silico studies in a synthetic small animal model for typical illumination patterns. Second, the applicability of this approach in tomographic imaging is validated in vitro using a small animal phantom with two fluorescent capillaries occluded by a highly absorbing inclusion. The simulation study demonstrates an improvement of signal transmitted (˜2 orders of magnitude) through the central portion of the small animal model for all patterns considered. A corresponding improvement in the signal at the emission wavelength by 1.6 orders of magnitude demonstrates the applicability of this technique for fluorescence molecular tomography. The successful discrimination and localization (˜1 mm error) of the two objects with higher resolution using the optimized patterns compared with nonoptimized illumination establishes the improvement in reconstruction performance when using this technique.

  3. Wide field strip-imaging optical system

    NASA Technical Reports Server (NTRS)

    Vaughan, Arthur H. (Inventor)

    1994-01-01

    A strip imaging wide angle optical system is provided. The optical system is provided with a 'virtual' material stop to avoid aberrational effects inherent in wide angle optical systems. The optical system includes a spherical mirror section for receiving light from a 180-degree strip or arc of a target image. Light received by the spherical mirror section is reflected to a frusto-conical mirror section for subsequent rereflection to a row of optical fibers. Each optical fiber transmits a portion of the received light to a detector. The optical system exploits the narrow cone of acceptance associated with optical fibers to substantially eliminate vignetting effects inherent in wide-angle systems. Further, the optical system exploits the narrow cone of acceptance of the optical fibers to substantially limit spherical aberration. The optical system is ideally suited for any application wherein a 180-degree strip image need be detected, and is particularly well adapted for use in hostile environments such as in planetary exploration.

  4. Optical Design of WFIRST-AFTA Wide-Field Instrument

    NASA Technical Reports Server (NTRS)

    Pasquale, Bert; Content, Dave; Kruk, Jeffrey; Vaughn, David; Gong, Qian; Howard, Joseph; Jurling, Alden; Mentzell, Eric; Armani, Nerses; Kuan, Gary

    2014-01-01

    The WFIRSTAFTA Wide-Field Infrared Survey Telescope TMA optical design provides 0.28-sq FOV at 0.11 pixel scale, operating between 0.6 2.4m, including a spectrograph mode (1.3-1.95m.) An IFU provides a discrete 3x3.15 field at 0.15 sampling.

  5. 'Virtual triple Schmidt' - Wide field two-stage optics

    NASA Technical Reports Server (NTRS)

    Manhart, Paul K.

    1989-01-01

    The design concept of an unobscured-wide-field two-stage optical system based on a virtual triple Schmidt (VTS) configuration is presented. It is pointed out that the single large aperture and field-partitioning capability of two-stage systems can lower material and fabrication costs, making the VTS optics suitable for ground-based and space telescopes. The VTS design combines a Schmidt-camera first stage and a second stage comprising two back-to-back Schmidt systems as a 1:1 relay. Aspheric Schmidt correction is achieved at the relayed pupil location for all three systems. The effects of the separation between the error-producing surface and the aperture stop are discussed; the performance of the wavefront-correction system is analyzed; and extensive diagrams, drawings, and graphs of projected performance data are provided.

  6. Data Reduction Algorithm for Optical Wide Field Patrol (OWL)

    NASA Astrophysics Data System (ADS)

    Park, S.; Park, Y.; Yim, H.; Jo, J.; Moon, H.; Bae, Y.; Lim, Y.; Choi, J.; Choi, Y.; Park, J.; Son, J.

    2014-09-01

    OWL (Optical Wide-field Patrol) has a detector system which has the chopper which consists of 4 blades in front of the CCD camera to acquire efficiently the position and time information of moving objects such as artificial satellites. Using this system, it is possible to get more position data by splitting the streaks of the moving object into many pieces with fast rotating blades during tracking. At the same time, the time data of the rotating chopper can be acquired by the time tagger connected to the photo diode. In order to derive the orbits of the targets, we need a sequential data reduction procedure including the calculation of WCS (World Coordinate System) solution to transform the positions into equatorial coordinate systems, and the combination of the time data from the time tagger and the position data. We present such a data reduction procedure and the preliminary results after applying this procedure to the observation images.

  7. Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems

    NASA Astrophysics Data System (ADS)

    Basden, A. G.; Atkinson, D.; Bharmal, N. A.; Bitenc, U.; Brangier, M.; Buey, T.; Butterley, T.; Cano, D.; Chemla, F.; Clark, P.; Cohen, M.; Conan, J.-M.; de Cos, F. J.; Dickson, C.; Dipper, N. A.; Dunlop, C. N.; Feautrier, P.; Fusco, T.; Gach, J. L.; Gendron, E.; Geng, D.; Goodsell, S. J.; Gratadour, D.; Greenaway, A. H.; Guesalaga, A.; Guzman, C. D.; Henry, D.; Holck, D.; Hubert, Z.; Huet, J. M.; Kellerer, A.; Kulcsar, C.; Laporte, P.; Le Roux, B.; Looker, N.; Longmore, A. J.; Marteaud, M.; Martin, O.; Meimon, S.; Morel, C.; Morris, T. J.; Myers, R. M.; Osborn, J.; Perret, D.; Petit, C.; Raynaud, H.; Reeves, A. P.; Rousset, G.; Sanchez Lasheras, F.; Sanchez Rodriguez, M.; Santos, J. D.; Sevin, A.; Sivo, G.; Stadler, E.; Stobie, B.; Talbot, G.; Todd, S.; Vidal, F.; Younger, E. J.

    2016-06-01

    Recent advances in adaptive optics (AO) have led to the implementation of wide field-of-view AO systems. A number of wide-field AO systems are also planned for the forthcoming Extremely Large Telescopes. Such systems have multiple wavefront sensors of different types, and usually multiple deformable mirrors (DMs). Here, we report on our experience integrating cameras and DMs with the real-time control systems of two wide-field AO systems. These are CANARY, which has been operating on-sky since 2010, and DRAGON, which is a laboratory AO real-time demonstrator instrument. We detail the issues and difficulties that arose, along with the solutions we developed. We also provide recommendations for consideration when developing future wide-field AO systems.

  8. Optical design of interferometric telescopes with wide fields of view.

    PubMed

    Sabatke, Erin E; Burge, James H; Hinz, Philip

    2006-11-01

    The performance of wide-field multiple-aperture imaging systems is dominated by easily understood, low-order errors. Each aperture produces an individual image, each pair of apertures produces a set of fringes under a diffraction envelope, and the system bandwidth produces a coherence envelope. For wide-field imaging, each of these elements must be coincident in the image plane as the field angle changes. We explore the causes of image degradation, derive first-order rules for preserving image quality across field, and give an example design that enforces some of the rules to achieve a relatively wide-field interferometric imaging telescope. PMID:17068543

  9. 3D defect detection using optical wide-field microscopy

    NASA Astrophysics Data System (ADS)

    Tympel, Volker; Schaaf, Marko; Srocka, Bernd

    2007-06-01

    We report a method to detect signed differences in two similar data sets representing 3-dimensional intensity profiles recorded by optical wide-field microscopes. The signed differences describe missing or unexpected intensity values, defined as defects. In technical applications like wafer and mask inspection, data sets often represent surfaces. The reported method is able to describe the size and position especially in relation to the neighboring surface and is called Three-Dimension-Aberration (TDA)-Technology. To increase the tool performance and to handle different sizes of defects a scaled bottom-up method is implemented and started with high reduced data sets for the search of large defects. Each analysis contains three steps. The first step is a correlation to calculate the displacement vector between the similar data sets. In the second step a new data set is created. The new data set consists of intensity differences. Extreme values in the data set represent the position of defects. By the use of linear and non-linear filters the stability of detection can be improved. If all differences are below a threshold the bottom-up method starts with the next larger scaled data set. In the other case it is assumed that the defect is detected and step three starts with the detection of the convex hull of the defect and the search of the neighboring surface. As a result the defect is described by a parameter set including the relative position. Because of the layered structure of the data set and the bottom-up technique the method is suitable for multi-core processor architectures.

  10. Wide-Field Optic for Autonomous Acquisition of Laser Link

    NASA Technical Reports Server (NTRS)

    Page, Norman A.; Charles, Jeffrey R.; Biswas, Abhijit

    2011-01-01

    An innovation reported in Two-Camera Acquisition and Tracking of a Flying Target, NASA Tech Briefs, Vol. 32, No. 8 (August 2008), p. 20, used a commercial fish-eye lens and an electronic imaging camera for initially locating objects with subsequent handover to an actuated narrow-field camera. But this operated against a dark-sky background. An improved solution involves an optical design based on custom optical components for the wide-field optical system that directly addresses the key limitations in acquiring a laser signal from a moving source such as an aircraft or a spacecraft. The first challenge was to increase the light collection entrance aperture diameter, which was approximately 1 mm in the first prototype. The new design presented here increases this entrance aperture diameter to 4.2 mm, which is equivalent to a more than 16 times larger collection area. One of the trades made in realizing this improvement was to restrict the field-of-view to +80 deg. elevation and 360 azimuth. This trade stems from practical considerations where laser beam propagation over the excessively high air mass, which is in the line of sight (LOS) at low elevation angles, results in vulnerability to severe atmospheric turbulence and attenuation. An additional benefit of the new design is that the large entrance aperture is maintained even at large off-axis angles when the optic is pointed at zenith. The second critical limitation for implementing spectral filtering in the design was tackled by collimating the light prior to focusing it onto the focal plane. This allows the placement of the narrow spectral filter in the collimated portion of the beam. For the narrow band spectral filter to function properly, it is necessary to adequately control the range of incident angles at which received light intercepts the filter. When this angle is restricted via collimation, narrower spectral filtering can be implemented. The collimated beam (and the filter) must be relatively large to

  11. Wide-Field Sky Monitoring - Optical and X-rays

    NASA Astrophysics Data System (ADS)

    Hudec, R.; BART Teams; Ondrejov Observatory Lobster Eye Team

    We report on selected projects in wide-field sky imaging. This includes the recent efforts to digitize the astronomical sky plate archives and to apply these data for various scientific projects. We also address and discuss the status of the development of related algorithms and software programs. These data may easily provide very long term monitoring over very extended time intervals (up to more than 100 years) with limiting magnitudes between 12 and 23. The further experiments include CCD sky monitors, OMC camera onboard the ESA Integral satellite, robotic telescopes, and innovative wide-field X-ray telescopes.

  12. Telescope with a wide field of view internal optical scanner

    NASA Technical Reports Server (NTRS)

    Degnan, III, John James (Inventor); Zheng, Yunhui (Inventor)

    2012-01-01

    A telescope with internal scanner utilizing either a single optical wedge scanner or a dual optical wedge scanner and a controller arranged to control a synchronous rotation of the first and/or second optical wedges, the wedges constructed and arranged to scan light redirected by topological surfaces and/or volumetric scatterers. The telescope with internal scanner further incorporates a first converging optical element that receives the redirected light and transmits the redirected light to the scanner, and a second converging optical element within the light path between the first optical element and the scanner arranged to reduce an area of impact on the scanner of the beam collected by the first optical element.

  13. Wide field/planetary camera optics study. [for the large space telescope

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Design feasibility of the baseline optical design concept was established for the wide field/planetary camera (WF/PC) and will be used with the space telescope (ST) to obtain high angular resolution astronomical information over a wide field. The design concept employs internal optics to relay the ST image to a CCD detector system. Optical design performance predictions, sensitivity and tolerance analyses, manufacturability of the optical components, and acceptance testing of the two mirror Cassegrain relays are discussed.

  14. Wide Field Survey for Sub-Second Optical Variability

    NASA Astrophysics Data System (ADS)

    O'Donnell, Liam; Pollacco, Don

    2008-02-01

    An Andor Ixon+EMCCD was used to monitor stellar variability and search, in the optical, for transient astronomical events at high time resolution (<1 sec) over a relatively large (9-degree) area of sky. A monitoring program, which targeted a 9-degree field in Lyra, was conducted during July 2006. The detector was equipped with a wide-angle lens and mounted piggyback on a commercial telescope located at the Roque de los Muchachos observing site on the island of La Palma. The field was monitored for 5 consecutive nights with a time resolution of a tenth of a second and an unfiltered limiting magnitude of 10. At present only a handful of astronomical objects have been monitored at this time resolution and there is limited survey data for large areas of sky. It is hoped the experiment will provide statistical analysis of optical variability of astronomical sources on sub-second timescales and potentially discover high-energy transient sources. The experiment will also investigate the applicability of the current generation of EMCCD detectors for such astronomical projects.

  15. An optical design for a wide-field optical spectrograph for TMT

    NASA Astrophysics Data System (ADS)

    Bernstein, Rebecca A.; Bigelow, Bruce C.

    2008-07-01

    We describe a preliminary optical design for a multi-object, wide-field, optical echellette spectrograph that is intended to serve a broad range of science. It will produce low-resolution, single-order spectra for survey-mode programs targeting as many objects as possible and also moderate-resolution, multiple-order spectra for a reduced number of targets. The design uses all refracting optics. The first optical element of the spectrograph is a wide-field corrector for the telescope that causes the chief rays to be perpendicular to the focal plane. The collimator, which has been designed on-axis, can then be duplicated to target multiple, off-axis fields in a multiple-barrel configuration. The collimator optics include an achromatic field lens group that forms a sharp pupil over the full optical band-pass (320-1000 nm), followed by a dichroic which splits the beam into a red and a blue channel. All remaining optical elements of the collimator, the gratings, the cameras, and the detectors are then optimized for red or blue wavelengths. Both red and blue channels of each beam of the spectrograph use reflection gratings to produce either a single-order spectrum at resolutions around R=λ/Δλ=1000 or a five-order, R>5000 echellette spectrum with prism cross-dispersion. Both modes can target objects anywhere in the collimated field of view. A direct imaging mode will also be provided.

  16. Optical system of large relative aperture and wide field using aspheric corrector for detecting

    NASA Astrophysics Data System (ADS)

    Ming, Ming; Wang, Jianli; Zhang, Jingxu

    2009-05-01

    The magnitude requirement of space target detecting determines that the image of detecting telescope should have several performances: small spots, small 80% encircled energy diameter and good MTF(Modulation transfer function). So the aperture and field of view of optical system have some demands accordingly. The larger aperture, the more energy that telescope collects and higher magnitude the telescope detects; the wider field of view, the more extensive range which the telescope searches. Now most of ground telescopes whose apertures are from 500mm to 1000mm is on-axis optical system, so wide field of view becomes the most importance problem. To obtain large relative aperture and wide field of view, the paper introduces a catadioptric telescope with small aperture aspheric refractive corrector, whose conic surface will be used to remove the aberrations due to large relative aperture and wide field of view. As to the optical system, there is only one aspheric refractive corrector, and it is relatively easy for manufacturing because of its concave figure and normal material. The paper gives the example, and optimizes this optical system with ZEMAX program. And then the paper provides a specific analysis program for testing the aspheric refractive corrector. The aperture of this optical system is 750mm, and its relative aperture is 0.82, and the field of view is 3.6° diameter(diagonal). Its structure is simple and the image quality is also very good.

  17. Adaptive optics scanning laser ophthalmoscope with integrated wide-field retinal imaging and tracking

    PubMed Central

    Ferguson, R. Daniel; Zhong, Zhangyi; Hammer, Daniel X.; Mujat, Mircea; Patel, Ankit H.; Deng, Cong; Zou, Weiyao; Burns, Stephen A.

    2010-01-01

    We have developed a new, unified implementation of the adaptive optics scanning laser ophthalmoscope (AOSLO) incorporating a wide-field line-scanning ophthalmoscope (LSO) and a closed-loop optical retinal tracker. AOSLO raster scans are deflected by the integrated tracking mirrors so that direct AOSLO stabilization is automatic during tracking. The wide-field imager and large-spherical-mirror optical interface design, as well as a large-stroke deformable mirror (DM), enable the AOSLO image field to be corrected at any retinal coordinates of interest in a field of >25 deg. AO performance was assessed by imaging individuals with a range of refractive errors. In most subjects, image contrast was measurable at spatial frequencies close to the diffraction limit. Closed-loop optical (hardware) tracking performance was assessed by comparing sequential image series with and without stabilization. Though usually better than 10 μm rms, or 0.03 deg, tracking does not yet stabilize to single cone precision but significantly improves average image quality and increases the number of frames that can be successfully aligned by software-based post-processing methods. The new optical interface allows the high-resolution imaging field to be placed anywhere within the wide field without requiring the subject to re-fixate, enabling easier retinal navigation and faster, more efficient AOSLO montage capture and stitching. PMID:21045887

  18. Scalable wide-field optical coherence tomography-based angiography for in vivo imaging applications

    PubMed Central

    Xu, Jingjiang; Wei, Wei; Song, Shaozhen; Qi, Xiaoli; Wang, Ruikang K.

    2016-01-01

    Recent advances in optical coherence tomography (OCT)-based angiography have demonstrated a variety of biomedical applications in the diagnosis and therapeutic monitoring of diseases with vascular involvement. While promising, its imaging field of view (FOV) is however still limited (typically less than 9 mm2), which somehow slows down its clinical acceptance. In this paper, we report a high-speed spectral-domain OCT operating at 1310 nm to enable wide FOV up to 750 mm2. Using optical microangiography (OMAG) algorithm, we are able to map vascular networks within living biological tissues. Thanks to 2,048 pixel-array line scan InGaAs camera operating at 147 kHz scan rate, the system delivers a ranging depth of ~7.5 mm and provides wide-field OCT-based angiography at a single data acquisition. We implement two imaging modes (i.e., wide-field mode and high-resolution mode) in the OCT system, which gives highly scalable FOV with flexible lateral resolution. We demonstrate scalable wide-field vascular imaging for multiple finger nail beds in human and whole brain in mice with skull left intact at a single 3D scan, promising new opportunities for wide-field OCT-based angiography for many clinical applications. PMID:27231630

  19. Concerning the Development of the Wide-Field Optics for WFXT Including Methods of Optimizing X-Ray Optical Prescriptions for Wide-Field Applications

    NASA Technical Reports Server (NTRS)

    Weisskopf, M. C.; Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.

    2010-01-01

    We present a progress report on the various endeavors we are undertaking at MSFC in support of the Wide Field X-Ray Telescope development. In particular we discuss assembly and alignment techniques, in-situ polishing corrections, and the results of our efforts to optimize mirror prescriptions including polynomial coefficients, relative shell displacements, detector placements and tilts. This optimization does not require a blind search through the multi-dimensional parameter space. Under the assumption that the parameters are small enough so that second order expansions are valid, we show that the performance at the detector can be expressed as a quadratic function with numerical coefficients derived from a ray trace through the underlying Wolter I optic. The optimal values for the parameters are found by solving the linear system of equations creating by setting derivatives of this function with respect to each parameter to zero.

  20. Design of a wide-field imaging optical system with super-resolution reconstruction

    NASA Astrophysics Data System (ADS)

    Shao, Xiaopeng; Xu, Jie; Wang, Jiaoyang; Chen, Xiaodong; Gong, Rui; Bi, Xiangli

    2015-05-01

    The need for a portable image acquiring system has become as strong as the extension of digital imaging technology, for this, a new mono-centric wide-field optical system is proposed. Recently, some high-resolution and wide-field imaging systems have been raised already, with which fairly clear and wide field of view (FOV) images could be easily obtained, however, their sizes are comparatively too large to be conveniently carried . With ZEMAX, a new optical design is emulated by scaling the structure of current wide-field optical systems and introducing the proposed lens-let arrays, the size of the whole system is comparatively smaller with the structure consisting of a two-glass mono-centric lens, lens-let array (the lenses in the array can be different), and a specific detector. Lens-let array is used to make the image plane from curve to almost flat. This hardware is small enough to apply to helmets and computers and the FOV of which is wide. Verified by a series of merit function, this optical design is found to have an acceptable imaging resolution and the computational imaging method is applied to this system to acquire a higher imaging resolution. From each lens-let a series of low resolution images are obtained and in this system a high-resolution image can be retrieved from multiple low-resolution images with super-resolution reconstruction method. Compared from the size and the imaging resolution, this new optical design is much smaller and has a higher imaging resolution.

  1. Wide-field three-dimensional optical imaging using temporal focusing for holographically trapped microparticles.

    PubMed

    Spesyvtsev, Roman; Rendall, Helen A; Dholakia, Kishan

    2015-11-01

    A contemporary challenge across the natural sciences is the simultaneous optical imaging or stimulation of small numbers of cells or colloidal particles organized into arbitrary geometries. We demonstrate the use of temporal focusing with holographic optical tweezers in order to achieve depth-resolved two-photon imaging of trapped objects arranged in arbitrary three-dimensional (3D) geometries using a single objective. Trapping allows for the independent position control of multiple objects by holographic beam shaping. Temporal focusing of ultrashort pulses provides the wide-field two-photon depth-selective activation of fluorescent samples. We demonstrate the wide-field depth-resolved illumination of both trapped fluorescent beads and trapped HL60 cells in suspension with full 3D positioning control. These approaches are compatible with implementation through scattering media and can be beneficial for emergent studies in colloidal science and particularly optogenetics, offering targeted photoactivation over a wide area with micrometer-precision depth control. PMID:26512465

  2. Application of a wide-field phantom eye for optical coherence tomography and reflectance imaging

    PubMed Central

    Corcoran, Anthony; Muyo, Gonzalo; van Hemert, Jano; Gorman, Alistair; Harvey, Andrew R.

    2015-01-01

    Optical coherence tomography (OCT) and reflectance imaging are used in clinical practice to measure the thickness and transverse dimensions of retinal features. The recent trend towards increasing the field of view (FOV) of these devices has led to an increasing significance of the optical aberrations of both the human eye and the device. We report the design, manufacture and application of the first phantom eye that reproduces the off-axis optical characteristics of the human eye, and allows the performance assessment of wide-field ophthalmic devices. We base our design and manufacture on the wide-field schematic eye, [Navarro, R. J. Opt. Soc. Am. A, 1985, 2.] as an accurate proxy to the human eye and enable assessment of ophthalmic imaging performance for a ±70∘ external FOV. We used multi-material 3D-printed retinal targets to assess imaging performance of the following ophthalmic instruments: the Optos 200Tx, Heidelberg Spectralis, Zeiss FF4 fundus camera and Optos OCT SLO and use the phantom to provide an insight into some of the challenges of wide-field OCT. PMID:26740737

  3. Application of a wide-field phantom eye for optical coherence tomography and reflectance imaging

    NASA Astrophysics Data System (ADS)

    Corcoran, Anthony; Muyo, Gonzalo; van Hemert, Jano; Gorman, Alistair; Harvey, Andrew R.

    2015-12-01

    Optical coherence tomography (OCT) and reflectance imaging are used in clinical practice to measure the thickness and transverse dimensions of retinal features. The recent trend towards increasing the field of view (FOV) of these devices has led to an increasing significance of the optical aberrations of both the human eye and the device. We report the design, manufacture and application of the first phantom eye that reproduces the off-axis optical characteristics of the human eye, and allows the performance assessment of wide-field ophthalmic devices. We base our design and manufacture on the wide-field schematic eye, [Navarro, R. J. Opt. Soc. Am. A, 1985, 2.] as an accurate proxy to the human eye and enable assessment of ophthalmic imaging performance for a ? external FOV. We used multi-material 3D-printed retinal targets to assess imaging performance of the following ophthalmic instruments: the Optos 200Tx, Heidelberg Spectralis, Zeiss FF4 fundus camera and Optos OCT SLO and use the phantom to provide an insight into some of the challenges of wide-field OCT.

  4. Wide-field optical mapping of neural activity and brain haemodynamics: considerations and novel approaches.

    PubMed

    Ma, Ying; Shaik, Mohammed A; Kim, Sharon H; Kozberg, Mariel G; Thibodeaux, David N; Zhao, Hanzhi T; Yu, Hang; Hillman, Elizabeth M C

    2016-10-01

    Although modern techniques such as two-photon microscopy can now provide cellular-level three-dimensional imaging of the intact living brain, the speed and fields of view of these techniques remain limited. Conversely, two-dimensional wide-field optical mapping (WFOM), a simpler technique that uses a camera to observe large areas of the exposed cortex under visible light, can detect changes in both neural activity and haemodynamics at very high speeds. Although WFOM may not provide single-neuron or capillary-level resolution, it is an attractive and accessible approach to imaging large areas of the brain in awake, behaving mammals at speeds fast enough to observe widespread neural firing events, as well as their dynamic coupling to haemodynamics. Although such wide-field optical imaging techniques have a long history, the advent of genetically encoded fluorophores that can report neural activity with high sensitivity, as well as modern technologies such as light emitting diodes and sensitive and high-speed digital cameras have driven renewed interest in WFOM. To facilitate the wider adoption and standardization of WFOM approaches for neuroscience and neurovascular coupling research, we provide here an overview of the basic principles of WFOM, considerations for implementation of wide-field fluorescence imaging of neural activity, spectroscopic analysis and interpretation of results.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. PMID:27574312

  5. Wide-field optical coherence tomography based microangiography for retinal imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Qinqin; Lee, Cecilia S.; Chao, Jennifer; Chen, Chieh-Li; Zhang, Thomas; Sharma, Utkarsh; Zhang, Anqi; Liu, Jin; Rezaei, Kasra; Pepple, Kathryn L.; Munsen, Richard; Kinyoun, James; Johnstone, Murray; van Gelder, Russell N.; Wang, Ruikang K.

    2016-02-01

    Optical coherence tomography angiography (OCTA) allows for the evaluation of functional retinal vascular networks without a need for contrast dyes. For sophisticated monitoring and diagnosis of retinal diseases, OCTA capable of providing wide-field and high definition images of retinal vasculature in a single image is desirable. We report OCTA with motion tracking through an auxiliary real-time line scan ophthalmoscope that is clinically feasible to image functional retinal vasculature in patients, with a coverage of more than 60 degrees of retina while still maintaining high definition and resolution. We demonstrate six illustrative cases with unprecedented details of vascular involvement in retinal diseases. In each case, OCTA yields images of the normal and diseased microvasculature at all levels of the retina, with higher resolution than observed with fluorescein angiography. Wide-field OCTA technology will be an important next step in augmenting the utility of OCT technology in clinical practice.

  6. Wide-field optical coherence tomography based microangiography for retinal imaging

    PubMed Central

    Zhang, Qinqin; Lee, Cecilia S.; Chao, Jennifer; Chen, Chieh-Li; Zhang, Thomas; Sharma, Utkarsh; Zhang, Anqi; Liu, Jin; Rezaei, Kasra; Pepple, Kathryn L.; Munsen, Richard; Kinyoun, James; Johnstone, Murray; Van Gelder, Russell N.; Wang, Ruikang K.

    2016-01-01

    Optical coherence tomography angiography (OCTA) allows for the evaluation of functional retinal vascular networks without a need for contrast dyes. For sophisticated monitoring and diagnosis of retinal diseases, OCTA capable of providing wide-field and high definition images of retinal vasculature in a single image is desirable. We report OCTA with motion tracking through an auxiliary real-time line scan ophthalmoscope that is clinically feasible to image functional retinal vasculature in patients, with a coverage of more than 60 degrees of retina while still maintaining high definition and resolution. We demonstrate six illustrative cases with unprecedented details of vascular involvement in retinal diseases. In each case, OCTA yields images of the normal and diseased microvasculature at all levels of the retina, with higher resolution than observed with fluorescein angiography. Wide-field OCTA technology will be an important next step in augmenting the utility of OCT technology in clinical practice. PMID:26912261

  7. Wide-field optical coherence tomography based microangiography for retinal imaging.

    PubMed

    Zhang, Qinqin; Lee, Cecilia S; Chao, Jennifer; Chen, Chieh-Li; Zhang, Thomas; Sharma, Utkarsh; Zhang, Anqi; Liu, Jin; Rezaei, Kasra; Pepple, Kathryn L; Munsen, Richard; Kinyoun, James; Johnstone, Murray; Van Gelder, Russell N; Wang, Ruikang K

    2016-01-01

    Optical coherence tomography angiography (OCTA) allows for the evaluation of functional retinal vascular networks without a need for contrast dyes. For sophisticated monitoring and diagnosis of retinal diseases, OCTA capable of providing wide-field and high definition images of retinal vasculature in a single image is desirable. We report OCTA with motion tracking through an auxiliary real-time line scan ophthalmoscope that is clinically feasible to image functional retinal vasculature in patients, with a coverage of more than 60 degrees of retina while still maintaining high definition and resolution. We demonstrate six illustrative cases with unprecedented details of vascular involvement in retinal diseases. In each case, OCTA yields images of the normal and diseased microvasculature at all levels of the retina, with higher resolution than observed with fluorescein angiography. Wide-field OCTA technology will be an important next step in augmenting the utility of OCT technology in clinical practice. PMID:26912261

  8. Developments of wide field submillimeter optics and lens antenna-coupled MKID cameras

    NASA Astrophysics Data System (ADS)

    Sekimoto, Y.; Nitta, T.; Karatsu, K.; Sekine, M.; Sekiguchi, S.; Okada, T.; Shu, S.; Noguchi, T.; Naruse, M.; Mitsui, K.; Okada, N.; Tsuzuki, T.; Dominjon, A.; Matsuo, H.

    2014-07-01

    Wide field cryogenic optics and millimeter-wave Microwave Kinetic Inductance Detector (MKID) cameras with Si lens array have been developed. MKID is a Cooper-pair breaking photon detector and consists of supercon- ducting resonators which enable microwave (~GHz) frequency multiplexing. Antenna-coupled Aluminum CPW resonators are put in a line on a Si substrate to be read by a pair of coaxial cables. A 220 GHz - 600 pixels MKID camera with anti-reflection (AR) coated Si lens has been demonstrated in an 0.1 K cryostat. A compact cryogenic system with high refractive index materials has been developed for the MKID camera.

  9. Scanner-Free and Wide-Field Endoscopic Imaging by Using a Single Multimode Optical Fiber

    NASA Astrophysics Data System (ADS)

    Choi, Youngwoon; Yoon, Changhyeong; Kim, Moonseok; Yang, Taeseok Daniel; Fang-Yen, Christopher; Dasari, Ramachandra R.; Lee, Kyoung Jin; Choi, Wonshik

    2012-11-01

    A single multimode fiber is considered an ideal optical element for endoscopic imaging due to the possibility of direct image transmission via multiple spatial modes. However, the wave distortion induced by the mode dispersion has been a fundamental limitation. In this Letter, we propose a method for eliminating the effect of mode dispersion and therefore realize wide-field endoscopic imaging by using only a single multimode fiber with no scanner attached to the fiber. Our method will potentially revolutionize endoscopy in various fields encompassing medicine and industry.

  10. Wide field adaptive optics laboratory demonstration with closed-loop tomographic control.

    PubMed

    Costille, Anne; Petit, Cyril; Conan, Jean-Marc; Kulcsár, Caroline; Raynaud, Henri-François; Fusco, Thierry

    2010-03-01

    HOMER, the new bench developed at ONERA devoted to wide field adaptive optics (WFAO) laboratory research, has allowed the first experimental validations of multi-conjugate adaptive optics (MCAO) and laser tomography adaptive optics (LTAO) concepts with a linear quadratic Gaussian (LQG) control approach. Results obtained in LTAO in closed loop show the significant gain in performance brought by LQG control, which allows tomographic reconstruction. We present a calibration and model identification strategy. Experimental results are shown to be consistent with end-to-end simulations. These results are very encouraging and demonstrate robustness of performance with respect to inevitable experimental uncertainties. They represent a first step for the study of very large telescope (VLT) and extremely large telescopes (ELT) instruments. PMID:20208937

  11. Progress Report on Optimizing X-ray Optical Prescriptions for Wide-Field Applications

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

    2011-01-01

    We report on the present status of our continuing efforts to develop a method for optimizing wide-field nested x-ray telescope mirror prescriptions. Utilizing extensive Monte-Carlo ray trace simulations, we find an analytic form for the root-mean-square dispersion of rays from a Wolter I optic on the surface of a flat focal plane detector as a function of detector tilt away from the nominal focal plane and detector displacement along the optical axis. The configuration minimizing the ray dispersion from a nested array of Wolter I telescopes is found by solving a linear system of equations for tilt and individual mirror pair displacement. Finally we outline our initial efforts at expanding this method to include higher order polynomial terms in the mirror prescriptions.

  12. Proto-Type Development of Optical Wide-field Patrol Network and Test Observation

    NASA Astrophysics Data System (ADS)

    Park, J.; Choi, Y.; Jo, J.; Moon, H.; Yim, H.; Park, Y.; Hae, Y.; Park, S.; Choi, J.; Son, J.

    2014-09-01

    We present a prototype system developed for optical satellite tracking and its early test observation results. The main objective of the OWL (Optical Wide-field patroL) network is to get orbital information for Korean domestic satellites using optical means only and to maintain their orbital elements. The network is composed of 5 small wide-field telescopes deployed over the world. Each observing station is operated in fully robotic manner from receiving observation schedule to reporting the result, and controlled by the headquarter located in Daejeon, Korea, where orbit calculation and observation strategy will be determined. We developed a compact telescope system for robotic observation and easy maintenance. The telescope is 0.5m of aperture diameter with Rechey-Cretian configuration and its field of view is 1.1 deg. It is equipped with 4K CCD with 9um pixel size, and its pixel scale is 1.2 arcsec/pixel. A chopper wheel with variable speed is adopted to get more points in a single shot. The CCD camera and all the rotating parts (chopper wheel, de-rotator, and filter wheel) are integrated into one compact component called a wheel station. Each observing station is equipped with a fully automatic dome and heavy duty environment monitoring system. We could get an image every 20 seconds and up to ~100 trail points in a single exposure. Each point is time-tagged by ~1/1000 second precision. For one of best cases, we could estimate satellite position with RMS ~ 0.5km accuracy in the along-track with only 4 exposures (~100 points). The first system was installed at the Mongolian site after completing verification test at the testbed site in Daejeon, Korea. The second and third system will be installed in the end of this year.

  13. Wide-field optical coherence microscopy of the mouse brain slice.

    PubMed

    Min, Eunjung; Lee, Junwon; Vavilin, Andrey; Jung, Sunwoo; Shin, Sungwon; Kim, Jeehyun; Jung, Woonggyu

    2015-10-01

    The imaging capability of optical coherence microscopy (OCM) has great potential to be used in neuroscience research because it is able to visualize anatomic features of brain tissue without labeling or external contrast agents. However, the field of view of OCM is still narrow, which dilutes the strength of OCM and limits its application. In this study, we present fully automated wide-field OCM for mosaic imaging of sliced mouse brains. A total of 308 segmented OCM images were acquired, stitched, and reconstructed as an en-face brain image after intensive imaging processing. The overall imaging area was 11.2×7.0  mm (horizontal×vertical), and the corresponding pixel resolution was 1.2×1.2  μm. OCM images were compared to traditional histology stained with Nissl and Luxol fast blue (LFB). In particular, the orientation of the fibers was analyzed and quantified in wide-field OCM. PMID:26421546

  14. Computational Optical Imaging Systems for Spectroscopy and Wide Field-of-View Gigapixel Photography

    NASA Astrophysics Data System (ADS)

    Kittle, David Scott

    This dissertation explores computational optical imaging methods to circumvent the physical limitations of classical sensing. An ideal imaging system would maximize resolution in time, spectral bandwidth, three-dimensional object space, and polarization. Practically, increasing any one parameter will correspondingly decrease the others. Spectrometers strive to measure the power spectral density of the object scene. Traditional pushbroom spectral imagers acquire high resolution spectral and spatial resolution at the expense of acquisition time. Multiplexed spectral imagers acquire spectral and spatial information at each instant of time. Using a coded aperture and dispersive element, the coded aperture snapshot spectral imagers (CASSI) here described leverage correlations between voxels in the spatial-spectral data cube to compressively sample the power spectral density with minimal loss in spatial-spectral resolution while maintaining high temporal resolution. Photography is limited by similar physical constraints. Low f/# systems are required for high spatial resolution to circumvent diffraction limits and allow for more photon transfer to the film plain, but require larger optical volumes and more optical elements. Wide field systems similarly suffer from increasing complexity and optical volume. Incorporating a multi-scale optical system, the f/#, resolving power, optical volume and wide field of view become much less coupled. This system uses a single objective lens that images onto a curved spherical focal plane which is relayed by small micro-optics to discrete focal planes. Using this design methodology allows for gigapixel designs at low f/# that are only a few pounds and smaller than a one-foot hemisphere. Computational imaging systems add the necessary step of forward modeling and calibration. Since the mapping from object space to image space is no longer directly readable, post-processing is required to display the required data. The CASSI system uses

  15. Methods of Optimizing X-Ray Optical Prescriptions for Wide-Field Applications

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

    2010-01-01

    We are working on the development of a method for optimizing wide-field x-ray telescope mirror prescriptions, including polynomial coefficients, mirror shell relative displacements, and (assuming 4 focal plane detectors) detector placement and tilt that does not require a search through the multi-dimensional parameter space. Under the assumption that the parameters are small enough that second order expansions are valid, we show that the performance at the detector surface can be expressed as a quadratic function of the parameters with numerical coefficients derived from a ray trace through the underlying Wolter I optic. The best values for the parameters are found by solving the linear system of equations creating by setting derivatives of this function with respect to each parameter to zero. We describe the present status of this development effort.

  16. Tomographic reconstruction for wide-field adaptive optics systems: Fourier domain analysis and fundamental limitations.

    PubMed

    Neichel, Benoit; Fusco, Thierry; Conan, Jean-Marc

    2009-01-01

    Several wide-field-of-view adaptive optics (WFAO) concepts such as multi-conjugate AO (MCAO), multi-object AO (MOAO), and ground-layer AO (GLAO) are currently being studied for the next generation of Extremely Large Telescopes (ELTs). All these concepts will use atmospheric tomography to reconstruct the turbulent-phase volume. In this paper, we explore different reconstruction algorithms and their fundamental limitations, conducting this analysis in the Fourier domain. This approach allows us to derive simple analytical formulations for the different configurations and brings a comprehensive view of WFAO limitations. We then investigate model and statistical errors and their effect on the phase reconstruction. Finally, we show some examples of different WFAO systems and their expected performance on a 42 m telescope case. PMID:19109619

  17. A small animal time-resolved optical tomography platform using wide-field excitation

    NASA Astrophysics Data System (ADS)

    Venugopal, Vivek

    Small animal imaging plays a critical role in present day biomedical research by filling an important gap in the translation of research from the bench to the bedside. Optical techniques constitute an emerging imaging modality which have tremendous potential in preclinical applications. Optical imaging methods are capable of non-invasive assessment of the functional and molecular characteristics of biological tissue. The three-dimensional optical imaging technique, referred to as diffuse optical tomography, provides an approach for the whole-body imaging of small animal models and can provide volumetric maps of tissue functional parameters (e.g. blood volume, oxygen saturation etc.) and/or provide 3D localization and quantification of fluorescence-based molecular markers in vivo. However, the complex mathematical reconstruction problem associated with optical tomography and the cumbersome instrumental designs limits its adoption as a high-throughput quantitative whole-body imaging modality in current biomedical research. The development of new optical imaging paradigms is thus necessary for a wide-acceptance of this new technology. In this thesis, the design, development, characterization and optimization of a small animal optical tomography system is discussed. Specifically, the platform combines a highly sensitive time-resolved imaging paradigm with multi-spectral excitation capability and CCD-based detection to provide a system capable of generating spatially, spectrally and temporally dense measurement datasets. The acquisition of such data sets however can take long and translate to often unrealistic acquisition times when using the classical point source based excitation scheme. The novel approach in the design of this platform is the adoption of a wide-field excitation scheme which employs extended excitation sources and in the process allows an estimated ten-fold reduction in the acquisition time. The work described herein details the design of the imaging

  18. Direct design of two freeform optical surfaces for wide field of view line imaging applications

    NASA Astrophysics Data System (ADS)

    Nie, Yunfeng; Thienpont, Hugo; Duerr, Fabian

    2016-04-01

    In this paper, we propose a multi-fields direct design method aiming to calculate two freeform surfaces with an entrance pupil incorporated for wide field of view on-axis line imaging applications. Both infinite and finite conjugate objectives can be designed with this approach. Since a wide angle imaging system requires more than few discrete perfect imaging points, the multi-fields design approach is based on partial coupling of multiple fields, which guarantees a much more balanced imaging performance over the full field of view. The optical path lengths (OPLs) and image points of numerous off-axis fields are calculated during the procedure, thus very few initial parameters are needed. The procedure to calculate such a freeform lens is explained in detail. We have designed an exemplary monochromatic single lens to demonstrate the functionality of the design method. A rotationally symmetric counterpart following the same specifications is compared in terms of RMS spot radius to demonstrate the clear benefit that freeform lens brings to on-axis line imaging systems. In addition, a practical achromatic wide angle objective is designed by combining our multi-fields design method with classic optical design strategies, serving as a very good starting point for further optimization in a commercial optical design program. The results from the perspective of aberrations plots and MTF values show a very good and well balanced performance over the full field of view.

  19. Static and predictive tomographic reconstruction for wide-field multi-object adaptive optics systems.

    PubMed

    Correia, C; Jackson, K; Véran, J-P; Andersen, D; Lardière, O; Bradley, C

    2014-01-01

    Multi-object adaptive optics (MOAO) systems are still in their infancy: their complex optical designs for tomographic, wide-field wavefront sensing, coupled with open-loop (OL) correction, make their calibration a challenge. The correction of a discrete number of specific directions in the field allows for streamlined application of a general class of spatio-angular algorithms, initially proposed in Whiteley et al. [J. Opt. Soc. Am. A15, 2097 (1998)], which is compatible with partial on-line calibration. The recent Learn & Apply algorithm from Vidal et al. [J. Opt. Soc. Am. A27, A253 (2010)] can then be reinterpreted in a broader framework of tomographic algorithms and is shown to be a special case that exploits the particulars of OL and aperture-plane phase conjugation. An extension to embed a temporal prediction step to tackle sky-coverage limitations is discussed. The trade-off between lengthening the camera integration period, therefore increasing system lag error, and the resulting improvement in SNR can be shifted to higher guide-star magnitudes by introducing temporal prediction. The derivation of the optimal predictor and a comparison to suboptimal autoregressive models is provided using temporal structure functions. It is shown using end-to-end simulations of Raven, the MOAO science, and technology demonstrator for the 8 m Subaru telescope that prediction allows by itself the use of 1-magnitude-fainter guide stars. PMID:24561945

  20. Wide-field lensless fluorescent microscopy using a tapered fiber-optic faceplate on a chip†

    PubMed Central

    Coskun, Ahmet F.; Sencan, Ikbal; Su, Ting-Wei; Ozcan, Aydogan

    2011-01-01

    We demonstrate lensless fluorescent microscopy over a large field-of-view of ~60 mm2 with a spatial resolution of <4 μm. In this on-chip fluorescent imaging modality, the samples are placed on a fiber-optic faceplate that is tapered such that the density of the fiber-optic waveguides on the top facet is >5 fold larger than the bottom one. Placed on this tapered faceplate, the fluorescent samples are pumped from the side through a glass hemisphere interface. After excitation of the samples, the pump light is rejected through total internal reflection that occurs at the bottom facet of the sample substrate. The fluorescent emission from the sample is then collected by the smaller end of the tapered faceplate and is delivered to an opto-electronic sensor-array to be digitally sampled. Using a compressive sampling algorithm, we decode these raw lensfree images to validate the resolution (<4 μm) of this on-chip fluorescent imaging platform using microparticles as well as labeled Giardia muris cysts. This wide-field lensfree fluorescent microscopy platform, being compact and high-throughput, might provide a valuable tool especially for cytometry, rare cell analysis (involving large area microfluidic systems) as well as for microarray imaging applications. PMID:21283900

  1. Fast wide-field photothermal and quantitative phase cell imaging with optical lock-in detection

    PubMed Central

    Eldridge, Will J.; Meiri, Amihai; Sheinfeld, Adi; Rinehart, Matthew T.; Wax, Adam

    2014-01-01

    We present a fast, wide-field holography system for detecting photothermally excited gold nanospheres with combined quantitative phase imaging. An interferometric photothermal optical lock-in approach (POLI) is shown to improve SNR for detecting nanoparticles (NPs) on multiple substrates, including a monolayer of NPs on a silanized coverslip, and NPs bound to live cells. Furthermore, the set up allowed for co-registered quantitative phase imaging (QPI) to be acquired in an off-axis holographic set-up. An SNR of 103 was obtained for NP-tagging of epidermal growth factor receptor (EGFR) in live cells with a 3 second acquisition, while an SNR of 47 was seen for 20 ms acquisition. An analysis of improvements in SNR due to averaging multiple frames is presented, which suggest that residual photothermal signal can be a limiting factor. The combination of techniques allows for high resolution imaging of cell structure via QPI with the ability to identify receptor expression via POLI. PMID:25136482

  2. The New Milky Way: A Wide-Field Survey of Optical Transients near the Galactic plane

    NASA Astrophysics Data System (ADS)

    Sokolovsky, K.; Korotkiy, S.; Lebedev, A.

    2014-12-01

    Currently, it may take days for a bright nova outburst to be detected. With a few exceptions, little is known about novae behaviour prior to maximum light. A theoretically-predicted population of ultra-fast novae with t2<1d is evading observational discovery because it is not possible to routinely organize fast follow-up observations of nova candidates. With the aim of bringing the detection time of novae and other bright (V<13.5) optical transients from days down to hours or less, we developed an automated wide-field (8°×6°) system capable of surveying the whole Milky Way area visible from the observing site in one night. The system is built using low-cost mass-produced components and the transient detection pipeline is based on the open source VaST software. We describe the instrument design and report results of the first observations conducted in 2011 October-November and 2012 January-April. The results include the discovery of Nova Sagittarii 2012 No. 1 as well as two X-ray emitting cataclysmic variables 1RXS J063214.8+25362 and XMMSL1 J014956.7+533504. The rapid detection of Nova Sagittarii 2012 No. 1 enabled us to conduct its X-ray and UV observations with Swift 22 hours after discovery (˜eq 31 hour after the outburst onset). All images obtained during the transient search survey are available online.

  3. Development of a Data Reduction algorithm for Optical Wide Field Patrol

    NASA Astrophysics Data System (ADS)

    Park, Sun-youp; Keum, Kang-Hoon; Lee, Seong-Whan; Jin, Ho; Park, Yung-Sik; Hong-Suh; Jo, Jung Hyun; Moon, Hong-Kyu; Bae, Young-Ho; Choi, Jin; Choi, Young-Jun; Park, Jang-Hyun; Lee, Jung-Ho

    2013-09-01

    The detector subsystem of the Optical Wide-field Patrol (OWL) network efficiently acquires the position and time information of moving objects such as artificial satellites through its chopper system, which consists of 4 blades in front of the CCD camera. Using this system, it is possible to get more position data with the same exposure time by changing the streaks of the moving objects into many pieces with the fast rotating blades during sidereal tracking. At the same time, the time data from the rotating chopper can be acquired by the time tagger connected to the photo diode. To analyze the orbits of the targets detected in the image data of such a system, a sequential procedure of determining the positions of separated streak lines was developed that involved calculating the World Coordinate System (WCS) solution to transform the positions into equatorial coordinate systems, and finally combining the time log records from the time tagger with the transformed position data. We introduce this procedure and the preliminary results of the application of this procedure to the test observation images.

  4. Refined Adaptive Optics simulation with wide field of view for the ELT.

    NASA Astrophysics Data System (ADS)

    Chebbo, M.; Fusco, T.; Sauvage, J.-F.; Conan, J.-M.; Meimon, S.; Le Roux, B.

    2011-09-01

    Refined simulation tools for wide field AO systems (such as MOAO, MCAO or LTAO) on ELTs present new challenges. Increasing the number of degrees of freedom (scales as the square of the telescope diameter) makes the standard codes useless due to the huge number of operations to be performed at each step of the AO loop process. This computational burden requires new approaches in the computation of the DM voltages from WFS data. The classical matrix inversion and the matrix vector multiplication have to be replaced by a cleverer iterative resolution of the Least Square or Minimum Mean Square Error criterion (based on sparse matrices approaches). Moreover, for this new generation of AO systems, concepts themselves will become more complex: data fusion coming from multiple Laser and natural guide stars will have to be optimized, mirrors covering all the field of view associated to dedicated mirrors inside the scientific instrument itself will have to be coupled with split or integrated tomography schemes, differential pupil or/and field rotations will have to be considered, etc ... All these new entries should be carefully simulated, analysed and quantified in terms of performance before any implementation in AO systems. In this paper we present a new E2E simulator, developed to deal with all these specific ELT challenges. It is based on an iterative resolution of the linear model with high number of degrees of freedom (using the sparse matrix) and includes new concepts of filtering and coupling between LGS and NGS to effectively manage modes such as tip / tilt and defocus in the entire process of tomographic reconstruction. The first application of this tool in the frame of the EAGLE project, a flagship instrument of the future E-ELT combining all these issues, is presented.

  5. The clustering of galaxies and galaxy clusters: constraints on primordial non-Gaussianity from future wide-field surveys

    NASA Astrophysics Data System (ADS)

    Fedeli, C.; Carbone, C.; Moscardini, L.; Cimatti, A.

    2011-06-01

    We investigate the constraints on primordial non-Gaussianity with varied bispectrum shapes that can be derived from the power spectrum of galaxies and clusters of galaxies detected in future wide field optical/near-infrared surveys. Having in mind the proposed ESA space mission Euclid as a specific example, we combine the spatial distribution of spectroscopically selected galaxies with that of weak lensing selected clusters. We use the physically motivated halo model in order to represent the correlation function of arbitrary tracers of the large-scale structure in the Universe. As naively expected, we find that galaxies are much more effective in jointly constrain the level of primordial non-Gaussianity fNL and the amplitude of the matter power spectrum σ8 than clusters of galaxies, due to the much lower abundance of the latter that is not adequately compensated by the larger effect on the power spectrum. Nevertheless, combination of the galaxy power spectrum with the cluster-galaxy cross-spectrum can decrease the error on the determination of fNL by up to a factor of ˜2. This decrement is particularly evident for the less studied non-Gaussian bispectrum shapes, the so-called enfolded and the orthogonal ones. Setting constraints on these models can shed new light on various aspects of the physics of the early Universe, and hence it is of extreme importance. By combining the power spectra of clusters and galaxies with the cluster-galaxy cross-spectrum we find constraints on primordial non-Gaussianity of the order ΔfNL˜ a few, competitive and possibly superior to future cosmic microwave background experiments.

  6. Development of a Reduction Algorithm of GEO Satellite Optical Observation Data for Optical Wide Field Patrol (OWL)

    NASA Astrophysics Data System (ADS)

    Park, Sun-youp; Choi, Jin; Jo, Jung Hyun; Son, Ju Young; Park, Yung-Sik; Yim, Hong-Suh; Moon, Hong-Kyu; Bae, Young-Ho; Choi, Young-Jun; Park, Jang-Hyun

    2015-09-01

    An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous orbit satellites (GOS satellites) is developed. The optical wide-field patrol system is capable of automatic observation using a pre-arranged schedule. Therefore, if this type of automatic analysis algorithm is available, daily unmanned monitoring of GEO satellites can be possible. For data acquisition for development, the COMS1 satellite was observed with 1-s exposure time and 1-m interval. The images were grouped and processed in terms of ¡°action¡±, and each action was composed of six or nine successive images. First, a reference image with the best quality in one action was selected. Next, the rest of the images in the action were geometrically transformed to fit in the horizontal coordinate system (expressed in azimuthal angle and elevation) of the reference image. Then, these images were median-combined to retain only the possible non-moving GEO candidates. By reverting the coordinate transformation of the positions of these GEO satellite candidates, the final coordinates could be calculated.

  7. Optical Design Trade Study for the Wide Field Infrared Survey Telescope [WFIRST

    NASA Technical Reports Server (NTRS)

    Content, David A.; Goullioud, R.; Lehan, John P.; Mentzell, John E.

    2011-01-01

    The Wide Field Infrared Survey Telescope (WFIRST) mission concept was ranked first in new space astrophysics mission by the Astro2010 Decadal Survey incorporating the Joint Dark Energy Mission (JDEM)-Omega payload concept and multiple science white papers. This mission is based on a space telescope at L2 studying exoplanets [via gravitational microlensing], probing dark energy, and surveying the near infrared sky. Since the release of NWNH, the WFIRST project has been working with the WFIRST science definition team (SDT) to refine mission and payload concepts. We present the driving requirements. The current interim reference mission point design, based on the use of a 1.3m unobscured aperture three mirror anastigmat form, with focal imaging and slitless spectroscopy science channels, is consistent with the requirements, requires no technology development, and out performs the JDEM-Omega design.

  8. Wide field of view three-mirror telescopes having a common optical axis

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry

    1988-01-01

    Two coincident-optical-axis, three-mirror telescopes have been designed that feature relatively low focal ratios (f/2.3 and f/3), unobscured optical aperture, large circular fields of view (6 and 8 deg), good resolution, flat field, reimaging with accessible field stop, Lyot or glare stop, effective stray light suppression, and ease of spectral filter integration. The design for the f/3 telescope with 8 deg field of view has been fabricated and validated using single-point diamond-turned optics.

  9. Development of a lightweight near-zero CTE optical bench for the Wide-Field Camera 3 instrument

    NASA Astrophysics Data System (ADS)

    Holz, Jill M.; Kunt, Cengiz; Lashley, Chris; McGuffey, Douglas B.

    2003-02-01

    The design and development of an optical bench (OB) for Wide Field Camera 3 (WFC3), a next generation science instrument for the Hubble Space Telescope (HST) has proven a challenging task. WFC3 will replace Wide Field Planetary Camera 2 (WF/PC 2) during the next servicing mission of the HST in 2004. The WFC3 program is re-using much of the hardware from WF/PC 1, returned from the First Servicing Mission, which has added complexity to the program. This posed some significant packaging challenges, further complicated by WFC3 utilizing two, separate optical channels. The WF/PC 1 optical bench could not house the additional optical components, so a new bench was developed. The new bench had to be designed to accommodate the sometimes-conflicting requirements of the two channels, which operate over a wavelength range of 200nm to 1800nm, from Near Ultraviolet to Near Infrared. In addition, the bench had to interface to the reused WF/PC 1 hardware, which was not optimized for this mission. To aid in the design of the bench, the team used software tools to merge structural, thermal and optical models to obtain performance (STOP) of the optical systems in operation. Several iterations of this performance analysis were needed during the design process to verify the bench would meet requirements. The fabrication effort included a rigorous material characterization program and significant tooling. After assembly, the optical bench underwent an extensive qualification program to prove the design and manufacturing processes. This paper provides the details of the design and development process of this highly optimized optical bench.

  10. A space stable optical bench structure for the space telescope wide field and planetary camera

    NASA Technical Reports Server (NTRS)

    Smith, D. D.

    1980-01-01

    The design, fabrication, and verification tests of two optical bench structures fabricated under contract to the Jet Propulsion Laboratory are discussed. It is noted that graphite-epoxy and invar have been selected as the structural materials for the bench. The ability to manufacture a precise graphite-epoxy optical system platform has been demonstrated. It is noted that the 19 channel laser interferometer was used to measure the CTE of the bench structure graphite-epoxy components and the two invar bulkheads.

  11. Removing static aberrations from the active optics system of a wide-field telescope.

    PubMed

    Schipani, Pietro; Noethe, Lothar; Arcidiacono, Carmelo; Argomedo, Javier; Dall'Ora, Massimo; D'Orsi, Sergio; Farinato, Jacopo; Magrin, Demetrio; Marty, Laurent; Ragazzoni, Roberto; Umbriaco, Gabriele

    2012-07-01

    The wavefront sensor in active and adaptive telescopes is usually not in the optical path toward the scientific detector. It may generate additional wavefront aberrations, which have to be separated from the errors due to the telescope optics. The aberrations that are not rotationally symmetric can be disentangled from the telescope aberrations by a series of measurements taken in the center of the field, with the wavefront sensor at different orientation angles with respect to the focal plane. This method has been applied at the VLT Survey Telescope on the ESO Paranal observatory. PMID:22751401

  12. An optical design of the telescope in the Wide Field of View Cherenkov/Fluorescence Telescope Array

    NASA Astrophysics Data System (ADS)

    Liu, Jiali; Yang, Rui; Xiao, Gang; Cao, Zhen; Ma, Lingling; Zha, Min; Zhang, Bingkai; Zhang, Shoushan; Zhang, Yong

    2015-07-01

    Spherical design and Davies-cotton design, which can supply a wide Field of View (FOV) and have a single optical element structure, are the two candidate optics for Wide FOV Cherenkov/Fluorescence Telescope Array (WFCTA). To obtain a good imaging quality, we have done a detailed study to acquire optimal configurations for these two optics. In this paper, first, a proper curvature radius for the reflector, an optimized location for the camera, as well as a tolerance for the distortion of images for two designs have been presented. Furthermore, using such optimal configurations, the features of Cherenkov images initiated by proton and iron showers both with two optics have been investigated. Based on these results, it can be concluded that spherical design has the prior optical properties, such as a wider FOV of 16°, a higher and more homogeneous resolution for all incident directions within the 16° FOV and a lower light loss in the spots, as well as more signals collected in an Cherenkov image, relatively shorter arrival time difference for lights in a shower and brighter PMTs in the central part of a shower track. Thus it will be chosen as WFCTA optics. Finally, the optical properties of the two designs with 10° FOV have also been investigated. It should be mentioned that with such a smaller FOV, Davies-cotton optics is an effective design for it has a great imaging quality comparing with the setup of 16° FOV.

  13. Design of wide-field Nasmyth optics for a submillimeter camera

    NASA Astrophysics Data System (ADS)

    Tsuzuki, Toshihiro; Nitta, Tom; Imada, Hiroaki; Seta, Masumichi; Nakai, Naomasa; Sekiguchi, Sigeyuki; Sekimoto, Yutaro

    2014-07-01

    We designed wide FoV (1 degree) Nasmyth optics which transformed the f/6 Nasmyth focus to f/1 at a 850GHz superconducting camera for a planning 10-m Ritchey-Chrétien telescope. This optical system consists of reflecting mirrors at room temperature and a refractive lens at 4K. It enables us to carry out wide FoV imaging observations at the diffraction limit (Strehl ratio < 0.89) with a more than 100,000 pixel camera equipped in a 10-m telescope. The size of this system is reasonably compact (whole size:1.6 mx3.3 mx2.6 m, cryogenic part:0.7 mx0.7 mx1.0 m). The cryogenic part of this system such as vacuum window, cryogenic lens and IR block filters can be made with existing technologies at reasonable cost. The optical system can extend to the millimeter wave and the terahertz domain.

  14. RETINOCHOROIDAL MORPHOLOGY DESCRIBED BY WIDE-FIELD MONTAGE IMAGING OF SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY

    PubMed Central

    Mori, Keisuke; Kanno, Junji

    2016-01-01

    Purpose: To present baseline images of the vitreous, retina, and choroid from the macula to the periphery in normal patients using a novel montaging technique of spectral domain optical coherence tomography. Methods: Twenty-six normal eyes of 22 healthy volunteers were enrolled in this study. Montaged images of four radial optical coherence tomography scans through the fovea were obtained from each subject. Results: In the macula, there were six identifiable retinal layers as well as four bands in the outer retina. In the periphery, the ganglion cell layer was not identifiable. The external limiting membrane, the second band, and the retinal pigment epithelium were continuously delineated from the macula to the periphery. The third band was not visible in the periphery. Conclusion: Spectral domain optical coherence tomography montaged images provide wide-angle images of the vitreous, retina, and choroid, allowing for evaluation of peripheral findings and examination of relationships between peripheral and posterior disease. The maximum scan length achieved here was 36 mm. The scan length is approximately three times than that provided by conventional posterior scanning and is consistent with known dimensions of the eye. This method is achievable with current commercially available devices and may contribute to decision making in clinical practice. PMID:26241154

  15. Innovative system of very wide field optical sensors for space surveillance in the LEO region

    NASA Astrophysics Data System (ADS)

    Dimare, L.; Farnocchia, D.; Gronchi, G.; Milani, A.; Bernardi, F.; Rossi, A.

    2011-09-01

    We present the results of a large scale simulation, reproducing the behavior of a data center for the build-up and maintenance of a complete catalog of space debris in the upper part of the low Earth orbits region (LEO). The purpose is to determine the achievable performances of a network of advanced optical sensors, through the use of the newest orbit determination algorithms developed by the Department of Mathematics of Pisa (DM). Such a network was designed and proposed to the European Space Agency (ESA) in the Space Situational Awareness (SSA) framework by Carlo Gavazzi Space SpA (CGS), Istituto Nazionale di Astrofisica (INAF), DM and Istituto di Scienza e Tecnologie dell'Informazione (ISTI-CNR). The latest developed orbit determination algorithms were used to process simulated observations from the proposed network. In particular two innovative methods for preliminary orbit determination based on the first integrals of the Kepler problem were compared, by using them to process the same data. In both cases, the results showed that it is possible to use a network of optical sensors to build up a catalog containing more than 98% of the objects with perigee height between 1100 and 2000 km, and diameter greater than 8 cm. Such a catalog is obtained in just two months of observations. However, such results depend upon specific assumptions on the sensor and on the software technologies.

  16. Mosaicing for fast wide-field-of-view optical resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Shao, Peng; Shi, Wei; Chee, Ryan K.; Forbrich, Alexander; Zemp, Roger J.

    2012-02-01

    The acquisition speed of previously reported mechanically-scanned Optical-Resolution Photoacoustic Microscopy (OR-PAM) systems has been limited by both laser pulse repetition rate and mechanical scanning speed. In this paper we introduce a mosaicing scheme wherein a grid of small sub-mm-scale field-of-view (FOV) patches are acquired in 0.5s per patch, and a 3-axis stepper-motor system is used to mechanically move the object to be imaged from patch-to-patch in less than 0.5s. Patch images are aligned and stitched to generate a large FOV image composite. This system retains the SNR-advantages of focused-transducer OR-PAM systems, and is a hybrid approach between optical-scanning and mechanical scanning. With this strategy we reduce the data acquisition time of previously reported large-FOV systems by a factor of around 23. SCID hairless mice are imaged. The wide-FOV, high-speed data acquisition OR-PAM system broadens the potential applications of the imaging modality.

  17. Wide field adaptive optics correction for the GMT using natural guide stars

    NASA Astrophysics Data System (ADS)

    van Dam, Marcos A.; Bouchez, Antonin H.; McLeod, Brian A.

    2014-07-01

    The conceptual design of the Giant Magellan Telescope has four wavefront sensors used to maintain the shape and alignment of the segmented primary and secondary mirrors. In this paper, we show that by reading the sensors at 200 Hz, we can also compensate for low altitude turbulence. As a result, there is a large improvement in image quality, even at visible wavelengths, over the entire science field of view of the telescope. A minimum-variance reconstructor is presented that takes slope measurements from four stars of arbitrary location and magnitude and produces the optimal adaptive secondary mirror commands. The performance of the adaptive optics system in this mode is simulated using YAO, an end-to-end simulation tool. We present the results of trade studies performed to optimize the science return of the telescope.

  18. The explosive transient camera - An automatic, wide-field sky monitor for short-timescale optical transients

    NASA Technical Reports Server (NTRS)

    Vanderspek, Roland K.; Ricker, George R.; Doty, John P.

    1992-01-01

    The Explosive Transient Camera (ETC) is a widefield sky monitor designed to detect short-timescale (1-l0 s) celestial optical flashes. It consists of two arrays of wide-field CCD cameras monitoring about 0.4 steradian of the night sky for optical transients with risetimes of about 1-10 s and peak magnitudes m(V) of less than about 10. The ETC was designed to be completely automated in order to make year-round observations with minimal human intervention. A small, powerful 68,000-based computer controls all aspects of observations, including roof motion, CCD readouts, and weather sensing: under software control, the ETC is able to perform all the functions of a human observer automatically.

  19. The explosive transient camera - An automatic, wide-field sky monitor for short-timescale optical transients

    NASA Astrophysics Data System (ADS)

    Vanderspek, Roland K.; Ricker, George R.; Doty, John P.

    The Explosive Transient Camera (ETC) is a widefield sky monitor designed to detect short-timescale (1-l0 s) celestial optical flashes. It consists of two arrays of wide-field CCD cameras monitoring about 0.4 steradian of the night sky for optical transients with risetimes of about 1-10 s and peak magnitudes m(V) of less than about 10. The ETC was designed to be completely automated in order to make year-round observations with minimal human intervention. A small, powerful 68,000-based computer controls all aspects of observations, including roof motion, CCD readouts, and weather sensing: under software control, the ETC is able to perform all the functions of a human observer automatically.

  20. Wide-field wavefront sensing in solar adaptive optics : modeling and effects on reconstruction

    NASA Astrophysics Data System (ADS)

    Béchet, Clémentine; Tallon, Michel; Montilla, Icíar; Langlois, Maud

    2013-12-01

    The planned 4-meter diameter of the European Solar Telescope (EST) is aimed at providing high spatial resolution and large photon collecting area, in order to understand in particular the mechanisms of magnetic coupling in the chromosphere and the photosphere. To reach its goals in the visible and the near-infrared, EST is designed with both a conventional and a multi-conjugate adaptive optics (AO) of similar complexity than the ones featured for the Extremely Large Telescopes. In addition, the AO on EST has to face a particularity of solar AO: the wavefront sensing on extended sources with measurement fields of about 10'' in size. Reviewing recent literature together with an independent analysis, we investigate the impact of extended-field sensing in AO for large solar telescopes. Sensing modeling and its effect on reconstruction performance are analyzed, thanks to simulations performed with the Fractal Iterative Method for tomography (FRiM-3D), showing the difficulty to correct high altitude turbulence. We introduce a new approximate direct model of extended-source sensing which greatly improves the quality of the end-to-end simulations for EST AO. Next, we try to improve the conventional solar AO correction by using this new model in the reconstruction. Our simulations do not show significant benefits from using such tomographic model in this conventional AO configuration and under typical atmospheric conditions.

  1. KMTNET: A Network of 1.6 m Wide-Field Optical Telescopes Installed at Three Southern Observatories

    NASA Astrophysics Data System (ADS)

    Kim, Seung-Lee; Lee, Chung-Uk; Park, Byeong-Gon; Kim, Dong-Jin; Cha, Sang-Mok; Lee, Yongseok; Han, Cheongho; Chun, Moo-Young; Yuk, Insoo

    2016-02-01

    The Korea Microlensing Telescope Network (KMTNet) is a wide-field photometric system installed by the Korea Astronomy and Space Science Institute (KASI). Here, we present the overall technical specifications of the KMTNet observation system, test observation results, data transfer and image processing procedure, and finally, the KMTNet science programs. The system consists of three 1.6 m wide-field optical telescopes equipped with mosaic CCD cameras of 18k by 18k pixels. Each telescope provides a 2.0 by 2.0 square degree field of view. We have finished installing all three telescopes and cameras sequentially at the Cerro-Tololo Inter-American Observatory (CTIO) in Chile, the South African Astronomical Observatory (SAAO) in South Africa, and the Siding Spring Observatory (SSO) in Australia. This network of telescopes, which is spread over three different continents at a similar latitude of about -30 degrees, enables 24-hour continuous monitoring of targets observable in the Southern Hemisphere. The test observations showed good image quality that meets the seeing requirement of less than 1.0 arcsec in I-band. All of the observation data are transferred to the KMTNet data center at KASI via the international network communication and are processed with the KMTNet data pipeline. The primary scientific goal of the KMTNet is to discover numerous extrasolar planets toward the Galactic bulge by using the gravitational microlensing technique, especially earth-mass planets in the habitable zone. During the non-bulge season, the system is used for wide-field photometric survey science on supernovae, asteroids, and external galaxies.

  2. Optically fast, wide field-of-view, five-mirror anastigmat (5MA) imagers for remote sensing applications

    NASA Astrophysics Data System (ADS)

    Silny, John F.; Kim, Eugene D.; Cook, Lacy G.; Moskun, Eric M.; Patterson, Robert L.

    2011-10-01

    Recent trends in focal plane array (FPA) technology have led naturally to the development of very large format remote sensors that require optically fast, wide field-of-view (FOV) imaging optics. Systems that cover broad spectral ranges, such as multispectral imagers (MSI) and hyperspectral imagers (HSI), require reflective optics to provide aberration and distortion control without the complication of wavelength dependent errors induced by powered refractive elements. These large format systems require even wider fields-of-view than offered by the conventional three-mirror anastigmat (TMA) and four-mirror anastigmat (4MA) designs. Recently, Raytheon has demonstrated in hardware the first-ever aligned and tested five-mirror anastigmat (5MA) imager. The 5MA was designed with an F/3.0 optical speed and a 36 degree cross-scan FOV for use with a large format imaging spectrometer. The 5MA imager has useful features such as: (1) a real entrance pupil to support a full-aperture calibrator or a small scan mirror, (2) an intermediate image for stray light control, and (3) a real exit pupil for optimal cold-shielding in infrared applications. A computer-aided alignment method was used to align the 5MA imager with a final target of balanced wavefront error (WFE) across the full 36 deg FOV. This paper discusses the design and development of the first-ever 5MA imager and some potential air- and space-borne remote sensing applications.

  3. FRD in optical fibres at low temperatures: investigations for Gemini's Wide-field Fibre Multi-Object Spectrograph

    NASA Astrophysics Data System (ADS)

    de Oliveira, A. C.; de Oliveira, L. S.; Dos Santos, J. B.; Arruda, M. V.; Dos Santos, L. G. C.; Rodrigues, F.; de Castro, F. L. F.

    2011-06-01

    While there is no direct evidence for the deterioration in Focal Ratio Degradation (FRD) of optical fibres in severe temperature gradients, the fibre ends inserted into metallic containment devices such as steel ferrules can be a source of stress, and hence increased FRD at low temperatures. In such conditions, instruments using optical fibres may suffer some increase in FRD and consequent loss of system throughput when they are working in environments with significant thermal gradients, a common characteristic of ground-based observatories. In this paper we present results of experiments with optical fibres inserted in different materials as a part of our prototyping study for Gemini's Wide-field Multi-Object Spectrograph (WFMOS) project. Thermal effects and the use of new holding techniques will be discussed in the context of Integral Field Units and multi-fibres systems. In this work, we have used careful methodologies that give absolute measurements of FRD to quantify the advantages of using epoxy-based composites rather than metals as support structures for the fibre ends. This is shown to be especially important in minimizing thermally induced stresses in the fibre terminations. Not only is this important for optimizing fibre spectrograph performance but the benefits of using such materials are demonstrated in the minimization of positional variations and the avoidance of metal-to-glass delamination. Furthermore, by impregnating the composites with small zirconium oxide particles the composite materials supply their own fine polishing grit which aids significantly to the optical quality of the finished product.

  4. Improvement of the dynamic range using background subtraction in single shot wide-field optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Anna, Tulsi; Singh Mehta, Dalip; Sato, Manabu

    2015-12-01

    We investigated on the signal in single shot wide-field optical coherence tomographic (SS-WF-OCT) system to improve the dynamic range (DR). The SS-WF-OCT system is based on two-dimensional (2D) polarization Michelson interferometer and superluminescent diode (center wavelength of 842.5 nm) as light source. Two π-phase-shifted interferograms were acquired simultaneously using a single CCD camera and after subtraction, the en-face OCT image (area (x) 4.0 mm × (y) 4.3 mm) is obtained using 2D Hilbert transform. The OCT signal including incoherent background noises was analyzed. To improve the DR, background noise subtraction has been introduced and its measurement process is presented. This method is valuable during the background noise is stable. Using the scattering samples, such as, grind metal and polymer sponge with background subtraction algorithm, a significant reduction in background noise and improvement in the DR was demonstrated .

