Sample records for future wide-field optical

  1. Adaptive wide-field optical tomography

    PubMed Central

    Venugopal, Vivek; Intes, Xavier

    2013-01-01

    Abstract. 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. PMID:23475290

  2. 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.

  3. Optical sectioning by wide-field photobleaching imprinting microscopy

    NASA Astrophysics Data System (ADS)

    Li, Chiye; Gao, Liang; Liu, Yan; Wang, Lihong V.

    2013-10-01

    We present a generic wide-field optical sectioning scheme, photobleaching imprinting microscopy (PIM), for depth-resolved cross-sectional fluorescence imaging. Wide-field PIM works by extracting a nonlinear component that depends on the excitation fluence as a result of photobleaching-induced fluorescence decay. Since no specific fluorescent dyes or illumination modules are required, wide-field PIM is easy to implement on a standard microscope. Moreover, wide-field PIM is superior to deconvolution microscopy in removing background fluorescence, yielding a six-fold improvement in image contrast.

  4. Adaptive optics wide-field microscopy using direct wavefront sensing

    E-print Network

    Sullivan, William T.

    Adaptive optics wide-field microscopy using direct wavefront sensing Oscar Azucena,1, * Justin, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USA 3 Laboratory for Adaptive Optics many of the objects of interest require the sample to be in its original environment [1,2,6]. Adaptive

  5. 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.

  6. Adaptive Optics Calibration for a Wide-Field Microscope Janice Castillo*

    E-print Network

    Adaptive Optics Calibration for a Wide-Field Microscope Janice Castillo* and Thomas Bifano Boston calibration of a novel wide-field scanning microscope is described, comparing relevant parameters for several, microscopy 1. INTRODUCTION The Adaptive Scanning Optical Microscope (ASOM, Thorlabs, Inc.) is a new type

  7. 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.

  8. Towards wide-field retinal imaging with adaptive optics

    Microsoft Academic Search

    M. Glanc; E. Gendron; F. Lacombe; D. Lafaille; J.-F Le Gargasson; P. Léna

    2004-01-01

    In vivo imaging of the retina on humans by means of adaptive optics can lead to a significant gain in resolution. We demonstrate the realization and use of a system made of a Shack–Hartmann wavefront sensor carefully matched to a 13-actuator bimorph deformable mirror sensor, operating at a closed loop frequency of 70 Hz at ?=835 nm. Even with this

  9. SLGLAO: An all-sky, wide field adaptive optics system for large aperture telescopes

    Microsoft Academic Search

    M. C. Britton; K. Taylor

    2004-01-01

    This paper describes an adaptive optics concept that uses a single sodium laser beacon driving a single deformable mirror to achieve partial compensation of atmospheric turbulence over a relatively wide field of view. The angular size of the corrected field of view increases with aperture diameter, while the degree of partial compensation decreases with aperture diameter. For a 30 meter

  10. 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 ?m 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

  11. 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.

  12. Wide field astronomical image compensation with multiple laser-guided adaptive optics

    Microsoft Academic Search

    Michael Hart; N. Mark Milton; Christoph Baranec; Thomas Stalcup; Keith Powell; Eduardo Bendek; Don McCarthy; Craig Kulesa

    2009-01-01

    We report closed-loop results obtained from the first adaptive optics system to deploy multiple laser guide beacons. The system is mounted on the 6.5 m MMT telescope in Arizona, and is designed to explore advanced altitude-conjugated techniques for wide-field image compensation. Five beacons are made by Rayleigh scattering of laser beams at 532 nm integrated over a range from 20

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

    Microsoft Academic Search

    Benoit Neichel; Thierry Fusco; Jean-Marc Conan

    2008-01-01

    Several Wide Field of view Adaptive Optics (WFAO) concepts like Multi-Conjugate AO (MCAO), Multi-Object AO (MOAO) or Ground-Layer AO (GLAO) are currently 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. We conduct this

  14. Wide field of view retinal imaging using one-micrometer adaptive optics scanning laser ophthalmoscope

    NASA Astrophysics Data System (ADS)

    Sasaki, Kazuhiro; Kurokawa, Kazuhiro; Makita, Shuichi; Tamada, Daiki; Lim, Yiheng; Cense, Barry; Yasuno, Yoshiaki

    2011-03-01

    Wide field of view (FOV) retinal imaging with high resolution has been demonstrated for quantitative analysis of retinal microstructures. An adaptive optics scanning laser ophthalmoscope (AO-SLO) that was built in our laboratory was improved by a customized scanning protocol for scanning wide region. A post-processing program was developed for generating wide FOV retinal images. The high resolution retinal image with 1.7 degree by 3.0 degree FOV were obtained.

  15. High-resolution wide-field imaging of retinal and choroidal blood perfusion with optical microangiography

    Microsoft Academic Search

    Lin An; Hrebesh M. Subhush; David J. Wilson; Ruikang K. Wang

    2010-01-01

    We present high-resolution wide-field imaging of retinal and choroidal blood perfusion with optical microangiography (OMAG) technology. Based on spatial frequency analysis, OMAG is capable of visualizing the vascular perfusion map down to capillary-level resolution. An OMAG system operating at 840 nm is used with an A-scan rate of 27,000 Hz, axial resolution of 8 mum, and sensitivity of 98 dB.

  16. Enola Gay: an integrated modelling optical toolbox applied to a wide-field telescope

    NASA Astrophysics Data System (ADS)

    Schipani, P.; Perrotta, F.

    2008-07-01

    The integrated modelling approach is fundamental in telescopes design where it is necessary to merge different disciplines together. This paper describes the integration of optical ray-tracing capabilities within the Matlab computational environment. This approach allows to write automatic procedures to implement a huge number of computations, that are very unpractical to perform in interactive mode by ray tracing software packages. Data produced by computations are stored and automatically analyzed. One of the main benefits from this approach comes from the traceability of the work, that is intrinsically impossible when the optical designer works in interactive mode. The right procedure is built and tuned just the first time and the computation software is available for inspection and check. Furthermore computations and results are easily reproducible simply re-running Matlab scripts. An automatic approach is especially helpful in wide-field telescope projects where the optical quality has to be studied over a wide field of view. This leads to repeat the same computations many times in a number of fields. In interactive mode this would cause a significant waste of optical designer time to repeat many times the same manual procedures. The solution proposed here allows to save time and prevent occasional mistakes.

  17. Optics integration of the OMM wide-field visible camera (Panoramix-II)

    NASA Astrophysics Data System (ADS)

    Thibault, S.; Wang, M.; Côté, P.; Drissen, L.; Brière, É.

    2006-06-01

    The advent of wide-field imagers on large telescopes (Megacam at CFHT, Suprime-Cam at Subaru, and others) with degree-wide fields of view is largely motivated by a renewed interest in our own solar system, in the history of the Milky Way and its neighbors, and in the large-scale structure of the Universe. Smaller, university-based telescopes can of course also benefit from wide-field imagery. We present in this paper the design and first results of Panoramix-II, the new wide-field imager of the Mont Megantic Observatory (OMM). This instrument is conceptually a focal reducer designed to image and correct the F/8 cassegrain focal plane of the telescope onto a pair of 2KX4K EEV detectors. The camera is optimized for the SLOAN g' (410-550 nm), r' (550-690 nm), i' (690-850 nm) and z' (850-950 nm) wave bands. The sky will be imaged onto the focal plane at an image scale of 0.52 arcsecond per 13.5 ?m pixel. The design image quality is 1.00 arcsecond 50% diffraction encircled energy over the central 35 arcmin field and no images worse than 1.25 arcsecond over the 49 arcminute diameter camera field. The optical design distortion at the corners is less than 1%. The Panoramix-II camera has a filter wheel at the internal stop. Panoramix-II can also support the FaNTOmM photon-counting camera used in conjunction with a Fabry-Perot interferometer to provide spectrometric data.

  18. Optimal grazing incidence optics and its application to wide-field X-ray imaging

    NASA Technical Reports Server (NTRS)

    Burrows, Christopher J.; Burg, Richard; Giacconi, Riccardo

    1992-01-01

    A class of high-resolution, efficient, and wide-field grazing incidence optics is discussed. Optical designs for searching efficiently for distant X-ray clusters are developed. It is shown that a rather general procedure exists for the design of an optical mission if well-defined scientific goals can be provided. Clusters of galaxies with an angular diameter of about 5 arcsec over a field of about 1 deg are resolved so that a comprehensive deep search is possible with a payload of 1/10 the linear dimensions of AXAF. By dropping the requirement for perfect on-axis imagery, searching within a suitably general class of telescope design, and optimizing a quantity directly related to the scientific requirement, it is shown that satisfactory designs do exist. The resulting telescope is shown to be no more difficult to fabricate than existing mirrors, and it can be nested.

  19. High-resolution wide-field imaging of retinal and choroidal blood perfusion with optical microangiography

    PubMed Central

    An, Lin; Subhush, Hrebesh M.; Wilson, David J.; Wang, Ruikang K.

    2010-01-01

    We present high-resolution wide-field imaging of retinal and choroidal blood perfusion with optical microangiography (OMAG) technology. Based on spatial frequency analysis, OMAG is capable of visualizing the vascular perfusion map down to capillary-level resolution. An OMAG system operating at 840 nm is used with an A-scan rate of 27,000 Hz, axial resolution of 8 ?m, and sensitivity of 98 dB. To achieve wide-field imaging, we capture 16 optical coherence tomography (OCT) 3-D datasets in a sequential order, which together provide an area of ?7.4×7.4 mm2 at the posterior segment of the human eye. For each of these datasets, the bulk tissue motion artifacts are eliminated by applying a phase compensation method based on histogram estimation of bulk motion phases, while the displacements occurring between adjacent B-frames are compensated for by 2-D cross correlation between two adjacent OMAG flow images. The depth-resolved capability of OMAG imaging also provides volumetric information on the ocular circulations. Finally, we compare the clinical fluorescein angiography and indocyanine green angiography imaging results with the OMAG results of blood perfusion map within the retina and choroid, and show excellent agreement between these modalities. PMID:20459256

  20. High-resolution wide-field imaging of retinal and choroidal blood perfusion with optical microangiography.

    PubMed

    An, Lin; Subhush, Hrebesh M; Wilson, David J; Wang, Ruikang K

    2010-01-01

    We present high-resolution wide-field imaging of retinal and choroidal blood perfusion with optical microangiography (OMAG) technology. Based on spatial frequency analysis, OMAG is capable of visualizing the vascular perfusion map down to capillary-level resolution. An OMAG system operating at 840 nm is used with an A-scan rate of 27,000 Hz, axial resolution of 8 mum, and sensitivity of 98 dB. To achieve wide-field imaging, we capture 16 optical coherence tomography (OCT) 3-D datasets in a sequential order, which together provide an area of approximately 7.4 x 7.4 mm(2) at the posterior segment of the human eye. For each of these datasets, the bulk tissue motion artifacts are eliminated by applying a phase compensation method based on histogram estimation of bulk motion phases, while the displacements occurring between adjacent B-frames are compensated for by 2-D cross correlation between two adjacent OMAG flow images. The depth-resolved capability of OMAG imaging also provides volumetric information on the ocular circulations. Finally, we compare the clinical fluorescein angiography and indocyanine green angiography imaging results with the OMAG results of blood perfusion map within the retina and choroid, and show excellent agreement between these modalities. PMID:20459256

  1. 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.

  2. Optical wide field monitor AROMA-W using multiple digital single-lens reflex cameras

    NASA Astrophysics Data System (ADS)

    Takahashi, Ichiro; Tsunashima, Kosuke; Tatsuhito, Takeda; Saori, Ono; Kazutaka, Yamaoka; Yoshida, Atsumasa

    2010-12-01

    We have developed and operated the automatic optical observation device Aoyama Gakuin University Robotic Optical Monitor for Astrophysical objects - Wide field (AROMA-W). It covers a large field of view of about 45 degrees W 30 degrees at a time by the multiple digital single-lens reflex cameras, and provides photometric data in four bands with a limiting V magnitude of about 12-13 magnitude (20 seconds, 3 sigma level). The automatic analysis pipeline which can analyze in parallel with observation has been constructed so far. It can draw the light curves of all stars in the field of view of AROMA-W. We are aiming at the simultaneous observation of the transients (e.g., X-ray nova, Supernova, GRB) that MAXI discovered by using the AROMA-W. We report the developmental status, the observational results of AROMA-W and a possibility of the simultaneous observation to the X-ray transients discovered with MAXI.

  3. Wide-field two-dimensional multifocal optical-resolution photoacoustic computed microscopy

    PubMed Central

    Xia, Jun; Li, Guo; Wang, Lidai; Nasiriavanaki, Mohammadreza; Maslov, Konstantin; Engelbach, John A.; Garbow, Joel R.; Wang, Lihong V.

    2014-01-01

    Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technique that directly images optical absorption in tissue at high spatial resolution. To date, the majority of OR-PAM systems are based on single focused optical excitation and ultrasonic detection, limiting the wide-field imaging speed. While one-dimensional multifocal OR-PAM (1D-MFOR-PAM) has been developed, the potential of microlens and transducer arrays has not been fully realized. Here, we present the development of two-dimensional multifocal optical-resolution photoacoustic computed microscopy (2D-MFOR-PACM), using a 2D microlens array and a full-ring ultrasonic transducer array. The 10 × 10 mm2 microlens array generates 1800 optical foci within the focal plane of the 512-element transducer array, and raster scanning the microlens array yields optical-resolution photoacoustic images. The system has improved the in-plane resolution of a full-ring transducer array from ?100 µm to 29 µm and achieved an imaging time of 36 seconds over a 10 × 10 mm2 field of view. In comparison, the 1D-MFOR-PAM would take more than 4 minutes to image over the same field of view. The imaging capability of the system was demonstrated on phantoms and animals both ex vivo and in vivo. PMID:24322226

  4. Wide-field two-dimensional multifocal optical-resolution photoacoustic-computed microscopy.

    PubMed

    Xia, Jun; Li, Guo; Wang, Lidai; Nasiriavanaki, Mohammadreza; Maslov, Konstantin; Engelbach, John A; Garbow, Joel R; Wang, Lihong V

    2013-12-15

    Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technique that directly images optical absorption in tissue at high spatial resolution. To date, the majority of OR-PAM systems are based on single-focused optical excitation and ultrasonic detection, limiting the wide-field imaging speed. While 1D multifocal OR-PAM (1D-MFOR-PAM) has been developed, the potential of microlens and transducer arrays has not been fully realized. Here we present the development of 2D multifocal optical-resolution photoacoustic-computed microscopy (2D-MFOR-PACM), using a 2D microlens array and a full-ring ultrasonic transducer array. The 10 mm×10 mm microlens array generates 1800 optical foci within the focal plane of the 512-element transducer array, and raster scanning the microlens array yields optical-resolution photoacoustic images. The system has improved the in-plane resolution of a full-ring transducer array from ?100 to 29 ?m and achieved an imaging time of 36 s over a 10 mm×10 mm field of view. In comparison, the 1D-MFOR-PAM would take more than 4 min to image over the same field of view. The imaging capability of the system was demonstrated on phantoms and animals both ex vivo and in vivo. PMID:24322226

  5. Optical design of PANORAMIX-II, the OMM wide-field VIS-NIR camera

    NASA Astrophysics Data System (ADS)

    Thibault, Simon; Doucet, Michel; Drissen, Laurent

    2004-09-01

    In this paper, we present the optical design of the optical train of Panoramix-II, a wide-field VIS-NIR camera to be installed at the cassegrain focus of OMM (Observatoire du Mont Megnantic, Quebec, Canada). This camera is optimized for g (0.41-0.55), r (0.556-0.689), i (0.693-0.867) and z (0.851-0.95) operating region and used a 2kX4k EEV detector. The sky will be imaged onto the focal plane at an optical speed of F/2.35 yielding an image scale of 0.75 arcsecond per 13.5 ?m pixel. The design image quality is 0.75 arcsecond 50% diffraction encircled energy over the central 27 arcmin field and no images worse than 0.85 arcsecond over the 55 arcminute diameter camera field. The optical design distortion at the corners is less than 0.08%. The Panoramix-II camera have a set of filters is used at the internal pupil. The image of the pupil is sufficiently sharp to limit the filter size. We discuss the principle characteristics of the imager, the specifications, the optical design, the performances, a ghost study and finally a tolerance anlaysis.

  6. 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.

  7. Tomographic reconstruction for Wide Field Adaptive Optics systems: Fourier domain analysis and fundamental limitations

    E-print Network

    B. Neichel; T. Fusco; J. -M. Conan

    2008-11-14

    Several Wide Field of view Adaptive Optics (WFAO) concepts like Multi-Conjugate AO (MCAO), Multi-Object AO (MOAO) or Ground-Layer AO (GLAO) are currently 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. We conduct 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 impact on the phase reconstruction. Finally, we show some examples of different WFAO systems and their expected performance on a 42m telescope case.

  8. Tomographic reconstruction for Wide Field Adaptive Optics systems: Fourier domain analysis and fundamental limitations

    E-print Network

    Neichel, B; Conan, J -M

    2008-01-01

    Several Wide Field of view Adaptive Optics (WFAO) concepts like Multi-Conjugate AO (MCAO), Multi-Object AO (MOAO) or Ground-Layer AO (GLAO) are currently 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. We conduct 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 impact on the phase reconstruction. Finally, we show some examples of different WFAO systems and their expected performance on a 42m telescope case.

  9. Dual-Conjugate Adaptive Optics Instrument for Wide-Field Retinal Imaging - Oral Paper

    NASA Astrophysics Data System (ADS)

    Thaung, Jörgen; Owner-Petersen, Mette; Popovic, Zoran

    2008-01-01

    To date only conventional single-conjugate adaptive optics (SCAO) systems are used to correct ocular aberrations. A major shortcoming of SCAO is the severely restricted corrected field of view. This can be solved with multi-conjugate adaptive optics (MCAO), a solution that is costly and gives bulky instruments. Another problem, especially in the study of the human eye, is unwanted light from parasitic source reflections and light from unwanted object regions. We present a dual-conjugate adaptive optics (DCAO) demonstrator that will enable wide field high resolution imaging of the human retina in vivo, implementing five retinal guide stars, two OKO micromachined membrane deformable mirrors; a 15 mm 37 channel pupil conjugate mirror, and a 40 mm 79 channel mirror conjugated to a plane in the vitreous body approximately 3 mm in front of the retina. The AO system runs with a closed-loop measurement wavelength of 835 nm. It incorporates an array of collimator lenses to spatially filter the light from all guide stars using only one adjustable iris, and a single camera to image the Hartmann patterns of multiple reference sources. Optical simulations in Zemax indicate an increase of the retinal isoplanatic patch from a radius of 0.5 degrees using SCAO to approximately 3.5 degrees or more using DCAO. The advantage of this is a clinically useful imaging area that is approximately 50 times the size of an SCAO system. This is corroborated by measurements on a model eye while performing SCAO, ground layer adaptive optics (GLAO), and DCAO correction.

  10. 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 ?m. 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 ?m) 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

  11. 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

    X-ray telescopes with spatial resolution optimized over the field of view (FOV) are of special interest for missions, such as WFXT, focused on moderately deep and deep surveys of the x-ray sky, and for solar x-ray observations. Here we report on the present status of an on-going study of the properties of Wolter I and polynominal grazing incidence designs with a view to gain a deeper insight into their properties and simply the design process. With these goals in mind, we present some results in the complementary topics of (1) properties of Wolter I x-ray optics and polynominal x-ray optic ray tracing. Of crucial importance for the design of wide-field x-ray optics is the optimization criteria. Here we have adopted the minimization of a merit function, M, which measures the spatial resolution averaged over the FOV: M= ((integral of d phi) between the limits of 0 and 2 pi) (integral of d theta theta w(theta) sigma square (theta,phi) between the limits of 0 and theta(sub FOV)) (integral of d phi between the limits of 0 and phi/4) (Integral of d theta theta w(theta) between the limits of 0 and theta(sub FOV) where w(theta(sub 1) is a weighting function and Merit function: sigma-square (theta, phi) = summation of (x,y,z) [-<(x,y,z)> (exp 2)] is the spatial variance for a point source on the sky at polar and azimuthal off-axis angles (theta,phi).

  12. 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

  13. 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.

  14. 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.

  15. Design of a Novel, Cost-Effective Wide Field-Of-View Surface-Normal Optical Phased Array

    E-print Network

    Chen, Ray

    )], it is possible to obtain a slow light effect or a region within the guided mode where the group velocity approaches zero, as shown in Fig. 2(a). The low group velocity slows down the photons sufficiently, therebyDesign of a Novel, Cost-Effective Wide Field-Of-View Surface-Normal Optical Phased Array Harish

  16. All-weather calibration of wide-field optical and NIR surveys

    SciTech Connect

    Burke, David L. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Saha, Abhijit; Claver, Jenna; Claver, Chuck [National Optical Astronomy Observatory, Tucson, AZ 85718 (United States); Axelrod, T. [Steward Observatory, University of Arizona, Tucson, AZ 85718 (United States); DePoy, Darren [Texas A and M University, College Station, TX 77843 (United States); Ivezi?, Željko; Jones, Lynne [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Smith, R. Chris [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Stubbs, Christopher W., E-mail: daveb@slac.stanford.edu [Harvard Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 02138 (United States)

    2014-01-01

    The science goals for ground-based large-area surveys, such as the Dark Energy Survey, Pan-STARRS, and the Large Synoptic Survey Telescope, require calibration of broadband photometry that is stable in time and uniform over the sky to precisions of a percent or better. This performance will need to be achieved with data taken over the course of many years, and often in less than ideal conditions. This paper describes a strategy to achieve precise internal calibration of imaging survey data taken in less than 'photometric' conditions, and reports results of an observational study of the techniques needed to implement this strategy. We find that images of celestial fields used in this case study with stellar densities ?1 arcmin{sup –2} and taken through cloudless skies can be calibrated with relative precision ?0.5% (reproducibility). We report measurements of spatial structure functions of cloud absorption observed over a range of atmospheric conditions, and find it possible to achieve photometric measurements that are reproducible to 1% in images that were taken through cloud layers that transmit as little as 25% of the incident optical flux (1.5 magnitudes of extinction). We find, however, that photometric precision below 1% is impeded by the thinnest detectable cloud layers. We comment on implications of these results for the observing strategies of future surveys.

  17. 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.

  18. Results from the Wide-field Infrared Survey Explorer (WISE) Future Uses Session at the WISE at 5 Meeting

    E-print Network

    Faherty, Jacqueline K; Anderson, L D; Assef, Roberto J; Gagliuffi, Daniella C Bardalez; Barry, Megan; Benford, Dominic J; Bilicki, Maciej; Burningham, Ben; Christian, Damian J; Cushing, Michael C; Eisenhardt, Peter R; Elvisx, Martin; Fajardo-Acosta, S B; Finkbeiner, Douglas P; Fischer, William J; Forrest, William J; Fowler, John; Gardner, Jonathan P; Gelino, Christopher R; Gorjian, V; Grillmair, Carl J; Gromadzki, Mariusz; Hall, Kendall P; Ivezi'c, Zeljko; Izumi, Natsuko; Kirkpatrick, J Davy; Kovács, András; Lang, Dustin; Leisawitz, David; Liu, Fengchuan; Mainzer, A; Malek, Katarzyna; Marton, Gábor; Masci, Frank J; McLean, Ian S; Meisner, Aaron; Nikutta, Robert; Padgett, Deborah L; Patel, Rahul; Rebull, L M; Rich, J A; Ringwald, Frederick A; Rose, Marvin; Schneider, Adam C; Stassun, Keivan G; Stern, Daniel; Tsai, Chao-Wei; Wang, Feige; Weston, Madalyn E; L., Edward; Wright,; Wu, Jingwen; Yang, Jinyi

    2015-01-01

    During the "WISE at 5: Legacy and Prospects" conference in Pasadena, CA -- which ran from February 10 - 12, 2015 -- attendees were invited to engage in an interactive session exploring the future uses of the Wide-field Infrared Survey Explorer (WISE) data. The 65 participants -- many of whom are extensive users of the data -- brainstormed the top questions still to be answered by the mission, as well as the complementary current and future datasets and additional processing of WISE/NEOWISE data that would aid in addressing these most important scientific questions. The results were mainly bifurcated between topics related to extragalactic studies (e.g. AGN, QSOs) and substellar mass objects. In summary, participants found that complementing WISE/NEOWISE data with cross-correlated multiwavelength surveys (e.g. SDSS, Pan-STARRS, LSST, Gaia, Euclid, etc.) would be highly beneficial for all future mission goals. Moreover, developing or implementing machine-learning tools to comb through and understand cross-corre...

  19. 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.

  20. On-sky wide field adaptive optics correction using multiple laser guide stars at the MMT

    E-print Network

    Baranec, Christoph; Milton, N Mark; Stalcup, Thomas; Powell, Keith; Snyder, Miguel; Vaitheeswaran, Vidhya; McCarthy, Don; Kulesa, Craig

    2008-01-01

    We describe results from the first astronomical adaptive optics system to use multiple laser guide stars, located at the 6.5-m MMT telescope in Arizona. Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wavefront correction within the 2 arc minute diameter laser beacon constellation, reducing the stellar image widths by as much as 53%, from 0.70 to 0.33 arc seconds at lambda = 2.14 microns. GLAO is achieved by applying a correction to the telescope's adaptive secondary mirror that is an average of wavefront measurements from five laser beacons supplemented with image motion from a faint stellar source. Optimization of the adaptive optics system in subsequent commissioning runs will further improve correction performance where it is predicted to deliver 0.1 to 0.2 arc second resolution in the near-infrared during a majority of seeing conditions.

  1. On-sky wide field adaptive optics correction using multiple laser guide stars at the MMT

    E-print Network

    Christoph Baranec; Michael Hart; N. Mark Milton; Thomas Stalcup; Keith Powell; Miguel Snyder; Vidhya Vaitheeswaran; Don McCarthy; Craig Kulesa

    2008-12-01

    We describe results from the first astronomical adaptive optics system to use multiple laser guide stars, located at the 6.5-m MMT telescope in Arizona. Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wavefront correction within the 2 arc minute diameter laser beacon constellation, reducing the stellar image widths by as much as 53%, from 0.70 to 0.33 arc seconds at lambda = 2.14 microns. GLAO is achieved by applying a correction to the telescope's adaptive secondary mirror that is an average of wavefront measurements from five laser beacons supplemented with image motion from a faint stellar source. Optimization of the adaptive optics system in subsequent commissioning runs will further improve correction performance where it is predicted to deliver 0.1 to 0.2 arc second resolution in the near-infrared during a majority of seeing conditions.

  2. 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.

  3. Wide-field solar adaptive optics in a layer-oriented approach

    NASA Astrophysics Data System (ADS)

    Kellerer, Aglaé

    2015-04-01

    We discuss a layer-oriented approach to multi-conjugate adaptive optics (MCAO) in solar imaging. The technique is a complement to the current star-oriented MCAO and appears as a necessary alternative when large field sizes are desired in solar observations. The basic procedure of the layer oriented method is indicated, and its characteristics are then illustrated in terms of numerical simulations.

  4. Improvements in Space Surveillance Processing for Wide Field of View Optical Sensors

    NASA Astrophysics Data System (ADS)

    Sydney, P.; Wetterer, C.

    2014-09-01

    For more than a decade, an autonomous satellite tracking system at the Air Force Maui Optical and Supercomputing (AMOS) observatory has been generating routine astrometric measurements of Earth-orbiting Resident Space Objects (RSOs) using small commercial telescopes and sensors. Recent work has focused on developing an improved processing system, enhancing measurement performance and response while supporting other sensor systems and missions. This paper will outline improved techniques in scheduling, detection, astrometric and photometric measurements, and catalog maintenance. The processing system now integrates with Special Perturbation (SP) based astrodynamics algorithms, allowing covariance-based scheduling and more precise orbital estimates and object identification. A merit-based scheduling algorithm provides a global optimization framework to support diverse collection tasks and missions. The detection algorithms support a range of target tracking and camera acquisition rates. New comprehensive star catalogs allow for more precise astrometric and photometric calibrations including differential photometry for monitoring environmental changes. This paper will also examine measurement performance with varying tracking rates and acquisition parameters.

  5. 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.

  6. 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

    Context. Upcoming spectroscopic galaxy surveys are extremely promising to help in addressing the major challenges of cosmology, in particular in understanding the nature of the dark universe. The strength of these surveys, naturally described in spherical geometry, comes from their unprecedented depth and width, but an optimal extraction of their three-dimensional information is of utmost importance to best constrain the properties of the dark universe. Aims: Although there is theoretical motivation and novel tools to explore these surveys using the 3D spherical Fourier-Bessel (SFB) power spectrum of galaxy number counts C?(k,k'), most survey optimisations and forecasts are based on the tomographic spherical harmonics power spectrum C(ij)_?. The goal of this paper is to perform a new investigation of the information that can be extracted from these two analyses in the context of planned stage IV wide-field galaxy surveys. Methods: We compared tomographic and 3D SFB techniques by comparing the forecast cosmological parameter constraints obtained from a Fisher analysis. The comparison was made possible by careful and coherent treatment of non-linear scales in the two analyses, which makes this study the first to compare 3D SFB and tomographic constraints on an equal footing. Nuisance parameters related to a scale- and redshift-dependent galaxy bias were also included in the computation of the 3D SFB and tomographic power spectra for the first time. Results: Tomographic and 3D SFB methods can recover similar constraints in the absence of systematics. This requires choosing an optimal number of redshift bins for the tomographic analysis, which we computed to be N = 26 for zmed ? 0.4, N = 30 for zmed ? 1.0, and N = 42 for zmed ? 1.7. When marginalising over nuisance parameters related to the galaxy bias, the forecast 3D SFB constraints are less affected by this source of systematics than the tomographic constraints. In addition, the rate of increase of the 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

  7. MegaCam: a wide-field optical/infrared camera for the UH 2.2-m telescope

    NASA Astrophysics Data System (ADS)

    Hora, Joseph L.; Luppino, Gerard A.; Hodapp, Klaus-Werner

    1994-06-01

    The MegaCam is a multi-purpose, wide-field, two-color camera being designed for use at the UH 2.2m telescope. The camera will utilize a Rockwell 1024 x 1024 HgCdTe detector array for 1-2.5 micrometers imaging, and a 2048 x 4096 frame-store CCD (2048 x 2048 active area) for optical imaging. The optics are based on a modified Offner relay design with additional lenses to give a 2:1 magnification in the infrared channel for a field of view of 5'.8 x 5'.8 (0.34 arcsec/pixel) using the f/10 telescope secondary, or a scale of 1'.9 x 1'.9 (0.15 arcsec/pixel) at f/31. This design provides a simple, high-throughput, and compact optical layout. A beamsplitter is placed in front of the IR optics at a low angle of incidence to form the optical image at 1:1 magnification on the CCD, for a field of view of 4'.7 x 4'.7 and 1'.5 x 1'.5 at f/10 and f/31, respectively. The optics and filters are to be housed in a LN(subscript 2)-cooled dewar. The CCD and IR arrays will be operated with modified SDSU-design controllers. The user interface will have several modes to make simultaneous optical/IR imaging simple to configure and perform at the telescope.

  8. 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.

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

    SciTech Connect

    Sick, Jonathan; Courteau, Stéphane [Department of Physics, Engineering Physics and Astronomy, Queen's University, Kingston, Ontario, K7L 3N6 (Canada); Cuillandre, Jean-Charles [Canada-France-Hawaii Telescope Corp., Kamuela, HI 96743 (United States); McDonald, Michael [Kavli Institute for Astrophysics and Space Research, MIT, Cambridge, MA 02139 (United States); De Jong, Roelof [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Tully, R. Brent, E-mail: jsick@astro.queensu.ca [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI (United States)

    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.

  10. 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.

  11. October 15, 2002 / Vol. 27, No. 20 / OPTICS LETTERS 1773 Noninterferometric wide-field optical profilometry with

    E-print Network

    a series of two-dimensional interfer- ograms. Closed-loop scanning along the optical axis with a typical to utilize kilohertz scanning mirrors, which greatly increases the cost. If the lateral scanning mechanism-field optically sectioning microscopy, we develop a noninterferometric optical profilometer without scanning

  12. Wide field of view telescope

    DOEpatents

    Ackermann, Mark R. (Albuquerque, NM); McGraw, John T. (Placitas, NM); Zimmer, Peter C. (Albuquerque, NM)

    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.

  13. Design and Characterization of a Nano-Encapsulated Self-Referenced Fluorescent Nitric Oxide Sensor for Wide-Field Optical Imaging

    Microsoft Academic Search

    Guodong Zhang; Florence P. Shu; Charles J. Robinson

    2007-01-01

    A nano-encapsulated fluorescence dye DAF-2 sensor that is specifically sensitive to nitric oxide (NO) was fabricated by using an electrostatic layer-by-layer (LbL) self-assembly technique. Fluorescence calibrations of the NO sensor were collected by a wide-field optical imaging system and a fluorescence spectrometer using NO standards generated by the self decomposition of S-nitrosol-acetyl-penicillamine (SNAP). The NO sensor consists of two fluorescence

  14. 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.

  15. On-Sky Wide-Field Adaptive Optics Correction Using Multiple Laser Guide Stars at the MMT

    Microsoft Academic Search

    Christoph Baranec; Michael Hart; N. Mark Milton; Thomas Stalcup; Keith Powell; Miguel Snyder; Vidhya Vaitheeswaran; Don McCarthy; Craig Kulesa

    2009-01-01

    We describe results from the first astronomical adaptive optics (AO) system to use multiple laser guide stars, located at the 6.5 m MMT telescope in Arizona. Its initial operational mode, ground-layer adaptive optics (GLAO), provides uniform stellar wave front correction within the 2' diameter laser beacon constellation, reducing the stellar image widths by as much as 53%, from 0farcs70 to

  16. Future Optical Networks

    Microsoft Academic Search

    Michael J. O'Mahony; Christina Politi; Dimitrios Klonidis; Reza Nejabati; Dimitra Simeonidou

    2006-01-01

    This paper presents views on the future of optical networking. A historical look at the emergence of optical networking is first taken, followed by a discussion on the drivers pushing for a new and pervasive network, which is based on photonics and can satisfy the needs of a broadening base of residential, business, and scientific users. Regional plans and targets

  17. Oceanographic wide field sensor

    NASA Technical Reports Server (NTRS)

    Kirk, R. G.

    1988-01-01

    The Oceanographic Wide Field Sensor (SeaWiFS) science project will provide measurements of ocean color from space to which will support research into: (1) the character of ocean physical and biological processes; (2) to assess the global oceanic biomass; and (3) to better understand the role of oceanic processes in modulating the Earth's biogeochemical cycles, including the CO2 cycle as it is affected by fossil fuel combustion. The present work extends previous work to study the feasibility of an ocean color mission using the proposed compact Wide-Field Sensor (SeaWiFS) and the EOSAT Corporation's LANDSAT-6 satellite. A Phase A study was conducted which defines a NASA Facility Data System and accompanying Science Program for the EOSAT Company's commercial ocean color instrument called SeaWiFS to be launched on board LANDSAT-6 in 1991.

  18. 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.

  19. 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

  20. 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

  1. Comparison of multispectral wide-field optical imaging modalities to maximize image contrast for objective discrimination of oral neoplasia

    NASA Astrophysics Data System (ADS)

    Roblyer, Darren; Kurachi, Cristina; Stepanek, Vanda; Schwarz, Richard A.; Williams, Michelle D.; El-Naggar, Adel K.; Lee, J. Jack; Gillenwater, Ann M.; Richards-Kortum, Rebecca

    2010-11-01

    Multispectral widefield optical imaging has the potential to improve early detection of oral cancer. The appropriate selection of illumination and collection conditions is required to maximize diagnostic ability. The goals of this study were to (i) evaluate image contrast between oral cancer/precancer and non-neoplastic mucosa for a variety of imaging modalities and illumination/collection conditions, and (ii) use classification algorithms to evaluate and compare the diagnostic utility of these modalities to discriminate cancers and precancers from normal tissue. Narrowband reflectance, autofluorescence, and polarized reflectance images were obtained from 61 patients and 11 normal volunteers. Image contrast was compared to identify modalities and conditions yielding greatest contrast. Image features were extracted and used to train and evaluate classification algorithms to discriminate tissue as non-neoplastic, dysplastic, or cancer; results were compared to histologic diagnosis. Autofluorescence imaging at 405-nm excitation provided the greatest image contrast, and the ratio of red-to-green fluorescence intensity computed from these images provided the best classification of dysplasia/cancer versus non-neoplastic tissue. A sensitivity of 100% and a specificity of 85% were achieved in the validation set. Multispectral widefield images can accurately distinguish neoplastic and non-neoplastic tissue; however, the ability to separate precancerous lesions from cancers with this technique was limited.

  2. An automated wide-field time-gated optically sectioning fluorescence lifetime imaging multiwell plate reader for high-content analysis of protein-protein interactions

    NASA Astrophysics Data System (ADS)

    Alibhai, Dominic; Kumar, Sunil; Kelly, Douglas; Warren, Sean; Alexandrov, Yuriy; Munro, Ian; McGinty, James; Talbot, Clifford; Murray, Edward J.; Stuhmeier, Frank; Neil, Mark A. A.; Dunsby, Chris; French, Paul M. W.

    2011-03-01

    We describe an optically-sectioned FLIM multiwell plate reader that combines Nipkow microscopy with wide-field time-gated FLIM, and its application to high content analysis of FRET. The system acquires sectioned FLIM images in <10 s/well, requiring only ~11 minutes to read a 96 well plate of live cells expressing fluorescent protein. It has been applied to study the formation of immature HIV virus like particles (VLPs) in live cells by monitoring Gag-Gag protein interactions using FLIM FRET of HIV-1 Gag transfected with CFP or YFP. VLP formation results in FRET between closely packed Gag proteins, as confirmed by our FLIM analysis that includes automatic image segmentation.

  3. 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.

  4. 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. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Price, Gareth J., E-mail: gareth.price@christie.nhs.uk [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Faculty of Medical and Human Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester (United Kingdom); Sharrock, Phil J. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Jackson, Andrew S.N. [Clinical Oncology, Southampton University Hospitals Foundation Trust, Southampton (United Kingdom); Stratford, Julie [Department of Radiotherapy, The Christie NHS Foundation Trust, Manchester (United Kingdom); Moore, Christopher J. [Developing Technologies, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester (United Kingdom); Faculty of Medical and Human Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester (United Kingdom)

    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.

  5. A processing work-flow for measuring erythrocytes velocity in extended vascular networks from wide field high-resolution optical imaging data.

    PubMed

    Deneux, Thomas; Takerkart, Sylvain; Grinvald, Amiram; Masson, Guillaume S; Vanzetta, Ivo

    2012-02-01

    Comprehensive information on the spatio-temporal dynamics of the vascular response is needed to underpin the signals used in hemodynamics-based functional imaging. It has recently been shown that red blood cells (RBCs) velocity and its changes can be extracted from wide-field optical imaging recordings of intrinsic absorption changes in cortex. Here, we describe a complete processing work-flow for reliable RBC velocity estimation in cortical networks. Several pre-processing steps are implemented: image co-registration, necessary to correct for small movements of the vasculature, semi-automatic image segmentation for fast and reproducible vessel selection, reconstruction of RBC trajectories patterns for each micro-vessel, and spatio-temporal filtering to enhance the desired data characteristics. The main analysis step is composed of two robust algorithms for estimating the RBCs' velocity field. Vessel diameter and its changes are also estimated, as well as local changes in backscattered light intensity. This full processing chain is implemented with a software suite that is freely distributed. The software uses efficient data management for handling the very large data sets obtained with in vivo optical imaging. It offers a complete and user-friendly graphical user interface with visualization tools for displaying and exploring data and results. A full data simulation framework is also provided in order to optimize the performances of the algorithm with respect to several characteristics of the data. We illustrate the performance of our method in three different cases of in vivo data. We first document the massive RBC speed response evoked by a spreading depression in anesthetized rat somato-sensory cortex. Second, we show the velocity response elicited by a visual stimulation in anesthetized cat visual cortex. Finally, we report, for the first time, visually-evoked RBC speed responses in an extended vascular network in awake monkey extrastriate cortex. PMID:21925275

  6. The XMM-Newton wide-field survey in the COSMOS field: III. optical identification and multiwavelength properties of a large sample of X-ray selected sources

    E-print Network

    M. Brusa; G. Zamorani; A. Comastri; G. Hasinger; N. Cappelluti; F. Civano; A. Finoguenov; V. Mainieri; M. Salvato; C. Vignali; M. Elvis; F. Fiore; R. Gilli; C. D. Impey; S. J. Lilly; M. Mignoli; J. Silverman; J. Trump; C. M. Urry; R. Bender; P. Capak; J. P. Huchra; J. P. Kneib; A. Koekemoer; A. Leauthaud; I. Lehmann; R. Massey; I. Matute; P. J. McCarthy; H. J. McCracken; J. Rhodes; N. Z. Scoville; Y. Taniguchi; D. Thompson

    2006-12-14

    [ABRIGED] We present the optical identification of a sample of 695 X-ray sources detected in the first 1.3 deg^2 of the XMM-COSMOS survey, down to a 0.5-2 keV (2-10 keV) limiting flux of ~10^-15 erg cm-2 s-1 (~5x10^-15 erg cm^-2 s-1). We were able to associate a candidate optical counterpart to ~90% (626) of the X-ray sources, while for the remaining ~10% of the sources we were not able to provide a unique optical association due to the faintness of the possible optical counterparts (I_AB>25) or to the presence of multiple optical sources within the XMM-Newton error circles. We also cross-correlated the candidate optical counterparts with the Subaru multicolor and ACS catalogs and with the Magellan/IMACS, zCOSMOS and literature spectroscopic data; the spectroscopic sample comprises 248 objects (~40% of the full sample). Our analysis reveals that for ~80% of the counterparts there is a very good agreement between the spectroscopic classification, the morphological parameters as derived from ACS data, and the optical to near infrared colors. About 20% of the sources show an apparent mismatch between the morphological and spectroscopic classifications. All the ``extended'' BL AGN lie at redshift <1.5, while the redshift distribution of the full BL AGN population peaks at z~1.5. Our analysis also suggests that the Type 2/Type 1 ratio decreases towards high luminosities, in qualitative agreement with the results from X-ray spectral analysis and the most recent modeling of the X-ray luminosity function evolution.

  7. New concept for Wide Field Imaging

    NASA Astrophysics Data System (ADS)

    Montilla, Iciar; Bakker, Eric J.; Pereira, Silvania F.; Braat, Joseph J. M.

    2003-02-01

    Wide Field Imaging is a natural extension to single boresight interferometry with an optical/infrared telescope array. It is an important tool to obtain interferometric data of extended objects and for astrometric measurements. Visibilities from many points on the sky can be obtained in one shot saving observation time. In this paper we introduce a new technique, the "staircase mirror" concept which offers potential advantages with respect to existing techniques to perform wide field of view operation on an optical stellar interferometer. This new concept is based on a pupil plane recombination scheme with an automatic field-dependent path length compensation in the intermediate image field of each array single telescope. The pathlength compensation is obtained via a staircase mirror whose position and step depth are a function of the pointing direction and the baseline vector of each telescope. The mirror must be actuated to follow the change of the baseline projected on the entrance pupil of the telescope. We have calculated the differential delay as a function of the field angle, studied and designed an experimental setup to show the applicability of the method and performed simulations for the Very Large Telescope Interferometer.

  8. 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 ?m with twice the angular resolution. We reach a 5? 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.

  9. 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.

  10. 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.

  11. 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.

  12. Wide Field X-ray Telescope (WFXT)

    NASA Astrophysics Data System (ADS)

    Murray, S. S.; Borgani, S.; Campana, S.; Citterio, O.; Forman, W.; Giacconi, R.; Gilli, R.; Paolillo, M.; Pareschi, G.; Ptak, A.; Rosati, P.; Tozzi, P.; Weisskopf, M.; the WFXT Team

    The Wide Field X-ray Telescope is the latest in a series of mission concepts to carry out a large area X-ray survey with sensitivity orders of magnitude fainter than the ROSAT All Sky Survey, and with angular resolution of 5 arcsec over the entire survey area. The science that can be addressed by such a mission and the technical readiness are discussed. The conclusion is that WFXT addresses many of the science issues raised in the 2010 New World New Horizons decadal survey and is well matched to the next generation of optical, IR and radio surveys currently being planned. The technologies needed for WFXT have all been demonstrated, and only the mirrors have a technical readiness level (TRL) that is less than 6. Three independent cost estimates for this mission, covering life-cycle costs, launch services and a GO program are below \\$1B (FY12), and suggest that the mission concept is mature and ready for implementation.

  13. Wide-field CCD imaging at CFHT: the MOCAM example

    E-print Network

    J. -C. Cuillandre; Y. Mellier; J. -P. Dupin; P. Tilloles; R. Murowinski; D. Crampton; R. Wooff; G. A. Luppino

    1996-09-18

    We describe a new 4096x4096 pixel CCD mosaic camera (MOCAM) available at the prime focus of the Canada-France-Hawaii Telescope (CFHT). The camera is a mosaic of four 2048x2048$ Loral frontside-illuminated CCDs with 15 $\\mu$m pixels, providing a field of view of 14'x14' at a scale of 0.21''/pixel. MOCAM is equipped with B, V, R and I filters and has demonstrated image quality of 0.5''-0.6'' FWHM over the entire field. MOCAM will also be used with the CFHT adaptive optic bonnette and will provide a field of view of 90'' at a scale of 0.02 ''/pixel. MOCAM works within the CFHT Pegasus software environment and observers familiar with this system require no additional training to use this camera effectively. The technical details, the performance and the first images obtained on the telescope with MOCAM are presented. In particular, we discuss some important improvements with respect to the standard single-CCD FOCAM camera, such as multi-output parallel readout and dynamic anti-blooming. We also discuss critical technical issues concerning future wide-field imaging facilities at the CFHT prime focus in light of our experience with MOCAM and our recent experience with the even larger UH 8192x8192 pixel CCD mosaic camera.

  14. Computational corrections for three-dimensional wide field fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Hanser, Bridget Martha

    2003-10-01

    Microscopy is a key means of analyzing biological activity and structures, covering a level accessible by few other approaches. Increasingly, live microscopy is being used as a unique means to study the dynamics, of structure, localization, and motion of processes to develop and test hypotheses of cellular dynamics. However, analysis of sub-micron structures within living specimens often becomes difficult or impossible as the image quality degrades with increasing depth in the sample. This degradation results from aberrations due to the specimen's refractive index properties, which alter image formation at the detector. These aberrations range from a general, depth-dependent-spherical aberration for relatively homogeneous samples, to position-dependent aberrations for more complex samples. My thesis project focuses on developing computational corrections of live specimen imaging problems encountered with widefield fluorescence microscopy. The main goal of this work is to study the imaging process for widefield microscopy and to develop improved deconvolution approaches based-on-the information gathered. A significant part of this work has been to develop an improved description of an optical microscope, based on techniques developed for astronomy. My project had been subdivided into the following specific steps for further discussion below: (1) Creation of a compact and modular description of the wide field microscope system using phase retrieval; (2) Development and use of depth dependent deconvolution approaches to correct for aberrations from a general sample refractive index mismatch; and (3) estimation of spatially varying PSFs by using ray tracing techniques for the future application in image deconvolution of optically complex samples.

  15. 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)

  16. 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.

  17. Wide-Field Surveys from the SNAP Mission

    Microsoft Academic Search

    Alex G. Kim; Carl W. Akerlof; Greg Aldering; R. Amanullah; Pierre Astier; E. Barrelet; Christopher Bebek; Lars Bergstrom; J. Bercovitz; Gary M. Bernstein; M. Bester; A. Bonissent; C. Bower; William C. Carithers Jr.; Eugene D. Commins; C. Day; Susana E. Deustua; R. DiGennaro; A. Ealet; Richard S. Ellis; M. Eriksson; Andrew Fruchter; Jean-Francois Genat; Gerson Goldhaber; Ariel Goobar; Donald E. Groom; Stewart E. Harris; Peter R. Harvey; Henry D. Heetderks; Steven E. Holland; Dragan Huterer; Armin Karcher; William F. Kolbe; B. Krieger; Robin E. Lafever; J. Lamoureux; Michael L. Lampton; Michael E. Levi; Daniel S. Levin; Eric V. Linder; Stewart C. Loken; Roger Malina; R. Massey; Timothy McKay; Shawn P. McKee; Ramon Miquel; E. Mortsell; N. Mostek; Stuart Mufson; J. A. Musser; Peter E. Nugent; Hakeem M. Oluseyi; Reynald Pain; Nicholas P. Palaio; David H. Pankow; Saul Perlmutter; R. Pratt; Eric Prieto; Alexandre Refregier; Jason Rhodes; Kem E. Robinson; N. Roe; Michael Sholl; Michael S. Schubnell; G. Smadja; George F. Smoot; Anthony Spadafora; Gregory Tarle; Andrew D. Tomasch; H. von der Lippe; D. Vincent; J.-P. Walder; Guobin Wang

    2002-01-01

    The Supernova \\/ Acceleration Probe (SNAP) is a proposed space-borne observatory that will survey the sky with a wide-field optical\\/near-infrared (NIR) imager. The images produced by SNAP will have an unprecedented combination of depth, solid-angle, angular resolution, and temporal sampling. For 16 months each, two 7.5 square-degree fields will be observed every four days to a magnitude depth of AB=27.7

  18. Innovative, non-contact wide field imaging of corneal endothelium

    NASA Astrophysics Data System (ADS)

    Aberra Guebrou, S.; Pataia, G.; Naigeon, N.; Bernard, A.; He, Z.; Gain, P.; Thuret, G.; Pinoli, J.-C.; Gavet, Y.

    2015-04-01

    In this paper, we investigated the possibility of getting wide-field images of corneal endothelium for patients. An optical set-up coupled to a numerical reconstruction based on Structured Illumination Mircoscopy (SIM) has been developed in order to isolate the tiny volume which contains the endothelial mono-layer found at the inner surface of the cornea. At this moment, this imaging system seems compromised for patients and further refinement are investigated for stored humans corneas banks.

  19. Very-wide-field ultraviolet sky survey

    NASA Technical Reports Server (NTRS)

    Courtes, G.; Viton, M.; Sivan, J. P.; Dechter, R.; Gary, A.

    1984-01-01

    Very-wide-field photographs of the sky were taken on Spacelab 1 at 1650, 1930, and 2530 angstroms with a limiting magnitude of 9.3 at 1930 angstroms. A 1.2 by 2.4 kiloparsec ultraviolet extension of the Shapley wing of the Small Magellanic Cloud is seen in some of the photographs.

  20. 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.

  1. 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.

  2. Future optical observations of solar flares

    Microsoft Academic Search

    R. Falciani

    1988-01-01

    Trends in optical observations of solar flares are reviewed, including recently developed instruments and facilities which could contribute to future studies. It is suggested that the physical significance of the visible spectral range data should be improved and that coherent and self-consistent analyses of different spectral signatures of the same physical phenomena in various layers of the flare atmosphere should

  3. An airborne pushbroom hyperspectral imager with wide field of view

    NASA Astrophysics Data System (ADS)

    Hu, Peixin; Lu, Qimin; Shu, Rong; Wang, Jianyu

    2005-12-01

    An airborne pushbroom hyperspectral imager (APHI) with wide field (42 deg. field of view) is presented. It is composed of two 22 deg. field of view (FOV) imagers and can provide 1304 pixels in spatial dimension, 124 bands in spectral dimension in one frame. APHI has a bandwidth ranging from 400 to 900 nm. The spectral resolution is 5 nm and the spatial resolution is 0.6 m at 1000-m height. The implementation of this system is helpful to overcome the restriction of FOV in pushbroom hyperspectral imaging in a more feasible way. The electronic and optical designs are also introduced in detail.

  4. FIBER-OPTIC ACCESS NETWORKS: PRESENT SCENARIO AND FUTURE PROSPECTS

    Microsoft Academic Search

    Satya Prasad Majumder

    After a brief historical introduction, this paper describes the various techniques of multi-channel transmission over a single optical fiber and evolution of WDM optical access network architectures for future generation demand. Detail description of present and future generation fiber optic access network architectures and their topology are provided. The next generation Wavelength division multiplexing (WDM) Passive optical network (WDM PON)

  5. 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.

