WorldWideScience

Sample records for 000301c ccd imaging

  1. Hubble Space Telescope STIS observations of GRB 000301C: CCD imaging and near-ultraviolet MAMA spectroscopy

    DEFF Research Database (Denmark)

    Smette, A.; Fruchter, A.S.; Gull, T.R.

    2001-01-01

    We present Space Telescope Imaging Spectrograph observations of the optical transient (OT) counterpart of the c-ray burster GRB 000301C obtained 5 days after the burst, on 2000 March 6. CCD clear-aperture imaging reveals a R similar or equal to 21.50 +/- 0.15 source with no apparent host galaxy. ...

  2. Ghost Images in Schmidt CCD Photometry

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The wide field of the Schmidt telescope implies a greater chance of the field containing bright objects, and the presence of a corrector lens produces a certain type of ghost images. We summarize and confirm the features of such ghost images in Schmidt CCD photometry. The ghost images could be star-like under special observational conditions. The zenith distance of the telescope, among other factors, is found to correlate with different patterns of the ghost images. Some relevant issues are discussed and possible applications of our results are suggested.

  3. Radiation events in astronomical CCD images

    OpenAIRE

    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.

    2001-01-01

    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 i...

  4. Novel CCD image processor for Z-plane architecture

    Science.gov (United States)

    Kemeny, S. E.; Eid, E.-S.; Fossum, E. R.

    1989-09-01

    The use of charge-coupled device (CCD) circuits in Z-plane architectures for focal-plane image processing is discussed. The low-power, compact layout nature of CCDs makes them attractive for Z-plane application. Three application areas are addressed: non-uniformity compensation using CCD MDAC circuits, neighborhood image processing functions implemented with CCD circuits, and the use of CCDs for buffering multiple image frames. Such buffering enables spatial-temporal image transformation for lossless compression.

  5. Method for eliminating artifacts in CCD imagers

    Science.gov (United States)

    Turko, B. T.; Yates, G. J.

    1990-06-01

    An electronic method for eliminating artifacts in a video camera employing a charge coupled device (CCD) as an image sensor is presented. The method comprises the step of initializing the camera prior to normal readout. The method includes a first dump cycle period for transferring radiation generated charge into the horizontal register. This occurs while the decaying image on the phosphor being imaged is being integrated in the photosites, and a second dump cycle period, occurring after the phosphor image has decayed, for rapidly dumping unwanted smear charge which has been generated in the vertical registers. Image charge is then transferred from the photosites and to the vertical registers and readout in conventional fashion. The inventive method allows the video camera to be used in environments having high ionizing radiation content, and to capture images of events of very short duration and occurring either within or outside the normal visual wavelength spectrum. Resultant images are free from ghost, smear, and smear phenomena caused by insufficient opacity of the registers, and are also free from random damage caused by ionization charges which exceed the charge limit capacity of the photosites.

  6. Radiation events in astronomical CCD images

    Science.gov (United States)

    Smith, Alan R.; McDonald, Richard J.; Hurley, D. C.; Holland, Steven E.; Groom, Donald E.; Brown, William E.; Gilmore, David K.; Stover, Richard J.; Wei, Mingzhi

    2002-04-01

    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 40K decay and the U and Th decay chains; these elements commonly 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 have significantly lower rates 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 fights does not appear to be a problem. Our conclusion are supported by tests at the Lawrence Berkeley National Laboratory low-level counting facilities in Berkeley and at Oroville, California (180 m underground).

  7. The afterglow of the short/intermediate-duration gamma-ray burst GRB 000301C: A jet at z=2.04

    DEFF Research Database (Denmark)

    Jensen, B.L.; Fynbo, J.U.; Gorosabel, J.

    2001-01-01

    We present Ulysses and NEAR data from the detection of the short or intermediate duration (2 s) gamma-ray burst GRB 000301C (2000 March 1.41 UT). The gamma-ray burst (GRB) was localised by the Inter Planetary Network (IPN) and RXTE to an area of similar to 50 arcmin(2). A fading optical counterpart...... the burst. The optical light curve is consistent with bring achromatic from 2 to 11 days after the burst and exhibits a break. A broken power-law fit yields a shallow pre-break decay power-law slope of alpha (1) = -0.72 +/- 0.06, a break time of t(break) = 4.39 +/- 0.26 days after the burst, and a post......-break slope of alpha (2) = -2.29 +/- 0.17. These properties of the light curve are best explained by a sideways expanding jet in an ambient medium of constant mean density. In the optical spectrum we find absorption features that are consistent with Fe II, C IV, C II, Si II and Ly alpha at a redshift of 2...

  8. 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.

  9. Atmospheric correction of CBERS CCD images with MODIS data

    Institute of Scientific and Technical Information of China (English)

    LI; Junsheng; ZHANG; Bing; CHEN; Zhengchao; SHEN; Qian

    2006-01-01

    China Brazil Earth Resource Satellite (CBERS) CCD images have much potential for inland water environmental monitoring. However, their atmospheric accuracy correction can affect their quantitative applications. This paper contains an atmospheric correction algorithm for CBERS CCD images with MODIS data from the same day, the use of which improves the atmospheric correction algorithm of ocean color remote sensing developed by Gordon (1993, 1994) and makes it applicable to inland waters. The improved algorithm retrieves atmospheric parameters from MODIS data and uses them to perform the atmospheric correction of CBERS CCD images. Experimental results show that the atmospheric correction algorithm of CBERS CCD images assisted by MODIS data is reliable. Furthermore, MODIS data can be freely obtained on a daily basis, making the algorithm developed in this paper useful for environmental monitoring of inland waters.

  10. Log-converting processor element for CCD linear imaging arrays.

    Science.gov (United States)

    Chang, S H; Boyd, J T

    1983-11-15

    A photosensor element suitable for incorporation into charge-coupled device (CCD) imaging arrays in which the charge injected into the CCD is proportional to the logarithm of incident light intensity is presented. The photosensor element consists of a photodiode directly coupled to a two-stage MOSFET common source amplifier. This element occupies an area of 25 x 100 microm and is arranged so that it could be incorporated into a linear CCD imaging array having a period of 25 microm. A logarithmic response is measured over a 68.6-dB range of incident light intensity with a sensitivity of 55 mV/decade of light intensity.

  11. Mid-IR image acquisition using a standard CCD camera

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Sørensen, Knud Palmelund; Pedersen, Christian

    2010-01-01

    Direct image acquisition in the 3-5 µm range is realized using a standard CCD camera and a wavelength up-converter unit. The converter unit transfers the image information to the NIR range were state-of-the-art cameras exist.......Direct image acquisition in the 3-5 µm range is realized using a standard CCD camera and a wavelength up-converter unit. The converter unit transfers the image information to the NIR range were state-of-the-art cameras exist....

  12. Experiments on the use of CCD's to detect photoelectron images

    Science.gov (United States)

    Choisser, J. P.

    1975-01-01

    Image tube design and processing requirements for building an ICCD are discussed. Work is under way at EVC for building an ICCD using the Fairchild CCD 201 (100 x 100) array, and progress will be reported. Demountable tests have been made, exposing parts of a CCD 201 to 15 kilovolt electrons over five radiation levels from approximately 10 to 1 million rads. Other tubes built by EVC over the last few years which successfully use semiconductors to detect photoelectrons will be described briefly.

  13. 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.

  14. 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.

  15. Performance of the low light level CCD camera for speckle imaging

    CERN Document Server

    Saha, S K

    2002-01-01

    A new generation CCD detector called low light level CCD (L3CCD) that performs like an intensified CCD without incorporating a micro channel plate (MCP) for light amplification was procured and tested. A series of short exposure images with millisecond integration time has been obtained. The L3CCD is cooled to about $-80^\\circ$ C by Peltier cooling.

  16. A new method to evaluate imaging quality of CCD cameras

    Institute of Scientific and Technical Information of China (English)

    LI Wen-juan; DU Hai-hui; DAI Jing-min; CHEN Ying-hang

    2005-01-01

    In order to evaluate the imaging quality of CCD cameras fully and rapidly,the minimum resolvable contrast (MRC) is presented in this paper and the system of measuring MRC is constructed as well,in which two integrating spheres are proposed to illuminate two sides of the target respectively.The variable contrast can be obtained by regulating the luminance of integrating spheres. Experimental results indicate that the error of measuring luminance is within ±0.3 cd/m2,MRC rises with the increase of the spatial frequency.The experimental results show that the method proposed is an effective approach to evaluate the imaging quality of CCD cameras.

  17. 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

    to photographic systems, in order to obtain spatially resolved data. However, the former option is extremely expensive and it is difficult to obtain quantitative data from the latter. This paper describes the use of a CCD camera for imaging both thermoluminescence and optically stimulated luminescence. The system...... 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...

  18. Scalable Track Detection in SAR CCD Images

    Energy Technology Data Exchange (ETDEWEB)

    Chow, James G [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Quach, Tu-Thach [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    Existing methods to detect vehicle tracks in coherent change detection images, a product of combining two synthetic aperture radar images ta ken at different times of the same scene, rely on simple, fast models to label track pixels. These models, however, are often too simple to capture natural track features such as continuity and parallelism. We present a simple convolutional network architecture consisting of a series of 3-by-3 convolutions to detect tracks. The network is trained end-to-end to learn natural track features entirely from data. The network is computationally efficient and improves the F-score on a standard dataset to 0.988, up fr om 0.907 obtained by the current state-of-the-art method.

  19. High definition 3D imaging lidar system using CCD

    Science.gov (United States)

    Jo, Sungeun; Kong, Hong Jin; Bang, Hyochoong

    2016-10-01

    In this study we propose and demonstrate a novel technique for measuring distance with high definition three-dimensional imaging. To meet the stringent requirements of various missions, spatial resolution and range precision are important properties for flash LIDAR systems. The proposed LIDAR system employs a polarization modulator and a CCD. When a laser pulse is emitted from the laser, it triggers the polarization modulator. The laser pulse is scattered by the target and is reflected back to the LIDAR system while the polarization modulator is rotating. Its polarization state is a function of time. The laser-return pulse passes through the polarization modulator in a certain polarization state, and the polarization state is calculated using the intensities of the laser pulses measured by the CCD. Because the function of the time and the polarization state is already known, the polarization state can be converted to time-of-flight. By adopting a polarization modulator and a CCD and only measuring the energy of a laser pulse to obtain range, a high resolution three-dimensional image can be acquired by the proposed three-dimensional imaging LIDAR system. Since this system only measures the energy of the laser pulse, a high bandwidth detector and a high resolution TDC are not required for high range precision. The proposed method is expected to be an alternative method for many three-dimensional imaging LIDAR system applications that require high resolution.

  20. Fifteen years of the Advanced CCD Imaging Spectrometer

    CERN Document Server

    Grant, Catherine E; Ford, Peter G; Plucinsky, Paul P

    2014-01-01

    As the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory enters its fifteenth year of operation on orbit, it continues to perform well and produce spectacular scientific results. The response of ACIS has evolved over the lifetime of the observatory due to radiation damage, molecular contamination and aging of the spacecraft in general. Here we present highlights from the instrument team's monitoring program and our expectations for the future of ACIS. The ACIS calibration source produces multiple line energies and fully illuminates the entire focal plane which has greatly facilitated the measurement of charge transfer inefficiency and absorption from contamination. While the radioactive decay of the source has decreased its utility, it continues to provide valuable data on the health of the instrument. Performance changes on ACIS continue to be manageable, and do not indicate any limitations on ACIS lifetime.

  1. PERFORMANCE EVALUATION OF SEVERAL FUSION APPROACHES FOR CCD/SAR IMAGES

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.

  2. Failure Analysis of CCD Image Sensors Using SQUID and GMR Magnetic Current Imaging

    Science.gov (United States)

    Felt, Frederick S.

    2005-01-01

    During electrical testing of a Full Field CCD Image Senor, electrical shorts were detected on three of six devices. These failures occurred after the parts were soldered to the PCB. Failure analysis was performed to determine the cause and locations of these failures on the devices. After removing the fiber optic faceplate, optical inspection was performed on the CCDs to understand the design and package layout. Optical inspection revealed that the device had a light shield ringing the CCD array. This structure complicated the failure analysis. Alternate methods of analysis were considered, including liquid crystal, light and thermal emission, LT/A, TT/A SQUID, and MP. Of these, SQUID and MP techniques were pursued for further analysis. Also magnetoresistive current imaging technology is discussed and compared to SQUID.

  3. A new segmentation algorithm for lunar surface terrain based on CCD images

    Science.gov (United States)

    Jiang, Hong-Kun; Tian, Xiao-Lin; Xu, Ao-Ao

    2015-09-01

    Terrain classification is one of the critical steps used in lunar geomorphologic analysis and landing site selection. Most of the published works have focused on a Digital Elevation Model (DEM) to distinguish different regions of lunar terrain. This paper presents an algorithm that can be applied to lunar CCD images by blocking and clustering according to image features, which can accurately distinguish between lunar highland and lunar mare. The new algorithm, compared with the traditional algorithm, can improve classification accuracy. The new algorithm incorporates two new features and one Tamura texture feature. The new features are generating an enhanced image histogram and modeling the properties of light reflection, which can represent the geological characteristics based on CCD gray level images. These features are applied to identify texture in order to perform image clustering and segmentation by a weighted Euclidean distance to distinguish between lunar mare and lunar highlands. The new algorithm has been tested on Chang'e-1 CCD data and the testing result has been compared with geological data published by the U.S. Geological Survey. The result has shown that the algorithm can effectively distinguish the lunar mare from highlands in CCD images. The overall accuracy of the proposed algorithm is satisfactory, and the Kappa coefficient is 0.802, which is higher than the result of combining the DEM with CCD images.

  4. 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.

  5. Method for implementation of back-illuminated CMOS or CCD imagers

    Science.gov (United States)

    Pain, Bedabrata (Inventor)

    2008-01-01

    A method for implementation of back-illuminated CMOS or CCD imagers. An oxide layer buried between silicon wafer and device silicon is provided. The oxide layer forms a passivation layer in the imaging structure. A device layer and interlayer dielectric are formed, and the silicon wafer is removed to expose the oxide layer.

  6. Automatic Seamless Stitching Method for CCD Images of Chang'E-I Lunar Mission

    Institute of Scientific and Technical Information of China (English)

    Mengjie Ye; Jian Li; Yanyan Liang; Zhanchuan Cai; Zesheng Tang

    2011-01-01

    A novel automatic seamless stitching method is presented.Compared to the traditional method,it can speed the processing and minimize the utilization of human resources to produce global lunar map.Meanwhile,a new global image map of the Moon with spatial resolution of~120 m has been completed by the proposed method from Chang'E-1 CCD image data.

  7. Test technology on divergence angle of laser range finder based on CCD imaging fusion

    Science.gov (United States)

    Shi, Sheng-bing; Chen, Zhen-xing; Lv, Yao

    2016-09-01

    Laser range finder has been equipped with all kinds of weapons, such as tank, ship, plane and so on, is important component of fire control system. Divergence angle is important performance and incarnation of horizontal resolving power for laser range finder, is necessary appraised test item in appraisal test. In this paper, based on high accuracy test on divergence angle of laser range finder, divergence angle test system is designed based on CCD imaging, divergence angle of laser range finder is acquired through fusion technology for different attenuation imaging, problem that CCD characteristic influences divergence angle test is solved.

  8. Inspection of calandria front area of Wolsung NPP using technique of mapping thermal infrared image into CCD image

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jai Wan; Kim, Chang Hoi; Seo, Yong Chil; Choi, Young Soo; Kim, Seung Ho [Advance Robotics Teams, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2002-11-15

    This paper describes the enhanced inspection performance of a thermal infrared camera for monitoring abnormal conditions of calandria reactor area of Wolsung nuclear power plant. Thermal infrared camera have poor image qualities compared to commercial CCD cameras, as in contrast, brightness, and resolution. To compensate the poor image quality problems associated with the thermal infrared camera, the technique of mapping thermal infrared image into real ccd image is proposed. The mobile robot KAEROT/m2, loaded with sensor head system at the mast, is entered to monitor leakage of heavy water and thermal abnormality of the calandria reactor area in overhaul period. The sensor head system is composed of thermal infrared camera and ccd camera in parallel. When thermal abnormality on observation points and areas of calandria reactor area is occurred, unusual hot image taken from thermal infrared camera is superimposed on real CCD image. In this inspection experiment, more accurate positions of thermal abnormalities on calandria reactor area can be estimated by using technique of mapping thermal infrared image into CCD image, which include characters arranged in MPOQ order.

  9. Smear correction of highly-variable, frame-transfer-CCD images with application to polarimetry

    CERN Document Server

    Iglesias, Francisco A; Nagaraju, K

    2015-01-01

    Image smear, produced by the shutter-less operation of frame transfer CCD detectors, can be detrimental for many imaging applications. Existing algorithms used to numerically remove smear, do not contemplate cases where intensity levels change considerably between consecutive frame exposures. In this report we reformulate the smearing model to include specific variations of the sensor illumination. The corresponding desmearing expression and its noise properties are also presented and demonstrated in the context of fast imaging polarimetry.

  10. Smear correction of highly variable, frame-transfer CCD images with application to polarimetry.

    Science.gov (United States)

    Iglesias, Francisco A; Feller, Alex; Nagaraju, Krishnappa

    2015-07-01

    Image smear, produced by the shutterless operation of frame-transfer CCD detectors, can be detrimental for many imaging applications. Existing algorithms used to numerically remove smear do not contemplate cases where intensity levels change considerably between consecutive frame exposures. In this report, we reformulate the smearing model to include specific variations of the sensor illumination. The corresponding desmearing expression and its noise properties are also presented and demonstrated in the context of fast imaging polarimetry.

  11. A Lossy Method for Compressing Raw CCD Images

    Directory of Open Access Journals (Sweden)

    Alan M. Watson

    2002-01-01

    Full Text Available 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 sobre-muestrean el ruido, no proporcionan información, y son difíciles o imposibles de comprimir. El método es con pérdida, pero proporciona ciertas garantías sobre la diferencia absoluta máxima, la diferencia RMS y la diferencia promedio entre la imagen comprimida y la imagen original; tales garantías implican que el método es adecuado para comprimir imágenes en bruto. El método produce imágenes comprimidas de 1/5 del tamaño de las imágenes originales cuando se cuantizan imágenes en las que ningún valor cambia más de 1/2 de la desviación estándar del fondo. Esta es una mejora importante con respecto a las razones de compresión producidas por métodos sin pérdida, y aparentemente las imágenes comprimidas con bzip2 no exceden el límite teórico por más de unas decenas de por ciento.

  12. Measuring the amplitude characteristic of an image recorder based on a CCD matrix

    NARCIS (Netherlands)

    Zhurovich, KA; Kirillov, VP; Mikhailov, YA; Sklizkov, GV; Starodub, AN; Sudakov, OA

    2001-01-01

    A method for studying the amplitude characteristic of an image recorder designed on the basis of a charge-coupled device (CCD) matrix is described. The recorder input signal is an intensity of distribution a monochromatic light formed upon Fraunhofer diffraction of the light by two identical slits.

  13. A configurable distributed high-performance computing framework for satellite's TDI-CCD imaging simulation

    Science.gov (United States)

    Xue, Bo; Mao, Bingjing; Chen, Xiaomei; Ni, Guoqiang

    2010-11-01

    This paper renders a configurable distributed high performance computing(HPC) framework for TDI-CCD imaging simulation. It uses strategy pattern to adapt multi-algorithms. Thus, this framework help to decrease the simulation time with low expense. Imaging simulation for TDI-CCD mounted on satellite contains four processes: 1) atmosphere leads degradation, 2) optical system leads degradation, 3) electronic system of TDI-CCD leads degradation and re-sampling process, 4) data integration. Process 1) to 3) utilize diversity data-intensity algorithms such as FFT, convolution and LaGrange Interpol etc., which requires powerful CPU. Even uses Intel Xeon X5550 processor, regular series process method takes more than 30 hours for a simulation whose result image size is 1500 * 1462. With literature study, there isn't any mature distributing HPC framework in this field. Here we developed a distribute computing framework for TDI-CCD imaging simulation, which is based on WCF[1], uses Client/Server (C/S) layer and invokes the free CPU resources in LAN. The server pushes the process 1) to 3) tasks to those free computing capacity. Ultimately we rendered the HPC in low cost. In the computing experiment with 4 symmetric nodes and 1 server , this framework reduced about 74% simulation time. Adding more asymmetric nodes to the computing network, the time decreased namely. In conclusion, this framework could provide unlimited computation capacity in condition that the network and task management server are affordable. And this is the brand new HPC solution for TDI-CCD imaging simulation and similar applications.

  14. CCD imaging for optical tomography of gel radiation dosimeters.

    Science.gov (United States)

    Wolodzko, J G; Marsden, C; Appleby, A

    1999-11-01

    Several investigations have been carried out by a number of researchers over the past few years to evaluate the utility of imaging gel dosimeters for the three-dimensional measurement of radiation fields. These have been proposed to be of particular value in mapping radiation dose distributions associated with emerging and complex approaches to cancer treatment such as conformal (CRT), intensity modulated (IMRT), "gamma knife," and pencil beam radiotherapies. Imaging of the gels has been successfully accomplished with clinical MRI units and via laser-based optical scanning. However, neither of these methods is generally accessible to all potential users, limiting the broader study and implementation of this valuable tool. We report here the design, methodology, and results of a preliminary study carried out to evaluate the utility of a new, inexpensive, and simplified approach to tomographic imaging of gel radiation dosimeters. For the purpose of this initial investigation, an array of liquid scintillation vials was prepared, containing a ferrous sulphate xylenol orange (FSX) gelatin formulation. The FSX formulation undergoes a change in optical absorption characteristics following irradiation, and the resulting color change can be observed visually. The vials were irradiated individually to different doses. Three-dimensional imaging was accomplished by tomographic reconstruction from two-dimensional optical images acquired using a diffuse, fluorescent light source, a digital charge-coupled device camera, single-photon-emission-computed tomography software, and other simple components designed by the authors. The resulting transverse images were evaluated through a region-of-interest (ROI) analysis to obtain the average change in image density in each vial as a function of radiation dose. These measured ROI values were subjected to a linear regression analysis to fit them to a straight line, and to determine the goodness of fit. Results from multiple imaging trials

  15. Novel driver method to improve ordinary CCD frame rate for high-speed imaging diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Tong-Ding, E-mail: snuohui@126.com; Li, Bin-Kang; Yang, Shao-Hua; Guo, Ming-An; Yan, Ming

    2016-06-21

    The use of ordinary Charge-coupled-Device (CCD) imagers for the analysis of fast physical phenomenon is restricted because of the low-speed performance resulting from their long output times. Even though the form of Intensified-CCD (ICCD), coupled with a gated image intensifier, has extended their use for high speed imaging, the deficiency remains to be solved that ICDD could record only one image in a single shot. This paper presents a novel driver method designed to significantly improve the ordinary interline CCD burst frame rate for high-speed photography. This method is based on the use of vertical registers as storage, so that a small number of additional frames comprised of reduced-spatial-resolution images obtained via a specific sampling operation can be buffered. Hence, the interval time of the received series of images is related to the exposure and vertical transfer times only and, thus, the burst frame rate can be increased significantly. A prototype camera based on this method is designed as part of this study, exhibiting a burst rate of up to 250,000 frames per second (fps) and a capacity to record three continuous images. This device exhibits a speed enhancement of approximately 16,000 times compared with the conventional speed, with a spatial resolution reduction of only 1/4.

  16. Deep Ly alpha imaging of two z=2.04 GRB host galaxy fields

    DEFF Research Database (Denmark)

    Fynbo, J.P.U.; Møller, Per; Thomsen, Bente

    2002-01-01

    We report on the results of deep narrow-band Lyalpha and broad-band U and I imaging of the fields of two Gamma-Ray bursts at redshift z = 2.04 (GRB 000301C and GRB 000926). We find that the host galaxy of GRB 000926 is an extended (more than 2 arcsec), strong Lyalpha emitter with a rest-frame equ......We report on the results of deep narrow-band Lyalpha and broad-band U and I imaging of the fields of two Gamma-Ray bursts at redshift z = 2.04 (GRB 000301C and GRB 000926). We find that the host galaxy of GRB 000926 is an extended (more than 2 arcsec), strong Lyalpha emitter with a rest...

  17. Structure for implementation of back-illuminated CMOS or CCD imagers

    Science.gov (United States)

    Pain, Bedabrata (Inventor); Cunningham, Thomas J. (Inventor)

    2009-01-01

    A structure for implementation of back-illuminated CMOS or CCD imagers. An epitaxial silicon layer is connected with a passivation layer, acting as a junction anode. The epitaxial silicon layer converts light passing through the passivation layer and collected by the imaging structure to photoelectrons. A semiconductor well is also provided, located opposite the passivation layer with respect to the epitaxial silicon layer, acting as a junction cathode. Prior to detection, light does not pass through a dielectric separating interconnection metal layers.

  18. Evaluation of Rational Function Model for Geometric Modeling of CHANG'E-1 CCD Images

    Science.gov (United States)

    Liu, Y.; Di, K.

    2011-08-01

    Rational Function Model (RFM) is a generic geometric model that has been widely used in geometric processing of high-resolution earth-observation satellite images, due to its generality and excellent capability of fitting complex rigorous sensor models. In this paper, the feasibility and precision of RFM for geometric modeling of China's Chang'E-1 (CE-1) lunar orbiter images is presented. The RFM parameters of forward-, nadir- and backward-looking CE-1 images are generated though least squares solution using virtual control points derived from the rigorous sensor model. The precision of the RFM is evaluated by comparing with the rigorous sensor model in both image space and object space. Experimental results using nine images from three orbits show that RFM can precisely fit the rigorous sensor model of CE-1 CCD images with a RMS residual error of 1/100 pixel level in image space and less than 5 meters in object space. This indicates that it is feasible to use RFM to describe the imaging geometry of CE-1 CCD images and spacecraft position and orientation. RFM will enable planetary data centers to have an option to supply RFM parameters of orbital images while keeping the original orbit trajectory data confidential.

  19. High-resolution image digitizing through 12x3-bit RGB-filtered CCD camera

    Science.gov (United States)

    Cheng, Andrew Y. S.; Pau, Michael C. Y.

    1996-09-01

    A high resolution computer-controlled CCD image capturing system is developed by using a 12 bits 1024 by 1024 pixels CCD camera and motorized RGB filters to grasp an image with color depth up to 36 bits. The filters distinguish the major components of color and collect them separately while the CCD camera maintains the spatial resolution and detector filling factor. The color separation can be done optically rather than electronically. The operation is simply by placing the capturing objects like color photos, slides and even x-ray transparencies under the camera system, the necessary parameters such as integration time, mixing level and light intensity are automatically adjusted by an on-line expert system. This greatly reduces the restrictions of the capturing species. This unique approach can save considerable time for adjusting the quality of image, give much more flexibility of manipulating captured object even if it is a 3D object with minimal setup fixers. In addition, cross sectional dimension of a 3D capturing object can be analyzed by adapting a fiber optic ring light source. It is particularly useful in non-contact metrology of a 3D structure. The digitized information can be stored in an easily transferable format. Users can also perform a special LUT mapping automatically or manually. Applications of the system include medical images archiving, printing quality control, 3D machine vision, and etc.

  20. 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.

  1. STRIPING NOISE REMOVAL OF IMAGES ACQUIRED BY CBERS 2 CCD CAMERA SENSOR

    Directory of Open Access Journals (Sweden)

    E. Amraei

    2014-10-01

    Full Text Available CCD Camera is a multi-spectral sensor that is carried by CBERS 2 satellite. Imaging technique in this sensor is push broom. In images acquired by the CCD Camera, some vertical striping noise can be seen. This is due to the detectors mismatch, inter detector variability, improper calibration of detectors and low signal-to-noise ratio. These noises are more profound in images acquired from the homogeneous surfaces, which are processed at level 2. However, the existence of these noises render the interpretation of the data and extracting information from these images difficult. In this work, spatial moment matching method is proposed to modify these images. In this method, the statistical moments such as mean and standard deviation of columns in each band are used to balance the statistical specifications of the detector array to those of reference values. After the removal of the noise, some periodic diagonal stripes remain in the image where their removal by using the aforementioned method seems impossible. Therefore, to omit them, frequency domain Butterworth notch filter was applied. Finally to evaluate the results, the image statistical moments such as the mean and standard deviation were deployed. The study proves the effectiveness of the method in noise removal.

  2. A new method of CCD dark current correction via extracting the dark information from scientific images

    CERN Document Server

    Ma, Bin; Hu, Yi; Liu, Qiang; Wang, Lifan; Wei, Peng

    2014-01-01

    We have developed a new method to correct dark current at relatively high temperatures for Charge-Coupled Device (CCD) images when dark frames cannot be obtained on the telescope. For images taken with the Antarctic Survey Telescopes (AST3) in 2012, due to the low cooling efficiency, the median CCD temperature was -46$^\\circ$C, resulting in a high dark current level of about 3$e^-$/pix/sec, even comparable to the sky brightness (10$e^-$/pix/sec). If not corrected, the nonuniformity of the dark current could even overweight the photon noise of the sky background. However, dark frames could not be obtained during the observing season because the camera was operated in frame-transfer mode without a shutter, and the telescope was unattended in winter. Here we present an alternative, but simple and effective method to derive the dark current frame from the scientific images. Then we can scale this dark frame to the temperature at which the scientific images were taken, and apply the dark frame corrections to the s...

  3. Design and Fabrication of High-Efficiency CMOS/CCD Imagers

    Science.gov (United States)

    Pain, Bedabrata

    2007-01-01

    An architecture for back-illuminated complementary metal oxide/semiconductor (CMOS) and charge-coupled-device (CCD) ultraviolet/visible/near infrared- light image sensors, and a method of fabrication to implement the architecture, are undergoing development. The architecture and method are expected to enable realization of the full potential of back-illuminated CMOS/CCD imagers to perform with high efficiency, high sensitivity, excellent angular response, and in-pixel signal processing. The architecture and method are compatible with next-generation CMOS dielectric-forming and metallization techniques, and the process flow of the method is compatible with process flows typical of the manufacture of very-large-scale integrated (VLSI) circuits. The architecture and method overcome all obstacles that have hitherto prevented high-yield, low-cost fabrication of back-illuminated CMOS/CCD imagers by use of standard VLSI fabrication tools and techniques. It is not possible to discuss the obstacles in detail within the space available for this article. Briefly, the obstacles are posed by the problems of generating light-absorbing layers having desired uniform and accurate thicknesses, passivation of surfaces, forming structures for efficient collection of charge carriers, and wafer-scale thinning (in contradistinction to diescale thinning). A basic element of the present architecture and method - the element that, more than any other, makes it possible to overcome the obstacles - is the use of an alternative starting material: Instead of starting with a conventional bulk-CMOS wafer that consists of a p-doped epitaxial silicon layer grown on a heavily-p-doped silicon substrate, one starts with a special silicon-on-insulator (SOI) wafer that consists of a thermal oxide buried between a lightly p- or n-doped, thick silicon layer and a device silicon layer of appropriate thickness and doping. The thick silicon layer is used as a handle: that is, as a mechanical support for the

  4. Fibre-optic coupling to high-resolution CCD and CMOS image sensors

    Science.gov (United States)

    van Silfhout, R. G.; Kachatkou, A. S.

    2008-12-01

    We describe a simple method of gluing fibre-optic faceplates to complementary metal oxide semiconductor (CMOS) active pixel and charge coupled device (CCD) image sensors and report on their performance. Cross-sectional cuts reveal that the bonding layer has a thickness close to the diameter of the individual fibres and is uniform over the whole sensor area. Our method requires no special tools or alignment equipment and gives reproducible and high-quality results. The method maintains a uniform bond layer thickness even if sensor dies are mounted at slight angles with their package. These fibre-coupled sensors are of particular interest to X-ray imaging applications but also provide a solution for compact optical imaging systems.

  5. A comparison of film and 3 digital imaging systems for natural dental caries detection: CCD, CMOS, PSP and film

    Energy Technology Data Exchange (ETDEWEB)

    Han, Won Jeong [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2004-03-15

    To evaluate the diagnostic accuracy of occlusal and proximal caries detection using CCD, CMOS, PSP and film system. 32 occlusal and 30 proximal tooth surfaces were radiographed under standardized conditions using 3 digital systems; CCD (CDX-2000HQ, Biomedysis Co., Seoul, Korea), CMOS (Schick, Schick Inc., Long Island, USA), PSP (Digora FMX, Orion Co./Soredex, Helsinki, Finland) and 1 film system (Kodak Insight, Eastman Kodak, Rochester, USA). 5 observers examined the radiographs for occlusal and proximal caries using a 5-point confidence scale. The presence of caries was validated histologically and radiographically. Diagnostic accuracy was evaluated using ROC curve areas (AZ). Analysis using ROC curves revealed the area under each curve which indicated a diagnostic accuracy. For occlusal caries, Kodak Insight film had an Az of 0.765, CCD one of 0.730, CMOS one of 0.742 and PSP one of 0.735. For proximal caries, Kodak Insight film had an Az of 0.833, CCD one of 0.832, CMOS one of 0.828 and PSP one of 0.868. No statistically significant difference was noted between any of the imaging modalities. CCD, CMOS, PSP and film performed equally well in the detection of occlusal and proximal dental caries. CCD, CMOS and PSP-based digital images provided a level of diagnostic performance comparable to Kodak Insight film.

  6. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    Science.gov (United States)

    Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus

    2016-06-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times.

  7. Imaging the Moon II: Webcam CCD observations & analysis (a two week lab for non-majors)

    CERN Document Server

    Sato, Takashi

    2013-01-01

    Presented is a successful two week lab involving real sky observations of the Moon in which students make telescopic observations and analyze their own images. Originally developed around the 35 mm film camera as a common household object adapted for astronomical work, the lab transitioned to use the webcam as film photography evolved into an obscure specialty technology and increasing numbers of students had little familiarity with it. The printed circuit board with the CCD is harvested from a retail webcam and affixed to a tube to mount on a telescope in place of an eyepiece. Image frames are compiled to form a lunar mosaic and crater sizes are measured. Students also work through the logistical steps of telescope time assignment and scheduling, keeping to schedule and working with uncertainties of weather, in ways paralleling research observations. Because there is no need for a campus observatory, this lab can be replicated at a wide variety of institutions.

  8. Digital image measurement of specimen deformation based on CCD cameras and Image J software: an application to human pelvic biomechanics

    Science.gov (United States)

    Jia, Yongwei; Cheng, Liming; Yu, Guangrong; Lou, Yongjian; Yu, Yan; Chen, Bo; Ding, Zuquan

    2008-03-01

    A method of digital image measurement of specimen deformation based on CCD cameras and Image J software was developed. This method was used to measure the biomechanics behavior of human pelvis. Six cadaveric specimens from the third lumbar vertebra to the proximal 1/3 part of femur were tested. The specimens without any structural abnormalities were dissected of all soft tissue, sparing the hip joint capsules and the ligaments of the pelvic ring and floor. Markers with black dot on white background were affixed to the key regions of the pelvis. Axial loading from the proximal lumbar was applied by MTS in the gradient of 0N to 500N, which simulated the double feet standing stance. The anterior and lateral images of the specimen were obtained through two CCD cameras. Based on Image J software, digital image processing software, which can be freely downloaded from the National Institutes of Health, digital 8-bit images were processed. The procedure includes the recognition of digital marker, image invert, sub-pixel reconstruction, image segmentation, center of mass algorithm based on weighted average of pixel gray values. Vertical displacements of S1 (the first sacral vertebrae) in front view and micro-angular rotation of sacroiliac joint in lateral view were calculated according to the marker movement. The results of digital image measurement showed as following: marker image correlation before and after deformation was excellent. The average correlation coefficient was about 0.983. According to the 768 × 576 pixels image (pixel size 0.68mm × 0.68mm), the precision of the displacement detected in our experiment was about 0.018 pixels and the comparatively error could achieve 1.11\\perthou. The average vertical displacement of S1 of the pelvis was 0.8356+/-0.2830mm under vertical load of 500 Newtons and the average micro-angular rotation of sacroiliac joint in lateral view was 0.584+/-0.221°. The load-displacement curves obtained from our optical measure system

  9. Development of an n-channel CCD, CCD-NeXT1, for Soft X-ray Imager onboard the NeXT satellite

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Shin-ichiro [Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Hamamatsu 435-8558 (Japan); Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: s-takagi@ssd.hpk.co.jp; Tsuru, Takeshi Go [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: tsuru@cr.scphys.kyoto-u.ac.jp; Inui, Tatsuya; Matsumoto, Hironori; Koyama, Katsuji [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Ozawa, Hideki; Tohiguchi, Masakuni; Matsuura, Daisuke; Miyata, Emi; Tsunemi, Hiroshi [Department of Earth and Space Science, Graduate School of Science, Osaka University, Machikaneyama-cho, Toyonaka-shi, Osaka 560-0043 (Japan); Miyaguchi, Kazuhisa; Maeda, Kentaro; Kohno, Hirohiko [Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Hamamatsu 435-8558 (Japan)

    2007-11-21

    NeXT (New X-ray Telescope) is the next Japanese X-ray astronomical satellite mission after the Suzaku satellite. NeXT aims to perform wide band imaging spectroscopy. Due to the successful development of a multilayer coated mirror, called a supermirror, NeXT can focus X-rays in the energy range from 0.1 up to 80 keV. To cover this wide energy range, we are in the process of developing a hybrid X-ray camera, Wideband X-ray Imager (WXI) as a focal plane detector of the supermirror. The WXI consists of X-ray CCDs (SXI) and CdTe pixelized detectors (HXI), which cover the lower and higher X-ray energy bands of 0.1-80 keV, respectively. The X-ray CCDs of the SXI are stacked above the CdTe pixelized detectors of the HXI. The X-ray CCDs of the SXI detect soft X-rays below {approx}10keV and allow hard X-rays pass into the CdTe detectors of the HXI without loss. Thus, we have been developing a 'back-supportless CCD' with a thick depletion layer, a thinned silicon wafer, and a back-supportless structure. In this paper, we report the development and performances of an evaluation model of CCD for the SXI, 'CCD-NeXT1'. We successfully fabricated two types of CCD-NeXT1, unthinned CCDs with 625-{mu}m thick wafer and 150-{mu}m thick thinned CCDs. By omitting the polishing process when making the thinned CCDs, we confirmed that the polishing process does not impact the X-ray performance. In addition, we did not find significant differences in the X-ray performance between the two types of CCDs. The energy resolution and readout noise are {approx}140eV (FWHM) at 5.9 keV and {approx}5 electrons (RMS), respectively. The estimated thickness of the depletion layer is {approx}80{mu}m. The performances almost satisfy the requirements of the baseline plan of the SXI.