  5. Spectral-Domain Optical Coherence Tomography, Wide-Field Photography, and Fundus Autofluorescence Correlation of Posterior Ophthalmomyiasis Interna.

    PubMed

    Paulus, Yannis M; Butler, Nicholas J

    2016-07-01

    Posterior ophthalmomyiasis interna is a rare, potentially devastating infestation of the posterior segment by fly larvae. The authors report the first demonstration of spectral-domain optical coherence tomography (SD-OCT) (Spectralis; Heidelberg Engineering, Heidelberg, Germany), wide-field angiography (Optos, Dunfermline, Scotland) and photography, and fundus autofluorescence with temporal progression during a period of 6 months. A 12-year-old white female presented with acute, painless vision loss with hand motions visual acuity. No larva was visible, so she was treated with oral ivermectin. Visual acuity improved to 20/80. OCT demonstrated hyporeflective spaces of the outer retina and retinal pigment epithelium, which resolved during 1-month period with improved ellipsoid layer by 6 months. Fundus autofluorescence demonstrated linear hypoautofluorescent tracks. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:682-685.]. PMID:27434903

  6. Active optics and modified-Rumsey wide-field telescopes: MINITRUST demonstrators with vase- and tulip-form mirrors

    NASA Astrophysics Data System (ADS)

    Lemaître, Gérard R.; Montiel, Pierre; Joulié, Patrice; Dohlen, Kjetil; Lanzoni, Patrick

    2005-12-01

    Wide-field astronomy requires the development of larger aperture telescopes. The optical properties of a three-mirror modified-Rumsey design provide significant advantages when compared to other telescope designs: (i) at any wavelength, the design has a flat field and is anastigmatic; (ii) the system is extremely compact, i.e., it is almost four times shorter than a Schmidt. Compared to the equally compact flat-field Ritchey-Chrétien with a doublet-lens corrector, as developed for the Sloan digital sky survey - and which requires the polishing of six optical surfaces - the proposed modified-Rumsey design requires only a two-surface polishing and provides a better imaging quality. All the mirrors are spheroids of the hyperboloid type. Starting from the classical Rumsey design, it is shown that the use of all eight available free parameters allows the simultaneous aspherization of the primary and tertiary mirrors by active optics methods from a single deformable substrate. The continuity conditions between the primary and the tertiary hyperbolizations are achieved by an intermediate narrow ring of constant thickness that is not optically used. After the polishing of a double vase form in a spherical shape, the primary-tertiary hyperbolizations are achieved by in situ stressing. The tulip-form secondary is hyperbolized by stress polishing. Other active optics alternatives are possible for a space telescope. The modified-Rumsey design is of interest for developing large space- and ground-based survey telescopes in UV, visible, or IR ranges, such as currently demonstrated with the construction of identical telescopes MINITRUST-1 and -2, f/5 - 2° field of view. Double-pass optical tests show diffraction-limited images.

  7. Active optics and modified-Rumsey wide-field telescopes: MINITRUST demonstrators with vase- and tulip-form mirrors.

    PubMed

    Lemaître, Gérard R; Montiel, Pierre; Joulié, Patrice; Dohlen, Kjetil; Lanzoni, Patrick

    2005-12-01

    Wide-field astronomy requires the development of larger aperture telescopes. The optical properties of a three-mirror modified-Rumsey design provide significant advantages when compared to other telescope designs: (i) at any wavelength, the design has a flat field and is anastigmatic; (ii) the system is extremely compact, i.e., it is almost four times shorter than a Schmidt. Compared to the equally compact flat-field Ritchey-Chrétien with a doublet-lens corrector, as developed for the Sloan digital sky survey-and which requires the polishing of six optical surfaces-the proposed modified-Rumsey design requires only a two-surface polishing and provides a better imaging quality. All the mirrors are spheroids of the hyperboloid type. Starting from the classical Rumsey design, it is shown that the use of all eight available free parameters allows the simultaneous aspherization of the primary and tertiary mirrors by active optics methods from a single deformable substrate. The continuity conditions between the primary and the tertiary hyperbolizations are achieved by an intermediate narrow ring of constant thickness that is not optically used. After the polishing of a double vase form in a spherical shape, the primary-tertiary hyperbolizations are achieved by in situ stressing. The tulip-form secondary is hyperbolized by stress polishing. Other active optics alternatives are possible for a space telescope. The modified-Rumsey design is of interest for developing large space- and ground-based survey telescopes in UV, visible, or IR ranges, such as currently demonstrated with the construction of identical telescopes MINITRUST-1 and -2, f/5-2 degrees field of view. Double-pass optical tests show diffraction-limited images. PMID:16353802

  8. Andromeda (M31) optical and infrared disk survey. I. Insights in wide-field near-IR surface photometry

    SciTech Connect

    Sick, Jonathan; Courteau, Stéphane; Cuillandre, Jean-Charles; McDonald, Michael; De Jong, Roelof; Tully, R. Brent

    2014-05-01

    We present wide-field near-infrared J and K{sub s} images of the Andromeda Galaxy (M31) taken with WIRCam at the Canada-France-Hawaii Telescope as part of the Andromeda Optical and Infrared Disk Survey. This data set allows simultaneous observations of resolved stars and near-infrared (NIR) surface brightness across M31's entire bulge and disk (within R = 22 kpc), permitting a direct test of the stellar composition of near-infrared light in a nearby galaxy. Here we develop NIR observation and reduction methods to recover a uniform surface brightness map across the 3° × 1° disk of M31 with 27 WIRCam fields. Two sky-target nodding strategies are tested, and we find that strictly minimizing sky sampling latency cannot improve background subtraction accuracy to better than 2% of the background level due to spatio-temporal variations in the NIR skyglow. We fully describe our WIRCam reduction pipeline and advocate using flats built from night-sky images over a single night, rather than dome flats that do not capture the WIRCam illumination field. Contamination from scattered light and thermal background in sky flats has a negligible effect on the surface brightness shape compared to the stochastic differences in background shape between sky and galaxy disk fields, which are ∼0.3% of the background level. The most dramatic calibration step is the introduction of scalar sky offsets to each image that optimizes surface brightness continuity. Sky offsets reduce the mean surface brightness difference between observation blocks from 1% to <0.1% of the background level, though the absolute background level remains statistically uncertain to 0.15% of the background level. We present our WIRCam reduction pipeline and performance analysis to give specific recommendations for the improvement of NIR wide-field imaging methods.

  9. 3D galaxy clustering with future wide-field surveys: Advantages of a spherical Fourier-Bessel analysis

    NASA Astrophysics Data System (ADS)

    Lanusse, F.; Rassat, A.; Starck, J.-L.

    2015-06-01

    figure of merit as a function of median redshift is higher for the 3D SFB method than for the 2D tomographic method. Conclusions: Constraints from the 3D SFB analysis are less sensitive to unavoidable systematics stemming from a redshift- and scale-dependent galaxy bias. Even for surveys that are optimised with tomography in mind, a 3D SFB analysis is more powerful. In addition, for survey optimisation, the figure of merit for the 3D SFB method increases more rapidly with redshift, especially at higher redshifts, suggesting that the 3D SFB method should be preferred for designing and analysing future wide-field spectroscopic surveys. CosmicPy, the Python package developed for this paper, is freely available at https://cosmicpy.github.io. Appendices are available in electronic form at http://www.aanda.org

  10. Wide-field imaging of retinal vasculature using optical coherence tomography-based microangiography provided by motion tracking

    NASA Astrophysics Data System (ADS)

    Zhang, Qinqin; Huang, Yanping; Zhang, Thomas; Kubach, Sophie; An, Lin; Laron, Michal; Sharma, Utkarsh; Wang, Ruikang K.

    2015-06-01

    Optical coherence tomography (OCT)-based optical microangiography (OMAG) is a high-resolution, noninvasive imaging technique capable of providing three-dimensional in vivo blood flow visualization within microcirculatory tissue beds in the eye. Although the technique has demonstrated early clinical utility by imaging diseased eyes, its limited field of view (FOV) and the sensitivity to eye motion remain the two biggest challenges for the widespread clinical use of the technology. Here, we report the results of retinal OMAG imaging obtained from a Zeiss Cirrus 5000 spectral domain OCT system with motion tracking capability achieved by a line scan ophthalmoscope (LSO). The tracking LSO is able to guide the OCT scanning, which minimizes the effect of eye motion in the final results. We show that the tracking can effectively correct the motion artifacts and remove the discontinuities and distortions of vascular appearance due to microsaccade, leading to almost motion-free OMAG angiograms with good repeatability and reliability. Due to the robustness of the tracking LSO, we also show the montage scan protocol to provide unprecedented wide field retinal OMAG angiograms. We experimentally demonstrate a 12×16 mm2 retinal OMAG angiogram acquired from a volunteer, which is the widest FOV retinal vasculature imaging up to now in the community.

  11. Tiling strategies for optical follow-up of gravitational-wave triggers by telescopes with a wide field of view

    NASA Astrophysics Data System (ADS)

    Ghosh, Shaon; Bloemen, Steven; Nelemans, Gijs; Groot, Paul J.; Price, Larry R.

    2016-08-01

    Aims: Binary neutron stars are among the most promising candidates for joint gravitational-wave and electromagnetic astronomy. The goal of this work is to investigate various observing strategies that telescopes with wide field of view might incorporate while searching for electromagnetic counterparts of gravitational-wave triggers. Methods: We examined various strategies of scanning the gravitational-wave sky localizations on the mock 2015-16 gravitational-wave events. First, we studied the performance of the sky coverage using a naive tiling system that completely covers a given confidence interval contour using a fixed grid. Then we propose the ranked-tiling strategy where we sample the localization in discrete two-dimensional intervals that are equivalent to the telescope's field of view and rank them based on their sample localizations. We then introduce an optimization of the grid by iterative sliding of the tiles. Next, we conducted tests for all the methods on a large sample of sky localizations that are expected in the first two years of operation of the Laser interferometer Gravitational-wave Observatory (LIGO) and Virgo detectors. We investigated the performance of the ranked-tiling strategy for telescope arrays and compared their performance against monolithic telescopes with a giant field of view. Finally, we studied the ability of optical counterpart detection by various types of telescopes. Results: Our analysis reveals that the ranked-tiling strategy improves the localization coverage over the contour-covering method. The improvement is more significant for telescopes with larger fields of view. We also find that while optimizing the position of the tiles significantly improves the coverage compared to contour-covering tiles. For ranked-tiles the same procedure leads to negligible improvement in the coverage of the sky localizations. We observed that distributing the field of view of the telescopes into arrays of multiple telescopes significantly

  12. Macroscopic optical imaging technique for wide-field estimation of fluorescence depth in optically turbid media for application in brain tumor surgical guidance

    NASA Astrophysics Data System (ADS)

    Kolste, Kolbein K.; Kanick, Stephen C.; Valdés, Pablo A.; Jermyn, Michael; Wilson, Brian C.; Roberts, David W.; Paulsen, Keith D.; Leblond, Frederic

    2015-02-01

    A diffuse imaging method is presented that enables wide-field estimation of the depth of fluorescent molecular markers in turbid media by quantifying the deformation of the detected fluorescence spectra due to the wavelength-dependent light attenuation by overlying tissue. This is achieved by measuring the ratio of the fluorescence at two wavelengths in combination with normalization techniques based on diffuse reflectance measurements to evaluate tissue attenuation variations for different depths. It is demonstrated that fluorescence topography can be achieved up to a 5 mm depth using a near-infrared dye with millimeter depth accuracy in turbid media having optical properties representative of normal brain tissue. Wide-field depth estimates are made using optical technology integrated onto a commercial surgical microscope, making this approach feasible for real-world applications.

  13. Instrumentation of LOTIS: Livermore Optical Transient Imaging System; a fully automated wide field of view telescope system searching for simultaneous optical counterparts of gamma ray bursts

    SciTech Connect

    Park, H.S.; Ables, E.; Barthelmy, S.D.; Bionta, R.M.; Ott, L.L.; Parker, E.L.; Williams, G.G.

    1998-03-06

    LOTIS is a rapidly slewing wide-field-of-view telescope which was designed and constructed to search for simultaneous gamma-ray burst (GRB) optical counterparts. This experiment requires a rapidly slewing ({lt} 10 sec), wide-field-of-view ({gt} 15{degrees}), automatic and dedicated telescope. LOTIS utilizes commercial tele-photo lenses and custom 2048 x 2048 CCD cameras to view a 17.6 x 17.6{degrees} field of view. It can point to any part of the sky within 5 sec and is fully automated. It is connected via Internet socket to the GRB coordinate distribution network which analyzes telemetry from the satellite and delivers GRB coordinate information in real-time. LOTIS started routine operation in Oct. 1996. In the idle time between GRB triggers, LOTIS systematically surveys the entire available sky every night for new optical transients. This paper will describe the system design and performance.

  14. Macroscopic optical imaging technique for wide-field estimation of fluorescence depth in optically turbid media for application in brain tumor surgical guidance

    PubMed Central

    Kolste, Kolbein K.; Kanick, Stephen C.; Valdés, Pablo A.; Jermyn, Michael; Wilson, Brian C.; Roberts, David W.; Paulsen, Keith D.; Leblond, Frederic

    2015-01-01

    Abstract. A diffuse imaging method is presented that enables wide-field estimation of the depth of fluorescent molecular markers in turbid media by quantifying the deformation of the detected fluorescence spectra due to the wavelength-dependent light attenuation by overlying tissue. This is achieved by measuring the ratio of the fluorescence at two wavelengths in combination with normalization techniques based on diffuse reflectance measurements to evaluate tissue attenuation variations for different depths. It is demonstrated that fluorescence topography can be achieved up to a 5 mm depth using a near-infrared dye with millimeter depth accuracy in turbid media having optical properties representative of normal brain tissue. Wide-field depth estimates are made using optical technology integrated onto a commercial surgical microscope, making this approach feasible for real-world applications. PMID:25652704

  15. BOMBOLO: a Multi-Band, Wide-field, Near UV/Optical Imager for the SOAR 4m Telescope

    NASA Astrophysics Data System (ADS)

    Angeloni, R.; Guzmán, D.; Puzia, T. H.; Infante, L.

    2014-10-01

    BOMBOLO is a new multi-passband visitor instrument for SOAR observatory. The first fully Chilean instrument of its kind, it is a three-arms imager covering the near-UV and optical wavelengths. The three arms work simultaneously and independently, providing synchronized imaging capability for rapid astronomical events. BOMBOLO will be able to address largely unexplored events in the minute-to-second timescales, with the following leading science cases: 1) Simultaneous Multiband Flickering Studies of Accretion Phenomena; 2) Near UV/Optical Diagnostics of Stellar Evolutionary Phases; 3) Exoplanetary Transits and 4) Microlensing Follow-Up. BOMBOLO optical design consists of a wide field collimator feeding two dychroics at 390 and 550 nm. Each arm encompasses a camera, filter wheel and a science CCD230-42, imaging a 7 x 7 arcmin field of view onto a 2k x 2k image. The three CCDs will have different coatings to optimise the efficiencies of each camera. The detector controller to run the three cameras will be Torrent (the NOAO open-source system) and a PanView application will run the instrument and produce the data-cubes. The instrument is at Conceptual Design stage, having been approved by the SOAR Board of Directors as a visitor instrument in 2012 and having been granted full funding from CONICYT, the Chilean State Agency of Research, in 2013. The Design Phase is starting now and will be completed in late 2014, followed by a construction phase in 2015 and 2016A, with expected Commissioning in 2016B and 2017A.

  16. WINGS: A WIde-field Nearby Galaxy-cluster Survey. II. Deep optical photometry of 77 nearby clusters

    NASA Astrophysics Data System (ADS)

    Varela, J.; D'Onofrio, M.; Marmo, C.; Fasano, G.; Bettoni, D.; Cava, A.; Couch, W. J.; Dressler, A.; Kjærgaard, P.; Moles, M.; Pignatelli, E.; Poggianti, B. M.; Valentinuzzi, T.

    2009-04-01

    Context: This is the second paper of a series devoted to the WIde Field Nearby Galaxy-cluster Survey (WINGS). WINGS is a long term project which is gathering wide-field, multi-band imaging and spectroscopy of galaxies in a complete sample of 77 X-ray selected, nearby clusters (0.04 < z < 0.07) located far from the galactic plane (|b|≥ 20°). The main goal of this project is to establish a local reference for evolutionary studies of galaxies and galaxy clusters. Aims: This paper presents the optical (B,V) photometric catalogs of the WINGS sample and describes the procedures followed to construct them. We have paid special care to correctly treat the large extended galaxies (which includes the brightest cluster galaxies) and the reduction of the influence of the bright halos of very bright stars. Methods: We have constructed photometric catalogs based on wide-field images in B and V bands using SExtractor. Photometry has been performed on images in which large galaxies and halos of bright stars were removed after modeling them with elliptical isophotes. Results: We publish deep optical photometric catalogs (90% complete at V ~ 21.7, which translates to ˜ M^*_V+6 at mean redshift), giving positions, geometrical parameters, and several total and aperture magnitudes for all the objects detected. For each field we have produced three catalogs containing galaxies, stars and objects of “unknown” classification (~6%). From simulations we found that the uncertainty of our photometry is quite dependent of the light profile of the objects with stars having the most robust photometry and de Vaucouleurs profiles showing higher uncertainties and also an additional bias of ~-0.2^m. The star/galaxy classification of the bright objects (V < 20) was checked visually making negligible the fraction of misclassified objects. For fainter objects, we found that simulations do not provide reliable estimates of the possible misclassification and therefore we have compared our data

  17. O-6 Optical Property Degradation of the Hubble Space Telescope's Wide Field Camera-2 Pick Off Mirror

    NASA Technical Reports Server (NTRS)

    McNamara, Karen M.; Hughes, D. W.; Lauer, H. V.; Burkett, P. J.; Reed, B. B.

    2011-01-01

    Degradation in the performance of optical components can be greatly affected by exposure to the space environment. Many factors can contribute to such degradation including surface contaminants; outgassing; vacuum, UV, and atomic oxygen exposure; temperature cycling; or combinations of parameters. In-situ observations give important clues to degradation processes, but there are relatively few opportunities to correlate those observations with post-flight ground analyses. The return of instruments from the Hubble Space Telescope (HST) after its final servicing mission in May 2009 provided such an opportunity. Among the instruments returned from HST was the Wide-Field Planetary Camera-2 (WFPC-2), which had been exposed to the space environment for 16 years. This work focuses on the identifying the sources of degradation in the performance of the Pick-off mirror (POM) from WFPC-2. Techniques including surface reflectivity measurements, spectroscopic ellipsometry, FTIR (and ATR-FTIR) analyses, SEM/EDS, X-ray photoelectron spectroscopy (XPS) with and without ion milling, and wet and dry physical surface sampling were performed. Destructive and contact analyses took place only after completion of the non-destructive measurements. Spectroscopic ellipsometry was then repeated to determine the extent of contaminant removal by the destructive techniques, providing insight into the nature and extent of polymerization of the contaminant layer.

  18. Dynamic registration of an optical see-through HMD into a wide field-of-view rotorcraft flight simulation environment

    NASA Astrophysics Data System (ADS)

    Viertler, Franz; Hajek, Manfred

    2015-05-01

    To overcome the challenge of helicopter flight in degraded visual environments, current research considers headmounted displays with 3D-conformal (scene-linked) visual cues as most promising display technology. For pilot-in-theloop simulations with HMDs, a highly accurate registration of the augmented visual system is required. In rotorcraft flight simulators the outside visual cues are usually provided by a dome projection system, since a wide field-of-view (e.g. horizontally > 200° and vertically > 80°) is required, which can hardly be achieved with collimated viewing systems. But optical see-through HMDs do mostly not have an equivalent focus compared to the distance of the pilot's eye-point position to the curved screen, which is also dependant on head motion. Hence, a dynamic vergence correction has been implemented to avoid binocular disparity. In addition, the parallax error induced by even small translational head motions is corrected with a head-tracking system to be adjusted onto the projected screen. For this purpose, two options are presented. The correction can be achieved by rendering the view with yaw and pitch offset angles dependent on the deviating head position from the design eye-point of the spherical projection system. Furthermore, it can be solved by implementing a dynamic eye-point in the multi-channel projection system for the outside visual cues. Both options have been investigated for the integration of a binocular HMD into the Rotorcraft Simulation Environment (ROSIE) at the Technische Universitaet Muenchen. Pros and cons of both possibilities with regard on integration issues and usability in flight simulations will be discussed.

  19. KMTNet: a network of 1.6-m wide field optical telescopes installed at three southern observatories

    NASA Astrophysics Data System (ADS)

    Lee, Chung-Uk; Kim, Seung-Lee; Cha, Sang-Mok; Lee, Yongseok; Kim, Dong-Jin; Park, Byeong-Gon; Lee, Dong-Joo; Koo, Jae-Rim; Hong, Kyeongsoo; Lee, Jae Woo; Ryu, Yoon-Hyun; Lim, Beomdu; Lim, Jin-Sun; Gho, Seung-Won; Kim, Min-Jun

    2015-08-01

    Korea Astronomy and Space Science Institute (KASI) have installed three identical 1.6-m telescopes, called Korea Microlensing Telescope Network (KMTNet), which cover 2 x 2 degree field of view with the plate scale of 0.4 arcsec/pixel at three observatories - CTIO, SSO and SAAO in southern hemisphere. The uniqueness of the system is the uninterupted 24-hour monitoring with a wide field optics in southern hemisphere. The telescope adopts prime focus using a parabolic mirror and four spherical flattening lenses. The structural design and driving systems are modified from the degin of 2MASS telescope. The one piece filter-shutter assembly has a sliding shutter and four 310-mm square filters. Each observation system produces a 680MB size image file at site and the images are transfered to KASI data center using the Global Ring Network for Advanced Application Development (GLORIAD) network with the band width of 50Mbps in average. The main science goal of the KMTNet is to discover Earth like extra solar planet using the microlensing technique during bulge season, and 50% of the total observation time is allocated for the science program solely. The other telescope times are allocated for pre-selected seven science programs during non-bulge season. From the test observation, we verify that the most important two requirements are satisfied: 10 arcsec in RMS for the pointing accuracy and 1 arcsec of delivered image quality in I-band. In this presentation, we introduce finally installed system at each observatory and its observational performance obtained from the test observation.

  20. Wide-field optical coherence elastography for intraoperative assessment of tumour margins in breast cancer (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Allen, Wes M.; Chin, Lixin; Sampson, David D.; Kennedy, Brendan F.

    2016-03-01

    Incomplete excision of tumour margins is a major issue in breast-conserving surgery. Currently 20 - 60% of cases require a second surgical procedure required as a result of cancer recurrence. A number of techniques have been proposed to assess margin status, including frozen section analysis and imprint cytology. However, the recurrence rate after using these techniques remains very high. Over the last several years, our group has been developing optical coherence elastography (OCE) as a tool for the intraoperative assessment of tumour margins in breast cancer. We have reported a feasibility study on 65 ex vivo samples from patients undergoing mastectomy or wide local excision demonstrates the potential of OCE in differentiating benign from malignant tissue. In this study, malignant tissue was readily distinguished from surrounding relative tissue by a distinctive heterogeneous pattern in micro-elastograms. To date the largest field of view for a micro-elastogram is 20 x 20mm, however, lumpectomy samples are typically ~50 x 50 x 30mm. For OCE to progress as a useful clinical tool, elastograms must be acquired over larger areas to allow a greater portion of the surface area of lumpectomies to be assessed. Here, we propose a wide-field OCE scanner that utilizes a piezoelectric transducer with an internal diameter of 65mm. In this approach partially overlapped elastograms are stitched together forming a mosaic with overall dimensions of 50 x 50mm in a total acquisition time of 15 - 30 minutes. We present results using this approach on both tissue-mimicking phantoms and tissue, and discuss prospects for shorter acquisitions times.

  1. Prime Focus Spectrograph: A very wide-field, massively multiplexed, optical & near-infrared spectrograph for Subaru Telescope

    NASA Astrophysics Data System (ADS)

    Tamura, Naoyuki

    This short article is about Prime Focus Spectrograph (PFS), a very wide-field, massively-multiplexed, and optical & near-infrared (NIR) spectrograph as a next generation facility instrument on Subaru Telescope. More details and updates are available on the PFS official website (http://pfs.ipmu.jp), blog (http://pfs.ipmu.jp/blog/), and references therein. The project, instrument, & timeline PFS will position 2400 fibers to science targets or blank sky in the 1.3 degree field on the Subaru prime focus. These fibers will be quickly (~60sec) reconfigurable and feed the photons during exposures to the Spectrograph System (SpS). SpS consists of 4 modules each of which accommodate ~600 fibers and deliver spectral images ranging from 380nm to 1260nm simultaneously at one exposure via the 3 arms of blue, red, and NIR cameras. The instrument development has been undertaken by the international collaboration at the initiative of Kavli IPMU. The project is now going into the construction phase aiming at system integration and on-sky engineering observations in 2017-2018, and science operation in 2019. The survey design has also been under development envisioning a survey spanning ~300 nights over ~5 years in the framework of Subaru Strategic Program (SSP). The key science areas are: Cosmology, galaxy/AGN evolution, and Galactic Archaeology (GA) (Takada et al. 2014). The cosmology program will be to constrain the nature of dark energy via a survey of emission line galaxies over a comoving volume of 10 Gpc3 at z=0.8-2.4. In the galaxy/AGN program, the wide wavelength coverage of PFS as well as the large field of view will be exploited to characterize the galaxy populations and its clustering properties over a wide redshift range. A survey of color-selected galaxies/AGN at z = 1-2 will be conducted over 20 square degrees yielding a fair sample of galaxies with stellar masses down to ~1010 M ⊙. In the GA program, radial velocities and chemical abundances of stars in the Milky

  2. Prime Focus Spectrograph: A very wide-field, massively multiplexed, optical & near-infrared spectrograph for Subaru Telescope

    NASA Astrophysics Data System (ADS)

    TAMURA, NAOYUKI

    2015-08-01

    PFS (Prime Focus Spectrograph), a next generation facility instrument on Subaru, is a very wide-field, massively-multiplexed, and optical & near-infrared spectrograph. Exploiting the Subaru prime focus, 2400 reconfigurable fibers will be distributed in the 1.3 degree field. The spectrograph will have 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm at one exposure. The development of this instrument has been undertaken by the international collaboration at the initiative of Kavli IPMU. The project is now going into the construction phase aiming at system integration and on-sky commissioning in 2017-2018, and science operation in 2019. In parallel, the survey design has also been developed envisioning a Subaru Strategic Program (SSP) that spans roughly speaking 300 nights over 5 years. The major science areas are three-folds: Cosmology, galaxy/AGN evolution, and Galactic archaeology (GA). The cosmology program will be to constrain the nature of dark energy via a survey of emission line galaxies over a comoving volume of ~10 Gpc^3 in the redshift range of 0.8 < z < 2.4. In the GA program, radial velocities and chemical abundances of stars in the Milky Way, dwarf spheroidal galaxies, and M31 will be used to understand the past assembly histories of those galaxies and the structures of their dark matter halos. Spectra will be taken for ~1 million stars as faint as V = 22 therefore out to large distances from the Sun. For the extragalactic program, our simulations suggest the wide wavelength coverage of PFS will be particularly powerful in probing the galaxy populations and its clustering properties over a wide redshift range. We will conduct a survey of color-selected 1 < z < 2 galaxies and AGN over 20 square degrees down to J = 23.4, yielding a fair sample of galaxies with stellar masses above ˜10^10 solar masses. Further, PFS will also provide unique spectroscopic opportunities even in the era of Euclid, LSST

  3. Wide field of view telescope

    DOEpatents

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  4. Invited Article: First flight in space of a wide-field-of-view soft x-ray imager using lobster-eye optics: Instrument description and initial flight results

    NASA Astrophysics Data System (ADS)

    Collier, Michael R.; Porter, F. Scott; Sibeck, David G.; Carter, Jenny A.; Chiao, Meng P.; Chornay, Dennis J.; Cravens, Thomas E.; Galeazzi, Massimiliano; Keller, John W.; Koutroumpa, Dimitra; Kujawski, Joseph; Kuntz, Kip; Read, Andy M.; Robertson, Ina P.; Sembay, Steve; Snowden, Steven L.; Thomas, Nicholas; Uprety, Youaraj; Walsh, Brian M.

    2015-07-01

    We describe the development, launch into space, and initial results from a prototype wide field-of-view soft X-ray imager that employs lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The sheath transport observer for the redistribution of mass is the first instrument using this type of optics launched into space and provides proof-of-concept for future flight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the Moon, and the solar wind interaction with planetary bodies like Venus and Mars [Kuntz et al., Astrophys. J. (in press)].

  5. Invited Article: First flight in space of a wide-field-of-view soft x-ray imager using lobster-eye optics: Instrument description and initial flight results.

    PubMed

    Collier, Michael R; Porter, F Scott; Sibeck, David G; Carter, Jenny A; Chiao, Meng P; Chornay, Dennis J; Cravens, Thomas E; Galeazzi, Massimiliano; Keller, John W; Koutroumpa, Dimitra; Kujawski, Joseph; Kuntz, Kip; Read, Andy M; Robertson, Ina P; Sembay, Steve; Snowden, Steven L; Thomas, Nicholas; Uprety, Youaraj; Walsh, Brian M

    2015-07-01

    We describe the development, launch into space, and initial results from a prototype wide field-of-view soft X-ray imager that employs lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The sheath transport observer for the redistribution of mass is the first instrument using this type of optics launched into space and provides proof-of-concept for future flight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the Moon, and the solar wind interaction with planetary bodies like Venus and Mars [Kuntz et al., Astrophys. J. (in press)]. PMID:26233339

  6. Active optics and the axisymmetric case: MINITRUST wide-field three-reflection telescopes with mirrors aspherized from tulip and vase forms

    NASA Astrophysics Data System (ADS)

    Lemaitre, Gerard R.; Montiel, Pierre; Joulie, Patrice; Dohlen, Kjetil; Lanzoni, Patrick

    2004-09-01

    Wide-field astronomy requires larger size telescopes. Compared to the catadioptric Schmidt, the optical properties of a three mirror telescope provides significant advantages. (1) The flat field design is anastigmatic at any wavelength, (2) the system is extremely compact -- four times shorter than a Schmidt -- and, (3) compared to a Schmidt with refractive corrector -- requiring the polishing of three optical surfaces --, the presently proposed Modified-Rumsey design uses all of eight available free parameters of a flat fielded anastigmatic three mirror telescope for mirrors generated by active optics methods. Compared to a Rumsey design, these parameters include the additional slope continuity condition at the primary-tertiary link for in-situ stressing and aspherization from a common sphere. Then, active optics allows the polishing of only two spherical surfaces: the combined primary-tertiary mirror and the secondary mirror. All mirrors are spheroids of the hyperboloid type. This compact system is of interest for space and ground-based astronomy and allows to built larger wide-field telescopes such as demonstrated by the design and construction of identical telescopes MINITRUST-1 and -2, f/5 - 2° FOV, consisting of an in-situ stressed double vase form primary-tertiary and of a stress polished tulip form secondary. Optical tests of these telescopes, showing diffraction limited images, are presented.

  7. Wide-Field Plate Database

    NASA Astrophysics Data System (ADS)

    Tsvetkov, M. K.; Stavrev, K. Y.; Tsvetkova, K. P.; Semkov, E. H.; Mutatov, A. S.

    The Wide-Field Plate Database (WFPDB) and the possibilities for its application as a research tool in observational astronomy are presented. Currently the WFPDB comprises the descriptive data for 400 000 archival wide field photographic plates obtained with 77 instruments, from a total of 1 850 000 photographs stored in 269 astronomical archives all over the world since the end of last century. The WFPDB is already accessible for the astronomical community, now only in batch mode through user requests sent by e-mail. We are working on on-line interactive access to the data via INTERNET from Sofia and parallel from the Centre de Donnees Astronomiques de Strasbourg. (Initial information can be found on World Wide Web homepage URL http://www.wfpa.acad.bg.) The WFPDB may be useful in studies of a variety of astronomical objects and phenomena, andespecially for long-term investigations of variable objects and for multi-wavelength research. We have analysed the data in the WFPDB in order to derive the overall characteristics of the totality of wide-field observations, such as the sky coverage, the distributions by observation time and date, by spectral band, and by object type. We have also examined the totality of wide-field observations from point of view of their quality, availability and digitisation. The usefulness of the WFPDB is demonstrated by the results of identification and investigation of the photometrical behaviour of optical analogues of gamma-ray bursts.

  8. Optomechanical design concept for GMACS: a wide-field multi-object moderate resolution optical spectrograph for the Giant Magellan Telescope (GMT)

    NASA Astrophysics Data System (ADS)

    Smee, Stephen A.; Prochaska, Travis; Shectman, Stephen A.; Hammond, Randolph P.; Barkhouser, Robert H.; DePoy, D. L.; Marshall, J. L.

    2012-09-01

    We describe the conceptual optomechanical design for GMACS, a wide-field, multi-object, moderate-resolution optical spectrograph for the Giant Magellan Telescope (GMT). GMACS is a candidate first-light instrument for the GMT and will be one of several instruments housed in the Gregorian Instrument Rotator (GIR) located at the Gregorian focus. The instrument samples a 9 arcminute x 18 arcminute field of view providing two resolution modes (i.e, low resolution, R ~ 2000, and moderate resolution, R ~ 4000) over a 3700 Å to 10200 Å wavelength range. To minimize the size of the optics, four fold mirrors at the GMT focal plane redirect the full field into four individual "arms", that each comprises a double spectrograph with a red and blue channel. Hence, each arm samples a 4.5 arcminute x 9 arcminute field of view. The optical layout naturally leads to three separate optomechanical assemblies: a focal plane assembly, and two identical optics modules. The focal plane assembly contains the last element of the telescope's wide-field corrector, slit-mask, tent-mirror assembly, and slit-mask magazine. Each of the two optics modules supports two of the four instrument arms and houses the aft-optics (i.e. collimators, dichroics, gratings, and cameras). A grating exchange mechanism, and articulated gratings and cameras facilitate multiple resolution modes. In this paper we describe the details of the GMACS optomechanical design, including the requirements and considerations leading to the design, mechanism details, optics mounts, and predicted flexure performance.

  9. Wide-field optical detection of nanoparticles using on-chip microscopy and self-assembled nanolenses

    NASA Astrophysics Data System (ADS)

    Mudanyali, Onur; McLeod, Euan; Luo, Wei; Greenbaum, Alon; Coskun, Ahmet F.; Hennequin, Yves; Allier, Cédric P.; Ozcan, Aydogan

    2013-03-01

    The direct observation of nanoscale objects is a challenging task for optical microscopy because the scattering from an individual nanoparticle is typically weak at optical wavelengths. Electron microscopy therefore remains one of the gold standard visualization methods for nanoparticles, despite its high cost, limited throughput and restricted field-of-view. Here, we describe a high-throughput, on-chip detection scheme that uses biocompatible wetting films to self-assemble aspheric liquid nanolenses around individual nanoparticles to enhance the contrast between the scattered and background light. We model the effect of the nanolens as a spatial phase mask centred on the particle and show that the holographic diffraction pattern of this effective phase mask allows detection of sub-100 nm particles across a large field-of-view of >20 mm2. As a proof-of-concept demonstration, we report on-chip detection of individual polystyrene nanoparticles, adenoviruses and influenza A (H1N1) viral particles.

  10. Wide-field optical detection of nanoparticles using on-chip microscopy and self-assembled nanolenses

    PubMed Central

    Mudanyali, Onur; McLeod, Euan; Luo, Wei; Greenbaum, Alon; Coskun, Ahmet F.; Hennequin, Yves; Allier, Cédric P.; Ozcan, Aydogan

    2013-01-01

    The direct observation of nanoscale objects is a challenging task for optical microscopy because the scattering from an individual nanoparticle is typically weak at optical wavelengths. Electron microscopy therefore remains one of the gold standard visualization methods for nanoparticles, despite its high cost, limited throughput and restricted field-of-view. Here, we describe a high-throughput, on-chip detection scheme that uses biocompatible wetting films to self-assemble aspheric liquid nanolenses around individual nanoparticles to enhance the contrast between the scattered and background light. We model the effect of the nanolens as a spatial phase mask centred on the particle and show that the holographic diffraction pattern of this effective phase mask allows detection of sub-100 nm particles across a large field-of-view of >20 mm2. As a proof-of-concept demonstration, we report on-chip detection of individual polystyrene nanoparticles, adenoviruses and influenza A (H1N1) viral particles. PMID:24358054

  11. Registration of orthogonally oriented wide-field of view OCT volumes using orientation-aware optical flow and retina segmentation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Lezama, Jose; Mukherjee, Dibyendu; McNabb, Ryan P.; Sapiro, Guillermo; Izatt, Joseph A.; Farsiu, Sina; Kuo, Anthony N.

    2016-03-01

    Patient motion artifacts are an important source of data irregularities in OCT imaging. With longer duration OCT scans - as is needed for large wide field of view scans or increased scan density - motion artifacts become increasingly problematic. Strategies to mitigate these motion artifacts are then necessary to ensure OCT data integrity. A popular strategy for reducing motion artifacts in OCT images is to capture two orthogonally oriented volumetric scans containing uncorrelated motion and subsequently reconstructing a motion-free volume by combining information from both datasets. While many different variations of this registration approach have been proposed, even the most recent methods might not be suitable for wide FOV OCT scans which can be lacking in features away from the optic nerve head or arcades. To address this problem, we propose a two-stage motion correction algorithm for wide FOV OCT volumes. In the first step, X and Y axes motion is corrected by registering OCT summed voxel projections (SVPs). To achieve this, we introduce a method based on a custom variation of the dense optical flow technique which is aware of the motion free orientation of the scan. Secondly, a depth (Z axis) correction approach based on the segmentation of the retinal layer boundaries in each B-scan using graph-theory and dynamic programming is applied. This motion correction method was applied to wide field retinal OCT volumes (approximately 80° FOV) of 3 subjects with substantial reduction in motion artifacts.

  12. The dawn of wide-field Sunyaev-Zel'dovich cluster surveys: Efficient optical follow-up

    NASA Astrophysics Data System (ADS)

    High, Fredrick William

    The South Pole Telescope team has recently reported the first 21 galaxy clusters uniformly selected by a blind Sunyaev-Zel'dovich (SZ) survey. Prompt optical imaging has confirmed the existence of red-sequence galaxy overdensities at the SZ locations, and provided first estimates of their redshift and optical richness. We have also followed up a subset spectroscopically. These are some of the most massive clusters in the universe, spanning redshifts from z=0.15 to z>1, with median of 0.74. This remarkable sample serves as proof of concept for SZ cluster surveys, which will provide a new, powerful window on the nature of dark energy. We are attacking the problem of following up many hundreds or thousands of SZ detections in the coming years by developing a real-time photometric calibration tool called Stellar Locus Regression. We also attack it from a hardware standpoint by building PISCO, a simultaneous multiband CCD imager. Optimizing the observing strategy alone using SLR provides a factor of 2 in cluster-confirmation yield over standard methods, and PISCO gives another factor of 3 to 4 for z<1 clusters. Finally, we provide the first sky background characterization in the new CCD y band at Cerro Tololo in Chile, which will be used in next-generation astronomical camera systems and will provide useful additional information. as well as new challenges, for cluster studies such as this.

  13. A WIDE-FIELD NARROWBAND OPTICAL SURVEY OF THE BRAID NEBULA STAR FORMATION REGION IN CYGNUS OB7

    SciTech Connect

    Magakian, Tigran Yu.; Nikogossian, Elena H.; Movsessian, Tigran; Aspin, Colin; Pyo, Tae-Soo; Khanzadyan, Tigran; Smith, Michael D.; Mitchison, Sharon; Davis, Chris J.; Beck, Tracy L.; Moriarty-Schieven, Gerald H. E-mail: elena@bao.sci.am E-mail: pyo@subaru.naoj.org E-mail: smm23@kent.ac.uk E-mail: c.davis@jach.hawaii.edu E-mail: gerald.schieven@nrc-cnrc.gc.ca

    2010-03-15

    We study the population of Herbig-Haro (HH) flows and jets in an area of Cygnus OB7 designated the Braid Nebula star formation region. This complex forms part of the L 1003 dark cloud, and hosts two FU Orionis (FUor)-like objects as well as several other active young stars. To trace outflow activity and to relate both known and newly discovered flows to young star hosts we intercompare new, deep, narrowband H{alpha} and [S II] optical images taken on the Subaru 8 m Telescope on Mauna Kea, Hawaii. Our images show that there is considerable outflow and jet activity in this region suggesting the presence of an extensive young star population. We confirm that both of the FUor-like objects drive extensive HH flows and document further members of the flows in both objects. The L 1003 star formation complex is a highly kinematically active region with young stars in several different stages of evolution. We trace collimated outflows from numerous young stars although the origin of some HH objects remains elusive.

  14. BRIGHTEST X-RAY CLUSTERS OF GALAXIES IN THE CFHTLS WIDE FIELDS: CATALOG AND OPTICAL MASS ESTIMATOR

    SciTech Connect

    Mirkazemi, M.; Finoguenov, A.; Lerchster, M.; Erfanianfar, G.; Seitz, S.; Pereira, M. J.; Egami, E.; Tanaka, M.; Brimioulle, F.; Kettula, K.; McCracken, H. J.; Mellier, Y.; Kneib, J. P.; Rykoff, E.; Erben, T.; Taylor, J. E.

    2015-01-20

    The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) presents a unique data set for weak-lensing studies, having high-quality imaging and deep multiband photometry. We have initiated an XMM-CFHTLS project to provide X-ray observations of the brightest X-ray-selected clusters within the wide CFHTLS area. Performance of these observations and the high quality of CFHTLS data allow us to revisit the identification of X-ray sources, introducing automated reproducible algorithms, based on the multicolor red sequence finder. We have also introduced a new optical mass proxy. We provide the calibration of the red sequence observed in the Canada-France-Hawaii filters and compare the results with the traditional single-color red sequence and photo-z. We test the identification algorithm on the subset of highly significant XMM clusters and identify 100% of the sample. We find that the integrated z-band luminosity of the red sequence galaxies correlates well with the X-ray luminosity, with a surprisingly small scatter of 0.20 dex. We further use the multicolor red sequence to reduce spurious detections in the full XMM and ROSAT All-Sky Survey (RASS) data sets, resulting in catalogs of 196 and 32 clusters, respectively. We made spectroscopic follow-up observations of some of these systems with HECTOSPEC and in combination with BOSS DR9 data. We also describe the modifications needed to the source detection algorithm in order to maintain high purity of extended sources in the shallow X-ray data. We also present the scaling relation between X-ray luminosity and velocity dispersion.

  15. In vivo wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography of human oral cavity with a forward-viewing probe.

    PubMed

    Yoon, Yeoreum; Jang, Won Hyuk; Xiao, Peng; Kim, Bumju; Wang, Taejun; Li, Qingyun; Lee, Ji Youl; Chung, Euiheon; Kim, Ki Hean

    2015-02-01

    We report multimodal imaging of human oral cavity in vivo based on simultaneous wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography (PS-OCT) with a forward-viewing imaging probe. Wide-field reflectance/fluorescence imaging and PS-OCT were to provide both morphological and fluorescence information on the surface, and structural and birefringent information below the surface respectively. The forward-viewing probe was designed to access the oral cavity through the mouth with dimensions of approximately 10 mm in diameter and 180 mm in length. The probe had field of view (FOV) of approximately 5.5 mm in diameter, and adjustable depth of field (DOF) from 2 mm to 10 mm by controlling numerical aperture (NA) in the detection path. This adjustable DOF was to accommodate both requirements for image-based guiding with high DOF and high-resolution, high-sensitivity imaging with low DOF. This multimodal imaging system was characterized by using a tissue phantom and a mouse model in vivo, and was applied to human oral cavity. Information of surface morphology and vasculature, and under-surface layered structure and birefringence of the oral cavity tissues was obtained. These results showed feasibility of this multimodal imaging system as a tool for studying oral cavity lesions in clinical applications. PMID:25780742

  16. In vivo wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography of human oral cavity with a forward-viewing probe

    PubMed Central

    Yoon, Yeoreum; Jang, Won Hyuk; Xiao, Peng; Kim, Bumju; Wang, Taejun; Li, Qingyun; Lee, Ji Youl; Chung, Euiheon; Kim, Ki Hean

    2015-01-01

    We report multimodal imaging of human oral cavity in vivo based on simultaneous wide-field reflectance/fluorescence imaging and polarization-sensitive optical coherence tomography (PS-OCT) with a forward-viewing imaging probe. Wide-field reflectance/fluorescence imaging and PS-OCT were to provide both morphological and fluorescence information on the surface, and structural and birefringent information below the surface respectively. The forward-viewing probe was designed to access the oral cavity through the mouth with dimensions of approximately 10 mm in diameter and 180 mm in length. The probe had field of view (FOV) of approximately 5.5 mm in diameter, and adjustable depth of field (DOF) from 2 mm to 10 mm by controlling numerical aperture (NA) in the detection path. This adjustable DOF was to accommodate both requirements for image-based guiding with high DOF and high-resolution, high-sensitivity imaging with low DOF. This multimodal imaging system was characterized by using a tissue phantom and a mouse model in vivo, and was applied to human oral cavity. Information of surface morphology and vasculature, and under-surface layered structure and birefringence of the oral cavity tissues was obtained. These results showed feasibility of this multimodal imaging system as a tool for studying oral cavity lesions in clinical applications. PMID:25780742

  17. Wide field corrector for the KMTNet telescope

    NASA Astrophysics Data System (ADS)

    Lee, Yongseok; Cha, Sang-Mok; Poteet, Wade; Lam, Philip; Lee, Chung-Uk; Kim, Seung-Lee; Park, Byeong-Gon; Buchroeder, Richard A.; Jin, Ho

    2014-07-01

    We present the design, assembly, alignment, and verification process of the wide field corrector for the Korea Microlensing Telescope Network (KMTNet) 1.6 meter optical telescope. The optical configuration of the KMTNet telescope is prime focus, having a wide field corrector and the CCD camera on the topside of Optical Tube Assembly (OTA). The corrector is made of four lenses designed to have all spherical surfaces, being the largest one of 552 mm physical diameter. Combining with a purely parabolic primary mirror, this optical design makes easier to fabricate, to align, and to test the wide field optics. The centering process of the optics in the lens cell was performed on a precision rotary table using an indicator. After the centering, we mounted three large and heavy lenses on each cell by injecting the continuous Room Temperature Vulcanizing (RTV) silicon rubber bonding via a syringe.

  18. Self-Management of Patient Body Position, Pose, and Motion Using Wide-Field, Real-Time Optical Measurement Feedback: Results of a Volunteer Study

    SciTech Connect

    Parkhurst, James M.; Price, Gareth J.; Sharrock, Phil J.; Jackson, Andrew S.N.; Stratford, Julie; Moore, Christopher J.

    2013-12-01

    Purpose: We present the results of a clinical feasibility study, performed in 10 healthy volunteers undergoing a simulated treatment over 3 sessions, to investigate the use of a wide-field visual feedback technique intended to help patients control their pose while reducing motion during radiation therapy treatment. Methods and Materials: An optical surface sensor is used to capture wide-area measurements of a subject's body surface with visualizations of these data displayed back to them in real time. In this study we hypothesize that this active feedback mechanism will enable patients to control their motion and help them maintain their setup pose and position. A capability hierarchy of 3 different level-of-detail abstractions of the measured surface data is systematically compared. Results: Use of the device enabled volunteers to increase their conformance to a reference surface, as measured by decreased variability across their body surfaces. The use of visual feedback also enabled volunteers to reduce their respiratory motion amplitude to 1.7 ± 0.6 mm compared with 2.7 ± 1.4 mm without visual feedback. Conclusions: The use of live feedback of their optically measured body surfaces enabled a set of volunteers to better manage their pose and motion when compared with free breathing. The method is suitable to be taken forward to patient studies.

  19. Reflection, phase and en- face sectional imaging of scattering objects using quasi-single-shot wide-field optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Anna, Tulsi; Kimura, Satoshi; Mehta, Dalip Singh; Sato, Manabu

    2015-10-01

    We report a quasi-single-shot wide-field optical coherence tomography system that enables to measure the reflection, phase and en- face OCT images from the same setup using the glass jig. The jig consisting of a wedge glass substrate and a glue dot is contacted to the tissue surfaces, and the data within glue dot is used to reduce the phase noise of the interference signal. The reconstructed image size of the object was 4.0 mm × 4.3 mm. The standard deviation (STD) of the phase variation was minimized by 54 % and obtained to be 0.027 rad for the poke tissue. The corresponding STD in optical path length change was measured to be 1.4 nm. The refractive index of the water and poke tissue at the surface is also evaluated as 1.36 and 1.39, respectively, using reflection intensity images. Further, the en- face sectional images of the tissue sample are also measured.

  20. Real-time GPU-accelerated processing and volumetric display for wide-field laser-scanning optical-resolution photoacoustic microscopy.

    PubMed

    Kang, Heesung; Lee, Sang-Won; Lee, Eun-Soo; Kim, Se-Hwa; Lee, Tae Geol

    2015-12-01

    Fast signal processing and real-time displays are essential for practical imaging modality in various fields of applications. However, the imaging speed in optical-resolution photoacoustic microscopy (OR-PAM), in particular, depends on factors such as the pulse repetition rate of the laser, scanning method, field of view (FOV), and signal processing time. In the past, efforts to increase acquisition speed either focused on developing new scanning methods or using lasers with higher pulse repetition rates. However, high-speed signal processing is also important for real-time volumetric display in OR-PAM. In this study, we carried out parallel signal processing using a graphics processing unit (GPU) to enable fast signal processing and wide-field real-time displays in laser-scanning OR-PAM. The average total GPU processing time for a B-mode PAM image was approximately 1.35 ms at a display speed of 480 fps when the data samples were acquired with 736 (axial) × 500 (lateral) points/B-mode-frame at a pulse repetition rate of 300 kHz. In addition, we successfully displayed maximum amplitude projection images of a mouse's ear as volumetric images with an FOV of 3 mm × 3 mm (500 × 500 pixels) at 1.02 s, corresponding to 0.98 fps. PMID:26713184

  1. Real-time GPU-accelerated processing and volumetric display for wide-field laser-scanning optical-resolution photoacoustic microscopy

    PubMed Central

    Kang, Heesung; Lee, Sang-Won; Lee, Eun-Soo; Kim, Se-Hwa; Lee, Tae Geol

    2015-01-01

    Fast signal processing and real-time displays are essential for practical imaging modality in various fields of applications. However, the imaging speed in optical-resolution photoacoustic microscopy (OR-PAM), in particular, depends on factors such as the pulse repetition rate of the laser, scanning method, field of view (FOV), and signal processing time. In the past, efforts to increase acquisition speed either focused on developing new scanning methods or using lasers with higher pulse repetition rates. However, high-speed signal processing is also important for real-time volumetric display in OR-PAM. In this study, we carried out parallel signal processing using a graphics processing unit (GPU) to enable fast signal processing and wide-field real-time displays in laser-scanning OR-PAM. The average total GPU processing time for a B-mode PAM image was approximately 1.35 ms at a display speed of 480 fps when the data samples were acquired with 736 (axial) × 500 (lateral) points/B-mode-frame at a pulse repetition rate of 300 kHz. In addition, we successfully displayed maximum amplitude projection images of a mouse’s ear as volumetric images with an FOV of 3 mm × 3 mm (500 × 500 pixels) at 1.02 s, corresponding to 0.98 fps. PMID:26713184

  2. ROSAT wide field camera mirrors.

    PubMed

    Willingale, R

    1988-04-15

    The ROSAT wide field camera (WFC) is an XUV telescope operating in the 12-250-eV energy band. The mirror system utilizes Wolter-Schwarzschild type I (WS I) grazing incidence optics with a focal length of 525 mm, comprised of three nested aluminum shells with an outermost diameter of 576 mm providing a geometric aperture area of 456 cm(2). The reflecting surfaces are electroless nickel plated and coated with gold to enhance their reflectivity in the XUV. The mirrors have undergone full aperture optical testing, narrow beam XUV testing, and full aperture XUV testing. Measurements of the reflectivity are compared to theoretical values derived from the optical constants of gold in the XUV range. Analysis of the focused distribution is used to estimate the surface roughness and figuring errors of the polished surfaces. The results are compared to the mechanical metrology data collected during manufacture of the shells and the power spectral density of the reflecting surfaces is found to have a power-law form. PMID:20531591

  3. Wide Field Imager for Athena

    NASA Astrophysics Data System (ADS)

    Meidinger, Norbert; Nandra, Kirpal; Rau, Arne; Plattner, Markus; WFI proto-Consortium

    2015-09-01

    The Wide Field Imager focal plane instrument on ATHENA will combine unprecedented survey power through its large field of view of 40 arcmin with a high count-rate capability (> 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.1 keV to 15 keV. At energy of 6 keV for example, the full width at half maximum of the line shall be not worse than 150 eV until the end of the mission. The performance is accomplished by a set of DEPFET active pixel sensor matrices with a pixel size well suited to the angular resolution of 5 arc sec (on-axis) of the mirror system.Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450 micron thick silicon bulk. Two different types of DEPFET sensors are planned for the WFI instrument: A set of large-area sensors to cover the physical size of 14 cm x 14 cm in the focal plane and a single gateable DEPFET sensor matrix optimized for the high count rate capability of the instrument. An overview will be given about the presently developed instrument concept and design, the status of the technology development, and the expected performance. An outline of the project organization, the model philosophy as well as the schedule will complete the presentation about the Wide Field Imager for Athena.

  4. Lensless imaging for wide field of view

    NASA Astrophysics Data System (ADS)

    Nagahara, Hajime; Yagi, Yasushi

    2015-02-01

    It is desirable to engineer a small camera with a wide field of view (FOV) because of current developments in the field of wearable cameras and computing products, such as action cameras and Google Glass. However, typical approaches for achieving wide FOV, such as attaching a fisheye lens and convex mirrors, require a trade-off between optics size and the FOV. We propose camera optics that achieve a wide FOV, and are at the same time small and lightweight. The proposed optics are a completely lensless and catoptric design. They contain four mirrors, two for wide viewing, and two for focusing the image on the camera sensor. The proposed optics are simple and can be simply miniaturized, since we use only mirrors for the proposed optics and the optics are not susceptible to chromatic aberration. We have implemented the prototype optics of our lensless concept. We have attached the optics to commercial charge-coupled device/complementary metal oxide semiconductor cameras and conducted experiments to evaluate the feasibility of our proposed optics.

  5. Real-time turbulence profiling with a pair of laser guide star Shack-Hartmann wavefront sensors for wide-field adaptive optics systems on large to extremely large telescopes.

    PubMed

    Gilles, L; Ellerbroek, B L

    2010-11-01

    Real-time turbulence profiling is necessary to tune tomographic wavefront reconstruction algorithms for wide-field adaptive optics (AO) systems on large to extremely large telescopes, and to perform a variety of image post-processing tasks involving point-spread function reconstruction. This paper describes a computationally efficient and accurate numerical technique inspired by the slope detection and ranging (SLODAR) method to perform this task in real time from properly selected Shack-Hartmann wavefront sensor measurements accumulated over a few hundred frames from a pair of laser guide stars, thus eliminating the need for an additional instrument. The algorithm is introduced, followed by a theoretical influence function analysis illustrating its impulse response to high-resolution turbulence profiles. Finally, its performance is assessed in the context of the Thirty Meter Telescope multi-conjugate adaptive optics system via end-to-end wave optics Monte Carlo simulations. PMID:21045893

  6. Wide Field Instrument Adjutant Scientist

    NASA Astrophysics Data System (ADS)

    Spergel, David

    As Wide Field Instrument Adjutant Scientist, my goal will be to maximize the science capability of the mission in a cost-contained environment. I hope to work with the HQ, project and the FSWG to assure mission success. I plan to play a leadership role in communicating the WFIRST science capabilities to the astronomy community , obtain input from both science teams and the broader community that help derive performance requirements and calibration metrics. I plan to focus on developing the observing program for the deep fields and focus on using them to calibrate instrument performance and capabilities. I plan to organize workshops that will bring together WFIRST team members with astronomers working on LSST, Euclid, JWST, and the ELTs to maximize combined science return. I am also eager to explore the astrometric and stellar seismology capabilities of the instrument with a goal of maximizing science return without affecting science requirements.

  7. Gemini Frontier Fields: Wide-field Adaptive Optics Ks-band Imaging of the Galaxy Clusters MACS J0416.1-2403 and Abell 2744

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Carrasco, E. R.; Pessev, P.; Garrel, V.; Winge, C.; Neichel, B.; Vidal, F.

    2015-04-01

    We have observed two of the six Frontier Fields galaxy clusters, MACS J0416.1-2403 and Abell 2744, using the Gemini Multi-Conjugate Adaptive Optics System (GeMS) and the Gemini South Adaptive Optics Imager (GSAOI). With 0.″ 08-0.″ 10 FWHM our data are nearly diffraction-limited over a 100\\prime\\prime × 100\\prime\\prime wide area. GeMS/GSAOI complements the Hubble Space Telescope (HST) redwards of 1.6 μm with twice the angular resolution. We reach a 5σ depth of {{K}s}˜ 25.6 mag (AB) for compact sources. In this paper, we describe the observations, data processing, and initial public data release. We provide fully calibrated, co-added images matching the native GSAOI pixel scale as well as the larger plate scales of the HST release, adding to the legacy value of the Frontier Fields. Our work demonstrates that even for fields at high galactic latitude where natural guide stars are rare, current multi-conjugated adaptive optics technology at 8 m telescopes has opened a new window on the distant universe. Observations of a third Frontier Field, Abell 370, are planned. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). Based on observations made with ESO Telescopes at the La Silla and Paranal Observatories, Chile.

  8. Wide-field optical coherence tomography angiography using extended field imaging technique to evaluate the nonperfusion area in retinal vein occlusion

    PubMed Central

    Kimura, Masayo; Nozaki, Miho; Yoshida, Munenori; Ogura, Yuichiro

    2016-01-01

    Purpose Optical coherence tomography angiography (OCTA) is a newly developed technology which allows us to reconstruct the three-dimensional chorioretinal vasculature without dye injection. OCTA is a noninvasive, rapid, and reproducible method to assess retinal ischemia. However, one of its limitations is the size of scanning area. A novel yet simple technique to expand the scan length on optical coherence tomography has been reported as an extended field imaging (EFI) technique. It involves imaging the posterior pole through trial frames fitted with a +20 diopter lens. We applied this technique to OCTA to evaluate retinal vein occlusion. Materials and methods Ten eyes of nine patients with retinal vein occlusion were studied. The average age was 69.0 years (range: 49–93 years). We obtained OCTA images by using RTVue XR Avanti OCT with AngioVue®. The images of OCTA with scan size of 8×8 mm were obtained with and without EFI, and then they were compared. Results OCTA with EFI technique was performed successfully in all eyes. The nonperfusion area was well defined in superficial capillary plexus layer. The images with EFI were able to capture the larger area of the fundus by an average of 188.5% than those without EFI. The posterior pole inside the vascular arcade was well covered with this technique. The area of the fundus imaged by OCTA with EFI technique was even larger than that of fluorescein angiography using Heidelberg Retina Angiograph 2, which captured a 30° field. Conclusion Our results suggested that OCTA with EFI technique is very useful to evaluate the retinal ischemia in retinal vein occlusion. PMID:27471374

  9. Okayama astrophysical observatory wide field camera

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Kenshi; Shimizu, Yasuhiro; Okita, Kiichi; Kuroda, Daisuke; Koyano, Hisashi; Tsutsui, Hironori; Toda, Hiroyuki; Izumiura, Hideyuki; Yoshida, Michitoshi; Ohta, Kouji; Kawai, Nobuyuki; Yamamuro, Tomoyasu

    2014-08-01

    Okayama Astrophysical Observatory Wide Field Camera: OAOWFC is a near-infrared (0.9-2.5 μm) survey telescope, whose aperture is 0.91m. It works at Y, J, H, and Ks bands. The optics are consisted of forward Cassegrain and quasi Schmidt which yield the image circle of Φ 52 mm or Φ 1.3 deg at the focal plane. The overall F-ratio is F/2.51 which is one of the fastest among near infrared imagers in the world. A HAWAII-1 detector array placed at the focal plane cuts the central 0.48 deg. x 0.48 deg. with a pixel scale of 1.67 arcsec/pix. It will be used to survey the Galactic plane for variability and search for transients such as Gamma-ray burst afterglows optical counterpart of gravitational wave sources.

  10. In vivo wide-field multispectral scanning laser ophthalmoscopy-optical coherence tomography mouse retinal imager: longitudinal imaging of ganglion cells, microglia, and Müller glia, and mapping of the mouse retinal and choroidal vasculature.

    PubMed

    Zhang, Pengfei; Zam, Azhar; Jian, Yifan; Wang, Xinlei; Li, Yuanpei; Lam, Kit S; Burns, Marie E; Sarunic, Marinko V; Pugh, Edward N; Zawadzki, Robert J

    2015-01-01

    Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) provide complementary views of the retina, with the former collecting fluorescence data with good lateral but relatively low-axial resolution, and the latter collecting label-free backscattering data with comparable lateral but much higher axial resolution. To take maximal advantage of the information of both modalities in mouse retinal imaging, we have constructed a compact, four-channel, wide-field (∼50  deg) system that simultaneously acquires and automatically coregisters three channels of confocal SLO and Fourier domain OCT data. The scanner control system allows “zoomed” imaging of a region of interest identified in a wide-field image, providing efficient digital sampling and localization of cellular resolution features in longitudinal imaging of individual mice. The SLO is equipped with a “flip-in” spectrometer that enables spectral “fingerprinting” of fluorochromes. Segmentation of retina layers and en face display facilitate spatial comparison of OCT data with SLO fluorescence patterns. We demonstrate that the system can be used to image an individual retinal ganglion cell over many months, to simultaneously image microglia and Müller glia expressing different fluorochromes, to characterize the distinctive spatial distributions and clearance times of circulating fluorochromes with different molecular sizes, and to produce unequivocal images of the heretofore uncharacterized mouse choroidal vasculature. PMID:26677070

  11. WIDE-FIELD ASTRONOMICAL MULTISCALE CAMERAS

    SciTech Connect

    Marks, Daniel L.; Brady, David J.

    2013-05-15

    In order to produce sufficiently low aberrations with a large aperture, telescopes have a limited field of view. Because of this narrow field, large areas of the sky at a given time are unobserved. We propose several telescopes based on monocentric reflective, catadioptric, and refractive objectives that may be scaled to wide fields of view and achieve 1.''1 resolution, which in most locations is the practical seeing limit of the atmosphere. The reflective and Schmidt catadioptric objectives have relatively simple configurations and enable large fields to be captured at the expense of the obscuration of the mirror by secondary optics, a defect that may be managed by image plane design. The refractive telescope design does not have an obscuration but the objective has substantial bulk. The refractive design is a 38 gigapixel camera which consists of a single monocentric objective and 4272 microcameras. Monocentric multiscale telescopes, with their wide fields of view, may observe phenomena that might otherwise be unnoticed, such as supernovae, glint from orbital space debris, and near-earth objects.

  12. Imaging spectrometer wide field catadioptric design

    DOEpatents

    Chrisp; Michael P.

    2008-08-19

    A wide field catadioptric imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The catadioptric design has zero Petzval field curvature. The imaging spectrometer comprises an entrance slit for transmitting light, a system with a catadioptric lens and a dioptric lens for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through the system for receiving the light to the detector array.

  13. Wide-field Infrared Survey Explorer

    NASA Technical Reports Server (NTRS)

    Padgett, Deborah

    2012-01-01

    We present WISE (Wide-field Infrared Survey Explorer) mid-infrared photometry of young stellar object candidates in the Canis Majoris clouds at a distance of 1 kpc. WISE has identified 682 objects with apparent 12 and 22 micron excess emission in a 7 deg x 10 deg field around the CMa Rl cloud . While a substantial fraction of these candidates are likely galaxies, AGB stars, and artifacts from confusion along the galactic plane, others are part of a spectacular cluster of YSOs imaged by WISE along a dark filament in the R1 cloud. Palomar Double Spectrograph observations of several sources in this cluster confirm their identity as young A and B stars with strong emission lines. In this contribution, we plot the optical -mid-infrared spectral energy distribution for the WISE YSO candidates and discuss potential contaminants to the sample . The data demonstrate the utility of WISE in performing wide-area surveys for young stellar objects.

  14. The Wide-Field Imaging Interferometry Testbed: Recent Progress

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.

    2010-01-01

    The Wide-Field Imaging Interferometry Testbed (WIIT) at NASA's Goddard Space Flight Center was designed to demonstrate the practicality and application of techniques for wide-field spatial-spectral ("double Fourier") interferometry. WIIT is an automated system, and it is now producing substantial amounts of high-quality data from its state-of-the-art operating environment, Goddard's Advanced Interferometry and Metrology Lab. In this paper, we discuss the characterization and operation of the testbed and present the most recent results. We also outline future research directions. A companion paper within this conference discusses the development of new wide-field double Fourier data analysis algorithms.

  15. Hubble Space Telescope, Wide Field Planetary Camera

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This illustration is a diagram of the Hubble Space Telescope's (HST's), Wide Field Planetary Camera (WF/PC), one of the five Scientific Instruments. The WF/PC uses a four-sided pyramid mirror to split a light image into quarters. It then focuses each quadrant onto one of two sets of four sensors. The sensors are charge-coupled detectors and function as the electronic equivalent of extremely sensitive photographic plates. The WF/PC operates in two modes. The Wide-Field mode that will view 7.2-arcmin sections of the sky, and the Planetary mode that will look at narrower fields of view, such as planets or areas within other galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  16. Wide field-of-view bifocal eyeglasses

    NASA Astrophysics Data System (ADS)

    Barbero, Sergio; Rubinstein, Jacob

    2015-09-01

    When vision is affected simultaneously by presbyopia and myopia or hyperopia, a solution based on eyeglasses implies a surface with either segmented focal regions (e.g. bifocal lenses) or a progressive addition profile (PALs). However, both options have the drawback of reducing the field-of-view for each power position, which restricts the natural eye-head movements of the wearer. To avoid this serious limitation we propose a new solution which is essentially a bifocal power-adjustable optical design ensuring a wide field-of-view for every viewing distance. The optical system is based on the Alvarez principle. Spherical refraction correction is considered for different eccentric gaze directions covering a field-of-view range up to 45degrees. Eye movements during convergence for near objects are included. We designed three bifocal systems. The first one provides 3 D for far vision (myopic eye) and -1 D for near vision (+2 D Addition). The second one provides a +3 D addition with 3 D for far vision. Finally the last system is an example of reading glasses with +1 D power Addition.

  17. Stereoscopic wide field of view imaging system

    NASA Technical Reports Server (NTRS)

    Prechtl, Eric F. (Inventor); Sedwick, Raymond J. (Inventor); Jonas, Eric M. (Inventor)

    2011-01-01

    A stereoscopic imaging system incorporates a plurality of imaging devices or cameras to generate a high resolution, wide field of view image database from which images can be combined in real time to provide wide field of view or panoramic or omni-directional still or video images.

  18. The wide field/planetary camera

    NASA Technical Reports Server (NTRS)

    Westphal, J. A.; Baum, W. A.; Code, A. D.; Currie, D. G.; Danielson, G. E.; Gunn, J. E.; Kelsall, T. F.; Kristian, J. A.; Lynds, C. R.; Seidelmann, P. K.

    1982-01-01

    A wide site of potential astronomical and solar system scientific studies using the wide field planetary camera on space telescope are described. The expected performance of the camera as it approaches final assembly and testing is also detailed.

  19. IOT Overview: Wide-Field Imaging

    NASA Astrophysics Data System (ADS)

    Selman, F. J.

    The Wide Field Imager (WFI) instrument at La Silla has been the workhorse of wide-field imaging instruments at ESO for several years. In this contribution I will summarize the issues relating to its productivity for the community both in terms of the quality and quantity of data that has come out of it. Although only surveys of limited scope have been completed using WFI, it is ESO's stepping-stone to the new generation of survey telescopes.

  20. Wide Field and Planetary Camera for Space Telescope

    NASA Technical Reports Server (NTRS)

    Lockhart, R. F.

    1982-01-01

    The Space Telescope's Wide Field and Planetary Camera instrument, presently under construction, will be used to map the observable universe and to study the outer planets. It will be able to see 1000 times farther than any previously employed instrument. The Wide Field system will be located in a radial bay, receiving its signals via a pick-off mirror centered on the optical axis of the telescope assembly. The external thermal radiator employed by the instrument for cooling will be part of the exterior surface of the Space Telescope. In addition to having a larger (1200-12,000 A) wavelength range than any of the other Space Telescope instruments, its data rate, at 1 Mb/sec, exceeds that of the other instruments. Attention is given to the operating modes and projected performance levels of the Wide Field Camera and Planetary Camera.

  1. Invited Article: First Flight in Space of a Wide-Field-of-View Soft X-Ray Imager Using Lobster-Eye Optics: Instrument Description and Initial Flight Results

    NASA Technical Reports Server (NTRS)

    Collier, Michael R.; Porter, Frederick S.; Sibeck, David G.; Carter, Jenny A.; Chiao, Meng P.; Chornay, Dennis J.; Cravens, Thomas E.; Galeazzi, Massimiliano; Keller, John W.; Koutroumpa, Dimitra; Kujawski, Joseph; Kuntz, Kip; Read, Andy M.; Robertson, Ina P.; Sembay, Steve; Snowden, Steven; Thomas, Nicholas; Uprety, Youaraj; Walsh, Brian M.

    2015-01-01

    We describe the development, launch into space, and initial results from a prototype wide eld-of-view (FOV) soft X-ray imager that employs Lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The Sheath Transport Observer for the Redistribution of Mass (STORM) is the rst instrument using this type of optics launched into space and provides proof-of-concept for future ight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the moon, and the solar wind interaction with planetary bodies like Venus and Mars.

  2. Invited Article: First Flight in Space of a Wide-field-of-view Soft X-Ray Imager Using Lobster-Eye Optics: Instrument Description and Initial Flight Results

    NASA Technical Reports Server (NTRS)

    Collier, Michael; Porter, F. Scott; Sibeck, David G.; Carter, Jenny A.; Chiao, Meng P.; Chomay, Dennis J.; Cravens, Thomas E.; Galeazzi, Massiniliano; Keller, John; Koutroumpa, Dimitra

    2015-01-01

    We describe the development, launch into space, and initial results from a prototype wide eld-of-view (FOV) soft X-ray imager that employs Lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The Sheath Transport Observer for the Redistribution of Mass (STORM) is the rst instrument using this type of optics launched into space and provides proof-of-concept for future ight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the moon, and the solar wind interaction with planetary bodies like Venus and Mars.

  3. Fiber Optics: A Bright Future.

    ERIC Educational Resources Information Center

    Rice, James, Jr.

    1980-01-01

    Presents an overview of the impact of fiber optics on telecommunications and its application to information processing and library services, including information retrieval, news services, remote transmission of library services, and library networking. (RAA)

  4. Wide field imaging problems in radio astronomy

    NASA Astrophysics Data System (ADS)

    Cornwell, T. J.; Golap, K.; Bhatnagar, S.