  6. Compact, wide field DRS explosive detector

    NASA Astrophysics Data System (ADS)

    Schundler, Elizabeth; Carlson, David; Vaillancourt, Robert; Rentz Dupuis, Julia; Schwarze, Craig

    2011-05-01

    OPTRA is developing a compact, wide field standoff diffuse reflectance spectrometer for trace explosive detection from a safe standoff. This system is comprised of two key components: a Risley scanner and an infrared tunable laser based spectrometer. The Risley scanner is a mature technology, which uses a pair of matched prisms to steer a laser beam anywhere inside a cone. The compact size, low operating power, and large field of view of the Risley scanner make it the ideal solution for rapidly scanning the laser over the field. The infrared tunable laser spectrometer utilizes a low-cost quartz crystal tuning fork (QCTF) in place of a traditional infrared detector. The large Q-factor of the QCTF enables high sensitivity, low noise detection of explosive signatures even for low concentrations and large standoffs. By coupling this demonstrated technology with a mature Risley scanner design, the field can be scanned both spatially and spectrally. Pairing this data with sophisticated algorithms results in a map of explosives in the field. This paper presents OPTRA's breadboard spectrometer design along with the TNT and RDX spectra it produced.

  7. The wide field upgrade for the Hobby-Eberly Telescope

    NASA Astrophysics Data System (ADS)

    Booth, John A.; MacQueen, Phillip J.; Good, John M.; Wesley, Gordon L.; Hill, Gary J.; Palunas, Povilas; Segura, Pedro R.; Calder, Robert E.

    2006-06-01

    A major performance upgrade for the Hobby-Eberly Telescope (HET) is in the conceptual design phase. The extensive upgrade will include a wide field optical corrector, a new HET tracker with increased payload capacity, and improved telescope pointing and tracking accuracy. The improvements will support the HET Dark Energy Experiment (HETDEX), which seeks to characterize the evolution of dark energy by mapping the imprint of baryonic oscillations on the large scale structure of the Universe. HETDEX will use the increased field-of-view and payload to feed an array of approximately 145 fiber-fed spectrometers, called VIRUS for "Visible Integral field Replicable Unit Spectrograph". The new corrector will have a science field-of-view diameter of 18 arcminutes, in contrast to the original corrector's 4 arcminute field, a twenty-fold increase in area. A new HET tracker with increased payload capacity will be designed to support the wide field corrector. Improved pointing and tracking will be accomplished using new autocollimation and distance measuring metrology combined with real-time wavefront sensing and correction. The upgrade will maintain operation of the current suite of facility instruments, consisting of low, medium, and high resolution spectrometers.

  8. Virtualized Optical Network (VON) for Future Internet and Applications

    NASA Astrophysics Data System (ADS)

    Jinno, Masahiko; Tsukishima, Yukio; Takara, Hidehiko; Kozicki, Bartlomiej; Sone, Yoshiaki; Sakano, Toshikazu

    A virtualized optical network (VON) is proposed as a key to implementing increased agility and flexibility into the future Internet and applications by providing any-to-any connectivity with the appropriate optical bandwidth at the appropriate time. The VON is enabled by introducing optical transparentization and optical fine granular grooming based on optical orthogonal frequency division multiplexing.

  9. The University of Hawaii Wide Field Imager (UHWFI)

    E-print Network

    Hodapp, K W; Luppino, G A; Wainscoat, R; Sousa, E; Yamada, H; Ryan, A; Shelton, R; Inouye, M; Pickles, A J; Ivanov, Y K; Hodapp, Klaus W.; Seifahrt, Andreas; Luppino, Gerard A.; Wainscoat, Richard; Sousa, Ed; Yamada, Hubert; Ryan, Alan; Shelton, Richard; Inouye, Mel; Pickles, Andrew J.; Ivanov, Yanko K.

    2006-01-01

    The University of Hawaii Wide-Field Imager (UHWFI) is a focal compressor system designed to project the full half-degree field of the UH 2.2 m telescope onto the refurbished UH 8Kx8K CCD camera. The optics use Ohara glasses and are mounted in an oil-filled cell to minimize light losses and ghost images from the large number of internal lens surfaces. The UHWFI is equipped with a six-position filter wheel and a rotating sector blade shutter,both driven by stepper motors. The instrument saw first light in 2004 in an engineering mode. After filling the lens cell with index matching oil, integration of all software components into the user interface, tuning of the CCD performance, and the purchase of the final filter set, UHWFI is now fully commissioned at the UH 2.2 m telescope.

  10. Wide-Field Surveys from the SNAP Mission

    E-print Network

    A. Kim; for the SNAP Collaboration

    2002-10-02

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

  11. 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

  12. 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.

  13. The University of Hawaii Wide Field Imager (UHWFI)

    E-print Network

    Klaus W. Hodapp; Andreas Seifahrt; Gerard A. Luppino; Richard Wainscoat; Ed Sousa; Hubert Yamada; Alan Ryan; Richard Shelton; Mel Inouye; Andrew J. Pickles; Yanko K. Ivanov

    2006-04-01

    The University of Hawaii Wide-Field Imager (UHWFI) is a focal compressor system designed to project the full half-degree field of the UH 2.2 m telescope onto the refurbished UH 8Kx8K CCD camera. The optics use Ohara glasses and are mounted in an oil-filled cell to minimize light losses and ghost images from the large number of internal lens surfaces. The UHWFI is equipped with a six-position filter wheel and a rotating sector blade shutter,both driven by stepper motors. The instrument saw first light in 2004 in an engineering mode. After filling the lens cell with index matching oil, integration of all software components into the user interface, tuning of the CCD performance, and the purchase of the final filter set, UHWFI is now fully commissioned at the UH 2.2 m telescope.

  14. 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.

  15. 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.

  16. 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 13.68?m. 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.

  17. Curved focal plane detector array for wide field cameras.

    PubMed

    Dumas, Delphine; Fendler, Manuel; Baier, Nicolas; Primot, Jérôme; le Coarer, Etienne

    2012-08-01

    Miniaturization is the main goal for system design in future cameras. This paper offers a novel method to scale down the optical system and to improve the image quality. As with the human retina, the detector array is spherically bent to fit the curved image surface; so the field curvature aberration is directly suppressed, leading to a better resolution and a simplified optical design. By thinning the substrate, the device is monolithically curved without modifying the fabrication process of the active pixels. Optical characterizations have been performed on planar and curved focal plane based cameras to illustrate the optical advantages of detector array curvature. PMID:22859030

  18. Fiber-Optics for Future EW Platforms

    Microsoft Academic Search

    R. Pirich; P. Anumolu

    2007-01-01

    An enabling technology for next-generation EW systems is an all fiber optic backplane. Fiber optic systems are rapidly evolving and this paper will review the application of fiber optics for aircraft and specifically EW applications.

  19. Wide-field-of-view star tracker camera

    NASA Astrophysics Data System (ADS)

    Lewis, Isabella T.; Ledebuhr, Arno G.; Axelrod, Timothy S.; Kordas, Joseph F.; Hills, Robert

    1991-07-01

    A prototype wide-field-of-view (WFOV) star tracker camera has been fabricated and tested for use in spacecraft navigation. The most unique feature of this device is its 28 degree(s) X 44 degree(s) FOV, which views a large enough sector of the sky to ensure the existence of at least 5 stars of mv equals 4.5 or brighter in all viewing directions. The WFOV requirement and the need to maximize both collection aperture (F/1.28) and spectral input band (0.4 to 1.1 micrometers ) to meet the light gathering needs for the dimmest star have dictated the use of a novel concentric optical design, which employs a fiber optic faceplate field flattener. The main advantage of the WFOV configuration is the smaller star map required for position processing, which results in less processing power and faster matching. Additionally, a size and mass benefit is seen with a large FOV/smaller effective focal length (efl) sensor. Prototype hardware versions have included both image intensified and un-intensified CCD cameras. Integration times of

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

    E-print Network

    Yang, Changhuei

    Wide-field, high-resolution Fourier ptychographic microscopy Guoan Zheng*, Roarke Horstmeyer, 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

  1. How to benchmark a wide field fluorescent microscope

    E-print Network

    How to benchmark a wide field fluorescent microscope Detection threshold(ms) Saturation to generate measurements that characterize a wide-field fluorescence microscope is useful to ensure nominal instrument performance. · The procedure described here benchmarks the microscope to a commercial fluorescent

  2. Wide-field stellar photometry in Piwnice Observatory

    E-print Network

    Gracjan Maciejewski

    2007-12-17

    In this paper research projects based on the wide-field CCD photometry performed in Piwnice Observatory are discussed. The used telescopes, as well as dedicated software pipeline for data reduction are presented. The prospects for collaboration between Polish and Bulgarian institutes in the field of wide-field photometry are also discussed.

  3. Double-helix microscopy for wide-field 3D single-molecule fluorescence imaging

    Microsoft Academic Search

    Ginni Sharma; S. R. P. Pavani; S. Quirin; R. Piestun

    2010-01-01

    We present methods to improve the localization accuracy in wide-field 3D single-molecule double-helix microscopy. We analyze the optical efficiency of the system, the fundamental limit for 3D localization, the estimation algorithms, and polarization sensitive detection.

  4. Three-Dimensional Resolution Doubling in Wide-Field Fluorescence Microscopy by Structured Illumination

    Microsoft Academic Search

    Mats G. L. Gustafsson; Lin Shao; Peter M. Carlton; C. J. Rachel Wang; Inna N. Golubovskaya; W. Zacheus Cande; David A. Agard; John W. Sedat

    2008-01-01

    Structured illumination microscopy is a method that can increase the spatial resolution of wide-field fluorescence microscopy beyond its classical limit by using spatially structured illumination light. Here we describe how this method can be applied in three dimensions to double the axial as well as the lateral resolution, with true optical sectioning. A grating is used to generate three mutually

  5. MEO and LEO space debris optical observations at Crimean Observatory: first experience and future perspectives.

    NASA Astrophysics Data System (ADS)

    Rumyantsev, Vasilij; Biryukov, Vadim; Agapov, Vladimir; Molotov, Igor

    The near Earth space observation group of Crimean Observatory is performing the regular op-tical monitoring of space debris at GEO region within framework of the International Scientific Optical Network (ISON). During last years we also paid attention to objects on lower orbits due to increasing interest to LEO and MEO regions caused by several catastrophic events happened in the recent past. Optical observations provide high quality information about position and physical properties of space debris at LEO and MEO so they can be considered as another source of data comple-mentary to traditional radar measurements. We will discuss our observations of fragments from Briz-M upper stage (object 28944) and Block-DM ullage motor (25054) explosions. Results of observation of USA-193 debris will be presented. Then we will focus on observations and some photometric properties of FengYun 1C debris as well as Cosmos 2251 and Iridium 33 fragments. Radar cross-section versus optical photometry will be compared. Moreover, estimates of orbital parameters as well as area-to-mass ratio for some observed objects will be given. Most of our observations which we discuss in the paper represent just the first attempt to investigate capabilities of our optical system to observe MEO and LEO objects. But these results are very promising and show good perspectives for the future. We will briefly describe future perspectives of our optical observations of space debris and other objects in MEO and LEO region after the new wide-field telescopes will be put into operation.

  6. Narrowband ultraviolet imaging experiment for wide-field surveys (NUVIEWS)

    NASA Astrophysics Data System (ADS)

    Fleischman, Judith R.; Friedman, Peter G.; Martin, Christopher; Schiminovich, David

    1993-11-01

    We are developing a rocket-borne, imaging, wide-field, survey experiment to study global interactions in the multiphase interstellar medium. The experiment will map diffuse C IV (C(superscript 3+)) (lambda) 1549, H(subscript 2) (lambda) (lambda) 1575 - 1645 Lyman band fluorescence, and dust-scattered starlight continuum ((lambda) (lambda) 1400 - 1900) emission over one quarter of the sky in a single rocket flight. Good imaging is maintained in two dimensions, permitting the direct exclusion of stars entering the field of view. The payload consists of four independent, co-aligned telescopes of identical optical construction. Three telescopes are made sensitive in a narrow band by depositing tuned all-dielectric multilayers on the mirror surfaces to achieve a so-called `self-filtering' camera. Each telescope incorporates a large-format imaging microchannel plate detector that is read out using a two- dimensional, crossed, serpentine delay line anode which we have developed. The rocket flight, scheduled for launch in 1994, will be the first flight of a two-dimensional, crossed, serpentine delay line anode.

  7. Fiber optic sensors in concrete: the future?

    Microsoft Academic Search

    C. K. Y Leung

    2001-01-01

    Fiber optic sensing systems have been successfully developed for many engineering applications. The objective of this review paper is to assess the potential of fiber optic sensors for the monitoring of concrete structures. In this paper, some current applications of fiber optic sensors in concrete structures are first reviewed to demonstrate their applicability in conventional monitoring applications. The advantages of

  8. Identifications of FIRST radio sources in the NOAO Deep Wide-Field Survey

    Microsoft Academic Search

    K. El Bouchefry; C. M. Cress

    2007-01-01

    In this paper we present the results of an optical and near infrared identification of 514 radio sources from the FIRST survey (Faint Images of the Radio Sky Survey at Twenty centimetres) with a flux-density limit of 1 mJy in the NOAO Deep Wide-Field Survey (NDWFS) Boötes field. Using optical ({B w, R, I}) and {K} band data with approximate

  9. Identifications of FIRST radio sources in the NOAO Deep-Wide Field Survey

    Microsoft Academic Search

    K. EL Bouchefry; C. M. Cress

    2007-01-01

    In this paper we present the results of an optical and near infrared\\u000aidentification of 514 radio sources from the FIRST survey (Faint Images of the\\u000aRadio Sky Survey at Twenty centimeters) with a flux-density limit of 1 mJy in\\u000athe NOAO Deep-Wide Field Survey (NDWFS) Bootes field. Using optical (Bw, R, I)\\u000aand K band data with approximate limits

  10. 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; Hee Ree, Chang; Jin, Ho; Choel Yang, Sun; Park, Hong-Young; Shin, Goo-Hwan; Seo, Joung-Ki; Rhee, Seung-Wu; Park, Jong-Oh; Mok Lee, Hyung; Murakami, Hiroshi; Matsumoto, Toshio

    2014-10-01

    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-? 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 ?m 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-? 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.

  11. Depth resolved wide field illumination for biomedical imaging and fabrication

    E-print Network

    So, Peter T. C.

    Nonlinear microscopic imaging is relatively slow due to the sequential nature of raster scanning. Recently, this limitation was overcome by developing a 3D-resolved wide-field two-photon microscope based on the concept of ...

  12. Deep Wide-field Near-Infrared Imaging for the Herschel Lensing Survey

    NASA Astrophysics Data System (ADS)

    Rawle, Tim; Egami, Eiichi; Rex, Marie; Bridge, Carrie; Walth, Greg

    2011-02-01

    ``The Herschel Lensing Survey'' (HLS; PI: E. Egami; 292.3 hrs) is imaging a sample of 44 massive galaxy clusters in five far-infrared bands 100-500 (mu)m. The goal is to surpass the nominal confusion- limited depth of Herschel observations by taking advantage of the gravitational lensing power of massive clusters. Our ability to accurately determine galaxy dust properties, and hence total infrared luminosity, from the Herschel SEDs is curtailed by the degeneracy between dust temperature and galaxy redshift. Near-infrared imaging via CTIO/NEWFIRM provides vital photometry at wavelengths relatively unaffected by dust, allowing tighter constraints on photometric redshifts for the Herschel-detected population, while also enabling us to measure the stellar mass of cluster and low-redshift sources. At the same time, the images give us the precise astrometry required for future NIR spectroscopy of the optically-faint high-redshift Herschel sources. Here, we propose four nights of observing to obtain J and K_s band images for 10 HLS clusters. NEWFIRM's wide field of view is well matched to our SPIRE coverage, so only a single pointing is required per cluster.

  13. 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. [Infrared Processing and Analysis Center, Caltech 100-22, Pasadena, CA 91125 (United States); Hoffman, Douglas I., E-mail: fmasci@ipac.caltech.edu [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    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. The Wide Field Spectrograph (WiFeS)

    E-print Network

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

    2007-05-02

    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 2.3m telescope at the Siding Spring Observatory. WiFeS is a powerful integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent thoughput, wavelength stability, spectrophotometric performance and superb image quality along with wide spectral coverage throughout the 320-950 nm wavelength region. It provides a 25x38 arcsec. field with 0.5 arcsec. sampling along each of twenty five 38X1 arcsec slitlets. The output format is optimized 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 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.

  15. Metal multilayer mirrors for EUV wide field telescopes

    SciTech Connect

    Smith, B.W.; Bloch, J.J.; Roussel-Dupre,D.

    1989-01-01

    Metal multilayer mirrors have been designed for the ALEXIS satellite, which is to carry six wide field telescopes to perform an all-sky survey in three or four narrow wavelength bands in the EUV. Comprised of alternating layers of molybdenum and silicon, the mirrors are optimized to provide maximum reflectivity at angles from 11.5 to 17/degree/ off normal incidence and at wavelengths of 133, 171, or 186A. Simultaneously, the mirrors use a ''wavetrap'' described below to suppress reflectivity at 304A, where the extremely strong geocoronal line of He II causes severe background problems. Low reflectivity at 304A is achieved by superposing two layer pairs that provide destructive interference with an effective 2d spacing of 152A. The Mo layers in this wavetrap must be very thin, about 10A each, in order to allow the shorter wavelengths desired for peak reflectivity to penetrate without significant attenuation. Because refraction changes the effective angle of passage through the wavetrap, a joint optimization between layer thicknesses in the deep layers and the wavetrap layers must be performed for each target peak wavelength. For the 186A mirror, the optimum design from substrate upward is 40 layer pairs, each 74A Si and 31A Mo, followed by 2 layer pairs, each 55A Si and 10A Mo. Calculations predict this design will have a peak reflectivity at 186A of 35 percent and a 304A reflectivity less than 10/sup /minus/5/, if available optical constants are correct and the multilayer can be fabricated without difficulty. We will present details of the calculations and laboratory measurements of the reflectivity performance attained with prototype mirrors. 6 refs., 2 figs.

  16. 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.

  17. Leveraging Optical Technology in Future Bus-based Chip Multiprocessors

    Microsoft Academic Search

    Nevin Kirman; Meyrem Kirman; Rajeev K. Dokania; Jose F. Martinez; Alyssa B. Apsel; Matthew A. Watkins; David H. Albonesi

    2006-01-01

    Although silicon optical technology is still in its formative stages, and the more near-term application is chip-to-chip communication, rapid advances have been made in the de- velopment of on-chip optical interconnects. In this paper, we investigate the integration of CMOS-compatible optical technology to on-chip cache-coherent buses in future CMPs. While not exhaustive, our investigation yields a hierarchi- cal opto-electrical system

  18. 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.

  19. Past, present, and future of optical design at the College of Optical Sciences

    NASA Astrophysics Data System (ADS)

    Sasián, José

    2014-09-01

    The College of Optical Sciences, OSC, has seen three periods of optical design teaching and development. The first years 1964-1969; the golden years 1970-1999; and the new millennia years. Today the college offers a comprehensive and professional curriculum in optical design learning, and enjoys a strong heritage in optical design. This paper provides a perspective into the history and future prospects in optical design at the OSC.

  20. 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).

  1. The Garching-Bonn Deep Survey (GaBoDS) Wide-Field-Imaging Reduction Pipeline

    E-print Network

    H. Hildebrandt; T. Erben; M. Schirmer; J. P. Dietrich; P. Schneider

    2007-05-03

    We introduce our publicly available Wide-Field-Imaging reduction pipeline THELI. The procedures applied for the efficient pre-reduction and astrometric calibration are presented. A special emphasis is put on the methods applied to the photometric calibration. As a test case the reduction of optical data from the ESO Deep Public Survey including the WFI-GOODS data is described. The end-products of this project are now available via the ESO archive Advanced Data Products section.

  2. Artist's Concept of Wide-field Infrared Survey Explorer (WISE)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Artist's concept of Wide-field Infrared Survey Explorer.

    A new NASA mission will scan the entire sky in infrared light in search of nearby cool stars, planetary construction zones and the brightest galaxies in the universe.

    Called the Wide-field Infrared Survey Explorer, the mission has been approved to proceed into the preliminary design phase as the next in NASA's Medium-class Explorer program of lower cost, highly focused, rapid-development scientific spacecraft. It is scheduled to launch in 2008.

  3. The depolarized fiber-optic gyro for future tactical applications

    NASA Astrophysics Data System (ADS)

    Bramson, Michael

    1991-02-01

    The requirements of fiber-optic gyros (FOGs) for the most demanding mission profiles of future weapon systems are examined. A concept of a high-performance depolarized FOG was developed that uses a standard single-mode fiber coil with a depolarized optical circuit including a multifunction integrated optic device, making it possible to achieve automated and reproducible production of high-performance tactical FOGs at low cost. The paper describes the optical configuration of this FOG and the gyro's electronics and presents the test data.

  4. CMB Optical Depth Measurements: Past, Present, Future

    E-print Network

    Brian Keating; Nathan Miller

    2005-12-08

    The polarization of the cosmic microwave background (CMB) is encoded with exactly the same cosmic information as the CMB's temperature anistropy. However, polarization has the additional promise of accurately probing the reionization history of the universe and potentially constraining, or detecting, the primordial background of gravitational waves produced by inflation. We demonstrate that these two CMB polarization goals are mutually compatible. A polarimeter optimized to detect the inflationary gravitational wave background signature in the polarization of the CMB is well situated to detect the signatures of realistic first-light scenarios. We also discuss current results and prospects for future CMB polarization experiments.

  5. Wide-field imaging and OCT vs clinical evaluation of patients referred from diabetic retinopathy screening

    PubMed Central

    Manjunath, V; Papastavrou, V; Steel, D H W; Menon, G; Taylor, R; Peto, T; Talks, J

    2015-01-01

    Purpose Compare wide-field Optomap imaging and optical coherence tomography (OCT) with clinical examination in diabetic retinopathy (DR). Methods Patients referred from Diabetic Eye Screening Programmes to three centres underwent dilated ophthalmoscopy and were assigned a DR grade. Wide-field colour imaging and OCT were then examined by the same clinician at that visit and a combined grade was assigned. Independent graders later reviewed the images and assigned an imaging-only grade. These three grades (clinical, combined, and imaging) were compared. The method that detected the highest grade of retinopathy, including neovascularisation, was determined. Results Two thousand and forty eyes of 1023 patients were assessed. Wide-field imaging compared with clinical examination had a sensitivity and specificity of 73% and 96%, respectively, for detecting proliferative DR, 84% and 69% for sight-threatening DR, and 64% and 90% for diabetic macular oedema. Imaging alone found 35 more eyes with new vessels (19% of eyes with new vessels) and the combined grade found 14 more eyes than clinical examination alone. Conclusions Assessment of wide-field images and OCT alone detected more eyes with higher grades of DR compared with clinical examination alone or when combined with imaging in a clinical setting. The sensitivity was not higher as the techniques were not the same, with imaging alone being more sensitive. Wide-field imaging with OCT could be used to assess referrals from DR screening to determine management, to enhance the quality of assessment in clinics, and to follow-up patients whose DR is above the screening referral threshold but does not actually require treatment. PMID:25592127

  6. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P. (Fermi National Accelerator Lab., Batavia, IL (United States)); Elliott, A. (Illinois Univ., Chicago, IL (United States))

    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.

  7. Optical signal acquisition and processing in future accelerator diagnostics

    SciTech Connect

    Jackson, G.P. [Fermi National Accelerator Lab., Batavia, IL (United States); Elliott, A. [Illinois Univ., Chicago, IL (United States)

    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.

  8. Technological status and future challenges of deep space optical communication

    NASA Astrophysics Data System (ADS)

    Lesh, James R.

    An account is given of the concepts, techniques, and system design features that may be used to realize an optical communications link for future planetary missions. Such a spacecraft subsystem would encompass a 10-30 cm aperture optical telescope for both transmitting and receiving. Uplink from a laser, in the form of pulsed ranging signals or command information, will be extracted by a tracking detector; downlink data, as well as detected ranging pulses, will be properly formatted and used to modulate the downlink laser. The optical receiving station may be either on the ground or in earth orbit.

  9. 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.

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

    PubMed Central

    Yang, Chenying; 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

  11. An Initial Assessment of the CALIPSO Wide Field Camera Performance

    Microsoft Academic Search

    M. C. Pitts; W. S. Luck; Y. Hu; D. M. Winker

    2006-01-01

    The Wide Field Camera (WFC) is one of three instruments in the CALIPSO science payload, with the other two being the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) and the Infrared Imaging Radiometer (IIR). The WFC is a narrow-band, push-broom imager that provides continuous high-spatial-resolution imagery during the daylight segments of the orbit over a swath centered on the lidar footprint.

  12. Astrophysical False Positives Encountered in Wide-Field Transit Searches

    Microsoft Academic Search

    David Charbonneau; Timothy M. Brown; Edward W. Dunham; David W. Latham; Dagny L. Looper; Georgi Mandushev

    2004-01-01

    Wide-field photometric transit surveys for Jupiter-sized planets are inundated by astrophysical false positives, namely systems that contain an eclipsing binary and mimic the desired photometric signature. We discuss several examples of such false alarms. These systems were initially identified as candidates by the PSST instrument at Lowell Observatory. For three of the examples, we present follow-up spectroscopy that demonstrates that

  13. Foregrounds in Wide-field Redshifted 21 cm Power Spectra

    NASA Astrophysics Data System (ADS)

    Thyagarajan, Nithyanandan; Jacobs, Daniel C.; Bowman, Judd D.; Barry, N.; Beardsley, A. P.; Bernardi, G.; Briggs, F.; Cappallo, R. J.; Carroll, P.; Corey, B. E.; de Oliveira-Costa, A.; Dillon, Joshua S.; Emrich, D.; Ewall-Wice, A.; Feng, L.; Goeke, R.; Greenhill, L. J.; Hazelton, B. J.; Hewitt, J. N.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kaplan, D. L.; Kasper, J. C.; Kim, Han-Seek; Kittiwisit, P.; Kratzenberg, E.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; Lynch, M. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Neben, A. R.; Oberoi, D.; Offringa, A. R.; Ord, S. M.; Paul, Sourabh; Pindor, B.; Pober, J. C.; Prabu, T.; Procopio, P.; Riding, J.; Rogers, A. E. E.; Roshi, A.; Udaya Shankar, N.; Sethi, Shiv K.; Srivani, K. S.; Subrahmanyan, R.; Sullivan, I. S.; Tegmark, M.; Tingay, S. J.; Trott, C. M.; Waterson, M.; Wayth, R. B.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C. L.; Wu, C.; Wyithe, J. S. B.

    2015-05-01

    Detection of 21 cm emission of H i from the epoch of reionization, at redshifts z\\gt 6, is limited primarily by foreground emission. We investigate the signatures of wide-field measurements and an all-sky foreground model using the delay spectrum technique that maps the measurements to foreground object locations through signal delays between antenna pairs. We demonstrate interferometric measurements are inherently sensitive to all scales, including the largest angular scales, owing to the nature of wide-field measurements. These wide-field effects are generic to all observations but antenna shapes impact their amplitudes substantially. A dish-shaped antenna yields the most desirable features from a foreground contamination viewpoint, relative to a dipole or a phased array. Comparing data from recent Murchison Widefield Array observations, we demonstrate that the foreground signatures that have the largest impact on the H i signal arise from power received far away from the primary field of view. We identify diffuse emission near the horizon as a significant contributing factor, even on wide antenna spacings that usually represent structures on small scales. For signals entering through the primary field of view, compact emission dominates the foreground contamination. These two mechanisms imprint a characteristic pitchfork signature on the “foreground wedge” in Fourier delay space. Based on these results, we propose that selective down-weighting of data based on antenna spacing and time can mitigate foreground contamination substantially by a factor of ?100 with negligible loss of sensitivity.

  14. The JPL Optical Communications Telescope Laboratory Test Bed for the Future Optical Deep Space Network

    Microsoft Academic Search

    K. E. Wilson; N. Page; J. Wu; M. Srinivasan

    2003-01-01

    The lower power consumption and lower mass of high-bandwidth optical telecom- munications relative to RF telecommunications make laser communication technol- ogy extremely attractive for returning data from future NASA\\/JPL deep-space probes. JPL is building a research and development optical communications tele- scope laboratory (OCTL) at its Table Mountain Facility in Southern California to evaluate strategies for supporting operations from future

  15. 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.

  16. 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.

  17. Optical communications for future deep-space missions

    NASA Astrophysics Data System (ADS)

    Rayman, Marc D.; Lesh, James R.

    1988-06-01

    The development of key technologies for an optical communications system for deep-space probes is discussed. Aspects of the technology include the pulse-position modulation technique for data transmission, a solid-state laser with a Nd:YAG crystal end, nondiffraction-limited receivers, and the application of avalanche photodiodes to improve photon detection. Mission benefits and flight opportunities and applications are discussed. Experiments to test optical communication systems are being planned for the Space Shuttle and the Mars Rover Sample Return misson. Future missions which will probably use the system include Cassini and the Mariner Mark II.

  18. Wide Field Imager in Space for Dark Energy and Planets

    E-print Network

    Gould, Andrew

    2009-01-01

    A wide-field imager in space could make remarkable progress in two very different frontiers of astronomy: dark energy and extra-solar planets. Embedding such an imager on a much larger and more complicated DE mission would be a poor science-approach under any circumstances and is a prescription for disaster in the present fiscal climate. The 2010 Decadal Committee must not lead the lemming stampede that is driving toward a DE mega-mission, but should stand clearly in its path.

  19. Metal multilayer mirrors for EUV wide field telescopes.

    NASA Astrophysics Data System (ADS)

    Smith, B. W.; Bloch, J. J.; Roussel-Dupré, D.

    1989-07-01

    Metal multilayer mirrors have been designed for the ALEXIS satellite, which is to carry six wide field telescopes to perform an all-sky survey in three or four narrow wavelength bands in the EUV. Comprised of alternating layers of molybdenum and silicon, the mirrors are optimized to provide maximum reflectivity at angles from 11.5 to 17° off normal incidence and at wavelengths of 133, 171, or 186 Å. The authors present details of the calculations and laboratory measurements of the reflectivity performance attained with prototype mirrors.

  20. Dither and drizzle strategies for Wide Field Camera 3

    NASA Astrophysics Data System (ADS)

    Mutchler, Max

    2010-07-01

    Hubble's 20th anniversary observation of Herbig-Haro object HH 901 in the Carina Nebula is used to illustrate observing strategies and corresponding data reduction methods for the new Wide Field Camera 3 (WFC3), which was installed during Servicing Mission 4 in May 2009. The key issues for obtaining optimal results with offline Multidrizzle processing of WFC3 data sets are presented. These pragmatic instructions in "cookbook" format are designed to help new WFC3 users quickly obtain good results with similar data sets.

  1. The Wide Field Spectrograph (WiFeS)

    Microsoft Academic Search

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

    2007-01-01

    This paper describes the Wide Field Spectrograph (WiFeS) under construction at the Research School of Astronomy and Astrophysics\\u000a (RSAA) of the Australian National University (ANU) for the ANU 2.3 m telescope at the Siding Spring Observatory. WiFeS is\\u000a a powerful integral field, double-beam, concentric, image-slicing spectrograph designed to deliver excellent throughput, wavelength\\u000a stability, spectrophotometric performance and superb image quality along with

  2. A Web-Based Image Viewer for Wide-Field Survey Data

    NASA Astrophysics Data System (ADS)

    Tody, Doug; Fitzpatrick, Mike

    NOAO is in the process of creating an archive for ground-based optical and infrared data. Initially this will be populated with data from the NOAO Surveys program which consists mainly of multiband wide-field imaging data and associated object catalogs. As part of this effort we are developing a number of Web services for interacting with and accessing these survey data products. Our motivation is not only to provide useful tools in the near term for accessing survey data, but also to explore the technology available for constructing Web services for science data access, and to aid in planning the full NOAO archive facility.

  3. A wide-field infrared camera for the Observatoire du mont Mégantic

    NASA Astrophysics Data System (ADS)

    Artigau, Etienne; Doyon, Rene; Nadeau, Daniel; Vallee, Philippe; Thibault, Simon

    2003-03-01

    A wide-field near-infrared (0.8 2.4 ?m) camera for the 1.6 m telescope of the Observatoire du mont Mégantic (OMM), is currently under construction at the Université de Montréal. The field of view is 30' × 30' and will have very little distortion. The optics comprise 8 spherical cryogenic lenses. The instrument features two filter wheels with provision for 10 filters including broad band I, z, J, H, K and other narrow-band filters. The camera is based on a 2048 × 2048 HgCdTe Hawaii-2 detector driven by a 32-output SDSU-II controller operating at ~250 kHz.

  4. Hyperspectral time-resolved wide-field fluorescence molecular tomography based on structured light and single-pixel detection.

    PubMed

    Pian, Qi; Yao, Ruoyang; Zhao, Lingling; Intes, Xavier

    2015-02-01

    We present a time-resolved fluorescence diffuse optical tomography platform that is based on wide-field structured illumination, single-pixel detection, and hyperspectral acquisition. Two spatial light modulators (digital micro-mirror devices) are employed to generate independently wide-field illumination and detection patterns, coupled with a 16-channel spectrophotometer detection module to capture hyperspectral time-resolved tomographic data sets. The main system characteristics are reported, and we demonstrate the feasibility of acquiring dense 4D tomographic data sets (space, time, spectra) for time domain 3D quantitative multiplexed fluorophore concentration mapping in turbid media. PMID:25680065

  5. Dwarf Irregular Galaxy Leo A: Suprime-Cam Wide-field Stellar Photometry

    NASA Astrophysics Data System (ADS)

    Stonkut?, Rima; Arimoto, Nobuo; Hasegawa, Takashi; Narbutis, Donatas; Tamura, Naoyuki; Vansevi?ius, Vladas

    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. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

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

    SciTech Connect

    Stonkut?, Rima; Narbutis, Donatas; Vansevi?ius, Vladas [Center for Physical Sciences and Technology, Savanoriu, 231, Vilnius LT-02300 (Lithuania); Arimoto, Nobuo [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 69720 (United States); Hasegawa, Takashi [Gunma Astronomical Observatory, 6860-86 Nakayama, Takayama-mura, Agatsuma-gun, Gunma 377-0702 (Japan); Tamura, Naoyuki, E-mail: vladas.vansevicius@ff.vu.lt [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan)

    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.

  7. HAWK-I: the new wide-field IR imager for the VLT

    NASA Astrophysics Data System (ADS)

    Casali, Mark; Pirard, Jean-Francois; Kissler-Patig, Markus; Moorwood, Alan; Bedin, Luigi; Biereichel, Peter; Delabre, Bernard; Dorn, Reinhold; Finger, Gert; Gojak, Domingo; Huster, Gotthard; Jung, Yves; Koch, Franz; Lizon, Jean-Louis; Mehrgan, Leander; Pozna, Eszter; Silber, Armin; Sokar, Barbara; Stegmeier, Joerg

    2006-06-01

    HAWK-I is a new wide-field infrared camera under development at ESO. With four Hawaii-2RG detectors, a 7.5 arcminute square field of view and 0.1 arcsecond pixels, it will be an optimum imager for the VLT, and a major enhancement to existing and future infrared capabilities at ESO. HAWK-I will eventually make use of ground-layer AO achieved through a deformable secondary mirror/laser guide star facility planned for the VLT.

  8. 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

  9. Tracing the Evolution of Elliptical Galaxies in the NOAO Deep Wide-Field Survey

    NASA Astrophysics Data System (ADS)

    Dey, A.; Greer, C.; Jannuzi, B. T.; Najita, J.; Stern, D.; Dawson, S.; Chaffee, F.; Spinrad, H.

    2000-12-01

    The NOAO Deep Wide-Field Survey will image a total of 18 square degrees in 3 optical bands (Bw, R, and I) and 3 near-infrared bands (J, H, and K). One of the prominent features in the Bw-R vs. R-I color-color diagram resulting from the preliminary NDWFS data is a `loop' which we hypothesize traces the evolution of the reddest elliptical galaxies. We investigate the evolution of these ellipticals in the optical color-color and color-magnitude planes as predicted by the Bruzual & Charlot (1999) evolutionary spectral synthesis models and compare the predictions with the preliminary NDWFS data. We find that the evolution of the red ellipticals is reproduced by Bruzual-Charlot models with an exponentially decreasing star formation rate and a moderately high formation redshift (zf > 5). Preliminary spectroscopy of the reddest Bw-R populations confirms the basic predictions of the models. The NOAO Deep Wide-Field Survey is being supported by the National Optical Astronomy Observatory which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation. C. Greer's research was supported by the NOAO/KPNO REU Program, funded by the National Science Foundation.

  10. Science with a wide-field UV transient explorer

    SciTech Connect

    Sagiv, I.; Gal-Yam, A.; Ofek, E. O.; Waxman, E.; Trakhtenbrot, B.; Topaz, J. [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Aharonson, O. [Helen Kimmel Center for Planetary Science, Weizmann Institute of Science, 76100 Rehovot (Israel); Kulkarni, S. R.; Phinney, E. S. [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Nakar, E.; Maoz, D. [School of Physics and Astronomy, Tel Aviv University, 93387 Tel Aviv (Israel); Beichman, C. [Division of Geophysics and Planetary Science, California Institute of Technology, Pasadena, CA 91105 (United States); Murthy, J. [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India); Worden, S. P. [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    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.

  11. The Impact Of Fiber Optics (Photonics) On Future Aircraft

    NASA Astrophysics Data System (ADS)

    Reich, Stanley M.; Ritter, Charles H.

    1990-02-01

    Military aircraft design has been in a state of evolutionary development since its invention. After the first usage of aircraft for military applications in World War I, the military has been seeking ways of improving mission effectiveness to maintain military superiority. The military has been constantly searching for new methods and technologies to accomplish this goal. In the early days of aviation, there were clear distinctions and divisions between aircraft system functions. Although they all served to support the flight of the aircraft, they operated independently of each other. With the modern trend of developing a high degree of integration between the various aircraft systems, requirements are emerging for a group of new technologies to support this trend. One such group of emerging technologies is the combination of photonics, integrated optics and fiber optics. The integrated approach to the development of the avionics, non-avionics and airframe of the aircraft is part of the approach to improving aircraft mission effectiveness through enhanced mission function performance and associated susceptibility (reliability, availability, survivability). This paper will discuss the general evolution of aircraft and, in particular, the role of photonics, integrated optics and fiber optics on the avionics, non avionics and airframe of past and future aircraft. Included will be the relationship of these emerging optical technologies to the military programs involving smart structures and smart skins.

  12. 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.

  13. 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

  14. 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.

  15. Automatic detection of asteroids and meteoroids --- a wide-field survey

    NASA Astrophysics Data System (ADS)

    Vereš, P.; Tóth, J.; Jedicke, R.; Tonry, J.; Denneau, L.; Wainscoat, R.; Kornoš, L.; Šilha, J.

    2014-07-01

    The small Near-Earth Asteroids (NEAs) represent a potential risk but also an easily accessible space resource for future robotic or human in-situ space exploration or commercial activities. However, the population of 1--300 m NEAs is not well understood in terms of size- frequency and orbital distribution. NEAs with diameters below 200 m tend to have much faster spin rates than large objects and they are believed to be monolithic and not rubble-pile like their large counterparts. Moreover, the current surveys do not systematically search for the small NEAs that are mostly overlooked. We propose a low- cost robotic optical survey (ADAM-WFS) aimed at small NEAs based on four state-of-the-art telescopes having extremely wide fields of view. The four Houghton-Terebizh 30-cm astrographs (Fig. left) with 4096×4096 -pixel CCD cameras will acquire 96 square degrees in one exposure with the plate scale of 4.4 arcsec/pixel. In 30 seconds, the system will be able to reach +17.5 mag in unfiltered mode. The survey will be operated on semi-automatic basis, covering the entire night sky three times per night and optimized toward fast moving targets recognition. The advantage of the proposed system is the usage of existing of-the-shelf components and software for the image processing and object identification and linking (Denneau et al., 2013). The one-year simulation of the survey (Fig. right) at the testing location at AGO Modra observatory in Slovakia revealed that we will detect 60--240 NEAs between 1--300 m that get closer than 10 lunar distances from the Earth. The number of detections will rise by a factor of 1.5--2 in case the survey is placed at a superb observing location such as Canary Islands. The survey will also serve as an impact warning system for imminent impactors. Our simulation showed that we have a 20 % chance of finding a 50-m NEA on a direct impact orbit. The survey will provide multiple byproducts from the all-sky scans, such as comet discoveries, sparse light curves of bright main-belt asteroids, space-debris detection, and stationary transient events like novae, supernovae, variable stars, and microlensing. The budget for the prototype development and testing is estimated to be 1,000,000 EUR. The planned development time is one year.

  16. The first light of Mini-MegaTORTORA wide-field monitoring system

    NASA Astrophysics Data System (ADS)

    Biryukov, A.; Beskin, G.; Karpov, S.; Bondar, S.; Ivanov, E.; Katkova, E.; Perkov, A.; Sasyuk, V.

    We describe the first light of a new 9-channel wide-field optical monitoring system with sub-second temporal resolution, Mini-MegaTORTORA, which is being tested now at the Special Astrophysical Observatory in Russian Caucasus. The system is able to observe the sky simultaneously in either wide ( ˜ 900 deg2) or narrow ( ˜ 100 deg2) fields of view, either in clear light or with any combination of color (Johnson B, V or R) and polarimetric filters installed, with exposure times ranging from 100 ms to 100 s. The primary goal of the system is the detection of rapid (with sub-second characteristic time scales) optical transients, but it may be also used for studying variability of sky objects over longer time scales.

  17. Diffuse optical tomography: Present status and its future

    NASA Astrophysics Data System (ADS)

    Yamada, Yukio; Okawa, Shinpei

    2014-05-01

    Diffuse optical tomography (DOT) is one of the emerging modalities for the non-invasive imaging of thick biological tissues using near-infrared (NIR) light. This article reviews the fundamentals and development of DOT technology since its advent in the early 1990s, including the modeling of light propagation in biological tissues which strongly scatter and weakly absorb NIR light, the optical properties of biological tissues in the NIR wavelength range, three typical measurement methods, image reconstruction algorithms, and so forth. Then various studies are referred to for improvement of the DOT images, which are essentially low in quality due to the ill-conditioned and underdetermined problem. Studies and clinical applications presently attracting much attention are discussed in some detail. Finally, the expected future developments are summarized.

  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. 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.

  20. 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

  1. Wide-field motion tuning in nocturnal hawkmoths

    PubMed Central

    Theobald, Jamie C.; Warrant, Eric J.; O'Carroll, David C.

    2010-01-01

    Nocturnal hawkmoths are known for impressive visually guided behaviours in dim light, such as hovering while feeding from nectar-bearing flowers. This requires tight visual feedback to estimate and counter relative motion. Discrimination of low velocities, as required for stable hovering flight, is fundamentally limited by spatial resolution, yet in the evolution of eyes for nocturnal vision, maintenance of high spatial acuity compromises absolute sensitivity. To investigate these trade-offs, we compared responses of wide-field motion-sensitive neurons in three species of hawkmoth: Manduca sexta (a crepuscular hoverer), Deilephila elpenor (a fully nocturnal hoverer) and Acherontia atropos (a fully nocturnal hawkmoth that does not hover as it feeds uniquely from honey in bees' nests). We show that despite smaller eyes, the motion pathway of D. elpenor is tuned to higher spatial frequencies and lower temporal frequencies than A. atropos, consistent with D. elpenor's need to detect low velocities for hovering. Acherontia atropos, however, presumably evolved low-light sensitivity without sacrificing temporal acuity. Manduca sexta, active at higher light levels, is tuned to the highest spatial frequencies of the three and temporal frequencies comparable with A. atropos. This yields similar tuning to low velocities as in D. elpenor, but with the advantage of shorter neural delays in processing motion. PMID:19906663

  2. Wide field-of-view fluorescence imaging of coral reefs.

    PubMed

    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

  3. 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.

  4. A new variational method for erythrocyte velocity estimation in wide-field imaging in vivo.

    PubMed

    Deneux, Thomas; Faugeras, Olivier; Takerkart, Sylvain; Masson, Guillaume S; Vanzetta, Ivo

    2011-08-01

    Measuring erythrocyte velocity in individual microvessels has important applications for biomedical and functional imaging. Recent multiphoton fluorescence microscopy approaches require injecting fluorescent tracers; moreover, only one or few vessels can be imaged at a time. To overcome these shortcomings, we used CCD-based optical imaging of intrinsic absorption changes in macroscopic vascular networks to record erythrocytes' trajectories over several mm (2) of cortical surface. We then demonstrate the feasibility of erythrocyte velocity estimation from such wide-field data, using two robust, independent, algorithms. The first one is a recently published Radon transform-based algorithm that estimates erythrocyte velocity locally. We adapt it to data obtained in wide-field imaging and show, for the first time, its performance on such datasets. The second ("fasttrack") algorithm is novel. It is based on global energy minimization techniques to estimate the full spatiotemporal erythrocytes' trajectories inside vessels. We test the two algorithms on both simulated and biological data, obtained in rat cerebral cortex in a spreading depression experiment. On vessels with medium-slow erythrocyte velocities both algorithms performed well, allowing their usage as benchmark one for another. However, our novel fasttrack algorithm outperformed the other one for higher velocities, as encountered in the arterial network. PMID:21427018

  5. 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.

  6. Objective evaluation of 3-D wide-field effect by human postural control analysis

    NASA Astrophysics Data System (ADS)

    Shimizu, Toshihiro; Yano, Sumio; Mitsuhashi, Tetsuo

    1992-08-01

    A new evaluation method of visual wide-field effects using human postural control analysis is proposed. In designing a television system for future, it is very important to understand the dynamic response of human beings in order to evaluate the visual effects of displayed images objectively. Visual effects produced by 3-D wide-field images are studied. An observer's body sway produced by postural control is discussed using rotating 2-D and 3-D images. Comparisons between stationary and rotating images are also performed. A local peak appears in power spectra of the body sway for the rotating images (3-D and 2-D). On the other hand, no distinctive component appears in the power spectra for the stationary images. By extending the visual field, the cyclic component can be proved from the audio-correlation function of the body sway for the rotating images. These results suggest that displayed images induce the postural control. The total length of the body sway locus is also analyzed to evaluate the postural control. The total length for the rotating images increases in proportion to viewing angles, and is nearly saturated after 50 (deg). Moreover, it is shown that the total length for the rotating 3-D image is greater than for the rotating 2-D image.

  7. Confirmation of Wide-field Signatures in Redshifted 21 cm Power Spectra

    NASA Astrophysics Data System (ADS)

    Thyagarajan, Nithyanandan; Jacobs, Daniel C.; Bowman, Judd D.; Barry, N.; Beardsley, A. P.; Bernardi, G.; Briggs, F.; Cappallo, R. J.; Carroll, P.; Deshpande, A. A.; de Oliveira-Costa, A.; Dillon, Joshua S.; Ewall-Wice, A.; Feng, L.; Greenhill, L. J.; Hazelton, B. J.; Hernquist, L.; Hewitt, J. N.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kaplan, D. L.; Kim, Han-Seek; Kittiwisit, P.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Neben, A. R.; Oberoi, D.; Offringa, A. R.; Ord, S. M.; Paul, Sourabh; Pindor, B.; Pober, J. C.; Prabu, T.; Procopio, P.; Riding, J.; Udaya Shankar, N.; Sethi, Shiv K.; Srivani, K. S.; Subrahmanyan, R.; Sullivan, I. S.; Tegmark, M.; Tingay, S. J.; Trott, C. M.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.; Wyithe, J. S. B.

    2015-07-01

    We confirm our recent prediction of the “pitchfork” foreground signature in power spectra of high-redshift 21 cm measurements where the interferometer is sensitive to large-scale structure on all baselines. This is due to the inherent response of a wide-field instrument and is characterized by enhanced power from foreground emission in Fourier modes adjacent to those considered to be the most sensitive to the cosmological H i signal. In our recent paper, many signatures from the simulation that predicted this feature were validated against Murchison Widefield Array (MWA) data, but this key pitchfork signature was close to the noise level. In this paper, we improve the data sensitivity through the coherent averaging of 12 independent snapshots with identical instrument settings and provide the first confirmation of the prediction with a signal-to-noise ratio \\gt 10. This wide-field effect can be mitigated by careful antenna designs that suppress sensitivity near the horizon. Simple models for antenna apertures that have been proposed for future instruments such as the Hydrogen Epoch of Reionization Array and the Square Kilometre Array indicate they should suppress foreground leakage from the pitchfork by ?40 dB relative to the MWA and significantly increase the likelihood of cosmological signal detection in these critical Fourier modes in the three-dimensional power spectrum.

  8. On illumination schemes for wide-field CARS I. Toytman,1,*

    E-print Network

    Palanker, Daniel

    . Ritsch-Marte, "Selective imaging of saturated and unsaturated lipids by wide-field CARS-microscopy," OptOn illumination schemes for wide-field CARS microscopy I. Toytman,1,* D. Simanovskii,1 and D@stanford.edu Abstract: New system for a wide-field CARS microscopy is demonstrated, including two schemes of non

  9. 1 Astrometric calibration for INT Wide Field Camera images The Wide Field Camera instrument on the Isaac Newton Telescope contains four CCD chips of

    E-print Network

    Taylor, Mark

    1 Astrometric calibration for INT Wide Field Camera images The Wide Field Camera instrument on the Isaac Newton Telescope contains four CCD chips of 2048 #2; 4096 pixels positioned roughly, it is necessary to correct for the exact orientation and position of each CCD in relation to the others, as well

  10. The Wide Field X-ray Telescope Mission-A Digital Sky Survey in X-rays

    Microsoft Academic Search

    S. Murray; R. Giacconi; A. Ptak; P. Rosati; M. Weisskopf; S. Borgani; C. Jones; G. Pareschi; P. Tozzi; R. Gilli; S. Campana; M. Paolillo; G. Tagliaferri; M. Bautz; A. Vikhlinin; R. Hickox; W. Forman

    2010-01-01

    Sensitive surveys of the X-ray universe have been limited to small areas of the sky due to the intrinsically small field of view of Wolter-I X-ray optics. High angular resolution is needed to achieve a low background per source, minimize source confusion, and distinguish point from extended objects. WFXT consists of three co-aligned wide field X-ray telescopes with a 1°

  11. 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.

  12. Simulating Wide-Field Slitless Spectroscopy with JWST/NIRISS

    NASA Astrophysics Data System (ADS)

    Dixon, William V.; Willott, C. J.; Abraham, R. G.; Sawicki, M.; Hutchings, J. B.; Fullerton, A. W.

    2013-06-01

    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 over the wavelength range 0.8 to 2.25 microns. In this band, NIRISS will be sensitive to Lyman-alpha emission from galaxies with redshifts 6 < z < 17. To explore its ability to observe such high-redshift galaxies, we have modeled a NIRISS observation of the massive galaxy cluster MACS J0647+7015. Using published images, photometry, and redshifts from the CLASH survey, we constructed a series of simulated direct and dispersed images in the six filters used for WFSS with NIRISS. To each image were added 180 high-redshift galaxies distributed uniformly in space, redshift, and magnitude. Using Source Extractor, we identified 7200 galaxies in the F200W direct image, including 165 of the high-redshift sources (the remainder were lost to bright foreground objects). From this catalog, we selected 1000 objects, including all 165 of the high-redshift sources. We performed photometry of these 1000 sources in each direct image and extracted their spectra (using the aXe software package) from each dispersed image. A subset of our team was given these data and asked to identify the high-redshift galaxies. We will present the results of this analysis and discuss their implications for the ability of NIRISS to detect and parameterize high-redshift galaxies in crowded fields. 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.

  13. 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.

  14. Improving vessel segmentation in ultra-wide field-of-view retinal fluorescein angiograms.

    PubMed

    Perez-Rovira, A; Zutis, K; Hubschman, J P; Trucco, E

    2011-01-01

    Vessel segmentation on ultra-wide field-of-view fluorescein angiogram sequences of the retina is a challenging problem. Vessel appearance undergoes severe changes, as different portions of the vascular structure become perfused in different frames. This paper presents a method for segmenting vessels in such sequences using steerable filters and automatic thresholding. We introduce a penalization stage on regions with high vessel response in the filtered image, improving the detection of peripheral vessels and reducing false positives around the optic disc and in regions of choroidal vessels and lesions. Quantitative results are provided, in which the penalization stage improves the segmentation precision segmentation by 11.84%, the recall by 12.98% and the accuracy by 0.40%. To facilitate further evaluation, usage, and algorithm comparison, the algorithm, the data set used, the ground truth, and the results are made available on the internet. PMID:22254877

  15. 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.