  10. Defect inspection in hot slab surface: multi-source CCD imaging based fuzzy-rough sets method

    Science.gov (United States)

    Zhao, Liming; Zhang, Yi; Xu, Xiaodong; Xiao, Hong; Huang, Chao

    2016-09-01

    To provide an accurate surface defects inspection method and make the automation of robust image region of interests(ROI) delineation strategy a reality in production line, a multi-source CCD imaging based fuzzy-rough sets method is proposed for hot slab surface quality assessment. The applicability of the presented method and the devised system are mainly tied to the surface quality inspection for strip, billet and slab surface etcetera. In this work we take into account the complementary advantages in two common machine vision (MV) systems(line array CCD traditional scanning imaging (LS-imaging) and area array CCD laser three-dimensional (3D) scanning imaging (AL-imaging)), and through establishing the model of fuzzy-rough sets in the detection system the seeds for relative fuzzy connectedness(RFC) delineation for ROI can placed adaptively, which introduces the upper and lower approximation sets for RIO definition, and by which the boundary region can be delineated by RFC region competitive classification mechanism. For the first time, a Multi-source CCD imaging based fuzzy-rough sets strategy is attempted for CC-slab surface defects inspection that allows an automatic way of AI algorithms and powerful ROI delineation strategies to be applied to the MV inspection field.

  11. Weak Lensing PSF Correction of Wide-field CCD Mosaic Images (SULI Paper)

    Energy Technology Data Exchange (ETDEWEB)

    Cevallos, Marissa; /Caltech /SLAC

    2006-01-04

    Gravitational lensing provides some of the most compelling evidence for the existence of dark matter. Dark matter on galaxy cluster scales can be mapped due to its weak gravitational lensing effect: a cluster mass distribution can be inferred from the net distortion of many thousands of faint background galaxies that it induces. Because atmospheric aberration and defects in the detector distort the apparent shape of celestial objects, it is of great importance to characterize accurately the point spread function (PSF) across an image. In this research, the PSF is studied in images from the Canada-France-Hawaii Telescope (CFHT), whose camera is divided into 12 CCD chips. Traditional weak lensing methodology involves averaging the PSF across the entire image: in this work we investigate the effects of measuring the PSF in each chip independently. This chip-by-chip analysis was found to reduce the strength of the correlation between star and galaxy shapes, and predicted more strongly the presence of known galaxy clusters in mass maps. These results suggest correcting the CFHT PSF on an individual chip basis significantly improves the accuracy of detecting weak lensing.

  12. Shuttle and Transfer Orbit Thermal Analysis and Testing of the Chandra X-Ray Observatory CCD Imaging Spectrometer Radiator Shades

    Science.gov (United States)

    Sharp, John R.

    2001-01-01

    Contents include the following: (1) Introduction: Chandra X-ray observatory. Advanced CCD imaging spectrometer. (2) LEO and transfer orbit analyses: Geometric modeling in TSS w/specularity. Low earth orbital heating calculations. (3) Thermal testing and LMAC. (4) Problem solving. (5) VDA overcoat analyses. (6) VDA overcoat testing and MSFC. (7) Post-MSFC test evaluation.

  13. Development of an n-channel CCD, CCD-NeXT1, for Soft X-ray Imager onboard the NeXT satellite

    CERN Document Server

    Takagi, Shin-ichiro; Inui, Tatsuya; Matsumoto, Hironori; Koyama, Katsuji; Ozawa, Hideki; Tohiguchi, Masakuni; Matsuura, Daisuke; Miyata, Emi; Tsunemi, Hiroshi; Miyaguchi, Kazuhisa; Maeda, Kentaro; Kohno, Hirohiko

    2007-01-01

    NeXT (New X-ray Telescope) is the next Japanese X-ray astronomical satellite mission after the Suzaku satellite. NeXT aims to perform wide band imaging spectroscopy. Due to the successful development of a multilayer coated mirror, called a supermirror, NeXT can focus X-rays in the energy range from 0.1 keV up to 80 keV. To cover this wide energy range, we are in the process of developing a hybrid X-ray camera, Wideband X-ray Imager (WXI) as a focal plane detector of the supermirror. The WXI consists of X-ray CCDs (SXI) and CdTe pixelized detectors (HXI), which cover the lower and higher X-ray energy bands of 0.1-80 keV, respectively. The X-ray CCDs of the SXI are stacked above the CdTe pixelized detectors of the HXI. The X-ray CCDs of the SXI detect soft X-rays below $\\sim$ 10 keV and allow hard X-rays pass into the CdTe detectors of the HXI without loss. Thus, we have been developing a "back-supportless CCD" with a thick depletion layer, a thinned silicon wafer, and a back-supportless structure. In this pape...

  14. A New Serial-direction Trail Effect in CCD Images of the Lunar-based Ultraviolet Telescope

    Science.gov (United States)

    Wu, C.; Deng, J. S.; Guyonnet, A.; Antilogus, P.; Cao, L.; Cai, H. B.; Meng, X. M.; Han, X. H.; Qiu, Y. L.; Wang, J.; Wang, S.; Wei, J. Y.; Xin, L. P.; Li, G. W.

    2016-10-01

    Unexpected trails have been seen subsequent to relative bright sources in astronomical images taken with the CCD camera of the Lunar-based Ultraviolet Telescope (LUT) since its first light on the Moon’s surface. The trails can only be found in the serial-direction of CCD readout, differing themselves from image trails of radiation-damaged space-borne CCDs, which usually appear in the parallel-readout direction. After analyzing the same trail defects following warm pixels (WPs) in dark frames, we found that the relative intensity profile of the LUT CCD trails can be expressed as an exponential function of the distance i (in number of pixels) of the trailing pixel to the original source (or WP), i.e., {\\mathtt{\\exp }}(α {\\mathtt{i}}+β ). The parameters α and β seem to be independent of the CCD temperature, intensity of the source (or WP), and its position in the CCD frame. The main trail characteristics show evolution occurring at an increase rate of ˜(7.3 ± 3.6) × 10-4 in the first two operation years. The trails affect the consistency of the profiles of different brightness sources, which make smaller aperture photometry have larger extra systematic error. The astrometric uncertainty caused by the trails is too small to be acceptable based on LUT requirements for astrometry accuracy. Based on the empirical profile model, a correction method has been developed for LUT images that works well for restoring the fluxes of astronomical sources that are lost in trailing pixels.

  15. Classification of volcanic ash particles from Sakurajima volcano using CCD camera image and cluster analysis

    Science.gov (United States)

    Miwa, T.; Shimano, T.; Nishimura, T.

    2012-12-01

    Quantitative and speedy characterization of volcanic ash particle is needed to conduct a petrologic monitoring of ongoing eruption. We develop a new simple system using CCD camera images for quantitatively characterizing ash properties, and apply it to volcanic ash collected at Sakurajima. Our method characterizes volcanic ash particles by 1) apparent luminance through RGB filters and 2) a quasi-fractal dimension of the shape of particles. Using a monochromatic CCD camera (Starshoot by Orion Co. LTD.) attached to a stereoscopic microscope, we capture digital images of ash particles that are set on a glass plate under which white colored paper or polarizing plate is set. The images of 1390 x 1080 pixels are taken through three kinds of color filters (Red, Green and Blue) under incident-light and transmitted-light through polarizing plate. Brightness of the light sources is set to be constant, and luminance is calibrated by white and black colored papers. About fifteen ash particles are set on the plate at the same time, and their images are saved with a bit map format. We first extract the outlines of particles from the image taken under transmitted-light through polarizing plate. Then, luminances for each color are represented by 256 tones at each pixel in the particles, and the average and its standard deviation are calculated for each ash particle. We also measure the quasi-fractal dimension (qfd) of ash particles. We perform box counting that counts the number of boxes which consist of 1×1 and 128×128 pixels that catch the area of the ash particle. The qfd is estimated by taking the ratio of the former number to the latter one. These parameters are calculated by using software R. We characterize volcanic ash from Showa crater of Sakurajima collected in two days (Feb 09, 2009, and Jan 13, 2010), and apply cluster analyses. Dendrograms are formed from the qfd and following four parameters calculated from the luminance: Rf=R/(R+G+B), G=G/(R+G+B), B=B/(R+G+B), and

  16. Surface cleaning of CCD imagers using an electrostatic dissipative formulation of First Contact polymer

    Science.gov (United States)

    Derylo, G.; Estrada, J.; Flaugher, B.; Hamilton, J.; Kubik, D.; Kuk, K.; Scarpine, V.

    2008-07-01

    We describe the results obtained cleaning the surface of DECam CCD detectors with a new electrostatic dissipative formulation of First ContactTM polymer from Photonic Cleaning Technologies. We demonstrate that cleaning with this new product is possible without ESD damage to the sensors and without degradation of the antireflective coating used to optimize the optical performance of the detector. We show that First ContactTM is more effective for cleaning a CCD than the commonly used acetone swab.

  17. Atmospheric correction of HJ-1A/B CCD images over Chinese coastal waters using MODIS-Terra aerosol data

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper demonstrates an atmospheric correction method to process HJ-1A/B CCD images over Chinese coastal waters with the aid of MODIS-Terra aerosol information.Based on the assumption of zero water-leaving radiance at the two near-infrared (NIR)bands or the shortwave infrared(SWIR)bands,the atmospheric aerosol optical depth(AOD)is firstly retrieved from MODIS-Terra with a simple extension of the NIR-SWIR combined atmospheric correction approach embedded in SeaDAS (SeaWiFS data analysis system).Then the"turbid"and"non-turbid"waters are separated by the turbid water index.Maximum probability of AOD at 551 nm band is derived based on the NIR information over"non-turbid"waters and FLAASH model is selected to do the atmospheric correction of the HJ-1A/B CCD imagery using the AOD values of highest probabilities as input.Similarly,according to the histogram of the AOD distribution at 551 nm band,the studied turbid water area is divided into several blocks and HJ-1A/B CCD imagery is corrected with the corresponding AOD values displayed with the highest frequency in each block.This method has been applied to several HJ-1A/B images over Chinese coastal waters and validated by synchronous in-situ data.The results have shown that this method is effective in the atmospheric correction process of HJ-1A/B CCD images for ocean color remote sensing study and application in the coastal waters.

  18. A comparison of CsI:Tl and GOS in a scintillator-CCD detector for nuclear medicine imaging

    Science.gov (United States)

    Bugby, S. L.; Jambi, L. K.; Lees, J. E.

    2016-09-01

    A number of portable gamma cameras for medical imaging use scintillator-CCD based detectors. This paper compares the performance of a scintillator-CCD based portable gamma camera with either a columnar CsI:Tl or a pixelated GOS scintillator installed. The CsI:Tl scintillator has a sensitivity of 40% at 140.5 keV compared to 54% with the GOS scintillator. The intrinsic spatial resolution of the pixelated GOS detector was 1.09 mm, over 4 times poorer than for CsI:Tl. Count rate capability was also found to be significantly lower when the GOS scintillator was used. The uniformity was comparable for both scintillators.

  19. Experimental comparison of the high-speed imaging performance of an EM-CCD and sCMOS camera in a dynamic live-cell imaging test case.

    Directory of Open Access Journals (Sweden)

    Hope T Beier

    Full Text Available The study of living cells may require advanced imaging techniques to track weak and rapidly changing signals. Fundamental to this need is the recent advancement in camera technology. Two camera types, specifically sCMOS and EM-CCD, promise both high signal-to-noise and high speed (>100 fps, leaving researchers with a critical decision when determining the best technology for their application. In this article, we compare two cameras using a live-cell imaging test case in which small changes in cellular fluorescence must be rapidly detected with high spatial resolution. The EM-CCD maintained an advantage of being able to acquire discernible images with a lower number of photons due to its EM-enhancement. However, if high-resolution images at speeds approaching or exceeding 1000 fps are desired, the flexibility of the full-frame imaging capabilities of sCMOS is superior.

  20. Subpixel translation of MEMS measured by discrete fourier transform analysis of CCD images

    NARCIS (Netherlands)

    Yamahata, C.; Sarajlic, E.; Stranczl, M.; Krijnen, G.J.M.; Gijs, M.A.M.

    2011-01-01

    We present a straightforward method for measuring in-plane linear displacements of microelectromechanical systems (MEMS) with subnanometer resolution. The technique is based on Fourier transform analysis of a video recorded with a Charge-Coupled Device (CCD) camera attached to an optical microscope

  1. Unusually rapid variability of the GRB000301C optical afterglow

    DEFF Research Database (Denmark)

    Masetti, N.; Bartolini, C.; Bernabei, S.;

    2000-01-01

    with BVI data has revealed complex behavior, with a long term flux decrease and various short time scale features superimposed. These features are uncommon among other observed afterglows. and might trace either intrinsic variability within the relativistic shock (re-acceleration and re...

  2. 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.

  3. Extrapolation of contrail investigations by LIDAR to larger scale measurements. Analysis and calibration of CCD camera and satellite images

    Energy Technology Data Exchange (ETDEWEB)

    Sussmann, R.; Homburg, F.; Freudenthaler, V.; Jaeger, H. [Frauenhofer Inst. fuer Atmosphaerische Umweltforschung, Garmisch-Partenkirchen (Germany)

    1997-12-31

    The CCD image of a persistent contrail and the coincident LIDAR measurement are presented. To extrapolate the LIDAR derived optical thickness to the video field of view an anisotropy correction and calibration has to be performed. Observed bright halo components result from highly regular oriented hexagonal crystals with sizes of 200 {mu}m-2 mm. This explained by measured ambient humidities below the formation threshold of natural cirrus. Optical thickness from LIDAR shows significant discrepancies to the result from coincident NOAA-14 data. Errors result from anisotropy correction and parameterized relations between AVHRR channels and optical properties. (author) 28 refs.

  4. 3D time-of-flight distance measurement with custom solid-state image sensors in CMOS/CCD-technology

    OpenAIRE

    Lange, Robert de

    2006-01-01

    Three-D time-of-flight distance measurement with custom solid-state image sensors in CMOS/CCD-technology Da wir in einer dreidimensionalen Welt leben, erfordert eine geeignete Beschreibung unserer Umwelt für viele Anwendungen Kenntnis über die relative Position und Bewegung der verschiedenen Objekte innerhalb einer Szene. Die daraus resultierende Anforderung räumlicher Wahrnehmung ist in der Natur dadurch gelöst, daß die meisten Tiere mindestens zwei Augen haben. Diese Fähigkeit des Stere...

  5. Design and implementation of fast bipolar clock drivers for CCD imaging systems in space applications

    Science.gov (United States)

    Jayarajan, Jayesh; Kumar, Nishant; Verma, Amarnath; Thaker, Ramkrishna

    2016-05-01

    Drive electronics for generating fast, bipolar clocks, which can drive capacitive loads of the order of 5-10nF are indispensable for present day Charge Coupled Devices (CCDs). Design of these high speed bipolar clocks is challenging because of the capacitive loads that have to be driven and a strict constraint on the rise and fall times. Designing drive electronics circuits for space applications becomes even more challenging due to limited number of available discrete devices, which can survive in the harsh radiation prone space environment. This paper presents the design, simulations and test results of a set of such high speed, bipolar clock drivers. The design has been tested under a thermal cycle of -15 deg C to +55 deg C under vacuum conditions and has been designed using radiation hardened components. The test results show that the design meets the stringent rise/fall time requirements of 50+/-10ns for Multiple Vertical CCD (VCCD) clocks and 20+/-5ns for Horizontal CCD (HCCD) clocks with sufficient design margins across full temperature range, with a pixel readout rate of 6.6MHz. The full design has been realized in flexi-rigid PCB with package volume of 140x160x50 mm3.

  6. GEM-based TPC with CCD imaging for directional dark matter detection

    Science.gov (United States)

    Phan, N. S.; Lauer, R. J.; Lee, E. R.; Loomba, D.; Matthews, J. A. J.; Miller, E. H.

    2016-11-01

    The most mature directional dark matter experiments at present all utilize low-pressure gas Time Projection Chamber (TPC) technologies. We discuss some of the challenges for this technology, for which balancing the goal of achieving the best sensitivity with that of cost effective scale-up requires optimization over a large parameter space. Critical for this are the precision measurements of the fundamental properties of both electron and nuclear recoil tracks down to the lowest detectable energies. Such measurements are necessary to provide a benchmark for background discrimination and directional sensitivity that could be used for future optimization studies for directional dark matter experiments. In this paper we describe a small, high resolution, high signal-to-noise GEM-based TPC with a 2D CCD readout designed for this goal. The performance of the detector was characterized using alpha particles, X-rays, gamma-rays, and neutrons, enabling detailed measurements of electron and nuclear recoil tracks. Stable effective gas gains of greater than 1 × 105 were obtained in 100 Torr of pure CF4 by a cascade of three standard CERN GEMs each with a 140 μm pitch. The high signal-to-noise and sub-millimeter spatial resolution of the GEM amplification and CCD readout, together with low diffusion, allow for excellent background discrimination between electron and nuclear recoils down below ∼10 keVee (∼23 keVr fluorine recoil). Even lower thresholds, necessary for the detection of low mass WIMPs for example, might be achieved by lowering the pressure and utilizing full 3D track reconstruction. These and other paths for improvements are discussed, as are possible fundamental limitations imposed by the physics of energy loss.

  7. 基于ARM&FPGA的CCD图像识别装置%CCD Image Recognition Apparatus Based on ARM and FPGA

    Institute of Scientific and Technical Information of China (English)

    胡胜; 杨雷; 宋跃; 胡必武; 李君

    2012-01-01

    A sort of design technique of CCD image recognition apparatus was presented. This apparatus regarded ARM and FPGA as master control chip. Concurrent control multiple channel data acquisition of CCD image signal based on Nios II and many core based on Nios II were devised. This paper mainly introduced the design of LCD drive based on Nios II for realizing LCD display , the design of A/D sampling control module for realizing multiple channel data acquisition, the design of SL811HS drive for realizing USB correspondence of ARM and PC and so on. Experiments show that this system has the advantages of high application value,high rate,high reliability and less accident.%给出了一种CCD图像识别装置的设计方法,该装置以ARM与FPGA为主控芯片,设计了基于Nios Ⅱ的A/D控制模块并行控制多路CCD图像信号的数据采集和基于Nios Ⅱ的多种内核,重点介绍了基于Nios Ⅱ的LCD驱动以实现液晶显示、设计A/D采样控制模块以实现多路数据采集以及设计SL811HS驱动以实现ARM与PC的USB通信等.实验结果表明系统具有应用价值高、速度高、可靠性高、故障少等优点.

  8. GEM-based TPC with CCD Imaging for Directional Dark Matter Detection

    CERN Document Server

    Phan, N S; Lee, E R; Loomba, D; Matthews, J A J; Miller, E H

    2015-01-01

    Directional dark matter detection will require scale-ups to large volumes if low-pressure gas Time Projection Chambers (TPCs) are the only viable technology. We discuss some of the challenges for this technology, where balancing the goal of achieving the best sensitivity with that of cost effective scale-up requires an optimization over a large parameter space. Critical for this are the precision measurements of the fundamental properties of both electron and nuclear recoil tracks down to the lowest energies. Such measurements would provide a benchmark for background discrimination and directional sensitivity that could be used for future optimization studies for directional dark matter experiments. In this paper we describe a small, high resolution, high signal-to-noise GEM-based TPC with a 2D CCD readout designed for this goal. The performance of the detector was characterized using X-rays, gamma-rays, and neutrons, enabling detailed measurements of electron and nuclear recoil tracks. Stable effective gas g...

  9. Photon counting imaging with an electron-bombarded CCD: Towards a parallel-processing photoelectronic time-to-amplitude converter

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Jiggins, Stephen; Sergent, Nicolas; Zanda, Gianmarco; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom)

    2014-12-15

    We have used an electron-bombarded CCD for optical photon counting imaging. The photon event pulse height distribution was found to be linearly dependent on the gain voltage. We propose on this basis that a gain voltage sweep during exposure in an electron-bombarded sensor would allow photon arrival time determination with sub-frame exposure time resolution. This effectively uses an electron-bombarded sensor as a parallel-processing photoelectronic time-to-amplitude converter, or a two-dimensional photon counting streak camera. Several applications that require timing of photon arrival, including Fluorescence Lifetime Imaging Microscopy, may benefit from such an approach. A simulation of a voltage sweep performed with experimental data collected with different acceleration voltages validates the principle of this approach. Moreover, photon event centroiding was performed and a hybrid 50% Gaussian/Centre of Gravity + 50% Hyperbolic cosine centroiding algorithm was found to yield the lowest fixed pattern noise. Finally, the camera was mounted on a fluorescence microscope to image F-actin filaments stained with the fluorescent dye Alexa 488 in fixed cells.

  10. Dynamic imaging with a triggered and intensified CCD camera system in a high-intensity neutron beam

    Science.gov (United States)

    Vontobel, P.; Frei, G.; Brunner, J.; Gildemeister, A. E.; Engelhardt, M.

    2005-04-01

    When time-dependent processes within metallic structures should be inspected and visualized, neutrons are well suited due to their high penetration through Al, Ag, Ti or even steel. Then it becomes possible to inspect the propagation, distribution and evaporation of organic liquids as lubricants, fuel or water. The principle set-up of a suited real-time system was implemented and tested at the radiography facility NEUTRA of PSI. The highest beam intensity there is 2×107 cm s, which enables to observe sequences in a reasonable time and quality. The heart of the detection system is the MCP intensified CCD camera PI-Max with a Peltier cooled chip (1300×1340 pixels). The intensifier was used for both gating and image enhancement, where as the information was accumulated over many single frames on the chip before readout. Although, a 16-bit dynamic range is advertised by the camera manufacturers, it must be less due to the inherent noise level from the intensifier. The obtained result should be seen as the starting point to go ahead to fit the different requirements of car producers in respect to fuel injection, lubricant distribution, mechanical stability and operation control. Similar inspections will be possible for all devices with repetitive operation principle. Here, we report about two measurements dealing with the lubricant distribution in a running motorcycle motor turning at 1200 rpm. We were monitoring the periodic stationary movements of piston, valves and camshaft with a micro-channel plate intensified CCD camera system (PI-Max 1300RB, Princeton Instruments) triggered at exactly chosen time points.

  11. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    OpenAIRE

    Hirvonen, Liisa Maija; Barber, Matthew; Suhling, Klaus

    2016-01-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, w...

  12. Sensors for 3D Imaging: Metric Evaluation and Calibration of a CCD/CMOS Time-of-Flight Camera.

    Science.gov (United States)

    Chiabrando, Filiberto; Chiabrando, Roberto; Piatti, Dario; Rinaudo, Fulvio

    2009-01-01

    3D imaging with Time-of-Flight (ToF) cameras is a promising recent technique which allows 3D point clouds to be acquired at video frame rates. However, the distance measurements of these devices are often affected by some systematic errors which decrease the quality of the acquired data. In order to evaluate these errors, some experimental tests on a CCD/CMOS ToF camera sensor, the SwissRanger (SR)-4000 camera, were performed and reported in this paper. In particular, two main aspects are treated: the calibration of the distance measurements of the SR-4000 camera, which deals with evaluation of the camera warm up time period, the distance measurement error evaluation and a study of the influence on distance measurements of the camera orientation with respect to the observed object; the second aspect concerns the photogrammetric calibration of the amplitude images delivered by the camera using a purpose-built multi-resolution field made of high contrast targets.

  13. Sensors for 3D Imaging: Metric Evaluation and Calibration of a CCD/CMOS Time-of-Flight Camera

    Directory of Open Access Journals (Sweden)

    Fulvio Rinaudo

    2009-12-01

    Full Text Available 3D imaging with Time-of-Flight (ToF cameras is a promising recent technique which allows 3D point clouds to be acquired at video frame rates. However, the distance measurements of these devices are often affected by some systematic errors which decrease the quality of the acquired data. In order to evaluate these errors, some experimental tests on a CCD/CMOS ToF camera sensor, the SwissRanger (SR-4000 camera, were performed and reported in this paper. In particular, two main aspects are treated: the calibration of the distance measurements of the SR-4000 camera, which deals with evaluation of the camera warm up time period, the distance measurement error evaluation and a study of the influence on distance measurements of the camera orientation with respect to the observed object; the second aspect concerns the photogrammetric calibration of the amplitude images delivered by the camera using a purpose-built multi-resolution field made of high contrast targets.

  14. High-resolution application of YAG:Ce and LuAG:Ce imaging detectors with a CCD X-ray camera

    Science.gov (United States)

    Touš, Jan; Horváth, Martin; Pína, Ladislav; Blažek, Karel; Sopko, Bruno

    2008-06-01

    A high-resolution CCD X-ray camera based on YAG:Ce or LuAG:Ce thin scintillators is presented. High-resolution in low-energy X-ray radiation is proved with several objects. The spatial resolution achieved in the images is about 1 μm. The high-resolution imaging system is a combination of a high-sensitivity digital CCD camera and an optical system with a thin scintillator-imaging screen. The screen can consist of YAG:Ce or LuAG:Ce inorganic scintillator [J.A. Mares, Radiat. Meas. 38 (2004) 353]. These materials have the advantages of mechanical and chemical stability and non-hygroscopicity. The high-resolution imaging system can be used with different types of radiation (X-ray, electrons, UV, and VUV [M. Nikl, Meas. Sci. Technol. 17 (2006) R37]). The objects used for the imaging tests are grids and small animals with features of several microns in size. The resolution capabilities were tested using different types of CCD cameras and scintillation imaging screens.

  15. Estimation of rice phenology date using integrated HJ-1 CCD and Landsat-8 OLI vegetation indices time-series images.

    Science.gov (United States)

    Wang, Jing; Huang, Jing-feng; Wang, Xiu-zhen; Jin, Meng-ting; Zhou, Zhen; Guo, Qiao-ying; Zhao, Zhe-wen; Huang, Wei-jiao; Zhang, Yao; Song, Xiao-dong

    2015-10-01

    Accurate estimation of rice phenology is of critical importance for agricultural practices and studies. However, the accuracy of phenological parameters extracted by remote sensing data cannot be guaranteed because of the influence of climate, e.g. the monsoon season, and limited available remote sensing data. In this study, we integrate the data of HJ-1 CCD and Landsat-8 operational land imager (OLI) by using the ordinary least-squares (OLS), and construct higher temporal resolution vegetation indices (VIs) time-series data to extract the phenological parameters of single-cropped rice. Two widely used VIs, namely the normalized difference vegetation index (NDVI) and 2-band enhanced vegetation index (EVI2), were adopted to minimize the influence of environmental factors and the intrinsic difference between the two sensors. Savitzky-Golay (S-G) filters were applied to construct continuous VI profiles per pixel. The results showed that, compared with NDVI, EVI2 was more stable and comparable between the two sensors. Compared with the observed phenological data of the single-cropped rice, the integrated VI time-series had a relatively low root mean square error (RMSE), and EVI2 showed higher accuracy compared with NDVI. We also demonstrate the application of phenology extraction of the single-cropped rice in a spatial scale in the study area. While the work is of general value, it can also be extrapolated to other regions where qualified remote sensing data are the bottleneck but where complementary data are occasionally available.

  16. Evaluation of crop yield loss of floods based on water turbidity index with multi-temporal HJ-CCD images

    Science.gov (United States)

    Gu, Xiaohe; Xu, Peng; Wang, Lei; Wang, Xiuhui

    2015-12-01

    Paddy is one of the most important food crops in China. Due to the intensive planting in the surrounding of rivers and lakes, paddy is vulnerable to flooding stress. The research on predicting crop yield loss derived from flooding stress will help the adjustment of crop planting structure and the claims of agricultural insurance. The paper aimed to develop a method of estimating yield loss of paddy derived from flooding by multi-temporal HJ CCD images. At first, the water pixels after flooding were extracted, from which the water line (WL) of turbid water pixels was generated. Secondly, the water turbidity index (WTI) and perpendicular vegetation index (PVI) was defined and calculated. By analyzing the relation among WTI, PVI and paddy yield, the model of evaluating yield loss of flooding was developed. Based on this model, the spatial distribution of paddy yield loss derived from flooding was mapped in the study area. Results showed that the water turbidity index (WTI) could be used to monitor the sediment content of flood, which was closely related to the plant physiology and per unit area yield of paddy. The PVI was the good indicator of paddy yield with significant correlation (0.965). So the PVI could be used to estimate the per unit area yield before harvesting. The PVI and WTI had good linear relation, which could provide an effective, practical and feasible method for monitoring yield loss of waterlogged paddy.

  17. A CCD-based fluorescence imaging system for real-time loop-mediated isothermal amplification-based rapid and sensitive detection of waterborne pathogens on microchips.

    Science.gov (United States)

    Ahmad, Farhan; Seyrig, Gregoire; Tourlousse, Dieter M; Stedtfeld, Robert D; Tiedje, James M; Hashsham, Syed A

    2011-10-01

    Rapid, sensitive, and low-cost pathogen diagnostic systems are needed for early disease diagnosis and treatment, especially in resource-limited settings. This study reports a low-cost charge-coupled device (CCD)-based fluorescence imaging system for rapid detection of waterborne pathogens by isothermal gene amplification in disposable microchips. Fluorescence imaging capability of this monochromatic CCD camera is evaluated by optimizing the gain, offset, and exposure time. This imaging system is validated for 12 virulence genes of major waterborne pathogens on cyclic olefin polymer (COP) microchips, using SYTO-82 dye and real time fluorescence loop-mediated isothermal amplification referred here as microRT(f)-LAMP. Signal-to-noise ratio (SNR) and threshold time (Tt) of microRT(f)-LAMP assays are compared with those from a commercial real-time polymerase chain reaction (PCR) instrument. Applying a CCD exposure of 5 s to 10(5) starting DNA copies of microRT(f)-LAMP assays increases the SNR by 8-fold and reduces the Tt by 9.8 min in comparison to a commercial real-time PCR instrument. Additionally, single copy level sensitivity for Campylobacter jejuni 0414 gene is obtained for microRT(f)-LAMP with a Tt of 19 min, which is half the time of the commercial real-time PCR instrument. Due to the control over the exposure time and the wide field imaging capability of CCD, this low-cost fluorescence imaging system has the potential for rapid and parallel detection of pathogenic microorganisms in high throughput microfluidic chips.

  18. Tracking of Human Gestures in RGB Image Sequence Based on Statistical Inference and Three-Dimensional Human Model Taken with Ocellar CCD Camera

    OpenAIRE

    我如古, 博之; 山城, 毅; 渡久地, 實; Ganeko, Hiroyuki; Yamashiro, Tsuyoshi; Toguchi, Minoru

    1999-01-01

    Many methods for tracking of Three-Dimensional human gestures have been proposed by using multiview scheme. However, at the present state these methods have been very far from the stage of practical application due to its high-cost. This paper describes a new method of Three-Dimensional human gesture from image sequence taken with Ocellar CCD camera. This tracking system is composed based on statistical inference and Three-Dimensional human model, and the Occlusion problem is solved by bottom...

  19. Color CCD Imaging Method for Measuring Light Pollution%彩色CCD成像法测量光污染

    Institute of Scientific and Technical Information of China (English)

    李岷舣; 贾果欣; 曲兴华

    2012-01-01

    Light environment is very important to urban people' s habitation environment, and the measurement of light environment helps us to monitor the light pollution. Firstly, the color calibration method was applied to the color CCD camera for measuring the luminance distribution of light environment, different color transformation matrices was analyzed by using the computer image processing technology, the results showed that the luminance values measured by the camera matched with the luminance meter each other, and the digital image RGB tristimulus values had a formula relation with the target luminance. After that, an experiment was designed to compare the values measured by the camera with the luminance meter, another one was designed to analyze the effects of lens vignetting on measurement accuracy, these experiments confirmed that this method had high measurement accuracy. Finally, in order to enlarge the measurement range of luminance and adapt the requirement of light environment measurement, the camera was calibrated several times under different lighting conditions, and there will be a good prospect for this method' s application in the field of urban light pollution measurement and prevention.%光环境是城市人居条件的一项重要内容,光污染的监测主要是针对光环境。将色彩校正的方法应用于彩色CCD测量光环境亮度分布,并结合计算机图像处理技术,对不同的颜色转换矩阵进行实验分析,使得亮度计算值和实测值很好地吻合,得出图像RGB三刺激值与目标亮度的函数关系式。通过实验,对相机测量值与亮度计实测值进行对比,分析镜头渐晕现象对测量精度的影响,从而证实了此方法具有较高的测量精度。通过在不同亮度条件下对相机进行多次标定,提高了相机的亮度测量范围,以适应光环境测量的要求,此方法将在城市光污染的测量与防治领域具有很好的应用前景。

  20. Quantitative estimation of Secchi disk depth using the HJ-1B CCD image and in situ observations in Sishili Bay, China

    Science.gov (United States)

    Yu, Dingfeng; Zhou, Bin; Fan, Yanguo; Li, Tantan; Liang, Shouzhen; Sun, Xiaoling

    2014-11-01

    Secchi disk depth (SDD) is an important optical property of water related to water quality and primary production. The traditional sampling method is not only time-consuming and labor-intensive but also limited in terms of temporal and spatial coverage, while remote sensing technology can deal with these limitations. In this study, models estimating SDD have been proposed based on the regression analysis between the HJ-1 satellite CCD image and synchronous in situ water quality measurements. The results illustrate the band ratio model of B3/B1 of CCD could be used to estimate Secchi depth in this region, with the mean relative error (MRE) of 8.6% and root mean square error (RMSE) of 0.1 m, respectively. This model has been applied to one image of HJ-1 satellite CCD, generating water transparency on June 23, 2009, which will be of immense value for environmental monitoring. In addition, SDD was deeper in offshore waters than in inshore waters. River runoffs, hydrodynamic environments, and marine aquaculture are the main factors influencing SDD in this area.

  1. Performance evaluation of different classifiers (Isoseg, Bhattacharyya, Maxver e Maxver-ICM, using CCD/CBERS-1 and ETM+/Landsat-7 fused images

    Directory of Open Access Journals (Sweden)

    Wilson Lins de Mello Filho

    2007-06-01

    Full Text Available The aim of this study was to compare the performance of image classifiers (Isoseg, Bhattacharyya, Maxver and Maxver-ICM based on an accuracy analysis (set percentage, area determination and Kappa coefficient, using as ground truth an edited thematic map. For this, pre-processing techniques (atmospheric, geometric and radiometric corrections, contrast enhancement (IHS data fusion and principal component analysis and classification of CCD/CBERS-1 and ETM+/Landsat-7 images were done. Amongst all classifiers tested, Isoseg and Bhattacharyya presented best performance for the studied classes and the study area. It is anticipated that these results are relevant to environmental analyses based on orbital satellite data.

  2. Caracterização espectral de áreas de gramíneas forrageiras infectadas com a doença "mela-das-sementes da braquiária" por meio de imagens CCD/CBERS-2 Spectral characterization of forage grasses infected with the disease "mela-das-sementes da braquiária" through CCD/CDBERS -2 images

    Directory of Open Access Journals (Sweden)

    José C. Rosatti

    2006-12-01

    Full Text Available Imagens CCD/CBERS-2, nas bandas espectrais CCD2, CCD3 e CCD4, dos anos de 2004 e 2005, de Mirante do Paranapanema - SP, foram transformadas em reflectância de superfície usando o modelo 5S de correção atmosférica e normalizadas radiometricamente. O objetivo principal foi caracterizar espectralmente áreas de pastagens de Brachiaria brizantha em fase de florescimento, isentas e infectadas com a doença "mela-das-sementes da braquiária", possibilitando a sua detecção por meio da comparação entre os valores de reflectância de superfície denominada de Fator de Reflectância Bidirecional de Superfície (FRBS. Teve-se, também, o objetivo de avaliar a eficácia das imagens CCD/CBERS-2 para a obtenção de respostas espectrais de pastagens. Os dosséis sadios e doentes da Brachiaria brizantha foram identificados por meio da análise dos valores de reflectância e dos dados observados no Índice de Estresse Hídrico Acumulativo Relativo da Cultura (ACWSI obtidos na área de estudo. Os resultados indicaram que as principais diferenças foram a diminuição da reflectância na banda CCD3 e o aumento da reflectância na banda CCD4 nas áreas doentes. A metodologia empregada com o uso de dados do sensor CCD/CBERS-2, associados ao ACWSI, mostrou-se eficaz para discriminar dosséis infectados com a "mela-das-sementes da braquiária".CCD/CBERS-2 images in the spectral bands of CCD2, CCD3 and CCD4 of the years 2004 and 2005, from Mirante do Paranapanema - SP (Brazil, were transformed into surface reflectance images using the 5S atmospheric correction model and radiometrically normalized. The main objective was to spectrally characterize pastures of Brachiaria brizantha in the flowering phase, exempt and infected with the disease "mela-das-sementes da braquiária" making it possible its detection through the comparison among the SBRF - Surface Bidirectional Reflectance Factor values. At the same time, it was aimed to evaluate the effectiveness of the

  3. Restoration of dichromatic images gained from CCD/CMOS camera by iterative detection networks with fragmented marginalization at the symbol block level

    Science.gov (United States)

    Kekrt, Daniel; Klíma, Miloš; Fliegel, Karel

    2009-08-01

    Image capturing by CCD/CMOS cameras is encumbered with two fundamental perturbing influences. Time invariant blurring (image convolution with fixed kernel) and time variant noises. Both of these influences can be successfully eliminated by the iterative detection networks (IDNs), that effectively and suboptimally (iteratively) solve 2D MAP criterion through the image decomposition to the small areas. Preferably to the individual pixel level, if this allows the noise distribution (statistically independent noise). Nevertheless, this task is so extremely numerically exacting and therefore the contemporary IDNs are limited only for restorations of dichromatic images. The IDNs are composed of certain, as simple as possible, statistical devices (SISO modules) and can be separated into two basic groups with variable topology (exactly matched to the blurring kernel) and with fixed topology, same for all possible kernels. The paper deals with second group of IDNs, concretely with IDNs whose SISO modules are concatenated in three directions (horizontal, vertical and diagonal). Advantages of such ordering rests in the application flexibility (can be comfortable applied to many irregular cores) and also in the low exigencies to number of memory devices it the IDN. The mentioned IDN type will be implemented in the two different variants suppressing defocusing in the lens of CCD/CMOS sensing system and will be verified in the sphere of a dichromatic 2D barcode detection.

  4. 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.

