WorldWideScience

Sample records for wide-field ccd mosaic

  1. Photon counting imaging with an electron-bombarded CCD: Towards wide-field time-correlated single photon counting (TCSPC)

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Jiggins, Stephen; Sergent, Nicolas; Zanda, Gianmarco; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk

    2015-07-01

    Single photon detecting capabilities of an electron-bombarded CCD (EBCCD), where a photon is converted into a photoelectron that is accelerated through a high voltage before hitting the CCD chip, were characterised. The photon event pulse height distribution was found to be linearly dependent on the gain voltage. Based on these results, we propose that a gain voltage sweep during exposure in an EBCCD or EBCMOS camera would allow photon arrival time determination from the photon event pulse height with sub-frame exposure time resolution. This effectively uses an electron-bombarded sensor as a parallel-processing photoelectronic time-to-amplitude converter (TAC), or a 2-dimensional streak camera. Several applications that require timing of photon arrival, including fluorescence lifetime imaging microscopy (FLIM), may benefit from this approach. Moreover, the EBCCD was used on a fluorescence microscope to image fluorescently labelled cells in single photon counting mode.

  2. Mosaic CCD method: A new technique for observing dynamics of cometary magnetospheres

    Science.gov (United States)

    Saito, T.; Takeuchi, H.; Kozuba, Y.; Okamura, S.; Konno, I.; Hamabe, M.; Aoki, T.; Minami, S.; Isobe, S.

    1992-12-01

    On April 29, 1990, the plasma tail of Comet Austin was observed with a CCD camera on the 105-cm Schmidt telescope at the Kiso Observatory of the University of Tokyo. The area of the CCD used in this observation is only about 1 sq cm. When this CCD is used on the 105-cm Schmidt telescope at the Kiso Observatory, the area corresponds to a narrow square view of 12 ft x 12 ft. By comparison with the photograph of Comet Austin taken by Numazawa (personal communication) on the same night, we see that only a small part of the plasma tail can be photographed at one time with the CCD. However, by shifting the view on the CCD after each exposure, we succeeded in imaging the entire length of the cometary magnetosphere of 1.6 x 106 km. This new technique is called 'the mosaic CCD method'. In order to study the dynamics of cometary plasma tails, seven frames of the comet from the head to the tail region were twice imaged with the mosaic CCD method and two sets of images were obtained. Six microstructures, including arcade structures, were identified in both the images. Sketches of the plasma tail including microstructures are included.

  3. Wide-Field Plate Database

    Science.gov (United States)

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

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

  4. The Ooty Wide Field Array

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 38; Issue 1. The Ooty Wide Field Array. C. R. Subrahmanya P. K. Manoharan Jayaram N. Chengalur. Review Article Volume 38 Issue 1 March 2017 Article ID ... Keywords. Cosmology: large scale structure of Universe; intergalactic medium; diffuse radiation.

  5. The LOFT wide field monitor

    DEFF Research Database (Denmark)

    Brandt, Søren; Hernanz, M.; Alvarez, L.

    2012-01-01

    be able to address fundamental questions about strong gravity in the vicinity of black holes and the equation of state of nuclear matter in neutron stars. The prime goal of the WFM will be to detect transient sources to be observed by the LAD. However, with its wide field of view and good energy...... to the community of ~100 gamma ray burst positions per year with a ~1 arcmin location accuracy within 30 s of the burst. This paper provides an overview of the design, configuration, and capabilities of the LOFT WFM instrument....

  6. 4.6 Å Cryo-EM reconstruction of tobacco mosaic virus from images recorded at 300 keV on a 4k × 4k CCD camera

    Science.gov (United States)

    Clare, Daniel K.; Orlova, Elena V.

    2010-01-01

    Tobacco mosaic virus (TMV) is a plant virus with a highly ordered organisation and has been described in three different structural states: As stacked disks without RNA (X-ray crystallography), as a helical form with RNA (X-ray fibre diffraction) and as a second distinct helical form with RNA (cryo-EM). Here we present a structural analysis of TMV as a test object to assess the quality of cryo-EM images recorded at 300 keV on a CCD camera. The 4.6 Å TMV structure obtained is consistent with the previous cryo-EM structure and confirms that there is a second helical form of TMV. The structure here also shows that with a similar number of TMV segments an equivalent resolution can be achieved with a 4k CCD camera at 300 keV. PMID:20558300

  7. 4.6A Cryo-EM reconstruction of tobacco mosaic virus from images recorded at 300 keV on a 4k x 4k CCD camera.

    Science.gov (United States)

    Clare, Daniel K; Orlova, Elena V

    2010-09-01

    Tobacco mosaic virus (TMV) is a plant virus with a highly ordered organisation and has been described in three different structural states: As stacked disks without RNA (X-ray crystallography), as a helical form with RNA (X-ray fibre diffraction) and as a second distinct helical form with RNA (cryo-EM). Here we present a structural analysis of TMV as a test object to assess the quality of cryo-EM images recorded at 300 keV on a CCD camera. The 4.6A TMV structure obtained is consistent with the previous cryo-EM structure and confirms that there is a second helical form of TMV. The structure here also shows that with a similar number of TMV segments an equivalent resolution can be achieved with a 4k CCD camera at 300 keV. Copyright 2010 Elsevier Inc. All rights reserved.

  8. Wide Field Imager for Athena

    Science.gov (United States)

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

    2015-09-01

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

  9. 4.6Å Cryo-EM reconstruction of tobacco mosaic virus from images recorded at 300keV on a 4k×4k CCD camera

    OpenAIRE

    Clare, Daniel K.; Orlova, Elena V.

    2010-01-01

    Tobacco mosaic virus (TMV) is a plant virus with a highly ordered organisation and has been described in three different structural states: As stacked disks without RNA (X-ray crystallography), as a helical form with RNA (X-ray fibre diffraction) and as a second distinct helical form with RNA (cryo-EM). Here we present a structural analysis of TMV as a test object to assess the quality of cryo-EM images recorded at 300?keV on a CCD camera. The 4.6?? TMV structure obtained is consistent with t...

  10. Michelson wide-field stellar interferometry

    NARCIS (Netherlands)

    Montilla, I.

    2004-01-01

    The main goal of this thesis is to develop a system to permit wide field operation of Michelson Interferometers. A wide field of view is very important in applications such as the observation of extended or multiple objects, the fringe acquisition and/ or tracking on a nearby unresolved object, and

  11. Wide-Field Imaging Using Nitrogen Vacancies

    Science.gov (United States)

    Englund, Dirk Robert (Inventor); Trusheim, Matthew Edwin (Inventor)

    2017-01-01

    Nitrogen vacancies in bulk diamonds and nanodiamonds can be used to sense temperature, pressure, electromagnetic fields, and pH. Unfortunately, conventional sensing techniques use gated detection and confocal imaging, limiting the measurement sensitivity and precluding wide-field imaging. Conversely, the present sensing techniques do not require gated detection or confocal imaging and can therefore be used to image temperature, pressure, electromagnetic fields, and pH over wide fields of view. In some cases, wide-field imaging supports spatial localization of the NVs to precisions at or below the diffraction limit. Moreover, the measurement range can extend over extremely wide dynamic range at very high sensitivity.

  12. IOT Overview: Wide-Field Imaging

    Science.gov (United States)

    Selman, F. J.

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

  13. CCD Camera

    Science.gov (United States)

    Roth, Roger R.

    1983-01-01

    A CCD camera capable of observing a moving object which has varying intensities of radiation eminating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other.

  14. New Subarray Readout Patterns for the ACS Wide Field Channel

    Science.gov (United States)

    Golimowski, D.; Anderson, J.; Arslanian, S.; Chiaberge, M.; Grogin, N.; Lim, Pey Lian; Lupie, O.; McMaster, M.; Reinhart, M.; Schiffer, F.; Serrano, B.; Van Marshall, M.; Welty, A.

    2017-04-01

    At the start of Cycle 24, the original CCD-readout timing patterns used to generate ACS Wide Field Channel (WFC) subarray images were replaced with new patterns adapted from the four-quadrant readout pattern used to generate full-frame WFC images. The primary motivation for this replacement was a substantial reduction of observatory and staff resources needed to support WFC subarray bias calibration, which became a new and challenging obligation after the installation of the ACS CCD Electronics Box Replacement during Servicing Mission 4. The new readout patterns also improve the overall efficiency of observing with WFC subarrays and enable the processing of subarray images through stages of the ACS data calibration pipeline (calacs) that were previously restricted to full-frame WFC images. The new readout patterns replace the original 512×512, 1024×1024, and 2048×2046-pixel subarrays with subarrays having 2048 columns and 512, 1024, and 2048 rows, respectively. Whereas the original square subarrays were limited to certain WFC quadrants, the new rectangular subarrays are available in all four quadrants. The underlying bias structure of the new subarrays now conforms with those of the corresponding regions of the full-frame image, which allows raw frames in all image formats to be calibrated using one contemporaneous full-frame "superbias" reference image. The original subarrays remain available for scientific use, but calibration of these image formats is no longer supported by STScI.

  15. Pixel History for Advanced Camera for Surveys Wide Field Channel

    Science.gov (United States)

    Borncamp, D.; Grogin, N.; Bourque, M.; Ogaz, S.

    2017-06-01

    Excess thermal energy present in a Charged Coupled Device (CCD) can result in additional electrical current. This excess charge is trapped within the silicon lattice structure of the CCD electronics. It can persist through multiple exposures and have an adverse effect on science performance of the detectors unless properly flagged and corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed. These images, generally referred to as "dark" images, allow for the measurement of the thermal-electron contamination present in each pixel of the CCD lattice. This so-called "dark current" can then be subtracted from the science images by re-scaling the dark to the corresponding exposure times. Pixels that have signal above a certain threshold are traditionally marked as "hot" and flagged in the data quality array. Many users will discard these because of the extra current. However, these pixels may not be unusable because of an unreliable dark subtraction; if we find these pixels to be stable over an anneal period, we can properly subtract the charge and the extra Poisson noise from this dark current will be propagated into the error arrays. Here we present the results of a pixel history study that analyzes every individual pixel of the Hubble Space Telescope's (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) CCDs over time and allows pixels that were previously flagged as unusable to be brought back into the science image as a reliable pixel.

  16. The LOFT wide field monitor simulator

    DEFF Research Database (Denmark)

    Donnarumma, I.; Evangelista, Y.; Campana, R.

    2012-01-01

    We present the simulator we developed for the Wide Field Monitor (WFM) aboard the Large Observatory For Xray Timing (LOFT) mission, one of the four ESA M3 candidate missions considered for launch in the 2022–2024 timeframe. The WFM is designed to cover a large FoV in the same bandpass as the Larg...

  17. Wide field imaging problems in radio astronomy

    Science.gov (United States)

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

    2005-03-01

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

  18. The Wide Field Imager for Athena

    Science.gov (United States)

    Rau, A.; Nandra, K.; Meidinger, N.; Plattner, M.

    2017-10-01

    The Wide Field Imager (WFI) is one of the two scientific instruments of Athena, ESA's next large X-ray Observatory with launch in 2028. The instrument will provide two defining capabilities to the mission sensitive wide-field imaging spectroscopy and excellent high-count rate performance. It will do so with the use of two separate detectors systems, the Large Detector Array (LDA) optimized for its field of view (40'×40') with a 100 fold survey speed increase compared to existing X-ray missions, and the Fast Detector (FD) tweaked for high throughput and low pile-up for point sources as bright as the Crab. In my talk I will present the key performance parameters of the instrument and their links to the scientific goals of Athena and summarize the status of the ongoing development activities.

  19. The Wide Field Imager Instrument for Athena

    OpenAIRE

    Meidinger, Norbert; Eder, Josef; Eraerds, Tanja; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Strecker, Rafael

    2017-01-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 amin x 40 amin together with excellent count rate capability (larger than 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 7 keV will be better than 17...

  20. WFIRST: Simulating the Wide-Field Sky

    Science.gov (United States)

    Peeples, Molly; WFIRST Wide Field Imager Simulations Working Group

    2018-01-01

    As astronomy’s first high-resolution wide-field multi-mode instrument, simulated data will play a vital role in the planning for and analysis of data from WFIRST’s WFI (Wide Field Imager) instrument. Part of the key to WFIRST’s scientific success lies in our ability to push the systematics limit, but in order to do so, the WFI pipeline will need to be able to measure and take out said systematics. The efficacy of this pipeline can only be verified with large suites of synthetic data; these data must include both the range of astrophysical sky scenes (from crowded starfields to high-latitude grism data observations) and the systematics from the detector and telescope optics the WFI pipeline aims to mitigate. We summarize here(1) the status of current and planned astrophysical simulations in support of the WFI,(2) the status of current WFI instrument simulators and requirements on future generations thereof, and(3) plans, methods, and requirements on interfacing astrophysical simulations and WFI instrument simulators.

  1. The OCA CCD Camera Controller

    Science.gov (United States)

    1996-01-01

    multi CCD arrays for wide field telescopes with an array of 8x8 1K CCDs in use at Las Campanas Observatory in Chile . The same group is also involved...Verify key EPROM -292H VIH . VIH Program security bitl 1 29AH . VPP Program security’ bit 2 *. .298H -Vpp Verify security bits - 9HVIH ViI NOTE: 1...Pulsed from V.. to VIL and returned to VIH . EPROM PROGRAMMING AND VERIFICATION ..t= 21’C to-+27 ’rC:-VCC= 5V ±10%VS3 = OV. SYMBOL I .-- PARAMETER MIN MAX

  2. Athena Wide Field Imager key science drivers

    Science.gov (United States)

    Rau, Arne; Nandra, Kirpal; Aird, James; Comastri, Andrea; Dauser, Thomas; Merloni, Andrea; Pratt, Gabriel W.; Reiprich, Thomas H.; Fabian, Andy C.; Georgakakis, Antonis; Güdel, Manuel; RóŻańska, Agata; Sanders, Jeremy S.; Sasaki, Manami; Vaughan, Simon; Wilms, Jörn; Meidinger, Norbert

    2016-07-01

    The Wide Field Imager (WFI) is one of two instruments for the Advanced Telescope for High-ENergy Astrophysics (Athena). In this paper we summarise three of the many key science objectives for the WFI { the formation and growth of supermassive black holes, non-gravitational heating in clusters of galaxies, and spin measurements of stellar mass black holes { and describe their translation into the science requirements and ultimately instrument requirements. The WFI will be designed to provide excellent point source sensitivity and grasp for performing wide area surveys, surface brightness sensitivity, survey power, and absolute temperature and density calibration for in-depth studies of the outskirts of nearby clusters of galaxies and very good high-count rate capability, throughput, and low pile-up, paired with very good spectral resolution, for detailed explorations of bright Galactic compact objects.

  3. A wide field of view plasma spectrometer

    Science.gov (United States)

    Skoug, R. M.; Funsten, H. O.; Möbius, E.; Harper, R. W.; Kihara, K. H.; Bower, J. S.

    2016-07-01

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

  4. The Wide Field Imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Barbera, Marco; Emberger, Valentin; Fürmetz, Maria; Manhart, Markus; Müller-Seidlitz, Johannes; Nandra, Kirpal; Plattner, Markus; Rau, Arne; Treberspurg, Wolfgang

    2017-08-01

    ESA's next large X-ray mission ATHENA is designed to address the Cosmic Vision science theme 'The Hot and Energetic Universe'. It will provide answers to the two key astrophysical questions how does ordinary matter assemble into the large-scale structures we see today and how do black holes grow and shape the Universe. The ATHENA spacecraft will be equipped with two focal plane cameras, a Wide Field Imager (WFI) and an X-ray Integral Field Unit (X-IFU). The WFI instrument is optimized for state-of-the-art resolution spectroscopy over a large field of view of 40 amin x 40 amin and high count rates up to and beyond 1 Crab source intensity. The cryogenic X-IFU camera is designed for high-spectral resolution imaging. Both cameras share alternately a mirror system based on silicon pore optics with a focal length of 12 m and large effective area of about 2 m2 at an energy of 1 keV. Although the mission is still in phase A, i.e. studying the feasibility and developing the necessary technology, the definition and development of the instrumentation made already significant progress. The herein described WFI focal plane camera covers the energy band from 0.2 keV to 15 keV with 450 μm thick fully depleted back-illuminated silicon active pixel sensors of DEPFET type. The spatial resolution will be provided by one million pixels, each with a size of 130 μm x 130 μm. The time resolution requirement for the WFI large detector array is 5 ms and for the WFI fast detector 80 μs. The large effective area of the mirror system will be completed by a high quantum efficiency above 90% for medium and higher energies. The status of the various WFI subsystems to achieve this performance will be described and recent changes will be explained here.

  5. The wide field imager instrument for Athena

    Science.gov (United States)

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

    2014-07-01

    The "Hot and Energetic Universe" has been selected as the science theme for ESA's L2 mission, scheduled for launch in 2028. The proposed Athena X-ray observatory provides the necessary capabilities to achieve the ambitious goals of the science theme. The X-ray mirrors are based on silicon pore optics technology and will have a 12 m focal length. Two complementary camera systems are foreseen which can be moved in and out of the focal plane by an interchange mechanism. These instruments are the actively shielded micro-calorimeter spectrometer X-IFU and the Wide Field Imager (WFI). The WFI will combine an unprecedented survey power through its large field of view of 40 arcmin with a high countrate capability (approx. 1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 keV to 15 keV during the entire mission lifetime (e.g. FWHM serial analog output. The architecture of sensor and readout ASIC allows readout in full frame mode and window mode as well by addressing selectively arbitrary sub-areas of the sensor allowing time resolution in the order of 10 μs. The further detector electronics has mainly the following tasks: digitization, pre-processing and telemetry of event data as well as supply and control of the detector system. Although the sensor will already be equipped with an on-chip light blocking filter, a filter wheel is necessary to provide an additional external filter, an on-board calibration source, an open position for outgassing, and a closed position for protection of the sensor. The sensor concept provides high quantum efficiency over the entire energy band and we intend to keep the instrumental background as low as possible by designing a graded Z-shield around the sensor. All these properties make the WFI a very powerful survey instrument, significantly surpassing currently existing observatories and in addition allow high-time resolution of the brightest X-ray sources with low pile-up and high efficiency. This

  6. The wide field imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Eder, Josef; Eraerds, Tanja; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Strecker, Rafael

    2016-07-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 amin x 40 amin together with excellent count rate capability (>= 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 7 keV will be MOSFET integrated onto a fully depleted 450 μm thick silicon bulk. Two detectors are planned for the WFI instrument: A large-area detector comprising four sensors with a total of 1024 x 1024 pixels and a fast detector optimized for high count rate observations. This high count rate capable detector permits for bright point sources with an intensity of 1 Crab a throughput of more than 80% and a pile-up of less than 1%. The fast readout of the DEPFET pixel matrices is facilitated by an ASIC development, called VERITAS-2. Together with the Switcher-A, a control ASIC that allows for operation of the DEPFET in rolling shutter mode, these elements form the key components of the WFI detectors. The detectors are surrounded by a graded-Z shield, which has in particular the purpose to avoid fluorescence lines that would contribute to the instrument background. Together with ultra-thin coating of the sensor and particle identification by the detector itself, the particle induced background shall be minimized in order to achieve the scientific requirement of a total instrumental background value smaller than 5 x 10-3 cts/cm2/s/keV. Each detector has its dedicated detector electronics (DE) for supply and data acquisition. Due to the high frame rate in combination with the large pixel array, signal correction and event filtering have to be done on-board and in real-time as the raw data rate would by far exceed the feasible telemetry rate. The data streams are merged and compressed in the Instrument Control and

  7. Ground-based complex for detection and investigation of fast optical transients in wide field

    Science.gov (United States)

    Molinari, Emilio; Beskin, Grigory; Bondar, Sergey; Karpov, Sergey; Plokhotnichenko, Vladimir; de-Bur, Vjacheslav; Greco, Guiseppe; Bartolini, Corrado; Guarnieri, Adriano; Piccioni, Adalberto

    2008-07-01

    To study short stochastic optical flares of different objects (GRBs, SNs, etc) of unknown localizations as well as NEOs it is necessary to monitor large regions of sky with high time resolution. We developed a system which consists of wide-field camera (FOW is 400-600 sq.deg.) using TV-CCD with time resolution of 0.13 s to record and classify optical transients, and a fast robotic telescope aimed to perform their spectroscopic and photometric investigation just after detection. Such two telescope complex TORTOREM combining wide-field camera TORTORA and robotic telescope REM operated from May 2006 at La Silla ESO observatory. Some results of its operation, including first fast time resolution study of optical transient accompanying GRB and discovery of its fine time structure, are presented. Prospects for improving the complex efficiency are given.

  8. Design status of WFCAM: a wide field camera for the UK infrared telescope

    Science.gov (United States)

    Henry, David M.; Casali, Mark M.; Montgomery, David; Burch, Keith; Laidlaw, Ken; Ives, Derek J.; Vick, Andrew J. A.; Bridger, Alan; Lunney, David; Adamson, Andrew J.; Rees, Nicholas P.; Chylek, Tomas; Chuter, Timothy C.

    2003-03-01

    An update on the design status of the UKIRT Wide Field Camera (WFCAM) is presented. WFCAM is a wide field infrared camera for the UK Infrared Telescope, designed to produce large scale infrared surveys. The complete system consists of a new IR camera with integral autoguider and a new tip/tilt secondary mirror unit. WFCAM is being designed and built by a team at the UK Astronomy Technology Centre in Edinburgh, supported by the Joint Astronomy Centre in Hawaii. The camera uses a novel quasi-Schmidt camera type design, with the camera mounted above the UKIRT primary mirror. The optical system operates over 0.7 - 2.4 μm and has a large corrected field of view of 0.9° diameter. The focal plane is sparsely populated with 4 2K x 2K Rockwell HAWAII-2 MCT array detectors, giving a pixel scale of 0.4 arcsec/pixel. A separate autoguider CCD is integrated into the focal plane unit. Parallel detector controllers are used, one for each of the four IR arrays and a fifth for the autoguider CCD.

  9. Michelson wide-field stellar interferometry : Principles and experimental verification

    NARCIS (Netherlands)

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

    2005-01-01

    A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in

  10. Wide-Field Infrared Survey Telescope (WFIRST) Integrated Modeling

    Science.gov (United States)

    Liu, Kuo-Chia; Blaurock, Carl

    2017-01-01

    Contents: introduction to WFIRST (Wide-Field Infrared Survey Telescope) and integrated modeling; WFIRST stability requirement summary; instability mitigation strategies; dynamic jitter results; STOP (structural-thermal-optical performance) (thermal distortion) results; STOP and jitter capability limitations; model validation philosophy.

  11. Wide-Field, Deep UV Raman Hyperspectral Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ChemImage Sensor Systems (CISS), teaming with the University of South Carolina, proposes a revolutionary wide-field Raman hyperspectral imaging system capable of...

  12. Mosaic Horses

    Science.gov (United States)

    Rudecki, Maryanna

    2009-01-01

    This article describes a lesson inspired by Sicilian mosaics. The author first presented a PowerPoint presentation of mosaics from the Villa Romana del Casale and reviewed complementary and analogous colors. Students then created mosaics using a variety of art materials. They presented their work to their peers and discussed the thought and…

  13. Ultra-wide-field imaging in diabetic retinopathy.

    Science.gov (United States)

    Ghasemi Falavarjani, Khalil; Tsui, Irena; Sadda, Srinivas R

    2017-10-01

    Since 1991, 7-field images captured with 30-50 degree cameras in the Early Treatment Diabetic Retinopathy Study were the gold standard for fundus imaging to study diabetic retinopathy. Ultra-wide-field images cover significantly more area (up to 82%) of the fundus and with ocular steering can in many cases image 100% of the fundus ("panretinal"). Recent advances in image analysis of ultra-wide-field imaging allow for precise measurements of the peripheral retinal lesions. There is a growing consensus in the literature that ultra-wide-field imaging improves detection of peripheral lesions in diabetic retinopathy and leads to more accurate classification of the disease. There is discordance among studies, however, on the correlation between peripheral diabetic lesions and diabetic macular edema and optimal management strategies to treat diabetic retinopathy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Advanced CCD camera developments

    Energy Technology Data Exchange (ETDEWEB)

    Condor, A. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Two charge coupled device (CCD) camera systems are introduced and discussed, describing briefly the hardware involved, and the data obtained in their various applications. The Advanced Development Group Defense Sciences Engineering Division has been actively designing, manufacturing, fielding state-of-the-art CCD camera systems for over a decade. These systems were originally developed for the nuclear test program to record data from underground nuclear tests. Today, new and interesting application for these systems have surfaced and development is continuing in the area of advanced CCD camera systems, with the new CCD camera that will allow experimenters to replace film for x-ray imaging at the JANUS, USP, and NOVA laser facilities.

  15. Detection of interstellar CCD

    Science.gov (United States)

    Combes, F.; Boulanger, F.; Encrenaz, P. J.; Gerin, M.; Bogey, M.

    1985-01-01

    The first detection of interstellar CCD has been obtained in the N = 3-2, J = 7/2-5/2 line at 216.3732 GHz towards the Kleinman-Low nebula. An abundance ratio CCD/CCH of 0.045 is found, indicating in this molecule a deuterium enhancement similar to that found for HNC, but an order of magnitude higher than for HCN. Negative results towards DR 21(OH), NGC 2264, L 134N, TM Cl, Rho OphB2, and IRC 10216 rule out a stronger D enhancement for CCD than for other deuterated molecules in these sources. Predictions of currently developed ion-molecule reaction schemes are consistent with the CCD line detected and the negative results.

  16. Wide-Field Imaging Telescope-0 (WIT0) with automatic observing system

    Science.gov (United States)

    Ji, Tae-Geun; Byeon, Seoyeon; Lee, Hye-In; Park, Woojin; Lee, Sang-Yun; Hwang, Sungyong; Choi, Changsu; Gibson, Coyne Andrew; Kuehne, John W.; Prochaska, Travis; Marshall, Jennifer L.; Im, Myungshin; Pak, Soojong

    2018-01-01

    We introduce Wide-Field Imaging Telescope-0 (WIT0), with an automatic observing system. It is developed for monitoring the variabilities of many sources at a time, e.g. young stellar objects and active galactic nuclei. It can also find the locations of transient sources such as a supernova or gamma-ray bursts. In 2017 February, we installed the wide-field 10-inch telescope (Takahashi CCA-250) as a piggyback system on the 30-inch telescope at the McDonald Observatory in Texas, US. The 10-inch telescope has a 2.35 × 2.35 deg field-of-view with a 4k × 4k CCD Camera (FLI ML16803). To improve the observational efficiency of the system, we developed a new automatic observing software, KAOS30 (KHU Automatic Observing Software for McDonald 30-inch telescope), which was developed by Visual C++ on the basis of a windows operating system. The software consists of four control packages: the Telescope Control Package (TCP), the Data Acquisition Package (DAP), the Auto Focus Package (AFP), and the Script Mode Package (SMP). Since it also supports the instruments that are using the ASCOM driver, the additional hardware installations become quite simplified. We commissioned KAOS30 in 2017 August and are in the process of testing. Based on the WIT0 experiences, we will extend KAOS30 to control multiple telescopes in future projects.

  17. SHOK—The First Russian Wide-Field Optical Camera in Space

    Science.gov (United States)

    Lipunov, V. M.; Gorbovskoy, E. S.; Kornilov, V. G.; Panasyuk, M. I.; Amelushkin, A. M.; Petrov, V. L.; Yashin, I. V.; Svertilov, S. I.; Vedenkin, N. N.

    2018-02-01

    Onboard the spacecraft Lomonosov is established two fast, fixed, very wide-field cameras SHOK. The main goal of this experiment is the observation of GRB optical emission before, synchronously, and after the gamma-ray emission. The field of view of each of the cameras is placed in the gamma-ray burst detection area of other devices located onboard the "Lomonosov" spacecraft. SHOK provides measurements of optical emissions with a magnitude limit of ˜ 9-10m on a single frame with an exposure of 0.2 seconds. The device is designed for continuous sky monitoring at optical wavelengths in the very wide field of view (1000 square degrees each camera), detection and localization of fast time-varying (transient) optical sources on the celestial sphere, including provisional and synchronous time recording of optical emissions from the gamma-ray burst error boxes, detected by the BDRG device and implemented by a control signal (alert trigger) from the BDRG. The Lomonosov spacecraft has two identical devices, SHOK1 and SHOK2. The core of each SHOK device is a fast-speed 11-Megapixel CCD. Each of the SHOK devices represents a monoblock, consisting of a node observations of optical emission, the electronics node, elements of the mechanical construction, and the body.

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

    Science.gov (United States)

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

    2016-03-01

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

  19. Advanced MOKE magnetometry in wide-field Kerr-microscopy

    Science.gov (United States)

    Soldatov, I. V.; Schäfer, R.

    2017-10-01

    The measurement of MOKE (Magneto-Optical Kerr Effect) magnetization loops in a wide-field Kerr microscope offers the advantage that the relevant domain images along the loop can be readily recorded. As the microscope's objective lens is exposed to the magnetic field, the loops are usually strongly distorted by non-linear Faraday rotations of the polarized light that occur in the objective lens and that are superimposed to the MOKE signal. In this paper, an experimental method, based on a motorized analyzer, is introduced which allows to compensate the Faraday contributions, thus leading to pure MOKE loops. A wide field Kerr microscope, equipped with this technology, works well as a laser-based MOKE magnetometer, additionally offering domain images and thus providing the basis for loop interpretation.

  20. DCC Case Study: Wide Field Astronomy Unit (WFAU)

    OpenAIRE

    Donnelly, Martin

    2005-01-01

    Case study on the Wide Field Astronomy Unit (WFAU), Edinburgh. Outlines data curation issues with which WFAU is involved, with an emphasis on interoperability. Particular regard is given to the transfer and reuse of data collected from disparate sources. The case study also covers other factors influencing data curation, including methodological development, standards and legal issues, evaluation, and human factors. A technical appendix outlines the technologies used i...

  1. Wide field focal plane arrays for UKIRT and VISTA

    Science.gov (United States)

    Ives, D.; Laidlaw, K.; Bezawada, N. N.

    This paper briefly describes the focal plane arrays of the UKIRT Wide Field Camera and the IR camera for the Visible and Infrared Survey Telescope for Astronomy (VISTA). Laboratory test results on the HAWAII-2 engineering grade detector are summarised. The interference problems resulting from the on-axis wavefront/autoguider sensors and their controllers (autoguider, wavefront sensor, etc.) are anticipated and possible options to eliminate or attenuate these effects are presented. Laboratory tests on the Electromagnetic Interference (EMI) issues are also reported.

  2. Vestibular rehabilitation using a wide field of view virtual environment.

    Science.gov (United States)

    Sparto, P J; Furman, J M; Whitney, S L; Hodges, L F; Redfern, M S

    2004-01-01

    This paper presents a theoretical justification for using a wide field of view (FOV) virtual reality display system for use in vestibular rehabilitation. A wide FOV environment offers some unique features that may be beneficial to vestibular rehabilitation. Primarily, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. If this hypothesis is correct, then wide FOV systems will have an advantage over narrow field of view input devices such as head mounted or desktop displays. Devices that we have incorporated into our system that are critical for monitoring improvement in this clinical population will also be described.

  3. Speckle correlation resolution enhancement of wide-field fluorescence imaging (Conference Presentation)

    Science.gov (United States)

    Yilmaz, Hasan

    2016-03-01

    Structured illumination enables high-resolution fluorescence imaging of nanostructures [1]. We demonstrate a new high-resolution fluorescence imaging method that uses a scattering layer with a high-index substrate as a solid immersion lens [2]. Random scattering of coherent light enables a speckle pattern with a very fine structure that illuminates the fluorescent nanospheres on the back surface of the high-index substrate. The speckle pattern is raster-scanned over the fluorescent nanospheres using a speckle correlation effect known as the optical memory effect. A series of standard-resolution fluorescence images per each speckle pattern displacement are recorded by an electron-multiplying CCD camera using a commercial microscope objective. We have developed a new phase-retrieval algorithm to reconstruct a high-resolution, wide-field image from several standard-resolution wide-field images. We have introduced phase information of Fourier components of standard-resolution images as a new constraint in our algorithm which discards ambiguities therefore ensures convergence to a unique solution. We demonstrate two-dimensional fluorescence images of a collection of nanospheres with a deconvolved Abbe resolution of 116 nm and a field of view of 10 µm × 10 µm. Our method is robust against optical aberrations and stage drifts, therefore excellent for imaging nanostructures under ambient conditions. [1] M. G. L. Gustafsson, J. Microsc. 198, 82-87 (2000). [2] H. Yilmaz, E. G. van Putten, J. Bertolotti, A. Lagendijk, W. L. Vos, and A. P. Mosk, Optica 2, 424-429 (2015).

  4. WFIRST: Astrometry with the Wide-Field Imager

    Science.gov (United States)

    Bellini, Andrea; WFIRST Astrometry Working Group

    2018-01-01

    The wide field of view and stable, sharp images delivered by WFIRST's Wide-Field Imager make it an excellent instrument for astrometry, one of five major discovery areas identified in the 2010 Decadal Survey. Compared to the Hubble Space Telescope, WFIRST's wider field of view with similar image quality will provide hundreds more astrometric targets per image as well as background galaxies and stars with precise positions in the Gaia catalog. In addition, WFIRST will operate in the infrared, a wavelength regime where the most precise astrometry has so far been achieved with adaptive optics images from large ground-based telescopes. WFIRST will provide at least a factor of three improvement in astrometry over the current state of the art in this wavelength range, while spanning a field of view thousands of times larger. WFIRST is thus poised to make major contributions to multiple science topics in which astrometry plays an important role, without major alterations to the planned mission or instrument. We summarize a few of the most compelling science cases where WFIRST astrometry could prove transformational.

  5. PERSPECTIVE: Toward a wide-field retinal prosthesis

    Science.gov (United States)

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

    2009-06-01

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

  6. Visibility retrieval in Michelson wide-field stellar interferometry

    Science.gov (United States)

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

    2006-04-01

    Wide-field interferometry has become a subject of increasing interest in recent years. New methods have been suggested in order to avoid the drawbacks of the standard wide-field method (homothetic mapping), which is not applicable when the aperture is highly diluted; for this reason, imaging with non-homothetic arrays is being extensively studied (E. Pedretti, et al., Astron. Astrophys. Suppl. Ser. 147 285 (2000); S. Gillet, et al., Astron. Astrophys. 400 393 (2003)). The field of view of a pupil-plane interferometer or a densified array consists of only a few resolution elements; in order to improve these systems, we have developed a new method consisting of a Michelson pupil-plane combination scheme where a wide field of view can be achieved in one shot. This technique, called the ‘staircase mirror’ approach, has been described in a previous paper (I. Montilla, S.F. Pereira and J.J.M. Braat, Appl. Optics 44 328 (2005)) and uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction of the differential delay for both the on- and off-axis image positions. Experimental results have been obtained showing the simultaneous recovery of the fringes of off-axis stars with an appreciable angular separation, and with a contrast similar to that of the on-axis reference star. With this example we demonstrate an increase of the field of view by a factor of 5, with no need for extra observation time. In this article, we present a further analysis of the method. We investigate how to retrieve the visibility when a star is focused on the edge of a step of the stair-shaped mirror. Even though the optical pathlength difference correction is discontinuous, we show both numerically and analytically that the visibility can be completely recovered, so that no information is lost. Our experimental results demonstrate that the visibility can be retrieved to within a 1% error.

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

    Directory of Open Access Journals (Sweden)

    Sun-youp Park

    2013-09-01

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

  8. Calibration of BVRI Photometry for the Wide Field Channel of the HST Advanced Camera for Surveys

    Science.gov (United States)

    Saha, Abhijit; Shaw, Richard A.; Claver, Jennifer A.; Dolphin, Andrew E.

    2011-04-01

    We present new observations of two Galactic globular clusters, PAL4 and PAL14, using the Wide Field Channel of the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST) and reanalyze archival data from a third, NGC2419. We matched our photometry of hundreds of stars in these fields from the ACS images to existing ground-based photometry of faint sequences that were calibrated on the standard BVRI system of Landolt. These stars are significantly fainter than those generally used for HST calibration purposes and therefore are much better matched to supporting precision photometry of ACS science targets. We were able to derive more accurate photometric transformation coefficients for the commonly used ACS broadband filters, compared with those published by Sirianni et al., due to the use of a factor of several more calibration stars that span a greater range of color. We find that the inferred transformations from each cluster individually do not vary significantly from the average, except for a small offset of the photometric zero point in the F850LP filter. Our results suggest that the published prescriptions for the time-dependent correction of CCD charge transfer efficiency appear to work very well over the ˜3.5 yr interval that spans our observations of PAL4 and PAL14 and the archived images of NGC2419.

  9. Mosaic Focal Plane Development

    Science.gov (United States)

    Mason, D.; Horner, S.; Aamodt, E.

    Advances in manufacturing and applied sciences have enabled the development of large ground and spaced based astronomical instruments having a Field of View (FOV) large enough to capture a large portion of the universe in a single image. A large FOV can be accomplished using light weighted optics, improved structures, and the development of mosaic Focal Plane Assemblies (mFPAs). A mFPA comprises multiple Charged Coupled Devices (CCD) mounted onto a single baseplate integrated at the focus plane of the instrument. Examples of current, or proposed, missions utilizing mFPA technology include FAME, GEST, Kepler, GAIA, LSST, and SNAP. The development of a mFPA mandates tight control on the design trades of component development, CCD definition and characterization, component integration, and performance verification testing. This paper addresses the results of the Lockheed Martin Space Systems Company (LMSSC), Advanced Technology Center (ATC) developed mFPA. The design trades and performance characterization are services provided by the LMSSC ATC but not detailed in this paper.

  10. Wide-field subdiffraction RESOLFT microscopy using fluorescent protein photoswitching.

    Science.gov (United States)

    Schwentker, Miriam A; Bock, Hannes; Hofmann, Michael; Jakobs, Stefan; Bewersdorf, Jörg; Eggeling, Christian; Hell, Stefan W

    2007-03-01

    Subdiffraction fluorescence imaging is presented in a parallelized wide-field arrangement exploiting the principle of reversible saturable/switchable optical transitions (RESOLFT). The diffraction barrier is overcome by photoswitching ensembles of the label protein asFP595 between a nonfluorescent off- and a fluorescent on-state. Relying on ultralow continuous-wave intensities, reversible protein switching facilitates parallelized fast image acquisition. The RESOLFT principle is implemented by illuminating with intensity distributions featuring zero intensity lines that are further apart than the conventional Abbe resolution limit. The subdiffraction resolution is verified by recording live Escherichia coli bacteria labeled with asFP595. The obtained resolution of 50 nm ( approximately lambda/12) is limited only by the spectroscopic properties of the proteins and the imperfections of the optical implementation, but not on principle grounds. (c) 2007 Wiley-Liss, Inc.

  11. Thermal design of the Wide Field/Planetary Camera

    Science.gov (United States)

    Garcia, R. D.; Jones, J. A.; Stultz, J. W.

    1989-01-01

    The Wide Field/Planetary Camera is an imaging system developed by the Jet Propulsion Laboratory for the NASA Hubble Space Telescope currently scheduled to be launched in December 1989 aboard the space shuttle. The temperature control design of the instrument utilizes multilayered insulation, electric resistance heaters, aluminum/ammonia heat pipes, thermoelectric coolers, temperature control coatings, and space radiators. A feedback control system maintains stable sensor temperatures. Thermal capacitance maintains stable optics and electronics temperatures during transient conditions. Schedule slips and launch delays have allowed extensive thermal testing of the instrument. Six instrument thermal vacuum tests and a spacecraft thermal vacuum test were performed. Several modifications have been made to the instrument to correct icing and contamination problems that have been discovered during thermal vacuum testing. This paper describes the thermal design, last instrument thermal vacuum test, results, and thermal model correlation.

  12. The design of the wide field monitor for LOFT

    DEFF Research Database (Denmark)

    Brandt, Søren; Hernanz, M.; Alvarez, L.

    2014-01-01

    is designed to carry on-board two instruments with sensitivity in the 2-50 keV range: a 10 m 2 class Large Area Detector (LAD) with a ... will be to detect transient sources to be observed by the LAD. However, thanks to its unique combination of a wide field of view (FoV) and energy resolution (better than 500 eV), the WFM will be also an excellent monitoring instrument to study the long term variability of many classes of X-ray sources. The WFM...... consists of 10 independent and identical coded mask cameras arranged in 5 pairs to provide the desired sky coverage. We provide here an overview of the instrument design, configuration, and capabilities of the LOFT WFM. The compact and modular design of the WFM could easily make the instrument concept...

  13. High-Speed and Wide-Field Photometry with TORTORA

    Directory of Open Access Journals (Sweden)

    G. Greco

    2010-01-01

    Full Text Available We present the photometric analysis of the extended sky fields observed by the TORTORA optical monitoring system. The technology involved in the TORTORA camera is based on the use of a fast TV-CCD matrix with an image intensifier. This approach can both significantly reduce the readout noise and shorten the focal length following to monitor relatively large sky regions with high temporal resolution and adequate detection limit. The performance of the system has been tested using the relative magnitudes of standard stars by means of long image sequences collected at different airmasses and at various intensities of the moon illumination. As expected from the previous laboratory measurements, artifact sources are negligible and do not affect the photometric results. The following analysis is based on a large sample of images acquired by the TORTORA instrument since July 2006.

  14. Wide-Field Ultraviolet Spectrometer for Planetary Exospheres and Thermospheres

    Science.gov (United States)

    Fillingim, M. O.; Wishnow, E. H.; Miller, T.; Edelstein, J.; Lillis, R. J.; Korpela, E.; England, S.; Shourt, W. V.; Siegmund, O.; McPhate, J.; Courtade, S.; Curtis, D. W.; Deighan, J.; Chaffin, M.; Harmoul, A.; Almatroushi, H. R.

    2016-12-01

    Understanding the composition, structure, and variability of a planet's upper atmosphere - the exosphere and thermosphere - is essential for understanding how the upper atmosphere is coupled to the lower atmosphere, magnetosphere and near-space environment, and the Sun. Ultraviolet spectroscopy can directly observe emissions from constituents in the exosphere and thermosphere. From such observations, the structure, composition, and variability can be determined.We will present the preliminary design for a wide field ultraviolet imaging spectrometer for remote sensing of planetary atmospheres. The imaging spectrometer achieves an extremely large instantaneous 110 degree field of view with no moving scanning mirror. The imaging resolution is very appropriate for extended atmospheric emission studies, with a resolution of better than 0.3 degrees at the center to 0.4 degrees at the edges of the field. The spectral range covers 120 - 170 nm, encompassing emissions from H, O, C, N, CO, and N2, with an average spectral resolution of 1.5 nm. The instrument is composed of a 2-element wide-field telescope, a 3-element Offner spectrometer, and a sealed MCP detector system contained within a compact volume of about 40 x 25 x 20 cm. We will present the optical and mechanical design as well as the predicted optical performance.The wide instantaneous FOV simplifies instrument and spacecraft operations by removing the need for multiple scans (either from a scan mirror or spacecraft slews) to cover the regions of interest. This instrumentation can allow for two-dimensional spectral information to be built up with simple spacecraft operation or just using spacecraft motion. Applications to the terrestrial geocorona and thermosphere will be addressed as well as applications to the upper atmospheres of other planetary objects.

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

    Science.gov (United States)

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

    2015-03-01

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

  16. Calibration and testing of wide-field UV instruments

    Science.gov (United States)

    Frey, H. U.; Mende, S. B.; Loicq, J.; Habraken, S.

    2017-06-01

    As with all optical systems the calibration of wide-field ultraviolet (UV) systems includes three main areas: sensitivity, imaging quality, and imaging capability. The one thing that makes UV calibrations difficult is the need for working in vacuum substantially extending the required time and effort compared to visible systems. In theory a ray tracing and characterization of each individual component of the optical system (mirrors, windows, and grating) should provide the transmission efficiency of the combined system. However, potentially unknown effects (contamination, misalignment, and measurement errors) can make the final error too large and unacceptable for most applications. Therefore, it is desirable to test and measure the optical properties of the whole system in vacuum and compare the overall response to the response of a calibrated photon detector. A proper comparison then allows the quantification of individual sources of uncertainty and ensures that the whole instrument performance is within acceptable tolerances or pinpoints which parts fail to meet requirements. Based on the experience with the IMAGE Spectrographic Imager, the Wide-band Imaging Camera, and the ICON Far Ultraviolet instruments, we discuss the steps and procedures for the proper radiometric sensitivity and passband calibration, spot size, imaging distortions, flatfield, and field of view determination.Plain Language SummaryAs with all optical systems the calibration of wide-field ultraviolet (UV) systems includes three main areas: sensitivity, imaging quality, and imaging capability. The one thing that makes UV calibrations difficult is the need for working in vacuum substantially extending the required time and effort compared to visible systems. Based on the experience with the IMAGE Spectrographic Imager, the Wide-band Imaging Camera (WIC), and the ICON Far Ultraviolet instruments, we discuss the steps and procedures for the proper radiometric sensitivity and pass-band calibration

  17. Extreme multiplex spectroscopy at wide-field 4-m telescopes

    Science.gov (United States)

    Content, Robert; Shanks, Tom

    2008-07-01

    We describe the design and science case for a spectrograph for the prime focus of classical 4-m wide-field telescopes that can deliver at least 4000 MOS slits over a 1° field. This extreme multiplex capability means that 25000 galaxy redshifts can be measured in a single night, opening up the possibilities for large galaxy redshift surveys out to z~0.7 and beyond for the purpose of measuring the Baryon Acoustic Oscillation (BAO) scale and for many other science goals. The design features four cloned spectrographs and exploits the exclusive possibility of tiling the focal plane of wide-field 4-m telescopes with CCDs for multi-object spectroscopic purposes. In ~200 night projects, such spectrographs have the potential to make galaxy redshift surveys of ~6×106 galaxies over a wide redshift range and thus may provide a low-cost alternative to other survey routes such as WFMOS and SKA. Two of these extreme multiplex spectrographs are currently being designed for the AAT (NG1dF) and Calar Alto (XMS) 4-m class telescopes. NG2dF, a larger version for the AAT 2° field, would have 12 clones and at least 12000 slits. The clones use a transparent design including a grism in which all optics are smaller than the clone square subfield so that the clones can be tightly packed with little gaps between the contiguous fields. Only low cost glasses are used; the variations in chromatic aberrations between bands are compensated by changing one or two of the lenses adjacent to the grism. The total weight and length is smaller with a few clones than a unique spectrograph which makes it feasible to place the spectrograph at the prime focus.

  18. Transmission electron microscope CCD camera

    Science.gov (United States)

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  19. Selected aspects of wide-field stellar interferometry

    Science.gov (United States)

    D'Arcio, Luigi Arsenio

    1999-11-01

    In Michelson stellar interferometry, the high-resolution information about the source structure is detected by performing observations with widely separated telescopes, interconnected to form an interferometer. At optical wavelengths, this method provides a technically viable approach for achieving angular resolutions in the milliarcsecond range, comparable to those of a 100 m diameter telescope, whose realization is beyond the immediate engineering capabilities. Considerable efforts are currently devoted to the definition of dedicated interferometric instruments, which will allow to address ambitious astronomical tasks such as high-resolution imaging, astrometry at microarcsecond level, and the direct detection of exoplanets. Astrometry and related techniques employ the so-called wide field-of-view interferometric mode, where phase measurements are performed simultaneously at two (or more) sources; often, the actual observable is the instantaneous phase difference of the two object signals. The future success of wide-field interferometry critically depends on the development of techniques for the accurate control of field-dependent (anisoplanatic) phase errors. In this thesis, we address two aspects of this problem in detail. The first one is theoretical in nature. For ground-based measurements, atmospheric turbulence is the largest source of random phase fluctuations between the on- and the off-axis fringes. We developed a model of the temporal power spectrum of this disturbance, whose validity is not limited to low frequencies only, as it is the case with earlier models. This extension opens the possibility of the analysis of dynamic issues, such as the determination of the allowable coherent integration time T for the off-axis fringes. The spectrum turns out to be well approximated by a sequences of four power-law branches. In first instance, its overall form is determined by the values of the baseline length, telescope diameter, and average beam separation in

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

    Science.gov (United States)

    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 Slitless Spectroscopy with JWST/NIRISS

    Science.gov (United States)

    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.

  2. Development of the wide field imager for Athena

    Science.gov (United States)

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

    2015-08-01

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

  3. Mosaic Messages

    Science.gov (United States)

    Baldauf, Annemarie

    2012-01-01

    Through the generosity of a Lowes Toolbox for Education Grant and a grant from the Bill Graham Foundation, an interdisciplinary mosaic mural was created and installed at Riverview Middle School in Bay Point, California. The actual mural, which featured a theme of nurturing students through music, art, sports, science, and math, took about three…

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

    Science.gov (United States)

    Venugopal, Vivek

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

  5. INT prime focus mosaic camera

    Science.gov (United States)

    Ives, Derek J.; Tulloch, Simon; Churchill, John

    1996-03-01

    The INT Prime Focus Mosaic Camera (INT PFC) is designed to provide a large field survey and supernovae search capability for the prime focus of the 2.5 m Isaac Newton Telescope (INT). It is a joint collaboration between the Royal Greenwich Observatory (UK), Kapteyn Sterrenwacht Werkgroep (Netherlands), and the Lawrence Berkeley Laboratories (USA). The INT PFC consists of a 4 chip mosaic utilizing thinned and anti-reflection coated CCDs. These are LORAL devices of the LICK3 design. They will be operated cryogenically in a purpose built camera assembly. A fifth CCD, of the same type, is co-mounted with the science array in the cryostat to provide autoguider functions. This cryostat then mounts to the main camera assembly at the prime focus. This assembly will include standard filters and a novel shutter wheel which has been specifically designed for this application. The camera will have an unvignetted field of 40 arcminutes and a focal ratio of f/3.3. This results in a very tight mechanical specification for co-planarity and flatness of the array of CCDs and also quite stringent flexure tolerance of the camera assembly. A method of characterizing the co- planarity and flatness of the array will be described. The overall system architecture will also be described. One of the main requirements is to read the whole array out within 100s, with less than 10e rms. noise and very low CCD cross talk.

  6. Development of a Data Reduction Algorithm for Optical Wide Field Patrol (OWL II: Improving Measurement of Lengths of Detected Streaks

    Directory of Open Access Journals (Sweden)

    Sun-Youp Park

    2016-09-01

    Full Text Available As described in the previous paper (Park et al. 2013, the detector subsystem of optical wide-field patrol (OWL provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.

  7. Testing fully depleted CCD

    Science.gov (United States)

    Casas, Ricard; Cardiel-Sas, Laia; Castander, Francisco J.; Jiménez, Jorge; de Vicente, Juan

    2014-08-01

    The focal plane of the PAU camera is composed of eighteen 2K x 4K CCDs. These devices, plus four spares, were provided by the Japanese company Hamamatsu Photonics K.K. with type no. S10892-04(X). These detectors are 200 μm thick fully depleted and back illuminated with an n-type silicon base. They have been built with a specific coating to be sensitive in the range from 300 to 1,100 nm. Their square pixel size is 15 μm. The read-out system consists of a Monsoon controller (NOAO) and the panVIEW software package. The deafualt CCD read-out speed is 133 kpixel/s. This is the value used in the calibration process. Before installing these devices in the camera focal plane, they were characterized using the facilities of the ICE (CSIC- IEEC) and IFAE in the UAB Campus in Bellaterra (Barcelona, Catalonia, Spain). The basic tests performed for all CCDs were to obtain the photon transfer curve (PTC), the charge transfer efficiency (CTE) using X-rays and the EPER method, linearity, read-out noise, dark current, persistence, cosmetics and quantum efficiency. The X-rays images were also used for the analysis of the charge diffusion for different substrate voltages (VSUB). Regarding the cosmetics, and in addition to white and dark pixels, some patterns were also found. The first one, which appears in all devices, is the presence of half circles in the external edges. The origin of this pattern can be related to the assembly process. A second one appears in the dark images, and shows bright arcs connecting corners along the vertical axis of the CCD. This feature appears in all CCDs exactly in the same position so our guess is that the pattern is due to electrical fields. Finally, and just in two devices, there is a spot with wavelength dependence whose origin could be the result of a defectous coating process.

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

    Science.gov (United States)

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

    2011-01-01

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

  9. CCD Camera Observations

    Science.gov (United States)

    Buchheim, Bob; Argyle, R. W.

    One night late in 1918, astronomer William Milburn, observing the region of Cassiopeia from Reverend T.H.E.C. Espin's observatory in Tow Law (England), discovered a hitherto unrecorded double star (Wright 1993). He reported it to Rev. Espin, who measured the pair using his 24-in. reflector: the fainter star was 6.0 arcsec from the primary, at position angle 162.4 ^{circ } (i.e. the fainter star was south-by-southeast from the primary) (Espin 1919). Some time later, it was recognized that the astrograph of the Vatican Observatory had taken an image of the same star-field a dozen years earlier, in late 1906. At that earlier epoch, the fainter star had been separated from the brighter one by only 4.8 arcsec, at position angle 186.2 ^{circ } (i.e. almost due south). Were these stars a binary pair, or were they just two unrelated stars sailing past each other? Some additional measurements might have begun to answer this question. If the secondary star was following a curved path, that would be a clue of orbital motion; if it followed a straight-line path, that would be a clue that these are just two stars passing in the night. Unfortunately, nobody took the trouble to re-examine this pair for almost a century, until the 2MASS astrometric/photometric survey recorded it in late 1998. After almost another decade, this amateur astronomer took some CCD images of the field in 2007, and added another data point on the star's trajectory, as shown in Fig. 15.1.

  10. Wide field imaging - I. Applications of neural networks to object detection and star/galaxy classification

    Science.gov (United States)

    Andreon, S.; Gargiulo, G.; Longo, G.; Tagliaferri, R.; Capuano, N.

    2000-12-01

    Astronomical wide-field imaging performed with new large-format CCD detectors poses data reduction problems of unprecedented scale, which are difficult to deal with using traditional interactive tools. We present here NExt (Neural Extractor), a new neural network (NN) based package capable of detecting objects and performing both deblending and star/galaxy classification in an automatic way. Traditionally, in astronomical images, objects are first distinguished from the noisy background by searching for sets of connected pixels having brightnesses above a given threshold; they are then classified as stars or as galaxies through diagnostic diagrams having variables chosen according to the astronomer's taste and experience. In the extraction step, assuming that images are well sampled, NExt requires only the simplest a priori definition of `what an object is' (i.e. it keeps all structures composed of more than one pixel) and performs the detection via an unsupervised NN, approaching detection as a clustering problem that has been thoroughly studied in the artificial intelligence literature. The first part of the NExt procedure consists of an optimal compression of the redundant information contained in the pixels via a mapping from pixel intensities to a subspace individualized through principal component analysis. At magnitudes fainter than the completeness limit, stars are usually almost indistinguishable from galaxies, and therefore the parameters characterizing the two classes do not lie in disconnected subspaces, thus preventing the use of unsupervised methods. We therefore adopted a supervised NN (i.e. a NN that first finds the rules to classify objects from examples and then applies them to the whole data set). In practice, each object is classified depending on its membership of the regions mapping the input feature space in the training set. In order to obtain an objective and reliable classification, instead of using an arbitrarily defined set of features

  11. Deep wide-field imaging down to the oldest main sequence turn-offs in the Sculptor dwarf spheroidal galaxy

    Science.gov (United States)

    de Boer, T. J. L.; Tolstoy, E.; Saha, A.; Olsen, K.; Irwin, M. J.; Battaglia, G.; Hill, V.; Shetrone, M. D.; Fiorentino, G.; Cole, A.