  16. 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.

  17. Thin wide-field-of-view HMD with free-form-surface prism and applications

    NASA Astrophysics Data System (ADS)

    Yamazaki, Shoichi; Inoguchi, Kazutaka; Saito, Yoshihiro; Morishima, Hideki; Taniguchi, Naosato

    1999-05-01

    The HMD optical system composed of 'free form surface prism' (FFS prism) was presented by Canon Inc. at the 1996 SPIE conference. This prism was consists of aspherical surfaces without rotational symmetry. This HMD was suitable for compact HMD and was the 180,000 pixels display which has 34 degrees horizontal FOV and less than 15mm prism thickness. We have developed a new see-through 3D HMD with high resolution, wide field of view (FOV) by improving this FFS prism technique. The new HMD with 51 degrees horizontal FOV and large viewing eyebox shows clear full color image with 920,000 pixels. In spite of the wide FOV, the thickness of this new FFS prism is very thin, 17.9 mm. In this paper, we report this new HMD and 'the AR2 hockey system' as an example of this HMD application.

  18. 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).

  19. Search for Correlations Between Sprites and Tgfs By Goddard Robotic Telescope Wide Field (GRT-WF)

    NASA Astrophysics Data System (ADS)

    Hegley, J.; Watanabe, K.; Vydra, E.; Luke, A.; Schiltz, J.; Sakamoto, T.; Donato, D.; Okajima, T.; Gehrels, N.

    2014-12-01

    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 any correlations between Sprites and TGFs. We constructed a wide field optical camera system (GRT-­WF) using off-­the-­shelf hardwares 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 hundreds of Sprites in the past three years. We have compared these Sprites with the TGFs detected by the Fermi Gamma-ray Space Telescope in times and locations. We discuss the preliminary results of our analysis.

  20. 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.

  1. Three wide-field telescopes with spherical primary mirrors

    NASA Astrophysics Data System (ADS)

    Blanco, Dan

    2014-07-01

    This paper presents three optical designs based on the work of Maurice Paul. Paul's three-mirror anastigmats produce well-corrected, distortion-free fields of view. His design equations can be solved for a spherical primary mirror with one limitation: the image field is curved. Adding all-spherical refractive field-flattening optics yields well-corrected, flat image-fields of two degrees angular diameter or more. These designs can be scaled to very large telescopes with current technology.

  2. Improving the performances of current optical interferometers & future designs

    NASA Astrophysics Data System (ADS)

    Arnold, L.; Le Coroller, H.; Surdej, J.

    2014-04-01

    The number of astrophysical studies making use of interferometers has steadily increased during the past 15 years. Nevertheless, the performances of interferometers are still limited: their sensitivity does not exceed magnitude V=12, and their imaging capability could yet be improved by increasing the number of telescopes/sub-apertures. In the context of the ELTs, it is not certain how future interferometry projects will be financed. However, interferometry remains the only way to observe compact astrophysical objects at very high angular resolution (< milli-arcsecond), like gravitational micro-lensing events, central engines of AGNs, proto-planetary disks, exoplanets, etc. The aim of this workshop was to review and discuss the development of technologies that could improve the performances of current and future interferometers: new optical designs; techniques to improve the accuracy of measurements (visibility, closure-phase, etc.); progress on delay-line performances; solutions without delay-lines; technologies for larger apertures at lower cost (ex: lightweight replica mirrors); optimized beam combiners (integrated optic, pupil densifier, etc.); fringe tracking systems; laser telemetry applied to interferometry; heterodyne interferometry; progress in heterodyne detection using new technologies (laser comb, time propagation technologies, etc.); progress in image reconstruction techniques; progress in nulling interferometry; and important science cases that could benefit from progress in interferometry (report of observations at the limit of current interferometers). Nearly 50 oral presentations have been delivered, followed by very lively discussions which eventually emerged with the proposition to organize the "Planet Formation Interferometer/Imager" (PFI) project. The present proceedings reflect most of the highlights of this international colloquium.

  3. Optical surveillance for international safeguards - present and future

    SciTech Connect

    Johnson, C.S.; Sonnier, C.S.; Waddoups, I.G.

    1983-01-01

    Optical surveillance, one of the principal Containment and Surveillance (C/S) measures, employed by the IAEA, is accomplished using film camera and video systems. Improved film camera and video systems developed in several countries are in the final stages of Agency evaluation and are expected to be placed into routine safeguards use in the near future. One system is the Surveillance and Television Recording (STAR) System. This system is a dual camera high capability unit which is expected to replace the current IAEA systems as time progresses. Another is the MINISTAR which is a much smaller, single camera unit which incorporates recent technology advances, and retains many of the basic STAR features at a considerably lower cost. Beyond these near-term advances, it is expected that video camera and recording technology will soon be available which will make video systems competitive with the film camera systems. The introduction of such technology will provide for other advanced techniques, such as laser disc recording and image processing, which are expected to improve the effectiveness of optical surveillance systems.

  4. Optical surveillance for international safeguards present and future

    SciTech Connect

    Johnson, C.S.; Sonnier, C.S.; Waddoups, I.G.

    1983-07-01

    Optical surveillance, one of the principal Containment and Surveillance (C/S) measures employed by the IAEA, is accomplished using film camera and video systems. Improved film camera and video systems developed in several countries are in the final stages of Agency evaluation and are expected to be placed into routine safeguards use in the near future. One system is the Surveillance and Television Recording (STAR) System. This system is a dual camera high capability unit which is expected to replace the current IAEA systems as time progresses. Another is the MINISTAR which is a much smaller, single camera unit which incorporates recent technology advances, and retains many of the basic STAR features at a considerably lower cost. Beyond these near-term advances, it is expected that video camera and recording technology will soon be available which will make video systems competitive with the film camera systems. The introduction of such technology will provide for other advanced techniques, such as laser disc recording and image processing, which are expected to improve the effectiveness of optical surveillance systems.

  5. 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 centralized processing is essential. There is a central role for sensor fusion of heterogeneous sensors in future processing. The changes that occur in the urban operations of the future due to the application of these new technologies will be the improved quality of information, with shorter reaction time, and with lower operator load.

  6. Towards wide-field high-resolution retinal imaging

    E-print Network

    Kellerer, Aglae

    2015-01-01

    Adaptive optical correction is an efficient technique to obtain high-resolution images of the retinal surface. A main limitation of adaptive optical correction, however, is the small size of the corrected image. For medical purposes it is important to increase the size of the corrected images. This can be done through composite imaging, but a major difficulty is then the introduction of reconstruction artifacts. Another approach is multi-conjugate adaptive optics. MCAO comes in two flavors. The star- oriented approach has been demonstrated on the eye and allows to increase the diameter of the corrected image by a factor of approximately 2-3. Difficulties in the tomographic reconstruction precludes the correction of larger fields. Here we have investigate the possibility to apply a layer-oriented MCAO approach to retinal imaging.

  7. Wide field x-ray telescope a moderate class mission

    E-print Network

    Murray, Stephen S.

    Sensitive surveys of the X-ray universe have been limited to small areas of the sky due to the intrinsically small field of view of Wolter-I X-ray optics, whose angular resolution degrades with the square of the off axis ...

  8. The NOAO Deep Wide-Field Survey: Design and Initial Results

    NASA Astrophysics Data System (ADS)

    Jannuzi, B. T.; Dey, A.; Brown, M. J. I.; Tiede, G. P.; NDWFS Team

    2002-12-01

    The NOAO Deep Wide-Field Survey (NDWFS) is a very deep optical and IR (BWRIJHK) imaging survey of 18 square degrees of the sky with the primary goal of studying the evolution of large-scale structure from z 1-4. The survey enables investigation of the formation and evolution of galaxies and the detection of luminous, very distant (z>4), star-forming galaxies and quasars. The images are also being used for weak-lensing studies and to provide information on the optical/IR counterparts to sources detected at other wavelengths. The extensive multi-wavelength observations targeting the NDWFS fields include observations with Chandra (x-rays), GALEX (UV), SIRTF (near, mid, and far IR), the VLA, and Westerbork (radio). I will review the design of the survey, the status of observations (nearing completion with 90% of the data obtained), and initial scientific results (e.g., evolution of clustering of red galaxies and EROs, see also contribution by M. Brown et al. at this meeting; IR properties of FIRST Survey detected radio galaxies in the NDWFS, see contribution by Henderson et al. this meeting). Our research is supported by the National Optical Astronomy Observatory which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation.

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

    NASA Astrophysics Data System (ADS)

    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.

    2012-05-01

    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.

  10. EOS Space Systems Wide Field Imager for SSA Applications

    NASA Astrophysics Data System (ADS)

    Ritchie, I.; Blundell, M.; Smith, C.

    2013-09-01

    EOS Space Systems (EOSSS) has designed and manufactured space surveillance imagers since 1999. From early adaptations of Celestron Nexstar tubes to use ICCD sensors, to current EMCCD sensors in custom designed optical assemblies, the company has been required to seek the widest fields possible on a systems small enough to ride on a larger telescope OTA. The latest 14 inch (350mm) variant uses f0.75 corrected optics to achieve real time (2 second) imaging to visual magnitude 16 or fainter, and fields of view up to 3 degrees given the appropriate image plane size. With mass of only 50 kg and up to 1 Mpix 14 bit sampling, this imager has many potential SSA applications.

  11. 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.

  12. Wide-field Ca(2+) imaging reveals visually evoked activity in the retrosplenial area.

    PubMed

    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 Ca(2+) 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 Ca(2+) imaging, which allows for whole brain mapping with high spatiotemporal resolution and cell-type specificity. PMID:26106292

  13. Wide field of view CT and acromioclavicular joint instability: A technical innovation.

    PubMed

    Dyer, David R; Troupis, John M; Kamali Moaveni, Afshin

    2015-06-01

    A 21-year-old female with a traumatic shoulder injury is investigated and managed for symptoms relating to this injury. Pathology at the acromioclavicular joint is detected clinically; however, clinical examination and multiple imaging modalities do not reach a unified diagnosis on the grading of this acromioclavicular joint injury. When management appropriate to that suggested injury grading fail to help the patient's symptoms, further investigation methods were utilised. Wide field of view, dynamic CT (4D CT) is conducted on the patient's affected shoulder using a 320?×?0.5?mm detector multislice CT. Scans were conducted with a static table as the patient completed three movements of the affected shoulder. Capturing multiple data sets per second over a z-axis of 16?cm, measurements of the acromioclavicular joint were made, to show dynamic changes at the joint. Acromioclavicular (AC) joint translations were witnessed in three planes (a previously unrecognised pathology in the grading of acromioclavicular joint injuries). Translation in multiple planes was also not evident on careful clinical examination of this patient. AC joint width, anterior-posterior translation, superior-inferior translation and coracoclavicular width were measured with planar reconstructions while volume-rendered images and dynamic sequences aiding visual understanding of the pathology. Wide field of view dynamic CT (4D CT) is an accurate and quick modality to diagnose complex acromioclavicular joint injury. It provides dynamic information that no other modality can; 4D CT shows future benefits for clinical approach to diagnosis and management of acromioclavicular joint injury, and other musculoskeletal pathologies. PMID:25707952

  14. Fiber optic interconnect and optoelectronic packaging challenges for future generation avionics

    Microsoft Academic Search

    Mark W. Beranek

    2007-01-01

    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

  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. 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

  17. hal-00258693,version1-24Feb2008 Wide-field Fourier transform spectral imaging

    E-print Network

    source in the object plane. This configuration constitutes a lensless Fourier holographic setup [9hal-00258693,version1-24Feb2008 Wide-field Fourier transform spectral imaging Michael Atlan). A numerical Fourier transform of the time-domain recording enables wide-field coherent spectral imaging

  18. A Wide-Field Infrared Camera for the Palomar 200-inch Telescope

    E-print Network

    Galis, Frietson

    A Wide-Field Infrared Camera for the Palomar 200-inch Telescope J. C. Wilsona, S. S. Eikenberrya, C of both large aperture telescopes and large format near-infrared (NIR) detectors are making wide-field NIR that provides the Palomar 200-inch telescope with such an imaging capability. WIRC features a field-of-view (FOV

  19. A purely reflective large wide-field telescope

    NASA Astrophysics Data System (ADS)

    Terebizh, V. Yu.

    2008-06-01

    Two versions of a fast, purely reflective Paul-Baker-type telescope are discussed, each with an 8.4-m aperture, 3° diameter flat field and f/1.25 focal ratio. The first version is based on a common, even asphere type of surface with zero conic constant. The primary and tertiary mirrors are 6th order aspheres, while the secondary mirror is an 8th order asphere (referred to here for brevity, as the 6/8/6 configuration). The D 80 diameter of a star image varies from 0?.18 on the optical axis up to 0?.27 at the edge of the field (9.3-13.5 ?m). The second version of the telescope is based on a polysag surface type, which uses a polynomial expansion in the sag z, r^2 = 2R_0 z - left( {1 + b} right)z^2 + a_3 z^3 + a_4 z^3 + a_4 z^4 + ldots + a_N z^N instead of the common form of aspheric surface. This approach results in somewhat better images, with D 80 ranging from 0?.16 to 0?.23, using a lower-order 3/4/3 combination of powers for the mirror surfaces. An additional example with 3.5-m aperture, 3°.5 diameter flat field, and f/1.25 focal ratio featuring near-diffraction-limited image quality is also presented.

  20. 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

  1. 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

  2. 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.

  3. MOA-cam3: a wide-field mosaic CCD camera for a gravitational microlensing survey in New Zealand

    Microsoft Academic Search

    T. Sako; T. Sekiguchi; M. Sasaki; K. Okajima; F. Abe; I. A. Bond; J. B. Hearnshaw; Y. Itow; K. Kamiya; P. M. Kilmartin; K. Masuda; Y. Matsubara; Y. Muraki; N. J. Rattenbury; D. J. Sullivan; T. Sumi; P. Tristram; T. Yanagisawa; P. C. M. Yock

    2008-01-01

    We have developed a wide-field mosaic CCD camera, MOA-cam3, mounted at the prime focus of the Microlensing Observations in\\u000a Astrophysics (MOA) 1.8-m telescope. The camera consists of ten E2V CCD4482 chips, each having 2k×4k pixels, and covers a 2.2\\u000a deg2 field of view with a single exposure. The optical system is well optimized to realize uniform image quality over this

  4. 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.

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

    SciTech Connect

    Luhman, K. L. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Sheppard, Scott S., E-mail: kluhman@astro.psu.edu [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015 (United States)

    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.

  6. The globular cluster system of NGC1316. I. Wide-field photometry in the Washington system

    E-print Network

    Richtler, T; Dirsch, B; Kumar, B

    2012-01-01

    NGC 1316 (Fornax A) is a prominent merger remnant in the outskirts of the Fornax cluster. The cluster system has not yet been studied in its entirety. We therefore present a wide-field study of the globular cluster system of NGC 1316, investigating its properties in relation to the global morphology of NGC 1316. We used the MOSAIC II camera at the 4-m Blanco telescope at CTIO in the filters Washington C and Harris R. We identify globular cluster candidates and study their color distribution and the structural properties of the system. In an appendix, we also make morphological remarks, present color maps, and present new models for the brightness and color profiles of the galaxy. The cluster system is well confined to the optically visible outer contours of NGC 1316. The color distribution of the entire sample is unimodal, but the color distribution of bright subsamples in the bulge shows two peaks that, by comparison with theoretical Washington colors with solar metallicity, correspond to ages of about 2 Gyr...

  7. A High Resolution Wide-Field Radio Survey of M51

    E-print Network

    Rampadarath, Hayden; Soria, Roberto; Tingay, Steven J; Reynolds, Cormac; Argo, Megan K; Dumas, Gaelle

    2015-01-01

    We present the highest resolution, wide-field radio survey of a nearby face-on star-forming galaxy to date. The multi-phase centre technique is used to survey the entire disk of M51 (77 square arc minutes) at a maximum resolution of 5 milli-arcseconds on a single 8 hr pointing with the European VLBI Network at 18 cm. In total, 7 billion pixels were imaged using 192 phase centres that resulted in the detection of six sources: the Seyfert nucleus, the supernova SN 2011dh, and four background AGNs. Using the wealth of archival data available in the radio (MERLIN and the VLA), optical (Hubble Space Telescope) and X-rays (Chandra) the properties of the individual sources were investigated in detail. The combined multi-wavelength observations reveal a very complex and puzzling core region that includes a low-luminosity parsec scale core-jet structure typical of AGNs, with evidence for a lateral shift corresponding to 0.27c. Furthermore, there is evidence for a fossil radio hotspot located 1.44 kpc from the Seyfert ...

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

    NASA Astrophysics Data System (ADS)

    Fors, Octavi; Núñez, Jorge; Luis Muiños, José; Javier Montojo, Francisco; Baena-Gallé, Roberto; Boloix, Jaime; Morcillo, Ricardo; Teresa Merino, María; 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°.40), moderate limiting magnitude (V˜19.5 mag), ability of tracking at arbitrary right ascension (?) and declination (?) 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.

  9. Hubble Space Telescope Wide Field Planetary Camera 2 observations of hyperluminous infrared galaxies

    NASA Astrophysics Data System (ADS)

    Farrah, D.; Verma, A.; Oliver, S.; Rowan-Robinson, M.; McMahon, R.

    2002-01-01

    We present Hubble Space Telescope Wide Field Planetary Camera 2 I-band imaging for a sample of nine hyperluminous infrared galaxies (HLIRGs) spanning a redshift range 0.45optical morphology. None of the sources in the sample, including F15307+3252, shows any evidence for gravitational lensing. We infer that the IR luminosities are thus real. Based on these results, and previous studies of HLIRGs, we conclude that this class of object is broadly consistent with being a simple extrapolation of the ULIRG population to higher luminosities; ULIRGs being mainly violently interacting systems powered by starbursts and/or active galactic nuclei. Only a small number of sources, the infrared luminosities of which exceed 1013Lsolar, are intrinsically less luminous objects that have been boosted by gravitational lensing.

  10. Wide field-of-view Talbot grid-based microscopy for multicolor fluorescence imaging

    PubMed Central

    Pang, Shuo; Han, Chao; Erath, Jessey; Rodriguez, Ana; Yang, Changhuei

    2013-01-01

    The capability to perform multicolor, wide field-of-view (FOV) fluorescence microscopy imaging is important in screening and pathology applications. We developed a microscopic slide-imaging system that can achieve multicolor, wide FOV, fluorescence imaging based on the Talbot effect. In this system, a light-spot grid generated by the Talbot effect illuminates the sample. By tilting the excitation beam, the Talbot-focused spot scans across the sample. The images are reconstructed by collecting the fluorescence emissions that correspond to each focused spot with a relay optics arrangement. The prototype system achieved an FOV of 12 × 10 mm2 at an acquisition time as fast as 23 s for one fluorescence channel. The resolution is fundamentally limited by spot size, with a demonstrated full-width at half-maximum spot diameter of 1.2 ?m. The prototype was used to image green fluorescent beads, double-stained human breast cancer SK-BR-3 cells, Giardia lamblia cysts, and the Cryptosporidium parvum oocysts. This imaging method is scalable and simple for implementation of high-speed wide FOV fluorescence microscopy. PMID:23787643

  11. 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.

  12. FAINT TIDAL FEATURES IN GALAXIES WITHIN THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY WIDE FIELDS

    SciTech Connect

    Atkinson, Adam M.; Abraham, Roberto G. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)] [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Ferguson, Annette M. N. [Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)] [Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

    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.

  13. 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.

  14. The Future of Fiber-Optic Computer Networks

    Microsoft Academic Search

    Paul E. Green

    1991-01-01

    The author discusses research activities in the area of third-generation (all-optical) fiber-optic networks and where they are heading. Applications, the era of single unrepeated links, the characteristics of fiber paths in networks, forms of addressing, overall network throughput capacity, technologies, protocol layers, and making the communication layers invisible are discussed

  15. Laser guide star adaptive optics: Present and future

    Microsoft Academic Search

    S. S. Olivier; C. E. Max

    1993-01-01

    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

  16. 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

  17. 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.

  18. Wide Field Super-Resolution Surface Imaging through Plasmonic Structured Illumination Microscopy

    E-print Network

    California at San Diego, University of

    Wide Field Super-Resolution Surface Imaging through Plasmonic Structured Illumination Microscopy-resolution imaging technique, plasmonic structured illumination microscopy (PSIM), by combining tunable SP interference (SPI) with structured illumination microscopy (SIM). By replacing the laser interference fringes

  19. A Wide-Field Survey of the Globular Cluster Systems of Giant Galaxies

    E-print Network

    Katherine L. Rhode

    2006-05-12

    I present selected results from a wide-field CCD survey of the globular cluster systems of giant galaxies, including showing how measurements of the specific frequency of metal-poor globular clusters can constrain the redshift of their formation.

  20. Interferometric Imaging with the 32 Element Murchison Wide-Field Array

    E-print Network

    Benkevitch, Leonid

    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 ...

  1. The discovery of y dwarfs using data from the wide-field infrared survey explorer (WISE)

    E-print Network

    Cushing, Michael C.

    We present the discovery of seven ultracool brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE). Near-infrared spectroscopy reveals deep absorption bands of H[subscript 2]O and CH[subscript 4] that ...

  2. A unified calibration method with a parametric approach for wide-field-of-view multiprojector displays

    E-print Network

    Raskar, Ramesh

    In this paper, we describe techniques for supporting a wide-field-of-view multiprojector curved screen display system. Our main contribution is in achieving automatic geometric calibration and efficient rendering for ...

  3. Optimized geometries for future generation optical lattice clocks

    E-print Network

    Krämer, Sebastian; Ritsch, Helmut

    2015-01-01

    Atoms trapped in magic wavelength optical lattices provide a Doppler- and collision-free dense ensemble of quantum emitters ideal for fast high precision spectroscopy and thus they are the basis of the best optical clock setups to date. Despite the minute optical dipole moments the inherent long range dipole-dipole interactions in such lattices at high densities generate measurable line shifts, increased dephasing and modified decay rates. We show that these effects can be resonantly enhanced or suppressed depending on lattice constant, geometry and excitation procedure. While these interactions generally limit the accuracy and precision of Ramsey spectroscopy, under optimal conditions collective effects can be exploited to yield zero effective shifts and long dipole lifetimes for a measurement precision beyond a noninteracting ensemble. In particular, 2D lattices with a lattice constant below the optical wavelength feature an almost ideal performance.

  4. Future Prospects for FEC in Fiber-Optic Communications

    Microsoft Academic Search

    Benjamin P. Smith; Frank R. Kschischang

    2010-01-01

    This paper reviews the application of forward error correction (FEC) techniques to long-haul fiber-optic communication systems. A brief tutorial on error-correcting codes and a discussion of their fundamental limits (on the additive white Gaussian noise channel and on a nonlinear fiber-optic transmission channel) is provided. To illustrate the potential for applying advanced FEC techniques that take channel nonlinearities into account,

  5. 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.

  6. Applications of photonic crystal fibers in optical communications - What is in the future?

    Microsoft Academic Search

    Anders Bjarklev; Chinlon Lin

    2005-01-01

    Superior control of guiding properties in photonic-crystal fibers led to several interesting applications in optical communications ranging from nonlinear optical signal processing to high-power fiber amplifiers. This paper will review recent developments and discuss the future possibilities.

  7. Optical Communications for NASA's Small Spacecraft Missions of the Future

    NASA Technical Reports Server (NTRS)

    Lesh, J. R.; Chen, C-C.; Hemmati, H.

    1993-01-01

    NASA's space missions of the future will be dominated by more moderate sized mini- and micro- spacecraft. Such missions will place stringent requirements on the mass and power consumption required for the various spacecraft subsystems.

  8. 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 1? 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.

  9. Advanced fiber optic networks using optical processing for future commercial aircrafts: multiple-access techniques and new hardware design

    Microsoft Academic Search

    Jian-Guo Zhang

    1993-01-01

    In this paper, we investigate the use of the advanced fiber optic multiple-access networks in future high-performance commercial aircrafts to support real time on-board flight control, sensing, voice communications, and TV distributions. Novel tunable optical code division multiple-access (OCDMA) networks using prime-code sequences are designed, which can be quickly programmed to generate the required OCDMA sequences. Using the newly proposed

  10. Ground-based astrometry with wide field imagers. V. Application to near-infrared detectors: HAWK-I@VLT/ESO

    NASA Astrophysics Data System (ADS)

    Libralato, M.; Bellini, A.; Bedin, L. R.; Piotto, G.; Platais, I.; Kissler-Patig, M.; Milone, A. P.

    2014-03-01

    High-precision astrometry requires accurate point-spread function modeling and accurate geometric-distortion corrections. This paper demonstrates that it is possible to achieve both requirements with data collected at the high acuity wide-field K-band imager (HAWK-I), a wide-field imager installed at the Nasmyth focus of UT4/VLT ESO 8 m telescope. Our final astrometric precision reaches ~3 mas per coordinate for a well-exposed star in a single image with a systematic error less than 0.1 mas. We constructed calibrated astro-photometric catalogs and atlases of seven fields: the Baade's window, NGC 6656, NGC 6121, NGC 6822, NGC 6388, NGC 104, and the James Webb Space Telescope calibration field (in the Large Magellanic Cloud). We make these catalogs and images electronically available to the community. Furthermore, as a demonstration of the efficacy of our approach, we combined archival material taken with the optical wide-field imager at the MPI/ESO 2.2 m with HAWK-I observations. We showed that we are able to achieve an excellent separation between cluster members and field objects for NGC 6656 and NGC 6121 with a time base-line of about 8 years. Using both HST and HAWK-I data, we also study the radial distribution of the SGB populations in NGC 6656 and conclude that the radial trend is flat within our uncertainty. We also provide membership probabilities for most of the stars in NGC 6656 and NGC 6121 catalogs and estimate membership for the published variable stars in these two fields. Catalogs, fortran code, and distortion maps are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/563/A80Based on observations with the 8 m VLT ESO telescope.

  11. UVUDF: Ultraviolet imaging of the Hubble ultra deep field with wide-field camera 3

    SciTech Connect

    Teplitz, Harry I.; Rafelski, Marc; Colbert, James W.; Hanish, Daniel J. [Infrared Processing and Analysis Center, MS 100-22, Caltech, Pasadena, CA 91125 (United States); Kurczynski, Peter; Gawiser, Eric [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States); Bond, Nicholas A.; Gardner, Jonathan P.; De Mello, Duilia F. [Laboratory for Observational Cosmology, Astrophysics Science Division, Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Grogin, Norman; Koekemoer, Anton M.; Brown, Thomas M.; Coe, Dan; Ferguson, Henry C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Atek, Hakim [Laboratoire d'Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland); Finkelstein, Steven L. [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Giavalisco, Mauro [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Gronwall, Caryl [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Lee, Kyoung-Soo [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Ravindranath, Swara, E-mail: hit@ipac.caltech.edu [Inter-University Centre for Astronomy and Astrophysics, Pune (India); and others

    2013-12-01

    We present an overview of a 90 orbit Hubble Space Telescope treasury program to obtain near-ultraviolet imaging of the Hubble Ultra Deep Field using the Wide Field Camera 3 UVIS detector with the F225W, F275W, and F336W filters. This survey is designed to: (1) investigate the episode of peak star formation activity in galaxies at 1 < z < 2.5; (2) probe the evolution of massive galaxies by resolving sub-galactic units (clumps); (3) examine the escape fraction of ionizing radiation from galaxies at z ? 2-3; (4) greatly improve the reliability of photometric redshift estimates; and (5) measure the star formation rate efficiency of neutral atomic-dominated hydrogen gas at z ? 1-3. In this overview paper, we describe the survey details and data reduction challenges, including both the necessity of specialized calibrations and the effects of charge transfer inefficiency. We provide a stark demonstration of the effects of charge transfer inefficiency on resultant data products, which when uncorrected, result in uncertain photometry, elongation of morphology in the readout direction, and loss of faint sources far from the readout. We agree with the STScI recommendation that future UVIS observations that require very sensitive measurements use the instrument's capability to add background light through a 'post-flash'. Preliminary results on number counts of UV-selected galaxies and morphology of galaxies at z ? 1 are presented. We find that the number density of UV dropouts at redshifts 1.7, 2.1, and 2.7 is largely consistent with the number predicted by published luminosity functions. We also confirm that the image mosaics have sufficient sensitivity and resolution to support the analysis of the evolution of star-forming clumps, reaching 28-29th magnitude depth at 5? in a 0.''2 radius aperture depending on filter and observing epoch.

  12. 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.

  13. Optical coherence elastography: current status and future applications

    NASA Astrophysics Data System (ADS)

    Sun, Cuiru; Standish, Beau; Yang, Victor X. D.

    2011-04-01

    Optical coherence tomography (OCT) has several advantages over other imaging modalities, such as angiography and ultrasound, due to its inherently high in vivo resolution, which allows for the identification of morphological tissue structures. Optical coherence elastography (OCE) benefits from the superior spatial resolution of OCT and has promising applications, including cancer diagnosis and the detailed characterization of arterial wall biomechanics, both of which are based on the elastic properties of the tissue under investigation. We present OCE principles based on techniques associated with static and dynamic tissue excitation, and their corresponding elastogram image-reconstruction algorithms are reviewed. OCE techniques, including the development of intravascular- or catheter-based OCE, are in their early stages of development but show great promise for surgical oncology or intravascular cardiology applications.

  14. MOA-cam3: a wide-field mosaic CCD camera for a gravitational microlensing survey in New Zealand

    E-print Network

    T. Sako; T. Sekiguchi; M. Sasaki; K. Okajima; F. Abe; I. A. Bond; J. B. Hearnshaw; Y. Itow; K. Kamiya; P. M. Kilmartin; K. Masuda; Y. Matsubara; Y. Muraki; N. J. Rattenbury; D. J. Sullivan; T. Sumi; P. Tristram; T. Yanagisawa; P. C. M. Yock

    2008-04-04

    We have developed a wide-field mosaic CCD camera, MOA-cam3, mounted at the prime focus of the Microlensing Observations in Astrophysics (MOA) 1.8-m telescope. The camera consists of ten E2V CCD4482 chips, each having 2kx4k pixels, and covers a 2.2 deg^2 field of view with a single exposure. The optical system is well optimized to realize uniform image quality over this wide field. The chips are constantly cooled by a cryocooler at -80C, at which temperature dark current noise is negligible for a typical 1-3 minute exposure. The CCD output charge is converted to a 16-bit digital signal by the GenIII system (Astronomical Research Cameras Inc.) and readout is within 25 seconds. Readout noise of 2--3 ADU (rms) is also negligible. We prepared a wide-band red filter for an effective microlensing survey and also Bessell V, I filters for standard astronomical studies. Microlensing studies have entered into a new era, which requires more statistics, and more rapid alerts to catch exotic light curves. Our new system is a powerful tool to realize both these requirements.

  15. 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

  16. High Resolution Observations using Adaptive Optics: Achievements and Future Needs

    E-print Network

    K. Sankarasubramanian; T. Rimmele

    2008-01-21

    Over the last few years, several interesting observations were obtained with the help of solar Adaptive Optics (AO). In this paper, few observations made using the solar AO are enlightened and briefly discussed. A list of disadvantages with the current AO system are presented. With telescopes larger than 1.5m are expected during the next decade, there is a need to develop the existing AO technologies for large aperture telescopes. Some aspects of this development are highlighted. Finally, the recent AO developments in India are also presented.

  17. Architectural Options for a Future Deep Space Optical Communications Network

    NASA Technical Reports Server (NTRS)

    Edwards, B. L.; Benjamin, T.; Scozzafava, J.; Khatri, F.; Sharma, J.; Parvin, B.; Liebrecht, P. E.; Fitzgerald, R. J.

    2004-01-01

    This paper provides an overview of different options at Earth to provide Deep Space optical communication services. It is based mainly on work done for the Mars Laser Communications Demonstration (MLCD) Project, a joint project between NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). It also reports preliminary conclusions from the Tracking and Data Relay Satellite System Continuation Study at GSFC. A lasercom flight terminal will be flown on the Mars Telecommunications Orbiter (MTO) to be launched by NASA in 2009, and will be the first high rate deep space demonstration of this revolutionary technology.

  18. Background simulations of the wide-field coded-mask camera for X-\\/Gamma-ray of the French-Chinese mission SVOM

    Microsoft Academic Search

    Olivier Godet; Didier Barret; Jacques Paul; Patrick Sizun; Pierre Mandrou; Bertrand Cordier

    2008-01-01

    SVOM (Space Variable Object Monitor) is a French-Chinese mission dedicated to the study of high-redshift GRBs, which is expected to be launched in 2012. The anti-Sun pointing strategy of SVOM along with a strong and integrated ground segment consisting of two wide-field robotic telescopes covering the near-IR and optical will optimise the ground-based GRB follow-ups by the largest telescopes and

  19. Flight performance of an advanced CZT imaging detector in a balloon-borne wide-field hard X-ray telescope—ProtoEXIST1

    NASA Astrophysics Data System (ADS)

    Hong, J.; Allen, B.; Grindlay, J.; Barthelemy, S.; Baker, R.; Garson, A.; Krawczynski, H.; Apple, J.; Cleveland, W. H.

    2011-10-01

    We successfully carried out the first high-altitude balloon flight of a wide-field hard X-ray coded-aperture telescope ProtoEXIST1, which was launched from the Columbia Scientific Balloon Facility at Ft. Sumner, New Mexico on October 9, 2009. ProtoEXIST1 is the first implementation of an advanced CdZnTe (CZT) imaging detector in our ongoing program to establish the technology required for next generation wide-field hard X-ray telescopes such as the High Energy Telescope (HET) in the Energetic X-ray Imaging Survey Telescope (EXIST). The CZT detector plane in ProtoEXIST1 consists of an 8×8 array of closely tiled 2 cm×2 cm×0.5 cm thick pixellated CZT crystals, each with 8×8 pixels, mounted on a set of readout electronics boards and covering a 256 cm2 active area with 2.5 mm pixels. A tungsten mask, mounted at 90 cm above the detector provides shadowgrams of X-ray sources in the 30-600 keV band for imaging, allowing a fully coded field of view of 9°×9° (and 19°×19° for 50% coding fraction) with an angular resolution of 20?. In order to reduce the background radiation, the detector is surrounded by semi-graded (Pb/Sn/Cu) passive shields on the four sides all the way to the mask. On the back side, a 26 cm×26 cm×2 cm CsI(Na) active shield provides signals to tag charged particle induced events as well as ?100keV background photons from below. The flight duration was only about 7.5 h due to strong winds (60 knots) at float altitude (38-39 km). Throughout the flight, the CZT detector performed excellently. The telescope observed Cyg X-1, a bright black hole binary system, for ˜1h at the end of the flight. Despite a few problems with the pointing and aspect systems that caused the telescope to track about 6.4° off the target, the analysis of the Cyg X-1 data revealed an X-ray source at 7.2? in the 30-100 keV energy band at the expected location from the optical images taken by the onboard daytime star camera. The success of this first flight is very encouraging for the future development of the advanced CZT imaging detectors (ProtoEXIST2, with 0.6 mm pixels), which will take advantage of the modularization architecture employed in ProtoEXIST1.

  20. 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.

  1. Negative optical inertia for enhancing the sensitivity of future gravitational-wave detectors

    SciTech Connect

    Khalili, Farid; Danilishin, Stefan [Faculty of Physics, Moscow State University, Moscow 119991 (Russian Federation); Mueller-Ebhardt, Helge [Max-Planck Institut fuer Gravitationsphysik (Albert-Einstein-Institut) and Leibniz Universitaet Hannover, Callinstr. 38, 30167 Hannover (Germany); Miao Haixing; Zhao Chunnong [School of Physics, University of Western Australia, WA 6009 (Australia); Chen Yanbei [Theoretical Astrophysics 130-33, California Institute of Technology, Pasadena, California 91125 (United States)

    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.

  2. Photonic integration and optical interconnects for future communications, computing, and signal processing systems

    NASA Astrophysics Data System (ADS)

    Yoo, S. J. Ben

    2009-02-01

    Photonic integration significantly reduces power consumption, cost, and size while it enhances reliability and functionality. As modern networking and computing systems require high-performance, low-power, and agile optical communications, photonic integration is emerging as critically important technology for future networking and computing. On the other hand, the main challenge with photonic integration lies in the yield and process-compatibility. This paper reviews the impact of photonic integration in optical communications, discusses the challenges, and probes the future prospects for photonic integration.

  3. OASIS: a new development for future high-accuracy optical pointing

    Microsoft Academic Search

    Jean-Louis Carel; J. M. Michelin; Michel Le Du; J. M. Betermier

    1995-01-01

    High accuracy pointing performances and also large autonomy from the host satellite are required for the future optical payloads designed to perform astronomy, laser communication, planetary observation, or other missions. In order to prepare these future applications, SFIM Industries\\/Ets d'Asnieres (SFIM\\/EA) has undertaken under CNES (French Space Agency) contract, the development of a new generic system able to fit a

  4. Adaptive Optics Imaging of Faint Companions: Current & Future Prospects

    NASA Astrophysics Data System (ADS)

    Close, Laird M.

    I briefly describe how diffraction-limited imaging with adaptive optics (AO) can detect low mass companions (young massive brown dwarfs for example). I review how current curvature AO systems can already detect point sources 1 million times fainter at separations of 3 arcsec in median seeing (0.65 arcsec). I show real examples of very faint companion detections made with the University of Hawaii AO system located at CFHT on Mauna Kea around the young (2 Myr) nearby (132 pc) Herbig Ae/Be star MWC480. Moreover, I show that the four faint (H=18--19 mag) companions within 6 arcsec of MWC480 (H=7.0 mag) are unlikely to be physical since they are non-common proper motion objects. I point out that the current 8--10m class AO systems will detect even fainter companions at closer separations with 0.03--0.06 arcsec NIR imaging.

  5. 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.

  6. Wide-Field, Motion-Sensitive Neurons and Optimal Matched Filters for Optic Flow

    Microsoft Academic Search

    Matthias O. Franz; Holger G. Krapp

    1998-01-01

    . We present a theory for the construction of an optimal matched filter for self-motion inducedoptic flow fields. The matched filter extracts local flow components along a set of pre-defined directionsand weights them according to an optimization principle which minimizes the difference between estimatedand real egomotion parameters. In contrast to previous approaches, prior knowledge about distance andtranslation statistics is incorporated

  7. Panchromatic properties of galaxies in wide-field optical spectroscopic and photometric surveys

    NASA Astrophysics Data System (ADS)

    Driver, Simon P.

    2012-08-01

    The past 15 years have seen an explosion in the number of redshifts recovered via wide area spectroscopic surveys. At the current time there are approximately 2 million spectroscopic galaxy redshifts known (and rising) which represents an extraordinary growth since the pioneering work of Marc Davis and John Huchra. Similarly there has been a parallel explosion in wavelength coverage with imaging surveys progressing from single band, to multi-band, to truly multiwavelength or pan-chromatic involving the coordination of multiple facilities. With these empirically motivated studies has come a wealth of new discoveries impacting almost all areas of astrophysics. Today individual surveys, as best demonstrated by the Sloan Digital Sky Survey, now rank shoulder-to-shoulder alongside major facilities. In the coming years this trend is set to continue as we begin the process of designing and conducting the next generation of spectroscopic surveys supported by multi-facility wavelength coverage.

  8. Performance Modeling of a Wide Field Ground Layer Adaptive Optics System

    E-print Network

    Tokovinin, Andrei A.

    , Laurent Jolissaint1 , N. Mark Milton3 , Richard Myers2 , Kei Szeto1 , Andrei Tokovinin5 , Jean-Pierre V´eran1 , Richard Wilson2 1 NRC Herzberg Institute of Astrophysics, 5071 W Saanich Road, Victoria, BC V9E, South Road, Durham DH1 3LE, UK, 3 Steward Observatory, University of Arizona, 933 North Cherry Avenue

  9. Orientation imaging of single molecules by wide-field epifluorescence microscopy

    E-print Network

    Enderlein, Jörg

    Orientation imaging of single molecules by wide-field epifluorescence microscopy Martin Bo imaging method for direct determination of single-molecule orientations is presented that uses a wide, allowing for direct determination of single-molecule orientation based on the characteristic intensity

  10. Wide-Field Kinematic Structure of Early-Type Galaxy Halos

    E-print Network

    Arnold, Jacob Antony

    2013-01-01

    vi List of Tables Properties of suveyed galaxiesiv List of Figures Color images of survey galaxies displayedList of Tables vii Abstract viii Dedication x Acknowledgments xi 1 Introduction 2 Wide-Field Stellar Kinematics in Early-Type Galaxies

  11. SPIE Proceedings, vol. 6442, 20071 Non-scanning CARS microscopy using wide-field geometry

    E-print Network

    Palanker, Daniel

    sample preparations have been explored. We demonstrated that CARS image of a 100x100 µm sample canSPIE Proceedings, vol. 6442, 20071 Non-scanning CARS microscopy using wide-field geometry I Anti-Stokes Raman Scattering (CARS) microscopy technique based on non-phase- matching illumination

  12. Wide-Field Millimagnitude Photometry with the HAT: A Tool for Extrasolar Planet Detection

    Microsoft Academic Search

    G. Bakos; R. W. Noyes; G. Kovács; K. Z. Stanek; D. D. Sasselov; I. Domsa

    2004-01-01

    We discuss the system requirements for obtaining millimagnitude photometric precision over a wide field using small-aperture, short focal length telescope systems such as those being developed by a number of research groups to search for transiting extrasolar planets. We describe a Hungarian Automated Telescope (HAT) system, which attempts to meet these requirements. The attainable precision of HAT has been significantly

  13. Wide-field fluorescence sectioning with hybrid speckle and uniform-illumination microscopy

    E-print Network

    Wide-field fluorescence sectioning with hybrid speckle and uniform-illumination microscopy Daryl. The method involves acquiring two images, one with nonuniform illumination (in our case, speckle) and another with uniform illumination (in our case, randomized speckle). An evaluation of the local contrast in the speckle-illumination

  14. Wide-field near-infrared all-reflecting camera with Fabry--Perot for astronomy

    E-print Network

    Ashley, Michael C. B.

    of the camera imaging system (section 2) will be followed by a discussion of the sensitivity of the systemWide-field near-infrared all-reflecting camera with Fabry--Perot for astronomy Yin-sheng Sun, Australia ABSTRACT We describe the specifications and design of a 1--5 pm camera (IRC-UNSW) being built

  15. Focal plane instrumentation for the Wide-Field X-ray Telescope

    E-print Network

    Bautz, Marshall W.

    The three X-ray imaging focal planes of the Wide-Field X-ray Telescope (WFXT) Mission will each have a field of view up to 1 degree square, pixel pitch smaller than 1 arcsec, excellent X-ray detection efficiency and spectral ...

  16. 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 either electron excitation (SEM-EDS) and, in a minority of cases for cores assessed as "difficult" targets, proton excitation (IBA). All samples were documented by electron imagery: backscattered electron imagery in the SEM, and where appropriate, secondary electron imagery during IBA.

  17. UVUDF: Ultraviolet Imaging of the Hubble Ultra Deep Field with Wide-Field Camera 3

    NASA Astrophysics Data System (ADS)

    Teplitz, Harry I.; Rafelski, Marc; Kurczynski, Peter; Bond, Nicholas A.; Grogin, Norman; Koekemoer, Anton M.; Atek, Hakim; Brown, Thomas M.; Coe, Dan; Colbert, James W.; Ferguson, Henry C.; Finkelstein, Steven L.; Gardner, Jonathan P.; Gawiser, Eric; Giavalisco, Mauro; Gronwall, Caryl; Hanish, Daniel J.; Lee, Kyoung-Soo; de Mello, Duilia F.; Ravindranath, Swara; Ryan, Russell E.; Siana, Brian D.; Scarlata, Claudia; Soto, Emmaris; Voyer, Elysse N.; Wolfe, Arthur M.

    2013-12-01

    We present an overview of a 90 orbit Hubble Space Telescope treasury program to obtain near-ultraviolet imaging of the Hubble Ultra Deep Field using the Wide Field Camera 3 UVIS detector with the F225W, F275W, and F336W filters. This survey is designed to: (1) investigate the episode of peak star formation activity in galaxies at 1 < z < 2.5; (2) probe the evolution of massive galaxies by resolving sub-galactic units (clumps); (3) examine the escape fraction of ionizing radiation from galaxies at z ~ 2-3; (4) greatly improve the reliability of photometric redshift estimates; and (5) measure the star formation rate efficiency of neutral atomic-dominated hydrogen gas at z ~ 1-3. In this overview paper, we describe the survey details and data reduction challenges, including both the necessity of specialized calibrations and the effects of charge transfer inefficiency. We provide a stark demonstration of the effects of charge transfer inefficiency on resultant data products, which when uncorrected, result in uncertain photometry, elongation of morphology in the readout direction, and loss of faint sources far from the readout. We agree with the STScI recommendation that future UVIS observations that require very sensitive measurements use the instrument's capability to add background light through a "post-flash." Preliminary results on number counts of UV-selected galaxies and morphology of galaxies at z ~ 1 are presented. We find that the number density of UV dropouts at redshifts 1.7, 2.1, and 2.7 is largely consistent with the number predicted by published luminosity functions. We also confirm that the image mosaics have sufficient sensitivity and resolution to support the analysis of the evolution of star-forming clumps, reaching 28-29th magnitude depth at 5? in a 0.''2 radius aperture depending on filter and observing epoch. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are #12534.

  18. Current concepts and future perspectives on surgical optical imaging in cancer

    NASA Astrophysics Data System (ADS)

    Ntziachristos, Vasilis; Yoo, Jung Sun; van Dam, Gooitzen M.

    2010-11-01

    There are vibrant developments of optical imaging systems and contrast-enhancing methods that are geared to enhancing surgical vision and the outcome of surgical procedures. Such optical technologies designed for intraoperative use can offer high integration in the operating room compared to conventional radiological modalities adapted to intraoperative applications. Simple fluorescence epi-illumination imaging, in particular, appears attractive but may lead to inaccurate observations due to the complex nature of photon-tissue interaction. Of importance therefore are emerging methods that account for the background optical property variation in tissues and can offer accurate, quantitative imaging that eliminates the appearance of false negatives or positives. In parallel, other nonfluorescent optical imaging methods are summarized and overall progress in surgical optical imaging applications is outlined. Key future directions that have the potential to shift the paradigm of surgical health care are also discussed.

  19. 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.

  20. Optical wireless links in future space communications with high data rate demands

    Microsoft Academic Search

    P. Brandl; T. Plank; E. Leitgeb

    2009-01-01

    The use of optical communication links is a growing and promising technology, with applications spreading over many areas of telecommunication. This paper will present the results of an investigation on interplanetary communication requirements for future space mission which was done under an ESA contract and SatNEx II. From the user point of view, the technology behind the data transmission is

  1. Optical Label Switching Technology and Energy-Efficient Future Networks S. J. Ben Yoo

    E-print Network

    Kolner, Brian H.

    of Electrical and Computer Engineering, University of California, Davis, California 95616, U.S.A. Abstract Switching Network Wireline O-CDMA LAN Satellite Network Reconfigurable Wireless Network DATA Center Figure 1. Future Internet with optical-label switching, wireless, and wireline networking in support of cloud

  2. Energy Efficiency in the Future Internet: The Role of Optical Packet Switching and Optical-Label Switching

    Microsoft Academic Search

    S. J. Ben Yoo

    2011-01-01

    This paper reviews the energy efficiency of optical- packet-switching (OPS) systems in comparison with electronic packet switching and hybrid packet switching in the context of future networks. The paper will first discuss the energy efficiency metrics that should include considerations for life-cycle analy- sis, applications, and network-wide goodput. The state-of-the-art electronic packet switching router is currently energy-limited in scalability as

  3. Wide field-of-view all-reflective objectives designed for multispectral image acquisition in photogrammetric applications

    NASA Astrophysics Data System (ADS)

    Seidl, Kristof; Richter, Katja; Knobbe, Jens; Maas, Hans-Gerd

    2011-10-01

    In many aerial and close-range photogrammetry applications, the near infrared (NIR) spectral range is required in addition to the visible (VIS) spectral range. Currently, many especially aerial photogrammetric systems use particularly optimized camera systems for each spectral band. Using separate cameras or lenses can introduce parallaxes and timedelays between the acquired images, and thus complicate the data fusion process. Furthermore, it adds additional weight to the entire system. With an image acquisition through a single objective, the complexity of the data fusion and the weight can be significantly reduced. However, to be able to only use one objective for different spectral bands, the optical system has to be free of chromatic aberrations. For photogrammetric applications, a wide field-of-view and a high resolution are frequent additional requirements. Therefore, we will present a design and an adapted photogrammetric calibration method of an all-reflective unobscured optical system optimized for full-frame imaging sensors. All-reflective unobscured optical systems may also be a very efficient imaging tool in combination with unmanned aerial vehicles (UAVs). Due to the limited payload capacity, many currently available UAVs can only be used with one spectrally limited camera system at the same time. With miniaturized all-reflective camera systems, the image data could be acquired in the visible and e.g. the NIR spectral range simultaneously.

  4. Wide-field fast-scanning photoacoustic microscopy based on a water-immersible MEMS scanning mirror.

    PubMed

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

    2012-08-01

    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 to sacrifice 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 microelectromechanical systems (MEMS) scanning mirror (MEMS-OR-PAM). In MEMS-OR-PAM, the optical and acoustic beams are confocally configured and simultaneously steered, which ensures the uniform detection sensitivity. A B-scan imaging speed as high as 400 Hz can be achieved over a 3 mm scanning range. Using the system, we imaged the flow dynamics of both red blood cells and carbon particles in a mouse ear in vivo. Presented results show that MEMS-OR-PAM could be a powerful tool for studying highly dynamic and time-sensitive biological phenomena. PMID:23224156

  5. Prime Focus Spectrograph - Subaru's future -

    E-print Network

    Sugai, Hajime; Takato, Naruhisa; Tamura, Naoyuki; Shimono, Atsushi; Ohyama, Youichi; Ueda, Akitoshi; Ling, Hung-Hsu; de Arruda, Marcio Vital; Barkhouser, Robert H; Bennett, Charles L; Bickerton, Steve; Braun, David F; Bruno, Robin J; Carr, Michael A; Oliveira, João Batista de Carvalho; Chang, Yin-Chang; Chen, Hsin-Yo; Dekany, Richard G; Dominici, Tania Pereira; Ellis, Richard S; Fisher, Charles D; Gunn, James E; Heckman, Timothy M; Ho, Paul T P; Hu, Yen-Shan; Jaquet, Marc; Karr, Jennifer; Kimura, Masahiko; Fèvre, Olivier Le; Mignant, David Le; Loomis, Craig; Lupton, Robert H; Madec, Fabrice; Marrara, Lucas Souza; Martin, Laurent; Murayama, Hitoshi; de Oliveira, Antonio Cesar; de Oliveira, Claudia Mendes; de Oliveira, Ligia Souza; Orndorff, Joe D; Vilaça, Rodrigo de Paiva; Macanhan, Vanessa Bawden de Paula; Prieto, Eric; Santos, Jesulino Bispo dos; Seiffert, Michael D; Smee, Stephen A; Smith, Roger M; Sodré, Laerte; Spergel, David N; Surace, Christian; Vives, Sebastien; Wang, Shiang-Yu; Yan, Chi-Hung

    2012-01-01

    The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution. Taking advantage of Subaru's wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a wide-field metrology camera. Fibers then carry l...

  6. Active wide-field illumination for high-throughput fluorescence lifetime imaging

    PubMed Central

    Zhao, Lingling; Abe, Ken; Barroso, Margarida; Intes, Xavier

    2014-01-01

    Wide-field fluorescence lifetime imaging allows for fast imaging of large sample areas at the cost of low sensitivity to weak fluorescence signals. To overcome this challenge, we developed an active wide-field illumination (AWFI) strategy to optimize the impinging spatial intensity for acquiring optimal fluorescence signals over the whole sample. We demonstrated the ability of AWFI to accurately estimate lifetimes from a multiwell plate sample with concentrations ranging over two orders of magnitude. We further reported its successful application to a quantitative Förster resonance energy transfer lifetime cell-based assay. Overall, this method allows for enhanced accuracy in lifetime-based imaging at high acquisition speed over samples with large fluorescence intensity distributions. PMID:24081103

  7. 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.