  5. 科学级CCD远程图像采集系统%Remote image acquisition system with scientific grade CCD

    Institute of Scientific and Technical Information of China (English)

    罗通顶; 李斌康; 郭明安; 杨少华; 周鸣

    2013-01-01

    The design method of a fiber transmission remote image acquisition system based on a high resolution EXview CCD is presented and the main units in the system are introduced in detail. The system utilizes a special IC to achieve time driving and takes double Complex Programmable Logic De-vices(CPLDs) to complete the logic control. In order to improve dynamic ranges, it uses a 16 bit high resolution Digital to Analog Converter(ADC) to digitalize video signals. Furthermore, the system can transfer mass video data in long-distances based on the TLK1501, and can perform data terminal collection with a computer by a USB. Finally, two important parameters: dynamic range and the system gain are estimated in an experiment. The system offers its specifications are a resolution of 1.4 million pixels, digitizer type of 16 bits, and remote transmission less than 30 km. Moreover, its dynamic range is 60 - 65 dB, system gain is 2.34 ADU/e-. Experiments show that designed system is fit for the science research which demands for the best quality mentioned above.%介绍了一种基于高分辨率超感光度(EXview)CCD的光纤远程传输采集系统的设计方法.该系统利用专用集成芯片实现其时序驱动;双复杂可编程逻辑器件(CPLD)完成系统的逻辑控制;采用带相关双采样的16位高精度模数变换器(ADC)对模拟视频进行数字化,从而提高系统动态范围.为满足其极端实验环境的应用,基于TLK1501进行大容量视频数据的远程传输;利用USB接口实现了计算机终端采集.最后,实验测试了系统的两个重要的评价参数:动态范围和系统灵敏度.该系统具有140万像素、16位高精度数字化位数、30 km以上的远程传输能力,其动态范围为1000~1500倍、灵敏度为2.34 ADU/e-左右,暗电流约为6 e-/pixel·s-1[>32℃].实验显示该系统适用于对分辨率、灵敏度、安全性等要求高的科学研究中.

  6. A comparison of colour micrographs obtained with a charged couple devise (CCD) camera and a 35-mm camera

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Smedegaard, Jesper; Jensen, Peter Koch

    2005-01-01

    ophthalmology, colour CCD camera, colour film, digital imaging, resolution, micrographs, histopathology, light microscopy......ophthalmology, colour CCD camera, colour film, digital imaging, resolution, micrographs, histopathology, light microscopy...

  7. Linear CCD attitude measurement system based on the identification of the auxiliary array CCD

    Science.gov (United States)

    Hu, Yinghui; Yuan, Feng; Li, Kai; Wang, Yan

    2015-10-01

    Object to the high precision flying target attitude measurement issues of a large space and large field of view, comparing existing measurement methods, the idea is proposed of using two array CCD to assist in identifying the three linear CCD with multi-cooperative target attitude measurement system, and to address the existing nonlinear system errors and calibration parameters and more problems with nine linear CCD spectroscopic test system of too complicated constraints among camera position caused by excessive. The mathematical model of binocular vision and three linear CCD test system are established, co-spot composition triangle utilize three red LED position light, three points' coordinates are given in advance by Cooperate Measuring Machine, the red LED in the composition of the three sides of a triangle adds three blue LED light points as an auxiliary, so that array CCD is easier to identify three red LED light points, and linear CCD camera is installed of a red filter to filter out the blue LED light points while reducing stray light. Using array CCD to measure the spot, identifying and calculating the spatial coordinates solutions of red LED light points, while utilizing linear CCD to measure three red LED spot for solving linear CCD test system, which can be drawn from 27 solution. Measured with array CCD coordinates auxiliary linear CCD has achieved spot identification, and has solved the difficult problems of multi-objective linear CCD identification. Unique combination of linear CCD imaging features, linear CCD special cylindrical lens system is developed using telecentric optical design, the energy center of the spot position in the depth range of convergence in the direction is perpendicular to the optical axis of the small changes ensuring highprecision image quality, and the entire test system improves spatial object attitude measurement speed and precision.

  8. 传输型CCD相机成像分辨率自动测试研究%Research on automatic testing of image resolution of transmission CCD camera

    Institute of Scientific and Technical Information of China (English)

    王锋; 高亚飞

    2013-01-01

    对CCD相机成像分辨率自动测试方法进行了研究,测试方案中改进设计了照相分辨率靶标,开展了数据分析处理,通过软硬件结合实现了对CCD相机整机分辨率的自动测试,结果数据经过专业测试比对确认有效。实验结果表明,方法客观、准确,能够避免以往人工测试分辨率带来的主观因素影响,具有很高的实用性。%The automatic testing method of an image resolution of CCD camera is researched. The photo resolution drone design is improved in the testing project. The data analyzing and processing is carried out,and the automatic testing of CCD camera resolution is realized through the combination of hardware and software. The effectiveness of the result data is verified by professional testing. The experiment results show that the method is impersonality and accurate,it can avoid the affect of subjec-tive factors brought by manual testing resolution,and has prominence practicability.

  9. 基于STM32的线阵CCD图像采集系统%A linear CCD image capture system based on STM32

    Institute of Scientific and Technical Information of China (English)

    王斌波; 汪涛

    2013-01-01

      本文采用STM32F103作为主控芯片,利用该芯片产生线阵CCD驱动时序,通过USB技术进行数据传输,使用Qt+Libusb进行上位机软件开发,实现了一个驱动时序稳定,传输速率高、可即插即用,跨平台的USB线阵CCD图像采集系统。%This text take STM32F103 as the main control chip.It uses this chip to produce the timing drive of linear CCD.Also,it translatedatas via USB technology.And use Qt+Libusb to develop the program on upper computer.In the end,it realize a USB linear CCD image capture system that have stable timing drive,transfer data in a high rate,can plug and play and cross-platform.

  10. CCD digital radiography system

    Science.gov (United States)

    Wang, Yi; Kang, Xi; Li, Yuanjing; Cheng, Jianping; Hou, Yafei; Han, Haiwei

    2009-07-01

    Amorphous silicon flat-panel detector is the mainstream used in digital radiography (DR) system. In latest years, scintillation screen coupled with CCD DR is becoming more popular in hospital. Compared with traditional amorphous silicon DR, CCD-DR has better spatial resolution and has little radiation damage. It is inexpensive and can be operated easily. In this paper, A kind of CCD based DR system is developed. We describe the construction of the system, the system performances and experiment results.

  11. Development of low-noise high-speed analog ASIC for X-ray CCD cameras and wide-band X-ray imaging sensors

    Science.gov (United States)

    Nakajima, Hiroshi; Hirose, Shin-nosuke; Imatani, Ritsuko; Nagino, Ryo; Anabuki, Naohisa; Hayashida, Kiyoshi; Tsunemi, Hiroshi; Doty, John P.; Ikeda, Hirokazu; Kitamura, Hisashi; Uchihori, Yukio

    2016-09-01

    We report on the development and performance evaluation of the mixed-signal Application Specific Integrated Circuit (ASIC) developed for the signal processing of onboard X-ray CCD cameras and various types of X-ray imaging sensors in astrophysics. The quick and low-noise readout is essential for the pile-up free imaging spectroscopy with a future X-ray telescope. Our goal is the readout noise of 5e- r . m . s . at the pixel rate of 1 Mpix/s that is about 10 times faster than those of the currently working detectors. We successfully developed a low-noise ASIC as the front-end electronics of the Soft X-ray Imager onboard Hitomi that was launched on February 17, 2016. However, it has two analog-to-digital converters per chain due to the limited processing speed and hence we need to correct the difference of gain to obtain the X-ray spectra. Furthermore, its input equivalent noise performance is not satisfactory (> 100 μV) at the pixel rate higher than 500 kpix/s. Then we upgrade the design of the ASIC with the fourth-order ΔΣ modulators to enhance its inherent noise-shaping performance. Its performance is measured using pseudo CCD signals with variable processing speed. Although its input equivalent noise is comparable with the conventional one, the integrated non-linearity (0.1%) improves to about the half of that of the conventional one. The radiation tolerance is also measured with regard to the total ionizing dose effect and the single event latch-up using protons and Xenon, respectively. The former experiment shows that all of the performances does not change after imposing the dose corresponding to 590 years in a low earth orbit. We also put the upper limit on the frequency of the latch-up to be once per 48 years.

  12. The Ortega Telescope Andor CCD

    Science.gov (United States)

    Tucker, M.; Batcheldor, D.

    2012-07-01

    We present a preliminary instrument report for an Andor iKon-L 936 charge-couple device (CCD) being operated at Florida Tech's 0.8 m Ortega Telescope. This camera will replace the current Finger Lakes Instrumentation (FLI) Proline CCD. Details of the custom mount produced for this camera are presented, as is a quantitative and qualitative comparison of the new and old cameras. We find that the Andor camera has 50 times less noise than the FLI, has no significant dark current over 30 seconds, and has a smooth, regular flat field. The Andor camera will provide significantly better sensitivity for direct imaging programs and, once it can be satisfactorily tested on-sky, will become the standard imaging device on the Ortega Telescope.

  13. Removal of stripe noise in CCD faint targets image%CCD弱目标图像条带噪声消除

    Institute of Scientific and Technical Information of China (English)

    赵立荣; 朱玮; 曹永刚; 张尧禹; 余毅; 孙俊喜

    2014-01-01

    The target imaging is faint on CCD , when optical-electronic theodolite traces the remote targets .Stripe noise reduces the image quality, covers useful image information and brings unfavourable effect for interpretation of images.This paper designs improved rectangular low-pass filter in view of power spectrum of striping noise .First, stripe noise model and distribution in frequency domain are analyzed .Then, rectangular low-pass filter to remove noise is introduced, which adopts the maximum approximation true noise by using the weight .The bandwidth of the rectangle low-pass filter is validated by test.Finally, the tests on faint images which are obtained by optical-electron-ic theodolite CCD show that rectangular low-pass filter reduces the stripe to a greater degree while retains the basic in-formation of image than ideal low-pass filter and gauss band stop filter.%光电经纬仪跟踪远距离目标时,在CCD上成像微弱。条带噪声的存在使图像质量下降,掩盖了有效的目标信息,对图像判读造成不利影响。针对条带噪声的功率谱,设计了改进的矩形低通滤波器。首先分析了条带噪声模型及其在频域的分布;然后,介绍了矩形低通滤波器通过加权的方式最大逼近真实噪声而实现噪声滤除的方法,通过实验进行矩形低通滤波器带宽的确定;最后,应用光电经纬仪CCD获得的弱目标图像进行去条带噪声实验,比较该方法与理想低通滤波及高斯带阻滤波去条带效果,结果表明该方法在有效地保留图像基本信息的前提下,获得最佳的去条带效果。

  14. Advanced microlens and color filter process technology for the high-efficiency CMOS and CCD image sensors

    Science.gov (United States)

    Fan, Yang-Tung; Peng, Chiou-Shian; Chu, Cheng-Yu

    2000-12-01

    New markets are emerging for digital electronic image device, especially in visual communications, PC camera, mobile/cell phone, security system, toys, vehicle image system and computer peripherals for document capture. To enable one-chip image system that image sensor is with a full digital interface, can make image capture devices in our daily lives. Adding a color filter to such image sensor in a pattern of mosaics pixel or wide stripes can make image more real and colorful. We can say 'color filter makes the life more colorful color filter is? Color filter means can filter image light source except the color with specific wavelength and transmittance that is same as color filter itself. Color filter process is coating and patterning green, red and blue (or cyan, magenta and yellow) mosaic resists onto matched pixel in image sensing array pixels. According to the signal caught from each pixel, we can figure out the environment image picture. Widely use of digital electronic camera and multimedia applications today makes the feature of color filter becoming bright. Although it has challenge but it is very worthy to develop the process of color filter. We provide the best service on shorter cycle time, excellent color quality, high and stable yield. The key issues of advanced color process have to be solved and implemented are planarization and micro-lens technology. Lost of key points of color filter process technology have to consider will also be described in this paper.

  15. 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.

  16. A study of cosmic ray flux based on the noise in raw CCD data from solar images

    Science.gov (United States)

    Shen, Z.-N.; Qin, G.

    2016-11-01

    Raw solar images from CCDs are often contaminated with single-pixel noise which is thought to be made by cosmic ray hits. The cosmic ray-affected pixels are usually outstanding when compared with the perimeter zone. In this work, we use a method based on the median filtering algorithm to identify and count the cosmic ray traces from SOHO/EIT solar images to estimate the cosmic ray (CR) flux. With such cosmic ray flux, we study the transient variations associated with the violent solar activities, such as the solar proton events (SPEs), which show good similarity with the observations of GOES 11 P6 channel with an energy interval 80-165 MeV. Further, using SPE list observed by SOHO/ERNE proton channels with more narrow energy intervals, it is found that CRs in the energy range 118-140 MeV affect the SOHO/EIT images the most. In addition, by using a robust automatic despiking method, we get the background of the cosmic ray flux from solar images, which is considered to be the galactic cosmic ray (GCR) flux. The GCR flux from solar images shows an 11 year period due to the solar modulation, similar to the SOHO/ERNE GCR flux and Newark neutron monitor count rates. Furthermore, GCRs from solar images have a 27 day period and show good anticorrelation with the changes of solar wind velocity.

  17. 浮胶引起的缺陷对CCD成像的影响分析%Effects of Defects of Float Photoresist on CCD Imaging

    Institute of Scientific and Technical Information of China (English)

    龙飞; 张故万; 吴可; 廖乃鏝; 李仁豪

    2013-01-01

    针对大面阵CCD成像黑缺陷多的特点,从机理和制作工艺上进行了分析研究.结果表明,CCD成像黑缺陷主要由光刻工艺缺陷引起.光刻LOCOS、地和沟阻工艺中产生的浮胶是CCD成像黑缺陷的主要来源.在制作多晶硅栅过程中,光刻浮胶可产生成像黑缺陷或导致信号电荷转移问题.最后,提出了减少光刻工艺产生浮胶的方法.%It is analyzed the dark defects in large-array CCD imaging from the aspects of mechanism and progress rules.The research results indicate the dark imaging defects were mainly caused by the photolithography defects,which are mainly resulted by the detaching of photoresist in the process of LOCOS,ground and channel stop patterns.In the fabrication process of polysilicon gate,the detaching of photoresist can bring the problems of dark defects or charge transfer.The methods for reducing the float photoresist are suggested.

  18. Spatio-temporal prediction of leaf area index of rubber plantation using HJ-1A/1B CCD images and recurrent neural network

    Science.gov (United States)

    Chen, Bangqian; Wu, Zhixiang; Wang, Jikun; Dong, Jinwei; Guan, Liming; Chen, Junming; Yang, Kai; Xie, Guishui

    2015-04-01

    Rubber (Hevea brasiliensis) plantations are one of the most important economic forest in tropical area. Retrieving leaf area index (LAI) and its dynamics by remote sensing is of great significance in ecological study and production management, such as yield prediction and post-hurricane damage evaluation. Thirteen HJ-1A/1B CCD images, which possess the spatial advantage of Landsat TM/ETM+ and 2-days temporal resolution of MODIS, were introduced to predict the spatial-temporal LAI of rubber plantation on Hainan Island by Nonlinear AutoRegressive networks with eXogenous inputs (NARX) model. Monthly measured LAIs at 30 stands by LAI-2000 between 2012 and 2013 were used to explore the LAI dynamics and their relationship with spectral bands and seven vegetation indices, and to develop and validate model. The NARX model, which was built base on input variables of day of year (DOY), four spectral bands and weight difference vegetation index (WDVI), possessed good accuracies during the model building for the data set of training (N = 202, R2 = 0.98, RMSE = 0.13), validation (N = 43, R2 = 0.93, RMSE = 0.24) and testing (N = 43, R2 = 0.87, RMSE = 0.31), respectively. The model performed well during field validation (N = 24, R2 = 0.88, RMSE = 0.24) and most of its mapping results showed better agreement (R2 = 0.54-0.58, RMSE = 0.47-0.71) with the field data than the results of corresponding stepwise regression models (R2 = 0.43-0.51, RMSE = 0.52-0.82). Besides, the LAI statistical values from the spatio-temporal LAI maps and their dynamics, which increased dramatically from late March (2.36 ± 0.59) to early May (3.22 ± 0.64) and then gradually slow down until reached the maximum value in early October (4.21 ± 0.87), were quite consistent with the statistical results of the field data. The study demonstrates the feasibility and reliability of retrieving spatio-temporal LAI of rubber plantations by an artificial neural network (ANN) approach, and provides some insight on the

  19. Radiation-induced noise in Charge-Coupled Device (CCD) and Charge-Injection Device (CID) imagers

    Science.gov (United States)

    Yates, George J.; Turko, Bojan T.

    1990-08-01

    Measurements of radiation sensitivity for interline transfer charge-coupled devices (CCDs) and charge-injection devices (CIDs) from irradiation with high-energy photons (CO-60 gammas and 3-to 5-MeV end-point Bremsstrahlung) and 14-MeV neutrons are presented to establish imager susceptibility in such environments. Results from electric clearing techniques designed for quick (approximately 300 microseconds for the CCDs and approximately 10 microseconds for CIDs) removal (or dumping) of radiation-induced charge from prompt sources are discussed. Application of the techniques coupled with long (microsecond to millisecond) persistence radiation-to-light converters for image retention is described. Typical data illustrating the effectiveness of charge clearing in removal of radiation noise are included for nanosecond duration pulsed x ray/gamma-ray doses (50 millirad to 5-rad range) and microsecond duration neutron fluences approaching 10(exp 8) n/sq cm.

  20. CCD characterization for a range of color cameras

    NARCIS (Netherlands)

    Withagen, P.J.; Groen, F.C.A.; Schutte, K.

    2005-01-01

    CCD cameras are widely used for remote sensing and image processing applications. However, most cameras are produced to create nice images, not to do accurate measurements. Post processing operations such as gamma adjustment and automatic gain control are incorporated in the camera. When a (CCD) cam

  1. The EMSS catalog of X-ray-selected clusters of galaxies. I. An atlas of CCD images of 41 distant clusters

    CERN Document Server

    Gioia, I M

    1994-01-01

    Abstract An atlas of deep, wide-field R-band CCD images of a complete sample of distant, X-ray-selected clusters of galaxies is presented. These clusters are the 41 most distant (z>= 0.15) and most X-ray luminous (Lx >= 2x10**44 erg\\s-1) clusters in the Einstein Observatory Extended Medium Sensitivity Survey (EMSS) catalog that are observable from Mauna Kea (delta > -40 deg). The sample spans a redshift range of 0.15 0.5. For the most part, the data are of superior quality, with a median seeing of 0''.8 FWHM and coverage of at least 1 Mpc X 1 Mpc in the cluster frame (Ho=50; q0=1/2). In addition, we update the available optical, X-ray and radio data on the entire EMSS sample of 104 clusters. We outline the cluster selection criteria in detail, and emphasize that X-ray-selected cluster samples may prove to be more useful for cosmological studies than optically selected samples. The EMSS cluster sample in particular can be exploited for diverse cosmological investigations, as demonstrated by the detection of ev...

  2. The Wasilewski sample of emission-line galaxies - Follow-up CCD imaging and spectroscopic and IRAS observations

    Science.gov (United States)

    Bothun, Gregory D.; Schmitz, Mark; Halpern, Jules P.; Lonsdale, Carol J.; Impey, Chris

    1989-06-01

    The results of an extensive imaging and spectroscopic follow-up of the objective prism-selected emission line galaxy (ELG) sample of Wasilewski (1982) are presented. Fluxes at 12, 25, 60, and 100 microns were also obtained from the coadded IRAS survey data. ELGs found by objective prism surveys are found to be generally small and underluminous galaxies which usually have higher than average optical surface brightness. The Seyfert detection rate in objective prism surveys is roughly 10 percent and the ratio of the space densities of Seyfert 2 to Seyfert 1 galaxies is significantly larger than unity. Most of the galaxies selected by objective prism surveys are star-forming, late-type spirals which often show disturbed morphology. About 25 percent of the galaxies detected by the surveys are faint, high-excitation metal-poor compact H II regions.

  3. 基于虚拟仪器和蓝牙技术的线阵CCD图像采集系统%A linear CCD image capture system based on virtual instrument and Bluetooth technology

    Institute of Scientific and Technical Information of China (English)

    许林林; 汪涛

    2015-01-01

    采用 ST 公司生产的 STM32F103系列主控芯片,该系列芯片能够产生系统所需要的驱动线阵 CCD 的时序信号,通过蓝牙技术进行数据传输,使用虚拟仪器编程软件 LabVIEW 进行上位机软件开发,从而能够完整地做出所要求的一个线阵 CCD 图像采集系统。该系统可以实现蓝牙无线数据方式采集,软件界面的开发时间缩短,操作性强。%This text takes STM32F103 as the main control chip. It uses this chip to produce the timing drive of linear CCD. Also, it translates data via bluetooth technology. And it uses the virtual instrument programming software LabVIEW to develop the program on upper computer. In the end, it realizes a linear CCD image capture system, which can realize Bluetooth wireless data gathering, shorten development time and operate strongly in the software interface.

  4. Vacuum compatible miniature CCD camera head

    Science.gov (United States)

    Conder, Alan D.

    2000-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  5. A comprehensive study of the young open star cluster NGC 6611 based on deep VRI CCD images and 2MASS data

    Directory of Open Access Journals (Sweden)

    I.M. Selim

    2016-06-01

    Full Text Available In the present study, we have used Deep CCD images of the extremely young open star cluster NGC 6611, up to a limiting magnitude of V ∼ 22.86 mag in V, R and I passbands. The resulting color-magnitude V; (V–I diagram as well as their radial density profiles has been determined. Using 2MASS data, we confirmed the consistency between the 2MASS photometry, by fitting isochrones, the extinction E(V–I = 0.530 ± 0.04 mag, E(J–H = 0.31 ± 0.02, from the color magnitude diagram the cluster distance =2.2 ± 0.21 kpc and age = 3.6 Myr, based on the fitting of theoretical stellar isochrones of solar metallicity Z = 0.019. The distance modulus of the cluster is estimated at 12.3. The radial stellar density profiles and the cluster center have been determined by two methods. The core and cluster radii are determined from the radial stellar density profiles. Only about 40% of the cluster members are present in the core region. The cluster luminosity function has been calculated. The mass function slope of the entire cluster is ∼−0.67 ± 0.12. The effects of mass segregation, most probably due to dynamical evolution, have been observed in the cluster.

  6. Robust CCD photoelectric autocollimator for outdoor use

    Institute of Scientific and Technical Information of China (English)

    Min Gao; Zuoren Dong; Zhenglan Bian; Qing Ye; Zujie Fang; Ronghui Qu

    2011-01-01

    A robust charge-coupled device (CCD) photoelectric autocollimator for outdoor use is designed and demonstrated. The influence of outdoor conditions on the signal-to-noise ratio (SNR) and imaging quality of the measuring system is experimentally analyzed. The pulse width modulation technology is applied to the automatic feedback control of the actively regulated illuminating light source of the measuring system to maximize SNR while avoiding image saturation. A Fourier phase shift method for subpixel estimation is adopted to achieve high-accuracy measurement in the presence of noises. Experimental results indicate that the technologies proposed here largely improve the measuring stability, dynamic range, and accuracy of the CCD photoelectric autocollimator used outdoors.%@@ A robust charge-coupled device(CCD)photoelectric autocollimator for outdoor use is designed and demonstrated.The influence of outdoor conditions on the signal-to-noise ratio(SNR)and imaging quality of the measuring system is experimentally analyzed.The pulse width modulation technology is applied to the automatic feedback control of the actively regulated illuminating light source of the measuring system to maximize SNR while avoiding image saturation.A Fourier phase shift method for subpixel estimation is adopted to achieve high-accuracy measurement in the presence of noises.Experimental results indicate that the technologies proposed here largely improve the measuring stability,dynamic range,and accuracy of the CCD photoelectric autocollimator used outdoors.

  7. Análise de mapas de represas publicados na web usando imagens orbitais CCD/CBERS no estado de Minas Gerais Analysis of dams maps published on the web by using orbital CCD/CBERS images in Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Elizabeth Ferreira

    2010-02-01

    Full Text Available Neste trabalho, bancos de dados públicos e gratuitos disponíveis na World Wide Web (WEB foram utilizados para avaliar as áreas das superfícies dos espelhos d'água das represas de Furnas e do Funil, no Estado de Minas Gerais. O objetivo foi comparar as informações obtidas nos bancos da WEB com os valores das áreas calculadas a partir de imagens do sensor CCD a bordo dos satélites CBERS2 e CBERS2B. A área da represa de Furnas obtida a partir das imagens CCD/CBERS2B, ano 2008, foi de 1.138 km², mas nos bancos de dados consultados esta área estava entre 1.182 e 1.503 km². A represa do Funil, construída em 2003, com superfície de espelho d'água de 29,37 km² e uma ilha com área de 1,93 km² não aparecem nos bancos Atlas, Geominas, IGAM e IBGE. Os resultados mostraram algumas discrepâncias nos bancos de dados publicados na WEB, tais como diferenças em áreas e supressão ou extrapolação de limites do espelho d'água. Concluiu-se que, até o momento, os responsáveis por algumas publicações de bancos de dados no Estado de Minas Gerais não tiveram rigor suficiente com as atualizações. As imagens CCD/CBERS, que também são dados públicos disponíveis na WEB, mostraram ser produtos adequados para verificar, atualizar e melhorar as informações publicadas.In this work some public databases from the World Wide Web (WEB were used to find the area of the Furnas and Funil Dams in Minas Gerais State. The purpose of this work was to compare the WEB public databases values and the real values obtained from the CCD camera images on board CBERS2 and CBERS2B satellites. The Furnas Dam area obtained from CCD/ CBERS2B images, in 2008, was 1.138 km², but in the consulted databases this area ranged from 1.182 to 1.503 km². The dam of the Funil, built in 2003, with a water surface of 29.37 km² and an island with 1.93 km² area, did not appear in Atlas, Geominas, IGAM and IBGE databases. The results revealed some problems in the WEB public

  8. 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.

  9. CCD characterization and measurements automation

    Energy Technology Data Exchange (ETDEWEB)

    Kotov, I.V., E-mail: kotov@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973 (United States); Frank, J.; Kotov, A.I. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Kubanek, P. [Institute of Physics of the Academy of Sciences, Prague, CZ 18221 (Czech Republic); Image Processing Laboratory, Universidad de Valencia (Spain); O' Connor, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Prouza, M. [Institute of Physics of the Academy of Sciences, Prague, CZ 18221 (Czech Republic); Radeka, V.; Takacs, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2012-12-11

    Modern mosaic cameras have grown both in size and in number of sensors. The required volume of sensor testing and characterization has grown accordingly. For camera projects as large as the LSST, test automation becomes a necessity. A CCD testing and characterization laboratory was built and is in operation for the LSST project. Characterization of LSST study contract sensors has been performed. The characterization process and its automation are discussed, and results are presented. Our system automatically acquires images, populates a database with metadata information, and runs express analysis. This approach is illustrated on {sup 55}Fe data analysis. {sup 55}Fe data are used to measure gain, charge transfer efficiency and charge diffusion. Examples of express analysis results are presented and discussed.

  10. Smear Removal Algorithm of CCD Imaging Sensors Based on Wavelet Transform in Star-sky Image%星图中基于小波变换的CCD传感器Smear现象消除方法

    Institute of Scientific and Technical Information of China (English)

    姚睿; 张艳宁; 孙瑾秋; 张永鹏

    2011-01-01

    When the frame transfer CCD image sensor shooting star-sky background image, the smear phenomenon caused by high brightness stars in the field of view will seriously affect the target detection.For removing the smear phenomenon,a smear removal algorithm based on wavelet transform in star-sky image was proposed. According to the mechanism of smear and characteristics of the star-sky image, the model of smear problem was established, the smear line was separated into the high frequency components and vertical components by using multi-layer two-dimension haar wavelet transform, and the smearremoved image was reconstructed. The expirmental results show that the method can effectively remove smear and retain original image information,and enhance the SNR of small target in smear area.%帧转移型CCD传感器在拍摄星空背景图像时,视场中高亮度恒星会产生Smear现象,从而对目标检测有严重影响.为了消除Smear现象,提出了一种星图中基于小波变换的Smear消除方法.首先根据Smear产生机理及星空图像特性,建立星图Smear问题的模型;然后使用多层二维Haar小波分解,把Smear亮线分离到低频分量及高频垂直分量中分别进行Snlear消除处理;最后重构出消除Smear的图像.实验结果表明:该方法能有效去除Smear,最大限度保留图像原有信息,并可增强Smear区域弱小目标信噪比.

  11. 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.

  12. Motion Measurement of Dual-CCD Imaging System Based on Optical Correlator%光学相关的双CCD成像系统图像运动位移测量

    Institute of Scientific and Technical Information of China (English)

    钱义先; 洪雪婷; 金伟民

    2013-01-01

    To measure the sub-pixel image motion caused by satellite attitude instability or various disturbance,an effective approach to measure image motion by dual-CCD imaging system based on joint transform correlator (JTC) is presented.An auxiliary high-speed CCD is used to capture image sequences which are the same scenes as those images captured by the prime CCD.These image sequences are optically calculated by JTC system,and then relatively motion displacement can be obtained.The principle of this approach is represented,and measurement precision is analyzed in the condition of noise and image motion.Motion measurement system is also presented,and the experimental results show that the measurement precision can be controlled within 0.1 pixel.%为测量卫星遥感相机因姿态不稳定以及各种扰动引起的亚像素像移,提出了基于光学相关的双CCD成像系统的图像运动测量方法.在主成像系统成像的同时,辅助高速CCD获取同一目标的图像序列,利用联合变换相关器对所采集的图像序列进行光学运算,测量出相邻图像序列的运动位移.阐述了使用光学相关方法测量像移的原理,并模拟分析了噪声和运动条件下的测量精度.建立了使用该方法测量像移的实验系统.实验结果证实了该方法的有效性,测量精度小于0.1 pixel,满足卫星遥感相机的使用要求.

  13. Charge transfer efficiency measurements at low signal levels on STIS/SOHO TK1024 CCD's. [Space Telescope Imaging Spectrograph / Solar Heliocentric Observatory

    Science.gov (United States)

    Orbock, J. D.; Murata-Seawalt, D.; Delamere, W. A.; Blouke, Morley M.

    1990-01-01

    Charge transfer efficiency (CTE) test methods are reviewed, and the results and conclusions of the tests are given. The test methods have been utilized to describe the CTE characteristics of the Tektronix 1024 by 1024 CCD to optimize low dark current, low readout noise, and high CTE at low signal levels. CTE modelling is described, and three test methods are set forth and compared. The Fe-55 X-ray response method utilizes the response of a CCD to X-ray photons from the radioactive source Fe-55. The extended pixel edge response method employs the measurement of the charge lost to successive pixels by a known initial signal as it is shifted through the array. The charge injection method consists of charge injection through the output amplifier reset transistor. These measurements were performed on several devices with known CTEs. The CTEs are found to be in agreement for the three methods, making application and test requirements the principal criteria for their use.

  14. Experimental Research on the SizeMeasurement of the High Temperature ForgingBased on Multicolor CCD Technology

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    In order to determine the size measurement accuracy of the high temperature forging's multicolor CCD image by using computerprograms, this paper obtained the high temperature forging's CCD image by multicolor CCD camera and its fact size by thevernier caliper on the forging field, and then measured the size of the high temperature forging from its CCD image, compared thesize from the CCD image and the size from the vernier caliper, the result shows that the measurement accuracy satisfied theindustrial production.

  15. 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.

  16. A quantitative striping removal algorithm for HY- 1 CCD data

    Institute of Scientific and Technical Information of China (English)

    孙凌; 唐军武; 张杰

    2002-01-01

    -- Striping is a common phenomenon in remote sensing imagery acquired by most spaceborne and airborne multispectral sensors. In contrast to the destriping of the images of optoelectronic mechanical scanners, fewer work has been done for push-broom CCD images. Based on the characteristics of HY-1 push-broom multispectral CCD camera and its prelaunch radiometric calibration results, the striping features are analyzed and a quantitative striping removal algorithm is proposed. The algorithm is to obtain the inter-detector equalization curves to reflect the differences between detectors by statistic analysis of the satellite imagery data set, and image stripes arising from the nonuniformity of the detectors of the CCD array can be removed using the estimated equalization curves. The preliminary results show that this method can effectively remove the stripes and preserve the radiometric accuracy of the raw data at the same time.

  17. Optimizing Low Light Level Imaging Techniques and Sensor Design Parameters using CCD Digital Cameras for Potential NASA Earth Science Research aboard a Small Satellite or ISS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project made use of two computational photography techniques, high dynamic range (HDR) imagery formulation and bilateral filters to enable novel imaging...

  18. CCD emulator design for LSST camera

    Science.gov (United States)

    Lu, W.; O'Connor, P.; Fried, J.; Kuczewski, J.

    2016-07-01

    As part of the LSST project, a comprehensive CCD emulator that operates three CCDs simultaneously has been developed for testing multichannel readout electronics. Based on an Altera Cyclone V FPGA for timing and control, the emulator generates 48 channels of simulated video waveform in response to appropriate sequencing of parallel and serial clocks. Two 256Mb serial memory chips are adopted for storage of arbitrary grayscale images. The arbitrary image or fixed pattern image can be generated from the emulator in triple as three real CCDs perform, for qualifying and testing the LSST 3-stripe Science Raft Electronics Board (REB) simultaneously. Using the method of comparator threshold scanning, all 24 parallel clocks and 24 serial clocks from the REB are qualified for sequence, duration and level before the video signal is generated. In addition, 66 channels of input bias and voltages are sampled through the multi-channel ADC to verify that correct values are applied to the CCD. In addition, either a Gigabit Ethernet connector or USB bus can be used to control and read back from the emulator board. A user-friendly PC software package has been developed for controlling and communicating with the emulator.

  19. Lunar Image Data Preprocessing and Quality Evaluation of CCD Stereo Camera on Chang'E-2%嫦娥二号CCD立体相机数据预处理与数据质量评价

    Institute of Scientific and Technical Information of China (English)

    刘建军; 任鑫; 谭旭; 李春来

    2013-01-01

    嫦娥二号是中国探月工程二期月面软着陆和巡视探测的先导星,经过为期半年多的科学探测,CCD立体相机获取了空间分辨率7 m的全月球影像数据,对于后续月球探测和月球科学研究具有非常重要的意义.本文介绍了CCD立体相机的数据获取、数据预处理、数据格式和数据质量情况,有助于月球科学家了解数据产品情况,挖掘数据中更多的科学信息,开展月球科学研究.%Chang'E-2 was launched on October 1st 2010, inaugurating the second phase of a three-step moon mission which will culminate in a soft-landing on the moon. After half a year's exploring, the globe image data of 7 m resolution had been acquired by CCD stereo camera on Chang'E-2. The image data acquiring and preprocessing, data format and quality are recommended, which are helpful for lunar scientists to understand and make use of these image data products, and to extract information for studying lunar science.

  20. 自动恒温控制在可见光CCD成像系统中的应用研究%Applications of Auto Constant Temperature Control System for Visible CCD Imaging

    Institute of Scientific and Technical Information of China (English)

    尹业宏; 高黎明

    2012-01-01

    随着高性能CCD传感器的发展,其在空间成像探测系统得到广泛应用。为解决传感器的成像质量和恒温控制问题,采用基于帕尔贴效应的热电制冷(Thermo—ElectricCooling,TEC)技术,以FPGA为控制芯片,运用PID控制算法,实现了小型温度控制系统。实验结果表明,该系统能快速准确地实现恒温控制,可扩展性强,具有一定的应用价值。%With the development of high performance cooling CCD imaging system in aerospace imaging detection, in order to improve sensor's imaging performance and keep sensor's temperature constant, a precision temperature control system is designed by using FPGA as digital control processor and a method of PID control and Thermo-Electric Cooling(TEC) technolo- gy, based on Peltier effect. The experiment results show that the system can work fast and accurately and can be well expanded. It has the good practicability.

  1. Anti-Stokes effect CCD camera and SLD based optical coherence tomography for full-field imaging in the 1550nm region

    Science.gov (United States)

    Kredzinski, Lukasz; Connelly, Michael J.

    2012-06-01

    Full-field Optical coherence tomography is an en-face interferometric imaging technology capable of carrying out high resolution cross-sectional imaging of the internal microstructure of an examined specimen in a non-invasive manner. The presented system is based on competitively priced optical components available at the main optical communications band located in the 1550 nm region. It consists of a superluminescent diode and an anti-stokes imaging device. The single mode fibre coupled SLD was connected to a multi-mode fibre inserted into a mode scrambler to obtain spatially incoherent illumination, suitable for OCT wide-field modality in terms of crosstalk suppression and image enhancement. This relatively inexpensive system with moderate resolution of approximately 24um x 12um (axial x lateral) was constructed to perform a 3D cross sectional imaging of a human tooth. To our knowledge this is the first 1550 nm full-field OCT system reported.

  2. BUNDLE ADJUSTMENTS CCD CAMERA CALIBRATION BASED ON COLLINEARITY EQUATION

    Institute of Scientific and Technical Information of China (English)

    Liu Changying; Yu Zhijing; Che Rensheng; Ye Dong; Huang Qingcheng; Yang Dingning

    2004-01-01

    The solid template CCD camera calibration method of bundle adjustments based on collinearity equation is presented considering the characteristics of space large-dimension on-line measurement. In the method, a more comprehensive camera model is adopted which is based on the pinhole model extended with distortions corrections. In the process of calibration, calibration precision is improved by imaging at different locations in the whole measurement space, multi-imaging at the same location and bundle adjustments optimization. The calibration experiment proves that the calibration method is able to fulfill calibration requirement of CCD camera applied to vision measurement.

  3. 高温物体成像时彩色CCD相机的自动调光方法%Automatic Light Adjustment Method for Color CCD Camera Used in Imaging of High-Temperature Object

    Institute of Scientific and Technical Information of China (English)

    李哲林; 夏琴香; 姜立军; 李一振; 宋阿生

    2013-01-01

    针对温度变化大的高温物体在CCD相机上成像时图像会发白或发黑,导致图像中物体特征被弱化这一问题,提出一种基于灰度均值的彩色CCD相机自动调光方法.文中首先阐述了CCD相机成像时物体热辐射对图像灰度的影响;然后分析了彩色CCD相机采集的850 ~1200℃高温物体图像的特点,建立了RGB基色图像灰度均值与积分时间的关系;最后提出一种自动调光方法,该方法通过采集一帧预测图像来计算物体所在的温度区间和最佳积分时间,根据最佳积分时间采集彩色图像,按照温度区间提取彩色图像对应的基色灰度图,并将其作为后续处理图像.实验结果表明,该调光方法对温度变化具有很好的鲁棒性,基于此方法的彩色CCD相机能采集到具有稳定灰度值的高温物体图像,有利于高温物体的几何测量和表面缺陷检测.%Due to the whitened or darkened CCD camera images of high-temperature objects with wide temperature change range, the object features in the images are weakened. In order to solve this problem, an automatic light adjustment method based on average gray value for color CCD camera is proposed. In the investigation, first, the effects of object heat radiation on the image gray during the imaging are discussed. Next, the image features of the object with the temperature of 850 ~ 1200℃ are analyzed. Then, the relationship between the average gray of RGB primary color images and the integral time is revealed. Finally, an automatic light adjustment method is constructed, which calculates the temperature zone and optimal integral time by using a prediction image frame, acquires the color image according to the optimal integral time, and extracts a proper primary gray image from the color image based on temperature zone for further usage. Experimental results show that the proposed method is robust to wide temperature change range and helps to acquire images with stable

  4. [Evaluation on the atmospheric correction methods for water color remote sensing by using HJ-1A/1B CCD image-taking Poyang Lake in China as a case].