    2005-03-01

    The new generation of synthesis radio telescopes now being proposed, designed, and constructed face substantial problems in making images over wide fields of view. Such observations are required either to achieve the full sensitivity limit in crowded fields or for surveys. The Square Kilometre Array (SKA Consortium, Tech. Rep., 2004), now being developed by an international consortium of 15 countries, will require advances well beyond the current state of the art. We review the theory of synthesis radio telescopes for large fields of view. We describe a new algorithm, W projection, for correcting the non-coplanar baselines aberration. This algorithm has improved performance over those previously used (typically an order of magnitude in speed). Despite the advent of W projection, the computing hardware required for SKA wide field imaging is estimated to cost up to $500M (2015 dollars). This is about half the target cost of the SKA. Reconfigurable computing is one way in which the costs can be decreased dramatically.

  5. The Wide-Field Infrared Explorer

    NASA Technical Reports Server (NTRS)

    Schember, Helene; Hacking, Perry

    1993-01-01

    More than 30% of current star formation is taking place ingalaxies known as starburst galaxies. Do starburst galaxies play a central role in the evolution of all galaxies, and can they lead us to the birth of galaxies and the source of quasars? We have proposed to build the Wide Field Infrared Explorer (WIRE), capable of detecting typical starburst galaxies at a redshift of 0.5, ultraluminous infrared galaxies behond a redshift of 2, and luminous protogalaxies beyond a redshift of 5.

  6. Wide-field microscopy using microcamera arrays

    NASA Astrophysics Data System (ADS)

    Marks, Daniel L.; Youn, Seo Ho; Son, Hui S.; Kim, Jungsang; Brady, David J.

    2013-02-01

    A microcamera is a relay lens paired with image sensors. Microcameras are grouped into arrays to relay overlapping views of a single large surface to the sensors to form a continuous synthetic image. The imaged surface may be curved or irregular as each camera may independently be dynamically focused to a different depth. Microcamera arrays are akin to microprocessors in supercomputers in that both join individual processors by an optoelectronic routing fabric to increase capacity and performance. A microcamera may image ten or more megapixels and grouped into an array of several hundred, as has already been demonstrated by the DARPA AWARE Wide-Field program with multiscale gigapixel photography. We adapt gigapixel microcamera array architectures to wide-field microscopy of irregularly shaped surfaces to greatly increase area imaging over 1000 square millimeters at resolutions of 3 microns or better in a single snapshot. The system includes a novel relay design, a sensor electronics package, and a FPGA-based networking fabric. Biomedical applications of this include screening for skin lesions, wide-field and resolution-agile microsurgical imaging, and microscopic cytometry of millions of cells performed in situ.

  7. Developing Wide-Field Spatio-Spectral Interferometry for Far-Infrared Space Applications

    NASA Technical Reports Server (NTRS)

    Leisawitz, David; Bolcar, Matthew R.; Lyon, Richard G.; Maher, Stephen F.; Memarsadeghi, Nargess; Rinehart, Stephen A.; Sinukoff, Evan J.

    2012-01-01

    Interferometry is an affordable way to bring the benefits of high resolution to space far-IR astrophysics. We summarize an ongoing effort to develop and learn the practical limitations of an interferometric technique that will enable the acquisition of high-resolution far-IR integral field spectroscopic data with a single instrument in a future space-based interferometer. This technique was central to the Space Infrared Interferometric Telescope (SPIRIT) and Submillimeter Probe of the Evolution of Cosmic Structure (SPECS) space mission design concepts, and it will first be used on the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). Our experimental approach combines data from a laboratory optical interferometer (the Wide-field Imaging Interferometry Testbed, WIIT), computational optical system modeling, and spatio-spectral synthesis algorithm development. We summarize recent experimental results and future plans.

  8. Design and development of a wide field telescope

    NASA Astrophysics Data System (ADS)

    Moon, Il; Lee, Sangon; Lim, Juhee; Yang, Ho-Soon; Rhee, Hyug-Gyo; Song, Jae Bong; Lee, Yun Woo; Lee, Jong Ung; Jin, Ho

    2012-09-01

    A prototype of large wide field telescope is a Cassegrain telescope which covers 2° field of view with two hyperbolic mirrors, a 0.5 m primary mirror and a 0.2 m secondary mirror with multiple correction lenses. To fulfill the optical and mechanical performance requirements in design and development phase extensive finite element analyses using NX NASTRAN and optical analyses with CODE V and PCFRINGE have been conducted for the structure of optical system. Analyses include static deformation (gravity and thermal), frequency, dynamic response analysis, and optical performance evaluations for minimum optical deformation. Image motion is also calculated based on line of sight sensitivity equations integrated in finite element models. A parametric process was performed for the design optimization to produce highest fundamental frequency for a given weight, as well as to deal with the normal concerns about global performance.

  9. The wide field imager instrument for Athena

    NASA Astrophysics Data System (ADS)

    Meidinger, Norbert; Nandra, Kirpal; Plattner, Markus; Porro, Matteo; Rau, Arne; Santangelo, Andrea E.; Tenzer, Chris; Wilms, Jörn

    2014-07-01

    The "Hot and Energetic Universe" has been selected as the science theme for ESA's L2 mission, scheduled for launch in 2028. The proposed Athena X-ray observatory provides the necessary capabilities to achieve the ambitious goals of the science theme. The X-ray mirrors are based on silicon pore optics technology and will have a 12 m focal length. Two complementary camera systems are foreseen which can be moved in and out of the focal plane by an interchange mechanism. These instruments are the actively shielded micro-calorimeter spectrometer X-IFU and the Wide Field Imager (WFI). The WFI will combine an unprecedented survey power through its large field of view of 40 arcmin with a high countrate capability (approx. 1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 keV to 15 keV during the entire mission lifetime (e.g. FWHM <= 150 eV at 6 keV). This performance is accomplished by a set of DEPFET active pixel sensor matrices with a pixel size matching the angular resolution of 5 arcsec (on-axis) of the mirror system. Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450 micron thick silicon bulk. The signal electrons generated by an X-ray photon are collected in a so-called internal gate below the transistor channel. The resulting change of the conductivity of the transistor channel is proportional to the number of electrons and thus a measure for the photon energy. DEPFETs have already been developed for the "Mercury Imaging X-ray Spectrometer" on-board of ESA's BepiColombo mission. For Athena we develop enhanced sensors with integrated electronic shutter and an additional analog storage area in each pixel. These features improve the peak-to-background ratio of the spectra and minimize dead time. The sensor will be read out with a new, fast, low-noise multi-channel analog signal processor with integrated sequencer and serial analog output. The architecture of sensor and readout

  10. Science with the Second Wide Field and Planetary Camera

    NASA Astrophysics Data System (ADS)

    Trauger, J.

    1992-07-01

    With the commencement of Cycle 4 observations, the General Observor community will have access to the second Wide Field and Planetary Camera (WFPC2), a replacement for the orginal WFPC instrument. WFPC2, a wide-field photometric camera which covers the spectrum from 12000 to 10000 Angstroms, will be installed in the Hubble radial bay during the currently manifested December 1993 Shuttle servicing mission. Besides optical correction for the aberrated Hubble primary mirror, the WFPC2 incorporates evolutionary improvement in photometric imaging capabilities. The CCD sensors, signal chain electronics, filter set, FUV performance, internal calibrations, and operational efficiency have all been improved through new technologies and lessons learned from WFPC operations and Hubble experience since launch. Here we provide an overview of the new instrument, beginning with the assumption that the reader is already familiar with the original WFPC now in service.

  11. Wide-field spatio-spectral interferometry for far-infrared space applications: A progress report

    NASA Astrophysics Data System (ADS)

    Leisawitz, David; Armstrong, J. T.; Bolcar, M. R.; Lyon, R.; Maher, S. F.; Memarsadeghi, N.; Rinehart, S.; Sinukoff, E.

    2014-01-01

    The NASA Astrophysics Roadmap Committee adopted the far-IR community’s vision and recommended far-IR interferometry as a needed capability in the 15 - 30 year time frame. The three major enabling technologies for such a mission are low-noise, high-speed detectors in small arrays; a demonstrated capability to cool optical system components to 4 K and focal planes to tens of mK with cryo-coolers; and the spatio-spectral interferometry (“double Fourier”) technique through which wide-field integral field spectroscopic data are derived from interferometric measurements. This paper reports on the current status of wide-field spatio-spectral interferometry and plans for maturation of the technique to space-flight readiness. Relatively simple spatial-spectral test patterns have been observed with the Wide-Field Imaging Interferometry Testbed at NASA’s Goddard Space Flight Center, and data cubes representing the observed scenes have been constructed based on the measured interferograms. A critical future milestone is the construction of an astronomically relevant, spatially and spectrally complex scene.

  12. The Wide-Field Imaging Interferometry Testbed: Recent Results

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen

    2006-01-01

    We present recent results from the Wide-Field Imaging Interferometry Testbed (WIIT). The data acquired with the WIIT is "double Fourier" data, including both spatial and spectral information within each data cube. We have been working with this data, and starting to develop algorithms, implementations, and techniques for reducing this data. Such algorithms and tools are of great importance for a number of proposed future missions, including the Space Infrared Interferometric Telescope (SPIRIT), the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS), and the Terrestrial Planet Finder Interferometer (TPF-I)/Darwin. Recent results are discussed and future study directions are described.

  13. MEMS for optical communication: present and future

    NASA Astrophysics Data System (ADS)

    Pu, Chuan; Lee, Shi-sheng; Park, Sangtae; Chu, Patrick B.; Brener, Igal

    2002-07-01

    The current fiber optical communication system has evolved into a complicated multi-wavelength system with the deployment of Wavelength Division Multiplexing (WDM) networks. Many innovative technologies are desired to materialize its vast capacities and promises. MEMS technology has recently emerged as a competitive candidate to solve many technical challenges encountered in current WDM networks. Its applications have spanned from large scale optical switch fabrics such as optical cross-connects, optical add/drop multiplexers, to a large variety of active and passive optical components for transmission networks, such as tunable lasers and filters, dispersion compensation devices, amplifier gain equalizers, polarization controllers, and many others. In this paper we will discuss the current development status, promises and challenges, and the future prospects of MEMS technologies for optical communication, with a primary focus on MEMS-based optical cross-connects.

  14. Experimental comparison of Wide Field AO control schemes using the Homer AO bench.

    NASA Astrophysics Data System (ADS)

    Parisot, Amélie; Petit, Cyril; Fusco, Thierry

    2011-09-01

    Wide Field Adaptive Optics (WFAO) concepts, such as Laser Tomography AO (LTAO) or Multi-Conjugate AO (MCAO) have been developed in order to overcome the anisoplanatism limit of classical AO. Most of the future AO-assisted instruments of ELTs rely on such concepts which have raised critical challenges such as tomographic estimation and from laser and natural guide star combined with efficient DM(s) control. In that context, the experimental validation of the various clever control solutions proposed by several teams in the past years is now essential to reach a level of maturity compatible with their implementation in future WFAO developments for ELT. The ONERA wide field AO facility (HOMER bench) has been developed for these very issues. Gathering a 3D turbulence generator, laser and natural guide stars, two deformable mirrors with variable altitude positions and a PC-based flexible and user-friendly RTC , HOMER allows the implementation and comparison of control schemes from the simplest least-square to the optimal Linear Quadratic Gaussian solutions including Virtual DM and Pseudo-closed loop approaches. After a description of the bench internal calibrations and ultimate performance, all the control schemes are compared experimentally. Their evolutions as a function of wavefront sensors SNR as well as their robustness to calibration / model errors are particularly emphasised. Finally, we derive from the previous works some specific calibrations and identifications procedures ensuring both robustness and efficiency of WFAO systems and we extrapolate their applications to the future ELT AO systems.

  15. A wide-field soft X-ray camera

    NASA Technical Reports Server (NTRS)

    Petre, R.

    1981-01-01

    A wide-field soft X-ray camera (WFSXC) sensitive in the 50 to 250 eV band is described. The camera features Wolter-Schwarzschild optics with an 8 degree field of view and 300 cu cu collecting area. The focal plane instrument is a microchannel plate detector. Broad-band energy discrimination is provided by thin-film filters mounted immediately in front of the focal plane. The WFSXC is capable of detecting sources with intensities greater than 5 percent of HZ 43 during typical sounding rocket exposures, and it would approach the same sensitivity range as EUVE during a typical exposure from the Shuttle.

  16. Astrometry in Wide-Field Surveys

    NASA Astrophysics Data System (ADS)

    Pál, A.; Bakos, G. Á.

    2007-07-01

    We present a general two-dimensional catalog matching algorithm that can efficiently be applied for wide-field astrometry where the acquired images are strained by distortions due to the large field-of-view. The algorithm is able to derive the transformations between a reference catalogue and the images up to arbitrary polynomial order. Our method is applied successfully in the Hungarian-made Automated Telescope Network \\citep[HATNet, see][]{bakos04} project both in real-time astrometrical guiding of the telescopes as well as during the reduction of the data. In this paper we summarize the key points of the newly developed parts of the algorithms as well as the performance on large set of wide FOV images taken by the telescopes of HATNet.

  17. Future metrology needs for FEL reflective optics.

    SciTech Connect

    Assoufid, L.

    2000-09-21

    An International Workshop on Metrology for X-ray and Neutron Optics has been held March 16-17, 2000, at the Advanced Photon Source, Argonne National Laboratory, near Chicago, Illinois (USA). The workshop gathered engineers and scientists from both the U.S. and around the world to evaluate metrology instrumentation and methods used to characterize surface figure and finish for long grazing incidence optics used in beamlines at synchrotrons radiation sources. This two-day workshop was motivated by the rapid evolution in the performance of x-ray and neutron sources along with requirements in optics figure and finish. More specifically, the performance of future light sources, such as free-electron laser (FEL)-based x-ray sources, is being pushed to new limits in term of both brilliance and coherence. As a consequence, tolerances on surface figure and finish of the next generation of optics are expected to become tighter. The timing of the workshop provided an excellent opportunity to study the problem, evaluate the state of the art in metrology instrumentation, and stimulate innovation on future metrology instruments and techniques to be used to characterize these optics. This paper focuses on FEL optics and metrology needs. (A more comprehensive summary of the workshop can be found elsewhere.) The performance and limitations of current metrology instrumentation will be discussed and recommendations from the workshop on future metrology development to meet the FEL challenges will be detailed.

  18. Wide-field in vivo oral OCT imaging

    PubMed Central

    Lee, Anthony M. D.; Cahill, Lucas; Liu, Kelly; MacAulay, Calum; Poh, Catherine; Lane, Pierre

    2015-01-01

    We have built a polarization-sensitive swept source Optical Coherence Tomography (OCT) instrument capable of wide-field in vivo imaging in the oral cavity. This instrument uses a hand-held side-looking fiber-optic rotary pullback catheter that can cover two dimensional tissue imaging fields approximately 2.5 mm wide by up to 90 mm length in a single image acquisition. The catheter spins at 100 Hz with pullback speeds up to 15 mm/s allowing imaging of areas up to 225 mm2 field-of-view in seconds. A catheter sheath and two optional catheter sheath holders have been designed to allow imaging at all locations within the oral cavity. Image quality of 2-dimensional image slices through the data can be greatly enhanced by averaging over the orthogonal dimension to reduce speckle. Initial in vivo imaging results reveal a wide-field view of features such as epithelial thickness and continuity of the basement membrane that may be useful in clinic for chair-side management of oral lesions. PMID:26203389

  19. Metrology systems of Hobby-Eberly Telescope wide field upgrade

    NASA Astrophysics Data System (ADS)

    Lee, Hanshin; Hill, Gary J.; Cornell, Mark E.; Vattiat, Brian L.; Perry, Dave M.; Rafferty, Tom H.; Taylor, Trey; Hart, Michael; Rafal, Marc D.; Savage, Richard D.

    2012-09-01

    The Hobby-Eberly Telescope (HET) Wide-Field Upgrade (WFU) will be equipped with new closed-loop metrology systems to actively control the optical alignment of the new four-mirror Wide-Field Corrector (WFC) as it tracks sidereal motion with respect to the fixed primary mirror. These systems include a tip/tilt camera (TTCam), distance measuring interferometers (DMI), guide probes (GP), and wavefront sensors (WFS). While the TTCam and DMIs are to monitor the mechanical alignment of the WFC, the WFSs and GPs will produce direct measurement of the optical alignment of the WFC with respect to the HET primary mirror. Together, these systems provide fully redundant alignment and pointing information for the telescope, thereby keeping the WFC in focus and suppressing alignment driven field aberrations. In addition to these closed-loop metrology systems, we will have a pupil viewing camera (PVCam) and a calibration wavefront sensor (CWFS). The PVCam will be used for occasional reflectance measurement of the HET primary mirror segments in the standard R,G,B colors. The CWFS will provide the reference wavefront signal against which the other two WFS are calibrated. We describe the current snapshot of these systems and discuss lab/on-sky performance test results of the systems.

  20. A Wide Field of View Plasma Spectrometer

    DOE PAGESBeta

    Skoug, Ruth M.; Funsten, Herbert O.; Moebius, Eberhard; Harper, Ron W.; Kihara, Keith H.; Bower, Jonathan S.

    2016-07-23

    Here we present a fundamentally new type of space plasma spectrometer, the wide field of view plasma spectrometer, whose field of view is >1.25π ster using fewer resources than traditional methods. The enabling component is analogous to a pinhole camera with an electrostatic energy-angle filter at the image plane. Particle energy-per-charge is selected with a tunable bias voltage applied to the filter plate relative to the pinhole aperture plate. For a given bias voltage, charged particles from different directions are focused by different angles to different locations. Particles with appropriate locations and angles can transit the filter plate and aremore » measured using a microchannel plate detector with a position-sensitive anode. Full energy and angle coverage are obtained using a single high-voltage power supply, resulting in considerable resource savings and allowing measurements at fast timescales. Lastly, we present laboratory prototype measurements and simulations demonstrating the instrument concept and discuss optimizations of the instrument design for application to space measurements.« less

  1. Wide field camera observations of Baade's Window

    NASA Technical Reports Server (NTRS)

    Holtzman, Jon A.; Light, R. M.; Baum, William A.; Worthey, Guy; Faber, S. M.; Hunter, Deidre A.; O'Neil, Earl J., Jr.; Kreidl, Tobias J.; Groth, E. J.; Westphal, James A.

    1993-01-01

    We have observed a field in Baade's Window using the Wide Field Camera (WFC) of the Hubble Space Telescope (HST) and obtain V- and I-band photometry down to V approximately 22.5. These data go several magnitudes fainter than previously obtained from the ground. The location of the break in the luminosity function suggests that there are a significant number of intermediate age (less than 10 Gyr) stars in the Galactic bulge. This conclusion rests on the assumptions that the extinction towards our field is similar to that seen in other parts of Baade's Window, that the distance to the bulge is approximately 8 kpc, and that we can determine fairly accurate zero points for the HST photometry. Changes in any one of these assumptions could increase the inferred age, but a conspiracy of lower reddening, a shorter distance to the bulge, and/or photometric zero-point errors would be needed to imply a population entirely older than 10 Gyr. We infer an initial mass function slope for the main-sequence stars, and find that it is consistent with that measured in the solar neighborhood; unfortunately, the slope is poorly constrained because we sample only a narrow range of stellar mass and because of uncertainties in the observed luminosity function at the faint end.

  2. Lithography optics: its present and future

    NASA Astrophysics Data System (ADS)

    Matsumoto, Koichi; Mori, Takashi

    1998-09-01

    Firstly, various technical aspects of ArF optics are surveyed. At present, the ArF excimer laser is regarded as one of the most promising candidates as a next-generation light source for optical lithography. Discussions are ranging over some critical issues of ArF optics. The lifetime of ArF optics supposedly limited by the radiation compaction of silica glass is estimated in comparison with KrF optics. Availability of calcium fluoride (CaF2) is also discussed. As a designing issue, a comparative study is made about the optical configuration, dioptric or catadioptric. In the end, our resist-based performance is shown. Secondly, estimated are the future trend regarding minimum geometry and the optical parameters, such as numerical aperture and wavelength. For the estimation, simulations based on aerial images are performed, where in the resolution limit is defined as a minimum feature size which retains practical depth of focus. Pattern geometry is classified into two categories, which are dense lines and isolated lines. Available wavelengths are assumed to be KrF excimer laser ((λ =248 nm), ArF excimer laser (λ =193 nm) and F2 excimer laser (λ =157 nm). Based upon the simulation results, the resolution limit is estimated for each geometry and each wavelength.

  3. OAOWFC: Okayama Astrophysical Observatory NIR Wide-Field Camera

    NASA Astrophysics Data System (ADS)

    Yoshida, M.; Yanagisawa, K.; Shimizu, Y.; Okita, K.; Nagayama, S.; Toda, H.; Ohta, K.; Kawai, N.

    2008-05-01

    In order to detect and trace the early phase of near-infrared (NIR) afterglows of Gamma Ray Bursts (GRBs) quickly, we are now developing the Okayama Astrophysical Observatory Wide-Field Camera, OAOWFC. The aperture size of OAOWFC is 91 cm. The focal plane is covered by a 2K×2K HAWAII2-RG detector with a pixel size of 18.5 μm×18.5 μm, resulting 0.95×0.95 deg2 field of view with an image scale of 1.6 arcsec/pixel. OAOWFC is designed to be a fully robotic instrument. This camera forms a part of Multicolor Imaging Telescopes for Survey and Monstrous Explosions (MITSuME), a multi telescope system dedicated to optical-NIR follow-up observations of GRB afterglows. Very wide field of view of OAOWFC enables us to catch GRB afterglows under less accurate localization sometimes given by the first alert. OAOWFC has an ability to detect bright GRB afterglow located at z = 10 easily, and it might be detectable at z = 18 if the conditions are met.

  4. OAOWFC: Okayama Astrophysical Observatory NIR Wide-Field Camera

    SciTech Connect

    Yoshida, M.; Yanagisawa, K.; Shimizu, Y.; Okita, K.; Nagayama, S.; Toda, H.; Ohta, K.; Kawai, N.

    2008-05-22

    In order to detect and trace the early phase of near-infrared (NIR) afterglows of Gamma Ray Bursts (GRBs) quickly, we are now developing the Okayama Astrophysical Observatory Wide-Field Camera, OAOWFC. The aperture size of OAOWFC is 91 cm. The focal plane is covered by a 2Kx2K HAWAII2-RG detector with a pixel size of 18.5 {mu}mx18.5 {mu}m, resulting 0.95x0.95 deg{sup 2} field of view with an image scale of 1.6 arcsec/pixel. OAOWFC is designed to be a fully robotic instrument. This camera forms a part of Multicolor Imaging Telescopes for Survey and Monstrous Explosions (MITSuME), a multi telescope system dedicated to optical-NIR follow-up observations of GRB afterglows. Very wide field of view of OAOWFC enables us to catch GRB afterglows under less accurate localization sometimes given by the first alert. OAOWFC has an ability to detect bright GRB afterglow located at z = 10 easily, and it might be detectable at z = 18 if the conditions are met.

  5. Facility calibration unit of Hobby Eberly Telescope wide field upgrade

    NASA Astrophysics Data System (ADS)

    Lee, Hanshin; Hill, Gary J.; Vattiat, Brian L.; Smith, Michael P.; Haeuser, Marco

    2012-09-01

    The Hobby-Eberly Telescope (HET) Wide-Field Upgrade (WFU) will be equipped with new Facility Calibration Unit (FCU). The FCU is in support of VIRUS and the facility instruments and consists of the head and source box. The FCU head, connected to the source box through two liquid light guides, is attached to the bottom of the WFU Wide-Field Corrector (WFC) and can be deployed into the beam to inject calibration light through the WFC whenever calibration is needed. A set of Fresnel lenses is used in the FCU head to mimic the caustics of M1 as much as possible to re-produce the telescope’s focal plane illumination pattern. Various imaging/non-imaging optical components (e.g. Compound Parabolic Concentrators, cone reflectors, condenser lenses) are used for efficient coupling between different types of calibration lamps and light guides, covering wavelengths from 350nm to 1800nm. In addition, we developed an efficient and tunable Light-Emitting Diode (LED) based source and coupler for UV and Visible spectral flat field calibration. This paper presents the designs, prototypes, and as-built components / subsystems of the FCU.

  6. Two-mirror, three-reflection telescopes as candidates for sky surveys in ground and space applications. The MINITRUST: an active optics warping telescope for wide-field astronomy

    NASA Astrophysics Data System (ADS)

    Viotti, Roberto F.; La Padula, Cesare D.; Vignato, Agostino; Lemaitre, Gerard R.; Montiel, Pierre; Dohlen, Kjetil

    2002-12-01

    A concept based on a two-mirror, three-reflection telescope has been investigated. Its anastigmatism and flat fielded properties, the compactness and optical performances over 2-2.5 arc deg field of view, make this optical system of high interest for the development of much larger telescopes than with Schmidt designs. The 2MTRT concept is a potential candidate for sky surveys with 2-3 meter class telescopes and particularily well adapted for UV space surveys. Preliminary developments have been carried out with the construction of a 30-cm prototype on Amoretti's design, providing encouraging results. At present, a 45-cm 2MTRT prototype has been realized for ground based sky survey of NEOs, based on active optics (MINITRUST), in order to overcome the difficulty of obtaining three aspherical surfaces. The primary and tertiary lie on the same double vase substrate, and have a rest profile. The hyperbolization is carried out in situ by air depressure. The secondary, in a tulip form substrate, has been hyperbolized by elastic relaxation. The project is planned for operation in 2003.

  7. PILOT: a wide-field telescope for the Antarctic plateau

    NASA Astrophysics Data System (ADS)

    Saunders, Will; Gillingham, Peter; McGrath, Andrew; Haynes, Roger; Brzeski, Jurek; Storey, John; Lawrence, Jon

    2008-07-01

    PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed Australian/European optical/infrared telescope for Dome C on the Antarctic Plateau, with target first light in 2012. The telescope is 2.4m diameter, with overall focal ratio f/10, and a 1 degree field-of-view. It is mounted on a 30m tower to get above most of the turbulent surface layer, and has a tip-tilt secondary for fast guiding. In median seeing conditions, it delivers 0.3" FWHM wide-field image quality, from 0.7-2.5 microns. In the best quartile of conditions, it delivers diffraction-limited imaging down to 1 micron, or even less with lucky imaging. The major challenges have been (a) preventing frost-laden external air reaching the optics, (b) overcoming residual surface layer turbulence, (c) keeping mirror, telescope and dome seeing to acceptable levels in the presence of large temperature variations with height and time, (d) designing optics that do justice to the site conditions. The most novel feature of the design is active thermal and humidity control of the enclosure, to closely match the temperature of external air while preventing its ingress.

  8. Prospects for a Wide Field CCD Camera Aboard NGST

    NASA Astrophysics Data System (ADS)

    Golimowski, D. A.; Ford, H. C.; Tsvetanov, Z. I.; Burrows, C. J.; Krist, J. E.; White, R. L.; Clampin, M.; Rafal, M.; Hartig, G.

    1998-05-01

    The importance of a Next Generation Space Telescope (NGST) for studying the infrared universe has often overshadowed NGST's potential benefit to optical astronomy. As currently envisioned, NGST could also provide views of the visible universe with resolution and sensitivity that are unmatched by any existing ground- or space-based observatory. We discuss the scientific advantages and technical feasibility of placing a wide-field CCD camera aboard NGST. Using simulated data, we compare the imaging performance of such a camera with that achieved or expected with the Keck Telescope and the HST Advanced Camera for Surveys. Finally, we discuss the technical challenges of temperature regulation and radiation shielding for a CCD camera in the NGST environment.

  9. Wide-field Fizeau imaging telescope: experimental results.

    PubMed

    Kendrick, R L; Aubrun, Jean-Noel; Bell, Ray; Benson, Robert; Benson, Larry; Brace, David; Breakwell, John; Burriesci, Larry; Byler, Eric; Camp, John; Cross, Gene; Cuneo, Peter; Dean, Peter; Digumerthi, Ramji; Duncan, Alan; Farley, John; Green, Andy; Hamilton, Howard H; Herman, Bruce; Lauraitis, Kris; de Leon, Erich; Lorell, Kenneth; Martin, Rob; Matosian, Ken; Muench, Tom; Ni, Mel; Palmer, Alice; Roseman, Dennis; Russell, Sheldon; Schweiger, Paul; Sigler, Rob; Smith, John; Stone, Richard; Stubbs, David; Swietek, Gregg; Thatcher, John; Tischhauser, C; Wong, Harvey; Zarifis, Vassilis; Gleichman, Kurt; Paxman, Rick

    2006-06-20

    A nine-aperture, wide-field Fizeau imaging telescope has been built at the Lockheed-Martin Advanced Technology Center. The telescope consists of nine, 125 mm diameter collector telescopes coherently phased and combined to form a diffraction-limited image with a resolution that is consistent with the 610 mm diameter of the telescope. The phased field of view of the array is 1 murad. The measured rms wavefront error is 0.08 waves rms at 635 nm. The telescope is actively controlled to correct for tilt and phasing errors. The control sensing technique is the method known as phase diversity, which extracts wavefront information from a pair of focused and defocused images. The optical design of the telescope and typical performance results are described. PMID:16778931

  10. Wide-field surveys from the SNAP mission

    SciTech Connect

    agkim@lbl.gov

    2002-07-23

    The Supernova/Acceleration Probe (SNAP) is a proposed space-borne observatory that will survey the sky with a wide-field optical/NIR imager. The images produced by SNAP will have an unprecedented combination of depth, solid-angle, angular resolution, and temporal sampling. Two 7.5 square-degree fields will be observed every four days over 16 months to a magnitude depth of AB = 27.7 in each of nine filters. Co-adding images over all epochs will give an AB = 30.3 per filter. A 300 square-degree field will be surveyed with no repeat visits to AB = 28 per filter. The nine filters span 3500-17000 {angstrom}. Although the survey strategy is tailored for supernova and weak gravitational lensing observations, the resulting data supports a broad range of auxiliary science programs.

  11. Optical MEMS: past, present and future

    NASA Astrophysics Data System (ADS)

    Ramani, Chandra Mouli

    2005-09-01

    Spurred by the growth of the internet, Optical Telecommunications bandwidth, experienced unprecedented growth during late 1990's. During this time of great economic expansion, the creation of new enterprises was vast and the expansion of established component, system and services companies was breathtaking. Unfortunately, this positive economic state was short-lived. This period was followed in 2001-2004 by one of the most significant market crashes in history. During those 10 years of economic growth, about $20B in venture capital was invested in the optical telecom industry, most of this investment was lost in recent years. Many start-up industries which experienced unprecedented growth at the end of the 20th century were lost at the start of the 21st. (1) During this time many, innovative technologies were born and buried. However, many new capabilities emerged from this period of unrest; one such example is the advent of Optical MEMS (MOEMS). Many academics and corporate laboratories pursued the development of MOEMS during the economic boom and, in the author's view; MOEMS surfaced as a powerful and versatile tool set that has proved invaluable and in the last few years during economic downturn, stood the test of time. In the Telecommunications industry, for optical switching and wavelength management applications MOEMS has proven to be the technology of choice. (2) Variable Optical Attenuators (VOA), Wavelength Blockers (WB), Dynamic Gain Equalizers (DGE), and most recently Wavelength Selective Switches (WSS) are being used in the numerous recent network deployments. Moreover, agile networks of the future will have MOEMS at every node. This presentation will provide an overview of the history of MOEMS in Telecommunications, discuss its byproducts and offer a window into the future of the technology.

  12. The future of large optical system verification

    NASA Astrophysics Data System (ADS)

    Matthews, Gary

    2005-08-01

    As optical systems grow in size, there becomes a point in which traditional system verification prior to launch will become impossible. This implies that observatory ground testing will not be completed. Our history does not support this premise and therefore results in an unacceptable programmatic risk. But, if the dream of building 20-30 meter systems is ever to become true, these realities must be accepted. To make this possible, new and better analytical tools and processes must be developed and certified on programs that can be tested on the ground. This change in paradigm does not eliminate critical testing; it just does it at different assembly levels and most likely adds alignment flexibility to correct optical errors after launch. This paper provides ideas on how the hardware, analysis tools, and testing may evolve to support these ambitious future programs.

  13. Wide-field-of-view (WFOV) night vision goggle

    NASA Astrophysics Data System (ADS)

    Isbell, Wayne; Estrera, Joseph P.

    2003-09-01

    The United States' armed forces continue to be presented with increased challenges in adverse operational environments with increasing risk and complexity - especially at night. To ensure continued operational success and battlefield superiority during darkness, our armed forces must be equipped with night vision (NV) systems providing increased situational awareness. Doing so will significantly enhance threat detection and engagement, as well as survivability, thus ensuring greater mission success. Northrop Grumman Electro-Optical Systems (EOS) continues to develop its Wide Field of View (WFOV) image intensification (I2) night vision system for ground forces. This system will provide a significant increase in visual coverage enabling US forces to continue "to own the night". Until now, NV systems have typically been limited to a 40-degree field of view (FOV), vertically and horizontally. This limited FOV reduces off-axis detection, restricts an individual soldier's recognition and engagement capabilities and hinders added peripheral vision. To counter this operational deficiency, EOS proposes the Wide Field of View (WFOV) night vision binocular. The WFOV system will have a 70-degree horizontal FOV, with a 55-degree vertical FOV. The increased FOV will result in increased situational awareness of soldiers' surrounding environment (including terrain, hazards, threat, etc) during normal night operations. It will also allow for rapid and safer movement, especially in MOUT operations. Additionally, the increased visual coverage of large areas will enable soldiers to detect and engage targets faster and with greater reliability. The WFOV binocular will significantly enhance survivability, threat detection and engagement, and hence, greater mission success rate.

  14. DMD-based programmable wide field spectrograph for Earth observation

    NASA Astrophysics Data System (ADS)

    Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Costes, Vincent; Hébert, Philippe-Jean

    2015-03-01

    In Earth Observation, Universe Observation and Planet Exploration, scientific return could be optimized in future missions using MOEMS devices. In Earth Observation, we propose an innovative reconfigurable instrument, a programmable wide-field spectrograph where both the FOV and the spectrum could be tailored thanks to a 2D micromirror array (MMA). For a linear 1D field of view (FOV), the principle is to use a MMA to select the wavelengths by acting on intensity. This component is placed in the focal plane of a first grating. On the MMA surface, the spatial dimension is along one side of the device and for each spatial point, its spectrum is displayed along the perpendicular direction: each spatial and spectral feature of the 1D FOV is then fully adjustable dynamically and/or programmable. A second stage with an identical grating recomposes the beam after wavelengths selection, leading to an output tailored 1D image. A mock-up has been designed, fabricated and tested. The micromirror array is the largest DMD in 2048 x 1080 mirrors format, with a pitch of 13.68μm. A synthetic linear FOV is generated and typical images have been recorded o at the output focal plane of the instrument. By tailoring the DMD, we could modify successfully each pixel of the input image: for example, it is possible to remove bright objects or, for each spatial pixel, modify the spectral signature. The very promising results obtained on the mock-up of the programmable wide-field spectrograph reveal the efficiency of this new instrument concept for Earth Observation.

  15. Wide-field, high-resolution Fourier ptychographic microscopy

    PubMed Central

    Zheng, Guoan; Horstmeyer, Roarke; Yang, Changhuei

    2014-01-01

    In this article, we report an imaging method, termed Fourier ptychographic microscopy (FPM), which iteratively stitches together a number of variably illuminated, low-resolution intensity images in Fourier space to produce a wide-field, high-resolution complex sample image. By adopting a wavefront correction strategy, the FPM method can also correct for aberrations and digitally extend a microscope’s depth-of-focus beyond the physical limitations of its optics. As a demonstration, we built a microscope prototype with a resolution of 0.78 μm, a field-of-view of ~120 mm2, and a resolution-invariant depth-of-focus of 0.3 mm (characterized at 632 nm). Gigapixel colour images of histology slides verify FPM’s successful operation. The reported imaging procedure transforms the general challenge of high-throughput, high-resolution microscopy from one that is coupled to the physical limitations of the system’s optics to one that is solvable through computation. PMID:25243016

  16. Hubble Space Telescope, Wide Field and Planetary Camera

    NASA Technical Reports Server (NTRS)

    1985-01-01

    In this photograph, engineers and technicians prepare the Hubble Space Telescope's (HST's) Wide Field and Planetary Camera (WF/PC) for installation at the Lockheed Missile and Space Company. The WF/PC is designed to investigate the age of the universe and to search for new planetary systems around young stars. It takes pictures of large numbers of galaxies and close-ups of planets in our solar system. The HST is the first of NASA's great observatories and the most complex and sensitive optical telescope ever made. The purpose of the HST is to study the cosmos from a low-Earth orbit by placing the telescope in space, enabling astronomers to collect data that is free of the Earth's atmosphere. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had overall responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company, Sunnyvale, California, produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  17. The Wide-Field Imaging Interferometry Testbed: Progress and Plans

    NASA Technical Reports Server (NTRS)

    Rinehart, S. A.; Leisawitz, D.; Leviton, D.; Martino, A.; Maynard, W.; Mundy, L. G.; Zhang, X.

    2004-01-01

    We describe the technique of wide field mosaic imaging for optical/IR interferometers and present early experimental results from a laboratory instrument designed to validate, experiment with, and refine the technique. A conventional single-detector stellar interferometer operating with narrow bandwidth at center wavelength lambda is limited in its field of view to the primary beam of the individual telescope apertures, or approx. lambda/D(sub tel) radians, where is the telescope diameter. Such a field is too small for many applications; often one wishes to image extended sources. We are developing and testing a technique analogous to the mosaic method employed in millimeter and radio astronomy, but applicable to optical/IR Michelson interferometers, in which beam combination is done in the pupil plane. An N(sub pix) x N(sub pix) detector array placed in the image plane of the interferometer is used to record simultaneously the fringe patterns from many contiguous telescope fields, effectively multiplying the field size by N(sub pix)/2, where the factor 2 allows for Nyquist sampling. This mosaic imaging technique will be especially valuable for far IR and submillimeter interferometric space observatories such as the Space Infrared Interferometric Telescope (SPIRIT) and the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS). SPIRIT and SPECS will be designed to provide sensitive, high angular resolution observations of fields several arcminutes in diameter, and views of the universe complementary to those provided by HST, NGST, and ALMA.

  18. Future for security applications of optical holography

    NASA Astrophysics Data System (ADS)

    Lancaster, Ian M.

    1995-07-01

    The use of holograms for security and authentication accounts for around half of all optical holograms produced. This sector is crucial to the hologram industry. Yet it is under threat, as holograms become the target of criminals around the world who wish to counterfeit the documents and products the holograms protect. It is possible to produce holograms using techniques and security procedures which raise the barriers to the counterfeiters, but the hologram industry appears to be complacent and inadequately prepared to deal with this threat to its future. This requires the production of appropriate holograms for each application, awareness, education, and policing. A suitable vehicle for the implementation of these tasks now exists in the International Hologram Manufacturers Association and its Hologram Image Register.

  19. Optical processing for future computer networks

    NASA Technical Reports Server (NTRS)

    Husain, A.; Haugen, P. R.; Hutcheson, L. D.; Warrior, J.; Murray, N.; Beatty, M.

    1986-01-01

    In the development of future data management systems, such as the NASA Space Station, a major problem represents the design and implementation of a high performance communication network which is self-correcting and repairing, flexible, and evolvable. To obtain the goal of designing such a network, it will be essential to incorporate distributed adaptive network control techniques. The present paper provides an outline of the functional and communication network requirements for the Space Station data management system. Attention is given to the mathematical representation of the operations being carried out to provide the required functionality at each layer of communication protocol on the model. The possible implementation of specific communication functions in optics is also considered.

  20. Toward future IP optical backbone networks

    NASA Astrophysics Data System (ADS)

    Urushidani, Shigeo

    2005-11-01

    The rapid and aggressive penetration of broadband access services such as fiber to the home (FTTH) has been accelerating the increase in IP traffic volume and new networking technologies are required in order to accommodate future traffic in a cost-effective manner. This paper overviews the advanced IP optical network architecture and technologies for very-large-scale IP backbone networks. These technologies are the key to accommodate the huge volumes of IP traffic expected and control network resources in an effective and dynamic manner. We describe advanced IP optical networking technologies which accommodate multiple service networks using multi-instance technologies, and enable multi-layer traffic engineering using virtual network topology technologies. The migration scenario is described from the existing networks to GMPLS networks; reference is made to the advanced Path Computation Element (PCE) which enables multi-layer traffic engineering and MPLS/GMPLS migration. New network concepts such as Layer 1 Virtual Private Network (L1VPN) and GMPLS interoperability issues, which are being discussed in IETF, are also described.

  1. A wide-field telescope with spherical optics

    NASA Technical Reports Server (NTRS)

    Jones, R. T.

    1976-01-01

    Utilizing a doublet lens to correct the aberrations of a spherical mirror, a small f/8 telescope for visual use was designed and constructed. The lens has considerable negative power, so that it serves as a Barlow lens as well as a corrector.

  2. The Wide-Field Imaging Interferometry Testbed (WIIT): Recent Progress and Results

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.; Frey, Bradley J.; Leisawitz, David T.; Lyon, Richard G.; Maher, Stephen F.; Martino, Anthony J.

    2008-01-01

    Continued research with the Wide-Field Imaging Interferometry Testbed (WIIT) has achieved several important milestones. We have moved WIIT into the Advanced Interferometry and Metrology (AIM) Laboratory at Goddard, and have characterized the testbed in this well-controlled environment. The system is now completely automated and we are in the process of acquiring large data sets for analysis. In this paper, we discuss these new developments and outline our future research directions. The WIIT testbed, combined with new data analysis techniques and algorithms, provides a demonstration of the technique of wide-field interferometric imaging, a powerful tool for future space-borne interferometers.

  3. Wide-Field Slitless Spectroscopy with JWST/NIRISS

    NASA Astrophysics Data System (ADS)

    Dixon, William V.; Ravindranath, Swara; Willott, Chris

    2015-08-01

    The Near Infrared Imager and Slitless Spectrograph (NIRISS) aboard the James Webb Space Telescope (JWST) will offer wide-field slitless spectroscopy (WFSS) with a resolving power R = 150 at wavelengths from 0.8 to 2.25 microns. In this band, NIRISS will be sensitive to Lyman-alpha emission lines and continuum breaks in the spectra of galaxies with redshifts 6 < z < 17, allowing it to probe the first stars and ionizing sources in the early universe. NIRISS observations of the high-redshift universe will provide a wealth of information on foreground objects, creating a unique library of optical emission-line spectra from the faintest galaxies at lower redshifts. To explore its ability to identify and characterize galaxies at all redshifts, we have modeled NIRISS observations of a massive strong-lensing galaxy cluster and analyzed the synthetic images using standard software tools. Our simulations demonstrate that WFSS with NIRISS will provide a powerful tool for the exploration of galaxies near and far.NIRISS is provided to the JWST project by the Canadian Space Agency under the leadership of René Doyon of the Université de Montréal. The prime contractor is COM DEV Canada.

  4. Wide field-of-view microscopy with Talbot pattern illumination

    NASA Astrophysics Data System (ADS)

    Wu, Jigang; Liu, Guangshuo

    2012-12-01

    Wide field-of-view (FOV) microscopy is useful for high-throughput applications because of the capability to obtain large amount of information from a single image. One way to implement a wide FOV microscope is to scan the sample with a two-dimensional focus grid. The transmission or reflection of the focal spots can then be used to reconstruct the sample image. This scheme is effectively a parallel scanning optical microscope (SOM), where the FOV depends on the area of the focus grid and the imaging resolution depends on the spot size of the foci. We use the Talbot image of a twodimensional aperture grid as the focus grid and developed a wide FOV microscope. Preliminary experimental results show the capability of our microscope to acquire wide FOV images of US air force target and MCF-7 cancer cell samples. Fluorescence images of fluorescence beads are also acquired. Because the diffraction of incident beam by the aperture grid contains complicated angular frequencies, the focal spots in Talbot pattern cannot be approximated as Gaussian beams as in conventional SOM. We characterized the focal spots in Talbot pattern and studied the evolution of the full width at half maximum (FWHM). We also simulated the SOM imaging under Talbot pattern illumination using the razor blade as the sample objects.

  5. Non-mydriatic, wide field, fundus video camera

    NASA Astrophysics Data System (ADS)

    Hoeher, Bernhard; Voigtmann, Peter; Michelson, Georg; Schmauss, Bernhard

    2014-02-01

    We describe a method we call "stripe field imaging" that is capable of capturing wide field color fundus videos and images of the human eye at pupil sizes of 2mm. This means that it can be used with a non-dilated pupil even with bright ambient light. We realized a mobile demonstrator to prove the method and we could acquire color fundus videos of subjects successfully. We designed the demonstrator as a low-cost device consisting of mass market components to show that there is no major additional technical outlay to realize the improvements we propose. The technical core idea of our method is breaking the rotational symmetry in the optical design that is given in many conventional fundus cameras. By this measure we could extend the possible field of view (FOV) at a pupil size of 2mm from a circular field with 20° in diameter to a square field with 68° by 18° in size. We acquired a fundus video while the subject was slightly touching and releasing the lid. The resulting video showed changes at vessels in the region of the papilla and a change of the paleness of the papilla.

  6. High-resolution LCD projector for extra-wide-field-of-view head-up display

    NASA Astrophysics Data System (ADS)

    Brown, Robert D.; Modro, David H.; Quast, Gerhardt A.; Wood, Robert B.

    2003-09-01

    LCD projection-based cockpit displays are beginning to make entry into military and commercial aircraft. Customers for commercial Head-Up Displays (HUDs)(including airframe manufacturers) are now interested in the adaptation of the technology into existing and future HUD optical systems. LCD projection can improve mean-time-between-failure rates because the LCDs are very robust and the light sources can be replaced with scheduled maintenance by the customer without the need for re-calibration. LCD projectors promise to lower the cost of the HUD because the cost of these displays continues to drop while the cost of CRTs remain stable. LCD projectors provide the potential for multi-colors, higher brightness raster, and all-digital communication between the flight computer and display unit. Another potential benefit of LCD projection is the ability to increase field of view and viewing eyebox without exceeding existing power budgets or reducing display lifetime and reliability compared to the capabilities provided by CRTs today. This paper describes the performance requirements and improved performance of a third-generation LCD projection image source for use in a wide field of view head-up display (HUD) optical system. This paper will focus on new HUD requirements and the application of various technologies such as LCOS microdisplays, arc lamps, and rear-projection screens. Measured performance results are compared to the design requirements.

  7. MIRIS: A Compact Wide-field Infrared Space Telescope

    NASA Astrophysics Data System (ADS)

    Han, Wonyong; Lee, Dae-Hee; Jeong, Woong-Seob; Park, Youngsik; Moon, Bongkon; Park, Sung-Joon; Pyo, Jeonghyun; Kim, Il-Joong; Park, Won-Kee; Lee, Dukhang; Seon, Kwang-Il; Nam, Uk-Won; Cha, Sang-Mok; Park, Kwijong; Park, Jang-Hyun; Yuk, In-Soo; Ree, Chang Hee; Jin, Ho; Choel Yang, Sun; Park, Hong-Young; Shin, Goo-Hwan; Seo, Joung-Ki; Rhee, Seung-Wu; Park, Jong-Oh; Lee, Hyung Mok; Murakami, Hiroshi; Matsumoto, Toshio

    2014-09-01

    A compact infrared space telescope called MIRIS (Multi-purpose Infra-Red Imaging System) was developed by the Korea Astronomy and Space Science Institute (KASI), and launched onboard the Science and Technology Satellite-3 of Korea (STSAT-3) in 2013 November. The main mission of MIRIS is the Paschen-α emission line survey along the Galactic plane and the cosmic infrared background (CIB) observation, particularly around the north ecliptic pole region. For these missions, a wide field of view (3.67 × 3.67°) with an angular resolution of 51.6'' and wavelength coverage from 0.9 ~ 2.0 μm have been adopted for MIRIS, having optical components consisting of a 80 mm main lens and four other lenses with F/2 focal ratio optics. The opto-mechanical system was carefully designed to minimize any effects from shock during the launch process and thermal variation. Also, the telescope was designed to use a passive cooling technique to maintain the temperature around 200 K in order to reduce thermal noise. A micro Stirling cooler was used to cool down the Teledyne PICNIC infrared array to 90 K, which was equipped in a dewar with four filters for infrared passbands of I, H, and Paschen-α and a dual-band continuum line filter. MIRIS system was integrated into the STSAT-3 as its primary payload and successfully passed required tests in the laboratory, such as thermal-vacuum, vibration, and shock tests. MIRIS is now operating in sun synchronous orbits for initial tests and has observed its first images successfully.

  8. The Wide-Field Imaging Interferometry Testbed: Progress and Plans

    NASA Astrophysics Data System (ADS)

    Leisawitz, D.; Leviton, D.; Martino, A.; Maynard, W.; Mundy, L. G.; Rinehart, S. A.; Zhang, X.; WIIT Science and Technical Advisory Group Team

    2001-12-01

    We describe the technique of wide field mosaic imaging for optical/IR interferometers and present early experimental results from a laboratory instrument designed to validate, experiment with, and refine the technique. A conventional single-detector stellar interferometer operating with narrow bandwidth at center wavelength λ is limited in its field of view to the primary beam of the individual telescope apertures, or ~ λ / Dtel radians, where Dtel is the telescope diameter. Such a field is too small for many applications; often one wishes to image extended sources. We are developing and testing a technique analogous to the mosaicing method employed in millimeter and radio astronomy, but applicable to optical/IR Michelson interferometers, in which beam combination is done in the pupil plane. An Npix x Npix array detector placed in the image plane of the interferometer is used to record simultaneously the fringe patterns from many contiguous telescope fields, effectively multiplying the field size by Npix/2, where the factor 2 allows for Nyquist sampling. This technology will be especially valuable for far IR and submillimeter interferometric space observatories such as the Space Infrared Interferometric Telescope (SPIRIT) and the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS). SPIRIT and SPECS will be designed to provide sensitive, high angular resolution observations of fields several arcminutes in diameter, and views of the universe complementary to those provided by HST, NGST, and ALMA. Funding for WIIT is provided by NASA Headquarters through the ROSS/SARA Program and by the Goddard Space Flight Center through its IR&D Program.

  9. The Wide Field Spectrograph (WiFeS)

    NASA Astrophysics Data System (ADS)

    Dopita, Michael; Hart, John; McGregor, Peter; Oates, Patrick; Bloxham, Gabe; Jones, Damien

    2007-08-01

    This paper describes the Wide Field Spectrograph (WiFeS) under construction at the Research School of Astronomy and Astrophysics (RSAA) of the Australian National University (ANU) for the ANU 2.3 m telescope at the Siding Spring Observatory. WiFeS is a powerful integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent throughput, wavelength stability, spectrophotometric performance and superb image quality along with wide spectral coverage throughout the 320 950 nm wavelength region. It provides a 25×38 arcsec field with 0.5 arcsec sampling along each of twenty five 38×1 arcsec slitlets. The output format is optimized to match the 4096×4096 pixel CCD detectors in each of two cameras individually optimized for the blue and the red ends of the spectrum, respectively. A process of “interleaved nod-and-shuffle” will be applied to permit quantum noise-limited sky subtraction. Using VPH gratings, spectral resolutions of 3000 and 7000 are provided. The full spectral range is covered in a single exposure at R=3000, and in two exposures in the R=7000 mode. The use of transmissive coated optics, VPH gratings and optimized mirror coatings ensures a throughput (including telescope atmosphere and detector) >30% over a wide spectral range. The concentric image-slicer design ensures an excellent and uniform image quality across the full field. To maximize scientific return, the whole instrument is configured for remote observing, pipeline data reduction, and the accumulation of calibration image libraries.

  10. PSF reconstruction for MUSE in wide field mode

    NASA Astrophysics Data System (ADS)

    Villecroze, R.; Fusco, Thierry; Bacon, Roland; Madec, Pierre-Yves

    2012-07-01

    The resolution of ground-based telescopes is dramatically limited by the atmospheric turbulence.. Adaptative optics (AO) is a real-time opto-mechanical approach which allows to correct for the turbulence effect and to reach the ultimate diffraction limit astronomical telescopes and their associated instrumentation. Nevertheless, the AO correction is never perfect especially when it has to deal with large Field of View (FoV). Hence, a posteriori image processing really improves the final estimation of astrophysical data. Such techniques require an accurate knowledge of the system response at any position in the FoV The purpose of this work is then the estimation of the AO response in the particular case of the MUSE [1] /GALACSI [2] instrument (a 3D mult-object spectrograph combined with a Laser-assisted wide field AO system which will be installed at the VLT in 2013). Using telemetry data coming from both AO Laser and natural guide stars, a Point Spread Function (PSF) is derived at any location of the FoV and for every wavelength of the MUSE spectrograph. This document presents the preliminary design of the MUSE WFM PSF reconstruction process. The various hypothesis and approximations are detailed and justified. A first description of the overall process is proposed. Some alternative strategies to improve the performance (in terms of computation time and storage) are described and have been implemented. Finally, after a validation of the proposed algorithm using end-to-end models, a performance analysis is conducted (with the help of a full end-to-end model). This performance analysis will help us to populate an exhaustive error budget table.

  11. Update on the Wide-field Infrared Survey Explorer (WISE)

    NASA Technical Reports Server (NTRS)

    Mainzer, Amanda K.; Eisenhardt, Peter; Wright, Edward L.; Liu, Feng-Chuan; Irace, William; Heinrichsen, Ingolf; Cutri, Roc; Duval, Valerie

    2006-01-01

    The Wide-field Infrared Survey Explorer (WISE), a NASA MIDEX mission, will survey the entire sky in four bands from 3.3 to 23 microns with a sensitivity 1000 times greater than the IRAS survey. The WISE survey will extend the Two Micron All Sky Survey into the thermal infrared and will provide an important catalog for the James Webb Space Telescope. Using 1024(sup 2) HgCdTe and Si:As arrays at 3.3, 4.7, 12 and 23 microns, WISE will find the most luminous galaxies in the universe, the closest stars to the Sun, and it will detect most of the main belt asteroids larger than 3 km. The single WISE instrument consists of a 40 cm diamond-turned aluminum afocal telescope, a two-stage solid hydrogen cryostat, a scan mirror mechanism, and reimaging optics giving 5 resolution (full-width-half-maximum). The use of dichroics and beamsplitters allows four color images of a 47' x47' field of view to be taken every 8.8 seconds, synchronized with the orbital motion to provide total sky coverage with overlap between revolutions. WISE will be placed into a Sun-synchronous polar orbit on a Delta 7320-10 launch vehicle. The WISE survey approach is simple and efficient. The three-axis-stabilized spacecraft rotates at a constant rate while the scan mirror freezes the telescope line of sight during each exposure. WISE has completed its mission Preliminary Design Review and its NASA Confirmation Review, and the project is awaiting confirmation from NASA to proceed to the Critical Design phase. Much of the payload hardware is now complete, and assembly of the payload will occur over the next year. WISE is scheduled to launch in late 2009; the project web site can be found at www.wise.ssl.berkeley.edu.

  12. Automated classification of periodic variable stars detected by the wide-field infrared survey explorer

    SciTech Connect

    Masci, Frank J.; Grillmair, Carl J.; Cutri, Roc M.; Hoffman, Douglas I.

    2014-07-01

    We describe a methodology to classify periodic variable stars identified using photometric time-series measurements constructed from the Wide-field Infrared Survey Explorer (WISE) full-mission single-exposure Source Databases. This will assist in the future construction of a WISE Variable Source Database that assigns variables to specific science classes as constrained by the WISE observing cadence with statistically meaningful classification probabilities. We have analyzed the WISE light curves of 8273 variable stars identified in previous optical variability surveys (MACHO, GCVS, and ASAS) and show that Fourier decomposition techniques can be extended into the mid-IR to assist with their classification. Combined with other periodic light-curve features, this sample is then used to train a machine-learned classifier based on the random forest (RF) method. Consistent with previous classification studies of variable stars in general, the RF machine-learned classifier is superior to other methods in terms of accuracy, robustness against outliers, and relative immunity to features that carry little or redundant class information. For the three most common classes identified by WISE: Algols, RR Lyrae, and W Ursae Majoris type variables, we obtain classification efficiencies of 80.7%, 82.7%, and 84.5% respectively using cross-validation analyses, with 95% confidence intervals of approximately ±2%. These accuracies are achieved at purity (or reliability) levels of 88.5%, 96.2%, and 87.8% respectively, similar to that achieved in previous automated classification studies of periodic variable stars.

  13. Automated Classification of Periodic Variable Stars Detected by the Wide-field Infrared Survey Explorer

    NASA Astrophysics Data System (ADS)

    Masci, Frank J.; Hoffman, Douglas I.; Grillmair, Carl J.; Cutri, Roc M.

    2014-07-01

    We describe a methodology to classify periodic variable stars identified using photometric time-series measurements constructed from the Wide-field Infrared Survey Explorer (WISE) full-mission single-exposure Source Databases. This will assist in the future construction of a WISE Variable Source Database that assigns variables to specific science classes as constrained by the WISE observing cadence with statistically meaningful classification probabilities. We have analyzed the WISE light curves of 8273 variable stars identified in previous optical variability surveys (MACHO, GCVS, and ASAS) and show that Fourier decomposition techniques can be extended into the mid-IR to assist with their classification. Combined with other periodic light-curve features, this sample is then used to train a machine-learned classifier based on the random forest (RF) method. Consistent with previous classification studies of variable stars in general, the RF machine-learned classifier is superior to other methods in terms of accuracy, robustness against outliers, and relative immunity to features that carry little or redundant class information. For the three most common classes identified by WISE: Algols, RR Lyrae, and W Ursae Majoris type variables, we obtain classification efficiencies of 80.7%, 82.7%, and 84.5% respectively using cross-validation analyses, with 95% confidence intervals of approximately ±2%. These accuracies are achieved at purity (or reliability) levels of 88.5%, 96.2%, and 87.8% respectively, similar to that achieved in previous automated classification studies of periodic variable stars.

  14. Deepest Wide-Field Colour Image in the Southern Sky

    NASA Astrophysics Data System (ADS)

    2003-01-01

    " (HDF-N in the northern and HDF-S in the southern sky, cf. e.g. ESO PR Photo 35a/98 ), but the field-of-view is about 200 times larger. The present image displays about 50 times more galaxies than the HDF images, and therefore provides a more representative view of the universe . The WFI CDF-S image will now form a most useful basis for the very extensive and systematic census of the population of distant galaxies and quasars, allowing at once a detailed study of all evolutionary stages of the universe since it was about 2 billion years old . These investigations have started and are expected to provide information about the evolution of galaxies in unprecedented detail. They will offer insights into the history of star formation and how the internal structure of galaxies changes with time and, not least, throw light on how these two evolutionary aspects are interconnected. GALAXIES IN THE WFI IMAGE ESO PR Photo 02b/03 ESO PR Photo 02b/03 [Preview - JPEG: 488 x 400 pix - 112k] [Normal - JPEG: 896 x 800 pix - 1.0M] [Full-Res - JPEG: 2591 x 2313 pix - 8.6M] Caption : PR Photo 02b/03 contains a collection of twelve subfields from the full WFI Chandra Deep Field South (WFI CDF-S), centred on (pairs or groups of) galaxies. Each of the subfields measures 2.5 x 2.5 arcmin 2 (635 x 658 pix 2 ; 1 pixel = 0.238 arcsec). North is up and East is left. Technical information is available below. The WFI CDF-S colour image - of which the full field is shown in PR Photo 02a/03 - was constructed from all available observations in the optical B- ,V- and R-bands obtained under good conditions with the Wide Field Imager (WFI) on the 2.2-m MPG/ESO telescope at the ESO La Silla Observatory (Chile), and now stored in the ESO Science Data Archive. It is the "deepest" image ever taken with this instrument. It covers a sky field measuring 36 x 34 arcmin 2 , i.e., an area somewhat larger than that of the full moon. The observations were collected during a period of nearly four years, beginning in

  15. Closed-loop tomographic control on HOMER wide-field AO bench: experimental results and identification issues

    NASA Astrophysics Data System (ADS)

    Parisot, Amelie; Costille, Anne; Petit, Cyril; Fusco, Thierry

    2010-07-01

    Adaptive Optics (AO) has a limited corrected field of view because of the anisoplanatism effect. Wide Field AO (WFAO) concepts, such as Multi-Conjugate AO (MCAO), have been developed to overcome this limitation. These complex WFAO systems raise critical challenges such as tomographic control and calibrations. We present new results obtained in closed-loop configuration with the laboratory bench HOMER which is devoted to implementation and validation of these WFAO concepts in the perspective of future VLT/ELT AO systems. Turbulence is generated with rotating phase screens and multi-directional analysis is performed. Tomographic control relies on Linear Quadratic Gaussian control (LQG). The correction can be applied thanks to two Deformable Mirrors (DM). We also focus on calibration issues and models identification. We investigate in particular identification of relative geometry of the wave front sensors, DM altitude and asterism and its impact on performance.

  16. A Precision Metrology System for the Hubble Space Telescope Wide Field Camera 3 Instrument

    NASA Technical Reports Server (NTRS)

    Toland, Ronald W.

    2003-01-01

    The Wide Field Camera 3 (WFC3) instrument for the Hubble Space Telescope (HST) will replace the current Wide Field and Planetary Camera 2 (WFPC2). By providing higher throughput and sensitivity than WFPC2, and operating from the near-IR to the near-UV, WFC3 will once again bring the pefiormance of HST above that from ground-based observatories. Crucial to the integration of the WFC3 optical bench is a pair of 2-axis cathetometers used to view targets which cannot be seen by other means when the bench is loaded into its enclosure. The setup and calibration of these cathetometers is described, along with results from a comparison of the cathetometer system with other metrology techniques. Finally, the use of the cathetometers on the flight optical bench and measurement results are given.

  17. Metrology systems for active alignment control of the Hobby-Eberly Telescope wide field corrector

    NASA Astrophysics Data System (ADS)

    Lee, Hanshin; Hill, Gary J.; Hart, Michael; Cornell, Mark E.; Savage, Richard; Vattiat, Brian; Perry, Dave; Moller, William M.; Rafferty, Tom; Taylor, Trey; Rafal, Marc D.

    2010-07-01

    The Hobby-Eberly Telescope (HET) Wide-Field Upgrade (WFU) will be equipped with new metrology systems to actively control the optical alignment of the new four-mirror Wide-Field Corrector (WFC) as it tracks sidereal motion with respect to the fixed primary mirror. These systems include a tip/tilt sensor (TTS), distance measuring interferometers (DMI), guide probes (GP), and wavefront sensors (WFS). While the TTS and DMIs are to monitor the mechanical alignment of the WFC, the WFSs and GPs will produce direct measurement of the optical alignment of the WFC with respect to the HET primary mirror. Together, these systems provide fully redundant alignment and pointing information for the telescope, thereby keeping the WFC in focus and suppressing alignment-driven field aberrations. We describe the current snapshot of these systems and discuss their roles, expected performance, and operation plans.

  18. Wide-field fluorescence molecular tomography with compressive sensing based preconditioning

    PubMed Central

    Yao, Ruoyang; Pian, Qi; Intes, Xavier

    2015-01-01

    Wide-field optical tomography based on structured light illumination and detection strategies enables efficient tomographic imaging of large tissues at very fast acquisition speeds. However, the optical inverse problem based on such instrumental approach is still ill-conditioned. Herein, we investigate the benefit of employing compressive sensing-based preconditioning to wide-field structured illumination and detection approaches. We assess the performances of Fluorescence Molecular Tomography (FMT) when using such preconditioning methods both in silico and with experimental data. Additionally, we demonstrate that such methodology could be used to select the subset of patterns that provides optimal reconstruction performances. Lastly, we compare preconditioning data collected using a normal base that offers good experimental SNR against that directly acquired with optimal designed base. An experimental phantom study is provided to validate the proposed technique. PMID:26713202

  19. Wide-Field Raman Imaging of Dental Lesions

    PubMed Central

    Yang, Shan; Li, Bolan; Akkus, Anna; Akkus, Ozan; Lang, Lisa

    2014-01-01

    Detection of dental caries at the onset remains as a great challenge in dentistry. Raman spectroscopy could be successfully applied towards detecting caries since it is sensitive to the amount of the Raman active mineral crystals, the most abundant component of enamel. Effective diagnosis requires full examination of a tooth surface via a Raman mapping. Point-scan Raman mapping is not clinically relevant (feasible) due to lengthy data acquisition time. In this work, a wide-field Raman imaging system was assembled based on a high-sensitivity 2D CCD camera for imaging the mineralization status of teeth with lesions. Wide-field images indicated some lesions to be hypomineralized and others to be hypermineralized. The observations of wide-field Raman imaging were in agreement with point-scan Raman mapping. Therefore, sound enamel and lesions can be discriminated by Raman imaging of the mineral content. In conclusion, wide-field Raman imaging is a potentially useful tool for visualization of dental lesions in the clinic. PMID:24781363

  20. Telecom optical componentry: past, present, future

    NASA Astrophysics Data System (ADS)

    Eldada, Louay A.

    2001-10-01

    We review and contrast key technologies developed to address the optical components market for telecom applications. We first look at different material systems, compare their properties, and describe the functions achieved to date in each of them. The material systems reviewed include silica fiber, silica on silicon, silicon on insulator, silicon oxynitride, sol-gels, polymers, thin film dielectrics, lithium niobate, indium phosphide, gallium arsenide, magneto-optic materials, and birefringent crystals. We then look at the most commonly used classes of technology and present their pros & cons as well as the functions achieved to date in each. The technologies reviewed include passive, actuation, and active technologies. The passive technologies described include fused fibers, dispersion-compensating fiber, beam steering (e.g., AWG), Bragg gratings, diffraction gratings, holographic elements, thin film filters, photonic crystals, microrings, and birefringent elements. The actuation technologies include thermo-optics, electro-optics, acousto-optics, magneto-optics, liquid crystals, total internal reflection technologies (e.g., bubble technology), and mechanical actuation (e.g., moving fibers, MEMS). We finally describe active technologies including heterostructures, quantum wells, rare earth doping, Raman amplification, and semiconductor amplification. We also investigate the use of different material systems and technologies to achieve building block functions including lasers, amplifiers, detectors, modulators, polarization controllers, couplers, filters, switches, attenuators, non-reciprocal elements for isolators and circulators, wavelength converters, chromatic dispersion compensators, and polarization mode dispersion (PMD) compensators. Some of the technologies presented are established in the industry, others have recently been proven to be commercially viable, and some others are still under development in laboratories.

  1. The Future of X-Ray Optics

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.

    2013-01-01

    The most important next step is the development of X-ray optics comparable to (or better than) Chandra in angular resolution that far exceed Chandra s effective area. Use the long delay to establish an adequately funded, competitive technology program along the lines I have recommended. Don't be diverted from this objective, except for Explorer-class missions. Progress in X-ray optics, with emphasis on the angular resolution, is central to the paradigm-shifting discoveries and the contributions of X-ray astronomy to multiwavelength astrophysics over the past 51 years.

  2. High-resolution wide-field Raman imaging through a fiber bundle

    NASA Astrophysics Data System (ADS)

    Doronina-Amitonova, Lyubov V.; Fedotov, Il'ya V.; Fedotov, Andrey B.; Zheltikov, Aleksei M.

    2013-04-01

    Wide-field Raman imaging with a spatial resolution of a few micrometers is demonstrated using bundles of thousands of hexagonally packed optical fibers. Raman images are synthesized pixel by pixel, by sequentially coupling the laser pump into individual fibers of the bundle with a galvanometric scanner and collecting the Raman response from the laser-excited region of the sample within the entire aperture of the distal end of the same fiber bundle.

  3. The second generation Wide-Field/Planetary Camera on the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Leschly, Kim; Allestad, David; Herrell, Linda

    1991-01-01

    The general design and principal features of the second generation Wide-Field/Planetary Camera (WFPC-2) for the Hubble Space Telescope are reviewed. The discussion covers the background of WFPC-2 development, science capabilities, key performance parameters, optical and electronic equipment, mechanisms, thermal control, and contamination control. Attention is also given to on-orbit operations, including commanding and telemetry and on-orbit servicing.

  4. Design Evolution of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Peabody, Hume; Peters, Carlton; Rodriguez, Juan; McDonald, Carson; Content, David A.; Jackson, Cliff

    2015-01-01

    The design of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) continues to evolve as each design cycle is analyzed. In 2012, two Hubble sized (2.4 m diameter) telescopes were donated to NASA from elsewhere in the Federal Government. NASA began investigating potential uses for these telescopes and identified WFIRST as a mission to benefit from these assets. With an updated, deeper, and sharper field of view than previous design iterations with a smaller telescope, the optical designs of the WFIRST instruments were updated and the mechanical and thermal designs evolved around the new optical layout. Beginning with Design Cycle 3, significant analysis efforts yielded a design and model that could be evaluated for Structural-Thermal-Optical-Performance (STOP) purposes for the Wide Field Imager (WFI) and provided the basis for evaluating the high level observatory requirements. Development of the Cycle 3 thermal model provided some valuable analysis lessons learned and established best practices for future design cycles. However, the Cycle 3 design did include some major liens and evolving requirements which were addressed in the Cycle 4 Design. Some of the design changes are driven by requirements changes, while others are optimizations or solutions to liens from previous cycles. Again in Cycle 4, STOP analysis was performed and further insights into the overall design were gained leading to the Cycle 5 design effort currently underway. This paper seeks to capture the thermal design evolution, with focus on major design drivers, key decisions and their rationale, and lessons learned as the design evolved.

  5. Design Evolution of the Wide Field Infrared Survey Telescope Using Astrophysics Focused Telescope Assets (WFIRST-AFTA) and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Peabody, Hume L.; Peters, Carlton V.; Rodriguez-Ruiz, Juan E.; McDonald, Carson S.; Content, David A.; Jackson, Clifton E.

    2015-01-01

    The design of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) continues to evolve as each design cycle is analyzed. In 2012, two Hubble sized (2.4 m diameter) telescopes were donated to NASA from elsewhere in the Federal Government. NASA began investigating potential uses for these telescopes and identified WFIRST as a mission to benefit from these assets. With an updated, deeper, and sharper field of view than previous design iterations with a smaller telescope, the optical designs of the WFIRST instruments were updated and the mechanical and thermal designs evolved around the new optical layout. Beginning with Design Cycle 3, significant analysis efforts yielded a design and model that could be evaluated for Structural-Thermal-Optical-Performance (STOP) purposes for the Wide Field Imager (WFI) and provided the basis for evaluating the high level observatory requirements. Development of the Cycle 3 thermal model provided some valuable analysis lessons learned and established best practices for future design cycles. However, the Cycle 3 design did include some major liens and evolving requirements which were addressed in the Cycle 4 Design. Some of the design changes are driven by requirements changes, while others are optimizations or solutions to liens from previous cycles. Again in Cycle 4, STOP analysis was performed and further insights into the overall design were gained leading to the Cycle 5 design effort currently underway. This paper seeks to capture the thermal design evolution, with focus on major design drivers, key decisions and their rationale, and lessons learned as the design evolved.

  6. Wide-Field Imaging Interferometry Spatial-Spectral Image Synthesis Algorithms

    NASA Technical Reports Server (NTRS)

    Lyon, Richard G.; Leisawitz, David T.; Rinehart, Stephen A.; Memarsadeghi, Nargess; Sinukoff, Evan J.