  8. A wide-field photometric study of the globular cluster system of NGC 4636

    Microsoft Academic Search

    Boris Dirsch; Ylva Schuberth; Tom Richtler

    2005-01-01

    Previous smaller-scale studies of the globular cluster system of NGC 4636, an elliptical galaxy in the southern part of the Virgo cluster, have revealed an unusually rich globular cluster system. We re-investigate the cluster system of NGC 4636 with wide-field Washington photometry. The globular cluster luminosity function can be followed roughly 1 mag beyond the turn-over magnitude found at {V}

  9. Deep Wide Field BVI CCD Photometry of the Sextans Dwarf Spheroidal Galaxy

    Microsoft Academic Search

    Myung Gyoon Lee; Hong Soo Park; Jang-Hyun Park; Young-Jong Sohn; Seung Joon Oh; In-Soo Yuk; Soo-Chang Rey; Sang-Gak Lee; Young-Wook Lee; Ho-Il Kim; Wonyong Han; Won-Kee Park; Joon Hyeop Lee; Young-Beom Jeon; Sang Chul Kim

    2003-01-01

    We present deep wide field $VI$ CCD photometry of the Sextans dwarf spheroidal galaxy (dSph) in the Local Group, covering a field of 42' x 28' located at the center of the galaxy. Color-magnitude diagrams of the Sextans dSph show well-defined red giant branch (RGB), blue horizontal branch (BHB), prominent red horizontal branch (RHB), asymptotic giant branch (AGB), about 120

  10. PISCES: A Wide-Field, 1-2.5 mum Camera for Large-Aperture Telescopes

    Microsoft Academic Search

    D. W. McCarthy Jr.; J. Ge; J. L. Hinz; R. A. Finn; R. S. de Jong

    2001-01-01

    Wide-field-of-view infrared cameras, operating on the new generation of large telescopes, offer unprecedented gains in the detection of faint sources and in observing efficiency for both direct imaging and spectroscopy. With a 1024×1024 pixel, 1-2.5 mum detector, the PISCES camera provides 8.5' and 3.16' fields at the 2.3 m Bok telescope and 6.5 m Multiple Mirror Telescope, respectively. Its refractive

  11. 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.

  12. Phase-retrieved pupil functions in wide-field fluorescence microscopy

    Microsoft Academic Search

    B. M. HANSER; M. G. L. GUSTAFSSON; D. A. AGARD; J. W. SEDAT

    2004-01-01

    Summary Pupil functions are compact and modifiable descriptions of the three-dimensional (3D) imaging properties of wide-field opti- cal systems. The pupil function of a microscope can be compu- tationally estimated from the measured point spread function (PSF) using phase retrieval algorithms. The compaction of a 3D PSF into a 2D pupil function suppresses artefacts and measurement noise without resorting to

  13. An assessment of the on-orbit performance of the CALIPSO wide field camera

    Microsoft Academic Search

    Michael C. Pitts; Larry W. Thomason; Yongxiang Hu; David M. Winker

    2007-01-01

    The Wide Field Camera (WFC) is one of three instruments in the CALIPSO science payload, with the other two being the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) and the Infrared Imaging Radiometer (IIR). The WFC is a narrow-band, push-broom imager that provides continuous high-spatial-resolution imagery during the daylight segments of the orbit over a swath centered on the CALIOP footprint.

  14. Wide-field spectroscopy and imaging at two plate scales with a focal three mirror anastigmat

    Microsoft Academic Search

    Michael J. Sholl; Michael L. Lampton; John P. Lehan; Michael E. Levi

    2010-01-01

    The key enabling element of the Joint Dark Energy Mission (JDEM)1,2,3 is a wide-field, high-magnification mixed spectroscopic and imaging telescope intended to study dark energy via measurement of the expansion history of the universe and the growth of large-scale structure. It is designed to provide tight constraints on the equation of state of dark energy and test the validity of

  15. Abstract--In future transparent optical networks, it is important to consider the impact of physical impairments in the

    E-print Network

    Vlachos, Kyriakos G.

    . Index Terms-- RWA, Genetic Algorithm, All-Optical Networks, Multi Objective Optimization. I various optical network optimization problems, as for example integer linear programming, [1]. Their highAbstract-- In future transparent optical networks, it is important to consider the impact

  16. 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.

  17. Three-dimensional orientation sensors by defocused imaging of gold nanorods through an ordinary wide-field microscope.

    PubMed

    Li, Tao; Li, Qiang; Xu, Yi; Chen, Xiao-Jun; Dai, Qiao-Feng; Liu, Haiying; Lan, Sheng; Tie, Shaolong; Wu, Li-Jun

    2012-02-28

    Gold (Au) nanoparticles, particularly nanorods, are actively employed as imaging probes because of their special nonblinking and nonbleaching absorption, scattering, and emitting properties that arise from the excitation of surface plasmons. Herein, we report a novel sensing method that detects feature orientation at the nanoscale via the defocused imaging of individual Au nanorods (AuNRs) with an ordinary wide-field optical microscope. By simultaneously recording defocused images and two-photon luminescence intensities for a large number of individual AuNRs, we correlate their defocused images with their three-dimensional spatial orientations. The spatial orientation of many individual AuNRs can be monitored in situ and in real-time within a single frame, enabling its use as a technique for high-throughput sensing. The probe size can be as small as several nanometers, which is highly desirable for minimization of any potential interference from the probe itself. Furthermore, the sensing property is insensitive to the excitation polarization and the distribution of the probe aspect ratio, which allows AuNRs of any length within a proper regime to be used as orientation sensors without changing the laser frequency and polarization. These unique features make the orientation probes proposed here outstanding candidates for optical imaging and sensing in materials science and biological applications. PMID:22264116

  18. Galaxy cluster searches based on photometric redshifts in the four CFHTLS Wide fields

    NASA Astrophysics Data System (ADS)

    Durret, F.; Adami, C.; Cappi, A.; Maurogordato, S.; Márquez, I.; Ilbert, O.; Coupon, J.; Arnouts, S.; Benoist, C.; Blaizot, J.; Edorh, T. M.; Garilli, B.; Guennou, L.; Le Brun, V.; Le Fèvre, O.; Mazure, A.; McCracken, H. J.; Mellier, Y.; Mezrag, C.; Slezak, E.; Tresse, L.; Ulmer, M. P.

    2011-11-01

    Context. Cosmological parameters can be constrained by counting clusters of galaxies as a function of mass and redshift and by considering regions of the sky sampled as deeply and as homogeneously as possible. Aims: Several methods for detecting clusters in large imaging surveys have been developed, among which the one used here, which is based on detecting structures. This method was first applied to the Canada France Hawaii Telescope Legacy Survey (CFHTLS) Deep 1 field by Mazure et al. (2007, A&A, 467, 49), then to all the Deep and Wide CFHTLS fields available in the T0004 data release by Adami et al. (2010, A&A, 509, A81). The validity of the cluster detection rate was estimated by applying the same procedure to galaxies from the Millennium simulation. Here we use the same method to analyse the full CFHTLS Wide survey, based on the T0006 data release. Methods: Our method is based on the photometric redshifts computed with Le Phare for all the galaxies detected in the Wide fields, limited to magnitudes z' ? 22.5. We constructed galaxy density maps in photometric redshift bins of 0.1 based on an adaptive kernel technique, detected structures with SExtractor at various detection levels, and built cluster catalogues by applying a minimal spanning tree algorithm. Results: In a total area of 154 deg2, we have detected 4061 candidate clusters at 3? or above (6802 at 2? and above), in the redshift range 0.1 ? z ? 1.15, with estimated mean masses between 1.3 × 1014 and 12.6 × 1014 M?. This catalogue of candidate clusters will be available at the CDS. We compare our detections with those made in various CFHTLS analyses with other methods. By stacking a subsample of clusters, we show that this subsample has typical cluster characteristics (colour - magnitude relation, galaxy luminosity function). We also confirm that the cluster-cluster correlation function is comparable to the one obtained for other cluster surveys and analyse large-scale filamentary galaxy distributions. Conclusions: We have increased the number of known optical high-redshift cluster candidates by a large factor, an important step towards obtaining reliable cluster counts to measure cosmological parameters. The clusters that we detect behave as expected if they are located at the intersection of filaments by which they are fed. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the CFHT Legacy Survey, a collaborative project of the NRC and CNRS.The catalog of candidate clusters is available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/535/A65

  19. The Hubble Wide Field Camera 3 Test of Surfaces in the Outer Solar System: Spectral Variation on Kuiper Belt Objects

    NASA Astrophysics Data System (ADS)

    Fraser, Wesley C.; Brown, Michael E.; Glass, Florian

    2015-05-01

    Here, we present additional photometry of targets observed as part of the Hubble Wide Field Camera 3 (WFC3) Test of Surfaces in the Outer Solar System. Twelve targets were re-observed with the WFC3 in the optical and NIR wavebands designed to complement those used during the first visit. Additionally, all of the observations originally presented by Fraser and Brown were reanalyzed through the same updated photometry pipeline. A re-analysis of the optical and NIR color distribution reveals a bifurcated optical color distribution and only two identifiable spectral classes, each of which occupies a broad range of colors and has correlated optical and NIR colors, in agreement with our previous findings. We report the detection of significant spectral variations on five targets which cannot be attributed to photometry errors, cosmic rays, point-spread function or sensitivity variations, or other image artifacts capable of explaining the magnitude of the variation. The spectrally variable objects are found to have a broad range of dynamical classes and absolute magnitudes, exhibit a broad range of apparent magnitude variations, and are found in both compositional classes. The spectrally variable objects with sufficiently accurate colors for spectral classification maintain their membership, belonging to the same class at both epochs. 2005 TV189 exhibits a sufficiently broad difference in color at the two epochs that span the full range of colors of the neutral class. This strongly argues that the neutral class is one single class with a broad range of colors, rather than the combination of multiple overlapping classes.

  20. Optically Stimulated Luminescence (OSL) Study of Ammonia-Doped Ice for Future Planetary Surveys

    Microsoft Academic Search

    T. Yada; K. Norizawa; M. Hirai; C. Yamanaka; M. Ikeya

    Optically stimulated luminescence (OSL) of ammonia-doped ices was investigated as a future dating technique for icy bodies in outer planetary worlds in the solar system. Lumines- cence of around 400 nm was measured for ?-irradiated H2O ice and ammonia-doped ices under LED light stimulation (623 nm) at 90 K. Ammonia-doped ice showed OSL of both short (?1\\/2 ? 100 s)

  1. SPIE Proceedings, Solid State Lasers, 2009.1 Solid state lasers for wide-field CARS microscopy

    E-print Network

    Palanker, Daniel

    SPIE Proceedings, Solid State Lasers, 2009.1 Solid state lasers for wide-field CARS microscopy D in Coherent Anti-Stokes Raman Scattering (CARS) microscopy and particularly in its wide-field modification and Stokes beams are similar for all CARS systems, requirements for pulse energy, repetition rate, pulse

  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. SIMULTANEOUS EXOPLANET CHARACTERIZATION AND DEEP WIDE-FIELD IMAGING WITH A DIFFRACTIVE PUPIL TELESCOPE

    SciTech Connect

    Guyon, Olivier; Eisner, Josh A.; Angel, Roger; Woolf, Neville J. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)] [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Bendek, Eduardo A.; Milster, Thomas D. [College of Optical Sciences, University of Arizona, Tucson, AZ 85721 (United States)] [College of Optical Sciences, University of Arizona, Tucson, AZ 85721 (United States); Ammons, S. Mark [Lawrence Livermore National Laboratory, Physics Division L-210, 7000 East Avenue, Livermore, CA 94550 (United States)] [Lawrence Livermore National Laboratory, Physics Division L-210, 7000 East Avenue, Livermore, CA 94550 (United States); Shao, Michael; Shaklan, Stuart; Levine, Marie; Nemati, Bijan [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)] [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Martinache, Frantz [National Astronomical Observatory of Japan, Subaru Telescope, Hilo, HI 96720 (United States)] [National Astronomical Observatory of Japan, Subaru Telescope, Hilo, HI 96720 (United States); Pitman, Joe [Exploration Sciences, P.O. Box 24, Pine, CO 80470 (United States)] [Exploration Sciences, P.O. Box 24, Pine, CO 80470 (United States); Woodruff, Robert A. [Lockheed Martin, 2081 Evergreen Avenue, Boulder, CO 80304 (United States)] [Lockheed Martin, 2081 Evergreen Avenue, Boulder, CO 80304 (United States); Belikov, Ruslan, E-mail: guyon@naoj.org [NASA Ames Research Center, Moffett Field, CA 94035 (United States)] [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2013-04-10

    High-precision astrometry can identify exoplanets and measure their orbits and masses while coronagraphic imaging enables detailed characterization of their physical properties and atmospheric compositions through spectroscopy. In a previous paper, we showed that a diffractive pupil telescope (DPT) in space can enable sub-{mu}as accuracy astrometric measurements from wide-field images by creating faint but sharp diffraction spikes around the bright target star. The DPT allows simultaneous astrometric measurement and coronagraphic imaging, and we discuss and quantify in this paper the scientific benefits of this combination for exoplanet science investigations: identification of exoplanets with increased sensitivity and robustness, and ability to measure planetary masses to high accuracy. We show how using both measurements to identify planets and measure their masses offers greater sensitivity and provides more reliable measurements than possible with separate missions, and therefore results in a large gain in mission efficiency. The combined measurements reliably identify potentially habitable planets in multiple systems with a few observations, while astrometry or imaging alone would require many measurements over a long time baseline. In addition, the combined measurement allows direct determination of stellar masses to percent-level accuracy, using planets as test particles. We also show that the DPT maintains the full sensitivity of the telescope for deep wide-field imaging, and is therefore compatible with simultaneous scientific observations unrelated to exoplanets. We conclude that astrometry, coronagraphy, and deep wide-field imaging can be performed simultaneously on a single telescope without significant negative impact on the performance of any of the three techniques.

  5. 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.

  6. Wide-field compact catadioptric telescope spanning 0.7-14 ?m 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 ?m. 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

  7. 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.

  8. Serial ultra wide field imaging for following up acute retinal necrosis cases.

    PubMed

    Tripathy, Koushik; Sharma, Yog Raj; Gogia, Varun; Venkatesh, Pradeep; Singh, Subodh Kumar; Vohra, Rajpal

    2015-01-01

    We describe two cases of acute retinal necrosis (ARN) in a post renal transplant diabetic patient and a pregnant female in the first trimester. Serial ultra wide field imaging (UWFI) with comprehensive ocular examination was done to monitor the progression of the disease. All the cases responded favorably with intravenous followed by oral acyclovir, which was captured with UWFI. UWFI provides objective proof of response to therapy in ARN. UWFI may also improve patient education and counseling for this peripheral retinal disorder. PMID:25709284

  9. Serial ultra wide field imaging for following up acute retinal necrosis cases

    PubMed Central

    Tripathy, Koushik; Sharma, Yog Raj; Gogia, Varun; Venkatesh, Pradeep; Singh, Subodh Kumar; Vohra, Rajpal

    2015-01-01

    We describe two cases of acute retinal necrosis (ARN) in a post renal transplant diabetic patient and a pregnant female in the first trimester. Serial ultra wide field imaging (UWFI) with comprehensive ocular examination was done to monitor the progression of the disease. All the cases responded favorably with intravenous followed by oral acyclovir, which was captured with UWFI. UWFI provides objective proof of response to therapy in ARN. UWFI may also improve patient education and counseling for this peripheral retinal disorder. PMID:25709284

  10. WPOL: a DSSD-based hard x-ray wide field imager and polarimeter

    NASA Astrophysics Data System (ADS)

    Laurent, P.; Bertoli, W.; Breelle, E.; Dolgorouky, Y.; Gouiffès, C.; Khalil, M.; Limousin, O.; Lebrun, F.; Rodriguez, J.

    2014-07-01

    WPOL (Wide field camera with POLarimetry) is a wide field camera which aims to monitor the X-ray/low gamma-ray sources and measures their polarimetric properties. This camera will be operated in space to trigger a main instrument in case of transient events (gamma-ray bursts, black hole binaries state transition, supernovae, …) and to map the Xray/ gamma-ray polarized sources of the Galaxy, which has never been done up to now. It will be proposed, as an accompanying instrument, in the context of the next medium mission ESA call (M4). The concept of the instrument is based upon a coded mask imaging with a detector unit composed of two planes of Silicon double sided stripped detectors (DSSD), a passive collimator and a tungsten mask. Mapping is done on the first plane through mask imaging and polarization is measured by studying Compton scattering events between the two planes. The source direction in the sky being known through the mask pattern projected on the detector plane, and the scattered photon direction being measured between the two planes, only the determination of the first energy deposit is needed to compute the whole Compton scattering kinetics and in particular, to determine the source photon energy

  11. 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.

  12. 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*.

  13. 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.

  14. Improved wide-field collimator for dynamic testing of the GOES imager and sounder

    NASA Astrophysics Data System (ADS)

    Bremer, James C.; Etemad, Shahriar; Zukowski, Barbara J.; Pasquale, Bert A.; Zukowski, Tmitri J.; Prince, Robert E.; Holmes, Vincent; Ryskewich, John A.; O'Neill, Patrick; Murphy-Morris, Jeanine E.

    2002-09-01

    The GOES Imager and Sounder instruments each observe the full Earth disk, 17.4° in diameter, from geostationary orbit. Pre-launch, each instrument's dynamic scanning performance is tested using the projection of a test pattern from a wide-field collimator. We are fabricating a second wide-field collimator (WFC2) to augment this test program. The WFC2 has several significant advantages over the existing WFC1. The WFC2 target illumination system uses an array of light-emitting diodes (LEDs) radiating at 680nm, which is within the visible bands of both the Imager and Sounder. The light from the LEDs is projected through a non-Lambertian diffuser plate and the target plate to the pupil of the projection lens. The WFC2's power dissipation is much lower than that of WFC1, decreasing stabilization time and eliminating the need for cooling fans. The WFC2's custom-designed 5-element projection lens has the same effective focal length (EFL) as the WFC1 projection lens. The WFC2 lens is optimized for the LED's narrow spectral band simplifying the design and improving image quality. The target plate is mounted in a frame with a mechanized micro-positioner system that controls three degrees of freedom: tip, tilt, and focus. The tip and tilt axes intersect in the WFC's image plane, and all adjustments are controlled remotely by the operator observing the target plate through an auto-collimating telescope.

  15. 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

  16. WISH, the Wide-field Imaging Surveyor for High-redshifts

    NASA Astrophysics Data System (ADS)

    Fazio, Giovanni G.; Yamada, T.; Melnick, G. J.; Smith, H. A.; Iwata, I.; Ashby, M. N.; Hora, J. L.; Huang, J.; Wang, Z.; Willner, S. P.; WISH Team

    2013-01-01

    WISH, the Wide-field Imaging Surveyor for High-redshifts, is an infrared Japanese (JAXA/ISAS) space mission concept to conduct very deep and wide-field infrared cosmological surveys at wavelengths from 1-5um to study the properties of galaxies at very high redshift, beyond the epoch of cosmic reionization. Our group at CfA has proposed to the NASA SALMON-2 Mission of Opportunity to provide the characterized focal plane for WISH, building on our experience with Spitzer -IRAC. The WISH mission concept has been developed and studied since 2008, and will be proposed for the upcoming JAXA/ISAS opportunity. WISH has a 1.5m-diameter primary mirror and a wide-field imager covering 850 sq-arcmin, with a pixel scale of 0.155 arcsec for 18um pitch, which fully samples the diffraction-limited image at 1.5um. The telescope is passive cooled and the baseline focal plane uses Teledyne H2RG arrays with a total coverage of about 128 million pixels, although alternatives are being evaluated. The main WISH scientific program is the Ultra Deep Survey (UDS) covering 100 sq-deg down to 28AB mag in at least in five broad infrared bands between about 1-5um. We expect to detect 10^4-5 galaxies at z=8-9, 10^3-4 galaxies at z= 11-12, and 50-100 galaxies at z> 14, many of which are likely to be targets for deep spectroscopy with JWST and extremely large ground-based telescopes. Another main science goal of the mission is the detection of type Ia SNe; our planned, recurrent deep observations will be able to detect them and monitor their light curves in rest-frame infrared wavelengths. During the mission’s 5 year observation lifetime, we expect to detect and monitor >2000 type-Ia SNe up to z ~2. WISH also conducts an Ultra Wide Survey, covering 1000sq-deg down to 24-25AB mag, and an Extreme Survey, covering a limited number of fields of view down to 29-30AB mag. We here report the progress of the WISH project including the basic telescope and satellite design.

  17. Investigating the Depth and Data of A Wide Field Survey of the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Paez, Margot; Conn, Blair

    2015-01-01

    We investigated the photometric depth of a wide field survey of the Small Magellanic Cloud (SMC) stellar halo. The aim of the survey is to search for evidence of galaxy mergers at the smallest scales. To achieve this it is crucial to understand how the data quality across the survey effects the apparent stellar density profile along different lines of sight. We explored the impact of a variety of factors on the photometric depth of the data including foreground dust extinction and employed two independent methods for determining the photometric completeness. These results will be used to help determine a global stellar density profile of the SMC, as well as show variations with azimuth and to highlight the presence of any deviations.

  18. 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.

  19. Performance analysis of a filtered wide field-of-view radiometer for earth radiation budget measurements

    NASA Technical Reports Server (NTRS)

    Cooper, J. E.; Luther, M. R.

    1978-01-01

    The proposed Earth Radiation Budget Satellite System (ERBSS) of the 1980's will include a wide field-of-view (WFOV) fixed axes earth radiator discriminator consisting of a shortwave channel and a total (unfiltered) channel. The broadband spectral isolation required for the shortwave channel is achieved by use of a hemispherical fused silica (Suprasil W) dome filter placed in front of a wire wound thermopile radiation detector. A description is presented of the thermal response of the single-fused silica dome filter in the ERBSS WFOV shortwave channel conceptual design and the impact of that response on the channel measurement. Results from design definition and performance analysis studies are included. Problems associated with achieving the desired levels of confidence in a high accuracy filtered, WFOV radiometer are discussed. Design approaches, ground calibration, and data reduction techniques which minimize measurement uncertainties are explained.

  20. A miniature design of near infrared spectrometer with wide field of view

    NASA Astrophysics Data System (ADS)

    Feng, Lei; Zhou, Jinsong; Wang, Dong

    2014-11-01

    The principle of all types of spectrometers and structural features are studied , a new metrhod to design prism spectrometer system with wide field of view is proposed ,which is based on the offner struture .This type of spectrometer allows twice dispersion through the same prism.Compared with the traditional dispersive spectrometer system ,which can be greater dispersion width and smaller volume.Compared with the gating spectrometer ,which overcomes low diffracion efficiency,spectrum overlapping, ghosts, low SIR and other shortcomings. Finally, the design results were analyzed, and the image quality was evaluated.The results from the design anslysis showed the spectrometer has a smaller spectrum bending ,the MTF of the system at different wavelengths is close to the diffraction limit and the design meets the requirements .

  1. A Wide-Field Photometric Survey of Globular Clusters in the Merger Remnant M85

    NASA Astrophysics Data System (ADS)

    Ko, Youkyung; Lee, Myung Gyoon; Sohn, Jubee; Lim, Sungsoon; Park, Hong Soo; Hwang, Narae; Park, Byeong-Gon

    2015-01-01

    M85 is an intriguing merger remnant in the northernmost region of the Virgo Cluster. It shows notable features indicating that it experienced the recent merging. In order to trace the merging history of M85, we obtained deep and wide field images of M85 covering one square degree using CFHT/MegaCam and ugi filters. We detect about 1000 globular cluster candidates in these images. The color distribution of globular clusters in the outer region shows a bimodality with stronger blue component, which is in contrast to the previous results based on HST/ACS images of a small central field in the ACSVCS. We find that the spatial distribution of the globular cluster candidates is elongated along the faint stellar light in the outer region of M85, and that this feature is prominent with the blue objects. We discuss these results in relation with the formation history of M85.

  2. 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: 0.01?m, 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[?m]) spectroscopic imaging of radiation lights emitted from human bodies itself

  3. A mobile phone-based retinal camera for portable wide field imaging.

    PubMed

    Maamari, Robi N; Keenan, Jeremy D; Fletcher, Daniel A; Margolis, Todd P

    2014-04-01

    Digital fundus imaging is used extensively in the diagnosis, monitoring and management of many retinal diseases. Access to fundus photography is often limited by patient morbidity, high equipment cost and shortage of trained personnel. Advancements in telemedicine methods and the development of portable fundus cameras have increased the accessibility of retinal imaging, but most of these approaches rely on separate computers for viewing and transmission of fundus images. We describe a novel portable handheld smartphone-based retinal camera capable of capturing high-quality, wide field fundus images. The use of the mobile phone platform creates a fully embedded system capable of acquisition, storage and analysis of fundus images that can be directly transmitted from the phone via the wireless telecommunication system for remote evaluation. PMID:24344230

  4. 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.

  5. 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 ?m, 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

  6. Vibrational phase imaging in wide-field CARS for nonresonant background suppression.

    PubMed

    Zheng, Juanjuan; Akimov, Denis; Heuke, Sandro; Schmitt, Michael; Yao, Baoli; Ye, Tong; Lei, Ming; Gao, Peng; Popp, Jürgen

    2015-04-20

    Coherent Anti-Stokes Raman Scattering (CARS) microscopy is a valuable tool for label-free imaging of biological samples. As a major drawback quantification based on CARS images is compromised by the appearance of a nonresonant background. In this paper we propose and demonstrate a wide-field CARS vibrational phase imaging scheme that allows for nonresonant background suppression. Several CARS images at a few consecutive planes perpendicular to the propagation direction were recorded to reconstruct a phase map utilizing the iteration phase retrieval method. Experimental results verify that the CARS background is efficiently suppressed by the phase imaging approach, as compared to traditional CARS imaging without background correction. The proposed background correction method is robust against environmental disturbance, since the experimental implementation of the suggested detection scheme requires no reference beam. PMID:25969113

  7. VARIABILITY FLAGGING IN THE WIDE-FIELD INFRARED SURVEY EXPLORER PRELIMINARY DATA RELEASE

    SciTech Connect

    Hoffman, D. I.; Cutri, R. M.; Masci, F. J.; Fowler, J. W.; Marsh, K. A.; Jarrett, T. H., E-mail: dhoffman@ipac.caltech.edu [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-05-15

    The Wide-field Infrared Survey Explorer Preliminary Data Release Source Catalog contains over 257 million objects. We describe the method used to flag variable source candidates in the Catalog. Using a method based on the chi-square of single-exposure flux measurements, we generated a variability flag for each object, and have identified almost 460,000 candidate sources that exhibit significant flux variability with greater than {approx}7{sigma} confidence. We discuss the flagging method in detail and describe its benefits and limitations. We also present results from the flagging method, including example light curves of several types of variable sources including Algol-type eclipsing binaries, RR Lyr, W UMa, and a blazar candidate.

  8. T80Cam: the wide field camera for the OAJ 83-cm telescope

    NASA Astrophysics Data System (ADS)

    Marin-Franch, A.; Taylor, K.; Cepa, J.; Laporte, R.; Cenarro, A. J.; Chueca, S.; Cristobal-Hornillos, D.; Ederoclite, A.; Gruel, N.; Hernández-Fuertes, J.; López-Sainz, A.; Luis-Simoes, R.; Moles, M.; Rueda-Teruel, F.; Rueda-Teruel, S.; Varela, J.; Yanes-Díaz, A.; Benitez, N.; Dupke, R.; Fernández-Soto, A.; Mendes de Oliveira, C.; Sims, G.; Sodré, L.; Toerne, K.

    2012-09-01

    The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located at the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys. The OAJ facility will have two wide-field telescopes: the JST/T250; a 2.55-m telescope with a 3° diameter field of view (FoV), and the JAST/T80; an 0.83-m telescope with a 2° diameter FoV. First light instrumentation is being designed to exploit the survey capabilities of the OAJ telescopes. This paper describes the T80Cam, a wide-field camera that will be installed at the Cassegrain focus of the JAST/T80. It is equipped with an STA 1600 backside illuminated detector. This is a 10.5k-by-10.5k, 9?m pixel, high efficiency CCD that is read from 16 ports simultaneously, allowing read times of ~20s with a typical read noise of 6 electrons (rms). This full wafer CCD covers a large fraction of the JAST/T80's FoV with a pixel scale of ~0.50"/pixel. T80Cam will observe in the wavelength range 330-1000nm through a set of 12 carefully optimized broad-, intermediate- and narrow-band filters. The camera is intended for surveys with the JAST/T80 telescope, starting with the planned J-PLUS (Javalambre Photometric Local Universe Survey), a multi-band photometric all-sky survey that will be completed in about 2 years and will reach AB˜ 23 mag (5? level) with the SDSS filters.

  9. Optical endomicroscopy and the road to real-time, in vivo pathology: present and future

    PubMed Central

    2012-01-01

    Epithelial cancers account for substantial mortality and are an important public health concern. With the need for earlier detection and treatment of these malignancies, the ability to accurately detect precancerous lesions has an increasingly important role in controlling cancer incidence and mortality. New optical technologies are capable of identifying early pathology in tissues or organs in which cancer is known to develop through stages of dysplasia, including the esophagus, colon, pancreas, liver, bladder, and cervix. These diagnostic imaging advances, together as a field known as optical endomicroscopy, are based on confocal microscopy, spectroscopy-based imaging, and optical coherence tomography (OCT), and function as “optical biopsies,” enabling tissue pathology to be imaged in situ and in real time without the need to excise and process specimens as in conventional biopsy and histopathology. Optical biopsy techniques can acquire high-resolution, cross-sectional images of tissue structure on the micron scale through the use of endoscopes, catheters, laparoscopes, and needles. Since the inception of these technologies, dramatic technological advances in accuracy, speed, and functionality have been realized. The current paradigm of optical biopsy, or single-area, point-based images, is slowly shifting to more comprehensive microscopy of larger tracts of mucosa. With the development of Fourier-domain OCT, also known as optical frequency domain imaging or, more recently, volumetric laser endomicroscopy, comprehensive surveillance of the entire distal esophagus is now achievable at speeds that were not possible with conventional OCT technologies. Optical diagnostic technologies are emerging as clinically useful tools with the potential to set a new standard for real-time diagnosis. New imaging techniques enable visualization of high-resolution, cross-sectional images and offer the opportunity to guide biopsy, allowing maximal diagnostic yields and appropriate staging without the limitations and risks inherent with current random biopsy protocols. However, the ability of these techniques to achieve widespread adoption in clinical practice depends on future research designed to improve accuracy and allow real-time data transmission and storage, thereby linking pathology to the treating physician. These imaging advances are expected to eventually offer a see-and-treat paradigm, leading to improved patient care and potential cost reduction. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5372548637202968 PMID:22889003

  10. The XMM-Newton wide-field survey in the COSMOS field. IV: X-ray spectral properties of Active Galactic Nuclei

    E-print Network

    V. Mainieri; G. Hasinger; N. Cappelluti; M. Brusa; H. Brunner; F. Civano; A. Comastri; M. Elvis; A. Finoguenov; F. Fiore; R. Gilli; I. Lehmann; J. Silverman; L. Tasca; C. Vignali; G. Zamorani; E. Schinnerer; C. Impey; J. Trump; S. Lilly; C. Maier; R. E. Griffiths; T. Miyaji; P. Capak; A. Koekemoer; N. Scoville; P. Shopbell; Y. Taniguchi

    2006-12-14

    We present a detailed spectral analysis of point-like X-ray sources in the XMM-COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10 keV energy band and have been identified through optical spectroscopy. The majority of the sources are well described by a simple power-law model with either no absorption (76%) or a significant intrinsic, absorbing column (20%).As expected, the distribution of intrinsic absorbing column densities is markedly different between AGN with or without broad optical emission lines. We find within our sample four Type-2 QSOs candidates (L_X > 10^44 erg/s, N_H > 10^22 cm^-2), with a spectral energy distribution well reproduced by a composite Seyfert-2 spectrum, that demonstrates the strength of the wide field XMM/COSMOS survey to detect these rare and underrepresented sources.

  11. Thermal Vacuum Test Performance of the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Variable Conductance Heat Pipe Assembly

    NASA Technical Reports Server (NTRS)

    Cleveland, Paul E.; Buchko, Matthew T.; Stavely, Richard A.

    2003-01-01

    The Variable Conductance Heat Pipe (VCHP) Assembly of the HST Wide Field Camera 3 was subjected to thermal vacuum (TN) environmental testing. The test program included both maximum and minimum environments as well as simulated on-orbit cycling. Elements of the VCHP assembly included a VCHP, an optical bench cold plate with an imbedded constant conductance heat pipe, and a VCHP reservoir radiator with a proportionally controlled heater. The purpose of the test was to characterize and demonstrate the assembly s ability to control the temperature of the cold plate, which provides a stable thermal environment for the instrument s optical bench. This paper discusses the VCHP Assembly control performance and control authority during the dynamic hot and cold 90-minute orbit cycling test phases.

  12. A new x-ray optics laboratory (XROL) at the ALS: mission, arrangement, metrology capabilities, performance, and future plans

    NASA Astrophysics Data System (ADS)

    Yashchuk, Valeriy V.; Artemiev, Nikolay A.; Lacey, Ian; McKinney, Wayne R.; Padmore, Howard A.

    2014-09-01

    The X-Ray Optics Laboratory (XROL) at the Advanced Light Source (ALS), a unique optical metrology lab, has been recently moved to a new, dedicated clean-room facility that provides improved environmental and instrumental conditions vitally required for high accuracy metrology with state-of-the-art X-ray optics. Besides the ALS, the XROL serves several DOE labs that lack dedicated on-site optical metrology capabilities, including the Linac Coherent Light Source (LCLS) at SLAC and LBNL's Center for X-Ray Optics (CXRO). The major role of XROL is to proactively support the development and optimal beamline use of x-ray optics. The application of different instruments available in the lab enables separate, often complementary, investigations and addresses of different potential sources of error affecting beamline performance. At the beamline, all the perturbations combine to produce a cumulative effect on the performance of the optic that makes it difficult to optimize the optic's operational performance. Ex situ metrology allows us to address the majority of the problems before the installation of the optic at a beamline, and to provide feedback on design and guidelines for the best usage of optics. We will review the ALS XROL mission, lab design and arrangement, ex situ metrology capabilities and performance, as well as the future plans for instrumentation upgrades. The discussion will be illustrated with the results of a broad spectrum of measurements of x-ray optics and optical systems performed at the XROL.

  13. Adaptive lobster-eye hard x-ray telescope with high-angular resolution and wide field of view

    NASA Astrophysics Data System (ADS)

    Grubsky, Victor; Gertsenshteyn, Michael; Shoemaker, Keith; Jannson, Tomasz

    2007-09-01

    High-resolution, wide-field-of-view hard X-ray telescopes are essential for detecting and studying cosmic sources in the 10-100 keV photon energy band, which are typically inaccessible to conventional Wolter I X-ray telescopes. To focus such high-energy photons, we developed special Lobster-Eye optics consisting of multiple reflective channels with square cross sections, which are formed by intersecting two sets of semiconductor-grade gold-coated flat silicon elements. Reflective channels with square cross sections The presented hard X-ray Lobster-Eye telescope lens designed for the 10-80 keV energy band consists of approximately 100 channels in both the horizontal and the vertical directions, with the angle between the adjacent plates being less than 1'. An array of such lenses, in which the orientation of each lens is independently controlled, can be used as an adaptive X-ray focusing device capable of changing its imaging properties depending on the user-selected mode. In the wide-angle operation, the individual lenses are aligned toward a common center to form a lobster-eye lens with a large (~2°) field of view, which would be suitable for monitoring stellar or galactic X-ray bursts. For observing a specific event, the telescope can be switched to the high-sensitivity mode by aligning the axes of the individual lenses in parallel so that they are all pointing to the region of interest, effectively adding up the effective areas of individual lenses (up to ~1600 cm2 at 40 keV). In the paper we will discuss the system performance simulations and the experimental results using initial prototype Lobster-Eye lenses.

  14. VizieR Online Data Catalog: Background galaxies in the WSRT wide-field Survey (Braun+, 2003)

    NASA Astrophysics Data System (ADS)

    Braun, R.; Thilker, D.; Walterbos, R. A. M.

    2003-08-01

    We have used the Westerbork array to carry out an unbiased wide-field survey for H I emission features, achieving an RMS sensitivity of about 18mJy/beam at a velocity resolution of 17km/s over 1800deg2 and between -1000optical associations are found within a 30' search radius for all but one of our HI detections in DSS images, although several are not previously catalogued or do not have published redshift determinations. Our detection without a DSS association is at low galactic latitude. Twenty-three of our objects are detected in HI for the first time. We classify almost half of our detections as "confused", since one or more companions is catalogued within a radius of 30' and a velocity interval of 400km/s. Nine of the detected galaxies fall so near the edges of the survey coverage (either spatially or in velocity) that their parameters can not be reliably determined. These nine objects are excluded from the enclosed table. (1 data file).

  15. Wide field array calibration dependence on the stability of measured dose distributions

    SciTech Connect

    Simon, Thomas A.; Simon, William E.; Kahler, Darren; Li, Jonathan; Liu, Chihray [Department of Nuclear and Radiological Engineering, University of Florida, 202 Nuclear Science Building, Gainesville, Florida 32611-8300, Department of Radiation Oncology, Health Science Center, University of Florida, P.O. Box 100385, Gainesville, Florida 32610-0385, and Sun Nuclear Corporation, 425-A Pineda Court, Melbourne, Florida 32940 (United States); Sun Nuclear Corporation, 425-A Pineda Court, Melbourne, Florida 32940 (United States); Department of Radiation Oncology, Health Science Center, University of Florida, P.O. Box 100385, Gainesville, Florida 32610-0385 (United States)

    2010-07-15

    Purpose: The aim of this work was to simulate the effect of dose distribution changes on detector array calibrations and to explore compensatory methods that are used during calibration measurements. Methods: The array calibration technique that was investigated is known as wide field (WF) calibration. Using this method, a linear array [y-axis (65 detectors) of the IC PROFILER (Sun Nuclear Corporation, Melbourne, FL)] is calibrated with three measurements ({alpha}, {theta}, and {lambda}); each measurement uses the same radiation field, which is larger than the array. For measurement configuration {theta}, the array is rotated by 180 deg. from its position in {alpha}; for {lambda}, the array is shifted by one detector from its position in {theta}. The relative detector sensitivities are then determined through ratios of detector readings at the same field locations (using {theta} and {lambda}). This method results in error propagation that is proportional to the number of detectors in the array. During the procedure, the calibration protocol operates under three postulates, which state that (a) the beam shape does not change between measurements; (b) the relative sensitivities of the detectors do not change; and (c) the scatter to the array does not change as the array is moved. The WF calibration's sensitivity to a postulate (a) violation was quantified by applying a sine shaped perturbation (of up to 0.1%) to {alpha}, {theta}, or {lambda}, and then determining the change relative to a baseline calibration. Postulate (a) violations were minimized by using a continuous beam and mechanized array movement during {theta} and {lambda}. A continuously on beam demonstrated more stable beam symmetry as compared to cycling the beam on and off between measurements. Additional side-scatter was also used to satisfy postulate (c). Results: Simulated symmetry perturbations of 0.1% to {theta} or {lambda} resulted in calibration errors of up to 2%; {alpha} was relatively immune to perturbation (<0.1% error). Wide field calibration error on a linear accelerator with similar symmetry variations was {+-}1.6%. Using a continuous beam during {theta} and {lambda} with additional side-scatter reduced the calibration error from {+-}1.6% to {+-}0.48%. Conclusions: This work increased the reproducibility of WF calibrations by limiting the effect of measurement perturbations primarily due to linear accelerator symmetry variations. The same technique would work for any array using WF calibration.

  16. Futurity

    NSDL National Science Digital Library

    The Futurity website features "the latest discoveries by scientists at top research universities in the US, UK, Canada and Australia." Currently, some of the participating universities include Boston University, Duke University, McGill University, and the University of Sheffield. Visitors to the homepage will note that there are four areas on the site: Earth & Environment, Health & Medicine, Science & Technology, and Society & Culture. Recently profiled news items include a compelling new discovery from New York University about the reality of a tractor beam that can pull microscopic particles. The Society & Culture section is a real find, as it contains engaging pieces like "Is zero tolerance too hard on students?" and "Big banks loom over finance 'ecosystem'." Also, visitors can browse news items by school or by topic area. Finally, the Week's Most Discussed area is a great way to learn about compelling new stories from around the globe.

  17. Recalibrating the Wide-field Infrared Survey Explorer (WISE) W4 Filter

    NASA Astrophysics Data System (ADS)

    Brown, M. J. I.; Jarrett, T. H.; Cluver, M. E.

    2014-12-01

    We present a revised effective wavelength and photometric calibration for the Wide-field Infrared Survey Explorer W4 band, including tests of empirically motivated modifications to its pre-launch laboratory-measured relative system response curve. We derived these by comparing measured W4 photometry with photometry synthesised from spectra of galaxies and planetary nebulae. The difference between measured and synthesised photometry using the pre-launch laboratory-measured W4 relative system response can be as large as 0.3 mag for galaxies and 1 mag for planetary nebulae. We find the W4 effective wavelength should be revised upward by 3.3%, from 22.1 to 22.8 ?m, and the W4 AB magnitude of Vega should be revised from m W4 = 6.59 to m W4 = 6.66. In an attempt to reproduce the observed W4 photometry, we tested three modifications to the pre-launch laboratory-measured W4 relative system response curve, all of which have an effective wavelength of 22.8 ?m. Of the three relative system response curve models tested, a model that matches the laboratory-measured relative system response curve, but has the wavelengths increased by 3.3% (or ? 0.73 ?m) achieves reasonable agreement between the measured and synthesised photometry.

  18. UVUDF: Ultraviolet Imaging of the Hubble Ultradeep Field with Wide-field Camera 3

    E-print Network

    Teplitz, Harry I; Kurczynski, Peter; Bond, Nicholas A; Grogin, Norman; Koekemoer, Anton M; Atek, Hakim; Brown, Thomas M; Coe, Dan; Colbert, James W; Ferguson, Henry C; Finkelstein, Steven L; Gardner, Jonathan P; Gawiser, Eric; Giavalisco, Mauro; Gronwall, Caryl; Hanish, Daniel J; Lee, Kyoung-Soo; de Mello, Duilia F; Ravindranath, Swara; Ryan, Russell E; Siana, Brian D; Scarlata, Claudia; Soto, Emmaris; Voyer, Elysse N; Wolfe, Arthur M

    2013-01-01

    We present an overview of a 90-orbit Hubble Space Telescope treasury program to obtain near ultraviolet imaging of the Hubble Ultra Deep Field using the Wide Field Camera 3 UVIS detector with the F225W, F275W, and F336W filters. This survey is designed to: (i) Investigate the episode of peak star formation activity in galaxies at 1

  19. A TECHNIQUE FOR PRIMARY BEAM CALIBRATION OF DRIFT-SCANNING, WIDE-FIELD ANTENNA ELEMENTS

    SciTech Connect

    Pober, Jonathan C.; Parsons, Aaron R. [Astronomy Department, University of California, Berkeley, CA (United States); Jacobs, Daniel C. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Aguirre, James E.; Moore, David F. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Bradley, Richard F.; Parashare, Chaitali R. [Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA (United States); Carilli, Chris L. [National Radio Astronomy Observatory, Socorro, NM (United States); Gugliucci, Nicole E. [Department of Astronomy, University of Virginia, Charlottesville, VA (United States)

    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.

  20. Wide-field computational color imaging using pixel super-resolved on-chip microscopy

    PubMed Central

    Greenbaum, Alon; Feizi, Alborz; Akbari, Najva; Ozcan, Aydogan

    2013-01-01

    Lens-free holographic on-chip imaging is an emerging approach that offers both wide field-of-view (FOV) and high spatial resolution in a cost-effective and compact design using source shifting based pixel super-resolution. However, color imaging has remained relatively immature for lens-free on-chip imaging, since a ‘rainbow’ like color artifact appears in reconstructed holographic images. To provide a solution for pixel super-resolved color imaging on a chip, here we introduce and compare the performances of two computational methods based on (1) YUV color space averaging, and (2) Dijkstra’s shortest path, both of which eliminate color artifacts in reconstructed images, without compromising the spatial resolution or the wide FOV of lens-free on-chip microscopes. To demonstrate the potential of this lens-free color microscope we imaged stained Papanicolaou (Pap) smears over a wide FOV of ~14 mm2 with sub-micron spatial resolution. PMID:23736466

  1. A wide-field photometric study of the globular cluster system of NGC 4636

    E-print Network

    Dirsch, B; Richtler, T; Dirsch, Boris; Schuberth, Ylva; Richtler, Tom

    2005-01-01

    We investigate the unusually rich cluster system of NGC4636 with wide-field Washington photometry. The globular cluster luminosity function can be followed roughly 1 mag beyond the turn-over magnitude. This corresponds to a distance modulus of m-M=31.24+-0.17, 0.4 mag larger than the distance determined from surface brightness fluctuations. The high specific frequency is confirmed, yet the exact value remains uncertain because of the uncertain distance: it varies between 5.6+-1.2 and 8.9+-1.2. The globular cluster system has a clearly bimodal color distribution. The color peak positions show no radial dependence and are in good agreement with the values found for other galaxies studied in the same filter system. However, a luminosity dependence is found: brighter clusters with an ``intermediate'' color exist. The clusters exhibit a shallow radial distribution within 7'.Within the same radial interval, the galaxy light has a distinctly steeper profile. Because of the difference in the cluster and light distrib...

  2. 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".

  3. Deep Wide Field BVI CCD Photometry of the Sextans Dwarf Spheroidal Galaxy

    E-print Network

    Lee, M G; Park, J H; Sohn, Y J; Oh, S J; Yuk, I S; Rey, S C; Lee, S G; Lee, Y W; Kim, H I; Han, W; Park, W K; Lee, J H; Jeon, Y B; Kim, S C; Lee, Myung Goon; Park, Hong Soo; Park, Jang-Hyun; Sohn, Young-Jong; Oh, Seung Joon; Yuk, In-Soo; Rey, Soo-Chang; Lee, Sang-Gak; Lee, Young-Wook; Kim, Ho-Il; Han, Wonyong; Park, Won-Kee; Lee, Joon Hyeop; Jeon, Young Beom; Kim, Sang Chul

    2003-01-01

    We present deep wide field $VI$ CCD photometry of the Sextans dwarf spheroidal galaxy (dSph) in the Local Group, covering a field of 42' x 28' located at the center of the galaxy. Color-magnitude diagrams of the Sextans dSph show well-defined red giant branch (RGB), blue horizontal branch (BHB), prominent red horizontal branch (RHB), asymptotic giant branch (AGB), about 120 variable star candidates including RR Lyraes and anomalous Cepheids, about 230 blue stragglers (BSs), and main sequence (MS) stars. The distance to the galaxy is derived using the $I$-band magnitude of the tip of the RGB at I(TRGB)=15.95+/-0.04: (m-M)_0=19.90+/-0.06 for an adopted reddening of E(B-V)=0.01. The mean metallicity of the RGB is estimated from the (V-I) color: [Fe/H]=-2.1+/-0.1(statistical error) +/-0.2(standard calibration error) dex, with a dispersion of sigma[Fe/H]=0.2 dex. The age of the MSTO of the main old population is estimated to be similar to that of M92, and there are seen some stellar populations with younger age. T...

  4. The Araucaria Project. Bright Variable Stars in NGC 6822 from a Wide-Field Imaging Survey

    E-print Network

    R. E. Mennickent; W. Gieren; I. Soszynski; G. Pietrzynski

    2006-01-18

    We have performed a search for variable stars in the dwarf irregular galaxy NGC 6822 using wide-field multi-epoch VI photometry down to a limiting magnitude $V$ $\\sim$ 22. Apart from the Cepheid variables in this galaxy already reported in an earlier paper by Pietrzynski et al. (2004), we have found 1019 "non-periodic" variable stars, 50 periodically variable stars with periods ranging from 0.12 to 66 days and 146 probably periodic variables. Twelve of these stars are eclipsing binaries and fifteen are likely new, low-amplitude Cepheids. Interestingly, seven of these Cepheid candidates have periods longer than 100 days, have very low amplitudes (less than 0.2 mag in $I$), and are very red. They could be young, massive Cepheids still embedded in dusty envelopes. The other objects span a huge range in colours and represent a mixture of different types of luminous variables. Many of the variables classified as non-periodic in the present study may turn out to be {\\it periodic} variables once a much longer time baseline will be available to study them. We provide the catalogue of photometric parameters and show the atlas of light curves for the new variable stars. Our present catalogue is complementary to the one of Baldacci et al. (2005) which has focussed on very short-period and fainter variables in a subfield in NGC 6822.

  5. 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. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Rebull, L. M. [Spitzer Science Center (SSC), California Institute of Technology, M/S 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Assef, R. J. [Jet Propulsion Laboratory, MS 169-530, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    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.

  6. 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

  7. 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.

  8. Single plane illumination module and micro-capillary approach for a wide-field microscope.

    PubMed

    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

  9. 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.

  10. New observational techniques and analysis tools for wide field CCD surveys and high resolution astrometry

    E-print Network

    O. Fors

    2006-04-06

    (Abridged) In the first part of this thesis, a general methodology for applying image deconvolution to wide-field CCD imagery. Results show that wavelet-based deconvolution can increase limiting magnitude up to 0.6 mag and improve limiting resolution 1 pixel with respect to original image with no astrometric accuracy degradation. In the second part, a new observational technique based on CCD fast drift scanning has been proposed for lunar occultations (LO) and speckle interferometry. This enables all kind of professional and high-end amateur observatories to perform such kind of observations. For LO, 16 new binaries up to 2mas of projected separation were detected and stellar diameters measurements in the 7 mas regime were obtained with that CCD and IR subarray based techniques. A new wavelet-based LO reduction pipeline was implemented. For speckle, CCD fast drift scanning technique was validated with the observation of four binary systems with well determined orbits. The results of separation, position angle and magnitude difference are in accordance with published measurements. A new approach for calibrating speckle transfer function from the binary power spectrum itself has been introduced. It does not require point source observations, which gives a more effective use of observation time.

  11. CALIBRATION OF LOW-FREQUENCY, WIDE-FIELD RADIO INTERFEROMETERS USING DELAY/DELAY-RATE FILTERING

    SciTech Connect

    Parsons, Aaron R.; Backer, Donald C. [Astronomy Department and Radio Astronomy Laboratory, University of California, Berkeley, CA 94720-3411 (United States)], E-mail: aparsons@astron.berkeley.edu

    2009-07-15

    We present a filtering technique that can be applied to individual baselines of wide-bandwidth, wide-field interferometric data to geometrically select regions on the celestial sphere that contain primary calibration sources. The technique relies on the Fourier transformation of wide-band frequency spectra from a given baseline to obtain one-dimensional 'delay images', and then the transformation of a time-series of delay images to obtain two-dimensional 'delay/delay-rate images'. Source selection is possible in these images given appropriate combinations of baseline, bandwidth, integration time, and source location. Strong and persistent radio frequency interference (RFI) limits the effectiveness of this source selection owing to the removal of data by RFI excision algorithms. A one-dimensional, complex CLEAN algorithm has been developed to compensate for RFI-excision effects. This approach allows CLEANed, source-isolated data to be used to isolate bandpass and primary beam gain functions. These techniques are applied to data from the Precision Array for Probing the Epoch of Reionization as a demonstration of their value in calibrating a new generation of low-frequency radio interferometers with wide relative bandwidths and large fields of view.