    Science.gov (United States)

    Zeng, Qun; Zhao, Yue; Tian, Li-Qiao; Chen, Xiao-Ling

    2013-05-01

    HJ-1A/1B satellite CCD images have higher spatial and temporal resolution, making them of great potential in quantitatively monitoring the water quality of inland lakes. However, the atmospheric correction of the images restricts their application. Therefore, taking Poyang Lake, the biggest freshwater lake in China as study area , and using the in-situ data collected in 2009 and 2011, this paper compares the atmospheric correction results done by the four methods: FLAASH, 6S, COST and QUAC, and analyzes the influence of these atmospheric correction methods on the inversion accuracy of the total suspended sediments (TSS) concentration. The results indicate: (1) the band 1 (blue band) of HJ-1A/1B CCD satellite images should be recalibrated while being applied into water quality remote sensing. The accuracy of atmospheric correction done from band 2 (green band) and band 3 (red band) is higher than that of others , especially that of the correction done by FLAASH, 6S and COST is much higher while that of correction done by QUAC is lower. So the algorithms of QUAC should be pointedly improved. (2) The ratios done from band 2 and band 3 have a good match with in-situ data , with an average relative error of 8.2%, 9.5%, 7.6% and 11.6% respectively for FLAASH, 6S, COST and QUAC. Therefore, it would be better to use the ratio done from band 2 and band 3 as inversion factors in Poyang Lake. (3) It is found that the accuracy of directly building models by using the four atmospheric corrected results and the TSS concentration is higher than the models built by the in-situ remote sensing reflectance and the TSS concentration. The accuracy of the TSS concentration inverted by FLAASH, 6S and COST is much high with an average error of only 10.0%, 10.2% and 8.0% respectively, while the error inverted by QUAC is a little bit higher of being 18.6%. So it is suggested to build model with atmospheric correction results and the TSS concentration data, because it can avoid the cumulate

  5. Printed circuit board for a CCD camera head

    Science.gov (United States)

    Conder, Alan D.

    2002-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close (0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  6. Recognition algorithm based on the path of the CCD image sensor analysis%基于CCD图像传感器的路径识别算法分析

    Institute of Scientific and Technical Information of China (English)

    尚在飞; 肖文健; 李永科

    2012-01-01

    随着汽车工业的发展,汽车智能化成为大势所趋。智能汽车(IV,Intelligent Vehicle)是一种集环境感知、规划决策、多等级辅助驾驶等功能于一体的综合系统,它集中地运用了计算机技术、人工智能与自动控制技术、现代传感器技术、信息与通信等技术,是典型的高新技术的综合体。文中以第六届全国大学生”飞思卡尔”杯智能汽车为背景,探讨了基于CCD图像传感器的图像跟踪算法。%With the development of the automotive industry, automotive intelligent become a trend .The Intelligent Vehicle is a set of environmental perception, planning and decision-making, muhi-level driver assistance features such as an integrated system, which focus on the use of computer technology, artificial intelligence and automatic control technology, modem sensor technology, information and communications technology is the typical high-tech complex. The Sixth National University "The Freescale Cup" Intelligent Car Competition as the background image tracking algorithm based on the CCD image sensor.

  7. 三基色测温法在CCD图像传感器测温中的应用%Three colors temperature measurement method in CCD image sensor measuring temperature of application

    Institute of Scientific and Technical Information of China (English)

    韩龙; 卜树坡; 赵杰; 王丽

    2011-01-01

    The non-contact temperature measurement system based on CCD image sensor is designed in this dissertation and Three Primary-Color temperature measurement method is studied. The simulation calculation of temperature field is made with the application of three primary-color temperature measurement according to the high-temp Gas Vane image of some solid racket motor. Comparison between three primary-color and colorimetric temperature measurement method shows that the former can measure surface temperature field of the high-temp Gas Vane efficiently and improve temperature measurement precision.%设计了CCD图像传感器的非接触式测温系统,对三基色测温法进行了介绍,并应用三基色测温法对采集的某固体火箭发动机的高温燃气舵图像进行了温度场仿真计算,并对比了CCD比色测温法和三基色测温法,结果表明本文提出的测温法能有效地测量出高温燃气舵表面温度场,提高了测温精度.

  8. ACS CCD Stability Monitor

    Science.gov (United States)

    Grogin, Norman

    2012-10-01

    A moderately crowded stellar field in the cluster 47 Tuc {6 arcmin West of the cluster core} is observed every four months with the WFC. The first visit exercises the full suite of broad and narrow band imaging filters and sub-array modes; following visits observe with only the six most popular Cycle 18 filters in full-frame mode. The positions and magnitudes of objects will be used to monitor local and large scale variations in the plate scale and the sensitivity of the detectors and to derive an independent measure of the detector CTE. One exposure in each sub-array mode with the WFC will allow us to verify that photometry obtained in full-frame and in sub-array modes are repeatable to better than 1%. This test is important for the ACS Photometric Cross-Calibration program, which uses sub-array exposures. This program may receive additional orbits to investigate ORIENT-dependent geometric distortion, which motivates the ORIENT and BETWEEN requirement on the first visit.

  9. ccdAB system and the encoding toxin protein-CcdB%ccdAB系统及其编码的毒素蛋白CcdB

    Institute of Scientific and Technical Information of China (English)

    贾卉; 井申荣

    2009-01-01

    ccdAB系统(control of cell division or death system)是目前已知的一种毒素-抗毒素系统(toxin-antitoxin system,TA系统),存在于致病性大肠杆菌F质粒及染色体骨架上,由ccdA和ccdB两个基因组成.质粒上的ccdAB系统编码一种毒素蛋白CcdB,在缺乏抗毒素的情况下,CcdB使细胞内促旋酶中毒,从而干扰DNA的合成,杀伤宿主细胞.本文对ccdAB系统的结构和功能,以及所编码CcdB的作用机制进行了综述.

  10. Evryscope Robotilter automated camera / ccd alignment system

    Science.gov (United States)

    Ratzloff, Jeff K.; Law, Nicholas M.; Fors, Octavi; Ser, Daniel d.; Corbett, Henry T.

    2016-08-01

    We have deployed a new class of telescope, the Evryscope, which opens a new parameter space in optical astronomy - the ability to detect short time scale events across the entire sky simultaneously. The system is a gigapixel-scale array camera with an 8000 sq. deg. field of view, 13 arcsec per pixel sampling, and the ability to detect objects brighter than g = 16 in each 2-minute exposure. The Evryscope is designed to find transiting exoplanets around exotic stars, as well as detect nearby supernovae and provide continuous records of distant relativistic explosions like gamma-ray-bursts. The Evryscope uses commercially available CCDs and optics; the machine and assembly tolerances inherent in the mass production of these parts introduce problematic variations in the lens / CCD alignment which degrades image quality. We have built an automated alignment system (Robotilters) to solve this challenge. In this paper we describe the Robotilter system, mechanical and software design, image quality improvement, and current status.

  11. Image mosaic for one aerial reconnaissance CCD camera based on object straight edge nodes%利用目标直线边缘交点的某型航侦CCD相机图像拼接

    Institute of Scientific and Technical Information of China (English)

    张德新; 马广富; 邵晓巍

    2012-01-01

    针对某型航侦CCD相机图像序列之间的特殊变换关系,提出了一种基于目标直线边缘交点的图像拼接方法.该方法在将相机图像重叠区域分割为较小独立区域的基础上,首先使用Canny边缘检测算子提取各个区域中的边缘信息,并用Hough变换提取边缘中的直线边缘.其次通过提出一种依据直线极坐标参数的区域扩展和选择策略来选择包含完整目标的子图像区域,并提取该区域中目标直线边缘的交点.最终根据提取到的直线边缘交点坐标实现图像配准,且采用双线性插值法融合配准区域,实现了图像的无缝拼接.实际的飞行效果验证了该图像拼接方法的有效性.%An image mosaic method of object straight edge nodes was proposed by the unique transformation relation between the image sequences of one aerial reconnaissance CCD camera. In that scheme, overlap area of images were first segmented into smaller sub-images independently, and Canny edge detection operator was employed to extract the edge information from each single area, then straight edges from the obtained edge information were also derived by Hough transform. Moreover, a strategy of area expanding and selection was proposed to extract the straight edge nodes, and it was applied to keep the segment area containing an effective object. Finally, image registration was finished according to the obtained straight edge nodes, and seamless mosaic image could be achieved by bilinear interpolation method. The actual mosaic results are also presented to verify the effectives of the proposed image mosaic approach.

  12. VizieR Online Data Catalog: CCD photometry of CY Aqr 2012-2015 (Wiedemair+, 2016)

    Science.gov (United States)

    Wiedemair, C.; Sterken, C.; Eenmae, T.; Tuvikene, T.; Niederkofler, D.; Franzinelli, P.; Durnwalder, J.; Nardi, R.; Franzinelli, T.; Morawetz, I.; Nugroho, S. K.; Damini Hofer, J.; Seeber, J.

    2016-10-01

    All photometric data reported in this paper were obtained through CCD imaging obtained over more than 50 partial nights comprising a total of more than 20000 useful CCD frames. Table 1 gives the journal of observations. Heliocentric Julian Date, differential magnitudes ys,bs,vs,us in the standard system, and instrumental differential magnitudes yi,bi,vi,ui. (4 data files).

  13. Precise Determination of Brillouin Scattering Spectrum Using a Virtually Imaged Phase Array (VIPA) Spectrometer and Charge-Coupled Device (CCD) Camera.

    Science.gov (United States)

    Meng, Zhaokai; Yakovlev, Vladislav V

    2016-08-01

    Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows noninvasive assessment of viscoelastic properties of materials. The use of atomic-molecular absorption cells as ultra-narrow notch filters allows acquisition of Brillouin spectra from turbid samples despite their strong elastic scattering. However, such systems alter the shapes of the Brillouin lines, making the precise determination of the Brillouin shift difficult. In this report, we propose a simple method for analyzing the Brillouin spectrum using a customized least-square fitting algorithm. The absorption spectrum induced by the atomic-molecular cell was taken into consideration. The capability of the method is confirmed by processing experimental spectroscopic data from the pure water at different temperatures. The accuracy of the measurements of ±1 MHz spectral line shift is experimentally demonstrated.

  14. CCD sensors in synchrotron X-ray detectors

    Science.gov (United States)

    Strauss, M. G.; Naday, I.; Sherman, I. S.; Kraimer, M. R.; Westbrook, E. M.; Zaluzec, N. J.

    1988-04-01

    The intense photon flux from advanced synchrotron light sources, such as the 7-GeV synchrotron being designed at Argonne, require integrating-type detectors. Charge-coupled devices (CCDs) are well suited as synchrotron X-ray detectors. When irradiated indirectly via a phosphor followed by reducing optics, diffraction patterns of 100 cm 2 can be imaged on a 2 cm 2 CCD. With a conversion efficiency of ˜ 1 CCD electron/X-ray photon, a peak saturation capacity of > 10 6 X-rays can be obtained. A programmable CCD controller operating at a clock frequency of 20 MHz has been developed. The readout rate is 5 × 10 6 pixels/s and the shift rate in the parallel registers is 10 6 lines/s. The test detector was evaluated in two experiments. In protein crystallography diffraction patterns have been obtained from a lysozyme crystal using a conventional rotating anode X-ray generator. Based on these results we expect to obtain at a synchrotron diffraction images at a rate of ˜ 1 frame/s or a complete 3-dimensional data set from a single crystal in ˜ 2 min. In electron energy-loss spectroscopy (EELS), the CCD was used in a parallel detection mode which is similar to the mode array detectors are used in dispersive EXAFS. With a beam current corresponding to 3 × 10 9 electron/s on the detector, a series of 64 spectra were recorded on the CCD in a continuous sequence without interruption due to readout. The frame-to-frame pixel signal fluctuations had σ = 0.4% from which DQE = 0.4 was obtained, where the detector conversion efficiency was 2.6 CCD electrons/X-ray photon. These multiple frame series also showed the time-resolved modulation of the electron microscope optics by stray magnetic fields.

  15. 月球主要构造特征:嫦娥一号月球影像初步研究%Research of Lunar Tectonic Features: Primary Results From Chang'E-1 Lunar CCD Image

    Institute of Scientific and Technical Information of China (English)

    王杰; 曾佐勋; 岳宗玉; 胡烨

    2011-01-01

    The Moon retains the information of initial period, because its geological activity was ceased 3.1billion years ago. This information is very important for us to recognize the formation and evolution of the Moon, the earth and even the solar system. On the basis of initial study and Chang'E-1 CCD images, the geological, topographic and geomorphologic features of the main tectonic patterns on the Moon are introduced. The two important kinds of structures on the moon are circular tectonics and linear tectonics. Circular tectonics are the annular appearances on remote sensing images displayed through architecture and color, which are the most striking features of lunar images. This article studies the formation of Mons Rumker, Hainzel Crater, King Crater and the fracture at the bottom of Humboldt Crater, and then, analyzes the difference in lunar crater both near and far side, the South and North Pole. Linear tectonics refer to those structures extended as linear on lunar surface, which can reflect the global or territorial stress condition and stress field of the lithosphere and tectonic forms on the planets. This article also studies the echelon structure nearby the Cauchy Crater, step scarp of Mare Humorum, regional fault nearby the Hippocrateson Crater, fault structures along Apennine Mountains, crater chain at the bottom of Davy Crater, Rima Hyginus and Vallis Alpes. The result shows that the Chang'E-I CCD images have sharp details and rich information which are clear enough to research the lunar tectonic features.%月球在31亿年前已基本停止地质活动,从而保留了其形成初期的信息.这些信息对于认识月球、地球乃至太阳系的形成演化具有重要意义.在已有研究成果的基础上,结合嫦娥一号探月卫星CCD影像数据,从月海穹窿、撞击坑、月岭、断裂、月坑链、月溪及月谷等方面介绍了月球主要构造形式的地质特征、形貌特征及遥感影像特征,对其成因

  16. 基于区域特征的线阵CCD图像自适应校正%Regional characteristics based Adaptive correction algorithm for linear array CCD images

    Institute of Scientific and Technical Information of China (English)

    尹楠; 顾济华; 邹丽新; 周强; 马心儒

    2013-01-01

    An adaptive correction algorithm is proposed in this paper to correct the distorted linear CCD images when the athletes reach the finish line in a track competition. Firstly, the head inclination and aspect ratio of the athletes are got by using morphological processing for obtaining the transformation factor corresponding to the angle. Then the athlete head is taken as a center, and the appropriate length in the horizontal direction is selected to get the edge abscissa in the horizontal direction to the athlete, and clip the image. The two-dimensional transform matrixes are adopted to make the interpolation projective transfor-mation of the image. The simulation result shows that this algorithm is easy to implement and can restore the distorted images. The satisfying result can be obtained through simulation analysis on the stretch of the normal images.%针对田径比赛中运动员到达终点时线阵CCD采集到的失真图像进行处理,通过对扫描同步的分析,得到了失真图像产生原因,提出了一种自适应的校正算法.首先经形态学处理得到运动员头部的倾角及长宽比,进而得到对应角度的变换因子;然后以头部为中心,在水平方向左右取合适长度,得到运动员水平方向上的边缘横坐标并剪裁图像;最后使用二维变换矩阵对该图像进行插值投影变换.仿真实验表明,该算法简单易行,能较好地还原失真图像.并且通过对正常图像拉伸的仿真分析,得到较为满意的结果.

  17. The ratio between CcdA and CcdB modulates the transcriptional repression of the ccd poison-antidote system.

    Science.gov (United States)

    Afif, H; Allali, N; Couturier, M; Van Melderen, L

    2001-07-01

    The ccd operon of the F plasmid encodes CcdB, a toxin targeting the essential gyrase of Escherichia coli, and CcdA, the unstable antidote that interacts with CcdB to neutralize its toxicity. Although work from our group and others has established that CcdA and CcdB are required for transcriptional repression of the operon, the underlying mechanism remains unclear. The results presented here indicate that, although CcdA is the DNA-binding element of the CcdA-CcdB complex, the stoichiometry of the two proteins determines whether or not the complex binds to the ccd operator-promoter region. Using electrophoretic mobility shift assays, we show that a (CcdA)2-(CcdB)2 complex binds DNA. The addition of extra CcdB to that protein-DNA complex completely abolishes DNA retardation. Based on these results, we propose a model in which the ratio between CcdA and CcdB regulates the repression state of the ccd operon. When the level of CcdA is superior or equal to that of CcdB, repression results. In contrast, derepression occurs when CcdB is in excess of CcdA. By ensuring an antidote-toxin ratio greater than one, this mechanism could prevent the harmful effect of CcdB in plasmid-containing bacteria.

  18. Proton irradiation test to scintillator-directory-coupled CCD onboard FFAST

    Science.gov (United States)

    Nagino, Ryo; Nakajima, Hiroshi; Sadamoto, Masaaki; Sasaki, Masayuki; Tsunemi, Hiroshi; Hayashida, Kiyoshi; Anabuki, Naohisa; Kitamura, Hisashi; Uchihori, Yukio

    2013-09-01

    FFAST is a large area sky survey mission at hard X-ray region by using a spacecraft formation flying. It consists of two small satellites, a telescope satellite, carrying a multilayer super mirror, and a detector satellite, carrying scintillator-deposited CCDs (SD-CCDs). SD-CCD is the imaging device which realized sensitivity to 80 keV by pasting up a scintillator on CCD directly. Soft X-ray events are directly detected in the CCD. On the other hand, Hard X-ray events are converted to optical photons by the scintillator and then the CCD detects the photons. We have obtained the spectrum with 109Cd and successfully detected the events originated from the CsI. For a space use of a CCD, we have to understand aged deterioration of CCD in high radiative environments. In addition, in the case of SD-CCD, we must investigate the influence of radio-activation of a scintillator. We performed experiments of proton irradiation to the SD-CCD as space environmental tests of cosmic rays. The SD-CCD is irradiated with the protons with the energy of 100 MeV and neglected for about 150 hours. As a result, the derived CTI profile of SD-CCD is similarly to ones of XIS/Suzaku and NeXT4 CCD/ASTRO-H. In contrast, CTIs derived from the data within 4 hours after irradiation is 10 times or more larger than the ones after 150 hours. This may be due to influence of an annealing. We also report a performance study of SD-CCD, including the detection of scintillation events, before proton irradiation.

  19. Benefits of image deconvolution in CCD imagery

    Directory of Open Access Journals (Sweden)

    O. Fors

    2006-01-01

    Full Text Available En este trabajo mostramos, cómo la deconvolución basada en ondículas de imágenes obtenidas con telescopios de campo ancho, incrementa el límite de magnitud en R0:6 y supone una mejora en la separación de imágenes. La precisión astrométrica no disminuye, lo cual hace que la técnica sea válida para proyectos astrométricos. Así mismo aplicamos el proceso de deconvolución a una serie de imágenes obtenidas con la repotenciada cámara Baker-Nunn del Observatorio Astrofísico de Rothney

  20. CCD Color Camera Characterization for Image Measurements

    NARCIS (Netherlands)

    Withagen, P.J.; Groen, F.C.A.; Schutte, K.

    2007-01-01

    In this article, we will analyze a range of different types of cameras for its use in measurements. We verify a general model of a charged coupled device camera using experiments. This model includes gain and offset, additive and multiplicative noise, and gamma correction. It is shown that for sever

  1. A CCD Spectrometer for One Dollar

    Science.gov (United States)

    Beaver, J.; Robert, D.

    2011-09-01

    We describe preliminary tests on a very low-cost system for obtaining stellar spectra for instructional use in an introductory astronomy laboratory. CCD imaging with small telescopes is now commonplace and relatively inexpensive. Giving students direct experience taking stellar spectra, however, is much more difficult, and the equipment can easily be out of reach for smaller institutions, especially if one wants to give the experience to large numbers of students. We have performed preliminary tests on an extremely low-cost (about $1.00) objective grating that can be coupled with an existing CCD camera or commercial digital single-lens reflex (DSLR) camera and a small telescope typical of introductory astronomy labs. With this equipment we believe it is possible for introductory astronomy students to take stellar spectra that are of high enough quality to distinguish between many MK spectral classes, or to determine standard B and V magnitudes. We present observational tests of this objective grating used on an 8" Schmidt-Cassegrain with a low-end, consumer DSLR camera. Some low-cost strategies for reducing the raw data are compared, with an eye toward projects ranging from individual undergraduate research projects to use by many students in a non-majors introductory astronomy lab. Toward this end we compare various trade offs between complexity of the observing and data reduction processes and the usefulness of the final results. We also describe some undergraduate astronomy education projects that this system could potentially be used for. Some of these projects could involve data-sharing collaborations between students at different institutions.

  2. CCD Photometry of M15

    Science.gov (United States)

    Ruelas, A.; Sánchez, L. J.; Herrera, G.; Nigoche-Netro, A.

    2011-10-01

    We present CCD observations of the galactic globular cluster M15, in the B and V filters. The cluster was reasonably covered, except in its northern region where our observations present a gap. We obtained a Hertszprung-Russell (HR) diagram for each region observed, and later we produced a combined HR diagram containing more than 3000 stars. We generate a clean Colour Magnitude Diagram (CMD) and a Super Fiducial Line (SFL). Application of several methods and isochrone fitting leads us to obtain values for the metallicity [Fe/H]_{M15} ˜ -2.16±0.10, the reddening E(B-V)_{M15} ˜ 0.11±0.03, and a distance modulus of [(m-M)_0]_{M15}˜ 15.03.

  3. Design of a very high frame rate camera based on an asynchronous CCD driving method

    Institute of Scientific and Technical Information of China (English)

    LI Bin-Kang; YANG Shao-Hua; GUO Ming-An; WANG gui-Lu; XIA Jing-Wao; LUO Tong-Ding

    2011-01-01

    A very high frame rate camera is designed based on an innovative CCD driving method. The CCD driving method is mainly implemented on frame transfer CCDs. Asynchronous drive timing sequences are applied in the image and storage section of the CCDs. Several rows of the charge in the image section are binned onto the same row in the storage section, and there are the same number of images to be stored in the storage section before they are read out. Based on the new driving method, the frame transfer CCDs can work at a very high frame rate in acquiring burst images though the reading speed remains at a lower level. A very high frame rate camera is designed in this paper. The innovative CCD driving method is mainly of concern. An e2v's CCD60 is adopted in the camera system, whose full size resolution is 128×128, and the up most frame rate is 1000 Hz in the conventional CCD driving method. By using the presented method, the CCD60 based imager is capable of operating at up to 40000 frames per second (fps) at a recognizable resolution of 128×32. Comparing cameras using traditional binning and region of interest technologies, the frame rate is normally less than 5000 fps while the resolution is only 32 × 32 lett.

  4. Robotic CCD microscope for enhanced crystal recognition

    Science.gov (United States)

    Segelke, Brent W.; Toppani, Dominique

    2007-11-06

    A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.

  5. Status Of Sofradir IR-CCD Detectors

    Science.gov (United States)

    Tribolet, Philippe; Radisson, Patrick

    1988-05-01

    The topics of this paper deal with the IR-CCD detectors manufactured by SOFRADIR the new French joint venture. Description of the IRCCD technology and the advantages of this approach are given. In conclusion, some IR-CCD typical results are given.

  6. Deep sub electron noise readout in CCD systems using digital filtering techniques

    CERN Document Server

    Cancelo, Gustavo; Moroni, Guillermo Fernandez; Treptow, Ken; Zmuda, Ted; Diehl, Tom

    2011-01-01

    Scientific CCDs designed in thick high resistivity silicon (Si) are excellent detectors for astronomy, high energy and nuclear physics, and instrumentation. Many applications can benefit from CCDs ultra low noise readout systems. The present work shows how sub electron noise CCD images can be achieved using digital signal processing techniques. These techniques allow readout bandwidths of up to 10 K pixels per second and keep the full CCD spatial resolution and signal dynamic range.

  7. 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.

  8. 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.

  9. Using a CCD for the direct detection of electrons in a low energy space plasma spectrometer

    Science.gov (United States)

    Bedington, R.; Kataria, D.; Walton, D.

    2012-01-01

    An E2V CCD64 back-illuminated, ion-implanted CCD (charge-coupled device) has been used as a direct electron imaging detector with CATS (Conceptual And Tiny Spectrometer), a highly miniaturised prototype plasma analyser head. This is in place of an MCP (microchannel plate) with a position sensing anode which would more conventionally be used as a detector in traditional low energy space plasma analyser instruments. The small size of CATS however makes it well matched to the size of the CCD, and the ion implants reduce the depth of the CCD backside electron potential well making it more sensitive to lower energy electrons than standard untreated silicon. Despite ionisation damage from prolonged exposure to excessively energetic electrons, the CCD has been able to detect electrons with energies above 500eV, at temperatures around room temperature. Using both a long integration 'current measuring' mode and a short integration `electron counting' mode it has been used to image the low energy electrons exiting the analyser, enhancing our understanding of the CATS electrostatic optics. The CCD has been selected as the detector for use with CATS for an instrument on a low-altitude student sounding rocket flight. Although it cannot detect the lowest energy electrons that an MCP can detect, and it is more sensitive to stray light, the low voltages required, the lack of vacuum requirements and its novelty and availability made it the most attractive candidate detector.

  10. Design of dual Beam multi-wavelength UV-visible absorbance detectors based on CCD

    Institute of Scientific and Technical Information of China (English)

    SHEN Shuang; TANG Zhen-an; LI Tong

    2006-01-01

    @@ Because the general multi-wavelength UV-Visible absorbance detector cannot avoid the noise and drift resulting from the intensity fluctuation of the light source,a dual beam multi-wavelength UV-Visible detector based on CCD was designed.The ray of light source is divided into a signal ray and a reference ray by the beam splitter after it passes through the chopper.The signal ray shines into the sample cell.The signal ray passing through the sample cell falls onto a concave mirror which focuses it onto a slot that is imaged on one portion of CCD by a concave grating.The reference ray is imaged on the other portion of CCD by the concave grating after the slot.The signal spectrum,the reference spectrum and the dark current of CCD can be measured on the same CCD under the cooperation of the optical system and accessorial circuits.The real-time compensation for the signal spectrum by using the reference spectrum and the dark current of CCD can effectively depress the noise and drift of the detector.The short-term noise is 10-5AU and the drift is 10-4AU/h.

  11. High frame rate CCD camera with fast optical shutter

    Energy Technology Data Exchange (ETDEWEB)

    Yates, G.J.; McDonald, T.E. Jr. [Los Alamos National Lab., NM (United States); Turko, B.T. [Lawrence Berkeley National Lab., CA (United States)

    1998-09-01

    A high frame rate CCD camera coupled with a fast optical shutter has been designed for high repetition rate imaging applications. The design uses state-of-the-art microchannel plate image intensifier (MCPII) technology fostered/developed by Los Alamos National Laboratory to support nuclear, military, and medical research requiring high-speed imagery. Key design features include asynchronous resetting of the camera to acquire random transient images, patented real-time analog signal processing with 10-bit digitization at 40--75 MHz pixel rates, synchronized shutter exposures as short as 200pS, sustained continuous readout of 512 x 512 pixels per frame at 1--5Hz rates via parallel multiport (16-port CCD) data transfer. Salient characterization/performance test data for the prototype camera are presented, temporally and spatially resolved images obtained from range-gated LADAR field testing are included, an alternative system configuration using several cameras sequenced to deliver discrete numbers of consecutive frames at effective burst rates up to 5GHz (accomplished by time-phasing of consecutive MCPII shutter gates without overlap) is discussed. Potential applications including dynamic radiography and optical correlation will be presented.

  12. CTK-II & RTK: The CCD-cameras operated at the auxiliary telescopes of the University Observatory Jena

    Science.gov (United States)

    Mugrauer, M.

    2016-03-01

    The Cassegrain-Teleskop-Kamera (CTK-II) and the Refraktor-Teleskop-Kamera (RTK) are two CCD-imagers which are operated at the 25 cm Cassegrain and 20 cm refractor auxiliary telescopes of the University Observatory Jena. This article describes the main characteristics of these instruments. The properties of the CCD-detectors, the astrometry, the image quality, and the detection limits of both CCD-cameras, as well as some results of ongoing observing projects, carried out with these instruments, are presented. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.

  13. CCD-photometry of comets at large heliocentric distances

    Science.gov (United States)

    Mueller, Beatrice E. A.

    1992-01-01

    CCD imaging and time series photometry are used to determine the state of activity, nuclear properties and eventually the rotational motion of cometary nuclei. Cometary activity at large heliocentric distances and mantle evolution are not yet fully understood. Results of observations carried out at the 2.1 telescope on Kitt Peak April 10-12 and May 15-16, 1991 are discussed. Color values and color-color diagrams are presented for several comets and asteroids. Estimations of nuclear radii and shapes are given.

  14. A 3-channel CCD photometer at the Xinglong Observatory

    Institute of Scientific and Technical Information of China (English)

    Yong-Na Mao; Xiao-Meng Lu; Jian-Feng Wang; Xiao-Jun Jiang

    2013-01-01

    We describe the design and construction of a new rapid 3-channel CCD photometer,dedicated to simultaneous multicolor photometric observations of rapidly variable objects.This photometer is equipped on the 1-meter telescope at the Xinglong Observatory.It allows simultaneous imaging within fields of view of 18.8' × 18.8',18.2' × 17.6' and 9.2' × 9.2' in the Sloan Digital Sky Survey's g',r' and i' bands,respectively.The results of its calibration and performance are reported.

  15. CCD BVI c observations of Cepheids

    Science.gov (United States)

    Berdnikov, L. N.; Kniazev, A. Yu.; Sefako, R.; Kravtsov, V. V.; Zhujko, S. V.

    2014-02-01

    In 2008-2013, we obtained 11333 CCD BVI c frames for 57 Cepheids from the General Catalogue of Variable Stars. We performed our observations with the 76-cm telescope of the South African Astronomical Observatory (SAAO, South Africa) and the 40-cm telescope of the Cerro Armazones Astronomical Observatory of the Universidad Católica del Norte (OCA, Chile) using the SBIG ST-10XME CCD camera. The tables of observations, the plots of light curves, and the current light elements are presented. Comparison of our light curves with those constructed from photoelectric observations shows that the differences between their mean magnitudes exceed 0ṃ05 in 20% of the cases. This suggests the necessity of performing CCD observations for all Cepheids.

  16. 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

    amount of charge lost from a star image are described. These results can serve as a direct input to the PLATO consortium to study the mission performance and as a basis for further optimization of the CCD operation.

  17. Operation of the CCD/Transit Instrument (CTI)

    Science.gov (United States)

    Mcgraw, J. T.; Cawson, M. G. M.; Keane, M. J.

    1986-01-01

    The fully automated imaging survey telescope at Kitt Peak known as the CCD/Transit Instrument (CTI) has no moving parts, and employs two CCDs aligned east-west in the focal plane that are operated in the time delay and integrate mode, at the apparent sidereal rate, in order to produce a strip image of the sky. This image is 8.25-arcmin wide in declination and 8 hr in duration, to yield about 15 sq deg of sky from each night's survey; this, over the course of a year, represents more than 40 sq deg in a continuous strip. The CTI is addressing such astronomical tasks as the determination of the supernova production rate by counting, galactic structure investigations, and the definition of a complete sample of quasars. Attention is given to the CTI's bimetallic, thermally self-compensating structure and three-mirror wide-field optical system.

  18. HIGH-PRECISION DETERMINATION OF THE ANGULAR POSITION FOR POINT LIGHT SOURCE WITH CCD-ARRAYS

    Directory of Open Access Journals (Sweden)

    Y. G. Lebedko

    2015-05-01

    Full Text Available Subject of study. A method of angular position measuring for point light source in the system with CCD arrays is proposed by converting of angle – time – code in low light conditions and at high signal / noise ratio. Assessment of the method potential accuracy is given. It is determined by instrumental irremovable random errors of measurement in terms of optimal processing of incoming information with a single reading it with CCD – arrays. Method. This work introduces an optoelectronic system circuit with CCD arrays with stretched sensing elements and a point of reference for angular position measuring. In this case the arrays have images projections of both the reference point source and the target point source, which angular position is measured with high precision. From the CCD array output the signals arrive at an optimal (or apt linear filter, and then to the signal peak position detection circuit. The scheme provides minimum error due to the influence of noise. Pulse edges, corresponding to the signals maximum, make a time interval filled with high-frequency counting pulses. The number of pulses in this interval will correspond to the measured angular position of the target point source. Main results. Analysis of random errors has been carried out in terms of statistical decision theory. Analysis takes into account the spectral function of the signals defined by transfer functions of the optical system and a CCD array as an image analyzer. Research of measurement accuracy is carried out depending on the clock frequency of reading information from CCD arrays for different values of signal-to-noise ratio. It has been shown that even with a single readout with CCD array by the proposed opto-electronic circuit measuring error does not exceed 0.01 of the sensing element size. Practical significance. The results are usable in high-precision measuring opto-electronic systems of star sensors for determining the angular position of the low

  19. 长脉冲激光对组成CCD图像传感器的MOS光敏单元的硬破坏机理研究%Mechanism for long pulse laser-induced hard damage to the MOS pixel of CCD image sensor

    Institute of Scientific and Technical Information of China (English)

    毕娟; 张喜和; 倪晓武

    2011-01-01

    The interaction process between 1.06μm wavelength Nd:YAG long pulse laser with a millisecond pulse width and the MOS pixel of frame transfer area CCD image sensor and its hard damage mechanism are studied by the finite element method.The thermal-mechanical coupled modeling for long pulse laser irradiation of a MOS pixel is established,and the distributions of temperature and stress are obtained.The results show that the spallations between O layer and S layer appear due to the S layer radial stress on the surface exceeding the compressive strength under the action of the long pulse laser,then it will extend to the entire layer before melting by radial stress,axial stress and hoop stress.Hard damage of pixel occurs as spallation,and one pixel or an array of pixels in the laser irradiation area of CCD sensor is completely in failure.This paper could provide foundation for both laser-induced damage and protection of CCD image sensor.%以帧转移型面阵CCD图像传感器为例,采用有限元法研究了波长1.06μm,脉宽ms量级长脉冲Nd:YAG激光与组成CCD传感器的MOS光敏单元的作用过程及硬破坏机理.建立了长脉冲激光辐照MOS光敏单元的热力耦合模型,模拟了MOS光敏单元的温度分布和应力分布.研究结果表明:在长脉冲激光作用下,由于S层表面径向压应力超过其抗压强度引起MOS光敏单元出现了OS层间分裂,进而受径向、环向和轴向压应力的共同作用下,在光敏单元还未熔融时,层间分裂就扩大至光敏单元的整个OS层间.OS层间完全分裂会使光敏单元发生硬破坏,并造成CCD传感器中激光照射区的单个或一列光敏单元的功能完全失效.文章的研究结果可为CCD图像传感器的激光损伤及防护提供必要的理论依据.

  20. Fully depleted back-illuminated p-channel CCD development

    Energy Technology Data Exchange (ETDEWEB)

    Bebek, Chris J.; Bercovitz, John H.; Groom, Donald E.; Holland, Stephen E.; Kadel, Richard W.; Karcher, Armin; Kolbe, William F.; Oluseyi, Hakeem M.; Palaio, Nicholas P.; Prasad, Val; Turko, Bojan T.; Wang, Guobin

    2003-07-08

    An overview of CCD development efforts at Lawrence Berkeley National Laboratory is presented. Operation of fully-depleted, back-illuminated CCD's fabricated on high resistivity silicon is described, along with results on the use of such CCD's at ground-based observatories. Radiation damage and point-spread function measurements are described, as well as discussion of CCD fabrication technologies.

  1. A Large Area CCD Camera for the Schmidt Telescope at the Venezuelan National Astronomical Observatory

    CERN Document Server

    Baltay, C; Andrews, P; Emmet, W; Schaefer, B; Sinnott, J; Bailyn, C D; Coppi, P S; Oemler, A E; Sabbey, C N; Sofia, S; Van Altena, W F; Vivas, A K; Abad, C; Briceño, C; Bruzual, G; Magris, G; Stock, J; Prugna, F D; Sánchez, G; Schenner, H; Adams, B; Gebhard, M; Honeycutt, R K; Musser, J; Harris, F; Geary, J; Sanchez, Ge.; Sanchez, Gu.

    2002-01-01

    We have designed, constructed and put into operation a large area CCD camera that covers a large fraction of the image plane of the 1 meter Schmidt telescope at Llano del Hato in Venezuela. The camera consists of 16 CCD devices arranged in a 4 x 4 mosaic covering 2.3 degrees x 3.5 degrees of sky. The CCDs are 2048 x 2048 LORAL devices with 15 micron pixels. The camera is optimized for drift scan photometry and objective prism spectroscopy. The design considerations, construction features and performance parameters are described in the following article.

  2. CCD Photometry of Asteroid (147) Protogeneia

    Institute of Scientific and Technical Information of China (English)

    Xi-Liang Zhang; Xiao-Bin Wang; Li-Yun Zhang

    2006-01-01

    We measured the light-curve of the asteroid (147) Protogeneia in November 2004, with a CCD detector attached to the 1-meter telescope at the Yunnan Observatory, China. The synodic period and maximum amplitude of (147) at this apparition are 7.852 hours and 0.25 mag, respectively. The value of a/b for (147), from a preliminary estimation, is not less than 1.26:1.

  3. Measurement of spatial object's exterior attitude based on linear CCD

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    It is difficult to realize real-time measurement of exterior attitude by the traditional systems based on the area image sensor which have conflict between speed and accuracy.The subsystem for three-dimensional (3D) coordinate rcconstruction of point target (S3DCRPT) which is composed of three one-dimensional (1D) cameras based on linear charge-coupled device (CCD) can determine the distant light spots' spatial position. The attitude angle of the measured object is determined by the spatial solution while the coordinate reconstruction is separately carried on by the S3DCRPT with some point cooperation targets (PCTs) on the measured object. A new optical system is designed to solve the interference problem with one-to-one relationship between the PCTs and the S3DCRPT optical subsystems,which improves the measurement accuracy and saves space. The mathematical model of the attitude measurement is established,and partial and global calibrations are realized for the multi-camera attitude measurement system.The test results show the feasibility of the exterior attitude measurement based on linear CCD.