    2012-01-01

    Developed is an algorithmic approach for wide field of view interferometric spatial-spectral image synthesis. The data collected from the interferometer consists of a set of double-Fourier image data cubes, one cube per baseline. These cubes are each three-dimensional consisting of arrays of two-dimensional detector counts versus delay line position. For each baseline a moving delay line allows collection of a large set of interferograms over the 2D wide field detector grid; one sampled interferogram per detector pixel per baseline. This aggregate set of interferograms, is algorithmically processed to construct a single spatial-spectral cube with angular resolution approaching the ratio of the wavelength to longest baseline. The wide field imaging is accomplished by insuring that the range of motion of the delay line encompasses the zero optical path difference fringe for each detector pixel in the desired field-of-view. Each baseline cube is incoherent relative to all other baseline cubes and thus has only phase information relative to itself. This lost phase information is recovered by having point, or otherwise known, sources within the field-of-view. The reference source phase is known and utilized as a constraint to recover the coherent phase relation between the baseline cubes and is key to the image synthesis. Described will be the mathematical formalism, with phase referencing and results will be shown using data collected from NASA/GSFC Wide-Field Imaging Interferometry Testbed (WIIT).

  7. Dynamic Optical Networks for Future Internet Environments

    NASA Astrophysics Data System (ADS)

    Matera, Francesco

    2014-05-01

    This article reports an overview on the evolution of the optical network scenario taking into account the exponential growth of connected devices, big data, and cloud computing that is driving a concrete transformation impacting the information and communication technology world. This hyper-connected scenario is deeply affecting relationships between individuals, enterprises, citizens, and public administrations, fostering innovative use cases in practically any environment and market, and introducing new opportunities and new challenges. The successful realization of this hyper-connected scenario depends on different elements of the ecosystem. In particular, it builds on connectivity and functionalities allowed by converged next-generation networks and their capacity to support and integrate with the Internet of Things, machine-to-machine, and cloud computing. This article aims at providing some hints of this scenario to contribute to analyze impacts on optical system and network issues and requirements. In particular, the role of the software-defined network is investigated by taking into account all scenarios regarding data centers, cloud computing, and machine-to-machine and trying to illustrate all the advantages that could be introduced by advanced optical communications.

  8. Michelson wide-field stellar interferometry: principles and experimental verification.

    PubMed

    Montilla, I; Pereira, S F; Braat, J J M

    2005-01-20

    A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction of the differential delay for the on-axis and off-axis image positions. Experimental results in a laboratory setup show that it is possible to recover the fringes of on-axis and off-axis stars with an angular separation of 1 arc min simultaneously and with a similar contrast. This new technique represents a considerable extension of the field of view of an interferometer without the need for extra observation time. PMID:15717821

  9. Time Delay Integration: A Wide-Field Survey Technique

    NASA Astrophysics Data System (ADS)

    Lapointe, Robert; Hill, E.; Leimer, L.; McMillian, K.; Miller, A.; Prindle, A.

    2009-05-01

    The Advanced Placement Physics class of Orange Lutheran High School has conducted a survey-imaging pro-ject using a Time Delay Integration (TDI) technique. TDI enables very wide-field images to be collected in the form of long strips of the sky. A series of five consecutive nights were captured, calibrated and compared to re-veal possible transient phenomena such as supernovae, asteroids, and other events that have a noticeable change over 24-hour intervals.

  10. In-Flight Performance of Wide Field Camera 3

    NASA Technical Reports Server (NTRS)

    Kimble, Randy

    2010-01-01

    Wide Field Camera 3 (WFC3), a powerful new UVNisible/IR imager, was installed into HST during Servicing Mission 4. After a successful commissioning in the Servicing Mission Orbital Verification program, WFC3 has been engaged in an exciting program of scientific observations. I review here the in-flight scientific performance of the instrument, addressing such topics as image quality, sensitivity, detector performance, and stability.

  11. Quantitative phase imaging by wide field lensless digital holographic microscope

    NASA Astrophysics Data System (ADS)

    Adinda-Ougba, A.; Koukourakis, N.; Essaidi, A.; Ger­hardt, N. C.; Hofmann, M. R.

    2015-05-01

    Wide field, lensless microscopes have been developed for telemedicine and for resource limited setting [1]. They are based on in-line digital holography which is capable to provide amplitude and phase information resulting from numerical reconstruction. The phase information enables achieving axial resolution in the nanometer range. Hence, such microscopes provide a powerful tool to determine three-dimensional topologies of microstructures. In this contribution, a compact, low-cost, wide field, lensless microscope is presented, which is capable of providing topological profiles of microstructures in transparent material. Our setup consist only of two main components: a CMOSsensor chip and a laser diode without any need of a pinhole. We use this very simple setup to record holograms of microobjects. A wide field of view of ~24 mm², and a lateral resolution of ~2 μm are achieved. Moreover, amplitude and phase information are obtained from the numerical reconstruction of the holograms using a phase retrieval algorithm together with the angular spectrum propagation method. Topographic information of highly transparent micro-objects is obtained from the phase data. We evaluate our system by recording holograms of lines with different depths written by a focused laser beam. A reliable characterization of laser written microstructures is crucial for their functionality. Our results show that this system is valuable for determination of topological profiles of microstructures in transparent material.

  12. Single layer retarder with negative dispersion of birefringence and wide field-of-view.

    PubMed

    Hwang, Jiyong; Yang, Seungbin; Choi, Yu-Jin; Lee, Yumin; Jeong, Kwang-Un; Lee, Ji-Hoon

    2016-08-22

    A single layer retarder possessing negative dispersion (ND) of birefringence as well as wide field-of-view (FOV) was long-term objective in optical science. We synthesized new guest reactive monomers with x-shape and mixed them with the host smectic reactive mesogen. The host-guest molecules formed two dimensionally self-organized nanostructure and showed both the ND of birefringence and wide FOV properties. We simulated the antireflection property of a circular polarizer using the optical properties of the retarder. The average reflectance of the retarder was 0.52% which was much smaller than that of the commercial single layer ND retarder 1.83%. PMID:27557268

  13. A Precision Metrology System for the Hubble Space Telescope Wide Field Camera 3 Instrument

    NASA Technical Reports Server (NTRS)

    Toland, Ronald W.

    2003-01-01

    The Wide Field Camera 3 (WFC3) instrument for the Hubble Space Telescope (HST) will replace the current Wide Field and Planetary Camera 2 (WFPC2). By providing higher throughput and sensitivity than WFPC2, and operating from the near-IR to the near-UV, WFC3 will once again bring the performance of HST above that from ground-based observatories. Crucial to the integration of the WFC3 optical bench is a pair of 2-axis cathetometers used to view targets which cannot be seen by other means when the bench is loaded into its enclosure. The setup and calibration of these cathetometers is described, along with results from a comparison of the cathetometer system with other metrology techniques.

  14. Automated motion correction using parallel-strip registration for wide-field en face OCT angiogram

    PubMed Central

    Zang, Pengxiao; Liu, Gangjun; Zhang, Miao; Dongye, Changlei; Wang, Jie; Pechauer, Alex D.; Hwang, Thomas S.; Wilson, David J.; Huang, David; Li, Dengwang

    2016-01-01

    We propose an innovative registration method to correct motion artifacts for wide-field optical coherence tomography angiography (OCTA) acquired by ultrahigh-speed swept-source OCT (>200 kHz A-scan rate). Considering that the number of A-scans along the fast axis is much higher than the number of positions along slow axis in the wide-field OCTA scan, a non-orthogonal scheme is introduced. Two en face angiograms in the vertical priority (2 y-fast) are divided into microsaccade-free parallel strips. A gross registration based on large vessels and a fine registration based on small vessels are sequentially applied to register parallel strips into a composite image. This technique is extended to automatically montage individual registered, motion-free angiograms into an ultrawide-field view. PMID:27446709

  15. Prime focus wide-field corrector designs with lossless atmospheric dispersion correction

    SciTech Connect

    Saunders, Will; Gillingham, Peter; Smith, Greg; Kent, Steve; Doel, Peter

    2014-07-18

    Wide-Field Corrector designs are presented for the Blanco and Mayall telescopes, the CFHT and the AAT. The designs are Terezibh-style, with 5 or 6 lenses, and modest negative optical power. They have 2.2-3 degree fields of view, with curved and telecentric focal surfaces suitable for fiber spectroscopy. Some variants also allow wide-field imaging, by changing the last WFC element. Apart from the adaptation of the Terebizh design for spectroscopy, the key feature is a new concept for a 'Compensating Lateral Atmospheric Dispersion Corrector', with two of the lenses being movable laterally by small amounts. This provides excellent atmospheric dispersion correction, without any additional surfaces or absorption. A novel and simple mechanism for providing the required lens motions is proposed, which requires just 3 linear actuators for each of the two moving lenses.

  16. Automated motion correction using parallel-strip registration for wide-field en face OCT angiogram.

    PubMed

    Zang, Pengxiao; Liu, Gangjun; Zhang, Miao; Dongye, Changlei; Wang, Jie; Pechauer, Alex D; Hwang, Thomas S; Wilson, David J; Huang, David; Li, Dengwang; Jia, Yali

    2016-07-01

    We propose an innovative registration method to correct motion artifacts for wide-field optical coherence tomography angiography (OCTA) acquired by ultrahigh-speed swept-source OCT (>200 kHz A-scan rate). Considering that the number of A-scans along the fast axis is much higher than the number of positions along slow axis in the wide-field OCTA scan, a non-orthogonal scheme is introduced. Two en face angiograms in the vertical priority (2 y-fast) are divided into microsaccade-free parallel strips. A gross registration based on large vessels and a fine registration based on small vessels are sequentially applied to register parallel strips into a composite image. This technique is extended to automatically montage individual registered, motion-free angiograms into an ultrawide-field view. PMID:27446709

  17. System and methods for wide-field quantitative fluorescence imaging during neurosurgery.

    PubMed

    Valdes, Pablo A; Jacobs, Valerie L; Wilson, Brian C; Leblond, Frederic; Roberts, David W; Paulsen, Keith D

    2013-08-01

    We report an accurate, precise and sensitive method and system for quantitative fluorescence image-guided neurosurgery. With a low-noise, high-dynamic-range CMOS array, we perform rapid (integration times as low as 50 ms per wavelength) hyperspectral fluorescence and diffuse reflectance detection and apply a correction algorithm to compensate for the distorting effects of tissue absorption and scattering. Using this approach, we generated quantitative wide-field images of fluorescence in tissue-simulating phantoms for the fluorophore PpIX, having concentrations and optical absorption and scattering variations over clinically relevant ranges. The imaging system was tested in a rodent model of glioma, detecting quantitative levels down to 20 ng/ml. The resulting performance is a significant advance on existing wide-field quantitative imaging techniques, and provides performance comparable to a point-spectroscopy probe that has previously demonstrated significant potential for improved detection of malignant brain tumors during surgical resection. PMID:23903142

  18. Development of a wide-field spherical aberration corrector for the Hobby Eberly Telescope

    NASA Astrophysics Data System (ADS)

    Burge, James H.; Benjamin, S.; Dubin, M.; Manuel, A.; Novak, M.; Oh, C. J.; Valente, M.; Zhao, C.; Booth, J. A.; Good, J. M.; Hill, Gary J.; Lee, H.; MacQueen, P. J.; Rafal, M.; Savage, R.; Smith, M. P.; Vattiat, B.

    2010-07-01

    A 4-mirror prime focus corrector is under development to provide seeing-limited images for the 10-m aperture Hobby- Eberly Telescope (HET) over a 22 arcminute wide field of view. The HET uses an 11-m fixed elevation segmented spherical primary mirror, with pointing and tracking performed by moving the prime focus instrument package (PFIP) such that it rotates about the virtual center of curvature of the spherical primary mirror. The images created by the spherical primary mirror are aberrated with 13 arcmin diameter point spread function. The University of Arizona is developing the 4-mirror wide field corrector to compensate the aberrations from the primary mirror and present seeing limited imaged to the pickoffs for the fiber-fed spectrographs. The requirements for this system pose several challenges, including optical fabrication of the aspheric mirrors, system alignment, and operational mechanical stability.

  19. The Wide-Field Imaging Interferometry Testbed: Enabling Techniques for High Angular Resolution Astronomy

    NASA Technical Reports Server (NTRS)

    Rinehart, S. A.; Armstrong, T.; Frey, Bradley J.; Jung, J.; Kirk, J.; Leisawitz, David T.; Leviton, Douglas B.; Lyon, R.; Maher, Stephen; Martino, Anthony J.; Pauls, T.

    2007-01-01

    The Wide-Field Imaging Interferometry Testbed (WIIT) was designed to develop techniques for wide-field of view imaging interferometry, using "double-Fourier" methods. These techniques will be important for a wide range of future spacebased interferometry missions. We have provided simple demonstrations of the methodology already, and continuing development of the testbed will lead to higher data rates, improved data quality, and refined algorithms for image reconstruction. At present, the testbed effort includes five lines of development; automation of the testbed, operation in an improved environment, acquisition of large high-quality datasets, development of image reconstruction algorithms, and analytical modeling of the testbed. We discuss the progress made towards the first four of these goals; the analytical modeling is discussed in a separate paper within this conference.

  20. Fiber optics for the future - Wavelength division multiplexing

    NASA Technical Reports Server (NTRS)

    Spencer, J. L.

    1982-01-01

    Optical wavelength division multiplexing (WDM) systems, with signals transmitted on different wavelengths through a single fiber, can have increased information capacity and fault isolation properties over single wavelength optical systems. This paper describes a typical WDM system. The applicability of future standards to such a system are discussed. Also, a state-of-the-art survey of optical multimode components which could be used to implement the system are made. The components to be surveyed are sources, multiplexers, and detectors. Emphasis is given to the demultiplexer techniques which are the major developmental components in the WDM system.

  1. Fiber optics for the future - wavelength division multiplexing

    NASA Technical Reports Server (NTRS)

    Spencer, J. L.

    1982-01-01

    Optical wavelength division multiplexing (WDM) systems, with signals transmitted on different wavelengths through a single fiber, can have increased information capacity and fault isolation properties over single wavelength optical systems. This paper describes a typical WDM system. The applicability of future standards to such a system are discussed. Also, a state-of-the-art survey of optical multimode components which could be used to implement the system are made. The components to be surveyed are sources, multiplexers, and detectors. Emphasis is given to the demultiplexer techniques which are the major developmental components in the WDM system.

  2. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P. ); Elliott, A. )

    1992-01-01

    Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signal to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.

  3. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P.; Elliott, A.

    1992-12-31

    Beam detectors such as striplines and wall current monitors rely on matched electrical networks to transmit and process beam information. Frequency bandwidth, noise immunity, reflections, and signal to noise ratio are considerations that require compromises limiting the quality of the measurement. Recent advances in fiber optics related technologies have made it possible to acquire and process beam signals in the optical domain. This paper describes recent developments in the application of these technologies to accelerator beam diagnostics. The design and construction of an optical notch filter used for a stochastic cooling system is used as an example. Conceptual ideas for future beam detectors are also presented.

  4. PERSPECTIVE: Toward a wide-field retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Ameri, Hossein; Ratanapakorn, Tanapat; Ufer, Stefan; Eckhardt, Helmut; Humayun, Mark S.; Weiland, James D.

    2009-06-01

    The purpose of this paper is to present a wide field electrode array that may increase the field of vision in patients implanted with a retinal prosthesis. Mobility is often impaired in patients with low vision, particularly in those with peripheral visual loss. Studies on low vision patients as well as simulation studies on normally sighted individuals have indicated a strong correlation between the visual field and mobility. In addition, it has been shown that an increased visual field is associated with a significant improvement in visual acuity and object discrimination. Current electrode arrays implanted in animals or human vary in size; however, the retinal area covered by the electrodes has a maximum projected visual field of about 10°. We have designed wide field electrode arrays that could potentially provide a visual field of 34°, which may significantly improve the mobility. Tests performed on a mechanical eye model showed that it was possible to fix 10 mm wide flexible polyimide dummy electrode arrays onto the retina using a single retinal tack. They also showed that the arrays could conform to the inner curvature of the eye. Surgeries on an enucleated porcine eye model demonstrated feasibility of implantation of 10 mm wide arrays through a 5 mm eye wall incision.

  5. Mitigating fluorescence spectral overlap in wide-field endoscopic imaging

    PubMed Central

    Hou, Vivian; Nelson, Leonard Y.; Seibel, Eric J.

    2013-01-01

    Abstract. The number of molecular species suitable for multispectral fluorescence imaging is limited due to the overlap of the emission spectra of indicator fluorophores, e.g., dyes and nanoparticles. To remove fluorophore emission cross-talk in wide-field multispectral fluorescence molecular imaging, we evaluate three different solutions: (1) image stitching, (2) concurrent imaging with cross-talk ratio subtraction algorithm, and (3) frame-sequential imaging. A phantom with fluorophore emission cross-talk is fabricated, and a 1.2-mm ultrathin scanning fiber endoscope (SFE) is used to test and compare these approaches. Results show that fluorophore emission cross-talk could be successfully avoided or significantly reduced. Near term, the concurrent imaging method of wide-field multispectral fluorescence SFE is viable for early stage cancer detection and localization in vivo. Furthermore, a means to enhance exogenous fluorescence target-to-background ratio by the reduction of tissue autofluorescence background is demonstrated. PMID:23966226

  6. The Wide-Field Imager for Solar Probe Plus (WISPR)

    NASA Astrophysics Data System (ADS)

    Vourlidas, Angelos; Howard, Russell A.; Plunkett, Simon P.; Korendyke, Clarence M.; Thernisien, Arnaud F. R.; Wang, Dennis; Rich, Nathan; Carter, Michael T.; Chua, Damien H.; Socker, Dennis G.; Linton, Mark G.; Morrill, Jeff S.; Lynch, Sean; Thurn, Adam; Van Duyne, Peter; Hagood, Robert; Clifford, Greg; Grey, Phares J.; Velli, Marco; Liewer, Paulett C.; Hall, Jeffrey R.; DeJong, Eric M.; Mikic, Zoran; Rochus, Pierre; Mazy, Emanuel; Bothmer, Volker; Rodmann, Jens

    2015-02-01

    The Wide-field Imager for Solar PRobe Plus (WISPR) is the sole imager aboard the Solar Probe Plus (SPP) mission scheduled for launch in 2018. SPP will be a unique mission designed to orbit as close as 7 million km (9.86 solar radii) from Sun center. WISPR employs a 95∘ radial by 58∘ transverse field of view to image the fine-scale structure of the solar corona, derive the 3D structure of the large-scale corona, and determine whether a dust-free zone exists near the Sun. WISPR is the smallest heliospheric imager to date yet it comprises two nested wide-field telescopes with large-format (2 K × 2 K) APS CMOS detectors to optimize the performance for their respective fields of view and to minimize the risk of dust damage, which may be considerable close to the Sun. The WISPR electronics are very flexible allowing the collection of individual images at cadences up to 1 second at perihelion or the summing of multiple images to increase the signal-to-noise when the spacecraft is further from the Sun. The dependency of the Thomson scattering emission of the corona on the imaging geometry dictates that WISPR will be very sensitive to the emission from plasma close to the spacecraft in contrast to the situation for imaging from Earth orbit. WISPR will be the first `local' imager providing a crucial link between the large-scale corona and the in-situ measurements.

  7. Science with a wide-field UV transient explorer

    SciTech Connect

    Sagiv, I.; Gal-Yam, A.; Ofek, E. O.; Waxman, E.; Trakhtenbrot, B.; Topaz, J.; Aharonson, O.; Kulkarni, S. R.; Phinney, E. S.; Nakar, E.; Maoz, D.; Beichman, C.; Murthy, J.; Worden, S. P.

    2014-04-01

    The time-variable electromagnetic sky has been well-explored at a wide range of wavelengths. In contrast, the ultra-violet (UV) variable sky is relatively poorly explored, even though it offers exciting scientific prospects. Here, we review the potential scientific impact of a wide-field UV survey on the study of explosive and other transient events, as well as known classes of variable objects, such as active galactic nuclei and variable stars. We quantify our predictions using a fiducial set of observational parameters which are similar to those envisaged for the proposed ULTRASAT mission. We show that such a mission would be able to revolutionize our knowledge about massive star explosions by measuring the early UV emission from hundreds of events, revealing key physical parameters of the exploding progenitor stars. Such a mission would also detect the UV emission from many tens of tidal-disruption events of stars by supermassive black holes at galactic nuclei and enable a measurement of the rate of such events. The overlap of such a wide-field UV mission with existing and planned gravitational-wave and high-energy neutrino telescopes makes it especially timely.

  8. The Spitzer Deep, Wide-Field Survey (SDWFS)

    NASA Astrophysics Data System (ADS)

    Ashby, Matthew; Stern, D.; Brodwin, M.; Griffith, R.; Eisenhardt, P.; Kozlowski, S.; Kochanek, C. S.; Bock, J.; Borys, C.; Brand, K.; Brown, M. J. I.; Cool, R.; Cooray, A.; Croft, S.; Dey, A.; Eisenstein, D.; Gonzalez, A.; Gorjian, V.; Grogin, N.; Ivison, R.; Jacob, J.; Jannuzi, B.; Mainzer, A.; Moustakas, L.; Rottgering, H.; Seymour, N.; Smith, H.; Stanford, A.; Stauffer, J. R.; Sullivan, I.; van Breugel, W.; Wright, E. L.; Willner, S. P.

    2009-05-01

    The Spitzer Deep, Wide-Field Survey (SDWFS) is four-epoch infrared survey of ten square degrees in the Bootes field of the NOAO Deep Wide-Field Survey using the IRAC instrument on the Spitzer Space Telescope. The four epochs, which span the interval from 2003 to 2008, make it possible to identify nearby, high-proper-motion targets, as well as infrared-variable objects. SDWFS is a Spitzer Cycle 4 Legacy program (PID 40839). The SDWFS catalogs are publicly available, and contain roughly 7e5, 5e5, 1e5, and 1e5 distinct sources brighter than the 5-sigma survey limits of 19.8, 18.8, 16.5, and 15.8 Vega magnitudes at 3.6, 4.5, 5.8, and 8.0 microns, respectively. In this contribution we describe the SDWFS survey and some initial findings. This work was supported by NASA grant number 1314516, administered by JPL.

  9. Wide field fluorescence imaging in narrow passageways using scanning fiber endoscope technology

    NASA Astrophysics Data System (ADS)

    Lee, Cameron M.; Chandler, John E.; Seibel, Eric J.

    2010-02-01

    An ultrathin scanning fiber endoscope (SFE) has been developed for high resolution imaging of regions in the body that are commonly inaccessible. The SFE produces 500 line color images at 30 Hz frame rate while maintaining a 1.2-1.7 mm outer diameter. The distal tip of the SFE houses a 9 mm rigid scan engine attached to a highly flexible tether (minimum bend radius < 8 mm) comprised of optical fibers and electrical wires within a protective sheath. Unlike other ultrathin technologies, the unique characteristics of this system have allowed the SFE to navigate narrow passages without sacrificing image quality. To date, the SFE has been used for in vivo imaging of the bile duct, esophagus and peripheral airways. In this study, the standard SFE operation was tailored to capture wide field fluorescence images and spectra. Green (523 nm) and blue (440 nm) lasers were used as illumination sources, while the white balance gain values were adjusted to accentuate red fluorescence signal. To demonstrate wide field fluorescence imaging of small lumens, the SFE was inserted into a phantom model of a human pancreatobiliary tract and navigated to a custom fluorescent target. Both wide field fluorescence and standard color images of the target were captured to demonstrate multimodal imaging.

  10. The Method of Measurements of Celestial Coordinates in Wide-Field TV-Frames

    NASA Astrophysics Data System (ADS)

    Kartashova, Anna P.

    2012-06-01

    We present a method for calculations of equatorial coordinates of any point in the single frame of the wide-field TV systems. This method can be applying for the different television systems [wide-field cameras, all-sky cameras, the cameras with the hybrid TV-system (the system with coupled of the Image Intensifier) et al.]. In that system the calculations of distortions are difficult. Therefore, we devised this method which helps decrease errors (due to distortion and the electro-optical system).The method can be used for measuring of equatorial coordinates of meteor tracks under difficult conditions during the observations such as partial cloudiness, small number of stars and large distortions of the coordinate grid in the frame. These restrictions cannot be overcome by other methods. In the case of the small number of stars the present method using of the reference stars received on a series of frames during the observation period. The accuracy of the method has been estimated to be 4'-8' (for cameras with fov 50° × 40° at the CCD 720 × 576 pixels) for maximum number of reference points in the frame. The method used 3 reference points for calculation of the equatorial coordinates of the object. One can use this method if the camera was re-oriented as well. We use this method for our wide field of view cameras.

  11. Wide-Field Fundus Autofluorescence for Retinitis Pigmentosa and Cone/Cone-Rod Dystrophy.

    PubMed

    Oishi, Akio; Oishi, Maho; Ogino, Ken; Morooka, Satoshi; Yoshimura, Nagahisa

    2016-01-01

    Retinitis pigmentosa and cone/cone-rod dystrophy are inherited retinal diseases characterized by the progressive loss of rod and/or cone photoreceptors. To evaluate the status of rod/cone photoreceptors and visual function, visual acuity and visual field tests, electroretinogram, and optical coherence tomography are typically used. In addition to these examinations, fundus autofluorescence (FAF) has recently garnered attention. FAF visualizes the intrinsic fluorescent material in the retina, which is mainly lipofuscin contained within the retinal pigment epithelium. While conventional devices offer limited viewing angles in FAF, the recently developed Optos machine enables recording of wide-field FAF. With wide-field analysis, an association between abnormal FAF areas and visual function was demonstrated in retinitis pigmentosa and cone-rod dystrophy. In addition, the presence of "patchy" hypoautofluorescent areas was found to be correlated with symptom duration. Although physicians should be cautious when interpreting wide-field FAF results because the peripheral parts of the image are magnified significantly, this examination method provides previously unavailable information. PMID:26427426

  12. Wide field-of-view dual-band multispectral muzzle flash detection

    NASA Astrophysics Data System (ADS)

    Montoya, J.; Melchor, J.; Spiliotis, P.; Taplin, L.

    2013-06-01

    Sensor technologies are undergoing revolutionary advances, as seen in the rapid growth of multispectral methodologies. Increases in spatial, spectral, and temporal resolution, and in breadth of spectral coverage, render feasible sensors that function with unprecedented performance. A system was developed that addresses many of the key hardware requirements for a practical dual-band multispectral acquisition system, including wide field of view and spectral/temporal shift between dual bands. The system was designed using a novel dichroic beam splitter and dual band-pass filter configuration that creates two side-by-side images of a scene on a single sensor. A high-speed CMOS sensor was used to simultaneously capture data from the entire scene in both spectral bands using a short focal-length lens that provided a wide field-of-view. The beam-splitter components were arranged such that the two images were maintained in optical alignment and real-time intra-band processing could be carried out using only simple arithmetic on the image halves. An experiment related to limitations of the system to address multispectral detection requirements was performed. This characterized the system's low spectral variation across its wide field of view. This paper provides lessons learned on the general limitation of key hardware components required for multispectral muzzle flash detection, using the system as a hardware example combined with simulated multispectral muzzle flash and background signatures.

  13. Wide-field Monitoring of the Galactic Plane in the K- and the H-band

    NASA Astrophysics Data System (ADS)

    Yanagisawa, K.; Nakada, Y.; Izumiura, H.; Watanabe, E.; Shimizu, Y.; Okada, N.; Okita, K.; Norimoto, K.; Okata, T.; Koyano, H.; Yoshida, M.

    The Okayama Astrophysical Observatory of NAOJ started the monitoring program of mass-losing AGB stars using an imaging camera named Okayama Astrophysical Observatory Wide Field Camera. The fast optics yields a field of view of 1¡ß1 deg2 and the pixel resolution of 2 arcsec at the focus of the 91-cm telescope. A HAWAII2 array will be installed inside the camera reaching the limiting magnitude of K=13 with a 45-s exposure. In 2003 the monitoring will start covering the Galactic plane from l=0 to 270 deg every three weeks.

  14. Range performance of the DARPA AWARE wide field-of-view visible imager.

    PubMed

    Nichols, J M; Judd, K P; Olson, C C; Novak, K; Waterman, J R; Feller, S; McCain, S; Anderson, J; Brady, D

    2016-06-01

    In a prior paper, we described a new imaging architecture that addresses the need for wide field-of-view imaging combined with the resolution required to identify targets at long range. Over the last two years substantive improvements have been made to the system, both in terms of the size, weight, and power of the camera as well as to the optics and data management software. The result is an overall improvement in system performance, which we demonstrate via a maritime target identification experiment. PMID:27411206

  15. Real-time monitoring of graphene patterning with wide-field four-wave mixing microscopy

    NASA Astrophysics Data System (ADS)

    Koivistoinen, Juha; Aumanen, Jukka; Hiltunen, Vesa-Matti; Myllyperkiö, Pasi; Johansson, Andreas; Pettersson, Mika

    2016-04-01

    The single atom thick two-dimensional graphene is a promising material for various applications due to its extraordinary electronic, optical, optoelectronic, and mechanical properties. The demand for developing graphene based applications has entailed a requirement for development of methods for fast imaging techniques for graphene. Here, we demonstrate imaging of graphene with femtosecond wide-field four-wave mixing microscopy. The method provides a sensitive, non-destructive approach for rapid large area characterization of graphene. We show that the method is suitable for online following of a laser patterning process of microscale structures on single-layer graphene.

  16. Curvature wavefront sensing performance simulations for active correction of the Javalambre wide-field telescopes

    NASA Astrophysics Data System (ADS)

    Chueca, Sergio; Marín-Franch, Antonio; Cenarro, Andrés. Javier; Varela, Jesús; Ederoclite, Alessandro; Cristóbal-Hornillos, David; Hernández-Monteagudo, Carlos; Gruel, Nicolás.; Moles, Mariano; Yanes, Axel; Rueda, Fernando; Rueda, Sergio; Luis-Simoes, Roberto; Hernández-Fuertes, Javier; López-Sainz, Angel; Maícas-Sacristán, Natalio; Lamadrid, José Luis; Díaz-Martín, Miguel Chioare; Taylor, Keith

    2012-09-01

    In order to maintain image quality during Javalambre wide field telescope operations, deformations and rigid body motions must be actively controlled to minimize optical disturbances. For JST/T250 the aberrations of the telescope will be measured with four curvature sensors at the focal plane. To correct the measured distortions, the secondary mirror position (with a hexapod support) and the camera position can be modified in a control closed loop. Multiple software tools have been developed to accomplish this goal, constituting the "Observatorio Astrofísico de Javalambre" (OAJ) Active Optics Pipeline. We present a comprehensive analysis of the wave-front sensing system, including the availability of reference stars, pupil registration, wavefront estimators and the iteration matrix evaluation techniques. Some preliminary simulations have been made using a telescope model with a Optical Ray Tracing Software.

  17. Wide field x-ray telescopes: Detecting x-ray transients/afterglows related to GRBs

    SciTech Connect

    Hudec, Rene; Pina, Ladislav; Inneman, Adolf; Gorenstein, Paul

    1998-05-16

    The recent discovery of X-ray afterglows of GRBs opens the possibility of analyses of GRBs by their X-ray detections. However, imaging X-ray telescopes in current use mostly have limited fields of view. Alternative X-ray optics geometries achieving very large fields of view have been theoretically suggested in the 70's but not constructed and used so far. We review the geometries and basic properties of the wide-field X-ray optical systems based on one- and two-dimensional lobster-eye geometry and suggest technologies for their development and construction. First results of the development of double replicated X-ray reflecting flats for use in one-dimensional X-ray optics of lobster-eye type are presented and discussed. The optimum strategy for locating GRBs upon their X-ray counterparts is also presented and discussed.

  18. Calibration Status and Results for Wide Field Camera 3

    NASA Technical Reports Server (NTRS)

    Kimble, Randy A.

    2006-01-01

    Wide Field Camera 3 (WFC3) is a general-purpose imager in development for installation in HST Servicing Mission 4 (SM4). Covering the wavelength range of 200-1700 nm in two observing channels, WFC3 offers powerful new capabilities, particularly in the near-ultraviolet and near-infrared bands. During 2004, the instrument was integrated and underwent a substantial suite of end-to-end characterization and performance tests. In this paper, we present a brief overview of the design and scientific purpose of WFC3, summarize the results of its test program to date, and highlight some recent developments in detector technology that will further enhance the performance of WFC3 s IR channel.

  19. Wide Field X-Ray Telescope Mission Concept Study Results

    NASA Technical Reports Server (NTRS)

    Hopkins, R. C.; Thomas, H. D.; Fabisinski, L. L.; Baysinger, M.; Hornsby, L. S.; Maples, C. D.; Purlee, T. E.; Capizzo, P. D.; Percy, T. K.

    2014-01-01

    The Wide Field X-Ray Telescope (WFXT) is an astrophysics mission concept for detecting and studying extra-galactic x-ray sources, including active galactic nuclei and clusters of galaxies, in an effort to further understand cosmic evolution and structure. This Technical Memorandum details the results of a mission concept study completed by the Advanced Concepts Office at NASA Marshall Space Flight Center in 2012. The design team analyzed the mission and instrument requirements, and designed a spacecraft that enables the WFXT mission while using high heritage components. Design work included selecting components and sizing subsystems for power, avionics, guidance, navigation and control, propulsion, structures, command and data handling, communications, and thermal control.

  20. Dynamic speckle illumination wide-field reflection phase microscopy

    PubMed Central

    Choi, Youngwoon; Hosseini, Poorya; Choi, Wonshik; Dasari, Ramachandra R.; So, Peter T. C.; Yaqoob, Zahid

    2014-01-01

    We demonstrate a quantitative reflection-phase microscope based on time-varying speckle-field illumination. Due to the short spatial coherence length of the speckle field, the proposed imaging system features superior lateral resolution, 520 nm, as well as high-depth selectivity, 1.03 µm. Off-axis interferometric detection enables wide-field and single-shot imaging appropriate for high-speed measurements. In addition, the measured phase sensitivity of this method, which is the smallest measurable axial motion, is more than 40 times higher than that available using a transmission system. We demonstrate the utility of our method by successfully distinguishing the motion of the top surface from that of the bottom in red blood cells. The proposed method will be useful for studying membrane dynamics in complex eukaryotic cells. PMID:25361156

  1. Wide-Field Plate Database: Included Ukrainian Plate Catalogues

    NASA Astrophysics Data System (ADS)

    Tsvetkova, Katya; Sergeeva, Tetyana

    2007-08-01

    We present the basic information for the archives of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine, included into the Wide-Field Plate Database last two years with total number of plates - 11260. The plates were obtained with the 0.40m Double Wide-angle Astrograph (DWA); 10cm, 11cm and 15cm Three Cameras Astrograph (TCA) and 12 cm Double Short focus Astrograph (DSA) in the period 1949-1998 in the frames of the following observing programmes: Photographic Survey of the Northern Sky; Investigation of the kinematics and the structure in the main meridian section of the Galaxy; selection of reference stars, minor planets observations, comet investigations.

  2. Wide-Field-of-View, High-Resolution, Stereoscopic Imager

    NASA Technical Reports Server (NTRS)

    Prechtl, Eric F.; Sedwick, Raymond J.

    2010-01-01

    A device combines video feeds from multiple cameras to provide wide-field-of-view, high-resolution, stereoscopic video to the user. The prototype under development consists of two camera assemblies, one for each eye. One of these assemblies incorporates a mounting structure with multiple cameras attached at offset angles. The video signals from the cameras are fed to a central processing platform where each frame is color processed and mapped into a single contiguous wide-field-of-view image. Because the resolution of most display devices is typically smaller than the processed map, a cropped portion of the video feed is output to the display device. The positioning of the cropped window will likely be controlled through the use of a head tracking device, allowing the user to turn his or her head side-to-side or up and down to view different portions of the captured image. There are multiple options for the display of the stereoscopic image. The use of head mounted displays is one likely implementation. However, the use of 3D projection technologies is another potential technology under consideration, The technology can be adapted in a multitude of ways. The computing platform is scalable, such that the number, resolution, and sensitivity of the cameras can be leveraged to improve image resolution and field of view. Miniaturization efforts can be pursued to shrink the package down for better mobility. Power savings studies can be performed to enable unattended, remote sensing packages. Image compression and transmission technologies can be incorporated to enable an improved telepresence experience.

  3. DWARF IRREGULAR GALAXY LEO A: SUPRIME-CAM WIDE-FIELD STELLAR PHOTOMETRY

    SciTech Connect

    Stonkutė, Rima; Narbutis, Donatas; Vansevičius, Vladas; Arimoto, Nobuo; Hasegawa, Takashi; Tamura, Naoyuki

    2014-10-01

    We have surveyed a complete extent of Leo A—an apparently isolated gas-rich low-mass dwarf irregular galaxy in the Local Group. The B, V, and I passband CCD images (typical seeing ∼0.''8) were obtained with the Subaru Telescope equipped with the Suprime-Cam mosaic camera. The wide-field (20' × 24') photometry catalog of 38,856 objects (V ∼ 16-26 mag) is presented. This survey is also intended to serve as ''a finding chart'' for future imaging and spectroscopic observation programs of Leo A.

  4. Imaging without lenses: achievements and remaining challenges of wide-field on-chip microscopy

    PubMed Central

    Greenbaum, Alon; Luo, Wei; Su, Ting-Wei; Göröcs, Zoltán; Xue, Liang; Isikman, Serhan O; Coskun, Ahmet F; Mudanyali, Onur; Ozcan, Aydogan

    2012-01-01

    We discuss unique features of lens-free computational imaging tools and report some of their emerging results for wide-field on-chip microscopy, such as the achievement of a numerical aperture (NA) of ~0.8–0.9 across a field of view (FOV) of more than 20 mm2 or an NA of ~0.1 across a FOV of ~18 cm2, which corresponds to an image with more than 1.5 gigapixels. We also discuss the current challenges that these computational on-chip microscopes face, shedding light on their future directions and applications. PMID:22936170

  5. Temporally focused wide-field two-photon microscopy: paraxial to vectorial.

    PubMed

    Yew, Elijah Y S; Sheppard, Colin J R; So, Peter T C

    2013-05-20

    Temporal focusing allows for optically sectioned wide-field microscopy. The optical sectioning arises because this method takes a pulsed input beam, stretches the pulses by diffracting off a grating, and focuses the stretched pulses such that only at the focal plane are the pulses re-compressed. This approach generates nonlinear optical processes at the focal plane and results in depth discrimination. Prior theoretical models of temporal focusing processes approximate the contributions of the different spectral components by their mean. This is valid for longer pulses that have narrower spectral bandwidth but results in a systematic deviation when broad spectrum, femtosecond pulses are used. Further, prior model takes the paraxial approximation but since these pulses are focused with high numerical aperture (NA) objectives, the effects of the vectorial nature of light should be considered. In this paper we present a paraxial and a vector theory of temporal focusing that takes into account the finite spread of the spectrum. Using paraxial theory we arrive at an analytical solution to the electric field at the focus for temporally focused wide-field two-photon (TF2p) microscopy as well as in the case of a spectrally chirped input beam. We find that using paraxial theory while accounting for the broad spectral spread gives results almost twice vector theory. Experiment results agree with predictions of the vector theory giving an axial full-width half maximum (FWHM) of 2.1 μmand1.8 μmrespectively as long as spectral spread is taken into account. Using our system parameters, the optical sectioning of the TF2p microscope is found to be 8 μm. The optical transfer function (OTF) of a TF2p microscope is also derived and is found to pass a significantly more limited band of axial frequencies than a point scanning two-photon (2p) microscope or a single photon (1p) confocal microscope. PMID:23736515

  6. Wide-Field Infrared Survey Telescope (WFIRST) Interim Report

    NASA Technical Reports Server (NTRS)

    Green, J.; Schechter, P.; Baltay, C.; Bean, R.; Bennett, D.; Brown, R.; Conselice, C.; Donahue, M.; Gaudi, S.; Lauer, T.; Perlmutter, S.; Rauscher, B.; Rhodes, J.; Roellig, T.; Stern, D.; Sumi, T.; Gerhels, N.; Sambruna, R.; Barry, R. K.; Content, D.; Grady, K; Jackson, C.; Kruk, J.; Melton, M.; Rioux, N.

    2011-01-01

    The New Worlds, New Horizons (NWNH) in Astronomy and Astrophysics 2010 Decadal Survey prioritized the community consensus for ground-based and space-based observatories. Recognizing that many of the community s key questions could be answered with a wide-field infrared survey telescope in space, and that the decade would be one of budget austerity, WFIRST was top ranked in the large space mission category. In addition to the powerful new science that could be accomplished with a wide-field infrared telescope, the WFIRST mission was determined to be both technologically ready and only a small fraction of the cost of previous flagship missions, such as HST or JWST. In response to the top ranking by the community, NASA formed the WFIRST Science Definition Team (SDT) and Project Office. The SDT was charged with fleshing out the NWNH scientific requirements to a greater level of detail. NWNH evaluated the risk and cost of the JDEM-Omega mission design, as submitted by NASA, and stated that it should serve as the basis for the WFIRST mission. The SDT and Project Office were charged with developing a mission optimized for achieving the science goals laid out by the NWNH re-port. The SDT and Project Office opted to use the JDEM-Omega hardware configuration as an initial start-ing point for the hardware implementation. JDEM-Omega and WFIRST both have an infrared imager with a filter wheel, as well as counter-dispersed moderate resolution spectrometers. The primary advantage of space observations is being above the Earth's atmosphere, which absorbs, scatters, warps and emits light. Observing from above the atmosphere enables WFIRST to obtain precision infrared measurements of the shapes of galaxies for weak lensing, infrared light-curves of supernovae and exoplanet microlensing events with low systematic errors, and infrared measurements of the H hydrogen line to be cleanly detected in the 1

  7. Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

    NASA Technical Reports Server (NTRS)

    Gong, Qian; Content, David; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas; Whipple, Arthur

    2016-01-01

    The slitless spectrometer plays an important role in the Wide-Field InfraRed Survey Telescope (WFIRST) mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies. The concept of the compound grism as a slitless spectrometer has been presented previously. The presentation briefly discusses the challenges and solutions of the optical design, and recent specification updates, as well as a brief comparison between the prototype and the latest design. However, the emphasis of this paper is the progress of the grism prototype: the fabrication and test of the complicated diffractive optical elements and powered prism, as well as grism assembly alignment and testing. Especially how to use different tools and methods, such as IR phase shift and wavelength shift interferometry, to complete the element and assembly tests. The paper also presents very encouraging results from recent element tests to assembly tests. Finally we briefly touch the path forward plan to test the spectral characteristic, such as spectral resolution and response.

  8. Wide-field profiling of smooth steep surfaces by structured illumination

    NASA Astrophysics Data System (ADS)

    Wang, Hongting; Tan, Jiubin; Liu, Chenguang; Liu, Jian; Li, Yong

    2016-05-01

    We propose sectioning structured illumination wide-field microscopy (SSIWM) combined with the coating of a readily removable thin fluorescent film (RTFF) for smooth steep surfaces. The profiling of smooth steep surfaces is difficult to achieve using conventional optical systems because these surfaces reflect lights away from the collective lens. In particular, when the angle between optical axis and the normal line of the surface is larger than sin-1(NA), no light reflected from the area can be collected by the collective lens. The proposed method employing an RTFF to the SSIWM can overcome the poor collection barrier and be used to measure the shape of the surface owing to the isotropic incoherent scattering property. Additionally, conventional SSIWM is a promising wide-field imaging technique with high axial sectioning ability and low cost; however, it cannot be introduced to measure a reflective surface because of the non-sectioning characteristic in using a laser (coherent). However, the proposed method can extend the application scope of SSIWM owing to the incoherent property of the coating surface. Simulations and experimental results are presented to show the validity of the proposed method.

  9. Space infrared telescope facility wide field and diffraction limited array camera (IRAC)

    NASA Technical Reports Server (NTRS)

    Fazio, Giovanni G.

    1988-01-01

    The wide-field and diffraction limited array camera (IRAC) is capable of two-dimensional photometry in either a wide-field or diffraction-limited mode over the wavelength range from 2 to 30 microns with a possible extension to 120 microns. A low-doped indium antimonide detector was developed for 1.8 to 5.0 microns, detectors were tested and optimized for the entire 1.8 to 30 micron range, beamsplitters were developed and tested for the 1.8 to 30 micron range, and tradeoff studies of the camera's optical system performed. Data are presented on the performance of InSb, Si:In, Si:Ga, and Si:Sb array detectors bumpbonded to a multiplexed CMOS readout chip of the source-follower type at SIRTF operating backgrounds (equal to or less than 1 x 10 to the 8th ph/sq cm/sec) and temperature (4 to 12 K). Some results at higher temperatures are also presented for comparison to SIRTF temperature results. Data are also presented on the performance of IRAC beamsplitters at room temperature at both 0 and 45 deg angle of incidence and on the performance of the all-reflecting optical system baselined for the camera.

  10. Adaptive optics high resolution spectroscopy: present status and future direction

    SciTech Connect

    Alcock, C; Angel, R; Ciarlo, D; Fugate, R O; Ge, J; Kuzmenko, P; Lloyd-Hart, M; Macintosh, B; Najita, J; Woolf, N

    1999-07-27

    High resolution spectroscopy experiments with visible adaptive optics (AO) telescopes at Starfire Optical Range and Mt. Wilson have demonstrated that spectral resolution can be routinely improved by a factor of - 10 over the seeing-limited case with no extra light losses at visible wavelengths. With large CCDs now available, a very wide wavelength range can be covered in a single exposure. In the near future, most large ground-based telescopes will be equipped with powerful A0 systems. Most of these systems are aimed primarily at diffraction-limited operation in the near IR. An exciting new opportunity will thus open up for high resolution IR spectroscopy. Immersion echelle gratings with much coarser grooves being developed by us at LLNL will play a critical role in achieving high spectral resolution with a compact and low cost IR cryogenically cooled spectrograph and simultaneous large wavelength coverage on relatively small IR detectors. We have constructed a new A0 optimized spectrograph at Steward Observatory to provide R = 200,000 in the optical, which is being commissioned at the Starfire Optical Range 3.5m telescope. We have completed the optical design of the LLNL IR Immersion Spectrograph (LISPEC) to take advantage of improved silicon etching technology. Key words: adaptive optics, spectroscopy, high resolution, immersion gratings

  11. Optics education for now and future from an entropy perspective

    NASA Astrophysics Data System (ADS)

    Donn, Shoang C.

    1995-10-01

    During the 20th century, the electronics industry has evolved from radio, television, and audio systems to computer systems. The trace of evolution is clearly from linear systems to nonlinear systems. This is by no means accidental, and is due to the fact that nonlinear systems are more versatile than linear systems. As of now, the successful commercial optical instruments are all linear systems. From the entropy point of view, as the knowledge of human beings further expands, we need more powerful computing capabilities such as memory association and self organization. Based on the fundamental differences between the electron and the photon, this paper presents the argument that optical computing will provide memory association and self organization ability (which compliments the current electronic logical computing). Thus, one can infer that the main future thrust of the optical industry will be in nonlinear optical systems and hybrid combinations with nonlinear electronic systems in order to provide both self organization and logical computing (to emulate, more or less, the computing power of the human brain). Currently, the stat of the ar has already demonstrated successful combinations of linear optical system with nonlinear electronic systems (computers). These kinds of hybrid systems are called electro-photonic systems in the following curriculum. Based on the above vision for the future and taking into account the need for immediate employment, the following curriculum is designed to provide a core training to the students who are interested in choosing optics or electro-photonics as their career. This curriculum is being offered in the upper years at the Physics Department of Chung Yuan University. Electronics, Optics, Electro-photonic System Design and Analysis, Optical System Design and Analysis, Introduction to Optical Computing, Holography, Nonlinear Optics, The Experimental Technology for Electro- photonics (I), The Experimental Technology for Electro

  12. Optical Surveys of Galaxies: Past, Present, and Future

    NASA Astrophysics Data System (ADS)

    Okamura, Sadanori

    2015-03-01

    A brief history is given of wide area optical surveys of galaxies and resulting catalogs, starting from the Shapley-Ames Catalog through POSS and CfA surveys to modern surveys. Scientific impacts of large surveys are described in terms of the complete sample, large homogeneous samples, and new discoveries. Upcoming and future ambitious surveys are also mentioned. A recent review of surveys in various wavelength regions is given by Djorgovski et al. (2012).

  13. Wide Field-of-View Fluorescence Imaging of Coral Reefs

    PubMed Central

    Treibitz, Tali; Neal, Benjamin P.; Kline, David I.; Beijbom, Oscar; Roberts, Paul L. D.; Mitchell, B. Greg; Kriegman, David

    2015-01-01

    Coral reefs globally are declining rapidly because of both local and global stressors. Improved monitoring tools are urgently needed to understand the changes that are occurring at appropriate temporal and spatial scales. Coral fluorescence imaging tools have the potential to improve both ecological and physiological assessments. Although fluorescence imaging is regularly used for laboratory studies of corals, it has not yet been used for large-scale in situ assessments. Current obstacles to effective underwater fluorescence surveying include limited field-of-view due to low camera sensitivity, the need for nighttime deployment because of ambient light contamination, and the need for custom multispectral narrow band imaging systems to separate the signal into meaningful fluorescence bands. Here we describe the Fluorescence Imaging System (FluorIS), based on a consumer camera modified for greatly increased sensitivity to chlorophyll-a fluorescence, and we show high spectral correlation between acquired images and in situ spectrometer measurements. This system greatly facilitates underwater wide field-of-view fluorophore surveying during both night and day, and potentially enables improvements in semi-automated segmentation of live corals in coral reef photographs and juvenile coral surveys. PMID:25582836

  14. Development of stable monolithic wide-field Michelson interferometers.

    PubMed

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-20

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations. PMID:21772398

  15. Wide-Field InfraRed Survey Telescope WFIRST

    NASA Technical Reports Server (NTRS)

    Green, J.; Schechter, P.; Baltay, C.; Bean, R.; Bennett, D.; Brown, R.; Conselice, C.; Donahue, M.; Fan, X.; Rauscher, B.; Rhodes, J.; Roellig, T.; Stern, D.; Gehrels, N.; Sambruna, R.; Traub, W.; Barry, R. K.; Content, D.; Goullioud, R.; Grady, K.; Kruk, J.; Melton, M.; Peddie, C.; Rioux, N.; Seiffert, M.

    2012-01-01

    In December 2010, NASA created a Science Definition Team (SDT) for WFIRST, the Wide Field Infra-Red Survey Telescope, recommended by the Astro 2010 Decadal Survey as the highest priority for a large space mission. The SDT was chartered to work with the WFIRST Project Office at GSFC and the Program Office at JPL to produce a Design Reference Mission (DRM) for WFIRST. Part of the original charge was to produce an interim design reference mission by mid-2011. That document was delivered to NASA and widely circulated within the astronomical community. In late 2011 the Astrophysics Division augmented its original charge, asking for two design reference missions. The first of these, DRM1, was to be a finalized version of the interim DRM, reducing overall mission costs where possible. The second of these, DRM2, was to identify and eliminate capabilities that overlapped with those of NASA's James Webb Space Telescope (henceforth JWST), ESA's Euclid mission, and the NSF's ground-based Large Synoptic Survey Telescope (henceforth LSST), and again to reduce overall mission cost, while staying faithful to NWNH. This report presents both DRM1 and DRM2.

  16. Wide Field-of-View Fluorescence Imaging of Coral Reefs

    NASA Astrophysics Data System (ADS)

    Treibitz, Tali; Neal, Benjamin P.; Kline, David I.; Beijbom, Oscar; Roberts, Paul L. D.; Mitchell, B. Greg; Kriegman, David

    2015-01-01

    Coral reefs globally are declining rapidly because of both local and global stressors. Improved monitoring tools are urgently needed to understand the changes that are occurring at appropriate temporal and spatial scales. Coral fluorescence imaging tools have the potential to improve both ecological and physiological assessments. Although fluorescence imaging is regularly used for laboratory studies of corals, it has not yet been used for large-scale in situ assessments. Current obstacles to effective underwater fluorescence surveying include limited field-of-view due to low camera sensitivity, the need for nighttime deployment because of ambient light contamination, and the need for custom multispectral narrow band imaging systems to separate the signal into meaningful fluorescence bands. Here we describe the Fluorescence Imaging System (FluorIS), based on a consumer camera modified for greatly increased sensitivity to chlorophyll-a fluorescence, and we show high spectral correlation between acquired images and in situ spectrometer measurements. This system greatly facilitates underwater wide field-of-view fluorophore surveying during both night and day, and potentially enables improvements in semi-automated segmentation of live corals in coral reef photographs and juvenile coral surveys.

  17. HST Wide Field and Planetary Camera II Status Update

    NASA Astrophysics Data System (ADS)

    Heyer, I.; Biretta, J.; Baggett, S.; Gonzaga, S.; Koekemoer, A.; Lubin, L.; Mack, J.; McMaster, M.; Platais, V.; Schultz, A.

    2001-12-01

    We review the status of the Wide Field and Planetary Camera II (WFPC2) onboard the Hubble Space Telescope, as well as recent enhancements to calibration and user support. The photometric, flat field, and PSF stabilities continue to be excellent. Charge Transfer Efficiency (CTE) in the CCDs remains a concern; we discuss the latest results from on-going monitor programs, as well as the latest correction procedures. Work is underway to update the entire set of flat fields; we discuss the new flats, as well as the low-noise flat fields corrections released last summer. The "On-the-Fly-Reprocessing" system continues to perform well, though we mention issues affecting a few images. The WFPC2 Exposure Time Calculator has been updated, and is available on our website. A new WFPC2 Pointings Search Interface tool for the HST Archive has been released. The WFPC2 Instrument Handbook has been updated for Cycle 11, and a new edition of the HST Data Handbook is currently in progress. The next Servicing Mission (SM3b) is slated for February 2002; and we summarize the post-SM tests which are planned for WFPC2. These and other issues will be discussed.

  18. Metrology of confined flows using wide field nanoparticle velocimetry

    PubMed Central

    Ranchon, Hubert; Picot, Vincent; Bancaud, Aurélien

    2015-01-01

    The manipulation of fluids in micro/nanofabricated systems opens new avenues to engineer the transport of matter at the molecular level. Yet the number of methods for the in situ characterization of fluid flows in shallow channels is limited. Here we establish a simple method called nanoparticle velocimetry distribution analysis (NVDA) that relies on wide field microscopy to measure the flow rate and channel height based on the fitting of particle velocity distributions along and across the flow direction. NVDA is validated by simulations, showing errors in velocity and height determination of less than 1% and 8% respectively, as well as with experiments, in which we monitor the behavior of 200 nm nanoparticles conveyed in channels of ~1.8 μm in height. We then show the relevance of this assay for the characterization of flows in bulging channels, and prove its suitability to characterize the concentration of particles across the channel height in the context of visco-elastic focusing. Our method for rapid and quantitative flow characterization has therefore a broad spectrum of applications in micro/nanofluidics, and a strong potential for the optimization of Lab-on-Chips modules in which engineering of confined transport is necessary. PMID:25974654

  19. Wide field of view multifocal scanning microscopy with sparse sampling

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Wu, Jigang

    2016-02-01

    We propose to use sparsely sampled line scans with a sparsity-based reconstruction method to obtain images in a wide field of view (WFOV) multifocal scanning microscope. In the WFOV microscope, we used a holographically generated irregular focus grid to scan the sample in one dimension and then reconstructed the sample image from line scans by measuring the transmission of the foci through the sample during scanning. The line scans were randomly spaced with average spacing larger than the Nyquist sampling requirement, and the image was recovered with sparsity-based reconstruction techniques. With this scheme, the acquisition data can be significantly reduced and the restriction for equally spaced foci positions can be removed, indicating simpler experimental requirement. We built a prototype system and demonstrated the effectiveness of the reconstruction by recovering microscopic images of a U.S. Air Force target and an onion skin cell microscope slide with 40, 60, and 80% missing data with respect to the Nyquist sampling requirement.

  20. Wide-Field Slitless Spectroscopy with JWST/NIRISS

    NASA Astrophysics Data System (ADS)

    Dixon, William V.

    2013-01-01

    The Near Infrared Imager and Slitless Spectrograph (NIRISS) is one of four scientific instruments that will fly aboard the James Webb Space Telescope (JWST) later in this decade. Among its capabilities, NIRISS offers wide-field slitless spectroscopy (WFSS) with a resolving power R = 150 over the wavelength range 1.0 to 2.25 microns using a pair of grisms that disperse light in orthogonal directions. Employing the software packages aXe and Source Extractor, we have developed the configuration files needed to model WFSS observations with NIRISS and to extract and calibrate the resulting spectra. These files, together with a cookbook detailing their use, are available on the JWST/NIRISS web site at STScI. Using these tools, we construct synthetic images of the near-IR sky, identify and extract the spectra of individual sources, and demonstrate that NIRISS can observe galaxies with redshifts up to z = 17. NIRISS is provided to the JWST project by the Canadian Space Agency under the leadership of René Doyon of the Université de Montréal. The prime contractor is COM DEV Canada.

  1. Integration of wide field-of-view imagery functions in a detector dewar cooler assembly

    NASA Astrophysics Data System (ADS)

    Druart, Guillaume; de la Barriere, Florence; Guerineau, Nicolas; Lasfargues, Gilles; Fendler, Manuel; Lhermet, Nicolas; Taboury, Jean; Reibel, Yann; Moullec, Jean-Baptiste

    2012-06-01

    Today, both military and civilian applications require miniaturized optical systems in order to give an imagery function to vehicles with small payload capacity. After the development of megapixel focal plane arrays (FPA) with micro-sized pixels, this miniaturization will become feasible with the integration of optical functions in the detector area. In the field of cooled infrared imaging systems, the detector area is the Detector-Dewar-Cooler Assembly (DDCA). A dewar is a sealed environment where the detector is cooled on a cold plate. We show in this paper that wide field of view imagery functions can be simply added to the dewar. We investigate two ways of integration and make two demonstrators. The first one called FISBI consists in replacing the window by a fish-eye lens and in integrating a lens in the cold shield. This optical system has a field of view of 180°. The second one, called IR-Cam-on-Chip, consists in integrating the optics directly on the focal plane array. This optical system has a field of view of 120°. The additional mass of the optics is sufficiently small to be compatible with the cryogenic environment of the DDCA. The performance of these cameras will be discussed and several evolutions of these cameras will be introduced too.

  2. PRIMO: A Wide Field Prime Focus Infrared Mosaic Camera

    NASA Astrophysics Data System (ADS)

    Fischer, D.; Bally, J.; Green, J.; Morse, J.; Probst, R.; Green, R.; Joyce, R.; Liang, M.; Arentz, R.; Reitsema, H.; Marriott, J.

    2000-12-01

    We describe a proposal for a major new facility infrared camera for the NOAO 4-m telescopes. With a half-degree field of view at prime focus, a refractive collimator-camera design, and a 1-2.5 um range, PRIMO will enable deep, wide-field infrared surveys. The need for surveys which bridge the five-magnitude gap between 2MASS and 8-10 m spectroscopic sensitivity is well established. PRIMO will enable high-latitude broadband surveys to trace the luminosity and clustering evolution of galaxies, investigations into the composition and history of young stellar populations throughout the total volume of star-forming complexes, narrow-band imaging surveys of star forming regions, and of nebulae formed in late stellar evolutionary stages. The NOAO 4-m telescopes are well suited to this role, and PRIMO will also empower US investment in Gemini and other new generation very large telescopes. By leveraging this instrument with the previous NSF investment in these telescopes, we will provide the US community with a survey facility comparable to the UK VISTA project at a fraction of the latter's cost. This project will be carried out through teaming of an accomplished university group, CU-Boulder, a national center, NOAO, and an aerospace industry partner, Ball Aerospace & Technologies Corp. Our approach is a new model for developing major ground-based astronomical instruments. The instrument concept has been developed and costed, and we meet our performance goals with a straightforward, low-risk design. The project schedule is aggressive: two years from start of funding to first light.

  3. Astrometric Calibration of Digitized Wide-Field Photographic Plates

    NASA Astrophysics Data System (ADS)

    Boyce, Peter B.; Truong, P. N.

    2006-12-01

    8000 photographic plates originally taken at Maria Mitchell Observatory from 1913 to 1996 were scanned and digitized in 2002-2003. The resulting scans are stored in TIFF format. We have investigated the use of currently existing tools to convert plate coordinates to RA and Dec to ready the scans for inclusion in the National Virtual Observatory. This involves converting the scans to FITS format and adding WCS headers. Five of the digitized images, with slightly different centers, covering 13° x 16° in Cygnus, were calibrated using the CDS Aladin program version 3.6. An initial Tangent Plane fit was produced by entering parameters applicable for the MMO plates. The images were first calibrated by parameters. The calibration was refined by matching stars images with their positions by overlaying the positions from the Bright Star Catalog. Once a reasonably accurate calibration has been determined, additional star catalogs can be used to refine the calibration. We find that the accuracy of the calibration for a Tangent Plane is not heavily dependent upon the number of stars used. Using a simple Tangent Plane model on these wide-field plates, the coordinates of objects near the edges of the plate often differ from coordinates of objects in the catalog by up to an arcminute. As a check, we also used the WCS Tools programs written by Doug Mink at the Harvard-Smithsonian CfA, and they yield the same results. A satisfactory astrometric calibration which covers the whole field will require the use of higher order polynomials. This project was supported by the NSF/REU grant AST-0354056, the NASA/AAS Small Research Grant Program and the Nantucket Maria Mitchell Association.

  4. Development of the wide field imager for Athena

    NASA Astrophysics Data System (ADS)

    Meidinger, Norbert; Eder, Josef; Fürmetz, Maria; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Reiffers, Jonas; Strecker, Rafael; Barbera, Marco; Brand, Thorsten; Wilms, Jörn

    2015-08-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 arcmin x 40 arcmin together with excellent count-rate capability (>= 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 6 keV will be <= 150 eV until the end of the nominal mission phase. This performance is accomplished by using DEPFET active pixel sensors with a pixel size of 130 μm x 130 μm well suited to the on-axis angular resolution of 5 arcsec of the mirror system. Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450 μm thick silicon bulk. Two different types of DEPFET sensors are planned for the WFI instrument: A set of four large-area sensors to cover the physical size of 14 cm x 14 cm in the focal plane and a single smaller gateable DEPFET sensor matrix optimized for high count-rate observations. Here we present the conceptual design of the instrument with focus on the critical subsystems and describe the instrument performance expectations. An outline of the model philosophy and the project organization completes the presentation.

  5. A fast, wide field of view, catadioptric telescope for Whipple

    NASA Astrophysics Data System (ADS)

    McGuire, James P.

    2014-12-01

    We describe the optical design of a spaceborne f/1.3 catadioptric telescope with a 9 degree field and 77 cm aperture that is being proposed to study objects in the Kuiper belt, Sedna Region, and Oort cloud.

  6. Making light work: illuminating the future of biomedical optics.

    PubMed

    Elwell, Clare E; Cooper, Chris E

    2011-11-28

    In 1996, the Royal Society held a Discussion Meeting entitled 'Near-infrared spectroscopy and imaging of living systems'. In 2010, this topic was revisited in a Theo Murphy Royal Society Scientific Discussion Meeting entitled 'Making light work: illuminating the future of biomedical optics'. The second meeting provided the opportunity for leading researchers to reflect on how the technology, methods and applications have evolved over the past 14 years and assess where they have made a major impact. Particular emphasis was placed on discussions of future prospects and associated challenges. This Introduction provides an overview of the state of the art of near-infrared spectroscopy (NIRS) and biomedical optics, with specific reference to the contributed papers from the invited speakers included in this issue. Importantly, we also reflect on the contributions from all of the attendees by highlighting the issues raised during oral presentations, facilitated panel sessions and discussions, and use these to summarize the current opinion on the development and application of optical systems for use in the clinical and life sciences. A notable outcome from the meeting was a plan to establish a biennial international conference for developers and users of NIRS technologies. PMID:22006895

  7. Wide-field medium-repetition-rate multiphoton microscopy reduces photodamage of living cells.

    PubMed

    Macias-Romero, C; Zubkovs, V; Wang, S; Roke, S

    2016-04-01

    Demands of higher spatial and temporal resolutions in linear and nonlinear imaging keep pushing the limits of optical microscopy. We showed recently that a multiphoton microscope with 200 kHz repetition rate and wide-field illumination has a 2-3 orders of magnitude improved throughput compared to a high repetition rate confocal scanning microscope. Here, we examine the photodamage mechanisms and thresholds in live cell imaging for both systems. We first analyze theoretically the temperature increase in an aqueous solution resulting from illuminating with different repetition rates (keeping the deposited energy and irradiated volume constant). The analysis is complemented with photobleaching experiments of a phenolsulfonphthalein (phenol red) solution. Combining medium repetition rates and wide-field illumination promotes thermal diffusivity, which leads to lower photodamage and allows for higher peak intensities. A three day proliferation assay is also performed on living cells to confirm these results: dwell times can be increased by a factor of 3×10(6) while still preserving cell proliferation. By comparing the proliferation data with the endogenous two-photon fluorescence decay, we propose to use the percentage of the remaining endogenous two-photon fluorescence after exposure as a simple in-situ viability test. These findings enable the possibility of long-term imaging and reduced photodamage. PMID:27446668

  8. Wide-field medium-repetition-rate multiphoton microscopy reduces photodamage of living cells

    PubMed Central

    Macias-Romero, C.; Zubkovs, V.; Wang, S.; Roke, S.

    2016-01-01

    Demands of higher spatial and temporal resolutions in linear and nonlinear imaging keep pushing the limits of optical microscopy. We showed recently that a multiphoton microscope with 200 kHz repetition rate and wide-field illumination has a 2–3 orders of magnitude improved throughput compared to a high repetition rate confocal scanning microscope. Here, we examine the photodamage mechanisms and thresholds in live cell imaging for both systems. We first analyze theoretically the temperature increase in an aqueous solution resulting from illuminating with different repetition rates (keeping the deposited energy and irradiated volume constant). The analysis is complemented with photobleaching experiments of a phenolsulfonphthalein (phenol red) solution. Combining medium repetition rates and wide-field illumination promotes thermal diffusivity, which leads to lower photodamage and allows for higher peak intensities. A three day proliferation assay is also performed on living cells to confirm these results: dwell times can be increased by a factor of 3×106 while still preserving cell proliferation. By comparing the proliferation data with the endogenous two-photon fluorescence decay, we propose to use the percentage of the remaining endogenous two-photon fluorescence after exposure as a simple in-situ viability test. These findings enable the possibility of long-term imaging and reduced photodamage.

  9. Image quality criteria for wide-field x-ray imaging applications

    NASA Astrophysics Data System (ADS)

    Thompson, Patrick L.; Harvey, James E.

    1999-10-01

    For staring, wide-field applications, such as a solar x-ray imager, the severe off-axis aberrations of the classical Wolter Type-I grazing incidence x-ray telescope design drastically limits the 'resolution' near the solar limb. A specification upon on-axis fractional encircled energy is thus not an appropriate image quality criterion for such wide-angle applications. A more meaningful image quality criterion would be a field-weighted-average measure of 'resolution.' Since surface scattering effects from residual optical fabrication errors are always substantial at these very short wavelengths, the field-weighted-average half- power radius is a far more appropriate measure of aerial resolution. If an ideal mosaic detector array is being used in the focal plane, the finite pixel size provides a practical limit to this system performance. Thus, the total number of aerial resolution elements enclosed by the operational field-of-view, expressed as a percentage of the n umber of ideal detector pixels, is a further improved image quality criterion. In this paper we describe the development of an image quality criterion for wide-field applications of grazing incidence x-ray telescopes which leads to a new class of grazing incidence designs described in a following companion paper.

  10. The 64 Mpixel wide field imager for the Wendelstein 2m telescope: design and calibration

    NASA Astrophysics Data System (ADS)

    Kosyra, Ralf; Gössl, Claus; Hopp, Ulrich; Lang-Bardl, Florian; Riffeser, Arno; Bender, Ralf; Seitz, Stella

    2014-11-01

    The Wendelstein Observatory of Ludwig Maximilians University of Munich has recently been upgraded with a modern 2m robotic telescope. One Nasmyth port of the telescope has been equipped with a wide-field corrector which preserves the excellent image quality (<0.8 " median seeing) of the site (Hopp et al. 2008) over a field of view of 0.7 degrees diameter. The available field is imaged by an optical imager (WWFI, the Wendelstein Wide Field Imager) built around a customized 2×2 mosaic of 4 k×4 k 15 μm e2v CCDs from Spectral Instruments. This paper provides an overview of the design and the WWFI's performance. We summarize the system mechanics (including a structural analysis), the electronics (and its electromagnetic interference (EMI) protection) and the control software. We discuss in detail detector system parameters, i.e. gain and readout noise, quantum efficiency as well as charge transfer efficiency (CTE) and persistent charges. First on sky tests yield overall good predictability of system throughput based on lab measurements.

  11. Electrowetting liquid lens array on curved substrates for wide field of view image sensor

    NASA Astrophysics Data System (ADS)

    Bang, Yousung; Lee, Muyoung; Won, Yong Hyub

    2016-03-01

    In this research, electrowetting liquid lens array on curved substrates is developed for wide field of view image sensor. In the conventional image sensing system, this lens array is usually in the form of solid state. However, in this state, the lens array which is similar to insect-like compound eyes in nature has several limitations such as degradation of image quality and narrow field of view because it cannot adjust focal length of lens. For implementation of the more enhanced system, the curved array of lenses based on electrowetting effect is developed in this paper, which can adjust focal length of lens. The fabrication of curved lens array is conducted upon the several steps, including chamber fabrication, electrode & dielectric layer deposition, liquid injection, and encapsulation. As constituent materials, IZO coated convex glass, UV epoxy (NOA 68), DI water, and dodecane are used. The number of lenses on the fabricated panel is 23 by 23 and each lens has 1mm aperture with 1.6mm pitch between adjacent lenses. When the voltage is applied on the device, it is observed that each lens is changed from concave state to convex state. From the unique optical characteristics of curved array of liquid lenses such as controllable focal length and wide field of view, we can expect that it has potential applications in various fields such as medical diagnostics, surveillance systems, and light field photography.

  12. Prototyping results for a wide-field fiber positioner for the Giant Segmented Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Moore, Anna M.; McGrath, Andrew J.

    2004-07-01

    Given the physical size of the GSMT prime focus field is approximately equivalent to that of the Subaru telescope it is possible to directly apply current technology developed for the Fiber Multi-Object Spectrograph instrument (FMOS, to be commissioned in 2005) and substantially reduce the risk associated with developing a new solution for wide-field multi-object spectroscopy on an ELT. The Anglo-Australian Observatory has recently completed a design study for an ~1000 fiber, Echidna-style positioner for the prime focus of the Giant Segmented Mirror Telescope (GSMT). The positioner forms part of the wide-field Multi-Object Multi-Fiber Optical Spectrograph (MOMFOS), an ELT prime focus instrument offering a minimum of 800 fibers patrolling the corrected 20 arcmin field. The design study identified 2 components of an equivalent MOMFOS positioner design that required prototyping. Firstly, a higher spine packing density is required to satisfy the proposed scientific program. Secondly, the fiber position measurement system adopted for FMOS cannot be simply scaled and applied to MOMFOS given space constraints in the top end unit. As such a new and, if possible, simpler system was required. Prototyping results for both components are presented.

  13. Fundamental study of flow field generated by rotorcraft blades using wide-field shadowgraph

    NASA Technical Reports Server (NTRS)

    Parthasarathy, S. P.; Cho, Y. I.; Back, L. H.