    2011-04-01

    We present wide-field photometry of resolved stars in the nearby Sculptor dwarf spheroidal galaxy using CTIO/MOSAIC, going down to the oldest main sequence turn-off. The accurately flux calibrated wide field colour-magnitude diagrams can be used to constrain the ages of different stellar populations, and also their spatial distribution. The Sculptor dSph contains a predominantly ancient stellar population (>10 Gyr old) which can be easily resolved into individual stars. A galaxy dominated by an old population provides a clear view of ancient processes of galaxy formation unimpeded by overlying younger populations. By using spectroscopic metallicities of RGB stars in combination with our deep main sequence turn-off photometry we can constrain the ages of different stellar populations with particular accuracy. We find that the known metallicity gradient in Sculptor is well matched to an age gradient. This is the first time that this link with age has been directly quantified. This gradient has been previously observed as a variation in horizontal branch properties and is now confirmed to exist for main sequence turn-offs as well. It is likely the Sculptor dSph first formed an extended metal-poor population at the oldest times, and subsequent more metal-rich, younger stars were formed more towards the centre until the gas was depleted or lost roughly 7 Gyr ago. The fact that these clear radial gradients have been preserved up to the present day is consistent with the apparent lack of signs of recent tidal interactions. Appendices are only available in electronic form at http://www.aanda.org

  12. CCD camera for an autoguider

    Science.gov (United States)

    Schempp, William V.

    1991-06-01

    The requirements of a charge coupled device (CCD) autoguider camera and the specifications of a camera that we propose to build to meet those requirements will be discussed. The design goals of both the package and the electronics will be considered.

  13. CCD Corner-Turning Memory.

    Science.gov (United States)

    1980-07-01

    devices and exhibits the characteristic 1-(0 + t/r )l transient with T- CL/ gmo -18 ns, where gmo Is the device transconductence at t - 0+. Figure 63(b...Diamon, A. M. Mohsen, and T. C. McGill, "Charge Transfer In Buried Channel CCD’s," ISSCC Philadelphia, Digest of Tech. Papers, 146 (1974). 14. See

  14. Wide-field human photoreceptor morphological analysis using phase-resolved sensorless adaptive optics swept-source OCT (Conference Presentation)

    Science.gov (United States)

    Ju, Myeong Jin; Heisler, Morgan; Zawadzki, Robert J.; Bonora, Stefano; Jian, Yifan; Sarunic, Marinko V.

    2017-02-01

    Adaptive optics optical coherence tomography (AO-OCT) systems capable of 3D high resolution imaging have been applied to posterior eye imaging in order to resolve the fine morphological features in the retina. Human cone photoreceptors have been extensively imaged and studied for the investigation of retinal degeneration resulting in photoreceptor cell death. However, there are still limitations of conventional approaches to AO in the clinic, such as relatively small field-of-view (FOV) and the complexities in system design and operation. In this research, a recently developed phase-resolved Sensorless AO Swept Source based OCT (SAO-SS-OCT) system which is compact in size and easy to operate is presented. Owing to its lens-based system design, wide-field imaging can be performed up to 6° on the retina. A phase stabilization unit was integrated with the OCT system. With the phase stabilized OCT signal, we constructed retinal micro-vasculature image using a phase variance technique. The retinal vasculature image was used to align and average multiple OCT volumes acquired sequentially. The contrast-enhanced photoreceptor projection image was then extracted from the averaged volume, and analyzed based on its morphological features through a novel photoreceptor structure evaluation algorithm. The retinas of twelve human research subjects (10 normal and 2 pathological cases) were measured in vivo. Quantitative parameters used for evaluating the cone photoreceptor mosaic such as cell density, cell area, and mosaic regularity are presented and discussed. The SAO-SS-OCT system and the proposed photoreceptor evaluation method has significant potential to reveal early stage retinal diseases associated with retinal degeneration.

  15. Structured illumination for wide-field Raman imaging of cell membranes

    Science.gov (United States)

    Chen, Houkai; Wang, Siqi; Zhang, Yuquan; Yang, Yong; Fang, Hui; Zhu, Siwei; Yuan, Xiaocong

    2017-11-01

    Although the diffraction limit still restricts their lateral resolution, conventional wide-field Raman imaging techniques offer fast imaging speeds compared with scanning schemes. To extend the lateral resolution of wide-field Raman microscopy using filters, standing-wave illumination technique is used, and an improvement of lateral resolution by a factor of more than two is achieved. Specifically, functionalized surface enhanced Raman scattering nanoparticles are employed to strengthen the desired scattering signals to label cell membranes. This wide-field Raman imaging technique affords various significant opportunities in the biological applications.

  16. CLEMENTINE HIRES MOSAIC

    Data.gov (United States)

    National Aeronautics and Space Administration — This CD contains portions of the Clementine HiRes Lunar Mosaic, a geometrically controlled, calibrated mosaic compiled from non-uniformity corrected, 750 nanometer...

  17. Wide Field-of-View (FOV) Soft X-Ray Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Wide Field-of-View (FOV) Soft X-Ray Imager proposes to be a state-of-art instrument with applications for numerous heliospheric and planetary...

  18. Optical Design of the WFIRST Phase-A Wide Field Instrument

    Science.gov (United States)

    Pasquale, Bert A.; Marx, Catherine T.; Gao, Guangjun; Armani, Nerses; Casey, Thomas

    2017-01-01

    The WFIRST Wide-Field Infrared Survey Telescope TMA optical design provides 0.28-sq degrees FOV at 0.11” pixel scale to the Wide Field Instrument, operating between 0.48-2.0 micrometers, including a spectrograph mode (1.0-2.0 micrometers). An Integral Field Channel provides 2-D discrete spectroscopy at 0.15” & 0.3” sampling.

  19. Firearm Projectile in the Maxillary Tuberosity Located by Adjunctive Examination of Wide-Field Optical Fluorescence.

    Science.gov (United States)

    Andrade, Sérgio Araújo; Varotti, Fernando de Pilla; Bagnato, Vanderlei Salvador; Pratavieira, Sebastião

    2017-10-10

    Demonstrate the use of wide-field optical fluorescence as an adjunctive examination in a clinical routine to oral diagnosis. Use of wide-field optical fluorescence in the oral cavity has been restricted to topics related to the detection and diagnosis of oral cancer. In a regular medical appointment, a 58-year-old female patient, without any complaint or oral symptom, underwent the complementary examination by wide-field optical fluorescence. A device with high-power light-emitting diode emitting light centered at a wavelength of (400 ± 10) nm and maximum irradiance of (0.040 ± 0.008) W/cm(2) was used for fluorescence visualization. We report the location of a firearm projectile, intraosseous, in the maxillary tuberosity using wide-field optical fluorescence. It is evidenced that wide-field optical fluorescence, within a clinical routine, can provide relevant images and data, with an immediate result, without the use of ionizing radiation, enabling an efficient oral diagnosis.

  20. Is Flat fielding Safe for Precision CCD Astronomy?

    Science.gov (United States)

    Baumer, Michael; Davis, Christopher P.; Roodman, Aaron

    2017-08-01

    The ambitious goals of precision cosmology with wide-field optical surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST) demand precision CCD astronomy as their foundation. This in turn requires an understanding of previously uncharacterized sources of systematic error in CCD sensors, many of which manifest themselves as static effective variations in pixel area. Such variation renders a critical assumption behind the traditional procedure of flat fielding—that a sensor’s pixels comprise a uniform grid—invalid. In this work, we present a method to infer a curl-free model of a sensor’s underlying pixel grid from flat-field images, incorporating the superposition of all electrostatic sensor effects—both known and unknown—present in flat-field data. We use these pixel grid models to estimate the overall impact of sensor systematics on photometry, astrometry, and PSF shape measurements in a representative sensor from the Dark Energy Camera (DECam) and a prototype LSST sensor. Applying the method to DECam data recovers known significant sensor effects for which corrections are currently being developed within DES. For an LSST prototype CCD with pixel-response non-uniformity (PRNU) of 0.4%, we find the impact of “improper” flat fielding on these observables is negligible in nominal .7″ seeing conditions. These errors scale linearly with the PRNU, so for future LSST production sensors, which may have larger PRNU, our method provides a way to assess whether pixel-level calibration beyond flat fielding will be required.

  1. Wide-field single photon counting imaging with an ultrafast camera and an image intensifier

    Energy Technology Data Exchange (ETDEWEB)

    Zanda, Gianmarco, E-mail: gianmarco.zanda@kcl.ac.uk [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom); Sergent, Nicolas; Green, Mark; Levitt, James A. [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom); Petrasek, Zdenek [Biotechnologisches Zentrum, Technische Universitaet Dresden, Tatzberg 47/49, 01307 Dresden (Germany); Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom)

    2012-12-11

    We are reporting a method for wide-field photon counting imaging using a CMOS camera with a 40 kHz frame rate coupled with a three-stage image intensifier mounted on a standard fluorescence microscope. This system combines high frame rates with single photon sensitivity. The output of the phosphor screen, consisting of single-photon events, is collected by a CMOS camera allowing to create a wide-field image with parallel positional and timing information of each photon. Using a pulsed excitation source and a luminescent sample, the arrival time of hundreds of photons can be determined simultaneously in many pixels with microsecond resolution.

  2. Wide-field single photon counting imaging with an ultrafast camera and an image intensifier

    Science.gov (United States)

    Zanda, Gianmarco; Sergent, Nicolas; Green, Mark; Levitt, James A.; Petrášek, Zdeněk; Suhling, Klaus

    2012-12-01

    We are reporting a method for wide-field photon counting imaging using a CMOS camera with a 40 kHz frame rate coupled with a three-stage image intensifier mounted on a standard fluorescence microscope. This system combines high frame rates with single photon sensitivity. The output of the phosphor screen, consisting of single-photon events, is collected by a CMOS camera allowing to create a wide-field image with parallel positional and timing information of each photon. Using a pulsed excitation source and a luminescent sample, the arrival time of hundreds of photons can be determined simultaneously in many pixels with microsecond resolution.

  3. CCD research. [design, fabrication, and applications

    Science.gov (United States)

    Gassaway, J. D.

    1976-01-01

    The fundamental problems encountered in designing, fabricating, and applying CCD's are reviewed. Investigations are described and results and conclusions are given for the following: (1) the development of design analyses employing computer aided techniques and their application to the design of a grapped structure; (2) the role of CCD's in applications to electronic functions, in particular, signal processing; (3) extending the CCD to silicon films on sapphire (SOS); and (4) all aluminum transfer structure with low noise input-output circuits. Related work on CCD imaging devices is summarized.

  4. SixPak: a wide-field IFU for the William Herschel Telescope

    NARCIS (Netherlands)

    Venema, Lars B.; Schoenmaker, Ton; Verheijen, Marc; Trager, Scott; Rutten, René; Bershady, Matthew; Larsen, Søren; Peletier, Reynier; Spaans, Marco

    2008-01-01

    We intend to construct SixPak, a wide-field fibre-based IFU for the 4.2-meter William Herschel Telescope on La Palma. The fibre bundle will consist of 238 fibres, each 3.0 arcsec in diameter, piping light from the Nasmyth focal plane of the WHT to the existing WYFFOS bench spectrograph. A total of

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

    Science.gov (United States)

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

    2016-05-01

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

  6. Astro-WISE Processing of Wide-field Images and Other Data

    NARCIS (Netherlands)

    Buddelmeijer, H.; Williams, O.R.; McFarland, J. P.; Belikov, A.; Ballester, P.; Egret, D.; Lorente, N.P.F.

    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

  7. Wide-field interferometric phase microscopy with molecular specificity using plasmonic nanoparticles.

    Science.gov (United States)

    Turko, Nir A; Peled, Anna; Shaked, Natan T

    2013-11-01

    We present a method for adding molecular specificity to wide-field interferometric phase microscopy (IPM) by recording the phase signatures of gold nanoparticles (AuNPs) labeling targets of interest in biological cells. The AuNPs are excited by time-modulated light at a wavelength corresponding to their absorption spectral peak, evoking a photothermal (PT) effect due to their plasmonic resonance. This effect induces a local temperature rise, resulting in local refractive index and phase changes that can be detected optically. Using a wide-field interferometric phase microscope, we acquired an image sequence of the AuNP sample phase profile without requiring lateral scanning, and analyzed the time-dependent profile of the entire field of view using a Fourier analysis, creating a map of the locations of AuNPs in the sample. The system can image a wide-field PT phase signal from a cluster containing down to 16 isolated AuNPs. AuNPs are then conjugated to epidermal growth factor receptor (EGFR) antibodies and inserted to an EGFR-overexpressing cancer cell culture, which is imaged using IPM and verified by confocal microscopy. To the best of our knowledge, this is the first time wide-field interferometric PT imaging is performed at the subcellular level without the need for total internal reflection effects or scanning.

  8. Infrared Testing of the Wide-field Infrared Survey Telescope Grism Using Computer Generated Holograms

    Science.gov (United States)

    Dominguez, Margaret Z.; Content, David A.; Gong, Qian; Griesmann, Ulf; Hagopian, John G.; Marx, Catherine T; Whipple, Arthur L.

    2017-01-01

    Infrared Computer Generated Holograms (CGHs) were designed, manufactured and used to measure the performance of the grism (grating prism) prototype which includes testing Diffractive Optical Elements (DOE). The grism in the Wide Field Infrared Survey Telescope (WFIRST) will allow the surveying of a large section of the sky to find bright galaxies.

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

    Science.gov (United States)

    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.

  10. Chromosomal mosaicism goes global

    Directory of Open Access Journals (Sweden)

    Yurov Yuri B

    2008-11-01

    Full Text Available Intercellular differences of chromosomal content in the same individual are defined as chromosomal mosaicism (alias intercellular or somatic genomic variations or, in a number of publications, mosaic aneuploidy. It has long been suggested that this phenomenon poorly contributes both to intercellular (interindividual diversity and to human disease. However, our views have recently become to change due to a series of communications demonstrated a higher incidence of chromosomal mosaicism in diseased individuals (major psychiatric disorders and autoimmune diseases as well as depicted chromosomal mosaicism contribution to genetic diversity, the central nervous system development, and aging. The later has been produced by significant achievements in the field of molecular cytogenetics. Recently, Molecular Cytogenetics has published an article by Maj Hulten and colleagues that has provided evidences for chromosomal mosaicism to underlie formation of germline aneuploidy in human female gametes using trisomy 21 (Down syndrome as a model. Since meiotic aneuploidy is suggested to be the leading genetic cause of human prenatal mortality and postnatal morbidity, these data together with previous findings define chromosomal mosaicism not as a casual finding during cytogenetic analyses but as a more significant biological phenomenon than previously recognized. Finally, the significance of chromosomal mosaicism can be drawn from the fact, that this phenomenon is involved in genetic diversity, normal and abnormal prenatal development, human diseases, aging, and meiotic aneuploidy, the intrinsic cause of which remains, as yet, unknown.

  11. Wide field monitoring of the X-ray sky using Rotation Modulation Collimators

    DEFF Research Database (Denmark)

    Lund, Niels; Brandt, Søren

    1995-01-01

    Wide field monitoring is of particular interest in X-ray astronomy due to the strong time-variability of most X-ray sources. Not only does the time-profiles of the persistent sources contain characteristic signatures of the underlying physical systems, but, additionally, some of the most intriguing...... sources have long periods of quiesense in which they are almost undetectable as X-ray sources, interspersed with relatively brief periods of intense outbursts, where we have unique opportunities of studying dynamical effects, in, for instance, the evolution of accretion discs. Another question for which...... wide field monitors may provide key information, is the origin and nature of the cosmic gamma ray bursts.Rotation Modulation Collimators (RMC's) were originally introduced in X-ray astronomy to provide accurate source localizations over extended fields. This role has since been taken over...

  12. The biocytin wide-field bipolar cell in the rabbit retina selectively contacts blue cones

    Science.gov (United States)

    MacNeil, Margaret A.; Gaul, Paulette A.

    2010-01-01

    The biocytin wide-field bipolar cell in rabbit retina is a sparsely populated ON cone bipolar cell with a broad dendritic arbor that does not contact all cones in its dendritic field. The purpose of our study was to identify the cone types that this cell contacts. We identified the bipolar cells by selective uptake of biocytin, labeled the cones with peanut agglutinin and then used antibodies against blue cone opsin and red-green cone opsin to identify the individual cone types. The biocytin-labeled cells selectively contacted cones whose outer segments stained for blue cone opsin and avoided cones that did not. We conclude that the biocytin wide-field bipolar cell is an ON blue cone bipolar cell in the rabbit retina and is homologous to the blue cone bipolar cells that have been previously described in primate, mouse, and ground squirrel retinas. PMID:17990268

  13. Biocytin wide-field bipolar cells in rabbit retina selectively contact blue cones.

    Science.gov (United States)

    MacNeil, Margaret A; Gaul, Paulette A

    2008-01-01

    The biocytin wide-field bipolar cell in rabbit retina has a broad axonal arbor in layer 5 of the inner plexiform layer and a wide dendritic arbor that does not contact all cones in its dendritic field. The purpose of our study was to identify the types of cones that this cell contacts. We identified the bipolar cells by selective uptake of biocytin, labeled the cones with peanut agglutinin, and then used antibodies against blue cone opsin and red-green cone opsin to identify the individual cone types. The biocytin-labeled cells selectively contacted cones whose outer segments stained for blue cone opsin and avoided cones that did not. We conclude that the biocytin wide-field bipolar cell is an ON blue cone bipolar cell in the rabbit retina and is homologous to the blue cone bipolar cells that have been previously described in primate, mouse, and ground squirrel retinas. Copyright 2007 Wiley-Liss, Inc.

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

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Will [Australian Astron. Observ.; Gillingham, Peter [Australian Astron. Observ.; Smith, Greg [Australian Astron. Observ.; Kent, Steve [Fermilab; Doel, Peter [University Coll. London

    2014-07-18

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

  15. Wide-field mid-infrared hyperspectral imaging of adhesives using a bolometer camera

    OpenAIRE

    Sugawara, Shigeru; Nakayama, Yoshihiko; Taniguchi, Hideya; Ishimaru, Ichiro

    2017-01-01

    By combining a bolometer detector with an imaging-type interferometer, an inexpensive, easy-to-handle wide-field mid-infrared hyperspectral imaging apparatus was produced. We measured the distributions of four types of thin adhesive layers on an aluminium plate and analysed the results using correlation coefficients to visualise the distribution of various adhesives that cannot be discerned by the naked eye or conventional methods such as visible/near-infrared spectroscopic/fluorescent photog...

  16. Wide-field surface-enhanced CARS microscopy of cells (Conference Presentation)

    Science.gov (United States)

    Fast, Alexander; Kenison, John T.; Potma, Eric O.

    2017-02-01

    We have previously demonstrated a total internal reflection, wide-field CARS microscope, where the signal is enhanced with the aid of a thin gold layer that supports surface plasmon polariton resonances. This surface-enhanced CARS microscope is capable of generating images of lipid structures in close proximity (visualizing lipids in aqueous media, including imaging of cells, with a unique surface-sensitive contrast that cannot be obtained with conventional CARS microscopy.

  17. Laser light-field fusion for wide-field lensfree on-chip phase contrast nanoscopy

    OpenAIRE

    Kazemzadeh, Farnoud; Wong, Alexander

    2016-01-01

    Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast nanoscopy, where interferometric laser light-field encodings acquired using an on-chip setup with laser pulsations at different wav...

  18. Wide-field monitoring strategy for the study of fast optical transients

    Science.gov (United States)

    Beskin, Grigory; Bondar, Sergey; Karpov, Sergey; Guarnieri, Adriano; Bartolini, Corrado; Greco, Giuseppe; Piccioni, Adalberto

    2010-10-01

    We discuss the strategy of search for fast optical transients accompanying gamma-ray bursts by means of continuous monitoring of wide sky fields with high temporal resolution. We describe the design, performance and results of our cameras, FAVOR and TORTORA. Also we discuss the perspectives of this strategy and possible design of next-generation equipment for wide-field monitoring which will be able to detect optical transients and to study their color and polarization properties with high time resolution.

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Monitoring with high temporal resolution to search for optical transients in the wide field

    Science.gov (United States)

    Beskin, Grigory; Bondar, Sergey; Ivanov, Evgeny; Karpov, Sergey; Katkova, Elena; Pozanenko, Alexei; Guarnieri, Adriano; Bartolini, Corrado; Piccioni, Adalberto; Greco, Giuseppe; Molinari, Emilio; Covino, Stefano

    2008-02-01

    In order to detect and investigate short stochastic optical flares from a number of variable astrophysical objects (GRBs, SNs, flare stars, CVs, X-Ray binaries) of unknown localizations as well as near-earth objects (NEOs), both natural and artificial, it is necessary to perform the systematic monitoring of large regions of the sky with high temporal resolution. Here we describe the design of a system able to perform such a task, which consists of a wide-field camera with high time resolution able to detect and classify the transient events on a subsecond time scale, and a fast robotic telescope aimed to perform their detailed investigation. In a last few years we've created the prototype FAVOR wide-field camera, placed at North Caucasus near Russian 6-m telescope, and a complete two-telescope complex TORTOREM, combining TORTORA wide-field camera with REM robotic telescope and placed at La Silla ESO observatory. Its technical parameters and first results of operation are described.

  1. CCD-based vertex detectors

    CERN Document Server

    Damerell, C J S

    2005-01-01

    Over the past 20 years, CCD-based vertex detectors have been used to construct some of the most precise 'tracking microscopes' in particle physics. They were initially used by the ACCMOR collaboration for fixed target experiments in CERN, where they enabled the lifetimes of some of the shortest-lived charm particles to be measured precisely. The migration to collider experiments was accomplished in the SLD experiment, where the original 120 Mpixel detector was later upgraded to one with 307 Mpixels. This detector was used in a range of physics studies which exceeded the capability of the LEP detectors, including the most precise limit to date on the Bs mixing parameter. This success, and the high background hit densities that will inevitably be encountered at the future TeV-scale linear collider, have established the need for a silicon pixel-based vertex detector at this machine. The technical options have now been broadened to include a wide range of possible silicon imaging technologies as well as CCDs (mon...

  2. Characteristics of rose mosaic diseases

    Directory of Open Access Journals (Sweden)

    Marek S. Szyndel

    2013-12-01

    Full Text Available Presented review of rose diseases, associated with the mosaic symptoms, includes common and yellow rose mosaic, rose ring pattern, rose X disease, rose line pattern, yellow vein mosaic and rose mottle mosaic disease. Based on symptomatology and graft transmissibility of causing agent many of those rose disorders are called "virus-like diseases" since the pathogen has never been identified. However, several viruses were detected and identified in roses expressing mosaic symptoms. Currently the most prevalent rose viruses are Prunus necrotic ringspot virus - PNRSV, Apple mosaic virus - ApMV (syn. Rose mosaic virus and Arabis mosaic virus - ArMV Symptoms and damages caused by these viruses are described. Tomato ringspot virus, Tobacco ringspot virus and Rose mottle mosaic virus are also mentioned as rose pa thogcns. Methods of control of rose mosaic diseases are discussed.

  3. Cryostat and CCD for MEGARA at GTC

    Science.gov (United States)

    Castillo-Domínguez, E.; Ferrusca, D.; Tulloch, S.; Velázquez, M.; Carrasco, E.; Gallego, J.; Gil de Paz, A.; Sánchez, F. M.; Vílchez Medina, J. M.

    2012-09-01

    MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is the new integral field unit (IFU) and multi-object spectrograph (MOS) instrument for the GTC. The spectrograph subsystems include the pseudo-slit, the shutter, the collimator with a focusing mechanism, pupil elements on a volume phase holographic grating (VPH) wheel and the camera joined to the cryostat through the last lens, with a CCD detector inside. In this paper we describe the full preliminary design of the cryostat which will harbor the CCD detector for the spectrograph. The selected cryogenic device is an LN2 open-cycle cryostat which has been designed by the "Astronomical Instrumentation Lab for Millimeter Wavelengths" at INAOE. A complete description of the cryostat main body and CCD head is presented as well as all the vacuum and temperature sub-systems to operate it. The CCD is surrounded by a radiation shield to improve its performance and is placed in a custom made mechanical mounting which will allow physical adjustments for alignment with the spectrograph camera. The 4k x 4k pixel CCD231 is our selection for the cryogenically cooled detector of MEGARA. The characteristics of this CCD, the internal cryostat cabling and CCD controller hardware are discussed. Finally, static structural finite element modeling and thermal analysis results are shown to validate the cryostat model.

  4. Development of CCD controller for scientific application

    Science.gov (United States)

    Khan, M. S.; Pathan, F. M.; Shah, U. V., Prof; Makwana, D. H., Prof; Anandarao, B. G., Prof

    2010-02-01

    Photoelectric equipment has wide applications such as spectroscopy, temperature measurement in infrared region and in astronomical research etc. A photoelectric transducer converts radiant energy into electrical energy. There are two types of photoelectric transducers namely photo-multiplier tube (PMT) and charged couple device (CCD) are used to convert radiant energy into electrical signal. Now the entire modern instruments use CCD technology. We have designed and developed a CCD camera controller using camera chip CD47-10 of Marconi which has 1K × 1K pixel for space application only.

  5. Turner/Down mosaicism

    African Journals Online (AJOL)

    Klinefelter, Down/XXXI and TumerlPatau syndromes.2 The Down/Klinefelter combination is the most frequent double aneuploidy recognised.3. Turner/Down mosaicism usually occurs as a phenotypical. Down syndrome with cytogenetic ...

  6. Photographic and CCD Sky Patrols with Small Telescopes

    Science.gov (United States)

    Kroll, Peter

    Since the twenties of the last century Sonneberg Observatory runs in each clear night a photographic Sky Patrol with a system of small telescopes (55/250 mm) reaching 14m in the blue and 13m in the yellow-red. In addition, a so-called Field Patrol is run with 2 astrographs (400/2000 mm) and a Schmidt camera (500/700/1720 mm) covering 80 selected fields along or near the Milky Way. From these instruments an archive of alomost 300,000 photographic plates arose, documenting the history of the starry night over more than 75 years. Currently much effort is made to take over this photographic sky patrol by a system of electronic detectors. Owing to the fact, that wide-field systems need either large CCDs or arrays of CCDs in order to cover the whole field of view, the technical availability of large detectors was one of the central problems in past. We now invent the use of a PHILIPS 4K×7K chip in wide-field astronomy for Whole-Sky Patrol. Although the chip has a quantum efficiency of only about 30 %, its big size (12μm pixel size) of 48×84 mm offers, for the first time, the replacement of large photographic plates by a single CCD chip. We report our first experiences with this chip when using it with a super wide-angle objective for whole-sky imaging each minute down to ca. 10m for investigating different targets (variable stars, meteors, GRB counterparts, etc.) and first trial to use the large-size chip with other small telescopes (400 to 600 mm diameter) at Sonneberg Observatory.

  7. CCD OBSERVATIONS V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — Charged Coupled Device (CCD) cameras from ESO were used by groups to observe the outburst of comet Halley using a variety of telescopes and chip sets.

  8. CCD Video Observation of Microgravity Crystallization of Lysozyme and Correlation with Accelerometer Data

    Science.gov (United States)

    Snell, E. H.; Boggon, T. J.; Helliwell, J. R.; Moskowitz, M. E.; Nadarajah, A.

    1997-01-01

    Lysozyme has been crystallized using the ESA Advanced Protein Crystallization Facility onboard the NASA Space Shuttle Orbiter during the IML-2 mission. CCD video monitoring was used to follow the crystallization process and evaluate the growth rate. During the mission some tetragonal crystals were observed moving over distances of up to 200 micrometers. This was correlated with microgravity disturbances caused by firings of vernier jets on the Orbiter. Growth-rate measurement of a stationary crystal (which had nucleated on the growth reactor wall) showed spurts and lulls correlated with an onboard activity; astronaut exercise. The stepped growth rates may be responsible for the residual mosaic block structure seen in crystal mosaicity and topography measurements.

  9. A Wide Field Auroral Imager (WFAI for low Earth orbit missions

    Directory of Open Access Journals (Sweden)

    N. P. Bannister

    2007-03-01

    Full Text Available A comprehensive understanding of the solar wind interaction with Earth's coupled magnetosphere-ionosphere system requires an ability to observe the charged particle environment and auroral activity from the same platform, generating particle and photon image data which are matched in time and location. While unambiguous identification of the particles giving rise to the aurora requires a Low Earth Orbit satellite, obtaining adequate spatial coverage of aurorae with the relatively limited field of view of current space bourne auroral imaging systems requires much higher orbits. A goal for future satellite missions, therefore, is the development of compact, wide field-of-view optics permitting high spatial and temporal resolution ultraviolet imaging of the aurora from small spacecraft in low polar orbit. Microchannel plate optics offer a method of achieving the required performance. We describe a new, compact instrument design which can observe a wide field-of-view with the required spatial resolution. We report the focusing of 121.6 nm radiation using a spherically-slumped, square-pore microchannel plate with a focal length of 32 mm and an F number of 0.7. Measurements are compared with detailed ray-trace simulations of imaging performance. The angular resolution is 2.7±0.2° for the prototype, corresponding to a footprint ~33 km in diameter for an aurora altitude of 110 km and a spacecraft altitude of 800 km. In preliminary analysis, a more recent optic has demonstrated a full width at half maximum of 5.0±0.3 arcminutes, corresponding to a footprint of ~1 km from the same spacecraft altitude. We further report the imaging properties of a convex microchannel plate detector with planar resistive anode readout; this detector, whose active surface has a radius of curvature of only 100 mm, is shown to meet the spatial resolution and sensitivity requirements of the new wide field auroral imager (WFAI.

  10. Wide-field Imaging of the Environments of LITTLE THINGS Dwarf Irregular Galaxies

    Science.gov (United States)

    Hunter, Deidre A.; Melton, Casey; Leshin, Stephen; Wong, Alson; Clark, Maurice; Kamienski, Jerald; Moriya, Netzer; Packwood, Burley; Birket, Bob; Edwards, William; Millward, Mervyn; Wheelband, Ian

    2018-01-01

    We have obtained wide-field images of 36 of the 41 LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The H I Nearby Galaxy Survey) nearby (limiting magnitudes of the images range from 19.7 to 28.3 mag arcsec‑2, with a median value of 25.9 mag arcsec‑2. We did not find any unknown companions. Two of the LITTLE THINGS galaxies, NGC 4163 and NGC 4214, and the fainter dwarf, UGCA 276, lie potentially within 100 kpc of each other, but our imaging does not reveal any stellar bridge between the galaxies. This project was part of the Lowell Amateur Research Initiative.

  11. The UKIRT wide-field camera (WFCAM): commissioning and performance on the telescope

    Science.gov (United States)

    Hirst, Paul; Casali, Mark; Adamson, Andy; Ives, Derek; Kerr, Tom

    2006-06-01

    The UKIRT Wide-Field Camera (WFCAM) was commissioned in two phases between October and December 2004, and March and April 2005. It has been carrying out full-scale sky survey operations since May 2005. This paper describes the commissioning process and compares actual performance on the telescope with specifications in four key areas: optical image quality including delivered FWHM and ghosting etc., noise and sensitivity in the infrared and on the visible autoguider, array artifacts such as crosstalk and persistent images, and observing efficiency. A comprehensive program of science verification was carried out before commencing the UKIRT Infrared Deep Sky Survey (UKIDSS).

  12. Wide-Field Plates Observations of Stars from Earth Orientation Catalogs (EOC)

    Science.gov (United States)

    Chapanov, Y.; Tsvetkova, K.; Tsvetkov, M.; Vondrak, J.; Ron, C.; Stefka, V.

    2012-01-01

    The Earth Orientation Catalogues (EOCs) are primarily meant to provide stable celestial reference frame in optical wavelengths for deriving Earth Orientation Parameters (EOP) from astrometric observations. The EOCs combine catalogues ARIHIP and TYCHO-2 with the rich observation material (variations of Latitude/Universal Time), obtained during the 20th century in programs of monitoring Earth orientation. Other possible source of information for improving the EOCs is the WFPDB (Wide-Field Plate Database). The number of plates, containing EOCs stars and their distribution in time are determined by means of the search engine of the WFPDB.

  13. Sherlock: An Automated Follow-Up Telescope for Wide-Field Transit Searches

    Science.gov (United States)

    Kotredes, Lewis; Charbonneau, David; Looper, Dagny L.; O'Donovan, Francis T.

    2004-06-01

    The most significant challenge currently facing photometric surveys for transiting gas-giant planets is that of confusion with eclipsing binary systems that mimic the photometric signature. A simple way to reject most forms of these false positives is high-precision, rapid-cadence monitoring of the suspected transit at higher angular resolution and in several filters. We are currently building a system that will perform higher-angular-resolution, multi-color follow-up observations of candidate systems identified by Sleuth (our wide-field transit survey instrument at Palomar), and its two twin system instruments in Tenerife and northern Arizona.

  14. Wide-field TCSPC-based fluorescence lifetime imaging (FLIM) microscopy

    Science.gov (United States)

    Suhling, Klaus; Hirvonen, Liisa M.; Becker, Wolfgang; Smietana, Stefan; Netz, Holger; Milnes, James; Conneely, Thomas; Le Marois, Alix; Jagutzki, Ottmar

    2016-05-01

    Time-correlated single photon counting (TCSPC) is a widely used, sensitive, precise, robust and mature technique to measure photon arrival times in applications such as fluorescence spectroscopy and microscopy, light detection and ranging (lidar) and optical tomography. Wide-field TCSPC detection techniques, where the position and the arrival time of the photons are recorded simultaneously, have seen several advances in the last few years, from the microsecond to the picosecond time scale. Here, we summarise some of our recent work in this field with emphasis on microsecond resolution phosphorescence lifetime imaging (PLIM) and nanosecond fluorescence lifetime imaging (FLIM) microscopy.

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

    Science.gov (United States)

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

    2014-07-01

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

  16. The biocytin wide-field bipolar cell in the rabbit retina selectively contacts blue cones

    OpenAIRE

    MacNeil, Margaret A.; Gaul, Paulette A.

    2008-01-01

    The biocytin wide-field bipolar cell in rabbit retina is a sparsely populated ON cone bipolar cell with a broad dendritic arbor that does not contact all cones in its dendritic field. The purpose of our study was to identify the cone types that this cell contacts. We identified the bipolar cells by selective uptake of biocytin, labeled the cones with peanut agglutinin and then used antibodies against blue cone opsin and red-green cone opsin to identify the individual cone types. The biocytin-...

  17. The High-Speed and Wide-Field TORTORA Camera: description & results .

    Science.gov (United States)

    Greco, G.; Beskin, G.; Karpov, S.; Guarnieri, A.; Bartolini, C.; Bondar, S.; Piccioni, A.; Molinari, E.

    We present the description and the most significant results of the wide-field and ultra-fast TORTORA camera devoted to the investigation of rapid changes in light intensity in a phenomenon occurring within an extremely short period of time and randomly distributed over the sky. In particular, the ground-based TORTORA observations synchronized with the gamma -ray BAT telescope on board of the Swift satellite has permitted to trace the optical burst time-structure of the Naked-Eye GRB 080319B with an unprecedented level of accuracy.

  18. Micrometeoroid Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Larger Particles

    Science.gov (United States)

    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.; hide

    2014-01-01

    The Wide Field and Planetary Camera 2 (WFPC2) was returned from the Hubble Space Telescope (HST) by shuttle mission STS-125 in 2009. In space for 16 years, the surface accumulated hundreds of impact features on the zinc orthotitanate paint, some penetrating through into underlying metal. Larger impacts were seen in photographs taken from within the shuttle orbiter during service missions, with spallation of paint in areas reaching 1.6 cm across, exposing alloy beneath. Here we describe larger impact shapes, the analysis of impactor composition, and the micrometeoroid (MM) types responsible.

  19. Application of SFM and laser scanning technology to the description of mosaics piece by piece

    Directory of Open Access Journals (Sweden)

    O. Ajioka

    2014-06-01

    Full Text Available Mosaic floors of surviving buildings in Ostia have been mainly recorded in photographs. From 2008, Japanese research group carries out a project of 3d measuring of the whole structure of ancient Roman city Ostia using laser scanners, including its landscape, city blocks, streets, buildings, wall paintings and mosaics. The laser scanner allows for a more detailed analysis and a greater potential for recording mosaics. We can record the data of mosaics, which are described piece by piece. However it is hard to acquire enough high dense point cloud and the internal camera of the laser scanner produce low quality images. We introduce a possible technology of 3D recording of mosaics with high-quality colour information; SFM. The use of this technique permits us to create 3D models from images provided from a CCD camera without heavy and large laser scanners. We applied SFM system to different three types of the mosaics laid down on the floors of "the House of the Dioscuroi", "the Insula of the Muse" and "the House of Jove and Ganymede", and created high resolution orthographic images. Then we examined to compare these orthographic images with that are created from the point cloud data. As a result, we confirmed that SFM system has sufficient practical utility for the mosaic research. And we present how much of density of point cloud or ground resolution are required for the documentation of mosaics accurately.

  20. Blind deconvolution with principal components analysis for wide-field and small-aperture telescopes

    Science.gov (United States)

    Jia, Peng; Sun, Rongyu; Wang, Weinan; Cai, Dongmei; Liu, Huigen

    2017-09-01

    Telescopes with a wide field of view (greater than 1°) and small apertures (less than 2 m) are workhorses for observations such as sky surveys and fast-moving object detection, and play an important role in time-domain astronomy. However, images captured by these telescopes are contaminated by optical system aberrations, atmospheric turbulence, tracking errors and wind shear. To increase the quality of images and maximize their scientific output, we propose a new blind deconvolution algorithm based on statistical properties of the point spread functions (PSFs) of these telescopes. In this new algorithm, we first construct the PSF feature space through principal component analysis, and then classify PSFs from a different position and time using a self-organizing map. According to the classification results, we divide images of the same PSF types and select these PSFs to construct a prior PSF. The prior PSF is then used to restore these images. To investigate the improvement that this algorithm provides for data reduction, we process images of space debris captured by our small-aperture wide-field telescopes. Comparing the reduced results of the original images and the images processed with the standard Richardson-Lucy method, our method shows a promising improvement in astrometry accuracy.

  1. Wide-field and high-resolution optical imaging for early detection of oral neoplasia

    Science.gov (United States)

    Pierce, Mark C.; Schwarz, Richard A.; Rosbach, Kelsey; Roblyer, Darren; Muldoon, Tim; Williams, Michelle D.; El-Naggar, Adel K.; Gillenwater, Ann M.; Richards-Kortum, Rebecca

    2010-02-01

    Current procedures for oral cancer screening typically involve visual inspection of the entire tissue surface at risk under white light illumination. However, pre-cancerous lesions can be difficult to distinguish from many benign conditions when viewed under these conditions. We have developed wide-field (macroscopic) imaging system which additionally images in cross-polarized white light, narrowband reflectance, and fluorescence imaging modes to reduce specular glare, enhance vascular contrast, and detect disease-related alterations in tissue autofluorescence. We have also developed a portable system to enable high-resolution (microscopic) evaluation of cellular features within the oral mucosa in situ. This system is a wide-field epi-fluorescence microscope coupled to a 1 mm diameter, flexible fiber-optic imaging bundle. Proflavine solution was used to specifically label cell nuclei, enabling the characteristic differences in N/C ratio and nuclear distribution between normal, dysplastic, and cancerous oral mucosa to be quantified. This paper discusses the technical design and performance characteristics of these complementary imaging systems. We will also present data from ongoing clinical studies aimed at evaluating diagnostic performance of these systems for detection of oral neoplasia.

  2. A wide-field suprachoroidal retinal prosthesis is stable and well tolerated following chronic implantation.

    Science.gov (United States)

    Villalobos, Joel; Nayagam, David A X; Allen, Penelope J; McKelvie, Penelope; Luu, Chi D; Ayton, Lauren N; Freemantle, Alexia L; McPhedran, Michelle; Basa, Meri; McGowan, Ceara C; Shepherd, Robert K; Williams, Chris E

    2013-05-01

    The safety of chronic implantation of a retinal prosthesis in the suprachoroidal space has not been established. This study aimed to determine the safety of a wide-field suprachoroidal electrode array following chronic implantation using histopathologic techniques and electroretinography. A platinum electrode array in a wide silicone substrate was implanted unilaterally in the suprachoroidal space in adult cats (n = 7). The lead and connector were tunneled out of the orbit and positioned subcutaneously. Postsurgical recovery was assessed using fundus photography and electroretinography (ERG). Following 3 months of passive implantation, the animals were terminated and the eyes assessed for the pathologic response to implantation. The implant was mechanically stable in the suprachoroidal space during the course of the study. The implanted eye showed a transient increase in ERG response amplitude at 2 weeks, which returned to normal by 3 months. Pigmentary changes were observed at the distal end of the implant, near the optic disc. Histopathologic assessment revealed a largely intact retina and a thin fibrous capsule around the suprachoroidal implant cavity. The foreign body response was minimal, with sporadic presence of macrophages and no active inflammation. All implanted eyes were negative for bacterial or fungal infections. A midgrade granuloma and thick fibrous buildup surrounded the extraocular cable. Scleral closure was maintained in six of seven eyes. There were no staphylomas or choroidal incarceration. A wide-field retinal prosthesis was stable and well tolerated during long-term suprachoroidal implantation in a cat model. The surgical approach was reproducible and overall safe.

  3. Stray-field-induced Faraday contributions in wide-field Kerr microscopy and -magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Markó, D.; Soldatov, I. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Metallic Materials, PO 270116, D-01171 Dresden (Germany); Dresden University of Technology, Institute for Materials Science, D-01062 Dresden (Germany); Tekielak, M. [Institute of Experimental Physics, University of Bialystok, Lipowa 41, Bialystok 15-424 Poland (Poland); Schäfer, R., E-mail: r.schaefer@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Metallic Materials, PO 270116, D-01171 Dresden (Germany); Dresden University of Technology, Institute for Materials Science, D-01062 Dresden (Germany)

    2015-12-15

    The magnetic domain contrast in wide-field Kerr microscopy on bulk specimens can be substantially distorted by non-linear, field-dependent Faraday rotations in the objective lens that are caused by stray-field components emerging from the specimen. These Faraday contributions, which were detected by Kerr-magnetometry on grain-oriented iron–silicon steel samples, are thoroughly elaborated and characterized. They express themselves as a field-dependent gray-scale offset to the domain contrast and in highly distorted surface magnetization curves if optically measured in a wide field Kerr microscope. An experimental method to avoid such distortions is suggested. In the course of these studies, a low-permeability part in the surface magnetization loop of slightly misoriented (110)-surfaces in iron–silicon sheets was discovered that is attributed to demagnetization effects in direction perpendicular to the sheet surface. - Highlights: • Magnetizing a finite sample in a Kerr microscope leads to sample-generated stray-fields. • They cause non-linear, field- and position-dependent Faraday rotations in the objective. • This leads to a modulation of the Kerr contrast and to distorted MOKE loops. • A method to compensate these Faraday rotations is presented.

  4. Microlensing Surveys of M31 in the Wide Field Imaging ERA

    Energy Technology Data Exchange (ETDEWEB)

    Baltz, E.

    2004-10-27

    The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way, thus it is an important laboratory for studying massive dark objects in galactic halos (MACHOs) by gravitational microlensing. Such studies strongly complement the studies of the Milky Way halo using the Large and Small Magellanic Clouds. We consider the possibilities for microlensing surveys of M31 using the next generation of wide field imaging telescopes with fields of view in the square degree range. We consider proposals for such imagers both on the ground and in space. For concreteness, we specialize to the SNAP proposal for a space telescope and the LSST proposal for a ground based telescope. We find that a modest space-based survey of 50 visits of one hour each is considerably better than current ground based surveys covering 5 years. Crucially, systematic effects can be considerably better controlled with a space telescope because of both the infrared sensitivity and the angular resolution. To be competitive, 8 meter class wide-field ground based imagers must take exposures of several hundred seconds with several day cadence.

  5. Spatially Resolved Two-Dimensional Infrared Spectroscopy via Wide-Field Microscopy.

    Science.gov (United States)

    Ostrander, Joshua S; Serrano, Arnaldo L; Ghosh, Ayanjeet; Zanni, Martin T

    2016-07-20

    We report the first wide-field microscope for measuring two-dimensional infrared (2D IR) spectroscopic images. We concurrently collect more than 16 000 2D IR spectra, made possible by a new focal plane array detector and mid-IR pulse shaping, to generate hyperspectral images with multiple frequency dimensions and diffraction-limited spatial resolution. Both frequency axes of the spectra are collected in the time domain by scanning two pairs of femtosecond pulses using a dual acousto-optic modulator pulse shaper. The technique is demonstrated by imaging a mixture of metal carbonyl absorbed polystyrene beads. The differences in image formation between FTIR and 2D IR microscopy are also explored by imaging a patterned USAF test target. We find that our 2D IR microscope has diffraction-limited spatial resolution and enhanced contrast compared to FTIR microscopy because of the nonlinear scaling of the 2D IR signal to the absorptivity coefficient for the vibrational modes. Images generated using off-diagonal peaks, created from vibrational anharmonicities, improve the molecular discrimination and eliminate noise. Two-dimensional wide-field IR microscopy provides information on vibrational lifetimes, molecular couplings, transition dipole orientations, and many other quantities that can be used for creating image contrast to help disentangle and interpret complex and heterogeneous samples. Such experiments made possible could include the study of amyloid proteins in tissues, protein folding in heterogeneous environments, and structural dynamics in devices employing mid-IR materials.

  6. HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Adam C.; Cushing, Michael C. [Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606 (United States); Kirkpatrick, J. Davy; Gelino, Christopher R. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Mace, Gregory N.; Wright, Edward L. [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Eisenhardt, Peter R. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Skrutskie, M. F. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Griffith, Roger L. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Marsh, Kenneth A., E-mail: Adam.Schneider@Utoledo.edu [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)

    2015-05-10

    We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments.

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Optically sectioned wide-field fluorescence lifetime imaging endoscopy enabled by structured illumination (Conference Presentation)

    Science.gov (United States)

    Hinsdale, Taylor; Malik, Bilal H.; Rico-Jimenez, Jose J.; Jo, Javier A.; Maitland, Kristen C.

    2016-03-01

    We present a wide-field fluorescence lifetime imaging (FLIM) system with optical sectioning by structured illumination microscopy (SIM). FLIM measurements were made using a time gated ICCD camera in conjunction with a pulsed nitrogen dye laser operating at 450 nm. Intensity images were acquired at multiple time delays from a trigger initiated by a laser pulse to create a wide-field FLIM image, which was then combined with three phase SIM to provide optical sectioning. Such a mechanism has the potential to increase the reliability and accuracy of the FLIM measurements by rejecting background intensity. SIM also provides the opportunity to create volumetric FLIM images with the incorporation of scanning mechanisms for the sample plane. We present multiple embodiments of such a system: one as a free space endoscope and the other as a fiber microendoscope enabled by the introduction of a fiber bundle. Finally, we demonstrate the efficacy of such an imaging system by imaging dyes embedded in a tissue phantom.

  9. Simple concept for a wide-field lensless digital holographic microscope using a laser diode

    Directory of Open Access Journals (Sweden)

    Adinda-Ougba A.

    2015-09-01

    Full Text Available Wide-field, lensless digital holographic microscopy is a new microscopic imaging technique for telemedicine and for resource limited setting [1]. In this contribution we propose a very simple wide-field lensless digital holographic microscope using a laser diode. It is based on in-line digital holography which is capable to provide amplitude and phase images of a sample resulting from numerical reconstruction. The numerical reconstruction consists of the angular spectrum propagation method together with a phase retrieval algorithm. Amplitude and phase images of the sample with a resolution of ∽2 µm and with ∽24 mm2 field of view are obtained. We evaluate our setup by imaging first the 1951 USAF resolution test chart to verify the resolution. Second, we record holograms of blood smear and diatoms. The individual specimen can be easily identified after the numerical reconstruction. Our system is a very simple, compact and low-cost possibility of realizing a microscope capable of imaging biological samples. The availability of the phase provide topographic information of the sample extending the application of this system to be not only for biological sample but also for transparent microstructure. It is suitable for fault detection, shape and roughness measurements of these structures.

  10. Evolutionary relationship of alfalfa mosaic virus with cucumber mosaic virus and brome mosaic virus

    OpenAIRE

    Savithri, HS; Murthy, MRN

    1983-01-01

    The amino acid sequences of the non-structural protein (molecular weight 35,000; 3a protein) from three plant viruses - cucumber mosaic, brome mosaic and alfalfa mosaic have been systematically compared using the partial genomic sequences for these three viruses already available. The 3a protein of cucumber mosaic virus has an amino acid sequence homology of 33.7% with the corresponding protein of brome mosaic virus. A similar protein from alfalfa mosaic virus has a homology of 18.2% and 14.2...

  11. Noncontact and Wide-Field Characterization of the Absorption and Scattering Properties of Apple Fruit Using Spatial-Frequency Domain Imaging

    Science.gov (United States)

    Hu, Dong; Fu, Xiaping; He, Xueming; Ying, Yibin

    2016-12-01

    Spatial-frequency domain imaging (SFDI), as a noncontact, low-cost and wide-field optical imaging technique, offers great potential for agro-product safety and quality assessment through optical absorption (μa) and scattering (μ) property measurements. In this study, a laboratory-based SFDI system was constructed and developed for optical property measurement of fruits and vegetables. The system utilized a digital light projector to generate structured, periodic light patterns and illuminate test samples. The diffuse reflected light was captured by a charge coupled device (CCD) camera with the resolution of 1280 × 960 pixels. Three wavelengths (460, 527, and 630 nm) were selected for image acquisition using bandpass filters in the system. The μa and μ were calculated in a region of interest (ROI, 200 × 300 pixels) via nonlinear least-square fitting. Performance of the system was demonstrated through optical property measurement of ‘Redstar’ apples. Results showed that the system was able to acquire spatial-frequency domain images for demodulation and calculation of the μa and μ. The calculated μa of apple tissue experiencing internal browning (IB) were much higher than healthy apple tissue, indicating that the SFDI technique had potential for IB tissue characterization.

  12. Global Hybrid HRSC+OMEGA Image Mosaics of Mars

    Science.gov (United States)

    McGuire, P. C.; Walter, S. H. G.; van Gasselt, S.; Dunke, A.; Dunker, T.; Gross, C.; Michael, G.; Wendt, L.; Audouard, J.; Ody, A.; Poulet, F.

    2014-04-01

    The High Resolution Stereo Camera (HRSC) on the Mars Express (MEx) orbiter has acquired 3640 images (with 'preliminary level 4' processing as described in [1]) of the Martian surface since arriving in orbit in 2003, covering over 90% of the planet [2]. At resolutions that can reach 10 meters/pixel, these MEx/HRSC images [3-4] are constructed in a pushbroom manner from 9 different CCD line sensors, including a panchromatic nadir-looking (Pan) channel, 4 color channels (R, G, B, IR), and 4 other panchromatic channels for stereo imaging or photometric imaging. In [5], we discussed our approach towards automatically mosaicking hundreds of the MEx/HRSC Pan or RGB images together. Herein, we present our latest results using this approach (Fig. 1; PDF is zoomable). Currently, our best results consist of adding a high-pass-filtered version of the HRSC mosaic to a low-pass-filtered version of the MEx/OMEGA [6] global mosaic.

  13. Infantile spasms and pigmentary mosaicism

    DEFF Research Database (Denmark)

    Hansen, Lars K; Bygum, Anette; Krogh, Lotte N

    2010-01-01

    Summary We present a 3-year-old boy with pigmentary mosaicism and persistent intractable infantile spasms due to mosaicism of chromosome 7. Getting the diagnosis of pigmentary mosaicism in a child with infantile spasms may not be easy, as most diagnostic work-up is done in infancy, at a time when...

  14. Radiometric calibration of wide-field camera system with an application in astronomy

    Science.gov (United States)

    Vítek, Stanislav; Nasyrova, Maria; Stehlíková, Veronika

    2017-09-01

    Camera response function (CRF) is widely used for the description of the relationship between scene radiance and image brightness. Most common application of CRF is High Dynamic Range (HDR) reconstruction of the radiance maps of imaged scenes from a set of frames with different exposures. The main goal of this work is to provide an overview of CRF estimation algorithms and compare their outputs with results obtained under laboratory conditions. These algorithms, typically designed for multimedia content, are unfortunately quite useless with astronomical image data, mostly due to their nature (blur, noise, and long exposures). Therefore, we propose an optimization of selected methods to use in an astronomical imaging application. Results are experimentally verified on the wide-field camera system using Digital Single Lens Reflex (DSLR) camera.

  15. Plastic optical fiber for wide field-of-view optical wireless receiver

    Science.gov (United States)

    Fallah, Hoorieh; Sterckx, Karel; Saengudomlert, Poompat; Mohammed, Waleed S.

    2016-10-01

    This paper demonstrates a working indoor optical wireless link for smart environment applications. The system utilizes a wide field-of-view (FOV) optical wireless receiver through cleaving the tip of large core plastic optical fibers (POFs) attached to the detector. The quality of the optical link is quantified through bit error rate (BER) measurements. The experimental results show a wide FOV with the uncoded BER in the order of 10-3 for transmission distances up to 35 cm when using two POFs for signal collection. The distance can be improved further by increasing the number of fibers. The transmitted signal format and how the BER measurement is achieved are discussed at length. In addition, details are provided for the design of the electronics to establish the optical wireless link.

  16. Programmable LED-based integrating sphere light source for wide-field fluorescence microscopy.

    Science.gov (United States)

    Rehman, Aziz Ul; Anwer, Ayad G; Goldys, Ewa M

    2017-12-01

    Wide-field fluorescence microscopy commonly uses a mercury lamp, which has limited spectral capabilities. We designed and built a programmable integrating sphere light (PISL) source which consists of nine LEDs, light-collecting optics, a commercially available integrating sphere and a baffle. The PISL source is tuneable in the range 365-490nm with a uniform spatial profile and a sufficient power at the objective to carry out spectral imaging. We retrofitted a standard fluorescence inverted microscope DM IRB (Leica) with a PISL source by mounting it together with a highly sensitive low- noise CMOS camera. The capabilities of the setup have been demonstrated by carrying out multispectral autofluorescence imaging of live BV2 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Deconvolution of wide field-of-view radiometer measurements of earth-emitted radiation. I - Theory

    Science.gov (United States)

    Smith, G. L.; Green, R. N.