  4. CCD Readout Electronics for the Subaru Prime Focus Spectrograph

    CERN Document Server

    Hope, Stephen C; Loomis, Craig P; Fitzgerald, Roger E; Peacock, Grant O

    2014-01-01

    We present details of the design for the CCD readout electronics for the Subaru Telescope Prime Focus Spectrograph (PFS). The spectrograph is comprised of four identical spectrograph modules, each collecting roughly 600 spectra. The spectrograph modules provide simultaneous wavelength coverage over the entire band from 380 nm to 1260 nm through the use of three separate optical channels: blue, red, and near infrared (NIR). A camera in each channel images the multi-object spectra onto a 4k x 4k, 15 um pixel, detector format. The two visible cameras use a pair of Hamamatsu 2k x 4k CCDs with readout provided by custom electronics, while the NIR camera uses a single Teledyne HgCdTe 4k x 4k detector and ASIC Sidecar to read the device. The CCD readout system is a custom design comprised of three electrical subsystems: the Back End Electronics (BEE), the Front End Electronics (FEE), and a Pre-amplifier. The BEE is an off-the-shelf PC104 computer, with an auxiliary Xilinx FPGA module. The computer serves as the main...

  5. CCD Camera Lens Interface for Real-Time Theodolite Alignment

    Science.gov (United States)

    Wake, Shane; Scott, V. Stanley, III

    2012-01-01

    Theodolites are a common instrument in the testing, alignment, and building of various systems ranging from a single optical component to an entire instrument. They provide a precise way to measure horizontal and vertical angles. They can be used to align multiple objects in a desired way at specific angles. They can also be used to reference a specific location or orientation of an object that has moved. Some systems may require a small margin of error in position of components. A theodolite can assist with accurately measuring and/or minimizing that error. The technology is an adapter for a CCD camera with lens to attach to a Leica Wild T3000 Theodolite eyepiece that enables viewing on a connected monitor, and thus can be utilized with multiple theodolites simultaneously. This technology removes a substantial part of human error by relying on the CCD camera and monitors. It also allows image recording of the alignment, and therefore provides a quantitative means to measure such error.

  6. OPTICAL OPTIMIZATION FOR LIQUID CRYSTAL TEST BY LASER-CCD SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Chang Ying; Zhu Henian; Zhang Ziliang; Yang Changxi

    2005-01-01

    For the narrowband of liner charge-coupled device (CCD) receiver and the imaging rule that cylindrical lens system can compress round facula into narrow and long one, the system is simplified and light force can concentrate on a strip facula. Considered the effective CCD length and selection of lens parameters, the system can be optimized. Correspondingly to the CCD pixels, the ray is composed of much angle information. By widening the parallel ray or increasing the lens aperture, luminous flux can be ensured when oblique incidence. Meanwhile, the effective working range can also be improved. Based on the experimental data, cylindrical system could be applied in accurate angle measurement. It has been proved feasible that the cylindrical system can be used in anchor behavior study for liquid crystal (LC) case. The low-power He-Ne laser cylindrical system can carry out the previous effect in high power laser spherical system.

  7. Direct detection of x-rays for protein crystallography employing a thick, large area CCD

    Science.gov (United States)

    Atac, Muzaffer; McKay, Timothy

    1999-01-01

    An apparatus and method for directly determining the crystalline structure of a protein crystal. The crystal is irradiated by a finely collimated x-ray beam. The interaction of the x-ray beam with the crystal produces scattered x-rays. These scattered x-rays are detected by means of a large area, thick CCD which is capable of measuring a significant number of scattered x-rays which impact its surface. The CCD is capable of detecting the position of impact of the scattered x-ray on the surface of the CCD and the quantity of scattered x-rays which impact the same cell or pixel. This data is then processed in real-time and the processed data is outputted to produce a image of the structure of the crystal. If this crystal is a protein the molecular structure of the protein can be determined from the data received.

  8. Modelling electron distributions within ESA's Gaia satellite CCD pixels to mitigate radiation damage

    CERN Document Server

    Seabroke, G M; Burt, D; Robbins, M S

    2009-01-01

    The Gaia satellite is a high-precision astrometry, photometry and spectroscopic ESA cornerstone mission, currently scheduled for launch in 2012. Its primary science drivers are the composition, formation and evolution of the Galaxy. Gaia will achieve its unprecedented positional accuracy requirements with detailed calibration and correction for radiation damage. At L2, protons cause displacement damage in the silicon of CCDs. The resulting traps capture and emit electrons from passing charge packets in the CCD pixel, distorting the image PSF and biasing its centroid. Microscopic models of Gaia's CCDs are being developed to simulate this effect. The key to calculating the probability of an electron being captured by a trap is the 3D electron density within each CCD pixel. However, this has not been physically modelled for the Gaia CCD pixels. In Seabroke, Holland & Cropper (2008), the first paper of this series, we motivated the need for such specialised 3D device modelling and outlined how its future resu...

  9. High performance CCD camera system for digitalisation of 2D DIGE gels.

    Science.gov (United States)

    Strijkstra, Annemieke; Trautwein, Kathleen; Roesler, Stefan; Feenders, Christoph; Danzer, Daniel; Riemenschneider, Udo; Blasius, Bernd; Rabus, Ralf

    2016-07-01

    An essential step in 2D DIGE-based analysis of differential proteome profiles is the accurate and sensitive digitalisation of 2D DIGE gels. The performance progress of commercially available charge-coupled device (CCD) camera-based systems combined with light emitting diodes (LED) opens up a new possibility for this type of digitalisation. Here, we assessed the performance of a CCD camera system (Intas Advanced 2D Imager) as alternative to a traditionally employed, high-end laser scanner system (Typhoon 9400) for digitalisation of differential protein profiles from three different environmental bacteria. Overall, the performance of the CCD camera system was comparable to the laser scanner, as evident from very similar protein abundance changes (irrespective of spot position and volume), as well as from linear range and limit of detection.

  10. Digging supplementary buried channels: investigating the notch architecture within the CCD pixels on ESA's Gaia satellite

    CERN Document Server

    Seabroke, G M; Murray, N J; Crowley, C; Hopkinson, G; Brown, A G A; Kohley, R; Holland, A

    2013-01-01

    The European Space Agency (ESA) Gaia satellite has 106 CCD image sensors which will suffer from increased charge transfer inefficiency (CTI) as a result of radiation damage. To aid the mitigation at low signal levels, the CCD design includes Supplementary Buried Channels (SBCs, otherwise known as `notches') within each CCD column. We present the largest published sample of Gaia CCD SBC Full Well Capacity (FWC) laboratory measurements and simulations based on 13 devices. We find that Gaia CCDs manufactured post-2004 have SBCs with FWCs in the upper half of each CCD that are systematically smaller by two orders of magnitude (<50 electrons) compared to those manufactured pre-2004 (thousands of electrons). Gaia's faint star (13 < G < 20 mag) astrometric performance predictions by Prod'homme et al. and Holl et al. use pre-2004 SBC FWCs as inputs to their simulations. However, all the CCDs already integrated onto the satellite for the 2013 launch are post-2004. SBC FWC measurements are not available for on...

  11. Asteroid detection using a single multi-wavelength CCD scan

    Science.gov (United States)

    Melton, Jonathan

    2016-09-01

    Asteroid detection is a topic of great interest due to the possibility of diverting possibly dangerous asteroids or mining potentially lucrative ones. Currently, asteroid detection is generally performed by taking multiple images of the same patch of sky separated by 10-15 minutes, then subtracting the images to find movement. However, this is time consuming because of the need to revisit the same area multiple times per night. This paper describes an algorithm that can detect asteroids using a single CCD camera scan, thus cutting down on the time and cost of an asteroid survey. The algorithm is based on the fact that some telescopes scan the sky at multiple wavelengths with a small time separation between the wavelength components. As a result, an object moving with sufficient speed will appear in different places in different wavelength components of the same image. Using image processing techniques we detect the centroids of points of light in the first component and compare these positions to the centroids in the other components using a nearest neighbor algorithm. The algorithm was used on a test set of 49 images obtained from the Sloan telescope in New Mexico and found 100% of known asteroids with only 3 false positives. This algorithm has the advantage of decreasing the amount of time required to perform an asteroid scan, thus allowing more sky to be scanned in the same amount of time or freeing a telescope for other pursuits.

  12. Edge determination algorithm of game road for intelligent automobile based on plane array CCD

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi-kun; WANG Fu-bin; PAN Xiao-di; LIU Jie; HUANG Chang-fa

    2009-01-01

    The contribution factor of automobile movement stability on the structure feature of seek road intelligent automobile chassis was analyzed. The kinematic model of linear two-degree freedom for intelligent automobile was established. The noise influence to the image of game road on the image rebuilding of different acquisition data of game road was analyzed. The threshold for image division was determined by the statistical analysis to grey histogram of game road image. This method indicates its adaption to CCD image of low distinguish ability.

  13. Evaluation of diagnostic ability of CCD digital radiography in the detection of incipient dental caries

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wan; Lee, Byung Do [Wonkwang University College of Medicine, Iksan (Korea, Republic of)

    2003-03-15

    The purpose of this experiment was to evaluate the diagnostic ability of a CCD-based digital system (CDX-2000HQ) in the detection of incipient dental caries. 93 extracted human teeth with sound proximal surfaces and interproximal artificial cavities were radiographed using 4 imaging methods. Automatically processed No.2 Insight film (Eastman Kodak Co., U.S.A.) was used for conventional radiography, scanned images of conventional radiograms for indirect digital radiography were used. For the direct digital radiography, the CDX-2000HQ CCD system (Biomedisys Co. Korea) was used. The subtraction images were made from two direct digital images by Sunny program in the CDX-2000HQ system. Two radiologists and three endodontists examined the presence of lesions using a five-point confidence scale and compared the diagnostic ability by ROC (Receiver Operating Characteristic) analysis and one way ANOVA test. The mean ROC areas of conventional radiography, indirect digital radiography, direct digital radiography, and digital subtraction radiography were 0.9093, 0.9102, 0.9184, and 0.9056, respectively. The diagnostic ability of direct digital radiography was better than the other imaging modalities, but there were no statistical differences among these imaging modalities (p>0.05). These results indicate that new CCD-based digital systems (CDX-2000HQ) have the potential to serve as an alternative to conventional radiography in the detection of incipient dental caries.

  14. New CCD Photometry Study of RV UMa

    CERN Document Server

    Tasselli, D

    2015-01-01

    All available CCD observation of RV UMa have been analyzed to obtain an accurate mathematical description of the ligh variation. We discuss in this paper a new study of variable star RV UMa, a short period RRab star, in orther to determine through the light curve and the physical parameters, the presence of "Blazhko effect". The Star were observed for a total of 839 sessions shooting, and exhibits light curve modulation with the shortest modulation Period=0.468002 ever observed. The result detect small but definite modification in temperature and mean radius of the star itself. All results are compared with previously published literature values and discussed.

  15. The Design of FPGA-based Array CCD Sensor Drive System

    Directory of Open Access Journals (Sweden)

    Chengtao Cai

    2014-01-01

    Full Text Available CCD Sensor is the crutial equipment for environment perception which is widely used in various fields such as surveilliance,vision navigation and machine vision. The commercial CCD device has been encapsulated the sensor driver inside which is not opened for secondary development. Even this mode facilitate the usage but it really can not content the customizable need. For solving this challenging but imperative issue, we designed a novel CCD sensor driver system which implement the efficient and effective image acquisition task in customizing approach. The working principle and driving timing sequence about ICX625AQA the interline CCD image sensor used in our system are discussed in detail. For handling with this data intensive task, a high performance Field Programmable GateArray (FPGA controller is used for data allocation and translation, the peripheral circuits including AD9974 and CXD3400 drive interface which process the horizontal signal and vertical signal, respectively. The designed system proposed at the end of this paper.

  16. High-performance visible/UV CCD focal plane technology for spacebased applications

    Science.gov (United States)

    Burke, B. E.; Mountain, R. W.; Gregory, J. A.; Huang, J. C. M.; Cooper, M. J.; Savoye, E. D.; Kosicki, B. B.

    1993-01-01

    We describe recent technology developments aimed at large CCD imagers for space based applications in the visible and UV. Some of the principal areas of effort include work on reducing device degradation in the natural space-radiation environment, improvements in quantum efficiency in the visible and UV, and larger-device formats. One of the most serious hazards for space based CCD's operating at low signal levels is the displacement damage resulting from bombardment by energetic protons. Such damage degrades charge-transfer efficiency and increases dark current. We have achieved improved hardness to proton-induced displacement damage by selective ion implants into the CCD channel and by reduced temperature of operation. To attain high quantum efficiency across the visible and UV we have developed a technology for back-illuminated CCD's. With suitable antireflection (AR) coatings such devices have quantum efficiencies near 90 percent in the 500-700-nm band. In the UV band from 200 to 400 nm, where it is difficult to find coatings that are sufficiently transparent and can provide good matching to the high refractive index of silicon, we have been able to substantially increase the quantum efficiency using a thin film of HfO2 as an AR coating. These technology efforts were applied to a 420 x 420-pixel frame-transfer imager, and future work will be extended to a 1024 x 1024-pixel device now under development.

  17. Fast Data Acquisition for X-ray CCD 165 SX Detector%X -ray CCD165-SX 探测器快速数据采集

    Institute of Scientific and Technical Information of China (English)

    柳义; 周平

    2014-01-01

    对X光探测器X-ray CCD165-SX在帧移模式下进行数据采集。选择合适开口高度的掩膜,使得CCD的曝光面仅是整个探测面的一小部份。利用TTL信号发生器产生的脉冲信号触发子潜像帧移,将各个不同时间内产生的子潜像储存在CCD的芯片上不同位置上,当芯片填满子潜像时,一次性读出。这种方式大大加快了实验数据的采集速度。实验中对快速升温的情况下对PE样品进行测试,成功地采集到了随时间快速变化的散射信号。%By installation of the mask with adjustable opening size and TTL generator ,X-ray Scattering data is collected by X-ray CCD 165 SX under Frameshift mode .In the process ,exposure area is onlysmall part of the detecting area of the CCD and sub -images produced at difference times are frame shifted by TTL trigger to difference parts on CCD chip subsequently .All the sub-images are read out at once until the chip reaches full-ness of sub -images.This approach greatly increases the data collection speed .Finally,we use PE as the sam-ple in fast temperature rising environment for the fast data acquisition measurement and successful ly collected the scattering data which changed with times .

  18. Medición de coeficientes de extinción en CASLEO y características del CCD ROPER-2048B del telescopio JS

    Science.gov (United States)

    Fernández-Lajús, E.; Gamen, R.; Sánchez, M.; Scalia, M. C.; Baume, G. L.

    2016-08-01

    From observations made with the ``Jorge Sahade'' telescope of the Complejo Astronomico El Leoncito, the UBVRI-band extinction coeficients were measured, and some parameters and characteristics of the direct-image CCD camera ROPER 2048B were determined.

  19. Event Pileup in AXAF's ACIS CCD Camera

    Science.gov (United States)

    McNamara, Brian R.

    1998-01-01

    AXAF's high resolution mirrors will focus a point source near the optical axis to a spot that is contained within a radius of about two pixels on the ACIS Charge Coupled Devices (CCD) camera. Because of the small spot size, the accuracy to which fluxes and spectral energy distributions of bright point sources can be measured will be degrad3ed by event pileup. Event pileup occurs when two or more X-ray photons arrive simultaneously in a single detection cell on a CCD readout frame. When pileup occurs, ACIS's event detection algorithm registers the photons as a single X-ray event. The pulse height channel of the event will correspond to an energy E approximately E-1 + E-2...E-n, where n is the number of photons registered per detection cell per readout frame. As a result, pileup artificially hardens the observed spectral energy distribution. I will discuss the effort at the AXAF Science Center Lo calibrate pileup in ACIS using focused, nearly monochromatic X-ray source. I will discuss techniques for modeling and correcting pileup effects in polychromatic spectra.

  20. Development of the data acquisition system for the x-ray CCD camera (SXI) onboard ASTRO-H

    Science.gov (United States)

    Fujinaga, Takahisa; Anabuki, Naohisa; Aoyama, Shoichi; Kawano, Hidenori; Ikeda, Shoma; Iwai, Masachika; Ozaki, Masanobu; Dotani, Tadayasu; Natsukari, Chikara; Matsuta, Keiko; Shimizu, Kazuma; Nakajima, Hiroshi; Hayashida, Kiyoshi; Tsunemi, Hiroshi; Ueda, Shutaro; Komatsu, Shoji; Murayoshi, Taku; Mori, Koji; Watanabe, Tatsuo; Uchida, Hiroyuki; Ohnishi, Takao; Hiraga, Junko S.

    2011-09-01

    We present the development of the data acquisition system for the X-ray CCD camera (SXI: Soft X-ray Imager) onboard the ASTRO-H satellite. Two types of breadboard models (BBMs) of SXI electronics have been produced to verify the functions of each circuit board and to establish the data acquisition system from CCD to SpaceWire (SpW) I/F. Using BBM0, we verified the basic design of the CCD driver, function of the Δ∑-ADC, data acquisition of the frame image, and stability of the SpW communication. We could demonstrate the energy resolution of 164 eV (FWHM) at 5.9 keV. Using BBM1, we verified acquisition of the housekeeping information and the frame images.

  1. Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source

    Energy Technology Data Exchange (ETDEWEB)

    M. J. Haugh and M. B. Schneider

    2008-10-31

    The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. The intensity distribution taken by the SXI camera during a NIF shot is used to determine how accurately NIF can aim laser beams. This is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 μm square pixels, and 15 μm thick. A multi-anode Manson X-ray source, operating up to 10kV and 10W, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/ΔE≈10. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within ±1% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation occurred at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was not observable below 4 keV. We were also able to observe debris, damage, and surface defects on the CCD chip. The Manson source is a powerful tool for characterizing the imaging errors of an X-ray CCD imager. These errors are quite different from those found in a visible CCD imager.

  2. Design and Characterization of the CCD Detector Assemblies for ICON FUV

    Science.gov (United States)

    Champagne, J.; Syrstad, E. A.; Siegmund, O.; Darling, N.; Jelinsky, S. R.; Curtis, T.

    2015-12-01

    The Far Ultraviolet Imaging Spectrograph (FUV) on the upcoming Ionospheric Connection Explorer (ICON) mission uses dual image-intensified CCD camera systems, capable of detecting individual UV photons from both spectrometer channels (135.6 and 155 nm). Incident photons are converted to visible light using a sealed tube UV converter. The converter output is coupled to the CCD active area using a bonded fiber optic taper. The CCD (Teledyne DALSA FTT1010M) is a 1024x1024 frame transfer architecture. The camera readout electronics provide video imagery to the spacecraft over a 21 bit serialized LVDS interface, nominally at 10 frames per second and in 512x512 format (2x2 pixel binning). The CCD and primary electronics assembly reside in separate thermal zones, to minimize dark current without active cooling.Engineering and flight camera systems have been assembled, integrated, and tested under both ambient pressure and thermal vacuum environments. The CCD cameras have been fully characterized with both visible light (prior to integration with the UV converter) and UV photons (following system integration). Measured parameters include camera dark current, dark signal non-uniformity, read noise, linearity, gain, pulse height distribution, dynamic range, charge transfer efficiency, resolution, relative efficiency, quantum efficiency, and full well capacity. UV characterization of the camera systems over a range of microchannel plate (MCP) voltages during thermal vacuum testing demonstrates that camera performance will meet the critical on-orbit FUV dynamic range requirements. Flight camera integration with the FUV instrument and sensor calibration is planned for Fall 2015. Camera design and full performance data for the engineering and flight model cameras will be presented.

  3. A toolkit for the characterization of CCD cameras for transmission electron microscopy.

    Science.gov (United States)

    Vulovic, M; Rieger, B; van Vliet, L J; Koster, A J; Ravelli, R B G

    2010-01-01

    Charge-coupled devices (CCD) are nowadays commonly utilized in transmission electron microscopy (TEM) for applications in life sciences. Direct access to digitized images has revolutionized the use of electron microscopy, sparking developments such as automated collection of tomographic data, focal series, random conical tilt pairs and ultralarge single-particle data sets. Nevertheless, for ultrahigh-resolution work photographic plates are often still preferred. In the ideal case, the quality of the recorded image of a vitrified biological sample would solely be determined by the counting statistics of the limited electron dose the sample can withstand before beam-induced alterations dominate. Unfortunately, the image is degraded by the non-ideal point-spread function of the detector, as a result of a scintillator coupled by fibre optics to a CCD, and the addition of several inherent noise components. Different detector manufacturers provide different types of figures of merit when advertising the quality of their detector. It is hard for most laboratories to verify whether all of the anticipated specifications are met. In this report, a set of algorithms is presented to characterize on-axis slow-scan large-area CCD-based TEM detectors. These tools have been added to a publicly available image-processing toolbox for MATLAB. Three in-house CCD cameras were carefully characterized, yielding, among others, statistics for hot and bad pixels, the modulation transfer function, the conversion factor, the effective gain and the detective quantum efficiency. These statistics will aid data-collection strategy programs and provide prior information for quantitative imaging. The relative performance of the characterized detectors is discussed and a comparison is made with similar detectors that are used in the field of X-ray crystallography.

  4. 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.

  5. New CCD photometry of asteroid (1028) Lydina

    Institute of Scientific and Technical Information of China (English)

    Yi-Bo Wang; Xiao-Bin Wang

    2012-01-01

    New CCD photometric observations for asteroid (1028) Lydina,carried out with the 1-m and 2.4-m telescopes at Yunnan Observatory from 2011 December 19 to 2012 February 3,are presented.Using the new light curves,the rotation period of 11.680±0.001 hours is derived with the Phase Dispersion Minimization (PDM) method.In addition,using the Amplitude-Aspect method,the elementary results of the pole orientation of asteroid (1028) Lydina are obtained:λp= 111°+4°-4°,βp= 31°+4°-5°.Meanwhile,the axial ratios of the tri-axial ellipsoid are estimated:a/b = 1.77+0.10-0.08and b/c = 1.17+0.07-0.09.

  6. Numerical simulations and analyses of temperature control loop heat pipe for space CCD camera

    Science.gov (United States)

    Meng, Qingliang; Yang, Tao; Li, Chunlin

    2016-10-01

    As one of the key units of space CCD camera, the temperature range and stability of CCD components affect the image's indexes. Reasonable thermal design and robust thermal control devices are needed. One kind of temperature control loop heat pipe (TCLHP) is designed, which highly meets the thermal control requirements of CCD components. In order to study the dynamic behaviors of heat and mass transfer of TCLHP, particularly in the orbital flight case, a transient numerical model is developed by using the well-established empirical correlations for flow models within three dimensional thermal modeling. The temperature control principle and details of mathematical model are presented. The model is used to study operating state, flow and heat characteristics based upon the analyses of variations of temperature, pressure and quality under different operating modes and external heat flux variations. The results indicate that TCLHP can satisfy the thermal control requirements of CCD components well, and always ensure good temperature stability and uniformity. By comparison between flight data and simulated results, it is found that the model is to be accurate to within 1°C. The model can be better used for predicting and understanding the transient performance of TCLHP.

  7. Measurements of surface roughness: use of a CCD camera to correlate doubly scattered speckle patterns

    Science.gov (United States)

    Basano, Lorenzo; Leporatti, Stefano; Ottonello, Pasquale; Palestini, Valeria; Rolandi, Ranieri

    1995-11-01

    We describe an instrument, built around a commercial CCD camera and some fast image-processing boards, that evaluates roughness height by measuring the average size of doubly scattered speckle patterns. The device is a variant of a recent proposal that was based on the use of a spatial modulator to perform the Fourier transform of a speckle image. In the present setup, the Fourier transform is replaced by the direct evaluation of a second-order correlation function. Strictly speaking, the device proposed in this paper is not a real-time device but its response time (approximately 10 s) is sufficiently short to be of practical value for many applications. Updated CCD cameras that will significantly improve the performance of our prototype are already on the market.

  8. Measuring high-resolution sky luminance distributions with a CCD camera.

    Science.gov (United States)

    Tohsing, Korntip; Schrempf, Michael; Riechelmann, Stefan; Schilke, Holger; Seckmeyer, Gunther

    2013-03-10

    We describe how sky luminance can be derived from a newly developed hemispherical sky imager (HSI) system. The system contains a commercial compact charge coupled device (CCD) camera equipped with a fish-eye lens. The projection of the camera system has been found to be nearly equidistant. The luminance from the high dynamic range images has been calculated and then validated with luminance data measured by a CCD array spectroradiometer. The deviation between both datasets is less than 10% for cloudless and completely overcast skies, and differs by no more than 20% for all sky conditions. The global illuminance derived from the HSI pictures deviates by less than 5% and 20% under cloudless and cloudy skies for solar zenith angles less than 80°, respectively. This system is therefore capable of measuring sky luminance with the high spatial and temporal resolution of more than a million pixels and every 20 s respectively.

  9. Comparison of a CCD and an APS for soft X-ray diffraction

    Science.gov (United States)

    Stewart, Graeme; Bates, R.; Blue, A.; Clark, A.; Dhesi, S. S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.

    2011-12-01

    We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 μm on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.

  10. e2v CCD and CMOS sensors and systems designed for astronomical applications

    Science.gov (United States)

    Jorden, Paul; Jerram, Paul; Jordan, Douglas; Pratlong, Jérôme; Robbins, Mark

    2016-08-01

    e2v continues to evolve its product range of sensors and systems, with CCD and CMOS sensors. We describe recent developments of high performance image sensors and precision system components. Several low noise backthinned CMOS sensors have been developed for scientific applications. CCDs have become larger whilst retaining very low noise and high quantum efficiency. Examples of sensors and sub-systems are presented including the recently completed 1.2 GigaPixel J-PAS cryogenic camera.

  11. Pre-Launch Absolute Calibration of CCD/CBERS-2B Sensor

    Science.gov (United States)

    Ponzoni, Flávio Jorge; Albuquerque, Bráulio Fonseca Carneiro

    2008-01-01

    Pre-launch absolute calibration coefficients for the CCD/CBERS-2B sensor have been calculated from radiometric measurements performed in a satellite integration and test hall in the Chinese Academy of Space Technology (CAST) headquarters, located in Beijing, China. An illuminated integrating sphere was positioned in the test hall facilities to allow the CCD/CBERS-2B imagery of the entire sphere aperture. Calibration images were recorded and a relative calibration procedure adopted exclusively in Brazil was applied to equalize the detectors responses. Averages of digital numbers (DN) from these images were determined and correlated to their respective radiance levels in order to calculate the absolute calibration coefficients. It has been the first time these pre-launch absolute calibration coefficients have been calculated considering the Brazilian image processing criteria. Now it will be possible to compare them to those that will be calculated from vicarious calibration campaigns. This comparison will permit the CCD/CBERS-2B monitoring and the frequently data updating to the user community. PMID:27873886

  12. Ground-based CCD astrometry with wide field imagers. II. A star catalogue for M67: WFI@2.2m MPG/ESO astrometry, FLAMES@VLT radial velocities

    CERN Document Server

    Yadav, R K S; Piotto, G; Anderson, J; Cassisi, S; Villanova, S; Platais, I; Pasquini, L; Momany, Y; Sagar, R

    2008-01-01

    The solar-age open cluster M67 (C0847+120, NGC2682) is a touchstone in studies of the old Galactic disk. Despite its outstanding role, the census of cluster membership for M67 at fainter magnitudes and their properties are not well-established. Using the proprietary and archival ESO data, we have obtained astrometric, photometric, and radial velocities of stars in a 34'x 33' field centered on the old open cluster M67. The two-epoch archival observations separated by 4 years and acquired with the Wide Field Imager at the 2.2m MPG/ESO telescope have been reduced with our new astrometric techniques, as described in the first paper of this series. The same observations served to derive calibrated BVI photometry in M67. Radial velocities were measured using the archival and new spectroscopic data obtained at VLT. We have determined relative proper motions and membership probabilities for ~2,400 stars. The precision of proper motions for optimally exposed stars is ~2 mas/yr, gradually degrading down to ~5 mas/yr at...

  13. The PLATO End-to-End CCD Simulator -- Modelling space-based ultra-high precision CCD photometry for the assessment study of the PLATO Mission

    CERN Document Server

    Zima, W; De Ridder, J; Salmon, S; Catala, C; Kjeldsen, H; Aerts, C

    2010-01-01

    The PLATO satellite mission project is a next generation ESA Cosmic Vision satellite project dedicated to the detection of exo-planets and to asteroseismology of their host-stars using ultra-high precision photometry. The main goal of the PLATO mission is to provide a full statistical analysis of exo-planetary systems around stars that are bright and close enough for detailed follow-up studies. Many aspects concerning the design trade-off of a space-based instrument and its performance can best be tackled through realistic simulations of the expected observations. The complex interplay of various noise sources in the course of the observations made such simulations an indispensable part of the assessment study of the PLATO Payload Consortium. We created an end-to-end CCD simulation software-tool, dubbed PLATOSim, which simulates photometric time-series of CCD images by including realistic models of the CCD and its electronics, the telescope optics, the stellar field, the pointing uncertainty of the satellite ...

  14. Super CCD SR是什么

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    我最近看到富士公司新上市的数字相机FinePix S3 Pro的像素为:617万S像素,617万R像素,共1234万像素。请问:什么是S像素,什么是R像素?为什么富士的相机的像素标明S和R像素.而其它品牌的数字相机没有这样标明.富士相机的Super CCD SR传感器与其他品牌数字相机的CCD传感器相比,有什么特点?为什么总像素1234万像素;而有效像素却只有610万像素?另外。数字相机用的CMOS传感器与CCD传感器有什么异同?

  15. 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

  16. Side 2: MSM positioning of STIS CCD Modes

    Science.gov (United States)

    Sahu, Kailash

    2000-07-01

    The MSM positions for different STIS modes are slightly different when the STIS is run through side 2 than when it is run from side 1. These MSM positions for various STIS prime CCD modes shall be confirmed by taking images with the IM Pt/Cr/Ne calibration lamp. For first order long-slit modes, the exposures shall be made through 52x0.1arcsec slit. For the echelle modes, the exposures shall be made through echelle slits of the nominal height, to avoid order confusion. One exposure shall be taken for each prime mode except for the medium dispersion{M}, long slit modes. For the medium dispersion, long-slit modes, additional exposures shall be taken at the long and short wavelength settings of the nominal scan range. Exposures shall be sufficiently long to bring out enough line features to confirm wavelength identifications, with sufficient signal to noise to reveal the shadows of the fiducials in the long slit images to confirm spatial pointing. This activity will test all primary modes and test the extremes of the MSM scanning cylinders by observing the extreme settings of the modes. RESULTS: All images will be downlinked and analyzed. The results are confirmation of the standard MSM encoder values for each mode. If the wavelength shifts are less than the budgeted value, the changes will be handled through updating the siaf files. If excess shifts are seen, new MSM positions will be derived and uplinked to the onboard MSM pointing table. Any modes for which revised MSM positions are uplinked will have to be re-observed for confirmation that the correct offsets were applied.

  17. Time-resolved spectra of dense plasma focus using spectrometer, streak camera, and CCD combination

    Energy Technology Data Exchange (ETDEWEB)

    Goldin, F. J. [Livermore Operations, National Security Technologies, LLC, Livermore, California 94550 (United States); Meehan, B. T.; Hagen, E. C. [North Las Vegas Facility, National Security Technologies, LLC, North Las Vegas, Nevada 89030 (United States); Wilkins, P. R. [Lawrence Livermore National Laboratories, Livermore, California 94550 (United States)

    2010-10-15

    A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny-Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments.

  18. Time-Resolved Spectra of Dense Plasma Focus Using Spectrometer, Streak Camera, CCD Combination

    Energy Technology Data Exchange (ETDEWEB)

    F. J. Goldin, B. T. Meehan, E. C. Hagen, P. R. Wilkins

    2010-10-01

    A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny–Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments.

  19. A tiled CCD detector with 2x2 array and tapered fibre optics for electron microscopy

    CERN Document Server

    Faruqi, A R; Cattermole, D M; Stubbings, S

    2002-01-01

    Charge coupled devices (CCD)-based detectors have made a major impact on data collection in electron microscopy over the past few years. There have been a number of successful applications of CCDs in electron crystallography of two-dimensional protein crystal arrays but high-resolution imaging has been hampered by the relatively poor spatial resolution (and fewer independent pixels) compared to film. A partial solution to this problem, presented in this paper, are to design detectors with larger effective pixel sizes and with more pixels. A CCD detector with a much greater number of 'independent' pixels, achieved by tiling a 2x2 array of CCDs, each of which has 1242x1152 pixels is described here. The sensitive area of the detector, using fibre optics with a demagnification of 2.5 : 1, is 140x130 mm sup 2; the pixel size is 56 mu m square and there is a total of approx 2500x2300 pixels.

  20. A Real-Time Lane Detection Algorithm Based on Intelligent CCD Parameters Regulation

    Directory of Open Access Journals (Sweden)

    Ping-shu Ge

    2012-01-01

    Full Text Available Lane departure warning system (LDWS has been regarded as an efficient method to lessen the damages of road traffic accident resulting from driver fatigue or inattention. Lane detection is one of the key techniques for LDWS. To overcome the contradiction between complexity of algorithm and the real-time requirement for vehicle onboard system, this paper introduces a new lane detection method based on intelligent CCD parameters regulation. In order to improve the real-time capability of the system, a CCD parameters regulating method is proposed which enhances the contrast between lane line and road surfaces and reduces image noise, so it lays a good foundation for the following lane detection. Hough transform algorithm is improved by selection and classification of seed points. Finally the lane line is extracted through some restrictions. Experimental results verify the effectiveness of the proposed method, which improves not only real-time capability but also the accuracy of the system.

  1. The Spectrum of Quantum Dots Film for UV CCD

    Directory of Open Access Journals (Sweden)

    Lin Jiang

    2013-01-01

    Full Text Available A new kind of UV-responsive film with quantum dots (QDs fabricated by a spin-coating method is proposed in this paper. In a previous study, the monolayer QDs film is deposited onto fused silica slides by the spin-coating way, which has some luminous problem. The introduction of composite QDs coating which adds PEDOT:PSS and poly-TPD films to the monolayer QDs film is found to have excellent performance. The reason can be that PEDOT:PSS and poly-TPD weaken the scattering and enhance the emitting of quantum dot fluorescence. The intensity of photoluminescence (PL for composite QDs coating is dozens of times stronger than that for monolayer QDs film. Experiment results show that this composite coating has excellent fluorescent properties and emits a blue purple glow together a wide excitation spectrum field from 190 nm to 300 nm. The spectrum of the composite coating matches accurately with the detected zone of CCD, which achieves an outstanding UV-responsive coating for conventional silicon-based image sensors.

  2. Low voltage electron multiplying CCD in a CMOS process

    Science.gov (United States)

    Dunford, Alice; Stefanov, Konstantin; Holland, Andrew

    2016-07-01

    Low light level and high-speed image sensors as required for space applications can suffer from a decrease in the signal to noise ratio (SNR) due to the photon-starved environment and limitations of the sensor's readout noise. The SNR can be increased by the implementation of Time Delay Integration (TDI) as it allows photoelectrons from multiple exposures to be summed in the charge domain with no added noise. Electron Multiplication (EM) can further improve the SNR and lead to an increase in device performance. However, both techniques have traditionally been confined to Charge Coupled Devices (CCD) due to the efficient charge transfer required. With the increase in demand for CMOS sensors with equivalent or superior functionality and performance, this paper presents findings from the characterisation of a low voltage EMCCD in a CMOS process using advanced design features to increase the electron multiplying gain. By using the CMOS process, it is possible to increase chip integration and functionality and achieve higher readout speeds and reduced pixel size. The presented characterisation results include analysis of the photon transfer curve, the dark current, the electron multiplying gain and analysis of the parameters' dependence on temperature and operating voltage.

  3. 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.

  4. Distortion of the pixel grid in HST WFC3/UVIS and ACS/WFC CCD detectors and its astrometric correction

    Science.gov (United States)

    Kozhurina-Platais, Vera; Mackenty, John; Golimovski, David; Sirianni, Marco; Borncamp, David; Anderson, Jay; Grogin, Norman

    2016-07-01

    The geometric distortion of the CCD detectors used in the Hubble Space TelescopeWide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) instruments is characterized by both large and fine-scale distortions. The large-scale distortion, due to the complexity of the HST optical assembly, can be modeled by a high-order polynomial. The majority of fine-distortion is inherent to the CCD detectors themselves, which manifests itself as fine-scale, correlated systematic offsets in the residuals from the best-fit polynomial solution. Such systematic offsets across the CCD chip introduce astrometric errors at the level of about 0.1 pix (up to 1.5 μm within the 15 μm pixels). These fine-scale and low-amplitude distortions apparently arise from the spatial irregularities in the pixel grid. For the WFC3/UVIS CCD chips, there is a clear pattern of periodic skew in the lithographic-mask stencil imprinted onto the detector. Similar irregularities in the pixel grid of ACS/WFC CCD chips are even more pronounced by the narrow (68×2048 pixel) lithographic-mask stencil. To remove these distortions, a 2-D correction in the form of a look-up table has been developed using HST images of very dense stellar fields. The post-correction of fine-scale astrometric errors can be removed down to the level of 0.01 pix (0.15 μm) or better.

  5. 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.

  6. A fast auto-focusing technique for the long focal lens TDI CCD camera in remote sensing applications

    Science.gov (United States)

    Wang, Dejiang; Ding, Xu; Zhang, Tao; Kuang, Haipeng

    2013-02-01

    The key issue in automatic focus adjustment for long focal lens TDI CCD camera in remote sensing applications is to achieve the optimum focus position as fast as possible. Existing auto-focusing techniques consume too much time as the mechanical focusing parts of the camera move in steps during the searching procedure. In this paper, we demonstrate a fast auto-focusing technique, which employs the internal optical elements and the TDI CCD itself to directly sense the deviations in back focal distance of the lens and restore the imaging system to a best-available focus. It is particularly advantageous for determination of the focus, due to that the relative motion between the TDI CCD and the focusing element can proceed without interruption. Moreover, the theoretical formulas describing the effect of imaging motion on the focusing precision and the effective focusing range are also developed. Finally, an experimental setup is constructed to evaluate the performance of the proposed technique. The results of the experiment show a ±5 μm precision of auto-focusing in a range of ±500 μmdefocus, and the searching procedure could be accomplished within 0.125 s, which leads to remarkable improvement on the real-time imaging capability for high resolution TDI CCD camera in remote sensing applications.