  12. Wide-field imaging on 8- to 100-meter class telescopes

    NASA Astrophysics Data System (ADS)

    Gentile, Giorgia; Diolaiti, Emiliano; Ragazzoni, Roberto; Arcidiacono, Carmelo; Baruffolo, Andrea; Farinato, Jacopo; Foppiani, Italo; Lombini, Matteo; Giallongo, Emanuele; Di Paola, Andrea; Pedichini, Fernando; Speziali, Roberto

    2006-06-01

    It is generally believed that very fast cameras imaging large Fields of View translate into huge optomechanics and mosaics of very large contiguous CCDs. It has already been suggested that seeing limited imaging cameras for telescopes whose diameters are larger than 20m are considered virtually impossible for a reasonable cost. It has also been suggested that using existing technology and at a moderate price, one can build a Smart Fast Camera, a device that placed on aberrated Field of View, including those of slow focal ratios, is able to provide imaging at an equivalent focal ratio as low as F/1, with a size that is identical to the large focal ratio focal plane size. The design allows for easy correction of aberrations over the Field of View. It has low weight and size with respect to any focal reducer or prime focus station of the same performance. It can be applied to existing 8m-class telescopes to provide a wide field fast focal plane or to achieve seeing-limited imaging on Extremely Large Telescopes. As it offers inherently fast read-out in a massive parallel mode, the SFC can be used as a pupil or focal plane camera for pupil-plane or Shack-Hartmann wavefront sensing for 30-100m class telescopes. Basing upon Smart Fast Camera concept, we present a study turned to explain the pliability of this instrument for different existing telescopes.

  13. Examining the Range of Cometary Dust Characteristics with the Wide-Field Infrared Survey Explorer

    NASA Astrophysics Data System (ADS)

    Stevenson, R.; Bauer, J. M.; Kramer, E.; Mainzer, A.; Masiero, J.; Grav, T.; Fernandez, Y. R.; Lisse, C. M.; Meech, K. J.; Weissman, P. R.; Tholen, D.; Walker, R.; Wright, E. L.

    2012-12-01

    Cometary dust provides insight into the composition of nuclei, as well as the forces behind its ejection and evolution. In this work, we will explore the characteristics of dust as seen in the near-nucleus environments around more than 100 active comets that were observed by the Wide-Field Infrared Explorer (WISE) mission. WISE conducted an all-sky survey at near- and mid-infrared wavelengths (3.4, 4.6, 12, and 22 microns) between January and December 2010. Many of the comets detected showed comae, tails, and/or trails, making this a rich dataset with which to examine the ensemble properties of cometary dust in the Solar System. Our work includes computing thermal fits for the dust, creating color temperature maps, and constraining the grain size distributions around the comets. With these results, we aim to provide context for the Rosetta mission results as well as a broad understanding of the range of cometary dust traits within the Solar System.

  14. 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.

  15. THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE): MISSION DESCRIPTION AND INITIAL ON-ORBIT PERFORMANCE

    SciTech Connect

    Wright, Edward L.; McLean, Ian [UCLA Astronomy, P.O. Box 951547, Los Angeles, CA 90095-1547 (United States); Eisenhardt, Peter R. M.; Mainzer, Amy K.; Ressler, Michael E.; Gautier, Thomas N. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Cutri, Roc M.; Jarrett, Thomas; Kirkpatrick, J. Davy; Padgett, Deborah [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); McMillan, Robert S. [University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721 (United States); Skrutskie, Michael [Department of Astronomy, University of Virginia, Charlottesville, VA 22903 (United States); Stanford, S. A. [Physics Department, University of California, Davis, CA 95616 (United States); Cohen, Martin; Walker, Russell G. [Monterey Institute for Research in Astronomy, 200 8th Street, Marina, CA 93933 (United States); Mather, John C.; Leisawitz, David; Benford, Dominic [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lonsdale, Carol J. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Blain, Andrew, E-mail: wright@astro.ucla.ed [California Institute of Technology, Pasadena, CA 91125 (United States)

    2010-12-15

    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 Two 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 (WISE) is mapping the whole sky following its launch on 2009 December 14. WISE began surveying the sky on 2010 January 14 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 2010 November). 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 {mu}m. 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 {mu}m, and the astrometric precision for high signal-to-noise sources is better than 0.''15.

  16. Exoplanets from the Arctic: The First Wide-field Survey at 80°N

    NASA Astrophysics Data System (ADS)

    Law, Nicholas M.; Carlberg, Raymond; Salbi, Pegah; Ngan, Wai-Hin Wayne; Ahmadi, Aida; Steinbring, Eric; Murowinski, Richard; Sivanandam, Suresh; Kerzendorf, Wolfgang

    2013-03-01

    Located within 10° of the North Pole, northern Ellesmere Island offers continuous darkness in the winter months. This capability can greatly enhance the detection efficiency of planetary transit surveys and other time domain astronomy programs. We deployed two wide-field cameras at 80°N, near Eureka, Nunavut, for a 152 hr observing campaign in 2012 February. The 16 megapixel camera systems were based on commercial f/1.2 lenses with 70 mm and 42 mm apertures, and they continuously imaged 504 and 1295 deg2, respectively. In total, the cameras took over 44,000 images and produced better than 1% precision light curves for approximately 10,000 stars. We describe a new high-speed astrometric and photometric data reduction pipeline designed for the systems, test several methods for the precision flat fielding of images from very-wide-angle cameras, and evaluate the cameras' image qualities. We achieved a scintillation-limited photometric precision of 1%-2% in each 10 s exposure. Binning the short exposures into 10 minute chunks provided a photometric stability of 2-3 mmag, sufficient for the detection of transiting exoplanets around the bright stars targeted by our survey. We estimate that the cameras, when operated over the full Arctic winter, will be capable of discovering several transiting exoplanets around bright (mV < 9.5) stars.

  17. Dome Degradation Characterization of Wide-Field-of-View Nonscanner aboard ERBE and it's Reprocessing

    NASA Astrophysics Data System (ADS)

    Shrestha, Alok; Kato, Seiji; Wong, Takmeng; Stackhouse, Paul; Rose, Fred; Miller, Walter; Bush, Kathryn; Rutan, David; Minnis, Patrick; Doelling, David; Smith, George; Su, Wenying

    2015-04-01

    Earth Radiation Budget Experiment (ERBE) wide-field-of-view (WFOV) nonscanner on Earth Radiation Budget Satellite (ERBS), NOAA-9, and NOAA-10 provided broadband shortwave and longwave irradiances from 1985 to 1998. The measurements at satellite altitude from ERBE WFOV nonscanners are converted to top-of-atmosphere (TOA) irradiances by inversion processes. The existing inversion-processing scheme for shortwave instrument assumes a spectrally constant degradation (gray assumption) and does not consider spectral dependent shortwave dome degradation. Based on knowledge from recent developments in the CERES process, we plan to reprocess WFOV nonscanners data by characterizing the spectral dependent degradation of the shortwave dome transmissivity. The characterization of the dome transmissivity will be performed using the solar data observed by these instruments during calibration days. In addition, the existing processing does not use the scene information for individual footprints but assumes mostly cloudy over ocean for the entire observation period. In the reprocessing, we plan to use imager derived cloud fraction and the cloud phase as well as surface type over the field of view of nonscanner instruments. This presentation will briefly explain the reprocessing technique and evaluation of results by comparing the existing WFOV nonscanner data with that obtained from the new approach.

  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. VizieR Online Data Catalog: WSRT wide-field HI survey. II. (Braun+, 2004)

    NASA Astrophysics Data System (ADS)

    Braun, R.; Thilker, D. A.

    2004-04-01

    We have used the Westerbork array to carry out an unbiased wide-field survey for HI emission features, achieving an RMS sensitivity of about 18mJy/Beam at a velocity resolution of 17km/s over 1800deg2 and between -1000). (1 data file).

  20. PNNL Future Power Grid Initiative-developed GridOPTICS Software System (GOSS)

    SciTech Connect

    None

    2014-11-03

    The power grid is changing and evolving. One aspect of this change is the growing use of smart meters and other devices, which are producing large volumes of useful data. However, in many cases, the data can’t be translated quickly into actionable guidance to improve grid performance. There's a need for innovative tools. The GridOPTICS(TM) Software System, or GOSS, developed through PNNL's Future Power Grid Initiative, is open source and became publicly available in spring 2014. The value of this middleware is that it easily integrates grid applications with sources of data and facilitates communication between them. Such a capability provides a foundation for developing a range of applications to improve grid management.

  1. Performance Comparisons Between Carbon Nanotubes, Optical, and Cu for Future High-Performance On-Chip Interconnect Applications

    Microsoft Academic Search

    Kyung-Hoae Koo; Hoyeol Cho; Pawan Kapur; Krishna C. Saraswat

    2007-01-01

    Optical interconnects and carbon nanotubes (CNTs) present promising options for replacing the existing Cu-based global\\/semiglobal (optics and CNT) and local (CNT) wires. We quantify the performance of these novel interconnects and compare it with Cu\\/low-kappa wires for future high-performance integrated circuits. We find that for a local wire, a CNT bundle exhibits a smaller latency than Cu for a given

  2. Current status of the Explosive Transient Camera. [automated sky survey instument sensitive to optical transients

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    The current configuration and performance of the Explosive Transient Camera (ETC), a wide-field sky monitor capable of detecting short-timescale optical transients, are briefly reviewed, as are plans for future improvements. The primary objective of the ETC is to detect an optical transient that is spatially and temporally coincident with a gamma-ray burster. However, the ETC is sensitive to all sources of short-timescale optical transients and will conduct a systematic survey of the night sky for all optical transients. Results of preliminary observations of the night sky conducted since January 1991 are summarized, and long-term variability searches with the ETC are discussed.

  3. Wide-field spectroscopy and imaging at two plate scales with a focal three mirror anastigmat

    NASA Astrophysics Data System (ADS)

    Sholl, Michael J.; Content, David A.; Lampton, Michael L.; Lehan, John P.; Levi, Michael E.

    2010-07-01

    The key enabling element of the Joint Dark Energy Mission (JDEM)1,2,3 is a wide-field, high-magnification mixed spectroscopic and imaging telescope intended to study dark energy via measurement of the expansion history of the universe and the growth of large-scale structure. It is designed to provide tight constraints on the equation of state of dark energy and test the validity of general relativity. Complementary observation of Baryon Acoustic Oscillations (BAO), Type 1a Supernovae (SNe) and Gravitational Weak Lensing (WL) are under consideration for the mission. The science goals of this mission call for a high-resolution imaging survey and a spectroscopic survey of at least 10,000 square degrees. Signal to noise requirements of the Baryon Acoustic Oscillation (BAO) survey favor a prism disperser with a ? • d ? /d ? of roughly 200 arcsec and a coarse plate scale (~0.45arsec/pixel). The WL imaging survey seeks the shapes of galaxies, and therefore prefers a finer plate scale of ~0.1-0.23 arcsec/pixel. Accommodation all of these goals may be accomplished with an afocal telescope but the results of this study suggest that a focal telescope is also capable of achieving these goals. Discussed herein are several novel prism concepts designed for use in a focal three mirror anastigmat telescope (TMA). Multiple elements are used for aberration balancing and tailoring resolving power over the observational band. Several options for simultaneous or staggered imaging and spectroscopy as well as the required plate scale change with a focal TMA are presented.

  4. A wide-field photometric study of the globular cluster system of NGC 4636

    E-print Network

    Boris Dirsch; Ylva Schuberth; Tom Richtler

    2005-03-13

    We investigate the unusually rich cluster system of NGC4636 with wide-field Washington photometry. The globular cluster luminosity function can be followed roughly 1 mag beyond the turn-over magnitude. This corresponds to a distance modulus of m-M=31.24+-0.17, 0.4 mag larger than the distance determined from surface brightness fluctuations. The high specific frequency is confirmed, yet the exact value remains uncertain because of the uncertain distance: it varies between 5.6+-1.2 and 8.9+-1.2. The globular cluster system has a clearly bimodal color distribution. The color peak positions show no radial dependence and are in good agreement with the values found for other galaxies studied in the same filter system. However, a luminosity dependence is found: brighter clusters with an ``intermediate'' color exist. The clusters exhibit a shallow radial distribution within 7'.Within the same radial interval, the galaxy light has a distinctly steeper profile. Because of the difference in the cluster and light distribution the specific frequency increases considerably with radius. At 7' and 9' the density profiles of the red and blue clusters, respectively, change strongly which indicates that we reach the outer rim of the cluster system at approximately 11'. This feature is seen for the first time in a globular cluster system. While the radial distribution of the cluster and field populations are rather different, this is not true for the ellipticity of the system: the elongation as well as the position angle of the cluster system agree well with the galaxy light. We compare the radial distribution of globular clusters with the light profiles for a sample of elliptical galaxies. The difference observed in NGC 4636 is typical of an elliptical galaxy of this luminosity.

  5. Dual-modality wide-field photothermal quantitative phase microscopy and depletion of cell populations

    NASA Astrophysics Data System (ADS)

    Turko, Nir A.; Barnea, Itay; Blum, Omry; Korenstein, Rafi; Shaked, Natan T.

    2015-03-01

    We review our dual-modality technique for quantitative imaging and selective depletion of populations of cells based on wide-field photothermal (PT) quantitative phase imaging and simultaneous PT cell extermination. The cells are first labeled by plasmonic gold nanoparticles, which evoke local plasmonic resonance when illuminated by light in a wavelength corresponding to their specific plasmonic resonance peak. This reaction creates changes of temperature, resulting in changes of phase. This phase changes are recorded by a quantitative phase microscope (QPM), producing specific imaging contrast, and enabling bio-labeling in phase microscopy. Using this technique, we have shown discrimination of EGFR over-expressing (EGFR+) cancer cells from EGFR under-expressing (EGFR-) cancer cells. Then, we have increased the excitation power in order to evoke greater temperatures, which caused specific cell death, all under real-time phase acquisition using QPM. Close to 100% of all EGFR+ cells were immediately exterminated when illuminated with the strong excitation beam, while all EGFR- cells survived. For the second experiment, in order to simulate a condition where circulating tumor cells (CTCs) are present in blood, we have mixed the EGFR+ cancer cells with white blood cells (WBCs) from a healthy donor. Here too, we have used QPM to observe and record the phase of the cells as they were excited for selective visualization and then exterminated. The WBCs survival rate was over 95%, while the EGFR+ survival rate was under 5%. The technique may be the basis for real-time detection and controlled treatment of CTCs.

  6. Wide-Field, R and H Band Imaging of Quasar Environments

    NASA Astrophysics Data System (ADS)

    Finn, R. A.; McCarthy, D. W.; Impey, C. D.; Hooper, E. J.

    1998-12-01

    This study examines the large-scale environments of radio-loud and radio-quiet quasars. The large-scale environments of quasars are interesting because quasars are thought to be triggered by interactions with neighboring galaxies and/or intercluster gas. Studies show that quasars reside in overdense regions, and radio-quiet quasars, while more likely to have close companions than field galaxies, tend to reside in poorer clusters than radio-loud quasars. To improve our understanding of the correlation between radio properties and environment, we imaged a carefully selected sample from the Large Bright Quasar Survey (LBQS). The sample consists of sixteen quasars in the redshift range 0.4 < z < 0.5 with absolute blue magnitudes between -23.0 and -26.5. Six of the quasars are radio-loud, and the ten remaining quasars have 8.4 GHz luminosities <= 10(23.5) W * Hz(-1) . R-band images of the quasars and control fields were taken at the Steward 90 inch. The same fields were then imaged in the H-band using a new wide-field infrared camera, PISCES. PISCES is an ideal instrument for this study because its 8.5' field corresponds to a projected distance of 2.4 Mpc at z ~ 0.4. This allows simultaneous sampling of the quasar environment and a control field. The H and R-band photometry allows identification of companion galaxies, and the color information helps to discriminate between foreground and cluster galaxies. Preliminary results are presented comparing galaxy counts within 1 Mpc of the quasars to field galaxy counts.

  7. NOTE: Multileaf collimator end leaf leakage: implications for wide-field IMRT

    NASA Astrophysics Data System (ADS)

    Hardcastle, N.; Metcalfe, P.; Ceylan, A.; Williams, M. J.

    2007-11-01

    The multi-leaf collimator (MLC) of a particular linear accelerator vendor (Millennium MLC, Varian Medical Systems, Palo Alto, CA, USA) has a maximum leaf extension of 14.5 cm. To achieve intensity modulated radiotherapy (IMRT) for fields wider than 14.5 cm all closed leaf pairs are restricted to placement inside the field. Due to the rounded leaf end design of the MLC end leaf leakage will occur in the treatment field. The implementation of direct aperture optimization in the IMRT module of a radiotherapy treatment planning system (Pinnacle, Philips Radiation Oncology Systems, Milpitas, CA) has facilitated the delivery of IMRT fields wider than 14.5 cm. The end leaf leakage of the Millennium MLC has been characterized for 6 MV photons using gafchromic and radiographic film, and the accuracy of the planning system verified. The maximum leakage measured for a single field was 0.39 cGy MU-1 for a 0 mm leaf gap and 0.51 cGy MU-1 for a 0.6 mm leaf gap. For a clinical IMRT field leaf end leakage contributed an additional 2-3 Gy over the course of treatment. The planning system underestimated the magnitude of end leaf leakage by 20-40%. The ability to deliver IMRT fields wider than 14.5 cm with the Millennium MLC has improved the efficiency and flexibility of IMRT treatments; however, significant extra dose can be introduced due to end leaf leakage. Caution should be exercised when delivering wide field IMRT as it is not a complete panacea. Any significant occurrences of end leaf leakage predicted by the planning system should be independently verified prior to delivery.

  8. THERMAL MODEL CALIBRATION FOR MINOR PLANETS OBSERVED WITH WIDE-FIELD INFRARED SURVEY EXPLORER/NEOWISE

    SciTech Connect

    Mainzer, A.; Masiero, J.; Bauer, J.; Ressler, M.; Eisenhardt, P. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Grav, T. [Department of Physics and Astronomy, Johns Hopkins University, 366 Bloomberg Center, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Wright, E. [UCLA Astronomy, P.O. Box 91547, Los Angeles, CA 90095-1547 (United States); Cutri, R. M. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); McMillan, R. S. [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Blvd., Kuiper Space Science Bldg. 92, Tucson, AZ 85721-0092 (United States); Cohen, M., E-mail: amainzer@jpl.nasa.gov [Radio Astronomy Laboratory, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States)

    2011-08-01

    With the Wide-field Infrared Survey Explorer (WISE), we have observed over 157,000 minor planets. Included in these are a number of near-Earth objects, main-belt asteroids, and irregular satellites which have well measured physical properties (via radar studies and in situ imaging) such as diameters. We have used these objects to validate models of thermal emission and reflected sunlight using the WISE measurements, as well as the color corrections derived in Wright et al. for the four WISE bandpasses as a function of effective temperature. We have used 50 objects with diameters measured by radar or in situ imaging to characterize the systematic errors implicit in using the WISE data with a faceted spherical near-Earth asteroid thermal model (NEATM) to compute diameters and albedos. By using the previously measured diameters and H magnitudes with a spherical NEATM model, we compute the predicted fluxes (after applying the color corrections given in Wright et al.) in each of the four WISE bands and compare them to the measured magnitudes. We find minimum systematic flux errors of 5%-10%, and hence minimum relative diameter and albedo errors of {approx}10% and {approx}20%, respectively. Additionally, visible albedos for the objects are computed and compared to the albedos at 3.4 {mu}m and 4.6 {mu}m, which contain a combination of reflected sunlight and thermal emission for most minor planets observed by WISE. Finally, we derive a linear relationship between subsolar temperature and effective temperature, which allows the color corrections given in Wright et al. to be used for minor planets by computing only subsolar temperature instead of a faceted thermophysical model. The thermal models derived in this paper are not intended to supplant previous measurements made using radar or spacecraft imaging; rather, we have used them to characterize the errors that should be expected when computing diameters and albedos of minor planets observed by WISE using a spherical NEATM model.

  9. A wide-field near- and mid-infrared Census of young stars in NGC 6334

    SciTech Connect

    Willis, S.; Marengo, M. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50010 (United States); Allen, L. [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Fazio, G. G.; Smith, H. A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Carey, S., E-mail: swillis@cfa.harvard.edu [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2013-12-01

    This paper presents a study of the rate and efficiency of star formation in the NGC 6334 star-forming region. We obtained observations at J, H, and K{sub s} taken with the NOAO Extremely Wide-Field Infrared Imager and combined them with observations taken with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope at wavelengths = 3.6, 4.5, 5.8, and 8.0 ?m. We also analyzed previous observations taken at 24 ?m using the Spitzer MIPS camera as part of the MIPSGAL survey. We have produced a point source catalog with >700, 000 entries. We have identified 2283 young stellar object (YSO) candidates, 375 Class I YSOs, and 1908 Class II YSOs using a combination of existing IRAC-based color classification schemes that we have extended and validated to the near-IR for use with warm Spitzer data. We have identified multiple new sites of ongoing star formation activity along filamentary structures extending tens of parsecs beyond the central molecular ridge of NGC 6334. By mapping the extinction, we derived an estimate for the gas mass, 2.2 × 10{sup 5} M {sub ?}. The heavy concentration of protostars along the dense filamentary structures indicates that NGC 6334 may be undergoing a 'mini-starburst' event with ?{sub SFR} > 8.2 M {sub ?} Myr{sup –1} pc{sup –2} and SFE > 0.10. We have used these estimates to place NGC 6334 in the Kennicutt-Schmidt diagram to help bridge the gap between observations of local low-mass star-forming regions and star formation in other galaxies.

  10. A Wide-field near- and Mid-infrared Census of Young Stars in NGC 6334

    NASA Astrophysics Data System (ADS)

    Willis, S.; Marengo, M.; Allen, L.; Fazio, G. G.; Smith, H. A.; Carey, S.

    2013-12-01

    This paper presents a study of the rate and efficiency of star formation in the NGC 6334 star-forming region. We obtained observations at J, H, and Ks taken with the NOAO Extremely Wide-Field Infrared Imager and combined them with observations taken with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope at wavelengths = 3.6, 4.5, 5.8, and 8.0 ?m. We also analyzed previous observations taken at 24 ?m using the Spitzer MIPS camera as part of the MIPSGAL survey. We have produced a point source catalog with >700, 000 entries. We have identified 2283 young stellar object (YSO) candidates, 375 Class I YSOs, and 1908 Class II YSOs using a combination of existing IRAC-based color classification schemes that we have extended and validated to the near-IR for use with warm Spitzer data. We have identified multiple new sites of ongoing star formation activity along filamentary structures extending tens of parsecs beyond the central molecular ridge of NGC 6334. By mapping the extinction, we derived an estimate for the gas mass, 2.2 × 105 M ?. The heavy concentration of protostars along the dense filamentary structures indicates that NGC 6334 may be undergoing a "mini-starburst" event with ?SFR > 8.2 M ? Myr–1 pc–2 and SFE > 0.10. We have used these estimates to place NGC 6334 in the Kennicutt-Schmidt diagram to help bridge the gap between observations of local low-mass star-forming regions and star formation in other galaxies.

  11. Galaxy pairs in the Sloan Digital Sky Survey - IX. Merger-induced AGN activity as traced by the Wide-field Infrared Survey Explorer

    NASA Astrophysics Data System (ADS)

    Satyapal, Shobita; Ellison, Sara L.; McAlpine, William; Hickox, Ryan C.; Patton, David R.; Mendel, J. Trevor

    2014-06-01

    Interactions between galaxies are predicted to cause gas inflows that can potentially trigger nuclear activity. Since the inflowing material can obscure the central regions of interacting galaxies, a potential limitation of previous optical studies is that obscured active galactic nuclei (AGNs) can be missed at various stages along the merger sequence. We present the first large mid-infrared study of AGNs in mergers and galaxy pairs, in order to quantify the incidence of obscured AGNs triggered by interactions. The sample consists of galaxy pairs and post-mergers drawn from the Sloan Digital Sky Survey that are matched to detections by the Wide-Field Infrared Sky Explorer. We find that the fraction of AGNs in the pairs, relative to a mass-, redshift- and environment-matched control sample, increases as a function of decreasing projected separation. This enhancement is most dramatic in the post-merger sample, where we find a factor of 10-20 excess in the AGN fraction compared with the control. Although this trend is in qualitative agreement with results based on optical AGN selection, the mid-infrared-selected AGN excess increases much more dramatically in the post-mergers than is seen for an optical AGN. Our results suggest that energetically dominant optically obscured AGNs become more prevalent in the most advanced mergers, consistent with theoretical predictions.

  12. The impact of misregistration upon composited wide field of view satellite data and implications for change detection

    Microsoft Academic Search

    David P. Roy

    2000-01-01

    Composited wide field of view satellite data are used for many applications and increasingly for studies of global change. Although several compositing schemes have been suggested, all assume perfect geometric registration, which is not operationally feasible. In this study, models of the satellite imaging, geometric registration, and compositing processes are used to investigate the impact of misregistration upon the position

  13. Matching a curved focal plane with CCD's - Wide field imaging of glancing incidence X-ray telescopes

    Microsoft Academic Search

    J. A. Nousek; G. P. Garmire; G. R. Ricker; M. W. Bautz; A. M. Levine; S. A. Collins

    1987-01-01

    The design of a wide field imaging camera suitable for use with a glancing incidence X-ray telescope is complicated by the sharply concave nature of the optimum focal surface of such a telescope. Such a camera made up of a mosaic of CCDs is being designed which is intended for flight aboard the Advanced X-ray Astrophysics Facility (AXAF). The design

  14. Phasor-based single-molecule fluorescence lifetime imaging using a wide-field photon-counting detector

    E-print Network

    Michalet, Xavier

    Phasor-based single-molecule fluorescence lifetime imaging using a wide- field photon in terms of signal level (and therefore limited frame rate). Recently, the phasor approach has been-molecule experiments. Here we discuss the advantages of combining phasor analysis with a new type of FLIM acquisition

  15. Wide-field-of-view GaAs AlxOy one-dimensional photonic crystal filter

    E-print Network

    Fainman, Yeshaiahu

    Wide-field-of-view GaAs AlxOy one-dimensional photonic crystal filter Chyong-Hua Chen, Kevin Tetz the environment (e.g., Sun, Moon, and other sources). The transmission bandwidth of such a filter needs to be wide high- refractive-index contrast material systems--called C.-H. Chen (chyong@ece.ucsd.edu), K. Tetz

  16. Ionization Structure in the 30 Doradus Nebula as seen with Hubble Space Telescope Wide Field Planetary Camera 2

    Microsoft Academic Search

    P. A. Scowen; J. J. Hester; R. Sankrit; J. S. Gallagher; G. E. Ballester; C. J. Burrows; J. T. Clarke; D. Crisp; R. W. Evans; R. E. Griffiths; J. G. Hoessel; J. A. Holtzman; J. Krist; J. R. Mould; K. R. Stapelfeldt; J. T. Trauger; A. M. Watson; J. A. Westphal

    1998-01-01

    Using the Hubble Space Telescope (HST) and Wide Field Planetary Camera 2, we have imaged the central 20 pc of the giant H ii region 30 Doradus Nebula in three different emission lines. The images allow us to study the nebula with a physical resolution that is within a factor of 2 of that of typical ground-based observations of Galactic

  17. Removing cosmic-ray hits from multiorbit HST Wide Field Camera images

    NASA Technical Reports Server (NTRS)

    Windhorst, Rogier A.; Franklin, Barbara E.; Neuschaefer, Lyman W.

    1994-01-01

    We present an optimized algorithm that removes cosmic rays ('CRs') from multiorbit Hubble Space Telescope (HST) Wide Field/Planetary Camera ('WF/PC') images. It computes the image noise in every iteration from the WF/PC CCD equation. This includes all known sources of random and systematic calibration errors. We test this algorithm on WF/PC stacks of 2-12 orbits as a function of the number of available orbits and the formal Poissonian sigma-clipping level. We find that the algorithm needs greater than or equal 4 WF/PC exposures to locate the minimal sky signal (which is noticeably affected by CRs), with an optimal clipping level at 2-2.5 x sigma(sub Poisson). We analyze the CR flux detected on multiorbit 'CR stacks,' which are constructed by subtracting the best CR filtered images from the unfiltered 8-12 orbit average. We use an automated object finder to determine the surface density of CRS as a function of the apparent magnitude (or ADU flux) they would have generated in the images had they not been removed. The power law slope of the CR 'counts' (gamma approximately = 0.6 for N(m) m(exp gamma)) is steeper than that of the faint galaxy counts down to V approximately = 28 mag. The CR counts show a drop off between 28 less than or approximately V less than or approximately 30 mag (the latter is our formal 2 sigma point source sensitivity without spherical aberration). This prevents the CR sky integral from diverging, and is likely due to a real cutoff in the CR energy distribution below approximately 11 ADU per orbit. The integral CR surface density is less than or approximately 10(exp 8)/sq. deg, and their sky signal is V approximately = 25.5-27.0 mag/sq. arcsec, or 3%-13% of our NEP sky background (V = 23.3 mag/sq. arcsec), and well above the EBL integral of the deepest galaxy counts (B(sub J) approximately = 28.0 mag/sq. arcsec). We conclude that faint CRs will always contribute to the sky signal in the deepest WF/PC images. Since WFPC2 has approximately 2.7x lower read noise and a thicker CCD, this will result in more CR detections than in WF/PC, potentially affecting approximately 10%-20% of the pixels in multiorbit WFPC2 data cubes.

  18. The WSRT wide-field HI survey: II. Local Group features

    E-print Network

    Robert Braun; David Thilker

    2003-12-12

    We have used the WSRT to carry out an unbiased wide-field survey of HI emission features, achieving an RMS sensitivity of about 18 mJy/Beam at a velocity resolution of 17 km/s over 1800 deg^2. In this paper we present our HI detections at negative velocities which could be distinguished from the Galactic foreground. Fully 29% of the entire survey area has high velocity HI emission with N_HI exceeding our 3 sigma limit of about 1.5x10^17cm^-2 over 30 km/s. A faint population of discrete HVCs is detected in the immediate vicinity of M31 which spans a large fraction of the M31 rotation velocity. This class of features is confined to about 12 deg (160 kpc) projected radius of M31 and appears to be physically associated. We detect a diffuse northern extension of the Magellanic Stream (MS) from at least Dec=+20 to +40 deg., which then loops back toward the south. Recent numerical simulations had predicted just such an MS extension corresponding to the apo-galacticon portion of the LMC/SMC orbit at a distance of 125 kpc. A faint bridge of HI emission appears to join the systemic velocities of M31 with that of M33 and continues beyond M31 to the north-west. This may be the first detection of HI associated with the warm-hot intergalactic medium (WHIM). The distribution of peculiar velocity HI associated with M31 can be described by a projected exponential of 25 kpc scale-length and 5x10^17cm^-2 peak column density. We present the distribution function of N_HI in the extended M31 environment, which agrees well with the low red-shift QSO absorption line data over the range log(N_HI)=17.2 to 21.9. Our data extend this comparison about two orders of magnitude lower than previously possible and provide the first image of the Lyman limit absorption system associated with an L* galaxy. (abridged)

  19. Characterizing AGB stars in Wide-field Infrared Survey Explorer (WISE) bands

    NASA Astrophysics Data System (ADS)

    Lian, Jianhui; Zhu, Qingfeng; Kong, Xu; He, Jinhua

    2014-04-01

    Aims: Since asymptotic giant branch (AGB) stars are bright and extended infrared objects, most Galactic AGB stars saturate the Wide-field Infrared Survey Explorer (WISE) detectors and therefore the WISE magnitudes that are restored by applying point-spread-function fitting need to be verified. Statistical properties of circumstellar envelopes around AGB stars are discussed on the basis of a WISE AGB catalog verified in this way. Methods: We cross-matched an AGB star sample with the WISE All-Sky Source Catalog and the Two Mircon All Sky Survey catalog. Infrared Space Observatory (ISO) spectra of a subsample of WISE AGB stars were also exploited. The dust radiation transfer code DUSTY was used to help predict the magnitudes in the W1 and W2 bands, the two WISE bands most affected by saturation, for calibration purpose, and to provide physical parameters of the AGB sample stars for analysis. Results: DUSTY is verified against the ISO spectra to be a good tool to reproduce the spectral energy distributions of these AGB stars. Systematic magnitude-dependent offsets have been identified in WISE W1 and W2 magnitudes of the saturated AGB stars, and empirical calibration formulas are obtained for them on the basis of 1877 (W1) and 1558 (W2) AGB stars that are successfully fit with DUSTY. According to the calibration formulas, the corrections for W1 at 5 mag and W2 at 4 mag are -0.383 and 0.217 mag, respectively. In total, we calibrated the W1/W2 magnitudes of 2390/2021 AGB stars. The model parameters from the DUSTY and the calibrated WISE W1 and W2 magnitudes are used to discuss the behavior of the WISE color-color diagrams of AGB stars. The model parameters also reveal that O-rich AGB stars with opaque circumstellar envelopes are much rarer than opaque C-rich AGB stars toward the anti-Galactic center direction, which we attribute to the metallicity gradient of our Galaxy. The synthetic photometry and input parameters for the model grid are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/564/A84

  20. Hubble Space Telescope Wide Field Planetary Camera 2 Observations of eta Carinae

    NASA Astrophysics Data System (ADS)

    Morse, Jon A.; Davidson, Kris; Bally, John; Ebbets, Dennis; Balick, Bruce; Frank, Adam

    1998-11-01

    Hubble Space Telescope (HST) continuum and emission-line images of eta Carinae obtained with the Planetary Camera (PC) of the Wide Field Planetary Camera 2 show a startling wealth of detailed structure in the expanding Homunculus Nebula and outer debris field. Using a combination of dithering and image deconvolutions, we have achieved a resolution of about 50 mas over the ~30" field of view covered by the PC. The complex network of bright cells and reddish, dusty lanes that lace the surfaces of the bipolar lobes of the Homunculus resemble similar structures observed in recent HST images of planetary nebulae. The contrast between these dust lanes and the adjacent bright cells, together with the dimensions of these features, is used to estimate the opacity and density of the obscuring material. Though radiation pressure is expected to accelerate the dust lanes by less than 10-20 km s^-1 with respect to the 650 km s^-1 expansion of the Homunculus, it may be the source of the instability responsible for their formation, and we discuss the formation of the bright cells and dusty filaments in this context. We present new data on the debris field beyond the Homunculus. This region contains a set of high-velocity ``whiskers'' (or ``streamers'') that show bipolar kinematics that associate them with the radially expanding lobes of the Homunculus and extend away from the central star like shrapnel from an explosion with trailing strings. The whiskers are several arcseconds long but often less than 0.1" wide, with some having length-to-width ratios exceeding 100. They are also remarkably uniform in brightness. We observe excess UV light several arcseconds northwest of the central star in the vicinity of a recent burst of radio emission. This ``blue glow'' appears to emanate from the equatorial region between the bipolar lobes. Though we cannot confirm temporal variability of this excess light, it may be connected with a burst of ultraviolet radiation that escaped the central region and ionized gas in this direction, perhaps generating radio-wavelength hydrogen recombination line emission. The near-ultraviolet glow in our images may be produced by fluorescent Fe II emission lines in the bandpass of the F336W filter, as seen in our recent HST Goddard High Resolution Spectrograph observations of this region.

  1. The Globular Cluster System in M87: A Wide-Field Study with CFHT/Megacam

    NASA Astrophysics Data System (ADS)

    Harris, William E.

    2009-09-01

    Canada-France-Hawaii Telescope Megacam data in (g', r', i') are used to obtain deep, wide-field photometry of the globular cluster system (GCS) around M87. A total of 6200 GCs brighter than i' = 23.0 (roughly equivalent to MI = -8.5) are included in the study, essentially containing almost the entire bright half of the total GC population in the galaxy. The classic bimodal metal-poor and metal-rich sequences of GCs show up clearly. While the spatial distribution of the GCs can be traced detectably outward to R gc sime 100 kpc and perhaps further, the blue, metal-poor subpopulation is very much more spatially extended than the red subpopulation. Both the red and blue GC subsystems have radial metallicity gradients, where mean heavy-element abundance scales with a projected galactocentric distance as Z ~ R -0.12 (blue) and R -0.17 (red). The blue sequence exhibits a strongly significant mass/metallicity relation (MMR) in which the mean metallicity gradually increases with cluster luminosity as Z ~ L 0.25 ± 0.05 for the luminosity range MI lsim -10 and the assumption of a constant M/L. However, this relation is also clearly nonlinear: fainter than this level, the sequence is more nearly vertical. This mass/metallicity trend can be understood as the result of self-enrichment within the most massive metal-poor GCs during their formation. The red sequence formally exhibits a negatively sloped MMR, but the numerical solutions and tests show that this red-GC slope is not very significant. In giant elliptical galaxies, the red GCs are likely to represent a broad composite population formed during several major starbursts. If so, the red sequence might display a population-based MMR that could in principle be either positive or negative. This research used the facilities of the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

  2. Measuring metallicities with Hubble space telescope/wide-field camera 3 photometry

    SciTech Connect

    Ross, Teresa L.; Holtzman, Jon A. [Department of Astronomy, New Mexico State University, P.O. Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Anthony-Twarog, Barbara J.; Twarog, Bruce [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045-7582 (United States); Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Saha, Abhijit [National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726 (United States); Walker, Alistair, E-mail: rosst@nmsu.edu, E-mail: holtz@nmsu.edu, E-mail: bjat@ku.edu, E-mail: btwarog@ku.edu, E-mail: heb11@psu.edu, E-mail: awalker@ctio.noao.edu [Cerro Tololo Inter-American Observatory (CTIO), National Optical Astronomy Observatory, Casilla 603, La Serena (Chile)

    2014-01-01

    We quantified and calibrated the metallicity and temperature sensitivities of colors derived from nine Wide-Field Camera 3 filters on board the Hubble Space Telescope using Dartmouth isochrones and Kurucz atmosphere models. The theoretical isochrone colors were tested and calibrated against observations of five well studied galactic clusters, M92, NGC 6752, NGC 104, NGC 5927, and NGC 6791, all of which have spectroscopically determined metallicities spanning –2.30 < [Fe/H] <+0.4. We found empirical corrections to the Dartmouth isochrone grid for each of the following color-magnitude diagrams (CMDs): (F555W-F814W, F814W), (F336W-F555W, F814W), (F390M-F555W, F814W), and (F390W-F555W, F814W). Using empirical corrections, we tested the accuracy and spread of the photometric metallicities assigned from CMDs and color-color diagrams (which are necessary to break the age-metallicity degeneracy). Testing three color-color diagrams [(F336W-F555W),(F390M-F555W),(F390W-F555W), versus (F555W-F814W)], we found the colors (F390M-F555W) and (F390W-F555W) to be the best suited to measure photometric metallicities. The color (F390W-F555W) requires much less integration time, but generally produces wider metallicity distributions and, at very low metallicity, the metallicity distribution function (MDF) from (F390W-F555W) is ?60% wider than that from (F390M-F555W). Using the calibrated isochrones, we recovered the overall cluster metallicity to within ?0.1 dex in [Fe/H] when using CMDs (i.e., when the distance, reddening, and ages are approximately known). The measured MDF from color-color diagrams shows that this method measures metallicities of stellar clusters of unknown age and metallicity with an accuracy of ?0.2-0.5 dex using F336W-F555W, ?0.15-0.25 dex using F390M-F555W, and ?0.2-0.4 dex with F390W-F555W, with the larger uncertainty pertaining to the lowest metallicity range.

  3. The Software Design for the Wide-Field Infrared Explorer Attitude Control System

    NASA Technical Reports Server (NTRS)

    Anderson, Mark O.; Barnes, Kenneth C.; Melhorn, Charles M.; Phillips, Tom

    1998-01-01

    The Wide-Field Infrared Explorer (WIRE), currently scheduled for launch in September 1998, is the fifth of five spacecraft in the NASA/Goddard Small Explorer (SMEX) series. This paper presents the design of WIRE's Attitude Control System flight software (ACS FSW). WIRE is a momentum-biased, three-axis stabilized stellar pointer which provides high-accuracy pointing and autonomous acquisition for eight to ten stellar targets per orbit. WIRE's short mission life and limited cryogen supply motivate requirements for Sun and Earth avoidance constraints which are designed to prevent catastrophic instrument damage and to minimize the heat load on the cryostat. The FSW implements autonomous fault detection and handling (FDH) to enforce these instrument constraints and to perform several other checks which insure the safety of the spacecraft. The ACS FSW implements modules for sensor data processing, attitude determination, attitude control, guide star acquisition, actuator command generation, command/telemetry processing, and FDH. These software components are integrated with a hierarchical control mode managing module that dictates which software components are currently active. The lowest mode in the hierarchy is the 'safest' one, in the sense that it utilizes a minimal complement of sensors and actuators to keep the spacecraft in a stable configuration (power and pointing constraints are maintained). As higher modes in the hierarchy are achieved, the various software functions are activated by the mode manager, and an increasing level of attitude control accuracy is provided. If FDH detects a constraint violation or other anomaly, it triggers a safing transition to a lower control mode. The WIRE ACS FSW satisfies all target acquisition and pointing accuracy requirements, enforces all pointing constraints, provides the ground with a simple means for reconfiguring the system via table load, and meets all the demands of its real-time embedded environment (16 MHz Intel 80386 processor with 80387 coprocessor running under the VRTX operating system). The mode manager organizes and controls all the software modules used to accomplish these goals, and in particular, the FDH module is tightly coupled with the mode manager.

  4. Near Earth Architectural Options for a Future Deep Space Optical Communications Network

    NASA Technical Reports Server (NTRS)

    Edwards, B. L.; Liebrecht, P. E.; Fitzgerald, R. J.

    2003-01-01

    In the near future the National Aeronautics and Space Administration anticipates a significant increase in demand for long-haul communications services from deep space to Earth. Distances will range from 0.1 to 40 AU, with data rate requirements in the 1's to 1000's of Mbits/second. The near term demand is driven by NASA's Space Science Enterprise which wishes to deploy more capable instruments onboard spacecraft and increase the number of deep space missions. The long term demand is driven by missions with extreme communications challenges such as very high data rates from the outer planets, supporting sub-surface exploration, or supporting NASA's Human Exploration and Development of Space Enterprise beyond Earth orbit. Laser communications is a revolutionary communications technology that will dramatically increase NASA's ability to transmit information across the solar system. Lasercom sends information using beams of light and optical elements, such as telescopes and optical amplifiers, rather than RF signals, amplifiers, and antennas. This paper provides an overview of different network options at Earth to meet NASA's deep space lasercom requirements. It is based mainly on work done for the Mars Laser Communications Demonstration Project, a joint project between NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). It reports preliminary conclusions from the Mars Lasercom Study conducted at MIT/LL and on additional work done for the Tracking and Data Relay Satellite System Continuation Study at GSFC. A lasercom flight terminal will be flown on the Mars Telesat Orbiter (MTO) to be launched by NASA in 2009, and will be the first high rate deep space demonstration of this revolutionary technology.

  5. Image-based calibration of a deformable mirror in wide-field microscopy

    E-print Network

    Holy, Timothy

    techniques such as light-sheet microscopy. In principle, image quality might be improved by adaptive optics called objective coupled pla- nar illumination microscopy (OCPI) [5]. In typical light-sheet microscopy to be illuminated and allows the entire illuminated plane to be imaged simultaneously. Thus light-sheet microscopy

  6. Future aspects of cellular and molecular research in clinical voice treatment aspects of optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Pedersen, Mette; Mahmood, Sanila

    2015-02-01

    Focus is upon our clinical experience in a prospective cohort study on cure of dystonia where the mode of treatment was fexofenadine tablets and local budesonide inhaler in the larynx, and in a randomized controlled trial of lifestyle change related to acid provocation of food and habits in laryngopharyngeal reflux (LPR). The advanced high-speed films is one new tool, another being optical coherence tomography (OCT), which should be used in the future in randomized controlled trials. We are focusing on OCT of the swallowing process in the oesophagaus and larynx as well as the vocal fold function. It can be shown on OCT how the layer of the vocal folds develop, possibly corresponding to hormonal and paediatric development. The arytenoid area in the larynx should also be focused upon with OCT in pathology. The thyroid function is related to voice and the swallowing function, both hormonally and pathoanatomically. We know too little about voice and thyroid hormones in an updated way as well as the outer anatomic supporting muscular structure of the larynx, related to thyroid immune degeneration and cysts. Also, here OCT analyses might be of value.

  7. Wide Field/Planetary Camera (WF/PC) contamination control assessment

    NASA Technical Reports Server (NTRS)

    Maag, C.; Millard, J.; Anderson, M.

    1988-01-01

    The major concern of this study was the formation of a haze on the transmissive optics when exposed to a vacuum environment. The phenomena was determined to be a result of molecular transport from a low outgassing structural adhesive. Detailed analysis, both chemical and analytical, were conducted to assess the formation of the haze. Results of the study are given as well as information on clean-up and problem elimination.

  8. Compressive imaging for difference image formation and wide-field-of-view target tracking

    Microsoft Academic Search

    Shikhar

    2010-01-01

    Use of imaging systems for performing various situational awareness tasks in military and commercial settings has a long history. There is increasing recognition, however, that a much better job can be done by developing non-traditional optical systems that exploit the task-specific system aspects within the imager itself. In some cases, a direct consequence of this approach can be real-time data

  9. The wide field imager for the International X-ray Observatory

    NASA Astrophysics Data System (ADS)

    Treis, J.; Bombelli, L.; Fiorini, C.; Herrmann, S.; Lauf, T.; Lechner, P.; Lutz, G.; Majewski, P.; Porro, M.; Richter, R. H.; Stefanescu, A.; Strüder, L.; de Vita, G.

    2009-08-01

    The large collecting area of the X-ray optics on the International X-ray Observatory (IXO), their good angular resolution, the wide bandwidth of X-ray energies and the high radiation tolerance required for the X-ray detectors in the focal plane have stimulated a new development of devices which unify all those science driven specifications in one single detector. The concept of a monolithic, back-illuminated silicon active pixel sensor (APS) based on the DEPFET structure is proposed for the IXO mission, being a fully depleted, back-illuminated 450 ?m thick detector with a physical size of about 10 × 10 cm2 corresponding to the 18 arcmin field of view. The backside will be covered with an integrated optical light and UV-filter. Corresponding to the 5 arcsec angular resolution of the X-ray optics, 100 x 100 cm2 large pixels in a format of approximately 1024 x 1024 are envisaged, matching the point spread function of approximately 500 ?m HEW of the optics. The energy range from 100 eV to 15 keV is achieved by an ultra thin radiation entrance window for the low energies and 450 ?m depleted silicon thickness for higher energies. The fast readout of 1.000 full frames per second is realized by a dedicated analog CMOS front end amplifier IC. The detector device is intrinsically radiation hard. The leakage current from the bulk damage is controlled through the operation temperature around -60 °C and by the high readout speed. Results of various prototype measurements will be shown.

  10. HAWK-I: A new wide-field 1- to 2.5-?m imager for the VLT

    NASA Astrophysics Data System (ADS)

    Pirard, Jean-Francois; Kissler-Patig, Markus; Moorwood, Alan; Biereichel, Peter; Delabre, Bernard; Dorn, Reinhold; Finger, Gert; Gojak, Domingo; Huster, Gotthard; Jung, Yves; Koch, Franz; Le Louarn, Miska; Lizon, Jean-Louis; Mehrgan, Leander; Pozna, Esther; Silber, Armin; Sokar, Barbara; Stegmeier, Joerg

    2004-09-01

    HAWK-I (High Acuity, Wide field K-band Imaging) is a 0.9 ?m - 2.5 ?m wide field near infrared imager designed to sample the best images delivered over a large field of 7.5 arcmin x 7.5 arcmin. HAWK-I is a cryogenic instrument to be installed on one of the Very Large Telescope Nasmyth foci. It employs a catadioptric design and the focal plane is equipped with a mosaic of four HAWAII 2 RG arrays. Two filter wheels allow to insert broad band and narrow band filters. The instrument is designed to remain compatible with an adaptive secondary system under study for the VLT.

  11. The cryo-mechanical design of SCUBA2: a wide-field imager for the James Clerk Maxwell Telescope

    Microsoft Academic Search

    David Gostick; Dave Montgomery; Bob Wall; Helen McGregor; Mark Cliffe; Adam Woodcraft; Fred Gannaway

    2004-01-01

    The SCUBA-2 instrument is a new wide-field imager under development for the James Clerk Maxwell Telescope on Mauna Kea in Hawaii and due to be operational in 2006. The instrument has two separate focal planes and is designed to observe simultaneously at wavelengths of 450 and 850mum. The instrument cryostat will weigh around 2500kg and has a volume of approximately

  12. Wide Field Planetary Camera 2 Observations of Leo A: A Predominantly Young Galaxy within the Local Group

    Microsoft Academic Search

    Eline Tolstoy; J. S. Gallagher; A. A. Cole; J. G. Hoessel; A. Saha; R. C. Dohm-Palmer; E. D. Skillman; Mario Mateo; D. Hurley-Keller

    1998-01-01

    The unprecedented detail of the Wide Field Planetary Camera 2 (WFPC2) color-magnitude diagrams (CMDs) of the resolved stellar population of Leo A presented here allows us to determine a new distance and an accurate star formation history for this extremely metal-poor Local Group dwarf irregular galaxy. From the position of the red clump, the helium-burning blue loops, and the tip

  13. Vegetation cover mapping in India using multi-temporal IRS Wide Field Sensor (WiFS) data

    Microsoft Academic Search

    P. K. Kumar Joshi; P. S. Roy; Sarnam Singh; Shefali Agrawal; Deepshikha Yadav

    2006-01-01

    In this study, we explored the potential of multi-temporal IRS Wide Field Sensor (WiFS) data for mapping of vegetation cover types in India. A vegetation cover type map was generated from a hybrid approach (supervised and unsupervised) classification of 8–10 months IRS WiFS composite data (Raw bands, Max NDVI) over the period of 1998 to 1999. The study has identified 35

  14. Wide-Field MultiParameter FLIM: Long-Term Minimal Invasive Observation of Proteins in Living Cells

    Microsoft Academic Search

    Marco Vitali; Fernando Picazo; Yury Prokazov; Alessandro Duci; Evgeny Turbin; Christian Götze; Juan Llopis; Roland Hartig; Antonie J. W. G. Visser; Werner Zuschratter; Laurent Kreplak

    2011-01-01

    Time-domain Fluorescence Lifetime Imaging Microscopy (FLIM) is a remarkable tool to monitor the dynamics of fluorophore-tagged protein domains inside living cells. We propose a Wide-Field Multi-Parameter FLIM method (WFMP-FLIM) aimed to monitor continuously living cells under minimum light intensity at a given illumination energy dose. A powerful data analysis technique applied to the WFMP-FLIM data sets allows to optimize the

  15. A one-meter aperture wide-field camera for the Japanese exposure module on space station

    Microsoft Academic Search

    Carl Pennypacker; Toshi Ebisuzaki; Toshihiro Handa; Peter Nugent; Andrew Fruchter; Reynald Pain; Greg Aldering; Francois Hammer; Don Groom; Yoshi Takahashi; James Hadaway; Ariel Goobar; Ken Nomoto; Maria Isaac; Gerson Goldhaber; Saul Perlmutter; John MacKenty; David Branch; Olga Tsiopa; Yuri Gnedin; Josef Jochum

    1999-01-01

    We propose to construct and deploy a one-meter, wide field camera for cosmological, science education and other studies and site it on the International Space Station's Japanese Exposure Module (JEM). The SHOUT Telescope (for S_pace H_ands-O_n U_niverse T_elescope) is an inexpensive powerful instrument that will yield some of the most significant measurements in astrophysics. The detector would consist of a

  16. Developments of optical clocks and their comparisons for future time reference

    NASA Astrophysics Data System (ADS)

    Koyama, Yasuhiro; Shiga, Nobuyasu; Yamaguchi, Atsushi; Goto, Tadahiro; Hanado, Yuko; Hosokawa, Mizuhiko; Fujieda, Miho; Hachisu, Hidekazu; Ido, Tetsuya; Kojima, Reiko; Kumagai, Motohiro; Li, Ying; Matsubara, Kensuke; Nagano, Shigeo

    2012-08-01

    Rapid developments of optical frequency standards have been so remarkable and it has been shown that the optical frequency standards have potential capabilities to improve the time reference. To realize the improved time reference, however, it is quite important to evaluate the accuracy and stability of the optical frequency standards and compare them located at different places. At National Institute of Information and Communications Technology (NICT), we have lately developed an optical lattice clock using 87 Sr atoms and a single - ion optical frequency standard using a 40Ca+ ion. Besides the comparisons and evaluations of the two optical frequency standards inside the institute, they have been compared with the Sr optical lattice clock at the University of Tokyo (UT) by using a fiber link. It is also planned to compare with optical frequency standards in foreign institutes by using Global Positioning System receivers. The results of such recent activities will be presented.