    1985-01-01

    The vortex trajectory and vortex wake generated by helicopter rotors are visualized using a wide-field shadowgraph technique. Use of a retro-reflective Scotchlite screen makes it possible to investigate the flow field generated by full-scale rotors. Tip vortex trajectories are visible in shadowgraphs for a range of tip Mach number of 0.38 to 0.60. The effect of the angle of attack is substantial. At an angle of attack greater than 8 degrees, the visibility of the vortex core is significant even at relatively low tip Mach numbers. The theoretical analysis of the sensitivity is carried out for a rotating blade. This analysis demonstrates that the sensitivity decreases with increasing dimensionless core radius and increases with increasing tip Mach number. The threshold value of the sensitivity is found to be 0.0015, below which the vortex core is not visible and above which it is visible. The effect of the optical path length is also discussed. Based on this investigation, it is concluded that the application of this wide-field shadowgraph technique to a large wind tunnel test should be feasible. In addition, two simultaneous shadowgraph views would allow three-dimensional reconstruction of vortex trajectories.

  14. Wide field OCT based microangiography in living human eye (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhang, Qinqin; Chen, Chieh-Li; Chu, Zhongdi; Zhang, Anqi; An, Lin; Durbin, Mary; Sharma, Utkarsh; Rosenfeld, Philip J.; Wang, Ruikang K.

    2016-03-01

    To investigate the application of optical microangiography (OMAG) in living human eye. Patients with different macular diseases were recruited, including diabetic retinopathy (DR), geographic atrophy (GA), retinitis pigmentosa (RP), and venous occlusion, et al. Wide field OCT angiography images can be generated by montage scanning protocol based on the tracking system. OMAG algorithm based on complex differentiation was used to extract the blood flow and removed the bulk motion by 2D cross-correlation method. The 3D angiography was segmented into 3 layers in the retina and 2 layers in the choroid. The en-face maximum projection was used to obtain 2-dimensional angiograms of different layers coded with different colors. Flow and structure images were combined for cross-sectional view. En face OMAG images of different macular diseases showed a great agreement with FA. Meanwhile, OMAG gave more distinct vascular network visions that were less affected by hemorrhage and leakage. The MAs were observed in both superficial and middle retinal layers based on OMAG angiograms in different layers of DR patients. The contour line of FAZ was extracted as well, which can be quantitative the retinal diseases. For GA patient, the damage of RPE layer enhanced the penetration of light and enabled the acquisition of choriocapillaries and choroidal vessels. The wide field OMAG angiogram enabled the capability of capturing the entire geographic atrophy. OMAG provides depth-resolved information and detailed vascular images of DR and GA patients, providing a better visualization of vascular network compared to FA.

  15. Lensless wide-field fluorescent imaging on a chip using compressive decoding of sparse objects

    PubMed Central

    Coskun, Ahmet F.; Sencan, Ikbal; Su, Ting-Wei; Ozcan, Aydogan

    2010-01-01

    We demonstrate the use of a compressive sampling algorithm for on-chip fluorescent imaging of sparse objects over an ultra-large field-of-view (>8 cm2) without the need for any lenses or mechanical scanning. In this lensfree imaging technique, fluorescent samples placed on a chip are excited through a prism interface, where the pump light is filtered out by total internal reflection after exciting the entire sample volume. The emitted fluorescent light from the specimen is collected through an on-chip fiber-optic faceplate and is delivered to a wide field-of-view opto-electronic sensor array for lensless recording of fluorescent spots corresponding to the samples. A compressive sampling based optimization algorithm is then used to rapidly reconstruct the sparse distribution of fluorescent sources to achieve ~10 µm spatial resolution over the entire active region of the sensor-array, i.e., over an imaging field-of-view of >8 cm2. Such a wide-field lensless fluorescent imaging platform could especially be significant for high-throughput imaging cytometry, rare cell analysis, as well as for micro-array research. PMID:20588904

  16. WISH: Wide-field Imaging Durvayor for High-redshift

    NASA Astrophysics Data System (ADS)

    Yamada, Toru

    2015-08-01

    We introduce the concept and current status of WISH project and discuss the science cases. WISH is a proposed space science mission for JAXA, which is dedicated for the deep and wide-field near-infrared imaging surveys. The mission contains the 1.5m cooled telescope as well as the imager with the FoV of ~850 square arcmin. The main goal of WISH is to detect and study galaxies at z=8-15 in the earliest history of structure formation in the universe. The key feature is to conduct WISH Ultra Deep Survey, which images in total of 100 square degrees in 6 broad-band filters at 0.9-4.5 micron down to 28AB magnitude. While more than 10^5 galaxies at z=8-9, 10^4 galaxies at z=11-12 will be detected, WISH-UDS is designed to constrain UV luminosity function at z=15. Depending on the models of the earliest evolution history, 1-1000 galaxies at z~15 (~100 galaxies for the moderate cases) will be detected. The UV spectral properties as well as the clustering properties of galaxies at z=8-15 can be studied as well; UV slope can be measured up to z=15, and the stellar and dark-matter-halo masses can be obtained up to z=9. WISH UDS can provide excellent opportunities for studying SNe at high redshift. Up to ~7000 type Ia SNe at z>1 can be detected and the distance modulus can be constrained with the precision of 0.9-1.5% at z>1.5. More than 100 Super Luminous SNe at z>6, and 10 SLSN at z>10 can also be detected, which allow us to study the earliest history of massive star formation in the universe. WISH imaging surveys as well as WISHSpec, which is an optional parallel-operation simple IFU spectrograph, also provide unique opportunities in various astronomical fields. WISH mission proposal was submitted to JAXA in February 2015 for the first down selection of JAXA Large Strategic Science Mission targeting the launch date in 2020-22. International collaborations including SAO (G.Fazio et al.), LAM (D. Burgarella et al.) and Canada (M.Sawicki et al.) are also actively coordinated.

  17. Future opportunities in production of disposable optics and electronics

    NASA Astrophysics Data System (ADS)

    Korhonen, Raimo

    2001-05-01

    The several production methods of paper processing chain can be used, by analogy, to generate novel ideas for production of optics and electronics. Paper processing is a very fast reel-to-reel process: In the beginning of the paper web production the process is running at the speed of over thousand meters per minute and the web width can be 10 meters, and still at the later stages the speed is several hundreds of meters per minute with the web width of a couple of meters. There are several potential reel-to-reel production methods like embossing, printing, laminating and different kinds of vacuum coating, for example evaporation and sputtering. End products are complex multi-layer composite structures. The benefits from this analogy for optics and electronics would be ideas for ultra fast production, paper-like disposable and recyclable products and the integration of optics and electronics into ordinary things like books, wallpapers, tissue papers and packages. Two experiments are presented to demonstrate the possibilities. In the first experiment optical patterns are embossed directly on paper. In the second one conductive polymers are printed on paper and plastic webs. In future, a wide network of cooperation will be needed to realize all the opportunities.

  18. Optical Packet & Circuit Integrated Network for Future Networks

    NASA Astrophysics Data System (ADS)

    Harai, Hiroaki

    This paper presents recent progress made in the development of an optical packet and circuit integrated network. From the viewpoint of end users, this is a single network that provides both high-speed, inexpensive services and deterministic-delay, low-data-loss services according to the users' usage scenario. From the viewpoint of network service providers, this network provides large switching capacity with low energy requirements, high flexibility, and efficient resource utilization with a simple control mechanism. The network we describe here will contribute to diversification of services, enhanced functional flexibility, and efficient energy consumption, which are included in the twelve design goals of Future Networks announced by ITU-T (International Telecommunication Union - Telecommunication Standardization Sector). We examine the waveband-based network architecture of the optical packet and circuit integrated network. Use of multi-wavelength optical packet increases the switch throughput while minimizing energy consumption. A rank accounting method provides a solution to the problem of inter-domain signaling for end-to-end lightpath establishment. Moving boundary control for packet and circuit services makes for efficient resource utilization. We also describe related advanced technologies such as waveband switching, elastic lightpaths, automatic locator numbering assignment, and biologically-inspired control of optical integrated network.

  19. Modeling the effect of high altitude turbulence in wide-field correlating wavefront sensing and its impact on the performance of solar AO systems

    NASA Astrophysics Data System (ADS)

    Montilla, I.; Tallon, M.; Langlois, M.; Béchet, C.; Collados Vera, M.

    2014-08-01

    Solar Adaptive Optics (AO) shares many issues with night-time AO, but it also has its own particularities. The wavefront sensing is performed using correlations to efficiently work on the solar granulation as a reference. The field of view for that measurement usually is around 10". A sensor collecting such a wide field of view averages wavefront information from different sky directions, and the anisoplanatism thus has a peculiar impact on the performance of solar AO and MCAO systems. Since we are entering the era of large solar telescopes (European Solar Telescope, Advanced Technology Solar Telescope) understanding this issue is crucial to evaluate its impact on the performance of future AO systems. In this paper we model the correlating wide field sensor and the way it senses the high altitude turbulence. Thanks to this improved modelling, we present an analysis of the influence of this sensing on the performance of each AO configuration, conventional AO and MCAO. In addition to the analytical study, simulations similar to the case of the EST AO systems with FRiM-3D (the Fractal Iterative Method for Atmospheric tomography) are used in order to highlight the relative influence of design parameters. In particular, results show the performance evolution when increasing the telescope diameter. We analyse the effect of high altitude turbulence correlation showing that increasing the diameter of the telescope does not degrade the performance when correcting on the same spatial and temporal scales.

  20. Instrumental Direction-dependent Effects in Wide-field Wide-band Interferometric Imaging

    NASA Astrophysics Data System (ADS)

    Bhatnagar, Sanjay; Rau, U.; Golap, K.

    2014-04-01

    Many next generation radio telescopes, some now in operation, offer significant improvement in the sensitivity and angular resolution compared to the telescopes operated in the past decades. This improvement in sensitivity is achieved with the use of wide-band receivers and larger collecting area. The effects of wide instantaneous fractional bandwidths that classical calibration and imaging algorithms ignore, lead to errors higher than the sensitivity that these new telescopes offer. Examples, relevant for some of the telescopes already in operation include the effects of time and frequency variant primary beams, frequency dependence of the emission from the sky and antenna pointing errors. The effects of wide fractional bandwidth and ionospheric phase screen limit the imaging performance below ~1 GHz. Additionally, significant variations in the shape of the wide-band primary beams (PB) for aperture array telescopes leads to errors of similar magnitude. Corrections for these effects increases the required computing power by many orders of magnitude. Furthermore, both wide fractional bandwidths and larger collecting area lead to many orders of magnitude increase in the data volume also, putting severe constraints on the run-time performance of the algorithms for calibration and imaging. In this talk, I will review the state-of-the-art algorithms for wide-field wide-band imaging and the run-time costs of the different approaches for correction of various direction-dependent effects and discuss the computational challenges in thermal noise-limited wide-field imaging with current and future radio telescopes.

  1. A smart metropolitan area optical network in the future

    NASA Astrophysics Data System (ADS)

    Yang, Wanchun; Ge, Zhenbin; Gu, Wanyi

    2005-02-01

    Currently Metropolitan Area Optical Networks are still based on SDH/SONET technologies. The disadvantages of such a rigid SDH/SONET rate hierarchy, especially when data applications such as Ethernet are considered, were soon realized. At the same time fast, link setup and release, and dynamic increase and decrease of the link bandwidth will be the scene of the future network. In order to meet the new requirements, the future network will combine with ASON/GMPLS, which is just the protocol to provide the basic function of topology and resource discovery and fast connection provision with intelligence. In this paper we discuss the new technologies and their combination in metropolitan area networks.

  2. Design of refocusing system for a high-resolution space TDICCD camera with wide-field of view

    NASA Astrophysics Data System (ADS)

    Lv, Shiliang; Liu, Jinguo

    2015-10-01

    This paper describes the design and realization of a refocusing system for a space TDICCD camera of 2.2-meter focal length, which, features a three mirror anastigmatic(TMA) optical system along with 8 TDICCDs assemble at the focal plane, is high resolution and wide field of view. TDICCDs assemble is a kind of major method of acquiring wide field of view for space camera. In this way, the swath width reach 60km. First, the design of TMA optical system and its advantage of this space TDICCD camera was introduced; Then, the refocusing system as well as the technique of mechanical interleaving assemble for TDICCDs focal plane of this space camera was discussed in detail, At last, the refocusing system was measured. Experimental results indicated that the precision of the refocusing system is +/- 3.12μm(3σ), which satisfy the refocusing control system requirements of higher precision and stabilization.

  3. Water-Immersible MEMS scanning mirror designed for wide-field fast-scanning photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Yao, Junjie; Huang, Chih-Hsien; Martel, Catherine; Maslov, Konstantin I.; Wang, Lidai; Yang, Joon-Mo; Gao, Liang; Randolph, Gwendalyn; Zou, Jun; Wang, Lihong V.

    2013-03-01

    By offering images with high spatial resolution and unique optical absorption contrast, optical-resolution photoacoustic microscopy (OR-PAM) has gained increasing attention in biomedical research. Recent developments in OR-PAM have improved its imaging speed, but have sacrificed either the detection sensitivity or field of view or both. We have developed a wide-field fast-scanning OR-PAM by using a water-immersible MEMS scanning mirror (MEMS-ORPAM). Made of silicon with a gold coating, the MEMS mirror plate can reflect both optical and acoustic beams. Because it uses an electromagnetic driving force, the whole MEMS scanning system can be submerged in water. In MEMS-ORPAM, the optical and acoustic beams are confocally configured and simultaneously steered, which ensures uniform detection sensitivity. A B-scan imaging speed as high as 400 Hz can be achieved over a 3 mm scanning range. A diffraction-limited lateral resolution of 2.4 μm in water and a maximum imaging depth of 1.1 mm in soft tissue have been experimentally determined. Using the system, we imaged the flow dynamics of both red blood cells and carbon particles in a mouse ear in vivo. By using Evans blue dye as the contrast agent, we also imaged the flow dynamics of lymphatic vessels in a mouse tail in vivo. The results show that MEMS-OR-PAM could be a powerful tool for studying highly dynamic and time-sensitive biological phenomena.

  4. GRAAL: a seeing enhancer for the NIR wide-field imager Hawk-I

    NASA Astrophysics Data System (ADS)

    Paufique, J.; Bruton, A.; Glindemann, A.; Jost, A.; Kolb, J.; Jochum, L.; Le Louarn, M.; Kiekebusch, M.; Hubin, N.; Madec, P.-Y.; Conzelmann, R.; Siebenmorgen, R.; Donaldson, R.; Arsenault, R.; Tordo, S.

    2010-07-01

    We describe the design and development status of GRAAL, the Ground-layer adaptive optics assisted by Laser, which will deliver enhanced images to the Hawk-I instrument on the VLT. GRAAL is an adaptive optics module, part of AOF, the Adaptive optics facility, using four Laser- and one natural guide-stars to measure the turbulence, and correcting for it by deforming the adaptive secondary mirror of a Unit telescope in the Paranal observatory. The outstanding feature of GRAAL is the extremely wide field of view correction, over 10 arcmin diameter, with an image enhancement of about 20% in average in K band. When observing GRAAL will provide FWHM better than 0.3" 40% of the time. Besides the Adaptive optics facility deformable mirror and Laser guide stars, the system uses subelectron L3-CCD and a real-time computing platform, SPARTA. GRAAL completed early this year a final design phase shared internally and outsourced for its mechanical part by the Spanish company NTE. It is now in manufacturing, with a first light in the laboratory planned in 2011.

  5. Micrometeoroid Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Smaller Particle Impacts

    NASA Technical Reports Server (NTRS)

    Ross, D. K.; Anz-Meador, P.; Liou, J.C.; Opiela, J.; Kearsley, A. T.; Grime, G.; Webb, R.; Jeynes, C.; Palitsin, V.; Colaux, J.; Griffin, T.; Gerlach, L.; Wozniakiewicz, P. J.; Price, M. C.; Burchell, M. J.; Cole, M. J.

    2014-01-01

    The radiator shield on the Wide Field and Planetary Camera 2 (WFPC2) was subject to optical inspection following return from the Hubble Space Telescope (HST) in 2009. The survey revealed over 600 impact features of > 300 micrometers diameter, from exposure in space for 16 years. Subsequently, an international collaborative programme of analysis was organized to determine the origin of hypervelocity particles responsible for the damage. Here we describe examples of the numerous smaller micrometeoroid (MM) impact features (< 700 micrometers diameter) which excavated zinc orthotitanate (ZOT) paint from the radiator surface, but did not incorporate material from underlying Al alloy; larger impacts are described by [3]. We discuss recognition and interpretation of impactor remains, and MM compositions found on WFPC2.

  6. Wide-field depth-sectioning fluorescence microscopy using projector-generated patterned illumination.

    PubMed

    Delica, Serafin; Blanca, Carlo Mar

    2007-10-10

    We present a simple and cost-effective wide-field, depth-sectioning, fluorescence microscope utilizing a commercial multimedia projector to generate excitation patterns on the sample. Highly resolved optical sections of fluorescent pollen grains at 1.9 microm axial resolution are constructed using the structured illumination technique. This requires grid excitation patterns to be scanned across the sample, which is straightforwardly implemented by creating slideshows of gratings at different phases, projecting them onto the sample, and synchronizing camera acquisition with slide transition. In addition to rapid dynamic pattern generation, the projector provides high illumination power and spectral excitation selectivity. We exploit these properties by imaging mouse neural cells in cultures multistained with Alexa 488 and Cy3. The spectral and structural neural information is effectively resolved in three dimensions. The flexibility and commercial availability of this light source is envisioned to open multidimensional imaging to a broader user base. PMID:17932535

  7. WISPIR: A Wide-Field Imaging SPectrograph for the InfraRed for the SPICA Observatory

    NASA Technical Reports Server (NTRS)

    Benford, Dominic J.; Mundy, Lee G.

    2010-01-01

    We have undertaken a study of a far infrared imaging spectrometer based on a Fourier transform spectrometer that uses well-understood, high maturity optics, cryogenics, and detectors to further our knowledge of the chemical and astrophysical evolution of the Universe as it formed planets, stars, and the variety of galaxy morphologies that we observe today. The instrument, Wide-field Imaging Spectrometer for the InfraRed (WISPIR), would operate on the SPICA observatory, and will feature a spectral range from 35 - 210 microns and a spectral resolving power of R=1,000 to 6,000, depending on wavelength. WISPIR provides a choice of full-field spectral imaging over a 2'x2' field or long-slit spectral imaging along a 2' slit for studies of astrophysical structures in the local and high-redshift Universe. WISPIR in long-slit mode will attain a sensitivity two orders of magnitude better than what is currently available.

  8. Quantitative microscopy and nanoscopy of sickle red blood cells performed by wide field digital interferometry

    NASA Astrophysics Data System (ADS)

    Shaked, Natan T.; Satterwhite, Lisa L.; Telen, Marilyn J.; Truskey, George A.; Wax, Adam

    2011-03-01

    We have applied wide-field digital interferometry (WFDI) to examine the morphology and dynamics of live red blood cells (RBCs) from individuals who suffer from sickle cell anemia (SCA), a genetic disorder that affects the structure and mechanical properties of RBCs. WFDI is a noncontact, label-free optical microscopy approach that can yield quantitative thickness profiles of RBCs and measurements of their membrane fluctuations at the nanometer scale reflecting their stiffness. We find that RBCs from individuals with SCA are significantly stiffer than those from a healthy control. Moreover, we show that the technique is sensitive enough to distinguish classes of RBCs in SCA, including sickle RBCs with apparently normal morphology, compared to the stiffer crescent-shaped sickle RBCs. We expect that this approach will be useful for diagnosis of SCA and for determining efficacy of therapeutic agents.

  9. Strategy for contamination control to improve Wide-Field/Planetary Camera far-ultraviolet performance

    NASA Technical Reports Server (NTRS)

    Leschly, Kim; Taylor, Daniel M.; Jenkins, Teresa; Barengoltz, Jack B.

    1990-01-01

    A multifaceted contamination control strategy has been developed for the second generated Wide-Field and Planetary Camera (WFPC-2) to improve the FUV stability by several orders of magnitude, compared to the first camera (WFPC-1). The strategy involves: improved on-orbit boil-off capability of the detector optics, added internal shielding and instrument venting, in-process subassembly vacuum bakeout at elevated temperatures, material substitution, sample testing in ultraclean vacuum facility, and internal instrument contamination-transport modeling. A science performance goal of 1 percent photometric accuracy at 1470 A over an extended time (of at least 30 days) has been established as a contamination control target for WFPC-2. The WFPC-2 is currently planned to be launched by the Shuttle in mid-1993 and replace the WFPC-1 which was recently launched with the HST.

  10. Sampling and Analysis of Impact Crater Residues Found on the Wide Field Planetary Camera-2 Radiator

    NASA Astrophysics Data System (ADS)

    Anz-Meador, P. D.; Liou, J.-C.; Ross, D.; Robinson, G. A.; Opiela, J. N.; Kearsley, A. T.; Grime, G. W.; Colaux, J. L.; Jeynes, C.; Palitsin, V. V.; Webb, R. P.; Griffin, T. J.; Reed, B. B.; Gerlach, L.

    2013-08-01

    After nearly 16 years in low Earth orbit (LEO), the Wide Field Planetary Camera-2 (WFPC2) was recovered from the Hubble Space Telescope (HST) in May 2009, during the 12 day shuttle mission designated STS-125. The WFPC-2 radiator had been struck by approximately 700 impactors producing crater features 300 μ m and larger in size. Following optical inspection in 2009, agreement was reached for joint NASA-ESA study of crater residues, in 2011. Over 480 impact features were extracted at NASA Johnson Space Center's (JSC) Space Exposed Hardware clean-room and curation facility during 2012, and were shared between NASA and ESA. We describe analyses conducted using scanning electron microscopy (SEM) - energy dispersive X-ray spectrometry (EDX): by NASA at JSC's Astromaterials Research and Exploration Science (ARES) Division; and for ESA at the Natural History Museum (NHM), with Ion beam analysis (IBA) using a scanned proton microbeam at the University of Surrey Ion Beam Centre (IBC).

  11. Sampling and Analysis of Impact Crater Residues Found on the Wide Field Planetary Camera-2 Radiator

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Grime, G. W.; Colaux, J. L.; Jeynes, C.; Palitsin, V. V.; Webb, R, P.; Griffin, T. J.; Reed, B. B.; Anz-Meador, P. D.; Kou, J.-C.; Robinson, G. A.; Opiela, J. N.; Gerlach, L.

    2013-01-01

    After nearly 16 years in low Earth orbit (LEO), the Wide Field Planetary Camera-2 (WFPC2) was recovered from the Hubble Space Telescope (HST) in May 2009, during the 12 day shuttle mission designated STS-125. The WFPC-2 radiator had been struck by approximately 700 impactors producing crater features 300 microns and larger in size. Following optical inspection in 2009, agreement was reached for joint NASA-ESA study of crater residues, in 2011. Over 480 impact features were extracted at NASA Johnson Space Center's (JSC) Space Exposed Hardware clean-room and curation facility during 2012, and were shared between NASA and ESA. We describe analyses conducted using scanning electron microscopy (SEM) - energy dispersive X-ray spectrometry (EDX): by NASA at JSC's Astromaterials Research and Exploration Science (ARES) Division; and for ESA at the Natural History Museum (NHM), with Ion beam analysis (IBA) using a scanned proton microbeam at the University of Surrey Ion Beam Centre (IBC).

  12. Wide field of view laser beacon system for three-dimensional aircraft position measurement

    NASA Technical Reports Server (NTRS)

    Sweet, L. M.; Miles, R. B.; Webb, S. G.; Wong, E. Y.

    1981-01-01

    This paper presents a new wide field of view laser beacon system for measurement, in three dimensions, of aircraft or other remote objects. The system is developed for aircraft collision hazard warning independent of ground-based hardware, as well as for flight research, helicopter-assisted construction and rescue, and robotic manipulation applications. Accurate information describing the relative range, elevation, and azimuth of the aircraft are generated by the sweep of a low-power fan-shaped rotating laser beacon past an array of optical detectors. The system achieves a wide angle of acceptance of laser beacon light through use of compound parabolic concentrators, which collimate the light for spectral filtering to minimize solar interference. An on-board microprocessor system converts the pulse sequence to aircraft position in real time. System reliability and performance are enhanced through narrow pass filtering of the pulse signals, digital logic design to mask spurious signals, and adaptive modulation of trigger threshold levels.

  13. Characterization of spatially varying aberrations for wide field-of-view microscopy

    PubMed Central

    Zheng, Guoan; Ou, Xiaoze; Horstmeyer, Roarke; Yang, Changhuei

    2013-01-01

    We describe a simple and robust approach for characterizing the spatially varying pupil aberrations of microscopy systems. In our demonstration with a standard microscope, we derive the location-dependent pupil transfer functions by first capturing multiple intensity images at different defocus settings. Next, a generalized pattern search algorithm is applied to recover the complex pupil functions at ~350 different spatial locations over the entire field-of-view. Parameter fitting transforms these pupil functions into accurate 2D aberration maps. We further demonstrate how these aberration maps can be applied in a phase-retrieval based microscopy setup to compensate for spatially varying aberrations and to achieve diffraction-limited performance over the entire field-of-view. We believe that this easy-to-use spatially-varying pupil characterization method may facilitate new optical imaging strategies for a variety of wide field-of-view imaging platforms. PMID:23842300

  14. All-spherical catadioptric telescope design for wide-field imaging.

    PubMed

    Bahrami, Mehdi; Goncharov, Alexander V

    2010-10-20

    The current trend in building medium-size telescopes for wide-field imaging is to use a Ritchey-Chrétien (RC) design with a multilens corrector near the focus. Our goal is to find a cost-effective alternative design to the RC system for seeing-limited observations. We present an f/4.5 all-spherical catadioptric system with a 1.5° field of view. The system consists of a 0.8 m spherical primary and 0.4 m flat secondary mirror combined with a meniscus lens and followed by a three-lens field corrector. The optical performance is comparable to an equivalent f/4.5 RC system. We conclude that, for telescopes with apertures up to 2 m, the catadioptric design is a good alternative to the RC system. PMID:20962933

  15. Signal-to-noise ratio for the wide field-planetary camera of the Space Telescope

    NASA Technical Reports Server (NTRS)

    Zissa, D. E.

    1984-01-01

    Signal-to-noise ratios for the Wide Field Camera and Planetary Camera of the Space Telescope were calculated as a function of integration time. Models of the optical systems and CCD detector arrays were used with a 27th visual magnitude point source and a 25th visual magnitude per arc-sq. second extended source. A 23rd visual magnitude per arc-sq. second background was assumed. The models predicted signal-to-noise ratios of 10 within 4 hours for the point source centered on a signal pixel. Signal-to-noise ratios approaching 10 are estimated for approximately 0.25 x 0.25 arc-second areas within the extended source after 10 hours integration.

  16. Wide-field Functional Imaging of Blood Flow and Hemoglobin Oxygen Saturation in the Rodent Dorsal Window Chamber

    PubMed Central

    Moy, Austin J.; White, Sean M.; Indrawan, Elmer S.; Lotfi, Justin; Nudelman, Matthew J.; Costantini, Samantha J.; Agarwal, Nikita; Jia, Wangcun; Kelly, Kristen M.; Sorg, Brian S.; Choi, Bernard

    2011-01-01

    The rodent dorsal window chamber is a widely used in vivo model of the microvasculature. The model consists of a 1cm region of exposed microvasculature in the rodent dorsal skin that is immobilized by surgically implanted titanium frames, allowing the skin microvasculature to be visualized. We describe a detailed protocol for surgical implantation of the dorsal window chamber which enables researchers to perform the window chamber implantation surgery. We further describe subsequent wide-field functional imaging of the chamber to obtain hemodynamic information in the form of blood oxygenation and blood flow on a cm size region of interest. Optical imaging techniques, such as intravital microscopy, have been applied extensively to the dorsal window chamber to study microvascular-related disease and conditions. Due to the limited field of view of intravital microscopy, detailed hemodynamic information typically is acquired from small regions of interest, typically on the order of hundreds of μm. The wide-field imaging techniques described herein complement intravital microscopy, allowing researchers to obtain hemodynamic information at both microscopic and macroscopic spatial scales. Compared with intravital microscopy, wide-field functional imaging requires simple instrumentation, is inexpensive, and can give detailed metabolic information over a wide field of view. PMID:21787792

  17. Wide-field high-performance geosynchronous imaging

    NASA Astrophysics Data System (ADS)

    Wood, H. John; Jenstrom, Del; Wilson, Mark; Hinkal, Sanford; Kirchman, Frank

    1998-01-01

    The NASA Mission to Planet Earth (MTPE) Program and the National Oceanographic and Atmospheric Administration (NOAA) are sponsoring the Advanced Geosynchronous Studies (AGS) to develop technologies and system concepts for Earth observation from geosynchronous orbit. This series of studies is intended to benefit both MTPE science and the NOAA GOES Program. Within the AGS program, advanced imager trade studies have investigated two candidate concepts for near-term advanced geosynchronous imagers. One concept uses a scan mirror to direct the line of sight from a 3-axis stabilized platform. Another eliminates the need for a scan mirror by using an agile spacecraft bus to scan the entire instrument. The purpose of this paper is to discuss the optical design trades and system issues encountered in evaluating the two scanning approaches. The imager design started with a look at first principles: what is the most efficient way to image the Earth in those numerous spectral bands of interest to MTPE scientists and NOAA weather forecasters. Optical design trades included rotating filter wheels and dispersive grating instruments. The design converged on a bandpass filter instrument using four focal planes to cover the spectral range 0.45 to 13.0 micrometers. The first imager design uses a small agile spacecraft supporting an afocal optical telescope. Dichroic beamsplitters feed refractive objectives to four focal planes. The detectors are a series of long linear and rectangular arrays which are scanned in a raster fashion over the 17 degree Earth image. The use of the spacecraft attitude control system to raster the imager field-of-view (FOV) back and forth over the Earth eliminates the need for a scan mirror. However, the price paid is significant energy and time required to reverse the spacecraft slew motions at the end of each scan line. Hence, it is desired to minimize the number of scan lines needed to cover the full Earth disk. This desire, coupled with the ground

  18. Wide-field high-performance geosynchronous imaging

    SciTech Connect

    Wood, H. John; Jenstrom, Del; Wilson, Mark; Hinkal, Sanford; Kirchman, Frank

    1998-01-15

    The NASA Mission to Planet Earth (MTPE) Program and the National Oceanographic and Atmospheric Administration (NOAA) are sponsoring the Advanced Geosynchronous Studies (AGS) to develop technologies and system concepts for Earth observation from geosynchronous orbit. This series of studies is intended to benefit both MTPE science and the NOAA GOES Program. Within the AGS program, advanced imager trade studies have investigated two candidate concepts for near-term advanced geosynchronous imagers. One concept uses a scan mirror to direct the line of sight from a 3-axis stabilized platform. Another eliminates the need for a scan mirror by using an agile spacecraft bus to scan the entire instrument. The purpose of this paper is to discuss the optical design trades and system issues encountered in evaluating the two scanning approaches. The imager design started with a look at first principles: what is the most efficient way to image the Earth in those numerous spectral bands of interest to MTPE scientists and NOAA weather forecasters. Optical design trades included rotating filter wheels and dispersive grating instruments. The design converged on a bandpass filter instrument using four focal planes to cover the spectral range 0.45 to 13.0 micrometers. The first imager design uses a small agile spacecraft supporting an afocal optical telescope. Dichroic beamsplitters feed refractive objectives to four focal planes. The detectors are a series of long linear and rectangular arrays which are scanned in a raster fashion over the 17 degree Earth image. The use of the spacecraft attitude control system to raster the imager field-of-view (FOV) back and forth over the Earth eliminates the need for a scan mirror. However, the price paid is significant energy and time required to reverse the spacecraft slew motions at the end of each scan line. Hence, it is desired to minimize the number of scan lines needed to cover the full Earth disk. This desire, coupled with the ground

  19. Engineering a highly segmented very wide-field spectrograph

    NASA Astrophysics Data System (ADS)

    Ragazzoni, R.; Fontana, A.; Maccagni, D.; Baruffolo, A.; Bianco, A. G.; diPaola, A.; Farinato, J.; Gentile, G.; Giallongo, E.; Pedichini, F.; Speziali, R.; Testa, V.

    2010-07-01

    The concept of segmenting the focal plane of an existing 8m class telescope in order to fill it with an array of several fast cameras has been developed further and in this work the status of an engineering program aimed to produce a design qualified for the construction, and to assess its cost estimates is presented. The original concept of just having simple cameras with all identical optical components other than a pupil plane corrector to remove the fixed aberrations at the off-axis field of a telescope has been extended to introduce a spectroscopic capability and to assess a trade-off between a very large number (of the order of thousand) of cameras with a small single Field of View with a smaller number of cameras able to compensate the aberration on a much larger Field of View with a combination of different optical elements and different ways to mount and align them. The scientific target of a few thousands multi-slit spectra over a Field of View of a few square degrees, combined with the ambition to mount this on an existing 8m class telescope makes the scientific rationale of such an instrument a very interesting one. In the paper we describe the different options for a possible optical design, the trade off between variations on the theme of the large segmentation and we describe briefly the way this kind of instrument can handle a multi-slit configuration. Finally, the feasibility of the components and a brief description of how the cost analysis is being performed are given. Perspectives on the construction of this spectrograph are given as well.

  20. Wide field snapshot imaging polarimeter using modified Savart plates

    NASA Astrophysics Data System (ADS)

    Saito, Naooki; Odate, Satoru; Otaki, Katsura; Kubota, Masahiro; Kitahara, Rintaro; Oka, Kazuhiko

    2013-09-01

    Without moving parts, the snapshot imaging polarimeter utilizing Savart plates is capable of stable and fast measurements of spatiallly distributed Stokes parameters. To increase feasibility of the optical design, we propose modi cations that enable a wider eld-of view. By changing the Savar plates' con guration and improving the calibration procedure, the unwanted effects associated with the increase in the eld of view can be reduced. We carried out the veri cation experiments of the wide eld of view snapshot imaging polarimeter.

  1. High-Resolution, Wide-Field-of-View Scanning Telescope

    NASA Technical Reports Server (NTRS)

    Sepulveda, Cesar; Wilson, Robert; Seshadri, Suresh

    2007-01-01

    A proposed telescope would afford high resolution over a narrow field of view (<0.10 ) while scanning over a total field of view nominally 16 wide without need to slew the entire massive telescope structure. The telescope design enables resolution of a 1-m-wide object in a 50- km-wide area of the surface of the Earth as part of a 200-km-wide area field of view monitored from an orbit at an altitude of 700 km. The conceptual design of this telescope could also be adapted to other applications both terrestrial and extraterrestrial in which there are requirements for telescopes that afford both wide- and narrow-field capabilities. In the proposed telescope, the scanning would be effected according to a principle similar to that of the Arecibo radio telescope, in which the primary mirror is stationary with respect to the ground and a receiver is moved across the focal surface of the primary mirror. The proposed telescope would comprise (1) a large spherical primary mirror that would afford high resolution over a narrow field of view and (2) a small displaceable optical relay segment that would be pivoted about the center of an aperture stop to effect the required scanning (see figure). Taken together, both comprise a scanning narrow-angle telescope that does not require slewing the telescope structure. In normal operation, the massive telescope structure would stare at a fixed location on the ground. The inner moveable relay optic would be pivoted to scan the narrower field of view over the wider one, making it possible to retain a fixed telescope orientation, while obtaining high-resolution images over multiple target areas during an interval of 3 to 4 minutes in the intended orbit. The pivoting relay segment of the narrow-angle telescope would include refractive and reflective optical elements, including two aspherical mirrors, to counteract the spherical aberration of the primary mirror. Overall, the combination of the primary mirror and the smaller relay optic

  2. Lessons Learned from the Wide Field Camera 3 TV1 Test Campaign and Correlation Effort

    NASA Technical Reports Server (NTRS)

    Peabody, Hume; Stavley, Richard; Bast, William

    2007-01-01

    In January 2004, shortly after the Columbia accident, future servicing missions to the Hubble Space Telescope (HST) were cancelled. In response to this, further work on the Wide Field Camera 3 instrument was ceased. Given the maturity level of the design, a characterization thermal test (TV1) was completed in case the mission was re-instated or an alternate mission found on which to fly the instrument. This thermal test yielded some valuable lessons learned with respect to testing configurations and modeling/correlation practices, including: 1. Ensure that the thermal design can be tested 2. Ensure that the model has sufficient detail for accurate predictions 3. Ensure that the power associated with all active control devices is predicted 4. Avoid unit changes for existing models. This paper documents the difficulties presented when these recommendations were not followed.

  3. Treatment strategies for inherited optic neuropathies: past, present and future

    PubMed Central

    Yu-Wai-Man, P; Votruba, M; Moore, A T; Chinnery, P F

    2014-01-01

    Bilateral visual loss secondary to inherited optic neuropathies is an important cause of registrable blindness among children and young adults. The two prototypal disorders seen in clinical practice are Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (DOA). About 90% of LHON cases are due to one of three mitochondrial DNA (mtDNA) point mutations: m.3460G>A, m.11778G>A, and m.14484T>C, which affect critical complex I subunits of the mitochondrial respiratory chain. The majority of patients with DOA harbour pathogenic mutations within OPA1, a nuclear gene that codes for a multifunctional inner mitochondrial membrane protein. Despite their contrasting genetic basis, LHON and DOA share overlapping pathological and clinical features that serve to highlight the striking tissue-specific vulnerability of the retinal ganglion cell (RGC) layer to disturbed mitochondrial function. In addition to severe visual loss secondary to progressive optic nerve degeneration, a subgroup of patients will also develop a more aggressive syndromic phenotype marked by significant neurological deficits. The management of LHON and DOA remains largely supportive, but major advances in our understanding of the mechanisms underpinning RGC loss in these two disorders are paving the way for novel forms of treatment aimed at halting or reversing visual deterioration at different stages of the disease process. In addition to neuroprotective strategies for rescuing RGCs from irreversible cell death, innovative in vitro fertilisation techniques are providing the tantalising prospect of preventing the germline transmission of pathogenic mtDNA mutations, eradicating in so doing the risk of disease in future generations. PMID:24603424

  4. Alignment of four-mirror wide field corrector for the Hobby-Eberly Telescope

    NASA Astrophysics Data System (ADS)

    Oh, Chang Jin; Frater, Eric H.; Coyle, Laura; Dubin, Matt; Lowman, Andrew; Zhao, Chunyu; Burge, James H.

    2013-09-01

    The Hobby-Eberly Telescope (HET) Wide Field Corrector (WFC) is a four-mirror optical system which corrects for aberrations from the 10-m segmented spherical primary mirror. The WFC mirror alignments must meet particularly tight tolerances for the system to meet performance requirements. The system uses 1-m class highly aspheric mirrors, which precludes conventional alignment methods. For the WFC system alignment a "center reference fixture" has been used as the reference for each mirror's vertex and optical axis. The center reference fixtures have both a CGH and sphere mounted retroreflector (SMR) nests. The CGH is aligned to the mirror's optical axis to provide a reference for mirror decenter and tilt. The vertex of each mirror is registered to the SMR nests on the center reference fixtures using a laser tracker. The spacing between the mirror vertices is measured during the system alignment using these SMR nest locations to determine the vertex locations. In this paper we present the procedures and results from creating and characterizing these center reference fixtures. As a verification of our alignment methods we also present results from their application in the WFC system alignment are also presented.

  5. Development of the wide-field IFU PPak

    NASA Astrophysics Data System (ADS)

    Kelz, Andreas; Verheijen, Marc; Roth, Martin M.; Laux, Uwe; Bauer, Svend-Marian

    2004-09-01

    PPak is a new fiber-bundle, developed at the Astrophysical Institute Potsdam for the existing PMAS 3D-instrument. The intention of PPak is to provide a large integral field-of-view in combination with a large collecting area per fiber for the study of extended low-surface brightness objects. The PPak system consists of a focal reducer lens and a fiber bundle, featuring an innovative design with object, sky and calibration fibers. With a field-of-view of 74 x 65 arcseconds, PPak currently is the world's widest integral field unit that provides a semi-contiguous regular sampling of extended astronomical objects. Its pre-optics and fiber-diameter, combined with the versatility and efficiency of the PMAS spectrograph, allows PPak to make a unique trade-off between total light-collecting power and spectral resolution.

  6. Wide-field Raman imaging for bone detection in tissue.

    PubMed

    Papour, Asael; Kwak, Jin Hee; Taylor, Zach; Wu, Benjamin; Stafsudd, Oscar; Grundfest, Warren

    2015-10-01

    Inappropriate bone growth in soft tissue can occur after trauma to a limb and can cause a disruption to the healing process. This is known as Heterotopic Ossification (HO) in which regions in the tissue start to mineralize and form microscopic bone-like structures. These structures continue to calcify and develop into large, non-functional bony masses that cause pain, limit limb movement, and expose the tissue to reoccurring infections; in the case of open wounds this can lead to amputation as a result of a failed wound. Both Magnetic Resonance Imaging (MRI) and X-ray imaging have poor sensitivity and specificity for the detection of HO, thus delaying therapy and leading to poor patient outcomes. We present a low-power, fast (1 frame per second) optical Raman imaging system with a large field of view (1 cm(2)) that can differentiate bone tissue from soft tissue without spectroscopy, this in contrast to conventional Raman microscopy systems. This capability may allow for the development of instrumentation which permits bedside diagnosis of HO. PMID:26504639

  7. Wide-field Ca2+ imaging reveals visually evoked activity in the retrosplenial area

    PubMed Central

    Murakami, Tomonari; Yoshida, Takashi; Matsui, Teppei; Ohki, Kenichi

    2015-01-01

    Due to recent advances of genetic manipulation, mouse brain has become a useful model for studying brain function, which demands whole brain functional mapping techniques in the mouse brain. In the present study, to finely map visual responsive areas in the mouse brain, we combined high-resolution wide-field optical imaging with transgenic mice containing the genetically encoded Ca2+ indicator, GCaMP3. With the high signal amplitude of GCaMP3 expressing in excitatory neurons, this system allowed neural activity to be observed with relatively fine spatial resolution and cell-type specificity. To evaluate this system, we examined whether non-visual areas exhibited a visual response over the entire surface of the mouse hemisphere. We found that two association areas, the retrosplenial area (RS) and secondary motor/anterior cingulate area (M2/AC), were significantly responsive to drifting gratings. Examination using gratings with distinct spatiotemporal frequency parameters revealed that the RS strongly responded to high-spatial and low-temporal frequency gratings. The M2/AC exhibited a response property similar to that of the RS, though it was not statistically significant. Finally, we performed cellular imaging using two-photon microscopy to examine orientation and direction selectivity of individual neurons, and found that a minority of neurons in the RS clearly showed visual responses sharply selective for orientation and direction. These results suggest that neurons in RS encode visual information of fine spatial details in images. Thus, the present study shows the usefulness of the functional mapping method using a combination of wide-field and two-photon Ca2+ imaging, which allows for whole brain mapping with high spatiotemporal resolution and cell-type specificity. PMID:26106292

  8. The development of a wide-field, high-resolution UV Raman hyperspectral imager

    NASA Astrophysics Data System (ADS)

    Gomer, Nathaniel R.; Nelson, Matthew P.; Angel, S. M.

    2015-05-01

    Raman spectroscopy is a valuable tool for the investigation and analysis of explosive and biological analytes because it provides a unique molecular fingerprint that allows for unambiguous target identification. Raman can be advantageous when utilized with deep UV excitation, but typical deep UV Raman systems have numerous limitations that hinder their performance and make their potential integration onto a field portable platform difficult. These systems typically offer very low throughput, are physically large and heavy, and can only probe an area the size of a tightly focused laser, severely diminishing the ability of the system to investigate large areas efficiently. The majority of these limitations are directly related to a system's spectrometer, which is typically dispersive grating based and requires a very narrow slit width and long focal length optics to achieve high spectral resolution. To address these shortcomings, ChemImage Sensor Systems (CISS), teaming with the University of South Carolina, are developing a revolutionary wide-field Raman hyperspectral imaging system capable of providing wide-area, high resolution measurements with greatly increased throughput in a small form factor, which would revolutionize the way Raman is conducted and applied. The innovation couples a spatial heterodyne spectrometer (SHS), a novel slit-less spectrometer that operates similar to Michelson interferometer, with a fiber array spectral translator (FAST) fiber array, a two-dimensional imaging fiber for hyperspectral imagery. This combination of technologies creates a novel wide-field, high throughput Raman hyperspectral imager capable of yielding very high spectral resolution measurements using defocused excitation, giving the system a greater area coverage and faster search rate than traditional Raman systems. This paper will focus on the need for an innovative UV Raman system, provide an overview of spatial heterodyne Raman spectroscopy, and discuss the development

  9. WiFeS: the wide field spectrograph

    NASA Astrophysics Data System (ADS)

    Dopita, Michael A.; Waldron, Liam E.; McGregor, Peter; Conroy, Peter; Doolan, Matthew C.; Zhelem, Ross; Bloxham, Gabe; Saunders, Will; Jones, Damien; Pfitzner, Lee

    2004-09-01

    WiFeS is a powerful integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent thoughput, precision spectrophotometric performance and superb image quality along with wide spectral coverage throughout the 320-1000 nm wavelength region. It is currently under construction at the Research School of Astronomy and Astrophysics of the Australian National University (ANU), and will be mounted on the ANU 2.3m telescope at Siding Spring Observatory. It will provide a 25x31 arc sec field with 0.5 arc sec sampling along each of twenty five 31x1.0 arc sec slitlets. The output format is arranged to match the 4096x4096 pixel CCD detectors in each of two cameras individually optimized for the blue and the red ends of the spectrum, respectively. A process of "interleaved nod-and-shuffle" will be applied to permit quantum noise-limited sky subtraction. Using VPH gratings, spectral resolutions modes of 3000 and 7000 will be provided. The full spectral range is covered in a single exposure in the R=3000 mode, and in two exposures in the R=7000 mode. The use of transmissive coated optics, VPH gratings and optimized mirror coatings ensures a throughput (including telescope and atmosphere) that peaks above 30%. The concentric image-slicer design ensures an excellent and uniform image quality across the full field. To maximize the scientific return, the whole instrument is configured for remote observing, pipeline data reduction, and the accumulation of calibration image libraries.

  10. Design of a wide field of view infrared scene projector

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenyu; Li, Lin; Huang, YiFan

    2008-03-01

    In order to make the projected scene cover the seeker's field-of-view promptly the conventional projection optical systems used for hardware-in-the-loop simulation test usually depend on the 5 axes flight-motion-simulator. Those flight-motion-simulator tables are controlled via servomechanisms. The servomechanism needs many axis position transducers and many electromechanical devices. The structure and controlling procedure of the system are complicated. It is hard to avoid the mechanical motion and controlling errors absolutely. The target image jitter will be induced by the vibration of mechanical platform, and the frequency response is limited by the structural performance. To overcome these defects a new infrared image simulating projection system for hardware-in-the-loop simulation test is presented in this paper. The system in this paper consists of multiple lenses joined side by side on a sphere surface. Each single lens uses one IR image generator or resistor array etc. Every IR image generator displays special IR image controlled by the scene simulation computer. The scene computer distributes to every IR image generator the needed image. So the scene detected by the missile seeker is integrated and uninterrupted. The entrance pupil of the seeker lies in the centre of the sphere. Almost semi-sphere range scene can be achieved by the projection system, and the total field of view can be extended by increasing the number of the lenses. However, the luminance uniformity in the field-of-view will be influenced by the joint between the lenses. The method of controlling the luminance uniformity of field-of-view is studied in this paper. The needed luminous exitance of each resist array is analyzed. The experiment shows that the new method is applicable for the hardware-in-the-loop simulation test.

  11. High spatial and temporal resolution wide-field imaging of neuron activity using quantum NV-diamond

    PubMed Central

    Hall, L. T.; Beart, G. C. G.; Thomas, E. A.; Simpson, D. A.; McGuinness, L. P.; Cole, J. H.; Manton, J. H.; Scholten, R. E.; Jelezko, F.; Wrachtrup, Jörg; Petrou, S.; Hollenberg, L. C. L.

    2012-01-01

    A quantitative understanding of the dynamics of biological neural networks is fundamental to gaining insight into information processing in the brain. While techniques exist to measure spatial or temporal properties of these networks, it remains a significant challenge to resolve the neural dynamics with subcellular spatial resolution. In this work we consider a fundamentally new form of wide-field imaging for neuronal networks based on the nanoscale magnetic field sensing properties of optically active spins in a diamond substrate. We analyse the sensitivity of the system to the magnetic field generated by an axon transmembrane potential and confirm these predictions experimentally using electronically-generated neuron signals. By numerical simulation of the time dependent transmembrane potential of a morphologically reconstructed hippocampal CA1 pyramidal neuron, we show that the imaging system is capable of imaging planar neuron activity non-invasively at millisecond temporal resolution and micron spatial resolution over wide-fields. PMID:22574249

  12. Future electro-optical sensors and processing in urban operations

    NASA Astrophysics Data System (ADS)

    Grönwall, Christina; Schwering, Piet B.; Rantakokko, Jouni; Benoist, Koen W.; Kemp, Rob A. W.; Steinvall, Ove; Letalick, Dietmar; Björkert, Stefan

    2013-10-01

    In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of local, distributed and centralized processing are proposed. In this way one can match processing functionality to the required power, and available communication systems data rates, to obtain the desired reaction times. In the study, three priority scenarios were defined. For these scenarios, present-day and future sensors and signal processing technologies were studied. The priority scenarios were camp protection, patrol and house search. A method for analyzing information quality in single and multi-sensor systems has been applied. A method for estimating reaction times for transmission of data through the chain of command has been proposed and used. These methods are documented and can be used to modify scenarios, or be applied to other scenarios. Present day data processing is organized mainly locally. Very limited exchange of information with other platforms is present; this is performed mainly at a high information level. Main issues that arose from the analysis of present-day systems and methodology are the slow reaction time due to the limited field of view of present-day sensors and the lack of robust automated processing. Efficient handover schemes between wide and narrow field of view sensors may however reduce the delay times. The main effort in the study was in forecasting the signal processing of EO-sensors in the next ten to twenty years. Distributed processing is proposed between hand-held and vehicle based sensors. This can be accompanied by cloud processing on board several vehicles. Additionally, to perform sensor fusion on sensor data originating from different platforms, and making full use of UAV imagery, a combination of distributed and

  13. Broadband and Wide Field-of-view Plasmonic Metasurface-enabled Waveplates

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi Hao; Lin, Lan; Ma, Ding; Yun, Seokho; Werner, Douglas H.; Liu, Zhiwen; Mayer, Theresa S.

    2014-12-01

    Quasi two-dimensional metasurfaces composed of subwavelength nanoresonator arrays can dramatically alter the properties of light in an ultra-thin planar geometry, enabling new optical functions such as anomalous reflection and refraction, polarization filtering, and wavefront modulation. However, previous metasurface-based nanostructures suffer from low efficiency, narrow bandwidth and/or limited field-of-view due to their operation near the plasmonic resonance. Here we demonstrate plasmonic metasurface-based nanostructures for high-efficiency, angle-insensitive polarization transformation over a broad octave-spanning bandwidth. The structures are realized by optimizing the anisotropic response of an array of strongly coupled nanorod resonators to tailor the interference of light at the subwavelength scale. Nanofabricated reflective half-wave and quarter-wave plates designed using this approach have measured polarization conversion ratios and reflection magnitudes greater than 92% over a broad wavelength range from 640 to 1290 nm and a wide field-of-view up to +/-40°. This work outlines a versatile strategy to create metasurface-based photonics with diverse optical functionalities.

  14. Broadband and Wide Field-of-view Plasmonic Metasurface-enabled Waveplates

    PubMed Central

    Jiang, Zhi Hao; Lin, Lan; Ma, Ding; Yun, Seokho; Werner, Douglas H.; Liu, Zhiwen; Mayer, Theresa S.

    2014-01-01

    Quasi two-dimensional metasurfaces composed of subwavelength nanoresonator arrays can dramatically alter the properties of light in an ultra-thin planar geometry, enabling new optical functions such as anomalous reflection and refraction, polarization filtering, and wavefront modulation. However, previous metasurface-based nanostructures suffer from low efficiency, narrow bandwidth and/or limited field-of-view due to their operation near the plasmonic resonance. Here we demonstrate plasmonic metasurface-based nanostructures for high-efficiency, angle-insensitive polarization transformation over a broad octave-spanning bandwidth. The structures are realized by optimizing the anisotropic response of an array of strongly coupled nanorod resonators to tailor the interference of light at the subwavelength scale. Nanofabricated reflective half-wave and quarter-wave plates designed using this approach have measured polarization conversion ratios and reflection magnitudes greater than 92% over a broad wavelength range from 640 to 1290 nm and a wide field-of-view up to ±40°. This work outlines a versatile strategy to create metasurface-based photonics with diverse optical functionalities. PMID:25524830

  15. Broadband and wide field-of-view plasmonic metasurface-enabled waveplates.

    PubMed

    Jiang, Zhi Hao; Lin, Lan; Ma, Ding; Yun, Seokho; Werner, Douglas H; Liu, Zhiwen; Mayer, Theresa S

    2014-01-01

    Quasi two-dimensional metasurfaces composed of subwavelength nanoresonator arrays can dramatically alter the properties of light in an ultra-thin planar geometry, enabling new optical functions such as anomalous reflection and refraction, polarization filtering, and wavefront modulation. However, previous metasurface-based nanostructures suffer from low efficiency, narrow bandwidth and/or limited field-of-view due to their operation near the plasmonic resonance. Here we demonstrate plasmonic metasurface-based nanostructures for high-efficiency, angle-insensitive polarization transformation over a broad octave-spanning bandwidth. The structures are realized by optimizing the anisotropic response of an array of strongly coupled nanorod resonators to tailor the interference of light at the subwavelength scale. Nanofabricated reflective half-wave and quarter-wave plates designed using this approach have measured polarization conversion ratios and reflection magnitudes greater than 92% over a broad wavelength range from 640 to 1290 nm and a wide field-of-view up to ± 40°. This work outlines a versatile strategy to create metasurface-based photonics with diverse optical functionalities. PMID:25524830

  16. A wide field-of-view microscope based on holographic focus grid

    NASA Astrophysics Data System (ADS)

    Wu, Jigang; Cui, Xiquan; Zheng, Guoan; Lee, Lap Man; Yang, Changhuei

    2010-02-01

    We have developed a novel microscope technique that can achieve wide field-of-view (FOV) imaging and yet possess resolution that is comparable to conventional microscope. The principle of wide FOV microscope system breaks the link between resolution and FOV magnitude of traditional microscopes. Furthermore, by eliminating bulky optical elements from its design and utilizing holographic optical elements, the wide FOV microscope system is more cost-effective. In our system, a hologram was made to focus incoming collimated beam into a focus grid. The sample is put in the focal plane and the transmissions of the focuses are detected by an imaging sensor. By scanning the incident angle of the incoming beam, the focus grid will scan across the sample and the time-varying transmission can be detected. We can then reconstruct the transmission image of the sample. The resolution of microscopic image is limited by the size of the focus formed by the hologram. The scanning area of each focus spot is determined by the separation of the focus spots and can be made small for fast imaging speed. We have fabricated a prototype system with a 2.4-mm FOV and 1-μm resolution. The prototype system was used to image onion skin cells for a demonstration. The preliminary experiments prove the feasibility of the wide FOV microscope technique, and the possibility of a wider FOV system with better resolution.

  17. Recent progress in the simulation and synthesis of Wide Field Imaging Interferometry Testbed (WIIT) data

    NASA Astrophysics Data System (ADS)

    Juanola-Parramon, Roser; Leisawitz, David; Bolcar, Matthew R.; Iacchetta, Alexander; Maher, Stephen F.; Rinehart, Stephen

    2016-06-01

    The Wide-field Imaging Interferometry Testbed (WIIT) is a double Fourier interferometer (DF) operating at optical wavelengths, and provides data that are highly representative of those from a space-based far-infrared interferometer like the Space Infrared Interferometric Telescope (SPIRIT). Developed at NASA’s Goddard Space Flight Center, this testbed produces high-quality interferometric data and is capable of observing spatially and spectrally complex hyperspectral test scenes, from geometrically simple to astronomically representative test scenes.Here we present the simulation of recent WIIT measurements using the Far-infrared Interferometer Instrument Simulator (FIInS). This simulation enables us to compare a synthesized spatial-spectral data cube based on FIInS-generated DF data with the input hyperspectral test scene. FIInS has been modified to perform the calculations at optical wavelengths and to include an extended field of view due to the presence of a detector array. The results from FIInS are compared with the results obtained from recent measurements with WIIT. For this current study, the test scene under consideration spatially consists of four reference point sources intended for spectral and spatial calibration, and six science sources, comprised of binary systems. Each binary pair member has a unique spectrum. Our results demonstrate that FIInS accurately describes the performance of a real double Fourier interferometer, and that the expected hyperspectral data cube can be reconstructed from synthetic or real interferometric data.

  18. A testbed for wide-field, high-resolution, gigapixel-class cameras

    NASA Astrophysics Data System (ADS)

    Kittle, David S.; Marks, Daniel L.; Son, Hui S.; Kim, Jungsang; Brady, David J.

    2013-05-01

    The high resolution and wide field of view (FOV) of the AWARE (Advanced Wide FOV Architectures for Image Reconstruction and Exploitation) gigapixel class cameras present new challenges in calibration, mechanical testing, and optical performance evaluation. The AWARE system integrates an array of micro-cameras in a multiscale design to achieve gigapixel sampling at video rates. Alignment and optical testing of the micro-cameras is vital in compositing engines, which require pixel-level accurate mappings over the entire array of cameras. A testbed has been developed to automatically calibrate and measure the optical performance of the entire camera array. This testbed utilizes translation and rotation stages to project a ray into any micro-camera of the AWARE system. A spatial light modulator is projected through a telescope to form an arbitrary object space pattern at infinity. This collimated source is then reflected by an elevation stage mirror for pointing through the aperture of the objective into the micro-optics and eventually the detector of the micro-camera. Different targets can be projected with the spatial light modulator for measuring the modulation transfer function (MTF) of the system, fiducials in the overlap regions for registration and compositing, distortion mapping, illumination profiles, thermal stability, and focus calibration. The mathematics of the testbed mechanics are derived for finding the positions of the stages to achieve a particular incident angle into the camera, along with calibration steps for alignment of the camera and testbed coordinate axes. Measurement results for the AWARE-2 gigapixel camera are presented for MTF, focus calibration, illumination profile, fiducial mapping across the micro-camera for registration and distortion correction, thermal stability, and alignment of the camera on the testbed.

  19. A testbed for wide-field, high-resolution, gigapixel-class cameras.

    PubMed

    Kittle, David S; Marks, Daniel L; Son, Hui S; Kim, Jungsang; Brady, David J

    2013-05-01

    The high resolution and wide field of view (FOV) of the AWARE (Advanced Wide FOV Architectures for Image Reconstruction and Exploitation) gigapixel class cameras present new challenges in calibration, mechanical testing, and optical performance evaluation. The AWARE system integrates an array of micro-cameras in a multiscale design to achieve gigapixel sampling at video rates. Alignment and optical testing of the micro-cameras is vital in compositing engines, which require pixel-level accurate mappings over the entire array of cameras. A testbed has been developed to automatically calibrate and measure the optical performance of the entire camera array. This testbed utilizes translation and rotation stages to project a ray into any micro-camera of the AWARE system. A spatial light modulator is projected through a telescope to form an arbitrary object space pattern at infinity. This collimated source is then reflected by an elevation stage mirror for pointing through the aperture of the objective into the micro-optics and eventually the detector of the micro-camera. Different targets can be projected with the spatial light modulator for measuring the modulation transfer function (MTF) of the system, fiducials in the overlap regions for registration and compositing, distortion mapping, illumination profiles, thermal stability, and focus calibration. The mathematics of the testbed mechanics are derived for finding the positions of the stages to achieve a particular incident angle into the camera, along with calibration steps for alignment of the camera and testbed coordinate axes. Measurement results for the AWARE-2 gigapixel camera are presented for MTF, focus calibration, illumination profile, fiducial mapping across the micro-camera for registration and distortion correction, thermal stability, and alignment of the camera on the testbed. PMID:23742532

  20. A Near IR Fabry-Perot Interferometer for Wide Field, Low Resolution Hyperspectral Imaging on the Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Barry, R. K.; Satyapal, S.; Greenhouse, M. A.; Barclay, R.; Amato, D.; Arritt, B.; Brown, G.; Harvey, V.; Holt, C.; Kuhn, J.

    2000-01-01

    We discuss work in progress on a near-infrared tunable bandpass filter for the Goddard baseline wide field camera concept of the Next Generation Space Telescope (NGST) Integrated Science Instrument Module (ISIM). This filter, the Demonstration Unit for Low Order Cryogenic Etalon (DULCE), is designed to demonstrate a high efficiency scanning Fabry-Perot etalon operating in interference orders 1 - 4 at 30K with a high stability DSP based servo control system. DULCE is currently the only available tunable filter for lower order cryogenic operation in the near infrared. In this application, scanning etalons will illuminate the focal plane arrays with a single order of interference to enable wide field lower resolution hyperspectral imaging over a wide range of redshifts. We discuss why tunable filters are an important instrument component in future space-based observatories.

  1. Status of the GRAAL system development: very wide-field correction with 4 laser guide-stars

    NASA Astrophysics Data System (ADS)

    Paufique, J.; Argomedo, J.; Arsenault, R.; Conzelmann, R.; Donaldson, R.; Hubin, N.; Jochum, L.; Jost, A.; Kiekebusch, M.; Kolb, J.; Kuntschner, H.; Le Louarn, M.; Madec, P.-Y.; Siebenmorgen, R.; Tordo, S.

    2012-07-01

    We recall the design and present the development status of GRAAL, the Ground-layer adaptive optics assisted by Laser, which will deliver wide-field (10 arcmin), enhanced images to the HAWK-I instrument on the VLT, with an improved seeing. GRAAL is an adaptive optics module, part of the Adaptive optics facility (AOF), using four Laser- and one natural guide-stars to measure the turbulence, and correcting for it by deforming the adaptive secondary mirror of a Unit telescope in the Paranal observatory. GRAAL is in the laboratory in Europe and the integration of its laser guide-star optics is completed. The first wave-front sensor camera will be ready for its integration in the coming weeks, allowing the first system tests to start.

  2. OP09O-OP404-9 Wide Field Camera 3 CCD Quantum Efficiency Hysteresis

    NASA Technical Reports Server (NTRS)

    Collins, Nick

    2009-01-01

    The HST/Wide Field Camera (WFC) 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. At the nominal operating temperature of -83C, the QEH feature contrast was typically 0.1-0.2% or less. The behavior was replicated using flight spare detectors. A visible light flat-field (540nm) with a several times full-well signal level can pin the detectors at both optical (600nm) and near-UV (230nm) wavelengths, suppressing the QEH behavior. We are characterizing the timescale for the detectors to become unpinned and developing a protocol for flashing the WFC3 CCDs with the instrument's internal calibration system in flight. The HST/Wide Field Camera 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. The first observed manifestation of QEH was the presence in a small percentage of flat-field images of a bowtie-shaped contrast that spanned the width of each chip. At the nominal operating temperature of -83C, the contrast observed for this feature was typically 0.1-0.2% or less, though at warmer temperatures contrasts up to 5% (at -50C) have been observed. The bowtie morphology was replicated using flight spare detectors in tests at the GSFC Detector Characterization Laboratory by power cycling the detector while cold. Continued investigation revealed that a clearly-related global QE suppression at the approximately 5% level can be produced by cooling the detector in the dark; subsequent flat-field exposures at a constant illumination show asymptotically increasing response. This QE "pinning" can be achieved with a single high signal flat-field or a series of lower signal flats; a visible light (500-580nm) flat-field with a signal level of several hundred thousand electrons per pixel is sufficient for QE pinning at both optical (600nm) and near-UV (230nm) wavelengths. We are characterizing the timescale for the detectors to become unpinned and developing a

  3. Mimir: A Near-Infrared Wide-Field Imager, Spectrometer and Polarimeter

    NASA Astrophysics Data System (ADS)

    Clemens, D. P.; Sarcia, D.; Grabau, A.; Tollestrup, E. V.; Buie, M. W.; Dunham, E.; Taylor, B.

    2007-12-01

    Mimir, a new facility-class near-infrared instrument for the 1.8 m Perkins telescope on Anderson Mesa outside Flagstaff, Arizona, was commissioned and has been operating for three years. Mimir is multifunction, performing wide-field (F/5) and narrow-field (F/17) imaging, long-slit spectroscopy, and imaging polarimetry. The F/5 mode images at 0.59" per pixel onto the 1024 × 1024 pixel ALADDIN III InSb array detector, giving a 10' × 10' field of view. In the F/17 mode, the plate scale is 0.18" per pixel. Optically, Mimir is a refractive reimager for the F/17.5 Perkins beam. A six-lens collimator produces an achromatic 25 mm pupil, which is imaged by a five-lens camera (F/5), a four-lens camera (F/17), or a two-lens pupil viewer onto the detector. Three filter wheels precede the pupil, one follows the pupil. The wheels contain a rotating half-wave plate, broadband filters, narrowband filters, grisms, long-pass filters, a wire grid, and thermal IR blockers. The first telescope focus is within Mimir, where a slit and decker unit, consisting of two linear motion cars, selects one of 13 slit scenes. The slit and decker cars, the four filter wheels, the half-wave plate rotation, and the camera selector are all driven by stepper motors within the cold vacuum space. Cooling is provided by a CTI 1050 two-stage, closed-cycle helium refrigerator, keeping the optics, filters, and internal surfaces between 65 and 75 K and the detector at 33.5 K. Switching between Mimir's different modes takes only a few seconds, making it a versatile tool for conducting a wide range of investigations and for quickly reacting to changing observing conditions. Mimir on the Perkins telescope achieves imaging sensitivities 2-4 mag deeper than 2MASS, moderate resolution (R ˜ 700) JHK spectra of virtually any 2MASS source, high-precision wide-field imaging polarimetry, and L' and M' band imaging and spectroscopy.

  4. Design of wide-field submillimeter-wave camera using SIS photon detectors

    NASA Astrophysics Data System (ADS)

    Matsuo, Hiroshi; Ariyoshi, Seiichiro; Otani, Chiko; Ezawa, Hajime; Kobayashi, Jun; Mori, Yuko; Nagata, Hirohisa; Shimizu, Hirohiko M.; Fujiwara, Mikio; Akiba, Makoto; Hosako, Iwao

    2004-10-01

    SIS photon detectors are niobium-based superconducting direct detectors for submillimeter-wave that show superior performance when compared with bolometric detectors for ground-based observations. We present the design and development of the SIS photon detectors together with optical and cryogenic components for wide field continuum observation system on Atacama Submillimeter Telescope Experiment (ASTE). Using antenna coupled distributed junctions, SIS photon detectors give wide band response in a 650-GHz atmospheric window as well as high current sensitivity, shot noise limited operation, fast response and high dynamic range. Optical noise equivalent power (NEP) was measured to be 1.6x10-16 W/Hz0.5 that is less than the background photon fluctuation limit for ground based submillimeter-wave observations. Fabrication of focal plane array with 9 detector pixels is underway to install in ASTE. Readout electronics with Si-JFETs operating at about 100 K will be used for this array. Development of readout electronics for larger array is based on GaAs-JFETs operating at 0.3 K. For the purpose of installing 100 element array of SIS photon detectors, we have developed remotely operable low-vibration cryostat, which now cools bolometers for 350, 450, 850-µm observations down to 0.34 K. GM-type 4-K cooler and He3/He4 sorption cooler is used, which can be remotely recycled to keep detectors at 0.34 K. Since we have large optical window for this cryostat, sapphire cryogenic window is used to block infrared radiation. The sapphire window is ante-reflection coated with SiO2 by chemical vapor deposition (CVD). The transmittance of the cryogenic window at 650 GHz is more than 95%.

  5. Multimodal wide-field two-photon excitation imaging: characterization of the technique for in vivo applications.

    PubMed

    Hwang, Jae Youn; Wachsmann-Hogiu, Sebastian; Ramanujan, V Krishnan; Nowatzyk, Andreas G; Koronyo, Yosef; Medina-Kauwe, Lali K; Gross, Zeev; Gray, Harry B; Farkas, Daniel L

    2011-01-01

    We report fast, non-scanning, wide-field two-photon fluorescence excitation with spectral and lifetime detection for in vivo biomedical applications. We determined the optical characteristics of the technique, developed a Gaussian flat-field correction method to reduce artifacts resulting from non-uniform excitation such that contrast is enhanced, and showed that it can be used for ex vivo and in vivo cellular-level imaging. Two applications were demonstrated: (i) ex vivo measurements of beta-amyloid plaques in retinas of transgenic mice, and (ii) in vivo imaging of sulfonated gallium(III) corroles injected into tumors. We demonstrate that wide-field two photon fluorescence excitation with flat-field correction provides more penetration depth as well as better contrast and axial resolution than the corresponding one-photon wide field excitation for the same dye. Importantly, when this technique is used together with spectral and fluorescence lifetime detection modules, it offers improved discrimination between fluorescence from molecules of interest and autofluorescence, with higher sensitivity and specificity for in vivo applications. PMID:21339880

  6. Optical Tecnology Developments in Biomedicine: History, Current and Future

    PubMed Central

    Nioka, Shoko; Chen, Yu

    2011-01-01

    Biomedical optics is a rapidly emerging field for medical imaging and diagnostics. This paper reviews several biomedical optical technologies that have been developed and translated for either clinical or pre-clinical applications. Specifically, we focus on the following technologies: 1) near-infrared spectroscopy and tomography, 2) optical coherence tomography, 3) fluorescence spectroscopy and imaging, and 4) optical molecular imaging. There representative biomedical applications are also discussed here. PMID:23905030

  7. Optical tecnology developments in biomedicine: history, current and future.

    PubMed

    Nioka, Shoko; Chen, Yu

    2011-09-01

    Biomedical optics is a rapidly emerging field for medical imaging and diagnostics. This paper reviews several biomedical optical technologies that have been developed and translated for either clinical or pre-clinical applications. Specifically, we focus on the following technologies: 1) near-infrared spectroscopy and tomography, 2) optical coherence tomography, 3) fluorescence spectroscopy and imaging, and 4) optical molecular imaging. There representative biomedical applications are also discussed here. PMID:23905030

  8. The Power of Wide Field HI Surveys: ALFALFA Imaging of Massive Tidal Features in the Leo Cloud of Galaxies

    NASA Astrophysics Data System (ADS)

    Leisman, Luke; Haynes, Martha P.; Giovanelli, Riccardo; ALFALFA Almost Darks Team

    2016-01-01

    Tidal interactions are well known to play an important role in galactic evolution in group environments, but the extent of these interactions, and their relative impact on the morphology-density relation is still unclear. Neutral hydrogen (HI) mapping can reveal the recent interaction history of group galaxies, but is difficult to execute due to the need for high sensitivity over wide fields. The Arecibo Legacy Fast ALFA survey (ALFALFA; Giovanelli et al. 2005; Haynes et al. 2011) provides high sensitivity, unbiased, wide field maps of HI in the local volume; here we will present a 50 deg2 ALFALFA map of a well studied region of the Leo Cloud of galaxies, which includes the NGC3226/7 group and HCG44. These observations reveal HI tails and plumes with extents exceeding 1.4 deg (~600 kpc), well beyond the primary beams of previous observations. These tails constitute a significant fraction of the total HI mass in NGC3226/7 (Arp 94) and HCG44. We will also present WSRT maps of the extended emission near Arp 94, which show tail morphologies inconsistent with 2 body interactions. These observations demonstrate that large scale group interactions will be an important science outcome for future sensitive, wide field HI surveys.This work is supported by NSF grants AST-0607007 and AST-1107390 and by grants from the Brinson Foundation.