  7. The CCD/Transit Instrument (CTI) data-analysis system

    Science.gov (United States)

    Cawson, M. G. M.; Mcgraw, J. T.; Keane, M. J.

    1995-01-01

    The automated software system for archiving, analyzing, and interrogating data from the CCD/Transit Instrument (CTI) is described. The CTI collects up to 450 Mbytes of image-data each clear night in the form of a narrow strip of sky observed in two colors. The large data-volumes and the scientific aims of the project make it imperative that the data are analyzed within the 24-hour period following the observations. To this end a fully automatic and self evaluating software system has been developed. The data are collected from the telescope in real-time and then transported to Tucson for analysis. Verification is performed by visual inspection of random subsets of the data and obvious cosmic rays are detected and removed before permanent archival is made to the optical disc. The analysis phase is performed by a pair of linked algorithms, one operating on the absolute pixel-values and the other on the spatial derivative of the data. In this way both isolated and merged images are reliably detected in a single pass. In order to isolate the latter algorithm from the effects of noise spikes a 3x3 Hanning filter is applied to the raw data before the analysis is run. The algorithms reduce the input pixel-data to a database of measured parameters for each image which has been found. A contrast filter is applied in order to assign a detection-probability to each image and then x-y calibration and intensity calibration are performed using known reference stars in the strip. These are added to as necessary by secondary standards boot-strapped from the CTI data itself. The final stages involve merging the new data into the CTI Master-list and History-list and the automatic comparison of each new detection with a set of pre-defined templates in parameter-space to find interesting objects such as supernovae, quasars and variable stars. Each stage of the processing from verification to interesting image selection is performed under a data-logging system which both controls the

  8. Retrieval of the optical depth using an all-sky CCD camera.

    Science.gov (United States)

    Olmo, Francisco J; Cazorla, Alberto; Alados-Arboledas, Lucas; López-Alvarez, Miguel A; Hernández-Andrés, Javier; Romero, Javier

    2008-12-01

    A new method is presented for retrieval of the aerosol and cloud optical depth using a CCD camera equipped with a fish-eye lens (all-sky imager system). In a first step, the proposed method retrieves the spectral radiance from sky images acquired by the all-sky imager system using a linear pseudoinverse algorithm. Then, the aerosol or cloud optical depth at 500 nm is obtained as that which minimizes the residuals between the zenith spectral radiance retrieved from the sky images and that estimated by the radiative transfer code. The method is tested under extreme situations including the presence of nonspherical aerosol particles. The comparison of optical depths derived from the all-sky imager with those retrieved with a sunphotometer operated side by side shows differences similar to the nominal error claimed in the aerosol optical depth retrievals from sunphotometer networks.

  9. Measuring neutron fluences and gamma/x ray fluxes with CCD cameras

    Science.gov (United States)

    Yates, G. J.; Smith, G. W.; Zagarino, P.; Thomas, M. C.

    The capability to measure bursts of neutron fluences and gamma/x-ray fluxes directly with charge coupled device (CCD) cameras while being able to distinguish between the video signals produced by these two types of radiation, even when they occur simultaneously, has been demonstrated. Volume and area measurements of transient radiation-induced pixel charge in English Electric Valve (EEV) Frame Transfer (FT) charge coupled devices (CCD's) from irradiation with pulsed neutrons (14 MeV) and Bremsstrahlung photons (4-12 MeV endpoint) are utilized to calibrate the devices as radiometric imaging sensors capable of distinguishing between the two types of ionizing radiation. Measurements indicate approx. = .05 V/rad responsivity with greater than or = 1 rad required for saturation from photon irradiation. Neutron-generated localized charge centers or 'peaks' binned by area and amplitude as functions of fluence in the 105 to 107 n/cc range indicate smearing over approx. 1 to 10 percent of the CCD array with charge per pixel ranging between noise and saturation levels.

  10. Highly Stable, Large Format EUV Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Higher detection efficiency and better radiation tolerance imagers are needed for the next generation of EUV instruments. Previously, CCD technology has demonstrated...

  11. 电荷耦合器件在电子束参数测量中的损伤问题%Damage problem of CCD in the electron beam parameters measure

    Institute of Scientific and Technical Information of China (English)

    王远; 江孝国; 李成刚; 禹海军; 张开志

    2012-01-01

    针对直线感应电子加速器(LIA)实验束参数测量技术应用过程中,电荷耦合器件(CCD)在纳秒激光辐照下工作的损伤效应方面进行研究.在分析 CCD 感光成像原理及其高能粒子测量应用的基础上,通过监测这种辐射下 CCD 输出信号的变化和实验后 CCD 的成像,对 CCD 中发生的软、硬损伤进行探讨,得到 CCD 能量损伤阈值的光子的响应特性和辐射损伤评估,保证了加速器束参数测量的可靠性.%There are strong electromagnetism interruption in the process of high power electron beam parameters measure and diagnosis. The Charge Coupled Devioes(CCD) is irradiated by strong electron pulse, laser and X-ray. According to the analysis on the CCD imaging principle and the measure on high energy particles, the changes of the CCD output signals under the radiation environment are monitored as well as the CCD imaging after the experiment. The soft-damage and hard-damage of CCD are discussed. It is found that the damage occurs at the grid electrode of the device instead of at the light activated elements. The response characteristics of beam whose energy reaches the damage threshold are obtained. The evaluation on radiation damage is given, which ensures the reliability of beam parameters measure of accelerator.

  12. Scientific CCD characterisation at Universidad Complutense LICA Laboratory

    Science.gov (United States)

    Tulloch, S.; Gil de Paz, A.; Gallego, J.; Zamorano, J.; Tapia, Carlos

    2012-07-01

    A CCD test-bench has been built at the Universidad Complutensés LICA laboratory. It is initially intended for commissioning of the MEGARA1 (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) instrument but can be considered as a general purpose scientific CCD test-bench. The test-bench uses an incandescent broad-band light source in combination with a monochromator and two filter wheels to provide programmable narrow-band illumination across the visible band. Light from the monochromator can be directed to an integrating sphere for flat-field measurements or sent via a small aperture directly onto the CCD under test for high accuracy diode-mode quantum efficiency measurements. Point spread function measurements can also be performed by interposing additional optics between sphere and the CCD under test. The whole system is under LabView control via a clickable GUI. Automated measurement scans of quantum efficiency can be performed requiring only that the user replace the CCD under test with a calibrated photodiode after each measurement run. A 20cm diameter cryostat with a 10cm window and Brooks Polycold PCC closed-cycle cooler also form part of the test-bench. This cryostat is large enough to accommodate almost all scientific CCD formats has initially been used to house an E2V CCD230 in order to fully prove the test-bench functionality. This device is read-out using an Astronomical Research Camera controller connected to the UKATC's UCAM data acquisition system.

  13. Development of X-ray CCD camera based X-ray micro-CT system

    Science.gov (United States)

    Sarkar, Partha S.; Ray, N. K.; Pal, Manoj K.; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y.; Sinha, A.; Gadkari, S. C.

    2017-02-01

    Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.

  14. Development of X-ray CCD camera based X-ray micro-CT system.

    Science.gov (United States)

    Sarkar, Partha S; Ray, N K; Pal, Manoj K; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y; Sinha, A; Gadkari, S C

    2017-02-01

    Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.

  15. PSF and MTF Measurement Methods for Thick CCD Sensor Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, P.Z.; Kotov, I.; Frank, J.; O' Connor, P.; Radeka, V.; Lawrence, D.M.

    2010-06-30

    Knowledge of the point spread function (PSF) of the sensors to be used in the Large Synoptic Survey Telescope (LSST) camera is essential for optimal extraction of subtle galaxy shape distortions caused by gravitational weak lensing. We have developed a number of techniques for measuring the PSF of candidate CCD sensors to be used in the LSST camera, each with its own strengths and weaknesses. The two main optical PSF measurement techniques that we use are the direct Virtual Knife Edge (VKE) scan as developed by Karcher, et al. and the indirect interference fringe method after Andersen and Sorensen that measures the modulation transfer function (MTF) directly. The PSF is derived from the MTF by Fourier transform. Other non-optical PSF measurement techniques that we employ include {sup 55}Fe x-ray cluster image size measurements and statistical distribution analysis, and cosmic ray muon track size measurements, but are not addressed here. The VKE technique utilizes a diffraction-limited spot produced by a Point-Projection Microscope (PPM) that is scanned across the sensor with sub-pixel resolution. This technique closely simulates the actual operating condition of the sensor in the telescope with the source spot size having an f/number close to the actual telescope design value. The interference fringe method uses a simple equal-optical-path Michelson-type interferometer with a single-mode fiber source that produces interference fringes with 100% contrast over a wide spatial frequency range sufficient to measure the MTF of the sensor directly. The merits of each measurement technique and results from the various measurement techniques on prototype LSST sensors are presented and compared.

  16. Design of Digital Imaging System for Optimization of Control Parameters

    Institute of Scientific and Technical Information of China (English)

    SONG Yong; HAO Qun; YANG Guang; SUN Hong-wei

    2007-01-01

    The design of experimental system of digital imaging system for control parameter is discussed in detail. Signal processing of digital CCD imaging system is first analyzed. Then the real time control of CCD driver and digital processing circuit and man-machine interaction are achieved by the design of digital CCD imaging module and control module. Experimental results indicate that the image quality of CCD experimental system makes a good response to the change of control parameters. The system gives an important base for improving image quality and the applicability of micro imaging system in complex environment.

  17. Stellar Astrophysics Using Ultra-High Precision CCD Time Series Photometry

    Science.gov (United States)

    Howell, S.; Everett, M.; Huber, M.; Ciardi, D.; van Belle, G.

    2001-05-01

    Using time-series CCD photometry and a wide-field imager, we have extended the techniques of differential photometry to provide robust photometric precisions for each star over the entire field of view. Reaching photometric precisions of 2 milli-magnitudes, we produced high cadence light curves for over 12,000 stars at mid- and high galactic latitude. The fraction of stars seen to be variable is higher than the canonical wisdom, being 10-14 will present the details of our techniques, sample light curves, methods to access the data, and a summary of astrophysical uses of such high precision data.

  18. Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source (HTPD 08 paper)

    Energy Technology Data Exchange (ETDEWEB)

    Haugh, M; Schneider, M B

    2008-04-28

    The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. The intensity distribution taken by the SXI camera during a NIF shot is used to determine how accurately NIF can aim laser beams. This is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 {micro}m square pixels, and 15 {micro}m thick. A multi-anode Manson X-ray source, operating up to 10kV and 10W, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/{Delta}E {approx} 10. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within {+-}1% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation occurred at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was not observable below 4 keV. We were also able to observe debris, damage, and surface defects on the CCD chip. The Manson source is a powerful tool for characterizing the imaging errors of an X-ray CCD imager. These errors are quite different from those found in a visible CCD imager.

  19. Low cost CCD camera protection against neutron radiation damage.

    Science.gov (United States)

    Kok, J G M

    2005-01-01

    At a radiotherapy department cancer patients are treated with high energy electron and photon beams. These beams are produced by a linear accelerator. A closed circuit television system is used to monitor patients during treatment. Although CCD cameras are rather resistant to stray radiation, they are damaged by the low flux of neutrons which are produced by the linac as a side effect. PVC can be used to reduce damage to CCD cameras induced by neutron radiation. A box with 6 cm thick walls will extend the life of the camera at least by a factor of two. A PVC neutron shield is inexpensive. PVC is easy to obtain and the box is simple to construct. A similar box made out of PE will not reduce neutron damage to a CCD camera. Although PE is a good medium to moderate faster neutrons, thereby reducing some of the bulk defects, it will not capture thermal neutrons which induce surface damage.

  20. 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.

  1. Thermal management for CCD peformance of one space telescope

    Science.gov (United States)

    Yang, Wengang; Wang, Yinghao; Feng, Liangjie; Wang, Chenjie; Ren, Guorui; Wang, Wei; Li, Chuang; Gao, Wei; Fan, Xuewu

    2012-10-01

    A space telescope containing two CCD cameras is being built for scientific observation. The CCD detectors need to operate at a temperature below -65°C in order to avoid unacceptable dark current. This cooling is achieved through detailed thermal design which minimizes the parasitic load to 2K×4K array with 13.5 micron pixels and cools this detector with a combination of thermo electric cooler(TEC). This paper will describe detailed thermal design necessary to maintain the CCD at its cold operating temperature while providing the means to reject the heat generated by the TECs. It will focus on optimized techniques developed to manage parasitic loads including material selection, surface finishes and thermal insulation. The paper will also address analytical techniques developed to characterize TEC performance. Finally, analysis results have been shown the temperature of key parts.

  2. A USB 2.0 computer interface for the UCO/Lick CCD cameras

    Science.gov (United States)

    Wei, Mingzhi; Stover, Richard J.

    2004-09-01

    The new UCO/Lick Observatory CCD camera uses a 200 MHz fiber optic cable to transmit image data and an RS232 serial line for low speed bidirectional command and control. Increasingly RS232 is a legacy interface supported on fewer computers. The fiber optic cable requires either a custom interface board that is plugged into the mainboard of the image acquisition computer to accept the fiber directly or an interface converter that translates the fiber data onto a widely used standard interface. We present here a simple USB 2.0 interface for the UCO/Lick camera. A single USB cable connects to the image acquisition computer and the camera's RS232 serial and fiber optic cables plug into the USB interface. Since most computers now support USB 2.0 the Lick interface makes it possible to use the camera on essentially any modern computer that has the supporting software. No hardware modifications or additions to the computer are needed. The necessary device driver software has been written for the Linux operating system which is now widely used at Lick Observatory. The complete data acquisition software for the Lick CCD camera is running on a variety of PC style computers as well as an HP laptop.

  3. The hard X-ray response of the XIS-CCD for Astro-E: qualification of the X-ray CCD detector

    CERN Document Server

    Nishiuchi, M; Awaki, H; Tsuru, T; Sakano, M; Hamaguchi, K; Murakami, H; Tsunemi, H; Hayashida, K; Kitamoto, S; Miyata, E; Dotani, T; Ozaki, M; Bautz, M; Doty, J; Kissel, S; Foster, R; Ricker, G

    1999-01-01

    We report on the hard X-ray response of the CCD detector for the X-ray imaging spectrometer (XIS), to be launched on the next Japanese X-ray Astronomical Satellite, ASTRO-E, in February 2000. XIS is prepared by an international team, comprised of MIT (USA), ISAS, Osaka University and Kyoto University (JAPAN). We have evaluated the X-ray response of the XIS in its high-energy band (1.5-10 keV). Data from the fluorescent line emission of Al, Cl, Ti, Ni, Fe, Zn, Se were used to construct the response function of the CCD detectors. Details of the response function - including the energy-scale, linearity, energy resolution, quantum efficiency -, are given as a function of incident X-ray energy. We find that the tail component of high-energy photopeaks are produced by events with incomplete charge collection. We also conclude that the size of the charge clouds can be estimated using the shapes of the tail components.

  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. Multi-digital Still Cameras with CCD

    Institute of Scientific and Technical Information of China (English)

    LIU Wen-jing; LONG Zai-chuan; XIONG Ping; HUAN Yao-xiong

    2006-01-01

    Digital still camera is a completely typical tool for capturing the digital images. With the development of IC technology and optimization-algorithm, the performance of digital still cameras(DSCs) will be more and more powerful in the world. But can we obtain the more and better info using the combined information from the multi-digital still camera? The answer is yes by some experiments. By using multi-DSC at different angles, the various 3-D informations of the object are obtained.

  7. Obstacle Avoidance Control for Mobile Robot Based on Single CCD Camera and Ultrasonic Sensors

    Science.gov (United States)

    Nara, Shunsuke; Takahashi, Satoru

    This paper proposes an available method of obstacle avoidance control by using a single CCD camera and ultrasonic sensors mounted on the mobile robot. First, depending on the change of the brightness on the image that occurs from the moving of the mobile robot, we calculate the optical flow by the block matching method based on the normalized correlation and detect the obstacle area on the image. Further, in order to reduce the error of the detection area, by combining the distance information obtained by ultrasonic sensors on the image shown the obstacle area we decide the position of obstacle with high accuracy. Dealing with the position information, we make the reference points for generating the trajectory of the mobile robot. This trajectory is smooth and is generated by minimizing a certain cost function. Then, the mobile robot moves according to the trajectory while avoiding around the obstacle. Finally, usefulness of our proposed method is shown through some experiments.

  8. A New Technique for CCD Camera Auto-Calibration

    Institute of Scientific and Technical Information of China (English)

    Xiaodong Zhang; Changku Sun; Zhixiong Wang; Wei Wei

    2003-01-01

    A novel feature-round-based coplanar drone for the CCD camera auto-calibration is designed. Based on the ellipse similarity, an ellipse recognition algorithm is proposed. The experiment indicates the calibration error is less than 0.4 pixel.

  9. Measurements of 42 Wide CPM Pairs with a CCD

    Science.gov (United States)

    Harshaw, Richard

    2015-11-01

    This paper addresses the use of a Skyris 618C color CCD camera as a means of obtaining data for analysis in the measurement of wide common proper motion stars. The equipment setup is described and data collection procedure outlined. Results of the measures of 42 CPM stars are presented, showing the Skyris is a reliable device for the measurement of double stars.

  10. Data acquisition system based on the Nios II for a CCD camera

    Science.gov (United States)

    Li, Binhua; Hu, Keliang; Wang, Chunrong; Liu, Yangbing; He, Chun

    2006-06-01

    The FPGA with Avalon Bus architecture and Nios soft-core processor developed by Altera Corporation is an advanced embedded solution for control and interface systems. A CCD data acquisition system with an Ethernet terminal port based on the TCP/IP protocol is implemented in NAOC, which is composed of a piece of interface board with an Altera's FPGA, 32MB SDRAM and some other accessory devices integrated on it, and two packages of control software used in the Nios II embedded processor and the remote host PC respectively. The system is used to replace a 7200 series image acquisition card which is inserted in a control and data acquisition PC, and to download commands to an existing CCD camera and collect image data from the camera to the PC. The embedded chip in the system is a Cyclone FPGA with a configurable Nios II soft-core processor. Hardware structure of the system, configuration for the embedded soft-core processor, and peripherals of the processor in the PFGA are described. The C program run in the Nios II embedded system is built in the Nios II IDE kits and the C++ program used in the PC is developed in the Microsoft's Visual C++ environment. Some key techniques in design and implementation of the C and VC++ programs are presented, including the downloading of the camera commands, initialization of the camera, DMA control, TCP/IP communication and UDP data uploading.

  11. A rehabilitation training system with double-CCD camera and automatic spatial positioning technique

    Science.gov (United States)

    Lin, Chern-Sheng; Wei, Tzu-Chi; Lu, An-Tsung; Hung, San-Shan; Chen, Wei-Lung; Chang, Chia-Chang

    2011-03-01

    This study aimed to develop a computer game for machine vision integrated rehabilitation training system. The main function of the system is to allow users to conduct hand grasp-and-place movement through machine vision integration. Images are captured by a double-CCD camera, and then positioned on a large screen. After defining the right, left, upper, and lower boundaries of the captured images, an automatic spatial positioning technique is employed to obtain their correlation functions, and lookup tables are defined for cameras. This system can provide rehabilitation courses and games that allow users to exercise grasp-and-place movements, in order to improve their upper limb movement control, trigger trunk control, and balance training.

  12. Anomalous visualization of sub-2 THz photons on standard silicon CCD and COMS sensors

    CERN Document Server

    Shalaby, Mostafa; Hauri, Christoph P

    2015-01-01

    We experimentally show that indirect light-induced electron transitions could lead to THz detection on standard CCD and CMOS sensors, introducing this well-established technological concept to the THz range. Unlike its optical counterpart, we found that the THz sensitivity is nonlinear. We imaged 1-13 THz radiation with photon energy less than 2% of the well-established band gap energy threshold. The unprecedented small pitch and large number of pixels uniquely allowed us to visualize the complex propagation of THz radiation, as it focuses down to the physical diffraction limit. Broadband pulses were detectable at a single shot. This opens a whole new field of real time THz imaging at the frame rate of the sensor.

  13. ULTRACAM: an ultra-fast, triple-beam CCD camera for high-speed astrophysics

    CERN Document Server

    Dhillon, V S; Stevenson, M J; Atkinson, D C; Kerry, P; Peacocke, P T; Vick, A J A; Beard, S M; Ives, D J; Lunney, D W; McLay, S A; Tierney, C J; Kelly, J; Littlefair, S P; Nicholson, R; Pashley, R; Harlaftis, E T; O'Brien, K

    2007-01-01

    ULTRACAM is a portable, high-speed imaging photometer designed to study faint astronomical objects at high temporal resolutions. ULTRACAM employs two dichroic beamsplitters and three frame-transfer CCD cameras to provide three-colour optical imaging at frame rates of up to 500 Hz. The instrument has been mounted on both the 4.2-m William Herschel Telescope on La Palma and the 8.2-m Very Large Telescope in Chile, and has been used to study white dwarfs, brown dwarfs, pulsars, black-hole/neutron-star X-ray binaries, gamma-ray bursts, cataclysmic variables, eclipsing binary stars, extrasolar planets, flare stars, ultra-compact binaries, active galactic nuclei, asteroseismology and occultations by Solar System objects (Titan, Pluto and Kuiper Belt objects). In this paper we describe the scientific motivation behind ULTRACAM, present an outline of its design and report on its measured performance.

  14. The two CcdA proteins of Bacillus anthracis differentially affect virulence gene expression and sporulation.

    Science.gov (United States)

    Han, Hesong; Wilson, Adam C

    2013-12-01

    The cytochrome c maturation system influences the expression of virulence factors in Bacillus anthracis. B. anthracis carries two copies of the ccdA gene, encoding predicted thiol-disulfide oxidoreductases that contribute to cytochrome c maturation, while the closely related organism Bacillus subtilis carries only one copy of ccdA. To investigate the roles of the two ccdA gene copies in B. anthracis, strains were constructed without each ccdA gene, and one strain was constructed without both copies simultaneously. Loss of both ccdA genes results in a reduction of cytochrome c production, an increase in virulence factor expression, and a reduction in sporulation efficiency. Complementation and expression analyses indicate that ccdA2 encodes the primary CcdA in B. anthracis, active in all three pathways. While CcdA1 retains activity in cytochrome c maturation and virulence control, it has completely lost its activity in the sporulation pathway. In support of this finding, expression of ccdA1 is strongly reduced when cells are grown under sporulation-inducing conditions. When the activities of CcdA1 and CcdA2 were analyzed in B. subtilis, neither protein retained activity in cytochrome c maturation, but CcdA2 could still function in sporulation. These observations reveal the complexities of thiol-disulfide oxidoreductase function in pathways relevant to virulence and physiology.

  15. Implementation of a parallel-beam optical-CT apparatus for three-dimensional radiation dosimetry using a high-resolution CCD camera

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Wen-Tzeng [Department of Computer Science and Information Engineering, Minghsin University of Science and Technology, Taiwan, ROC (China); Chen, Chin-Hsing [Department of Management Information Systems, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC (China); Hung, Chao-Nan; Tuan, Chiu-Ching [Graduate Institute of Computer and Communication Engineering, National Taipei University of Technology, Taiwan, ROC (China); Chang, Yuan-Jen, E-mail: ronchang@ctust.edu.tw [Department of Management Information Systems, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC (China)

    2015-06-01

    In this study, a charge-coupled device (CCD) camera with 2-megapixel (1920×1080-pixel) and 12-bit resolution was developed for optical computed tomography(optical CT). The signal-to-noise ratio (SNR) of our system was 30.12 dB, better than that of commercially available CCD cameras (25.31 dB). The 50% modulation transfer function (MTF50) of our 1920×1080-pixel camera gave a line width per picture height (LW/PH) of 745, which is 73% of the diffraction-limited resolution. Compared with a commercially available 1-megapixel CCD camera (1296×966-pixel) with a LW/PH=358 and 46.6% of the diffraction-limited resolution, our camera system provided higher spatial resolution and better image quality. The NIPAM gel dosimeter was used to evaluate the optical CT with a 2-megapixel CCD. A clinical five-field irradiation treatment plan was generated using the Eclipse planning system (Varian Corp., Palo Alto, CA, USA). The gel phantom was irradiated using a 6-MV Varian Clinac IX linear accelerator (Varian). The measured NIPAM gel dose distributions and the calculated dose distributions, generated by the treatment planning software (TPS), were compared using the 3% dose-difference and 3 mm distance-to-agreement criteria. The gamma pass rate was as high as 98.2% when 2-megapixel CCD camera was used in optical CT. However, the gamma pass rate was only 96.0% when a commercially available 1-megapixel CCD camera was used. - Highlights: • An optical CT system with a 2-megapixel CCD showed high uniformity of reconstructed images of the gel phantom. • The gamma pass rate was as high as 98.2% with the 3% dose difference and 3 mm dose to agreement criteria. • Our CCD with 12-bit information could guarantee better SNR performance, of 30.12 dB. • Our 2-megapixel CCD camera gave a LW/PH of 745, 73% of the diffraction-limited resolution.

  16. The research of digital circuit system for high accuracy CCD of portable Raman spectrometer

    Science.gov (United States)

    Yin, Yu; Cui, Yongsheng; Zhang, Xiuda; Yan, Huimin

    2013-08-01

    The Raman spectrum technology is widely used for it can identify various types of molecular structure and material. The portable Raman spectrometer has become a hot direction of the spectrometer development nowadays for its convenience in handheld operation and real-time detection which is superior to traditional Raman spectrometer with heavy weight and bulky size. But there is still a gap for its measurement sensitivity between portable and traditional devices. However, portable Raman Spectrometer with Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS) technology can enhance the Raman signal significantly by several orders of magnitude, giving consideration in both measurement sensitivity and mobility. This paper proposed a design and implementation of driver and digital circuit for high accuracy CCD sensor, which is core part of portable spectrometer. The main target of the whole design is to reduce the dark current generation rate and increase signal sensitivity during the long integration time, and in the weak signal environment. In this case, we use back-thinned CCD image sensor from Hamamatsu Corporation with high sensitivity, low noise and large dynamic range. In order to maximize this CCD sensor's performance and minimize the whole size of the device simultaneously to achieve the project indicators, we delicately designed a peripheral circuit for the CCD sensor. The design is mainly composed with multi-voltage circuit, sequential generation circuit, driving circuit and A/D transition parts. As the most important power supply circuit, the multi-voltage circuits with 12 independent voltages are designed with reference power supply IC and set to specified voltage value by the amplifier making up the low-pass filter, which allows the user to obtain a highly stable and accurate voltage with low noise. What's more, to make our design easy to debug, CPLD is selected to generate sequential signal. The A/D converter chip consists of a correlated

  17. Research of optical rainfall sensor based on CCD linear array

    Institute of Scientific and Technical Information of China (English)

    YANG; Bifeng; LIU; Yuyan; LU; Ying; WU; Shangqian

    2015-01-01

    Rainfall monitoring is one of the most important meteorological observation elements for the disaster weather. The maintenance of current tipping bucket rain gauge and weighing type rain gauge is a critical issue. The optical rainfall sensor based on CCD linear array is mainly studied in this paper. Because of the maintenance-free time and good adaptability,it can be widely used in the automatic rainfall monitoring in severe environment and have a good perspective in using.

  18. Applications in radiation therapy of a scintillating screen viewed by a CCD camera

    CERN Document Server

    Schippers, J M; Luijk, P V

    2002-01-01

    A two-dimensional (2D) dosimetry system has been designed for position-sensitive dose-measurement applications in modern radiation therapy. The system consists of a scintillating screen (Gd sub 2 O sub 2 S : Tb), observed by a low-noise CCD camera with a long integration time. The system allows reliable and accurate simultaneous 2D imaging of therapeutic dose distributions in the scintillator with sub millimeter spatial resolution. This system has been applied successfully at different applications in radiation therapy. Results of dose measurements in a treatment modality using a scanning proton beam are reported. It is shown that a quick and reliable measurement can be done. The screen+CCD system has proven to perform accurate dosimetry in applications where beams with a small (1-5 mm) diameter are used and where absolute dosimetry by means of standard ionization chambers is not possible due to their relatively large size. For the routine measurements of the alignment of therapeutic beams with respect to the...

  19. A CCD-based system for the detection of DNA in electrophoresis gels by UV absorption

    Science.gov (United States)

    Mahon, Alex R.; MacDonald, John H.; Ott, Robert J.; Mainwood, Alison

    1999-06-01

    A method and apparatus for the detection and quantification of large fragments of unlabelled nucleic acids in agarose gels is presented. The technique is based on ultraviolet (UV) absorption by nucleotides. A deuterium source illuminates individual sample lanes of an electrophoresis gel via an array of optical fibres. As DNA bands pass through the illuminated region of the gel the amount of UV light transmitted is reduced because of absorption by the DNA. During electrophoresis the regions of DNA are detected on-line using a UV-sensitive charge coupled device (CCD). As the absorption coefficient is proportional to the mass of DNA the technique is inherently quantitative. The mass of DNA in a region of the gel is approximately proportional to the integrated signal in the corresponding section of the CCD image. This system currently has a detection limit of less than 1.25 ng compared with 2-10 ng for the most popular conventional technique, ethidium bromide (EtBr) staining. In addition the DNA sample remains in its native state. The removal of the carcinogenic dye from the detection procedure greatly reduces associated biological hazards.

  20. Measurement and analysis of image sensors

    Science.gov (United States)

    Vitek, Stanislav

    2005-06-01

    For astronomical applications is necessary to have high precision in sensing and processing the image data. In this time are used the large CCD sensors from the various reasons. For the replacement of CCD sensors with CMOS sensing devices is important to know transfer characteristics of used CCD sensors. In the special applications like the robotic telescopes (fully automatic, without human interactions) seems to be good using of specially designed smart sensors, which have integrated more functions and have more features than CCDs.

  1. 14位10MHz CCD/CIS信号处理器%14-bit, 10MHz CCD/CIS signal processors

    Institute of Scientific and Technical Information of China (English)

    彭京湘

    2000-01-01

    @@ Burr-Brown公司的VSP3100是一款工作在+5V单电源的完整CCD/CIS图像处理器.这种完整的图像处理器包含处理CCD(电荷耦合器件)信号的3个相关双取样器(CDS)和可编程增益放大器(PGA)(见图1).3个通道输入(RINP--红色通道模拟输入,GINP--绿色通道模拟输入,BINP--兰色通道模拟输入)也为接触图像传感器(CIS)提供输入.

  2. Test technology on CCD anti-sunlight jamming based on complex circumstance

    Science.gov (United States)

    Shi, Sheng-bing; Chen, Zhen-xing; Han, Fu-li

    2016-09-01

    Visible-light reconnaissance device based on CCD is applied to all kinds of weapons, CCD cannot work because of saturation when it faces intense light. Sun is intense light source in nature and assignably influences CCD performance. In this paper, aim is appraising CCD anti-sunlight ability, object reflection characteristic test system is designed, based on typical background reflection characteristic including grant, sand and so on, complex circumstance is formulated and test project is optimized with orthogonal design method, problem that is without test technology on CCD anti-sunlight jamming is solved.

  3. Focusing optics of a parallel beam CCD optical tomography apparatus for 3D radiation gel dosimetry.

    Science.gov (United States)

    Krstajić, Nikola; Doran, Simon J

    2006-04-21

    Optical tomography of gel dosimeters is a promising and cost-effective avenue for quality control of radiotherapy treatments such as intensity-modulated radiotherapy (IMRT). Systems based on a laser coupled to a photodiode have so far shown the best results within the context of optical scanning of radiosensitive gels, but are very slow ( approximately 9 min per slice) and poorly suited to measurements that require many slices. Here, we describe a fast, three-dimensional (3D) optical computed tomography (optical-CT) apparatus, based on a broad, collimated beam, obtained from a high power LED and detected by a charged coupled detector (CCD). The main advantages of such a system are (i) an acquisition speed approximately two orders of magnitude higher than a laser-based system when 3D data are required, and (ii) a greater simplicity of design. This paper advances our previous work by introducing a new design of focusing optics, which take information from a suitably positioned focal plane and project an image onto the CCD. An analysis of the ray optics is presented, which explains the roles of telecentricity, focusing, acceptance angle and depth-of-field (DOF) in the formation of projections. A discussion of the approximation involved in measuring the line integrals required for filtered backprojection reconstruction is given. Experimental results demonstrate (i) the effect on projections of changing the position of the focal plane of the apparatus, (ii) how to measure the acceptance angle of the optics, and (iii) the ability of the new scanner to image both absorbing and scattering gel phantoms. The quality of reconstructed images is very promising and suggests that the new apparatus may be useful in a clinical setting for fast and accurate 3D dosimetry.

  4. SWNT Imaging Using Multispectral Image Processing

    Science.gov (United States)

    Blades, Michael; Pirbhai, Massooma; Rotkin, Slava V.

    2012-02-01

    A flexible optical system was developed to image carbon single-wall nanotube (SWNT) photoluminescence using the multispectral capabilities of a typical CCD camcorder. The built in Bayer filter of the CCD camera was utilized, using OpenCV C++ libraries for image processing, to decompose the image generated in a high magnification epifluorescence microscope setup into three pseudo-color channels. By carefully calibrating the filter beforehand, it was possible to extract spectral data from these channels, and effectively isolate the SWNT signals from the background.

  5. 用于 CCD 立靶的双光幕触发系统研究%Dual-screen triggering system for CCD vertical target

    Institute of Scientific and Technical Information of China (English)

    董涛; 华灯鑫; 李言; 倪晋平

    2014-01-01

    On the request of the stable and reliable trigger required in charge-coupled device (CCD) vertical target measurement system in the condition of firing range ,a dual-screen trig-ging system was presented .The trigging detecting screen was composed of lens-type screen detector ,working with the high-intensity LED slow-scattering light ,and the velocity-measur-ing system consists of two identical screen detectors working together with chronometer ,and then it judged whether the projectile passing through the screen was real based on the measured velocity and whether to output the trigging signal or not .The time for projectile flying from impacting screen to detecting screen was achieved according to the velocity value V and the dis-tance between impacting screen and detecting screen ,and then the triggering signal was output while the projectile was approaching to CCD detecting screen .The proposed scheme can im-prove the stability of the system ,prevent the system from being interfered by unreal targets , and can transmit trigging signal at the precise time to follow-up CCD image-acquisition system . It has been proved by experiment that the speed measurement error of the designed dual-screen triggering system is not more than 0 .4% ,fully meeting the demand of the stable and reliable trigger requirement of the CCD vertical target .%针对靶场测试当中CCD立靶测量系统需要稳定可靠触发的需求,提出一种双光幕触发系统。采用镜头式光幕探测器配合高亮度L ED慢散射光源组成触发探测光幕,利用2个同样的光幕探测器配合测时装置组成区截测速系统,根据测得的速度值判定飞越探测光幕的目标是否为真实弹丸,并决定是否输出触发信号。根据速度值V 和触发光幕至CCD探测光幕的距离计算出弹丸飞越至探测光幕的时间,然后在弹丸飞越将近至探测光幕的时刻输出触发信号。该方案不但可以提高系统的稳定性,避免非真

  6. Crystallization of the C-terminal domain of the addiction antidote CcdA in complex with its toxin CcdB

    Energy Technology Data Exchange (ETDEWEB)

    Buts, Lieven; De Jonge, Natalie; Loris, Remy, E-mail: reloris@vub.ac.be; Wyns, Lode; Dao-Thi, Minh-Hoa [Department of Molecular and Cellular Interactions, Vlaams Interinuversitair Instituut voor Biotechnologie and Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel (Belgium)

    2005-10-01

    The CcdA C-terminal domain was crystallized in complex with CcdB in two crystal forms that diffract to beyond 2.0 Å resolution. CcdA and CcdB are the antidote and toxin of the ccd addiction module of Escherichia coli plasmid F. The CcdA C-terminal domain (CcdA{sub C36}; 36 amino acids) was crystallized in complex with CcdB (dimer of 2 × 101 amino acids) in three different crystal forms, two of which diffract to high resolution. Form II belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 37.6, b = 60.5, c = 83.8 Å and diffracts to 1.8 Å resolution. Form III belongs to space group P2{sub 1}, with unit-cell parameters a = 41.0, b = 37.9, c = 69.6 Å, β = 96.9°, and diffracts to 1.9 Å resolution.

  7. 以HJ-CCD影像为基础的冬小麦孕穗期关键苗情参数遥感定量反演%Quantitative Inversion of Key Seedling Condition Parameters in Winter Wheat at Booting Stage Using Remote Sensing Based on HJ-CCD Images

    Institute of Scientific and Technical Information of China (English)

    谭昌伟; 杨昕; 罗明; 马昌; 严翔; 陈亭亭

    2015-01-01

    [Objective]Application of satellite remote sensing data can timely get field planting crops ‘planar’ growth information, accurately reflect the situation and trend of crop seedling condition, serve the yield forecast and actual production. The purpose of this research was to deepen the mechanism and methods of remote sensing inversion of winter wheat seedling condition in the key period, and this research will provide timely support information and technology for farm production management.[Method]Based on experimental data obtained from 2011-2013 in the fixed-point observation experiment, and using HJ-CCD satellite images, the quantitative correlations between key seedling condition parameters of winter wheat at booting stage in sampling regions and the grain quality parameters, production, and remote sensing variables were emphatically analyzed. In order to further enhance the mechanism and reproducibility of remote sensing inversion models, which were built and analyzed with ground measuring results, the quantitative level and reliability of remote sensing inversion models were raised. Models for monitoring the leaf area index, biomass, SPAD value, and leaf nitrogen content of winter wheat at booting stage using remote sensing variables extracted from the HJ-CCD images were built and assessed, respectively.[Result]It is possible to invert leaf area index, SPAD value and leaf nitrogen content of winter wheat at booting stage by plant senescence reflectance index (PSRI), and invert biomass by ratio vegetation index (RVI), respectively. The remote sensing inversion models of the leaf area index, SPAD value, leaf nitrogen content and biomass of winter wheat were credible, and higher precision was obtained with determination coefficient (R2) of 0.651, 0.585, 0.630 and 0.675, respectively, and with root mean square error (RMSE) of 1.344, 4.62, 0.618% and 2 804.3 kg·hm-2, respectively. It was especially reliable to inverse leaf nitrogen content by PSRI. According

  8. Soft X-ray response of a CCD with a grating spectrometer

    CERN Document Server

    Shouho, M; Katayama, H; Kohmura, T; Tsunemi, H; Kitamoto, S; Hayashida, K; Miyata, E; Hashimotodani, K; Yoshita, K; Koyama, K; Ricker, G; Bautz, M W; Foster, R; Kissel, S

    1999-01-01

    We calibrate the X-ray imaging spectrometers, which are CCD cameras installed on the ASTRO-E satellite, by using dispersed continuous soft X-rays from a grating spectrometer. We obtained the signal-pulse height and energy-resolution as a function of X-ray energies continuously. However, the wings of the line spread function of the grating distorts the center of the signal-pulse height derived by a simple analysis. An estimation of this distortion is presented. We also describe two methods of extracting the pure signal-pulse-height distribution from the data using the spectrometer. A brief description of the low-energy tail is presented.