    1981-01-01

    The theory of deconvolution of wide field-of-view (WFOV) radiometer measurements of earth-emitted radiation provides a technique by which the resolution of such measurements can be enhanced to provide radiant exitance at the top of the atmosphere with a finer resolution than the field of view. An analytical solution for the earth-emitted radiant exitance in terms of WFOV radiometer measurements is derived for the nonaxisymmetric (or regional) case, in which the measurements and radiant exitance are considered to be functions of both latitude and longitude. This solution makes it possible to deconvolve a set of WFOV radiometer measurements of earth-emitted radiation and obtain information with a finer resolution than the instantaneous field of view of the instrument. It is shown that there are tradeoffs involved in the selection between WFOV and scanning radiometers.

  18. Miniaturized high-resolution wide-field contact lens for panretinal photocoagulation

    Directory of Open Access Journals (Sweden)

    Koushan K

    2014-04-01

    Full Text Available Keyvan Koushan, KV Chalam Department of Ophthalmology, University of Florida College of Medicine, Jacksonville, FL, USA Background and objective: We describe a miniaturized lightweight high-refractive-index panretinal contact lens for diagnostic and therapeutic visualization of the peripheral retina. Instrument design: The miniaturized high-resolution wide-field contact lens includes three optical elements in a light (15 g and miniaturized (16 mm footplate, 24 mm external aperture, and 21 mm vertical height casing contributing to a total dioptric power of +171 diopters. This lens provides up to 165° visualization of the retina for diagnostic and therapeutic applications while allowing easier placement due to its miniaturization. Conclusion: This new lens (50% lighter and 89% smaller improves upon earlier contact lenses for visualization of the peripheral retina. Keywords: contact lens, panretinal photocoagulation, retinal examination, peripheral retina, high resolution view, wide-angle lens, lens

  19. Readout electronics for the Wide Field of view Cherenkov/Fluorescence Telescope Array

    Science.gov (United States)

    Zhang, J.; Zhang, S.; Zhang, Y.; Zhou, R.; Bai, L.; Zhang, J.; Huang, J.; Yang, C.; Cao, Z.

    2015-08-01

    The aim of the Large High Altitude Air Shower Observatory (LHAASO), supported by IHEP of the Chinese Academy of Sciences, is a multipurpose project with a complex detectors array for high energy gamma ray and cosmic ray detection. The Wide Field of view Cherenkov Telescope Array (WFCTA), as one of the components of the LHAASO project, aim to tag each primary particle that causes an air shower. The WFCTA is a portable telescope array used to detect cosmic ray spectra. The design of the readout electronics of the WFCTA is described in this paper Sixteen photomultiplier tubes (PMTs), together with their readout electronics are integrated into a single sub-cluster. To maintain good resolution and linearity over a wide dynamic range, a dual-gain amplification configuration on an analog board is used The digital board contains two 16channel 14-bit, 50 Msps analog-to-digital converters (ADC) and its power consumption, noise level, and relative deviation are all tested.

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

    Science.gov (United States)

    Ross, D. K.; Anz-Meador, P.; Liou, J.C.; Opiela, J.; Kearsley, A. T.; Grime, G.; Webb, R.; Jeynes, C.; Palitsin, V.; Colaux, J.; hide

    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.

  1. Wide-field mid-infrared hyperspectral imaging of adhesives using a bolometer camera.

    Science.gov (United States)

    Sugawara, Shigeru; Nakayama, Yoshihiko; Taniguchi, Hideya; Ishimaru, Ichiro

    2017-09-29

    By combining a bolometer detector with an imaging-type interferometer, an inexpensive, easy-to-handle wide-field mid-infrared hyperspectral imaging apparatus was produced. We measured the distributions of four types of thin adhesive layers on an aluminium plate and analysed the results using correlation coefficients to visualise the distribution of various adhesives that cannot be discerned by the naked eye or conventional methods such as visible/near-infrared spectroscopic/fluorescent photography. The measurement wavelength range, obtained spectrum's wavenumber resolution, and measurement time was 8-14 μm, about 9 cm-1, and about 30 s, respectively. Using conventional methods, adhesives could not be distinguished from the others. By using this method, we found that adhesives could be precisely distinguished by setting an appropriate threshold value for the correlation coefficient. Thus, our approach can accurately measure the spatial distribution of different types of adhesive that cannot be discriminated by conventional methods.

  2. San Pedro meeting on Wide Field Variability Surveys: Some concluding comments

    Directory of Open Access Journals (Sweden)

    Feast Michael W.

    2017-01-01

    Full Text Available This is a written version of the closing talk at the 22nd Los Alamos Stellar pulsation conference on wide field variability surveys. It comments on some of the issues which arise from the meeting. These include the need for attention to photometric standardization (especially in the infrared and the somewhat controversial problem of statistical bias in the use of parallaxes (and other methods of distance determination. Some major advances in the use of pulsating variables to study Galactic structure are mentioned. The paper includes a clarification of apparently conflicting results from classical Cepheids and RR Lyrae stars in the inner Galaxy and bulge. The importance of understanding non-periodic phenomena in variable stars, particularly asymptotic giant branch variables and R Coronae Borealis stars, is stressed, especially for its relevance to mass-loss in which pulsation may only play a minor role.

  3. Wide-field microscopic FRET imaging using simultaneous spectral unmixing of excitation and emission spectra.

    Science.gov (United States)

    Du, Mengyan; Zhang, Lili; Xie, Shusen; Chen, Tongsheng

    2016-07-11

    Simultaneous spectral unmixing of excitation and emission spectra (ExEm unmixing) has the inherent ability to resolve donor emission, fluorescence resonance energy transfer (FRET)-sensitized acceptor emission and directly excited acceptor emission. We here develop an ExEm unmixing-based quantitative FRET measurement method (EES-FRET) independent of excitation intensity and detector parameter setting. The ratio factor (rK), predetermined using a donor-acceptor tandem construct, of total acceptor absorption to total donor absorption in excitation wavelengths used is introduced for determining the concentration ratio of acceptor to donor. We implemented EES-FRET method on a wide-field microscope to image living cells expressing tandem FRET constructs with different donor-acceptor stoichiometry.

  4. Meteor observations with Mini-Mega-TORTORA wide-field monitoring system

    Science.gov (United States)

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

    2016-12-01

    Here we report on the results of meteor observations with 9-channel Mini-Mega-TORTORA (MMT-9) optical monitoring system with the wide field and high temporal resolution. During the first 1.5 years of operation more than 90 thousands of meteors have been detected, at a rate of 300-350 per night, with durations from 0.1 to 2.5 seconds and angular velocities up to 38 degrees per second. The faintest detected meteors have peak brightnesses about 10 mag, while the majority have them ranging from 4 to 8 mag. Some of the meteors have been observed in BVR filters simultaneously. Color variations along the trail for them have been determined. The parameters of the detected meteors have been published online. The database also includes data from 10 thousands of meteors detected by our previous FAVOR camera during 2006-2009.

  5. Precision Pointing for the Wide-Field Infrared Survey Telescope(WFIRST)

    Science.gov (United States)

    Stoneking, Eric T.; Hsu, Oscar C.; Welter, Gary

    2017-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission, scheduled for a mid-2020's launch, is currently in its definition phase. The mission is designed to investigate essential questions in the areas of dark energy, exoplanets, and infrared astrophysics. WFIRST will use a 2.4-meter primary telescope (same size as the Hubble Space Telescope's primary mirror) and two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). In order to address the critical science requirements, the WFIRST mission will conduct large-scale surveys of the infrared sky, requiring both agility and precision pointing (11.6 milli-arcsec stability, 14 milli-arcsec jitter). This paper describes some of the challenges this mission profile presents to the Guidance, Navigation, and Control (GNC) subsystem, and some of the design elements chosen to accommodate those challenges. The high-galactic-latitude survey is characterized by 3-minute observations separated by slews ranging from 0.025 deg to 0.8 deg. The need for observation efficiency drives the slew and settle process to be as rapid as possible. A description of the shaped slew profile chosen to minimize excitation of structural oscillation, and the handoff from star tracker-gyro control to fine guidance sensor control is detailed. Also presented is the fine guidance sensor (FGS), which is integral with the primary instrument (WFI). The FGS is capable of tracking up to 18 guide stars, enabling robust FGS acquisition and precision pointing. To avoid excitation of observatory structural jitter, reaction wheel speeds are operationally maintained within set limits. In addition, the wheel balance law is designed to maintain 1-Hz separation between the wheel speeds to avoid reinforcing jitter excitation at any particular frequency. The wheel balance law and operational implications are described. Finally, the candidate GNC hardware suite needed to meet the requirements of the mission is presented.

  6. Signal-to-noise characterization of time-gated intensifiers used for wide-field time-domain FLIM

    Energy Technology Data Exchange (ETDEWEB)

    McGinty, J; Requejo-Isidro, J; Munro, I; Talbot, C B; Dunsby, C; Neil, M A A; French, P M W [Photonics Group, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2BW (United Kingdom); Kellett, P A; Hares, J D, E-mail: james.mcginty@imperial.ac.u [Kentech Instruments Ltd, Isis Building, Howbery Park, Wallingford, OX10 8BA (United Kingdom)

    2009-07-07

    Time-gated imaging using gated optical intensifiers provides a means to realize high speed fluorescence lifetime imaging (FLIM) for the study of fast events and for high throughput imaging. We present a signal-to-noise characterization of CCD-coupled micro-channel plate gated intensifiers used with this technique and determine the optimal acquisition parameters (intensifier gain voltage, CCD integration time and frame averaging) for measuring mono-exponential fluorescence lifetimes in the shortest image acquisition time for a given signal flux. We explore the use of unequal CCD integration times for different gate delays and show that this can improve the lifetime accuracy for a given total acquisition time.

  7. Active Pixel Sensors: Are CCD's Dinosaurs?

    Science.gov (United States)

    Fossum, Eric R.

    1993-01-01

    Charge-coupled devices (CCD's) are presently the technology of choice for most imaging applications. In the 23 years since their invention in 1970, they have evolved to a sophisticated level of performance. However, as with all technologies, we can be certain that they will be supplanted someday. In this paper, the Active Pixel Sensor (APS) technology is explored as a possible successor to the CCD. An active pixel is defined as a detector array technology that has at least one active transistor within the pixel unit cell. The APS eliminates the need for nearly perfect charge transfer -- the Achilles' heel of CCDs. This perfect charge transfer makes CCD's radiation 'soft,' difficult to use under low light conditions, difficult to manufacture in large array sizes, difficult to integrate with on-chip electronics, difficult to use at low temperatures, difficult to use at high frame rates, and difficult to manufacture in non-silicon materials that extend wavelength response.

  8. Turner/Down mosaicism

    African Journals Online (AJOL)

    mosaicism and Crohn's disease. Acca Paediarr Scant! 1988; 77: 922-924. 3. Gauad AR. Congenital dislocation of the knees in a child with Down-mos'!ic. Tumersyndrome.JMedGener 1981; 18: 148-151. 4. MacFaul R, Turner T, Mason MK. Down'slTurner's mos,ucism: double aneuploidy as a rare cause of missed prenatal ...

  9. Handmade Tile Mosaics

    Science.gov (United States)

    Keeler, Rusty

    2007-01-01

    Just like the classroom, children's outdoor environments should be filled with artistic creations that add sparkle and imagination to the space. One of the author's favorite ways to add art to the outdoors is by installing a mosaic mural of child-made tiles. The process of making the tiles is fun for all; each tile is a charming work of art in…

  10. On-Line High Dose-Rate Gamma Ray Irradiation Test of the CCD/CMOS Cameras

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jai Wan; Jeong, Kyung Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    In this paper, test results of gamma ray irradiation to CCD/CMOS cameras are described. From the CAMS (containment atmospheric monitoring system) data of Fukushima Dai-ichi nuclear power plant station, we found out that the gamma ray dose-rate when the hydrogen explosion occurred in nuclear reactors 1{approx}3 is about 160 Gy/h. If assumed that the emergency response robot for the management of severe accident of the nuclear power plant has been sent into the reactor area to grasp the inside situation of reactor building and to take precautionary measures against releasing radioactive materials, the CCD/CMOS cameras, which are loaded with the robot, serve as eye of the emergency response robot. In the case of the Japanese Quince robot system, which was sent to carry out investigating the unit 2 reactor building refueling floor situation, 7 CCD/CMOS cameras are used. 2 CCD cameras of Quince robot are used for the forward and backward monitoring of the surroundings during navigation. And 2 CCD (or CMOS) cameras are used for monitoring the status of front-end and back-end motion mechanics such as flippers and crawlers. A CCD camera with wide field of view optics is used for monitoring the status of the communication (VDSL) cable reel. And another 2 CCD cameras are assigned for reading the indication value of the radiation dosimeter and the instrument. In the preceding assumptions, a major problem which arises when dealing with CCD/CMOS cameras in the severe accident situations of the nuclear power plant is the presence of high dose-rate gamma irradiation fields. In the case of the DBA (design basis accident) situations of the nuclear power plant, in order to use a CCD/CMOS camera as an ad-hoc monitoring unit in the vicinity of high radioactivity structures and components of the nuclear reactor area, a robust survivability of this camera in such intense gamma-radiation fields therefore should be verified. The CCD/CMOS cameras of various types were gamma irradiated at a

  11. Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate

    Science.gov (United States)

    Poddar, Raju; Migacz, Justin V.; Schwartz, Daniel M.; Werner, John S.; Gorczynska, Iwona

    2017-10-01

    We present noninvasive, three-dimensional, depth-resolved imaging of human retinal and choroidal blood circulation with a swept-source optical coherence tomography (OCT) system at 1065-nm center wavelength. Motion contrast OCT imaging was performed with the phase-variance OCT angiography method. A Fourier-domain mode-locked light source was used to enable an imaging rate of 1.7 MHz. We experimentally demonstrate the challenges and advantages of wide-field OCT angiography (OCTA). In the discussion, we consider acquisition time, scanning area, scanning density, and their influence on visualization of selected features of the retinal and choroidal vascular networks. The OCTA imaging was performed with a field of view of 16 deg (5 mm×5 mm) and 30 deg (9 mm×9 mm). Data were presented in en face projections generated from single volumes and in en face projection mosaics generated from up to 4 datasets. OCTA imaging at 1.7 MHz A-scan rate was compared with results obtained from a commercial OCTA instrument and with conventional ophthalmic diagnostic methods: fundus photography, fluorescein, and indocyanine green angiography. Comparison of images obtained from all methods is demonstrated using the same eye of a healthy volunteer. For example, imaging of retinal pathology is presented in three cases of advanced age-related macular degeneration.

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

    Science.gov (United States)

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

    2011-01-21

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

  13. Protein diffraction experiments with Atlas CCD detector

    Czech Academy of Sciences Publication Activity Database

    Dohnálek, Jan; Kovaľ, Tomáš; Dušek, Michal

    2008-01-01

    Roč. 64, Suppl. - abstracts (2008), C192 ISSN 0108-7673. [Congress of the International Union of Crystallography (IUCr) /21./. 23.08.2008-31.08.2008, Osaka] Institutional research plan: CEZ:AV0Z10100521 Keywords : x-ray data collection * CCD detectors * protein crystallography applications Subject RIV: BM - Solid Matter Physics ; Magnetism

  14. Wide-field imaging through scattering media by scattered light fluorescence microscopy

    Science.gov (United States)

    Zhou, Yulan; Li, Xun

    2017-08-01

    To obtain images through scattering media, scattered light fluorescence (SLF) microscopy that utilizes the optical memory effect has been developed. However, the small field of view (FOV) of SLF microscopy limits its application. In this paper, we have introduced a re-modulation method to achieve wide-field imaging through scattering media by SLF microscopy. In the re-modulation method, to raster scan the focus across the object plane, the incident wavefront is re-modulated via a spatial light modulator (SLM) in the updated phase compensation calculated using the optimized iterative algorithm. Compared with the conventional optical memory effect method, the re-modulation method can greatly increase the FOV of a SLF microscope. With the phase compensation theoretically calculated, the process of updating the phase compensation of a high speed SLM is fast. The re-modulation method does not increase the imaging time. The re-modulation method is, therefore, expected to make SLF microscopy have much wider applications in biology, medicine and physiology.

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

    Science.gov (United States)

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

    2016-03-01

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

  16. WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF THE EVOLUTION OF MASSIVE STAR-FORMING REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Wide field imaging spectrometer for ESA's future X-ray mission: XEUS

    CERN Document Server

    Strüder, L

    1999-01-01

    An active pixel sensor (APS) based on the DEpleted P-channel junction Field Effect Transistor (DEPFET) concept will be described as a potential wide field imager for ESA's high resolution, high throughput mission: 'X-ray Evolving Universe Spectroscopy' (XEUS). It comprises a parallel multichannel readout, low noise at high speed readout, backside illumination and a fill factor of 100% over the whole field of view. The depleted thickness will be 500 microns. These design parameters match the scientific requirements of the mission. The fabrication techniques of the DEPFET arrays are related to the high resistivity process of the X-ray pn-CCDs. Potential extensions of the already realized DEPFET structures are a non-destructive repetitive readout of the signal charges. This concept will be presented. As an alternative solution, frame store pn-CCDs are considered having the same format and pixel sizes as the proposed DEPFET arrays. Their development is a low risk, straightforward continuation of the XMM devices. ...

  18. Application of a wide-field electromagnetic method to shale gas exploration in South China

    Science.gov (United States)

    Yang, Xue-Li; Li, Bo; Peng, Chuan-Sheng; Yang, Yang

    2017-09-01

    In an effort to reduce the shale gas exploration risks and costs, we applied the wide-field electromagnetic method (WFEM), because of its strong anti-interference capability, high resolution, ability to conduct exploration at large depths, and high efficiency, to the Bayan Syncline in the South Huayuan block, Hunan Province. We collected rock samples and analyzed their resistivity and induced polarization (IP) and built A series of two-dimensional models for geological conditions to investigate the applicability of WFEM to different geological structures. We also analyzed the correlation between TOC of shale and the resistivity and IP ratio to determine the threshold for identifying target formations. We used WFEM to identify the underground structures and determine the distribution, depth, and thickness of the target strata. Resistivity, IP, and total organic carbon were used to evaluate the shale gas prospects and select favorable areas (sweet spots) for exploration and development. Subsequently, drilling in these areas proved the applicability of WFEM in shale gas exploration.

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

    Science.gov (United States)

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

    2013-03-01

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

  20. Wide-field OCT imaging of oral lesions in vivo: quantification and classification (Conference Presentation)

    Science.gov (United States)

    Raizada, Rashika; Lee, Anthony M. D.; Liu, Kelly Y.; MacAulay, Calum E.; Ng, Samson; Poh, Catherine F.; Lane, Pierre M.

    2017-02-01

    Worldwide, there are over 450,000 new cases of oral cancer reported each year. Late-stage diagnosis remains a significant factor responsible for its high mortality rate (>50%). In-vivo non-invasive rapid imaging techniques, that can visualise clinically significant changes in the oral mucosa, may improve the management of oral cancer. We present an analysis of features extracted from oral images obtained using our hand- held wide-field Optical Coherence Tomography (OCT) instrument. The images were analyzed for epithelial scattering, overall tissue scattering, and 3D basement membrane topology. The associations between these three features and disease state (benign, pre-cancer, or cancer), as measured by clinical assessment or pathology, were determined. While scattering coefficient has previously been shown to be sensitive to cancer and dysplasia, likely due to changes in nuclear and cellular density, the addition of basement membrane topology may increase diagnostic ability- as it is known that the presence of bulbous rete pegs in the basement membrane are characteristic of dysplasia. The resolution and field-of-view of our oral OCT system allowed analysis of these features over large areas of up to 2.5mm x 90mm, in a timely fashion, which allow for application in clinical settings.

  1. Wide-Field Infrared Survey Explorer Observations of the Evolution of Massive Star-Forming Regions

    Science.gov (United States)

    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.

  2. Studies of prototype DEPFET sensors for the Wide Field Imager of Athena

    Science.gov (United States)

    Treberspurg, Wolfgang; Andritschke, Robert; Bähr, Alexander; Behrens, Annika; Hauser, Günter; Lechner, Peter; Meidinger, Norbert; Müller-Seidlitz, Johannes; Treis, Johannes

    2017-08-01

    The Wide Field Imager (WFI) of ESA's next X-ray observatory Athena will combine a high count rate capability with a large field of view, both with state-of-the-art spectroscopic performance. To meet these demands, specific DEPFET active pixel detectors have been developed and operated. Due to the intrinsic amplification of detected signals they are best suited to achieve a high speed and low noise performance. Different fabrication technologies and transistor geometries have been implemented on a dedicated prototype production in the course of the development of the DEPFET sensors. The main modifications between the sensors concern the shape of the transistor gate - regarding the layout - and the thickness of the gate oxide - regarding the technology. To facilitate the fabrication and testing of the resulting variety of sensors the presented studies were carried out with 64×64 pixel detectors. The detector comprises a control ASIC (Switcher-A), a readout ASIC (VERITAS- 2) and the sensor. In this paper we give an overview on the evaluation of different prototype sensors. The most important results, which have been decisive for the identification of the optimal fabrication technology and transistor layout for subsequent sensor productions are summarized. It will be shown that the developments result in an excellent performance of spectroscopic X-ray DEPFETs with typical noise values below 2.5 ENC at 2.5 μs/row.

  3. WIDE-FIELD WIDE-BAND INTERFEROMETRIC IMAGING: THE WB A-PROJECTION AND HYBRID ALGORITHMS

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, S.; Rau, U.; Golap, K., E-mail: sbhatnag@nrao.edu, E-mail: rurvashi@nrao.edu, E-mail: kgolap@nrao.edu [National Radio Astronomy Observatory, Socorro, NM 87801 (United States)

    2013-06-20

    Variations of the antenna primary beam (PB) pattern as a function of time, frequency, and polarization form one of the dominant direction-dependent effects at most radio frequency bands. These gains may also vary from antenna to antenna. The A-Projection algorithm, published earlier, accounts for the effects of the narrow-band antenna PB in full polarization. In this paper, we present the wide-band A-Projection algorithm (WB A-Projection) to include the effects of wide bandwidth in the A-term itself and show that the resulting algorithm simultaneously corrects for the time, frequency, and polarization dependence of the PB. We discuss the combination of the WB A-Projection and the multi-term multi-frequency synthesis (MT-MFS) algorithm for simultaneous mapping of the sky brightness distribution and the spectral index distribution across a wide field of view. We also discuss the use of the narrow-band A-Projection algorithm in hybrid imaging schemes that account for the frequency dependence of the PB in the image domain.

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

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, Adam M.; Abraham, Roberto G. [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)

    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.

  5. Advances on Hubble Wide Field Camera 3 Grism Calibration and Slitless Spectroscopy Analysis

    Science.gov (United States)

    Fowler, Julia; Brammer, Gabriel; Ryan, Russell; Deustua, Susana; Pirzkal, Nor

    2018-01-01

    Grisms are spectral elements combining a grating and prism to conduct slitless spectroscopy; presently they make up approximately 13% of all Wide Field Camera 3 (WFC3) observations on the Hubble Space Telescope (HST). WFC3 contains three grisms, two for the infrared (IR) channel and one for the ultraviolet-visible (UVIS). Here we summarize recent results from an ongoing effort to improve the analysis tools, characterization, and calibration of WFC3 slitless spectroscopic observations. This includes (1) calibrating the IR wavelength solutions with respect to compact zeroth order images, (2) improved IR throughput curves from modelling grism flux by extending the pixel range of effective point spread functions, (3) IR linear-reconstruction solving methods that solve for optimal, non-parametric spectra, (4) calibrating the UVIS +1 and -1 order over the entire field of view of both chips (allowing for spectral extraction from the entire UVIS detector.) With these efforts we continue to improve and advance the science possible with WFC3 grism observations.

  6. The ARGO-YBJ legacy to next generation wide field-of-view experiments

    Directory of Open Access Journals (Sweden)

    Di Sciascio Giuseppe

    2017-01-01

    Full Text Available The ARGO-YBJ experiment has been in stable data taking for more than 5 years at the YangBaJing Cosmic Ray Observatory (Tibet, P.R. China, 4300 m a.s.l., 606 g/cm2. With a duty-cycle greater than 86% the detector collected about 5×1011 events in a wide energy range, from few hundreds GeV up to about 10 PeV. High altitude location and detector features make ARGO-YBJ capable of investigating a wide range of important issues in Cosmic Ray and Astroparticle Physics by imaging the front of atmospheric showers with unprecedented resolution and detail. In this contribution some of the latest physics results obtained by ARGO-YBJ in gamma-ray astronomy and in cosmic ray physics are summarized. The prospects of TeV gamma-ray observations with new ground-based wide field-of-view detectors are presented.

  7. Mapping absolute tissue endogenous fluorophore concentrations with chemometric wide-field fluorescence microscopy

    Science.gov (United States)

    Xu, Zhang; Reilley, Michael; Li, Run; Xu, Min

    2017-06-01

    We report chemometric wide-field fluorescence microscopy for imaging the spatial distribution and concentration of endogenous fluorophores in thin tissue sections. Nonnegative factorization aided by spatial diversity is used to learn both the spectral signature and the spatial distribution of endogenous fluorophores from microscopic fluorescence color images obtained under broadband excitation and detection. The absolute concentration map of individual fluorophores is derived by comparing the fluorescence from "pure" fluorophores under the identical imaging condition following the identification of the fluorescence species by its spectral signature. This method is then demonstrated by characterizing the concentration map of endogenous fluorophores (including tryptophan, elastin, nicotinamide adenine dinucleotide, and flavin adenine dinucleotide) for lung tissue specimens. The absolute concentrations of these fluorophores are all found to decrease significantly from normal, perilesional, to cancerous (squamous cell carcinoma) tissue. Discriminating tissue types using the absolute fluorophore concentration is found to be significantly more accurate than that achievable with the relative fluorescence strength. Quantification of fluorophores in terms of the absolute concentration map is also advantageous in eliminating the uncertainties due to system responses or measurement details, yielding more biologically relevant data, and simplifying the assessment of competing imaging approaches.

  8. SAAO's new robotic telescope and WiNCam (Wide-field Nasmyth Camera)

    Science.gov (United States)

    Worters, Hannah L.; O'Connor, James E.; Carter, David B.; Loubser, Egan; Fourie, Pieter A.; Sickafoose, Amanda; Swanevelder, Pieter

    2016-08-01

    The South African Astronomical Observatory (SAAO) is designing and manufacturing a wide-field camera for use on two of its telescopes. The initial concept was of a Prime focus camera for the 74" telescope, an equatorial design made by Grubb Parsons, where it would employ a 61mmx61mm detector to cover a 23 arcmin diameter field of view. However, while in the design phase, SAAO embarked on the process of acquiring a bespoke 1-metre robotic alt-az telescope with a 43 arcmin field of view, which needs a homegrown instrument suite. The Prime focus camera design was thus adapted for use on either telescope, increasing the detector size to 92mmx92mm. Since the camera will be mounted on the Nasmyth port of the new telescope, it was dubbed WiNCam (Wide-field Nasmyth Camera). This paper describes both WiNCam and the new telescope. Producing an instrument that can be swapped between two very different telescopes poses some unique challenges. At the Nasmyth port of the alt-az telescope there is ample circumferential space, while on the 74 inch the available envelope is constrained by the optical footprint of the secondary, if further obscuration is to be avoided. This forces the design into a cylindrical volume of 600mm diameter x 250mm height. The back focal distance is tightly constrained on the new telescope, shoehorning the shutter, filter unit, guider mechanism, a 10mm thick window and a tip/tilt mechanism for the detector into 100mm depth. The iris shutter and filter wheel planned for prime focus could no longer be accommodated. Instead, a compact shutter with a thickness of less than 20mm has been designed in-house, using a sliding curtain mechanism to cover an aperture of 125mmx125mm, while the filter wheel has been replaced with 2 peripheral filter cartridges (6 filters each) and a gripper to move a filter into the beam. We intend using through-vacuum wall PCB technology across the cryostat vacuum interface, instead of traditional hermetic connector-based wiring. This

  9. Wide-field fluorescent microscopy and fluorescent imaging flow cytometry on a cell-phone.

    Science.gov (United States)

    Zhu, Hongying; Ozcan, Aydogan

    2013-04-11

    Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general relatively bulky and costly, making them less effective in the resource limited settings. To potentially address these limitations, we have recently demonstrated the integration of wide-field fluorescent microscopy and imaging flow cytometry tools on cell-phones using compact, light-weight, and cost-effective opto-fluidic attachments. In our flow cytometry design, fluorescently labeled cells are flushed through a microfluidic channel that is positioned above the existing cell-phone camera unit. Battery powered light-emitting diodes (LEDs) are butt-coupled to the side of this microfluidic chip, which effectively acts as a multi-mode slab waveguide, where the excitation light is guided to uniformly excite the fluorescent targets. The cell-phone camera records a time lapse movie of the fluorescent cells flowing through the microfluidic channel, where the digital frames of this movie are processed to count the number of the labeled cells within the target solution of interest. Using a similar opto-fluidic design, we can also image these fluorescently labeled cells in static mode by e.g. sandwiching the fluorescent particles between two glass slides and capturing their fluorescent images using the cell-phone camera, which can achieve a spatial resolution of e.g. - 10 μm over a very large field-of-view of - 81 mm(2). This cell-phone based fluorescent imaging flow cytometry and microscopy platform might be useful especially in resource limited settings, for e.g. counting of CD4+ T cells toward monitoring of HIV+ patients or for detection of water-borne parasites in drinking water.

  10. WIDE-FIELD PRECISION KINEMATICS OF THE M87 GLOBULAR CLUSTER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Strader, Jay [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Romanowsky, Aaron J.; Brodie, Jean P.; Beasley, Michael A.; Arnold, Jacob A. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Spitler, Lee R. [Center for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Tamura, Naoyuki [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Sharples, Ray M. [Department of Physics, University of Durham, South Road, Durham (United Kingdom); Arimoto, Nobuo, E-mail: jstrader@cfa.harvard.edu [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)

    2011-12-01

    We present the most extensive combined photometric and spectroscopic study to date of the enormous globular cluster (GC) system around M87, the central giant elliptical galaxy in the nearby Virgo Cluster. Using observations from DEIMOS and the Low Resolution Imaging Spectrometer at Keck, and Hectospec on the Multiple Mirror Telescope, we derive new, precise radial velocities for 451 GCs around M87, with projected radii from {approx}5 to 185 kpc. We combine these measurements with literature data for a total sample of 737 objects, which we use for a re-examination of the kinematics of the GC system of M87. The velocities are analyzed in the context of archival wide-field photometry and a novel Hubble Space Telescope catalog of half-light radii, which includes sizes for 344 spectroscopically confirmed clusters. We use this unique catalog to identify 18 new candidate ultracompact dwarfs and to help clarify the relationship between these objects and true GCs. We find much lower values for the outer velocity dispersion and rotation of the GC system than in earlier papers and also differ from previous work in seeing no evidence for a transition in the inner halo to a potential dominated by the Virgo Cluster, nor for a truncation of the stellar halo. We find little kinematical evidence for an intergalactic GC population. Aided by the precision of the new velocity measurements, we see significant evidence for kinematical substructure over a wide range of radii, indicating that M87 is in active assembly. A simple, scale-free analysis finds less dark matter within {approx}85 kpc than in other recent work, reducing the tension between X-ray and optical results. In general, out to a projected radius of {approx}150 kpc, our data are consistent with the notion that M87 is not dynamically coupled to the Virgo Cluster; the core of Virgo may be in the earliest stages of assembly.

  11. Performance Improvement of Near Earth Space Survey (NESS Wide-Field Telescope (NESS-2 Optics

    Directory of Open Access Journals (Sweden)

    Sung-Yeol Yu

    2010-06-01

    Full Text Available We modified the optical system of 500 mm wide-field telescope of which point spread function showed an irregularity. The telescope has been operated for Near Earth Space Survey (NESS located at Siding Spring Observatory (SSO in Australia, and the optical system was brought back to Korea in January 2008. After performing a numerical simulation with the tested value of surface figure error of the primary mirror using optical design program, we found that the surface figure error of the mirror should be fabricated less than root mean square (RMS λ/10 in order to obtain a stellar full width at half maximum (FWHM below 28 μm. However, we started to figure the mirror for the target value of RMS λ/20, because system surface figure error would be increased by the error induced by the optical axis adjustment, mirror cell installation, and others. The radius of curvature of the primary mirror was 1,946 mm after the correction. Its measured surface figure error was less than RMS λ/20 on the table of polishing machine, and RMS λ/15 after installation in the primary mirror cell. A test observation performed at Daeduk Observatory at Korea Astronomy and Space Science Institute by utilizing the exiting mount, and resulted in 39.8 μm of stellar FWHM. It was larger than the value from numerical simulation, and showed wing-shaped stellar image. It turned out that the measured-curvature of the secondary mirror, 1,820 mm, was not the same as the designed one, 1,795.977 mm. We fabricated the secondary mirror to the designed value, and finally obtained a stellar FWHM of 27 μm after re-installation of the optical system into SSO NESS Observatory in Australia.

  12. Anisoplanatic error evaluation and wide-field adaptive optics performance at Dome C, Antarctica

    Science.gov (United States)

    Carbillet, M.; Aristidi, É.; Giordano, C.; Vernin, J.

    2017-11-01

    The aim of this paper is twofold: (i) to deduce the most representative C_N^2 profile(s) for Dome C (DC), Antarctica, from the latest measurements, and (ii) to evaluate the performance of a wide-field adaptive optics (AO) system equipping a 2-3 m telescope. Two models of the C_N^2 profile, corresponding to the bimodal distribution of seeing (a poor seeing mode and a good seeing mode), are composed from both Single Star Scidar data and balloon radio soundings. The anisoplanatic error is first evaluated for a standard AO system from Monte Carlo simulations. DC is shown to outperform Mauna Kea for both seeing modes. A simple ground-layer AO (GLAO) system is then considered. This provides an anisoplanatic error of less than 150 nm over a field of 30 arcmin for the good seeing mode, corresponding to a basic performance Strehl ratio (considering also the fitting and the servo-lag errors) of more than ˜80 per cent in K and ˜50 per cent in J. The poor seeing model shows performance comparable to the Mauna Kea model. We also studied the influence of telescope elevation, showing that a telescope at 40 m would perform, in the poor seeing mode, like a telescope observing 8 m above the ground in the good seeing mode. Finally, we show that while tip-tilt-only correction permits high levels of correction in the good seeing mode at 40 m, it is not as efficient as the GLAO system, even at an altitude of 8 m, and it is not sufficient for high levels of correction for poor seeing, even at a height of 40 m.

  13. Evaluation of illumination system uniformity for wide-field biomedical hyperspectral imaging

    Science.gov (United States)

    Sawyer, Travis W.; Siri Luthman, A.; E Bohndiek, Sarah

    2017-04-01

    Hyperspectral imaging (HSI) systems collect both spatial (morphological) and spectral (chemical) information from a sample. HSI can provide sensitive analysis for biological and medical applications, for example, simultaneously measuring reflectance and fluorescence properties of a tissue, which together with structural information could improve early cancer detection and tumour characterisation. Illumination uniformity is a critical pre-condition for quantitative data extraction from an HSI system. Non-uniformity can cause glare, specular reflection and unwanted shading, which negatively impact statistical analysis procedures used to extract abundance of different chemical species. Here, we model and evaluate several illumination systems frequently used in wide-field biomedical imaging to test their potential for HSI. We use the software LightTools and FRED. The analysed systems include: a fibre ring light; a light emitting diode (LED) ring; and a diffuse scattering dome. Each system is characterised for spectral, spatial, and angular uniformity, as well as transfer efficiency. Furthermore, an approach to measure uniformity using the Kullback-Leibler divergence (KLD) is introduced. The KLD is generalisable to arbitrary illumination shapes, making it an attractive approach for characterising illumination distributions. Although the systems are quite comparable in their spatial and spectral uniformity, the most uniform angular distribution is achieved using a diffuse scattering dome, yielding a contrast of 0.503 and average deviation of 0.303 over a ±60° field of view with a 3.9% model error in the angular domain. Our results suggest that conventional illumination sources can be applied in HSI, but in the case of low light levels, bespoke illumination sources may offer improved performance.

  14. Automatic detection of diabetic retinopathy features in ultra-wide field retinal images

    Science.gov (United States)

    Levenkova, Anastasia; Sowmya, Arcot; Kalloniatis, Michael; Ly, Angelica; Ho, Arthur

    2017-03-01

    Diabetic retinopathy (DR) is a major cause of irreversible vision loss. DR screening relies on retinal clinical signs (features). Opportunities for computer-aided DR feature detection have emerged with the development of Ultra-WideField (UWF) digital scanning laser technology. UWF imaging covers 82% greater retinal area (200°), against 45° in conventional cameras3 , allowing more clinically relevant retinopathy to be detected4 . UWF images also provide a high resolution of 3078 x 2702 pixels. Currently DR screening uses 7 overlapping conventional fundus images, and the UWF images provide similar results1,4. However, in 40% of cases, more retinopathy was found outside the 7-field ETDRS) fields by UWF and in 10% of cases, retinopathy was reclassified as more severe4 . This is because UWF imaging allows examination of both the central retina and more peripheral regions, with the latter implicated in DR6 . We have developed an algorithm for automatic recognition of DR features, including bright (cotton wool spots and exudates) and dark lesions (microaneurysms and blot, dot and flame haemorrhages) in UWF images. The algorithm extracts features from grayscale (green "red-free" laser light) and colour-composite UWF images, including intensity, Histogram-of-Gradient and Local binary patterns. Pixel-based classification is performed with three different classifiers. The main contribution is the automatic detection of DR features in the peripheral retina. The method is evaluated by leave-one-out cross-validation on 25 UWF retinal images with 167 bright lesions, and 61 other images with 1089 dark lesions. The SVM classifier performs best with AUC of 94.4% / 95.31% for bright / dark lesions.

  15. Wide field imager instrument for the Advanced Telescope for High Energy Astrophysics

    Science.gov (United States)

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

    2015-01-01

    The Advanced Telescope for High Energy Astrophysics (Athena) has been selected for ESA's L2 mission, scheduled for launch in 2028. It will provide the necessary capabilities to achieve the ambitious goals of the science theme "The Hot and Energetic Universe." Athena's x-ray mirrors will be based on silicon pore optics technology with a 12-m focal length. Two complementary focal plane camera systems are foreseen, which can be moved interchangeably to the focus of the mirror system: the actively shielded micro-calorimeter spectrometer X-IFU and the wide field imager (WFI). The WFI camera will provide an unprecedented survey power through its large field of view of 40 arc min with a high count-rate capability (˜1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 to 15 keV during the entire mission lifetime (e.g., full width at half maximum ≤150 eV at 6 keV). This performance is accomplished by a set of depleted P-channel field effect transistor (DEPFET) active pixel sensor matrices with a pixel size well suited to the angular resolution of 5 arc sec (on-axis) of the mirror system. Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450-μm-thick silicon bulk. This manuscript will summarize the current instrument concept and design, the status of the technology development, and the envisaged baseline performance.

  16. SkICAT: A cataloging and analysis tool for wide field imaging surveys

    Science.gov (United States)

    Weir, N.; Fayyad, U. M.; Djorgovski, S. G.; Roden, J.

    1992-01-01

    We describe an integrated system, SkICAT (Sky Image Cataloging and Analysis Tool), for the automated reduction and analysis of the Palomar Observatory-ST ScI Digitized Sky Survey. The Survey will consist of the complete digitization of the photographic Second Palomar Observatory Sky Survey (POSS-II) in three bands, comprising nearly three Terabytes of pixel data. SkICAT applies a combination of existing packages, including FOCAS for basic image detection and measurement and SAS for database management, as well as custom software, to the task of managing this wealth of data. One of the most novel aspects of the system is its method of object classification. Using state-of-theart machine learning classification techniques (GID3* and O-BTree), we have developed a powerful method for automatically distinguishing point sources from non-point sources and artifacts, achieving comparably accurate discrimination a full magnitude fainter than in previous Schmidt plate surveys. The learning algorithms produce decision trees for classification by examining instances of objects classified by eye on both plate and higher quality CCD data. The same techniques will be applied to perform higher-level object classification (e.g., of galaxy morphology) in the near future. Another key feature of the system is the facility to integrate the catalogs from multiple plates (and portions thereof) to construct a single catalog of uniform calibration and quality down to the faintest limits of the survey. SkICAT also provides a variety of data analysis and exploration tools for the scientific utilization of the resulting catalogs. We include initial results of applying this system to measure the counts and distribution of galaxies in two bands down to Bj is approximately 21 mag over an approximate 70 square degree multi-plate field from POSS-II. SkICAT is constructed in a modular and general fashion and should be readily adaptable to other large-scale imaging surveys.

  17. Design of a multifunction astronomical CCD camera

    Science.gov (United States)

    Yao, Dalei; Wen, Desheng; Xue, Jianru; Chen, Zhi; Wen, Yan; Jiang, Baotan; Xi, Jiangbo

    2015-07-01

    To satisfy the requirement of the astronomical observation, a novel timing sequence of frame transfer CCD is proposed. The multiple functions such as the adjustments of work pattern, exposure time and frame frequency are achieved. There are four work patterns: normal, standby, zero exposure and test. The adjustment of exposure time can set multiple exposure time according to the astronomical observation. The fame frequency can be adjusted when dark target is imaged and the maximum exposure time cannot satisfy the requirement. On the design of the video processing, offset correction and adjustment of multiple gains are proposed. Offset correction is used for eliminating the fixed pattern noise of CCD. Three gains pattern can improve the signal to noise ratio of astronomical observation. Finally, the images in different situations are collected and the system readout noise is calculated. The calculation results show that the designs in this paper are practicable.

  18. A self triggered intensified CCD (STIC)

    Science.gov (United States)

    Charon, Y.; Laniece, P.; Bendali, M.; Gaillard, J. M.; Leblanc, M.; Mastrippolito, R.; Tricoire, H.; Valentin, L.

    1991-12-01

    We are developing a new device based on the results reported previously of the successful coincidence detection of β - particles with a high spatial resolution. The novelty of the device consists in triggering and intensified CCD, i.e. a CCD coupled to an image intensifier (II), by an electrical signal collected from the II itself. This is a suitable procedure for detecting low light and rare events with high efficiency and high resolution. The trigger pulse is obtained from the secondary electrons produced by multiplication in a double microchannel plate (MCP) and collected on the aluminized layer protecting the phosphor screen in the II. Triggering efficiencies up to 80% have already been achieved.

  19. Systems, computer-implemented methods, and tangible computer-readable storage media for wide-field interferometry

    Science.gov (United States)

    Lyon, Richard G. (Inventor); Leisawitz, David T. (Inventor); Rinehart, Stephen A. (Inventor); Memarsadeghi, Nargess (Inventor)

    2012-01-01

    Disclosed herein are systems, computer-implemented methods, and tangible computer-readable storage media for wide field imaging interferometry. The method includes for each point in a two dimensional detector array over a field of view of an image: gathering a first interferogram from a first detector and a second interferogram from a second detector, modulating a path-length for a signal from an image associated with the first interferogram in the first detector, overlaying first data from the modulated first detector and second data from the second detector, and tracking the modulating at every point in a two dimensional detector array comprising the first detector and the second detector over a field of view for the image. The method then generates a wide-field data cube based on the overlaid first data and second data for each point. The method can generate an image from the wide-field data cube.

  20. Automatic Processing of Chinese GF-1 Wide Field of View Images

    Science.gov (United States)

    Zhang, Y.; Wan, Y.; Wang, B.; Kang, Y.; Xiong, J.

    2015-04-01

    The wide field of view (WFV) imaging instrument carried on the Chinese GF-1 satellite includes four cameras. Each camera has 200km swath-width that can acquire earth image at the same time and the observation can be repeated within only 4 days. This enables the applications of remote sensing imagery to advance from non-scheduled land-observation to periodically land-monitoring in the areas that use the images in such resolutions. This paper introduces an automatic data analysing and processing technique for the wide-swath images acquired by GF-1 satellite. Firstly, the images are validated by a self-adaptive Gaussian mixture model based cloud detection method to confirm whether they are qualified and suitable to be involved into the automatic processing workflow. Then the ground control points (GCPs) are quickly and automatically matched from the public geo-information products such as the rectified panchromatic images of Landsat-8. Before the geometric correction, the cloud detection results are also used to eliminate the invalid GCPs distributed in the cloud covered areas, which obviously reduces the ratio of blunders of GCPs. The geometric correction module not only rectifies the rational function models (RFMs), but also provides the self-calibration model and parameters for the non-linear distortion, and it is iteratively processed to detect blunders. The maximum geometric distortion in WFV image decreases from about 10-15 pixels to 1-2 pixels when compensated by self-calibration model. The processing experiments involve hundreds of WFV images of GF-1 satellite acquired from June to September 2013, which covers the whole mainland of China. All the processing work can be finished by one operator within 2 days on a desktop computer made up by a second-generation Intel Core-i7 CPU and a 4-solid-State-Disk array. The digital ortho maps (DOM) are automatically generated with 3 arc second Shuttle Radar Topography Mission (SRTM). The geometric accuracies of the

  1. Wide-Field Gamma-Spectrometer BDRG: GRB Monitor On-Board the Lomonosov Mission

    Science.gov (United States)

    Svertilov, S. I.; Panasyuk, M. I.; Bogomolov, V. V.; Amelushkin, A. M.; Barinova, V. O.; Galkin, V. I.; Iyudin, A. F.; Kuznetsova, E. A.; Prokhorov, A. V.; Petrov, V. L.; Rozhkov, G. V.; Yashin, I. V.; Gorbovskoy, E. S.; Lipunov, V. M.; Park, I. H.; Jeong, S.; Kim, M. B.

    2018-02-01

    The study of GRB prompt emissions (PE) is one of the main goals of the Lomonosov space mission. The payloads of the GRB monitor (BDRG) with the wide-field optical cameras (SHOK) and the ultra-fast flash observatory (UFFO) onboard the Lomonosov satellite are intended for the observation of GRBs, and in particular, their prompt emissions. The BDRG gamma-ray spectrometer is designed to obtain the temporal and spectral information of GRBs in the energy range of 10-3000 keV as well as to provide GRB triggers on several time scales (10 ms, 1 s and 20 s) for ground and space telescopes, including the UFFO and SHOK. The BDRG instrument consists of three identical detector boxes with axes shifted by 90° from each other. This configuration allows us to localize a GRB source in the sky with an accuracy of ˜ 2°. Each BDRG box contains a phoswich NaI(Tl)/CsI(Tl) scintillator detector. A thick CsI(Tl) crystal in size of \\varnothing 130 × 17 mm is placed underneath the NaI(Tl) as an active shield in the soft energy range and as the main detector in the hard energy range. The ratio of the CsI(Tl) to NaI(Tl) event rates at varying energies can be employed as an independent metric to distinguish legitimate GRB signals from false positives originating from electrons in near-Earth vicinities. The data from three detectors are collected in a BA BDRG information unit, which generates a GRB trigger and a set of data frames in output format. The scientific data output is ˜ 500 Mb per day, including ˜ 180 Mb of continuous data for events with durations in excess of 100 ms for 16 channels in each detector, detailed energy spectra, and sets of frames with ˜ 5 Mb of detailed information for each burst-like event. A number of pre-flight tests including those for the trigger algorithm and calibration were carried out to confirm the reliability of the BDRG for operation in space.

  2. 45,X/46,XY mosaicism

    DEFF Research Database (Denmark)

    Lindhardt Johansen, Marie; Hagen, Casper P; Rajpert-De Meyts, Ewa

    2012-01-01

    Most previous studies of 45,X/46,XY mosaicism are case reports or have described single aspects of the disease.......Most previous studies of 45,X/46,XY mosaicism are case reports or have described single aspects of the disease....

  3. Clinical assessment of human breast cancer margins with wide-field optical coherence micro-elastography (Conference Presentation)

    Science.gov (United States)

    Allen, Wes M.; Chin, Lixin; Wijesinghe, Philip; Kirk, Rodney W.; Latham, Bruce; Sampson, David D.; Saunders, Christobel M.; Kennedy, Brendan F.

    2017-02-01

    Breast cancer has the second highest mortality rate of all cancers in females. Surgical excision of malignant tissue forms a central component of breast-conserving surgery (BCS) procedures. Incomplete excision of malignant tissue is a major issue in BCS with typically 20 - 30% cases requiring a second surgical procedure due to postoperative detection of tumor in the margin. A major challenge for surgeons during BCS is the lack of effective tools to assess the surgical margin intraoperatively. Such tools would enable the surgeon to more effectively remove all tumor during the initial surgery, hence reducing re-excision rates. We report advances in the development of a new tool, optical coherence micro-elastography, which forms images, known as elastograms, based on mechanical contrast within the tissue. We demonstrate the potential of this technique to increase contrast between malignant tumor and healthy stroma in elastograms over OCT images. We demonstrate a key advance toward clinical translation by conducting wide-field imaging in intraoperative time frames with a wide-field scanning system, acquiring mosaicked elastograms with overall dimensions of 50 × 50 mm, large enough to image an entire face of most lumpectomy specimens. We describe this wide-field imaging system, and demonstrate its operation by presenting wide-field optical coherence tomography images and elastograms of a tissue mimicking silicone phantom and a number of representative freshly excised human breast specimens. Our results demonstrate the feasibility of scanning large areas of lumpectomies, which is an important step towards practical intraoperative margin assessment.

  4. Wide-Field Multi-Parameter FLIM: Long-Term Minimal Invasive Observation of Proteins in Living Cells.

    NARCIS (Netherlands)

    Vitali, M.; Picazo, F.; Prokazov, Y.; Duci, A.; Turbin, E.; Götze, C.; Llopis, J.; Hartig, R.; Visser, A.J.W.G.; Zuschratter, W.

    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

  5. Initial evaluation of safety of wide-field irradiation in the treatment of hematopoietic neoplasia in the cat.

    Science.gov (United States)

    Husbands, Brian D; McNiel, Elizabeth A; Modiano, Jaime F

    2010-01-01

    Localized radiation therapy is well tolerated in cats with confined tumors; however, the use of wide-field radiation therapy to treat disseminated neoplasia has not been evaluated systematically in this species. Wide-field external beam radiation therapy, which we define as irradiation of cranial or caudal halves of the body either individually or sequentially, was undertaken as an experimental option to treat cats with either chemotherapy-refractory or naive hematopoietic neoplasia considered to have a poor prognosis. Fifteen cats with hematopoietic malignancies received wide-field external beam radiation therapy between 2003 and 2006. Cats received 8 Gy delivered in 4 Gy fractions with 60Co photons. Treatment-related toxicity was scored according to criteria established by the Veterinary Cooperative Oncology Group. Animals without preexisting abnormalities on hemograms exhibited no or mild (Grade 1 or 2) hematopoietic toxicity. Although most cats (14 of 15) had preexisting gastrointestinal (GI) signs, these signs were stable (29%) or improved (42%) following irradiation. Worsening GI signs following irradiation occurred transiently in two cats and in association with progressive disease in two others. No pulmonary, renal, hepatic, or dermatologic toxicities were detected. In summary, wide-field external beam radiation therapy can be administered safely to, and may provide therapeutic benefit for, cats with disseminated hematopoietic neoplasia.

  6. Moon - False Color Mosaic

    Science.gov (United States)

    1992-01-01

    This false-color mosaic was constructed from a series of 53 images taken through three spectral filters by Galileo's imaging system as the spacecraft flew over the northern regions of the Moon on December 7, 1992. The part of the Moon visible from Earth is on the left side in this view. The color mosaic shows compositional variations in parts of the Moon's northern hemisphere. Bright pinkish areas are highlands materials, such as those surrounding the oval lava-filled Crisium impact basin toward the bottom of the picture. Blue to orange shades indicate volcanic lava flows. To the left of Crisium, the dark blue Mare Tranquillitatis is richer in titanium than the green and orange maria above it. Thin mineral-rich soils associated with relatively recent impacts are represented by light blue colors; the youngest craters have prominent blue rays extending from them. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.

  7. Searching for Transients using Whole-Sky Patrol with 4 K×7 K-CCD Chips

    Science.gov (United States)

    Kroll, Peter

    Currently much effort is made to take over the Sonneberg's photographic sky patrol by a system of electronic detectors. Owing to the fact, that wide-field systems need either large CCDs or arrays of CCDs in order to cover the whole field of view, the technical availability of large detectors was one of the central problems in past. We now invent the use of a PHILIPS 4K×7K chip in wide-field astronomy for Whole-Sky Patrol. Although the chip has a quantum efficiency of only about 30%, its big size (12μm pixel size) of 48×84 mm offers, for the first time, the replacement of large photographic plates by a single CCD chip. A first system using this chip with a super wide-angle objective for whole-sky imaging each minute down to ca. 10m offers the possibility of monitoring large portions of the sky simultaneously for transients of extrasolar planets. We report on our experience with this system and estimate its efficiency to detect such events.

  8. Whole-Sky Patrol with 4 K×7 K-CCD Chips

    Science.gov (United States)

    Kroll, Peter

    Since the twenties of the last century Sonneberg Observatory runs in each clear night a photographic Sky Patrol with a system of small telescopes reaching 14m in the blue and 13m in the yellow-red. Currently much effort is made to take over this photographic sky patrol by a system of electronic detectors. Owing to the fact, that wide-field systems need either large CCDs or arrays of CCDs in order to cover the whole field of view, the technical availability of large detectors was one of the central problems in past. We now invent the use of a PHILIPS 4K×7K chip in wide-field astronomy for Whole-Sky Patrol. Although the chip has a quantum efficiency of only about 30 %, its big size (12μm pixel size) of 48×84 mm offers, for the first time, the replacement of large photographic plates by a single CCD chip. We report our first experience with this chip when using it with a super wide-angle objective for whole-sky imaging each minute down to ca. 10m for investigating different targets (variable stars, meteors, GRB counterparts, etc.).

  9. First observations from a CCD all-sky spectrograph at Barentsburg (Spitsbergen

    Directory of Open Access Journals (Sweden)

    S. A. Chernouss

    2008-05-01

    Full Text Available A digital CCD all-sky spectrograph was made by the Polar Geophysical Institute (PGI to support IPY activity in auroral research. The device was tested at the Barentsburg observatory of PGI during the winter season of 2005–2006. The spectrograph is based on a cooled CCD and a transmission grating. The main features of this spectrograph are: a wide field of view (~180°, a wide spectral range (380–740 nm, a spectral resolution of 0.6 nm, a background level of about 100 R at 1-min exposure time. Several thousand spectra of nightglow and aurora were recorded during the observation season. It was possible to register both the strong auroral emissions, as well as weak ones. Spectra of aurora, including nitrogen and oxygen molecular and atomic emissions, as well as OH emissions of the nightglow are shown. A comparison has been conducted of auroral spectra obtained by the film all-sky spectral camera C-180-S at Spitsbergen during IGY, with spectra obtained at Barentsburg during the last winter season. The relationship between the red (630.0 nm and green (557.7 nm auroral emissions shows that the green emission is dominant near the minimum of the solar cycle activity (2005–2006. The opposite situation is observed during 1958–1959, with a maximum solar cycle activity.