  17. A new low cost wide-field illumination method for photooxidation of intracellular fluorescent markers.

    PubMed

    da Silva Filho, Manoel; Santos, Daniel Valle Vasconcelos; Costa, Kauê Machado

    2013-01-01

    Analyzing cell morphology is crucial in the fields of cell biology and neuroscience. One of the main methods for evaluating cell morphology is by using intracellular fluorescent markers, including various commercially available dyes and genetically encoded fluorescent proteins. These markers can be used as free radical sources in photooxidation reactions, which in the presence of diaminobenzidine (DAB) forms an opaque and electron-dense precipitate that remains localized within the cellular and organelle membranes. This method confers many methodological advantages for the investigator, including absence of photo-bleaching, high visual contrast and the possibility of correlating optical imaging with electron microscopy. However, current photooxidation techniques require the continuous use of fluorescent or confocal microscopes, which wastes valuable mercury lamp lifetime and limits the conversion process to a few cells at a time. We developed a low cost optical apparatus for performing photooxidation reactions and propose a new procedure that solves these methodological restrictions. Our "photooxidizer" consists of a high power light emitting diode (LED) associated with a custom aluminum and acrylic case and a microchip-controlled current source. We demonstrate the efficacy of our method by converting intracellular DiI in samples of developing rat neocortex and post-mortem human retina. DiI crystals were inserted in the tissue and allowed to diffuse for 20 days. The samples were then processed with the new photooxidation technique and analyzed under optical microscopy. The results show that our protocols can unveil the fine morphology of neurons in detail. Cellular structures such as axons, dendrites and spine-like appendages were well defined. In addition to its low cost, simplicity and reliability, our method precludes the use of microscope lamps for photooxidation and allows the processing of many labeled cells simultaneously in relatively large tissue samples with high efficacy. PMID:23441199

  18. Method of achieving a wide field-of-view head-mounted display with small distortion.

    PubMed

    Yang, Jianming; Liu, Weiqi; Lv, Weizhen; Zhang, Daliang; He, Fei; Wei, Zhonglun; Kang, Yusi

    2013-06-15

    We present a method of achieving a wide-angle, lightweight, optical see-through, distortion-free head-mounted display (HMD) by using two similar ellipsoids. An HMD that achieves a single channel field-of-view (FOV) of 120°×120° with a 6 mm eye box and a total binocular FOV of 160°×120° with an 80° field overlap is designed as an example. This method can solve the complex tiling problem and the distortion problem of other catadioptric structures. This structure is used to offset distortion and correct aberrations. PMID:23938968

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

    NASA Technical Reports Server (NTRS)

    Fazio, G. G.

    1986-01-01

    IRAC focal plane detector technology was developed and studies of alternate focal plane configurations were supported. While any of the alternate focal planes under consideration would have a major impact on the Infrared Array Camera, it was possible to proceed with detector development and optical analysis research based on the proposed design since, to a large degree, the studies undertaken are generic to any SIRTF imaging instrument. Development of the proposed instrument was also important in a situation in which none of the alternate configurations has received the approval of the Science Working Group.

  20. THE CLOSELY POSITIONED THREE RADIO TRANSIENTS IN THE NASU 1.4 GHz WIDE-FIELD SURVEY

    SciTech Connect

    Matsumura, N.; Niinuma, K.; Kuniyoshi, M.; Takefuji, K.; Asuma, K.; Daishido, T. [Institute for Astrophysics, Project Research Institutes, Comprehensive Research Organization, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Kida, S.; Tanaka, T.; Aoki, T.; Ishikawa, S.; Hirano, K.; Nakagawa, S. [Astrophysics, Major in Pure and Applied Physics, Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)], E-mail: nob.matsumura@gmail.com

    2009-09-15

    In 2004, we started the Nasu 1.4 GHz wide-field survey to study the dynamic universe by simultaneously performing the surveillance of the wide-field sky. We have detected six radio transients with flux densities larger than 1 Jy. In this paper, we report the detection of three new radio transients in the drift-scanning observations at {delta} {approx} +41.{sup 0}7. Based on their positions in the sky and flux densities, we considered the candidate types of astronomical objects for transients. As a result, it is suggested that the three radio transients could be massive radio flares associated with known extragalactic sources, such as active galactic nuclei, which are usually very faint in X-ray and radio wavelengths. The three transients were found in the sky of 2{sup 0} x 1{sup 0}, while nine transients, including the three transients reported in this paper, are distributed at both high and low Galactic latitude. According to the observational results, we suggest that the wide-field survey simultaneously performed would be useful in searching for radio transients to study the dynamic radio sky.

  1. Current and future activities in the area of optical space communications in Japan

    Microsoft Academic Search

    Masayuki Fujise; Ken'ichi Araki; Hiroshi Arikawa; Yoji Furuhama

    1991-01-01

    An account is given of current and prospective activities in Japan in the field of optical space communications (OSC) and its associated optical technologies. These activities are conducted by NASDA, the Advanced Telecommunications Research Institute, and the Ministry of Posts and Telecommunications. Attention is given to such initiatives as high-precision tracking, bidirectional OSC, laser beam propagation, optical ground stations, and

  2. Results of Kirari optical communication demonstration experiments with NICT optical ground station (KODEN) aiming for future classical and quantum communications in space

    NASA Astrophysics Data System (ADS)

    Toyoshima, Morio; Takenaka, Hideki; Shoji, Yozo; Takayama, Yoshihisa; Koyama, Yoshisada; Kunimori, Hiroo

    2012-05-01

    Bi-directional ground-to-satellite laser communication experiments were successfully performed between the optical ground station developed by the National Institute of Information and Communications Technology (NICT), located in Koganei City in suburban Tokyo, and a low earth orbit (LEO) satellite, the "Kirari" Optical Inter-orbit Communications Engineering Test Satellite (OICETS). The experiments were conducted in cooperation with the Japan Aerospace Exploration Agency (JAXA), and called the Kirari Optical communication Demonstration Experiments with the NICT optical ground station (or KODEN). The ground-to-OICETS laser communication experiment was the first in-orbit demonstration involving the LEO satellite. The laser communication experiment was conducted since March 2006. The polarization characteristics of an artificial laser source in space, such as Stokes parameters, and the degree of polarization were measured through space-to-ground atmospheric transmission paths, which results contribute to the link estimation for quantum key distribution via space and provide the potential for enhancements in quantum cryptography on a global scale in the future. The Phase-5 experiment, international laser communications experiments were also successfully conducted with four optical ground stations located in the United States, Spain, Germany, and Japan from April 2009 to September 2009. The purpose of the Phase-5 experiment was to establish OICETS-to-ground laser communication links from the different optical ground stations and the statistical analyses such as the normalized power, scintillation index, probability density function, auto-covariance function, and power spectral density were performed. Thus the applicability of the satellite laser communications was demonstrated, aiming not only for geostationary earth orbit-LEO links but also for ground-to-LEO optical links. This paper presents the results of the KODEN experiments and mainly introduces the common analyses among the different optical ground stations.

  3. Micro-optical resonators for microlasers and integrated optoelectronics recent advances and future challenges

    E-print Network

    Benson, T M; Sewell, P; Vukovic, A; Greedy, S C; Nosich, A I; Benson, Trevor M.; Boriskina, Svetlana V.; Sewell, Phillip; Vukovic, Ana; Greedy, Stephen C.; Nosich, Alexander I.

    2005-01-01

    Optical microcavities trap light in compact volumes by the mechanisms of almost total internal reflection or distributed Bragg reflection, enable light amplification, and select out specific (resonant) frequencies of light that can be emitted or coupled into optical guides, and lower the thresholds of lasing. Such resonators have radii from 1 to 100 mkm and can be fabricated in a wide range of materials. Devices based on optical resonators are essential for cavity quantum-electro-dynamic experiments, frequency stabilization, optical filtering and switching, light generation, biosensing, and nonlinear optics.

  4. Direct design approach to calculate a two-surface lens with an entrance pupil for application in wide field-of-view imaging

    NASA Astrophysics Data System (ADS)

    Nie, Yunfeng; Duerr, Fabian; Thienpont, Hugo

    2015-01-01

    In this work, a multifields optical design method aiming to calculate two high-order aspheric lens profiles with an embedded entrance pupil is proposed. This direct design algorithm is capable of partially coupling more than three ray bundles that enter the same pupil with only two surfaces. Both infinite and finite conjugate objectives can be designed with this approach. Additional constraints such as surface continuity and smoothness are taken into account to calculate smooth and accurate surface contours described by point clouds. The calculated points are then fitted with rotationally symmetric functions commonly used in optical design tools. A presented subaperture sampling strategy that introduces a weighting function for different fields allows for a very well-balanced imaging performance over a wide field of view (FOV). As an example, a ±45 deg f/7.5 wide-angle objective is designed and analyzed to demonstrate the potential of this design method. It provides an excellent starting point for further optimization of the surfaces' coefficients and initial design parameters, resulting in a very good and well-balanced imaging performance over the entire FOV.

  5. The Infrared Eye of the Wide-Field Camera 3 on the Hubble Space Telescope Reveals Multiple Main Sequences of Very Low Mass Stars in NGC 2808

    NASA Astrophysics Data System (ADS)

    Milone, A. P.; Marino, A. F.; Cassisi, S.; Piotto, G.; Bedin, L. R.; Anderson, J.; Allard, F.; Aparicio, A.; Bellini, A.; Buonanno, R.; Monelli, M.; Pietrinferni, A.

    2012-08-01

    We use images taken with the infrared channel of the Wide Field Camera 3 on the Hubble Space Telescope to study the multiple main sequences (MSs) of NGC 2808. Below the turnoff, the red, the middle, and the blue MS, previously detected from visual-band photometry, are visible over an interval of about 3.5 F160W magnitudes. The three MSs merge together at the level of the MS bend. At fainter magnitudes, the MS again splits into two components containing ~65% and ~35% of stars, with the most-populated MS being the bluest one. Theoretical isochrones suggest that the latter is connected to the red MS discovered in the optical color-magnitude diagram (CMD) and hence corresponds to the first stellar generation, having primordial helium and enhanced carbon and oxygen abundances. The less-populated MS in the faint part of the near-IR CMD is helium-rich and poor in carbon and oxygen, and it can be associated with the middle and the blue MS of the optical CMD. The finding that the photometric signature of abundance anti-correlation is also present in fully convective MS stars reinforces the inference that they have a primordial origin. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  6. Wide-field imaging design for a multiple-capillary DNA-sequencing system

    NASA Astrophysics Data System (ADS)

    Nay, Lyle M.; Sinclair, Robert; Swerdlow, Harold

    1997-05-01

    A laser-induced fluorescence detection system compatible with a capillary electrophoresis array was developed. The design incorporates fiber-optic excitation and a detection system including a diffraction grating and a CCD camera. The system employs no moving parts and is capable of producing data comparable to commercially available systems. It is based on a spectrally-resolved four-dye sequencing scheme. The conceptual design was proven, however, refinements must be made to optimize performance for high-throughput capillary-array DNA sequencing. Automated sample preparation and loading in combination with a refillable separation- matrix capillary-array system could prove to be an invaluable tool for completion of the Human Genome Project.

  7. Toward increasing the accuracy and realism of future optical turbulence calculations

    Microsoft Academic Search

    A. Tunick

    2005-01-01

    Due to the increased use of laser and ground-to-satellite communications the need for reliable optical turbulence information is growing. Optical turbulence information is important because it describes an atmospheric effect that can degrade the performance of electromagnetic systems and sensors, e.g., free-space optical communications and infrared imaging. However, analysis of selected past research indicates that there are some areas (i.e.,

  8. Wide field imaging of solar system objects with an 8192 x 8192 CCD mosaic

    NASA Technical Reports Server (NTRS)

    Hall, Donald N. B.

    1995-01-01

    As part of this program, we successfully completed the construction of the world's largest CCD camera, an 8192 x 8192 CCD mosaic. The system employs 8 2K x 4K 3-edge buttable CCDs arranged in a 2 x 4 chip mosaic. The focal plane has small gaps (less than 1 mm) between mosaic elements and measures over 120 mm x 120 mm. The initial set of frontside illuminated CCDs were developed with Loral-Fairchild in a custom foundry run. The initial lots yielded of order 20 to 25 functional devices, of which we selected the best eight for inclusion for the camera. We have designed a custom 3-edge-buttable package that ensures the CCD dies are mounted flat to plus or minus 10 microns over the entire area of the mosaic. The mosaic camera system consists of eight separate readout signal chains controlled by two independent DSP microcontrollers. These are in turn interfaced to a Sun Sparc-10 workstation through two high speed fiber optic interfaces. The system saw first-light on the Canada-France-Hawaii Telescope on Mauna Kea in March 1995. First-light on the University of Hawaii 2.2-M Telescope on Mauna Kea was in July 1995. Both runs were quite successful. A sample of some of the early science from the first light run is reported in the publication, 'Observations of Weak Lensing in Clusters with an 8192 x 8192 CCD Mosaic Camera'.

  9. Wide-field flexible endoscope for simultaneous color and NIR fluorescence image acquisition during surveillance colonoscopy

    NASA Astrophysics Data System (ADS)

    García-Allende, P. Beatriz; Nagengast, Wouter B.; Glatz, Jürgen; Ntziachristos, Vasilis

    2013-03-01

    Colorectal cancer (CRC) is the third most common form of cancer and, despite recent declines in both incidence and mortality, it still remains the second leading cause of cancer-related deaths in the western world. Colonoscopy is the standard for detection and removal of premalignant lesions to prevent CRC. The major challenges that physicians face during surveillance colonoscopy are the high adenoma miss-rates and the lack of functional information to facilitate decision-making concerning which lesions to remove. Targeted imaging with NIR fluorescence would address these limitations. Tissue penetration is increased in the NIR range while the combination with targeted NIR fluorescent agents provides molecularly specific detection of cancer cells, i.e. a red-flag detection strategy that allows tumor imaging with optimal sensitivity and specificity. The development of a flexible endoscopic fluorescence imaging method that can be integrated with standard medical endoscopes and facilitates the clinical use of this potential is described in this work. A semi-disposable coherent fiber optic imaging bundle that is traditionally employed in the exploration of biliary and pancreatic ducts is proposed, since it is long and thin enough to be guided through the working channel of a traditional video colonoscope allowing visualization of proximal lesions in the colon. A custom developed zoom system magnifies the image of the proximal end of the imaging bundle to fill the dimensions of two cameras operating in parallel providing the simultaneous color and fluorescence video acquisition.

  10. Thermostructural Analysis of the SOFIA Fine Field and Wide Field Imagers Subjected to Convective Thermal Shock

    NASA Technical Reports Server (NTRS)

    Kostyk, Christopher B.

    2012-01-01

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is a highly modified Boeing 747-SP with a 17- ton infrared telescope installed in the aft portion of the aircraft. Unlike ground- and space-based platforms, SOFIA can deploy to make observations anytime, anywhere, in the world. The originally designed aircraft configuration included a ground pre-cool system, however, due to various factors in the history of the project, that system was not installed. This lack of ground pre-cooling was the source of the concern about whether or not the imagers would be exposed to a potentially unsafe thermostructural environment. This concern was in addition to the already-existing concern of some project members that the air temperature rate of change during flight (both at the same altitude as well as ascent or descent) could cause the imagers to be exposed to an unsafe thermostructural environment. Four optical components were identified as the components of concern: two of higher concern (one in each imager), and two of lower concern (one in each imager). The analysis effort began by analyzing one component, after which the analyses for the other components was deemed unnecessary. The purpose of this report is to document these findings as well as lessons learned from the effort.

  11. Enhanced signal coupling in wide-field fiber-coupled imagers.

    PubMed

    Arianpour, Ashkan; Motamedi, Nojan; Agurok, Ilya P; Ford, Joseph E

    2015-02-23

    Some high-performance imaging systems, including wide angle "monocentric" lenses made of concentric spherical shells, form a deeply curved image surface coupled to focal plane sensors by optical fiber bundles with a curved input and flat output face. However, refraction at the angled input facet limits the range of input angles, even for fiber bundles with numerical aperture 1. Here we investigate using a curved beam deflector near the focal surface to increase the field of view and improve spatial resolution at the edges of the field of view. We show the field of view of such an imager can be increased from approximately 60° (full width at half maximum intensity) to over 90° using an embossed refractive microprism array, where the prism angle varies across the aperture to maintain coupling. We describe a proof-of-principle experiment using a f = 17.8mm fiber-coupled monocentric singlet lens, and show that a local region of microprisms embossed into a thin layer of SU-8 photopolymer can increase the field of view by 50%. PMID:25836560

  12. Megacam: A Wide-Field CCD Imager for the MMT and Magellan

    NASA Astrophysics Data System (ADS)

    McLeod, Brian; Geary, John; Conroy, Maureen; Fabricant, Daniel; Ordway, Mark; Szentgyorgyi, Andrew; Amato, Stephen; Ashby, Matthew; Caldwell, Nelson; Curley, Dylan; Gauron, Thomas; Holman, Matthew; Norton, Timothy; Pieri, Mario; Roll, John; Weaver, David; Zajac, Joseph; Palunas, Povilas; Osip, David

    2015-04-01

    Megacam is a large-format optical camera that can be operated at the f/5 Cassegrain foci of the MMT on Mount Hopkins, Arizona, and the Magellan Clay telescope at Las Campanas Observatory, Chile. Megacam's focal plane is composed of 36 closely packed e2v CCD42-90 CCDs, each with 2048 × 4608 pixels, assembled in an 18,432 × 18,432 array. Two additional CCD42-90s are provided for autoguiding and focus control. The CCDs have 13.5 ?m square pixels that subtend at the f/5 foci, yielding a 25' × 25' field-of-view. The camera system includes a focal plane shutter, two filter wheels, two liquid nitrogen reservoirs, a central chamber that holds the CCD mosaic array, and two electronics boxes. Megacam is equipped with a variety of broadband and narrowband filters. Software features include automatic calculation of twilight flat exposure times.

  13. Thermostructural Analysis of the SOFIA Fine Field and Wide Field Imagers Subjected to Convective Thermal Shock

    NASA Technical Reports Server (NTRS)

    Kostyk, Chris

    2011-01-01

    The originally designed SOFIA aircraft configuration included a system to pre-cool the telescope cavity on the ground before flight, however, due to various factors in the history of the project that system was not installed. This lack of ground pre-cooling was thus the source of the concern over whether or not the imagers would be exposed to a potentially unsafe thermostructural environment when the telescope cavity door was opened at altitude. This concern was in addition to the already existing concern that the air temperature rate of change during flight (both at the same altitude as well as ascent or descent) could cause the imagers to be exposed to an unsafe thermostructural environment. Four optical components were identified as the components of concern - two of higher concern (one in each imager) and two of lower concern (one in each imager). The requirement was to perform transient, coupled thermostructural analyses to determine whether the stress would ever achieve unsafe levels in these components. The analysis effort began by analyzing one component, after which the analyses for the other components was deemed unnecessary.

  14. Wide Field Astronomy at Dome C: two IR surveys complementary to SNAP

    E-print Network

    D. Burgarella; M. Ferrari; T. Fusco; M. Langlois; B. Leroux; G. Moretto; M. Nicole

    2006-11-17

    Surveys provide a wealth of data to the astronomical community that are used well after their completion. In this paper, we propose a project that would take the maximum benefit of Dome C in Antarctica by performing two surveys, in the wavelength range from 1-5 micron, complementary to SNAP space surveys. The first one over 1000 sq. deg. (1 KdF) for 4 years and the second one over 15 sq. deg (SNAP-IR) for the next 4 years at the same time as SNAP 0.35-1.7 microns survey. By using a Ground-Layer Adaptive Optics system, we would be able to recover, at the ice level and over at least half a degree in radius, the 300 mas angular resolution available above the 30-m high turbulent layer. Such a survey, combining a high angular resolution with high sensitivities in the NIR and MIR, should also play the role of a pre-survey for JWST and ALMA.

  15. SITELLE: a wide-field imaging Fourier transform spectrometer for the Canada-France-Hawaii Telescope

    NASA Astrophysics Data System (ADS)

    Drissen, L.; Bernier, A.-P.; Rousseau-Nepton, L.; Alarie, A.; Robert, C.; Joncas, G.; Thibault, S.; Grandmont, F.

    2010-07-01

    We describe the concept of a new instrument for the Canada-France-Hawaii telescope (CFHT), SITELLE (Spectromètre Imageur à Transformée de Fourier pour l'Etude en Long et en Large de raies d'Emission), as well as a science case and a technical study of its preliminary design. SITELLE will be an imaging Fourier transform spectrometer capable of obtaining the visible (350 nm - 950 nm) spectrum of every source of light in a field of view of 15 arcminutes, with 100% spatial coverage and a spectral resolution ranging from R = 1 (deep panchromatic image) to R = 104 (for gas dynamics). SITELLE will cover a field of view 100 to 1000 times larger than traditional integral field spectrographs, such as GMOS-IFU on Gemini or the future MUSE on the VLT. It is a legacy from BEAR, the first imaging FTS installed on the CFHT and the direct successor of SpIOMM, a similar instrument attached to the 1.6-m telescope of the Observatoire du Mont-Mégantic in Québec. SITELLE will be used to study the structure and kinematics of HII regions and ejecta around evolved stars in the Milky Way, emission-line stars in clusters, abundances in nearby gas-rich galaxies, and the star formation rate in distant galaxies.

  16. X-RAY GROUPS OF GALAXIES IN THE AEGIS DEEP AND WIDE FIELDS

    SciTech Connect

    Erfanianfar, G.; Lerchster, M.; Nandra, K.; Connelly, J. L.; Mirkazemi, M. [Max Planck-Institute for Extraterrestrial Physics, P.O. Box 1312, Giessenbachstr. 1., D-85741 Garching (Germany); Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Haellstroemin katu 2a, FI-00014 Helsinki (Finland); Tanaka, M. [Institute for the Physics and Mathematics of the Universe, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583 (Japan); Laird, E. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Bielby, R. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Faber, S. M.; Kocevski, D.; Jeltema, T. [UCO/Lick Observatories, Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Cooper, M. [Center for Galaxy Evolution, Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); Newman, J. A. [Department of Physics and Astronomy, University of Pittsburgh, 401-C Allen Hall, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States); Coil, A. L. [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, MC 0424, San Diego, CA 92093 (United States); Brimioulle, F. [University Observatory Munich, Ludwigs-Maximilians University Munich, Scheinerstr. 1, D-81679 Munich (Germany); Davis, M. [Department of Astronomy, University of California, Berkeley, Berkeley, CA 94720 (United States); McCracken, H. J. [Institut d'Astrophysique de Paris, UMR 7095 CNRS, Universite Pierre et Marie Curie, 98 bis boulevard Arago, F-75014 Paris (France); Willmer, C. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Gerke, B., E-mail: erfanian@mpe.mpg.de [Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 90R4000, Berkeley, CA 94720 (United States); and others

    2013-03-10

    We present the results of a search for extended X-ray sources and their corresponding galaxy groups from 800 ks Chandra coverage of the All-wavelength Extended Groth Strip International Survey (AEGIS). This yields one of the largest X-ray-selected galaxy group catalogs from a blind survey to date. The red-sequence technique and spectroscopic redshifts allow us to identify 100% of reliable sources, leading to a catalog of 52 galaxy groups. These groups span the redshift range z {approx} 0.066-1.544 and virial mass range M{sub 200} {approx} 1.34 Multiplication-Sign 10{sup 13}-1.33 Multiplication-Sign 10{sup 14} M{sub Sun }. For the 49 extended sources that lie within DEEP2 and DEEP3 Galaxy Redshift Survey coverage, we identify spectroscopic counterparts and determine velocity dispersions. We select member galaxies by applying different cuts along the line of sight or in projected spatial coordinates. A constant cut along the line of sight can cause a large scatter in scaling relations in low-mass or high-mass systems depending on the size of the cut. A velocity-dispersion-based virial radius can cause a larger overestimation of velocity dispersion in comparison to an X-ray-based virial radius for low-mass systems. There is no significant difference between these two radial cuts for more massive systems. Independent of radial cut, an overestimation of velocity dispersion can be created in the case of the existence of significant substructure and compactness in X-ray emission, which mostly occur in low-mass systems. We also present a comparison between X-ray galaxy groups and optical galaxy groups detected using the Voronoi-Delaunay method for DEEP2 data in this field.

  17. Lensfree Fluorescent On-Chip Imaging of Transgenic Caenorhabditis elegans Over an Ultra-Wide Field-of-View

    PubMed Central

    Ozcan, Aydogan

    2011-01-01

    We demonstrate lensfree on-chip fluorescent imaging of transgenic Caenorhabditis elegans (C. elegans) over an ultra-wide field-of-view (FOV) of e.g., >2–8 cm2 with a spatial resolution of ?10µm. This is the first time that a lensfree on-chip platform has successfully imaged fluorescent C. elegans samples. In our wide-field lensfree imaging platform, the transgenic samples are excited using a prism interface from the side, where the pump light is rejected through total internal reflection occurring at the bottom facet of the substrate. The emitted fluorescent signal from C. elegans samples is then recorded on a large area opto-electronic sensor-array over an FOV of e.g., >2–8 cm2, without the use of any lenses, thin-film interference filters or mechanical scanners. Because fluorescent emission rapidly diverges, such lensfree fluorescent images recorded on a chip look blurred due to broad point-spread-function of our platform. To combat this resolution challenge, we use a compressive sampling algorithm to uniquely decode the recorded lensfree fluorescent patterns into higher resolution images, demonstrating ?10 µm resolution. We tested the efficacy of this compressive decoding approach with different types of opto-electronic sensors to achieve a similar resolution level, independent of the imaging chip. We further demonstrate that this wide FOV lensfree fluorescent imaging platform can also perform sequential bright-field imaging of the same samples using partially-coherent lensfree digital in-line holography that is coupled from the top facet of the same prism used in fluorescent excitation. This unique combination permits ultra-wide field dual-mode imaging of C. elegans on a chip which could especially provide a useful tool for high-throughput screening applications in biomedical research. PMID:21253611

  18. Installing the Future. Fiber Optics Program Readies Students for Lucrative Jobs.

    ERIC Educational Resources Information Center

    Serrano, Kenneth M.

    1995-01-01

    A fiber optics program at Somerset County Technical Institute (SCTI) prepares college students and trades workers for telecommunication's new wave of installation. The program was born of a partnership among an electricians' union, AT&T, and SCTI to meet the expected need for fiber optic technicians. (JOW)

  19. High speed, high capacity ATM optical switches for future telecommunication transport networks

    Microsoft Academic Search

    F. Masetti; J. Benoit; F. Brillouet; J. M. Gabriagues; A. Jourdan; M. Renaud; D. Bottle; G. Eilenberger; K. Wiinstel; M. Schilling; D. Chiaroni; P. Gavignet; J. B. Jacob; G. Bendelli; P. Cinato; P. Gambini; M. Puleo; T. Martinson; P. Vogel; T. Durhuus; C. Joergensen; K. Stubkjaer; R. Baets; P. Van Daele; J. C. Bouley; R. Lefevre; M. Bachmann; W. Hunziker; H. Melchior; A. McGuire; F. Ratovelomanana; N. Vodjdani

    1996-01-01

    This paper describes the work carried out in the RACE Project R2039 ATMOS (asynchronous transfer mode optical switching). The project is briefly illustrated, together with its main goal: to develop and assess concepts and technology suitable for optical fast packet switching. The project's technical approach consisted in the exploitation of the space and wavelength domains for fast routing and buffering:

  20. Wide-Field Stellar Distributions around the Remote Young Galactic Globular Clusters Palomar 3 and Palomar 4

    Microsoft Academic Search

    Young-Jong Sohn; Jang-Hyun Park; Soo-Chang Rey; Young-Wook Lee; Ho-Il Kim; Seung Joon Oh; Sang-Gak Lee; Myung Gyoon Lee; Wonyong Han

    2003-01-01

    In a search for tidal extension features and\\/or streams of the probable parent satellite galaxies around the remote young globular clusters Pal 3 and Pal 4, we used wide-field VI photometry of an area a~1.3d×1.3d around Pal 3 and an area a~1.3d×0.9d around Pal 4, obtained with the CFH12K mosaic CCD. Applying the CMD-mask algorithm to stars in the vicinity

  1. VizieR Online Data Catalog: MYStIX Wide-Field NIR data: crowded fields (King+, 2013)

    NASA Astrophysics Data System (ADS)

    King, R. R.; Naylor, T.; Broos, P. S.; Getman, K. V.; Feigelson, E. D.

    2014-01-01

    The data were obtained using WFCAM, the IR wide-field camera on UKIRT in Hawaii for 11 regions (DR 21, Eagle Nebula, Lagoon Nebula, M 17, NGC 1893, NGC 2264, NGC 2362, NGC 6334, NGC 6357, Rosette Nebula and the Trifid Nebula). Roughly half the fields were observed as part of the Galactic Plane Survey (GPS; Lucas et al. 2008, Cat. II/316) component of UKIDSS with the remainder being obtained in Director's Discretionary Time (DDT) using identical observing procedures. (1 data file).

  2. High-resolution corneal topography and tomography of fish eye using wide-field white light interference microscopy

    NASA Astrophysics Data System (ADS)

    Srivastava, Vishal; Nandy, Sreyankar; Singh Mehta, Dalip

    2013-04-01

    Topography and tomography of fish cornea is reconstructed using high resolution white light interference microscopy. White light interferograms at different depths were recorded by moving the object axially. For each depth position, five phase shifted interferograms were recorded and analyzed. From the reconstructed phase maps, the corneal topography and hence the refractive index was determined and from amplitude images the cross-sectional image of fish cornea was reconstructed. In the present method, we utilize a nearly common-path interference microscope and wide field illumination and hence do not require any mechanical B-scan. Therefore, the phase stability of the recorded data is improved.

  3. WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF YOUNG STELLAR OBJECTS IN THE WESTERN CIRCINUS MOLECULAR CLOUD

    SciTech Connect

    Liu, Wilson M.; Fajardo-Acosta, Sergio [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Padgett, Deborah L. [Spitzer Science Center, California Institute of Technology, MC 314-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Leisawitz, David; Koenig, Xavier P., E-mail: wliu@ipac.caltech.edu [NASA Goddard Space Flight Center, Code 605, Greenbelt, MD 20771 (United States)

    2011-05-20

    The Wide-field Infrared Survey Explorer has uncovered a population of young stellar objects (YSOs) in the Western Circinus molecular cloud. Images show the YSOs to be clustered into two main groups that are coincident with dark filamentary structure in the nebulosity. Analysis of photometry shows numerous Class I and II objects. The locations of several of these objects are found to correspond to known dense cores and CO outflows. Class I objects tend to be concentrated in dense aggregates, and Class II objects more evenly distributed throughout the region.

  4. Matching a curved focal plane with CCD's - Wide field imaging of glancing incidence X-ray telescopes

    NASA Technical Reports Server (NTRS)

    Nousek, J. A.; Garmire, G. P.; Ricker, G. R.; Bautz, M. W.; Levine, A. M.; Collins, S. A.

    1987-01-01

    The design of a wide field imaging camera suitable for use with a glancing incidence X-ray telescope is complicated by the sharply concave nature of the optimum focal surface of such a telescope. Such a camera made up of a mosaic of CCDs is being designed which is intended for flight aboard the Advanced X-ray Astrophysics Facility (AXAF). The design rationale and tradeoffs are discussed, and the layout for the imaging CCD array is presented. The related issue of optimizing performance of transmission objective gratings is also discussed, and the array of CCD orientations suitable for this problem is presented.

  5. 3D-HST: A WIDE-FIELD GRISM SPECTROSCOPIC SURVEY WITH THE HUBBLE SPACE TELESCOPE

    SciTech Connect

    Brammer, Gabriel B. [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Van Dokkum, Pieter G.; Skelton, Rosalind E.; Nelson, Erica; Bezanson, Rachel; Leja, Joel; Lundgren, Britt [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Labbe, Ivo [Leiden Observatory, Leiden University, Leiden (Netherlands); Rix, Hans-Walter; Schmidt, Kasper B.; Da Cunha, Elisabete [Max Planck Institute for Astronomy (MPIA), Koenigstuhl 17, 69117 Heidelberg (Germany); Kriek, Mariska [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Erb, Dawn K. [Department of Physics, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201 (United States); Fan, Xiaohui [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Foerster Schreiber, Natascha [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Illingworth, Garth D.; Magee, Dan, E-mail: gbrammer@eso.org [Astronomy Department, University of California, Santa Cruz, CA 95064 (United States); and others

    2012-06-01

    We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for a sample of {approx}7000 galaxies at 1 < z < 3.5, the epoch when {approx}60% of all star formation took place, the number density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in galaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin{sup 2}) of the CANDELS Treasury survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of {approx}5 per resolution element at H{sub 140} {approx} 23.1 and a 5{sigma} emission-line sensitivity of {approx}5 Multiplication-Sign 10{sup -17} erg s{sup -1} cm{sup -2} for typical objects, improving by a factor of {approx}2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1 to 1.6 {mu}m at a spatial resolution of {approx}0.''13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary reduction and analysis of the grism observations, including emission-line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of {sigma}(z) = 0.0034(1 + z), or {sigma}(v) Almost-Equal-To 1000 km s{sup -1}. We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z = 4.7, quiescent galaxies at z {approx} 2, and the most distant T-type brown dwarf star known. The combination of the CANDELS and 3D-HST surveys will provide the definitive imaging and spectroscopic data set for studies of the 1 < z < 3.5 universe until the launch of the James Webb Space Telescope.

  6. Looking for Speed!! Go Optical Ultra-Fast Photonic Logic Gates for the Future Optical Communication and Computing

    NASA Technical Reports Server (NTRS)

    Abdeldayem, Hossin; Frazier, Donald O.; Penn, Benjamin; Paley, Mark S.

    2003-01-01

    Recently, we developed two ultra-fast all-optical switches in the nanosecond and picosecond regimes. The picosecond switch is made of a polydiacetylene thin film coated on the interior wall of a hollow capillary of approximately 50 micron diameter by a photo-polymerization process. In the setup a picosecond Nd:YAG laser at 10 Hz and at 532 nm with a pulse duration of approximately 40 ps was sent collinearly along a cw He-Ne laser beam and both were waveguided through the hollow capillary. The setup functioned as an Exclusive OR gate. On the other hand, the material used in the nanosecond switch is a phthalocyanine thin film, deposited on a glass substrate by a vapor deposition technique. In the setup a nanosecond, 10 Hz, Nd:YAG laser of 8 ns pulse duration was sent collinearly along a cw He-Ne laser beam and both were wave-guided through the phthalocyanine thin film. The setup in this case functioned as an all-optical AND logic gate. The characteristic table of the ExOR gate in polydiacetylene film was attributed to an excited state absorption process, while that of the AND gate was attributed to a saturation process of the first excited state. Both mechanisms were thoroughly investigated theoretically and found to agree remarkably well with the experimental results. An all-optical inverter gate has been designed but has not yet been demonstrated. The combination of all these three gates form the foundation for building all the necessary gates needed to build a prototype of an all-optical system.

  7. Wide-Field InfraRed Survey Telescope (WFIRST) Mission and Synergies with LISA and LIGO-Virgo

    NASA Astrophysics Data System (ADS)

    Gehrels, N.; Spergel, D.; the" post="">WFIRST SDT, Wide-Field InfraRed Survey Telescope (WFIRST) is a NASA space mission in study for launch in 2024. It has a 2.4 m telescope, wide-field IR instrument operating in the 0.7 - 2.0 micron range and an exoplanet imaging coronagraph instrument operating in the 400 - 1000 nm range. The observatory will perform galaxy surveys over thousands of square degrees to J=27 AB for dark energy weak lensing and baryon acoustic oscillation measurements and will monitor a few square degrees for dark energy SN Ia studies. It will perform microlensing observations of the galactic bulge for an exoplanet census and direct imaging observations of nearby exoplanets with a pathfinder coronagraph. The mission will have a robust and well- funded guest observer program for 25% of the observing time. WFIRST will be a powerful tool for time domain astronomy and for coordinated observations with gravitational wave experiments. Gravitational wave events produced by mergers of nearby binary neutron stars (LIGO-Virgo) or extragalactic supermassive black hole binaries (LISA) will produce electromagnetic radiation that WFIRST can observe.

  8. Phasor-based single-molecule fluorescence lifetime imaging using a wide-field photon-counting detector.

    PubMed

    Colyer, R; Siegmund, O; Tremsin, A; Vallerga, J; Weiss, S; Michalet, X

    2009-01-24

    Fluorescence lifetime imaging (FLIM) is a powerful approach to studying the immediate environment of molecules. For example, it is used in biology to study changes in the chemical environment, or to study binding processes, aggregation, and conformational changes by measuring Förster resonance energy transfer (FRET) between donor and acceptor fluorophores. FLIM can be acquired by time-domain measurements (time-correlated single-photon counting) or frequency-domain measurements (with PMT modulation or digital frequency domain acquisition) in a confocal setup, or with wide-field systems (using time-gated cameras). In the best cases, the resulting data is analyzed in terms of multicomponent fluorescence lifetime decays with demanding requirements in terms of signal level (and therefore limited frame rate). Recently, the phasor approach has been proposed as a powerful alternative for fluorescence lifetime analysis of FLIM, ensemble, and single-molecule experiments. Here we discuss the advantages of combining phasor analysis with a new type of FLIM acquisition hardware presented previously, consisting of a high temporal and spatial resolution wide-field single-photon counting device (the H33D detector). Experimental data with live cells and quantum dots will be presented as an illustration of this new approach. PMID:21625298

  9. Omega Prime: the wide-field near-infrared camera for the 3.5-m telescope of the Calar Alto Observatory

    NASA Astrophysics Data System (ADS)

    Bizenberger, Peter; McCaughrean, Mark J.; Birk, Christoph; Thompson, Dave; Storz, Clemens

    1998-08-01

    Omega Prime is a wide-field near-IR camera for the prime focus of the Calar Alto 3.5 m telescope in Spain. The detector is a 1024 X 1024 pixel HAWAII array made by Rockwell. The image scale is 0.4 arcsec/pixel, giving a field of view of 6.8 by 6.8 arcmin. In order to maximize the throughput, the optics were designed as a prime focus corrector with only three lenses. This simple design without a cold pupil provides an excellent image quality over the entire field of view. To reduce thermal background at wavelengths longer than 2.2 micrometers , Omega Prime has a series of cold internal baffles and an additional torodial mirror outside the dewar. This annular reflector causes detector pixels to 'see' mostly the cold interior of the camera. The camera has been in operation since May 1996 and has been used for a variety of scientific programs. Including a very deep K survey covering 1000 square arcmin to a 5 (sigma) limit for point-sources of 20.5 magnitude.

  10. CEPHEID PERIOD-LUMINOSITY RELATIONS IN THE NEAR-INFRARED AND THE DISTANCE TO M31 FROM THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    SciTech Connect

    Riess, Adam G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Fliri, Juergen; Valls-Gabaud, David, E-mail: ariess@stsci.edu, E-mail: jurgen.fliri@obspm.fr, E-mail: david.valls-gabaud@obspm.fr [LERMA, CNRS UMR 8112, Observatoire de Paris, 61 Avenue de l'Observatoire, F-75014 Paris (France)

    2012-02-01

    We present measurements of 68 classical Cepheids, most detected from the Canada-France-Hawaii Telescope POMME Survey, with periods from 10 to 78 days observed in the near-infrared by the Panchromatic Hubble Andromeda Treasury Program using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). The combination of HST's resolution and the use of near-infrared measurements provide a dramatic reduction in the dispersion of the period-luminosity relation over the present optical, ground-based data. Even using random phase magnitudes we measure a dispersion of just 0.17 mag, implying a dispersion of just 0.12 mag for mean magnitudes. The error in the mean for this relation is 1% in distance. Combined with similar observations of Cepheids in other hosts and independent distance determinations, we measure a distance to M31 of {mu}{sub 0} = 24.38 {+-} 0.06(statistical) {+-} 0.03(systematic), 752 {+-} 27 kpc, in good agreement with past measurements though with a better, 3% precision here. The result is also in good agreement with independent distance determinations from two detached eclipsing binaries allowing for an independent calibration of the Cepheid luminosities and a determination of the Hubble constant.

  11. MID-INFRARED SELECTION OF ACTIVE GALACTIC NUCLEI WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER. I. CHARACTERIZING WISE-SELECTED ACTIVE GALACTIC NUCLEI IN COSMOS

    SciTech Connect

    Stern, Daniel; Assef, Roberto J.; Eisenhardt, Peter [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Benford, Dominic J. [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Blain, Andrew [Department of Physics and Astronomy, University of Leicester, LE1 7RH Leicester (United Kingdom); Cutri, Roc; Griffith, Roger L.; Jarrett, T. H.; Masci, Frank; Tsai, Chao-Wei; Yan, Lin [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Dey, Arjun [National Optical Astronomical Observatory, 950 N. Cherry Ave., Tucson, AZ 85719 (United States); Lake, Sean; Petty, Sara; Wright, E. L. [Physics and Astronomy Department, University of California, Los Angeles, CA 90095 (United States); Stanford, S. A. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Harrison, Fiona; Madsen, Kristin, E-mail: daniel.k.stern@jpl.nasa.gov [Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-07-01

    The Wide-field Infrared Survey Explorer (WISE) is an extremely capable and efficient black hole finder. We present a simple mid-infrared color criterion, W1 - W2 {>=} 0.8 (i.e., [3.4]-[4.6] {>=}0.8, Vega), which identifies 61.9 {+-} 5.4 active galactic nucleus (AGN) candidates per deg{sup 2} to a depth of W2 {approx} 15.0. This implies a much larger census of luminous AGNs than found by typical wide-area surveys, attributable to the fact that mid-infrared selection identifies both unobscured (type 1) and obscured (type 2) AGNs. Optical and soft X-ray surveys alone are highly biased toward only unobscured AGNs, while this simple WISE selection likely identifies even heavily obscured, Compton-thick AGNs. Using deep, public data in the COSMOS field, we explore the properties of WISE-selected AGN candidates. At the mid-infrared depth considered, 160 {mu}Jy at 4.6 {mu}m, this simple criterion identifies 78% of Spitzer mid-infrared AGN candidates according to the criteria of Stern et al. and the reliability is 95%. We explore the demographics, multiwavelength properties and redshift distribution of WISE-selected AGN candidates in the COSMOS field.

  12. Applications of Optical Fiber Assemblies in Harsh Environments, the Journey Past, Present and Future

    NASA Technical Reports Server (NTRS)

    Ott, Melanie N.; LaRocca, Frank; Thomas, William Joe; Switzer, Robert; Chuska, Richard; Macmurphy, Shawn

    2008-01-01

    Over the past ten years, NASA has studied the effects of harsh environments on optical fiber assemblies for communication systems, lidar systems, and science missions. The culmination of this has resulted in recent technologies that are unique and tailored to meeting difficult requirements under challenging performance constraints. This presentation will focus on the past mission applications of optical fiber assemblies including; qualification information, lessons learned and new technological advances that will enable the road ahead.

  13. Thermal Vacuum Test Performance of the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Variable Conductance Heat Pipe Assembly

    NASA Technical Reports Server (NTRS)

    Cleveland, Paul E.; Buchko, Matthew T.; Stavely, Richard A.; Simpson, Alda (Technical Monitor)

    2002-01-01

    The Hubble Space Telescope (HST) is one of NASA s premier astronomical observatories. A unique design feature of the spacecraft is its capacity to be serviced and refurbished on-orbit. Repairs to the HST are made during events called Servicing Missions (SM). The SM consists of several phases that include: shuttle launch, ascent, rendezvous with HST, grapple, Extra Vehicular Activity (EVA) servicing, redeployment of the HST, shuttle entry and landing. The purpose of a SM is to upgrade the HST scientific capabilities and to repair or replace failed equipment. The benefit of the SM is to enhance the scientific capability of the HST and to extend its operational lifetime to a decade or more. Extra Vehicular Activity (EVA) days, the crew will replace the Wide Field Planetary Camera II (WFPCII) with the Wide Field Camera 3 (WFC3). The HST slot for these instruments is the "-V3 Radial Instrument" position. Servicing Mission 4 (SM-4) is currently scheduled for Spring 2005. During one of the five The WFC3 contains both Ultraviolet and Infrared detectors. Due to the differing thermal requirements for these items and their associated assemblies, the WFC3 contains several thermal subsystems within the instrument enclosure. One of these subsystems is the Variable Conductance Heat Pipe (VCHP) assembly. contains an integral constant conductance heat pipe (CCHP); a variable conductance heat pipe (VCHP); and a VCHP reservoir radiator (offset from the main WFC3 external radiator). The VCHP condenser utilizes the main WFC3 external radiator to reject its heat to space. The WFC3 VCHP assembly consists of the Optical Bench Cold Plate (OBCP), which The primary challenge for the VCHP assembly is to maintain the OBCP at -5 C +/- 2 C for various heat loads while subject to a 90-minute orbit cycling environment which ranges from 0 C to -143 C. Key components that provide active control include a 10 W heater system, the reservoir, and a proportional controller. This paper summarizes the overall thermal vacuum test program for the VCHP assembly. This includes performance during the 90-minute orbit cycling case, maximum capacity case, and cold system shut down case. The test was conducted in Building 7, Chamber #237 at the NASA/Goddard Space Flight Center. It lasted approximately fourteen days, from 5-28-02 to 6-10-02. Included in this paper is a comparison of the results with thermal model temperature predictions.

  14. Prime focus spectrograph: Subaru's future

    NASA Astrophysics Data System (ADS)

    Sugai, Hajime; Karoji, Hiroshi; Takato, Naruhisa; Tamura, Naoyuki; Shimono, Atsushi; Ohyama, Youichi; Ueda, Akitoshi; Ling, Hung-Hsu; Vital de Arruda, Marcio; Barkhouser, Robert H.; Bennett, Charles L.; Bickerton, Steve; Braun, David F.; Bruno, Robin J.; Carr, Michael A.; Batista de Carvalho Oliveira, João.; Chang, Yin-Chang; Chen, Hsin-Yo; Dekany, Richard G.; Pereira Dominici, Tania; Ellis, Richard S.; Fisher, Charles D.; Gunn, James E.; Heckman, Timothy; Ho, Paul T. P.; Hu, Yen-Shan; Jaquet, Marc; Karr, Jennifer; Kimura, Masahiko; Le Fèvre, Olivier C.; Le Mignant, David; Loomis, Craig; Lupton, Robert H.; Madec, Fabrice; Marrara, Lucas; Martin, Laurent; Murayama, Hitoshi; Cesar de Oliveira, Antonio; Mendes de Oliveira, Claudia; Souza de Oliveira, Ligia; Orndorff, Joseph D.; de Paiva Vilaça, Rodrigo M. P.; Macanhan, Vanessa B. d. P.; Prieto, Eric; Bispo dos Santos, Jesulino; Seiffert, Michael; Smee, Stephen A.; Smith, Roger M.; Sodré, Laerte; Spergel, David N.; Surace, Christian; Vives, Sebastien; Wang, Shiang-Yu; Yan, Chi-Hung

    2012-09-01

    The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution. Taking advantage of Subaru's wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a widefield metrology camera. Fibers then carry light to a set of four identical fast-Schmidt spectrographs with three color arms each: the wavelength ranges from 0.38 ?m to 1.3 ?m will be simultaneously observed with an average resolving power of 3000. Before and during the era of extremely large telescopes, PFS will provide the unique capability of obtaining spectra of 2400 cosmological/astrophysical targets simultaneously with an 8-10 meter class telescope. The PFS collaboration, led by IPMU, consists of USP/LNA in Brazil, Caltech/JPL, Princeton, and JHU in USA, LAM in France, ASIAA in Taiwan, and NAOJ/Subaru.

  15. Brca1/p53 deficient mouse breast tumor hemodynamics during hyperoxic respiratory challenge monitored by a novel wide-field functional imaging (WiFI) system

    NASA Astrophysics Data System (ADS)

    Moy, Austin; Kim, Jae G.; Lee, Eva Y. H. P.; Tromberg, Bruce; Cerussi, Albert; Choi, Bernard

    2009-02-01

    Current imaging modalities allow precise visualization of tumors but do not enable quantitative characterization of the tumor metabolic state. Such quantitative information would enhance our understanding of tumor progression and response to treatment, and to our overall understanding of tumor biology. To address this problem, we have developed a wide-field functional imaging (WiFI) instrument which combines two optical imaging modalities, spatially modulated imaging (MI) 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 × 5 cm) field of view. Using MI, the spatially-resolved reflectance of sinusoidal patterns projected onto the tissue is assessed, and optical properties of the tissue are estimated using a Monte Carlo model. From the spatial maps of local absorption and reduced scattering coefficients, tissue composition information is extracted in the form of oxy-, deoxy-, and total hemoglobin concentrations, and percentage of lipid and water. Using LSI, the reflectance of a 785 nm laser speckle pattern on the tissue is acquired and analyzed to compute maps of blood perfusion in the tissue. Tissue metabolism state is estimated from the values of blood perfusion, volume and oxygenation state. We currently are employing the WiFI instrument to study tumor development in a BRCA1/p53 deficient mice breast tumor model. The animals are monitored with WiFI during hyperoxic respiratory challenge. At present, four tumors have been measured with WiFI, and preliminary data suggest that tumor metabolic changes during hyperoxic respiratory challenge can be determined.

  16. Sol-gel coatings for high power laser optics-past, present and future

    SciTech Connect

    Thomas, I.M.

    1993-12-21

    An investigation into the preparation of sol-gel coatings for high power lasers was started at LLNL in 1983 and AR coatings were successfully developed for use in the Nova laser in 1984. Several other large lasers now use these coatings. Subsequent work on HR coatings resulted in AlOOH/SiO{sub 2} and later ZrO{sub 2} or HfO{sub 2}/SiO{sub 2} systems of good optical performance. The use of organic polymer binders gave increased damage threshold and enhanced optical performance. We are in the process of scaling up HR fabrication for substrates approximately 38 cm square. Concurrently we are developing sol-gel random phase plates for laser beam smoothing. These have a patterned surface design of silica which induces phase shifts in the beam by variation in the optical path length. Plates of this type on 80 cm diameter substrates have been used successfully on the Nova.

  17. 3D-resolved fluorescence and phosphorescence lifetime imaging using temporal focusing wide-field two-photon excitation

    PubMed Central

    Choi, Heejin; Tzeranis, Dimitrios S.; Cha, Jae Won; Clémenceau, Philippe; de Jong, Sander J. G.; van Geest, Lambertus K.; Moon, Joong Ho; Yannas, Ioannis V.; So, Peter T. C.

    2012-01-01

    Fluorescence and phosphorescence lifetime imaging are powerful techniques for studying intracellular protein interactions and for diagnosing tissue pathophysiology. While lifetime-resolved microscopy has long been in the repertoire of the biophotonics community, current implementations fall short in terms of simultaneously providing 3D resolution, high throughput, and good tissue penetration. This report describes a new highly efficient lifetime-resolved imaging method that combines temporal focusing wide-field multiphoton excitation and simultaneous acquisition of lifetime information in frequency domain using a nanosecond gated imager from a 3D-resolved plane. This approach is scalable allowing fast volumetric imaging limited only by the available laser peak power. The accuracy and performance of the proposed method is demonstrated in several imaging studies important for understanding peripheral nerve regeneration processes. Most importantly, the parallelism of this approach may enhance the imaging speed of long lifetime processes such as phosphorescence by several orders of magnitude. PMID:23187477

  18. A flexible wide-field FLIM endoscope utilising blue excitation light for label-free contrast of tissue.

    PubMed

    Sparks, Hugh; Warren, Sean; Guedes, Joana; Yoshida, Nagisa; Charn, Tze Choong; Guerra, Nadia; Tatla, Taranjit; Dunsby, Christopher; French, Paul

    2015-01-01

    Fluorescence lifetime imaging (FLIM) has previously been shown to provide contrast between normal and diseased tissue. Here we present progress towards clinical and preclinical FLIM endoscopy of tissue autofluorescence, demonstrating a flexible wide-field endoscope that utilised a low average power blue picosecond laser diode excitation source and was able to acquire ?mm-scale spatial maps of autofluorescence lifetimes from fresh ex vivo diseased human larynx biopsies in ?8 seconds using an average excitation power of ?0.5 mW at the specimen. To illustrate its potential for FLIM at higher acquisition rates, a higher power mode-locked frequency doubled Ti:Sapphire laser was used to demonstrate FLIM of ex vivo mouse bowel at up to 2.5 Hz using 10 mW of average excitation power at the specimen. PMID:24573953

  19. Wide-field hyperspectral 3D imaging of functionalized gold nanoparticles targeting cancer cells by reflected light microscopy.