  9. Managing the Development of the Wide-Field Infrared Survey Explorer Mission

    NASA Technical Reports Server (NTRS)

    Irace, William; Cutri, Roc; Duval, Valerie; Eisenhardt, Peter; Elwell, John; Greanias, George; Heinrichsen, Ingolf; Howard, Joan; Liu, Feng-Chuan; Royer, Donald; Wright, Edward L.

    2010-01-01

    The Wide-field Infrared Survey Explorer (WISE), a NASA Medium-Class Explorer (MIDEX) mission, is surveying the entire sky in four bands from 3.4 to 22 microns with a sensitivity hundreds to hundreds of thousands times better than previous all-sky surveys at these wavelengths. The single WISE instrument consists of a 40 cm three-mirror anastigmatic telescope, a two-stage solid hydrogen cryostat, a scan mirror mechanism, and reimaging optics giving 6" resolution (full-width-half-maximum). WISE was placed into a Sun-synchronous polar orbit on a Delta II 7320 launch vehicle on December 14, 2009. NASA selected WISE as a MIDEX in 2002 following a rigorous competitive selection process. To gain further confidence in WISE, NASA extended the development period one year with an option to cancel the mission if certain criteria were not met. MIDEX missions are led by the principal investigator who in this case delegated day-to-day management to the project manager. With a cost cap and relatively short development schedule, it was essential for all WISE partners to work seamlessly together. This was accomplished with an integrated management team representing all key partners and disciplines. The project was developed on budget and on schedule in spite of the need to surmount significant technical challenges. This paper describes our management approach, key challenges and critical decisions made. Results are described from a programmatic, technical and scientific point of view. Lessons learned are offered for projects of this type.

  10. Wide-field laser ophthalmoscopy for imaging of gas-filled eyes after macular hole surgery

    PubMed Central

    Nakao, Shintaro; Arita, Ryoichi; Sato, Yuki; Enaida, Hiroshi; Ueno, Akifumi; Matsui, Takaaki; Salehi-Had, Hani; Ishibashi, Tatsuro; Sonoda, Koh-hei

    2016-01-01

    Background and objective Existing ophthalmoscopy methods are unable to obtain clear fundus autofluorescence (FAF) images in gas-filled eyes. The purpose of this study was to evaluate the capability of wide-field laser ophthalmoscopy (Optos) in obtaining FAF images in gas-filled eyes for the assessment of macular hole (MH) closure after surgery. Methods This was an interventional case series. Eighteen consecutive patients with unilateral MH underwent vitrectomy with internal limiting membrane peeling and 20% sulfur hexafluoride gas tamponade. FAF images using Optos were recorded preoperatively and postoperatively (days 1, 2, and 7). Results On postoperative days 1, 2, and 7, FAF images were obtained from 11/18 (61.1%), 9/18 (50.0%), and 17/18 eyes (94.4%), respectively, using Optos. The quality of FAF images using Optos was sufficient to determine MH closure in 9/18 (50.0%) of gas-filled eyes postoperatively. Quantitative analysis of FAF images was helpful in determining complete or partial closure of the MH. Conclusion FAF imaging using Optos might be a useful adjunct to optical coherence tomography as a supportive method to guide the release from facedown posturing in some cases of MH. PMID:27601877

  11. Characterization of high proper motion objects from the wide-field infrared survey explorer

    SciTech Connect

    Luhman, K. L.; Sheppard, Scott S.

    2014-06-01

    We present an analysis of high proper motion objects that we have found in a recent study and in this work with multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE). Using photometry and proper motions from the Two Micron All-Sky Survey and WISE, we have identified the members of this sample that are likely to be late-type, nearby, or metal-poor. We have performed optical and near-infrared spectroscopy on 41 objects, from which we measure spectral types that range from M4-T2.5. This sample includes 11 blue L dwarfs and 5 subdwarfs; the latter were also classified as such in the recent study by Kirkpatrick and coworkers. Based on their spectral types and photometry, several of our spectroscopic targets may have distances of <20 pc with the closest at ∼12 pc. The tangential velocities implied by the spectrophotometric distances and proper motions indicate that four of the five subdwarfs are probably members of the Galactic halo while several other objects, including the early-T dwarf WISE J210529.08–623558.7, may belong to the thick disk.

  12. Blind Depth-variant Deconvolution of 3D Data in Wide-field Fluorescence Microscopy.

    PubMed

    Kim, Boyoung; Naemura, Takeshi

    2015-01-01

    This paper proposes a new deconvolution method for 3D fluorescence wide-field microscopy. Most previous methods are insufficient in terms of restoring a 3D cell structure, since a point spread function (PSF) is simply assumed as depth-invariant, whereas a PSF of microscopy changes significantly along the optical axis. A few methods that consider a depth-variant PSF have been proposed; however, they are impractical, since they are non-blind approaches that use a known PSF in a pre-measuring condition, whereas an imaging condition of a target image is different from that of the pre-measuring. To solve these problems, this paper proposes a blind approach to estimate depth-variant specimen-dependent PSF and restore 3D cell structure. It is shown by experiments on that the proposed method outperforms the previous ones in terms of suppressing axial blur. The proposed method is composed of the following three steps: First, a non-parametric averaged PSF is estimated by the Richardson Lucy algorithm, whose initial parameter is given by the central depth prediction from intensity analysis. Second, the estimated PSF is fitted to Gibson's parametric PSF model via optimization, and depth-variant PSFs are generated. Third, a 3D cell structure is restored by using a depth-variant version of a generalized expectation-maximization. PMID:25950821

  13. A wide-field study of Holmberg II and evidence for ram pressure stripping.

    NASA Astrophysics Data System (ADS)

    Bernard, E. J.; Ferguson, A. M. N.; Barker, M. K.; Irwin, M. J.; Jablonka, P.; Arimoto, N.

    We present a deep, wide-field optical study of the M81 group dwarf galaxy Holmberg II (HoII) based on Subaru/Suprime-Cam imaging. Individual stars are resolved down to I˜25.2, i.e., about 1.5 mag below the tip of the red giant branch (RGB). We use resolved star counts in the outskirts of the galaxy to measure the radial surface brightness profile down to mu_V ˜ 32 mag arcsec-2, from which we determine a projected exponential scalelength of 0.70arcmin ±0.01arcmin (i.e., 0.69± 0.01 kpc). The low surface-brightness stellar component of HoII is regular and symmetric and has an extent much smaller than the vast H I cloud in which it is embedded. We compare the spatial distribution of the young and old stellar populations, and find that the old RGB stars are significantly more centrally concentrated than the young stellar populations, contrary to what is observed in most dwarf galaxies of the Local Universe. We discuss these properties in the context of the comet-like distribution of H I gas around HoII, and argue for the presence of a hot intragroup medium in the vicinity of HoII to explain the contrasting morphologies of the gas and stars.

  14. Wide-field conserved scalar imaging in turbulent diffusion flames by a Raman and Rayleigh method

    SciTech Connect

    Kelman, J.B.; Masri, A.R.; Staarner, S.H.; Bilger, R.W.

    1994-12-31

    A new experimental approach to two-dimensional (2D) measurements of mixture fraction and other scalars in turbulent flames has been developed, based on simultaneous fuel Raman and Rayleigh imaging. The inherently weak Raman signal is enhanced by high laser energy, low f-number optics, and a multipass cell. Measurements have been obtained in piloted flames of air-diluted methane, at Reynolds number 28,000--53,000. With the assumptions of unity Lewis number and a one-step reaction, single-shot images of mixture fraction, fuel mass fraction, and temperature have been derived with spatial resolution of about 10 Kolmogorov scales. Advantages and difficulties in the use of the multipass cell are discussed and some early results presented. The wide-field images enable determination of scalar turbulence macroscales that are found to be anisotropic and to vary with radius. The location of the instantaneous stoichiometric mixture fraction contours indicates that there is little reaction in the outer regions where entrainment takes place. Generally, the stoichiometric contour is aligned with regions of high scalar dissipation.

  15. Design of four-mirror afocal principal system for wide field multichannel infrared imaging

    NASA Astrophysics Data System (ADS)

    Hu, Bin; Huang, Ying; Li, Yan

    2015-08-01

    The image space scanning system is widely used for multichannel infrared imaging to overcome the absence of large infrared focal plane array. The field of view of afocal system directly influences the time resolution of the image space scanning system. The field of view of afocal system is generally less than 7°. Therefore, it is significant to design larger field of view of afocal system for increasing time resolution. The method of four-mirror afocal system design based on primary aberration is explored. The structural parameters are calculated according to magnification and obscuration ratio of each mirror. The conic parameters are calculated according to primary aberration coefficients. The procedure for calculating initial structural parameters is programmed. Then a four-mirror afocal system is designed with an entrance pupil diameter of 200mm, a field of view of 20°×1°, the operating wave band of 3~12μm, compression ratio of 2.5 times and the distance of exit pupil of 620mm. The results indicate that the maximum root mean square (RMS) wavefront error is less than 0.042λ(λ=7.5μm), the maximum optical path difference(OPD) is less than λ/4(λ=3~12μm). It has high imaging quality and the modulation transfer function (MTF) is approached to the diffraction limit. The method of afocal system design can be widely used for wide field multichannel infrared imaging.

  16. Miniature wide field-of-view star trackers for spacecraft attitude sensing and navigation

    NASA Technical Reports Server (NTRS)

    Mccarty, William; Curtis, Eric; Hull, Anthony; Morgan, William

    1993-01-01

    Introducing a family of miniature, wide field-of-view star trackers for low cost, high performance spacecraft attitude determination and navigation applications. These devices, derivative of the WFOV Star Tracker Camera developed cooperatively by OCA Applied Optics and the Lawrence Livermore National Laboratory for the Brilliant Pebbles program, offer a suite of options addressing a wide range of spacecraft attitude measurement and control requirements. These sensors employ much wider fields than are customary (ranging between 20 and 60 degrees) to assure enough bright stars for quick and accurate attitude determinations without long integration intervals. The key benefit of this approach are light weight, low power, reduced data processing loads and high information carrier rates for wide ACS bandwidths. Devices described range from the proven OCA/LLNL WFOV Star Tracker Camera (a low-cost, space-qualified star-field imager utilizing the spacecraft's own computer and centroiding and position-finding), to a new autonomous subsystem design featuring dual-redundant cameras and completely self-contained star-field data processing with output quaternion solutions accurate to 100 micro-rad, 3 sigma, for stand-alone applications.

  17. Automated segmentation of oral mucosa from wide-field OCT images (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Goldan, Ryan N.; Lee, Anthony M. D.; Cahill, Lucas; Liu, Kelly; MacAulay, Calum; Poh, Catherine F.; Lane, Pierre

    2016-03-01

    Optical Coherence Tomography (OCT) can discriminate morphological tissue features important for oral cancer detection such as the presence or absence of basement membrane and epithelial thickness. We previously reported an OCT system employing a rotary-pullback catheter capable of in vivo, rapid, wide-field (up to 90 x 2.5mm2) imaging in the oral cavity. Due to the size and complexity of these OCT data sets, rapid automated image processing software that immediately displays important tissue features is required to facilitate prompt bed-side clinical decisions. We present an automated segmentation algorithm capable of detecting the epithelial surface and basement membrane in 3D OCT images of the oral cavity. The algorithm was trained using volumetric OCT data acquired in vivo from a variety of tissue types and histology-confirmed pathologies spanning normal through cancer (8 sites, 21 patients). The algorithm was validated using a second dataset of similar size and tissue diversity. We demonstrate application of the algorithm to an entire OCT volume to map epithelial thickness, and detection of the basement membrane, over the tissue surface. These maps may be clinically useful for delineating pre-surgical tumor margins, or for biopsy site guidance.

  18. Telescope Fabra ROA Montsec: A New Robotic Wide Field Baker-Nunn Facility

    NASA Astrophysics Data System (ADS)

    Fors, Octavi; Núñez, Jorge; Muiños, José Luis; Montojo, Francisco Javier; Baena-Gallé, Roberto; Boloix, Jaime; Morcillo, Ricardo; Merino, María Teresa; Downey, Elwood C.; Mazur, Michael J.

    2013-05-01

    A Baker-Nunn Camera (BNC), originally installed at the Real Instituto y Observatorio de la Armada (ROA) in 1958, was refurbished and robotized. The new facility, called Telescope Fabra ROA Montsec (TFRM), was installed at the Observatori Astronòmic del Montsec (OAdM). The process of refurbishment is described in detail. Most of the steps of the refurbishment project were accomplished by purchasing commercial components, which involve little posterior engineering assembling work. The TFRM is a 0.5 m aperture f/0.96 optically modified BNC, which offers a unique combination of instrumental specifications: fully robotic and remote operation, wide field of view (4°.4 × 4°.4), moderate limiting magnitude (V ~ 19.5 mag), ability of tracking at arbitrary right ascension (α) and declination (δ) rates, as well as opening and closing CCD shutter at will during an exposure. Nearly all kinds of image survey programs can benefit from those specifications. Apart from other less time-consuming programs, since the beginning of science TFRM operations we have been conducting two specific and distinct surveys: super-Earths transiting around M-type dwarfs stars, and geostationary debris in the context of Space Situational Awareness/Space Surveillance and Tracking (SSA/SST) programs. Preliminary results for both cases will be shown.

  19. New wide field camera for Subaru Telescope: Hyper Suprime-Cam

    NASA Astrophysics Data System (ADS)

    Miyazaki, Satoshi

    2015-08-01

    Hyper Suprime-Cam (HSC) is a new wide field optical imaging camera built for 8.2 m Subaru telescope. The field of view is 1.5 degree in diameter and the nearly 50 cm image circle was paved by 116 fully depleted CCDs (2k x 4k 15 micron square pixels). To realize a seeing limit imaging at Mauna Kea, the specification on the overall instrument PSF is set as 0.32 arc-second (FWHM). This is crucial for our primary scientific objectives: weak gravitational lensing survey to probe dark matter distribution. We started building the camera in 2006 and had a first light in 2012. The delivered image quality turned out to be mostly seeing limited as designed. We once observed the seeing size of 0.43 arc-second (median value over the field of view) in Y-band with 300 seconds exposure. Our 300 nights observing proposal has been accepted. The program started in March 2014 and continues over 5 years. The wide survey plans to cover 1,400 square degree with the limiting magnitude of i_AB = 26 (5 sigma, 2 arcsec aperture). General observer programs are carried out in parallel. In this talk, we will present the design and the actual performance of the camera as well as how we implement the massive (1.6 GByte/exposure) data management system.

  20. Development and clinical translation of OTIS: a wide-field OCT imaging device for ex-vivo tissue characterization

    NASA Astrophysics Data System (ADS)

    Munro, Elizabeth A.; Rempel, David; Danner, Christine; Atchia, Yaaseen; Valic, Michael S.; Berkeley, Andrew; Davoudi, Bahar; Magnin, Paul A.; Akens, Margarete; Done, Susan J.; Kulkarni, Supriya; Leong, Wey-Liang; Wilson, Brian C.

    2016-03-01

    We have developed an automated, wide-field optical coherence tomography (OCT)-based imaging device (OTISTM Perimeter Medical Imaging) for peri-operative, ex-vivo tissue imaging. This device features automated image acquisition, enabling rapid capture of high-resolution (15 μm) OCT images from samples up to 10 cm in diameter. We report on the iterative progression of device development from phantom and pre-clinical (tumor xenograft) models through to initial clinical results. We discuss the challenges associated with proving a novel imaging technology against the clinical "gold standard" of conventional post-operative pathology.

  1. Rapid wide-field Mueller matrix polarimetry imaging based on four photoelastic modulators with no moving parts.

    PubMed

    Alali, Sanaz; Gribble, Adam; Vitkin, I Alex

    2016-03-01

    A new polarimetry method is demonstrated to image the entire Mueller matrix of a turbid sample using four photoelastic modulators (PEMs) and a charge coupled device (CCD) camera, with no moving parts. Accurate wide-field imaging is enabled with a field-programmable gate array (FPGA) optical gating technique and an evolutionary algorithm (EA) that optimizes imaging times. This technique accurately and rapidly measured the Mueller matrices of air, polarization elements, and turbid phantoms. The system should prove advantageous for Mueller matrix analysis of turbid samples (e.g., biological tissues) over large fields of view, in less than a second. PMID:26974110

  2. Cost-effective and compact wide-field fluorescent imaging on a cell-phone†

    PubMed Central

    Zhu, Hongying; Yaglidere, Oguzhan; Su, Ting-Wei; Tseng, Derek

    2011-01-01

    We demonstrate wide-field fluorescent and darkfield imaging on a cell-phone with compact, light-weight and cost-effective optical components that are mechanically attached to the existing camera unit of the cell-phone. For this purpose, we used battery powered light-emitting diodes (LEDs) to pump the sample of interest from the side using butt-coupling, where the pump light was guided within the sample cuvette to uniformly excite the specimen. The fluorescent emission from the sample was then imaged using an additional lens that was positioned right in front of the existing lens of the cell-phone camera. Because the excitation occurs through guided waves that propagate perpendicular to our detection path, an inexpensive plastic colour filter was sufficient to create the dark-field background required for fluorescent imaging, without the need for a thin-film interference filter. We validate the performance of this platform by imaging various fluorescent micro-objects in 2 colours (i.e., red and green) over a large field-of-view (FOV) of ~81 mm2 with a raw spatial resolution of ~20 μm. With additional digital processing of the captured cell-phone images, through the use of compressive sampling theory, we demonstrate ~2 fold improvement in our resolving power, achieving ~10 μm resolution without a trade-off in our FOV. Further, we also demonstrate darkfield imaging of non-fluorescent specimen using the same interface, where this time the scattered light from the objects is detected without the use of any filters. The capability of imaging a wide FOV would be exceedingly important to probe large sample volumes (e.g., >0.1 mL) of e.g., blood, urine, sputum or water, and for this end we also demonstrate fluorescent imaging of labeled white-blood cells from whole blood samples, as well as water-borne pathogenic protozoan parasites such as Giardia Lamblia cysts. Weighing only ~28 g (~1 ounce), this compact and cost-effective fluorescent imaging platform attached to a

  3. Wide-field computational imaging of pathology slides using lens-free on-chip microscopy.

    PubMed

    Greenbaum, Alon; Zhang, Yibo; Feizi, Alborz; Chung, Ping-Luen; Luo, Wei; Kandukuri, Shivani R; Ozcan, Aydogan

    2014-12-17

    Optical examination of microscale features in pathology slides is one of the gold standards to diagnose disease. However, the use of conventional light microscopes is partially limited owing to their relatively high cost, bulkiness of lens-based optics, small field of view (FOV), and requirements for lateral scanning and three-dimensional (3D) focus adjustment. We illustrate the performance of a computational lens-free, holographic on-chip microscope that uses the transport-of-intensity equation, multi-height iterative phase retrieval, and rotational field transformations to perform wide-FOV imaging of pathology samples with comparable image quality to a traditional transmission lens-based microscope. The holographically reconstructed image can be digitally focused at any depth within the object FOV (after image capture) without the need for mechanical focus adjustment and is also digitally corrected for artifacts arising from uncontrolled tilting and height variations between the sample and sensor planes. Using this lens-free on-chip microscope, we successfully imaged invasive carcinoma cells within human breast sections, Papanicolaou smears revealing a high-grade squamous intraepithelial lesion, and sickle cell anemia blood smears over a FOV of 20.5 mm(2). The resulting wide-field lens-free images had sufficient image resolution and contrast for clinical evaluation, as demonstrated by a pathologist's blinded diagnosis of breast cancer tissue samples, achieving an overall accuracy of ~99%. By providing high-resolution images of large-area pathology samples with 3D digital focus adjustment, lens-free on-chip microscopy can be useful in resource-limited and point-of-care settings. PMID:25520396

  4. Wide-field direct CCD observations supporting the Astro-1 Space Shuttle mission's Ultraviolet Imaging Telescope

    NASA Technical Reports Server (NTRS)

    Hintzen, Paul; Angione, Ron; Talbert, Freddie; Cheng, K.-P.; Smith, Eric; Stecher, Theodore P.

    1993-01-01

    Wide field direct CCD observations are being obtained to support and complement the vacuum-ultraviolet (VUV) images provided by Astro's Ultraviolet Imaging Telescope (UIT) during a Space Shuttle flight in December 1990. Because of the wide variety of projects addressed by UIT, the fields observed include (1) galactic supernova remnants such as the Cygnus Loop and globular clusters such as Omega Cen and M79; (2) the Magellanic Clouds, M33, M81, and other galaxies in the Local Group; and (3) rich clusters of galaxies, principally the Perseus cluster and Abell 1367. Ground-based observations have been obtained for virtually all of the Astro-1 UIT fields. The optical images allow identification of individual UV sources in each field and provide the long baseline in wavelength necessary for accurate analysis of UV-bright sources. To facilitate use of our optical images for analysis of UIT data and other projects, we plan to archive them, with the UIT images, at the National Space Science Data Center (NSSDC), where they will be universally accessible via anonymous FTP. The UIT, one of three telescopes comprising the Astro spacecraft, is a 38-cm f/9 Ritchey-Chretien telescope on which high quantum efficiency, solar-blind image tubes are used to record VUV images on photographic film. Five filters with passbands centered between 1250A and 2500A provide both VUV colors and a measurement of extinction via the 2200A dust feature. The resulting calibrated VUV pictures are 40 arcminutes in diameter at 2.5 arcseconds resolution. The capabilities of UIT, therefore, complement HST's WFPC: the latter has 40 times greater collecting area, while UIT's usable field has 170 times WFPC's field area.

  5. FAINT TIDAL FEATURES IN GALAXIES WITHIN THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY WIDE FIELDS

    SciTech Connect

    Atkinson, Adam M.; Abraham, Roberto G.; Ferguson, Annette M. N.

    2013-03-01

    We present an analysis of the detectability of faint tidal features in galaxies from the wide-field component of the Canada-France-Hawaii Telescope Legacy Survey. Our sample consists of 1781 luminous (M{sub r{sup '}}<-19.3 mag) galaxies in the magnitude range 15.5 mag < r' < 17 mag and in the redshift range 0.04 < z < 0.2. Although we have classified tidal features according to their morphology (e.g., streams, shells, and tails), we do not attempt to interpret them in terms of their physical origin (e.g., major versus minor merger debris). Instead, we provide a catalog that is intended to provide raw material for future investigations which will probe the nature of low surface brightness substructure around galaxies. We find that around 12% of the galaxies in our sample show clear tidal features at the highest confidence level. This fraction rises to about 18% if we include systems with convincing, albeit weaker tidal features, and to 26% if we include systems with more marginal features that may or may not be tidal in origin. These proportions are a strong function of rest-frame color and of stellar mass. Linear features, shells, and fans are much more likely to occur in massive galaxies with stellar masses >10{sup 10.5} M {sub Sun }, and red galaxies are twice as likely to show tidal features than are blue galaxies.

  6. Demonstration of the Wide-Field Imaging Interferometer Testbed Using a Calibrated Hyperspectral Image Projector

    NASA Technical Reports Server (NTRS)

    Bolcar, Matthew R.; Leisawitz, David; Maher, Steve; Rinehart, Stephen

    2012-01-01

    The Wide-field Imaging Interferometer testbed (WIIT) at NASA's Goddard Space Flight Center uses a dual-Michelson interferometric technique. The WIIT combines stellar interferometry with Fourier-transform interferometry to produce high-resolution spatial-spectral data over a large field-of-view. This combined technique could be employed on future NASA missions such as the Space Infrared Interferometric Telescope (SPIRIT) and the Sub-millimeter Probe of the Evolution of Cosmic Structure (SPECS). While both SPIRIT and SPECS would operate at far-infrared wavelengths, the WIIT demonstrates the dual-interferometry technique at visible wavelengths. The WIIT will produce hyperspectral image data, so a true hyperspectral object is necessary. A calibrated hyperspectral image projector (CHIP) has been constructed to provide such an object. The CHIP uses Digital Light Processing (DLP) technology to produce customized, spectrally-diverse scenes. CHIP scenes will have approximately 1.6-micron spatial resolution and the capability of . producing arbitrary spectra in the band between 380 nm and 1.6 microns, with approximately 5-nm spectral resolution. Each pixel in the scene can take on a unique spectrum. Spectral calibration is achieved with an onboard fiber-coupled spectrometer. In this paper we describe the operation of the CHIP. Results from the WIIT observations of CHIP scenes will also be presented.

  7. Wide-field observations in the SDSS Stripe 82 with the European VLBI Network

    NASA Astrophysics Data System (ADS)

    Cao, H.-M.; Gurvits, L. I.; Yang, J.; Hong, X.-Y.; Frey, S.; Paragi, Z.; Deller, A. T.; Ivezić, Ž.

    2014-07-01

    We observed an area of sky located within the SDSS Stripe 82 field at 1.6 GHz with the European VLBI Network (EVN). There are fifteen mJy/sub-mJy radio sources within the primary beam of a typical 30-m class EVN radio telescope. Our aim was to obtain information on compact radio structures of all VLBI-detectable sources within this primary beam area. The source of particular interest is the recently identified radio quasar J222843.54+011032.2 (J2228+0110) at z = 5.95. The data correlation was performed at the EVN software correlator at JIVE (SFXC). Three targets (J2228+0110, J222851.45+011203.4, J222941.76+011428.5) were detected, all three with position offsets not exceeding the 3σ accuracy of the original low-resolution radio surveys. The detection rate of 20% is consistent with other wide-field VLBI experiments carried out recently (e.g. Middelberg et al. 2013). The project presented here demonstrates the ability of EVN in multiple-phase-centre experiments and paves the way for future large-scale EVN surveys of compact structures in extragalactic radio sources using the multiple-phase-centre VLBI technique.

  8. Faint Tidal Features in Galaxies within the Canada-France-Hawaii Telescope Legacy Survey Wide Fields

    NASA Astrophysics Data System (ADS)

    Atkinson, Adam M.; Abraham, Roberto G.; Ferguson, Annette M. N.

    2013-03-01

    We present an analysis of the detectability of faint tidal features in galaxies from the wide-field component of the Canada-France-Hawaii Telescope Legacy Survey. Our sample consists of 1781 luminous (M_{r^\\prime }<-19.3 mag) galaxies in the magnitude range 15.5 mag < r' < 17 mag and in the redshift range 0.04 < z < 0.2. Although we have classified tidal features according to their morphology (e.g., streams, shells, and tails), we do not attempt to interpret them in terms of their physical origin (e.g., major versus minor merger debris). Instead, we provide a catalog that is intended to provide raw material for future investigations which will probe the nature of low surface brightness substructure around galaxies. We find that around 12% of the galaxies in our sample show clear tidal features at the highest confidence level. This fraction rises to about 18% if we include systems with convincing, albeit weaker tidal features, and to 26% if we include systems with more marginal features that may or may not be tidal in origin. These proportions are a strong function of rest-frame color and of stellar mass. Linear features, shells, and fans are much more likely to occur in massive galaxies with stellar masses >1010.5 M ⊙, and red galaxies are twice as likely to show tidal features than are blue galaxies.

  9. A DEEP, WIDE-FIELD H{alpha} SURVEY OF NEARBY CLUSTERS OF GALAXIES: DATA

    SciTech Connect

    Sakai, Shoko; Kennicutt, Robert C. Jr.; Moss, Chris

    2012-04-01

    We present the results of a wide-field H{alpha} imaging survey of eight nearby (z = 0.02-0.03) Abell clusters. We have measured H{alpha} fluxes and equivalent widths for 465 galaxies, of which 360 are new detections. The survey was designed to obtain complete emission-line-selected inventories of star-forming galaxies in the inner regions of these clusters, extending to star formation rates below 0.1 M{sub Sun} yr{sup -1}. This paper describes the observations, data processing, and source identification procedures, and presents an H{alpha} and R-band catalog of detected cluster members and other candidates. Future papers in the series will use these data to study the completeness of spectroscopically based star formation surveys, and to quantify the effects of cluster environment on the present-day populations of star-forming galaxies. The data will also provide a valuable foundation for imaging surveys of redshifted H{alpha} emission in more distant clusters.

  10. Optical lead flint glasses: key material in optics since centuries and in future

    NASA Astrophysics Data System (ADS)

    Hartmann, Peter

    2015-09-01

    fluorescence light bands simultaneously. These outstanding properties of the lead flint glass types caused SCHOTT to keep them in the glass program and not to replace them completely as other glass companies have done. The improvements of the last two decades with respect to homogeneity and transmittance underline their suitability for future extreme quality optics with applications in medical and general research and in astronomy for large beam shaping and atmospheric dispersion correction.

  11. Integrated optics developments over past decade, future prospects

    NASA Astrophysics Data System (ADS)

    Yu, Rongjin

    1985-06-01

    Some of the progress on guided-wave optics, fabrication and measurement of waveguides, devices, monolithic integration and microfabrication techniques in China over the past 10 years is surveyed. A brief comment on anticipated trends and needs in the field of integrated optics is given.

  12. From classical to modern near-field optics and the future

    NASA Astrophysics Data System (ADS)

    Ohtsu, Motoichi

    2014-11-01

    This paper reviews the framework of classical near-field optics and recent progress in modern near-field optics. Some applications are also reviewed, including novel optical functional devices, nano-fabrication technologies, energy conversion technologies, and information processing systems. Novel theoretical models based on mathematical science are also presented, as well as an outlook for the future, hinting at the possibilities of near-field optics.

  13. Study of GLAO-corrected PSF evolution for the MUSE Wide Field Mode. Expected performance and requirements for PSF reconstruction

    NASA Astrophysics Data System (ADS)

    Fusco, T.; Villecroze, R.; Jarno, A.; Bacon, R.

    2011-09-01

    The second generation instrument MUSE for the VLT has been designed to profit of the ESO Adaptive Optics Facility (AOF). The two Adaptive Optics (AO) modes (GLAO in Wide Field Mode [WFM] and LTAO in Narrow Field Mode [NFM]) will be used. To achieve its key science goals, MUSE will require information on the full system (Atmosphere, AO, telescope and instrument) image quality and its variation with Field position and wavelength. For example, optimal summation of a large number of deep field exposures in WFM will require a good knowledge of the PSF. In this paper, we will present an exhaustive analysis of the MUSE Wide Field Mode PSF evolution both spatially and spectrally. For that purpose we have coupled a complete AO simulation tool developed at ONERA with the MUSE instrumental PSF simulation. Relative impact of atmospheric and system parameters (seeing, Cn^2, LGS and NGS positions etc ...) with respect to differential MUSE aberrations per channel (i.e. slicer and IFU) is analysed. The results allow us (in close collaboration with astronomers) to define pertinent parameters (fit parameters using a Moffat function) for a PSF reconstruction process (estimation of this parameters using GLAO telemetry) and to propose an efficient and robust algorithm to be implemented in the MUSE pipeline. The extension of the spatial and spectral PSF analysis to the NFM case is discussed and preliminary results are given. Some specific requirements for the generalisation of the GLAO PSF reconstruction process to the LTAO case are derived from these early results.

  14. Fiber optic interconnect and optoelectronic packaging challenges for future generation avionics

    NASA Astrophysics Data System (ADS)

    Beranek, Mark W.

    2007-02-01

    Forecasting avionics industry fiber optic interconnect and optoelectronic packaging challenges that lie ahead first requires an assumption that military avionics architectures will evolve from today's centralized/unified concept based on gigabit laser, optical-to-electrical-to-optical switching and optical backplane technology, to a future federated/distributed or centralized/unified concept based on gigabit tunable laser, electro-optical switch and add-drop wavelength division multiplexing (WDM) technology. The requirement to incorporate avionics optical built-in test (BIT) in military avionics fiber optic systems is also assumed to be correct. Taking these assumptions further indicates that future avionics systems engineering will use WDM technology combined with photonic circuit integration and advanced packaging to form the technical basis of the next generation military avionics onboard local area network (LAN). Following this theme, fiber optic cable plants will evolve from today's multimode interconnect solution to a single mode interconnect solution that is highly installable, maintainable, reliable and supportable. Ultimately optical BIT for fiber optic fault detection and isolation will be incorporated as an integral part of a total WDM-based avionics LAN solution. Cost-efficient single mode active and passive photonic component integration and packaging integration is needed to enable reliable operation in the harsh military avionics application environment. Rugged multimode fiber-based transmitters and receivers (transceivers) with in-package optical BIT capability are also needed to enable fully BIT capable single-wavelength fiber optic links on both legacy and future aerospace platforms.

  15. Cone of Darkness: Finding Blank-sky Positions for Multi-object Wide-field Observations

    NASA Astrophysics Data System (ADS)

    Lorente, N. P. F.

    2014-05-01

    We present the Cone of Darkness, an application to automatically configure blank-sky positions for a series of stacked, wide-field observations, such as those carried out by the SAMI instrument on the Anglo-Australian Telescope (AAT). The Sydney-AAO Multi-object Integral field spectrograph (SAMI) uses a plug-plate to mount its 13×61 core imaging fibre bundles (hexabundles) in the optical plane at the telescope's prime focus. To make the most efficient use of each plug-plate, several observing fields are typically stacked to produce a single plate. When choosing blank-sky positions for the observations it is most effective to select these such that one set of 26 holes gives valid sky positions for all fields on the plate. However, when carried out manually this selection process is tedious and includes a significant risk of error. The Cone of Darkness software aims to provide uniform blank-sky position coverage over the field of observation, within the limits set by the distribution of target positions and the chosen input catalogs. This will then facilitate the production of the best representative median sky spectrum for use in sky subtraction. The application, written in C++, is configurable, making it usable for a range of instruments. Given the plate characteristics and the positions of target holes, the software segments the unallocated space on the plate and determines the position which best fits the uniform distribution requirement. This position is checked, for each field, against the selected catalog using a TAP ADQL search. The process is then repeated until the desired number of sky positions is attained.

  16. Wide field imager instrument for the Advanced Telescope for High Energy Astrophysics

    NASA Astrophysics Data System (ADS)

    Meidinger, Norbert; Nandra, Kirpal; Plattner, Markus; Porro, Matteo; Rau, Arne; Santangelo, Andrea; Tenzer, Chris; Wilms, Jörn

    2015-01-01

    The Advanced Telescope for High Energy Astrophysics (Athena) has been selected for ESA's L2 mission, scheduled for launch in 2028. It will provide the necessary capabilities to achieve the ambitious goals of the science theme "The Hot and Energetic Universe." Athena's x-ray mirrors will be based on silicon pore optics technology with a 12-m focal length. Two complementary focal plane camera systems are foreseen, which can be moved interchangeably to the focus of the mirror system: the actively shielded micro-calorimeter spectrometer X-IFU and the wide field imager (WFI). The WFI camera will provide an unprecedented survey power through its large field of view of 40 arc min with a high count-rate capability (˜1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 to 15 keV during the entire mission lifetime (e.g., full width at half maximum ≤150 eV at 6 keV). This performance is accomplished by a set of depleted P-channel field effect transistor (DEPFET) active pixel sensor matrices with a pixel size well suited to the angular resolution of 5 arc sec (on-axis) of the mirror system. Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450-μm-thick silicon bulk. This manuscript will summarize the current instrument concept and design, the status of the technology development, and the envisaged baseline performance.

  17. Towards future systems with nano-optics contributions

    NASA Astrophysics Data System (ADS)

    Kaminska, Bozena; Najiminaini, Mohamadreza; Chuo, Yindar; Landrock, Clint; Omrane, Badr; Carson, Jeffrey J. L.

    2013-03-01

    The long anticipated deployment of nano-optics that can enable next generation computing has encountered several practical impediments that have delayed widespread adoption in commercial processes. However, the global market in nano-enabled products is expected to grow to over $80B USD within the next 3 years. In response, the research community is creating solutions to overcome challenging issues such as reliability and cost-effective fabrication. New approaches in sensing, continuous uptime powering, and post silicon manufacturing will maximize overall performance and allow unprecedented commercial applications. This paper reviews present limitations of nano-optics and then considers the new generation of devices and their manufacturing that may turn promises into reality. We highlight several recent innovations: high sensitivity/selectivity nano-optical sensing devices; sustainable power from polymer energy harvesting and storage; optical variable devices for visual authentication of secure documents; and nano-template masters for high-volume manufacturing.

  18. A unified future for ground and space optical telescopes

    NASA Astrophysics Data System (ADS)

    Kilston, Steven

    2005-08-01

    We view broadly the science and technology drivers for both space and ground optical telescopes, in order to identify the unique capabilities and limitations in each domain. This leads us to consider the potential for effective "divisions of labor" and synergies to enhance scientific value. We project the influence of new enabling technologies, human priorities, international collaboration issues, and funding expectations. Finally, we discuss current NASA and ESA optical astronomy mission goals, and speculate on long-term forecasts.

  19. Laser guide star adaptive optics: Present and future

    SciTech Connect

    Olivier, S.S.; Max, C.E.

    1993-03-01

    Feasibility demonstrations using one to two meter telescopes have confirmed the utility of laser beacons as wavefront references for adaptive optics systems. Laser beacon architectures suitable for the new generation of eight and ten meter telescopes are presently under study. This paper reviews the concept of laser guide star adaptive optics and the progress that has been made by groups around the world implementing such systems. A description of the laser guide star program at LLNL and some experimental results is also presented.

  20. SuperBIT: Wide-field, Sub-arcsecond Imaging from the Super-Pressure Balloon Platform

    NASA Astrophysics Data System (ADS)

    Jones, William

    The scientific potential of diffraction-limited imaging from mid-latitude ultra-long duration balloon payloads is immense. The combination of diffraction-limited angular resolution, extreme stability, space-like backgrounds, and long integrations enables transformative opportunities in studies ranging from the weak lensing of galaxy clusters and cosmic shear, to the search for exoplanets. Pioneering research, spear-headed by the co-investigators of this proposal, has led to the development of the precision tip/tilt and de-rotation systems that are required to realize the potential of the super-pressure balloon (SPB) platform for deep, wide-field imaging. Under a separately funded Canadian Space Agency program, a half-meter class telescope has been integrated with a prototype sub-arcsecond pointing system. We propose a highly focused five-year program to develop and fly a comparable instrument on the mid-latitude SPB platform, demonstrating the imaging capability during an ultra-long duration balloon flight while providing space-quality weak lensing measurements for a large catalog of galaxy clusters. This instrument will provide imaging with a half-degree field of view and 0.3-arcsecond resolution in five bands between 300 and 1000 nm, with sensitivities in the shape-band exceeding 24th magnitude (> 5 sigma) in 300 seconds of integration. We propose an observing schedule that is split between a performance verification sample, a photometric and spectroscopic calibration set, a deep field, and a science catalog. The performance verification set prioritizes a sample of thirty clusters that have been previously well studied with the HST Advanced Camera for Surveys, the Chandra X-ray observatory, and for which there are Compton-Y parameter data from millimeter wavelengths. The photometric calibration set will be selected from the COSMOS field. The science catalog will draw from a set of more than 150 Sunyaev-Zel'dovich, X-ray, and optically-selected clusters spanning a

  1. A Panchromatic Catalog of Early-type Galaxies at Intermediate Redshift in the Hubble Space Telescope Wide Field Camera 3 Early Release Science Field

    NASA Astrophysics Data System (ADS)

    Rutkowski, M. J.; Cohen, S. H.; Kaviraj, S.; O'Connell, R. W.; Hathi, N. P.; Windhorst, R. A.; Ryan, R. E., Jr.; Crockett, R. M.; Yan, H.; Kimble, R. A.; Silk, J.; McCarthy, P. J.; Koekemoer, A.; Balick, B.; Bond, H. E.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, J. A.; Hall, D. N. B.; Holtzman, J. A.; Paresce, F.; Saha, A.; Trauger, J. T.; Walker, A. R.; Whitmore, B. C.; Young, E. T.

    2012-03-01

    In the first of a series of forthcoming publications, we present a panchromatic catalog of 102 visually selected early-type galaxies (ETGs) from observations in the Early Release Science (ERS) program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) of the Great Observatories Origins Deep Survey-South (GOODS-S) field. Our ETGs span a large redshift range, 0.35 lsim z lsim 1.5, with each redshift spectroscopically confirmed by previous published surveys of the ERS field. We combine our measured WFC3 ERS and Advanced Camera for Surveys (ACS) GOODS-S photometry to gain continuous sensitivity from the rest-frame far-UV to near-IR emission for each ETG. The superior spatial resolution of the HST over this panchromatic baseline allows us to classify the ETGs by their small-scale internal structures, as well as their local environment. By fitting stellar population spectral templates to the broadband photometry of the ETGs, we determine that the average masses of the ETGs are comparable to the characteristic stellar mass of massive galaxies, 1011 < M *[M ⊙]<1012. By transforming the observed photometry into the Galaxy Evolution Explorer FUV and NUV, Johnson V, and Sloan Digital Sky Survey g' and r' bandpasses we identify a noteworthy diversity in the rest-frame UV-optical colors and find the mean rest-frame (FUV-V) = 3.5 and (NUV-V) = 3.3, with 1σ standard deviations sime1.0. The blue rest-frame UV-optical colors observed for most of the ETGs are evidence for star formation during the preceding gigayear, but no systems exhibit UV-optical photometry consistent with major recent (lsim50 Myr) starbursts. Future publications which address the diversity of stellar populations likely to be present in these ETGs, and the potential mechanisms by which recent star formation episodes are activated, are discussed.

  2. THE FIRST HUNDRED BROWN DWARFS DISCOVERED BY THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE)

    SciTech Connect

    Davy Kirkpatrick, J.; Gelino, Christopher R.; Griffith, Roger L.; Marsh, Kenneth A.; Tsai, Chao-Wei; Beichman, Charles A.; Cushing, Michael C.; Mainzer, A.; Eisenhardt, Peter R.; Bauer, James M.; Skrutskie, Michael F.; Wright, Edward L.; McLean, Ian S.; Lake, Sean E.; Petty, Sara M.; Thompson, Maggie A.; Benford, Dominic J.; Bridge, Carrie R.; Stanford, S. A.; Bailey, Vanessa; and others

    2011-12-01

    We present ground-based spectroscopic verification of 6 Y dwarfs (see also Cushing et al.), 89 T dwarfs, 8 L dwarfs, and 1 M dwarf identified by the Wide-field Infrared Survey Explorer (WISE). Eighty of these are cold brown dwarfs with spectral types {>=}T6, six of which have been announced earlier by Mainzer et al. and Burgasser et al. We present color-color and color-type diagrams showing the locus of M, L, T, and Y dwarfs in WISE color space. Near-infrared and, in a few cases, optical spectra are presented for these discoveries. Near-infrared classifications as late as early Y are presented and objects with peculiar spectra are discussed. Using these new discoveries, we are also able to extend the optical T dwarf classification scheme from T8 to T9. After deriving an absolute WISE 4.6 {mu}m (W2) magnitude versus spectral type relation, we estimate spectrophotometric distances to our discoveries. We also use available astrometric measurements to provide preliminary trigonometric parallaxes to four of our discoveries, which have types of L9 pec (red), T8, T9, and Y0; all of these lie within 10 pc of the Sun. The Y0 dwarf, WISE 1541-2250, is the closest at 2.8{sup +1.3}{sub -0.6} pc; if this 2.8 pc value persists after continued monitoring, WISE 1541-2250 will become the seventh closest stellar system to the Sun. Another 10 objects, with types between T6 and >Y0, have spectrophotometric distance estimates also placing them within 10 pc. The closest of these, the T6 dwarf WISE 1506+7027, is believed to fall at a distance of {approx}4.9 pc. WISE multi-epoch positions supplemented with positional info primarily from the Spitzer/Infrared Array Camera allow us to calculate proper motions and tangential velocities for roughly one-half of the new discoveries. This work represents the first step by WISE to complete a full-sky, volume-limited census of late-T and Y dwarfs. Using early results from this census, we present preliminary, lower limits to the space density of

  3. The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, J. Davy; Cushing, Michael C.; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Mainzer, A.; Eisenhardt, Peter R.; McLean, Ian S.; Thompson, Maggie A.; Bauer, James M.; Benford, Dominic J.; Bridge, Carrie R.; Lake, Sean E.; Petty, Sara M.; Stanford, S. A.; Tsai, Chao-Wei; Bailey, Vanessa; Beichman, Charles A.; Bloom, Joshua S.; Bochanski, John J.; Burgasser, Adam J.; Capak, Peter L.; Cruz, Kelle L.; Hinz, Philip M.; Kartaltepe, Jeyhan S.; Knox, Russell P.; Manohar, Swarnima; Masters, Daniel; Morales-Calderón, Maria; Prato, Lisa A.; Rodigas, Timothy J.; Salvato, Mara; Schurr, Steven D.; Scoville, Nicholas Z.; Simcoe, Robert A.; Stapelfeldt, Karl R.; Stern, Daniel; Stock, Nathan D.; Vacca, William D.

    2011-12-01

    We present ground-based spectroscopic verification of 6 Y dwarfs (see also Cushing et al.), 89 T dwarfs, 8 L dwarfs, and 1 M dwarf identified by the Wide-field Infrared Survey Explorer (WISE). Eighty of these are cold brown dwarfs with spectral types >=T6, six of which have been announced earlier by Mainzer et al. and Burgasser et al. We present color-color and color-type diagrams showing the locus of M, L, T, and Y dwarfs in WISE color space. Near-infrared and, in a few cases, optical spectra are presented for these discoveries. Near-infrared classifications as late as early Y are presented and objects with peculiar spectra are discussed. Using these new discoveries, we are also able to extend the optical T dwarf classification scheme from T8 to T9. After deriving an absolute WISE 4.6 μm (W2) magnitude versus spectral type relation, we estimate spectrophotometric distances to our discoveries. We also use available astrometric measurements to provide preliminary trigonometric parallaxes to four of our discoveries, which have types of L9 pec (red), T8, T9, and Y0; all of these lie within 10 pc of the Sun. The Y0 dwarf, WISE 1541-2250, is the closest at 2.8+1.3 -0.6 pc if this 2.8 pc value persists after continued monitoring, WISE 1541-2250 will become the seventh closest stellar system to the Sun. Another 10 objects, with types between T6 and >Y0, have spectrophotometric distance estimates also placing them within 10 pc. The closest of these, the T6 dwarf WISE 1506+7027, is believed to fall at a distance of ~4.9 pc. WISE multi-epoch positions supplemented with positional info primarily from the Spitzer/Infrared Array Camera allow us to calculate proper motions and tangential velocities for roughly one-half of the new discoveries. This work represents the first step by WISE to complete a full-sky, volume-limited census of late-T and Y dwarfs. Using early results from this census, we present preliminary, lower limits to the space density of these objects and discuss

  4. The origin, history and future of fiber-optic interferometric acoustic sensors for US Navy applications

    NASA Astrophysics Data System (ADS)

    Cole, James H.; Bucaro, Joseph A.; Kirkendall, Clay K.; Dandridge, Anthony

    2011-05-01

    Fiber-optic interferometric acoustic sensors were first proposed for US Navy applications 36 years ago. This paper will review the origin, development and deployment of these sensors. Future applications will also be discussed.

  5. Elastic Optical Path Network Architecture: Framework for Spectrally-Efficient and Scalable Future Optical Networks

    NASA Astrophysics Data System (ADS)

    Jinno, Masahiko; Takara, Hidehiko; Sone, Yoshiaki; Yonenaga, Kazushige; Hirano, Akira

    This paper presents an elastic optical path network architecture as a novel networking framework to address the looming capacity crunch problem in internet protocol (IP) and optical networks. The basic idea is to introduce elasticity and adaptation into the optical domain to yield spectrally-efficient optical path accommodation, heightened network scalability through IP traffic offloading to the elastic optical layer, and enhanced survivability for serious disasters.

  6. Depth-resolved incoherent and coherent wide-field high-content imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    So, Peter T.

    2016-03-01

    Recent advances in depth-resolved wide-field imaging technique has enabled many high throughput applications in biology and medicine. Depth resolved imaging of incoherent signals can be readily accomplished with structured light illumination or nonlinear temporal focusing. The integration of these high throughput systems with novel spectroscopic resolving elements further enable high-content information extraction. We will introduce a novel near common-path interferometer and demonstrate its uses in toxicology and cancer biology applications. The extension of incoherent depth-resolved wide-field imaging to coherent modality is non-trivial. Here, we will cover recent advances in wide-field 3D resolved mapping of refractive index, absorbance, and vibronic components in biological specimens.

  7. Wavelet image processing applied to optical and digital holography: past achievements and future challenges

    NASA Astrophysics Data System (ADS)

    Jones, Katharine J.

    2005-08-01

    The link between wavelets and optics goes back to the work of Dennis Gabor who both invented holography and developed Gabor decompositions. Holography involves 3-D images. Gabor decompositions involves 1-D signals. Gabor decompositions are the predecessors of wavelets. Wavelet image processing of holography, both optical holography and digital holography, will be examined with respect to past achievements and future challenges.

  8. Upconverting nanoparticles: a versatile platform for wide-field two-photon microscopy and multi-modal in vivo imaging.

    PubMed

    Park, Yong Il; Lee, Kang Taek; Suh, Yung Doug; Hyeon, Taeghwan

    2015-03-21

    Lanthanide-doped upconverting nanoparticles (UCNPs) have recently attracted enormous attention in the field of biological imaging owing to their unique optical properties: (1) efficient upconversion photoluminescence, which is intense enough to be detected at the single-particle level with a (nonscanning) wide-field microscope setup equipped with a continuous wave (CW) near-infrared (NIR) laser (980 nm), and (2) resistance to photoblinking and photobleaching. Moreover, the use of NIR excitation minimizes adverse photoinduced effects such as cellular photodamage and the autofluorescence background. Finally, the cytotoxicity of UCNPs is much lower than that of other nanoparticle systems. All these advantages can be exploited simultaneously without any conflicts, which enables the establishment of a novel UCNP-based platform for wide-field two-photon microscopy. UCNPs are also useful for multimodal in vivo imaging because simple variations in the composition of the lattice atoms and dopant ions integrated into the particles can be easily implemented, yielding various distinct biomedical activities relevant to magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET). These multiple functions embedded in a single type of UCNPs play a crucial role in precise disease diagnosis. The application of UCNPs is extended to therapeutic fields such as photodynamic and photothermal cancer therapies through advanced surface conjugation schemes. PMID:25042637

  9. A Wide-Field NV Diamond Magnetic Imager for Highly Parallel Detection of Rare Biological Targets

    NASA Astrophysics Data System (ADS)

    Glenn, David; Lee, Kyungheon; Lee, Hakho; Walsworth, Ronald

    2014-05-01

    We have developed a wide-field magnetic imaging device based on Nitrogen Vacancy centers in diamond, optimized for the detection of rare, immunomagnetically labeled biological targets such as circulating tumor cells. The new imager allows simultaneous magnetic imaging over a ~ 1 mm2 field of view, approximately two orders of magnitude larger than previous implementations. We describe experiments to detect cancer cells tagged with superparamagnetic nanoparticles, including validation studies for a cell detection assay and technical considerations associated magnetic imaging over very wide fields of view.

  10. A multichannel fiber optic photometer present performance and future developments

    NASA Technical Reports Server (NTRS)

    Barwig, H.; Schoembs, R.; Huber, G.

    1988-01-01

    A three channel photometer for simultaneous multicolor observations was designed with the aim of making possible highly efficient photometry of fast variable objects like cataclysmic variables. Experiences with this instrument over a period of three years are presented. Aspects of the special techniques applied are discussed with respect to high precision photometry. In particular, the use of fiber optics is critically analyzed. Finally, the development of a new photometer concept is discussed.

  11. Extreme Adaptive Optics Testbed: Results and Future Work

    SciTech Connect

    Evans, J W; Sommargren, G; Poyneer, L; Macintosh, B; Severson, S; Dillon, D; Sheinis, A; Palmer, D; Kasdin, J; Olivier, S

    2004-07-15

    'Extreme' adaptive optics systems are optimized for ultra-high-contrast applications, such as ground-based extrasolar planet detection. The Extreme Adaptive Optics Testbed at UC Santa Cruz is being used to investigate and develop technologies for high-contrast imaging, especially wavefront control. A simple optical design allows us to minimize wavefront error and maximize the experimentally achievable contrast before progressing to a more complex set-up. A phase shifting diffraction interferometer is used to measure wavefront errors with sub-nm precision and accuracy. We have demonstrated RMS wavefront errors of <1.3 nm and a contrast of >10{sup -7} over a substantial region using a shaped pupil. Current work includes the installation and characterization of a 1024-actuator Micro-Electro-Mechanical- Systems (MEMS) deformable mirror, manufactured by Boston Micro-Machines, which will be used for wavefront control. In our initial experiments we can flatten the deformable mirror to 1.8-nm RMS wavefront error within a control radius of 5-13 cycles per aperture. Ultimately this testbed will be used to test all aspects of the system architecture for an extrasolar planet-finding AO system.

  12. Optimized geometries for future generation optical lattice clocks

    NASA Astrophysics Data System (ADS)

    Krämer, S.; Ostermann, L.; Ritsch, H.

    2016-04-01

    Atoms deeply trapped in magic wavelength optical lattices provide a Doppler- and collision-free dense ensemble of quantum emitters ideal for high-precision spectroscopy and they are the basis of some of the best optical atomic clocks to date. However, despite their minute optical dipole moments the inherent long-range dipole-dipole interactions in such lattices still generate line shifts, dephasing and modified decay. We show that in a perfectly filled lattice line shifts and decay are resonantly enhanced depending on the lattice constant and geometry. Potentially, this yields clock shifts of many atomic linewidths and reduces the measurement by optimizing the lattice geometry. Such collective effects can be tailored to yield zero effective shifts and prolong dipole lifetimes beyond the single-atom decay. In particular, we identify dense 2D hexagonal or square lattices as the most promising configurations for an accuracy and precision well below the independent ensemble limit. This geometry should also be an ideal basis for related applications such as superradiant lasers, precision magnetometry or long-lived quantum memories.

  13. Sampling and Analysis of Impact Crater Residues found on the Wide Field Planetary Camera-2 Radiator

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Grime, G. W.; Colaux, J. L.; Jeynes, C.; Palitsin, V. V.; Webb, R. P.; Griffin, T. J.; Reed, B. B.; Anz-Meador, P. D.; Kou, J.-C.; Robinson, G. A.; Opiela, J. N.; Gerlach, L.

    2013-01-01

    After nearly 16 years on orbit, the Wide Field Planetary Camera-2 (WFPC-2) was recovered from the Hubble Space Telescope in May 2009 during the 12 day shuttle mission designated STS-125. During that exposure to the low Earth orbit environment, the WFPC-2 radiator was struck by approximately 700 impactors producing crater features 300 micrometers and larger in size. Following an optical inspection of these features in 2009, an agreement was reached for the joint NASA-ESA examination and characterization of crater residues, the remnants of the projectile, in 2011. Active examination began in 2012, with 486 of the impact features being cored at NASA Johnson Space Center fs (JSC) Space Exposed Hardware cleanroom and curation facility. The core samples were subsequently divided between NASA and ESA. NASA's analysis was conducted at JSC fs Astromaterials Research and Exploration Science (ARES) Division, using scanning electron microscopy (SEM)/ energy dispersive X-ray spectrometry (EDS) methods, and ESA's analysis was conducted at the Natural History Museum (NHM) again using SEM/EDS, and at the University of Surrey Ion Beam Centre (IBC) using ion beam analysis (IBA) with a scanned proton microbeam. As detailed discussion of the joint findings remains premature at this point, this paper reports on the coring technique developed; the practical taxonomy developed to classify residues as belonging either to anthropogenic "orbital debris" or micrometeoroids; and the protocols for examination of crater residues. Challenges addressed in coring were the relative thickness of the surface to be cut, protection of the impact feature from contamination while coring, and the need to preserve the cleanroom environment so as to preclude or minimize cross-contamination. Classification criteria are summarized, including the assessment of surface contamination and surface cleaning. Finally, we discuss the analytical techniques used to examine the crater residues. We employed EDS from

  14. Lightweight x-ray optics for future space missions

    NASA Astrophysics Data System (ADS)

    Hudec, Rene; Pina, Ladislav; Inneman, Adolf V.; Ticha, Hana; Brozek, Vlastimil; Zentkova, Maria; Zentko, Anton; Chylek, Tomas

    2003-03-01

    The future X-ray astrophysics space missions require very light-weight but large and precise X-ray mirrors shells. Clearly, developments of innovative techniques and approaches are necessary. We discuss the possible alternative techniques with focus on the technologies and experience available in the Czech Republic. They include light ceramics replication by plasma spraying as well as by CVD and PVD technologies, SiC, thin glass technology, improved electroforming, glossy carbon, as well as glossy metals.

  15. Short wavelength optics for future free electron lasers

    SciTech Connect

    Attwood, D.T.

    1984-04-01

    Although much free-electron laser work is directed toward achieving sufficient single-pass gain to be useful for research purposes, the availability of mirrors of high reflectance for the vacuum ultraviolet and soft x-ray regime would make resonant cavities a possibility. In addition, as in ordinary synchrotron radiation work, mirrors are required for the construction of realistic experiments and for beam manipulation purposes such as folding and extraction. The Working Group discussed a number of approaches to reflecting optics for free electron lasers, which are summarized here, and described in some detail. 16 references, 2 figures.

  16. The status of NASA's wide-field meteor camera network and preliminary results

    NASA Astrophysics Data System (ADS)

    Blaauw, R.; Cooke, W.; Kingery, A.; Suggs, R.

    2014-04-01

    NASA's Meteoroid Environment Office (MEO) recently established two wide-field cameras to detect meteors in the millimeter-size-range. This paper outlines the concepts of the system, the hardware and software, and results of 3,440 orbits seen from December 13, 2012 until May 14, 2014.

  17. Estimating crop production in Iowa from Advanced Wide Field Sensor (AWiFS) data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Indian National Remote Sensing Agency ResourceSat-1 Advanced Wide Field Sensor (AWiFS) data for the USA is being provided online by the USDA Foreign Agricultural Service (FAS) and Arctic Slope Regional Corporation – Management Services (ASRC-MS). Because of the frequent revisit time and pixel sizes...

  18. The Status of NASA's Wide-Field Meteor Camera Network and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Blaauw, R.; Cooke, W.; Kingery, A.; Suggs, R.

    2014-01-01

    NASA's Meteoroid Environment Office (MEO) recently established two wide-field cameras to detect meteors in the millimeter-size-range. This paper outlines the concepts of the system, the hardware and software, and results of 3,440 orbits seen from December 13, 2012 until May 14, 2014.

  19. Application of the wide-field shadowgraph technique to rotor wake visualization

    NASA Technical Reports Server (NTRS)

    Norman, Thomas R.; Light, Jeffrey S.

    1989-01-01

    The wide field shadowgraph technique is reviewed along with its application to the visualization of rotor wakes. In particular, current experimental methods and data reduction requirements are discussed. Sample shadowgraphs are presented. These include shadowgraphs of model-scale helicopter main rotors and tilt rotors, and full scale tail rotors, both in hover and in forward flight.

  20. Micrometeoroid Impacts on the Hubble Sace Telescope Wide Field and Planetary Camera 2: Ion Beam Analysis of Subtle Impactor Traces

    NASA Technical Reports Server (NTRS)

    Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V. V.; Colaux, J. L.; Kearsley, A. T.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; Griffin, T.; Gerlach, L.; Wozniakiewicz, P. J.; Price, M. C.; Burchell, M. J.; Cole, M. J.

    2014-01-01

    Recognition of origin for particles responsible for impact damage on spacecraft such as the Hubble Space Telescope (HST) relies upon postflight analysis of returned materials. A unique opportunity arose in 2009 with collection of the Wide Field and Planetary Camera 2 (WFPC2) from HST by shuttle mission STS-125. A preliminary optical survey confirmed that there were hundreds of impact features on the radiator surface. Following extensive discussion between NASA, ESA, NHM and IBC, a collaborative research program was initiated, employing scanning electron microscopy (SEM) and ion beam analysis (IBA) to determine the nature of the impacting grains. Even though some WFPC2 impact features are large, and easily seen without the use of a microscope, impactor remnants may be hard to find.

  1. ISS-Lobster: a low-cost wide-field X-ray transient detector on the ISS

    NASA Astrophysics Data System (ADS)

    Petre, Robert; Camp, Jordan; Barthelmy, Scott; Gehrels, Neil; Racusin, Judith; Marshall, Frank; Ptak, Andrew

    2015-04-01

    ISS-Lobster is a wide-field X-ray transient detector proposed to be deployed on the International Space Station. Through its unique imaging X-ray optics that allow a 30 deg by 30 deg FoV, a 1 arc min position resolution and a 10-11 erg/(sec cm2) sensitivity in 2000 sec, ISS-Lobster will observe numerous events per year of X-ray transients related to compact objects, including: tidal disruptions of stars, supernova shock breakouts, neutron star bursts and superbursts, high redshift Gamma-Ray Bursts, and perhaps most exciting, X-ray counterparts of gravitational wave detections involving stellar mass and possibly supermassive black holes. The mission includes a 3-axis gimbal system that allows fast Target of Opportunity pointing, and a small gamma-ray burst monitor to be contributed by the Technion (Israel Institute of Technology).

  2. KOALA: a wide-field 1000 element integral-field unit for the Anglo-Australian Telescope

    NASA Astrophysics Data System (ADS)

    Ellis, S. C.; Ireland, M.; Lawrence, J. S.; Tims, J.; Staszak, N.; Brzeski, J.; Parker, Q. A.; Sharp, R.; Bland-Hawthorn, J.; Case, S.; Colless, M.; Croom, S.; Couch, W.; De Marco, O.; Glazebrook, K.; Saunders, W.; Webster, R.; Zucker, D. B.

    2012-09-01

    KOALA, the Kilofibre Optimised Astronomical Lenslet Array, is a wide-field, high efficiency integral field unit being designed for use with the bench mounted AAOmega spectrograph on the AAT. KOALA will have 1000 fibres in a rectangular array with a selectable field of view of either 1390 or 430 sq. arcseconds with a spatial sampling of 1.25" or 0.7" respectively. To achieve this KOALA will use a telecentric double lenslet array with interchangeable fore-optics. The IFU will feed AAOmega via a 31m fibre run. The efficiency of KOALA is expected to be ≍ 52% at 3700A and ≍ 66% at 6563°Å with a throughput of > 52% over the entire wavelength range.

  3. Design and analysis of the tracker bridge for the Hobby-Eberly Telescope wide-field upgrade

    NASA Astrophysics Data System (ADS)

    Worthington, Michael S.; Mollison, Nicholas T.; Soukup, Ian M.; Zierer, Joseph J.; Good, John M.; Nichols, Steven P.

    2010-07-01

    A large structural weldment has been designed to serve as the new star tracker bridge for the Wide Field Upgrade to the Hobby-Eberly Telescope at McDonald Observatory in support of the Hobby-Eberly Telescope Dark Energy Experiment‡. The modeling approach, analysis techniques and design details will be of interest to designers of large structures where stiffness is the primary design driver. The design includes detailed structural analysis using finite element models to maximize natural frequency response and limit deflections and light obscuration. Considerable fabrication challenges are overcome to allow integration of precision hardware required for positioning the corrector optics to a precision of less than 5 microns along the 4-meter travel range. Detailed descriptions of the bridge geometry, analysis results and challenging fabrication issues are discussed.

  4. Mathematical Design Optimization of Wide-Field X-ray Telescopes: Mirror Nodal Positions and Detector Tilts

    NASA Technical Reports Server (NTRS)

    Elsner, Ronald; O'Dell, Stephen; Ramsey, Brian; Weisskopf, Martin

    2011-01-01

    We describe a mathematical formalism for determining the mirror shell nodal positions and detector tilts that optimize the spatial resolution averaged over a field-of-view for a nested x-ray telescope, assuming known mirror segment surface prescriptions and known detector focal surface. The results are expressed in terms of ensemble averages over variable combinations of the ray positions and wavevectors in the flat focal plane intersecting the optical axis at the nominal on-axis focus, which can be determined by Monte-Carlo ray traces of the individual mirror shells. This work is part of our continuing efforts to provide analytical tools to aid in the design process for wide-field survey x-ray astronomy missions.

  5. Mathematical Design Optimization of Wide-Field X-ray Telescopes: Mirror Nodal Positions and Detector Tilts

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

    2011-01-01

    We describe a mathematical formalism for determining the mirror shell nodal positions and detector tilts that optimize the spatial resolution averaged over a field-of-view for a nested x-ray telescope, assuming known mirror segment surface prescriptions and known detector focal surface. The results are expressed in terms of ensemble averages over variable combinations of the ray positions and wave vectors in the flat focal plane intersecting the optical axis at the nominal on-axis focus, which can be determined by Monte-Carlo ray traces of the individual mirror shells. This work is part of our continuing efforts to provide analytical tools to aid in the design process for wide-field survey x-ray astronomy missions.

  6. A low-cost and versatile system for projecting wide-field visual stimuli within fMRI scanners.

    PubMed

    Greco, V; Frijia, F; Mikellidou, K; Montanaro, D; Farini, A; D'Uva, M; Poggi, P; Pucci, M; Sordini, A; Morrone, M C; Burr, D C

    2016-06-01

    We have constructed and tested a custom-made magnetic-imaging-compatible visual projection system designed to project on a very wide visual field (~80°). A standard projector was modified with a coupling lens, projecting images into the termination of an image fiber. The other termination of the fiber was placed in the 3-T scanner room with a projection lens, which projected the images relayed by the fiber onto a screen over the head coil, viewed by a participant wearing magnifying goggles. To validate the system, wide-field stimuli were presented in order to identify retinotopic visual areas. The results showed that this low-cost and versatile optical system may be a valuable tool to map visual areas in the brain that process peripheral receptive fields. PMID:26092392

  7. Preliminary results on the various U.V. straylight sources for the VWFC onboard SL 1. [Very Wide Field Camera

    NASA Technical Reports Server (NTRS)

    Viton, M.; Courtes, G.; Sivan, J. P.; Decher, R.; Gary, A.

    1985-01-01

    Technical difficulties encountered using the Very Wide Field Camera (VWFC) during the Spacelab 1 Shuttle mission are reported. The VWFC is a wide low resolution (5 arcmin half-half width) photographic camera, capable of operating in both spectrometric and photometric modes. The bandpasses of the photometric mode of the VWFC are defined by three Al + MgF2 interference filters. A piggy-back spectrograph attached to the VWFC was used for observations in the spectrometric mode. A total of 48 astronomical frames were obtained using the VWFC, of which only 20 were considered to be of adequate quality for astronomical data processing. Preliminary analysis of the 28 poor-quality images revealed the following possible defects in the VWFC: darkness in the spacing frames, twilight/dawn UV straylight, and internal UV straylight. Improvements in the VWFC astronomical data processing scheme are expected to help identify and eliminate UV straylight sources in the future.

  8. Advanced multilayer optical data storage: origins and future prospect

    NASA Astrophysics Data System (ADS)

    Esener, Sadik

    2008-02-01

    Fifty years have elapsed since the first concepts in volumetric memories have been put forward. Nowadays, the perceived need for low cost removable TB/disk storage systems is one more time fueling the development of 3D media, recording and readout systems. This paper, by reviewing some of the key historic moments and accomplishments in the development of volumetric recording systems attempts to shine light on possible future developments and directions while paying a tribute to many of the researchers that have contributed to the development of this field: in particular to Dr. Hans J. Coufal who for many years has provided vision, guidance, and leadership by leading recent INSIC Technology Roadmap efforts and organizing this conference. He is and will be greatly missed at a time when our common dreams may become a commercial reality.

  9. Center for Applied Optics Studies: an investment in Indiana's future

    NASA Astrophysics Data System (ADS)

    Schuh, Delbert J., II; Khorana, Brij M.

    1992-05-01

    To understand the involvement of the State of Indiana with the Center for Applied Optics at Rose-Hulman Institute of Technology, it is best to start with an explanation of the Indiana Corporation for Science and Technology (CST), its basic charter and its programs. Established in 1982 as a private not-for-profit corporation, CST was formed to promote economic development within the State of Indiana. Two programs that were initially a part of CST's charter and supported with state dollars were a seed capital investment program, aimed at developing new products and processes, and the establishment of university centers of technology development. The former was conceived to create jobs and new, technologically advanced industries in Indiana. The latter was an attempt to encourage technology transfer from the research laboratories of the state universities to the production lines of Indiana industry. Recently, CST has undergone a name change to the Indiana Business Modernization and Technology Corporation (BMT) and adopted an added responsibility of proactive assistance to small- and medium-sized businesses in order to enhance the state's industrial competitiveness.

  10. Effects of spatial and spectral frequencies on wide-field functional imaging (wifi) characterization of preclinical breast cancer models

    NASA Astrophysics Data System (ADS)

    Moy, Austin; Kim, Jae G.; Lee, Eva Y. H. P.; Choi, Bernard

    2010-02-01

    A common strategy to study breast cancer is the use of the preclinical model. These models provide a physiologically relevant and controlled environment in which to study both response to novel treatments and the biology of the cancer. Preclinical models, including the spontaneous tumor model and mammary window chamber model, are very amenable to optical imaging and to this end, we have developed a wide-field functional imaging (WiFI) instrument that is perfectly suited to studying tumor metabolism in preclinical models. WiFI combines two optical imaging modalities, spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI). Our current WiFI imaging protocol consists of multispectral imaging in the near infrared (650-980 nm) spectrum, over a wide (7 cm x 5 cm) field of view. Using SFDI, the spatially-resolved reflectance of sinusoidal patterns projected onto the tissue is assessed, and optical properties of the tissue are determined, which are then used to extract tissue chromophore concentrations in the form of oxy-, deoxy-, and total hemoglobin concentrations, and percentage of lipid and water. In the current study, we employ Monte Carlo simulations of SFDI light propagation in order to characterize the penetration depth of light in both the spontaneous tumor model and mammary window chamber model. Preliminary results suggest that different spatial frequency and wavelength combinations have different penetration depths, suggesting the potential depth sectioning capability of the SFDI component of WiFI.

  11. Probing other solar systems with current and future adaptive optics

    SciTech Connect

    Macintosh, B; Marois, C; Phillion, D; Poyneer, L; Graham, J; Zuckerman, B; Gavel, D; Veran, J; Wilhelmsen-Evans, J; Mellis, C

    2008-09-08

    Over the past decade, the study of extrasolar planets through indirect techniques--primarily Doppler measurements--has revolutionized our understanding of other solar systems. The next major step in this field will be the direct detection and characterization, via imaging and spectroscopy, of the planets themselves. To achieve this, we must separate the light from the faint planet from the extensive glare of its parent star. We pursued this goal using the current generation of adaptive optics (AO) systems on large ground-based telescopes, using infrared imaging to search for the thermal emission from young planets and developing image processing techniques to distinguish planets from telescope-induced artifacts. Our new Angular Differential Imaging (ADI) technique, which uses the sidereal rotation of the Earth and telescope, is now standard for ground-based high-contrast imaging. Although no young planets were found in our surveys, we placed the strongest limits yet on giant planets in wide orbits (>30 AU) around young stars and characterized planetary companion candidates. The imaging of planetary companions on solar-system-like scales (5-30 AU) will require a new generation of advanced AO systems that are an order of magnitude more powerful than the LLNL-built Keck AO system. We worked to develop and test the key technologies needed for these systems, including a spatially-filtered wavefront sensor, efficient and accurate wavefront reconstruction algorithms, and precision AO wavefront control at the sub-nm level. LLNL has now been selected by the Gemini Observatory to lead the construction of the Gemini Planet Imager, a $24M instrument that will be the most advanced AO system in the world.