  10. Charge-coupled device /CCD/ visible light sensor for the Teal Ruby Experiment

    Science.gov (United States)

    Roberts, A.

    The Teal Ruby Experiment (TRE), employing a Space-Shuttle-launched infrared telescope, will mark a major milestone in the application of mosaic infrared detectors in space. However, it is generally recognized that supplemental overview imagery acquired in the visible portion of the spectrum is necessary to assist in accurately interpreting the data generated by the infrared focal plane. For this purpose, the TRE will be equipped with a Charge Coupled Device (CCD) Visible Light Sensor (VLS) that will yield the cloud and ground truth data needed to assist in pointing and scene verification. The optical format of the VLS is designed to overlay the TRE footprint on the earth from a distance of 1000 nautical miles. The VLS is designed, built and will be qualified to meet the environmental and reliability requirements for an on-orbit mission in excess of one year. The TRE/VLS is tentatively scheduled for launch in mid 1983.

  11. Enumerating Photography from Spot Meter to CCD

    OpenAIRE

    Cubitt, Sean; Palmer, Daniel; Walkling, Les

    2015-01-01

    The transition from analogue to digital photography was not accomplished in a single step. It required a number of feeder technologies which enabled and structured the nature of digital photography. Among those traced in this article, the most important is the genesis of the raster grid, which is now hard-wired into the design of the most widely employed photographic chip, the charge-coupled device (CCD). In tracing this history from origins in half-tone printing, the authors argue that quali...

  12. The Dark Energy Survey CCD imager design

    Energy Technology Data Exchange (ETDEWEB)

    Cease, H.; DePoy, D.; Diehl, H.T.; Estrada, J.; Flaugher, B.; Guarino, V.; Kuk, K.; Kuhlmann, S.; Schultz, K.; Schmitt, R.L.; Stefanik, A.; /Fermilab /Ohio State U. /Argonne

    2008-06-01

    The Dark Energy Survey is planning to use a 3 sq. deg. camera that houses a {approx} 0.5m diameter focal plane of 62 2kx4k CCDs. The camera vessel including the optical window cell, focal plate, focal plate mounts, cooling system and thermal controls is described. As part of the development of the mechanical and cooling design, a full scale prototype camera vessel has been constructed and is now being used for multi-CCD readout tests. Results from this prototype camera are described.

  13. Hubble Space Telescope Wide Field Planetary Camera 2 Observations of Neptune

    Science.gov (United States)

    1995-01-01

    Two groups have recently used the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC 2) to acquire new high-resolution images of the planet Neptune. Members of the WFPC-2 Science Team, lead by John Trauger, acquired the first series of images on 27 through 29 June 1994. These were the highest resolution images of Neptune taken since the Voyager-2 flyby in August of 1989. A more comprehensive program is currently being conducted by Heidi Hammel and Wes Lockwood. These two sets of observations are providing a wealth of new information about the structure, composition, and meteorology of this distant planet's atmosphere.Neptune is currently the most distant planet from the sun, with an orbital radius of 4.5 billion kilometers (2.8 billion miles, or 30 Astronomical Units). Even though its diameter is about four times that of the Earth (49,420 vs. 12,742 km), ground-based telescopes reveal a tiny blue disk that subtends less than 1/1200 of a degree (2.3 arc-seconds). Neptune has therefore been a particularly challenging object to study from the ground because its disk is badly blurred by the Earth's atmosphere. In spite of this, ground-based astronomers had learned a great deal about this planet since its position was first predicted by John C. Adams and Urbain Leverrier in 1845. For example, they had determined that Neptune was composed primarily of hydrogen and helium gas, and that its blue color caused by the presence of trace amounts of the gas methane, which absorbs red light. They had also detected bright cloud features whose brightness changed with time, and tracked these clouds to infer a rotation period between 17 and 22 hours.When the Voyager-2 spacecraft flew past the Neptune in 1989, its instruments revealed a surprising array of meteorological phenomena, including strong winds, bright, high-altitude clouds, and two large dark spots attributed to long-lived giant storm systems. These bright clouds and dark spots were tracked as they moved

  14. CCD developed for scientific application by Hamamatsu

    CERN Document Server

    Miyaguchi, K; Dezaki, J; Yamamoto, K

    1999-01-01

    We have developed CCDs for scientific applications that feature a low readout noise of less than 5 e-rms and low dark current of 10-25 pA/cm sup 2 at room temperature. CCDs with these characteristics will prove extremely useful in applications such as spectroscopic measurement and dental radiography. In addition, a large-area CCD of 2kx4k pixels and 15 mu m square pixel size has recently been completed for optical use in astronomical observations. Applications to X-ray astronomy require the most challenging device performance in terms of deep depletion, high CTE, and focal plane size, among others. An abuttable X-ray CCD, having 1024x1024 pixels and 24 mu m square pixel size, is to be installed in an international space station (ISS). We are now striving to achieve the lowest usable cooling temperature by means of a built-in TEC with limited power consumption. Details on the development status are described in this report. We would also like to present our future plans for a large active area and deep depleti...

  15. CCD Camera Detection of HIV Infection.

    Science.gov (United States)

    Day, John R

    2017-01-01

    Rapid and precise quantification of the infectivity of HIV is important for molecular virologic studies, as well as for measuring the activities of antiviral drugs and neutralizing antibodies. An indicator cell line, a CCD camera, and image-analysis software are used to quantify HIV infectivity. The cells of the P4R5 line, which express the receptors for HIV infection as well as β-galactosidase under the control of the HIV-1 long terminal repeat, are infected with HIV and then incubated 2 days later with X-gal to stain the infected cells blue. Digital images of monolayers of the infected cells are captured using a high resolution CCD video camera and a macro video zoom lens. A software program is developed to process the images and to count the blue-stained foci of infection. The described method allows for the rapid quantification of the infected cells over a wide range of viral inocula with reproducibility, accuracy and at relatively low cost.

  16. New Design Concept for Universal CCD Controller

    Directory of Open Access Journals (Sweden)

    Wonyong Han

    1994-06-01

    Full Text Available Currently, the CCDs are widely used in astronomical observations either in direct imaging use or spectroscopic mode. However according to the recent technical advances, new large format CCDs are rapidly developed which have better performances with higher quantum efficiency and sensitivity. In many cases, some microprocessors have been adopted to deal with necessary digital logic for a CCD imaging system. This could often lack the flexibility of a system for a user to upgrade with new devices, especially of it is a commercial product. A new design concept has been explored which could provide the opportunity to deal with any format of devices from ant manufactures effectively for astronomical purposes. Recently available PLD (Programmable Logic Devices technology makes it possible to develop such digital circuit design, which can be integrated into a single component, instead of using microprocessors. The design concept could dramatically increase the efficiency and flexibility of a CCD imaging system, particularly when new or large format devices are available and to upgrade the performance of a system. Some variable system control parameters can be selected by a user with a wider range of choice. The software can support such functional requirements very conveniently. This approach can be applied not only to astronomical purpose, but also to some related fields, such as remote sensing and industrial applications.

  17. Southern Clusters for Standardizing CCD Photometry

    Science.gov (United States)

    Moon, T. T.

    2017-06-01

    Standardizing photometric measurements typically involves undertaking all-sky photometry. This can be laborious and time-consuming and, for CCD photometry, particularly challenging. Transforming photometry to a standard system is, however, a crucial step when routinely measuring variable stars, as it allows photoelectric measurements from different observers to be combined. For observers in the northern hemisphere, standardized UBVRI values of stars in open clusters such as M67 and NGC 7790 have been established, greatly facilitating quick and accurate transformation of CCD measurements. Recently the AAVSO added the cluster NGC 3532 for southern hemisphere observers to similarly standardize their photometry. The availability of NGC 3532 standards was announced on the AAVSO Variable Star Observing, Photometry forum on 27 October 2016. Published photometry, along with some new measurements by the author, provide a means of checking these NGC 3532 standards which were determined through the AAVSO's Bright Star Monitor (BSM) program (see: https://www.aavso.org/aavsonet-epoch-photometry-database). New measurements of selected stars in the open clusters M25 and NGC 6067 are also included.

  18. Optical system design of multi-spectral and large format color CCD aerial photogrammetric camera

    Science.gov (United States)

    Qian, Yixian; Sun, Tianxiang; Gao, Xiaodong; Liang, Wei

    2007-12-01

    Multi-spectrum and high spatial resolution is the vital problem for optical design of aerial photogrammetric camera all the time. It is difficult to obtain an outstanding optical system with high modulation transfer function (MTF) as a result of wide band. At the same time, for acquiring high qualified image, chromatic distortion in optical system must be expected to be controlled below 0.5 pixels; it is a trouble thing because of wide field and multi-spectrum. In this paper, MTF and band of the system are analyzed. A Russar type photogrammetric objective is chosen as the basic optical structure. A novel optical system is presented to solve the problem. The new optical photogrammetric system, which consists of panchromatic optical system and chromatic optical system, is designed. The panchromatic optical system, which can obtain panchromatic image, makes up of a 9k×9k large format CCD and high-accuracy photographic objective len, its focal length is 69.83mm, field angle is 60°×60°, the size of CCD pixels is 8.75um×8.75um, spectral scope is from 0.43um to 0.74um, modulation transfer function is all above 0.4 in whole field when spatial frequency is at 60lp/mm, distortion is less than 0.007%. In a chromatic optical system, three 2k×2k array CCDs combine individually three same photographic objectives, the high resolution chromatic image is acquired by the synthesis of red, green, blue image data information delivered by three CCD sensors. For the chromatic system, their focal length is 24.83mm and they have the same spectral range of 0.39um to 0.74um. A difference is that they are coated in different film on their protect glass. The pixel number is 2048 × 2048; its MTF exceeds 0.4 in full field when spatial frequency is 30lp/mm. The advantages of digital aerial photogrammetric camera comparison with traditional film camera are described. It is considered that the two development trends on digital aerial photogrammetric camera are high-spectral resolution and

  19. Picosecond wide-field time-correlated single photon counting fluorescence microscopy with a delay line anode detector

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Le Marois, Alix; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Becker, Wolfgang; Smietana, Stefan [Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin (Germany); Milnes, James; Conneely, Thomas [Photek Ltd., 26 Castleham Rd, Saint Leonards-on-Sea TN38 9NS (United Kingdom); Jagutzki, Ottmar [Institut für Kernphysik, Max-von-Laue-Str. 1, 60438 Frankfurt (Germany)

    2016-08-15

    We perform wide-field time-correlated single photon counting-based fluorescence lifetime imaging (FLIM) with a crossed delay line anode image intensifier, where the pulse propagation time yields the photon position. This microchannel plate-based detector was read out with conventional fast timing electronics and mounted on a fluorescence microscope with total internal reflection (TIR) illumination. The picosecond time resolution of this detection system combines low illumination intensity of microwatts with wide-field data collection. This is ideal for fluorescence lifetime imaging of cell membranes using TIR. We show that fluorescence lifetime images of living HeLa cells stained with membrane dye di-4-ANEPPDHQ exhibit a reduced lifetime near the coverslip in TIR compared to epifluorescence FLIM.

  20. Laser Light-field Fusion for Wide-field Lensfree On-chip Phase Contrast Microscopy of Nanoparticles.

    Science.gov (United States)

    Kazemzadeh, Farnoud; Wong, Alexander

    2016-12-13

    Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast microscopy for detecting nanoparticles, where interferometric laser light-field encodings acquired using a lensfree, on-chip setup with laser pulsations at different wavelengths are fused to produce marker-free phase contrast images of particles at the nanometer scale. As a proof of concept, we demonstrate, for the first time, a wide-field lensfree on-chip instrument successfully detecting 300 nm particles across a large field-of-view of ~30 mm(2) without any specialized or intricate sample preparation, or the use of synthetic aperture- or shift-based techniques.

  1. Wide-field time-resolved luminescence imaging and spectroscopy to decipher obliterated documents in forensic science

    Science.gov (United States)

    Suzuki, Mototsugu; Akiba, Norimitsu; Kurosawa, Kenji; Kuroki, Kenro; Akao, Yoshinori; Higashikawa, Yoshiyasu

    2016-01-01

    We applied a wide-field time-resolved luminescence (TRL) method with a pulsed laser and a gated intensified charge coupled device (ICCD) for deciphering obliterated documents for use in forensic science. The TRL method can nondestructively measure the dynamics of luminescence, including fluorescence and phosphorescence lifetimes, which prove to be useful parameters for image detection. First, we measured the TRL spectra of four brands of black porous-tip pen inks on paper to estimate their luminescence lifetimes. Next, we acquired the TRL images of 12 obliterated documents at various delay times and gate times of the ICCD. The obliterated contents were revealed in the TRL images because of the difference in the luminescence lifetimes of the inks. This method requires no pretreatment, is nondestructive, and has the advantage of wide-field imaging, which makes it is easy to control the gate timing. This demonstration proves that TRL imaging and spectroscopy are powerful tools for forensic document examination.

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

    Science.gov (United States)

    Lv, Shiliang; Liu, Jinguo

    2015-10-01

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

  3. Status and Perspectives of the Mini-MegaTORTORA Wide-field Monitoring System with High Temporal Resolution

    Directory of Open Access Journals (Sweden)

    Sergey Karpov

    2013-01-01

    Full Text Available Here we briefly summarize our long-term experience of constructing and operating wide-field monitoring cameras with sub-second temporal resolution to look for optical components of GRBs, fast-moving satellites and meteors. The general hardware requirements for these systems are discussed, along with algorithms for real-time detection and classification of various kinds of short optical transients. We also give a status report on the next generation, the MegaTORTORA multi-objective and transforming monitoring system, whose 6-channel (Mini-MegaTORTORA-Spain and 9-channel prototypes (Mini-MegaTORTORA-Kazan we have been building at SAO RAS. This system combines a wide field of view with subsecond temporal resolution in monitoring regime, and is able, within fractions of a second, to reconfigure itself to follow-up mode, which has better sensitivity and simultaneously provides multi-color and polarimetric information on detected transients.

  4. Laser Light-field Fusion for Wide-field Lensfree On-chip Phase Contrast Microscopy of Nanoparticles

    Science.gov (United States)

    Kazemzadeh, Farnoud; Wong, Alexander

    2016-12-01

    Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast microscopy for detecting nanoparticles, where interferometric laser light-field encodings acquired using a lensfree, on-chip setup with laser pulsations at different wavelengths are fused to produce marker-free phase contrast images of particles at the nanometer scale. As a proof of concept, we demonstrate, for the first time, a wide-field lensfree on-chip instrument successfully detecting 300 nm particles across a large field-of-view of ~30 mm2 without any specialized or intricate sample preparation, or the use of synthetic aperture- or shift-based techniques.

  5. Searching for fast optical transients by means of a wide-field monitoring observations with high temporal resolution

    Science.gov (United States)

    Beskin, G.; Karpov, S.; Plokhotnichenko, V.; Bondar, S.; Ivanov, E.; Perkov, A.; Greco, G.; Guarnieri, A.; Bartolini, C.

    We discuss the strategy of search for fast optical transients accompanying gamma-ray bursts by means of continuous monitoring of wide sky fields with high temporal resolution. We describe the design, performance and results of our cameras, FAVOR and TORTORA. Also we discuss the perspectives of this strategy and possible design of next-generation equipment for wide-field monitoring which will be able to detect optical transients and to study their color and polarization properties with high time resolution.

  6. Obtaining Sub-uas Astrometry on a Wide-field, Coronagraph Equipped, Space Telescope Using a Diffractive Pupil

    Science.gov (United States)

    Bendek, Eduardo; Belikov, R.; Guyon, O.

    2013-01-01

    Detection and mass measurement of earth-size exoplanets using the astrometric signal of the host star requires sub-uas measurement precision. One major challenge in achieving this precision using medium-size space telescopes is the calibration of dynamic distortions. To solve this problem, we propose a diffractive pupil approach in which an array of dots on the primary mirror generates polychromatic diffraction spikes in the focal plane used to calibrate the distortions in the optical system. According to our simulations, this technique enables 0.2microarcsecond or better single-visit precision astrometric measurements on a 2.4m wide-field (>0.1deg2) space telescope. We present the laboratory results of the diffractive pupil concept performed at the University of Arizona, showing that this approach can calibrate dynamic distortion errors even for wide field applications. Also, this technique can be used simultaneously with a high-performance coronagraph to determine/constrain the masses, composition, atmospheric properties, and planetary system architectures. Numerical simulations and experiments performed at the NASA Ames ACE test bed have shown that the diffractive pupil does not affect the coronagraph performance. Finally, we assess the compatibility of a diffractive pupil telescope with a general astrophysics mission, showing that the spikes are too faint to impact wide field observations.

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

    Science.gov (United States)

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

    2011-01-13

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

  8. Mosaic Conservation Opportunity Areas - Liberal Model (ECO_RES.COA_MOSAIC33)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The COA_Mosaic33 layer designates areas with potential for forest/grassland mosaic conservation. These are areas of natural or semi-natural forest/grassland mosaic...

  9. Astrometrica: Astrometric data reduction of CCD images

    Science.gov (United States)

    Raab, Herbert

    2012-03-01

    Astrometrica is an interactive software tool for scientific grade astrometric data reduction of CCD images. The current version of the software is for the Windows 32bit operating system family. Astrometrica reads FITS (8, 16 and 32 bit integer files) and SBIG image files. The size of the images is limited only by available memory. It also offers automatic image calibration (Dark Frame and Flat Field correction), automatic reference star identification, automatic moving object detection and identification, and access to new-generation star catalogs (PPMXL, UCAC 3 and CMC-14), in addition to online help and other features. Astrometrica is shareware, available for use for a limited period of time (100 days) for free; special arrangements can be made for educational projects.

  10. Programmable Clock Waveform Generation for CCD Readout

    Energy Technology Data Exchange (ETDEWEB)

    Vicente, J. de; Castilla, J.; Martinez, G.; Marin, J.

    2006-07-01

    Charge transfer efficiency in CCDs is closely related to the clock waveform. In this paper, an experimental framework to explore different FPGA based clock waveform generator designs is described. Two alternative design approaches for controlling the rise/fall edge times and pulse width of the CCD clock signal have been implemented: level-control and time-control. Both approaches provide similar characteristics regarding the edge linearity and noise. Nevertheless, dissimilarities have been found with respect to the area and frequency range of application. Thus, while the time-control approach consumes less area, the level control approach provides a wider range of clock frequencies since it does not suffer capacitor discharge effect. (Author) 8 refs.

  11. Full Jupiter Mosaic

    Science.gov (United States)

    2007-01-01

    This image of Jupiter is produced from a 2x2 mosaic of photos taken by the New Horizons Long Range Reconnaissance Imager (LORRI), and assembled by the LORRI team at the Johns Hopkins University Applied Physics Laboratory. The telescopic camera snapped the images during a 3-minute, 35-second span on February 10, when the spacecraft was 29 million kilometers (18 million miles) from Jupiter. At this distance, Jupiter's diameter was 1,015 LORRI pixels -- nearly filling the imager's entire (1,024-by-1,024 pixel) field of view. Features as small as 290 kilometers (180 miles) are visible. Both the Great Red Spot and Little Red Spot are visible in the image, on the left and lower right, respectively. The apparent 'storm' on the planet's right limb is a section of the south tropical zone that has been detached from the region to its west (or left) by a 'disturbance' that scientists and amateur astronomers are watching closely. At the time LORRI took these images, New Horizons was 820 million kilometers (510 million miles) from home -- nearly 51/2 times the distance between the Sun and Earth. This is the last full-disk image of Jupiter LORRI will produce, since Jupiter is appearing larger as New Horizons draws closer, and the imager will start to focus on specific areas of the planet for higher-resolution studies.

  12. Low-noise video amplifiers for imaging CCD's

    Science.gov (United States)

    Scinicariello, F.

    1976-01-01

    Various techniques were developed which enable the CCD (charge coupled device) imaging array user to obtain optimum performance from the device. A CCD video channel was described, and detector-preamplifier interface requirements were examined. A noise model for the system was discussed at length and laboratory data presented and compared to predicted results.

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

    Science.gov (United States)

    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

  14. Optical System and Desing Of The New 1.6 Meter Wide-Field Telescope With Active Optics

    Science.gov (United States)

    Papushev, Pavel; Denisenko, Sergey; Kamus, Sergey; Pimenov, Yury; Tergoev, Vladim

    2006-08-01

    In this report we present and discuss the design, construction and capabilities of the two meters class wide field survey telescope. The designs based on modified R-C system with two or three lens correctors in visible and near infrared (2,2 mkm) spectral range. The optical systems of the 1.6 meters telescope with up to 3 degrees field of view and less than 15% obscuration area are considered in detail. Optical performance of system, its mount and separate element of the active optics system are examined.

  15. Preliminary Analysis of Ground-based Orbit Determination Accuracy for the Wide Field Infrared Survey Telescope (WFIRST)

    Science.gov (United States)

    Sease, Brad

    2017-01-01

    The Wide Field Infrared Survey Telescope is a 2.4-meter telescope planned for launch to the Sun-Earth L2 point in 2026. This paper details a preliminary study of the achievable accuracy for WFIRST from ground-based orbit determination routines. The analysis here is divided into two segments. First, a linear covariance analysis of early mission and routine operations provides an estimate of the tracking schedule required to meet mission requirements. Second, a simulated operations scenario gives insight into the expected behavior of a daily Extended Kalman Filter orbit estimate over the first mission year given a variety of potential momentum unloading schemes.

  16. ISS-Lobster: A Proposed Wide-Field X-Ray Telescope on the International Space Station

    Science.gov (United States)

    Camp, Jordan

    2012-01-01

    The Lobster wide-field imaging telescope combines simultaneous high FOV, high sensitivity and good position resolution. These characteristics can open the field of X-Ray time domain astronomy, which will study many interesting transient sources, including tidal disruptions of stars, supernova shock breakouts, and high redshift gamma-ray bursts. Also important will be its use for the X-ray follow-up of gravitational wave detections. I will describe our present effort to propose the Lobster concept for deployment on the International Space Station through a NASA Mission of Opportunity this fall.

  17. A wide-field TCSPC FLIM system based on an MCP PMT with a delay-line anode

    OpenAIRE

    Becker, Wolfgang; Hirvonen, Liisa; Milnes, James; Conneely, Thomas; Jagutzki, Ottmar; Netz, Holger; Smietana, Stefan; Suhling, Klaus

    2016-01-01

    We report on the implementation of a wide-field time-correlated single photon counting (TCSPC) method for fluorescence lifetime imaging (FLIM). It is based on a 40 mm diameter crossed delay line anode detector, where the readout is performed by three standard TCSPC boards. Excitation is performed by a picosecond diode laser with 50 MHz repetition rate. The photon arrival timing is obtained directly from the microchannel plates, with an instrumental response of ∼190 to 230 ps full width at hal...

  18. All sky coordination initiative, simple service for wide-field monitoring systems to cooperate in searching for fast optical transients

    Science.gov (United States)

    Karpov, S.; Sokołowski, M.; Gorbovskoy, E.

    Here we stress the necessity of cooperation between different wide-field monitoring projects (FAVOR/TORTORA, Pi of the Sky, MASTER, etc), aimed for independent detection of fast optical transients, in order to maximize the area of the sky covered at any moment and to coordinate the monitoring of gamma-ray telescopes' field of view. We review current solutions available for it and propose a simple protocol with dedicated service (ASCI) for such systems to share their current status and pointing schedules.

  19. Impacts on the Hubble Space Telescope Wide Field and Planetary Camera 2: Experimental Simulation of Micrometeoroid Capture

    Science.gov (United States)

    Price, M. C.; Kearsley, A. T.; Wozniakiewicz, P. J.; Spratt, J.; Burchell, M. J.; Cole, M. J.; Anz-Meador, P.; Liou, J. C.; Ross, D. K.; Opiela, J.; hide

    2014-01-01

    Hypervelocity impact features have been recognized on painted surfaces returned from the Hubble Space Telescope (HST). Here we describe experiments that help us to understand their creation, and the preservation of micrometeoroid (MM) remnants. We simulated capture of silicate and sulfide minerals on the Zinc orthotitanate (ZOT) paint and Al alloy plate of the Wide Field and Planetary Camera 2 (WFPC2) radiator, which was returned from HST after 16 years in low Earth orbit (LEO). Our results also allow us to validate analytical methods for identification of MM (and orbital debris) impacts in LEO.

  20. High-resolution CCD imagers using area-array CCD's for sensing spectral components of an optical line image

    Science.gov (United States)

    Elabd, Hammam (Inventor); Kosonocky, Walter F. (Inventor)

    1987-01-01

    CCD imagers with a novel replicated-line-imager architecture are abutted to form an extended line sensor. The sensor is preceded by optics having a slit aperture and having an optical beam splitter or astigmatic lens for projecting multiple line images through an optical color-discriminating stripe filter to the CCD imagers. A very high resolution camera suitable for use in a satellite, for example, is thus provided. The replicated-line architecture of the imager comprises an area-array CCD, successive rows of which are illuminated by replications of the same line segment, as transmitted by respective color filter stripes. The charge packets formed by accumulation of photoresponsive charge in the area-array CCD are read out row by row. Each successive row of charge packets is then converted from parallel to serial format in a CCD line register and its amplitude sensed to generate a line of output signal.

  1. Combining HJ CCD, GF-1 WFV and MODIS Data to Generate Daily High Spatial Resolution Synthetic Data for Environmental Process Monitoring.

    Science.gov (United States)

    Wu, Mingquan; Huang, Wenjiang; Niu, Zheng; Wang, Changyao

    2015-08-20

    The limitations of satellite data acquisition mean that there is a lack of satellite data with high spatial and temporal resolutions for environmental process monitoring. In this study, we address this problem by applying the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) and the Spatial and Temporal Data Fusion Approach (STDFA) to combine Huanjing satellite charge coupled device (HJ CCD), Gaofen satellite no. 1 wide field of view camera (GF-1 WFV) and Moderate Resolution Imaging Spectroradiometer (MODIS) data to generate daily high spatial resolution synthetic data for land surface process monitoring. Actual HJ CCD and GF-1 WFV data were used to evaluate the precision of the synthetic images using the correlation analysis method. Our method was tested and validated for two study areas in Xinjiang Province, China. The results show that both the ESTARFM and STDFA can be applied to combine HJ CCD and MODIS reflectance data, and GF-1 WFV and MODIS reflectance data, to generate synthetic HJ CCD data and synthetic GF-1 WFV data that closely match actual data with correlation coefficients (r) greater than 0.8989 and 0.8643, respectively. Synthetic red- and near infrared (NIR)-band data generated by ESTARFM are more suitable for the calculation of Normalized Different Vegetation Index (NDVI) than the data generated by STDFA.

  2. Radiation events in astronomical CCD images

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.R.; McDonald, R.J.; Hurley, D.L.; Holland, S.E.; Groom, D.E.; Brown, W.E.; Gilmore, D.K.; Stover, R.J.; Wei, M.

    2001-12-18

    The remarkable sensitivity of depleted silicon to ionizing radiation is a nuisance to astronomers. ''Cosmic rays'' degrade images because of struck pixels, leading to modified observing strategies and the development of algorithms to remove the unwanted artifacts. In the new-generation CCD's with thick sensitive regions, cosmic-ray muons make recognizable straight tracks and there is enhanced sensitivity to ambient gamma radiation via Compton-scattered electrons (''worms''). Beta emitters inside the dewar, for example high-potassium glasses such as BK7, also produce worm-like tracks. The cosmic-ray muon rate is irreducible and increases with altitude. The gamma rays are mostly by-products of the U and Th decay chains; these elements always appear as traces in concrete and other materials. The Compton recoil event rate can be reduced significantly by the choice of materials in the environment and dewar and by careful shielding. Telescope domes appear to be significantly cleaner than basement laboratories and Coude spectrograph rooms. Radiation sources inside the dewar can be eliminated by judicious choice of materials. Cosmogenic activation during high-altitude flights does not appear to be a problem. Our conclusions are supported by tests at the Lawrence Berkeley National Laboratory low-level counting facilities in Berkeley and at Oroville, California (180 m underground).

  3. Linearity measurement for image-intensified CCD

    Science.gov (United States)

    Zhao, Yuhuan; Zhang, Liwei; Yan, Feng; Gu, Yongqiang; Wan, Liying

    2010-10-01

    To the characteristic of the ultraviolet CCD (UV ICCD), technique of the linearity measurement of the UV ICCD camera is studied based on the theory of radiometry. Approach of linearity measurement is discussed, and a kind of measurement system of the UV ICCD has been developed based on the method of neutral density filter. It is very important that the transmittance of the filter is independent of the wavelength in the method of neutral density filter. Black metal screen mesh with different transmittance is used in our system, and calibration of the filters' transmittance in different working positions has been done. Meanwhile, to assure the uniform of the received radiation on the target of the detector at any test points, an integrating sphere is placed behind the neutral filter to balance light. The whole measurement system mainly consists of a deuterium lamp with high stabilization, the attenuation film with transmission, integrating sphere, optical guide and electro-shift platform. Auto control is realized via special software during the test. With this instrument, the linearity of the UV ICCD was measured. Experimental results show that the nonlinearity of the UV ICCD under fixed-gain is less than 2% and the uncertainty of measurement system is less than 4%.

  4. Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Schütze, Christopher; Ritter, Markus; Blum, Robert; Zotter, Stefan; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2014-11-01

    To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography. This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation. Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.

  5. Wide-Field Landers Temporary Keratoprosthesis in Severe Ocular Trauma: Functional and Anatomical Results after One Year

    Science.gov (United States)

    Nowomiejska, Katarzyna; Haszcz, Dariusz; Forlini, Cesare; Forlini, Matteo; Moneta-Wielgos, Joanna; Maciejewski, Ryszard; Zarnowski, Tomasz; Juenemann, Anselm G.

    2015-01-01

    Purpose. To evaluate longitudinal functional and anatomical results after combined pars plana vitrectomy (PPV) and penetrating keratoplasty (PKP) using a wide-field Landers intraoperative temporary keratoprosthesis (TKP) in patients with vitreoretinal pathology and corneal opacity due to severe ocular trauma. Material and Methods. Medical records of 12 patients who had undergone PPV/PKP/KP due to severe eye trauma were analyzed. Functional (best-corrected visual acuity) and anatomic outcomes (clarity of the corneal graft, retinal attachment, and intraocular pressure) were assessed during the follow-up (mean 16 months). Results. Final visual acuities varied from NLP to CF to 2 m. Visual acuity improved in 7 cases, was unchanged in 4 eyes, and worsened in 1 eye. The corneal graft was transparent during the follow-up in 3 cases and graft failure was observed in 9 eyes. Silicone oil was used as a tamponade in all cases and retina was reattached in 92% of cases. Conclusions. Combined PPV and PKP with the use of wide-field Landers TKP allowed for surgical intervention in patients with vitreoretinal pathology coexisting with corneal wound. Although retina was attached in most of the cases, corneal graft survived only in one-fourth of patients and final visual acuities were poor. PMID:26617994

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

    Science.gov (United States)

    Gehrels, N.; Spergel, D.

    2015-01-01

    The 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 wellfunded 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.

  7. Wide-field retinal optical coherence tomography with wavefront sensorless adaptive optics for enhanced imaging of targeted regions.

    Science.gov (United States)

    Polans, James; Keller, Brenton; Carrasco-Zevallos, Oscar M; LaRocca, Francesco; Cole, Elijah; Whitson, Heather E; Lad, Eleonora M; Farsiu, Sina; Izatt, Joseph A

    2017-01-01

    The peripheral retina of the human eye offers a unique opportunity for assessment and monitoring of ocular diseases. We have developed a novel wide-field (>70°) optical coherence tomography system (WF-OCT) equipped with wavefront sensorless adaptive optics (WSAO) for enhancing the visualization of smaller (23°) retina. We demonstrated the ability of our WF-OCT system to acquire non wavefront-corrected wide-field images rapidly, which could then be used to locate regions of interest, zoom into targeted features, and visualize the same region at different time points. A pilot clinical study was conducted on seven healthy volunteers and two subjects with prodromal Alzheimer's disease which illustrated the capability to image Drusen-like pathologies as far as 32.5° from the fovea in un-averaged volume scans. This work suggests that the proposed combination of WF-OCT and WSAO may find applications in the diagnosis and treatment of ocular, and potentially neurodegenerative, diseases of the peripheral retina, including diabetes and Alzheimer's disease.

  8. Wide-Field Landers Temporary Keratoprosthesis in Severe Ocular Trauma: Functional and Anatomical Results after One Year

    Directory of Open Access Journals (Sweden)

    Katarzyna Nowomiejska

    2015-01-01

    Full Text Available Purpose. To evaluate longitudinal functional and anatomical results after combined pars plana vitrectomy (PPV and penetrating keratoplasty (PKP using a wide-field Landers intraoperative temporary keratoprosthesis (TKP in patients with vitreoretinal pathology and corneal opacity due to severe ocular trauma. Material and Methods. Medical records of 12 patients who had undergone PPV/PKP/KP due to severe eye trauma were analyzed. Functional (best-corrected visual acuity and anatomic outcomes (clarity of the corneal graft, retinal attachment, and intraocular pressure were assessed during the follow-up (mean 16 months. Results. Final visual acuities varied from NLP to CF to 2 m. Visual acuity improved in 7 cases, was unchanged in 4 eyes, and worsened in 1 eye. The corneal graft was transparent during the follow-up in 3 cases and graft failure was observed in 9 eyes. Silicone oil was used as a tamponade in all cases and retina was reattached in 92% of cases. Conclusions. Combined PPV and PKP with the use of wide-field Landers TKP allowed for surgical intervention in patients with vitreoretinal pathology coexisting with corneal wound. Although retina was attached in most of the cases, corneal graft survived only in one-fourth of patients and final visual acuities were poor.

  9. GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry

    Science.gov (United States)

    Dominik, Martin; Mackay, Craig; Steele, Iain; Snodgrass, Colin; Hirsch, Michael; Gråe Jørgensen, Uffe; Hundertmark, Markus; Rebolo, Rafael; Horne, Keith; Bridle, Sarah; Sicardy, Bruno; Bramich, Daniel; Alsubai, Khalid

    2015-12-01

    The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100 EMCCDs, that will open up two entirely new windows to ground-based astronomy: (1) wide-field high-resolution imaging, and (2) wide-field high-speed photometry. Potential applications include (a) a gravitational microlensing survey going 4 magnitudes deeper than current efforts, and thereby gaining a factor 100 in mass at the same sensitivity, which means probing down to Lunar mass or even below, (b) extra-solar planet hunting via transits in galactic bulge fields, with high time resolution well-suited for transit timing variation studies, (c) variable stars in crowded fields, with sensitivity to very short periods, (d) asteroseismology with many bright stars in one pointing, (e) serendipitous occultations of stars by small solar system bodies, giving access to the small end of the Kuiper Belt size distribution and potentially leading to the first detection of true Oort cloud objects, while predicted occultations at high time resolution can reveal atmospheres, satellites, or rings, (f) general data mining of the high-speed variable sky (down to 40 ms cadence).

  10. Prenatal diagnosis of mosaic tetrasomy 18p

    Directory of Open Access Journals (Sweden)

    Chih-Ping Chen

    2012-12-01

    Conclusion: There is cytogenetic discrepancy between amniocytes and cord blood lymphocytes in prenatally detected mosaic tetrasomy 18p. Interphase FISH on uncultured amniocytes has the advantage of rapid confirmation of low-level mosaicism for tetrasomy 18p at amniocentesis.

  11. Cutaneous mosaicisms: concepts, patterns and classifications

    OpenAIRE

    Kouzak, Samara Silva; Mendes, Marcela Sena Teixeira; Costa, Izelda Maria Carvalho

    2013-01-01

    A mosaic is an organism composed of two or more genetically distinct cell populations derived from a genetically homogeneous zygote. Cutaneous mosaicisms are the clinical expressions of these disorders. The main event which allows the existence of mosaicism is a genetic mutation, either structural or functional. Cutaneous mosaicisms usually manifest by specific patterns on the skin and the archetypic pattern is the system of Blaschko lines, but others include checkerboard, phylloid, large pat...

  12. Gaspra - Highest Resolution Mosaic

    Science.gov (United States)

    1992-01-01

    This picture of asteroid 951 Gaspra is a mosaic of two images taken by the Galileo spacecraft from a range of 5,300 kilometers (3,300 miles), some 10 minutes before closest approach on October 29, 1991. The Sun is shining from the right; phase angle is 50 degrees. The resolution, about 54 meters/pixel, is the highest for the Gaspra encounter and is about three times better than that in the view released in November 1991. Additional images of Gaspra remain stored on Galileo's tape recorder, awaiting playback in November. Gaspra is an irregular body with dimensions about 19 x 12 x 11 kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view is about 18 kilometers (11 miles) from lower left to upper right. The north pole is located at upper left; Gaspra rotates counterclockwise every 7 hours. The large concavity on the lower right limb is about 6 kilometers (3.7 miles) across, the prominent crater on the terminator, center left, about 1.5 kilometers (1 mile). A striking feature of Gaspra's surface is the abundance of small craters. More than 600 craters, 100-500 meters (330-1650 feet) in diameter are visible here. The number of such small craters compared to larger ones is much greater for Gaspra than for previously studied bodies of comparable size such as the satellites of Mars. Gaspra's very irregular shape suggests that the asteroid was derived from a larger body by nearly catastrophic collisions. Consistent with such a history is the prominence of groove-like linear features, believed to be related to fractures. These linear depressions, 100-300 meters wide and tens of meters deep, are in two crossing groups with slightly different morphology, one group wider and more pitted than the other. Grooves had previously been seen only on Mars's moon Phobos, but were predicted for asteroids as well. Gaspra also shows a variety of enigmatic curved depressions and ridges in the terminator region at left. The Galileo project, whose primary mission is the

  13. Highest Resolution Gaspra Mosaic

    Science.gov (United States)

    1992-01-01

    This picture of asteroid 951 Gaspra is a mosaic of two images taken by the Galileo spacecraft from a range of 5,300 kilometers (3,300 miles), some 10 minutes before closest approach on October 29, 1991. The Sun is shining from the right; phase angle is 50 degrees. The resolution, about 54 meters/pixel, is the highest for the Gaspra encounter and is about three times better than that in the view released in November 1991. Additional images of Gaspra remain stored on Galileo's tape recorder, awaiting playback in November. Gaspra is an irregular body with dimensions about 19 x 12 x 11 kilometers (12 x 7.5 x 7 miles). The portion illuminated in this view is about 18 kilometers (11 miles) from lower left to upper right. The north pole is located at upper left; Gaspra rotates counterclockwise every 7 hours. The large concavity on the lower right limb is about 6 kilometers (3.7 miles) across, the prominent crater on the terminator, center left, about 1.5 kilometers (1 mile). A striking feature of Gaspra's surface is the abundance of small craters. More than 600 craters, 100-500 meters (330-1650 feet) in diameter are visible here. The number of such small craters compared to larger ones is much greater for Gaspra than for previously studied bodies of comparable size such as the satellites of Mars. Gaspra's very irregular shape suggests that the asteroid was derived from a larger body by nearly catastrophic collisions. Consistent with such a history is the prominence of groove-like linear features, believed to be related to fractures. These linear depressions, 100-300 meters wide and tens of meters deep, are in two crossing groups with slightly different morphology, one group wider and more pitted than the other. Grooves had previously been seen only on Mars's moon Phobos, but were predicted for asteroids as well. Gaspra also shows a variety of enigmatic curved depressions and ridges in the terminator region at left. The Galileo project, whose primary mission is the

  14. AWARE Wide Field View

    Science.gov (United States)

    2016-04-29

    RGB colors to the standard sRGB to allow spectrally consistent colors on monitors for viewing . Finally, the images from each sensor are corrected based ...on the exposure time used and the calibrated sensitivity of each image sensor, again based on the flat field calibration, to allow viewing of imagery...prediction is scaled based on available bandwidth and the computational resources of the cluster. In addition to the interface described in the

  15. CCD charge collection efficiency and the photon transfer technique

    Science.gov (United States)

    Janesick, J.; Klaasen, K.; Elliott, T.

    1985-01-01

    The charge-coupled device (CCD) has shown unprecendented performance as a photon detector in the areas of spectral response, charge transfer, and readout noise. Recent experience indicates, however, that the full potential for the CCD's charge collection efficiency (CCE) lies well beyond that which is realized in currently available devices. A definition of CCE performance is presented and a standard test tool (the photon transfer technique) for measuring and optimizing this important CCD parameter is introduced. CCE characteristics for different types of CCDs are compared; the primary limitations in achieving high CCE performance are discussed, and the prospects for future improvement are outlined.

  16. Trisomy 4 mosaicism : Delineation of the phenotype

    NARCIS (Netherlands)

    Bouman, Arjan; van der Kevie-Kersemaekers, Anne-Marie; Huijsdens-van Amsterdam, Karin; Dahhan, Nordin; Knegt, Lia; Vansenne, Fleur; Cobben, Jan Maarten

    Trisomy 4 mosaicism in liveborns is very rare. We describe a 17-month-old girl with trisomy 4 mosaicism. Clinical findings in this patient are compared to previously reported patients. Based on the few descriptions available in the literature the common phenotype of trisomy 4 mosaicism seems to

  17. On-ground and in-orbit characterisation plan for the PLATO CCD normal cameras

    Science.gov (United States)

    Gow, J. P. D.; Walton, D.; Smith, A.; Hailey, M.; Curry, P.; Kennedy, T.

    2017-11-01

    PLAnetary Transits and Ocillations (PLATO) is the third European Space Agency (ESA) medium class mission in ESA's cosmic vision programme due for launch in 2026. PLATO will carry out high precision un-interrupted photometric monitoring in the visible band of large samples of bright solar-type stars. The primary mission goal is to detect and characterise terrestrial exoplanets and their systems with emphasis on planets orbiting in the habitable zone, this will be achieved using light curves to detect planetary transits. PLATO uses a novel multi- instrument concept consisting of 26 small wide field cameras The 26 cameras are made up of a telescope optical unit, four Teledyne e2v CCD270s mounted on a focal plane array and connected to a set of Front End Electronics (FEE) which provide CCD control and readout. There are 2 fast cameras with high read-out cadence (2.5 s) for magnitude ~ 4–8 stars, being developed by the German Aerospace Centre and 24 normal (N) cameras with a cadence of 25 s to monitor stars with a magnitude greater than 8. The N-FEEs are being developed at University College London's Mullard Space Science Laboratory (MSSL) and will be characterised along with the associated CCDs. The CCDs and N-FEEs will undergo rigorous on-ground characterisation and the performance of the CCDs will continue to be monitored in-orbit. This paper discusses the initial development of the experimental arrangement, test procedures and current status of the N-FEE. The parameters explored will include gain, quantum efficiency, pixel response non-uniformity, dark current and Charge Transfer Inefficiency (CTI). The current in-orbit characterisation plan is also discussed which will enable the performance of the CCDs and their associated N-FEE to be monitored during the mission, this will include measurements of CTI giving an indication of the impact of radiation damage in the CCDs.

  18. Enzymatic study on AtCCD4 and AtCCD7 and their potential to form acyclic regulatory metabolites

    KAUST Repository

    Bruno, Mark

    2016-09-29

    The Arabidopsis carotenoid cleavage dioxygenase 4 (AtCCD4) is a negative regulator of the carotenoid content of seeds and has recently been suggested as a candidate for the generation of retrograde signals that are thought to derive from the cleavage of poly-cis-configured carotene desaturation intermediates. In this work, we investigated the activity of AtCCD4 in vitro and used dynamic modeling to determine its substrate preference. Our results document strict regional specificity for cleavage at the C9–C10 double bond in carotenoids and apocarotenoids, with preference for carotenoid substrates and an obstructing effect on hydroxyl functions, and demonstrate the specificity for all-trans-configured carotenes and xanthophylls. AtCCD4 cleaved substrates with at least one ionone ring and did not convert acyclic carotene desaturation intermediates, independent of their isomeric states. These results do not support a direct involvement of AtCCD4 in generating the supposed regulatory metabolites. In contrast, the strigolactone biosynthetic enzyme AtCCD7 converted 9-cis-configured acyclic carotenes, such as 9-cis-ζ-carotene, 9\\'-cis-neurosporene, and 9-cis-lycopene, yielding 9-cis-configured products and indicating that AtCCD7, rather than AtCCD4, is the candidate for forming acyclic retrograde signals.

  19. UV-sensitive scientific CCD image sensors

    Science.gov (United States)

    Vishnevsky, Grigory I.; Kossov, Vladimir G.; Iblyaminova, A. F.; Lazovsky, Leonid Y.; Vydrevitch, Michail G.

    1997-06-01

    An investigation of probe laser irradiation interaction with substances containing in an environment has long since become a recognized technique for contamination detection and identification. For this purpose, a near and midrange-IR laser irradiation is traditionally used. However, as many works presented on last ecology monitoring conferences show, in addition to traditional systems, rapidly growing are systems with laser irradiation from near-UV range (250 - 500 nm). Use of CCD imagers is one of the prerequisites for this allowing the development of a multi-channel computer-based spectral research system. To identify and analyze contaminating impurities on an environment, such methods as laser fluorescence analysis, UV absorption and differential spectroscopy, Raman scattering are commonly used. These methods are used to identify a large number of impurities (petrol, toluene, Xylene isomers, SO2, acetone, methanol), to detect and identify food pathogens in real time, to measure a concentration of NH3, SO2 and NO in combustion outbursts, to detect oil products in a water, to analyze contaminations in ground waters, to define ozone distribution in the atmosphere profile, to monitor various chemical processes including radioactive materials manufacturing, heterogeneous catalytic reactions, polymers production etc. Multi-element image sensor with enhanced UV sensitivity, low optical non-uniformity, low intrinsic noise and high dynamic range is a key element of all above systems. Thus, so called Virtual Phase (VP) CCDs possessing all these features, seems promising for ecology monitoring spectral measuring systems. Presently, a family of VP CCDs with different architecture and number of pixels is developed and being manufactured. All CCDs from this family are supported with a precise slow-scan digital image acquisition system that can be used in various image processing systems in astronomy, biology, medicine, ecology etc. An image is displayed directly on a PC

  20. Target Image Matching Algorithm Based on Binocular CCD Ranging

    Directory of Open Access Journals (Sweden)

    Dongming Li

    2014-01-01

    Full Text Available This paper proposed target image in a subpixel level matching algorithm for binocular CCD ranging, which is based on the principle of binocular CCD ranging. In the paper, firstly, we introduced the ranging principle of the binocular ranging system and deduced a binocular parallax formula. Secondly, we deduced the algorithm which was named improved cross-correlation matching algorithm and cubic surface fitting algorithm for target images matched, and it could achieve a subpixel level matching for binocular CCD ranging images. Lastly, through experiment we have analyzed and verified the actual CCD ranging images, then analyzed the errors of the experimental results and corrected the formula of calculating system errors. Experimental results showed that the actual measurement accuracy of a target within 3 km was higher than 0.52%, which meet the accuracy requirements of the high precision binocular ranging.

  1. EARTH BASED CCD OBSERVATIONS V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set presents images of 26P/Grigg-Skjellerup obtained by various observers at several ground-based observatories using CCD instruments. These data have not...

  2. Micrometer and CCD measurements of double stars (Series 51

    Directory of Open Access Journals (Sweden)

    Popović G.M.

    1998-01-01

    Full Text Available 36 micrometric measurements of 20 double or multiple systems carried out with the Zeiss 65/1055 cm Refractor of Belgrade Observatory are communicated. Also 35 CCD measurements of 15 double or multiple systems are included.

  3. Correlation and image compression for limited-bandwidth CCD.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Douglas G.

    2005-07-01

    As radars move to Unmanned Aerial Vehicles with limited-bandwidth data downlinks, the amount of data stored and transmitted with each image becomes more significant. This document gives the results of a study to determine the effect of lossy compression in the image magnitude and phase on Coherent Change Detection (CCD). We examine 44 lossy compression types, plus lossless zlib compression, and test each compression method with over 600 CCD image pairs. We also derive theoretical predictions for the correlation for most of these compression schemes, which compare favorably with the experimental results. We recommend image transmission formats for limited-bandwidth programs having various requirements for CCD, including programs which cannot allow performance degradation and those which have stricter bandwidth requirements at the expense of CCD performance.

  4. A search for a distant companion to the sun with the wide-field infrared survey explorer

    Energy Technology Data Exchange (ETDEWEB)

    Luhman, K. L., E-mail: kluhman@astro.psu.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-01-20

    I have used multi-epoch astrometry from the Wide-field Infrared Survey Explorer to perform a search for a distant companion to the Sun via its parallactic motion. I have not found an object of this kind down to W2 = 14.5. This limit corresponds to analogs of Saturn and Jupiter at 28,000 and 82,000 AU, respectively, according to models of the Jovian planets by Fortney and coworkers. Models of brown dwarfs by Burrows and coworkers predict fainter fluxes at a given mass for the age of the solar system, producing a closer distance limit of 26,000 AU for a Jupiter-mass brown dwarf. These constraints exclude most combinations of mass and separation at which a solar companion has been suggested to exist by various studies over the years.

  5. Wide-Field Multi-Parameter FLIM: long-term minimal invasive observation of proteins in living cells.

    Science.gov (United States)

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

    2011-02-02

    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.

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

    Science.gov (United States)

    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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Wide-field time-correlated single photon counting (TCSPC) microscopy with time resolution below the frame exposure time

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M. [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Petrášek, Zdeněk [Max Planck Institute of Biochemistry, Department of Cellular and Molecular Biophysics, Am Klopferspitz 18, D-82152 Martinsried (Germany); Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

    2015-07-01

    Fast frame rate CMOS cameras in combination with photon counting intensifiers can be used for fluorescence imaging with single photon sensitivity at kHz frame rates. We show here how the phosphor decay of the image intensifier can be exploited for accurate timing of photon arrival well below the camera exposure time. This is achieved by taking ratios of the intensity of the photon events in two subsequent frames, and effectively allows wide-field TCSPC. This technique was used for measuring decays of ruthenium compound Ru(dpp) with lifetimes as low as 1 μs with 18.5 μs frame exposure time, including in living HeLa cells, using around 0.1 μW excitation power. We speculate that by using an image intensifier with a faster phosphor decay to match a higher camera frame rate, photon arrival time measurements on the nanosecond time scale could well be possible.

  8. KOALA: a wide-field 1000 element integral-field unit for the Anglo-Australian Telescope

    Science.gov (United States)

    Ellis, S. C.; Ireland, M.; Lawrence, J. S.; Tims, J.; Staszak, N.; Brzeski, J.; Parker, Q. A.; Sharp, R.; Bland-Hawthorn, J.; Case, S.; Colless, M.; Croom, S.; Couch, W.; De Marco, O.; Glazebrook, K.; Saunders, W.; Webster, R.; Zucker, D. B.

    2012-09-01

    KOALA, the Kilofibre Optimised Astronomical Lenslet Array, is a wide-field, high efficiency integral field unit being designed for use with the bench mounted AAOmega spectrograph on the AAT. KOALA will have 1000 fibres in a rectangular array with a selectable field of view of either 1390 or 430 sq. arcseconds with a spatial sampling of 1.25" or 0.7" respectively. To achieve this KOALA will use a telecentric double lenslet array with interchangeable fore-optics. The IFU will feed AAOmega via a 31m fibre run. The efficiency of KOALA is expected to be ≍ 52% at 3700A and ≍ 66% at 6563°Å with a throughput of > 52% over the entire wavelength range.

  9. Combining wide-field super-resolution microscopy and electron tomography: rendering nanoscopic correlative arrays on subcellular architecture.

    Science.gov (United States)

    Braet, Filip; Cheng, Delfine; Huynh, Minh; Henriquez, Jeffrey; Shami, Gerry; Lampe, Marko

    2014-01-01

    In this chapter, the authors outline in full detail, an uncomplicated approach that enables the combination of wide-field fluorescence super-resolution microscopy with electron tomography, thereby providing an approach that affords the best possible confidence in the structures investigated. The methodical steps to obtain these high-throughput correlative nanoscopic arrays will be visually explored and outlined in detail. The authors will demonstrate the feasibility of the method on cultured Caco-2 colorectal cancer cells that are labeled for filamentous actin. The presented images, morphometric data, and generated models illustrate the strengths of our correlative approach for future advanced structural-biology-oriented questions. Correlative nanoscopy applications can be readily found in which there is a need to reveal biomolecular information at unprecedented resolution on subcellular behavior in various biological and pathobiological processes. © 2014 Elsevier Inc. All rights reserved.

  10. Mini-Mega-TORTORA wide-field monitoring system with sub-second temporal resolution: first year of operation

    Science.gov (United States)

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

    2016-12-01

    Here we present the summary of first years of operation and the first results of a novel 9-channel wide-field optical monitoring system with sub-second temporal resolution, Mini-Mega-TORTORA (MMT-9), which is in operation now at Special Astrophysical Observatory on Russian Caucasus. The system is able to observe the sky simultaneously in either wide (˜900 square degrees) or narrow (˜100 square degrees) fields of view, either in clear light or with any combination of color (Johnson-Cousins B, V or R) and polarimetric filters installed, with exposure times ranging from 0.1 s to hundreds of seconds. The real-time system data analysis pipeline performs automatic detection of rapid transient events, both near-Earth and extragalactic. The objects routinely detected by MMT include faint meteors and artificial satellites. The pipeline for a longer time scales variability analysis is still in development.

  11. VizieR Online Data Catalog: Wide-field spectrosc. survey of GCs in Virgo cluster (Ko+, 2017)

    Science.gov (United States)

    Ko, Y.; Hwang, H. S.; Lee, M. G.; Park, H. S.; Lim, S.; Sohn, J.; Jang, I. S.; Hwang, N.; Park, B.-G.

    2017-08-01

    We selected globular cluster (GC) candidates using the Next Generation Virgo Cluster Survey (NGVS; Ferrarese+ 2012ApJS..200....4F) archival images covering the central region of the Virgo cluster. The NGVS is a wide-field imaging survey of the Virgo cluster using MegaCam with a field of view of 1°x1° attached at the Canada-French-Hawaii Telescope. We carried out spectroscopic observation of GC candidates in the Virgo using the Hectospec mounted on the 6.5m Multiple-Mirror Telescope in queue mode under program ID 2014A-UAO-G18 (PI: Myung Gyoon Lee) between 2014 February and March (wavelength range: 3650Å to 9200Å). (3 data files).

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

    Science.gov (United States)

    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.; hide

    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.

  13. Micrometeoroid Impacts on the Hubble Sace Telescope Wide Field and Planetary Camera 2: Ion Beam Analysis of Subtle Impactor Traces

    Science.gov (United States)

    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.; hide

    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.

  14. Wide-field infrared survey explorer observations of young stellar objects in the Lynds 1509 dark cloud in Auriga

    Energy Technology Data Exchange (ETDEWEB)

    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 μm, 4.6 μm, 12 μm, and 22 μm, 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.