  9. Quantum efficiency of the CCD camera (XIS) for the ASTRO-E mission

    CERN Document Server

    Katayama, H; Kohmura, T; Katayama, K; Yoshita, K; Tsunemi, H; Kitamoto, S; Hayashida, K; Miyata, E; Hashimotodani, K; Koyama, K; Ricker, G; Bautz, M W; Foster, R; Kissel, S

    1999-01-01

    We measured the optical and the X-ray transmission of the optical blocking filters for the X-ray Imaging Spectrometers (XISs) which are the X-ray CCD cameras of the ASTRO-E satellite. We conclude that the oxidation of the aluminum reduces the optical transmission down to approx 60-70% of the theoretical value of the aluminum. We achieved optical transmission below 5x10 sup - sup 5 in the range from 4000 to 9500 A by using aluminum thickness of 1200 A, while the theoretical calculation requires 800 A. The measurement of absolute quantum efficiency of XIS is also performed at several particular energies. We confirmed 20% quantum efficiency at 0.5 keV for the XIS engineering model (XIS EM).

  10. Reverse engineering of the homogeneous-entity product profiles based on CCD

    Science.gov (United States)

    Gan, Yong; Zhong, Jingru; Sun, Ning; Sun, Aoran

    2011-08-01

    This measurement system uses delaminated measurement principle, measures the three perpendicular direction values of the entities. When the measured entity is immerged in the liquid layer by layer, every layer's image are collected by CCD and digitally processed. It introduces the basic measuring principle and the working process of the measure method. According to Archimedes law, the related buoyancy and volume that soaked in different layer's depth are measured by electron balance and the mathematics models are established. Through calculating every layer's weight and centre of gravity by computer based on the method of Artificial Intelligence, we can reckon 3D coordinate values of every minute entity cell in different layers and its 3D contour picture is constructed. The experimental results show that for all the homogeneous entity insoluble in water, it can measure them. The measurement velocity is fast and non-destructive test, it can measure the entity with internal hole.

  11. Ground-Based Sub-Millimagnitude CCD Photometry of Bright Stars using Snapshot Observations

    CERN Document Server

    Mann, Andrew W; Aldering, Greg

    2011-01-01

    We demonstrate ground-based sub-millimagnitude (10^7 electrons) to be acquired in a single integration; (iii) pointing the telescope so that all stellar images fall on the same detector pixels; and (iv) using a region of the CCD detector that is free of non-linear or aberrant pixels. We describe semi-automated observations with the Supernova Integrated Field Spectrograph (SNIFS) on the University of Hawaii 2.2m telescope on Mauna Kea, with which we achieved photometric precision as good as 5.2x10^-4 (0.56 mmag) with a 5 minute cadence over a two hour interval. In one experiment, we monitored 8 stars, each separated by several degrees, and achieved sub-mmag precision with a cadence (per star) of ~17 min. Our snapshot technique is suitable for automated searches for planetary transits among multiple, bright-stars.

  12. Application of CCD Cameras to Investigations of Mixing on Boundaries of a Thermal Plasma Jet

    Institute of Scientific and Technical Information of China (English)

    J.HLINA; J.(S)ONSKY; J.(S)LECHTA

    2007-01-01

    Mixing of a thermal plasma jet with the surrounding atmosphere was studied using two CCD cameras (PCO SensiCam) situated detecting simultaneously the radiation of argon and nitrogen.The evaluation of image differences between two records showed that the location of regions on plasma jet boundaries characterised by stronger nitrogen radiation changes with the plasma flow rate.Close-to-laminar flow results in a small mixing rate and consequently low nitrogen optical emission on plasma jet boundaries.The increase of the flow rate leads to the formation of a relatively thick and stable layer on the boundaries characterised by strong nitrogen radiation.Further enhancement of the flow rate results in the formation of unstable regions of excited nitrogen molecules moving along the jet.

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

    CERN Document Server

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

    2008-01-01

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

  14. Direct measurement and calibration of the Kepler CCD Pixel Response Function for improved photometry and astrometry

    Science.gov (United States)

    Ninkov, Zoran

    Stellar images taken with telescopes and detectors in space are usually undersampled, and to correct for this, an accurate pixel response function is required. The standard approach for HST and KEPLER has been to measure the telescope PSF combined ("convolved") with the actual pixel response function, super-sampled by taking into account dithered or offset observed images of many stars (Lauer [1999]). This combined response function has been called the "PRF" (Bryson et al. [2011]). However, using such results has not allowed astrometry from KEPLER to reach its full potential (Monet et al. [2010], [2014]). Given the precision of KEPLER photometry, it should be feasible to use a pre-determined detector pixel response function (PRF) and an optical point spread function (PSF) as separable quantities to more accurately correct photometry and astrometry for undersampling. Wavelength (i.e. stellar color) and instrumental temperature should be affecting each of these differently. Discussion of the PRF in the "KEPLER Instrument Handbook" is limited to an ad-hoc extension of earlier measurements on a quite different CCD. It is known that the KEPLER PSF typically has a sharp spike in the middle, and the main bulk of the PSF is still small enough to be undersampled, so that any substructure in the pixel may interact significantly with the optical PSF. Both the PSF and PRF are probably asymmetric. We propose to measure the PRF for an example of the CCD sensors used on KEPLER at sufficient sampling resolution to allow significant improvement of KEPLER photometry and astrometry, in particular allowing PSF fitting techniques to be used on the data archive.

  15. Polarization Imager Technology. Phase I

    Science.gov (United States)

    2007-11-02

    of Figure 5 shows an inten- sity image of a HMMWV entirely draped with U.S. Woodland Net Camouflage and about 30% occluded by bush vegetation on the...onto the CCD photosensing chip such that the three 00, 450, 900 states are sensed simultaneously. Figure 8 10 COMPETITION SENSITIVE AND PROPRIETARY...respectively at adjacent single columns of pixels, is deposited onto the CCD chip . The sensing rate of complete polarization images using this design is

  16. CCD time-resolved photometry of faint cataclysmic variables. III

    Science.gov (United States)

    Howell, Steve B.; Szkody, Paula; Kreidl, Tobias J.; Mason, Keith O.; Puchnarewicz, E. M.

    1990-01-01

    CCD time-resolved photometry in V, B, and near-IR for 17 faint cataclysmic variables (CVs) is presented and analyzed. The data are obtained at Kitt Peak National Observatory, the Perkins reflector, Lowell Observatory, and the Observatorio del Roque de los Muchachos from April-June 1989. The degree of variability and periodicities for the CVs are examined. It is observed that the variability of most of the stars is consistent with CV class behavior. Orbital periods for five CVs are determined, and three potential eclipsing systems are detected.

  17. CCD Photometry of Dwarf Nova AL Com in Superoutburst

    OpenAIRE

    Pych, W.; Olech, A.

    1995-01-01

    We report a CCD optical photometry of a dwarf nova AL Com in superoutburst. Before superhumps occurred the light curve was highly variable with dominant periods about 41 minutes and 81.5 minutes for different nights. The period of observed superhumps is 82.5 minutes and seems to be stable. The first harmonic of the basic period is also present. We detected a weak signal corresponding to period 78.1 minutes. One of the periods 78.1 or 81.5 is suspected to be a possible signature of orbital mot...

  18. Modelling Gaia CCD pixels with Silvaco 3D engineering software

    CERN Document Server

    Seabroke, G M; Hopkinson, G; Burt, D; Robbins, M; Holland, A

    2010-01-01

    Gaia will only achieve its unprecedented measurement accuracy requirements with detailed calibration and correction for radiation damage. We present our Silvaco 3D engineering software model of the Gaia CCD pixel and two of its applications for Gaia: (1) physically interpreting supplementary buried channel (SBC) capacity measurements (pocket-pumping and first pixel response) in terms of e2v manufacturing doping alignment tolerances; and (2) deriving electron densities within a charge packet as a function of the number of constituent electrons and 3D position within the charge packet as input to microscopic models being developed to simulate radiation damage.

  19. Application of digital auto-focus technique in CCD splicing apparatus%数字自动调焦技术在CCD拼接仪中的应用

    Institute of Scientific and Technical Information of China (English)

    杨利红

    2014-01-01

    In order to get enlarged CCD images of high definition in the CCD splicing process , the digital auto-focus tech-nique which is fit for the CCD splicing apparatus is achieved . Firstly , the central region of the enlarged image is selected as the focusing region . Secondly , the modified Laplacian function is selected as the image definition evaluation function in the actual splic-ing process . The focusing time consumption for the focusing region is 20 percent of the time consumption for the whole image . A definition evaluation operation of the modified Laplacian function costs only 2 . 5ms . With the search process , the best focusing posi-tion can be determined accurately and quickly . Using the digital auto-focus in the CCD splicing apparatus , the complex operation and the insufficient precision of manual focusing can be avoided .%为了获得拼接过程所需的高清晰度 CCD 像元放大图像,针对 CCD 拼接仪硬件条件实现了数字自动调焦技术的应用。选取整幅放大图像的中心区域作为调焦区域,采用改进 Laplacian 函数作为清晰度评价函数。实验结果表明,对中心区域进行调焦所耗费的时间仅为针对整幅图像调焦的20%。改进 Laplacian 函数进行一次清晰度评价用时2.5 ms ,结合搜索过程,能快速准确地定位最佳聚焦平面。在 CCD 拼接仪上应用数字自动调焦技术,解决了手动调焦操作复杂和精度不足的问题。

  20. Comparison of lens- and fiber-coupled CCD detectors for X-ray computed tomography.

    Science.gov (United States)

    Uesugi, K; Hoshino, M; Yagi, N

    2011-03-01

    X-ray imaging detectors with an identical phosphor and a CCD chip but employing lens- and fiber-coupling between them have been compared. These are designed for X-ray imaging experiments, especially computed tomography, at the medium-length beamline at the SPring-8 synchrotron radiation facility. It was found that the transmittance of light to the CCD is about four times higher in the fiber-coupled detector. The uniformity of response in the lens-coupled detector has a global shading of up to 40%, while pixel-to-pixel variation owing to a chicken-wire pattern was dominant in the fiber-coupled detector. Apart from the higher transmittance, the fiber-coupled detector has a few characteristics that require attention when it is used for computed tomography, which are browning of the fiber, discontinuity in the image, image distortion, and dark spots in the chicken-wire pattern. Thus, it is most suitable for high-speed tomography of samples that tend to deform, for example biological and soft materials.

  1. CCD Photometric Study and Period Investigation of AH Tauri

    Science.gov (United States)

    Xiang, Fu-Yuan; Xiao, Ting-Yu; Yu, Yun-Xia

    2015-07-01

    In this paper, we present new CCD photometric observations of AH Tauri in the R band observed in 2006 at the Yunnan Observatory. Two new times of light minima were derived from these observations. We modeled the light curves using the 2003 version of the Wilson-Devinney program. The results show that the variations of the light curves can be expained by a cool spot on the primary star. The fill-out factor is about 6.6%, indicating that AH Tauri is a shallow-contact system. The mass ratio was determined to be about 0.505. In addition, the orbital period variations of AH Tauri were investigated based on all of the photoelectric and CCD light minimum times, including our two new data. It was found that the orbital period exhibits a possible periodic variation with a period of {P}{mod}=54.62\\(+/- 0.20) years and a secular period decrease of {dP}/{dt}=-(1.823+/- 0.215)× {10}-7 {days} {{yr}}-1. Since AH Tauri is an overcontact solar-like system, we discuss three mechanisms of the mass transfer, the light-time effect of the third body, and magnetic activity responsible for the orbital period changes.

  2. The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)

    CERN Document Server

    Zacharias, Norbert; Girard, Terry; Henden, Arne; Bartlett, Jennifer; Monet, Dave; Zacharias, Marion

    2012-01-01

    The fourth United States Naval Observatory (USNO) CCD Astrograph Catalog, UCAC4 was released in August 2012 (double-sided DVD and CDS data center Vizier catalog I/322). It is the final release in this series and contains over 113 million objects; over 105 million of them with proper motions. UCAC4 is an updated version of UCAC3 with about the same number of stars also covering all-sky. Bugs were fixed, Schmidt plate survey data were avoided, and precise 5-band photometry were added. Astrograph observations have been supplemented for bright stars by FK6, Hipparcos and Tycho-2 data to compile a UCAC4 star catalog complete to about magnitude R = 16. Epoch 1998 to 2004 positions are obtained from observations with the 20 cm aperture USNO Astrograph's red lens, equipped with a 4k by 4k CCD. Mean positions and proper motions are derived by combining these observations with over 140 ground- and space-based catalogs, including Hipparcos/Tycho and the AC2000.2, as well as unpublished measures of over 5000 plates from ...

  3. The second US Naval Observatory CCD Astrograph Catalog (UCAC2)

    CERN Document Server

    Zacharias, N; Zacharias, M I; Wycoff, G L; Hall, D M; Monet, D G; Rafferty, T J

    2004-01-01

    The second USNO CCD Astrograph Catalog, UCAC2 was released in July 2003. Positions and proper motions for 48,330,571 sources (mostly stars) are available on 3 CDs, supplemented with 2MASS photometry for 99.5% of the sources. The catalog covers the sky area from -90 to +40 degrees declination, going up to +52 in some areas; this completely supersedes the UCAC1 released in 2001. Current epoch positions are obtained from observations with the USNO 8-inch Twin Astrograph equipped with a 4k CCD camera. The precision of the positions are 15 to 70 mas, depending on magnitude, with estimated systematic errors of 10 mas or below. Proper motions are derived by utilizing over 140 ground-and space-based catalogs, including Hipparcos/Tycho, the AC2000.2, as well as yet unpublished re-measures of the AGK2 plates and scans from the NPM and SPM plates. Proper motion errors are about 1 to 3 mas/yr for stars to 12th magnitude, and about 4 to 7 mas/yr for fainter stars to 16th magnitude. The observational data, astrometric redu...

  4. CCD-Based Astrometric Measurement of Photographic Plates

    Directory of Open Access Journals (Sweden)

    I. H. Bustos Fierro

    2003-01-01

    Full Text Available Se ha desarrollado la metodología para la medición astromètrica de placas fotográficas haciendo uso de una cámara CCD. Para la medición de una placa de 2º x 2º se tomó un mosaico de 8 x 8 imágenes con 50% de superposición en ambas coordenadas. La segmentación y el centrado de las imágenes estelares se llevó a cabo con SExtractor, y por medio de software propio se identificaron las exposiciones triples. Se encontró una notable distorsión radial producida por el sistema óptico que fue corregida. La reducción a coordenadas celestes se efectuó mediante la técnica de ajuste en bloque, usándose el catálogo Tycho-2 como referencia. Las diferencias con Tycho-2 sugieren que el error de las posiciones obtenidas con CCD a partir de la placa CdC está entre 0:0020 y 0:0025. También se discute la completitud de los catálogos obtenidos.

  5. Comparison between ASI, CNES and JAXA CCD analysis software for optical space debris monitoring

    Science.gov (United States)

    Paolillo, Fabrizio; Laas-Bourez, Myrtille; Yanagisawa, Toshifumi; Cappelletti, Chantal; Graziani, Filippo; Vidal, Bruno

    Since nineties Italian Space Agency (ASI), Centre National d'Etudes Spatiales CNES and Japan Aerospace Exploration Agency (JAXA) play an important role in Inter-Agency Space Debris Coordination Committee (IADC) activities. Respectively the Group of Astrodynamics of Uni-versity Sapienza of Rome (GAUSS), TAROT team (Télescope a Action Rapide pour les Objets Transitoires) and Institute of Aerospace Technology (IAT), participate in optical space debris monitoring activities (WG1 at IADC ) with the following facilities: 1. SpaDE observatory of ASI/GAUSS in Collepardo (Fr.), country-regionplaceItaly. 2. TAROT observatories of CNES: one in Chili (ESO LA Silla) and one in placecountry-regionFrance (Observatoire de la Côte d'Azur, at Calern). 3. Nyukasayama Observatory of IAT/JAXA, country-regionplaceJapan. Due to the large amount of data collected during the IADC coordinated observation campaigns and the autonomous campaigns, these research groups developed three different software for image processing automation and for the correlation of the detected objects with the catalogue. Using these software the three different observatories are improving the knowledge of the space debris population, in particular in the so-called geostationary belt (AI23.4 IADC International 2007 optical observation campaigns in higher Earth orbits and AI23.2 Investigation of high A/m ratio debris in higher Earth orbits), but they use different space debris monitoring techniques. With the aim to improve CCD analysis capabilities of each research group, during the 27th IADC meeting ASI, CNES and JAXA started a cooperation in this field on the comparison between the image processing software. The objectives of this activity are: 1. Test of ASI, CNES and JAXA CCD analysis software on real images taken in the 3 dif-ferent observation strategies (each observatory uses a particular objects extraction pro-cedure). 2. Results comparison: number of bad detection, number of good detection, processing

  6. HST/WFC3: understanding and mitigating radiation damage effects in the CCD detectors

    Science.gov (United States)

    Baggett, S. M.; Anderson, J.; Sosey, M.; Gosmeyer, C.; Bourque, M.; Bajaj, V.; Khandrika, H.; Martlin, C.

    2016-07-01

    At the heart of the Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) UVIS channel is a 4096x4096 pixel e2v CCD array. While these detectors continue to perform extremely well after more than 7 years in low-earth orbit, the cumulative effects of radiation damage are becoming increasingly evident. The result is a continual increase of the hotpixel population and the progressive loss in charge-transfer efficiency (CTE) over time. The decline in CTE has two effects: (1) it reduces the detected source flux as the defects trap charge during readout and (2) it systematically shifts source centroids as the trapped charge is later released. The flux losses can be significant, particularly for faint sources in low background images. In this report, we summarize the radiation damage effects seen in WFC3/UVIS and the evolution of the CTE losses as a function of time, source brightness, and image-background level. In addition, we discuss the available mitigation options, including target placement within the field of view, empirical stellar photometric corrections, post-flash mode and an empirical pixel-based CTE correction. The application of a post-flash has been remarkably effective in WFC3 at reducing CTE losses in low-background images for a relatively small noise penalty. Currently, all WFC3 observers are encouraged to consider post-flash for images with low backgrounds. Finally, a pixel-based CTE correction is available for use after the images have been acquired. Similar to the software in use in the HST Advanced Camera for Surveys (ACS) pipeline, the algorithm employs an observationally-defined model of how much charge is captured and released in order to reconstruct the image. As of Feb 2016, the pixel-based CTE correction is part of the automated WFC3 calibration pipeline. Observers with pre-existing data may request their images from MAST (Mikulski Archive for Space Telescopes) to obtain the improved products.

  7. 基于CCD的工件直径动态检测%Dynamic Testing of The Workpiece Diameter based on CCD

    Institute of Scientific and Technical Information of China (English)

    张永枫; 杨中雨

    2011-01-01

    为实现工件直径的在线检测,本文采用了CCD动态检测方法,它以CCD和微型计算机为核心构成了工件直径动态检测系统.将工件直径影像成像于 CCD光敏面上,经光电转换可获得CCD像元的电荷图像,以CCD像元(素)的间距为尺子实现对工件影像的度量,所以它属于模数变换法.将CCD输出的光电脉冲经放大、整形后输入计算机,通过运算处理即得到工件直径值.用标准工件直径做了大量的实验测试,其系统精确度超过1.5 μm,从而得到CCD动态检测系统具有精确度高和实际应用 价值的结论.%In modern production, in order to achieve workpiece diameter on-line measurement, this paper uses the CCD dynamic detection method. The method to CCD and microcomputer as the core constitutes a workpiece diameter dynamic detection system. The diameter of the workpiece and imaging in CCD photosensitive surface. After the photoelectric conversion into CCD pixel charge image. The method to CCD pixel ( ET ) spacing on the workpiece image measurement ruler, so it belongs to die - transformation method. The CCD output of the photoelectric pulse amplifying, shaping input into the computer after processing, will receive the workpiece diameter value. Using the standard workpiece diameter do lots of experiments, the precision of the system is smaller than 1.5 UG / M results, so as to get CCD dynamic detection system with high accuracy and practical value of the conclusion.

  8. The MATPHOT Algorithm for Digital Point Spread Function CCD Stellar Photometry

    Science.gov (United States)

    Mighell, Kenneth J.

    Most CCD stellar photometric reduction packages use analytical functions to represent the stellar Point Spread Function (PSF). These PSF-fitting programs generally compute all the major partial derivatives of the observational model by differentiating the volume integral of the PSF over a pixel. Real-world PSFs are frequently very complicated and may not be exactly representable with any combination of analytical functions. Deviations of the real-world PSF from the analytical PSF are then generally stored in a residual matrix. Diffraction rings and spikes can provide a great deal of information about the position of a star, yet information about such common observational effects generally resides only in the residual matrix. Such useful information is generally not used in the PSF-fitting process except for the final step involving the determination of the chi-square goodness-of-fit between the CCD observation and the model where the intensity-scaled residual matrix is added to the mathematical model of the observation just before the goodness-of-fit is computed. I describe some of the key features of my MATPHOT algorithm for digital PSF-fitting CCD stellar photometry where the PSF is represented by a matrix of numbers. The mathematics of determining the partial derivatives of the observational model with respect to the x and y direction vectors is exactly the same with analytical or digital PSFs. The implementation methodology, however, is quite different. In the case of digital PSFs, the partial derivatives can be determined using numerical differentiation techniques on the digital PSFs. I compare the advantages and disadvantages with respect to traditional PSF-fitting algorithms based on analytical representations of the PSF. The MATPHOT algorithm is an ideal candidate for parallel processing. Instead of operating in the traditional single-processor mode of analyzing one pixel at a time, the MATPHOT algorithm can be written to operate on an image-plane basis

  9. Consequences of CCD imperfections for cosmology determined by weak lensing surveys: From laboratory measurements to cosmological parameter bias

    CERN Document Server

    Okura, Yuki; May, Morgan; Plazas, Andrés A; Tamagawa, Toru

    2016-01-01

    Weak gravitational lensing causes subtle changes in the apparent shapes of galaxies due to the bending of light by the gravity of foreground masses. By measuring the shapes of large numbers of galaxies (millions in recent surveys, up to tens of billions in future surveys) we can infer the parameters that determine cosmology. Imperfections in the detectors used to record images of the sky can introduce changes in the apparent shape of galaxies, which in turn can bias the inferred cosmological parameters. In this paper we consider the effect of two widely discussed sensor imperfections: tree-rings, due to impurity gradients which cause transverse electric fields in the Charge-Coupled Devices (CCD), and pixel-size variation, due to periodic CCD fabrication errors. These imperfections can be observed when the detectors are subject to uniform illumination (flat field images). We develop methods to determine the spurious shear and convergence (due to the imperfections) from the flat-field images. We calculate how t...

  10. The Near Earth Object Surveillance Satellite: Mission status and CCD evolution after 18 months on-orbit

    Science.gov (United States)

    Wallace, B.; Scott, R.; Sale, M.

    2014-09-01

    The Near Earth Object Surveillance Satellite (NEOSSat) is a small telescope equipped microsatellite designed to perform both Space Situational Awareness (SSA) experiments and asteroid detection. NEOSSat was launched on 25 February 2013, however, due to time pressures, NEOSSat was launched with only the minimal software required to keep the spacecraft safe. The time pressure also resulted in the spacecraft undergoing reduced system and environmental testing on the ground. The full software suite, required to obtain imagery and maintain stable pointing, has since been uploaded to the spacecraft. NEOSSat has obtained imagery since June 2013, with the shutter both open and closed, but as of March 2014 has not achieved the fine pointing required to obtain scientifically useful data. The collected imagery is being used to characterize the on-board CCD camera. While gain and dark current values agree with pre-launch values, unexpected artefacts have appeared in the images. Methods for mitigating the artefacts through image processing have been developed, and spacecraft-level fixes are currently being investigated. In addition, damage from high energy particles impacting the CCD has produced hot pixels in imagery. We have been able to measure the evolution of these hot pixels over several months, both in terms of numbers and characteristics; these results will be presented. In addition, early results from the mission (image quality issues and evolution, early imagery examples), as well as the mission status (including fine pointing), will be discussed.

  11. A 14-bit 40-MHz analog front end for CCD application

    Science.gov (United States)

    Jingyu, Wang; Zhangming, Zhu; Shubin, Liu

    2016-06-01

    A 14-bit, 40-MHz analog front end (AFE) for CCD scanners is analyzed and designed. The proposed system incorporates a digitally controlled wideband variable gain amplifier (VGA) with nearly 42 dB gain range, a correlated double sampler (CDS) with programmable gain functionality, a 14-bit analog-to-digital converter and a programmable timing core. To achieve the maximum dynamic range, the VGA proposed here can linearly amplify the input signal in a gain range from -1.08 to 41.06 dB in 6.02 dB step with a constant bandwidth. A novel CDS takes image information out of noise, and further amplifies the signal accurately in a gain range from 0 to 18 dB in 0.035 dB step. A 14-bit ADC is adopted to quantify the analog signal with optimization in power and linearity. An internal timing core can provide flexible timing for CCD arrays, CDS and ADC. The proposed AFE was fabricated in SMIC 0.18 μm CMOS process. The whole circuit occupied an active area of 2.8 × 4.8 mm2 and consumed 360 mW. When the frequency of input signal is 6.069 MHz, and the sampling frequency is 40 MHz, the signal to noise and distortion (SNDR) is 70.3 dB, the effective number of bits is 11.39 bit. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033), the National High-Tech Program of China (No. 2013AA014103), and the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory (No. ZHD201302).

  12. Development of the control circuits for the TID-CCD stereo camera of the Chang'E-2 satellite based on FPGAs

    Science.gov (United States)

    Duan, Yong-Qiang; Gao, Wei; Qiao, Wei-Dong; Wen, De-Sheng; Zhao, Bao-Chang

    2013-09-01

    The TDI-CCD Stereo Camera is the optical sensor on the Chang'E-2 (CE-2) satellite created for the Chinese Lunar Exploration Program. The camera was designed to acquire three-dimensional stereoscopic images of the lunar surface based upon three-line array photogrammetric theory. The primary objective of the camera is, (1) to obtain about 1-m pixel spatial resolution images of the preparative landing location from an ellipse orbit at an altitude of ~15km, and (2) to obtain about 7-m pixel spatial resolution global images of the Moon from a circular orbit at an altitude of ~100km. The focal plane of the camera is comprised of two TDI-CCDs. The control circuits of the camera are designed based on two SRAM-type FPGAs, XQR2V3000-4CG717. In this paper, a variable frequency control and multi-tap data readout technology for the TDI-CCD is presented, which is able to change the data processing capabilities according to the different orbit mode for the TDI-CCD stereo camera. By this way, the data rate of the camera is extremely reduced from 100Mbps to 25Mbps at high orbit mode, which is benefit to raise the reliability of the image transfer. The results of onboard flight validate that the proposed methodology is reasonable and reliable.

  13. CCD camera automatic calibration technology and ellipse recognition algorithm

    Institute of Scientific and Technical Information of China (English)

    Changku Sun; Xiaodong Zhang; Yunxia Qu

    2005-01-01

    A novel two-dimensional (2D) pattern used in camera calibration is presented. With one feature circle located at the center, an array of circles is photo-etched on this pattern. An ellipse recognition algorithm is proposed to implement the acquisition of interest calibration points without human intervention. According to the circle arrangement of the pattern, the relation between three-dimensional (3D) and 2D coordinates of these points can be established automatically and accurately. These calibration points are computed for intrinsic parameters calibration of charge-coupled device (CCD) camera with Tsai method. A series of experiments have shown that the algorithm is robust and reliable with the calibration error less than 0.4 pixel. This new calibration pattern and ellipse recognition algorithm can be widely used in computer vision.

  14. CCD $UBV(RI)_{C}$ Photometry of Twenty Open Clusters

    CERN Document Server

    Oralhan, Inci Akkaya; Schuster, William J; Michel, Raúl; Chavarría, Carlos

    2014-01-01

    Fundamental astrophysical parameters have been derived for 20 open clusters (O\\!Cs) using CCD~$U\\!BV\\!(RI)_C$ photometric data observed with the 84~cm telescope at the San Pedro M\\'artir National Astronomical Observatory, M\\'exico. The interstellar reddenings, metallicities, distances, and ages have been compared to the literature values. Significant differences are usually due to the usage of diverse empirical calibrations and differing assumptions, such as concerning cluster metallicity, as well as distinct isochrones which correspond to differing element-abundance ratios, internal stellar physics, and photometric systems. Different interstellar reddenings, as well as varying reduction and cluster-membership techniques, are also responsible for these kinds of systematic differences and errors. The morphological ages, which are derived from the morphological indices ($\\delta V$ and $\\delta 1$) in the CM diagrams, are in good agreement with the isochrone ages of 12 O\\!Cs, those with good red clump (RC) and re...

  15. CCD based beam loss monitor for ion accelerators

    Science.gov (United States)

    Belousov, A.; Mustafin, E.; Ensinger, W.

    2014-04-01

    Beam loss monitoring is an important aspect of proper accelerator functioning. There is a variety of existing solutions, but each has its own disadvantages, e.g. unsuitable dynamic range or time resolution, high cost, or short lifetime. Therefore, new options are looked for. This paper shows a method of application of a charge-coupled device (CCD) video camera as a beam loss monitor (BLM) for ion beam accelerators. The system was tested with a 500 MeV/u N+7 ion beam interacting with an aluminum target. The algorithms of camera signal processing with LabView based code and beam loss measurement are explained. Limits of applicability of this monitor system are discussed.

  16. Electromagnetic Compatibility Assessment of CCD Detector Acquisition Chains not Synchronized

    Science.gov (United States)

    Nicoletto, M.; Boschetti, D.; Ciancetta, E.; Maiorano, E.; Stagnaro, L.

    2016-05-01

    Euclid is a space observatory managed by the European Space Agency; it is the second medium class mission (see Figure 1) in the frame of Cosmic Vision 2015-2025 program.In the frame of this project, the electromagnetic interference between two different and not synchronized Charge Coupled Device (CCD) (see Figure 2) acquisition chains has been evaluated. The key parameter used for this assessment is the electromagnetic noise induced on each other. Taking into account the specificity of the issue, radiation coupling at relative low frequency and in near field conditions, classical approach based on simulations and testing on qualification model cannot be directly applied. Based on that, it has been decided to investigate the issue by test in an incremental way.

  17. Optimal CCD readout by digital correlated double sampling

    CERN Document Server

    Alessandri, Cristobal; Guzman, Dani; Passalacqua, Ignacio; Alvarez-Fontecilla, Enrique; Guarini, Marcelo

    2015-01-01

    Digital correlated double sampling (DCDS), a readout technique for charge-coupled devices (CCD), is gaining popularity in astronomical applications. By using an oversampling ADC and a digital filter, a DCDS system can achieve a better performance than traditional analogue readout techniques at the expense of a more complex system analysis. Several attempts to analyse and optimize a DCDS system have been reported, but most of the work presented in the literature has been experimental. Some approximate analytical tools have been presented for independent parameters of the system, but the overall performance and trade-offs have not been yet modelled. Furthermore, there is disagreement among experimental results that cannot be explained by the analytical tools available. In this work, a theoretical analysis of a generic DCDS readout system is presented, including key aspects such as the signal conditioning stage, the ADC resolution, the sampling frequency and the digital filter implementation. By using a time-dom...

  18. Measuring the Flatness of Focal Plane for Very Large Mosaic CCD Camera

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Jiangang; Estrada, Juan; Cease, Herman; Diehl, H.Thomas; Flaugher, Brenna L.; Kubik, Donna; Kuk, Keivin; Kuropatkine, Nickolai; Lin, Huan; Montes, Jorge; Scarpine, Vic; /Fermilab

    2010-06-08

    Large mosaic multiCCD camera is the key instrument for modern digital sky survey. DECam is an extremely red sensitive 520 Megapixel camera designed for the incoming Dark Energy Survey (DES). It is consist of sixty two 4k x 2k and twelve 2k x 2k 250-micron thick fully-depleted CCDs, with a focal plane of 44 cm in diameter and a field of view of 2.2 square degree. It will be attached to the Blanco 4-meter telescope at CTIO. The DES will cover 5000 square-degrees of the southern galactic cap in 5 color bands (g, r, i, z, Y) in 5 years starting from 2011. To achieve the science goal of constraining the Dark Energy evolution, stringent requirements are laid down for the design of DECam. Among them, the flatness of the focal plane needs to be controlled within a 60-micron envelope in order to achieve the specified PSF variation limit. It is very challenging to measure the flatness of the focal plane to such precision when it is placed in a high vacuum dewar at 173 K. We developed two image based techniques to measure the flatness of the focal plane. By imaging a regular grid of dots on the focal plane, the CCD offset along the optical axis is converted to the variation the grid spacings at different positions on the focal plane. After extracting the patterns and comparing the change in spacings, we can measure the flatness to high precision. In method 1, the regular dots are kept in high sub micron precision and cover the whole focal plane. In method 2, no high precision for the grid is required. Instead, we use a precise XY stage moves the pattern across the whole focal plane and comparing the variations of the spacing when it is imaged by different CCDs. Simulation and real measurements show that the two methods work very well for our purpose, and are in good agreement with the direct optical measurements.

  19. Study of Distortions in Statistics of Counts in CCD Observations using the Fano Factor

    CERN Document Server

    Afanasieva, I V

    2016-01-01

    Factors distorting the statistics of photocounts when acquiring objects with low fluxes were considered here. Measurements of the Fano factor for existing CCD systems were conducted. The study allows one to conclude on the quality of the CCD video signal processing channel. The optimal strategy for faint object observations was suggested.

  20. 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.

  1. Multiplexed Oversampling Digitizer in 65 nm CMOS for Column-Parallel CCD Readout

    Energy Technology Data Exchange (ETDEWEB)

    Grace, Carl; Walder, Jean-Pierre; von der Lippe, Henrik

    2012-04-10

    A digitizer designed to read out column-parallel charge-coupled devices (CCDs) used for high-speed X-ray imaging is presented. The digitizer is included as part of the High-Speed Image Preprocessor with Oversampling (HIPPO) integrated circuit. The digitizer module comprises a multiplexed, oversampling, 12-bit, 80 MS/s pipelined Analog-to-Digital Converter (ADC) and a bank of four fast-settling sample-and-hold amplifiers to instrument four analog channels. The ADC multiplexes and oversamples to reduce its area to allow integration that is pitch-matched to the columns of the CCD. Novel design techniques are used to enable oversampling and multiplexing with a reduced power penalty. The ADC exhibits 188 ?V-rms noise which is less than 1 LSB at a 12-bit level. The prototype is implemented in a commercially available 65 nm CMOS process. The digitizer will lead to a proof-of-principle 2D 10 Gigapixel/s X-ray detector.

  2. Optical characterization of the SOFIA telescope using fast EM-CCD cameras

    Science.gov (United States)

    Pfüller, Enrico; Wolf, Jürgen; Hall, Helen; Röser, Hans-Peter

    2012-09-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) has recently demonstrated its scientific capabilities in a first series of astronomical observing flights. In parallel, special measurements and engineering flights were conducted aiming at the characterization and the commissioning of the telescope and the complete airborne observatory. To support the characterization measurements, two commercial Andor iXon EM-CCD cameras have been used, a DU-888 dubbed Fast Diagnostic Camera (FDC) running at frame rates up to about 400 fps, and a DU-860 as a Super Fast Diagnostic Camera (SFDC) providing 2000 fps. Both cameras have been mounted to the telescope’s Focal Plane Imager (FPI) flange in lieu of the standard FPI tracking camera. Their fast image sequences have been used to analyze and to improve the telescope’s pointing stability, especially to help tuning active mass dampers that suppress eigenfrequencies in the telescope system, to characterize and to optimize the chopping secondary mirror and to investigate the structure and behavior of the shear layer that forms over the open telescope cavity in flight. In June 2011, a collaboration between the HIPO science instrument team, the MIT’s stellar occultation group and the FDC team, led to the first SOFIA observation of a stellar occultation by the dwarf planet Pluto over the Pacific.

  3. 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.

  4. Design of operation parameters of a high speed TDI CCD line scan camera

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper analyzes the operation parameters of the time delay and integration (TDI) line scan CCD camera, such as resolution, line rate, clock frequency, etc. and their mathematical relationship is deduced. By analyzing and calculating these parameters, the working clocks of the TDI CCD line scan camera are designed,which guarantees the synchronization of the line scan rate and the camera movement speed. The IL - E2 TDI CCD of DALSA Co. is used as the sensor of the camera in the paper. The working clock generator used for the TDI CCD sensor is realized by using the programmable logic device (PLD). The experimental results show that the working clock generator circuit satisfies the requirement of high speed TDI CCD line scan camera.

  5. Methods in Astronomical Image Processing

    Science.gov (United States)

    Jörsäter, S.

    A Brief Introductory Note History of Astronomical Imaging Astronomical Image Data Images in Various Formats Digitized Image Data Digital Image Data Philosophy of Astronomical Image Processing Properties of Digital Astronomical Images Human Image Processing Astronomical vs. Computer Science Image Processing Basic Tools of Astronomical Image Processing Display Applications Calibration of Intensity Scales Calibration of Length Scales Image Re-shaping Feature Enhancement Noise Suppression Noise and Error Analysis Image Processing Packages: Design of AIPS and MIDAS AIPS MIDAS Reduction of CCD Data Bias Subtraction Clipping Preflash Subtraction Dark Subtraction Flat Fielding Sky Subtraction Extinction Correction Deconvolution Methods Rebinning/Combining Summary and Prospects for the Future

  6. Images

    Data.gov (United States)

    National Aeronautics and Space Administration — Images for the website main pages and all configurations. The upload and access points for the other images are: Website Template RSW images BSCW Images HIRENASD...

  7. Super-resolution imaging based on virtual Airy spot

    Science.gov (United States)

    Liu, Zhengjun; Guo, Cheng; Cui, Junning; Wu, Qun

    2015-02-01

    Based on the theoretical model of Airy spot, a method is proposed for improving the imaging speed from confocal microscopy. The virtual Airy spot is designed for obtaining the pattern on CCD at detecting plane. Here the size of the spot is determined by the parameters of imaging system and intensity data from point detector, which can receive data quicker than CCD. The treatment can improve the speed of imaging comparing with CCD at receiving end. The virtual structured detection is also utilized for generating high-resolution image. Some numerical simulation results are provided for demonstrating the validity of the proposed method.