    PubMed

    2015-05-01

    We present a new hyperspectral reflected light microscopy system with a scanned broadband supercontinuum light source. This wide-field and low phototoxic hyperspectral imaging system has been successful for performing spectral three-dimensional (3D) localization and spectroscopic identification of CD44-targeted PEGylated AuNPs in fixed cell preparations. Such spatial and spectral information is essential for the improvement of nanoplasmonic-based imaging, disease detection and treatment in complex biological environment. The presented system can be used for real-time 3D NP tracking as spectral sensors, thus providing new avenues in the spatio-temporal characterization and detection of bioanalytes. 3D image of the distribution of functionalized AuNPs attached to CD44-expressing MDA-MB-231 human cancer cells. PMID:24961507

  20. Scanning fiber endoscopy with highly flexible, 1-mm catheterscopes for wide-field, full-color imaging

    PubMed Central

    Lee, Cameron M.; Engelbrecht, Christoph J.; Soper, Timothy D.; Helmchen, Fritjof; Seibel, Eric J.

    2011-01-01

    In modern endoscopy, wide field of view and full color are considered necessary for navigating inside the body, inspecting tissue for disease and guiding interventions such as biopsy or surgery. Current flexible endoscope technologies suffer from reduced resolution when device diameter shrinks. Endoscopic procedures today using coherent fiber bundle technology, on the scale of 1 mm, are performed with such poor image quality that the clinician’s vision meets the criteria for legal blindness. Here, we review a new and versatile scanning fiber imaging technology and describe its implementation for ultrathin and flexible endoscopy. This scanning fiber endoscope (SFE) or catheterscope enables high quality, laser-based, video imaging for ultrathin clinical applications while also providing new options for in vivo biological research of subsurface tissue and high resolution fluorescence imaging. PMID:20336702

  1. Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Microanalysis and Recognition of Micrometeoroid Compositions

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    Postflight surveys of the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope have located hundreds of features on the 2.2 by 0.8 m curved plate, evidence of hypervelocity impact by small particles during 16 years of exposure to space in low Earth orbit (LEO). The radiator has a 100 - 200 micron surface layer of white paint, overlying 4 mm thick Al alloy, which was not fully penetrated by any impact. Over 460 WFPC2 samples were extracted by coring at JSC. About half were sent to NHM in a collaborative program with NASA, ESA and IBC. The structural and compositional heterogeneity at micrometer scale required microanalysis by electron and ion beam microscopes to determine the nature of the impactors (artificial orbital debris, or natural micrometeoroids, MM). Examples of MM impacts are described elsewhere. Here we describe the development of novel electron beam analysis protocols, required to recognize the subtle traces of MM residues.

  2. PRELIMINARY RESULTS FROM NEOWISE: AN ENHANCEMENT TO THE WIDE-FIELD INFRARED SURVEY EXPLORER FOR SOLAR SYSTEM SCIENCE

    SciTech Connect

    Mainzer, A.; Bauer, J.; Masiero, J.; Eisenhardt, P. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Grav, T. [Department of Astronomy, Johns Hopkins University, Baltimore, MD (United States); Cutri, R. M.; Dailey, J.; Alles, R.; Beck, R.; Brandenburg, H.; Conrow, T.; Evans, T.; Fowler, J.; Jarrett, T. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); McMillan, R. S. [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Kuiper Space Science Bldg. 92, Tucson, AZ 85721-0092 (United States); Wright, E. [UCLA Astronomy, P.O. Box 91547, Los Angeles, CA 90095-1547 (United States); Walker, R. [Monterey Institute for Research in Astronomy, Monterey, CA (United States); Jedicke, R.; Tholen, D. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Spahr, T., E-mail: amainzer@jpl.nasa.gov [Minor Planet Center, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2011-04-10

    The Wide-field Infrared Survey Explorer (WISE) has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the Infrared Astronomical Satellite and the Cosmic Background Explorer. NASA's Planetary Science Division has funded an enhancement to the WISE data processing system called 'NEOWISE' that allows detection and archiving of moving objects found in the WISE data. NEOWISE has mined the WISE images for a wide array of small bodies in our solar system, including near-Earth objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in 2011 February, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and {approx}120 comets. The NEOWISE data set will enable a panoply of new scientific investigations.

  3. Aluminum/ammonia heat pipe gas generation and long term system impact for the Space Telescope's Wide Field Planetary Camera

    NASA Technical Reports Server (NTRS)

    Jones, J. A.

    1983-01-01

    In the Space Telescope's Wide Field Planetary Camera (WFPC) project, eight heat pipes (HPs) are used to remove heat from the camera's inner electronic sensors to the spacecraft's outer, cold radiator surface. For proper device functioning and maximization of the signal-to-noise ratios, the Charge Coupled Devices (CCD's) must be maintained at -95 C or lower. Thermoelectric coolers (TEC's) cool the CCD's, and heat pipes deliver each TEC's nominal six to eight watts of heat to the space radiator, which reaches an equilibrium temperature between -15 C to -70 C. An initial problem was related to the difficulty to produce gas-free aluminum/ammonia heat pipes. An investigation was, therefore, conducted to determine the cause of the gas generation and the impact of this gas on CCD cooling. In order to study the effect of gas slugs in the WFPC system, a separate HP was made. Attention is given to fabrication, testing, and heat pipe gas generation chemistry studies.

  4. Wide-Field Infrared Survey Explorer Observations of Young Stellar Objects in the Lynds 1509 Dark Cloud in Auriga

    NASA Technical Reports Server (NTRS)

    Liu, Wilson M.; Padgett, Deborah L.; Terebey, Susan; Angione, John; Rebull, Luisa M.; McCollum, Bruce; Fajardo-Acosta, Sergio; Leisawitz, David

    2015-01-01

    The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4, 4.6, 12, and 22 microns, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc.

  5. Wide-field infrared survey explorer observations of young stellar objects in the Lynds 1509 dark cloud in Auriga

    SciTech Connect

    Liu, Wilson M.; McCollum, Bruce; Fajardo-Acosta, Sergio [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Padgett, Deborah L. [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Terebey, Susan; Angione, John [Department of Physics and Astronomy, California State University, Los Angeles, CA 90032 (United States); Rebull, Luisa M. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Leisawitz, David, E-mail: wliu@ipac.caltech.edu [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 605, Greenbelt, MD 20771 (United States)

    2014-06-01

    The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4 ?m, 4.6 ?m, 12 ?m, and 22 ?m, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc.

  6. Wide-Field Multi-Parameter FLIM: Long-Term Minimal Invasive Observation of Proteins in Living Cells

    PubMed Central

    Vitali, Marco; Picazo, Fernando; Prokazov, Yury; Duci, Alessandro; Turbin, Evgeny; Götze, Christian; Llopis, Juan; Hartig, Roland; Visser, Antonie J. W. G.; Zuschratter, Werner

    2011-01-01

    Time-domain Fluorescence Lifetime Imaging Microscopy (FLIM) is a remarkable tool to monitor the dynamics of fluorophore-tagged protein domains inside living cells. We propose a Wide-Field Multi-Parameter FLIM method (WFMP-FLIM) aimed to monitor continuously living cells under minimum light intensity at a given illumination energy dose. A powerful data analysis technique applied to the WFMP-FLIM data sets allows to optimize the estimation accuracy of physical parameters at very low fluorescence signal levels approaching the lower bound theoretical limit. We demonstrate the efficiency of WFMP-FLIM by presenting two independent and relevant long-term experiments in cell biology: 1) FRET analysis of simultaneously recorded donor and acceptor fluorescence in living HeLa cells and 2) tracking of mitochondrial transport combined with fluorescence lifetime analysis in neuronal processes. PMID:21311595

  7. Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science

    NASA Astrophysics Data System (ADS)

    Mainzer, A.; Bauer, J.; Grav, T.; Masiero, J.; Cutri, R. M.; Dailey, J.; Eisenhardt, P.; McMillan, R. S.; Wright, E.; Walker, R.; Jedicke, R.; Spahr, T.; Tholen, D.; Alles, R.; Beck, R.; Brandenburg, H.; Conrow, T.; Evans, T.; Fowler, J.; Jarrett, T.; Marsh, K.; Masci, F.; McCallon, H.; Wheelock, S.; Wittman, M.; Wyatt, P.; DeBaun, E.; Elliott, G.; Elsbury, D.; Gautier, T., IV; Gomillion, S.; Leisawitz, D.; Maleszewski, C.; Micheli, M.; Wilkins, A.

    2011-04-01

    The Wide-field Infrared Survey Explorer (WISE) has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the Infrared Astronomical Satellite and the Cosmic Background Explorer. NASA's Planetary Science Division has funded an enhancement to the WISE data processing system called "NEOWISE" that allows detection and archiving of moving objects found in the WISE data. NEOWISE has mined the WISE images for a wide array of small bodies in our solar system, including near-Earth objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in 2011 February, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and ~120 comets. The NEOWISE data set will enable a panoply of new scientific investigations.

  8. Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science

    E-print Network

    Mainzer, A; Grav, T; Masiero, J; Cutri, R M; Dailey, J; Eisenhardt, P; McMillan, R S; Wright, E; Walker, R; Jedicke, R; Spahr, T; Tholen, D; Alles, R; Beck, R; Brandenburg, H; Conrow, T; Evans, T; Fowler, J; Jarrett, T; Marsh, K; Masci, F; McCallon, H; Wheelock, S; Wittman, M; Wyatt, P; DeBaun, E; Elliott, G; Elsbury, D; Gautier, T; Gomillion, S; Leisawitz, D; Maleszewski, C; Micheli, M; Wilkins, A

    2011-01-01

    The \\emph{Wide-field Infrared Survey Explorer} has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the \\emph{Infrared Astronomical Satellite} and the \\emph{Cosmic Background Explorer}. NASA's Planetary Science Division has funded an enhancement to the \\WISE\\ data processing system called "NEOWISE" that allows detection and archiving of moving objects found in the \\WISE\\ data. NEOWISE has mined the \\WISE\\ images for a wide array of small bodies in our Solar System, including Near-Earth Objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in February 2011, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and $\\sim$120 comets. The NEOWISE dataset will enable a panoply of new scientific investigations.

  9. Future trends in optical coatings for high-power laser applications

    SciTech Connect

    Kozlowski, M.R.; Thomas, I.M.

    1994-07-01

    Inertial Confinement Fusion (ICF) research has historically been a driver in the development of high performance, high damage threshold optical coatings. This is particularly the case now as the ICF community develops plans for a proposed 1.8 mega-joule solid state (Nd{sup +3}-phosphate glass) laser system. The new system, the National Ignition Facility, is possible in part due to advances in optical coatings technology including the laser-conditioning of multilayer dielectrics and broadened applications for room-temperature deposited coatings. Sol-gel AR coatings are the standard for large, high-power laser optics and sol-gel HR coatings are being developed. For mirror and polarizer coatings, e-beam-deposited dielectric continue to provide the highest damage threshold coatings, but their laser damage thresholds and optical performance are limited by {mu}m-scale defects and poor control over layer thickness, respectively. More energetic deposition techniques such as IAD and IBS, now popular in the commercial market, offer both advantages and disadvantages in this high-damage-threshold coatings market.

  10. Development of Laser Beam Transmission Strategies for Future Ground-to-Space Optical Communications

    NASA Technical Reports Server (NTRS)

    Wilson, Keith E.; Kovalik, Joseph M.; Biswas, Abhijit; Roberts, William T.

    2007-01-01

    Optical communications is a key technology to meet the bandwidth expansion required in the global information grid. High bandwidth bi-directional links between sub-orbital platforms and ground and space terminals can provide a seamless interconnectivity for rapid return of critical data to analysts. The JPL Optical Communications Telescope Laboratory (OCTL) is located in Wrightwood California at an altitude of 2.2.km. This 200 sq-m facility houses a state-of- the-art 1-m telescope and is used to develop operational strategies for ground-to-space laser beam propagation that include safe beam transmission through navigable air space, adaptive optics correction and multi-beam scintillation mitigation, and line of sight optical attenuation monitoring. JPL has received authorization from international satellite owners to transmit laser beams to more than twenty retro-reflecting satellites. This paper presents recent progress in the development of these operational strategies tested by narrow laser beam transmissions from the OCTL to retro-reflecting satellites. We present experimental results and compare our measurements with predicted performance for a variety of atmospheric conditions.

  11. Novel optics for high-performance digital projection systems and monitors: current and future

    Microsoft Academic Search

    Young Ghi Hong; John W. Bowron

    2003-01-01

    Recently, digital projection systems have evolved quickly in accordance with their important role in multimedia displays and the market demand for higher performance. The general trend has been, higher performance requires more bulky and expensive systems. There are several approaches for the projection and illumination optics to overcome this trend. Among these is the use of aspheric lenses. Normally a

  12. In the (Not So) Distant Future: Fiber Optic Distance Learning at the University of Northern Iowa.

    ERIC Educational Resources Information Center

    Bozik, Mary

    Currently every Area Education Agency, community college, and Regent University in Iowa is connected by a fiber optic system known as the Iowa Communications Network (ICN). Every semester, 7 to 13 college credit classes have been offered at the University of Northern Iowa (UNI) via the ICN since 1993. In the Spring of 1995 seven classes (six…

  13. FSAN OAN-WG and future issues for broadband optical access networks

    Microsoft Academic Search

    Y. Maeda; K. Okada; D. Faulkner

    2001-01-01

    Network operators are aiming to provide a broadband access network to facilitate the next-generation telecom services. They have established the Full Services Access Networks (FSAN) group in order to find the best way to achieve early and cost-effective deployment of broadband optical access systems. They concluded that a single worldwide broadband access system should be investigated in the FSAN and

  14. Undersea fiber optic cable communications system of the future: Operational, reliability, and systems considerations

    Microsoft Academic Search

    D. Paul; K. Greene; G. Koepf

    1984-01-01

    The systems and operational requirements, reliability, and cost estimates for several undersea fiber optic cable communications systems of varying capacities, data transmission rates, and link distances are analyzed in detail to highlight relevant design tradeoff parameters. It is shown that systems with a high data rate per fiber are more economical and reliable than low data rate systems with multiple

  15. WIYN OPEN CLUSTER STUDY LII: WIDE-FIELD CCD PHOTOMETRY OF THE OLD OPEN CLUSTER NGC 6819

    SciTech Connect

    Yang, Soung-Chul; Kim, Sang Chul; Kyeong, Jaemann [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Sarajedini, Ata [Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, FL 32611 (United States)] [Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, FL 32611 (United States); Deliyannis, Constantine P.; Sarrazine, Angela R., E-mail: sczoo@kasi.re.kr, E-mail: ata@astro.ufl.edu, E-mail: con@astro.indiana.edu, E-mail: asarrazi@bellsouth.net [Department of Astronomy, 319 Swain Hall West, 727 East 3rd Street, Indiana University, Bloomington, IN 47401-7501 (United States)

    2013-01-01

    We present a comprehensive photometric study of the old open cluster, NGC 6819, using 1 Degree-Sign Multiplication-Sign 1 Degree-Sign field VI MOSAIC CCD imaging taken with the WIYN 0.9 m telescope. The resultant color-magnitude diagram (CMD) shows a well-developed main sequence (MS) extending from V {approx} 14.5 mag down to our photometric limit of V {approx} 21 mag. Fitting theoretical isochrones with the adopted values of the reddening and metallicity (E(B - V) = 0.14, [Fe/H] = +0.09 dex) to the observed CMD yields a distance modulus of (m - M){sub 0} = 11.93 {+-} 0.10 and an age of {approx}2.6 Gyr for NGC 6819. Our wide-field imaging reveals that NGC 6819 is larger in areal extent (R = 13') than previously thought. The wide field also benefits our estimate of the degree of field star contamination, and ultimately yields improved measurements of the structural parameters (r{sub c} = 2.'80, r{sub t} = 38.'2, and r{sub h} = 7') and tidal mass of the cluster (M {sub tid} = 3542.4 M {sub Sun }). The flattened luminosity and mass functions indicate that NGC 6819 has experienced mass segregation as a result of its dynamical evolution. Our variability study of the cluster blue straggler star (BSS) population using the Welch-Stetson variability index (I {sub WS}) has revealed a number of variable BSS candidates.

  16. Optical imaging in vivo with a focus on paediatric disease: technical progress, current preclinical and clinical applications and future perspectives

    PubMed Central

    Napp, Joanna; Mathejczyk, Julia E.

    2011-01-01

    To obtain information on the occurrence and location of molecular events as well as to track target-specific probes such as antibodies or peptides, drugs or even cells non-invasively over time, optical imaging (OI) technologies are increasingly applied. Although OI strongly contributes to the advances made in preclinical research, it is so far, with the exception of optical coherence tomography (OCT), only very sparingly applied in clinical settings. Nevertheless, as OI technologies evolve and improve continuously and represent relatively inexpensive and harmful methods, their implementation as clinical tools for the assessment of children disease is increasing. This review focuses on the current preclinical and clinical applications as well as on the future potential of OI in the clinical routine. Herein, we summarize the development of different fluorescence and bioluminescence imaging techniques for microscopic and macroscopic visualization of microstructures and biological processes. In addition, we discuss advantages and limitations of optical probes with distinct mechanisms of target-detection as well as of different bioluminescent reporter systems. Particular attention has been given to the use of near-infrared (NIR) fluorescent probes enabling observation of molecular events in deeper tissue. PMID:21221568

  17. Paralytic shellfish poisoning (PSP) toxin binders for optical biosensor technology: problems and possibilities for the future: a review

    PubMed Central

    Campbell, K.; Rawn, D.F.K.; Niedzwiadek, B.; Elliott, C.T.

    2011-01-01

    This review examines the developments in optical biosensor technology, which uses the phenomenon of surface plasmon resonance, for the detection of paralytic shellfish poisoning (PSP) toxins. Optical biosensor technology measures the competitive biomolecular interaction of a specific biological recognition element or binder with a target toxin immobilised onto a sensor chip surface against toxin in a sample. Different binders such as receptors and antibodies previously employed in functional and immunological assays have been assessed. Highlighted are the difficulties in detecting this range of low molecular weight toxins, with analogues differing at four chemical substitution sites, using a single binder. The complications that arise with the toxicity factors of each toxin relative to the parent compound, saxitoxin, for the measurement of total toxicity relative to the mouse bioassay are also considered. For antibodies, the cross-reactivity profile does not always correlate to toxic potency, but rather to the toxin structure to which it was produced. Restrictions and availability of the toxins makes alternative chemical strategies for the synthesis of protein conjugate derivatives for antibody production a difficult task. However, when two antibodies with different cross-reactivity profiles are employed, with a toxin chip surface generic to both antibodies, it was demonstrated that the cross-reactivity profile of each could be combined into a single-assay format. Difficulties with receptors for optical biosensor analysis of low molecular weight compounds are discussed, as are the potential of alternative non-antibody-based binders for future assay development in this area. PMID:21623494

  18. A history of avionic fiber optic cable development and future requirements

    Microsoft Academic Search

    C. Pegge; R. Brunelle

    2005-01-01

    In mid 1980's General Cable worked with Boeing (formerly the McDonnell Douglas Corporation) to develop one of the first optical fiber cable for avionic systems for the AV-8B Harrier. An innovative micro loose tube cable construction was chosen for these fiber types. The specific designs that resulted from this early work have been employed on several aircraft. The fiber used

  19. Progress on indirect glass slumping for future x-ray telescope optics

    NASA Astrophysics Data System (ADS)

    Winter, Anita; Breunig, Elias; Friedrich, Peter; Proserpio, Laura

    2014-07-01

    Large X-ray telescopes for future observations need to combine a big collecting area with good angular resolution. Due to the mass limits of the launching rocket, light-weight materials are needed in order to enhance the collecting area in future telescopes. We study the development of mirror segments made from thin glass sheets which are shaped by thermal slumping. At MPE we follow the indirect approach which enables us the production of the parabolic and hyperbolic part of the Wolter type I mirrors in one piece. In our recent research we have used a test mould made of CeSiC™ for slumping processes in our lab furnace as well as in a heatable vacuum chamber, to avoid oxidation and air enclosure. Additional slumping tests in the vacuum furnace have been carried out using a Kovar mould and are compared with results under air. We describe the experimental set-up, the slumping process and the metrology methods and give an outlook on future activities.

  20. LSST Camera Optics Design

    Microsoft Academic Search

    V J Riot; S Olivier; B Bauman; S Pratuch; L Seppala; D Gilmore; J Ku; M Nordby; M Foss; P Antilogus; N Morgado

    2012-01-01

    The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope

  1. A 21 Centimeter Absorber Identified with a Spiral Galaxy: Hubble Space Telescope Faint Object Spectrograph and Wide-Field Camera Observations of 3CR 196

    NASA Technical Reports Server (NTRS)

    Cohen, Ross D.; Beaver, E. A.; Diplas, Athanassios; Junkkarinen, Vesa T.; Barlow, Thomas A.; Lyons, Ronald W.

    1996-01-01

    We present imaging and spectroscopy of the quasar 3CR 196 (z(sub e) = 0.871), which has 21 cm and optical absorption at z(sub a) = 0.437. We observed the region of Ly alpha absorption in 3CR 196 at z(sub a) = 0.437 with the Faint Object Spectrograph on the Hubble Space Telescope. This region of the spectrum is complicated because of the presence of a Lyman limit and strong lines from a z(sub a) approx. z(sub e) system. We conclude that there is Ly alpha absorption with an H I column density greater than 2.7 x 10(exp 19) cm(exp -2) and most probably 1.5 x 10(exp 20) cm(exp -2). Based on the existence of the high H I column density along both the optical and radio lines of sight, separated by more than 15 kpc, we conclude that the Ly alpha absorption must arise in a system comparable in size to the gaseous disks of spiral galaxies. A barred spiral galaxy, previously reported as a diffuse object in the recent work of Boisse and Boulade, can be seen near the quasar in an image taken at 0.1 resolution with the Wide Field Planetary Camera 2 on the HST. If this galaxy is at the absorption redshift, the luminosity is approximately L(sub *) and any H I disk should extend in front of the optical quasar and radio lobes of 3CR 196, giving rise to both the Ly alpha and 21 cm absorption. In the z(sub a) approx. z(sub e) system we detect Lyman lines and the Lyman limit, as well as high ion absorption lines of C III, N V, S VI, and O VI. This absorption probably only partially covers the emission-line region. The ionization parameter is approximately 0.1. Conditions in this region may be similar to those in broad absorption line QSOs.

  2. A Wide-Field Camera for 1-2.5mu M Imaging at the 2.3 and 6.5m Telescopes

    NASA Astrophysics Data System (ADS)

    McCarthy, D. W.; Ge, J.; Hinz, J. L.; Finn, R. A.; Low, F. J.; Cheselka, M.; Salvestrini, K.

    1998-12-01

    The advent of large format focal plane arrays permits efficient wide-field imaging at near-infrared wavelengths. We have commissioned a new camera (PISCES) to provide circular fields of 8.5 and 3.0 arcmin diameter at the f/9 foci of the 2.3m Bok telescope and 6.5m MMT. The design uses refractive optics with spherical lenses made from conventional materials (CaF_2, BaF_2, IR-SiO_2). The dewar window is an achromatic doublet which produces a high quality pupil image. A cold pupil stop yields low emissivity by baffling the telescope's central obscuration, primary edge, and spider vanes. Pupil-viewing optics provide precise alignment of the telescope pupil. Four additional lenses then reimage the telescope focal plane at f/3.3, leading to scales of 0.5 and 0.18 arcsec/pixel, respectively. These scales are well matched to the seeing at the two sites. The focal plane array is a 1024x1024 pixel HgCdTe (HAWAII readout) detector from Rockwell. PISCES utilizes an SDSU array controller based on fiber-optic communication with a PCI-bus computer. Performance measurements have been conducted at the 2.3m telescope. Image quality is FWHM <2 pixels across the full array from 1-2.5mu m. Overall instrument transmission is 50-55%, including the detector quantum efficiency. Emissivity is measured to be 5-7%. On the 2.3m telescope, point source detection limits of J=17.5, H=17.0, K_s=16.5 (10-sigma/min) are achieved routinely. At the 6.5m MMT we anticipate an improvement of ~ 2 magnitudes. PISCES is currently being used for scientific studies of quasar environments (Finn et al., this conference), searches for brown dwarfs as common proper motion companions, and imaging of star formation regions. PISCES and its successor (ARIES) on the 6.5m MMT are supported by the NSF through grant AST-9623788.

  3. Utility of galaxy catalogs for following up gravitational waves from binary neutron star mergers with wide-field telescopes

    SciTech Connect

    Hanna, Chad [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Mandel, Ilya; Vousden, Will, E-mail: chad.hanna@ligo.org, E-mail: imandel@star.sr.bham.ac.uk, E-mail: will@star.sr.bham.ac.uk [University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2014-03-20

    The first detections of gravitational waves from binary neutron star mergers with advanced LIGO and Virgo observatories are anticipated in the next five years. These detections could pave the way for multi-messenger gravitational-wave (GW) and electromagnetic (EM) astronomy if GW triggers are successfully followed up with targeted EM observations. However, GW sky localization is relatively poor, with expected localization areas of ?10-100 deg{sup 2}; this presents a challenge for following up GW signals from compact binary mergers. Even for wide-field instruments, tens or hundreds of pointings may be required. Prioritizing pointings based on the relative probability of successful imaging is important since it may not be possible to tile the entire gravitational-wave localization region in a timely fashion. Galaxy catalogs were effective at narrowing down regions of the sky to search in initial attempts at joint GW/EM observations. The relatively limited range of initial GW instruments meant that few galaxies were present per pointing and galaxy catalogs were complete within the search volume. The next generation of GW detectors will have a 10-fold increase in range thereby increasing the expected number of galaxies per unit solid angle by a factor of ?1000. As an additional complication, catalogs will be highly incomplete. Nevertheless, galaxy catalogs can still play an important role in prioritizing pointings for the next era of GW searches. We show how to quantify the advantages of using galaxy catalogs to prioritize wide-field follow-ups as a function of only two parameters: the three-dimensional volume within the field of view of a telescope after accounting for the GW distance measurement uncertainty, and the fraction of the GW sky localization uncertainty region that can be covered with telescope pointings. We find that the use of galaxy catalogs can improve the probability of successful imaging by ?10% to ?300% relative to follow-up strategies that do not utilize such catalogs for the scenarios we considered. We determine that catalogs with a 75% completeness perform comparably to complete catalogs in most cases, while 33%-complete catalogs can lead to lower follow-up success rates than complete catalogs for small fields of view, though still providing an advantage over strategies that do not use a catalog at all.

  4. Trends and future applications of optical remote sensing and computed tomography to map air contaminants

    NASA Astrophysics Data System (ADS)

    Todd, Lori A.; Yost, Michael G.; Hashmonay, Ram A.

    1999-02-01

    More than twenty years have passed since the concept of combining Computed Tomography (CT) and Optical Remote Sensing (ORS) was first suggested to map air contaminants. However, there have been no commercial applications of CT-ORS due to a variety of reasons including hardware limitations and slow acceptance by the occupational and environmental scientific communities. A CT-ORS monitoring system provides the potential for near real-time mapping of multiple gases over large areas. Not just another nifty tool, this technology represents a major departure from conventional sampling methods and could allow us to understand chemical transport and exposure in ways, which are unavailable using conventional methods. Yet critical questions remain unanswered: which contaminant sources are most appropriate for this technology and how does this data apply to human exposure assessment? We discuss potential applications of CT-ORS, such a using open-path Fourier Transform Infrared spectroscopy for mapping leaks and evaluating worker exposures and quantifying emission flux from a process facility. Large scale (greater than 1 km) CT reconstructions could be obtained from a variety of ORS devices (Tunable Diode Laser, Differential Optical Absorption Spectroscopy, or Differential Absorption Lidar). Reconstructions could help locate industrial emissions and provide improved estimates of pollutant transport.

  5. A wide-field photometric survey for extratidal tails around five metal-poor globular clusters in the Galactic halo

    E-print Network

    Chun, Sang-Hyun; Sohn, Sangmo T; Park, Jang-Hyun; Han, Wonyong; Kim, Ho-Il; Lee, Young-Wook; Lee, Myung Gyoon; Lee, Sang-Gak; Sohn, Young-Jong

    2009-01-01

    Wide-field deep gri images obtained with the Megacam of the Canada-France-Hawaii Telescope (CFHT) are used to investigate the spatial configuration of stars around five metal-poor globular cluster M15, M30, M53, NGC 5053, and NGC 5466, in a field-of-view ~3 degree. Applying a mask filtering algorithm to the color-magnitude diagrams of the observed stars, we sorted cluster's member star candidates that are used to examine the characteristics of the spatial stellar distribution surrounding the target clusters. The smoothed surface density maps and the overlaid isodensity contours indicate that all of the five metal-poor globular clusters exhibit strong evidence of extratidal overdensity features over their tidal radii, in the form of extended tidal tails around the clusters. The orientations of the observed extratidal features show signatures of tidal tails tracing the clusters' orbits, inferred from their proper motions, and effects of dynamical interactions with the Galaxy. Our findings include detections of ...

  6. Refining the Search for Suitable KBOs: Calibration of the HST/ACS Wide Field Camera Ramp Filters.

    NASA Astrophysics Data System (ADS)

    Trafton, Laurence M.

    2014-11-01

    After the New Horizons flyby of Pluto, the spacecraft will travel on to fly by one or more KBO objects. These are yet to be determined; searches are currently underway to locate suitable candidates. Once some candidates are identified, further observations are likely in order to decide on the actual targets; e.g., spectra or narrow-band observations vs. rotational phase to determine the presence of frozen volatiles. With its wide field, clear and broad band B and I filters, and its suite of medium band filters (9% FWHM), the ACS WFC camera on board HST is useful for searches over the CCD wavelength range. Moreover, its suite of narrow band (2%) ramp filters, which are also distributed over this wavelength range, are potentially useful for identifying the signature of spectral features, such as solid methane bands, for KBOs as dim as V = +25. However, the transmission of these ramp filters is uncertain since it was never calibrated. We report the calibration of 9 ACS/WFC ramp filters at 15 selected central wavelengths. A comparison of the calibrated transmissions to the existing uncalibrated ramp filters is presented. Corrective flats have been submitted for insertion into the ACS data reduction pipeline.This program was supported through HST-AR-10981.01-A.

  7. A new wide field-of-view confocal imaging system and its applications in drug discovery and pathology

    NASA Astrophysics Data System (ADS)

    Li, Gang; Damaskinos, Savvas; Dixon, Arthur E.; Lee, Lucy E. J.

    2005-11-01

    Conventional widefield light microscopy and confocal scanning microscopy have been indispensable for pathology and drug discovery research. Clinical specimens from diseased tissues are examined, new drug candidates are tested on drug targets, and the morphological and molecular biological changes of cells and tissues are observed. High throughput screening of drug candidates requires highly efficient screening instruments. A standard biomedical slide is 1 by 3 inches (25.4 by 76.2 mm) in size. A typical tissue specimen is 10 mm in diameter. To form a high resolution image of the entire specimen, a conventional widefield light microscope must acquire a large number of small images of the specimen, and then tile them together, which is tedious, inefficient and error-prone. A patented new wide field-of-view confocal scanning laser imaging system has been developed for tissue imaging, which is capable of imaging an entire microscope slide without tiling. It is capable of operating in brightfield, reflection and epi-fluorescence imaging modes. Three (red, green and blue (RGB)) lasers are used to produce brightfield and reflection images, and to excite various fluorophores. This new confocal system makes examination of large biomedical specimens more efficient, and makes fluorescence examination of large specimens possible for the first time without tiling. Description of the new confocal technology and applications of the imaging system in pathology and drug discovery research, for example, imaging large tissue specimens, tissue microarrays, and zebrafish sections, are reported in this paper.

  8. Wide-field spectral imaging of human ovary autofluorescence and oncologic diagnosis via previously collected probe data

    PubMed Central

    Hatch, Kenneth D.; Utzinger, Urs

    2012-01-01

    Abstract. With no sufficient screening test for ovarian cancer, a method to evaluate the ovarian disease state quickly and nondestructively is needed. The authors have applied a wide-field spectral imager to freshly resected ovaries of 30 human patients in a study believed to be the first of its magnitude. Endogenous fluorescence was excited with 365-nm light and imaged in eight emission bands collectively covering the 400- to 640-nm range. Linear discriminant analysis was used to classify all image pixels and generate diagnostic maps of the ovaries. Training the classifier with previously collected single-point autofluorescence measurements of a spectroscopic probe enabled this novel classification. The process by which probe-collected spectra were transformed for comparison with imager spectra is described. Sensitivity of 100% and specificity of 51% were obtained in classifying normal and cancerous ovaries using autofluorescence data alone. Specificity increased to 69% when autofluorescence data were divided by green reflectance data to correct for spatial variation in tissue absorption properties. Benign neoplasm ovaries were also found to classify as nonmalignant using the same algorithm. Although applied ex vivo, the method described here appears useful for quick assessment of cancer presence in the human ovary. PMID:22502561

  9. Quantitative evaluation of observation capability of GF-1 wide field of view sensors for soil moisture inversion

    NASA Astrophysics Data System (ADS)

    Chen, Nengcheng; Li, Jizhen; Zhang, Xiang

    2015-01-01

    Currently, many satellite data are used to invert soil moisture. However, there is no study about quantitative evaluation of observation capability of GF-1 wide field of view (WFV) sensors for soil moisture inversion. Therefore, we proposed a method to evaluate it. We used WFV, Landsat8 Operational Land Imager (OLI), and Moderate-resolution Imaging Spectroradiometer (MODIS) data to invert soil moistures in Wuhan from September 2013 to September 2014 based on the Perpendicular Drought Index (PDI) and modified PDI (MPDI). From the estimated results, the R2 values, and standard error, we found that both the PDI and MPDI had a significantly negative linear correlation with soil moisture (P<0.01). Through the values of R, mean absolute error, mean relative error, and root mean square error, we found that a strong relativity existed between the estimated and observed soil moistures. It was evident from the results for the WFV, OLI, and MODIS that the performances of WFV and OLI were consistent and that WFV performed better than MODIS. All the results indicated that WFV sensors had a high observation capability for soil moisture inversion in Wuhan. The comprehensive evaluation results for the performance of the PDI and MPDI proved that the MPDI performed better for soil moisture inversion than did the PDI.

  10. Spatial frequency selective error sensing for space-based, wide field-of-view, multiple-aperture imaging systems

    NASA Astrophysics Data System (ADS)

    Erteza, Ahmed; Schneeberger, Timothy J.

    1991-12-01

    High-resolution space-based imaging applications are limited by the difficulty of placing large monolithic mirrors in space and by technology limitations on the diameter achievable in monolithic mirrors. Multiple-mirror imaging systems can overcome these limitations but require precise alignment-error sensing and correcting schemes to maintain all elements in phase. When a wide field of view is desired, the complexity increases substantially since significant error terms will be a function of field angle. Approaches which can reduce the complexity of the error sensing/correcting schemes are thus of great interest. By sampling selected spatial frequencies, representative of both the individual subapertures and errors between subapertures, measurement of all error terms except absolute piston can be achieved. A technique which places a nonredundant mask in the compacted pupil plane of a phased-array imager and senses the selected spatial-frequency magnitude and phase in the focal plane has been analyzed. This technique can reduce complexity in the local error-sensing system while accounting for all tilt, geometry, magnification, and relative piston errors.

  11. Wide-field spectral imaging of human ovary autofluorescence and oncologic diagnosis via previously collected probe data

    NASA Astrophysics Data System (ADS)

    Renkoski, Timothy E.; Hatch, Kenneth D.; Utzinger, Urs

    2012-03-01

    With no sufficient screening test for ovarian cancer, a method to evaluate the ovarian disease state quickly and nondestructively is needed. The authors have applied a wide-field spectral imager to freshly resected ovaries of 30 human patients in a study believed to be the first of its magnitude. Endogenous fluorescence was excited with 365-nm light and imaged in eight emission bands collectively covering the 400- to 640-nm range. Linear discriminant analysis was used to classify all image pixels and generate diagnostic maps of the ovaries. Training the classifier with previously collected single-point autofluorescence measurements of a spectroscopic probe enabled this novel classification. The process by which probe-collected spectra were transformed for comparison with imager spectra is described. Sensitivity of 100% and specificity of 51% were obtained in classifying normal and cancerous ovaries using autofluorescence data alone. Specificity increased to 69% when autofluorescence data were divided by green reflectance data to correct for spatial variation in tissue absorption properties. Benign neoplasm ovaries were also found to classify as nonmalignant using the same algorithm. Although applied ex vivo, the method described here appears useful for quick assessment of cancer presence in the human ovary.

  12. A new 30 cm three-reflection telescope for wide-field Astronomy on the Antarctic Plateau

    NASA Astrophysics Data System (ADS)

    Nanni, Domenico; Viotti, Roberto F.; Badiali, M.; Di Lellis, Andrea M.; Ferrari, Marc

    2002-12-01

    We describe a new three-reflection telescope (TRT) prototype, where the 30-cm primary mirror is acting as the first and the third reflecting surfaces with different figurings. The two surfaces were realized and polished separately, and then accurately aligned and glued together. This technique has added more flexibility to the original design. The telescope provides: wide (2°x2° square degrees) corrected and unvignetted field of view, flat-field focal surface, small encumbrance, and easy access to the focal plane instrumentation. These characteristics make the TRT in combination with large area CCD cameras, a useful instrument for wide-field observations from remote and hostile ground sites, such as the Antarctic Plateau. The prototype has been equipped with a 2kx2k thermoelectric cooled CCD camera using the San Diego State University SDSU controller. A second custom controller prototype has been developed for ongoing space and Antarctica applications, characterized by synchronous fast readout capabilities (two 14-bit channels each sampled at 3.3 Msamples/s) and suitable to be scaled to large array mosaic applications. This project is aimed at the discovery and tracking of potentially hazardous NEOs, and identification of transient events such as GRBs.

  13. NEW YOUNG STAR CANDIDATES IN THE TAURUS-AURIGA REGION AS SELECTED FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

    SciTech Connect

    Rebull, L. M.; Padgett, D. L.; Noriega-Crespo, A., E-mail: rebull@ipac.caltech.edu, E-mail: alberto@ipac.caltech.edu, E-mail: Deborah.L.Padgett@nasa.gov, E-mail: karl.r.stapelfeldt@nasa.gov [Spitzer Science Center (SSC), California Institute of Technology, M/S 220-6, 1200 E. California Blvd., Pasadena, CA 91125 (United States)

    2011-09-01

    The Taurus Molecular Cloud subtends a large solid angle on the sky, in excess of 250 deg{sup 2}. The search for legitimate Taurus members to date has been limited by sky coverage as well as the challenge of distinguishing members from field interlopers. The Wide-field Infrared Survey Explorer has recently observed the entire sky, and we take advantage of the opportunity to search for young stellar object (YSO) candidate Taurus members from a {approx}260 deg{sup 2} region designed to encompass previously identified Taurus members. We use near- and mid-infrared colors to select objects with apparent infrared excesses and incorporate other catalogs of ancillary data to present a list of rediscovered Taurus YSOs with infrared excesses (taken to be due to circumstellar disks), a list of rejected YSO candidates (largely galaxies), and a list of 94 surviving candidate new YSO-like Taurus members. There is likely to be contamination lingering in this candidate list, and follow-up spectra are warranted.

  14. Optical imaging of intracranial hemorrhages in newborns: modern strategies in diagnostics and direction for future research

    NASA Astrophysics Data System (ADS)

    Pavlov, A. N.; Semyachkina-Glushkovskaya, O. V.; Lychagov, V. V.; Bibikova, O. A.; Sindeev, S. S.; Pavlova, O. N.; Shuvalova, E. P.; Tuchin, V. V.

    2014-05-01

    Using Doppler optical coherence tomography (DOCT) we study stress-related intracranial hemorrhages (ICHs) in newborn rats. We investigate a masked stage of ICH development that corresponds to the first 4 h after the stress. We show that this period is characterized by significant changes in the diameter of the sagittal vein and the velocity of the cerebral venous blood flow (CVBF). We discuss diagnostic abilities of wavelet-based methods and consider an adaptive technique allowing us to reveal clearest distinctions in the dynamics of CVBF between normal and stressed newborn rats. Finally, we conclude that the venous insufficiency in newborns and a reduced response of the sagittal vein to adrenaline are related to important prognostic markers of the risk of ICH development.

  15. Ten years optically pumped semiconductor lasers: review, state-of-the-art, and future developments

    NASA Astrophysics Data System (ADS)

    Kannengiesser, Christian; Ostroumov, Vasiliy; Pfeufer, Volker; Seelert, Wolf; Simon, Christoph; von Elm, Rüdiger; Zuck, Andreas

    2010-02-01

    Optically Pumped Semiconductor Lasers - OPSLs - have been introduced in 2001. Their unique features such as power scalability and wavelength flexibility, their excellent beam parameters, power stability and reliability opened this pioneering technology access to a wide range of applications such as flow cytometry, confocal microscopy, sequencing, medical diagnosis and therapy, semiconductor inspection, graphic arts, forensic, metrology. This talk will introduce the OPSL principles and compare them with ion, diode and standard solid state lasers. It will revue the first 10 years of this exciting technology, its current state and trends. In particular currently accessible wavelengths and power ranges, frequency doubling, ultra-narrow linewidth possibilities will be discussed. A survey of key applications will be given.

  16. Results from an Integrated Optical/Acoustic Communication System Installed at CORK 857D: Implications for Future Seafloor Observatories

    NASA Astrophysics Data System (ADS)

    Tivey, M.; Farr, N.; Ware, J.; Pontbriand, C.

    2011-12-01

    A CORK (Circulation Obviation Retrofit Kit) borehole represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor under controlled conditions (e.g. hydrologically sealed), and a standard interface for communication. Typically, however, due to power constraints and a limited frequency of data download opportunities, data sampling has been limited to rates on the order of several minutes. For full seismic wave sampling, at least 1 Hz or better is required. While some CORK systems are now being connected to an underwater cable to provide continuous power and real-time data (cf. Neptune network in the Northeast Pacific), there will be locations where cabled observatories are not viable. Another mode of communication is required to enable both high data rate communication and access for data download via more conventional vessels and not limited to those with ROV or submersibles. We here report on technology to enable high data rate download and transfer of data and information using underwater optical communications, which can be accomplished from a surface vessel of opportunity or, in the future, by autonomous underwater vehicle. In 2010, we successfully deployed and tested an underwater optical communication system that provides high data rate communications over a range of 100 meters from a deep sea CORK borehole observatory located in the northeast Pacific at IODP Hole 857D. The CORK is instrumented with a thermistor string and pressure sensors that record downhole formation pressures and temperatures within oceanic basement and is pressure sealed from the overlying water column. The seafloor Optical Telemetry System (OTS) was plugged into the CORK's existing underwater matable connector to provide an optical and acoustic communication interface and additional data storage and battery power for the CORK to sample at 1 Hz data-rate, an increase over the normal 15 sec data sample rate. A CTD-mounted OTS lowered by wire from a surface ship established an optical communication link at 100 meters range at rates of 1, 5 and 10 Mbps with no bit errors. This mode of communication demonstrates the effectiveness of using a ship-based system to interrogate the system remotely. The OTS was designed to be installed at the seafloor CORK for a year. In 2011, we will revisit the CORK and OTS using the ROV Jason to test the system, download the data collected during this period and to refurbish the batteries for a further year-long deployment period. We will report on the results of those tests at the meeting. As the need to observe oceanic and earth phenomenon over periods not limited to weather windows or cruise schedules increases, the borehole observatory will provide an important venue for gaining access to such timescales. High data-rate underwater communications will be required to make full use of such observatory infrastructure. The use of free water optical communication methods provides a logical way to accomplish these goals in the future.

  17. Future Prospects for Very High Angular Resolution Imaging in the UV/Optical

    NASA Astrophysics Data System (ADS)

    Allen, R. J.

    2004-05-01

    Achieving the most demanding science goals outlined by the previous speakers will ultimately require the development of coherent space-based arrays of UV/Optical light collectors spread over distances of hundreds of meters. It is possible to envisage ``in situ" assembly of large segmented filled-aperture telescopes in space using components ferried up with conventional launchers. However, the cost will grow roughly as the mass of material required, and this will ultimately limit the sizes of the apertures we can afford. Furthermore, since the collecting area and the angular resolution are coupled for diffraction-limited filled apertures, the sensitivity may be much higher than is actually required to do the science. Constellations of collectors deployed over large areas as interferometer arrays or sparse apertures offer the possibility of independently tailoring the angular resolution and the sensitivity in order to optimally match the science requirements. Several concept designs have been proposed to provide imaging data for different classes of targets such as protoplanetary disks, the nuclear regions of the nearest active galaxies, and the surfaces of stars of different types. Constellations of identical collectors may be built and launched at lower cost through mass production, but new challenges arise when they have to be deployed. The ``aperture" synthesized is only as good as the accuracy with which the individual collectors can be placed and held to the required figure. This ``station-keeping" problem is one of the most important engineering problems to be solved before the promise of virtually unlimited angular resolution in the UV/Optical can be realized. Among the attractive features of an array of free-flying collectors configured for imaging is the fact that the figure errors of the ``aperture" so produced may be much more random than is the case for monolithic or segmented telescopes. This can result in a significant improvement in the dynamic range and permit imaging of faint objects near much brighter extraneous nearby sources, a task presently reserved for specially-designed coronagraphs on filled apertures.

  18. A DEEP, WIDE-FIELD, AND PANCHROMATIC VIEW OF 47 Tuc AND THE SMC WITH HST: OBSERVATIONS AND DATA ANALYSIS METHODS

    SciTech Connect

    Kalirai, Jason S.; Anderson, Jay; Dotter, Aaron, E-mail: jkalirai@stsci.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

    2012-01-15

    In Hubble Space Telescope (HST) Cycle 17, we imaged the well-known globular star cluster 47 Tucanae for 121 orbits using the Wide Field Channel of the Advanced Camera for Surveys (ACS) and both the UV/visible (UVIS) and IR channels of the newly installed Wide Field Camera 3 (WFC3) instrument (GO-11677, PI: H. Richer). This unique data set was obtained to address many scientific questions that demand a very deep, panchromatic, and panoramic view of the cluster's stellar populations. In total, the program obtained over 0.75 Ms of imaging exposure time with the three HST cameras, over a time span of 9 months in 2010. The primary ACS field was imaged in the two broadband filters F606W and F814W, at 13 orientations, for all 121 orbits. The parallel WFC3 imaging provides a panchromatic (0.4-1.7 {mu}m) and contiguous imaging swath over a 250 Degree-Sign azimuthal range at impact radii of 6.5-17.9 pc in 47 Tuc. This imaging totals over 60 arcmin{sup 2} in area and utilizes the F390W and F606W broadband filters on WFC3/UVIS and the F110W and F160W broadband filters on WFC3/IR. In this paper, we describe the observational design of the new survey and one of the methods used to analyze all of the imaging data. This analysis combines over 700 full-frame images taken with the three HST cameras into a handful of ultra-deep, well-sampled combined images in each of the six filters. We discuss in detail the methods used to calculate accurate transformations that provide optimal alignment of the input images, the methods used to perform sky background offsets in the input stack and the flagging of deviant pixels, and the balance reached between the input-pixel drop size onto an output supersampled pixel grid. Careful photometric, morphological, and astrometric measurements are performed on the stacks using iterative PSF-fitting techniques, and reveal unprecedented color-magnitude diagrams of the cluster extending to >30th magnitude in the optical, 29th magnitude in the UV, and 27th magnitude in the IR. The data set provides a characterization of the complete stellar populations of 47 Tuc, extending from the faintest hydrogen-burning dwarfs through the main-sequence and giant branches down to very cool white dwarf remnants in the cluster. The imaging also provides the deepest probe of the stellar populations of the background Small Magellanic Cloud galaxy, resolving low-mass main-sequence dwarfs with M {approx}< 0.2 M{sub Sun }.

  19. A Deep, Wide-field, and Panchromatic View of 47 Tuc and the SMC with HST: Observations and Data Analysis Methods

    NASA Astrophysics Data System (ADS)

    Kalirai, Jason S.; Richer, Harvey B.; Anderson, Jay; Dotter, Aaron; Fahlman, Gregory G.; Hansen, Brad M. S.; Hurley, Jarrod; King, Ivan R.; Reitzel, David; Rich, R. M.; Shara, Michael M.; Stetson, Peter B.; Woodley, Kristin A.

    2012-01-01

    In Hubble Space Telescope (HST) Cycle 17, we imaged the well-known globular star cluster 47 Tucanae for 121 orbits using the Wide Field Channel of the Advanced Camera for Surveys (ACS) and both the UV/visible (UVIS) and IR channels of the newly installed Wide Field Camera 3 (WFC3) instrument (GO-11677, PI: H. Richer). This unique data set was obtained to address many scientific questions that demand a very deep, panchromatic, and panoramic view of the cluster's stellar populations. In total, the program obtained over 0.75 Ms of imaging exposure time with the three HST cameras, over a time span of 9 months in 2010. The primary ACS field was imaged in the two broadband filters F606W and F814W, at 13 orientations, for all 121 orbits. The parallel WFC3 imaging provides a panchromatic (0.4-1.7 ?m) and contiguous imaging swath over a 250° azimuthal range at impact radii of 6.5-17.9 pc in 47 Tuc. This imaging totals over 60 arcmin2 in area and utilizes the F390W and F606W broadband filters on WFC3/UVIS and the F110W and F160W broadband filters on WFC3/IR. In this paper, we describe the observational design of the new survey and one of the methods used to analyze all of the imaging data. This analysis combines over 700 full-frame images taken with the three HST cameras into a handful of ultra-deep, well-sampled combined images in each of the six filters. We discuss in detail the methods used to calculate accurate transformations that provide optimal alignment of the input images, the methods used to perform sky background offsets in the input stack and the flagging of deviant pixels, and the balance reached between the input-pixel drop size onto an output supersampled pixel grid. Careful photometric, morphological, and astrometric measurements are performed on the stacks using iterative PSF-fitting techniques, and reveal unprecedented color-magnitude diagrams of the cluster extending to >30th magnitude in the optical, 29th magnitude in the UV, and 27th magnitude in the IR. The data set provides a characterization of the complete stellar populations of 47 Tuc, extending from the faintest hydrogen-burning dwarfs through the main-sequence and giant branches down to very cool white dwarf remnants in the cluster. The imaging also provides the deepest probe of the stellar populations of the background Small Magellanic Cloud galaxy, resolving low-mass main-sequence dwarfs with M <~ 0.2 M ?. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with proposal GO-11677.

  20. Calibration System with Optical Fibers for Calorimeters at Future Linear Collider Experiments

    E-print Network

    ,

    2012-01-01

    We report on several versions of the calibration and monitoring system dedicated to scintillator tile calorimeters built within the CALICE collaboration and intended for future linear collider experiments. Whereas the first, a 1 m3 analogue hadron calorimeter prototype, was already built and tested in beam, second-technological prototype-is currently being developed. Both prototypes are based on scintillating tiles that are individually read out by new photodetectors, silicon photomultipliers (SiPMs). Since the SiPM response shows a strong dependence on the temperature and bias voltage and the SiPM saturates due to the limited number of pixels, it needs to be monitored. The monitoring system has to have sufficient flexibility to perform several different tasks. The self-calibration property of the SiPMs can be used for the gain monitoring using a low intensity of the LED light. A routine monitoring of all SiPMs during test beam operations is achieved with a fixed-intensity light pulse. The full SiPM response ...

  1. Neon: the UK Met office electro-optic tactical decision aid-current and future capability

    NASA Astrophysics Data System (ADS)

    Fox, S.; Wilson, D.; Lewis, W.

    2010-10-01

    The thermal contrast between two surfaces can vary dramatically with the atmospheric conditions. "Neon" is an application to predict the thermal contrast between different surfaces and their backgrounds, and the apparent contrast, given atmospheric conditions, when a target surface and background are viewed through a remotely situated infra-red camera. It is typically used in military assessments of how visible a target will be at a particular range. Recent research work to Neon has concentrated on the conversion of these apparent temperatures to more user-relevant descriptions of the detectability of the target. Accordingly, a development version of Neon now outputs "Detect", "Recognize" and "Identify" guidance. This paper briefly outlines the Neon concepts and then explores the methods behind the calculation of these detectability ranges and probabilities, and their comparison with a simple target acquisition range based only on the apparent contrast of the target and background. It finally explores how variations in the atmosphere impact upon the detectability of a target, and how the atmospheric impact will change with future improvements in sensor technology.