  15. Background Stratospheric Aerosol Investigations Using Multi-Color Wide-Field Polarization Measurements of the Twilight Sky

    CERN Document Server

    Ugolnikov, Oleg S

    2016-01-01

    First results of multi-wavelength polarization measurements of the twilight sky background using Wide-Angle Polarization Camera (WAPC) with RGB-color CCD conducted in spring and early summer of 2016 in central Russia (55.2 deg N, 37.5 deg E) are discussed. They show the effect of aerosol scattering at altitudes up to 35 km which significantly increases to the long-wave range (620 nm, R channel). Analysis of sky color behavior during the light period of twilight with account of ozone Chappuis absorption allows to retrieve the angle dependencies of intensity and polarization of scattering on the stratospheric aerosol particles. This is used to find their effective radius, being close to 0.18-0.19 microns for stratospheric altitude range.

  16. Multi-feature combined cloud and cloud shadow detection in GaoFen-1 wide field of view imagery

    Science.gov (United States)

    Li, Zhiwei; Shen, Huanfeng; Li, Huifang; Xia, Guisong; Gamba, Paolo; Zhang, Liangpei

    2017-03-01

    The wide field of view (WFV) imaging system onboard the Chinese GaoFen-1 (GF-1) optical satellite has a 16-m resolution and four-day revisit cycle for large-scale Earth observation. The advantages of the high temporal-spatial resolution and the wide field of view make the GF-1 WFV imagery very popular. However, cloud cover is an inevitable problem in GF-1 WFV imagery, which influences its precise application. Accurate cloud and cloud shadow detection in GF-1 WFV imagery is quite difficult due to the fact that there are only three visible bands and one near-infrared band. In this paper, an automatic multi-feature combined (MFC) method is proposed for cloud and cloud shadow detection in GF-1 WFV imagery. The MFC algorithm first implements threshold segmentation based on the spectral features and mask refinement based on guided filtering to generate a preliminary cloud mask. The geometric features are then used in combination with the texture features to improve the cloud detection results and produce the final cloud mask. Finally, the cloud shadow mask can be acquired by means of the cloud and shadow matching and follow-up correction process. The method was validated using 108 globally distributed scenes. The results indicate that MFC performs well under most conditions, and the average overall accuracy of MFC cloud detection is as high as 96.8%. In the contrastive analysis with the official provided cloud fractions, MFC shows a significant improvement in cloud fraction estimation, and achieves a high accuracy for the cloud and cloud shadow detection in the GF-1 WFV imagery with fewer spectral bands. The proposed method could be used as a preprocessing step in the future to monitor land-cover change, and it could also be easily extended to other optical satellite imagery which has a similar spectral setting.

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

    Science.gov (United States)

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

    2003-02-01

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

  18. Collection and processing data for high quality CCD images.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2007-03-01

    Coherent Change Detection (CCD) with Synthetic Aperture Radar (SAR) images is a technique whereby very subtle temporal changes can be discerned in a target scene. However, optimal performance requires carefully matching data collection geometries and adjusting the processing to compensate for imprecision in the collection geometries. Tolerances in the precision of the data collection are discussed, and anecdotal advice is presented for optimum CCD performance. Processing considerations are also discussed.

  19. Portable lensless wide-field microscopy imaging platform based on digital inline holography and multi-frame pixel super-resolution

    National Research Council Canada - National Science Library

    Antonio C Sobieranski; Fatih Inci; H Cumhur Tekin; Mehmet Yuksekkaya; Eros Comunello; Daniel Cobra; Aldo Von Wangenheim; Utkan Demirci

    2015-01-01

      In this paper, an irregular displacement-based lensless wide-field microscopy imaging platform is presented by combining digital in-line holography and computational pixel super-resolution using multi-frame processing...

  20. Mosaic HIV envelope immunogenic polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon; Sodroski, Joseph; Haynes, Barton

    2018-01-02

    Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in a subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.

  1. Identification of virus isolates inducing mosaic of sugarcane in ...

    African Journals Online (AJOL)

    Sugarcane mosaic disease caused by sugarcane mosaic virus (SCMV), Johnsongrass mosaic virus (JGMV), maize dwarf mosaic virus (MDMV) and sorghum mosaic Virus (SrMV) is an economically important viral disease of sugarcane worldwide. Field survey was conducted to assess the presence of the viruses involve in ...

  2. The HST/WFC3 Quicklook Project: A User Interface to Hubble Space Telescope Wide Field Camera 3 Data

    Science.gov (United States)

    Bourque, Matthew; Bajaj, Varun; Bowers, Ariel; Dulude, Michael; Durbin, Meredith; Gosmeyer, Catherine; Gunning, Heather; Khandrika, Harish; Martlin, Catherine; Sunnquist, Ben; Viana, Alex

    2017-06-01

    The Hubble Space Telescope's Wide Field Camera 3 (WFC3) instrument, comprised of two detectors, UVIS (Ultraviolet-Visible) and IR (Infrared), has been acquiring ~ 50-100 images daily since its installation in 2009. The WFC3 Quicklook project provides a means for instrument analysts to store, calibrate, monitor, and interact with these data through the various Quicklook systems: (1) a ~ 175 TB filesystem, which stores the entire WFC3 archive on disk, (2) a MySQL database, which stores image header data, (3) a Python-based automation platform, which currently executes 22 unique calibration/monitoring scripts, (4) a Python-based code library, which provides system functionality such as logging, downloading tools, database connection objects, and filesystem management, and (5) a Python/Flask-based web interface to the Quicklook system. The Quicklook project has enabled large-scale WFC3 analyses and calibrations, such as the monitoring of the health and stability of the WFC3 instrument, the measurement of ~ 20 million WFC3/UVIS Point Spread Functions (PSFs), the creation of WFC3/IR persistence calibration products, and many others.

  3. Wide-field spectral imaging of human ovary autofluorescence and oncologic diagnosis via previously collected probe data

    Science.gov (United States)

    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.

  4. THE LOW-FREQUENCY CHARACTERISTICS OF PSR J0437–4715 OBSERVED WITH THE MURCHISON WIDE-FIELD ARRAY

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, N. D. R.; Ord, S. M.; Tremblay, S. E.; Tingay, S. J.; Oronsaye, S.; Emrich, D. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); Deshpande, A. A. [Raman Research Institute, Bangalore 560080 (India); Van Straten, W.; Briggs, F. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Curtin University, Bentley, WA 6102 (Australia); Bernardi, G. [Square Kilometre Array South Africa, 3rd Floor, The Park, Park Road, Pinelands, 7405 (South Africa); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Cappallo, R. J.; Corey, B. E. [MIT Haystack Observatory, Westford, MA 01886 (United States); Goeke, R.; Hewitt, J. N. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Greenhill, L. J.; Kasper, J. C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hazelton, B. J. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Kaplan, D. L. [Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201 (United States); and others

    2014-08-20

    We report on the detection of the millisecond pulsar PSR J0437–4715 with the Murchison Wide-field Array (MWA) at a frequency of 192 MHz. Our observations show rapid modulations of pulse intensity in time and frequency that arise from diffractive scintillation effects in the interstellar medium (ISM), as well as prominent drifts of intensity maxima in the time-frequency plane that arise from refractive effects. Our analysis suggests that the scattering screen is located at a distance of ∼80-120 pc from the Sun, in disagreement with a recent claim that the screen is closer (∼10 pc). Comparisons with higher frequency data from Parkes reveal a dramatic evolution of the pulse profile with frequency, with the outer conal emission becoming comparable in strength to that from the core and inner conal regions. As well as demonstrating the high time resolution science capabilities currently possible with the MWA, our observations underscore the potential to conduct low-frequency investigations of timing-array millisecond pulsars, which may lead to increased sensitivity in the detection of nanoHertz gravitational waves via the accurate characterization of ISM effects.

  5. Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars

    Science.gov (United States)

    Garling, Christopher; Willman, Beth; Sand, David J.; Hargis, Jonathan; Crnojević, Denija; Bechtol, Keith; Carlin, Jeffrey L.; Strader, Jay; Zou, Hu; Zhou, Xu; Nie, Jundan; Zhang, Tianmeng; Zhou, Zhimin; Peng, Xiyan

    2018-01-01

    We investigate the hypothesized tidal disruption of the Hercules ultra-faint dwarf galaxy (UFD). Previous tidal disruption studies of the Hercules UFD have been hindered by the high degree of foreground contamination in the direction of the dwarf. We bypass this issue by using RR Lyrae stars, which are standard candles with a very low field-volume density at the distance of Hercules. We use wide-field imaging from the Dark Energy Camera on CTIO to identify candidate RR Lyrae stars, supplemented with observations taken in coordination with the Beijing–Arizona Sky Survey on the Bok Telescope. Combining color, magnitude, and light-curve information, we identify three new RR Lyrae stars associated with Hercules. All three of these new RR Lyrae stars lie outside its published tidal radius. When considered with the nine RR Lyrae stars already known within the tidal radius, these results suggest that a substantial fraction of Hercules’ stellar content has been stripped. With this degree of tidal disruption, Hercules is an interesting case between a visibly disrupted dwarf (such as the Sagittarius dwarf spheroidal galaxy) and one in dynamic equilibrium. The degree of disruption also shows that we must be more careful with the ways we determine object membership when estimating dwarf masses in the future. One of the three discovered RR Lyrae stars sits along the minor axis of Hercules, but over two tidal radii away. This type of debris is consistent with recent models that suggest Hercules’ orbit is aligned with its minor axis.

  6. An experiment in big data: storage, querying and visualisation of data taken from the Liverpool Telescope's wide field cameras

    Science.gov (United States)

    Barnsley, R. M.; Steele, Iain A.; Smith, R. J.; Mawson, Neil R.

    2014-07-01

    The Small Telescopes Installed at the Liverpool Telescope (STILT) project has been in operation since March 2009, collecting data with three wide field unfiltered cameras: SkycamA, SkycamT and SkycamZ. To process the data, a pipeline was developed to automate source extraction, catalogue cross-matching, photometric calibration and database storage. In this paper, modifications and further developments to this pipeline will be discussed, including a complete refactor of the pipeline's codebase into Python, migration of the back-end database technology from MySQL to PostgreSQL, and changing the catalogue used for source cross-matching from USNO-B1 to APASS. In addition to this, details will be given relating to the development of a preliminary front-end to the source extracted database which will allow a user to perform common queries such as cone searches and light curve comparisons of catalogue and non-catalogue matched objects. Some next steps and future ideas for the project will also be presented.

  7. Development of digital system for the wide-field x-ray imaging detector aboard Kanazawa-SAT3

    Science.gov (United States)

    Kagawa, Yasuaki; Yonetoku, Daisuke; Sawano, Tatsuya; Mihara, Tatehiro; Kyutoku, Koutarou; Ikeda, Hirokazu; Yoshida, Kazuki; Ina, Masao; Ota, Kaichi; Suzuki, Daichi; Miyao, Kouga; Watanabe, Syouta; Hatori, Satoshi; Kume, Kyo; Mizushima, Satoshi; Hasegawa, Takashi

    2017-08-01

    We are planning to launch a micro satellite, Kanazawa-SAT3 , at the end of FY2018 to localize X-ray transients associated with gravitational wave sources. Now we are testing a prototype model of wide-field Xray imaging detector named T-LEX (Transient Localization EXperiment). T-LEX is an orthogonally distributed two sets of 1-dimensional silicon strip detectors with coded aperture masks, and covers more than 1 steradian field of view in the energy range of 1 - 20 keV. Each dimension has 512 readout electrodes (totally 1,024 channels), and they are read out with application specific integrated circuits (ASICs) controlled by two onboard FPGAs. Moreover, each FPGA calculates the cross correlation between the X-ray intensity and mask patterns every 64 msec, makes a histogram of lightcurves and energy spectra, and also plays a role of telemetry/command interface to mission CPU. In this paper, we report an overview of digital electronics system. Especially, we focus on the high-speed imaging processor on FPGA and demonstrate its performance as an X-ray imaging system.

  8. Gradient Permittivity Meta-Structure model for Wide-field Super-resolution imaging with a sub-45 nm resolution.

    Science.gov (United States)

    Cao, Shun; Wang, Taisheng; Xu, Wenbin; Liu, Hua; Zhang, Hongxin; Hu, Bingliang; Yu, Weixing

    2016-03-21

    A gradient permittivity meta-structure (GPMS) model and its application in super-resolution imaging were proposed and discussed in this work. The proposed GPMS consists of alternate metallic and dielectric films with a gradient permittivity which can support surface plasmons (SPs) standing wave interference patterns with a super resolution. By employing the rigorous numerical FDTD simulation method, the GPMS was carefully simulated to find that the period of the SPs interference pattern is only 84 nm for a 532 nm incident light. Furthermore, the potential application of the GPMS for wide-field super-resolution imaging was also discussed and the simulation results show that an imaging resolution of sub-45 nm can be achieved based on the plasmonic structure illumination microscopic method, which means a 5.3-fold improvement on resolution has been achieved in comparison with conventional epifluorescence microscopy. Moreover, besides the super-resolution imaging application, the proposed GPMS model can also be applied for nanolithography and other areas where super resolution patterns are needed.

  9. Cross-Comparative Analysis of GF-1 Wide Field View and Landsat-7 Enhanced Thematic Mapper Plus Data

    Science.gov (United States)

    Wei, X.-Q.; Gu, X.-F.; Meng, Q.-Y.; Yu, T.; Jia, K.; Zhan, Y.-L.; Wang, Ch.-M.

    2017-11-01

    The wide field view (WFV) sensor on-board GF-1 satellite can acquire multi-spectral data with moderate spatial resolution, which holds great potential for monitoring the Earth's surface. This study assesses WFV data through cross-comparison of spectral band reflectances and vegetation indices with Landsat-7 Enhanced Thematic Mapper plus (ETM+) data. The four vegetation indices considered in this study are the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), the ratio vegetation index (RVI), and the soil adjusted vegetation index (SAVI). The R2 between the WFV and ETM+ data were 0.82, 0.89, 0.92, and 0.80 for the blue, green, red, and near-infrared bands reflectance, and 0.90, 0.84, 0.83, and 0.91 for NDVI, EVI, RVI, and SAVI, respectively. The results displayed a high correlation between the spectral reflectances and vegetation indices of the two sensors' data, which indicated the reliability of the WFV data. Furthermore, the WFV data were better than the ETM+ data with regards to spatial and temporal resolutions.

  10. Wide field of view tabletop light field display based on piece-wise tracking and off-axis pickup

    Science.gov (United States)

    Zhu, Yanhong; Sang, Xinzhu; Yu, Xunbo; Wang, Peng; Xing, Shujun; Chen, Duo; Yan, Binbin; Wang, Kuiru; Yu, Chongxiu

    2017-11-01

    A wide field of view (FOV) tabletop light field display (LFD) based on piece-wise tracking and off-axis pickup is presented to display the floating three-dimensional (3D) scene, which is 360°surrounding viewable. The demonstrated LFD is specially designed with an integral imaging display (IID) with 83 × 83 viewpoints and a full-parallax holographic functional screen (HFS). To improve the FOV, a piece-wise tracking based FOV enhancement method is proposed. The relationship between the viewing zone and the elemental images (EIs) is formulated. A ray-tracing based method using off-axis pickup instead of parallel pickup directly is adopted to render the 3D scene to EIs. Then the piece-wise tracking method of varying the viewing zone by placing the EIs according to the position of viewer is analyzed. The floating 3D scene with a FOV of 70° × 70°is experimentally demonstrated with a good 3D perception.

  11. ON THE BINARY FREQUENCY OF THE LOWEST MASS MEMBERS OF THE PLEIADES WITH HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, E. V. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff (United States); Dupuy, Trent J. [The University of Texas at Austin, Department of Astronomy, 2515 Speedway C1400, Austin, TX 78712 (United States); Allers, Katelyn N. [Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Liu, Michael C. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Deacon, Niall R., E-mail: eugenio.v.garcia@gmail.com [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, AL1 5TL (United Kingdom)

    2015-05-01

    We present the results of a Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging survey of 11 of the lowest mass brown dwarfs in the Pleiades known (25–40 M{sub Jup}). These objects represent the predecessors to T dwarfs in the field. Using a semi-empirical binary point-spread function (PSF)-fitting technique, we are able to probe to 0.″ 03 (0.75 pixel), better than 2x the WFC3/UVIS diffraction limit. We did not find any companions to our targets. From extensive testing of our PSF-fitting method on simulated binaries, we compute detection limits which rule out companions to our targets with mass ratios of ≳0.7 and separations ≳4 AU. Thus, our survey is the first to attain the high angular resolution needed to resolve brown dwarf binaries in the Pleiades at separations that are most common in the field population. We constrain the binary frequency over this range of separation and mass ratio of 25–40 M{sub Jup} Pleiades brown dwarfs to be <11% for 1σ (<26% at 2σ). This binary frequency is consistent with both younger and older brown dwarfs in this mass range.

  12. A wide-field TCSPC FLIM system based on an MCP PMT with a delay-line anode.

    Science.gov (United States)

    Becker, Wolfgang; Hirvonen, Liisa M; Milnes, James; Conneely, Thomas; Jagutzki, Ottmar; Netz, Holger; Smietana, Stefan; Suhling, Klaus

    2016-09-01

    We report on the implementation of a wide-field time-correlated single photon counting (TCSPC) method for fluorescence lifetime imaging (FLIM). It is based on a 40 mm diameter crossed delay line anode detector, where the readout is performed by three standard TCSPC boards. Excitation is performed by a picosecond diode laser with 50 MHz repetition rate. The photon arrival timing is obtained directly from the microchannel plates, with an instrumental response of ∼190 to 230 ps full width at half maximum depending on the position on the photocathode. The position of the photon event is obtained from the pulse propagation time along the two delay lines, one in x and one in y. One end of a delay line is fed into the "start" input of the corresponding TCSPC board, and the other end is delayed by 40 ns and fed into the "stop" input. The time between start and stop is directly converted into position, with a resolution of 200-250 μm. The data acquisition software builds up the distribution of the photons over their spatial coordinates, x and y, and their times after the excitation pulses, typically into 512 × 512 pixels and 1024 time channels per pixel. We apply the system to fluorescence lifetime imaging of cells labelled with Alexa 488 phalloidin in an epi-fluorescence microscope and discuss the application of our approach to other fluorescence microscopy methods.

  13. Measuring galaxy [O ii] emission line doublet with future ground-based wide-field spectroscopic surveys

    Science.gov (United States)

    Comparat, Johan; Kneib, Jean-Paul; Bacon, Roland; Mostek, Nick J.; Newman, Jeffrey A.; Schlegel, David J.; Yèche, Christophe

    2013-11-01

    The next generation of wide-field spectroscopic redshift surveys will map the large-scale galaxy distribution in the redshift range 0.7 ≤ z ≤ 2 to measure baryonic acoustic oscillations (BAO). The primary optical signature used in this redshift range comes from the [Oii] emission line doublet, which provides a unique redshift identification that can minimize confusion with other single emission lines. To derive the required spectrograph resolution for these redshift surveys, we simulate observations of the [Oii] (λλ 3727, 3729) doublet for various instrument resolutions, and line velocities. We foresee two strategies for the choice of the resolution for future spectrographs for BAO surveys. For bright [Oii] emitter surveys ([Oii] flux ~30 × 10-17 erg cm-2 s-1 like SDSS-IV/eBOSS), a resolution of R ~ 3300 allows the separation of 90 percent of the doublets. The impact of the sky lines on the completeness in redshift is less than 6 percent. For faint [Oii] emitter surveys ([Oii] flux ~10 × 10-17 erg cm-2 s-1 like DESi), the detection improves continuously with resolution, so we recommend the highest possible resolution, the limit being given by the number of pixels (4k by 4k) on the detector and the number of spectroscopic channels (2 or 3).

  14. A wide-field TCSPC FLIM system based on an MCP PMT with a delay-line anode

    Science.gov (United States)

    Becker, Wolfgang; Hirvonen, Liisa M.; Milnes, James; Conneely, Thomas; Jagutzki, Ottmar; Netz, Holger; Smietana, Stefan; Suhling, Klaus

    2016-09-01

    We report on the implementation of a wide-field time-correlated single photon counting (TCSPC) method for fluorescence lifetime imaging (FLIM). It is based on a 40 mm diameter crossed delay line anode detector, where the readout is performed by three standard TCSPC boards. Excitation is performed by a picosecond diode laser with 50 MHz repetition rate. The photon arrival timing is obtained directly from the microchannel plates, with an instrumental response of ˜190 to 230 ps full width at half maximum depending on the position on the photocathode. The position of the photon event is obtained from the pulse propagation time along the two delay lines, one in x and one in y. One end of a delay line is fed into the "start" input of the corresponding TCSPC board, and the other end is delayed by 40 ns and fed into the "stop" input. The time between start and stop is directly converted into position, with a resolution of 200-250 μm. The data acquisition software builds up the distribution of the photons over their spatial coordinates, x and y, and their times after the excitation pulses, typically into 512 × 512 pixels and 1024 time channels per pixel. We apply the system to fluorescence lifetime imaging of cells labelled with Alexa 488 phalloidin in an epi-fluorescence microscope and discuss the application of our approach to other fluorescence microscopy methods.

  15. Argus+: The Future of Wide-Field, Spectral-Line Imaging at 3-mm with the Green Bank Telescope

    Science.gov (United States)

    Maddalena, Ronald; Frayer, David; Lockman, Felix; O'Neil, Karen; White, Steven; Argus+ Collaboration

    2018-01-01

    The Robert C Byrd Green Bank Telescope has met its design goal of providing high-quality observations at 115 GHz. Observers also have access to the new, 16-pixel, 3-mm Argus receiver, which is providing high-dynamic range images over wide fields for the multitude of spectral lines between 85 and 115 GHz, including CO, 13CO, C18O, SiO, HCN, HCO+, HNC, N2H+, and CS. The small number of pixels in Argus limits its ability to map many of the most interesting objects whose extent exceeds many arc-minutes. The successful performance of Argus, and its modular design, demonstrates that receivers with many more pixels could be built for the GBT. A 12 x 12 array of the Argus design would have mapping speeds about nine times faster than Argus without suffering any degradation in performance for the outer pixels in the array. We present our plans to build the next-generation Argus instrument (Argus+) with 144-pixels, a footprint 5’x5’, and 7" resolution at 110 GHz. The project will be a collaboration between the Green Bank Observatory and university groups, who will supply key components. The key science drivers for Argus+ are studies of molecular filaments in the Milky Way, studies of molecular clouds in nearby galaxies, and the observations of rapidly evolving solar system objects.

  16. Visual enhancement of laparoscopic nephrectomies using the 3-CCD camera

    Science.gov (United States)

    Crane, Nicole J.; Kansal, Neil S.; Dhanani, Nadeem; Alemozaffar, Mehrdad; Kirk, Allan D.; Pinto, Peter A.; Elster, Eric A.; Huffman, Scott W.; Levin, Ira W.

    2006-02-01

    Many surgical techniques are currently shifting from the more conventional, open approach towards minimally invasive laparoscopic procedures. Laparoscopy results in smaller incisions, potentially leading to less postoperative pain and more rapid recoveries . One key disadvantage of laparoscopic surgery is the loss of three-dimensional assessment of organs and tissue perfusion. Advances in laparoscopic technology include high-definition monitors for improved visualization and upgraded single charge coupled device (CCD) detectors to 3-CCD cameras, to provide a larger, more sensitive color palette to increase the perception of detail. In this discussion, we further advance existing laparoscopic technology to create greater enhancement of images obtained during radical and partial nephrectomies in which the assessment of tissue perfusion is crucial but limited with current 3-CCD cameras. By separating the signals received by each CCD in the 3-CCD camera and by introducing a straight forward algorithm, rapid differentiation of renal vessels and perfusion is accomplished and could be performed real time. The newly acquired images are overlaid onto conventional images for reference and comparison. This affords the surgeon the ability to accurately detect changes in tissue oxygenation despite inherent limitations of the visible light image. Such additional capability should impact procedures in which visual assessment of organ vitality is critical.

  17. Design, analysis, and testing of a CCD array mounting structure

    Science.gov (United States)

    Sultana, John A.; O'Neill, Mark B.

    1991-12-01

    A method has been developed for mounting charge-coupled device (CCD) arrays in an optical telescope so as to minimize thermal defocusing errors. The mounting arrangement was developed for a six-inch aperture, visible band, off-axis reimaging telescope attached to an experimental satellite. The mounting arrangement consists of two pieces: a fiberglass frame which holds the actively cooled CCD package and provides thermal isolation from the telescope body; and a titanium flexure, which acts to minimize structural distortions caused by the difference in thermal expansion properties of the CCD array and the telescope body. This paper describes the design, analysis, and testing of this CCD array mounting arrangement. A detailed finite-element model of the CCD array and the mount was developed and used to predict thermally-induced defocus and gravity sag deformations, as well as natural frequencies. Experimental tests to verify the computer model results were performed using holographic interferometry. Vibration tests were also performed to verify the natural frequencies as well as structural integrity during launch. A comparison of the computer model predictions and the holographic interferometric measurements of thermally-induced defocussing indicates agreement to within 15 to 20%. Both the experimental and computer results indicate that the mounting structure provides focus stability over the operational temperature range of the telescope with sufficient structural integrity to survive the anticipated spacecraft launch loads.

  18. CCD Astrophotography High-Quality Imaging from the Suburbs

    CERN Document Server

    Stuart, Adam

    2006-01-01

    This is a reference book for amateur astronomers who have become interested in CCD imaging. Those glorious astronomical images found in astronomy magazines might seem out of reach to newcomers to CCD imaging, but this is not the case. Great pictures are attainable with modest equipment. Adam Stuart’s many beautiful images, reproduced in this book, attest to the quality of – initially – a beginner’s efforts. Chilled-chip astronomical CCD-cameras and software are also wonderful tools for cutting through seemingly impenetrable light-pollution. CCD Astrophotography from the Suburbs describes one man’s successful approach to the problem of getting high-quality astronomical images under some of the most light-polluted conditions. Here is a complete and thoroughly tested program that will help every CCD-beginner to work towards digital imaging of the highest quality. It is equally useful to astronomers who have perfect observing conditions, as to those who have to observe from light-polluted city skies.

  19. Purification and crystallization of Vibrio fischeri CcdB and its complexes with fragments of gyrase and CcdA

    Energy Technology Data Exchange (ETDEWEB)

    De Jonge, Natalie, E-mail: ndejonge@vub.ac.be; Buts, Lieven; Vangelooven, Joris [Department of Molecular and Cellular Interactions, VIB, Pleinlaan 2, 1050 Brussels (Belgium); Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); Mine, Natacha; Van Melderen, Laurence [Laboratoire de Génétique des Procaryotes, Institut de Biologie et de Médecine, Université Libre de Bruxelles, Gosselies (Belgium); Wyns, Lode; Loris, Remy [Department of Molecular and Cellular Interactions, VIB, Pleinlaan 2, 1050 Brussels (Belgium); Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium)

    2007-04-01

    A CcdB homologue from V. fischeri was overexpressed in E. coli and purified. The free protein was crystallized, as were its complexes with fragments of E. coli and V. fischeri gyrase and with the F-plasmid CcdA C-terminal domain. The ccd toxin–antitoxin module from the Escherichia coli F plasmid has a homologue on the Vibrio fischeri integron. The homologue of the toxin (CcdB{sub Vfi}) was crystallized in two different crystal forms. The first form belongs to space group I23 or I2{sub 1}3, with unit-cell parameter a = 84.5 Å, and diffracts to 1.5 Å resolution. The second crystal form belongs to space group C2, with unit-cell parameters a = 58.5, b = 43.6, c = 37.5 Å, β = 110.0°, and diffracts to 1.7 Å resolution. The complex of CcdB{sub Vfi} with the GyrA14{sub Vfi} fragment of V. fischeri gyrase crystallizes in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 53.5, b = 94.6, c = 58.1 Å, and diffracts to 2.2 Å resolution. The corresponding mixed complex with E. coli GyrA14{sub Ec} crystallizes in space group C2, with unit-cell parameters a = 130.1, b = 90.8, c = 58.1 Å, β = 102.6°, and diffracts to 1.95 Å. Finally, a complex between CcdB{sub Vfi} and part of the F-plasmid antitoxin CcdA{sub F} crystallizes in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 46.9, b = 62.6, c = 82.0 Å, and diffracts to 1.9 Å resolution.

  20. Mosaic Conservation Opportunity Areas - Conservativel Model (ECO_RES.COA_MOSAIC66)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The COA_Mosaic66 layer designates areas with potential for forest/grassland mosaic conservation. These are areas of natural or semi-natural forest/grassland land...

  1. Thinned back-illuminated CCD for x-ray microscopy

    Science.gov (United States)

    Meyer-Ilse, Werner; Wilhein, Thomas; Guttmann, Peter

    1993-07-01

    X-ray microscopy requires image detectors for soft x-rays (2.4 nm to 4.5 nm wavelength) with high detective quantum efficiency for a low radiation dosage applied to the sample. A thinned backside illuminated CCD has been attached to the Gottingen x-ray microscope, which is installed at the BESSY electron storage ring in Berlin. The CCD was a commercially available device with 1024 by 1024 pixels (each 24 micrometers square) without the anti-reflecting coating, which is applied to the standard device. First experiments performed at the primarily used x- ray wavelength of 2.4 nm show a considerable reduction of exposure time compared to the previously used photographic emulsion. This greatly reduces the radiation dose applied to the sample specimen. There was no degradation in performance of the CCD detected after one week of operation.

  2. Noise analysis for CCD-based ultraviolet and visible spectrophotometry.

    Science.gov (United States)

    Davenport, John J; Hodgkinson, Jane; Saffell, John R; Tatam, Ralph P

    2015-09-20

    We present the results of a detailed analysis of the noise behavior of two CCD spectrometers in common use, an AvaSpec-3648 CCD UV spectrometer and an Ocean Optics S2000 Vis spectrometer. Light sources used include a deuterium UV/Vis lamp and UV and visible LEDs. Common noise phenomena include source fluctuation noise, photoresponse nonuniformity, dark current noise, fixed pattern noise, and read noise. These were identified and characterized by varying light source, spectrometer settings, or temperature. A number of noise-limiting techniques are proposed, demonstrating a best-case spectroscopic noise equivalent absorbance of 3.5×10(-4)  AU for the AvaSpec-3648 and 5.6×10(-4)  AU for the Ocean Optics S2000 over a 30 s integration period. These techniques can be used on other CCD spectrometers to optimize performance.

  3. DepAstroCCD an original astrometric tool

    Directory of Open Access Journals (Sweden)

    Stojanović I.

    2006-01-01

    Full Text Available A complex software for preparation and treatment of astro photographic plates and double-star observations recorded with CCD cameras is developed. The preparation interface contains a catalogue base for the choice of observation objects and an interface for bringing into accordance the telescope and CCD camera performance with the assumptions of the postprocessor interface. The processing is based on the original development of image gradient removing software and classical FFT method and autocorrelation. The software has been tested on several theoretical and real images of double stars.

  4. Technology validation of the PLATO CCD at ESA

    Science.gov (United States)

    Prod'homme, Thibaut; Verhoeve, Peter; Beaufort, Thierry; Duvet, Ludovic; Lemmel, Frederic; Smit, Hans; Blommaert, Sander; Oosterbroek, Tim; van der Luijt, Cornelis; Visser, Ivo; Heijnen, Jerko; Butler, Bart

    2016-07-01

    PLATO { PLAnetary Transits and Oscillations of stars { is the third medium-class mission to be selected in the European Space Agency (ESA) Science and Robotic Exploration Cosmic Vision programme. Due for launch in 2025, the payload makes use of a large format (8 cm x 8 cm) Charge-Coupled Devices (CCDs) the e2v CCD270 operated at 4 MHz. The manufacture of such large device in large quantity constitutes an unprecedented effort. To de-risk the PLATO CCD procurement and aid the mission definition process, ESA's Payload Technology Validation team is characterizing the electro-optical performance of a number of PLATO devices before and after proton irradiation.

  5. ESA's CCD test bench for the PLATO mission

    Science.gov (United States)

    Beaufort, Thierry; Duvet, Ludovic; Bloemmaert, Sander; Lemmel, Frederic; Prod'homme, Thibaut; Verhoeve, Peter; Smit, Hans; Butler, Bart; van der Luijt, Cornelis; Heijnen, Jerko; Visser, Ivo

    2016-08-01

    PLATO { PLAnetary Transits and Oscillations of stars { is the third medium-class mission to be selected in the European Space Agency (ESA) Science and Robotic Exploration Cosmic Vision programme. Due for launch in 2025, the payload makes use of a large format (8 cm x 8 cm) Charge-Coupled Devices (CCDs), the e2v CCD270 operated at 4 MHz and at -70 C. To de-risk the PLATO CCD qualification programme initiated in 2014 and support the mission definition process, ESA's Payload Technology Validation section from the Future Missions Office has developed a dedicated test bench.

  6. Digital Printing Quality Detection and Analysis Technology Based on CCD

    Science.gov (United States)

    He, Ming; Zheng, Liping

    2017-12-01

    With the help of CCD digital printing quality detection and analysis technology, it can carry out rapid evaluation and objective detection of printing quality, and can play a certain control effect on printing quality. It can be said CDD digital printing quality testing and analysis of the rational application of technology, its digital printing and printing materials for a variety of printing equipments to improve the quality of a very positive role. In this paper, we do an in-depth study and discussion based on the CCD digital print quality testing and analysis technology.

  7. Wide Field-of-View Fluorescence Imaging with Optical-Quality Curved Microfluidic Chamber for Absolute Cell Counting

    Directory of Open Access Journals (Sweden)

    Mohiuddin Khan Shourav

    2016-07-01

    Full Text Available Field curvature and other aberrations are encountered inevitably when designing a compact fluorescence imaging system with a simple lens. Although multiple lens elements can be used to correct most such aberrations, doing so increases system cost and complexity. Herein, we propose a wide field-of-view (FOV fluorescence imaging method with an unconventional optical-quality curved sample chamber that corrects the field curvature caused by a simple lens. Our optics simulations and proof-of-concept experiments demonstrate that a curved substrate with lens-dependent curvature can reduce greatly the distortion in an image taken with a conventional planar detector. Following the validation study, we designed a curved sample chamber that can contain a known amount of sample volume and fabricated it at reasonable cost using plastic injection molding. At a magnification factor of approximately 0.6, the curved chamber provides a clear view of approximately 119 mm2, which is approximately two times larger than the aberration-free area of a planar chamber. Remarkably, a fluorescence image of microbeads in the curved chamber exhibits almost uniform intensity over the entire field even with a simple lens imaging system, whereas the distorted boundary region has much lower brightness than the central area in the planar chamber. The absolute count of white blood cells stained with a fluorescence dye was in good agreement with that obtained by a commercially available conventional microscopy system. Hence, a wide FOV imaging system with the proposed curved sample chamber would enable us to acquire an undistorted image of a large sample volume without requiring a time-consuming scanning process in point-of-care diagnostic applications.

  8. THE SIZE EVOLUTION OF PASSIVE GALAXIES: OBSERVATIONS FROM THE WIDE-FIELD CAMERA 3 EARLY RELEASE SCIENCE PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Outcome of universal newborn eye screening with wide-field digital retinal image acquisition system: a pilot study.

    Science.gov (United States)

    Goyal, P; Padhi, T R; Das, T; Pradhan, L; Sutar, S; Butola, S; Behera, U C; Jain, L; Jalali, S

    2017-07-24

    PurposeTo evaluate the outcome of universal newborn eye screening with wide-field digital retinal imaging (WFDRI) system.MethodsIn this pilot study, we examined 1152 apparently healthy newborn infants in the obstetrics and gynecology ward of a civil hospital in Eastern India over 1.5 years. The examination included external eye examination, red reflex test and fundus imaging by WFDRI (RetCam II, Clarity medical system, Pleasanton, CA, USA) by a trained optometrist. The pathologies detected, net monetary gain and skilled manpower saved were documented. The results were compared with three similar studies thus far published in the literature.ResultsOcular abnormality of any kind was seen in 172 (14.93%) babies. Retinal hemorrhage in 153 babies (88.9% of all abnormal findings) was the most common abnormality; it was bilateral in 118 (77.12%) babies and 4 babies had foveal hemorrhage. Other abnormalities included vitreous hemorrhage (n=1), congenital glaucoma (n=2), uveal coloboma (n=2), retinopathy mimicking retinopathy of prematurity (n=2), and cystic fovea (n=3). The retinal hemorrhages resolved spontaneously in all eyes. One baby with congenital glaucoma received surgery and the other was treated medically. The benefits included savings in skilled manpower, a net monetary gain of INR 4.195 million (US$ 62,612) and skilled manpower saving by 319.4 h.ConclusionsThe universal neonatal eye screening using WFDRI detected pathologies that needed immediate care or regular follow up; saved skilled manpower with a net monetary gain. But compared to a red reflex test the benefits were marginal in terms of detecting treatment warranting ocular pathologies.Eye advance online publication, 24 July 2017; doi:10.1038/eye.2017.129.

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

    Science.gov (United States)

    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.

  11. A deep, wide-field study of Holmberg II with Suprime-Cam: evidence for ram pressure stripping

    Science.gov (United States)

    Bernard, Edouard J.; Ferguson, Annette M. N.; Barker, Michael K.; Irwin, Michael J.; Jablonka, Pascale; Arimoto, Nobuo

    2012-11-01

    We present a deep, wide-field optical study of the M81 group dwarf galaxy Holmberg II (HoII) based on Subaru/Suprime-Cam imaging. Individual stars are resolved down to I ˜ 25.2, that is, about 1.5 mag below the tip of the red giant branch (RGB). We use resolved star counts in the outskirts of the galaxy to measure the radial surface brightness profile down to μV ˜ 32 mag arcsec-2, from which we determine a projected exponential scalelength of 0.70 ± 0.01 arcmin (i.e. 0.69 ± 0.01 kpc). The composite profile, ranging from the cored centre out to R = 7 arcmin, is best fitted by an Elson-Fall-Freeman profile which gives a half-light radius of 1.41 ± 0.04 arcmin (i.e. 1.39 ± 0.04 kpc), and an absolute magnitude MV = -16.3. The low surface brightness stellar component of HoII is regular and symmetric and has an extent much smaller than the vast H I cloud in which it is embedded. We compare the spatial distribution of the young, intermediate-age and old stellar populations, and find that the old RGB stars are significantly more centrally concentrated than the young stellar populations, contrary to what is observed in most dwarf galaxies of the local Universe. We discuss these properties in the context of the comet-like distribution of H I gas around HoII, and argue for the presence of a hot intragroup medium in the vicinity of HoII to explain the contrasting morphologies of gas and stars. Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  12. Quantitative analysis of wide field-of-view and broadband quarter-wave plate based on metasurface

    Science.gov (United States)

    Chen, Yanjun; Guo, Zhe; Liu, Ke; Liu, Lihui; Li, Yanqiu

    2018-01-01

    As the numerical aperture (NA) of the projection objective increases continually and the exposure pattern feature size decreases gradually, the polarization illumination is introduced into the lithography system. Therefore, it is necessary to design a wide field-of-view (FOV) wave plate to eliminate the effect of oblique incident light on the phase delay of the traditional zero order wave plate effectively. The quarter-wave plate with 20° FOV based on birefringent optical crystals has been designed in our laboratory by Dong et al. In order to obtain a wider FOV, we explore a previously reported Ag patch ultrathin quarter-wave plate whose performances were not analyzed by finite-difference time-domain (FDTD) method. In this paper, we mainly investigate three performances of the Ag patch quarter-wave plate consisting of FOV, achromatic band and achromatic band transmission. The simulation results indicate that when phase difference error is controlled at +/-2° (1) the range of FOV of the quarter-wave plate is +/-29° at 632nm; (2) the achromatic band ranges from 618nm to 658nm at normal incidence; (3) the achromatic band transmission ranges from 11% to 30%. Compared with the traditional wave plate made of birefringent crystals, the achromatic band and transmission is slightly lower but the FOV of this quarter-wave plate is much wider. Thus, this Ag patch nanoscale wide FOV quarter-wave plate can be effectively used in high NA lithography projection exposure systems to reduce the polarization aberration caused by oblique incidence of light.

  13. THE HUBBLE WIDE FIELD CAMERA 3 TEST OF SURFACES IN THE OUTER SOLAR SYSTEM: SPECTRAL VARIATION ON KUIPER BELT OBJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, Wesley C. [Herzberg Institute of Astrophysics, 5071 West Saanich Road Victoria, BC V9E 2E7 (Canada); Brown, Michael E. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91101 (United States); Glass, Florian, E-mail: wesley.fraser@nrc.ca [Observatoire de Genve, Universit de Genve, 51 chemin des Maillettes, CH-1290 Sauverny (Switzerland)

    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.

  14. Detector Control and Data Acquisition for the Wide-Field Infrared Survey Telescope (WFIRST) with a Custom ASIC

    Science.gov (United States)

    Smith, Brian S.; Loose, Markus; Alkire, Greg; Joshi, Atul; Kelly, Daniel; Siskind, Eric; Rossetti, Dino; Mah, Jonathan; Cheng, Edward; Miko, Laddawan; hide

    2016-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) will have the largest near-IR focal plane ever flown by NASA, a total of 18 4K x 4K devices. The project has adopted a system-level approach to detector control and data acquisition where 1) control and processing intelligence is pushed into components closer to the detector to maximize signal integrity, 2) functions are performed at the highest allowable temperatures, and 3) the electronics are designed to ensure that the intrinsic detector noise is the limiting factor for system performance. For WFIRST, the detector arrays operate at 90 to 100 K, the detector control and data acquisition functions are performed by a custom ASIC at 150 to 180 K, and the main data processing electronics are at the ambient temperature of the spacecraft, notionally approx.300 K. The new ASIC is the main interface between the cryogenic detectors and the warm instrument electronics. Its single-chip design provides basic clocking for most types of hybrid detectors with CMOS ROICs. It includes a flexible but simple-to-program sequencer, with the option of microprocessor control for more elaborate readout schemes that may be data-dependent. All analog biases, digital clocks, and analog-to-digital conversion functions are incorporated and are connected to the nearby detectors with a short cable that can provide thermal isolation. The interface to the warm electronics is simple and robust through multiple LVDS channels. It also includes features that support parallel operation of multiple ASICs to control detectors that may have more capability or requirements than can be supported by a single chip.

  15. Atmospheric characterization of five hot Jupiters with the wide field Camera 3 on the Hubble space telescope

    Energy Technology Data Exchange (ETDEWEB)

    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 μm) 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 μm, 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 1σ 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 1σ 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.

  16. Atmospheric Characterization of Five Hot Jupiters with the Wide Field Camera 3 on the Hubble Space Telescope

    Science.gov (United States)

    Ranjan, Sukrit; Charbonneau, David; Desert, Jean-Michel; Madhusudhan, Nikku; Deming, Drake; Wilkins, Ashlee; Mandell, Avi M.

    2014-01-01

    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 micrometers) 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 micrometers, 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 1s 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 sigma precision per bin corresponds to a planet-to-star flux ratio of 1.5 x 10(exp -4) and 2.1 x 10(exp -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.

  17. Astrometric CCD Observations of Three Double Stars Measurements

    Science.gov (United States)

    Nand, Angela

    2017-04-01

    CCD astrometric observations of three double star groups from the Orion constellation were made. Position angles and separations of corresponding pairs were obtained from the data acquired and compared to previous observations listed in the Washington Double Star Catalog. Present data agrees with previous observational data.

  18. CCD Measurements of WDS 13510+6819 STTA127

    Science.gov (United States)

    Alzaben, Faisal; Vasilenko, Dmitrii; Ganbold, Gunbold; McClanahan, Stuart; Boyce, Pat; Boyce, Grady

    2017-07-01

    WDS 13510+6819, a three-star star system, discoverer code STTA 127, is imaged using CCD cameras for astrometric measurements in comparison to historic data contained in the Washington Double Star Catalog. The historical data outlines measurements between the A-B and the B-C components and the 2016 measurements support the trend outlined in the WDS Historical File.

  19. Developments in X-ray and astronomical CCD imagers

    CERN Document Server

    Gregory, J A; Kosicki, B B; Reich, R K

    1999-01-01

    There have been many recent developments in the attributes and capabilities of silicon-based CCD detectors for use in space and ground-based astronomy. The imagers used as X-ray detectors require very low noise and excellent quantum efficiency over the energy range of 200-10000 eV. This is achieved using a combination of front and back-illuminated imagers fabricated on a 5000 OMEGA-cm resistivity material. A requirement for ground-based imagers is very good sensitivity between 350 and 1000 nm, as well as low noise and a high degree of spatial uniformity. We will describe the fabrication and performance of these imagers. Special features integrated into the CCD pixel architecture have increased the capability of the imagers. A fast electronic shutter has been developed for a wavefront sensor in an adaptive optics system. An orthogonal transfer CCD has been designed to compensate for the image motion relative to the CCD focal plane. Also, an antiblooming drain process has been developed so bright sources do not...

  20. A GRAPH READER USING A CCD IMAGE SENSOR

    African Journals Online (AJOL)

    2008-01-18

    Jan 18, 2008 ... 3. Data Processing. The microcontroller, the CCD sensor, the stepper motor and the rest of the system are interfaced to the PC where data processing and overall control are done. A software program in. QUICKBASIC is used to process the pixels. First the 1024 pixels of an image line are received from the.

  1. Storage and compression design of high speed CCD

    Science.gov (United States)

    Cai, Xichang; Zhai, LinPei

    2009-05-01

    In current field of CCD measurement, large area and high resolution CCD is used to obtain big measurement image, so that, speed and capacity of CCD requires high performance of later storage and process system. The paper discusses how to use SCSI hard disk to construct storage system and use DSPs and FPGA to realize image compression. As for storage subsystem, Because CCD is divided into multiplex output, SCSI array is used in RAID0 way. The storage system is com posed of high speed buffer, DM A controller, control M CU, SCSI protocol controller and SCSI hard disk. As for compression subsystem, according to requirement of communication and monitor system, the output is fixed resolution image and analog PA L signal. The compression means is JPEG 2000 standard, in which, 9/7 wavelets in lifting format is used. 2 DSPs and FPGA are used to com pose parallel compression system. The system is com posed of FPGA pre-processing module, DSP compression module, video decoder module, data buffer module and communication module. Firstly, discrete wavelet transform and quantization is realized in FPGA. Secondly, entropy coding and stream adaption is realized in DSPs. Last, analog PA L signal is output by Video decoder. Data buffer is realized in synchronous dual-port RAM and state of subsystem is transfer to controller. Through subjective and objective evaluation, the storage and compression system satisfies the requirement of system.

  2. Diagnostics of the CCD using the mesh experiment

    CERN Document Server

    Tsunemi, H; Mori, K; Yoshita, K; Miyata, E

    1999-01-01

    We present here the results of a mesh experiment with which we can measure the shape of a charge cloud generated by the photoabsorption of X-rays inside a charge-coupled device (CCD). The mesh used is made of gold of 13-mu m thickness, and has many holes of 1.4 mu m diameter spaced 48 mu m apart. The CCD used has 12 mu m square pixels. A new criterion with which we can determine the precise alignment in the experiment is introduced to eliminate uncertainties. We measured the charge cloud size at three X-ray energies: Al-K (1.5 keV), Mo-L (2.3 keV) and Ti-K (4.5 keV). The shapes can be well represented not by a point-symmetric Gaussian function, but by an axial symmetric Gaussian function with sigma of 0.7-1.5 mu m. The charge cloud size depends weakly on the mean absorption length in silicon. We find that the charge cloud size can be well explained by a simple model inside the CCD. We discuss that the knowledge of the charge cloud size will enable us to improve the position resolution of the CCD.

  3. A luminescence imaging system based on a CCD camera

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.; Markey, B.G.

    1997-01-01

    described here has a maximum spatial resolution of 17 mu m; though this may be varied under software control to alter the signal-to-noise ratio. The camera has been mounted on a Riso automated TL/OSL reader, and both the reader and the CCD are under computer control. In the near u.v and blue part...

  4. Wide-Field Survey around Local Group Dwarf Spheroidal Galaxy Leo II: Spatial Distribution of Stellar Content

    Science.gov (United States)

    Komiyama, Yutaka; Doi, Mamoru; Furusawa, Hisanori; Hamabe, Masaru; Imi, Katsumi; Kimura, Masahiko; Miyazaki, Satoshi; Nakata, Fumiaki; Okada, Norio; Okamura, Sadanori; Ouchi, Masami; Sekiguchi, Maki; Shimasaku, Kazuhiro; Yagi, Masafumi; Yasuda, Naoki

    2007-08-01

    We carried out a wide-field V, I imaging survey of the Local Group dwarf spheroidal galaxy Leo II using the Subaru Prime Focus Camera on the 8.2 m Subaru Telescope. The survey covered an area of 26.67×26.67 arcmin2, far beyond the tidal radius of Leo II (8.63'), down to the limiting magnitude of V~=26, which is roughly 1 mag deeper than the turnoff point of the main-sequence stars of Leo II. Radial number density profiles of bright and faint red giant branch (RGB) stars were found to change their slopes at around the tidal radius, and extend beyond the tidal radius with shallower slopes. A smoothed surface brightness map of Leo II suggests the existence of a small substructure (4×2.5 arcmin2, 270×170 pc 2 in physical size) of globular cluster luminosity beyond the tidal radius. We investigated the properties of the stellar population by means of a color-magnitude diagram. The horizontal branch (HB) morphology index shows a radial gradient in which red HB stars are more concentrated than blue HB stars, which is common to many Local Group dwarf spheroidal galaxies. The color distribution of RGB stars around the mean RGB sequence shows a larger dispersion at the center than in the outskirts, indicating a mixture of stellar populations at the center and a more homogeneous population in the outskirts. Based on the age estimation using subgiant branch stars, we found that although the major star formation took place ~8 Gyr ago, a considerable stellar population younger than 8 Gyr is found at the center; such a younger population is insignificant in the outskirts. The following star formation history is suggested for Leo II. Star-forming activity occurred more than ~8 Gyr ago throughout the galaxy at a modest star formation rate. The star-forming region gradually shrank from the outside toward the center, and star-forming activity finally dropped to ~0 by ~4 Gyr ago, except for the center, where a small population younger than 4 Gyr is present. Based on data collected

  5. Stellar photometry in the inner bulge of M31 using the Hubble Space Telescope wide field camera

    Science.gov (United States)

    Rich, R. M.; Mighell, K. J.

    1995-01-01

    We present photometry of two fields in the M31 bulge imaged with the Hubble Space Telescope (HST) Wide-Field Camara (WFC). The nuclear field (r less than 40 arcsecs = 150 pc) giant branch extends to I = 19.5, M(sub I) = -5 (Cousins system), a full 0.9 mag brighter than the giant-branch tips of metal-poor Galactic globular clusters and M31 halo fields. This is also approximately = 1.5 mag brighter than the giant branches of metal-rich Galactic globular clusters, but is no brighter than Mould's (1986) M31 bulge field 1 kpc from the nucleus. The data also suggest that the brighter stars may be preferentially concentrated to the center. The 648 luminous stars detected in 2 x 10(exp 9) solar luminosity is approximately = 25% that expected from a hypothetical population of evolved asymptotic giant branch (AGB) stars with lifetimes approximately = 10(exp 5) yr, with the cautionary note that we are near the detection limit. The number of bright stars is also consistent with the progeny of blue stragglers, if one uses a lifetime for the thermal-pulsing AGB of 2 x 10(exp 6) yr. We strongly caution that incompleteness becomes severe below I = 19.9 mag and that future surveys are likely to find numbers of bright stars too large to accomodate the blue straggler progeny hypothesis. We have imaged an additional field 2 arcmin = 500 pc south of the nucleus. The brightest stars in this field are also I = 19.5, but bright stars appear less numerous than in the nuclear field. If the population resembles that of the Galactic bulge, then M(sub bol) = -4.5 is a lower limit to the giant-branch tip luminosity; infrared studies should reveal stars 0.5 mag or more brighter. Either high-metallicity or (more likely) age approximately = 10 Gyr may be responsible for the presence of these luminous AGB stars. These observations confirm that previous ground-based infrared studies (e.g., Rich & Mould 1991) very likely detect an extended giant branch and not spurious luminous stars caused by

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

    Science.gov (United States)

    Tamura, Naoyuki

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

  7. ProtoEXIST2: Advanced Wide-field Imaging CZT Detector Development For The HET On The Proposed EXIST Mission

    Science.gov (United States)

    Hong, JaeSub; Allen, B.; Grindlay, J.; Barthelmy, S.; Baker, R.; Gehrels, N.; Cook, W.; Kaye, S.; Harrison, F.

    2010-03-01

    We describe our development of ProtoEXIST2, the advanced CZT imaging detector and wide field telescope prototype for the High Energy Telescope (HET) on the proposed Energetic X-ray Imaging Survey Telescope (EXIST) mission. EXIST is a multi-wavelength Medium class mission which would explore the early Universe using high redshift Gamma-ray Bursts and survey black holes on all scales. ProtoEXIST2 will demonstrate the feasibility of a large scale imaging module (256 cm2) with a close-tiled array of fine pixel (0.6 mm) CZT with a balloon flight test in 2010 or 2011. This second generation close-tiled CZT imager follows ProtoEXIST1, which had a recent successful balloon flight (see Allen et al in this meeting) using the same area CZT detector module (256 cm2) but with larger pixel size (2.5mm). For signal readout and event processing, we use the Direct-Bond (DB) ASIC, developed for the NuSTAR mission to be used in a close-tiled 2 x 2 array of 2x2 cm2 CZT detectors, each with 32x32 pixels. The DB-ASIC is attractive for a large scale implementation of tiled imaging CZT detectors given its low noise and power consumption (70uW/pixel). We are developing readout for the DB-ASIC that incorporates our back-end FPGA readout architecture developed for ProtoEXIST1 in order to accomplish the 256 cm2 detector module area with totally vertical integration (i.e. no auxialliary boards to the sides of the module. This is required to tile large numbers of modules into the very large total area (4.5m^2) proposed for the HET on EXIST. We review the design of the EXIST/HET and its optimum shielding in light of our ProtoEXIST1 balloon flight and our plan for future development of ProtoEXIST3, a final EXIST/HET detector module that would incorporate a still lower power version of the DB ASIC.

  8. [Revertant somatic mosaicism in primary immunodeficiency diseases].

    Science.gov (United States)

    Wada, Taizo

    2014-01-01

    Revertant somatic mosaicism has been described in an increasing number of genetic disorders including primary immunodeficiency diseases. Both back mutations leading to restoration of wild-type sequences and second-site mutations resulting in compensatory changes have been demonstrated in mosaic individuals. Recent studies identifying revertant somatic mosaicism caused by multiple independent genetic changes further support its frequent occurrence in primary immunodeficiency diseases. Revertant mosaicism acquires a particular clinical relevance because it may lead to selective growth advantage of the corrected cells, resulting in improvement of disease symptoms or atypical clinical presentations. This phenomenon also provides us unique opportunities to evaluate the biological effects of restored gene expression in different cell lineages. Here we review the recent findings of revertant somatic mosaicism in primary immunodeficiency diseases and discuss its clinical implications.

  9. Gold detector: modular CCD area detector for macromolecular crystallography

    Science.gov (United States)

    Naday, Istvan; Ross, Stephan W.; Kanyo, Miklos; Westbrook, Mary L.; Westbrook, Edwin M.; Phillips, Walter C.; Stanton, Martin J.; O'Mara, Daniel M.