  12. Negative optical inertia for enhancing the sensitivity of future gravitational-wave detectors

    SciTech Connect

    Khalili, Farid; Danilishin, Stefan; Mueller-Ebhardt, Helge; Miao Haixing; Zhao Chunnong; Chen Yanbei

    2011-03-15

    We consider enhancing the sensitivity of future gravitational-wave detectors by using double optical spring. When the power, detuning and bandwidth of the two carriers are chosen appropriately, the effect of the double optical spring can be described as a 'negative inertia', which cancels the positive inertia of the test masses and thus increases their response to gravitational waves. This allows us to surpass the free-mass standard quantum limit (SQL) over a broad frequency band, through signal amplification, rather than noise cancellation, which has been the case for all broadband SQL-beating schemes so far considered for gravitational-wave detectors. The merit of such signal amplification schemes lies in the fact that they are less susceptible to optical losses than noise-cancellation schemes. We show that it is feasible to demonstrate such an effect with the Gingin High Optical Power Test Facility, and it can eventually be implemented in future advanced GW detectors.

  13. Simultaneous multicolor imaging of wide-field epi-fluorescence microscopy with four-bucket detection

    PubMed Central

    Park, Kwan Seob; Kim, Dong Uk; Lee, Jooran; Kim, Geon Hee; Chang, Ki Soo

    2016-01-01

    We demonstrate simultaneous imaging of multiple fluorophores using wide-field epi-fluorescence microscopy with a monochrome camera. The intensities of the three lasers are modulated by a sinusoidal waveform in order to excite each fluorophore with the same modulation frequency and a different time-delay. Then, the modulated fluorescence emissions are simultaneously detected by a camera operating at four times the excitation frequency. We show that two different fluorescence beads having crosstalk can be clearly separated using digital processing based on the phase information. In addition, multiple organelles within multi-stained single cells are shown with the phase mapping method, demonstrating an improved dynamic range and contrast compared to the conventional fluorescence image. These findings suggest that wide-field epi-fluorescence microscopy with four-bucket detection could be utilized for high-contrast multicolor imaging applications such as drug delivery and fluorescence in situ hybridization. PMID:27375944

  14. Wide field-of-view soft X-ray imaging for solar wind-magnetosphere interactions

    NASA Astrophysics Data System (ADS)

    Walsh, B. M.; Collier, M. R.; Kuntz, K. D.; Porter, F. S.; Sibeck, D. G.; Snowden, S. L.; Carter, J. A.; Collado-Vega, Y.; Connor, H. K.; Cravens, T. E.; Read, A. M.; Sembay, S.; Thomas, N. E.

    2016-04-01

    Soft X-ray imagers can be used to study the mesoscale and macroscale density structures that occur whenever and wherever the solar wind encounters neutral atoms at comets, the Moon, and both magnetized and unmagnetized planets. Charge exchange between high charge state solar wind ions and exospheric neutrals results in the isotropic emission of soft X-ray photons with energies from 0.1 to 2.0 keV. At Earth, this process occurs primarily within the magnetosheath and cusps. Through providing a global view, wide field-of-view imaging can determine the significance of the various proposed solar wind-magnetosphere interaction mechanisms by evaluating their global extent and occurrence patterns. A summary of wide field-of-view (several to tens of degrees) soft X-ray imaging is provided including slumped micropore microchannel reflectors, simulated images, and recent flight results.

  15. Whole-cell-analysis of live cardiomyocytes using wide-field interferometric phase microscopy

    PubMed Central

    Shaked, Natan T.; Satterwhite, Lisa L.; Bursac, Nenad; Wax, Adam

    2010-01-01

    We apply wide-field interferometric microscopy techniques to acquire quantitative phase profiles of ventricular cardiomyocytes in vitro during their rapid contraction with high temporal and spatial resolution. The whole-cell phase profiles are analyzed to yield valuable quantitative parameters characterizing the cell dynamics, without the need to decouple thickness from refractive index differences. Our experimental results verify that these new parameters can be used with wide field interferometric microscopy to discriminate the modulation of cardiomyocyte contraction dynamics due to temperature variation. To demonstrate the necessity of the proposed numerical analysis for cardiomyocytes, we present confocal dual-fluorescence-channel microscopy results which show that the rapid motion of the cell organelles during contraction preclude assuming a homogenous refractive index over the entire cell contents, or using multiple-exposure or scanning microscopy. PMID:21258502

  16. Wide Field Infra-Red Survey Telescope (WFIRST) 2.4-Meter Mission Study

    NASA Technical Reports Server (NTRS)

    Content, D.; Aaron, K.; Alplanalp, L.; Anderson, K.; Capps, R.; Chang, Z.; Dooley, J.; Egerman, R.; Goullioud, R.; Klein, D.; Kruk, J.; Kuan, G.; Melton, M.; Ruffa, J.; Underhill, M.; Buren, D. Van

    2013-01-01

    The most recent study of the Wide Field Infrared Survey Telescope (WFIRST) mission is based on reuse of an existing 2.4m telescope. This study was commissioned by NASA to examine the potential science return and cost effectiveness of WFIRST by using this significantly larger aperture telescope. We review the science program envisioned by the WFIRST 2012-2013 Science Definition Team (SDT), an overview of the mission concept, and the telescope design and status. Comparisons against the previous 1.3m and reduced cost 1.1m WFIRST design concepts are discussed. A significant departure from past point designs is the option for serviceability and the geostationary orbit location which enables servicing and replacement instrument insertion later during mission life. Other papers at this conference provide more in depth discussion of the wide field instrument and the optional exoplanet imaging coronagraph instrument.

  17. Simultaneous multicolor imaging of wide-field epi-fluorescence microscopy with four-bucket detection.

    PubMed

    Park, Kwan Seob; Kim, Dong Uk; Lee, Jooran; Kim, Geon Hee; Chang, Ki Soo

    2016-06-01

    We demonstrate simultaneous imaging of multiple fluorophores using wide-field epi-fluorescence microscopy with a monochrome camera. The intensities of the three lasers are modulated by a sinusoidal waveform in order to excite each fluorophore with the same modulation frequency and a different time-delay. Then, the modulated fluorescence emissions are simultaneously detected by a camera operating at four times the excitation frequency. We show that two different fluorescence beads having crosstalk can be clearly separated using digital processing based on the phase information. In addition, multiple organelles within multi-stained single cells are shown with the phase mapping method, demonstrating an improved dynamic range and contrast compared to the conventional fluorescence image. These findings suggest that wide-field epi-fluorescence microscopy with four-bucket detection could be utilized for high-contrast multicolor imaging applications such as drug delivery and fluorescence in situ hybridization. PMID:27375944

  18. Segmented X-Ray Optics for Future Space Telescopes

    NASA Technical Reports Server (NTRS)

    McClelland, Ryan S.

    2013-01-01

    Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of approx.17 sq cm/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

  19. An EUV Wide-Field Imager and Spectrometer for the ISS

    NASA Technical Reports Server (NTRS)

    Golub, Leon; Savage, Sabrina

    2016-01-01

    The Coronal Spectrographic Imager in the EUV, COSIE, combines a wide-field solar coronal EUV imager (EUVC) and an on-disk EUV imaging spectrometer (EUVS). Located on the International Space Station (ISS), the goal of the mission is to enhance our understanding of the dynamics of the Transition Corona (the region in which the coronal magnetic field transitions from closed to open), and to provide improved detection and tracking of solar eruptive events for space weather research.

  20. Hubble Space Telescope: Wide field and planetary camera instrument handbook. Version 2.1

    NASA Technical Reports Server (NTRS)

    Griffiths, Richard (Editor)

    1990-01-01

    An overview is presented of the development and construction of the Wide Field and Planetary Camera (WF/PC). The WF/PC is a duel two dimensional spectrophotometer with rudimentary polarimetric and transmission grating capabilities. The instrument operates from 1150 to 11000 A with a resolution of 0.1 arcsec per pixel or 0.043 arcsec per pixel. Data products and standard calibration methods are briefly summarized.

  1. Sensors for the Hubble Space Telescope wide field and planetary cameras (1 and 2)

    NASA Technical Reports Server (NTRS)

    Trauger, John T.

    1990-01-01

    The technology of the wide field planetary camera (WFPC-2) CCD technology is examined with reference to the WFPC-1 experience. Strategies are presented for elimination of quantum efficiency (QE) hysteresis and implementation of maintenance-free QE stability, improved far-UV performance, on-orbit photometric calibrations, refinements in CCD electronics, and anticipated CCD particle radiation effects. Absorption depth vs. wavelength in silicon and a cross section of the CCD membrane are shown.

  2. Wide Field Infrared Survey Telescope [WFIRST]: Telescope Design and Simulated Performance

    NASA Technical Reports Server (NTRS)

    Goullioud, R.; Content, D. A.; Kuan, G. M.; Moore, J. D.; Chang, Z.; Sunada, E. T.; Villalvazo, J.; Hawk, J. P.; Armani, N. V.; Johnson, E. L.; Powell, C. A.

    2012-01-01

    The ASTRO2010 Decadal Survey proposed multiple missions with NIR focal planes and 3 mirror wide field telescopes in the 1.5m aperture range. None of them would have won as standalone missions WFIRST is a combination of these missions, created by Astro 2010 committee. WFIRST Science Definition Team (SDT) tasked to examine the design. Project team is a GSFC-JPL-Caltech collaboration. This interim mission design is a result of combined work by the project team with the SDT.

  3. Using APART for wall visibility calculations in the calibration channel of wide field planetary camera II

    NASA Technical Reports Server (NTRS)

    Scholl, James W.; Scholl, Marija S.

    1993-01-01

    The cone visibility from the CCD detector array plane in the calibration channel of wide field planetary camera II (WFPC II) is analyzed, using APART, for three representative wavelengths as characterized by indices of refraction. The light pipe walls are visible from the corners of the equivalent CCD detector array when imaging with the smallest index of refraction, n = 1.375. Painting the inside of the light pipe walls will result in a decrease in their visibility.

  4. Applications of lobster eye optics

    NASA Astrophysics Data System (ADS)

    Hudec, R.; Pina, L.; Inneman, A.; Tichy, V.

    2015-05-01

    Applications of wide field Lobster Eye X ray telescopes are presented and discussed. The wide field X ray optics was originally proposed for use in X-ray astronomy, but there are numerous other application areas as well.

  5. Intra-familial Similarity of Wide-Field Fundus Autofluorescence in Inherited Retinal Dystrophy.

    PubMed

    Furutani, Yuka; Ogino, Ken; Oishi, Akio; Gotoh, Norimoto; Makiyama, Yukiko; Oishi, Maho; Kurimoto, Masafumi; Yoshimura, Nagahisa

    2016-01-01

    To examine the similarity of wide-field fundus autofluorescence (FAF) imaging in inherited retinal dystrophy between siblings and between parents and their children. The subjects included 17 siblings (12 with retinitis pigmentosa and 5 with cone rod dystrophy) and 10 parent-child pairs (8 with retinitis pigmentosa and 2 with cone rod dystrophy). We quantified the similarity of wide-field FAF using image processing techniques of cropping, binarization, superimposition, and subtraction. The estimated similarity of the siblings was compared with that of the parent-child pairs and that of the age-matched unrelated patients. The similarity between siblings was significantly higher that of parent-child pairs or that of age-matched unrelated patients (P = 0.004 and P = 0.049, respectively). Wide-field FAF images were similar between siblings with inherited retinal dystrophy but different between parent-child pairs. This suggests that aging is a confounding factor in genotype-phenotype correlation studies. PMID:26427425

  6. Wide-field four-channel fluorescence imager for biological applications

    NASA Astrophysics Data System (ADS)

    Thakur, Madhuri; Melnik, Dmitry; Barnett, Heather; Daly, Kevin; Moran, Christine H.; Chang, Wei-Shun; Link, Stephan; Bucher, Christopher Theodore; Kittrell, Carter; Curl, Robert

    2010-03-01

    A wide-field four-channel fluorescence imager has been developed. The instrument uses four expanded laser beams to image a large section (6 mm×9 mm). An object can be sequentially illuminated with any combination of 408-, 532-, 658-, and 784-nm lasers for arbitrary (down to 1 ms) exposure times for each laser. Just two notch filters block scattered light from all four lasers. The design approach described here offers great flexibility in treatment of objects, very good sensitivity, and a wide field of view at low cost. There appears to be no commercial instrument capable of simultaneous fluorescence imaging of a wide field of view with four-laser excitation. Some possible applications are following events such as flow and mixing in microchannel systems, the transmission of biological signals across a culture, and following simulations of biological membrane diffusion. It can also be used in DNA sequencing by synthesis to follow the progress of the photolytic removal of dye and terminator. Without utilizing its time resolution, it can be used to obtain four independent images of a single tissue section stained with four targeting agents, with each coupled to a different dye matching one of the lasers.

  7. Optical Tweezers and Optical Trapping Improved for Future Automated Micromanipulation and Characterization

    NASA Technical Reports Server (NTRS)

    Wrbanek, Susan Y.; Decker, Arthur J.

    2005-01-01

    Optical trap arrays are being developed at the NASA Glenn Research Center for holding, manipulating, and optically interrogating arrays of nanotube sensors. The trap arrays, for example, might be used to arrange arrays of chemical sensors for insertion onto a chip in liquid, air, and vacuum environments. Neural-network-controlled spatial light modulators (SLMs) are to generate and control the trap positions and trap profiles in three dimensions.

  8. Analysis of active alignment control of the Hobby-Eberly Telescope wide-field corrector using Shack-Hartmann wavefront sensors

    NASA Astrophysics Data System (ADS)

    Lee, Hanshin; Hart, Michael; Hill, Gary J.; Rafal, M. D.

    2010-07-01

    One of the key aspects of the Wide-Field Upgrade (WFU) for the 10m Hobby-Eberly Telescope (HET) is the use of wavefront sensing (WFS) to close the loop of active alignment control of the new four-mirror Wide-Field Corrector (WFC), as it tracks sidereal motion, with respect to the fixed spherical segmented primary mirror. This makes the telescope pupil dynamically change in shape. This is a unique challenge to the WFS on the HET, in addition to various influences of seeing, primary mirror segment errors, and dynamic deflection of the internal optical components of the WFC. We conducted extensive simulations to understand the robustness of the WFS in the face of these errors and the results of these analyses are discussed in this paper.

  9. Utilization of a Curved Focal Surface Array in a 3.5m Wide Field of View Telescope

    NASA Astrophysics Data System (ADS)

    Blake, T.; Faccenda, W.; Lambour, R.; Shah, R.; Smith, A.; Gregory, J. G.; Pearce, E. C.; Woods, D.; Sundbeck, S.; Bolden, M.

    2013-09-01

    Wide field of view optical telescopes have a range for uses in both the astronomical and space surveillance purposes. In designing these systems, a number of factors must be taken into account and design trades accomplished to best balance the performance and cost of the system to meet various program constraints. One design trade that has been discussed of the past decade is the curving of the digital focal surface array to meet the field curvature versus the utilization of optical elements to flatten the field curvature for a more traditional focal plane array. For the Defense Advanced Research Projects Agency (DARPA) 3.5m Space Surveillance Telescope (SST) the choice was made to curve the array to best satisfy the stressing telescope performance parameters, along with programmatic challenges. The results of this design choice led to a system that meets all of the initial program goals and stands ready to dramatically improve the nation's space surveillance capabilities. This paper will discuss the implementation of the curved focal surface array, the performance achieved by the array and the delta cost difference in the curved array versus a typical flat array.

  10. Wide-field imaging of birefringent synovial fluid crystals using lens-free polarized microscopy for gout diagnosis

    PubMed Central

    Zhang, Yibo; Lee, Seung Yoon Celine; Zhang, Yun; Furst, Daniel; Fitzgerald, John; Ozcan, Aydogan

    2016-01-01

    Gout is a form of crystal arthropathy where monosodium urate (MSU) crystals deposit and elicit inflammation in a joint. Diagnosis of gout relies on identification of MSU crystals under a compensated polarized light microscope (CPLM) in synovial fluid aspirated from the patient’s joint. The detection of MSU crystals by optical microscopy is enhanced by their birefringent properties. However, CPLM partially suffers from the high-cost and bulkiness of conventional lens-based microscopy, and its relatively small field-of-view (FOV) limits the efficiency and accuracy of gout diagnosis. Here we present a lens-free polarized microscope which adopts a novel differential and angle-mismatched polarizing optical design achieving wide-field and high-resolution holographic imaging of birefringent objects with a color contrast similar to that of a standard CPLM. The performance of this computational polarization microscope is validated by imaging MSU crystals made from a gout patient’s tophus and steroid crystals used as negative control. This lens-free polarized microscope, with its wide FOV (>20 mm2), cost-effectiveness and field-portability, can significantly improve the efficiency and accuracy of gout diagnosis, reduce costs, and can be deployed even at the point-of-care and in resource-limited clinical settings. PMID:27356625

  11. Wide-field imaging of birefringent synovial fluid crystals using lens-free polarized microscopy for gout diagnosis

    NASA Astrophysics Data System (ADS)

    Zhang, Yibo; Lee, Seung Yoon Celine; Zhang, Yun; Furst, Daniel; Fitzgerald, John; Ozcan, Aydogan

    2016-06-01

    Gout is a form of crystal arthropathy where monosodium urate (MSU) crystals deposit and elicit inflammation in a joint. Diagnosis of gout relies on identification of MSU crystals under a compensated polarized light microscope (CPLM) in synovial fluid aspirated from the patient’s joint. The detection of MSU crystals by optical microscopy is enhanced by their birefringent properties. However, CPLM partially suffers from the high-cost and bulkiness of conventional lens-based microscopy, and its relatively small field-of-view (FOV) limits the efficiency and accuracy of gout diagnosis. Here we present a lens-free polarized microscope which adopts a novel differential and angle-mismatched polarizing optical design achieving wide-field and high-resolution holographic imaging of birefringent objects with a color contrast similar to that of a standard CPLM. The performance of this computational polarization microscope is validated by imaging MSU crystals made from a gout patient’s tophus and steroid crystals used as negative control. This lens-free polarized microscope, with its wide FOV (>20 mm2), cost-effectiveness and field-portability, can significantly improve the efficiency and accuracy of gout diagnosis, reduce costs, and can be deployed even at the point-of-care and in resource-limited clinical settings.

  12. Wide-field imaging of birefringent synovial fluid crystals using lens-free polarized microscopy for gout diagnosis.

    PubMed

    Zhang, Yibo; Lee, Seung Yoon Celine; Zhang, Yun; Furst, Daniel; Fitzgerald, John; Ozcan, Aydogan

    2016-01-01

    Gout is a form of crystal arthropathy where monosodium urate (MSU) crystals deposit and elicit inflammation in a joint. Diagnosis of gout relies on identification of MSU crystals under a compensated polarized light microscope (CPLM) in synovial fluid aspirated from the patient's joint. The detection of MSU crystals by optical microscopy is enhanced by their birefringent properties. However, CPLM partially suffers from the high-cost and bulkiness of conventional lens-based microscopy, and its relatively small field-of-view (FOV) limits the efficiency and accuracy of gout diagnosis. Here we present a lens-free polarized microscope which adopts a novel differential and angle-mismatched polarizing optical design achieving wide-field and high-resolution holographic imaging of birefringent objects with a color contrast similar to that of a standard CPLM. The performance of this computational polarization microscope is validated by imaging MSU crystals made from a gout patient's tophus and steroid crystals used as negative control. This lens-free polarized microscope, with its wide FOV (>20 mm(2)), cost-effectiveness and field-portability, can significantly improve the efficiency and accuracy of gout diagnosis, reduce costs, and can be deployed even at the point-of-care and in resource-limited clinical settings. PMID:27356625

  13. CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope

    NASA Astrophysics Data System (ADS)

    Harding, L. K.; Hallinan, G.; Milburn, J.; Gardner, P.; Konidaris, N.; Singh, N.; Shao, M.; Sandhu, J.; Kyne, G.; Schlichting, H. E.

    2016-04-01

    The Caltech HIgh-speed Multi-colour camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of the Hale 200-inch telescope. Simultaneous optical imaging in two bands is enabled by a dichroic beam splitter centred at 567 nm, with Sloan u' and g' bands available on the blue arm and Sloan r', i' and z_s bands available on the red arm. Additional narrow-band filters will also become available as required. An electron multiplying CCD (EMCCD) detector is employed for both optical channels, each capable of simultaneously delivering sub-electron effective read noise under multiplication gain and frame rates of up to 26 fps full frame (several 1000 fps windowed), over a fully corrected 5 × 5 arcmin field of view. CHIMERA was primarily developed to enable the characterization of the size distribution of sub-km Kuiper Belt Objects via stellar occultation, a science case that motivates the frame-rate, the simultaneous multi-colour imaging and the wide field of view of the instrument. In addition, it also has unique capability in the detection of faint near-Earth asteroids and will be used for the monitoring of short-duration transient and periodic sources, particularly those discovered by the intermediate Palomar Transient Factory (iPTF), and the upcoming Zwicky Transient Facility (ZTF).

  14. An integrative approach for analyzing hundreds of neurons in task performing mice using wide-field calcium imaging

    PubMed Central

    Mohammed, Ali I.; Gritton, Howard J.; Tseng, Hua-an; Bucklin, Mark E.; Yao, Zhaojie; Han, Xue

    2016-01-01

    Advances in neurotechnology have been integral to the investigation of neural circuit function in systems neuroscience. Recent improvements in high performance fluorescent sensors and scientific CMOS cameras enables optical imaging of neural networks at a much larger scale. While exciting technical advances demonstrate the potential of this technique, further improvement in data acquisition and analysis, especially those that allow effective processing of increasingly larger datasets, would greatly promote the application of optical imaging in systems neuroscience. Here we demonstrate the ability of wide-field imaging to capture the concurrent dynamic activity from hundreds to thousands of neurons over millimeters of brain tissue in behaving mice. This system allows the visualization of morphological details at a higher spatial resolution than has been previously achieved using similar functional imaging modalities. To analyze the expansive data sets, we developed software to facilitate rapid downstream data processing. Using this system, we show that a large fraction of anatomically distinct hippocampal neurons respond to discrete environmental stimuli associated with classical conditioning, and that the observed temporal dynamics of transient calcium signals are sufficient for exploring certain spatiotemporal features of large neural networks. PMID:26854041

  15. History of optical theory of reflecting telescopes and implications for future projects

    NASA Astrophysics Data System (ADS)

    Wilson, Raymond N.

    1997-03-01

    This contribution, The History of Optical Theory of Reflecting Telescopes and Implications for Future Projects, is a shortened form of the Karl Schwarzschild lecture given in Bochum in September 1993. Some material has been added from an invited paper given in Padua in December 1992. For a full account, with figures and tables, the reader is referred to these two papers.

  16. A PANCHROMATIC CATALOG OF EARLY-TYPE GALAXIES AT INTERMEDIATE REDSHIFT IN THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 EARLY RELEASE SCIENCE FIELD

    SciTech Connect

    Rutkowski, M. J.; Cohen, S. H.; Windhorst, R. A.; Kaviraj, S.; Crockett, R. M.; Silk, J.; O'Connell, R. W.; Hathi, N. P.; McCarthy, P. J.; Ryan, R. E. Jr.; Koekemoer, A.; Bond, H. E.; Yan, H.; Kimble, R. A.; Balick, B.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, J. A.; Hall, D. N. B.; and others

    2012-03-01

    In the first of a series of forthcoming publications, we present a panchromatic catalog of 102 visually selected early-type galaxies (ETGs) from observations in the Early Release Science (ERS) program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) of the Great Observatories Origins Deep Survey-South (GOODS-S) field. Our ETGs span a large redshift range, 0.35 {approx}< z {approx}< 1.5, with each redshift spectroscopically confirmed by previous published surveys of the ERS field. We combine our measured WFC3 ERS and Advanced Camera for Surveys (ACS) GOODS-S photometry to gain continuous sensitivity from the rest-frame far-UV to near-IR emission for each ETG. The superior spatial resolution of the HST over this panchromatic baseline allows us to classify the ETGs by their small-scale internal structures, as well as their local environment. By fitting stellar population spectral templates to the broadband photometry of the ETGs, we determine that the average masses of the ETGs are comparable to the characteristic stellar mass of massive galaxies, 10{sup 11} < M{sub *}[M{sub Sun }]<10{sup 12}. By transforming the observed photometry into the Galaxy Evolution Explorer FUV and NUV, Johnson V, and Sloan Digital Sky Survey g' and r' bandpasses we identify a noteworthy diversity in the rest-frame UV-optical colors and find the mean rest-frame (FUV-V) = 3.5 and (NUV-V) = 3.3, with 1{sigma} standard deviations {approx_equal}1.0. The blue rest-frame UV-optical colors observed for most of the ETGs are evidence for star formation during the preceding gigayear, but no systems exhibit UV-optical photometry consistent with major recent ({approx}<50 Myr) starbursts. Future publications which address the diversity of stellar populations likely to be present in these ETGs, and the potential mechanisms by which recent star formation episodes are activated, are discussed.

  17. Calibration of Wide-Field Deconvolution Microscopy for Quantitative Fluorescence Imaging

    PubMed Central

    Lee, Ji-Sook; Wee, Tse-Luen (Erika); Brown, Claire M.

    2014-01-01

    Deconvolution enhances contrast in fluorescence microscopy images, especially in low-contrast, high-background wide-field microscope images, improving characterization of features within the sample. Deconvolution can also be combined with other imaging modalities, such as confocal microscopy, and most software programs seek to improve resolution as well as contrast. Quantitative image analyses require instrument calibration and with deconvolution, necessitate that this process itself preserves the relative quantitative relationships between fluorescence intensities. To ensure that the quantitative nature of the data remains unaltered, deconvolution algorithms need to be tested thoroughly. This study investigated whether the deconvolution algorithms in AutoQuant X3 preserve relative quantitative intensity data. InSpeck Green calibration microspheres were prepared for imaging, z-stacks were collected using a wide-field microscope, and the images were deconvolved using the iterative deconvolution algorithms with default settings. Afterwards, the mean intensities and volumes of microspheres in the original and the deconvolved images were measured. Deconvolved data sets showed higher average microsphere intensities and smaller volumes than the original wide-field data sets. In original and deconvolved data sets, intensity means showed linear relationships with the relative microsphere intensities given by the manufacturer. Importantly, upon normalization, the trend lines were found to have similar slopes. In original and deconvolved images, the volumes of the microspheres were quite uniform for all relative microsphere intensities. We were able to show that AutoQuant X3 deconvolution software data are quantitative. In general, the protocol presented can be used to calibrate any fluorescence microscope or image processing and analysis procedure. PMID:24688321

  18. Micrometeoroid Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Larger Particles

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Grime, G. W.; Webb, R. P.; Jeynes, C.; Palitsin, V.; Colaux, J. L.; Ross, D. K.; Anz-Meador, P.; Liou, J. C.; Opiela, J.; Griffin, G. T.; Gerlach, L.; Wozniakiewicz, P. J.; Price, M. C.; Burchell, M. J.; Cole, M. J.

    2014-01-01

    The Wide Field and Planetary Camera 2 (WFPC2) was returned from the Hubble Space Telescope (HST) by shuttle mission STS-125 in 2009. In space for 16 years, the surface accumulated hundreds of impact features on the zinc orthotitanate paint, some penetrating through into underlying metal. Larger impacts were seen in photographs taken from within the shuttle orbiter during service missions, with spallation of paint in areas reaching 1.6 cm across, exposing alloy beneath. Here we describe larger impact shapes, the analysis of impactor composition, and the micrometeoroid (MM) types responsible.

  19. Far ultraviolet wide field imaging with a SPARTAN /Experiment of Opportunity/ Payload

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.; Heckathorn, H. M.; Opal, C. B.

    1982-01-01

    A wide-field electrographic Schmidt camera, sensitive in the far UV (1230-2000 A), has been developed and utilized in three sounding rocket flights. It is now being prepared for Shuttle flight as an Experiment of Opportunity Payload (EOP) (recently renamed as the SPARTAN program). In this paper, we discuss (1) design of the instrument and payload, particularly as influenced by our experience in rocket flights; (2) special problems of EOP in comparison to sounding rocket missions; (3) relationship of this experiment to, and special capabilities in comparison to, other space astronomy instruments such as Space Telescope; and (4) a tentative observing plan for an EOP mission.

  20. Far ultraviolet wide field imaging and photometry - Spartan-202 Mark II Far Ultraviolet Camera

    NASA Technical Reports Server (NTRS)

    Carruthers, George R.; Heckathorn, Harry M.; Opal, Chet B.; Witt, Adolf N.; Henize, Karl G.

    1988-01-01

    The U.S. Naval Research Laboratory' Mark II Far Ultraviolet Camera, which is expected to be a primary scientific instrument aboard the Spartan-202 Space Shuttle mission, is described. This camera is intended to obtain FUV wide-field imagery of stars and extended celestial objects, including diffuse nebulae and nearby galaxies. The observations will support the HST by providing FUV photometry of calibration objects. The Mark II camera is an electrographic Schmidt camera with an aperture of 15 cm, a focal length of 30.5 cm, and sensitivity in the 1230-1600 A wavelength range.

  1. Estimating the Supernova Cosmological Constraints Possible With the Wide-Field Infrared Survey Telescope

    NASA Astrophysics Data System (ADS)

    Currie, Miles; Rubin, David; Aldering, Greg Scott; Baltay, Charles; Fagrelius, Parker; Law, David R.; Perlmutter, Saul; Pontoppidan, Klaus

    2016-01-01

    The proposed Wide-Field Infrared Survey Telescope (WFIRST) supernova survey will measure precision distances continuously in redshift to 1.7 with excellent systematics control. However, the Science Definition Team report presented a idealized version of the survey, and we now work to add realism. Using SNe from HST programs, we investigate the expected contamination from the host-galaxy light to estimate required exposure times. We also present estimates of purity and completeness, generated by degrading well-measured nearby SN spectra to WFIRST resolution and signal-to-noise. We conclude with a more accurate prediction of the cosmological constraints possible with WFIRST SNe.

  2. Wide-field in vivo background free imaging by selective magnetic modulation of nanodiamond fluorescence

    PubMed Central

    Sarkar, Susanta K.; Bumb, Ambika; Wu, Xufeng; Sochacki, Kem A.; Kellman, Peter; Brechbiel, Martin W.; Neuman, Keir C.

    2014-01-01

    The sensitivity and resolution of fluorescence-based imaging in vivo is often limited by autofluorescence and other background noise. To overcome these limitations, we have developed a wide-field background-free imaging technique based on magnetic modulation of fluorescent nanodiamond emission. Fluorescent nanodiamonds are bright, photo-stable, biocompatible nanoparticles that are promising probes for a wide range of in vitro and in vivo imaging applications. Our readily applied background-free imaging technique improves the signal-to-background ratio for in vivo imaging up to 100-fold. This technique has the potential to significantly improve and extend fluorescent nanodiamond imaging capabilities on diverse fluorescence imaging platforms. PMID:24761300

  3. The First Hundred Brown Dwarfs Discovered by the Wide-Field Infrared Survey Explorer (WISE)

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, J. Davy; Cushing, Michael C.; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Mainzer, Amanda K.; Eisenhardt, Peter R.; McLean, Ian S.; Bauer, James M.; Benford, Dominic J.; Lake, Sean E.; Petty, Sara M.; Tsai, Chao-Wei; Beichman, Charles; Stapelfeldt, Karl R.; Stern, Daniel; Vacca, William D.

    2011-01-01

    We present ground-based spectroscopic verification of six Y dwarfs also Cushing et al.), eighty-nine T dwarfs, eight L dwarfs, and one M dwarf identified by the Wide-field Infrared Survey Explorer (WISE). Eighty of these are cold brown dwarfs with spectral types > or =T6, six of which have been announced earlier in Mainzer et al. and I3urgasser et al. We present color-color and colortype diagrams showing the locus of M, L, T, and Y dwarfs in WISE color space. "

  4. On the Design of Wide-Field X-ray Telescopes

    NASA Technical Reports Server (NTRS)

    Elsner, Ronald F.; O'Dell, Stephen L.; Ramsey, Brian D.; Weiskopf, Martin C.

    2009-01-01

    X-ray telescopes having a relatively wide field-of-view and spatial resolution vs. polar off-axis angle curves much flatter than the parabolic dependence characteristic of Wolter I designs are of great interest for surveys of the X-ray sky and potentially for study of the Sun s X-ray emission. We discuss the various considerations affecting the design of such telescopes, including the possible use of polynomial mirror surface prescriptions, a method of optimizing the polynomial coefficients, scaling laws for mirror segment length vs. intersection radius, the loss of on-axis spatial resolution, and the positioning of focal plane detectors.

  5. Wide-field compact catadioptric telescope spanning 0.7-14 μm wavelengths.

    PubMed

    Marks, Daniel L; Hagen, Nathan; Durham, Mark; Brady, David J

    2013-06-20

    We present a wide-field compact f-1.2, f-1.6 effective illumination catadioptric telescope that spans the wavelengths 0.7-14.0 μm. Such a telescope replaces several telescopes designed for different infrared bands, while having a track length shorter than most single-band telescopes. Incorporated with a suitable multiband focal plane array, many wavelength bands may be imaged simultaneously in the same instrument. We have constructed and tested prototypes of the telescopes and found the performance is near the predicted values. PMID:23842177

  6. Wide-field prime focus corrector for the Anglo-Australian telescope.

    PubMed

    Jones, D J

    1994-11-01

    A wide-field (2°) prime focus corrector has been designed and built for the Anglo-Australian Telescope. The corrector incorporates an atmospheric dispersion compensator for the spectral range 365-1014 nm. A four-element lens system is the basis of the corrector, and it provides a satisfactory state of correction over a full field of 2°. The design of the lens system is described. The choice of layout is related directly to the intrinsic properties of each component. PMID:20941295

  7. Wide Field Camera 3: A Powerful New Imager for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Kimble, Randy

    2008-01-01

    Wide Field Camera 3 (WFC3) is a powerful UV/visible/near-infrared camera in development for installation into the Hubble Space Telescope during upcoming Servicing Mission 4. WFC3 provides two imaging channels. The UVIS channel incorporates a 4096 x 4096 pixel CCD focal plane with sensitivity from 200 to 1000 nm. The IR channel features a 1024 x 1024 pixel HgCdTe focal plane covering 850 to 1700 nm. We report here on the design of the instrument, the performance of its flight detectors, results of the ground test and calibration program, and the plans for the Servicing Mission installation and checkout.

  8. The NOAO Deep Wide-Field Survey Image Cutout Web Service

    NASA Astrophysics Data System (ADS)

    Davis, Lindsey E.; Fitzpatrick, Mike; Tody, Doug

    A Web service for extracting multi-band science grade image cutouts from the NOAO Deep Wide-Field Survey (NDWFS) is described. The NDWFS data is stored as a multi-band database of large images on the NDWFS archive server. Given a cutout center and size the NDWFS image cutout service creates cutout images on-the-fly. The service provides high performance access to the survey data and isolates the client from the details of how the survey data is stored in the archive.

  9. Wide field-of-view lens-free fluorescent imaging on a chip

    PubMed Central

    Coskun, Ahmet F.; Su, Ting-Wei

    2010-01-01

    We demonstrate an on-chip fluorescent detection platform that can simultaneously image fluorescent micro-objects or labeled cells over an ultra-large field-of-view of 2.5 cm × 3.5 cm without the use of any lenses, thin-film filters and mechanical scanners. Such a wide field-of-view lensless fluorescent imaging modality, despite its limited resolution, might be very important for high-throughput screening applications as well as for detection and counting of rare cells within large-area microfluidic devices. PMID:20379564

  10. Wide field fluorescent imaging of extracellular spatiotemporal potassium dynamics in vivo.

    PubMed

    Bazzigaluppi, Paolo; Dufour, Suzie; Carlen, Peter L

    2015-01-01

    Potassium homeostasis is fundamental for the physiological functioning of the brain. Increased [K(+)] in the extracellular fluid has a major impact on neuronal physiology and can lead to ictal events. Compromised regulation of extracellular [K(+)] is involved in generation of seizures in animal models and potentially also in humans. For this reason, the investigation of K(+) spatio-temporal dynamics is of fundamental importance for neuroscientists in the field of epilepsy and other related pathologies. To date, the majority of studies investigating changes in extracellular K(+) have been conducted using a micropipette filled with a K(+) sensitive solution. However, this approach presents a major limitation: the area of the measurement is circumscribed to the tip of the pipette and it is not possible to know the spatiotemporal distribution or origin of the focally measured K(+) signal. Here we propose a novel approach, based on wide field fluorescence, to measure extracellular K(+) dynamics in neural tissue. Recording the local field potential from the somatosensory cortex of the mouse, we compared responses obtained from a K(+)-sensitive microelectrode to the spatiotemporal increases in fluorescence of the fluorophore, Asante Potassium Green-2, in physiological conditions and during 4-AP induced ictal activity. We conclude that wide field imaging is a valuable and versatile tool to measure K(+) dynamics over a large area of the cerebral cortex and is capable of capturing fast dynamics such as during ictal events. Moreover, the present technique is potentially adaptable to address questions regarding spatiotemporal dynamics of other ionic species. PMID:25312775

  11. WSCLEAN: an implementation of a fast, generic wide-field imager for radio astronomy

    NASA Astrophysics Data System (ADS)

    Offringa, A. R.; McKinley, B.; Hurley-Walker, N.; Briggs, F. H.; Wayth, R. B.; Kaplan, D. L.; Bell, M. E.; Feng, L.; Neben, A. R.; Hughes, J. D.; Rhee, J.; Murphy, T.; Bhat, N. D. R.; Bernardi, G.; Bowman, J. D.; Cappallo, R. J.; Corey, B. E.; Deshpande, A. A.; Emrich, D.; Ewall-Wice, A.; Gaensler, B. M.; Goeke, R.; Greenhill, L. J.; Hazelton, B. J.; Hindson, L.; Johnston-Hollitt, M.; Jacobs, D. C.; Kasper, J. C.; Kratzenberg, E.; Lenc, E.; Lonsdale, C. J.; Lynch, M. J.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Kudryavtseva, N.; Oberoi, D.; Ord, S. M.; Pindor, B.; Procopio, P.; Prabu, T.; Riding, J.; Roshi, D. A.; Shankar, N. Udaya; Srivani, K. S.; Subrahmanyan, R.; Tingay, S. J.; Waterson, M.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C. L.

    2014-10-01

    Astronomical wide-field imaging of interferometric radio data is computationally expensive, especially for the large data volumes created by modern non-coplanar many-element arrays. We present a new wide-field interferometric imager that uses the w-stacking algorithm and can make use of the w-snapshot algorithm. The performance dependences of CASA's w-projection and our new imager are analysed and analytical functions are derived that describe the required computing cost for both imagers. On data from the Murchison Widefield Array, we find our new method to be an order of magnitude faster than w-projection, as well as being capable of full-sky imaging at full resolution and with correct polarization correction. We predict the computing costs for several other arrays and estimate that our imager is a factor of 2-12 faster, depending on the array configuration. We estimate the computing cost for imaging the low-frequency Square Kilometre Array observations to be 60 PetaFLOPS with current techniques. We find that combining w-stacking with the w-snapshot algorithm does not significantly improve computing requirements over pure w-stacking. The source code of our new imager is publicly released.

  12. Microlensing Surveys of M31 in the Wide Field Imaging ERA

    SciTech Connect

    Baltz, E.

    2004-10-27

    The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way, thus it is an important laboratory for studying massive dark objects in galactic halos (MACHOs) by gravitational microlensing. Such studies strongly complement the studies of the Milky Way halo using the Large and Small Magellanic Clouds. We consider the possibilities for microlensing surveys of M31 using the next generation of wide field imaging telescopes with fields of view in the square degree range. We consider proposals for such imagers both on the ground and in space. For concreteness, we specialize to the SNAP proposal for a space telescope and the LSST proposal for a ground based telescope. We find that a modest space-based survey of 50 visits of one hour each is considerably better than current ground based surveys covering 5 years. Crucially, systematic effects can be considerably better controlled with a space telescope because of both the infrared sensitivity and the angular resolution. To be competitive, 8 meter class wide-field ground based imagers must take exposures of several hundred seconds with several day cadence.

  13. A comparison of super wide field microscopy systems in mohs surgery.

    PubMed

    Goldsberry, Anne; Hanke, C William; Countryman, Nicholas B

    2014-12-01

    Microscopic frozen section interpretation is one of the cornerstones of Mohs surgery. The recent development of super wide field (SWF) microscopy can improve accuracy and efficiency while reading microscope sections, and also decrease the physician's musculoskeletal and ocular strain. Super wide field microscopy systems increase viewable field area (VA) by combining low magnification objectives, eg, 1x or 2x (Figure 1), with eyepieces that have a higher field number. This article reviews 3 SWF microscopy systems: Leica DM2000 (Leica Microsystems, Wetzlar, Germany), Nikon Eclipse Ni (Nikon Instruments Inc., Melville, NY), and Olympus BX43 (Olympus, Center Valley, PA). The Leica DM2000's 1.25x objective results in a VA of 314.16 mm2. The Nikon Eclipse Ni's 1x objective results in a VA of 490.87 mm2. The Olympus BX43's 1.25x objective results in a VA of 352.99 mm2. The maximum VA at the lowest objective for Nikon is nearly 40% greater than for the Olympus and over 50% greater than for the Leica. The Nikon Eclipse Ni has a significantly higher maximum VA than the other 2 systems. PMID:25607789

  14. Design and implementation of coating hardware for the Hobby-Eberly Telescope wide-field corrector

    NASA Astrophysics Data System (ADS)

    Good, John; Lee, Hanshin; Hill, Gary J.; Vattiat, Brian; Perry, David; Kriel, Herman; Savage, Richard

    2014-07-01

    A major upgrade of the HET is in progress that will substantially increase the pupil size to 10 meters and the field of view to 22 arc-minutes by replacing the spherical aberration corrector. The new Wide Field Corrector is a 4-element assembly weighing 750kg and measuring 1.34 meters diameter by 2.1 meter in length. Special fixtures were required in order to support the mirrors of the Wide-Field Corrector and adapt them to the coaters chamber, during the vacuum coating process. For the 1 meter-class mirrors, the only suitable support interface was located on a 80mm wide cylindrical surface on the periphery of each mirror. The vacuum compatible system had to support the mirrors with the surface facing downward, and accommodate thermal ranges from ambient to 100C without inducing stresses in the substrate. The fixture also had to accommodate washing, as well as support of witness samples during testing and production runs, and provide masking for alignment fixtures in the center apertures of each mirror. Design principles, materials, implementation details, as well as lessons learned are covered*.

  15. Interferometric Imaging with the 32 Element Murchison Wide-Field Array

    NASA Astrophysics Data System (ADS)

    Ord, S. M.; Mitchell, D. A.; Wayth, R. B.; Greenhill, L. J.; Bernardi, G.; Gleadow, S.; Edgar, R. G.; Clark, M. A.; Allen, G.; Arcus, W.; Benkevitch, L.; Bowman, J. D.; Briggs, F. H.; Bunton, J. D.; Burns, S.; Cappallo, R. J.; Coles, W. A.; Corey, B. E.; deSouza, L.; Doeleman, S. S.; Derome, M.; Deshpande, A.; Emrich, D.; Goeke, R.; Gopalakrishna, M. R.; Herne, D.; Hewitt, J. N.; Kamini, P. A.; Kaplan, D. L.; Kasper, J. C.; Kincaid, B. B.; Kocz, J.; Kowald, E.; Kratzenberg, E.; Kumar, D.; Lonsdale, C. J.; Lynch, M. J.; McWhirter, S. R.; Madhavi, S.; Matejek, M.; Morales, M. F.; Morgan, E.; Oberoi, D.; Pathikulangara, J.; Prabu, T.; Rogers, A. E. E.; Roshi, A.; Salah, J. E.; Schinkel, A.; Udaya Shankar, N.; Srivani, K. S.; Stevens, J.; Tingay, S. J.; Vaccarella, A.; Waterson, M.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C.

    2010-11-01

    The Murchison Wide-Field Array (MWA) is a low-frequency radio telescope, currently under construction, intended to search for the spectral signature of the epoch of reionization (EOR) and to probe the structure of the solar corona. Sited in western Australia, the full MWA will comprise 8192 dipoles grouped into 512 tiles and will be capable of imaging the sky south of 40° declination, from 80 MHz to 300 MHz with an instantaneous field of view that is tens of degrees wide and a resolution of a few arcminutes. A 32 station prototype of the MWA has been recently commissioned and a set of observations has been taken that exercise the whole acquisition and processing pipeline. We present Stokes I, Q, and U images from two ~4 hr integrations of a field 20° wide centered on Pictoris A. These images demonstrate the capacity and stability of a real-time calibration and imaging technique employing the weighted addition of warped snapshots to counter extreme wide-field imaging distortions.

  16. Wide-field heterodyne interferometric vibrometry for two-dimensional surface vibration measurement

    NASA Astrophysics Data System (ADS)

    Choi, Samuel; Maruyama, Yuta; Suzuki, Takamasa; Nin, Fumiaki; Hibino, Hiroshi; Sasaki, Osami

    2015-12-01

    Conventional laser Doppler vibrometry and heterodyne interferometry suffer during the simultaneous measurement of the spatial distribution of vibration parameters such as the amplitude, frequency and phase in a wide field of view. Although demand is increasing for methods that can measure vibrations over a wide field of view for a wide range of applications from industrial product inspections to biological measurements, full-field (FF) techniques for high-speed vibration measurements without a spatial scan are untapped. We propose a new method for high-speed FF vibration measurement that can easily be combined with profilometry and tomographic interferometry using a conventional CCD or CMOS camera. In principle, the measurable vibration frequency is unrestricted because the heterodyne signal produced by the modulated interferogram can be controlled to accommodate the CCD frame rate. The validity of the proposed method and the measurement accuracy of the spatial vibration amplitude were evaluated through simulations and experiments. In experiments, the spatial vibration parameters of a mirror vibrated at a frequency of 1 kHz and amplitude of approximately 5-65 nm were successfully measured with a spatial fluctuation of 3%-6.5%.

  17. Generalized mesh-based Monte Carlo for wide-field illumination and detection via mesh retessellation

    PubMed Central

    Yao, Ruoyang; Intes, Xavier; Fang, Qianqian

    2015-01-01

    Monte Carlo methods are commonly used as the gold standard in modeling photon transport through turbid media. With the rapid development of structured light applications, an accurate and efficient method capable of simulating arbitrary illumination patterns and complex detection schemes over large surface area is in great need. Here we report a generalized mesh-based Monte Carlo algorithm to support a variety of wide-field illumination methods, including spatial-frequency-domain imaging (SFDI) patterns and arbitrary 2-D patterns. The extended algorithm can also model wide-field detectors such as a free-space CCD camera. The significantly enhanced flexibility of source and detector modeling is achieved via a fast mesh retessellation process that combines the target domain and the source/detector space in a single tetrahedral mesh. Both simulations of complex domains and comparisons with phantom measurements are included to demonstrate the flexibility, efficiency and accuracy of the extended algorithm. Our updated open-source software is provided at http://mcx.space/mmc. PMID:26819826

  18. Grazing-incidence hyperboloid-hyperboloid designs for wide-field x-ray imaging applications.

    PubMed

    Harvey, J E; Krywonos, A; Thompson, P L; Saha, T T

    2001-01-01

    The classical Wolter type I grazing-incidence x-ray telescope consists of a paraboloidal primary mirror and a confocal hyperboloidal secondary mirror. This design exhibits stigmatic imaging on-axis but suffers from coma, astigmatism, field curvature, and higher-order aberrations such as oblique spherical aberration. Wolter-Schwarzschild designs have been developed that strictly satisfy the Abbe sine condition and thus exhibit no spherical aberration or coma. However, for wide-field applications such as the solar x-ray imager (SXI), there is little merit in a design with stigmatic imaging on-axis. Instead, one needs to optimize some area-weighted-average measure of resolution over the desired operational field of view. This has traditionally been accomplished by mere despacing of the focal plane of the classical Wolter type I telescope. Here we present and evaluate in detail a family of hyperboloid-hyperboloid grazing-incidence x-ray telescope designs whose wide-field performance is much improved over that of an optimally despaced Wolter type I and even somewhat improved over that of an optimally despaced Wolter-Schwarzschild design. PMID:18356984

  19. Using Wide-Field Meteor Cameras to Actively Engage Students in Science

    NASA Astrophysics Data System (ADS)

    Kuehn, D. M.; Scales, J. N.

    2012-08-01

    Astronomy has always afforded teachers an excellent topic to develop students' interest in science. New technology allows the opportunity to inexpensively outfit local school districts with sensitive, wide-field video cameras that can detect and track brighter meteors and other objects. While the data-collection and analysis process can be mostly automated by software, there is substantial human involvement that is necessary in the rejection of spurious detections, in performing dynamics and orbital calculations, and the rare recovery and analysis of fallen meteorites. The continuous monitoring allowed by dedicated wide-field surveillance cameras can provide students with a better understanding of the behavior of the night sky including meteors and meteor showers, stellar motion, the motion of the Sun, Moon, and planets, phases of the Moon, meteorological phenomena, etc. Additionally, some students intrigued by the possibility of UFOs and "alien visitors" may find that actual monitoring data can help them develop methods for identifying "unknown" objects. We currently have two ultra-low light-level surveillance cameras coupled to fish-eye lenses that are actively obtaining data. We have developed curricula suitable for middle or high school students in astronomy and earth science courses and are in the process of testing and revising our materials.

  20. Bilocal visual noise as a probe of wide field motion computation.

    PubMed

    Roy, Suva; de Ruyter van Steveninck, Rob

    2016-05-01

    Using an apparent visual motion stimulus with motion energies limited to specific separations in space and time, we study the computational structure of wide-field motion sensitive neurons in the fly visual brain. There is ample experimental evidence for correlation-based motion computation in many biological systems, but one of its central properties, namely that the response is proportional to the product of two bilocal signal amplitudes, remains to be tested. The design of the apparent motion stimuli used here allows us to manipulate the amplitudes of the bilocal input signals that serve as inputs to the computation. We demonstrate that the wide-field motion response of H1 and V1 neurons indeed shows bilinear behavior, even under contrast sign reversal, as predicted. But the response also varies inversely with contrast variance, an effect not described by the correlator operation. We also quantify the correlator contributions for different spatial and temporal separations. With suitable modification, the apparent motion stimuli used here can be applied to a broad range of neurophysiological as well as human psychophysical studies on motion perception. PMID:27177388

  1. Astro-WISE Processing of Wide-field Images and Other Data

    NASA Astrophysics Data System (ADS)

    Buddelmeijer, H.; Williams, O. R.; McFarland, J. P.; Belikov, A.

    2012-09-01

    Astro-WISE (Vriend et al. 2012) is the Astronomical Wide-field Imaging System for Europe (Valentijn et al. 2007). It is a scientific information system which consists of hardware and software federated over about a dozen institutes throughout Europe. It has been developed to exploit the ever increasing avalanche of data produced by astronomical surveys and data intensive scientific experiments in general. The demo explains the architecture of the Astro-WISE information system and shows the use of Astro-WISE interfaces. Wide-field astronomical images are derived from the raw image to the final catalog according to the user's request. The demo is based on the standard Astro-WISE guided tour, which can be accessed from the Astro-WISE website. The typical Astro-WISE data processing chain is shown, which can be used for data handling for a variety of different instruments, currently 14, including OmegaCAM, MegaCam, WFI, WFC, ACS/HST, etc.

  2. Cryogenic Optical Performance of a Light-weight Mirror Assembly for Future Space Astronomical Telescopes: Optical Test Results and Thermal Optical Model

    NASA Technical Reports Server (NTRS)

    Eng, Ron; Arnold, William; Baker, Markus A.; Bevan, Ryan M.; Carpenter, James R.; Effinger, Michael R.; Gaddy, Darrell E.; Goode, Brian K.; Kegley, Jeffrey R.; Hogue, William D.; Siler, Richard D.; Smith, W. Scott; Stahl. H. Philip; Tucker, John M.; Wright, Ernest R.; Kirk, Charles S.; Hanson, Craig; Burdick, Gregory; Maffett, Steven

    2013-01-01

    A 40 cm diameter mirror assembly was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5 m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two face sheets. The 93% lightweighted Corning ULE mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model.

  3. Cryogenic Optical Performance of a Lightweighted Mirror Assembly for Future Space Astronomical Telescopes: Correlating Optical Test Results and Thermal Optical Model

    NASA Technical Reports Server (NTRS)

    Eng, Ron; Arnold, William R.; Baker, Marcus A.; Bevan, Ryan M.; Burdick, Gregory; Effinger, Michael R.; Gaddy, Darrell E.; Goode, Brian K.; Hanson, Craig; Hogue, William D.; Kegley, Jeffrey R.; Kirk, Charlie; Maffett, Steven P.; Matthews, Gary W.; Siler, Richard D.; Smith, W. Scott; Stahl, H. Philip; Tucker, John M.; Wright, Ernest R.

    2013-01-01

    A 43cm diameter stacked core mirror demonstrator was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two CNC pocket milled face sheets. The 93% lightweighted Corning ULE® mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model.

  4. GRT-WF (Goddard Robotic Telescope Wide Field) Observations on Sprites to Study Correlations Between Sprites and TGFs

    NASA Astrophysics Data System (ADS)

    Watanabe, Ken; Hegley, Jakob; Vydra, Ekaterina; Sakamoto, Takanori; Okajima, Takashi; Gehrels, Neil

    2015-08-01

    It is believed that accelerated electrons are responsible for both Sprites and terrestrial gamma- ray flashes (TGFs). Although several theoretical explanations have been made, we still do not fully understand how TGFs are generated. Therefore, we search for correlations between Sprites and TGFs. We constructed a wide field optical camera system (GRT- WF) using off- the- shelf hardware in June, 2011 at Florida Gulf Coast University (FGCU), Fort Myers, Florida where a high thunderstorm activity during summer is observed. Seven cameras have been set to point along azimuth directions to cover most of the visible sky. The field of view of each camera is ~40 x 60 deg. The events are captured automatically by off- the- shelf software. We have observed around five hundred Sprites in the past four years. We have compared these Sprites with the TGFs detected by the Fermi Gamma-ray Space Telescope LAT in times and locations as well as other instruments. We discuss the preliminary results of our study.

  5. Wide-field imaging and flow cytometric analysis of cancer cells in blood by fluorescent nanodiamond labeling and time gating.

    PubMed

    Hui, Yuen Yung; Su, Long-Jyun; Chen, Oliver Yenjyh; Chen, Yit-Tsong; Liu, Tzu-Ming; Chang, Huan-Cheng

    2014-01-01

    Nanodiamonds containing high density ensembles of negatively charged nitrogen-vacancy (NV(-)) centers are promising fluorescent biomarkers due to their excellent photostability and biocompatibility. The NV(-) centers in the particles have a fluorescence lifetime of up to 20 ns, which distinctly differs from those (<10 ns) of cell and tissue autofluorescence, making it possible to achieve background-free detection in vivo by time gating. Here, we demonstrate the feasibility of using fluorescent nanodiamonds (FNDs) as optical labels for wide-field time-gated fluorescence imaging and flow cytometric analysis of cancer cells with a nanosecond intensified charge-coupled device (ICCD) as the detector. The combined technique has allowed us to acquire fluorescence images of FND-labeled HeLa cells in whole blood covered with a chicken breast of ~0.1-mm thickness at the single cell level, and to detect individual FND-labeled HeLa cells in blood flowing through a microfluidic device at a frame rate of 23 Hz, as well as to locate and trace FND-labeled lung cancer cells in the blood vessels of a mouse ear. It opens a new window for real-time imaging and tracking of transplanted cells (such as stem cells) in vivo. PMID:24994610

  6. Wide-field imaging and flow cytometric analysis of cancer cells in blood by fluorescent nanodiamond labeling and time gating

    NASA Astrophysics Data System (ADS)

    Hui, Yuen Yung; Su, Long-Jyun; Chen, Oliver Yenjyh; Chen, Yit-Tsong; Liu, Tzu-Ming; Chang, Huan-Cheng

    2014-07-01

    Nanodiamonds containing high density ensembles of negatively charged nitrogen-vacancy (NV-) centers are promising fluorescent biomarkers due to their excellent photostability and biocompatibility. The NV- centers in the particles have a fluorescence lifetime of up to 20 ns, which distinctly differs from those (<10 ns) of cell and tissue autofluorescence, making it possible to achieve background-free detection in vivo by time gating. Here, we demonstrate the feasibility of using fluorescent nanodiamonds (FNDs) as optical labels for wide-field time-gated fluorescence imaging and flow cytometric analysis of cancer cells with a nanosecond intensified charge-coupled device (ICCD) as the detector. The combined technique has allowed us to acquire fluorescence images of FND-labeled HeLa cells in whole blood covered with a chicken breast of ~0.1-mm thickness at the single cell level, and to detect individual FND-labeled HeLa cells in blood flowing through a microfluidic device at a frame rate of 23 Hz, as well as to locate and trace FND-labeled lung cancer cells in the blood vessels of a mouse ear. It opens a new window for real-time imaging and tracking of transplanted cells (such as stem cells) in vivo.

  7. ISS-Lobster: a low-cost wide-field x-ray transient detector on the ISS

    NASA Astrophysics Data System (ADS)

    Camp, Jordan; Barthelmy, Scott; Petre, Rob; Gehrels, Neil; Marshall, Francis; Ptak, Andy; Racusin, Judith

    2015-05-01

    ISS-Lobster is a wide-field X-ray transient detector proposed to be deployed on the International Space Station. Through its unique imaging X-ray optics that allow a 30 deg by 30 deg FoV, a 1 arc min position resolution and a 1.6x10-11 erg/(sec cm2) sensitivity in 2000 sec, ISS-Lobster will observe numerous events per year of X-ray transients related to compact objects, including: tidal disruptions of stars by supermassive black holes, supernova shock breakouts, neutron star bursts and superbursts, high redshift Gamma-Ray Bursts, and perhaps most exciting, X-ray counterparts of gravitational wave detections involving stellar mass and possibly supermassive black holes. The mission includes a 3-axis gimbal system that allows fast Target of Opportunity pointing, and a small gamma-ray burst monitor. In this article we focus on ISS-Lobster measurements of X-ray counterparts of detections by the world-wide ground-based gravitational wave network.

  8. Continuation of Search for Correlations Between Sprites and Tgfs By Goddard Robotic Telescope Wide Field (GRT-WF)

    NASA Astrophysics Data System (ADS)

    Hegley, J. C.; Watanabe, K.; Sakamoto, T.; Schlitz, J. R.; Vydra, E.; Okajima, T.; Gehrels, N.

    2015-12-01

    It is believed that accelerated electrons are responsible for both Sprites and terrestrial gamma- ray flashes (TGFs). Although several theoretical explanations have been made, we still do not fully understand how TGFs are generated. Therefore, we search for correlations between Sprites and TGFs. We constructed a wide field optical camera system (GRT- WF) using off- the- shelf hardware in June, 2011 at Florida Gulf Coast University (FGCU), Fort Myers, Florida where a high thunderstorm activity during summer is observed. Seven cameras have been set to point along azimuth directions to cover most of the visible sky. The field of view of each camera is ~40 x 60 deg. The events are captured automatically by off- the- shelf software. We have observed over five hundred of Sprites in the past four years. We search for the temporal and locational coincidence of these Sprites with the TGFs detected by the Fermi Gamma-ray Space Telescope and RHESSI. We discuss the preliminary results of our analysis with new data we have detected since we presented at the last AGU Fall meeting.

  9. A Very Wide-Field Hybrid (Focusing/Coded Mask) X-Ray Telescope Concept

    NASA Astrophysics Data System (ADS)

    Gorenstein, Paul

    2011-09-01

    The success of Swift at detecting and positioning variable hard X-ray sources, most notably gamma-ray bursts (GRBs), demonstrates that investigations with a very wide field telescope should continue permanently, like the continuing search for supernovas, and its scope expanded. The softer X-ray band is likely to be an even richer arena in which to search for ever more distant GRBs. The X-ray component of their spectra will be enriched by the redshift especially at large distances where the redshift increases very rapidly with distance. Furthermore most GRBs are likely to have an X-ray afterglow, which a very wide field telescope would detect from its birth. Multiple X-ray afterglows can be studied simultaneously. Some GRB models predict that X-ray afterglows will be more numerous than GRBs because they are less narrowly beamed. In addition many other types of variable X-ray sources can be monitored even more effectively than by scanning instruments. There are three possible approaches to a very wide field X-ray telescope, a 2D coded mask like Swift, a 2D lobster-eye telescope, and a hybrid that is a lobster-eye telescope in one dimension and a coded mask in the other. For the same field of view and the same focal length all three could use the same detector system including an omni-directional gamma-ray detector. We offer reasons why the hybrid, which is composed of identical flat mirrors, is the best of the three. It has much less background from diffuse X-rays and known X-ray sources than the 2D coded mask, and has substantially more area and bandwidth than the 2D lobster-eye. While positions are expected to be an arc minute or better, a small number of the mirrors used to fabricate the hybrid can be configured as a KB telescope that when pointed refines positions to arc second precision.

  10. Optic variables used to judge future ball arrival position in expert and novice soccer players.

    PubMed

    Craig, Cathy M; Goulon, Cédric; Berton, Eric; Rao, Guillaume; Fernandez, Laure; Bootsma, Reinoud J

    2009-04-01

    Although many studies have looked at the perceptual-cognitive strategies used to make anticipatory judgments in sport, few have examined the informational invariants that our visual system may be attuned to. Using immersive interactive virtual reality to simulate the aerodynamics of the trajectory of a ball with and without sidespin, the present study examined the ability of expert and novice soccer players to make judgments about the ball's future arrival position. An analysis of their judgment responses showed how participants were strongly influenced by the ball's trajectory. The changes in trajectory caused by sidespin led to erroneous predictions about the ball's future arrival position. An analysis of potential informational variables that could explain these results points to the use of a first-order compound variable combining optical expansion and optical displacement. PMID:19304642

  11. A wide field-of-view scanning endoscope for whole anal canal imaging.

    PubMed

    Han, Chao; Huangfu, Jiangtao; Lai, Lily L; Yang, Changhuei

    2015-02-01

    We report a novel wide field-of-view (FOV) scanning endoscope, the AnCam, which is based on contact image sensor (CIS) technology used in commercialized business card scanners. The AnCam can capture the whole image of the anal canal within 10 seconds with a resolution of 89 μm, a maximum FOV of 100 mm × 120 mm, and a depth-of-field (DOF) of 0.65 mm at 5.9 line pairs per mm (lp/mm). We demonstrate the performance of the AnCam by imaging the entire anal canal of pigs and tracking the dynamics of acetowhite testing. We believe the AnCam can potentially be a simple and convenient solution for screening of the anal canal for dysplasia and for surveillance in patients following treatment for anal cancer. PMID:25780750

  12. The Wide Field/Planetary Camera 2 (WFPC-2) molecular adsorber

    NASA Technical Reports Server (NTRS)

    Barengoltz, Jack; Moore, Sonya; Soules, David; Voecks, Gerald

    1995-01-01

    A device has been developed at the Jet Propulsion Laboratory, California Institute of Technology, for the adsorption of contaminants inside a space instrument during flight. The molecular adsorber was developed for use on the Wide Field Planetary Camera 2, and it has been shown to perform at its design specifications in the WFPC-2. The basic principle of the molecular adsorber is a zeolite-coated ceramic honeycomb. The arrangement is efficient for adsorption and also provides the needed rigidity to retain the special zeolite coating during the launch vibrational environment. The adsorber, on other forms, is expected to be useful for all flight instruments sensitive to internal sources of contamination. Typically, some internal contamination is unavoidable. A common design solution is to increase the venting to the exterior. However, for truly sensitive instruments, the external contamination environment is more severe. The molecular adsorber acts as a one-way vent to solve this problem. Continued development is planned for this device.

  13. FINDING PERSISTENT SOURCES WITH THE BeppoSAX/WIDE FIELD CAMERA: AN IN-DEPTH ANALYSIS

    SciTech Connect

    Capitanio, F.; Fiocchi, M.; Ubertini, P.; Bird, A. J.; Scaringi, S.

    2011-07-01

    During the operational life of the Italian/Dutch X-ray satellite (1996-2002), BeppoSAX, its two Wide Field Cameras (WFCs) performed observations that covered the full sky at different epochs. Although the majority of analysis performed on BeppoSAX WFC data concentrated on the detection of transient sources, we have now applied the same techniques developed for the INTEGRAL/IBIS survey to produce the same work with the BeppoSAX WFC data. This work represents the first unbiased source list compilation produced from the overall WFC data set optimized for faint persistent source detection. This approach recovered 182 more sources compared to the previous WFC catalog reported in Verrecchia et al. The catalog contains 404 sources detected between 3 and 17 keV, 10 of which are yet to be seen by the new generation of telescopes.

  14. SpIOMM and SITELLE: Wide-field Imaging FTS for the Study of Galaxy Evolution

    NASA Astrophysics Data System (ADS)

    Drissen, Laurent; Bernier, Anne-Pier; Robert, Carmelle; Robert

    2011-12-01

    SpIOMM, a wide-field Imaging Fourier Transform Spectrometer attached to the Mont Mégantic 1.6-m telescope, is capable of obtaining the visible spectrum of every source of light in a 12 arcminute field of view, with a spectral resolution ranging from R = 1 (wide-band image) to R = 25 000, resulting in 1.7 million spectra with a spatial resolution of one arcsecond. SITELLE will be a similar instrument attached to the Canada-France-Hawaii telescope, and will be in operation in early 2013. We present a short description of these instruments and illustrate their capabilities to study nearby galaxies with the results of a data cube of M51.

  15. Morphological analysis of Bacillux polymyxa colonies: digital image analysis in wide-field microscopy

    NASA Astrophysics Data System (ADS)

    Guerrero, Lina M.; Plata G., Arturo; Rincón C., Giovanna; Gutiérrez A., Henry; Plata, Alexandra

    2013-11-01

    In the last twenty years the growth of bacterial colonies has been studied experimentally using images with different growth patterns, but the resolution of those images is in areas of tenths of microns without range information. On the other hand, theoretical studies considering the bacteria as systems with collective behavior controlled by a reduced number of parameters have been developed. The present work aims to study morphological and dynamic growth of Bacillus polymyxa colonies by the technique of digital image analysis in wide-field microscopy, which provides high resolution, both in texture and topography. Getting a three-dimensional behavior of dynamic biological systems is useful to create structures and materials with different physical and biological properties for industrial applications.

  16. Deconvolution of wide field-of-view radiometer measurements of earth-emitted radiation. I - Theory

    NASA Technical Reports Server (NTRS)

    Smith, G. L.; Green, R. N.

    1981-01-01

    The theory of deconvolution of wide field-of-view (WFOV) radiometer measurements of earth-emitted radiation provides a technique by which the resolution of such measurements can be enhanced to provide radiant exitance at the top of the atmosphere with a finer resolution than the field of view. An analytical solution for the earth-emitted radiant exitance in terms of WFOV radiometer measurements is derived for the nonaxisymmetric (or regional) case, in which the measurements and radiant exitance are considered to be functions of both latitude and longitude. This solution makes it possible to deconvolve a set of WFOV radiometer measurements of earth-emitted radiation and obtain information with a finer resolution than the instantaneous field of view of the instrument. It is shown that there are tradeoffs involved in the selection between WFOV and scanning radiometers.

  17. Satellite Detection in AdvancedCamera for Surveys/Wide Field Channel Images

    NASA Astrophysics Data System (ADS)

    Borncamp, D.; Lim, Pey-Lian

    2016-01-01

    This document explains the process by which satellite trails can be found within individual chips of an Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) image. Since satellites are transient and sporadic events, we used the Hubble Frontier Fields (HFF) dataset which is manually checked for satellite trails has been used as a truth set to verify that the method in this document does a complete job without a high false positive rate. This document also details the process of producing a mask that will update data quality information to inform users where the trail traverses the image and properly account for the affected pixels. Along with this document, the Python source code used to detect and mask satellite trails will be released to users with as a stand-alone product within the STSDAS acstools package.

  18. Current status of the Hobby-Eberly Telescope wide-field upgrade

    NASA Astrophysics Data System (ADS)

    Savage, Richard; Booth, John; Cornell, Mark; Good, John; Hill, Gary J.; Lee, Hanshin; MacQueen, Phillip; Rafal, Marc; Vattiat, Brian; Gebhardt, Karl; Beno, Joseph; Zierer, Joseph; Perry, Dave; Rafferty, Tom; Ramiller, Chuck; Taylor, Charles, III; Beets, Timothy; Hayes, Richard; Heisler, James; Hinze, Sarah; Soukup, Ian; Jackson, John; Mock, Jason; Worthington, Michael; Mollison, Nicholas; Molina, Omar; South, Brian; Wardell, Douglas; Wedeking, Gregory

    2010-07-01

    The Hobby-Eberly Telescope (HET) is an innovative large telescope of 9.2 meter aperture, located in West Texas at the McDonald Observatory (MDO). The HET operates with a fixed segmented primary and has a tracker which moves the four-mirror corrector and prime focus instrument package to track the sidereal and non-sidereal motions of objects. A major upgrade of the HET is in progress that will increase the pupil size to 10 meters and the field of view to 22' by replacing the corrector, tracker and prime focus instrument package. In addition to supporting the existing suite of instruments, this wide field upgrade will feed a revolutionary new integral field spectrograph called VIRUS, in support of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX‡). This paper discusses the current status of this upgrade.

  19. Current status of the Hobby-Eberly Telescope wide field upgrade

    NASA Astrophysics Data System (ADS)

    Hill, Gary J.; Booth, John A.; Cornell, Mark E.; Good, John M.; Gebhardt, Karl; Kriel, Herman J.; Lee, Hanshin; Leck, Ron; Moreira, Walter; MacQueen, Phillip J.; Perry, Dave M.; Rafal, Marc D.; Rafferty, Tom H.; Ramiller, Chuck; Savage, Richard D.; Taylor, Charles A.; Vattiat, Brian L.; Ramsey, Lawrence W.; Beno, Joseph H.; Beets, Timothy A.; Esguerra, Jorge D.; Häuser, Marco; Hayes, Richard J.; Heisler, James T.; Soukup, Ian M.; Zierer, Joseph J.; Worthington, Michael S.; Mollison, Nicholas T.; Wardell, Douglas R.; Wedeking, Gregory A.

    2012-09-01

    The Hobby-Eberly Telescope (HET) is an innovative large telescope of 9.2 meter aperture, located in West Texas at the McDonald Observatory (MDO). The HET operates with a fixed segmented primary and has a tracker which moves the four-mirror corrector and prime focus instrument package to track the sidereal and non-sidereal motions of objects. A major upgrade of the HET is in progress that will increase the pupil size to 10 meters and the field of view to 22' by replacing the corrector, tracker and prime focus instrument package. In addition to supporting the existing suite of instruments, this wide field upgrade will feed a revolutionary new integral field spectrograph called VIRUS, in support of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEXχ). This paper discusses the current status of this upgrade.

  20. Current status of the Hobby-Eberly Telescope wide field upgrade and VIRUS

    NASA Astrophysics Data System (ADS)

    Savage, Richard D.; Booth, John A.; Gebhardt, Karl; Good, John M.; Hill, Gary J.; MacQueen, Phillip J.; Rafal, Marc D.; Smith, Michael P.; Vattiat, Brian L.