  2. Applications of high-frequency resolution, wide-field VLBI: observations of nearby star-forming galaxies & habitable exoplanetary candidates

    NASA Astrophysics Data System (ADS)

    Rampadarath, Hayden

    2014-04-01

    Until recently, the maximum observable field of view of Very Long Baseline Interferometric (VLBI) observations was limited, predominantly, by the ability to process large volumes of data. However, the availability of software correlators and high performance computing have provided the means to overcome these restrictions, giving rise to the technique of wide-field VLBI. This thesis reports on the application of this technique to investigate two different science cases: (1) to explore the use of VLBI for targeted searches for extra-terrestrial intelligence (SETI); (2) to investigate the compact radio source populations, supernovae, and star formation rates and the interstellar media of nearby star-forming galaxies. Radio sources detected with VLBI will display characteristic variations as a function of time and frequency that are dependent on their locations with respect to the observing phase centre. Thus, a planet with a radio emitting civilisation, bright enough to be detected, can be identified and separated from human generated signals through VLBI observations. This idea was tested on a VLBI observation of the planetary system Gliese 581. The dataset was searched for candidate SETI signals, in both time and frequency, with amplitudes greater than five times the baseline sensitivity on all baselines. Candidate signals were selected and through the use of automated, statistical data analysis techniques were ruled out as originating from the Gliese 581 system. The results of this study place an upper limit of 7 MW/Hz on the power output of any isotropic emitter located in the Gliese 581 system, within this frequency range. While the study was unable to identify any signals originating from Gliese 581, the techniques presented are applicable to the next-generation interferometers, such as the long baselines of the Square Kilometre Array.

  3. First Light for Mimir, a Near-Infrared Wide-Field Imager, Spectrometer, and Polarimeter for the Perkins Telescope

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

    The Mimir instrument completed its 5-year development in our Boston University lab and was delivered this past July to Flagstaff, Arizona and the Perkins telescope for commissioning. Mimir is a "facility-class" multi-function near-infrared imager, spectrometer, and polarimeter developed under a joint program by Boston University and Lowell Observatory scientists, staff, and engineers. It fully covers the wavelength range 1-5 microns onto its 1024x1024 Aladdin III InSb array detector. In its wide-field imaging mode, a 10x10 arcmin field is sampled at 0.6 arcsec per pixel. In its narrow-field mode, the field is 3x3 arcmin, sampled at 0.2 arcsec per pixel. A full complement of JHKsL'M' broad-band filters are present in its four filter wheels. Spectroscopy is accomplished using a matched slit-plate and selector system, three grisms, and special spectroscopy filters (for order suppression). Polarimetry is accomplished using rotating half-wave plates and a fixed wire grid. All of these modes were certified in the lab; all have been certified at the Perkins telescope during the August/September commissioning run. Mode switches are accomplished in a matter of only seconds, making Mimir exceedingly versatile. The poster highlights the designs and components of Mimir as well as examples of images, spectra, and polarimetry from the commissioning telescope runs this past fall. Internal, shared-risk observations with Mimir begin this quarter. Mimir design and development has been funded by NASA, NSF, and the W.M. Keck Foundation.

  4. THE SIZE EVOLUTION OF PASSIVE GALAXIES: OBSERVATIONS FROM THE WIDE-FIELD CAMERA 3 EARLY RELEASE SCIENCE PROGRAM

    SciTech Connect

    Ryan, R. E. Jr. [Physics Department, University of California, Davis, CA 95616 (United States); McCarthy, P. J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); Cohen, S. H.; Rutkowski, M. J.; Mechtley, M. R.; Windhorst, R. A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Yan, H. [Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Hathi, N. P. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Koekemoer, A. M.; Bond, H. E.; Bushouse, H. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); O'Connell, R. W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Crockett, R. M. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Disney, M. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, M. A. [Research School of Astronomy and Astrophysics, The Australian National University, Weston Creek, ACT 2611 (Australia); Frogel, J. A. [Galaxies Unlimited, Lutherville, MD 21093 (United States); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Holtzman, J. A., E-mail: rryan@physics.ucdavis.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); and others

    2012-04-10

    We present the size evolution of passively evolving galaxies at z {approx} 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z {approx}> 1.5. We identify 30 galaxies in {approx}40 arcmin{sup 2} to H < 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 {mu}m {approx}< {lambda}{sub obs} {approx}< 1.6 {mu}m with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of {approx}0.033(1 + z). We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M{sub *} {approx} 10{sup 11} M{sub Sun }) undergo the strongest evolution from z {approx} 2 to the present. Parameterizing the size evolution as (1 + z){sup -{alpha}}, we find a tentative scaling of {alpha} Almost-Equal-To (- 0.6 {+-} 0.7) + (0.9 {+-} 0.4)log (M{sub *}/10{sup 9} M{sub Sun }), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of high-redshift systems. We discuss the implications of this result for the redshift evolution of the M{sub *}-R{sub e} relation for red galaxies.

  5. Atmospheric characterization of five hot Jupiters with the wide field Camera 3 on the Hubble space telescope

    SciTech Connect

    Ranjan, Sukrit; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Désert, Jean-Michel [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Madhusudhan, Nikku [Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06511 (United States); Deming, Drake; Wilkins, Ashlee [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Mandell, Avi M., E-mail: sranjan@cfa.harvard.edu [NASA's Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-04-20

    We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 ?m) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 ?m, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometric light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1? precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1? precision per bin corresponds to a planet-to-star flux ratio of 1.5 × 10{sup –4} and 2.1 × 10{sup –4} for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.

  6. A one-meter aperture wide-field camera for the Japanese exposure module on space station

    NASA Astrophysics Data System (ADS)

    Pennypacker, Carl; Ebisuzaki, Toshi; Handa, Toshihiro; Nugent, Peter; Fruchter, Andrew; Pain, Reynald; Aldering, Greg; Hammer, Francois; Groom, Don; Takahashi, Yoshi; Hadaway, James; Goobar, Ariel; Nomoto, Ken; Isaac, Maria; Goldhaber, Gerson; Perlmutter, Saul; MacKenty, John; Branch, David; Tsiopa, Olga; Gnedin, Yuri; Jochum, Josef

    1999-01-01

    We propose to construct and deploy a one-meter, wide field camera for cosmological, science education and other studies and site it on the International Space Station's Japanese Exposure Module (JEM). The SHOUT Telescope (for S_pace H_ands-O_n U_niverse T_elescope) is an inexpensive powerful instrument that will yield some of the most significant measurements in astrophysics. The detector would consist of a 15,000×15,000 pixel2 imaging CCD made of high-resistivity silicon, with quantum efficiency of approximately 50% at one micron. In addition, a single channel spectrograph is included for spectroscopy on any interesting photometric discoveries. Advances in graphite carbon mirrors and telescope construction enable an instrument weight of about 100-200 kg. Such a low-weight instrument could be placed on a mass-limited shuttle launch. This system would have a performance for finding point objects in a random field ~100x of that of the Advanced Camera system on HST at a wavelength of one micron. It would fill an under-exploited niche of the electromagnetic and time-variability spectrum and enable a broad range of synoptic measurements at high redshifts. In addition, cosmological effects measured in supernovae, quasars, galaxies, are large at z~1 to 2, ideally suited for I band studies-a region of great sensitivity for this instrument. The scientific program would include the discovery and follow-up of approximately 1000 Type 1a supernovae, discovery and studies of quasar lenses, a determination of this distribution and nature of micro-lensing sources, a deep field covering many square degrees in several colors to 27th magnitude and 0.2 arc-second resolution. A unique feature of this mission is that a strong collaboration between scientists, teachers, and students will be embedded in the operations of this system. Students will be able to collaborate on all of the science undertaken.

  7. A WIDE-FIELD PHOTOMETRIC SURVEY FOR EXTRATIDAL TAILS AROUND FIVE METAL-POOR GLOBULAR CLUSTERS IN THE GALACTIC HALO

    SciTech Connect

    Chun, Sang-Hyun; Lee, Young-Wook; Sohn, Young-Jong [Department of Astronomy, Yonsei University, Seoul 120-749 (Korea, Republic of); Kim, Jae-Woo [Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Sohn, Sangmo T. [Center for Space Astrophysics, Yonsei University, Seoul 120-749 (Korea, Republic of); Park, Jang-Hyun; Han, Wonyong; Kim, Ho-Il [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Lee, Myung Gyoon; Lee, Sang-Gak [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)], E-mail: sohnyj@yonsei.ac.kr

    2010-02-15

    Wide-field deep g'r'i' images obtained with the Megacam of the Canada-France-Hawaii Telescope are used to investigate the spatial configuration of stars around five metal-poor globular clusters M15, M30, M53, NGC 5053, and NGC 5466, in a field-of-view {approx}3 deg. Applying a mask filtering algorithm to the color-magnitude diagrams of the observed stars, we sorted cluster's member star candidates that are used to examine the characteristics of the spatial stellar distribution surrounding the target clusters. The smoothed surface density maps and the overlaid isodensity contours indicate that all of the five metal-poor globular clusters exhibit strong evidence of extratidal overdensity features over their tidal radii, in the form of extended tidal tails around the clusters. The orientations of the observed extratidal features show signatures of tidal tails tracing the clusters' orbits, inferred from their proper motions, and effects of dynamical interactions with the Galaxy. Our findings include detections of a tidal bridge-like feature and an envelope structure around the pair of globular clusters M53 and NGC 5053. The observed radial surface density profiles of target clusters have a deviation from theoretical King models, for which the profiles show a break at 0.5-0.7r{sub t} , extending the overdensity features out to 1.5-2r{sub t} . Both radial surface density profiles for different angular sections and azimuthal number density profiles confirm the overdensity features of tidal tails around the five metal-poor globular clusters. Our results add further observational evidence that the observed metal-poor halo globular clusters originate from an accreted satellite system, indicative of the merging scenario of the formation of the Galactic halo.

  8. Extragalactic Synchrotron Transients in the Era of Wide-field Radio Surveys. I. Detection Rates and Light Curve Characteristics

    NASA Astrophysics Data System (ADS)

    Metzger, Brian D.; Williams, P. K. G.; Berger, Edo

    2015-06-01

    The impending era of wide-field radio surveys has the potential to revolutionize our understanding of astrophysical transients. Here we evaluate the prospects of a wide range of planned and hypothetical radio surveys using the properties and volumetric rates of known and hypothetical classes of extragalactic synchrotron radio transients (e.g., on-axis and off-axis gamma-ray bursts (GRBs), supernovae, tidal disruption events, compact object mergers). Utilizing these sources and physically motivated considerations we assess the allowed phase space of radio luminosity and peak timescale for extragalactic transients. We also include for the first time effects such as redshift evolution of the rates, K-corrections, and non-Euclidean luminosity distance, which affect the detection rates of the most sensitive surveys. The number of detected events is calculated by means of a Monte Carlo method, using the various survey properties (depth, cadence, area) and realistic detection criteria that include a cut on the minimum variability of the transients during the survey and an assessment of host galaxy contamination. We find that near-term GHz frequency surveys (ASKAP/VAST, Very Large Array Sky Survey) will detect few events: ? 30-50 on- and off-axis long GRBs (LGRBs) and off-axis tidal disruption events, and ? 50-100 neutron star binary mergers if ? 0.5% of the mergers result in a stable millisecond magnetar. Low-frequency surveys (e.g., LOFAR) are unlikely to detect any transients, while a hypothetical large-scale mm survey may detect ?40 on-axis LGRBs. On the other hand, we find that SKA1 surveys at ? 0.1-1 GHz have the potential to uncover thousands of transients, mainly on-axis and off-axis LGRBs, on-axis short GRBs, off-axis TDEs, and neutron star binary mergers with magnetar remnants.

  9. Fire Spectroscopy of Five Late-type T Dwarfs Discovered with the Wide-field Infrared Survey Explorer

    NASA Astrophysics Data System (ADS)

    Burgasser, Adam J.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Griffith, Roger L.; Looper, Dagny L.; Tinney, Christopher; Simcoe, Robert A.; Bochanski, John J.; Skrutskie, Michael F.; Mainzer, A.; Thompson, Maggie A.; Marsh, Kenneth A.; Bauer, James M.; Wright, Edward L.

    2011-07-01

    We present the discovery of five late-type T dwarfs identified with the Wide-field Infrared Survey Explorer (WISE). Low-resolution near-infrared spectroscopy obtained with the Magellan Folded-port InfraRed Echellette reveal strong H2O and CH4 absorption in all five sources, and spectral indices and comparison to spectral templates indicate classifications ranging from T5.5 to T8.5:. The spectrum of the latest-type source, WISE J1812+2721, is an excellent match to that of the T8.5 companion brown dwarf Wolf 940B. WISE-based spectrophotometric distance estimates place these T dwarfs at 12-13 pc from the Sun, assuming they are single. Preliminary fits of the spectral data to the atmosphere models of Saumon & Marley indicate effective temperatures ranging from 600 K to 930 K, both cloudy and cloud-free atmospheres, and a broad range of ages and masses. In particular, two sources show evidence of both low surface gravity and cloudy atmospheres, tentatively supporting a trend noted in other young brown dwarfs and exoplanets. In contrast, the high proper motion T dwarf WISE J2018-7423 exhibits a suppressed K-band peak and blue spectrophotometric J - K colors indicative of an old, massive brown dwarf; however, it lacks the broadened Y-band peak seen in metal-poor counterparts. These results illustrate the broad diversity of low-temperature brown dwarfs that will be uncovered with WISE. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  10. The Size Evolution of Passive Galaxies: Observations From the Wide-Field Camera 3 Early Release Science Program

    NASA Technical Reports Server (NTRS)

    Ryan, R. E., Jr.; Mccarthy, P.J.; Cohen, S. H.; Yan, H.; Hathi, N. P.; Koekemoer, A. M.; Rutkowski, M. J.; Mechtley, M. R.; Windhorst, R. A.; O’Connell, R. W.; Balick, B.; Bond, H. E.; Bushouse, H.; Calzetti, D.; Crockett, R. M.; Disney, M.; Dopita, M. A.; Frogel, J. A.; Hall, D., N., B.; Holtzman, J. A.; Kaviraj, S.; Kimble, R. A.; MacKenty, J.; Trauger, J.; Young, E.

    2012-01-01

    We present the size evolution of passively evolving galaxies at z approximately 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z greater than approximately 1.5. We identify 30 galaxies in approximately 40 arcmin(sup 2) to H less than 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 micrometers less than approximately lambda (sub obs) 1.6 micrometers with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of approximately 0.033(1+z).We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M(sub *) approximately 10(sup 11) solar mass) undergo the strongest evolution from z approximately 2 to the present. Parameterizing the size evolution as (1 + z)(sup - alpha), we find a tentative scaling of alpha approximately equals (-0.6 plus or minus 0.7) + (0.9 plus or minus 0.4) log(M(sub *)/10(sup 9 solar mass), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of highredshift systems. We discuss the implications of this result for the redshift evolution of the M(sub *)-R(sub e) relation for red galaxies.

  11. Seeing the corona with the solar probe plus mission: the wide-field imager for solar probe+ (WISPR)

    NASA Astrophysics Data System (ADS)

    Vourlidas, Angelos; Howard, Russell A.; Plunkett, Simon P.; Korendyke, Clarence M.; Carter, Michael T.; Thernisien, Arnaud F. R.; Chua, Damien H.; Van Duyne, Peter; Socker, Dennis G.; Linton, Mark G.; Liewer, Paulett C.; Hall, Jeffrey R.; Morrill, Jeff S.; DeJong, Eric M.; Mikic, Zoran; Rochus, Pierre L. P. M.; Bothmer, Volker; Rodman, Jens; Lamy, Philippe

    2013-09-01

    The Solar Probe Plus (SPP) mission scheduled for launch in 2018, will orbit between the Sun and Venus with diminishing perihelia reaching as close as 7 million km (9.86 solar radii) from Sun center. In addition to a suite of in-situ probes for the magnetic field, plasma, and energetic particles, SPP will be equipped with an imager. The Wide-field Imager for the Solar PRobe+ (WISPR), with a 95° radial by 58° transverse field of view, will image the fine-scale coronal structure of the corona, derive the 3D structure of the large-scale corona, and determine whether a dust-free zone exists near the Sun. Given the tight mass constrains of the mission, WISPR incorporates an efficient design of two widefield telescopes and their associated focal plane arrays based on novel large-format (2kx2k) APS CMOS detectors into the smallest heliospheric imaging package to date. The flexible control electronics allow WISPR to collect individual images at cadences up to 1 second at perihelion or sum several of them to increase the signal-to-noise during the outbound part of the orbit. The use of two telescopes minimizes the risk of dust damage which may be considerable close to 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.

  12. Wide-Field-of-View Millimeter-Wave Telescope Design with Ultra-Low Cross-Polarization

    SciTech Connect

    Bernacki, Bruce E.; Kelly, James F.; Sheen, David M.; Hatchell, Brian K.; Valdez, Patrick LJ; Tedeschi, Jonathan R.; Hall, Thomas E.; McMakin, Douglas L.

    2012-05-01

    As millimeter-wave arrays become available, off-axis imaging performance of the fore optics increases in importance due to the relatively large physical extent of the arrays. Typically, simple optical telescope designs are adapted to millimeter-wave imaging but single-mirror spherical or classic conic designs cannot deliver adequate image quality except near the optical axis. Since most millimeter-wave designs are quasi-optical, optical ray tracing and commercial design software can be used to optimize designs to improve off-axis imaging as well as minimize cross-polarization. Methods that obey the Dragone-Mizuguchi condition for the design of reflective millimeter-wave telescopes with low cross-polarization also provide additional degrees of freedom that offer larger fields of view than possible with single-reflector designs. Dragone’s graphical design method does not lend itself readily to computer-based optical design approaches, but subsequent authors expanded on Dragone’s geometric design approach with analytic expressions that describe the location, shape, off-axis height and tilt of the telescope elements that satisfy Dragone’s design rules and can be used as a first-order design for subsequent computer-based design and optimization. We investigate two design variants that obey the Dragone-Mizuguchi conditions that exhibit ultra-low polarization crosstalk and a large diffraction-limited field of view well suited to millimeter-wave imaging arrays.

  13. Evidence of a hot population in the SMC/LMC bridge detected by the very wide field camera of Spacelab-1

    NASA Technical Reports Server (NTRS)

    Viton, M.; Sivan, M. J. P.; Courtes, M. G.; Gary, M. A.; Decher, R.

    1985-01-01

    Deep 66-degree field photographs of the sky have been taken by the SL - 1 Very Wide Field Camera (experiment 1-ES-022) at 1650, 1930 and 2530 A, with a limiting magnitude of 9.3 at 1930 A. A 1, 2 x 2, 4 Kpc ultraviolet extension of the Shapley's wing of the Small Magellanic Cloud is revealed.

  14. Galaxy formation in the reionization epoch as hinted by Wide Field Camera 3 observations of the Hubble Ultra Deep Field

    NASA Astrophysics Data System (ADS)

    Yan, Hao-Jing; Windhorst, Rogier A.; Hathi, Nimish P.; Cohen, Seth H.; Ryan, Russell E.; O'Connell, Robert W.; McCarthy, Patrick J.

    2010-09-01

    We present a large sample of candidate galaxies at z approx 7-10, selected in the Hubble Ultra Deep Field using the new observations of the Wide Field Camera 3 that was recently installed on the Hubble Space Telescope. Our sample is composed of 20 z850-dropouts (four new discoveries), 15 Y105-dropouts (nine new discoveries) and 20 J125-dropouts (all new discoveries). The surface densities of the z850-dropouts are close to what was predicted by earlier studies, however, those of the Y105- and J125-dropouts are quite unexpected. While no Y105- or J125-dropouts have been found at AB <= 28.0 mag, their surface densities seem to increase sharply at fainter levels. While some of these candidates seem to be close to foreground galaxies and thus could possibly be gravitationally lensed, the overall surface densities after excluding such cases are still much higher than what would be expected if the luminosity function does not evolve from z ~ 7 to 10. Motivated by such steep increases, we tentatively propose a set of Schechter function parameters to describe the luminosity functions at z approx 8 and 10. As compared to their counterpart at z approx 7, here L* decreases by a factor of ~ 6.5 and varphi* increases by a factor of 17-90. Although such parameters are not yet demanded by the existing observations, they are allowed and seem to agree with the data better than other alternatives. If these luminosity functions are still valid beyond our current detection limit, this would imply a sudden emergence of a large number of low-luminosity galaxies when looking back in time to z approx 10, which, while seemingly exotic, would naturally fit in the picture of the cosmic hydrogen reionization. These early galaxies could easily account for the ionizing photon budget required by the reionization, and they would imply that the global star formation rate density might start from a very high value at z approx 10, rapidly reach the minimum at z approx 7, and start to rise again towards z approx 6. In this scenario, the majority of the stellar mass that the universe assembled through the reionization epoch seems still undetected by current observations at z approx 6.

  15. Binarity in Brown Dwarfs: T Dwarf Binaries Discovered with the Hubble Space Telescope Wide Field Planetary Camera 2

    NASA Astrophysics Data System (ADS)

    Burgasser, Adam J.; Kirkpatrick, J. Davy; Reid, I. Neill; Brown, Michael E.; Miskey, Cherie L.; Gizis, John E.

    2003-03-01

    We present the discovery of two T dwarf binaries, 2MASS 1225-2739AB and 2MASS 1534-2952AB, identified in a sample of 10 T dwarfs imaged with the Hubble Space Telescope (HST) Wide Field Planetary Camera 2. Companionship is established by the uniquely red F814W-F1042M colors of the binary components, caused by heavily pressure-broadened K I absorption centered at 7665 and 7699 Å. The separations of the two binary systems are 0.282"+/-0.005" and 0.065"+/-0.007", implying projected separations of 3.17+/-0.14 and 1.0+/-0.3 AU, respectively. These close separations are similar to those found in previous brown dwarf binary searches and permit orbital mapping over the coming decade. 2MASS 1225-2739AB has a substantially fainter secondary, with ?MF814W=1.59+/-0.04 and ?MF1042M=1.05+/-0.03 this system is likely composed of a T6 primary and T8 secondary with mass ratio 0.7-0.8. The observed binary fraction of our HST sample, 20+17-7%, is consistent with results obtained for late-type M and L field dwarfs and implies a bias-corrected binary fraction of 9+15-4% for a>~1 AU and q>~0.4, significantly lower than the binary fractions of F-G and early-type M dwarf stars. Neither of the T binaries have separations a>~10 AU, consistent with results from other brown dwarf binary searches. Using the statistical models of Weinberg, Shapiro, & Wasserman, we conclude that tidal disruption by passing stars or giant molecular clouds, which limits the extent of wide stellar binaries, plays no role in eliminating wide brown dwarf binaries, implying either disruption very early in the formation process (ages <~1-10 Myr) or a formation mechanism that precludes such systems. We find that the maximum binary separation in the brown dwarf regime appears to scale as M2total, a possible clue to the physical mechanism that restricts wide substellar systems.

  16. Wide-field time-domain fluorescence lifetime imaging microscopy (FLIM): Molecular snapshots of metabolic function in biological systems

    NASA Astrophysics Data System (ADS)

    Sud, Dhruv

    2008-12-01

    Steady-state fluorescence imaging is routinely employed to obtain physiological information but is susceptible to artifacts such as absorption and photobleaching. FLIM provides an additional source of contrast oblivious to these but is affected by factors such as pH, gases, and temperature. Here we focused on developing a resolution-enhanced FLIM system for quantitative oxygen sensing. Oxygen is one of the most critical components of metabolic machinery and affects growth, differentiation, and death. FLIM-based oxygen sensing provides a valuable tool for biologists without the need of alternate technologies. We also developed novel computational approaches to improve spatial resolution of FLIM images, extending its potential for thick tissue studies. We designed a wide-field time-domain UV-vis-NIR FLIM system with high temporal resolution (50 ps), large temporal dynamic range (750 ps -- 1 mus), short data acquisition/processing times (15 s) and noise-removal capability. Lifetime calibration of an oxygen-sensitive, ruthenium dye (RTDP) enabled in vivo oxygen level measurements (resolution = 8 muM, range = 1 -- 300 muM). Combining oxygen sensing with endogenous imaging allowed for the study of two key molecules (NADH and oxygen) consumed at the termini of the oxidative phosphorylation pathway in Barrett's adenocarcinoma columnar (SEG-1) cells and Esophageal normal squamous cells (HET-1). Starkly higher intracellular oxygen and NADH levels in living SEG-1 vs. HET-1 cells were detected by FLIM and attributed to altered metabolic pathways in malignant cells. We performed FLIM studies in microfluidic bioreactors seeded with mouse myoblasts. For these systems, oxygen concentrations play an important role in cell behavior and gene expression. Oxygen levels decreased with increasing cell densities and were consistent with simulated model outcomes. In single bioreactor loops, FLIM detected spatial heterogeneity in oxygen levels as high as 20%. We validated our calibration with EPR spectroscopy, the gold standard for intracellular oxygen measurements. Differences between FLIM and EPR results were explained by cell lysate-FLIM studies. We proposed a new protocol for estimating oxygen levels by using a reference cell line and cellular lysate analysis. Lastly, we proposed and compared two different image restoration approaches, direct lifetime vs. intensity-overlay. Both approaches improve resolution while maintaining veracity of lifetime.

  17. Atmospheric tomography with Rayleigh laser beacons for correction of wide fields and 30-m-class telescopes

    Microsoft Academic Search

    J. Roger P. Angel; Michael Lloyd-Hart

    2000-01-01

    Single sodium beacons will likely be the most convenient for adaptive systems to correct 6 - 10 m class telescopes over a small field of view (the isoplanatic angle), provided reliable, powerful 589 nm lasers become available and affordable. However, when adaptive optics are applied to extended fields of view and correction of telescopes as large as 32 m diameter,

  18. Ionization Structure in the 30 Doradus Nebula as seen with Hubble Space Telescope Wide Field Planetary Camera 2

    NASA Astrophysics Data System (ADS)

    Scowen, P. A.; Hester, J. J.; Sankrit, R.; Gallagher, J. S.; Ballester, G. E.; Burrows, C. J.; Clarke, J. T.; Crisp, D.; Evans, R. W.; Griffiths, R. E.; Hoessel, J. G.; Holtzman, J. A.; Krist, J.; Mould, J. R.; Stapelfeldt, K. R.; Trauger, J. T.; Watson, A. M.; Westphal, J. A.

    1998-07-01

    Using the Hubble Space Telescope (HST) and Wide Field Planetary Camera 2, we have imaged the central 20 pc of the giant H ii region 30 Doradus Nebula in three different emission lines. The images allow us to study the nebula with a physical resolution that is within a factor of 2 of that of typical ground-based observations of Galactic H ii regions. We present a gallery of interesting objects within the region studied. These include a tube blown by the wind of a high-velocity star and a discrete H ii region around an isolated B star. This small isolated H ii region appears to be in the midst of the champagne flow phase of its evolution. Most of the emission within 30 Dor is confined to a thin zone located between the hot interior of the nebula and surrounding dense molecular material. This zone appears to be directly analogous to the photoionized photoevaporative flows that dominate emission from small, nearby H ii regions. For example, a column of material protruding from the cavity wall to the south of the main cluster is found to be a direct analog to elephant trunks in M16. Surface brightness profiles across this structure are very similar to surface brightness profiles taken at ground-based resolution across the head of the largest column in M16. The dynamical effects of the photoevaporative flow can be seen as well. An arcuate feature located above this column and a similar feature surrounding a second nearby column are interpreted as shocks in which the photoevaporative flow stagnates against the high-temperature gas that fills the majority of the nebula. The ram pressure in the photoevaporative flow, derived from thermal pressure at the surface of the column, is found to balance with the pressure in the interior of the nebula derived from previous X-ray observations. By analogy with the comparison of ground-based and HST images of M16, we infer that the same sharply stratified structure seen in HST images of M16 almost certainly underlies the observed structure in 30 Doradus, which is a crucial case because it allows us to bridge the gap between nearby H ii regions and the giant H ii regions seen in distant galaxies. The real significance of this result is that it demonstrates that the physical understanding gained from detailed study of photoevaporative interfaces in nearby H ii regions can be applied directly to interpretation of giant H ii regions. Stated another way, interpretation of observations of giant H ii regions must account for the fact that this emission arises not from expansive volumes of ionized gas but instead from highly localized and extremely sharply stratified physical structures.

  19. A wide field survey at the Northern Ecliptic Pole I: Number counts and angular correlation functions in K

    E-print Network

    M. W. Kuemmel; S. J. Wagner

    1999-11-10

    We present the results from a multi colour survey performed at the Northern Ecliptic Pole (NEP). The survey is designed to identify the counterparts of faint sources from the ROSAT All Sky Survey and the IRAS survey and to study their optical/near-infrared properties. We observed the central square degree around the NEP in the optical bands B_J and R and in the near-infrared band K. A shallower survey was carried out in the optical I band. Here we present the results of the K-band survey. We discuss the source counts in the magnitude range 7mag < K < 17.5mag and the angular correlation function of galaxies with K < 17.0mag. The galaxy counts at the NEP display a subeuklidean slope in dlog(N)/dm. Our shallower slope does not require the large effects of galaxy evolution or density evolution suggested to explain the steeper slopes found in earlier surveys. The angular correlation function of galaxies follows a power law w(\\theta) = A\\theta^-\\delta with A=5.7+-0.8 x 10^-3 and \\delta=0.98+-0.15. This is in accordance with the expected values for stable clustering.

  20. FLAMINGOS-2: The Facility Near-Infrared Wide-field Imager & Multi-Object Spectrograph for Gemini

    E-print Network

    Eikenberry, S; Bennett, J G; Bessoff, A; Branch, M; Corley, R; Dunn, J; Elston, R; Eriksen, J D; Fletcher, M; Frommeyer, S; Gardhouse, W R; González, A; Hanna, K; Hardy, T; Herlevich, M; Hon, D; Julian, J; Julian, R; Leckie, B; Marin-Franch, A; Martí, J; Murphey, C; Raines, S N; Rashkin, D; Warner, C; Wooff, R; Bessoff, Aaron; Branch, Matt; Corley, Richard; Dunn, Jennifer; Eikenberry, Stephen; Elston, Richard; Eriksen, John-David; Fletcher, Murray; Frommeyer, Skip; Gonzalez, Anthony; Hanna, Kevin; Hardy, Tim; Herlevich, Michael; Hon, David; Julian, Jeff; Julian, Roger; Leckie, Brian; Marin-Franch, Antonio; Marti, Jose; Murphey, Charlie; Rashkin, David; Warner, Craig; Wooff, Robert

    2006-01-01

    We report on the design and status of the FLAMINGOS-2 instrument - a fully-cryogenic facility near-infrared imager and multi-object spectrograph for the Gemini 8-meter telescopes. FLAMINGOS-2 has a refractive all-spherical optical system providing 0.18-arcsecond pixels and a 6.2-arcminute circular field-of-view on a 2048x2048-pixel HAWAII-2 0.9-2.4 mm detector array. A slit/decker wheel mechanism allows the selection of up to 9 multi-object laser-machined plates or 3 long slits for spectroscopy over a 6x2-arcminute field of view, and selectable grisms provide resolutions from $\\sim$ 1300 to $\\sim $3000 over the entire spectrograph bandpass. FLAMINGOS-2 is also compatible with the Gemini Multi-Conjugate Adaptive Optics system, providing multi-object spectroscopic capabilities over a 3x1-arcminute field with high spatial resolution (0.09-arcsec/pixel). We review the designs of optical, mechanical, electronics, software, and On-Instrument WaveFront Sensor subsystems. We also present the current status of the pro...

  1. The design of passively athermalized narrow- and wide-field-of-view infrared objectives for the OBSERVER unmanned air vehicle

    NASA Astrophysics Data System (ADS)

    Simmons, Richard C.; Manning, Paul A.; Chamberlain, Trevor V.

    2004-12-01

    Some years ago QinetiQ introduced a short-range reconnaissance unmanned air vehicle (UAV), known as OBSERVER, which carried a visible three-camera sensor. To increase its versatility, a compatible infrared (IR) thermal imaging (TI) sensor was developed for the vehicle for operation in the 8-12mm waveband with a dual field of view function. The sensor incorporates a specially designed camera board, employing two IR lead scandium tantalate (PST) detectors based on UK un-cooled TI technology. Since no cooling engine is required for the detectors, the sensor module is very lightweight and hence well suited to its UAV application. So as to achieve the minimum possible payload for the vehicle, in addition to the lightweight detectors and electronics board, compact low mass optical solutions were devised for the camera objectives. These functioned at a relative aperture of f/1.0 and were designed to provide stable focus and imaging performance over a comparatively large temperature span (-10°C to + 50°C) to enable all weather operation. In order to achieve an athermalisation scheme devoid of elaborate electro-mechanical drives, thermally passive solutions were developed for the objectives in which the differing thermal characteristics of the components were designed to self-cancel optically. In this paper, the design and performance limitations of the optics are discussed and the procedure employed for establishing a thin lens pre-design for one of the objectives is described.

  2. Mid-infrared Selection of Active Galactic Nuclei with the Wide-field Infrared Survey Explorer. II. Properties of WISE-selected Active Galactic Nuclei in the NDWFS Boötes Field

    NASA Astrophysics Data System (ADS)

    Assef, R. J.; Stern, D.; Kochanek, C. S.; Blain, A. W.; Brodwin, M.; Brown, M. J. I.; Donoso, E.; Eisenhardt, P. R. M.; Jannuzi, B. T.; Jarrett, T. H.; Stanford, S. A.; Tsai, C.-W.; Wu, J.; Yan, L.

    2013-07-01

    Stern et al. presented a study of Wide-field Infrared Survey Explorer (WISE) selection of active galactic nuclei (AGNs) in the 2 deg2 COSMOS field, finding that a simple criterion W1-W2 >= 0.8 provides a highly reliable and complete AGN sample for W2 < 15.05, where the W1 and W2 passbands are centered at 3.4 ?m and 4.6 ?m, respectively. Here we extend this study using the larger 9 deg2 NOAO Deep Wide-Field Survey Boötes field which also has considerably deeper WISE observations than the COSMOS field, and find that this simple color cut significantly loses reliability at fainter fluxes. We define a modified selection criterion combining the W1-W2 color and the W2 magnitude to provide highly reliable or highly complete AGN samples for fainter WISE sources. In particular, we define a color-magnitude cut that finds 130 ± 4 deg-2 AGN candidates for W2 < 17.11 with 90% reliability. Using the extensive UV through mid-IR broadband photometry available in this field, we study the spectral energy distributions of WISE AGN candidates. We find that, as expected, the WISE AGN selection can identify highly obscured AGNs, but that it is biased toward objects where the AGN dominates the bolometric luminosity output. We study the distribution of reddening in the AGN sample and discuss a formalism to account for sample incompleteness based on the step-wise maximum-likelihood method of Efstathiou et al. The resulting dust obscuration distributions depend strongly on AGN luminosity, consistent with the trend expected for a receding torus. At L AGN ~ 3 × 1044 erg s-1, 29% ± 7% of AGNs are observed as Type 1, while at ~4 × 1045 erg s-1 the fraction is 64% ± 13%. The distribution of obscuration values suggests that dust in the torus is present as both a diffuse medium and in optically thick clouds.

  3. The Hubble Space Telescope Wide Field Camera 3 Early Release Science Data: Panchromatic Faint Object Counts for 0.2-2 mum Wavelength

    Microsoft Academic Search

    Rogier A. Windhorst; Seth H. Cohen; Nimish P. Hathi; Patrick J. McCarthy; Russell E. Ryan Jr.; Haojing Yan; Ivan K. Baldry; Simon P. Driver; Jay A. Frogel; David T. Hill; Lee S. Kelvin; Anton M. Koekemoer; Matt Mechtley; Robert W. O'Connell; Aaron S. G. Robotham; Michael J. Rutkowski; Mark Seibert; Amber N. Straughn; Richard J. Tuffs; Bruce Balick; Howard E. Bond; Howard Bushouse; Daniela Calzetti; Mark Crockett; Michael J. Disney; Michael A. Dopita; Donald N. B. Hall; Jon A. Holtzman; Sugata Kaviraj; Randy A. Kimble; John W. MacKenty; Max Mutchler; Francesco Paresce; Abihit Saha; Joseph I. Silk; John T. Trauger; Alistair R. Walker; Bradley C. Whitmore; Erick T. Young

    2011-01-01

    We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early Release Science (ERS) observations in the Great Observatories Origins Deep Survey (GOODS) South field. The new WFC3 ERS data provide calibrated, drizzled mosaics in the UV filters F225W, F275W, and F336W, as well as in the near-IR filters F098M (Ys ), F125W (J), and F160W (H) with

  4. Global Measurements of the Magnetic Field of the Inner Heliosphere with the Mileura Wide Field Array in Support of LWS Sentinels

    Microsoft Academic Search

    J. C. Kasper; O. D; J. E. Salah; C. J. Lonsdale

    2006-01-01

    The Mileura Wide-Field Array Low Frequency Demonstrator (MWA) is an 80-300 MHz interferometric radio array consisting of 8000 antennas distributed in 16-antenna tiles over several square kilometers in Mileura Station, Western Australia. Selected by the NSF in June 2006, antenna deployment will begin in 2007, and the array is scheduled to become operational within three years. The primary goal of

  5. Influence of ocean circulation on phytoplankton biomass distribution in the Balearic Sea: Study based on Sea-viewing Wide Field-of-view Sensor and altimetry satellite data

    Microsoft Academic Search

    Antoni Jordi; Gotzon Basterretxea; Sílvia Anglès

    2009-01-01

    This paper analyzes the spatial time series of surface chlorophyll (Chl) from the Sea-viewing Wide Field-of-view Sensor and sea level anomaly (SLA) from altimetry satellite data from July 2002 to December 2007 in order to characterize the influence of the regional circulation on the phytoplankton biomass in the Balearic Sea. Correlations between Chl and SLA at seasonal and interannual time

  6. HST Cycle 21 Focus and Optical Monitor

    NASA Astrophysics Data System (ADS)

    Cox, Colin

    2013-10-01

    This program is the Cycle 21 implementation of the HST Optical Monitoring Program. The 9 orbits comprising this proposal will utilize ACS {Wide Field channel} and WFC3 {UVIS channel} to observe stellar cluster members in parallel with multiple exposures over an orbit. Phase retrieval performed on the PSF in each image will be used to measure primarily focus, with the ability to explore apparent coma, astigmatism, and third order spherical changes in WFC3. The goals of this program are to:1.} monitor the overall OTA focal length for the purposes of maintaining focus within science tolerances.2.} gain experience with the relative effectiveness of phase retrieval on WFC3/UVIS PSFs.3.} determine focus offset between the imagers and identify any SI-specific focus behavior and dependencies.If need is determined, future visits will be modified to interleave WFC3/IR channel and STIS/CCD focii measurements.

  7. HST Cycle 19 Focus and Optical Monitor

    NASA Astrophysics Data System (ADS)

    Cox, Colin

    2011-10-01

    This program is the Cycle 18 implementation of the HST Optical Monitoring Program. The 12 orbits comprising this proposal will utilize ACS {Wide Field channel} and WFC3 {UVIS channel} to observe stellar cluster members in parallel with multiple exposures over an orbit. Phase retrieval performed on the PSF in each image will be used to measure primarily focus, with the ability to explore apparent coma, astigmatism, and third order spherical changes in WFC3. The goals of this program are to:1.} monitor the overall OTA focal length for the purposes of maintaining focus within science tolerances.2.} gain experience with the relative effectiveness of phase retrieval on WFC3/UVIS PSFs.3.} determine focus offset between the imagers and identify any SI-specific focus behavior and dependencies.If need is determined, future visits will be modified to interleave WFC3/IR channel and STIS/CCD focii measurements.

  8. HST Cycle 20 Focus and Optical Monitor

    NASA Astrophysics Data System (ADS)

    Cox, Colin

    2012-10-01

    TBDThis program is the Cycle 20 implementation of the HST Optical Monitoring Program. The 11 orbits comprising this proposal will utilize ACS {Wide Field channel} and WFC3 {UVIS channel} to observe stellar cluster members in parallel with multiple exposures over an orbit. Phase retrieval performed on the PSF in each image will be used to measure primarily focus, with the ability to explore apparent coma, astigmatism, and third order spherical changes in WFC3. The goals of this program are to:1.} monitor the overall OTA focal length for the purposes of maintaining focus within science tolerances.2.} gain experience with the relative effectiveness of phase retrieval on WFC3/UVIS PSFs.3.} determine focus offset between the imagers and identify any SI-specific focus behavior and dependencies.If need is determined, future visits will be modified to interleave WFC3/IR channel and STIS/CCD focii measurements.

  9. HST Cycle 18 Focus and Optical Monitor

    NASA Astrophysics Data System (ADS)

    Cox, Colin

    2010-09-01

    This program is the Cycle 18 implementation of the HST Optical Monitoring Program. The 12 orbits comprising this proposal will utilize ACS {Wide Field channel} and WFC3 {UVIS channel} to observe stellar cluster members in parallel with multiple exposures over an orbit. Phase retrieval performed on the PSF in each image will be used to measure primarily focus, with the ability to explore apparent coma, astigmatism, and third order spherical changes in WFC3. The goals of this program are to:1.} monitor the overall OTA focal length for the purposes of maintaining focus within science tolerances.2.} gain experience with the relative effectiveness of phase retrieval on WFC3/UVIS PSFs.3.} determine focus offset between the imagers and identify any SI-specific focus behavior and dependencies.If need is determined, future visits will be modified to interleave WFC3/IR channel and STIS/CCD focii measurements.

  10. Using wide-field quantitative diffuse reflectance spectroscopy in combination with high-resolution imaging for margin assessment

    NASA Astrophysics Data System (ADS)

    Kennedy, Stephanie; Mueller, Jenna; Bydlon, Torre; Brown, J. Quincy; Ramanujam, Nimmi

    2011-03-01

    Due to the large number of women diagnosed with breast cancer and the lack of intra-operative tools, breast cancer margin assessment presents a significant unmet clinical need. Diffuse reflectance spectral imaging provides a method for quantitatively interrogating margins of lumpectomy specimens. We have previously found that [?- carotene]/?s' is a diagnostically important parameter but both parameters, [?-carotene] and ?s', were derived from a low resolution parameter map and are subject to the tissue type and heterogeneity present in the breast. In this study, we used diffuse reflectance measurements from individual sites co-registered with high resolution microendoscopy (HRME) images to determine if the combined performance of these technologies could improve margin assessment. By comparing the optical parameters of [?-carotene] and ?s' to the quantitative HRME image endpoints of feature size, feature density and normalized fluorescence, we determined that adding HRME to spectral imaging can improve the specificity of our diffuse reflectance spectral imaging system.

  11. XMS and NG1dF: extreme multiplex spectrographs for wide-field multi-object spectroscopy

    NASA Astrophysics Data System (ADS)

    Content, Robert; Barden, Sam; Becerril, Santiago; Boehm, Armin; Clark, Paul; Costillo, Pedro; Dubbeldam, C. Mark; Farrell, Tony; Glazebrook, Karl; Haynes, Roger; Meisenheimer, Klaus; Miziarski, Stan; Nikoloudakis, Nikolaos; Prada, Luis Francisco; Rohloff, Ralf-Rainer; Shanks, Tom; Sharples, Ray M.; Wagner, Karl

    2010-07-01

    Two feasibility studies for spectrographs that can deliver at least 4000 MOS slits over a 1° field at the prime focuses of the Anglo-Australian and Calar Alto Observatories have been completed. We describe the design and science case of the Calar Alto eXtreme Multiplex Spectrograph (XMS) for which an extended study, half way between feasibility study and phase-A, was made. The optical design is quite similar than in the AAO study for the Next Generation 1 degree Field (NG1dF) but the mechanical design of XMS is quite different and much more developed. In a single night, 25000 galaxy redshifts can be measured to z~0.7 and beyond for measuring the Baryon Acoustic Oscillation (BAO) scale and many other science goals. This may provide a low-cost alternative to WFMOS for example and other large fibre spectrographs. The design features four cloned spectrographs which gives a smaller total weight and length than a unique spectrograph to makes it placable at prime focus. The clones use a transparent design including a grism in which all optics are about the size or smaller than the clone rectangular subfield so that they can be tightly packed with little gaps between subfields. Only low cost glasses are used; the variations in chromatic aberrations between bands are compensated by changing a box containing the grism and two adjacent lenses. Three bands cover the 420nm to 920nm wavelength range at 10A resolution while another cover the Calcium triplet at 3A. An optional box does imaging. We however also studied different innovative methods for acquisition without imaging. A special mask changing mechanism was also designed to compensate for the lack of space around the focal plane. Conceptual designs for larger projects (AAT 2º field, CFHT, VISTA) have also been done.

  12. Recent progress and future prospect of optical communication systems using InP based opto-electronic devices

    Microsoft Academic Search

    Kohroh Kobayashi

    1998-01-01

    Since the very early research and development stage of optical fiber communication systems in mid 1970's, their performance has been drastically and continuously improved. For example, the transmission bit-rate and the transmission distance product of optical fiber communication systems has progressed more than million times over the 20 years. There were many factors behind the progress. Strong demand for the

  13. High speed (>100 Gbps) key components for a scalable optical data link to be implemented in future maskless lithography applications

    Microsoft Academic Search

    A. Paraskevopoulos; S.-H. Voss; M. Talmi; G. Walf

    2009-01-01

    Maskless lithography based on electron beam parallelization requires well adapted data links, capable of transmitting the corresponding data volume at rates up to the Tbps domain. In this paper we focus on two key components, the high-speed data buffer unit and the integrated optical receiver, which are part of a scalable (24 - 140 Gbps) optical data link. The high-speed

  14. WIDE-FIELD VLBI OBSERVATIONS OF M31: A UNIQUE PROBE OF THE IONIZED INTERSTELLAR MEDIUM OF A NEARBY GALAXY

    SciTech Connect

    Morgan, John S.; Argo, Megan K.; Trott, Cathryn M.; Macquart, Jean-Pierre; Miller-Jones, James; Tingay, Steven J. [International Center for Radio Astronomy Research, Curtin University, G.P.O. Box U1987, Perth, WA 6845 (Australia); Deller, Adam [ASTRON, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo (Netherlands); Middelberg, Enno, E-mail: john.morgan@icrar.org [Astronomisches Institut der Ruhr-Universitaet Bochum, Universitaetsstrasse 150, D-44801 Bochum (Germany)

    2013-05-01

    The Very Long Baseline Array was used at 1.6 GHz to observe a target field 50' in diameter including the core of M31. Novel very long baseline interferometry correlation techniques were used to observe 200 sources simultaneously, of which 16 were detected. We classify all 16 as background active galactic nuclei based on their X-ray properties and arcsecond- and mas-scale morphology. The detected sources were then analyzed for evidence of scatter-broadening due to the ionized interstellar medium (ISM) of M31. The detection of a compact background source only 0.25 kpc projected distance from M31* places a constraint on the extent of any extreme scattering region associated with the center of M31. However, the two sources closest to the core show evidence of scatter broadening consistent with that which would be seen for a compact source if it were observed through the inner disk of our Galaxy, at the inclination of M31. We interpret this as a detection of the ionized ISM of M31 along two lines of sight. With the increases in bandwidth and sensitivity envisaged for future long-baseline interferometers, this should prove to be a remarkably powerful technique for understanding the ionized ISM in external galaxies.

  15. LSST Camera Optics Design

    SciTech Connect

    Riot, V J; Olivier, S; Bauman, B; Pratuch, S; Seppala, L; Gilmore, D; Ku, J; Nordby, M; Foss, M; Antilogus, P; Morgado, N

    2012-05-24

    The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope mirrors to optimize performance. We discuss the rationale for the LSST camera optics design, describe the methodology for fabricating, coating, mounting and testing the lenses and filters, and present the results of detailed analyses demonstrating that the camera optics will meet their performance goals.

  16. SUBARU Wide Field Imaging Of Near-infrared [ Fe II ] And H2 Toward L1551 And XZ \\/ HL Tau Regions

    Microsoft Academic Search

    Tae-Soo Pyo; M. Hayashi

    2007-01-01

    We present wide-field imaging of near-infrared [Fe II], H2, H-, and Ks-bands around L1551 and XZ\\/HL Tau regions taken by MOIRCS (Multi-Object InfraRed Camera and Spectrograph) equipped on Subaru Telescope atop Mauna Kea of Hawaii. The total FOV of mosaic image is 14.4' X 16.8'. We report new features in L1551, L1551-NE, XZ\\/HL Tau, HH30 region: (1) a redshifted jet

  17. Optical imaging in vivo with a focus on paediatric disease: technical progress, current preclinical and clinical applications and future perspectives

    Microsoft Academic Search

    Joanna Napp; Julia E. Mathejczyk; Frauke Alves

    2011-01-01

    To obtain information on the occurrence and location of molecular events as well as to track target-specific probes such as\\u000a antibodies or peptides, drugs or even cells non-invasively over time, optical imaging (OI) technologies are increasingly applied.\\u000a Although OI strongly contributes to the advances made in preclinical research, it is so far, with the exception of optical\\u000a coherence tomography (OCT),

  18. Adaptive optics point spread function reconstruction: lessons learned from on-sky experiment on Altair/Gemini and pathway for future systems

    E-print Network

    Jolissaint, Laurent; Tolstoy, Eline; Wizinowich, Peter

    2010-01-01

    We present the results of an on-sky point spread function reconstruction (PSF-R) experiment for the Gemini North telescope adaptive optics system, Altair, in the simplest mode, bright on-axis natural guise star. We demonstrate that our PSF-R method does work for system performance diagnostic but suffers from hidden telescope and system aberrations that are not accounted for in the model, making the reconstruction unsuccessful for Altair, for now. We discuss the probable origin of the discrepancy. In the last section, we propose alternative PSF-R methods for future multiple natural and laser guide stars systems.

  19. Adaptive optics point spread function reconstruction: lessons learned from on-sky experiment on Altair/Gemini and pathway for future systems

    NASA Astrophysics Data System (ADS)

    Jolissaint, Laurent; Christou, Julian; Wizinowich, Peter; Tolstoy, Eline

    2010-07-01

    We present the results of an on-sky point spread function reconstruction (PSF-R) experiment for the Gemini North telescope adaptive optics system, Altair, in the simplest mode, bright on-axis natural guise star. We demonstrate that our PSF-R method does work for system performance diagnostic but suffers from hidden telescope and system aberrations that are not accounted for in the model, making the reconstruction unsuccessful for Altair, for now. We discuss the probable origin of the discrepancy. In the last section, we propose alternative PSF-R methods for future multiple natural and laser guide stars systems.

  20. Global Measurements of the Magnetic Field of the Inner Heliosphere with the Mileura Wide- Field Array in Support of LWS Sentinels

    NASA Astrophysics Data System (ADS)

    Kasper, J. C.; D, O.; Salah, J. E.; Lonsdale, C. J.

    2006-12-01

    The Mileura Wide-Field Array Low Frequency Demonstrator (MWA) is an 80-300 MHz interferometric radio array consisting of 8000 antennas distributed in 16-antenna tiles over several square kilometers in Mileura Station, Western Australia. Selected by the NSF in June 2006, antenna deployment will begin in 2007, and the array is scheduled to become operational within three years. The primary goal of MWA-LFD is to demonstrate the capabilities of a digital array for conducting groundbreaking heliospheric and astrophysical science through wide fields of view, high sensitivity, and multiple beam capabilities. The heliospheric science goals of MWA are to characterize the density, velocity, and magnetic field of the inner heliosphere, from the outer corona to interplanetary space, and to image and localize solar radio bursts. The recently released Sentinels Science and Technology Definition Team report describes the value of supporting observations from ground-based instruments such as the MWA. We will present the MWA and discuss how we will use the array to reconstruct the magnetic connection between the corona and the inner heliosphere, both during quiet times and in the presence of CMEs. In particular, we will demonstrate how observing simultaneously the Faraday rotation of polarized radio emission from hundreds of galaxies within 80 Rs of the Sun will be used to trace the magnetic field topology out to the planned Sentinels orbit. These measurements will provide a global context for the Sentinels observations.