    1995-04-01

    We have designed, fabricated, and tested a modular CCD area detector system for macromolecular crystallography at synchrotron x-ray sources, code-named the `gold' detector system. The sensitive area of the detector is 150 mm X 150 mm, with 3,072 X 3,072 pixel sampling, resulting in roughly a 50 micrometers pixel raster. The x-ray image formed on the face of the detector is converted to visible light by a thin phosphor layer. This image is transferred optically to nine CCD sensors by nine square fiberoptic tapers (one for each CCD), arranged in a 3 X 3 array. Each taper demagnifies the image by a factor of approximately 2. Each CCD has a 1,024 X 1,024 pixel raster and is read out through two independent data channels. After each x-ray exposure period the x-ray shutter is closed and the electronic image is digitized (16-bit) and read out in 1.8s. Alteratively, the image may be binned 2 X 2 during readout, resulting in a 1,536 X 1,536 raster of 100 micrometers pixels; this image can be read out in 0.4s. The CCD sensors are operated at -40 degree(s)C to reduce electronic noise. The detector is operated under full computer control: all operational parameters (readout rates, CCD temperature, etc.) can be adjusted from the console. The image data (18 MByte/image) are transferred via a fast VME system to a control processor and ultimately to disk storage. During April 1994 we carried out a complete set of measurements at the Stanford Synchrotron Radiation Laboratory (SSRL) for a full characterization of the gold detector. Characterization includes quantitative evaluation of the instrument's conversion gain (signal level/x-ray photon); detective quantum efficiency (DQE); point-spread function; sensitivity as a function of x-ray energy; geometrical distortion of images; spatial uniformity; read noise; and dark image and dark image noise. Characterization parameters derived from these measurements show that this detector will be extraordinarily valuable for macromolecular

  10. Discoveries and controversies in cutaneous mosaicism.

    Science.gov (United States)

    Castori, Marco; Tadini, Gianluca

    2016-06-01

    Genetic mosaicism is thought to be a common phenomenon in inherited skin disorders. It is the leading molecular mechanism explaining cutaneous hamartomas and nevoid disorders, skin manifestations of most X-linked genodermatoses and specific forms of clinical variability and topographic distribution in autosomal skin disorders. The developmental (in utero) origin and timing dependence are two major attributes for the current definition of cutaneous mosaicism. Chromosomal mosaicism, lyonization in X-linked genodermatoses, and various types of mosaicism (i.e. type 1, type 2 and revertant mosaicism) in autosomal skin disorders are mechanisms well defined at the molecular level. All these concepts have been fully included in the current medical terminology in dermatology and genetics. Mitotic crossing-over, paradominant inheritance, monoallelic expression of autosomal traits and mosaicism in acquired skin disorders remain without a formal molecular proof and still represent sources of debate in the scientific community. This review summarizes current concepts, discoveries and controversies in the field of cutaneous mosaicism for practitioners and clinical researchers to enhance their understanding of such a underestimated clinical phenomenon and its biological basis.

  11. The interaction of DNA gyrase with the bacterial toxin CcdB

    DEFF Research Database (Denmark)

    Kampranis, S C; Howells, A J; Maxwell, A

    1999-01-01

    CcdB is a bacterial toxin that targets DNA gyrase. Analysis of the interaction of CcdB with gyrase reveals two distinct complexes. An initial complex (alpha) is formed by direct interaction between GyrA and CcdB; this complex can be detected by affinity column and gel-shift analysis, and has...

  12. Trisomy 9 Mosaicism Diagnosed In Utero

    Directory of Open Access Journals (Sweden)

    Hironori Takahashi

    2010-01-01

    Full Text Available We present three cases of trisomy 9 mosaicism diagnosed by amniocentesis with ongoing pregnancies after referral to our center due to fetal abnormalities. Two cases were associated with severe fetal growth restriction (FGR, each of which resulted in an intrauterine fetal demise (IUFD in the third trimester. The other case involved mild FGR with a congenital diaphragmatic hernia and resulted in a live birth with severe development delay. A major prenatal finding of trisomy 9 mosaicism is FGR. Fetuses with trisomy 9 mosaicism can rarely survive in the case of severe FGR.

  13. Optimization of polarimetry sensitivity for X-ray CCD

    Energy Technology Data Exchange (ETDEWEB)

    Hayashida, K. E-mail: hayasida@ess.sci.osaka-u.ac.jp; Tanaka, S.; Tsunemi, H.; Hashimoto, Y.; Ohtani, M

    1999-10-21

    X-ray polarimetry with CCD has been performed using a polarized X-ray beam from an electron impact X-ray source. The standard data reduction method employing double-pixel events yields the modulation factor M of 0.14 at 27 keV and 0.24 at 43 keV for the 12 {mu}m pixel size CCD chip. We develop a new data reduction method, in which multi-pixel events are employed, and which approximates the charge spread as an oval shape. We optimize the reduction parameters, so that we improve the P{sub min} (minimum detectable polarization degree) by factor of three from the value obtained through the usual double-pixel event method.

  14. Optimization of polarimetry sensitivity for X-ray CCD

    CERN Document Server

    Hayashida, K; Tsunemi, H; Hashimoto, Y; Ohtani, M

    1999-01-01

    X-ray polarimetry with CCD has been performed using a polarized X-ray beam from an electron impact X-ray source. The standard data reduction method employing double-pixel events yields the modulation factor M of 0.14 at 27 keV and 0.24 at 43 keV for the 12 mu m pixel size CCD chip. We develop a new data reduction method, in which multi-pixel events are employed, and which approximates the charge spread as an oval shape. We optimize the reduction parameters, so that we improve the P sub m sub i sub n (minimum detectable polarization degree) by factor of three from the value obtained through the usual double-pixel event method.

  15. CCD Photometry of bright stars using objective wire mesh

    Energy Technology Data Exchange (ETDEWEB)

    Kamiński, Krzysztof; Zgórz, Marika [Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University, Słoneczna 36, 60-286 Poznań (Poland); Schwarzenberg-Czerny, Aleksander, E-mail: chrisk@amu.edu.pl [Copernicus Astronomical Centre, ul. Bartycka 18, PL 00-716 Warsaw (Poland)

    2014-06-01

    Obtaining accurate photometry of bright stars from the ground remains problematic due to the danger of overexposing the target and/or the lack of suitable nearby comparison stars. The century-old method of using objective wire mesh to produce multiple stellar images seems promising for the precise CCD photometry of such stars. Furthermore, our tests on β Cep and its comparison star, differing by 5 mag, are very encouraging. Using a CCD camera and a 20 cm telescope with the objective covered by a plastic wire mesh, in poor weather conditions, we obtained differential photometry with a precision of 4.5 mmag per two minute exposure. Our technique is flexible and may be tuned to cover a range as big as 6-8 mag. We discuss the possibility of installing a wire mesh directly in the filter wheel.

  16. Stroboscope Based Synchronization of Full Frame CCD Sensors

    Directory of Open Access Journals (Sweden)

    Liang Shen

    2017-04-01

    Full Text Available The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.

  17. Series of CCD cameras for low-light-level applications

    Science.gov (United States)

    Peri, Michal L.; Weaver, Daniel W.; Ambrose, Tom P.; Hirpara, Dan; Gallagher, Susan; Hall, Andrew M.; Bone, Gregg

    1996-03-01

    We describe a series of five CCD cameras designed by Gordian for low light-level applications. The first device is a low-cost non-imaging astronomical autoguiding tracker based on the Texas Instruments TC255 CCD chip and an MC6811 microcontroller. Mounting off-axis, it provides standardized tracking-motor signals for any telescope with a dual-axis drive corrector, automatically compensating for the mechanical peculiarities of the drive, set- up factors, and pointing errors. The tracker can guide to +/- 1 arcsec on an 8th magnitude star when used with an 8' aperture, f/10 telescope. The basic autoguider design has been extended to produce self-contained 8-bit and 16-bit imaging cameras with autoguiding functionality. Images are buffered in PSRAM, then relayed to a host PC via an RS-232 serial connection. The addition of regulated thermoelectric cooling reduces CCD thermal noise and alleviates dark current saturation. Gordian has also designed two high-resolution cameras based on the Kodak KAF-0400 and KAF-1600 CCDs. The cameras produce 16-bit images with 768 X 512 pixels or 1536 X 1024 pixels, respectively. Pixel size is 9 micrometers square. The camera head contains the CCD, thermoelectric cooling mechanism, analog electronics, and a custom-designed electromechanical shutter based on FlexinolTM actuator wire. A separate base unit houses a Motorola 68306 microprocessor and associated electronics for telescope control and on-board image processing. A stepper-motor based filter wheel can be attached directly to the camera head. The camera communicates with a personal computer via SCSI or serial connection. Software for the host PC provides additional control options, data storage, and image processing capability.

  18. Design, development, and performance of the STEREO SECCHI CCD cameras

    Science.gov (United States)

    Waltham, Nick; Eyles, Chris

    2007-09-01

    We report the design, development and performance of the SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) CCD camera electronics on NASA's Solar Terrestrial Relations Observatory (STEREO). STEREO consists of two nearly identical space-based observatories; one ahead of Earth in its orbit, the other trailing behind to provide the first-ever stereoscopic (3D) measurements to study the Sun and the nature of its coronal mass ejections. The SECCHI instrument suite consists of five telescopes that will observe the solar corona, and inner heliosphere all the way from the surface of the Sun to the orbit of the Earth, and beyond. Each telescope contains a large-format science-grade CCD; two within the Heliospheric Imager (HI) instrument, and three in a separate instrument package (SCIP) consisting of two coronagraphs and an EUV imager. The CCDs are operated from two Camera Electronics Boxes. Constraints on the size, mass, and power available for the camera electronics required the development of a miniaturised solution employing digital and mixed-signal ASICs, FPGAs, and compact surface-mount construction. Operating more than one CCD from a single box also provides economy on the number of DC-DC converters and interface electronics required. We describe the requirements for the overall design and implementation, and in particular the design and performance of the camera's space-saving mixed-signal CCD video processing ASIC. The performance of the camera is reviewed together with sample images obtained since the STEREO mission was successfully launched on October 25 2006 from Cape Canaveral.

  19. CCD readout of GEM-based neutron detectors

    CERN Document Server

    Fraga, F A F; Fetal, S T G; Fraga, M; Guérard, B; Manzini, G; Margato, L M S; Oed, A; Policarpo, Armando; Vuure, T V

    2002-01-01

    We report on the optical readout of the gas electron multiplier (GEM) operated with a gaseous mixture suitable for the detection of thermal neutrons: sup 3 He-CF sub 4. A CCD system operating in the 400-1000 nm band was used to collect the light. Spectroscopic data on the visible and NIR scintillation of He-CF sub 4 are presented. Images of the tracks of the proton and triton recorded with a triple GEM detector are also shown.

  20. Multiband CCD Photometry of CY Aquarii Using the AAVSOnet

    Science.gov (United States)

    Cowall, D. E.

    2015-12-01

    delta Scuti stars are a class of short-period pulsating variable stars that include CY Aquarii. Multiband CCD photometry was performed on that star using instruments in Massachusetts, New Mexico, and Australia from the AAVSO's global robotic telescope network. Rapid cadence, multi-hour time series yielded high precision light curves and 21 new maxima. Data analyses revealed a pulsation pattern consistent with the existing model that describes the origin of SXPHE stars.

  1. A CCD Photometric Study of Close Binary V445 Cep

    Directory of Open Access Journals (Sweden)

    Kyu-Dong Oh

    2010-06-01

    Full Text Available We present new BVR CCD photometric light curves for the close binary star V445 Cep. A new photometric solution and absolute physical dimensions of the system were derived by applying the Wilson-Devinney program to our observed light curves and radial velocity curves published by Pych et al. The evolutional status of V445 Cep was found to coincide with those of the general low mass ratio contact binary systems.

  2. Design of a CCD Camera for Space Surveillance

    Science.gov (United States)

    2016-03-05

    demonstration of the SensorSat satellite to scan the geosynchronous- orbit belt from low Earth orbit . This mission is technology pathfinder follow-on for the...the geo belt from an equatorial orbit . This is done with a novel approach via microsatellite of only 120 Kg. The satellite will scan the belt...electronics design for observing satellites in the geo belt. The paper discusses the design overview, tactics for tuning operation of a CCD, and

  3. Ortho projection and drawing for archeological artifacts using CCD camera

    Science.gov (United States)

    Yokoyama, Hiroshi; Chikatsu, Hirofumi; Miyatsuka, Yoshito

    1995-09-01

    In the compilation of archival records for archeological artifacts, true orthographic drawings of these artifacts have to be drawn by the archeologists themselves or part-timer, expending a great deal of time, labor, and skills. This paper describes the real time orthographic drawing system using a CCD camera. Finally, it demonstrates real time orthographic drawing results for Jomon pottery by using this system instead of the manual method which requires 3-4 hours.

  4. Mosaic Conservation Opportunity Areas - Liberal Model (ECO_RES.COA_MOSAIC33)

    Science.gov (United States)

    The COA_Mosaic33 layer designates areas with potential for forest/grassland mosaic conservation. These are areas of natural or semi-natural forest/grassland mosaic land cover patches that are at least 75 meters away from roads and away from patch edges. OAs were modeled by creating distance grids using the National Land Cover Database and the Census Bureau's TIGER roads files

  5. Analysis of Dark Current in BRITE Nanostellite CCD Sensors

    Directory of Open Access Journals (Sweden)

    Adam Popowicz

    2018-02-01

    Full Text Available The BRightest Target Explorer (BRITE is the pioneering nanosatellite mission dedicated for photometric observations of the brightest stars in the sky. The BRITE charge coupled device (CCD sensors are poorly shielded against extensive flux of energetic particles which constantly induce defects in the silicon lattice. In this paper we investigate the temporal evolution of the generation of the dark current in the BRITE CCDs over almost four years after launch. Utilizing several steps of image processing and employing normalization of the results, it was possible to obtain useful information about the progress of thermal activity in the sensors. The outcomes show a clear and consistent linear increase of induced damage despite the fact that only about 0.14% of CCD pixels were probed. By performing the analysis of temperature dependencies of the dark current, we identified the observed defects as phosphorus-vacancy (PV pairs, which are common in proton irradiated CCD matrices. Moreover, the Meyer-Neldel empirical rule was confirmed in our dark current data, yielding E M N = 24.8 meV for proton-induced PV defects.

  6. A Bridge Deflection Monitoring System Based on CCD

    Directory of Open Access Journals (Sweden)

    Baohua Shan

    2016-01-01

    Full Text Available For long-term monitoring of the midspan deflection of Songjiazhuang cloverleaf junction on 309 national roads in Zibo city, this paper proposes Zhang’s calibration-based DIC deflection monitoring method. CCD cameras are used to track the change of targets’ position, Zhang’s calibration algorithm is introduced to acquire the intrinsic and extrinsic parameters of CCD cameras, and the DIC method is combined with Zhang’s calibration algorithm to measure bridge deflection. The comparative test between Zhang’s calibration and scale calibration is conducted in lab, and experimental results indicate that the proposed method has higher precision. According to the deflection monitoring scheme, the deflection monitoring software for Songjiazhuang cloverleaf junction is developed by MATLAB, and a 4-channel CCD deflection monitoring system for Songjiazhuang cloverleaf junction is integrated in this paper. This deflection monitoring system includes functions such as image preview, simultaneous collection, camera calibration, deflection display, and data storage. In situ deflection curves show a consistent trend; this suggests that the proposed method is reliable and is suitable for the long-term monitoring of bridge deflection.

  7. Prenatal Diagnosis and Genetic Counseling for Mosaic Trisomy 13

    Directory of Open Access Journals (Sweden)

    Chih-Ping Chen

    2010-03-01

    Full Text Available Counseling parents of a fetus with trisomy 13 mosaicism remains difficult because of the phenotypic variability associated with the condition; some patients exhibit the typical phenotype of complete trisomy 13 with neonatal death, while others have few dysmorphic features and prolonged survival. This article provides a comprehensive review of the prenatal diagnosis and genetic counseling for mosaic trisomy 13, including confined placental mosaicism 13, mosaic trisomy 13 diagnosed at amniocentesis, and phylloid hypomelanosis in association with mosaic trisomy 13.

  8. C.C.D. Readout Of A Picosecond Streak Camera With An Intensified C.C.D.

    Science.gov (United States)

    Lemonier, M.; Richard, J. C.; Cavailler, C.; Mens, A.; Raze, G.

    1985-02-01

    This paper deals with a digital streak camera readout device. The device consists in a low light level television camera made of a solid state C.C.D. array coupled to an image intensifier associated to a video-digitizer coupled to a micro-computer system. The streak camera images are picked-up as a video signal, digitized and stored. This system allows the fast recording and the automatic processing of the data provided by the streak tube. Starting from the output screen of the streak camera, the constitutive elements are : - A fiber optic taper (A.O. Scientific Instruments) set in contact with the fiber optic output window of the streak tube achieves the image demagnification ; - A double proximity focused image intensifier (RTC - XX1410 SP) achieves the bright-ness amplification without any distortion ; - A second fiber optic taper achieves the dimensional matching between intensifier output and C.C.D. sensitive area ;

  9. Recurrence risk for germinal mosaics revisited

    NARCIS (Netherlands)

    Meulen ,van der Martin; te Meerman, G J

    A formula to calculate recurrence risk for germline mosaicism published by Hartl in 1971 has been updated to include marker information. For practical genetic counselling new, more elaborate tables are given.

  10. Aerial Photos - Photo Reference Mosaics -CS

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — USGS and Non USGS Agencies Aerial Photo Reference Mosaics inventory contains indexes to aerial photographs. The inventory contains imagery from various government...

  11. Optical and dark characterization of the PLATO CCD at ESA

    Science.gov (United States)

    Verhoeve, Peter; Prod'homme, Thibaut; Oosterbroek, Tim; Duvet, Ludovic; Beaufort, Thierry; Blommaert, Sander; Butler, Bart; Heijnen, Jerko; Lemmel, Frederic; van der Luijt, Cornelis; Smit, Hans; Visser, Ivo

    2016-07-01

    PLATO - PLAnetary Transits and Oscillations of stars - is the third medium-class mission (M3) to be selected in the European Space Agency (ESA) Science and Robotic Exploration Cosmic Vision programme. It is due for launch in 2025 with the main objective to find and study terrestrial planets in the habitable zone around solar-like stars. The payload consists of >20 cameras; with each camera comprising 4 Charge-Coupled Devices (CCDs), a large number of flight model devices procured by ESA shall ultimately be integrated on the spacecraft. The CCD270 - specially designed and manufactured by e2v for the PLATO mission - is a large format (8 cm x 8 cm) back-illuminated device operating at 4 MHz pixel rate and coming in two variants: full frame and frame transfer. In order to de-risk the PLATO CCD procurement and aid the mission definition process, ESA's Payload Technology Validation section is currently validating the PLATO CCD270. This validation consists in demonstrating that the device achieves its specified electrooptical performance in the relevant environment: operated at 4 MHz, at cold and before and after proton irradiation. As part of this validation, CCD270 devices have been characterized in the dark as well as optically with respect to performance parameters directly relevant for the photometric application of the CCDs. Dark tests comprise the measurement of gain sensitivity to bias voltages, charge injection tests, and measurement of hot and variable pixels after irradiation. In addition, the results of measurements of Quantum Efficiency for a range of angles of incidence, intra- pixel response (non-)uniformity, and response to spot illumination, before and after proton irradiation. In particular, the effect of radiation induced degradation of the charge transfer efficiency on the measured charge in a star-like spot has been studied as a function of signal level and of position on the pixel grid, Also, the effect of various levels of background light on the

  12. Ground to on-orbit alignment study of the WFIRST wide-field channel and resulting changes in the telescope architecture

    Science.gov (United States)

    Hagopian, John; Armani, Nerses; Bartusek, Lisa; Casey, Tom; Content, Dave; Conturie, Yves; Gao, Guangjun; Jurling, Alden; Marx, Cathy; Marzouk, Joe; Pasquale, Bert; Smith, J. Scott; Tang, Hong; Whipple, Arthur

    2017-08-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission[1] is the top-ranked large space mission in the New Worlds, New Horizon (NWNH) Decadal Survey of Astronomy and Astrophysics. WFIRST will settle essential questions in both exoplanet and dark energy research and will advance topics ranging from galaxy evolution to the study of objects within the galaxy. The WFIRST mission uses a repurposed 2.4-m Forward Optical Telescope assembly (FOA), which, when completed with new aft optics will be an Integrated Optical Assembly (IOA). WFIRST is equipped with a Wide Field Instrument (WFI) and a Coronagraph Instrument (CGI). An Instrument Carrier (IC) meters these payload elements together and to the spacecraft bus (S/C). A distributed ground system receives the data, uploads commands and software updates, and processes the data. After transition from the study phase, Pre-Phase-A (a.k.a., "Cycle 6") design to NASA Phase A formulation, a significant change to the IOA was initiated; including moving the tertiary mirror from the instrument package to a unified three-mirror anastigmat (TMA) placement, that provides a wide 0.28-sq° instrumented field of view to the Wide Field Instrument (WFI). In addition, separate relays from the primary and secondary mirror feed the Wide Field Instrument (WFI) and Coronagraph Instrument (CGI). During commissioning the telescope is aligned using wavefront sensing with the WFI[2]. A parametric and Monte-Carlo analysis was performed, which determined that alignment compensation with the secondary mirror alone degraded performance in the other instruments. This led to the addition of a second compensator in the WFI optical train to alleviate this concern. This paper discusses the trades and analyses that were performed and resulting changes to the WFIRST telescope architecture.

  13. Low-frequency wide-field fluorescence lifetime imaging using a high-power near-infrared light-emitting diode light source

    OpenAIRE

    Gioux, Sylvain; Lomnes, Stephen J.; Choi, Hak Soo; Frangioni, John V.

    2010-01-01

    Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR light source for the clinical translation of wide-field (larger than 5 cm in diameter) FLi at frequenc...

  14. Asteroid Ida - Five Frame Mosaic

    Science.gov (United States)

    1993-01-01

    This view of the asteroid 243 Ida is a mosaic of five image frames acquired by the Galileo spacecraft's solid-state imaging system at ranges of 3,057 to 3,821 kilometers (1,900 to 2,375 miles) on August 28, 1993, about 3-1/2 minutes before the spacecraft made its closest approach to the asteroid. Galileo flew about 2,400 kilometers (1,500 miles) from Ida at a relative velocity of 12.4 km/sec (28,000 mph). Asteroid and spacecraft were 441 million kilometers (274 million miles) from the Sun. Ida is the second asteroid ever encountered by a spacecraft. It appears to be about 52 kilometers (32 miles) in length, more than twice as large as Gaspra, the first asteroid observed by Galileo in October 1991. Ida is an irregularly shaped asteroid placed by scientists in the S class (believed to be like stony or stony iron meteorites). It is a member of the Koronis family, presumed fragments left from the breakup of a precursor asteroid in a catastrophic collision. This view shows numerous craters, including many degraded craters larger than any seen on Gaspra. The extensive cratering seems to dispel theories about Ida's surface being geologically youthful. This view also seems to rule out the idea that Ida is a double body. The south pole is believed to be in the darkside near the middle of the asteroid. The camera's clear filter was used to produce this extremely sharp picture. Spatial resolution is 31 to 38 meters (roughly 100 feet) per pixel. A 30-frame mosaic was taken to assure capturing Ida; its position was somewhat uncertain before the Galileo encounter. Galileo shuttered and recorded a total of 150 images in order to capture Ida 21 different times during a five hour period (about one rotation of the asteroid). Color filters were used at many of these times to allow reconstruction of color images. Playback to Earth of the remaining images is planned for April through June 1994. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995

  15. Incidence du Yam mosaic virus (YMV) et du Cucumber mosaic virus ...

    African Journals Online (AJOL)

    Incidence du Yam mosaic virus (YMV) et du Cucumber mosaic virus (CMV) sur des variétés de Dioscorea spp. cultivées dans les régions de Bouaké et de Toumodi en Côte d'Ivoire. K Seka, AH Diallo, NK Kouassi, S Ake ...

  16. Tubule-forming capacity of the movement proteins of alfalfa mosaic virus and brome mosaic virus

    NARCIS (Netherlands)

    Kasteel, D. T.; van der Wel, N. N.; Jansen, K. A.; Goldbach, R. W.; van Lent, J. W.

    1997-01-01

    The structural phenotype of the movement proteins (MPs) of two representatives of the Bromoviridae, alfalfa mosaic virus (AMV) and brome mosaic virus (BMV), was studied in protoplasts. Immunofluorescence microscopy showed that the MPs of these viruses, for which there has been no evidence of a

  17. Multiplex Real Time PCR For Detection of Wheat Streak Mosaic Virus and Triticum Mosaic Virus

    Science.gov (United States)

    Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TRIMV) are widespread throughout the southwestern Great Plains states. Using conventional diagnostics such as Enzyme-Linked Immunosorbent Assays (ELISA), these two viruses are commonly found together in infected wheat samples. Methods for m...

  18. Comparative Analysis of Chinese HJ-1 CCD, GF-1 WFV and ZY-3 MUX Sensor Data for Leaf Area Index Estimations for Maize

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2018-01-01

    Full Text Available In recent years, China has developed and launched several satellites with high spatial resolutions, such as the resources satellite No. 3 (ZY-3 with a multi-spectral camera (MUX and 5.8 m spatial resolution, the satellite GaoFen No. 1 (GF-1 with a wide field of view (WFV camera and 16 m spatial resolution, and the environment satellite (HJ-1A/B with a charge-coupled device (CCD sensor and 30 m spatial resolution. First, to analyze the potential application of ZY-3 MUX, GF-1 WFV, and HJ-1 CCD to extract the leaf area index (LAI at the regional scale, this study estimated LAI from the relationships between physical model-based spectral vegetation indices (SVIs and LAI values that were generated from look-up tables (LUTs, simulated from the combination of the PROSPECT-5B leaf model and the scattering by arbitrarily inclined leaves with the hot-spot effect (SAILH canopy reflectance model. Second, to assess the surface reflectance quality of these sensors after data preprocessing, the well-processed surface reflectance products of the Landsat-8 operational land imager (OLI sensor with a convincing data quality were used to compare the performances of ZY-3 MUX, GF-1 WFV, and HJ-1 CCD sensors both in theory and reality. Apart from several reflectance fluctuations, the reflectance trends were coincident, and the reflectance values of the red and near-infrared (NIR bands were comparable among these sensors. Finally, to analyze the accuracy of the LAI estimated from ZY-3 MUX, GF-1 WFV, and HJ-1 CCD, the LAI estimations from these sensors were validated based on LAI field measurements in Huailai, Hebei Province, China. The results showed that the performance of the LAI that was inversed from ZY-3 MUX was better than that from GF-1 WFV, and HJ-1 CCD, both of which tended to be systematically underestimated. In addition, the value ranges and accuracies of the LAI inversions both decreased with decreasing spatial resolution.

  19. Rotational spectra of vibrationally excited CCH and CCD.

    Science.gov (United States)

    Killian, T C; Gottlieb, C A; Thaddeus, P

    2007-09-21

    The millimeter-wave rotational spectra of the lowest bending and stretching vibrational levels of CCH and CCD were observed in a low pressure discharge through acetylene and helium. The rotational, centrifugal distortion, and fine structure constants were determined for the (02(0)0) and (02(2)0) bending states, the (100) and (001) stretching levels, and the (011) combination level of CCH. The same pure bending and stretching levels, and the (110) combination level were observed in CCD. Apparent anomalies in the spectroscopic constants in the bending states were shown to be due to l-type resonances. Hyperfine constants, which in CCH are sensitive to the degree of admixture of the A 2Pi excited electronic state, were determined in the excited vibrational levels of both isotopic species. Theoretical Fermi contact and dipole-dipole hyperfine constants calculated by Peric et al. [J. Mol. Spectrosc. 150, 70 (1991)] were found to be in excellent agreement with the measured constants. In CCD, new rotational lines tentatively assigned to the (100) level largely on the basis of the observed hyperfine structure support the assignment of the C-H stretching fundamental (nu1) by Stephens et al. [J. Mol. Struct. 190, 41 (1988)]. Rotational lines in the excited vibrational levels of CCH are fairly intense in our discharge source because the vibrational excitation temperatures of the bending vibrational levels and the (110) and (011) combination levels are only about 100 K higher than the gas kinetic temperature, unlike the higher frequency stretching vibrations, where the excitation temperatures are five to ten times higher.

  20. Apical dominance in saffron and the involvement of the branching enzymes CCD7 and CCD8 in the control of bud sprouting

    Science.gov (United States)

    2014-01-01

    Background In saffron (Crocus sativus), new corms develop at the base of every shoot developed from the maternal corm, a globular underground storage stem. Since the degree of bud sprouts influences the number and size of new corms, and strigolactones (SLs) suppress growth of pre-formed axillary bud, it was considered appropriate to investigate SL involvement in physiology and molecular biology in saffron. We focused on two of the genes within the SL pathway, CCD7 and CCD8, encoding carotenoid cleavage enzymes required for the production of SLs. Results The CsCCD7 and CsCCD8 genes are the first ones isolated and characterized from a non-grass monocotyledonous plant. CsCCD7 and CsCCD8 expression showed some overlapping, although they were not identical. CsCCD8 was highly expressed in quiescent axillary buds and decapitation dramatically reduced its expression levels, suggesting its involvement in the suppression of axillary bud outgrowth. Furthermore, in vitro experiments showed also the involvement of auxin, cytokinin and jasmonic acid on the sprouting of axillary buds from corms in which the apical bud was removed. In addition, CsCCD8 expression, but not CsCCD7, was higher in the newly developed vascular tissue of axillary buds compared to the vascular tissue of the apical bud. Conclusions We showed that production and transport of auxin in saffron corms could act synergistically with SLs to arrest the outgrowth of the axillary buds, similar to the control of above-ground shoot branching. In addition, jasmonic acid seems to play a prominent role in bud dormancy in saffron. While cytokinins from roots promote bud outgrowth. In addition the expression results of CsCCD8 suggest that SLs could positively regulate procambial activity and the development of new vascular tissues connecting leaves with the mother corm. PMID:24947472

  1. Accurate wavelength calibration method for compact CCD spectrometer.

    Science.gov (United States)

    Sun, Y C; Huang, C; Xia, G; Jin, S Q; Lu, H B

    2017-04-01

    Wavelength calibration is an important step in charge-coupled device (CCD) spectrometers. In this paper, an accurate calibration method is proposed. A model of a line profile spectrum is built at the beginning, followed by noise reduction, bandwidth correction, and automatic peak-seeking treatment. Experimental tests are conducted on the USB4000 spectrometer with a mercury-argon calibration light source. Compared with the traditional method, the results show that this wavelength calibration procedure obtains higher accuracy and the deviations are within 0.1 nm.

  2. A Lossy Method for Compressing Raw CCD Images

    OpenAIRE

    Watson, Alan M.

    2002-01-01

    Se presenta un método para comprimir las imágenes en bruto de dispositivos como los CCD. El método es muy sencillo: cuantizaciòn con pérdida y luego compresión sin pérdida con herramientas de uso general como gzip o bzip2. Se convierten los archivos comprimidos a archivos de FITS descomprimiéndolos con gunzip o bunzip2, lo cual es una ventaja importante en la distribución de datos comprimidos. El grado de cuantizaciòn se elige para eliminar los bits de bajo orden, los cuales...

  3. Mosaic convergence of rodent dentitions.

    Directory of Open Access Journals (Sweden)

    Vincent Lazzari

    Full Text Available BACKGROUND: Understanding mechanisms responsible for changes in tooth morphology in the course of evolution is an area of investigation common to both paleontology and developmental biology. Detailed analyses of molar tooth crown shape have shown frequent homoplasia in mammalian evolution, which requires accurate investigation of the evolutionary pathways provided by the fossil record. The necessity of preservation of an effective occlusion has been hypothesized to functionally constrain crown morphological changes and to also facilitate convergent evolution. The Muroidea superfamily constitutes a relevant model for the study of molar crown diversification because it encompasses one third of the extant mammalian biodiversity. METHODOLOGY/PRINCIPAL FINDINGS: Combined microwear and 3D-topographic analyses performed on fossil and extant muroid molars allow for a first quantification of the relationships between changes in crown morphology and functionality of occlusion. Based on an abundant fossil record and on a well resolved phylogeny, our results show that the most derived functional condition associates longitudinal chewing and non interlocking of cusps. This condition has been reached at least 7 times within muroids via two main types of evolutionary pathways each respecting functional continuity. In the first type, the flattening of tooth crown which induces the removal of cusp interlocking occurs before the rotation of the chewing movement. In the second type however, flattening is subsequent to rotation of the chewing movement which can be associated with certain changes in cusp morphology. CONCLUSION/SIGNIFICANCE: The reverse orders of the changes involved in these different pathways reveal a mosaic evolution of mammalian dentition in which direction of chewing and crown shape seem to be partly decoupled. Either can change in respect to strong functional constraints affecting occlusion which thereby limit the number of the possible

  4. Fundamental performance differences of CMOS and CCD imagers: part V

    Science.gov (United States)

    Janesick, James R.; Elliott, Tom; Andrews, James; Tower, John; Pinter, Jeff

    2013-02-01

    Previous papers delivered over the last decade have documented developmental progress made on large pixel scientific CMOS imagers that match or surpass CCD performance. New data and discussions presented in this paper include: 1) a new buried channel CCD fabricated on a CMOS process line, 2) new data products generated by high performance custom scientific CMOS 4T/5T/6T PPD pixel imagers, 3) ultimate CTE and speed limits for large pixel CMOS imagers, 4) fabrication and test results of a flight 4k x 4k CMOS imager for NRL's SoloHi Solar Orbiter Mission, 5) a progress report on ultra large stitched Mk x Nk CMOS imager, 6) data generated by on-chip sub-electron CDS signal chain circuitry used in our imagers, 7) CMOS and CMOSCCD proton and electron radiation damage data for dose levels up to 10 Mrd, 8) discussions and data for a new class of PMOS pixel CMOS imagers and 9) future CMOS development work planned.

  5. CCD Astrometry of Selected Compact Extragalactic Radio Sources

    Science.gov (United States)

    Fedorov, P.; Velichko, F.; Filonenko, V.; Myznikov, A.; Sergeev, V.

    The 64 optical positions relative to the Catalog of Astrometric Standards (USNO-A2.0) and 9 optical positions relative to the Extragalactic Reference Link Catalog (de Vegt at al., 2001) had been obtained for the optical counterparts of 50 northern compact extragalactic radio sources (CERS). These positions were determined at the Kharkov Astronomical Observatory with use the CCD-camera ST-6 of the 0.7-m telescope AZT-8. More than 325 CCD-images of field 10.5' × 8' with optical counterparts of selected CERS had been obtained during 1997-2001. Positions of reference stars (from 6 to 12 stars for each CERS) were obtained from USNO-A2.0 catalogue, Extragalactic Reference Link Catalog and Nikolayev AMC catalogue (Pinigin & Shulga, 1999). The mean internal formal errors of the optical positions of these CERS are 100 mas in right ascension and 70 mas in declination. A comparison with VLBI radio positions for these sources is presented. The mean differences between radio and optical positions from our observations are not significantly differing from zero on the 0.05 significance level. The optical data which we obtained is potentially useful to possibly improve the current link of the Hipparcos reference frame to the ICRS. References de Vegt, C., Hindsley, R., Zacharias, N., Winter, L. 2001, AJ, 2815 Pinigin, G.I., Shulga A.V., 1999, Proc. JOURNESS 1999 & IX. Lohrmann-Kolloquium, Dresden (Germany), 64

  6. Precise CCD positions of Phoebe in 2011-2014

    Science.gov (United States)

    Peng, Q. Y.; Wang, N.; Vienne, A.; Zhang, Q. F.; Li, Z.; Meng, X. H.

    2015-05-01

    346 new CCD observations during the years 2011-2014 have been reduced to derive the precise positions of Phoebe, the ninth satellite of Saturn. The observations were made by the 2.4 m telescope at Yunnan Observatory over nine nights. Due to the use of a focal-reducer on the telescope, its significant geometric distortion is solved for and removed for each CCD field of view. The positions of Phoebe are measured with respect to the stars in UCAC2 catalogue. The theoretical position of Phoebe was retrieved from the Institute de Méchanique Céleste et de Calcul des Éphémérides ephemeris which includes the latest theory PH12 by Desmars et al., while the position of Saturn was obtained from the Jet Propulsion Laboratory ephemeris DE431. Our results show that the mean O-Cs (observed minus computed) are -0.02 and -0.07 arcsec in right ascension and declination, respectively. The dispersions of our observations are estimated at about 0.04 arcsec in each direction.

  7. Simulations of the x-ray imaging capabilities of the silicon drift detectors (SDD) for the LOFT wide-field monitor

    DEFF Research Database (Denmark)

    Evangelista, Y.; Campana, R.; Del Monte, E.

    2012-01-01

    The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M3 candidate missions to undergo an assessment phase, will revolutionize the study of compact objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. The Large Area...... Detector (LAD), carrying an unprecedented effective area of 10 m^2, is complemented by a coded-mask Wide Field Monitor, in charge of monitoring a large fraction of the sky potentially accessible to the LAD, to provide the history and context for the sources observed by LAD and to trigger its observations...

  8. Wide-field-of-view phase-contrast imaging of nanostructures with a comparatively large polychromatic soft x-ray plasma source.

    Science.gov (United States)

    Gasilov, S V; Faenov, A Ya; Pikuz, T A; Fukuda, Y; Kando, M; Kawachi, T; Skobelev, I Yu; Daido, H; Kato, Y; Bulanov, S V

    2009-11-01

    Polychromatic soft x-ray plasma sources were not previously considered to be among the sources suitable for the propagation based phase contrast imaging because of their comparatively large emission-zone size. In the current work a scheme based on the combination of soft x-ray emission of multicharged ions, generated by the interaction of femtosecond laser pulses with an ultrasonic jet of gas clusters, and an LiF crystal detector was used to obtain phase-enhanced high-resolution images of micro- and nanoscale objects in a wide field of view.

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

    Science.gov (United States)

    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 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.

  10. Infrared image mosaic using point feature operators

    Science.gov (United States)

    Huang, Zhen; Sun, Shaoyuan; Shen, Zhenyi; Hou, Junjie; Zhao, Haitao

    2016-10-01

    In this paper, we study infrared image mosaic around a single point of rotation, aiming at expanding the narrow view range of infrared images. We propose an infrared image mosaic method using point feature operators including image registration and image synthesis. Traditional mosaic algorithms usually use global image registration methods to extract the feature points in the global image, which cost too much time as well as considerable matching errors. To address this issue, we first roughly calculate the image shift amount using phase correlation and determine the overlap region between images, and then extract image features in overlap region, which shortens the registration time and increases the quality of feature points. We improve the traditional algorithm through increasing constraints of point matching based on prior knowledge of image shift amount based on which the weighted map is computed using fade in-out method. The experimental results verify that the proposed method has better real time performance and robustness.

  11. GENERATION OF GEOMETRIC ORNAMENTS IN ANCIENT MOSAIC ART

    Directory of Open Access Journals (Sweden)

    SASS Ludmila

    2015-06-01

    Full Text Available The paper examines geometrical ornaments from ancient mosaic.We studied the geometric generation by using Computer Aided Graphics for three examples of ancient mosaic: a mosaic of Ancient Corinth, a mosaic of the sacred geometry Flower of Life (exposed in the National Museum of Israel and a mosaic of fortress Masada - Israel. The technique of drawing ancient mosaic is recomposed using computer aided graphics. A program has been developed that can help draw a petal-type arc (semicircle of the mosaic that is the Byzantine church of Masada. Based on these mosaics, other variants of aesthetic images in monochrome or black and white and polychrome were drawn, all of which can be materialized in decorative art to embellish various surfaces: walls, floors, pools, fountains, etc.

  12. Tractability gains in symmetry-adapted perturbation theory including coupled double excitations: CCD+ST(CCD) dispersion with natural orbital truncations

    Science.gov (United States)

    Parrish, Robert M.; Hohenstein, Edward G.; Sherrill, C. David

    2013-11-01

    This work focuses on efficient and accurate treatment of the intermolecular dispersion interaction using the CCD+ST(CCD) dispersion approach formulated by Williams et al. [J. Chem. Phys. 103, 4586 (1995)]. We apply natural orbital truncation techniques to the solution of the monomer coupled-cluster double (CCD) equations, yielding substantial accelerations in this computationally demanding portion of the SAPT2+(CCD), SAPT2+(3)(CCD), and SAPT2+3(CCD) analyses. It is shown that the wholly rate-limiting dimer-basis particle-particle ladder term can be computed in a reduced natural virtual space which is essentially the same size as the monomer-basis virtual space, with an error on the order of a few thousandths of 1 kcal mol-1. Coupled with our existing natural orbital techniques for the perturbative triple excitation contributions [E. G. Hohenstein and C. D. Sherrill, J. Chem. Phys. 133, 104107 (2010)], this technique provides speedups of greater than an order of magnitude for the evaluation of the complete SAPT2+3(CCD) decomposition, with a total error of a few hundredths of 1 kcal mol-1. The combined approach yields tractability gains of almost 2× in the system size, allowing for SAPT2+3(CCD)/aug-cc-pVTZ analysis to be performed for systems such as adenine-thymine for the first time. Natural orbital based SAPT2+3(CCD)/aug-cc-pVTZ results are presented for stacked and hydrogen-bonded configurations of uracil dimer and the adenine-thymine dimer.

  13. Prenatal Diagnosis and Genetic Counseling for Mosaic Trisomy 13

    OpenAIRE

    Chen, Chih-Ping

    2010-01-01

    Counseling parents of a fetus with trisomy 13 mosaicism remains difficult because of the phenotypic variability associated with the condition; some patients exhibit the typical phenotype of complete trisomy 13 with neonatal death, while others have few dysmorphic features and prolonged survival. This article provides a comprehensive review of the prenatal diagnosis and genetic counseling for mosaic trisomy 13, including confined placental mosaicism 13, mosaic trisomy 13 diagnosed at amniocent...

  14. Mosaic partial trisomy 17q2.

    Science.gov (United States)

    King, P A; Ghosh, A; Tang, M

    1991-01-01

    Examination of an infant born after prenatal diagnosis of mosaic partial trisomy 17q2 showed the unique phenotypic features of this chromosomal abnormality, that is, frontal bossing, large mouth, brachyrhizomelia, and hexadactyly. Amniocentesis was performed because of polyhydramnios and ultrasound diagnosis of fetal craniofacial dysmorphology and rhizomelic shortening of the limbs. Chromosomal mosaicism was restricted to fetal tissue and amniotic fluid cells. The placental chromosomal complement was normal, suggesting that the abnormality developed after differentiation of embryonic and trophoblastic cells. This emphasises the usefulness of cytogenetic evaluation of placental, fetal, and amniotic fluid cells in delineating the pathogenesis of congenital abnormalities. Images PMID:1956067

  15. Global HRSC Image Mosaics of Mars: Dodging for High-Pass Filtering, Combined with Low-Pass-Filtered OMEGA Mosaics

    Science.gov (United States)

    McGuire, P. C.; Walter, S. H. G.; van Gasselt, S.; Dumke, A.; Dunker, T.; Gross, C.; Michael, G.; Wendt, L.; Audouard, J.; Ody, A.; Poulet, F.

    2014-07-01

    We discuss our approach towards automatically mosaicking hundreds of the HRSC panchromatic or RGB images together. Our best results consist of adding a high-pass-filtered HRSC mosaic to a low-pass-filtered OMEGA global mosaic.

  16. MONOCLONAL ANTIBODIES TO IDENTIFY TOMATO MOSAIC TOBAMOVIRUS (TOMV

    Directory of Open Access Journals (Sweden)

    Duarte Keila M.R.

    2001-01-01

    Full Text Available Monoclonal antibodies were obtained against Tomato mosaic tobamovirus (ToMV isolated in Brazil. One antibody (8G7G2 isotyped as IgG2b (kappa light chain showed strong specificity and very low cross reaction with the Tobacco mosaic virus (TMV. It can be used in identification of tomato mosaic virus (ToMV.

  17. Complete nucleotide sequence analysis of Cymbidium mosaic virus ...

    Indian Academy of Sciences (India)

    Phylogenetic analyses on the basis of RNA-dependent RNA polymerase (RdRp), triple gene block protein and coat protein (CP) amino acid sequences revealed that CymMV is closely related to the Narcissus mosaic virus (NMV), Scallion virus X (SVX), Pepino mosaic virus (PepMV) and Potato aucuba mosaic virus (PAMV).

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

    Science.gov (United States)

    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.

  19. The FLARE mission: deep and wide-field 1-5um imaging and spectroscopy for the early universe: a proposal for M5 cosmic vision call

    Science.gov (United States)

    Burgarella, D.; Levacher, P.; Vives, S.; Dohlen, K.; Pascal, S.

    2016-07-01

    FLARE (First Light And Reionization Explorer) is a space mission that will be submitted to ESA (M5 call). Its primary goal (~80% of lifetime) is to identify and study the universe before the end of the reionization at z > 6. A secondary objective (~20% of lifetime) is to survey star formation in the Milky Way. FLARE's strategy optimizes the science return: imaging and spectroscopic integral-field observations will be carried out simultaneously on two parallel focal planes and over very wide instantaneous fields of view. FLARE will help addressing two of ESA's Cosmic Vision themes: a) universe originate and what is it made of? » and b) « What are the conditions for planet formation and the emergence of life? >> and more specifically, >. FLARE will provide to the ESA community a leading position to statistically study the early universe after JWST's deep but pin-hole surveys. Moreover, the instrumental development of wide-field imaging and wide-field integral-field spectroscopy in space will be a major breakthrough after making them available on ground-based telescopes.

  20. DOUBLE STARS IN THE USNO CCD ASTROGRAPHIC CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Hartkopf, William I.; Mason, Brian D.; Finch, Charlie T.; Zacharias, Norbert; Wycoff, Gary L.; Hsu, Danley, E-mail: wih@usno.navy.mil, E-mail: bdm@usno.navy.mil, E-mail: finch@usno.navy.mil, E-mail: nz@usno.navy.mil [US Naval Observatory, Washington, DC 20392 (United States)

    2013-10-01

    The newly completed Fourth USNO CCD Astrographic Catalog (UCAC4) has proven to be a rich source of double star astrometry and photometry. Following initial comparisons of UCAC4 results against those obtained by speckle interferometry, the UCAC4 catalog was matched against known double stars in the Washington Double Star Catalog in order to provide additional differential astrometry and photometry for these pairs. Matches to 58,131 pairs yielded 61,895 astrometric and 68,935 photometric measurements. Finally, a search for possible new common proper motion (CPM) pairs was made using new UCAC4 proper motion data; this resulted in 4755 new potential CPM doubles (and an additional 27,718 astrometric and photometric measures from UCAC and other sources)

  1. CCD-based optical CT scanning of highly attenuating phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Al-Nowais, Shamsa [Department of Physics, University of Surrey, Guildford (United Kingdom); Doran, Simon J [CRUK Clinical MR Research Group, Institute of Cancer Research, Sutton (United Kingdom)], E-mail: Simon.Doran@icr.ac.uk

    2009-05-01

    The introduction of optical computed tomography (optical-CT) offers economic and easy to use 3-D optical readout for gel dosimeters. However, previous authors have noted some challenges regarding the accuracy of such imaging techniques at high values of optical density. In this paper, we take a closer look at the 'cupping' artefact evident in both light-scattering polymer systems and highly light absorbing phantoms using our CCD-based optical scanner. In addition, a technique is implemented whereby the maximum measurable optical absorbance is extended to correct for any errors that may have occurred in the estimated value of the dark current or ambient light reaching the detector. The results indicate that for absorbance values up to 2.0, the optical scanner results have good accuracy, whereas this is not the case at high absorbance values for reasons yet to be explained.

  2. Contribution of the Chromosomal ccdAB Operon to Bacterial Drug Tolerance.

    Science.gov (United States)

    Gupta, Kritika; Tripathi, Arti; Sahu, Alishan; Varadarajan, Raghavan

    2017-10-01

    One of the first identified and best-studied toxin-antitoxin (TA) systems in Escherichia coli is the F-plasmid-based CcdAB system. This system is involved in plasmid maintenance through postsegregational killing. More recently, ccdAB homologs have been found on the chromosome, including in pathogenic strains of E. coli and other bacteria. However, the functional role of chromosomal ccdAB genes, if any, has remained unclear. We show that both the native ccd operon of the E. coli O157 strain (ccdO157) and the ccd operon from the F plasmid (ccdF), when inserted on the E. coli chromosome, lead to protection from cell death under multiple antibiotic stress conditions through formation of persisters, with the O157 operon showing higher protection. While the plasmid-encoded CcdB toxin is a potent gyrase inhibitor and leads to bacterial cell death even under fully repressed conditions, the chromosomally encoded toxin leads to growth inhibition, except at high expression levels, where some cell death is seen. This was further confirmed by transiently activating the chromosomal ccd operon through overexpression of an active-site inactive mutant of F-plasmid-encoded CcdB. Both the ccdF and ccdO157 operons may share common mechanisms for activation under stress conditions, eventually leading to multidrug-tolerant persister cells. This study clearly demonstrates an important role for chromosomal ccd systems in bacterial persistence.IMPORTANCE A large number of free-living and pathogenic bacteria are known to harbor multiple toxin-antitoxin systems, on plasmids as well as on chromosomes. The F-plasmid CcdAB system has been extensively studied and is known to be involved in plasmid maintenance. However, little is known about the function of its chromosomal counterpart, found in several pathogenic E. coli strains. We show that the native chromosomal ccd operon of the E. coli O157 strain is involved in drug tolerance and confers protection from cell death under multiple antibiotic

  3. Mosaic Conservation Opportunity Areas - Conservativel Model (ECO_RES.COA_MOSAIC66)

    Science.gov (United States)

    The COA_Mosaic66 layer designates areas with potential for forest/grassland mosaic conservation. These are areas of natural or semi-natural forest/grassland land cover patches that area at least 395 meters away from roads and away from patch edges. OAs were modeled by creating distance grids using the National Land Cover Database and the Census Bureau's TIGER road files.

  4. Document image mosaicing: A novel approach

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    sort of overlapping region (OR) to produce a single and complete image of the document. In this paper, we ... An improved unidirectional algorithm to mosaic the split images with time complexity of. O(n3) is given in ... algorithm 1 scanning of the image takes place only from left to right to identify the overlapping region in the ...

  5. Pulling the Internet Together with Mosaic.

    Science.gov (United States)

    Sheehan, Mark

    1995-01-01

    Presents the history of the Internet with specific emphasis on Mosaic; discusses hypertext and hypermedia information; and describes software and hardware requirements. Sidebars include information on the National Center for Super Computing Applications (NCSA); World Wide Web browsers for use in Windows, Macintosh, and X-Windows (UNIX); and…

  6. Identification of cowpea mosaic virus isolates

    NARCIS (Netherlands)

    Agrawal, H.O.

    1964-01-01

    Five isolates of the beetle-transmitted cowpea mosaic virus were studied. The symptoms produced by each on a number of hosts were described. The occurrence of amorphous inclusion bodies in the epidermal cells of infected cowpea and pea plants was reported. A purification procedure was described.

  7. Diploid/triploid mosaicism in dysmorphic patients

    NARCIS (Netherlands)

    van de Laar, [No Value; Rabelink, G; Hochstenbach, R; Tuerlings, J; Giltay, J

    2002-01-01

    Diploid/triploid mosaicism is a dysmorphology syndrome consisting of mental retardation, truncal obesity, body and/or facial asymmetry, growth retardation, hypotonia, a small phallus, malformed low-set ears and micrognathia. In 75% of the cases, the blood karyotype is normal and the diagnosis can

  8. Landsat Thematic Mapper Image Mosaic of Colorado

    Science.gov (United States)

    Cole, Christopher J.; Noble, Suzanne M.; Blauer, Steven L.; Friesen, Beverly A.; Bauer, Mark A.

    2010-01-01

    The U.S. Geological Survey (USGS) Rocky Mountain Geographic Science Center (RMGSC) produced a seamless, cloud-minimized remotely-sensed image spanning the State of Colorado. Multiple orthorectified Landsat 5 Thematic Mapper (TM) scenes collected during 2006-2008 were spectrally normalized via reflectance transformation and linear regression based upon pseudo-invariant features (PIFS) following the removal of clouds. Individual Landsat scenes were then mosaicked to form a six-band image composite spanning the visible to shortwave infrared spectrum. This image mosaic, presented here, will also be used to create a conifer health classification for Colorado in Scientific Investigations Map 3103. An archive of past and current Landsat imagery exists and is available to the scientific community (http://glovis.usgs.gov/), but significant pre-processing was required to produce a statewide mosaic from this information. Much of the data contained perennial cloud cover that complicated analysis and classification efforts. Existing Landsat mosaic products, typically three band image composites, did not include the full suite of multispectral information necessary to produce this assessment, and were derived using data collected in 2001 or earlier. A six-band image mosaic covering Colorado was produced. This mosaic includes blue (band 1), green (band 2), red (band 3), near infrared (band 4), and shortwave infrared information (bands 5 and 7). The image composite shown here displays three of the Landsat bands (7, 4, and 2), which are sensitive to the shortwave infrared, near infrared, and green ranges of the electromagnetic spectrum. Vegetation appears green in this image, while water looks black, and unforested areas appear pink. The lines that may be visible in the on-screen version of the PDF are an artifact of the export methods used to create this file. The file should be viewed at 150 percent zoom or greater for optimum viewing.

  9. Substrate promiscuity of RdCCD1, a carotenoid cleavage oxygenase from Rosa damascena.

    Science.gov (United States)

    Huang, Fong-Chin; Horváth, Györgyi; Molnár, Péter; Turcsi, Erika; Deli, József; Schrader, Jens; Sandmann, Gerhard; Schmidt, Holger; Schwab, Wilfried

    2009-03-01

    Several of the key flavor compounds in rose essential oil are C(13)-norisoprenoids, such as beta-damascenone, beta-damascone, and beta-ionone which are derived from carotenoid degradation. To search for genes putatively responsible for the cleavage of carotenoids, cloning of carotenoid cleavage (di-)oxygenase (CCD) genes from Rosa damascena was carried out by a degenerate primer approach and yielded a full-length cDNA (RdCCD1). The RdCCD1 gene was expressed in Escherichia coli and recombinant protein was assayed for its cleavage activity with a multitude of carotenoid substrates. The RdCCD1 protein was able to cleave a variety of carotenoids at the 9-10 and 9'-10' positions to produce a C(14) dialdehyde and two C(13) products, which vary depending on the carotenoid substrates. RdCCD1 could also cleave lycopene at the 5-6 and 5'-6' positions to produce 6-methyl-5-hepten-2-one. Expression of RdCCD1 was studied by real-time PCR in different tissues of rose. The RdCCD1 transcript was present predominantly in rose flower, where high levels of volatile C(13)-norisoprenoids are produced. Thus, the accumulation of C(13)-norisoprenoids in rose flower is correlated to the expression of RdCCD1.