    2008-07-01

    The Hobby-Eberly Telescope (HET) is an innovative large telescope of 9.2 meter aperture, located in West Texas at the McDonald Observatory. The HET operates with a fixed segmented primary and has a tracker which moves the fourmirror corrector and prime focus instrument package to track the sidereal and non-sidereal motions of objects. A major upgrade of the HET is in progress that will substantially increase the field of view by replacing the corrector, tracker and prime focus instrument package. In addition to supporting the existing suite of instruments, this wide field upgrade will feed a revolutionary new integral field spectrograph called VIRUS, in support of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). This paper discusses the current status of this upgrade.

  1. Palm-size wide-field Fourier spectroscopic imager with uncooled infrared microbolometer arrays for smartphone

    NASA Astrophysics Data System (ADS)

    Kawashima, Natsumi; Suzuki, Yo; Qi, Wei; Hosono, Satsuki; Saito, Tsubasa; Ogawa, Satoshi; Sato, Shun; Fujiwara, Masaru; Nishiyama, Akira; Wada, Kenji; Tanaka, Naotaka; Ishimaru, Ichiro

    2015-03-01

    We proposed the imaging-type 2-dimensional Fourier spectroscopy that is a near-common-path interferometer with strong robustness against mechanical vibrations. We introduced the miniature uncooled infrared microbolometer arrays for smartphone (e.g. product name: FILR ONE price: around 400USD). And we constructed the phase-shifter with the piezo impact drive mechanism (maker: Technohands.co.Ltd., stroke: 4.5mm, resolution: 0.01μm, size: 20mm, price: around 800USD). Thus, we realized the palm-size mid-infrared spectroscopic imager [size: L56mm×W69mm×H43mm weight: 500g]. And by using wide-angle lens as objective lens, the proposed method can obtain the wide-field 2- dimensional middle-infrared (wavelength: 7.5-13.5[μm]) spectroscopic imaging of radiation lights emitted from human bodies itself

  2. Science yield estimate with the Wide-Field Infrared Survey Telescope coronagraph

    NASA Astrophysics Data System (ADS)

    Traub, Wesley A.; Breckinridge, James; Greene, Thomas P.; Guyon, Olivier; Jeremy Kasdin, N.; Macintosh, Bruce

    2016-01-01

    The coronagraph instrument (CGI) on the Wide-Field Infrared Survey Telescope will directly image and spectrally characterize planets and circumstellar disks around nearby stars. Here we estimate the expected science yield of the CGI for known radial-velocity (RV) planets and potential circumstellar disks. The science return is estimated for three types of coronagraphs: the hybrid Lyot and shaped pupil are the currently planned designs, and the phase-induced amplitude apodizing complex mask coronagraph is the backup design. We compare the potential performance of each type for imaging as well as spectroscopy. We find that the RV targets can be imaged in sufficient numbers to produce substantial advances in the science of nearby exoplanets. To illustrate the potential for circumstellar disk detections, we estimate the brightness of zodiacal-type disks, which could be detected simultaneously during RV planet observations.

  3. The NOAA-9 Earth Radiation Budget Experiment Wide Field-of-View Data Set

    NASA Technical Reports Server (NTRS)

    Bush, Kathryn A.; Smith, G. Louis; Young, David F.

    1999-01-01

    The Earth Radiation Budget Experiment (ERBE) consisted of wide field-of-view (WFOV) radiometers and scanning radiometers for measuring outgoing longwave radiation and solar radiation reflected from the Earth. These instruments were carried by the dedicated Earth Radiation Budget Satellite (ERBS) and by the NOAA-9 and -10 operational spacecraft. The WFOV radiometers provided data from which instantaneous fluxes at the top of the atmosphere (TOA) are computed by use of a numerical filter algorithm. Monthly mean fluxes over a 5-degree equal angle grid are computed from the instantaneous TOA fluxes. The WFOV radiometers aboard the NOAA-9 spacecraft operated from February 1985 through December 1992, at which time a failure of the shortwave radiometer ended the usable data after nearly 8 years. This paper examines the monthly mean products from that data set.

  4. Readout electronics for the Wide Field of view Cherenkov/Fluorescence Telescope Array

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Zhang, S.; Zhang, Y.; Zhou, R.; Bai, L.; Zhang, J.; Huang, J.; Yang, C.; Cao, Z.

    2015-08-01

    The aim of the Large High Altitude Air Shower Observatory (LHAASO), supported by IHEP of the Chinese Academy of Sciences, is a multipurpose project with a complex detectors array for high energy gamma ray and cosmic ray detection. The Wide Field of view Cherenkov Telescope Array (WFCTA), as one of the components of the LHAASO project, aim to tag each primary particle that causes an air shower. The WFCTA is a portable telescope array used to detect cosmic ray spectra. The design of the readout electronics of the WFCTA is described in this paper Sixteen photomultiplier tubes (PMTs), together with their readout electronics are integrated into a single sub-cluster. To maintain good resolution and linearity over a wide dynamic range, a dual-gain amplification configuration on an analog board is used The digital board contains two 16channel 14-bit, 50 Msps analog-to-digital converters (ADC) and its power consumption, noise level, and relative deviation are all tested.

  5. An optimal numerical filter for wide-field-of-view measurements of earth-emitted radiation

    NASA Technical Reports Server (NTRS)

    Smith, G. L.; House, F. B.

    1981-01-01

    A technique is described in which all data points along an arc of the orbit may be used in an optimal numerical filter for wide-field-of-view measurements of earth emitted radiation. The statistical filter design is derived whereby the filter is required to give a minimum variance estimate of the radiative exitance at discrete points along the ground track of the satellite. An equation for the optimal numerical filter is given by minimizing the estimate error variance equation with respect to the filter weights, resulting in a discrete form of the Wiener-Hopf equation. Finally, variances of the errors in the radiant exitance can be computed along the ground track and in the cross track directions.

  6. Stellar photometry with the Hubble Space Telescope Wide-field/Planetary camera - A progress report

    NASA Technical Reports Server (NTRS)

    Holtzman, Jon A.; Hunter, Deidre; Groth, Edward J.; Light, Robert M.; Faber, S. M.

    1991-01-01

    The prospects for the use of the Wide-Field/Planetary Camera (WFPC) for stellar photometry are described. The large halos of the point-spread function (PSF) resulting from spherical aberration and from spatial, temporal, and color variations of the PSF are the main limitations to accurate photometry. Degradations caused by crowding are exacerbated by the halos of the PSF. An attempt is made to quantify these effects and determine the current accuracy of stellar photometry with the WFPC. In realistic cases, the brighter stars in crowded fields have 0.09 mag errors; fainter stars have larger errors depending on the degree of crowding. It is shown that measuring Cepheids in Virgo Cluster galaxies is not currently possible without inordinate increases in exposure times.

  7. The Wide-Field Nearby Galaxy-Cluster Survey (WINGS) and Its Extension OMEGAWINGS

    NASA Astrophysics Data System (ADS)

    Poggianti, B. M.; Fasano, G.; Bettoni, D.; Cava, A.; Couch, W.; D'Onofrio, M.; Dressler, A.; Fritz, J.; Kjaergaard, P.; Gullieuszik, M.; Moles, M.; Moretti, A.; Omizzolo, A.; Paccagnella, A.; Varela, J.; Vulcani, B.

    WINGS is a wide-field multi-wavelength survey of 76 X-ray selected clusters at low redshift. The WINGS database has been used for a variety of cluster and cluster galaxy studies, investigating galaxy star formation, morphologies, structure, stellar mass functions and other properties. We present the recent wider-field extension of WINGS, OMEGAWINGS, conducted with OmegaCAM@VST and AAOmega@AAT. We show two of our latest results regarding jellyfish galaxies and galaxy sizes. OMEGAWINGS has allowed the first systematic search of galaxies with signs of ongoing ram pressure stripping (jellyfishes), yielding a catalog of ˜ 240 galaxies in 41 clusters. We discuss the first results obtained from this sample and the prospects for integral field data. Finally, we summarize our results regarding the discovery of compact massive galaxies at low redshift, their properties, dependence on environment and the implications for the evolution of galaxy sizes from high- to low-z.

  8. Geometry of the Hubble Space Telescope Wide Field/Planetary Camera field

    NASA Technical Reports Server (NTRS)

    Gould, Andrew; Yanny, Brian

    1994-01-01

    We present a solution for the relative positions and orientations of the four charge coupled device (CCD) chips on the Hubble Space Telescope (HST) Planetary Camera (PC). An accurate solution is required when matching HST images with ground-based images or with one another. The solution is accurate to about 2/3 PC pixel or about .03 sec, a tenfold improvement over the best previous solution. The CCDs are rotated relative to one another by up to 1 deg. The solution is based on images taken between December 1990 and June 1992 and is stable over that entire period. We also present a solution for the relative positions and orientations of the four CCD chips on the HST Wide Field Camera (WFC). This solution is accurate to about 1/2 WFC pixel or about .05 sec.

  9. Wide-field endoscopic fluorescence imaging for gastrointestinal tumor detection with glucose analogue

    NASA Astrophysics Data System (ADS)

    He, Yun; Qu, Yawei; Bai, Jing; Liu, Haifeng

    2014-05-01

    The lack of functional information and targeted imaging in conventional white-light endoscopy leads to a high miss-rate of gastrointestinal tumor. The combination of near-infrared fluorescence imaging and endoscopy presents a promising approach. Here we introduce a new endoscopy method employing a home-made flexible wide-field epi-fluorescence endoscope, that can be inserted through the biopsy channel of a gastrointestinal endoscope, with the glucose analogue 2- DeoxyGlucosone as the near-infrared fluorescent probe. System characterization indicates a good sensitivity and linearity over a large field of view. Its capability of tumor identification and location is demonstrated with in-vivo imaging of xenografted tumor model.

  10. Wide-field FTIR microscopy using mid-IR pulse shaping.

    PubMed

    Serrano, Arnaldo L; Ghosh, Ayanjeet; Ostrander, Joshua S; Zanni, Martin T

    2015-07-13

    We have developed a new table-top technique for collecting wide-field Fourier transform infrared (FTIR) microscopic images by combining a femtosecond pulse shaper with a mid-IR focal plane array. The pulse shaper scans the delay between a pulse pair extremely rapidly for high signal-to-noise, while also enabling phase control of the individual pulses to under-sample the interferograms and subtract background. Infrared absorption images were collected for a mixture of W(CO)₆ or Mn₂(CO)₁₀ absorbed polystyrene beads, demonstrating that this technique can spatially resolve chemically distinct species. The images are sub-diffraction limited, as measured with a USAF test target patterned on CaF₂ and verified with scalar wave simulations. We also find that refractive, rather than reflective, objectives are preferable for imaging with coherent radiation. We discuss this method with respect to conventional FTIR microscopes. PMID:26191843

  11. WFC3RED: A HST Wide Field Camera 3 Image Processing Pipeline

    NASA Astrophysics Data System (ADS)

    Magee, D. K.; Bouwens, R. J.; Illingworth, G. D.

    2011-07-01

    WFC3RED is a pipeline for automatically processing imaging data taken with the Wide Field Camera 3 instrument on the Hubble Space Telescope (HST). The pipeline currently supports processing of imaging data from both the IR and UVIS channels and is written in Python and C. The automated processing steps include cosmic-ray removal (UVIS), super-sky subtraction, user defined artifact masking, robust alignment and registration for large mosaics, weight map generation, and drizzling onto a final image mosaic. WFC3RED can combined data across different HST observations, visits and proposals without the need for any pre-defined associations. WFC3RED can create imaging products with a signal-to-noise ratio that matches the most careful step-by-step manual WFC3 reductions.

  12. Wide-field FTIR microscopy using mid-IR pulse shaping

    PubMed Central

    Serrano, Arnaldo L.; Ghosh, Ayanjeet; Ostrander, Joshua S.; Zanni, Martin T.

    2015-01-01

    We have developed a new table-top technique for collecting wide-field Fourier transform infrared (FTIR) microscopic images by combining a femtosecond pulse shaper with a mid-IR focal plane array. The pulse shaper scans the delay between a pulse pair extremely rapidly for high signal-to-noise, while also enabling phase control of the individual pulses to under-sample the interferograms and subtract background. Infrared absorption images were collected for a mixture of W(CO)6 or Mn2(CO)10 absorbed polystyrene beads, demonstrating that this technique can spatially resolve chemically distinct species. The images are sub-diffraction limited, as measured with a USAF test target patterned on CaF2 and verified with scalar wave simulations. We also find that refractive, rather than reflective, objectives are preferable for imaging with coherent radiation. We discuss this method with respect to conventional FTIR microscopes. PMID:26191843

  13. A Powerful New Imager for HST: Performance and Early Science Results from Wide Field Camera 3

    NASA Technical Reports Server (NTRS)

    Kimble, Randy

    2009-01-01

    Wide Field Camera 3 (WFC3) was installed into the Hubble Space Telescope during the highly successful Servicing Mission 4 in May, 2009. WFC3 offers sensitive, high resolution imaging over a broad wavelength range from the near UV through the visible to the near IR (200nm - 1700nm). Its capabilities in the near UV and near IR ends of that range represent particularly large advances vs. those of previous HST instruments. In this talk, I will review the purpose and design of the instrument, describe its performance in flight, and highlight some of the initial scientific results from the instrument, including its use in deep infrared surveys in search of galaxies at very high redshift, in investigations of the global processes of star formation in nearby galaxies, and in the study of the recent impact on Jupiter.

  14. Continuous wide-field characterization of drug release from skin substitute using off-axis interferometry.

    PubMed

    Gabai, Haniel; Baranes-Zeevi, Maya; Zilberman, Meital; Shaked, Natan T

    2013-08-15

    We achieved continuous, noncontact wide-field imaging and characterization of drug release from a polymeric device in vitro by uniquely using off-axis interferometric imaging. Unlike the current gold-standard methods in this field, which are usually based on chromatography and spectroscopy, our method requires no user intervention during the experiment and involves less lab consumable instruments. Using a simplified interferometric imaging system, we experimentally demonstrate the characterization of anesthetic drug release (Bupivacaine) from a soy-based protein matrix, which is used as a skin substitute for wound dressing. Our results demonstrate the potential of interferometric imaging as an inexpensive and easy-to-use alternative for characterization of drug release in vitro. PMID:24104636

  15. A wide field-of-view scanning endoscope for whole anal canal imaging

    PubMed Central

    Han, Chao; Huangfu, Jiangtao; Lai, Lily L.; Yang, Changhuei

    2015-01-01

    We report a novel wide field-of-view (FOV) scanning endoscope, the AnCam, which is based on contact image sensor (CIS) technology used in commercialized business card scanners. The AnCam can capture the whole image of the anal canal within 10 seconds with a resolution of 89 μm, a maximum FOV of 100 mm × 120 mm, and a depth-of-field (DOF) of 0.65 mm at 5.9 line pairs per mm (lp/mm). We demonstrate the performance of the AnCam by imaging the entire anal canal of pigs and tracking the dynamics of acetowhite testing. We believe the AnCam can potentially be a simple and convenient solution for screening of the anal canal for dysplasia and for surveillance in patients following treatment for anal cancer. PMID:25780750

  16. The achievements and future prospects of Chinese space optical remote sensor technology

    NASA Astrophysics Data System (ADS)

    Zhou, Feng; Liu, Zhaojun

    2011-08-01

    The launched space optical Remote Sensors, including the three generations of space film remote sensor, the space CCD remote sensor and the IRMSS for resources survey, the first generation CCD and IR remote sensor for disaster monitoring, the first generation CCD and IR camera for ocean monitoring, the related remote sensor in polar orbit and geostationary orbit for meteorological detection and forecasting, the first generation related remote sensor for deep space exploration, etc, are presented in detail in the paper. The related technologies, including system design technology, the lens technology, the FPA video technology, the manufacture technology, the AIT technology, etc, are also introduced in the paper. The Chinese great achievements in the field of space optical remote sensor are shown. The prospects on future development of the space serial optical remote sensors and the related technologies are made.

  17. Cortical activation following chronic passive implantation of a wide-field suprachoroidal retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Villalobos, Joel; Fallon, James B.; Nayagam, David A. X.; Shivdasani, Mohit N.; Luu, Chi D.; Allen, Penelope J.; Shepherd, Robert K.; Williams, Chris E.

    2014-08-01

    Objective. The research goal is to develop a wide-field retinal stimulating array for prosthetic vision. This study aimed at evaluating the efficacy of a suprachoroidal electrode array in evoking visual cortex activity after long term implantation. Approach. A planar silicone based electrode array (8 mm × 19 mm) was implanted into the suprachoroidal space in cats (ntotal = 10). It consisted of 20 platinum stimulating electrodes (600 μm diameter) and a trans-scleral cable terminated in a subcutaneous connector. Three months after implantation (nchronic = 6), or immediately after implantation (nacute = 4), an electrophysiological study was performed. Electrode total impedance was measured from voltage transients using 500 μs, 1 mA pulses. Electrically evoked potentials (EEPs) and multi-unit activity were recorded from the visual cortex in response to monopolar retinal stimulation. Dynamic range and cortical activation spread were calculated from the multi-unit recordings. Main results. The mean electrode total impedance in vivo following 3 months was 12.5 ± 0.3 kΩ. EEPs were recorded for 98% of the electrodes. The median evoked potential threshold was 150 nC (charge density 53 μC cm-2). The lowest stimulation thresholds were found proximal to the area centralis. Mean thresholds from multiunit activity were lower for chronic (181 ± 14 nC) compared to acute (322 ± 20 nC) electrodes (P < 0.001), but there was no difference in dynamic range or cortical activation spread. Significance. Suprachoroidal stimulation threshold was lower in chronic than acute implantation and was within safe charge limits for platinum. Electrode-tissue impedance following chronic implantation was higher, indicating the need for sufficient compliance voltage (e.g. 12.8 V for mean impedance, threshold and dynamic range). The wide-field suprachoroidal array reliably activated the retina after chronic implantation.

  18. Reaching the Diffraction Limit - Differential Speckle and Wide-Field Imaging for the WIYN Telescope

    NASA Technical Reports Server (NTRS)

    Scott, Nic J.; Howell, Steve; Horch, Elliott

    2016-01-01

    Speckle imaging allows telescopes to achieve diffraction limited imaging performance. The technique requires cameras capable of reading out frames at a very fast rate, effectively 'freezing out' atmospheric seeing. The resulting speckles can be correlated and images reconstructed that are at the diffraction limit of the telescope. These new instruments are based on the successful performance and design of the Differential Speckle Survey Instrument (DSSI).The instruments are being built for the Gemini-N and WIYN telescopes and will be made available to the community via the peer review proposal process. We envision their primary use to be validation and characterization of exoplanet targets from the NASA, K2 and TESS missions and RV discovered exoplanets. Such targets will provide excellent follow-up candidates for both the WIYN and Gemini telescopes. We expect similar data quality in speckle imaging mode with the new instruments. Additionally, both cameras will have a wide-field mode and standard SDSS filters. They will be highly versatile instruments and it is that likely many other science programs will request time on the cameras. The limiting magnitude for speckle observations will remain around 13-14th at WIYN and 16-17th at Gemini, while wide-field, normal CCD imaging operation should be able to go to much fainter, providing usual CCD imaging and photometric capabilities. The instruments will also have high utility as scoring cameras for telescope engineering purposes, or other applications where high time resolution is needed. Instrument support will be provided, including a software pipeline that takes raw speckle data to fully reconstructed images.

  19. An experiment in big data: storage, querying and visualisation of data taken from the Liverpool Telescope's wide field cameras

    NASA Astrophysics Data System (ADS)

    Barnsley, R. M.; Steele, Iain A.; Smith, R. J.; Mawson, Neil R.

    2014-07-01

    The Small Telescopes Installed at the Liverpool Telescope (STILT) project has been in operation since March 2009, collecting data with three wide field unfiltered cameras: SkycamA, SkycamT and SkycamZ. To process the data, a pipeline was developed to automate source extraction, catalogue cross-matching, photometric calibration and database storage. In this paper, modifications and further developments to this pipeline will be discussed, including a complete refactor of the pipeline's codebase into Python, migration of the back-end database technology from MySQL to PostgreSQL, and changing the catalogue used for source cross-matching from USNO-B1 to APASS. In addition to this, details will be given relating to the development of a preliminary front-end to the source extracted database which will allow a user to perform common queries such as cone searches and light curve comparisons of catalogue and non-catalogue matched objects. Some next steps and future ideas for the project will also be presented.

  20. Lessons Learned from the Wide Field Camera 3 TV1 and TV2 Thermal Vacuum Test Campaigns

    NASA Technical Reports Server (NTRS)

    Peabody, Hume; Stavely, Richard; Bast, William

    2008-01-01

    The Wide Field Camera 3 (WFC3) instrument has undergone two complete thermal vacuum tests (TV1 and TV2), during which valuable lessons were learned regarding test configuration, test execution, model capabilities, and modeling practices. The very complex thermal design of WFC3 produced a number of challenging aspects to ground testing with numerous ThermoElectric Coolers and heat pipes, not all of which were functional. Lessons learned during TV1 resulted in significant upgrades to the model capabilities and a change in the test environment approach for TV2. These upgrades proved invaluable during TV2 when pretest modeling assumptions proved to be false. Each of the lessons learned relate to one of two following broad statements: 1. Ensure the design can be tested and that the effect of non-flight like conditions is well understood, particularly with respect to non passive devices (TECs, Heat Pipes, etc) 2. Ensure that the model is sufficiently detailed and is capable of predicting off-nominal behavior and the power dissipation of any thermal devices, especially TECs This paper outlines a number of the lessons learned over these two test campaigns with respect to the thermal design, model, and test configuration and presents recommendations for future tests.

  1. Radiation-induced Backgrounds in Astronomical Instruments: Considerations for Geosynchronous Orbit and Implications for the Design of the WFIRST Wide-field Instrument

    NASA Astrophysics Data System (ADS)

    Kruk, Jeffrey W.; Xapsos, Michael A.; Armani, Nerses; Stauffer, Craig; Hirata, Christopher M.

    2016-03-01

    Geosynchronous orbits are appealing for solar or astrophysical observatories because they permit continuous data downlink at high rates. The radiation environment in these orbits presents unique challenges, however. This paper describes both the characteristics of the radiation environment in geosynchronous orbit and the mechanisms by which this radiation generates backgrounds in photon detectors. Shielding considerations are described, and a preliminary shielding design for the proposed Wide-Field InfraRed Survey Telescope observatory is presented as a reference for future space telescope concept studies that consider a geosynchronous orbit.

  2. The optical antenna system design research on earth integrative network laser link in the future

    NASA Astrophysics Data System (ADS)

    Liu, Xianzhu; Fu, Qiang; He, Jingyi

    2014-11-01

    Earth integrated information network can be real-time acquisition, transmission and processing the spatial information with the carrier based on space platforms, such as geostationary satellites or in low-orbit satellites, stratospheric balloons or unmanned and manned aircraft, etc. It is an essential infrastructure for China to constructed earth integrated information network. Earth integrated information network can not only support the highly dynamic and the real-time transmission of broadband down to earth observation, but the reliable transmission of the ultra remote and the large delay up to the deep space exploration, as well as provide services for the significant application of the ocean voyage, emergency rescue, navigation and positioning, air transportation, aerospace measurement or control and other fields.Thus the earth integrated information network can expand the human science, culture and productive activities to the space, ocean and even deep space, so it is the global research focus. The network of the laser communication link is an important component and the mean of communication in the earth integrated information network. Optimize the structure and design the system of the optical antenna is considered one of the difficulty key technologies for the space laser communication link network. Therefore, this paper presents an optical antenna system that it can be used in space laser communication link network.The antenna system was consisted by the plurality mirrors stitched with the rotational paraboloid as a substrate. The optical system structure of the multi-mirror stitched was simulated and emulated by the light tools software. Cassegrain form to be used in a relay optical system. The structural parameters of the relay optical system was optimized and designed by the optical design software of zemax. The results of the optimal design and simulation or emulation indicated that the antenna system had a good optical performance and a certain

  3. Design of integration time for the space-borne multi-spectral imager with super-wide field of view based on freeform mirror

    NASA Astrophysics Data System (ADS)

    Yin, Huan; Zhu, Jun; Zhang, Yongchao; Lu, Chunling; Wang, Chao; Ge, Xianying

    2015-08-01

    The freeform optics is extensively applied in the fields of aerospace, aviation, lighting, medical treatment, et al.. For the linearly push-broom space-borne imager, integration time of different field of view can be affected by the optical system design of the imager, orbits of the satellite, maneuver of the attitudes, rotation of the Earth, light delay due to the refraction and transmission of the atmosphere, terrain error and so on. The dynamically imaging quality should be affected by the accuracy and adjusting mode of the integration time. In this paper, a new method which is especially appropriate to imaging model simulating and integration time calculating for the wide-field-of-view remote sensor is proposed. Then, the integration time of specified viewing direction for the imager with a single projection center and a super-wide field of view based on freeform mirror, which is mounted on a sun-synchronous orbit satellite, is calculated. And influence on imaging quality of adjusting integration time of different grouping modes for the focal plane assembly is analyzed. The results indicate that with the constraint condition of satellite roll angle and the modulation transfer function (MTF) influence factor no more than 20°and 2% respectively, integration time of all CCDs for the whole focal plane assembly divided into two groups with each adopting the uniform integration time, can fulfill the requirements of the imaging quality for the imager.

  4. Ray tracing simulations for the wide-field x-ray telescope of the Einstein Probe mission based on Geant4 and XRTG4

    NASA Astrophysics Data System (ADS)

    Zhao, Donghua; Zhang, Chen; Yuan, Weimin; Willingale, Richard; Ling, Zhixing; Feng, Hua; Li, Hong; Ji, Jianfeng; Wang, Wenxin; Zhang, Shuangnan

    2014-07-01

    Einstein Probe (EP) is a proposed small scientific satellite dedicated to time-domain astrophysics working in the soft X-ray band. It will discover transients and monitor variable objects in 0.5-4 keV, for which it will employ a very large instantaneous field-of-view (60° × 60°), along with moderate spatial resolution (FWHM ˜ 5 arcmin). Its wide-field imaging capability will be achieved by using established technology in novel lobster-eye optics. In this paper, we present Monte-Carlo simulations for the focusing capabilities of EP's Wide-field X-ray Telescope (WXT). The simulations are performed using Geant4 with an X-ray tracer which was developed by cosine (http://cosine.nl/) to trace X-rays. Our work is the first step toward building a comprehensive model with which the design of the X-ray optics and the ultimate sensitivity of the instrument can be optimized by simulating the X-ray tracing and radiation environment of the system, including the focal plane detector and the shielding at the same time.

  5. Wide-field SCUBA-2 observations of NGC 2264: submillimetre clumps and filaments

    NASA Astrophysics Data System (ADS)

    Buckle, J. V.; Richer, J. S.

    2015-10-01

    We present wide-field observations of the NGC 2264 molecular cloud in the dust continuum at 850 and 450 μm using SCUBA-2 on the James Clerk Maxwell Telescope. Using 12CO 3 → 2 molecular line data, we determine that emission from CO contaminates the 850 μm emission at levels ˜30 per cent in localized regions associated with high-velocity molecular outflows. Much higher contamination levels of 60 per cent are seen in shocked regions near the massive star S Mon. If not removed, the levels of CO contamination would contribute an extra 13 per cent to the dust mass in NGC 2264. We use the FELLWALKER routine to decompose the dust into clumpy structures, and a Hessian-based routine to decompose the dust into filamentary structures. The filaments can be described as a hub-filament structure, with lower column density filaments radiating from the NGC 2264 C protocluster hub. Above mean filament column densities of 2.4 × 1022 cm-2, star formation proceeds with the formation of two or more protostars. Below these column densities, filaments are starless, or contain only a single protostar.

  6. Pulsed light imaging for wide-field dosimetry of photodynamic therapy in the skin

    NASA Astrophysics Data System (ADS)

    Davis, Scott C.; Sexton, Kristian; Chapman, Michael Shane; Maytin, Edward; Hasan, Tayyaba; Pogue, Brian W.

    2014-03-01

    Photodynamic therapy using aminoluvelinic acid (ALA) is an FDA-approved treatment for actinic keratoses, pre-cancerous skin lesions which pose a significant risk for immunocompromised individuals, such as organ transplant recipients. While PDT is generally effective, response rates vary, largely due to variations in the accumulation of the photosensitizer protoporphyrin IX (PpIX) after ALA application. The ability to quantify PpIX production before treatment could facilitate the use of additional interventions to improve outcomes. While many groups have demonstrated the ability to image PpIX in the clinic, these systems generally require darkening the room lights during imaging, which is unpopular with clinicians. We have developed a novel wide-field imaging system based on pulsed excitation and gated acquisition to image photosensitizer activity in the skin. The tissue is illuminated using four pulsed LED's to excite PpIX, and the remitted light acquired with a synchronized ICCD. This approach facilitates real-time background subtraction of ambient light, precluding the need to darken the exam room. Delivering light in short bursts also allows the use of elevated excitation intensity while remaining under the maximum permissible exposure limits, making the modality more sensitive to photosensitizer fluorescence than standard approaches. Images of tissue phantoms indicate system sensitivity down to 250nM PpIX and images of animals demonstrate detection of PpIX fluorescence in vivo under normal room light conditions.

  7. Characterization of flight detector arrays for the wide-field infrared survey explorer

    NASA Astrophysics Data System (ADS)

    Mainzer, Amy; Larsen, Mark; Stapelbroek, Maryn G.; Hogue, Henry; Garnett, James; Zandian, Majid; Mattson, Reed; Masterjohn, Stacy; Livingston, John; Lingner, Nicole; Alster, Natali; Ressler, Michael; Masci, Frank

    2008-07-01

    The Wide-field Infrared Survey Explorer is a NASA Midex mission launching in late 2009 that will survey the entire sky at 3.3, 4.7, 12, and 23 microns (PI: Ned Wright, UCLA). Its primary scientific goals are to find the nearest stars (actually most likely to be brown dwarfs) and the most luminous galaxies in the universe. WISE uses three dichroic beamsplitters to take simultaneous images in all four bands using four 1024×1024 detector arrays. The 3.3 and 4.7 micron channels use HgCdTe arrays, and the 12 and 23 micron bands employ Si:As arrays. In order to make a 1024×1024 Si:As array, a new multiplexer had to be designed and produced. The HgCdTe arrays were developed by Teledyne Imaging Systems, and the Si:As array were made by DRS. All four flight arrays have been delivered to the WISE payload contractor, Space Dynamics Laboratory. We present initial ground-based characterization results for the WISE arrays, including measurements of read noise, dark current, flat field and latent image performance, etc. These characterization data will be useful in producing the final WISE data product, an all-sky image atlas and source catalog.

  8. Brief wide-field photostimuli evoke and modulate oscillatory reverberating activity in cortical networks

    PubMed Central

    Pulizzi, Rocco; Musumeci, Gabriele; Van den Haute, Chris; Van De Vijver, Sebastiaan; Baekelandt, Veerle; Giugliano, Michele

    2016-01-01

    Cell assemblies manipulation by optogenetics is pivotal to advance neuroscience and neuroengineering. In in vivo applications, photostimulation often broadly addresses a population of cells simultaneously, leading to feed-forward and to reverberating responses in recurrent microcircuits. The former arise from direct activation of targets downstream, and are straightforward to interpret. The latter are consequence of feedback connectivity and may reflect a variety of time-scales and complex dynamical properties. We investigated wide-field photostimulation in cortical networks in vitro, employing substrate-integrated microelectrode arrays and long-term cultured neuronal networks. We characterized the effect of brief light pulses, while restricting the expression of channelrhodopsin to principal neurons. We evoked robust reverberating responses, oscillating in the physiological gamma frequency range, and found that such a frequency could be reliably manipulated varying the light pulse duration, not its intensity. By pharmacology, mathematical modelling, and intracellular recordings, we conclude that gamma oscillations likely emerge as in vivo from the excitatory-inhibitory interplay and that, unexpectedly, the light stimuli transiently facilitate excitatory synaptic transmission. Of relevance for in vitro models of (dys)functional cortical microcircuitry and in vivo manipulations of cell assemblies, we give for the first time evidence of network-level consequences of the alteration of synaptic physiology by optogenetics. PMID:27099182

  9. Wide field-of-view fluorescence image deconvolution with aberration-estimation from Fourier ptychography

    PubMed Central

    Chung, Jaebum; Kim, Jinho; Ou, Xiaoze; Horstmeyer, Roarke; Yang, Changhuei

    2016-01-01

    This paper presents a method to simultaneously acquire an aberration-corrected, wide field-of-view fluorescence image and a high-resolution coherent bright-field image using a computational microscopy method. First, the procedure applies Fourier ptychographic microscopy (FPM) to retrieve the amplitude and phase of a sample, at a resolution that significantly exceeds the cutoff spatial frequency of the microscope objective lens. At the same time, redundancy within the set of acquired FPM bright-field images offers a means to estimate microscope aberrations. Second, the procedure acquires an aberrated fluorescence image, and computationally improves its resolution through deconvolution with the estimated aberration map. An experimental demonstration successfully improves the bright-field resolution of fixed, stained and fluorescently tagged HeLa cells by a factor of 4.9, and reduces the error caused by aberrations in a fluorescence image by up to 31%, over a field of view of 6.2 mm by 9.3 mm. For optimal deconvolution, we show the fluorescence image needs to have a signal-to-noise ratio of at least ~18. PMID:26977345

  10. Single Plane Illumination Module and Micro-capillary Approach for a Wide-field Microscope

    PubMed Central

    Bruns, Thomas; Schickinger, Sarah; Schneckenburger, Herbert

    2014-01-01

    A module for light sheet or single plane illumination microscopy (SPIM) is described which is easily adapted to an inverted wide-field microscope and optimized for 3-dimensional cell cultures, e.g., multi-cellular tumor spheroids (MCTS). The SPIM excitation module shapes and deflects the light such that the sample is illuminated by a light sheet perpendicular to the detection path of the microscope. The system is characterized by use of a rectangular capillary for holding (and in an advanced version also by a micro-capillary approach for rotating) the samples, by synchronous adjustment of the illuminating light sheet and the objective lens used for fluorescence detection as well as by adaptation of a microfluidic system for application of fluorescent dyes, pharmaceutical agents or drugs in small quantities. A protocol for working with this system is given, and some technical details are reported. Representative results include (1) measurements of the uptake of a cytostatic drug (doxorubicin) and its partial conversion to a degradation product, (2) redox measurements by use of a genetically encoded glutathione sensor upon addition of an oxidizing agent, and (3) initiation and labeling of cell necrosis upon inhibition of the mitochondrial respiratory chain. Differences and advantages of the present SPIM module in comparison with existing systems are discussed. PMID:25146321

  11. Wide field-of-view fluorescence image deconvolution with aberration-estimation from Fourier ptychography.

    PubMed

    Chung, Jaebum; Kim, Jinho; Ou, Xiaoze; Horstmeyer, Roarke; Yang, Changhuei

    2016-02-01

    This paper presents a method to simultaneously acquire an aberration-corrected, wide field-of-view fluorescence image and a high-resolution coherent bright-field image using a computational microscopy method. First, the procedure applies Fourier ptychographic microscopy (FPM) to retrieve the amplitude and phase of a sample, at a resolution that significantly exceeds the cutoff spatial frequency of the microscope objective lens. At the same time, redundancy within the set of acquired FPM bright-field images offers a means to estimate microscope aberrations. Second, the procedure acquires an aberrated fluorescence image, and computationally improves its resolution through deconvolution with the estimated aberration map. An experimental demonstration successfully improves the bright-field resolution of fixed, stained and fluorescently tagged HeLa cells by a factor of 4.9, and reduces the error caused by aberrations in a fluorescence image by up to 31%, over a field of view of 6.2 mm by 9.3 mm. For optimal deconvolution, we show the fluorescence image needs to have a signal-to-noise ratio of at least ~18. PMID:26977345

  12. WIDE-FIELD WIDE-BAND INTERFEROMETRIC IMAGING: THE WB A-PROJECTION AND HYBRID ALGORITHMS

    SciTech Connect

    Bhatnagar, S.; Rau, U.; Golap, K. E-mail: rurvashi@nrao.edu

    2013-06-20

    Variations of the antenna primary beam (PB) pattern as a function of time, frequency, and polarization form one of the dominant direction-dependent effects at most radio frequency bands. These gains may also vary from antenna to antenna. The A-Projection algorithm, published earlier, accounts for the effects of the narrow-band antenna PB in full polarization. In this paper, we present the wide-band A-Projection algorithm (WB A-Projection) to include the effects of wide bandwidth in the A-term itself and show that the resulting algorithm simultaneously corrects for the time, frequency, and polarization dependence of the PB. We discuss the combination of the WB A-Projection and the multi-term multi-frequency synthesis (MT-MFS) algorithm for simultaneous mapping of the sky brightness distribution and the spectral index distribution across a wide field of view. We also discuss the use of the narrow-band A-Projection algorithm in hybrid imaging schemes that account for the frequency dependence of the PB in the image domain.

  13. Blood vessel segmentation and width estimation in ultra-wide field scanning laser ophthalmoscopy.

    PubMed

    Pellegrini, Enrico; Robertson, Gavin; Trucco, Emanuele; MacGillivray, Tom J; Lupascu, Carmen; van Hemert, Jano; Williams, Michelle C; Newby, David E; van Beek, Edwin; Houston, Graeme

    2014-12-01

    Features of the retinal vasculature, such as vessel widths, are considered biomarkers for systemic disease. The aim of this work is to present a supervised approach to vessel segmentation in ultra-wide field of view scanning laser ophthalmoscope (UWFoV SLO) images and to evaluate its performance in terms of segmentation and vessel width estimation accuracy. The results of the proposed method are compared with ground truth measurements from human observers and with existing state-of-the-art techniques developed for fundus camera images that we optimized for UWFoV SLO images. Our algorithm is based on multi-scale matched filters, a neural network classifier and hysteresis thresholding. After spline-based refinement of the detected vessel contours, the vessel widths are estimated from the binary maps. Such analysis is performed on SLO images for the first time. The proposed method achieves the best results, both in vessel segmentation and in width estimation, in comparison to other automatic techniques. PMID:25574441

  14. Revisiting Earth Radiation Budget from ERBE Wide-Field-of-View Nonscanner

    NASA Astrophysics Data System (ADS)

    Shrestha, A. K.; Kato, S.; Wong, T.; Stackhouse, P. W.; Smith, G. L.; Rose, F. G.; Miller, W. F.; Bush, K.; Rutan, D. A.; Minnis, P.; Doelling, D.

    2014-12-01

    Earth Radiation Budget Experiment (ERBE) wide-field-of-view (WFOV) nonscanner on Earth Radiation Budget Satellite (ERBS) and NOAA-9/NOAA-10 provided broadband shortwave and longwave irradiances from 1985 to 1998. The observations from nonscanner at satellite altitude are converted to TOA flux by inversion processes, which involve applying so-called shape factors. However, the nonscanner processing used only one partly cloudy scene type to determine the shape factor. In addition, it does not consider spectral dependent shortwave filter degradation. Based on knowledge from recent developments in the CERES process, we propose to revise inversion processes for ERBS, NOAA9, and NoAA10 WFOV nonscanners. We will consider spectral dependent degradation of the shortwave filter transmissivity and apply scene type dependent shape factors. In the proposed inversion process, we will use imager derived cloud fraction to identify the scene type over the field of view of nonscanner instruments. In this presentation, we will present proposed inversion processes and some preliminary results.

  15. Calibrating Wide Field Channel Imagery for the Post-SM4 Advanced Camera for Surveys

    NASA Astrophysics Data System (ADS)

    Armstrong, Amber; Grogin, N.; Lim, P.; Golimowski, D.; Smith, L.

    2011-01-01

    The Wide Field Channel detector of the Advanced Camera for Surveys on board the Hubble Space Telescope was restored to operation during HST Servicing Mission 4 in May 2009. With new control electronics and almost nine years in low Earth orbit, the ACS WFC presents a variety of calibration challenges both old and new. These include mode-dependent bias gradients, bias striping noise, bad columns, cold columns, hot pixels, bad pixels, "scarring,” read-out amplifier crosstalk, and substantial charge-transfer inefficiency. Fortunately, most of these detector irregularities are already corrected or flagged by the existing ACS WFC calibration pipeline, designed prior to the WFC failure. However, our close inspection of post-SM4 calibration images, including bias frames, dark exposures, and astronomical reference fields has motivated us to modernize the WFC calibration pipeline so that we may continue to deliver images of the highest possible quality to the HST observer. We provide a quantitative summary of the various post-SM4 WFC image calibration issues, as well as our strategies for addressing them both within the automated calibration pipeline and outside the pipeline as optional stand-alone calibration utilities available to the HST user community.

  16. Wide Field Camera 3 Instrument Handbook for Cycle 21 v. 5.0

    NASA Astrophysics Data System (ADS)

    Dressel, L.

    2012-12-01

    The Wide Field Camera 3 (WFC3) is a fourth-generation imaging instrument. It was installed in the Hubble Space Telescope (HST) during Servicing Mission 4 (SM4) in May 2009. WFC3 saw first light on June 24, 2009, following the cooling of its detectors. Servicing Mission 4 Observatory Verification (SMOV) activities were completed in late August 2009, and were followed by the Cycle 17 calibration and science programs. This WFC3 Instrument Handbook has been prepared by the WFC3 team at STScI. It is the basic technical reference manual for WFC3 observers. The information in this Handbook is intended to be useful for Cycle 21 Phase I proposers, for the subsequently selected General Observers (GOs) as they prepare their Phase II specifications, and for those analyzing WFC3 data. The HST Primer and the HST Call for Proposals also contain valuable information for proposers, and the Call for Proposals is the final authority on HST policy. This edition of the WFC3 Instrument Handbook (Version 5.0) was written near the end of the execution of the Cycle 19 calibration plan. It supersedes Version 4.0, and includes results from analysis of the first three cycles of on-orbit performance.

  17. LAIWO: a new wide-field CCD camera for Wise Observatory

    NASA Astrophysics Data System (ADS)

    Baumeister, Harald; Afonso, Cristina; Marien, Karl-Heinz; Klein, Ralf

    2006-06-01

    LAIWO is a new CCD wide-field camera for the 40-inch Ritchey-Chretien telescope at Wise Observatory in Mitzpe Ramon/Israel. The telescope is identical to the 40-in. telescope at Las Campanas Observatory, Chile, which is described in [2]. LAIWO was designed and built at Max-Planck-Institute for Astronomy in Heidelberg, Germany. The scientific aim of the instrument is to detect Jupiter-sized extra-solar planets around I=14-15 magnitude stars with the transit method, which relies on the temporary drop in brightness of the parent star harboring the planet. LAIWO can observe a 1.4 x 1.4 degree field-of-view and has four CCDs with 4096*4096 pixels each The Fairchild Imaging CCDs have a pixel size of 15 microns. Since they are not 2-side buttable, they are arranged with spacings between the chips that is equal to the size of a single CCD minus a small overlap. The CCDs are cooled by liquid nitrogen to a temperature of about -100 °C. The four science CCDs and the guider CCD are mounted on a common cryogenic plate which can be adjusted in three degrees of freedom. Each of these detectors can also be adjusted independently by a similar mechanism. The instrument contains large shutter and filter mechanisms, both designed in a modular way for fast exchange and easy maintenance.

  18. The First Ultra-cool Brown Dwarf Discovered by the Wide-field Infrared Survey Explorer

    NASA Astrophysics Data System (ADS)

    Mainzer, A.; Cushing, Michael C.; Skrutskie, M.; Gelino, C. R.; Kirkpatrick, J. Davy; Jarrett, T.; Masci, F.; Marley, Mark S.; Saumon, D.; Wright, E.; Beaton, R.; Dietrich, M.; Eisenhardt, P.; Garnavich, P.; Kuhn, O.; Leisawitz, D.; Marsh, K.; McLean, I.; Padgett, D.; Rueff, K.

    2011-01-01

    We report the discovery of the first new ultra-cool brown dwarf (BDs) found with the Wide-field Infrared Survey Explorer (WISE). The object's preliminary designation is WISEPC J045853.90+643451.9. Follow-up spectroscopy with the LUCIFER instrument on the Large Binocular Telescope indicates that it is a very late-type T dwarf with a spectral type approximately equal to T9. Fits to an IRTF/SpeX 0.8-2.5 μm spectrum to the model atmospheres of Marley and Saumon indicate an effective temperature of approximately 600 K as well as the presence of vertical mixing in its atmosphere. The new BD is easily detected by WISE, with a signal-to-noise ratio of ~36 at 4.6 μm. Current estimates place it at a distance of 6-10 pc. This object represents the first in what will likely be hundreds of nearby BDs found by WISE that will be suitable for follow-up observations, including those with the James Webb Space Telescope. One of the two primary scientific goals of the WISE mission is to find the coolest, closest stars to our Sun; the discovery of this new BD proves that WISE is capable of fulfilling this objective.

  19. The silicon micro-strip detector plane for the LOFT/wide-field monitor

    NASA Astrophysics Data System (ADS)

    Goldwurm, A.; Ferrando, P.; Götz, D.; Laurent, P.; Lebrun, F.; Limousin, O.; Basa, S.; Bertoli, W.; Delagnes, Eric; Dolgorouky, Y.; Gevin, O.; Gros, A.; Gouiffes, C.; Jeanneau, F.; Lachaud, C.; Llored, M.; Olivetto, C.; Prevot, G.; Renaud, D.; Rodriguez, J.; Rossin, C.; Schanne, S.; Soldi, S.; Varniere, P.

    2012-09-01

    The main objective of the Wide Field Monitor (WFM) on the LOFT mission is to provide unambiguous detection of the high-energy sources in a large field of view, in order to support science operations of the LOFT primary instrument, the LAD. The monitor will also provide by itself a large number of results on the timing and spectral behavior of hundreds of galactic compact objects, Active Galactic Nuclei and Gamma-Ray Bursts. The WFM is based on the coded aperture concept where a position sensitive detector records the shadow of a mask projected by the celestial sources. The proposed WFM detector plane, based on Double Sided micro-Strip Silicon Detectors (DSSD), will allow proper 2-dimensional recording of the projected shadows. Indeed the positioning of the photon interaction in the detector with equivalent fine resolution in both directions insures the best imaging capability compatible with the allocated budgets for this telescope on LOFT. We will describe here the overall configuration of this 2D-WFM and the design and characteristics of the DSSD detector plane including its imaging and spectral performances. We will also present a number of simulated results discussing the advantages that this configuration offers to LOFT. A DSSD-based WFM will in particular reduce significantly the source confusion experienced by the WFM in crowded regions of the sky like the Galactic Center and will in general increase the observatory science capability of the mission.

  20. Toward Epoch of Reionization Measurements with Wide-Field Radio Observations

    NASA Astrophysics Data System (ADS)

    Morales, Miguel F.; Hewitt, Jacqueline

    2004-11-01

    This paper explores the potential for statistical epoch of reionization (EOR) measurements using wide-field radio observations. New developments in low-frequency radio instrumentation and signal processing allow very sensitive EOR measurements, and the analysis techniques enabled by these advances offer natural ways of separating the EOR signal from the residual foreground emission. This paper introduces the enabling technologies and proposes an analysis technique designed to make optimal use of the capabilities of next-generation low-frequency radio arrays. The observations we propose can directly observe the power spectrum of the EOR using relatively short observations and are significantly more sensitive than other techniques that have been discussed in the literature. For example, in the absence of foreground contamination the measurements we propose would produce five 3 σ power spectrum points in 100 hr of observation with only 4 MHz bandwidth with LOFAR for simple models of the high-redshift 21 cm emission. The challenge of residual foreground removal may be addressed by the symmetries in the three-dimensional (two spatial frequencies and radio frequency) radio interferometric data. These symmetries naturally separate the EOR signal from most classes of residual unsubtracted foreground contamination, including all foreground continuum sources and radio line emission from the Milky Way.

  1. Performance verification testing for HET wide-field upgrade tracker in the laboratory

    NASA Astrophysics Data System (ADS)

    Good, John; Hayes, Richard; Beno, Joseph; Booth, John; Cornell, Mark E.; Hill, Gary J.; Lee, Hanshin; Mock, Jason; Rafal, Marc; Savage, Richard; Soukup, Ian

    2010-07-01

    To enable the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), the McDonald Observatory (MDO) and the Center for Electro-mechanics (CEM) at the University of Texas at Austin are developing a new HET tracker in support of the Wide-Field Upgrade (WFU) and the Visible Integral-Field Replicable Unit Spectrograph (VIRUS). The precision tracker is required to maintain the position of a 3,100 kg payload within ten microns of its desired position relative to the telescope's primary mirror. The hardware system to accomplish this has ten precision controlled actuators. Prior to installation on the telescope, full performance verification is required of the completed tracker in CEM's lab, without a primary mirror or the telescope's final instrument package. This requires the development of a laboratory test stand capable of supporting the completed tracker over its full range of motion, as well as means of measurement and methodology that can verify the accuracy of the tracker motion over full travel (4m diameter circle, 400 mm deep, with 9 degrees of tip and tilt) at a cost and schedule in keeping with the HET WFU requirements. Several techniques have been evaluated to complete this series of tests including: photogrammetry, laser tracker, autocollimator, and a distance measuring interferometer, with the laser tracker ultimately being identified as the most viable method. The design of the proposed system and its implementation in the lab is presented along with the test processes, predicted accuracy, and the basis for using the chosen method*.

  2. The DECam NEO Survey: A sensitive, wide-field search for near-Earth asteroids

    NASA Astrophysics Data System (ADS)

    Allen, Lori; Trilling, David; Valdes, Frank; Fuentes, Cesar; James, David; Herrera, David; Rajagopal, Jayadev; Burt, Brian; Axelrod, Tim

    2014-11-01

    We report preliminary results from a survey for near-Earth asteroids with the Dark Energy Camera. DECam is a facility-class 520 Megapixel wide-field imager on the 4m Blanco telescope at Cerro Tololo Inter-american Observatory. It has a 3.2 square degree field of view, and a focal plane consisting of 62 2Kx4K red-optimized CCDs. In spite of its large number of pixels, DECam reads out in less than 30 seconds, making it possible to cover a large area of sky efficiently. Compared to the largest aperture of the currently most productive NEO searches, the Blanco has an aperture that is several times larger and a comparable field of view. Our goal is to measure the size distribution of NEOs well below 140m, and we have been allocated 30 nights through the NOAO Survey program to achieve it. Here we report on results from the first 10 nights of our survey.

  3. Wide-field wide-band Interferometric Imaging: The WB A-Projection and Hybrid Algorithms

    NASA Astrophysics Data System (ADS)

    Bhatnagar, S.; Rau, U.; Golap, K.

    2013-06-01

    Variations of the antenna primary beam (PB) pattern as a function of time, frequency, and polarization form one of the dominant direction-dependent effects at most radio frequency bands. These gains may also vary from antenna to antenna. The A-Projection algorithm, published earlier, accounts for the effects of the narrow-band antenna PB in full polarization. In this paper, we present the wide-band A-Projection algorithm (WB A-Projection) to include the effects of wide bandwidth in the A-term itself and show that the resulting algorithm simultaneously corrects for the time, frequency, and polarization dependence of the PB. We discuss the combination of the WB A-Projection and the multi-term multi-frequency synthesis (MT-MFS) algorithm for simultaneous mapping of the sky brightness distribution and the spectral index distribution across a wide field of view. We also discuss the use of the narrow-band A-Projection algorithm in hybrid imaging schemes that account for the frequency dependence of the PB in the image domain.

  4. Intraoperative detection and removal of microscopic residual sarcoma using wide-field imaging

    PubMed Central

    Mito, Jeffrey K; Ferrer, Jorge M; Brigman, Brian E; Lee, Chang-Lung; Dodd, Rebecca D; Eward, William C; Marshall, Lisa F; Cuneo, Kyle C; Carter, Jessica E; Ramasunder, Shalini; Kim, Yongbaek; Lee, W David; Griffith, Linda G; Bawendi, Moungi G; Kirsch, David G

    2012-01-01

    Abstract BACKGROUND: The goal of limb-sparing surgery for a soft tissue sarcoma of the extremity is to remove all malignant cells while preserving limb function. After initial surgery, microscopic residual disease in the tumor bed will cause a local recurrence in approximately 33% of patients with sarcoma. To help identify these patients, the authors developed an in vivo imaging system to investigate the suitability of molecular imaging for intraoperative visualization. METHODS: A primary mouse model of soft tissue sarcoma and a wide field-of-view imaging device were used to investigate a series of exogenously administered, near-infrared (NIR) fluorescent probes activated by cathepsin proteases for real-time intraoperative imaging. RESULTS: The authors demonstrated that exogenously administered cathepsin-activated probes can be used for image-guided surgery to identify microscopic residual NIR fluorescence in the tumor beds of mice. The presence of residual NIR fluorescence was correlated with microscopic residual sarcoma and local recurrence. The removal of residual NIR fluorescence improved local control. CONCLUSIONS: The authors concluded that their technique has the potential to be used for intraoperative image-guided surgery to identify microscopic residual disease in patients with cancer. Cancer 2012. © 2012 American Cancer Society. PMID:22437667

  5. Preliminary Results from the Wide-field Infrared Survey Explorer's NEOWISE Search for Minor Planets

    NASA Astrophysics Data System (ADS)

    Mainzer, A.; Bauer, J. M.; Grav, T.; Masiero, J.; McMillan, R. S.; Walker, R.; Tholen, D. J.; Wright, E.; Eisenhardt, P.; Cutri, R.; Neowise Team

    2011-12-01

    The Wide-Field Infrared Survey Explorer (WISE) imaged the entire sky twice between January, 2010 and January, 2011 at four wavelengths spanning the near through mid-IR at sensitivities hundreds of times greater than previous surveys [1]. The WISE band-passes (3.4, 4.6, 12 and 22mm) sample the flux from most inner-solar-system bodies near the peak of their thermal emission. Overlapping sky regions were sampled repeatedly at 3 hour intervals. The same region of sky was observed a minimum of 8 times. While the primary WISE science objectives focus on ultra-luminous infrared galaxies and brown dwarfs, additions to the baseline WISE pipeline (collectively known as "NEOWISE") have enabled the detection of undiscovered moving objects, as well as previously known bodies [2]. NEOWISE has detected more than 155,000 minor planets, including more than 500 near-Earth objects (NEOs), ~2000 Jupiter Trojans, ~120 comets, and ~20 outer Solar System objects such as Centaurs. The survey has discovered ~34,000 new minor planets, including 130 new NEOs and 20 new comets. The NEOWISE data will drive a wide range of new Solar System investigations. NEOWISE allows precise determination of IR-derived diameters and albedos for minor planets throughout the Solar System [3],[4]. We will summarize the latest results from the project, including studies of the statistical properties of asteroid populations such as the NEOs, and comparisons between albedo and asteroid taxonomic classification.

  6. A TECHNIQUE FOR PRIMARY BEAM CALIBRATION OF DRIFT-SCANNING, WIDE-FIELD ANTENNA ELEMENTS

    SciTech Connect

    Pober, Jonathan C.; Parsons, Aaron R.; Jacobs, Daniel C.; Aguirre, James E.; Moore, David F.; Bradley, Richard F.; Parashare, Chaitali R.; Carilli, Chris L.; Gugliucci, Nicole E.

    2012-02-15

    We present a new technique for calibrating the primary beam of a wide-field, drift-scanning antenna element. Drift-scan observing is not compatible with standard beam calibration routines, and the situation is further complicated by difficult-to-parameterize beam shapes and, at low frequencies, the sparsity of accurate source spectra to use as calibrators. We overcome these challenges by building up an interrelated network of source 'crossing points'-locations where the primary beam is sampled by multiple sources. Using the single assumption that a beam has 180 Degree-Sign rotational symmetry, we can achieve significant beam coverage with only a few tens of sources. The resulting network of crossing points allows us to solve for both a beam model and source flux densities referenced to a single calibrator source, circumventing the need for a large sample of well-characterized calibrators. We illustrate the method with actual and simulated observations from the Precision Array for Probing the Epoch of Reionization.

  7. Dome Degradation Characterization of Wide-Field-of-View Nonscanner Aboard ERBE and Its Reprocessing

    NASA Technical Reports Server (NTRS)

    Shrestha, Alok K.; Kato, Seiji; Wong, Takmeng; Su, Wenying; Stackhouse, Paul W., Jr.; Rose, Fred; Miller, Walter F.; Bush, Kathryn; Rutan, David A.; Minnis, Patrick; Doelling, David R.; Smith, George L.

    2015-01-01

    Earth Radiation Budget Experiment (ERBE) wide-field-of-view (WFOV) nonscanners aboard ERBS and NOAA- 9/NOAA-10 provided broadband shortwave and longwave irradiances from 1985 to 1999. The previous analysis showed dome degradation in the shortwave nonscanner instruments. The correction was performed with a constant spectral (gray assumption) degradation. We suspect that the gray assumption affected daytime longwave irradiance and led to a day-minus-night longwave flux differences (little change in night time longwave) increase over time. Based on knowledge from the CERES process, we will reprocess entire ERBE nonscanner radiation dataset by characterizing shortwave dome transmissivity with spectral dependent degradation using the solar data observed by these instruments. Once spectral dependent degradation is derived, imager derived cloud fraction and the cloud phase as well as surface type over the FOV of nonscanner instruments will be used to model unfiltering coefficients. This poster primarily explains the reprocessing techniques and includes initial comparison of several months of data processed with existing and our recent methods.

  8. The Wide-Field Infrared Survey Explorer (WISE): Mission Description and Initial On-Orbit Performance

    NASA Technical Reports Server (NTRS)

    Wright, Edward L.; Eisenhardt, Peter R. M.; Mainzer, Amy; Ressler, Michael E.; Cutri, Roc M.; Jarrett, Thomas; Kirkpatrick, J. Davy; Padgett, Deborah; McMillan, Robert S.; Skrutskie,Michael; Stanford, S. A.; Cohen, Martin; Walker, Russell G.; Mather, John C.; Leisawitz, David; Gautier, Thomas N., III; McLean, Ian; Benford, Dominic; Lonsdale,Carol J.; Blain, Andrew; Mendez,Bryan; Irace, William R.; Duval, Valerie; Liu, Fengchuan; Royer, Don

    2010-01-01

    The all sky surveys done by the Palomar Observatory Schmidt, the European Southern Observatory Schmidt, and the United Kingdom Schmidt, the InfraRed Astronomical Satellite and the 2 Micron All Sky Survey have proven to be extremely useful tools for astronomy with value that lasts for decades. The Wide-field Infrared Survey Explorer is mapping the whole sky following its launch on 14 December 2009. WISE began surveying the sky on 14 Jan 2010 and completed its first full coverage of the sky on July 17. The survey will continue to cover the sky a second time until the cryogen is exhausted (anticipated in November 2010). WISE is achieving 5 sigma point source sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the ecliptic in bands centered at wavelengths of 3.4, 4.6, 12 and 22 micrometers. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background. The angular resolution is 6.1", 6.4", 6.5" and 12.0" at 3.4, 4.6, 12 and 22 micrometers, and the astrometric precision for high SNR sources is better than 0.15".

  9. Brief wide-field photostimuli evoke and modulate oscillatory reverberating activity in cortical networks.

    PubMed

    Pulizzi, Rocco; Musumeci, Gabriele; Van den Haute, Chris; Van De Vijver, Sebastiaan; Baekelandt, Veerle; Giugliano, Michele

    2016-01-01

    Cell assemblies manipulation by optogenetics is pivotal to advance neuroscience and neuroengineering. In in vivo applications, photostimulation often broadly addresses a population of cells simultaneously, leading to feed-forward and to reverberating responses in recurrent microcircuits. The former arise from direct activation of targets downstream, and are straightforward to interpret. The latter are consequence of feedback connectivity and may reflect a variety of time-scales and complex dynamical properties. We investigated wide-field photostimulation in cortical networks in vitro, employing substrate-integrated microelectrode arrays and long-term cultured neuronal networks. We characterized the effect of brief light pulses, while restricting the expression of channelrhodopsin to principal neurons. We evoked robust reverberating responses, oscillating in the physiological gamma frequency range, and found that such a frequency could be reliably manipulated varying the light pulse duration, not its intensity. By pharmacology, mathematical modelling, and intracellular recordings, we conclude that gamma oscillations likely emerge as in vivo from the excitatory-inhibitory interplay and that, unexpectedly, the light stimuli transiently facilitate excitatory synaptic transmission. Of relevance for in vitro models of (dys)functional cortical microcircuitry and in vivo manipulations of cell assemblies, we give for the first time evidence of network-level consequences of the alteration of synaptic physiology by optogenetics. PMID:27099182

  10. Flatfielding and photometric accuracy of the first Hubble Space Telescope Wide Field Camera

    NASA Technical Reports Server (NTRS)

    Phillips, Andrew C.; Forbes, Duncan A.; Bershady, Matthew A.; Illingworth, Garth D.; Koo, David C.

    1994-01-01

    Long exposures with the original Hubble Space Telescope (HST) Wide Field Camera (WFC) through the F555W and F785LP filters show gradients in the background following standard pipeline calibration. We show that these gradients also appear in stellar photometry, and thus must be predominantly the result of inaccurate flatfielding at a level of 10 to 20%. Color errors may be even larger. Applying corrections to the flatfield frames based on the background structure leads to an improved accuracy of approximately 4% for single-measurement photometry within a single CCD chip, compared to the approximately 10% accuracy suggested by previous studies. We have reanalyzed the F555W and F785LP calibration photometry to derive zero points appropriate for corrected data; these new zero points have internal consistency at a level of approximately 1.2%, based on comparison between the chip-to-chip offsets and the sky levels observed in corrected images. This indicates that relative photometry approaching 1 to 2% is achievable with the WFC. The new zero point values for corrected data are 22.90, 23.04, 23.04, and 22.96 (F555W), and 21.56, 21.64, 21.44, and 21.47 (F785LP) for chips WF1-WF4, respectively. Comparison is made with other zero points, and the applicability of 'delta flats' is briefly discussed.

  11. Hubble Space Telescope Wide Field Camera imaging of the gravitational lens 2237 + 0305

    NASA Technical Reports Server (NTRS)

    Rix, Hans-Walter; Schneider, Donald P.; Bahcall, John N.

    1992-01-01

    Images of the gravitational lens system 2237 + 0305, taken with the HST Wide Field Camera, are analyzed. Positions for the four quasar images, accurate to +/-0.015 arcsec, and relative magnitudes in U and R, accurate to +/-0.06 and 0.04 mag, respectively, are determined. The upper limits on the observed brightness of the fifth image are found to be less than or approximately equal to 7 percent of the brightest quasar image. The mass of the lens inside 0.9 arcsec is found to be 1.08 +/-0.02 x 10 exp 10 solar masses/h100 corresponding to a mass-to-light ratio in B of 12.3h100. This solar mass/solar luminosity estimate agrees with values obtained from stellar dynamics for other elliptical galaxies. A comparison of predictions from this mass model with the measured central velocity dispersion yields a distance-independent agreement to within 10 percent, assuming isotropic velocity dispersions.

  12. Wide Field Collimator 2 (WFC2) for GOES Imager and Sounder

    NASA Technical Reports Server (NTRS)

    Etemad, Shahriar; Bremer, James C.; Zukowski, Barbara J.; Pasquale, Bert A.; zukowski, Tmitri J.; Prince, Robert E.; O'Neill, Patrick A.; Ross, Robert W.

    2004-01-01

    Two of the GOES instruments, the Imager and the Sounder, perform scans of the Earth to provide a full disc picture of the Earth. To verify the entire scan process, an image of a target that covers an 18 deg. circular field-of-view is collimated and projected into the field of regard of each instrument. The Wide Field Collimator 2 (WFC2) has many advantages over its predecessor, WFC1, including lower thermal dissipation higher fir field MTF, smaller package, and a more intuitive (faster) focusing process. The illumination source is an LED array that emits in a narrow spectral band centered at 689 nm, within the visible spectral bands of the Imager and Sounder. The illumination level can be continuously adjusted electronically. Lower thermal dissipation eliminates the need for forced convection cooling and minimizes time to reach thermal stability. The lens system has been optimized for the illumination source spectral output and athernalized to remain in focus during bulk temperature changes within the laboratory environment. The MTF of the lens is higher than that of the WFC1 at the edge of FOV. The target is focused in three orthogonal motions, controlled by an ergonomic system that saves substantial time and produces a sharper focus. Key words: Collimator, GOES, Imager, Sounder, Projector

  13. Wide-Field Infrared Survey Explorer Observations of the Evolution of Massive Star-Forming Regions

    NASA Technical Reports Server (NTRS)

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Rebull, L. M.; Padgett, D. L.; Asslef, R. J.

    2012-01-01

    We present the results of a mid-infrared survey of II outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the "fireworks hypothesis" since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

  14. Wide-Field Infrared Survey Explorer Observations of the Evolution of Massive Star-Forming Regions

    NASA Technical Reports Server (NTRS)

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Rebull, L. M.; Padgett, D. L.; Assef, R. J.

    2011-01-01

    We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars.We dub this process the "fireworks hypothesis" since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks.We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

  15. WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF THE EVOLUTION OF MASSIVE STAR-FORMING REGIONS

    SciTech Connect

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Padgett, D. L.; Rebull, L. M.

    2012-01-10

    We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the 'fireworks hypothesis' since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

  16. Enhanced flight symbology for wide-field-of-view helmet-mounted displays

    NASA Astrophysics Data System (ADS)

    Rogers, Steven P.; Asbury, Charles N.; Szoboszlay, Zoltan P.

    2003-09-01

    A series of studies was conducted to improve the Army aviator's ability to perform night missions by developing innovative symbols that capitalize on the advantages of new wide field-of-view (WFOV) helmet-mounted displays (HMDs). The most important outcomes of the research were two new symbol types called the Cylinder and the Flight Path Predictor. The Cylinder provides a large symbolic representation of real-world orientation that enables pilots to maintain the world frame of reference even if the visibility of the world is lost due to dust, smoke, snow, or inadvertent instrument meteorological conditions (IMC). Furthermore, the Cylinder is peripherally presented, supporting the "ambient" visual mode so that it does not require the conscious attention of the viewer. The Flight Path Predictor was developed to show the predicted flight path of a maneuvering aircraft using earth-referenced HMD symbology. The experimental evidence and the pilot interview results show that the new HMD symbology sets are capable of preventing spatial disorientation, improving flight safety, enhancing flight maneuver precision, and reducing workload so that the pilot can more effectively perform the critical mission tasks.

  17. Electrolocation-based underwater obstacle avoidance using wide-field integration methods.

    PubMed

    Dimble, Kedar D; Faddy, James M; Humbert, J Sean

    2014-03-01

    Weakly electric fish are capable of efficiently performing obstacle avoidance in dark and navigationally challenging aquatic environments using electrosensory information. This sensory modality enables extraction of relevant proximity information about surrounding obstacles by interpretation of perturbations induced to the fish's self-generated electric field. In this paper, reflexive obstacle avoidance is demonstrated by extracting relative proximity information using spatial decompositions of the perturbation signal, also called an electric image. Electrostatics equations were formulated for mathematically expressing electric images due to a straight tunnel to the electric field generated with a planar electro-sensor model. These equations were further used to design a wide-field integration based static output feedback controller. The controller was implemented in quasi-static simulations for environments with complicated geometries modelled using finite element methods to demonstrate sense and avoid behaviours. The simulation results were confirmed by performing experiments using a computer operated gantry system in environments lined with either conductive or non-conductive objects acting as global stimuli to the field of the electro-sensor. The proposed approach is computationally inexpensive and readily implementable, making underwater autonomous navigation in real-time feasible. PMID:24451219

  18. An Automatic Technique for Finding Faint Moving Objects in Wide Field CCD Images

    NASA Astrophysics Data System (ADS)

    Hainaut, O. R.; Meech, K. J.

    1996-09-01

    The traditional method used to find moving objects in astronomical images is to blink pairs or series of frames after registering them to align the background objects. While this technique is extremely efficient in terms of the low signal-to-noise ratio that the human sight can detect, it proved to be extremely time-, brain- and eyesight-consuming. The wide-field images provided by the large CCD mosaic recently built at IfA cover a field of view of 20 to 30' over 8192(2) pixels. Blinking such images is an enormous task, comparable to that of blinking large photographic plates. However, as the data are available digitally (each image occupying 260Mb of disk space), we are developing a set of computer codes to perform the moving object identification in sets of frames. This poster will describe the techniques we use in order to reach a detection efficiency as good as that of a human blinker; the main steps are to find all the objects in each frame (for which we rely on ``S-Extractor'' (Bertin & Arnouts (1996), A&ASS 117, 393), then identify all the background objects, and finally to search the non-background objects for sources moving in a coherent fashion. We will also describe the results of this method applied to actual data from the 8k CCD mosaic. {This work is being supported, in part, by NSF grant AST 92-21318.}

  19. Wide Field CO Mapping in the Region of IRAS 19312+1950

    NASA Astrophysics Data System (ADS)

    Nakashima, Jun-ichi; Ladeyschikov, Dmitry A.; Sobolev, Andrej M.; Zhang, Yong; Hsia, Chih-Hao; Yung, Bosco H. K.

    2016-07-01

    We report the results of wide field CO mapping in the region of IRAS 19312+1950. This Infrared Astronomical Satellite (IRAS) object exhibits SiO/H2O/OH maser emission, and is embedded in a chemically rich molecular component, the origin of which is still unknown. In order to reveal the entire structure and gas mass of the surrounding molecular component for the first time, we have mapped a wide region around IRAS 19312+1950 in the 12CO J = 1–0, 13CO J = 1–0 and C18O J = 1–0 lines using the Nobeyama 45 m telescope. In conjunction with archival CO maps, we investigated a region up to 20‧ × 20‧ in size around this IRAS object. We calculated the CO gas mass assuming local thermal equilibrium, the stellar velocity through the interstellar medium assuming an analytic model of bow shock, and the absolute luminosity, using the latest archival data and trigonometric parallax distance. The derived gas mass (225 M ⊙–478 M ⊙) of the molecular component and the relatively large luminosity (2.63 × 104 L ⊙) suggest that the central SiO/H2O/OH maser source is a red supergiant rather than an asymptotic giant branch (AGB) star or post-AGB star.

  20. (Sn)DICE: A Calibration System Designed for Wide Field Imagers

    NASA Astrophysics Data System (ADS)

    Regnault, N.; Barrelet, E.; Guyonnet, A.; Juramy, C.; Rocci, P.-F.; Le Guillou, L.; Schahmanèche, K.; Villa, F.

    2016-05-01

    Dark Energy studies with type Ia supernovae set very tight constraints on the photometric calibration of the imagers used to detect the supernovae and follow up their flux variations. Among the key challenges is the measurement of the shape and normalization of the instrumental throughput. The DICE system was developed by members of the Supernova Legacy Survey (SNLS) , building upon the lessons learnt working with the MegaCam imager. It consists in a very stable light source, placed in the telescope enclosure, and generating compact, conical beams, yielding an almost flat illumination of the imager focal plane. The calibration light is generated by narrow spectrum LEDs selected to cover the entire wavelength range of the imager. It is monitored in real time using control photodiodes. A first DICE demonstrator, SnDICE has been installed at CFHT. A second generation instrument (SkyDICE) has been installed in the enclosure of the SkyMapper telescope. We present the main goals of the project. We discuss the main difficulties encoutered when trying to calibrate a wide field imager, such as MegaCam (or SkyMapper) using such a calibrated light source.