  10. System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor

    Directory of Open Access Journals (Sweden)

    J. Misun

    1993-11-01

    Full Text Available The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video signals, which are processed in the analog signal processor. The output signal is continually converted to 8-bit data words in A/D converter. This data words maybe transfer over a bus driver to the operation memory of personal computer, by setting one of the three work regimes of digital CCD camera. Some application possibilities and basic technical parameters of this system are given.

  11. Study on enhancing dynamic range of CCD imaging based on digital micro-mirror device

    Science.gov (United States)

    Zhou, Wang

    2009-05-01

    DMD used as SLM modulation area array CCD design is proposed in the paper. It can Solve a problem in exposing high-contrast scenes by ordinary CCD camera, with images appearing over-exposure or under exposure, bringing a loss of the details of the photo. The method adoptes a forecast imaging scene, CCD is purposely designed by way of more exposure regions and exposure times. Through modulation function of DMD micro-mirror, CCD is exposed with sub-region and time-sharing, at the same time a purposely designed structure of image data enhances the area CCD dynamic range. Experiments shows: This method not only improves visible quality of an image and clear details in the backlighting or highlight, but also enhances the dynamic range of image data. The high-quality image and high dynamic range data are real-time captured, the "fused" software is no longer required.

  12. High-Voltage Clock Driver for Photon-Counting CCD Characterization

    Science.gov (United States)

    Baker, Robert

    2013-01-01

    A document discusses the CCD97 from e2v technologies as it is being evaluated at Goddard Space Flight Center's Detector Characterization Laboratory (DCL) for possible use in ultra-low background noise space astronomy applications, such as Terrestrial Planet Finder Coronagraph (TPF-C). The CCD97 includes a photoncounting mode where the equivalent output noise is less than one electron. Use of this mode requires a clock signal at a voltage level greater than the level achievable by the existing CCD (charge-coupled-device) electronics. A high-voltage waveform generator has been developed in code 660/601 to support the CCD97 evaluation. The unit generates required clock waveforms at voltage levels from -20 to +50 V. It deals with standard and arbitrary waveforms and supports pixel rates from 50 to 500 kHz. The system is designed to interface with existing Leach CCD electronics.

  13. Design of 1-μm-pitch liquid crystal spatial light modulators having dielectric shield wall structure for holographic display with wide field of view

    Science.gov (United States)

    Isomae, Yoshitomo; Shibata, Yosei; Ishinabe, Takahiro; Fujikake, Hideo

    2017-04-01

    In the development of electronic holographic displays with a wide field of view, one issue is the realization of 1-μm-pitch spatial light modulators (SLMs) using liquid crystal on silicon (LCOS) techniques. We clarified that it is necessary to suppress not only the leakage of fringe electric fields from adjacent pixels but also the effect of elastic forces in the liquid crystal to achieve full-phase modulation (2 π) in individual pixels. We proposed a novel LCOS-SLM with a dielectric shield wall structure, and achieved driving of individual 1-μm-pitch pixels. We also investigated the optimum values for width and dielectric constant of the wall structure when enlarging the area that can modulate light in the pixels. These results contribute to the design of 1-μm-pitch LCOS-SLM devices for wide-viewing-angle holographic displays.

  14. Green-to-red photoconvertible fluorescent proteins: tracking cell and protein dynamics on standard wide-field mercury arc-based microscopes

    Directory of Open Access Journals (Sweden)

    Buckheit Robert W

    2010-02-01

    Full Text Available Abstract Background Green fluorescent protein (GFP and other FP fusions have been extensively utilized to track protein dynamics in living cells. Recently, development of photoactivatable, photoswitchable and photoconvertible fluorescent proteins (PAFPs has made it possible to investigate the fate of discrete subpopulations of tagged proteins. Initial limitations to their use (due to their tetrameric nature were overcome when monomeric variants, such as Dendra, mEos, and mKikGR were cloned/engineered. Results Here, we report that by closing the field diaphragm, selective, precise and irreversible green-to-red photoconversion (330-380 nm illumination of discrete subcellular protein pools was achieved on a wide-field fluorescence microscope equipped with standard DAPI, Fluorescein, and Rhodamine filter sets and mercury arc illumination within 5-10 seconds. Use of a DAPI-filter cube with long-pass emission filter (LP420 allowed the observation and control of the photoconversion process in real time. Following photoconversion, living cells were imaged for up to 5 hours often without detectable phototoxicity or photobleaching. Conclusions We demonstrate the practicability of this technique using Dendra2 and mEos2 as monomeric, photoconvertible PAFP representatives fused to proteins with low (histone H2B, medium (gap junction channel protein connexin 43, and high (α-tubulin; clathrin light chain dynamic cellular mobility as examples. Comparable efficient, irreversible green-to-red photoconversion of selected portions of cell nuclei, gap junctions, microtubules and clathrin-coated vesicles was achieved. Tracking over time allowed elucidation of the dynamic live-cycle of these subcellular structures. The advantage of this technique is that it can be performed on a standard, relatively inexpensive wide-field fluorescence microscope with mercury arc illumination. Together with previously described laser scanning confocal microscope-based photoconversion

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

    Science.gov (United States)

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

    2012-09-01

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

  16. Reconstruction of Daily 30 m Data from HJ CCD, GF-1 WFV, Landsat, and MODIS Data for Crop Monitoring

    Directory of Open Access Journals (Sweden)

    Mingquan Wu

    2015-12-01

    Full Text Available With the recent launch of new satellites and the developments of spatiotemporal data fusion methods, we are entering an era of high spatiotemporal resolution remote-sensing analysis. This study proposed a method to reconstruct daily 30 m remote-sensing data for monitoring crop types and phenology in two study areas located in Xinjiang Province, China. First, the Spatial and Temporal Data Fusion Approach (STDFA was used to reconstruct the time series high spatiotemporal resolution data from the Huanjing satellite charge coupled device (HJ CCD, Gaofen satellite no. 1 wide field-of-view camera (GF-1 WFV, Landsat, and Moderate Resolution Imaging Spectroradiometer (MODIS data. Then, the reconstructed time series were applied to extract crop phenology using a Hybrid Piecewise Logistic Model (HPLM. In addition, the onset date of greenness increase (OGI and greenness decrease (OGD were also calculated using the simulated phenology. Finally, crop types were mapped using the phenology information. The results show that the reconstructed high spatiotemporal data had a high quality with a proportion of good observations (PGQ higher than 0.95 and the HPLM approach can simulate time series Normalized Different Vegetation Index (NDVI very well with R2 ranging from 0.635 to 0.952 in Luntai and 0.719 to 0.991 in Bole, respectively. The reconstructed high spatiotemporal data were able to extract crop phenology in single crop fields, which provided a very detailed pattern relative to that from time series MODIS data. Moreover, the crop types can be classified using the reconstructed time series high spatiotemporal data with overall accuracy equal to 0.91 in Luntai and 0.95 in Bole, which is 0.028 and 0.046 higher than those obtained by using multi-temporal Landsat NDVI data.

  17. Autoguiding and Defocus Experiments for CCD Differential Photometry

    Science.gov (United States)

    Sturm, E. J.

    2004-12-01

    A number of smaller observatories utilize relatively low-cost, off-the-shelf telescopes and CCD cameras to obtain differential photometric measurements of variable stars. Obtaining the best-possible differential photometric precision, as evidenced by the standard deviations of the comparison-check differentials, is often a vital goal. This series of experiments is investigating, for two different Meade LX-200 telescopes (each equipped with an SBIG ST-7XE camera), the relationship between: (1) autoguiding precision and differential photometric precision, and (2) focus precision and differential photometric precision. The effects of purposefully introducing both autoguiding "errors" (i.e. small telescope movements) and image defocus on differential photometric precision are being evaluated. Telescope time is being provided by the Orion and Dark Ridge Observatories. I acknowledge the assistance of Russell Genet (Orion Observatory), Thomas Smith (Dark Ridge Observatory), and John Mottmann (California Polytechnic State University), as well as the financial support by the Department of Physics, California Polytechnic State University for conference and travel expenses.

  18. NIR spectrophotometric system based on a conventional CCD camera

    Science.gov (United States)

    Vilaseca, Meritxell; Pujol, Jaume; Arjona, Montserrat

    2003-05-01

    The near infrared spectral region (NIR) is useful in many applications. These include agriculture, the food and chemical industry, and textile and medical applications. In this region, spectral reflectance measurements are currently made with conventional spectrophotometers. These instruments are expensive since they use a diffraction grating to obtain monochromatic light. In this work, we present a multispectral imaging based technique for obtaining the reflectance spectra of samples in the NIR region (800 - 1000 nm), using a small number of measurements taken through different channels of a conventional CCD camera. We used methods based on the Wiener estimation, non-linear methods and principal component analysis (PCA) to reconstruct the spectral reflectance. We also analyzed, by numerical simulation, the number and shape of the filters that need to be used in order to obtain good spectral reconstructions. We obtained the reflectance spectra of a set of 30 spectral curves using a minimum of 2 and a maximum of 6 filters under the influence of two different halogen lamps with color temperatures Tc1 = 2852K and Tc2 = 3371K. The results obtained show that using between three and five filters with a large spectral bandwidth (FWHM = 60 nm), the reconstructed spectral reflectance of the samples was very similar to that of the original spectrum. The small amount of errors in the spectral reconstruction shows the potential of this method for reconstructing spectral reflectances in the NIR range.

  19. CCD Parallaxes for 309 Late-type Dwarfs and Subdwarfs

    Energy Technology Data Exchange (ETDEWEB)

    Dahn, Conard C.; Harris, Hugh C.; Subasavage, John P.; Ables, Harold D.; Guetter, Harry H.; Harris, Fred H.; Luginbuhl, Christian B.; Monet, Alice B.; Monet, David G.; Munn, Jeffrey A.; Pier, Jeffrey R.; Stone, Ronald C.; Vrba, Frederick J.; Walker, Richard L.; Tilleman, Trudy M. [US Naval Observatory, Flagstaff Station, 10391 W. Naval Observatory Road, Flagstaff, AZ 86005-8521 (United States); Canzian, Blaise J. [L-3 Communications/Brashear, 615 Epsilon Drive, Pittsburgh, PA 15238-2807 (United States); Henden, Arne H. [AAVSO, Cambridge, MA 02138 (United States); Leggett, S. K. [Gemini Observatory, Northern Operations Center, 670 N. A’ohoku Place, Hilo, HI 96720 (United States); Levine, Stephen E., E-mail: jsubasavage@nofs.navy.mil [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001-4499 (United States)

    2017-10-01

    New, updated, and/or revised CCD parallaxes determined with the Strand Astrometric Reflector at the Naval Observatory Flagstaff Station are presented. Included are results for 309 late-type dwarf and subdwarf stars observed over the 30+ years that the program operated. For 124 of the stars, parallax determinations from other investigators have already appeared in the literature and we compare the different results. Also included here are new or updated VI photometry on the Johnson–Kron-Cousins system for all but a few of the faintest targets. Together with 2MASS JHK{sub s} near-infrared photometry, a sample of absolute magnitude versus color and color versus color diagrams are constructed. Because large proper motion was a prime criterion for targeting the stars, the majority turn out to be either M-type subdwarfs or late M-type dwarfs. The sample also includes 50 dwarf or subdwarf L-type stars, and four T dwarfs. Possible halo subdwarfs are identified in the sample based on tangential velocity, subluminosity, and spectral type. Residuals from the solutions for parallax and proper motion for several stars show evidence of astrometric perturbations.

  20. Machine vision: recent advances in CCD video camera technology

    Science.gov (United States)

    Easton, Richard A.; Hamilton, Ronald J.

    1997-09-01

    This paper describes four state-of-the-art digital video cameras, which provide advanced features that benefit computer image enhancement, manipulation, and analysis. These cameras were designed to reduce the complexity of imaging systems while increasing the accuracy, dynamic range, and detail enhancement of product inspections. Two cameras utilize progressive scan CCD sensors enabling the capture of high- resolution image of moving objects without the need for strobe lights or mechanical shutters. The second progressive scan camera has an unusually high resolution of 1280 by 1024 and a choice of serial or parallel digital interface for data and control. The other two cameras incorporate digital signal processing (DSP) technology for improved dynamic range, more accurate determination of color, white balance stability, and enhanced contrast of part features against the background. Successful applications and future product development trends are discussed. A brief description of analog and digital image capture devices will address the most common questions regarding interface requirements within a typical machine vision system overview.

  1. An Intensive CCD Photometry Campaign to Observe DW Ursae Majoris

    Science.gov (United States)

    Boyd, David; Gaensicke, Boris

    2009-05-01

    We report on a coordinated observing campaign in April and May 2008 to study the eclipsing dwarf nova DW Ursae Majoris. This belongs to the group of SW Sex stars, nova-like variables containing accretion disks which exhibit superhumps in their light curves suggesting that their accretion disks are elliptical and precessing on time scales of a few days due to tidal interactions with the companion star. It has been suggested that the changing geometry will cause the depth of eclipses to be modulated on the accretion disk precession period. The aim of this campaign was to provide for the first time sufficient continuous photometric coverage of an eclipsing super-humper to test this hypothesis. 26 experienced amateur CCD photometrists in 7 countries participated in the project and altogether made almost 55,000 magnitude measurements over a 4 week period, keeping DW UMa under observation for more than 50% of the time. The results provide direct measurements of the orbital, super-hump and disk precession periods, confirming unambiguously that the superhump signal is a beat between the orbital and precession periods. They also reveal modulation not only of the eclipse depth but also of the eclipse time of minimum and width on the accretion disk precession period. The project is a good example of cooperation between the amateur and professional communities to address an open research issue.

  2. Assembling the HST Carina Nebula Mosaic

    Science.gov (United States)

    Levay, Zoltan G.; Smith, N.; Bond, H. E.; Christian, C. A.; Frattare, L. M.; Hamilton, F.; Januszewski, W.; Mutchler, M.; Knoll, K. S.

    2007-12-01

    Hubble Space Telescope has obtained numerous images of the Carina Nebula with ACS/WFC using the F658N filter (Hα+[N II]), revealing exquisite detail in this active star-forming region rich in finely detailed structure. Forty-eight overlapping fields were composited into a nearly contiguous mosaic of WFC pointings, resulting in a monochrome image of roughly 500 megapixels spanning ˜24'×12'. In addition, overlapping, wider-field images obtained with the CTIO 4m and MOSAIC2 camera in three narrow-band filters were combined into a color composite. We demonstrate a luminosity layering technique (LRGB) to reconstruct a high-resolution color image by combining the monochrome HST image with the color composite CTIO data which preserves the high spatial resolution brightness structure superimposed on the lower spatial resolution color values. We also touch on some cosmetic techniques to clean the image, including filling in small areas of data gaps and saturation.

  3. Germline mosaicism at the fragile X locus.

    Science.gov (United States)

    Prior, T W; Papp, A C; Snyder, P J; Sedra, M S; Guida, M; Enrile, B G

    1995-01-30

    We have identified a fragile X syndrome pedigree where the disorder is associated with a molecular deletion. The deletion was present in the DNA of 2 sons but was absent in the mother's somatic cell (lymphocyte) DNA. The results are consistent with the deletion arising as a postzygotic event in the mother, who therefore is germinally mosaic. This finding has important implications for counseling fragile X families with deletion mutations.

  4. CCD TV focal plane guider development and comparison to SIRTF applications

    Science.gov (United States)

    Rank, David M.

    1989-01-01

    It is expected that the SIRTF payload will use a CCD TV focal plane fine guidance sensor to provide acquisition of sources and tracking stability of the telescope. Work has been done to develop CCD TV cameras and guiders at Lick Observatory for several years and have produced state of the art CCD TV systems for internal use. NASA decided to provide additional support so that the limits of this technology could be established and a comparison between SIRTF requirements and practical systems could be put on a more quantitative basis. The results of work carried out at Lick Observatory which was designed to characterize present CCD autoguiding technology and relate it to SIRTF applications is presented. Two different design types of CCD cameras were constructed using virtual phase and burred channel CCD sensors. A simple autoguider was built and used on the KAO, Mt. Lemon and Mt. Hamilton telescopes. A video image processing system was also constructed in order to characterize the performance of the auto guider and CCD cameras.

  5. The Landsat Image Mosaic of Antarctica

    Science.gov (United States)

    Bindschadler, R.; Vornberger, P.; Fleming, A.; Fox, A.; Mullins, J.; Binnie, D.; Paulsen, S.J.; Granneman, B.; Gorodetzky, D.

    2008-01-01

    The Landsat Image Mosaic of Antarctica (LIMA) is the first true-color, high-spatial-resolution image of the seventh continent. It is constructed from nearly 1100 individually selected Landsat-7 ETM+ scenes. Each image was orthorectified and adjusted for geometric, sensor and illumination variations to a standardized, almost seamless surface reflectance product. Mosaicing to avoid clouds produced a high quality, nearly cloud-free benchmark data set of Antarctica for the International Polar Year from images collected primarily during 1999-2003. Multiple color composites and enhancements were generated to illustrate additional characteristics of the multispectral data including: the true appearance of the surface; discrimination between snow and bare ice; reflectance variations within bright snow; recovered reflectance values in regions of sensor saturation; and subtle topographic variations associated with ice flow. LIMA is viewable and individual scenes or user defined portions of the mosaic are downloadable at http://lima.usgs.gov. Educational materials associated with LIMA are available at http://lima.nasa.gov.

  6. Reassessing Jacob Strauss and the Mosaic Code

    Directory of Open Access Journals (Sweden)

    Joel McDurmon

    2012-01-01

    Full Text Available This article reviewed claims made by modern scholars Ford Lewis Battles, G.H. Williams, and Theodore Tappert concerning the views of Jacob Strauss (1480–1530, court preacher at Eisenach, particularly in regard to the imposition of Mosaic Law upon the civil realm. Most pointedly, Battles claims Strauss proposed to replace European civil law completely with the ‘entire Mosaic code’. This study examined Strauss’s relevant writings to determine his position on Mosaic Law and civil law and demonstrated that the claims of Battles, Williams, and Tappert were not supported by the primary source evidence. Selections from Strauss’ 51 theses on usury are translated into English for the first time. To a much lesser degree, this study addressed the issue in regard to the Weimar court preacher Wolfgang Stein, against whom the same claims were made. A paucity of evidence rendered those claims dubious in his case. In the end we were left only with unsubstantiated second-hand claims against these men.

  7. KARAKTERISASICYMBIDIUM MOSAIC VIRUS (CYMMV PADA TANAMAN ANGGREK

    Directory of Open Access Journals (Sweden)

    KHAMDAN KHALIMI

    2012-11-01

    Full Text Available Characterization ofCymbidium mosaic virus (CymMV on Orchid Plant Orchids are affected by more virus disease problems than most crops, reducing their commercial values considerably. Orchid viruses are widespread in cultivated orchids, withCymbidium mosaic potexvirus (CymMV being the most prevalent. CymMV high incidence in cultivated orchids has been attributed to the stability and ease of transmission of this virus through cultural practices. CymMV induces floral and foliar necrosis. The virus also reduce plant vigor and lower flower quality, which affect their economic value. The objective of the research is to characterize the virus causing mosaic or chlorotic and necrotic on orchids in West Java. A reverse transcription-polymerase chain reaction (RT- PCR assays using oligonucleotide primers specific to CymMV were also successfully amplified the regions of the coat protein (CP gene of the virus. Analysis by using sodium dodecyl sulphate- polyacrylamide gel electrophoresis (SDS-PAGE revealed that the virus have a major structural protein with an estimated molecular weight of 28 kDa. Aligments of partial nucleotide sequences of the CP gene displayed 86 to 92% homology to CymMV isolates from other countries.

  8. The carotenoid cleavage dioxygenase CCD2 catalysing the synthesis of crocetin in spring crocuses and saffron is a plastidial enzyme.

    Science.gov (United States)

    Ahrazem, Oussama; Rubio-Moraga, Angela; Berman, Judit; Capell, Teresa; Christou, Paul; Zhu, Changfu; Gómez-Gómez, Lourdes

    2016-01-01

    The apocarotenoid crocetin and its glycosylated derivatives, crocins, confer the red colour to saffron. Crocetin biosynthesis in saffron is catalysed by the carotenoid cleavage dioxygenase CCD2 (AIG94929). No homologues have been identified in other plant species due to the very limited presence of crocetin and its derivatives in the plant kingdom. Spring Crocus species with yellow flowers accumulate crocins in the stigma and tepals. Four carotenoid CCDs, namely CaCCD1, CaCCD2 and CaCCD4a/b and CaCCD4c were first cloned and characterized. CaCCD2 was localized in plastids, and a longer CCD2 version, CsCCD2L, was also localized in this compartment. The activity of CaCCD2 was assessed in Escherichia coli and in a stable rice gene function characterization system, demonstrating the production of crocetin in both systems. The expression of all isolated CCDs was evaluated in stigma and tepals at three key developmental stages in relation with apocarotenoid accumulation. CaCCD2 expression parallels crocin accumulation, but C14 apocarotenoids most likely are associated to the CaCCD1 activity in Crocus ancyrensis flowers. The specific CCD2 localization and its membrane interaction will contribute to the development of a better understanding of the mechanism of crocetin biosynthesis and regulation in the chromoplast. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  9. Fibromyalgia in patients with chronic CCD and CMD - A retrospective study of 555 patients.

    Science.gov (United States)

    Losert-Bruggner, Brigitte; Hülse, Manfred; Hülse, Roland

    2017-06-05

    Craniomandibular dysfunction (CMD) and craniocervical dysfunction (CCD) are clearly defined musculoskeletal pain syndromes. Relationships with fibromyalgia syndrome (FMS) have not yet been investigated. The aim of the present study is to establish possible relationships between FMS and CMD/ CCD. In a retrospective study, 555 patients with CCD and CMD were investigated with respect to the diagnostic criteria of FMS. In addition to otolaryngologic and dental examination, an instrumental functional analysis for the diagnosis of CMD/CCD was performed. Three hundred fifty-one (63%) of the 555 patients evaluated met the diagnostic criteria for FMS. Seventy-two percent of the patients had a widespread pain index of at least 7 and a severity scale score of at least 5. Twenty-nine percent had a widespread pain index of 3-6 and a severity scale score of at least 9. Using myocentric bite splint therapy and therapy with oral orthesis in combination with neuromuscular relaxation measures, a good to very good improvement of physical symptoms was seen in 84% of CMD-FMS patients, and an improvement of the symptoms in the jaw was achieved in 77% of cases. The substantial proportion of CMD and CCD patients who meet the criteria for FMS emphasizes the complexity of the two diseases. It must be assumed that FMS is a crucial factor for the formation of CMD and CCD. Conversely, CMD/ CCD could also be responsible for diverse clinical pictures of the FMS. FMS patients with synchronous CCD/CMD benefit from an interdisciplinary CMD/CCD treatment.

  10. RI: CCD-FO Assembly for Spectroscopic Characterization of Flame Synthesis Processes

    Science.gov (United States)

    2012-02-15

    involving thermite reactions with nano-Al. Specifically, the CCD-FO component of 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 15-02-2012 13...for nano-energetic applications involving thermite reactions with nano-Al. Specifically, the CCD-FO component of the detector is used as part of a...energetic applications involving thermite reactions with nano-Al. Specifically, the CCD-FO component of the detector is used as part of a laser-based

  11. Discriminação de variedades de citros em imagens CCD/CBERS-2 Discrimination of citrus varieties using CCD/CBERS-2 satellite imagery

    Directory of Open Access Journals (Sweden)

    Ieda Del'Arco Sanches

    2008-02-01

    Full Text Available O presente trabalho teve o objetivo de avaliar as imagens CCD/CBERS-2 quanto à possibilidade de discriminarem variedades de citros. A área de estudo localiza-se em Itirapina (SP e, para este estudo, foram utilizadas imagens CCD de três datas (30/05/2004, 16/08/2004 e 11/09/2004. Um modelo que integra os elementos componentes da cena citrícola sensoriada é proposto com o objetivo de explicar a variabilidade das respostas das parcelas de citros em imagens orbitais do tipo CCD/CBERS-2. Foram feitas classificações pelos algoritmos Isoseg e Maxver e, de acordo com o índice kappa, concluiu-se que é possível obterem-se exatidões qualificadas como muito boas, sendo que as melhores classificações foram conseguidas com imagens da estação seca.This paper was aimed at evaluating the possibility of discriminating citrus varieties in CCD imageries from CBERS-2 satellite ("China-Brazil Earth Resouces Satellite". The study area is located in Itirapina, São Paulo State. For this study, three CCD images from 2004 were acquired (May 30, August 16, and September 11. In order to acquire a better understanding and for explaining the variability of the spectral behavior of the citrus areas in orbital images (like as the CCD/CBERS-2 images a model that integrates the elements of the citrus scene is proposed and discussed. The images were classified by Isoseg and MaxVer classifiers. According to kappa index, it was possible to obtain classifications qualified as 'very good'. The best results were obtained with the images from the dry season.

  12. Retinal Astrocytes and GABAergic Wide-Field Amacrine Cells Express PDGFRα: Connection to Retinal Ganglion Cell Neuroprotection by PDGF-AA.

    Science.gov (United States)

    Takahama, Shokichi; Adetunji, Modupe O; Zhao, Tantai; Chen, Shan; Li, Wei; Tomarev, Stanislav I

    2017-09-01

    Our previous experiments demonstrated that intravitreal injection of platelet-derived growth factor-AA (PDGF-AA) provides retinal ganglion cell (RGC) neuroprotection in a rodent model of glaucoma. Here we used PDGFRα-enhanced green fluorescent protein (EGFP) mice to identify retinal cells that may be essential for RGC protection by PDGF-AA. PDGFRα-EGFP mice expressing nuclear-targeted EGFP under the control of the PDGFRα promoter were used. Localization of PDGFRα in the neural retina was investigated by confocal imaging of EGFP fluorescence and immunofluorescent labeling with a panel of antibodies recognizing different retinal cell types. Primary cultures of mouse RGCs were produced by immunopanning. Neurobiotin injection of amacrine cells in a flat-mounted retina was used for the identification of EGFP-positive amacrine cells in the inner nuclear layer. In the mouse neural retina, PDGFRα was preferentially localized in the ganglion cell and inner nuclear layers. Immunostaining of the retina demonstrated that astrocytes in the ganglion cell layer and a subpopulation of amacrine cells in the inner nuclear layer express PDGFRα, whereas RGCs (in vivo or in vitro) did not. PDGFRα-positive amacrine cells are likely to be Type 45 gamma-aminobutyric acidergic (GABAergic) wide-field amacrine cells. These data indicate that the neuroprotective effect of PDGF-AA in a rodent model of glaucoma could be mediated by astrocytes and/or a subpopulation of amacrine cells. We suggest that after intravitreal injection of PDGF-AA, these cells secrete factors protecting RGCs.

  13. Evaluation of Visunex Medical's PanoCam(TM) LT and PanoCam(TM) Pro wide-field imaging systems for the screening of ROP in newborn infants.

    Science.gov (United States)

    Wood, Edward H; Moshfeghi, Andrew A; Nudleman, Eric D; Moshfeghi, Darius M

    2016-08-01

    Retinopathy of Prematurity (ROP) is a leading cause of childhood blindness. The incidence of ROP is rising, placing greater demands on the healthcare providers that serve these patients and their families. Telemedicine remote digital fundus imaging (TM-RDFI) plays a pivotal role in ROP management, and has allowed for the expansion of ROP care into previously underserved areas. A broad literature review through the pubmed index was undertaken with the goal of summarizing the current state of ROP and guidelines for its screening . Furthermore, all currently used telemedicine remote digital fundus imaging devices were analyzed both via the literature and the companies' websites/brochures. Finally, the PanoCam LT™ and PanoCam™ Pro created by Visunex Medical were analyzed via the company website/brochures. Expert commentary: The PanoCam LT™ and PanoCam™ Pro have recently been approved for use within the USA and CE marked for international commercialization in European Union and other countries requiring CE mark. These wide-field imaging systems have the intended use of ophthalmic imaging of all newborn babies and meet the requirements for ROP screening, thereby serving as competition within the ROP screening market previously dominated by one camera imaging system.

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

    Science.gov (United States)

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

    2015-10-01

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

  15. 3D wide field-of-view Gabor-domain optical coherence microscopy advancing real-time in-vivo imaging and metrology

    Science.gov (United States)

    Canavesi, Cristina; Cogliati, Andrea; Hayes, Adam; Tankam, Patrice; Santhanam, Anand; Rolland, Jannick P.

    2017-02-01

    Real-time volumetric high-definition wide-field-of-view in-vivo cellular imaging requires micron-scale resolution in 3D. Compactness of the handheld device and distortion-free images with cellular resolution are also critically required for onsite use in clinical applications. By integrating a custom liquid lens-based microscope and a dual-axis MEMS scanner in a compact handheld probe, Gabor-domain optical coherence microscopy (GD-OCM) breaks the lateral resolution limit of optical coherence tomography through depth, overcoming the tradeoff between numerical aperture and depth of focus, enabling advances in biotechnology. Furthermore, distortion-free imaging with no post-processing is achieved with a compact, lightweight handheld MEMS scanner that obtained a 12-fold reduction in volume and 17-fold reduction in weight over a previous dual-mirror galvanometer-based scanner. Approaching the holy grail of medical imaging - noninvasive real-time imaging with histologic resolution - GD-OCM demonstrates invariant resolution of 2 μm throughout a volume of 1 x 1 x 0.6 mm3, acquired and visualized in less than 2 minutes with parallel processing on graphics processing units. Results on the metrology of manufactured materials and imaging of human tissue with GD-OCM are presented.

  16. A Wide-Field Fluorescence Microscope Extension for Ultrafast Screening of One-Bead One-Compound Libraries Using a Spectral Image Subtraction Approach.

    Science.gov (United States)

    Heusermann, Wolf; Ludin, Beat; Pham, Nhan T; Auer, Manfred; Weidemann, Thomas; Hintersteiner, Martin

    2016-05-09

    The increasing involvement of academic institutions and biotech companies in drug discovery calls for cost-effective methods to identify new bioactive molecules. Affinity-based on-bead screening of combinatorial one-bead one-compound libraries combines a split-mix synthesis design with a simple protein binding assay operating directly at the bead matrix. However, one bottleneck for academic scale on-bead screening is the unavailability of a cheap, automated, and robust screening platform that still provides a quantitative signal related to the amount of target protein binding to individual beads for hit bead ranking. Wide-field fluorescence microscopy has long been considered unsuitable due to significant broad spectrum autofluorescence of the library beads in conjunction with low detection sensitivity. Herein, we demonstrate how such a standard microscope equipped with LED-based excitation and a modern CMOS camera can be successfully used for selecting hit beads. We show that the autofluorescence issue can be overcome by an optical image subtraction approach that yields excellent signal-to-noise ratios for the detection of bead-associated target proteins. A polymer capillary attached to a semiautomated bead-picking device allows the operator to efficiently isolate individual hit beads in less than 20 s. The system can be used for ultrafast screening of >200,000 bead-bound compounds in 1.5 h, thereby making high-throughput screening accessible to a wider group within the scientific community.

  17. Addressing Thermal Model Run Time Concerns of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA)

    Science.gov (United States)

    Peabody, Hume; Guerrero, Sergio; Hawk, John; Rodriguez, Juan; McDonald, Carson; Jackson, Cliff

    2016-01-01

    The Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) utilizes an existing 2.4 m diameter Hubble sized telescope donated from elsewhere in the federal government for near-infrared sky surveys and Exoplanet searches to answer crucial questions about the universe and dark energy. The WFIRST design continues to increase in maturity, detail, and complexity with each design cycle leading to a Mission Concept Review and entrance to the Mission Formulation Phase. Each cycle has required a Structural-Thermal-Optical-Performance (STOP) analysis to ensure the design can meet the stringent pointing and stability requirements. As such, the models have also grown in size and complexity leading to increased model run time. This paper addresses efforts to reduce the run time while still maintaining sufficient accuracy for STOP analyses. A technique was developed to identify slews between observing orientations that were sufficiently different to warrant recalculation of the environmental fluxes to reduce the total number of radiation calculation points. The inclusion of a cryocooler fluid loop in the model also forced smaller time-steps than desired, which greatly increases the overall run time. The analysis of this fluid model required mitigation to drive the run time down by solving portions of the model at different time scales. Lastly, investigations were made into the impact of the removal of small radiation couplings on run time and accuracy. Use of these techniques allowed the models to produce meaningful results within reasonable run times to meet project schedule deadlines.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Reconsidering the advantages of the three-dimensional representation of the interferometric transform for imaging with non-coplanar baselines and wide fields of view

    Science.gov (United States)

    Smith, D. M. P.; Young, A.; Davidson, D. B.

    2017-07-01

    Radio telescopes with baselines that span thousands of kilometres and with fields of view that span tens of degrees have been recently deployed, such as the Low Frequency Array, and are currently being developed, such as the Square Kilometre Array. Additionally, there are proposals for space-based instruments with all-sky imaging capabilities, such as the Orbiting Low Frequency Array. Such telescopes produce observations with three-dimensional visibility distributions and curved image domains. In most work to date, the visibility distribution has been converted to a planar form to compute the brightness map using a two-dimensional Fourier transform. The celestial sphere is faceted in order to counter pixel distortion at wide angles, with each such facet requiring a unique planar form of the visibility distribution. Under the above conditions, the computational and storage complexities of this approach can become excessive. On the other hand, when using the direct Fourier transform approach, which maintains the three-dimensional shapes of the visibility distribution and celestial sphere, the non-coplanar visibility component requires no special attention. Furthermore, as the celestial samples are placed directly on the curved surface of the celestial sphere, pixel distortion at wide angles is avoided. In this paper, a number of examples illustrate that under these conditions (very long baselines and very wide fields of view) the costs of the direct Fourier transform may be comparable to (or even lower than) methods that utilise the two-dimensional fast Fourier transform.

  20. Wide-field color imaging of scatter-based tissue contrast using both high spatial frequency illumination and cross-polarization gating.

    Science.gov (United States)

    Carlson, Mackenzie L; McClatchy, David M; Gunn, Jason R; Elliott, Jonathan T; Paulsen, Keith D; Kanick, Stephen C; Pogue, Brian W

    2017-08-11

    This study characterizes the scatter-specific tissue contrast that can be obtained by high spatial frequency (HSF) domain imaging and cross-polarization (CP) imaging, using a standard color imaging system, and how combining them may be beneficial. Both HSF and CP approaches are known to modulate the sensitivity of epi-illumination reflectance images between diffuse multiply scattered and superficially backscattered photons, providing enhanced contrast from microstructure and composition than what is achieved by standard wide-field imaging. Measurements in tissue-simulating optical phantoms show that CP imaging returns localized assessments of both scattering and absorption effects, while HSF has uniquely specific sensitivity to scatter-only contrast, with a strong suppression of visible contrast from blood. The combination of CP and HSF imaging provided an expanded sensitivity to scatter compared with CP imaging, while rejecting specular reflections detected by HSF imaging. ex vivo imaging of an atlas of dissected rodent organs/tissues demonstrated the scatter-based contrast achieved with HSF, CP and HSF-CP imaging, with the white light spectral signal returned by each approach translated to a color image for intuitive encoding of scatter-based contrast within images of tissue. The results suggest that visible CP-HSF imaging could have the potential to aid diagnostic imaging of lesions in skin or mucosal tissues and organs, where just CP is currently the standard practice imaging modality. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The Fifteen-Year Attitude History of the Wide Field Planetary Camera 2 Radiator and Collection Efficiencies for Micrometeoroids and Orbital Debris

    Science.gov (United States)

    Anz-Meador, Phillip D.; Liou, Jer-Chyi; Cooke, William J.; Koehler, H.

    2010-01-01

    An examination of the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC-2) radiator assembly was conducted at NASA Goddard Space Flight Center (GSFC) during the summer of 2009. Immediately apparent was a distinct biasing of the largest 45 impact features towards one side of the radiator, in contrast to an approximately uniform distribution of smaller impacts. Such a distribution may be a consequence of the HST s attitude history and pointing requirements for the cold radiator, or of environmental effects, such as an anisotropic distribution of the responsible population in that size regime. Understanding the size-dependent spatial distribution of impact features is essential to the general analysis of these features. We have obtained from GSFC a 15 minute temporal resolution record of the state vector (Earth Centered Inertial position and velocity) and HST attitude, consisting of the orientation of the velocity and HST-sun vectors in HST body coordinates. This paper reviews the actual state vector and attitude history of the radiator in the context of the randomly tumbling plate assumption and assesses the statistical likelihood (or collection efficiency) of the radiator for the micrometeoroid and orbital debris environments. The NASA Marshall Space Flight Center s Meteoroid Environment Model is used to assess the micrometeoroid component. The NASA Orbital Debris Engineering Model (ORDEM) is used to model the orbital debris component. Modeling results are compared with observations of the impact feature spatial distribution, and the relative contribution of each environmental component are examined in detail.

  2. Lensfree optofluidic plasmonic sensor for real-time and label-free monitoring of molecular binding events over a wide field-of-view

    Science.gov (United States)

    Coskun, Ahmet F.; Cetin, Arif E.; Galarreta, Betty C.; Alvarez, Daniel Adrianzen; Altug, Hatice; Ozcan, Aydogan

    2014-01-01

    We demonstrate a high-throughput biosensing device that utilizes microfluidics based plasmonic microarrays incorporated with dual-color on-chip imaging toward real-time and label-free monitoring of biomolecular interactions over a wide field-of-view of >20 mm2. Weighing 40 grams with 8.8 cm in height, this biosensor utilizes an opto-electronic imager chip to record the diffraction patterns of plasmonic nanoapertures embedded within microfluidic channels, enabling real-time analyte exchange. This plasmonic chip is simultaneously illuminated by two different light-emitting-diodes that are spectrally located at the right and left sides of the plasmonic resonance mode, yielding two different diffraction patterns for each nanoaperture array. Refractive index changes of the medium surrounding the near-field of the nanostructures, e.g., due to molecular binding events, induce a frequency shift in the plasmonic modes of the nanoaperture array, causing a signal enhancement in one of the diffraction patterns while suppressing the other. Based on ratiometric analysis of these diffraction images acquired at the detector-array, we demonstrate the proof-of-concept of this biosensor by monitoring in real-time biomolecular interactions of protein A/G with immunoglobulin G (IgG) antibody. For high-throughput on-chip fabrication of these biosensors, we also introduce a deep ultra-violet lithography technique to simultaneously pattern thousands of plasmonic arrays in a cost-effective manner. PMID:25346102

  3. Simulator sickness when performing gaze shifts within a wide field of view optic flow environment: preliminary evidence for using virtual reality in vestibular rehabilitation

    Directory of Open Access Journals (Sweden)

    Whitney Susan L

    2004-12-01

    Full Text Available Abstract Background Wide field of view virtual environments offer some unique features that may be beneficial for use in vestibular rehabilitation. For one, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. However, wide FOV devices also have been found to result in greater simulator sickness. Before a wide FOV device can be used in a clinical setting, its safety must be demonstrated. Methods Symptoms of simulator sickness were recorded by 9 healthy adult subjects after they performed gaze shifting tasks to locate targets superimposed on an optic flow background. Subjects performed 8 trials of gaze shifting on each of the six separate visits. Results The incidence of symptoms of simulator sickness while subjects performed gaze shifts in an optic flow environment was lower than the average reported incidence for flight simulators. The incidence was greater during the first visit compared with subsequent visits. Furthermore, the incidence showed an increasing trend over the 8 trials. Conclusion The performance of head unrestrained gaze shifts in a wide FOV optic flow environment is tolerated well by healthy subjects. This finding provides rationale for testing these environments in people with vestibular disorders, and supports the concept of using wide FOV virtual reality for vestibular rehabilitation.

  4. Simulator sickness when performing gaze shifts within a wide field of view optic flow environment: preliminary evidence for using virtual reality in vestibular rehabilitation.

    Science.gov (United States)

    Sparto, Patrick J; Whitney, Susan L; Hodges, Larry F; Furman, Joseph M; Redfern, Mark S

    2004-12-23

    BACKGROUND: Wide field of view virtual environments offer some unique features that may be beneficial for use in vestibular rehabilitation. For one, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. However, wide FOV devices also have been found to result in greater simulator sickness. Before a wide FOV device can be used in a clinical setting, its safety must be demonstrated. METHODS: Symptoms of simulator sickness were recorded by 9 healthy adult subjects after they performed gaze shifting tasks to locate targets superimposed on an optic flow background. Subjects performed 8 trials of gaze shifting on each of the six separate visits. RESULTS: The incidence of symptoms of simulator sickness while subjects performed gaze shifts in an optic flow environment was lower than the average reported incidence for flight simulators. The incidence was greater during the first visit compared with subsequent visits. Furthermore, the incidence showed an increasing trend over the 8 trials. CONCLUSION: The performance of head unrestrained gaze shifts in a wide FOV optic flow environment is tolerated well by healthy subjects. This finding provides rationale for testing these environments in people with vestibular disorders, and supports the concept of using wide FOV virtual reality for vestibular rehabilitation.

  5. A Panchromatic Catalog of Early-type Galaxies at Intermediate Redshift in the Hubble Space Telescope Wide Field Camera 3 Early Release Science Field

    Science.gov (United States)

    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 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.

  6. THE FLAT TRANSMISSION SPECTRUM OF THE SUPER-EARTH GJ1214b FROM WIDE FIELD CAMERA 3 ON THE HUBBLE SPACE TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Berta, Zachory K.; Charbonneau, David; Desert, Jean-Michel; Irwin, Jonathan [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Miller-Ricci Kempton, Eliza; Fortney, Jonathan J.; Nutzman, Philip [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); McCullough, Peter R. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Burke, Christopher J. [SETI Institute/NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Homeier, Derek, E-mail: zberta@cfa.harvard.edu [Centre de Recherche Astrophysique de Lyon, UMR 5574, CNRS, Universite de Lyon, Ecole Normale Superieure de Lyon, F-69364 Lyon Cedex 07 (France)

    2012-03-01

    Capitalizing on the observational advantage offered by its tiny M dwarf host, we present Hubble Space Telescope/Wide Field Camera 3 (WFC3) grism measurements of the transmission spectrum of the super-Earth exoplanet GJ1214b. These are the first published WFC3 observations of a transiting exoplanet atmosphere. After correcting for a ramp-like instrumental systematic, we achieve nearly photon-limited precision in these observations, finding the transmission spectrum of GJ1214b to be flat between 1.1 and 1.7 {mu}m. Inconsistent with a cloud-free solar composition atmosphere at 8.2{sigma}, the measured achromatic transit depth most likely implies a large mean molecular weight for GJ1214b's outer envelope. A dense atmosphere rules out bulk compositions for GJ1214b that explain its large radius by the presence of a very low density gas layer surrounding the planet. High-altitude clouds can alternatively explain the flat transmission spectrum, but they would need to be optically thick up to 10 mbar or consist of particles with a range of sizes approaching 1 {mu}m in diameter.

  7. Optimizing ultrafast wide field-of-view illumination for high-throughput multi-photon imaging and screening of mutant fluorescent proteins

    Science.gov (United States)

    Stoltzfus, Caleb; Mikhailov, Alexandr; Rebane, Aleksander

    2017-02-01

    Fluorescence induced by 1wo-photon absorption (2PA) and three-photon absorption (3PA) is becoming an increasingly important tool for deep-tissue microscopy, especially in conjunction with genetically-encoded functional probes such as fluorescent proteins (FPs). Unfortunately, the efficacy of the multi-photon excitation of FPs is notoriously low, and because relations between a biological fluorophore's nonlinear-optical properties and its molecular structure are inherently complex, there are no practical avenues available that would allow boosting the performance of current FPs. Here we describe a novel method, where we apply directed evolution to optimize the 2PA properties of EGFP. Key to the success of this approach consists in high-throughput screening of mutants that would allow selection of variants with promising 2PA and 3PA properties in a broad near-IR excitation range of wavelength. For this purpose, we construct and test a wide field-of-view (FOV), femtosecond imaging system that we then use to quantify the multi-photon excited fluorescence in the 550- 1600 nm range of tens of thousands of E. coli colonies expressing randomly mutated FPs in a standard 10 cm diameter Petri dish configuration. We present a quantitative analysis of different factors that are currently limiting the maximum throughput of the femtosecond multi-photon screening techniques and also report on quantitative measurement of absolute 2PA and 3PA cross sections spectra.

  8. Globular Cluster Photometry with the Hubble Space Telescope. VII. Color Gradients and Blue Stragglers in the Central Region of M30 from Wide Field Planetary Camera 2 Observations

    Science.gov (United States)

    Guhathakurta, Puragra; Webster, Zodiac T.; Yanny, Brian; Schneider, Donald P.; Bahcall, John N.

    1998-10-01

    We present F555W (V), F439W (B), and F336W (U) photometry of 9507 stars in the central 2' of the dense, post-core-collapse cluster M30 (NGC 7099) derived from Hubble Space Telescope Wide Field Planetary Camera 2 images. These data are used to study the mix of stellar populations in the central region of the cluster. Forty-eight blue straggler stars are identified; they are found to be strongly concentrated toward the cluster center. The specific frequency of blue stragglers, F_BSS = N(BSS)/N(V responsible for about half of the observed color gradient; the rest of the gradient is caused by the relative underabundance of faint red main-sequence stars near the cluster center (presumably a result of mass segregation). The luminosity function of M30's evolved stars does not match the luminosity function shape derived from standard stellar evolutionary models: the ratio of the number of bright giants to the number of turnoff stars in the cluster is 30% higher than predicted by the model (3.8 sigma effect), roughly independent of red giant brightness over the range M_V = -2 to +2. 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 NAS 5-26555. Lick Observatory Bulletin No. 1377.

  9. Mosaic anisotropy model for magnetic interactions in mesostructured crystals

    Directory of Open Access Journals (Sweden)

    Abby R. Goldman

    2017-10-01

    Full Text Available We propose a new model for interpreting the magnetic interactions in crystals with mosaic texture called the mosaic anisotropy (MA model. We test the MA model using hematite as a model system, comparing mosaic crystals to polycrystals, single crystal nanoparticles, and bulk single crystals. Vibrating sample magnetometry confirms the hypothesis of the MA model that mosaic crystals have larger remanence (Mr/Ms and coercivity (Hc compared to polycrystalline or bulk single crystals. By exploring the magnetic properties of mesostructured crystalline materials, we may be able to develop new routes to engineering harder magnets.

  10. MULTIMODAL IMAGING OF MOSAIC RETINOPATHY IN CARRIERS OF HEREDITARY X-LINKED RECESSIVE DISEASES.

    Science.gov (United States)

    Wu, An-Lun; Wang, Jung-Pan; Tseng, Yun-Ju; Liu, Laura; Kang, Yu-Chuan; Chen, Kuan-Jen; Chao, An-Ning; Yeh, Lung-Kun; Chen, Tun-Lu; Hwang, Yih-Shiou; Wu, Wei-Chi; Lai, Chi-Chun; Wang, Nan-Kai

    2017-04-03

    To investigate the clinical features in carriers of X-linked retinitis pigmentosa, X-linked ocular albinism, and choroideremia (CHM) using multimodal imaging and to assess their diagnostic value in these three mosaic retinopathies. We prospectively examined 14 carriers of 3 X-linked recessive disorders (X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM). Details of abnormalities of retinal morphology were evaluated using fundus photography, fundus autofluorescence (FAF) imaging, and spectral domain optical coherence tomography. In six X-linked retinitis pigmentosa carriers, fundus appearance varied from unremarkable to the presence of tapetal-like reflex and pigmentary changes. On FAF imaging, all carriers exhibited a bright radial reflex against a dark background. By spectral domain optical coherence tomography, loss of the ellipsoid zone in the macula was observed in 3 carriers (50%). Regarding the retinal laminar architecture, 4 carriers (66.7%) showed thinning of the outer nuclear layer and a dentate appearance of the outer plexiform layer. All five X-linked ocular albinism carriers showed a characteristic mud-splatter patterned fundus, dark radial streaks against a bright background on FAF imaging, and a normal-appearing retinal structure by spectral domain optical coherence tomography imaging. Two of the 3 CHM carriers (66.7%) showed a diffuse moth-eaten appearance of the fundus, and all 3 showed irregular hyper-FAF and hypo-FAF spots throughout the affected area. In the CHM carriers, the structural changes observed by spectral domain optical coherence tomography imaging were variable. Our findings in an Asian cohort suggest that FAF imaging is a practical diagnostic test for differentiating X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM carriers. Wide-field FAF is an easy and helpful adjunct to testing for the correct diagnosis and identification of lyonization in carriers of these three mosaic retinopathies.

  11. arXiv Single-electron and single-photon sensitivity with a silicon Skipper CCD

    CERN Document Server

    Tiffenberg, Javier; Drlica-Wagner, Alex; Essig, Rouven; Guardincerri, Yann; Holland, Steve; Volansky, Tomer; Yu, Tien-Tien

    2017-09-26

    We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068  e- rms/pixel. This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime. Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while ...

  12. MMT OBSERVATORY 6.5M CCD47 RAW DATA OBSERVATIONS OF LCROSS

    Data.gov (United States)

    National Aeronautics and Space Administration — This archive contains raw observations of the 2009-10-09 impact of the LCROSS spacecraft on the moon by the CCD47 camera on the MMT Observatory 6.5m telescope. The...

  13. VizieR Online Data Catalog: NGC 6811 CCD UBVRI photometry (Yontan+, 2015)

    Science.gov (United States)

    Yontan, T.; Bilir, S.; Bostanc, Z. F.; Ak, T.; Karaali, S.; Guver, T.; Ak, S.; Duran, S.; Paunzen, E.

    2015-09-01

    CCD UBVRI observations of NGC 6811 were carried out on 18th July 2012 using the 1m Ritchey-Chretien telescope (T100) located at the TUBITAK National Observatory (TUG) in Bakirlitepe, Antalya/Turkey. (1 data file).

  14. Researchers develop CCD image sensor with 20ns per row parallel readout time

    CERN Multimedia

    Bush, S

    2004-01-01

    "Scientists at the Rutherford Appleton Laboratory (RAL) in Oxfordshire have developed what they claim is the fastest CCD (charge-coupled device) image sensor, with a readout time which is 20ns per row" (1/2 page)

  15. JERS-1 Synthetic Aperture Radar, 1- km Mosaic, Amazon Basin: 1995-1996

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains two image mosaics of L-band radar backscatter and two image mosaics of first order texture. The two backscatter images are mosaics...

  16. Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology.

    Science.gov (United States)

    vanEngelsdorp, Dennis; Traynor, Kirsten S; Andree, Michael; Lichtenberg, Elinor M; Chen, Yanping; Saegerman, Claude; Cox-Foster, Diana L

    2017-01-01

    Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors

  17. Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology

    Science.gov (United States)

    Traynor, Kirsten S.; Andree, Michael; Lichtenberg, Elinor M.; Chen, Yanping; Saegerman, Claude; Cox-Foster, Diana L.

    2017-01-01

    Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors

  18. Colony Collapse Disorder (CCD and bee age impact honey bee pathophysiology.

    Directory of Open Access Journals (Sweden)

    Dennis vanEngelsdorp

    Full Text Available Honey bee (Apis mellifera colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions, and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees, we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and

  19. Preliminary examination of a CCD camera with a scintillator coated fiber optic plate for neutron imaging

    Science.gov (United States)

    Matsubayashi, Masahito; Soyama, Kazuhiko

    2004-08-01

    A charge coupled device (CCD) camera with a scintillator coated fiber optic plate (FOP) was examined for neutron imaging. The FOP coupling and the lens coupling in terms of efficient optical coupling with a CCD, and 6LiF:ZnS(Ag) and Gd 2O 2S(Tb) in terms of light emission efficiency and spatial resolution were discussed. The spatial resolution for each imaging system was obtained as edge spread functions or observations of modulation transfer function charts.

  20. Practical performance evaluation of a 10k × 10k CCD for electron cryo-microscopy.

    Science.gov (United States)

    Bammes, Benjamin E; Rochat, Ryan H; Jakana, Joanita; Chiu, Wah

    2011-09-01

    Electron cryo-microscopy (cryo-EM) images are commonly collected using either charge-coupled devices (CCD) or photographic film. Both film and the current generation of 16 megapixel (4k × 4k) CCD cameras have yielded high-resolution structures. Yet, despite the many advantages of CCD cameras, more than two times as many structures of biological macromolecules have been published in recent years using photographic film. The continued preference to film, especially for subnanometer-resolution structures, may be partially influenced by the finer sampling and larger effective specimen imaging area offered by film. Large format digital cameras may finally allow them to overtake film as the preferred detector for cryo-EM. We have evaluated a 111-megapixel (10k × 10k) CCD camera with a 9 μm pixel size. The spectral signal-to-noise ratios of low dose images of carbon film indicate that this detector is capable of providing signal up to at least 2/5 Nyquist frequency potentially retrievable for 3D reconstructions of biological specimens, resulting in more than double the effective specimen imaging area of existing 4k × 4k CCD cameras. We verified our estimates using frozen-hydrated ε15 bacteriophage as a biological test specimen with previously determined structure, yielding a ∼7 Å resolution single particle reconstruction from only 80 CCD frames. Finally, we explored the limits of current CCD technology by comparing the performance of this detector to various CCD cameras used for recording data yielding subnanometer resolution cryo-EM structures submitted to the electron microscopy data bank (http://www.emdatabank.org/). Copyright © 2011 Elsevier Inc. All rights reserved.

  1. JAstroCam - A New Tool for Data Gathering with CCD

    Science.gov (United States)

    Budyn, M.; Zola, S.; Wojcik, K.

    2010-12-01

    We present a new acquisition program for observations with CCD. The code is written in the JAVA language, currently supports Photometrics S300, SBIG, APOGEE and Andor CCDs. New hardware support can be extended by adding plugins for either a new type of CCD or a filter wheel. The software is capable of performing an on-line reduction of frames coming in real time either on non-processed or reduced for bias/dark/flat frames.

  2. A Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Software

    Directory of Open Access Journals (Sweden)

    S. H. Oh

    2007-12-01

    Full Text Available We present a software which we developed for the multi-purpose CCD camera. This software can be used on the all 3 types of CCD - KAF-0401E (768×512, KAF-1602E (15367times;1024, KAF-3200E (2184×1472 made in KODAK Co.. For the efficient CCD camera control, the software is operated with two independent processes of the CCD control program and the temperature/shutter operation program. This software is designed to fully automatic operation as well as manually operation under LINUX system, and is controled by LINUX user signal procedure. We plan to use this software for all sky survey system and also night sky monitoring and sky observation. As our results, the read-out time of each CCD are about 15sec, 64sec, 134sec for KAF-0401E, KAF-1602E, KAF-3200E., because these time are limited by the data transmission speed of parallel port. For larger format CCD, the data transmission is required more high speed. we are considering this control software to one using USB port for high speed data transmission.

  3. Germline mosaicism at the fragile X locus

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A.C.; Snyder, P.J.; Sedra, M.S. [Ohio State Univ., Columbus, OH (United States)] [and others

    1994-09-01

    The fragile X full mutation, which is associated with the phenotypic expression of the disorder, is characterized by an expansion of CGG repeat and hypermethylation of the CpG island adjacent to the FMR1 gene. New mutations leading to amplification of the CGG repeat have not been reported. We have identified a fragile X syndrome pedigree where the disorder is associated with a molecular deletion. The deletion was present in the DNA of two affected sons but was absent in the mother`s somatic cell (lymphocyte) DNA. This was confirmed by dosage analysis of the Southern blot using StB12-3 and an additional probe against the dystrophin gene and by PCR analysis of DXS548 alleles. The results are consistent with the deletion arising as a postzygotic event in the mother, who therefore is germinally mosaic. The case reported here clearly demonstrates that FMR1 deletions, unlike the expansions, are not always inherited and the finding of heterozygosity or normal dosage from lymphocyte DNA in the mother of a deletion case does not necessarily rule out the possibility of having a second affected child. The deletion of FMR1 gene may be responsible for a small but significant number of fragile X cases. Therefore, it is imperative that those involved in genetic counseling recognize this diagnostic pitfall. Since it depends upon the size of the mutant clone in the mosaic mother, the exact recurrence risk in germline carriers is unknown. However, prenatal and carrier testing should be performed independently of the outcome of the mother. Furthermore, it is possible that the deletion may not be restricted to the germline, and therefore the mother may actually be a somatic mosaic.

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

    Science.gov (United States)

    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 7.2σ 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

  5. Thermographic mosaic of Yellowstone National Park

    Science.gov (United States)

    Williams, R. S., Jr.; Hasell, P. G., Jr.; Sellman, A. N.; Smedes, H. W.

    1976-01-01

    An uncontrolled aerial thermographic mosaic of Yellowstone National Park was assembled from the videotape record of 13 individual thermographs obtained with linescan radiometers. Post mission processing of the videotape record rectified the nadir line to a topographic map base, corrected for v/h variations in adjacent flight lanes, corrected for yaw and pitch distortions, and distortions produced by nonlinearity of the side-wise scan. One of the purposes of the thermographic study was to delineate the areas of thermal emission (hot springs, geysers, etc.) throughout the Park, a study which could have great value in reconnaissance surveys of geothermal areas in remote regions or regions of high relief.

  6. Statistical Mechanics Characterization of Neuronal Mosaics

    CERN Document Server

    Costa, Luciano da Fontoura; de Lima, Silene Maria Araujo

    2005-01-01

    The spatial distribution of neuronal cells is an important requirement for achieving proper neuronal function in several parts of the nervous system of most animals. For instance, specific distribution of photoreceptors and related neuronal cells, particularly the ganglion cells, in mammal's retina is required in order to properly sample the projected scene. This work presents how two concepts from the areas of statistical mechanics and complex systems, namely the \\emph{lacunarity} and the \\emph{multiscale entropy} (i.e. the entropy calculated over progressively diffused representations of the cell mosaic), have allowed effective characterization of the spatial distribution of retinal cells.

  7. Mosaic crystal algorithm for Monte Carlo simulations

    CERN Document Server

    Seeger, P A

    2002-01-01

    An algorithm is presented for calculating reflectivity, absorption, and scattering of mosaic crystals in Monte Carlo simulations of neutron instruments. The algorithm uses multi-step transport through the crystal with an exact solution of the Darwin equations at each step. It relies on the kinematical model for Bragg reflection (with parameters adjusted to reproduce experimental data). For computation of thermal effects (the Debye-Waller factor and coherent inelastic scattering), an expansion of the Debye integral as a rapidly converging series of exponential terms is also presented. Any crystal geometry and plane orientation may be treated. The algorithm has been incorporated into the neutron instrument simulation package NISP. (orig.)

  8. Mosaic Turner syndrome and hyperinsulinaemic hypoglycaemia

    DEFF Research Database (Denmark)

    Alkhayyat, H.; Christesen, Henrik Thybo; Steer, J.

    2006-01-01

    BACKGROUND: A common and well recognised feature of Turner's syndrome (partial or total monosomy X) is impaired glucose tolerance or type 2 diabetes mellitus. A small percentage of patients with Turner's syndrome have a complex mosaic karyotype with atypical clinical features and mental retardation...... chromosome, and both the ring and marker chromosomes, respectively. FISH studies showed the abnormal chromosomes to originate from an X. The X inactivation locus (XIST) was present in the ring, but not in the marker chromosome. CONCLUSIONS: The recognition of hypoglycaemia in children with atypical Turner...

  9. An Optically Faint Quasar Survey at z ˜ 5 in the CFHTLS Wide Field: Estimates of the Black Hole Masses and Eddington Ratios

    Science.gov (United States)

    Ikeda, H.; Nagao, T.; Matsuoka, K.; Kawakatu, N.; Kajisawa, M.; Akiyama, M.; Miyaji, T.; Morokuma, T.

    2017-09-01

    We present the result of our spectroscopic follow-up observation for faint quasar candidates at z ˜ 5 in part of the Canada-France-Hawaii Telescope Legacy Survey wide field. We select nine photometric candidates and identify three z ˜ 5 faint quasars, one z ˜ 4 faint quasar, and a late-type star. Since two faint quasar spectra show the C IV emission line without suffering from a heavy atmospheric absorption, we estimate their black hole masses ({M}{BH}) and Eddington ratios (L/{L}{Edd}). The inferred {log}{M}{BH} are 9.04 ± 0.14 and 8.53 ± 0.20, respectively. In addition, the inferred {log}(L/{L}{Edd}) are -1.00 ± 0.15 and -0.42 ± 0.22, respectively. If we adopt that L/{L}{Edd}={constant} {or}\\propto {(1+z)}2, the seed black hole masses ({M}{seed}) of our z ˜ 5 faint quasars are expected to be > {10}5 {M}⊙ in most cases. We also compare the observational results with a mass accretion model, where angular momentum is lost due to supernova explosions. Accordingly, {M}{BH} of the z ˜ 5 faint quasars in our sample can be explained even if {M}{seed} is ˜ {10}3 {M}⊙ . Since z ˜ 6 luminous qusars and our z ˜ 5 faint quasars are not on the same evolutionary track, z ˜ 6 luminous quasars and our z ˜ 5 quasars are not the same populations but different populations, due to the difference of a period of the mass supply from host galaxies. Furthermore, we confirm that one can explain {M}{BH} of z ˜ 6 luminous quasars and our z ˜ 5 faint quasars even if their seed black holes are formed at z ˜ 7.

  10. Surgical feasibility and biocompatibility of wide-field dual-array suprachoroidal-transretinal stimulation prosthesis in middle-sized animals.

    Science.gov (United States)

    Lohmann, Tibor Karl; Kanda, Hiroyuki; Morimoto, Takeshi; Endo, Takao; Miyoshi, Tomomitsu; Nishida, Kentaro; Kamei, Motohiro; Walter, Peter; Fujikado, Takashi

    2016-04-01

    To investigate the safety and efficacy of a newly-developed wide-field dual-array suprachoroidal-transretinal stimulation (STS) prosthesis in middle-sized animals. The prosthesis consisted of two arrays with 50 to 74 electrodes. To test the feasibility of implanting the prosthesis and its efficacy, the prosthesis was implanted for 14 days into two rabbits. Optical coherence tomography (OCT) and ophthalmoscopy were performed 7 and 14 days after the implantation. Then the rabbits were euthanized, eyes were enucleated, and the posterior segment of the eye was examined histologically. In a second experiment, the arrays were implanted into two cats, and their ability to elicit neural responses was determined by electrically evoked potentials (EEPs) at the chiasm and by optical imaging of the retina. All arrays were successfully implanted, and no major complications occurred during the surgery or during the 2-week postoperative period. Neither OCT nor ophthalmoscopy showed any major complications or instability of the arrays. Histological evaluations showed only mild cellular infiltration and overall good retinal preservation. Stimulation of the retina by the arrays evoked EEPs recorded from the chiasm. Retinal imaging showed that the electrical pulses from the arrays altered the retinal images indicating an activation of retinal neurons. The thresholds were as low as 100 μA for a chiasm response and 300 μA for the retinal imaging. Implantation of a newly-developed dual-array STS prosthesis for 2 weeks in rabbits was feasible surgically, and safe. The results of retinal imaging showed that the dual-array system was able to activate retinal neurons. We conclude that the dual-array design can be implanted without complication and is able to activate retinal neurons and optic nerve axons.

  11. A Wide-field Study of the z 0.8 Cluster RX J0152.7-1357: The Role of Environment in Galaxy Evolution

    Science.gov (United States)

    Patel, Shannon; Kelson, D. D.; Holden, B. P.; Illingworth, G. D.; Franx, M.; van der Wel, A.; Ford, H.

    2009-01-01

    We study the influence of local environment on the formation and evolution of galaxies in the z 0.8 galaxy cluster RX J0152.7-1357 (RXJ0152-13) and its outskirts. Simulations show that massive clusters like RXJ0152-13 will grow in mass by a factor of 2-3 by z=0 through accretion of infalling galaxies and groups of galaxies. Our goal is to understand the transformation process that changes these infalling galaxies into red, early-type cluster members. We used a low-dispersion prism in the IMACS spectrograph at Magellan to obtain low-resolution spectroscopy for large numbers of galaxies over a wide field (D 30') in order to identify members in the vicinity of the cluster. With a mass limited sample (M>4x1010 MSun), we examined the rest-frame colors of galaxies as a function of local projected galaxy density. We found that the high-density regions in the core of the cluster and in the infalling groups support a high fraction of red galaxies compared to the lower density regions, as others have found at lower redshift. Intermediate density regions also revealed an elevated fraction of red galaxies. We also studied the star formation rates (SFRs) of members using Spitzer MIPS 24µm flux as a tracer. Our initial results show a lack of star-forming galaxies in the core of the cluster and in the high-density regions of the groups in the outskirts, which is consistent with their red colors discussed above. These results suggest that many future cluster members are transformed into passively evolving, red, early-types in infalling groups and in the surrounding filamentary structure of the cluster.

  12. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    Energy Technology Data Exchange (ETDEWEB)

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E. [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States); Ryan, R. E.; Koekemoer, A. M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Schneider, G.; Fan, X. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hathi, N. P. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Keel, W. C. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Roettgering, H. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Schneider, D. P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Strauss, M. A. [Princeton University Observatory, Princeton, NJ 08544 (United States); Yan, H. J. [Department of Physics and Astronomy, The University of Missouri, 701 South College Ave, Columbia, MO 65211 (United States)

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  13. Low-frequency wide-field fluorescence lifetime imaging using a high-power near-infrared light-emitting diode light source.

    Science.gov (United States)

    Gioux, Sylvain; Lomnes, Stephen J; Choi, Hak Soo; Frangioni, John V

    2010-01-01

    Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR light source for the clinical translation of wide-field (larger than 5 cm in diameter) FLi at frequencies up to 35 MHz. Lifetime imaging of indocyanine green (ICG), IRDye 800-CW, and 3,3(')-diethylthiatricarbocyanine iodide (DTTCI) was performed over a large field of view (10 cm by 7.5 cm) using the LED light source. For comparison, a laser diode light source was employed as a gold standard. Experiments were performed both on the bench by diluting the fluorescent dyes in various chemical environments in Eppendorf tubes, and in vivo by injecting the fluorescent dyes mixed in Matrigel subcutaneously into CD-1 mice. Last, measured fluorescence lifetimes obtained using the LED and the laser diode sources were compared with those obtained using a state-of-the-art time-domain imaging system and with those previously described in the literature. On average, lifetime values obtained using the LED and the laser diode light sources were consistent, exhibiting a mean difference of 3% from the expected values and a coefficient of variation of 12%. Taken together, our study offers an alternative to laser diodes for clinical translation of FLi and explores the use of relatively low frequency modulation for in vivo imaging.

  14. Microneedles rollers as a potential device to increase ALA diffusion and PpIX production: evaluations by wide-field fluorescence imaging and fluorescence spectroscopy

    Science.gov (United States)

    Gracielli Sousa, R. Phamilla; de Menezes, Priscila F. C.; Fujita, Alessandra K. L.; Requena, Michelle B.; Govone, Angelo Biassi; Escobar, André; de Nardi, Andrigo B.; Kurachi, Cristina; Bagnato, Vanderlei Salvador

    2014-03-01

    One of the limitations of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) is the poor ability to penetrate biological barriers of skin and the recurrence rates in treatments. This study aimed to identify possible signs of increased diffusion of ALA-induced PpIX by fluorescence images and fluorescence spectroscopy. The research was done using in vivo porcine skin model. Before the cream application, microholes was performed with microneedles rollers in only one direction, afterward the ALA cream was applied at a 2.5cm2 area in triplicate and an occlusive dressing was placed. PpIX production was monitored using fluorescence spectroscopy collected at skin surface after 70, 100, 140, and 180 minutes of ALA incubation. About 100 fluorescence spectra of each treatment were collected, distributed by about five points for each site. Wide-field fluorescence imaging was made after 70, 90, and 170 minutes after treatment. The results obtained by imaging analysis indicated increase of the PpIX diffusion in the skin surface using the microneedles rollers (MNs) before ALA application. Circular regions of red fluorescence around the microholes were observed. In addition, the fluorescence spectra showed a greater intensity (2 times as many) in groups microneedles rollers associated. In conclusion, our data shown greater homogeneity and PpIX production in the groups pre-treated with microneedles indicating that the technique can be used to greater uniformity of PpIX production throughout the area to be treated reducing the chances of recurrent tumor as well as has potential for decreasing the time of therapy. (FUNDING SUPPORT:CAPES, CNPq and FAPESP)

  15. Wide-Field Variability Survey of the Globular Cluster M 79 and a New Period-Luminosity Relation for SX Phe Stars

    Science.gov (United States)

    Kopacki, G.

    2015-03-01

    We present the results of a search for variable stars in a 26×39 arcmin2 field around globular cluster M 79 (NGC 1904). The search was made by means of an extended version of image subtraction, which allows us to analyze in a uniform manner CCD frames obtained with different telescopes and cameras of different sizes and resolutions. The search resulted in finding 20 new variable stars, among which 13 are cluster members. The members include one new RR Lyr star of subtype c, three SX Phe stars, and nine variable red giants. We also show that V7 is a W Vir star with a period of 13.985 d. Revised mean periods of RRab and RRc stars, ab=0.71 d and c=0.34 d, respectively, and relative percentage of RRc stars, Nc/(Nab+Nc)=45% confirm that M 79 belongs to the Oosterhoff II group of globular clusters. The mean V magnitude of the horizontal branch of M 79 based on ten RR Lyr stars has been estimated to be VHB=RR=16.11±0.03 mag. In one RRc star, V9, light changes with three close frequencies were detected, indicating excitation of nonradial modes. An SX Phe star, V18, is a double-mode pulsator with two radial modes excited, fundamental and first overtone. Moreover, we have discovered two SX Phe or δ Sct stars and one W UMa type system, all likely field objects. We also studied the period-luminosity relation for SX Phe stars. Using 62 fundamental and fundamentalized periods of radial double-mode and high-amplitude SX Phe stars known in Galactic globular clusters, we have derived the slope and zero point of this relation to be, -3.3±0.27 and 2.68±0.03 mag (at log(P/d)=-1.24), respectively.

  16. Prenatal diagnosis of a trisomy 7/trisomy 13 mosaicism

    NARCIS (Netherlands)

    Huijsdens-van Amsterdam, Karin; Barge-Schaapveld, Daniela Q. C. M.; Mathijssen, Inge B.; Alders, Mariëlle; Pajkrt, Eva; Knegt, Alida C.

    2012-01-01

    Double aneuploidy mosaicism of two different aneuploidy cell lines is rare. We describe for the first time a double trisomy mosaicism, involving chromosomes 7 and 13 in a fetus presenting with multiple congenital anomalies. No evidence for chimerism was found by DNA genotyping. The origin of both

  17. Status of cassava mosaic disease and whitefly population in Zambia ...

    African Journals Online (AJOL)

    Cassava mosaic disease is the most important disease affecting cassava in Zambia. A study was conducted through a survey to determine the status of cassava mosaic disease incidence, severity and whitefly abundance in farmers' fields in six provinces: Lusaka, Northern, North-Western, Luapula, Eastern and Western ...

  18. Sex mosaics in a male dimorphic ant Cardiocondyla kagutsuchi

    Science.gov (United States)

    Yoshizawa, Juri; Mimori, Kohei; Yamauchi, Katsusuke; Tsuchida, Koji

    2009-01-01

    Gynandromorphy, or the development of organisms with a combination of male and female morphological features, is common in Hymenoptera. The underlying mechanism is likely associated with the sex-determination system, and studying this phenomenon should lead to a deeper understanding of both embryonic development and sex determination. The reproductive capabilities of gynandromorphs (hereafter, sex mosaics) remain unclear. We studied gynandromorphy in the Malaysian ant Cardiocondyla kagutsuchi, which has sex mosaics of queens (gynandromorphs; mosaic of queens and winged male) and workers (ergatandromorphs; mosaic of worker and wingless ergatoid male). These sex mosaics were classified into seven morphological categories. Most individuals had more male than female body areas. Behavioral observations revealed that sex mosaics behave more in accordance with the “sex” of their brain than that of the reproductive organs (gaster). Relative DNA quantities showed that both female and male regions contained haploid and diploid nuclei, irrespective of their phenotypic appearance, indicating that external appearance did not reflect internal tissues. Nearly one third of the adults were sex mosaics and they were not infected with Wolbachia. Our results suggest that the production of sex mosaics in this species does not pose a substantial cost to colonies and that the underlying causes are therefore not strongly selected against.

  19. Sex mosaics in a male dimorphic ant Cardiocondyla kagutsuchi.

    Science.gov (United States)

    Yoshizawa, Juri; Mimori, Kohei; Yamauchi, Katsusuke; Tsuchida, Koji

    2009-01-01

    Gynandromorphy, or the development of organisms with a combination of male and female morphological features, is common in Hymenoptera. The underlying mechanism is likely associated with the sex-determination system, and studying this phenomenon should lead to a deeper understanding of both embryonic development and sex determination. The reproductive capabilities of gynandromorphs (hereafter, sex mosaics) remain unclear. We studied gynandromorphy in the Malaysian ant Cardiocondyla kagutsuchi, which has sex mosaics of queens (gynandromorphs; mosaic of queens and winged male) and workers (ergatandromorphs; mosaic of worker and wingless ergatoid male). These sex mosaics were classified into seven morphological categories. Most individuals had more male than female body areas. Behavioral observations revealed that sex mosaics behave more in accordance with the "sex" of their brain than that of the reproductive organs (gaster). Relative DNA quantities showed that both female and male regions contained haploid and diploid nuclei, irrespective of their phenotypic appearance, indicating that external appearance did not reflect internal tissues. Nearly one third of the adults were sex mosaics and they were not infected with Wolbachia. Our results suggest that the production of sex mosaics in this species does not pose a substantial cost to colonies and that the underlying causes are therefore not strongly selected against.

  20. Chromosomal mosaicism in human preimplantation embryos : a systematic review

    NARCIS (Netherlands)

    van Echten-Arends, Jannie; Mastenbroek, Sebastiaan; Sikkema-Raddatz, Birgit; Korevaar, Johanna C.; Heineman, Maas Jan; van der Veen, Fulco; Repping, Sjoerd

    2011-01-01

    BACKGROUND: Although chromosomal mosaicism in human preimplantation embryos has been described for almost two decades, its exact prevalence is still unknown. The prevalence of mosaicism is important in the context of preimplantation genetic screening in which the chromosomal status of an embryo is

  1. Barley stripe mosaic virus: Structure and relationship to the tobamoviruses

    Energy Technology Data Exchange (ETDEWEB)

    Kendall, Amy [Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, TN 37235 (United States); Williams, Dewight [Department of Molecular Physiology and Biophysics and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232 (United States); Bian, Wen [Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, TN 37235 (United States); Stewart, Phoebe L. [Department of Molecular Physiology and Biophysics and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232 (United States); Stubbs, Gerald, E-mail: gerald.stubbs@vanderbilt.edu [Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, TN 37235 (United States)

    2013-09-01

    Barley stripe mosaic virus (BSMV) is the type member of the genus Hordeivirus, rigid, rod-shaped viruses in the family Virgaviridae. We have used fiber diffraction and cryo-electron microscopy to determine the helical symmetry of BSMV to be 23.2 subunits per turn of the viral helix, and to obtain a low-resolution model of the virus by helical reconstruction methods. Features in the model support a structural relationship between the coat proteins of the hordeiviruses and the tobamoviruses. - Highlights: • We report a low-resolution structure of barley stripe mosaic virus. • Barley stripe mosaic virus has 23.2 subunits per turn of the viral helix. • We compare barley stripe mosaic virus with tobacco mosaic virus.

  2. Modulating STDP Balance Impacts the Dendritic Mosaic

    Directory of Open Access Journals (Sweden)

    Nicolangelo Iannella

    2017-06-01

    Full Text Available The ability for cortical neurons to adapt their input/output characteristics and information processing capabilities ultimately relies on the interplay between synaptic plasticity, synapse location, and the nonlinear properties of the dendrite. Collectively, they shape both the strengths and spatial arrangements of convergent afferent inputs to neuronal dendrites. Recent experimental and theoretical studies support a clustered plasticity model, a view that synaptic plasticity promotes the formation of clusters or hotspots of synapses sharing similar properties. We have previously shown that spike timing-dependent plasticity (STDP can lead to synaptic efficacies being arranged into spatially segregated clusters. This effectively partitions the dendritic tree into a tessellated imprint which we have called a dendritic mosaic. Here, using a biophysically detailed neuron model of a reconstructed layer 2/3 pyramidal cell and STDP learning, we investigated the impact of altered STDP balance on forming such a spatial organization. We show that cluster formation and extend depend on several factors, including the balance between potentiation and depression, the afferents' mean firing rate and crucially on the dendritic morphology. We find that STDP balance has an important role to play for this emergent mode of spatial organization since any imbalances lead to severe degradation- and in some case even destruction- of the mosaic. Our model suggests that, over a broad range of of STDP parameters, synaptic plasticity shapes the spatial arrangement of synapses, favoring the formation of clustered efficacy engrams.

  3. Mosaic Neurofibromatosis Type 1: A Systematic Review.

    Science.gov (United States)

    García-Romero, Maria Teresa; Parkin, Patricia; Lara-Corrales, Irene

    2016-01-01

    Confusion is widespread regarding segmental or mosaic neurofibromatosis type 1 (MNF1). Physicians should use the same terms and be aware of its comorbidities and risks. The objective of the current study was to identify and synthesize data for cases of MNF1 published from 1977 to 2012 to better understand its significance and associations. After a literature search in PubMed, we reviewed all available relevant articles and abstracted and synthetized the relevant clinical data about manifestations, associated findings, family history and genetic testing. We identified 111 articles reporting 320 individuals. Most had pigmentary changes or neurofibromas only. Individuals with pigmentary changes alone were identified at a younger age. Seventy-six percent had localized MNF1 restricted to one segment; the remainder had generalized MNF1. Of 157 case reports, 29% had complications associated with NF1. In one large case series, 6.5% had offspring with complete NF1. The terms "segmental" and "type V" neurofibromatosis should be abandoned, and the correct term, mosaic NF1 (MNF1), should be used. All individuals with suspected MNF1 should have a complete physical examination, genetic testing of blood and skin, counseling, and health surveillance. © 2015 Wiley Periodicals, Inc.

  4. Modulating STDP Balance Impacts the Dendritic Mosaic

    Science.gov (United States)

    Iannella, Nicolangelo; Launey, Thomas

    2017-01-01

    The ability for cortical neurons to adapt their input/output characteristics and information processing capabilities ultimately relies on the interplay between synaptic plasticity, synapse location, and the nonlinear properties of the dendrite. Collectively, they shape both the strengths and spatial arrangements of convergent afferent inputs to neuronal dendrites. Recent experimental and theoretical studies support a clustered plasticity model, a view that synaptic plasticity promotes the formation of clusters or hotspots of synapses sharing similar properties. We have previously shown that spike timing-dependent plasticity (STDP) can lead to synaptic efficacies being arranged into spatially segregated clusters. This effectively partitions the dendritic tree into a tessellated imprint which we have called a dendritic mosaic. Here, using a biophysically detailed neuron model of a reconstructed layer 2/3 pyramidal cell and STDP learning, we investigated the impact of altered STDP balance on forming such a spatial organization. We show that cluster formation and extend depend on several factors, including the balance between potentiation and depression, the afferents' mean firing rate and crucially on the dendritic morphology. We find that STDP balance has an important role to play for this emergent mode of spatial organization since any imbalances lead to severe degradation- and in some case even destruction- of the mosaic. Our model suggests that, over a broad range of of STDP parameters, synaptic plasticity shapes the spatial arrangement of synapses, favoring the formation of clustered efficacy engrams. PMID:28649195

  5. Intelligent real-time CCD data processing system based on variable frame rate

    Science.gov (United States)

    Chen, Su-ting

    2009-07-01

    In order to meet the need of image shooting with CCD in unmanned aerial vehicles, a real-time high resolution CCD data processing system based on variable frame rate is designed. The system is consisted of three modules: CCD control module, data processing module and data display module. In the CCD control module, real-time flight parameters (e.g. flight height, velocity and longitude) should be received from GPS through UART (Universal Asynchronous Receiver Transmitter) and according to the corresponding flight parameters, the variable frame rate is calculated. Based on the calculated variable frame rate, CCD external synchronization control impulse signal is generated in the control of FPGA and then CCD data is read out. In the data processing module, data segmentation is designed to extract ROI (region of interest), whose resolution is equal to valid data resolution of HDTV standard conforming to SMPTE (1080i). On one hand, Ping-pong SRAM storage controller is designed in FPGA to real-time store ROI data. On the other hand, according to the need of intelligent observing, changeable window position is designed, and a flexible area of interest is obtained. In the real-time display module, a special video encoder is used to accomplish data format conversion. Data after storage is packeted to HDTV format by creating corresponding format information in FPGA. Through inner register configuration, high definition video analog signal is implemented. The entire system has been implemented in FPGA and validated. It has been used in various real-time CCD data processing situations.

  6. The ArTéMiS wide-field sub-millimeter camera: preliminary on-sky performance at 350 microns

    Science.gov (United States)

    Revéret, Vincent; André, Philippe; Le Pennec, Jean; Talvard, Michel; Agnèse, Patrick; Arnaud, Agnès.; Clerc, Laurent; de Breuck, Carlos; Cigna, Jean-Charles; Delisle, Cyrille; Doumayrou, Eric; Duband, Lionel; Dubreuil, Didier; Dumaye, Luc; Ercolani, Eric; Gallais, Pascal; Groult, Elodie; Jourdan, Thierry; Leriche, Bernadette; Maffei, Bruno; Lortholary, Michel; Martignac, Jérôme; Rabaud, Wilfried; Relland, Johan; Rodriguez, Louis; Vandeneynde, Aurélie; Visticot, François

    2014-07-01

    ArTeMiS is a wide-field submillimeter camera operating at three wavelengths simultaneously (200, 350 and 450 μm). A preliminary version of the instrument equipped with the 350 μm focal plane, has been successfully installed and tested on APEX telescope in Chile during the 2013 and 2014 austral winters. This instrument is developed by CEA (Saclay and Grenoble, France), IAS (France) and University of Manchester (UK) in collaboration with ESO. We introduce the mechanical and optical design, as well as the cryogenics and electronics of the ArTéMiS camera. ArTeMiS detectors consist in Si:P:B bolometers arranged in 16×18 sub-arrays operating at 300 mK. These detectors are similar to the ones developed for the Herschel PACS photometer but they are adapted to the high optical load encountered at APEX site. Ultimately, ArTeMiS will contain 4 sub-arrays at 200 μm and 2×8 sub-arrays at 350 and 450 μm. We show preliminary lab measurements like the responsivity of the instrument to hot and cold loads illumination and NEP calculation. Details on the on-sky commissioning runs made in 2013 and 2014 at APEX are shown. We used planets (Mars, Saturn, Uranus) to determine the flat-field and to get the flux calibration. A pointing model was established in the first days of the runs. The average relative pointing accuracy is 3 arcsec. The beam at 350 μm has been estimated to be 8.5 arcsec, which is in good agreement with the beam of the 12 m APEX dish. Several observing modes have been tested, like "On- The-Fly" for beam-maps or large maps, spirals or raster of spirals for compact sources. With this preliminary version of ArTeMiS, we concluded that the mapping speed is already more than 5 times better than the previous 350 μm instrument at APEX. The median NEFD at 350 μm is 600 mJy.s1/2, with best values at 300 mJy.s1/2. The complete instrument with 5760 pixels and optimized settings will be installed during the first half of 2015.

  7. A PANCHROMATIC CATALOG OF EARLY-TYPE GALAXIES AT INTERMEDIATE REDSHIFT IN THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 EARLY RELEASE SCIENCE FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Rutkowski, M. J.; Cohen, S. H.; Windhorst, R. A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Kaviraj, S.; Crockett, R. M.; Silk, J. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); O' Connell, R. W. [Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903 (United States); Hathi, N. P.; McCarthy, P. J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); Ryan, R. E. Jr.; Koekemoer, A.; Bond, H. E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Yan, H. [Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Kimble, R. A. [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Disney, M. J. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, M. A. [Research School of Physics and Astronomy, The Australian National University, ACT 2611 (Australia); Frogel, J. A. [Astronomy Department, King Abdulaziz University, P.O. Box 80203, Jeddah (Saudi Arabia); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); and others

    2012-03-01

    In the first of a series of forthcoming publications, we present a panchromatic catalog of 102 visually selected early-type galaxies (ETGs) from observations in the Early Release Science (ERS) program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) of the Great Observatories Origins Deep Survey-South (GOODS-S) field. Our ETGs span a large redshift range, 0.35 {approx}< z {approx}< 1.5, with each redshift spectroscopically confirmed by previous published surveys of the ERS field. We combine our measured WFC3 ERS and Advanced Camera for Surveys (ACS) GOODS-S photometry to gain continuous sensitivity from the rest-frame far-UV to near-IR emission for each ETG. The superior spatial resolution of the HST over this panchromatic baseline allows us to classify the ETGs by their small-scale internal structures, as well as their local environment. By fitting stellar population spectral templates to the broadband photometry of the ETGs, we determine that the average masses of the ETGs are comparable to the characteristic stellar mass of massive galaxies, 10{sup 11} < M{sub *}[M{sub Sun }]<10{sup 12}. By transforming the observed photometry into the Galaxy Evolution Explorer FUV and NUV, Johnson V, and Sloan Digital Sky Survey g' and r' bandpasses we identify a noteworthy diversity in the rest-frame UV-optical colors and find the mean rest-frame (FUV-V) = 3.5 and (NUV-V) = 3.3, with 1{sigma} standard deviations {approx_equal}1.0. The blue rest-frame UV-optical colors observed for most of the ETGs are evidence for star formation during the preceding gigayear, but no systems exhibit UV-optical photometry consistent with major recent ({approx}<50 Myr) starbursts. Future publications which address the diversity of stellar populations likely to be present in these ETGs, and the potential mechanisms by which recent star formation episodes are activated, are discussed.

  8. ANALYZING STAR CLUSTER POPULATIONS WITH STOCHASTIC MODELS: THE HUBBLE SPACE TELESCOPE/WIDE FIELD CAMERA 3 SAMPLE OF CLUSTERS IN M83

    Energy Technology Data Exchange (ETDEWEB)

    Fouesneau, Morgan; Lancon, Ariane [Observatoire astronomique and CNRS UMR 7550, Universite de Strasbourg, Strasbourg (France); Chandar, Rupali [Department of Physics and Astronomy, University of Toledo, Toledo, OH (United States); Whitmore, Bradley C., E-mail: morgan.fouesneau@astro.u-strasbg.fr [Space Telescope Science Institute, Baltimore, MD (United States)

    2012-05-01

    The majority of clusters in the universe have masses well below 10{sup 5} M{sub Sun }. Hence, their integrated fluxes and colors can be affected by the presence or absence of a few bright stars introduced by stochastic sampling of the stellar mass function. Specific methods are being developed to extend the analysis of cluster energy distributions into the low-mass regime. In this paper, we apply such a method to real observations of star clusters, in the nearby spiral galaxy M83. We reassess the ages and masses of a sample of 1242 clusters for which UBVIH{alpha} fluxes were obtained from observations with the Wide Field Camera 3 instrument on board the Hubble Space Telescope. Synthetic clusters with known properties are used to characterize the limitations of the method (valid range and resolution in age and mass, method artifacts). The ensemble of color predictions of the discrete cluster models are in good agreement with the distribution of observed colors. We emphasize the important role of the H{alpha} data in the assessment of the fraction of young objects, particularly in breaking the age-extinction degeneracy that hampers an analysis based on UBVI data only. We find the mass distribution of the cluster sample to follow a power law of index -2.1 {+-} 0.2, and the distribution of ages a power law of index -1.0 {+-} 0.2 for log (M/ M{sub Sun }) > 3.5, and ages between 10{sup 7} and 10{sup 9} yr. An extension of our main method, which makes full use of the probability distributions of age and mass obtained for the individual clusters of the sample, is explored. It produces similar power-law slopes and will deserve further investigation. Although the properties derived for individual clusters significantly differ from those obtained with traditional, non-stochastic models in about 30% of the objects, the first-order aspect of the age and mass distributions is similar to those obtained previously for this M83 sample in the range of overlap of the studies. We

  9. Wide field of view computed tomography and mid carpal instability: The value of the sagittal radius–lunate–capitate axis – Preliminary experience

    Energy Technology Data Exchange (ETDEWEB)

    Repse, Stephen E., E-mail: stephrep@gmail.com [Department of Diagnostic Imaging, Monash Health, VIC (Australia); Koulouris, George, E-mail: GeorgeK@melbourneradiology.com.au [Melbourne Radiology Clinic, Ground Floor, 3-6/100 Victoria Parade, East Melbourne, VIC (Australia); Centre for Orthopaedic Research, School of Surgery, University of Western Australia, Nedlands, WA (Australia); Troupis, John M., E-mail: john.troupis@gmail.com [Department of Diagnostic Imaging & Monash Cardiovascular Research Centre, Monash Health and Department of Biomedical Radiation Sciences, Faculty of Medicine, Nursing & Health Sciences, Monash University, VIC (Australia)

    2015-05-15

    Highlights: • Unique insight into the assessment of mid carpal instability. • 4D CT using sagittal reconstructions along the radius–lunate–capitate axis. • 4D CT observations of vacuum phenomenon, trigger lunate and capitate subluxation. • Earlier recognition of mid carpal instability. - Abstract: Purpose: Dynamic four dimensional (4D) computed tomography (CT) has recently emerged as a practical method for evaluating complex functional abnormality of joints. We retrospectively analysed 4D CT studies undertaken as part of the clinical management of hand and wrist symptoms. We present our initial experience of 4D CT in the assessment of functional abnormalities of the wrist in a group of patients with mid carpal instability (MCI), specifically carpal instability non-dissociative. We aim to highlight unique features in assessment of the radius–lunate–capitate (RLC) axis which allows insight and understanding of abnormalities in function, not just morphology, which may be contributing to symptoms. Materials and methods: Wide field of view multi-detector CT scanner (320 slices, 0.5 mm detector thickness) was used to acquire bilateral continuous motion assessment in hand flexion and extension. A maximum z-axis coverage of 16 cm was available for each acquisition, and a large field of view (FOV) was used. Due to the volume acquisition during motion, reconstructions at multiple time points were undertaken. Dynamic and anatomically targeted multi-planar-reconstructions (MPRs) were then used to establish the kinematic functionality of the joint. Results: Our initial cohort of 20 patients was reviewed. Three findings were identified which were present either in isolation or in combination. These are vacuum phenomenon, triggering of the lunate and capitate subluxation. We provide 4D CT representations of each and highlight features considered of clinical importance and their significance. We also briefly discuss how the current classifications of dynamic wrist

  10. Development and evaluation of a CCD-based digital imaging system for mammography

    Science.gov (United States)

    Piccaro, Michele F.; Toker, Emre

    1993-05-01

    We have developed a CCD-based, high performance, filmless imaging system for stereotactic biopsy procedures in mammography. The CCD camera is based on a 1024 X 1024 pixel format, full-frame, scientific grade, front-illuminated, MPP mode CCD, directly coupled to an X-ray intensifying screen via a 2:1 fiber optic reducer. The CCD is cooled to -10 degree(s)C, and is digitized in slow-scan, correlated double sampling mode at 500 Kpixels/second with 12-bit contrast resolution. X-ray images acquired with the system are processed and displayed on a high resolution monitor within 20 seconds of exposure. System design and specifications will be described, and evaluation of physical performance characteristics will be discussed. The system has been used in over 100 stereotactic breast biopsy procedures to date, and has been shown to significantly improve the speed and accuracy of the biopsy procedure, due to the near real-time acquisition and display of x-ray images. Initial results also indicate that the fiber optic coupled CCD-based imaging system provides superior detectability of low contrast breast lesions and microcalcifications at lower patient dose, as compared to conventional film-screen detectors.

  11. Parallel-Processing Software for Creating Mosaic Images

    Science.gov (United States)

    Klimeck, Gerhard; Deen, Robert; McCauley, Michael; DeJong, Eric

    2008-01-01

    A computer program implements parallel processing for nearly real-time creation of panoramic mosaics of images of terrain acquired by video cameras on an exploratory robotic vehicle (e.g., a Mars rover). Because the original images are typically acquired at various camera positions and orientations, it is necessary to warp the images into the reference frame of the mosaic before stitching them together to create the mosaic. [Also see "Parallel-Processing Software for Correlating Stereo Images," Software Supplement to NASA Tech Briefs, Vol. 31, No. 9 (September 2007) page 26.] The warping algorithm in this computer program reflects the considerations that (1) for every pixel in the desired final mosaic, a good corresponding point must be found in one or more of the original images and (2) for this purpose, one needs a good mathematical model of the cameras and a good correlation of individual pixels with respect to their positions in three dimensions. The desired mosaic is divided into slices, each of which is assigned to one of a number of central processing units (CPUs) operating simultaneously. The results from the CPUs are gathered and placed into the final mosaic. The time taken to create the mosaic depends upon the number of CPUs, the speed of each CPU, and whether a local or a remote data-staging mechanism is used.

  12. Solar Mosaic Inc. Mosaic Home Solar Loan SunShot 9 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Colin James [Solar Mosaic Inc., Oakland, CA (United States)

    2017-02-09

    The 6686 Mosaic SunShot award has helped Solar Mosaic Inc to progress from an early stage startup focused on commercial crowdfunding to a leading multi-state residential solar lender. The software platform is now used by the majority of the nation's top solar installers and offers a variety of simple home solar loans. Mosaic is has originated approximately $1Bil in solar loans to date to put solar on over 35k rooftops. The company now lends to homeowners with a wide range of credit scores across multiple states and mitigates boundaries preventing them from profiting from ownership of a home solar system. The project included milestones in 5 main categories: 1. Lending to homeowners outside of CA 2. Lending to homeowners with FICO scores under 700 3. Packaging O&M with the home solar loan 4. Allowing residential installers to process home solar loans via API 5. Lowering customer acquisition costs below $1500 This report includes a detailed review of the final results achieved and key findings.

  13. Molecular Dissection of Isolated Disease Features in Mosaic Neurofibromatosis Type 1

    National Research Council Canada - National Science Library

    Maertens, Ophélia; De Schepper, Sofie; Vandesompele, Jo; Brems, Hilde; Heyns, Ine; Janssens, Sandra; Speleman, Frank; Legius, Eric; Messiaen, Ludwine

    2007-01-01

    ..., however, remains incompletely understood. Mosaic NF1 is caused by a postzygotic NF1 lesion 5–7 and can present as mild generalized disease, segmental disease, or gonadal mosaicism. 8 Revertant mosaicism, as reported to be caused by a postzygotic back mutation in some disorders, 9 has not yet been described in cases of NF1. The mosaic phenotype...

  14. Demonstration of the temporal illusion and mosaic.

    Science.gov (United States)

    Zhou, Feng; Qiu, Huaqing; Yan, Siqi; Cheng, Zhao; Dong, Jianji; Zhang, Xinliang

    2017-05-29

    We introduce and experimentally demonstrate a flexible temporal illusion at telecommunication data rate in optical fiber communication system. The temporal illusion cannot only transform an event to another event as expected, but also mask the event with high-level signal, providing a novel method to conceal the confidential information. We successfully transform the output temporal waveforms of a return-to-zero (RZ), dark RZ and nonreturn-to-zero (NRZ) event into that of any above modulation format event and high-level signal at different illusion bits and mosaic bits at a data rate of 5 Gb/s, respectively. Our works offer us new perspectives on illusion optics for falsifying event rather than object, which has potential applications in secure communication, data encryption and other military applications.

  15. A Mosaic of Creativity in Occupational Therapy

    Directory of Open Access Journals (Sweden)

    Molly Bathje MS, OTR/L

    2014-07-01

    Full Text Available Martha Branson-Banks, OT, provided the cover art for the summer 2014 issue of the Open Journal of Occupational Therapy. The piece is titled “Garden with thanks to Klimt” and is one of several mosaic art pieces in her collection of works. She created the piece with art glass and resin on an abandoned door. Her use of a repurposed door represents her belief in the capacity for transformation and beauty within each individual she has treated and taught throughout her career. Martha’s work as an occupational therapist, educator, and artist reminds us of the foundational beliefs of the occupational therapy profession, including the benefits of engagement in meaningful and creative activities.

  16. Quantum efficiency modeling for a thick back-illuminated astronomical CCD

    Science.gov (United States)

    Groom, D. E.; Haque, S.; Holland, S. E.; Kolbe, W. F.

    2017-08-01

    The quantum efficiency and reflectivity of thick, back-illuminated CCD's being fabricated at the Lawrence Berkeley National Laboratory for astronomical applications are modeled and compared with experiments. The treatment differs from standard thin-film optics in that (a) absorption is permitted in any film, (b) the 200-500 μm thick silicon substrate is considered as a thin film in order to observe the fringing behavior at long wavelengths, and (c) by using approximate boundary conditions, absorption in the surface films is separated from absorption in the substrate. For quantum efficiency measurements, the CCD's are normally operated as CCD's, usually at T =-140 ° C, and at higher temperatures, as photodiodes. They are mounted on mechanical substrates. Reflectivity is measured on air-backed wafer samples at room temperature. The agreement between model expectation and quantum efficiency measurement is in general satisfactory.

  17. High-aperture monochromator-reflectometer and its usefulness for CCD calibration

    Science.gov (United States)

    Vishnyakov, Eugene A.; Shcherbakov, Alexander V.; Pertsov, Andrei A.; Polkovnikov, Vladimir N.; Pestov, Alexey E.; Pariev, Dmitry E.; Chkhalo, Nikolai I.

    2017-05-01

    We present a laboratory high-aperture monochromator-reflectometer employing laser-plasma radiation source and three replaceable Schwarzschild objectives for a certain range of applications in the soft X-ray spectral waveband. Three sets of X-ray multilayer mirrors for the Schwarzschild objectives enable operation of the reflectometer at the wavelengths of 135, 171 and 304 Å, while a goniometer with three degrees of freedom allows different measurement modes. We have used the facility for a laboratory CCD calibration at the wavelengths specified. Combined with the results of the CCD sensitivity measurements conducted in the VUV spectral waveband, the total outcome provides a more comprehensive understanding of the CCD effectivity in a wide spectral range.

  18. Investigation of the radiation performance of CCD sensors in a vertex detector application

    CERN Document Server

    Stefanov, K D; Miyamoto, A; Sugimoto, Y; Tamura, N; Takahashi, S; Abe, K; Nagamine, T; Aso, T

    1999-01-01

    The radiation performance of a Hamamatsu S5466 and an EEV CCD02-06 silicon CCD sensors, working in a Multi-Pinned Phase (MPP) mode has been evaluated, in view of their possible use in the vertex detector of a future linear collider. We have examined the influence of the electron irradiation from a beta-source with fluencies up to 4.3x10 sup 1 sup 2 e sup - /cm sup 2 on the parameters of the CCD sensors such as dark current, dark current spikes, drive pulse voltages and charge transfer inefficiency (CTI). The changes of the parameters of the devices resulting from the irradiation are reported and discussed.

  19. Magneto-optic Kerr effect CCD imaging with polarization modulation technique

    Directory of Open Access Journals (Sweden)

    Satoru Nakayama

    2017-05-01

    Full Text Available We have developed a magneto-optic Kerr effect (MOKE imaging system with a charge-coupled-device (CCD camera by using the rotating compensator technique. We chose optimal conditions of the rotation frequency of the compensator with stable rotation along with a CCD camera frame rate that allowed precise control of the exposure timing in order to link with the angle of the compensator. Precise timing management of the CCD exposure enables us to carry out repeated experiments, which greatly improves the signal-to-noise ratio of the longitudinal MOKE signal. We applied the technique to the material characterization of the Ni81 Fe19 thin film and its microstructure, and succeeded in evaluating the spatial variation of the complex magneto-optic constant Q of the sample. Because of its attractive advantages such as high-speed and compactness, the present method provides a novel platform for investigating the domain structures in various magnetic materials.

  20. Magneto-optic Kerr effect CCD imaging with polarization modulation technique

    Science.gov (United States)

    Nakayama, Satoru; Okano, Makoto; Nozaki, Yukio; Watanabe, Shinichi

    2017-05-01

    We have developed a magneto-optic Kerr effect (MOKE) imaging system with a charge-coupled-device (CCD) camera by using the rotating compensator technique. We chose optimal conditions of the rotation frequency of the compensator with stable rotation along with a CCD camera frame rate that allowed precise control of the exposure timing in order to link with the angle of the compensator. Precise timing management of the CCD exposure enables us to carry out repeated experiments, which greatly improves the signal-to-noise ratio of the longitudinal MOKE signal. We applied the technique to the material characterization of the Ni81 Fe19 thin film and its microstructure, and succeeded in evaluating the spatial variation of the complex magneto-optic constant Q of the sample. Because of its attractive advantages such as high-speed and compactness, the present method provides a novel platform for investigating the domain structures in various magnetic materials.

  1. Retrieval of absorption and backscattering coefficients from HJ-1A/CCD imagery in coastal waters.

    Science.gov (United States)

    Chen, Jun; Quan, Wenting; Yao, Guoqing; Cui, Tingwei

    2013-03-11

    A simple semi-analytical model (SAB) was developed for computing a(560) and b(b)(550) from HJ-1A/CCD images. By comparison with field measurements, the SAB model produces 5.3-23.5% uncertainty for a(560) and b(b)(550) retrievals. The a(560) and b(b)(550) are also retrieved from satellite images. The match-up analysis results indicate that a(560) and b(b)(550) may be derived from the HJ-1A/CCD images with respective uncertainties of 29.84 and 21.35%. These findings imply that, provided that an atmospheric correction scheme for the green bands is available, the extensive database of HJ-1A/CCD imagery may be used for the quantitative monitoring of optical properties in coastal waters.

  2. Mosaic DCX deletion causes subcortical band heterotopia in males.

    Science.gov (United States)

    Quélin, Chloé; Saillour, Yoann; Souville, Isabelle; Poirier, Karine; N'guyen-Morel, Marie Ange; Vercueil, Laurent; Millisher-Bellaiche, Anne Elodie; Boddaert, Nathalie; Dubois, Fanny; Chelly, Jamel; Beldjord, Cherif; Bahi-Buisson, Nadia

    2012-11-01

    Subcortical band heterotopia (SBH) is a neuronal migration disorder usually described in females carrying heterozygous mutations in the X-linked doublecortin (DCX) gene. Hemizygous DCX mutations in males result in lissencephaly. Recently, exonic deletions of DCX resulting in a severer form of agyria have been reported. Nevertheless, rare male patients with SBH have been described with somatic mosaicism of point mutations. Here, we identified a somatic mosaicism for a deletion of exon 4 in the DCX gene in a male patient with SBH detected prenatally. This finding points to the possible implication of mosaic deletions in the DCX gene in unexplained forms of SBH and may allow for detection of SBH prenatally.

  3. Volumetric Diffuse Optical Tomography for Small Animals Using a CCD-Camera-Based Imaging System

    Directory of Open Access Journals (Sweden)

    Zi-Jing Lin

    2012-01-01

    Full Text Available We report the feasibility of three-dimensional (3D volumetric diffuse optical tomography for small animal imaging by using a CCD-camera-based imaging system with a newly developed depth compensation algorithm (DCA. Our computer simulations and laboratory phantom studies have demonstrated that the combination of a CCD camera and DCA can significantly improve the accuracy in depth localization and lead to reconstruction of 3D volumetric images. This approach may present great interests for noninvasive 3D localization of an anomaly hidden in tissue, such as a tumor or a stroke lesion, for preclinical small animal models.

  4. PROCESSING METHOD EFFECT ON SUN DIAMETER MEASUREMENT WITH CCD SOLAR ASTROLABE

    Energy Technology Data Exchange (ETDEWEB)

    Djafer, Djelloul [Unite de Recherche Appliquee en Energies Renouvelables, BP 88, Ghardaiea (Algeria); Irbah, Abdenour, E-mail: djdjafer@gmail.com, E-mail: abdenour.irbah@latmos.ipsl.fr [Laboratoire Atmospheres, Milieux, Observations Spatiales (LATMOS), CNRS UMR8190, Universite Paris VI, Pierre et Marie Curie, Universite de Versailles Saint-Quentin-en-Yvelines INSU, 78280 Guyancourt (France)

    2012-05-01

    Photometric Sun diameter measurement is based on the calculation of the inflection point of the solar limb. In ground measurement, this point is located at a position on the solar limb where the signal-to-noise ratio is very high, which necessitates the appropriate filtering techniques to eliminate the noise while preserving its position. In this paper, we compare the filtering method currently in use to process the CCD solar astrolabe data, the FFTD method widely used, with a different method that we propose. Using the acquired data from the CCD astrolabe at Calern, France during 1997, we can obtain a mean difference of 130 mas in the measured radii.

  5. Processing Method Effect on Sun Diameter Measurement with CCD Solar Astrolabe

    Science.gov (United States)

    Djafer, Djelloul; Irbah, Abdenour

    2012-05-01

    Photometric Sun diameter measurement is based on the calculation of the inflection point of the solar limb. In ground measurement, this point is located at a position on the solar limb where the signal-to-noise ratio is very high, which necessitates the appropriate filtering techniques to eliminate the noise while preserving its position. In this paper, we compare the filtering method currently in use to process the CCD solar astrolabe data, the FFTD method widely used, with a different method that we propose. Using the acquired data from the CCD astrolabe at Calern, France during 1997, we can obtain a mean difference of 130 mas in the measured radii.

  6. Preliminary examination of a CCD camera with a scintillator coated fiber optic plate for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsubayashi, Masahito E-mail: matsu3@popsvr.tokai.jaeri.go.jp; Soyama, Kazuhiko

    2004-08-21

    A charge coupled device (CCD) camera with a scintillator coated fiber optic plate (FOP) was examined for neutron imaging. The FOP coupling and the lens coupling in terms of efficient optical coupling with a CCD, and {sup 6}LiF:ZnS(Ag) and Gd{sub 2}O{sub 2}S(Tb) in terms of light emission efficiency and spatial resolution were discussed. The spatial resolution for each imaging system was obtained as edge spread functions or observations of modulation transfer function charts.

  7. Construction of a photochemical reactor combining a CCD spectrophotometer and a LED radiation source.

    Science.gov (United States)

    Gombár, Melinda; Józsa, Éva; Braun, Mihály; Ősz, Katalin

    2012-10-01

    An inexpensive photoreactor using LED light sources and a fibre-optic CCD spectrophotometer as a detector was built by designing a special cell holder for standard 1.000 cm cuvettes. The use of this device was demonstrated by studying the aqueous photochemical reaction of 2,5-dichloro-1,4-benzoquinone. The developed method combines the highly quantitative data collection of CCD spectrophotometers with the possibility of illuminating the sample independently of the detecting light beam, which is a substantial improvement of the method using diode array spectrophotometers as photoreactors.

  8. A 2014 nationwide survey of the distribution of Soybean mosaic virus (SMV), Soybean yellow mottle mosaic virus (SYMMV) and Soybean yellow common mosaic virus (SYCMV) major viruses in South Korean soybean fields, and changes

    Science.gov (United States)

    In 2014 symptomatic soybean samples were collected throughout Korea, and were tested for the most important soybean viruses found in Korea, namely Soybean mosaic virus (SMV), Soybean yellow common mosaic virus (SYCMV), and Soybean yellow mottle mosaic virus (SYMMV). SYMMV was most commonly detected,...

  9. Mosaicism for a chromosome 8-derived minute marker chromosome in a patient with manifestations of trisomy 8 mosaicism

    Energy Technology Data Exchange (ETDEWEB)

    Spinner, N.B.; Grace, K.R.; Owens, N.L. [Children`s Hospital of Philadelphia, PA (United States)] [and others

    1995-03-13

    We describe a patient with manifestations of the mosaic trisomy 8 syndrome and mosaicism for a minute marker chromosome. Fluorescence in situ hybridization (FISH) with a chromosome 8 probe confirmed that the marker was derived from chromosome 8. This is the smallest piece of chromosome 8 to be reported in a patient with mosaic trisomy 8 syndrome. When the clinical picture is strongly suggestive of trisomy for a specific chromosome region, we believe that FISH can be used to test markers in a guided, rather than random, fashion. 8 refs., 3 figs.

  10. 1935 15' Quad #363 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  11. 1935 15' Quad #375 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  12. 1935 15' Quad #417 Aerial Photo Mosaic Index - AZ

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  13. 1935 15' Quad #437 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  14. 1935 15' Quad #410 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  15. 1935 15' Quad #454 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  16. 1935 15' Quad #371 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  17. 1935 15' Quad #101 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  18. 1935 15' Quad #087 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  19. 1935 15' Quad #177 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  20. 1935 15' Quad #267 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  1. 1935 15' Quad #386 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  2. 1935 15' Quad #078 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  3. 1935 15' Quad #195 Aerial Photo Mosaic Index - NM

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  4. 1935 15' Quad #055 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  5. 1935 15' Quad #131 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  6. 1935 15' Quad #248 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  7. 1935 15' Quad #411 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  8. 1935 15' Quad #202 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  9. 1935 15' Quad #037 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  10. 1935 15' Quad #133 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  11. 1935 15' Quad #152 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  12. 1935 15' Quad #318 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  13. 1935 15' Quad #195 Aerial Photo Mosaic Index - AZ

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  14. Use of morphological characters to identify cassava mosaic disease ...

    African Journals Online (AJOL)

    Use of morphological characters to identify cassava mosaic disease and cassava bacterial blight resistance. ... Both the improved cassava breeds and local germplasms in the International Institute of Tropical Agriculture, Ibadan expressed wide genetic variability in morphological characters and diseases resistance.

  15. 1935 15' Quad #098 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  16. 1935 15' Quad #266 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  17. 1935 15' Quad #009 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  18. 1935 15' Quad #125 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  19. 1935 15' Quad #032 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  20. 1935 15' Quad #149 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...