  8. Salt marsh mapping based on a short-time interval NDVI time-series from HJ-1 CCD imagery

    Science.gov (United States)

    SUN, C.

    2015-12-01

    Salt marshes are regard as one of the most dynamic and valuable ecosystems in coastal zone. It is crucial to obtain accurate information on the species composition and spatial distribution of salt marshes in time since they are experiencing tremendous replacement and disappearance. However, discriminating various types of salt marshes is a rather difficult task because of the strong spectral similarities. In previous studies, salt marsh mappings were mainly focused on high-spatial and hyperspectral resolution imageries combined with auxiliary information but this method can hardly extend to a large region. With high temporal and moderate spatial resolutions, Chinese HJ-1 CCD imagery would not only allow monitoring phenological changes of salt marsh vegetation in short-time intervals, but also cover large areas of salt marshes. Taking the middle coast of Jiangsu (east China) as an example, our study first constructed a monthly NDVI time-series to classify various types of salt marshes. Then, we tested the idea of compressed time-series continuously to broaden the applicability and portability of this particular approach. The results showed that (1) the overall accuracy of salt marsh mapping based on the monthly NDVI time-series reached 90.3%, which increased approximately 16.0% in contrast with a single-phase classification strategy; (2) a compressed time-series, including NDVI from six key months (April, June to September, and November) demonstrated very little decline (2.3%) in overall accuracy but led to obvious improvements in unstable regions; (3) Spartina alterniflora identification could be achieved with only a scene NDVI image from November, which could provide an effective way to regularly monitor its distribution. Besides, by comparing the calibrated performance between HJ-1 CCD and other sensors (i.e., Landsat TM/ETM+, OLI), we certified the reliability of HJ-1 CCD imagery, which is expected to pave the way for laws expansibility from this imagery.

  9. LiCHy: The CAF’s LiDAR, CCD and Hyperspectral Integrated Airborne Observation System

    Directory of Open Access Journals (Sweden)

    Yong Pang

    2016-05-01

    Full Text Available We describe the design, implementation and performance of a novel airborne system, which integrates commercial waveform LiDAR, CCD (Charge-Coupled Device camera and hyperspectral sensors into a common platform system. CAF’s (The Chinese Academy of Forestry LiCHy (LiDAR, CCD and Hyperspectral Airborne Observation System is a unique system that permits simultaneous measurements of vegetation vertical structure, horizontal pattern, and foliar spectra from different view angles at very high spatial resolution (~1 m on a wide range of airborne platforms. The horizontal geo-location accuracy of LiDAR and CCD is about 0.5 m, with LiDAR vertical resolution and accuracy 0.15 m and 0.3 m, respectively. The geo-location accuracy of hyperspectral image is within 2 pixels for nadir view observations and 5–7 pixels for large off-nadir observations of 55° with multi-angle modular when comparing to LiDAR product. The complementary nature of LiCHy’s sensors makes it an effective and comprehensive system for forest inventory, change detection, biodiversity monitoring, carbon accounting and ecosystem service evaluation. The LiCHy system has acquired more than 8000 km2 of data over typical forests across China. These data are being used to investigate potential LiDAR and optical remote sensing applications in forest management, forest carbon accounting, biodiversity evaluation, and to aid in the development of similar satellite configurations. This paper describes the integration of the LiCHy system, the instrument performance and data processing workflow. We also demonstrate LiCHy’s data characteristics, current coverage, and potential vegetation applications.

  10. Wide Field CCD photometry around nine open clusters

    CERN Document Server

    Sharma, S; Ogura, K; Mito, H; Tarusawa, K; Sagar, R

    2006-01-01

    In this paper we study the evolution of core and corona of nine open clusters using the projected radial density profiles derived from homogeneous CCD photometric data obtained through the 105-cm Kiso Schmidt telescope. The age and galactocentric distance of the target clusters varies from 16 Myr to 2000 Myr and 9 kpcto 10.8 kpc respectively. Barring Be 62, which is young open cluster, other clusters show a uniform reddening across the cluster region. The reddening in Be 62varies from $E(B-V)_{min}$= 0.70 mag to $E(B-V)_{max}$= 1.00 mag. The corona of six of the clusters in the present sample is found to be elongated, however on the basis of the present sample it is not possible to establish any correlation between the age and shape of the core. The elongated core in the case of young cluster Be 62 may reflect the initial conditions in the parental molecular cloud. The other results of the present study are (i) Core radius `$r_c$' and corona size $`r_{cn}$'/cluster radius $`r_{cl}$' are linearly correlated. (...

  11. CCD photometry of distant open clusters; 2, NGC 6791

    CERN Document Server

    Kaluzny, J; Kaluzny, Janusz; Rucinski, Slavek

    1995-01-01

    Three new photometric CCD-based datasets are presented for NGC~6791. They consist of deep UBV photometry (to V_{lim} =24, B_{lim}=24, U_{lim} = 23) of the central parts of the cluster and of selected fields around it, and of relatively shallower UBVI photometry for the whole cluster (23' \\times 23'). The data have been used to discuss the reddening, metallicity and age ofNGC~6791, a cluster which is particularly important because of (1)~its most-advanced age among open clusters, (2)~metallicity higher than solar and (3)~particularly large number of member stars. We discovered two new very blue stars increasing the total of sdB objects in the cluster to ten. They are located in a very narrow range magnitudes V=17.7 \\pm 0.5; their blue colors strongly constrain our determination of the reddening of the cluster to E(B-V)=0.17 \\pm 0.01. We detected no other blue stars except a population of faint objects with V \\approx 22 in the center of the cluster. We have used the new theoretical isochrones in a differential ...

  12. CCD UBV(RI)C photometry of twenty open clusters

    Science.gov (United States)

    Oralhan, İnci Akkaya; Karataş, Yüksel; Schuster, William J.; Michel, Raúl; Chavarría, Carlos

    2015-01-01

    Fundamental astrophysical parameters have been derived for 20 open clusters (OCs) using CCD UBV(RI)C photometric data observed with the 84 cm telescope at the San Pedro Mártir National Astronomical Observatory, México. The interstellar reddenings, metallicities, distances, and ages have been compared to the literature values. Significant differences are usually due to the usage of diverse empirical calibrations and differing assumptions, such as concerning cluster metallicity, as well as distinct isochrones which correspond to differing element-abundance ratios, internal stellar physics, and photometric systems. Different interstellar reddenings, as well as varying reduction and cluster-membership techniques, are also responsible for these kinds of systematic differences and errors. The morphological ages, which are derived from the morphological indices (δV and δ1) in the CM diagrams, are in good agreement with the isochrone ages of 12 OCs, those with good red clump (RC) and red giant (RG) star candidates. No metal abundance gradient is detected for the range 6.82⩽RGC⩽15.37 kpc, nor any correlation between the cluster ages and metal abundances for these 20 OCs. Young, metal-poor OCs, observed here in the third Galactic quadrant, may be associated with stellar over-densities, such as that in Canis Major (Martin et al.) and the Monoceros Ring (Newberg et al.), or signatures of past accretion events, as discussed by Yong et al. and Carraro et al.

  13. Upgrade of ESO's FIERA CCD Controller and PULPO Subsystem

    Science.gov (United States)

    Reyes-Moreno, J.; Geimer, C.; Balestra, A.; Haddad, N.

    An overview of FIERA is presented with emphasis on its recent upgrade to PCI. The PCI board hosts two DSPs, one for real time control of the camera and another for on-the-fly processing of the incoming video data. In addition, the board is able to make DMA transfers, to synchronize to other boards alike, to be synchronized by a TIM bus and to control PULPO via RS232. The design is based on the IOP480 chip from PLX, for which we have developed a device driver for both Solaris and Linux. One computer is able to host more than one board and therefore can control an array of FIERA detector electronics. PULPO is a multifunctional subsystem widely used at ESO for the housekeeping of CCD cryostat heads and for shutter control. The upgrade of PULPO is based on an embedded PC running Linux. The upgraded PULPO is able to handle 29 temperature sensors, control 8 heaters and one shutter, read out one vacuum sensor and log any combination of parameters.

  14. Perfecting the Photometric Calibration of the ACS CCD Cameras

    CERN Document Server

    Bohlin, Ralph C

    2016-01-01

    Newly acquired data and improved data reduction algorithms mandate a fresh look at the absolute flux calibration of the CCD cameras on the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The goals are to achieve a 1\\% accuracy and to make this calibration more accessible to the HST guest investigator. Absolute fluxes from the CALSPEC\\footnote{http://www.stsci.edu/hst/observatory/crds/calspec.html} database for three primary hot 30,000--60,000K WDs define the sensitivity calibrations for the WFC and HRC filters. The external uncertainty for the absolute flux is $\\sim$1\\%, while the internal consistency of the sensitivities in the broadband ACS filters is $\\sim$0.3\\% among the three primary WD flux standards. For stars as cool as K type, the agreement with the CALSPEC standards is within 1\\% at the WFC1-1K subarray position, which achieves the 1\\% precision goal for the first time. After making a small adjustment to the filter bandpass for F814W, the 1\\% precision goal is achieved over the full ...

  15. 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.

  16. Eliminating "Hotspots" in Digital Image Processing

    Science.gov (United States)

    Salomon, P. M.

    1984-01-01

    Signals from defective picture elements rejected. Image processing program for use with charge-coupled device (CCD) or other mosaic imager augmented with algorithm that compensates for common type of electronic defect. Algorithm prevents false interpretation of "hotspots". Used for robotics, image enhancement, image analysis and digital television.

  17. Data Acquisition and Control System for High-Performance Large-Area CCD Systems

    CERN Document Server

    Afanasieva, I V

    2015-01-01

    Astronomical CCD systems based on second-generation DINACON controllers were developed at the SAO RAS Advanced Design Laboratory more than seven years ago and since then have been in constant operation at the 6-meter and Zeiss-1000 telescopes. Such systems use monolithic large-area CCDs. We describe the software developed for the control of a family of large-area CCD systems equipped with a DINACON-II controller. The software suite serves for acquisition, primary reduction, visualization, and storage of video data, and also for the control, setup, and diagnostics of the CCD system.

  18. Searching for bulk motions in the ICM of massive, merging clusters with Chandra CCD data

    CERN Document Server

    Liu, Ang; Tozzi, Paolo; Zhu, Zong-Hong

    2016-01-01

    We search for bulk motions in the Intra Cluster Medium (ICM) of massive clusters showing evidence of an ongoing or a recent major merger, with spatially resolved spectroscopy in {\\sl Chandra} CCD data. We identify a sample of 6 merging clusters with >150 ks {\\sl Chandra} exposure in the redshift range 0.1 1000$ km/s in the ICM of massive merging clusters at 0.1 < z < 0.3. Despite the CCD spectral resolution is not sufficient for a detailed analysis of the ICM dynamics, {\\sl Chandra} CCD data constitute a key diagnostic tool complementary to X-ray bolometers onboard future X-ray missions.

  19. Non-Metric CCD Camera Calibration Algorithm in a Digital Photogrammetry System

    Institute of Scientific and Technical Information of China (English)

    YANG Hua-chao; DENG Ka-zhong; ZHANG Shu-bi; GUO Guang-li; ZHOU Ming

    2006-01-01

    Camera calibration is a critical process in photogrammetry and a necessary step to acquire 3D information from a 2D image. In this paper, a flexible approach for CCD camera calibration using 2D direct linear transformation (DLT) and bundle adjustment is proposed. The proposed approach assumes that the camera interior orientation elements are known, and addresses a new closed form solution in planar object space based on homogenous coordinate representation and matrix factorization. Homogeneous coordinate representation offers a direct matrix correspondence between the parameters of the 2D DLT and the collinearity equation. The matrix factorization starts by recovering the elements of the rotation matrix and then solving for the camera position with the collinearity equation. Camera calibration with high precision is addressed by bundle adjustment using the initial values of the camera orientation elements. The results show that the calibration precision of principal point and focal length is about 0.2 and 0.3 pixels respectively, which can meet the requirements of close-range photogrammetry with high accuracy.

  20. Optical Readout of a Two Phase Liquid Argon TPC using CCD Camera and TGEMs

    CERN Document Server

    Mavrokoridis, K; Carroll, J; Lazos, M; McCormick, K J; Smith, N A; Touramanis, C; Walker, J

    2014-01-01

    This paper presents a preliminary study into the use of CCDs to image secondary scintillation light generated by Thick Gas Electron Multipliers (TGEMs) in a two phase LAr TPC. A Sony ICX285AL CCD chip was mounted above a double TGEM in the gas phase of a 40 litre two-phase LAr TPC with the majority of the camera electronics positioned externally via a feedthrough. An Am-241 source was mounted on a rotatable motion feedthrough allowing the positioning of the alpha source either inside or outside of the field cage. Developed for and incorporated into the TPC design was a novel high voltage feedthrough featuring LAr insulation. Furthermore, a range of webcams were tested for operation in cryogenics as an internal detector monitoring tool. Of the range of webcams tested the Microsoft HD-3000 (model no:1456) webcam was found to be superior in terms of noise and lowest operating temperature. In ambient temperature and atmospheric pressure 1 ppm pure argon gas, the TGEM gain was approximately 1000 and using a 1 msec...

  1. [Evaluation of four dark object atmospheric correction methods based on ZY-3 CCD data].

    Science.gov (United States)

    Guo, Hong; Gu, Xing-fa; Xie, Yong; Yu, Tao; Gao, Hai-liang; Wei, Xiang-qin; Liu, Qi-yue

    2014-08-01

    The present paper performed the evaluation of four dark-object subtraction(DOS) atmospheric correction methods based on 2012 Inner Mongolia experimental data The authors analyzed the impacts of key parameters of four DOS methods when they were applied to ZY-3 CCD data The results showed that (1) All four DOS methods have significant atmospheric correction effect at band 1, 2 and 3. But as for band 4, the atmospheric correction effect of DOS4 is the best while DOS2 is the worst; both DOS1 and DOS3 has no obvious atmospheric correction effect. (2) The relative error (RE) of DOS1 atmospheric correction method is larger than 10% at four bands; The atmospheric correction effect of DOS2 works the best at band 1(AE (absolute error)=0.0019 and RE=4.32%) and the worst error appears at band 4(AE=0.0464 and RE=19.12%); The RE of DOS3 is about 10% for all bands. (3) The AE of atmospheric correction results for DOS4 method is less than 0. 02 and the RE is less than 10% for all bands. Therefore, the DOS4 method provides the best accuracy of atmospheric correction results for ZY-3 image.

  2. Performance Characterization of the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) CCD Cameras

    Science.gov (United States)

    Joiner, Reyann; Kobayashi, Ken; Winebarger, Amy; Champey, Patrick

    2014-01-01

    The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a sounding rocket instrument currently being developed by NASA's Marshall Space Flight Center (MSFC), the National Astronomical Observatory of Japan (NAOJ), and other partners. The goal of this instrument is to observe and detect the Hanle effect in the scattered Lyman-Alpha UV (121.6nm) light emitted by the Sun's chromosphere. The polarized spectrum imaged by the CCD cameras will capture information about the local magnetic field, allowing for measurements of magnetic strength and structure. In order to make accurate measurements of this effect, the performance characteristics of the three on- board charge-coupled devices (CCDs) must meet certain requirements. These characteristics include: quantum efficiency, gain, dark current, read noise, and linearity. Each of these must meet predetermined requirements in order to achieve satisfactory performance for the mission. The cameras must be able to operate with a gain of 2.0+/- 0.5 e--/DN, a read noise level less than 25e-, a dark current level which is less than 10e-/pixel/s, and a residual non- linearity of less than 1%. Determining these characteristics involves performing a series of tests with each of the cameras in a high vacuum environment. Here we present the methods and results of each of these performance tests for the CLASP flight cameras.

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

    Science.gov (United States)

    Collins, Nick

    2009-01-01

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

  4. 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...... of this initial complex with ATP in the presence of GyrB and DNA slowly converts it to a second complex (beta), which has a lower rate of ATP hydrolysis and is unable to catalyse supercoiling. The efficiency of formation of this inactive complex is dependent on the concentrations of ATP and CcdB. We suggest...

  5. MISR Level 1A CCD Science data, all cameras V002

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the Reformatted Annotated Level 1A product for the CCD science data. The data numbers (DN) have been commuted from 12-bit numbers to 16-bit byte aligned...

  6. Residual images in charged-coupled device detectors

    Science.gov (United States)

    Rest, Armin; Mündermann, Lars; Widenhorn, Ralf; Bodegom, Erik; McGlinn, T. C.

    2002-05-01

    We present results of a systematic study of persistent, or residual, images that occur in charged-coupled device (CCD) detectors. A phenomenological model for these residual images, also known as "ghosting," is introduced. This model relates the excess dark current in a CCD after exposure to the number of filled impurity sites which is tested for various temperatures and exposure times. We experimentally derive values for the cross section, density, and characteristic energy of the impurity sites responsible for the residual images.

  7. A high-sensitivity EM-CCD camera for the open port telescope cavity of SOFIA

    Science.gov (United States)

    Wiedemann, Manuel; Wolf, Jürgen; McGrotty, Paul; Edwards, Chris; Krabbe, Alfred

    2016-08-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) has three target acquisition and tracking cameras. All three imagers originally used the same cameras, which did not meet the sensitivity requirements, due to low quantum efficiency and high dark current. The Focal Plane Imager (FPI) suffered the most from high dark current, since it operated in the aircraft cabin at room temperatures without active cooling. In early 2013 the FPI was upgraded with an iXon3 888 from Andor Techonolgy. Compared to the original cameras, the iXon3 has a factor five higher QE, thanks to its back-illuminated sensor, and orders of magnitude lower dark current, due to a thermo-electric cooler and "inverted mode operation." This leads to an increase in sensitivity of about five stellar magnitudes. The Wide Field Imager (WFI) and Fine Field Imager (FFI) shall now be upgraded with equally sensitive cameras. However, they are exposed to stratospheric conditions in flight (typical conditions: T≍-40° C, p≍ 0:1 atm) and there are no off-the-shelf CCD cameras with the performance of an iXon3, suited for these conditions. Therefore, Andor Technology and the Deutsches SOFIA Institut (DSI) are jointly developing and qualifying a camera for these conditions, based on the iXon3 888. These changes include replacement of electrical components with MIL-SPEC or industrial grade components and various system optimizations, a new data interface that allows the image data transmission over 30m of cable from the camera to the controller, a new power converter in the camera to generate all necessary operating voltages of the camera locally and a new housing that fulfills airworthiness requirements. A prototype of this camera has been built and tested in an environmental test chamber at temperatures down to T=-62° C and pressure equivalent to 50 000 ft altitude. In this paper, we will report about the development of the camera and present results from the environmental testing.

  8. Infrared upconversion hyperspectral imaging

    DEFF Research Database (Denmark)

    Kehlet, Louis Martinus; Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin

    2015-01-01

    In this Letter, hyperspectral imaging in the mid-IR spectral region is demonstrated based on nonlinear frequency upconversion and subsequent imaging using a standard Si-based CCD camera. A series of upconverted images are acquired with different phase match conditions for the nonlinear frequency...... conversion process. From this, a sequence of monochromatic images in the 3.2-3.4 mu m range is generated. The imaged object consists of a standard United States Air Force resolution target combined with a polystyrene film, resulting in the presence of both spatial and spectral information in the infrared...... image. (C) 2015 Optical Society of America...

  9. Scintillator-CCD camera system light output response to dosimetry parameters for proton beam range measurement

    Energy Technology Data Exchange (ETDEWEB)

    Daftari, Inder K., E-mail: idaftari@radonc.ucsf.edu [Department of Radiation Oncology, 1600 Divisadero Street, Suite H1031, University of California-San Francisco, San Francisco, CA 94143 (United States); Castaneda, Carlos M.; Essert, Timothy [Crocker Nuclear Laboratory,1 Shields Avenue, University of California-Davis, Davis, CA 95616 (United States); Phillips, Theodore L.; Mishra, Kavita K. [Department of Radiation Oncology, 1600 Divisadero Street, Suite H1031, University of California-San Francisco, San Francisco, CA 94143 (United States)

    2012-09-11

    The purpose of this study is to investigate the luminescence light output response in a plastic scintillator irradiated by a 67.5 MeV proton beam using various dosimetry parameters. The relationship of the visible scintillator light with the beam current or dose rate, aperture size and the thickness of water in the water-column was studied. The images captured on a CCD camera system were used to determine optimal dosimetry parameters for measuring the range of a clinical proton beam. The method was developed as a simple quality assurance tool to measure the range of the proton beam and compare it to (a) measurements using two segmented ionization chambers and water column between them, and (b) with an ionization chamber (IC-18) measurements in water. We used a block of plastic scintillator that measured 5 Multiplication-Sign 5 Multiplication-Sign 5 cm{sup 3} to record visible light generated by a 67.5 MeV proton beam. A high-definition digital video camera Moticam 2300 connected to a PC via USB 2.0 communication channel was used to record images of scintillation luminescence. The brightness of the visible light was measured while changing beam current and aperture size. The results were analyzed to obtain the range and were compared with the Bragg peak measurements with an ionization chamber. The luminescence light from the scintillator increased linearly with the increase of proton beam current. The light output also increased linearly with aperture size. The relationship between the proton range in the scintillator and the thickness of the water column showed good linearity with a precision of 0.33 mm (SD) in proton range measurement. For the 67.5 MeV proton beam utilized, the optimal parameters for scintillator light output response were found to be 15 nA (16 Gy/min) and an aperture size of 15 mm with image integration time of 100 ms. The Bragg peak depth brightness distribution was compared with the depth dose distribution from ionization chamber measurements

  10. Síntese, caracterização e estudos de interação de um análogo da antitoxina CcdA empregando fluorescência no estado estacionário Synthesis, characterization and interaction studies of an analog of CcdA antitoxin by steady state fluorescence

    Directory of Open Access Journals (Sweden)

    Camila Aparecida Cotrim

    2010-01-01

    Full Text Available Toxin-antitoxin (TA systems contribute to plasmid stability by a mechanism called post-segregational killing. The ccd was the first TA system to be discovered with CcdB being the toxin and CcdA the antitoxin. CcdA, an 8.3 kDa protein, interacts with CcdB (11.7 kDa, preventing the cytotoxic activity of CcdB on the DNA gyrase. As an approach to understanding this interaction, CcdA41, a polypeptide derived from CcdA, was synthesized by solid-phase methodology and its interaction with CcdB was analyzed by steady state fluorescence. CcdA41 formed a stable complex with CcdBET2, a peptide based on CcdB, the more recently described bacterial topoisomerase inhibitor.

  11. Spectrally Adaptable Compressive Sensing Imaging System

    Science.gov (United States)

    2014-05-01

    viewed by a Stingray F-033C CCD Color Camera. The desired bands are depicted in (g). The original desired bands are shown in (a). Reconstructed images...would be viewed by a Stingray F-033C CCD Color Camera. The desired bands are indicated in (e). The original desired bands are shown in (a). Reconstructed...times and the mean PSNR is estimated. The resulting spectral data cubes are shown as they would be viewed by a Stingray F-033C CCD Color Camera. Figure

  12. Space optical remote sensor image motion velocity vector computational modeling, error budget and synthesis

    Institute of Scientific and Technical Information of China (English)

    Jiaqi Wang; Ping Yu; Changxiang Yan; Jianyue Ren; Bin He

    2005-01-01

    @@ For space optical remote sensor (SORS) with either film or time delay and integrate charge coupled device (TDI-CCD) imaging, in order to achieve higher resolution it requires more accurate real-time image motion compensation.

  13. Research and Application of Toxin Protein CcdB in the Construction of Various Vectors%毒素蛋白CcdB在载体构建中的研究及应用

    Institute of Scientific and Technical Information of China (English)

    范凯荣; 覃石磊; 黄进波; 晁耐霞

    2014-01-01

    大肠杆菌毒素-抗毒素系统ccd(control of cell division or death system)编码的毒素蛋白CcdB使细胞内DNA促旋酶失活,杀伤宿主细胞,而抗毒素蛋白CcdA可以中和毒素CcdB使宿主存活.利用这个原理,CcdB可作为细菌转化时的筛选标记,在构建各种高效低背景载体上发挥重要作用.我们简要综述毒素蛋白CcdB的毒性原理及其在质粒载体构建中的广泛应用.

  14. Establishing Information Security Systems via Optical Imaging

    Science.gov (United States)

    2015-08-11

    Laser Object Computer Fig. 5. A schematic setup for the proposed method using holography: BSC, Beam splitter cube; CCD, Charge-coupled device. The...SLM Object~~~, ........ . . . . . . . . . . . . . . . . . Laser CCD DJ Fig. 9. A schematic for computational ghost imaging: BD, bucket detector...polarization. (c) Since the sophisticated optoelectronic devices and systems should be analyzed before the retrieval, any hostile hacker will need to

  15. Evaluation of the photoelectric performance parameters measurement for electron multiplying CCD

    Science.gov (United States)

    Fang, Jie; Zhang, Wenwen; Gao, Jin; Li, Chaowei; Chen, Qian; Gu, Guohua

    2016-10-01

    The measurement of the electron multiplying CCD(EMCCD) photoelectric performance parameters plays an important role in the development of the chip and imaging system. Measurement uncertainty is an important index to evaluate the quality of the measurement results. A measurement platform for EMCCD photoelectric performance parameters is set up. An EMCCD camera's photoelectric performance parameters are measured based on photon transfer technique and the uncertainty of the measurement results is analyzed. Based on the method of GUM, the influences of the integrating sphere light source stability, EMCCD camera electronics system stability, installation posture, stray light in dark environment, camera's digital resolution and measurement sampling on the measurement results are analyzed. Based on the theoretical model of different photoelectric performance parameters, the uncertainty sources are discussed. The combined standard uncertainty is determined by the type A uncertainty and the type B uncertainty. The uncertainty evaluation model is established for the measurement of EMCCD photoelectric performance parameters, including convert gain, readout noise, full well, signal to noise ratio and multiplication gain. The uncertainty of the measurement results is calculated by using the established model. At last, we get the following results: relative standard uncertainty of the convert gain is 0.637% (k = 1), relative standard uncertainty of the readout noise is 0.653% (k = 1), relative standard uncertainty of the full well is 2.384% (k = 1), relative standard uncertainty of the signal to noise ratio is 2.301% (k = 1) and relative standard uncertainty of the multiplication gain is 1.259% (k = 1). The above uncertainty results show that the measurement results of this paper are accurate and reliable.

  16. Image sensors for radiometric measurements in the ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Desa, B.A.E.

    The signal to noise (SNR) performance of selected linear array image sensors belonging to the CCD (charge coupled device), SSPDA (self scanning photodiode array), and PCD (plasma coupled device) families is analysed. Our purpose was to investigate...

  17. $\\mathtt{ComEst}$: a Completeness Estimator of Source Extraction on Astronomical Imaging

    CERN Document Server

    Chiu, I-Non; Liu, Jiayi

    2016-01-01

    The completeness of source detection is critical for analyzing the photometric and spatial properties of the population of interest observed by astronomical imaging. We present a software package $\\mathtt{ComEst}$, which calculates the completeness of source detection on charge-coupled device (CCD) images of astronomical observations, especially for the optical and near-infrared (NIR) imaging of galaxies and point sources. The completeness estimator $\\mathtt{ComEst}$ is designed for the source finder $\\mathtt{SExtractor}$ used on the CCD images saved in the Flexible Image Transport System (FITS) format. Specifically, $\\mathtt{ComEst}$ estimates the completeness of the source detection by deriving the detection rate of synthetic point sources and galaxies simulated on the observed CCD images. In order to capture any observational artifacts or noise properties while deriving the completeness, $\\mathtt{ComEst}$ directly carries out the detection of simulated sources on the observed images. Given an observed CCD ...

  18. CCD: Efficient Customized Content Dissemination in Distributed Publish/Subscribe

    Science.gov (United States)

    Jafarpour, Hojjat; Hore, Bijit; Mehrotra, Sharad; Venkatasubramanian, Nalini

    In this paper, we propose a new content-based publish/subscribe (pub/sub) framework that enables a pub/sub system to accommodate richer content formats including multimedia publications with image and video content. The pub/sub system besides being responsible for matching and routing the published content, is also responsible for converting the content into the suitable (target) format for each subscriber. Content conversion is achieved through a set of content adaptation operators (e.g., image transcoder, document translator, etc.) at different nodes in the overlay network. We study algorithms for placement of such operators in the pub/sub broker overlay in order to minimize the communication and computation resource consumption. Our experimental results show that careful placement of these operators in pub/sub overlay network can lead to significant cost reduction.

  19. Parallel optical coherence tomography using a CCD camera

    Institute of Scientific and Technical Information of China (English)

    Junle Qu(屈军乐); Ravi S.Jonnal; Donald T. Miller

    2004-01-01

    Parallel optical coherence tomography is demonstrated using a 12-bit scientific-grade charge-coupled device array.A superluminescent diode in combination with a free-space Michelson interferometer was employed to achieve 10-μm axial resolution and 1.1-μm transverse resolution on a 902×575 μm2 field of view.We imaged a test mirror and bovine retinal tissue using a four-step phase shift method.

  20. Signal Detection of Multi-Channel Capillary Electrophoresis Chip Based on CCD

    Science.gov (United States)

    Lv, Hongfeng; Yan, Weiping; Yang, Xiaobo; Li, Jiechao; Zhu, Jieying

    2012-12-01

    A kind of multi-channel capillary electrophoresis (CE) chip signal detection system based on CCD was developed. The output signal of the CCD sensor was processed by a series of pre-processing circuits and ADC, and then it was collected by the Field Programmable Gate Array (FPGA) chip which communicated with a host computer. The core in FPGA was designed to control the signal flow of the CCD and transfer the data to PC based on a Nios II embedded soft-processor. The application of PC was used to store the data and demonstrate the curve. The measurement of the fluorescent signals for different concentration Rhodamine B dyes is presented and the comparison with other detection systems is also discussed.

  1. Super CCD EXR技术运用到长焦机型

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    相比普通的影像传感器,Super CCD EXR光线信号的采集效率得到了大幅提升,从而有效地提升了成像质量,特别是明显提高了高感光度下的性噪比,其性能在首款采用Super CCD EXR的富士FinePix F200EXR相机上得到了充分证明。富士FinePix F75EXR和富士FinePix S205EXR因为采用了富士公司当前的看家法宝——Super CCD EXR技术,所以受到广泛的关注。

  2. Development of a fast readout system of an X-ray CCD

    CERN Document Server

    Awaki, H; Koyama, K; Tomida, H; Tsuru, T

    1999-01-01

    In the course of developing a fast readout system of an X-ray CCD camera with low noise using HPK-CCD, we have succeeded in making a clock generator to read data from a CCD with the speed of 2 Mpixel/s. This generator is fabricated from commercially available products in order to simplify the manufacturing procedure. To determine the noise of the system, we are evaluating the noise from each part which conceivably contributes. It is known that the readout noise depends on the clock speed. Thus, to begin with, we measured the dependency of the system noise from the ADC in the data acquisition system on its clock speed.

  3. Long-term aldosterone treatment induces decreased apical but increased basolateral expression of AQP2 in CCD of rat kidney

    DEFF Research Database (Denmark)

    de Seigneux, Sophie; Nielsen, Jakob; Olesen, Emma T B;

    2007-01-01

    of hypokalemia in aldosterone-treated rats, we studied dietary-induced hypokalemia in rats, which also reduced apical AQP2 expression in the CCD but did not induce any increase in basolateral AQP2 expression in the CCD as observed with aldosterone treatment. The aldosterone-induced basolateral AQP2 expression...... in the CCD was thus independent of hypokalemia but was dependent on the presence of sodium and aldosterone. This redistribution was clearly blocked by mineralocorticoid receptor blockade. The increased basolateral expression of AQP2 induced by aldosterone may play a significant role in water metabolism...... in conditions with increased sodium reabsorption in the CCD....

  4. Design of the driving system for visible near-infrared spatial programmable push-broom remote CCD sensor

    Science.gov (United States)

    Xu, Zhipeng; Wei, Jun; Zhou, Qianting; Weng, Dongshan; Li, Jianwei

    2010-11-01

    VNIR multi-spectral image sensor has wide applications in remote sensing and imaging spectroscopy. An image spectrometer of a spatial remote programmable push-broom sensing satellite requires visible near infrared band ranges from 0.4μm to 1.04μm which is one of the most important bands in remote sensing. This paper introduces a method of design the driving system for 1024x1024 VNIR CCD sensor for programmable push-broom remote sensing. The digital driving signal is generated by the FPGA device. There are seven modules in the FPGA program and all the modules are coded by VHDL. The driving system have five mainly functions: drive the sensor as the demand of timing schedule, control the AD convert device to work, get the parameter via RS232 from control platform, process the data input from the AD device, output the processed data to PCI sample card to display in computer end. All the modules above succeed working on FPGA device APA600. This paper also introduced several important keys when designing the driving system including module synchronization, critical path optimization.

  5. Imaging ellipsometer with large field-of-view

    Science.gov (United States)

    Gu, Liyuan; Zeng, Aijun; Hu, Shiyu; Yuan, Qiao; Cheng, Weilin; Zhang, Shanhua; Hu, Guohang; He, Hongbo; Huang, Huijie

    2016-11-01

    A polarizer-compensator-sample-analyzer (PCSA) imaging ellipsometer with large field of view is presented. The sample is imaged on a CCD sensor by a telecentric imaging system and its tilt is monitored by an optical autocollimator. The sample, the telecentric imaging system and the CCD sensor satisfy the Scheimpflug condition. In measurement, the light extinction measurement method and the four quadrants average method are used to improve the accuracy. In experiments, a chromium thin film sample is measured by the imaging ellipsometer and a spectroscopic ellipsometer. The measurement results by two ellipsometers are consistent. The usefulness of the imaging ellipsometer is verified.

  6. Fabry-Perot CCD annular-summing spectroscopy: study and implementation for aeronomy applications.

    Science.gov (United States)

    Coakley, M M; Roesler, F L; Reynolds, R J; Nossal, S

    1996-11-20

    The technique of Fabry-Perot CCD annular-summing spectroscopy, with particular emphasis on applications in aeronomy, is discussed. Parameter choices for optimizing performance by the use of a standard format CCD array are detailed. Spectral calibration methods, techniques for determining the ring pattern center, and effects imposed by limited radial resolution caused by superpixel size, variable by on-chip binning, are demonstrated. The technique is carefully evaluated experimentally relative to the conventional scanning Fabry-Perot that uses a photomultiplier detector. We evaluate three extreme examples typical of aeronomical spectroscopy using calculated signal-to-noise ratios. Predicted sensitivity gains of 10-30 are typical. Of the cases considered, the largest savings in integration time are estimated for the day sky thermospheric O(1)D case, in which the bright sky background dominates the CCD read noise. For profile measurements of faint night sky emission lines, such as exospheric hydrogen Balmer-α, long integration times are required to achieve useful signal-to-noise ratios. In such cases, CCD read noise is largely overcome. Predictions of a factor of 10-15 savings in integration time for night sky Balmer-α observations are supported by field tests. Bright, isolated night sky lines such as thermospheric O(1)D require shorter integration times, and more modest gains dependent on signal level are predicted. For such cases it appears from estimate results that the Fabry-Perot CCD annular-summing technique with a conventional rectangular format may be outperformed by a factor of 2-5 by special CCD formats or by unusual optical coupling configurations that reduce the importance of read noise, based on the ideal transmission for any additional optics used in these configurations.

  7. Quantitative estimation of the shrub canopy LAI from atmosphere-corrected HJ-1 CCD data in Mu Us Sandland

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The leaf area index(LAI) is an important ecological parameter that characterizes the interface between vegetation canopy and the atmosphere.In addition,it is used by most process-oriented ecosystem models.This paper investigates the potential of HJ-1 CCD data combined with linear spectral unmixing and an inverted geometric-optical model for the retrieval of the shrub LAI in Wushen Banner of Inner Mongolia in the Mu Us Sandland.MODTRAN(Moderate Resolution Atmospheric Radiance and Transmittance Model) was used for atmospheric correction.Shrubland was extracted using the threshold of the normalized difference vegetation index,with which water bodies and farmland were separated,in combination with a vegetation map of the People’s Republic of China(1:1000000).Using the geometric-optical model,we derive the per-pixel reflectance as a simple linear combination of two components,namely sunlit background and other.The fraction of sunlit background is related to the shrub LAI.With the support of HJ-1 CCD data,we employ linear spectral unmixing to obtain the fraction of sunlit background in an atmospherically corrected HJ image.In addition,we use the measured shrub canopy structural parameters for shrub communities to invert the geometric-optical model and retrieve the pixel-based shrub LAI.In total,18 sample plots collected in Wushen Banner of Inner Mongolia are used for validation.The results of the shrub LAI show good agreement with R2 of 0.817 and a root-mean-squared error of 0.173.

  8. Sensitivity of linear CCD array based film scanners used for film dosimetry.

    Science.gov (United States)

    Devic, Slobodan; Wang, Yi-Zhen; Tomic, Nada; Podgorsak, Ervin B

    2006-11-01

    Film dosimetry is commonly performed by using linear CCD array transmission optical densitometers. However, these devices suffer from a variation in response along the detector array. If not properly corrected for, this nonuniformity may lead to significant overestimations of the measured dose as one approaches regions close to the edges of the scanning region. In this note, we present measurements of the spatial response of an AGFA Arcus II document scanner used for radiochromic film dosimetry. Results and methods presented in this work can be generalized to other CCD based transmission scanners used for film dosimetry employing either radiochromic or radiographic films.

  9. 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.

  10. Characteristics and Performance of the CCD Photometric System at Lulin Observatory

    Institute of Scientific and Technical Information of China (English)

    Daisuke Kinoshita; Chin-Wei Chen; Hung-Chin Lin; Zhong-Yi Lin; Kui-Yun Huang; Yung-Shin Chang; Wen-Ping Chen

    2005-01-01

    The Lulin One-meter Telescope at Lulin Observatory in Taiwan started open-use observations in J anuary 2003. In order to evaluate the performance of the CCD photometric system, the characteristics and quality of the site, we obtained data of photometric standards as well as calibration data from February to November 2004. We report here the results of our analysis including the gain,readout noise, dark current and linearity of the CCD camera, and transformation coefficients, total throughputs, night sky brightnesses and limiting magnitudes for UBVRI bands.

  11. Engineering Study on the CCD-based Measurement of Pulse Laser far-field Divergence Angle%基于CCD的脉冲激光器远场发散角工程化研究

    Institute of Scientific and Technical Information of China (English)

    邢勇; 邢冀川; 宋艳

    2011-01-01

    简述了激光光束的基本参数及特性,并介绍了采用CCD进行激光发散角测量的基本原理和装置.用CCD测量光斑可以及时获得光斑的二维扫描结果.实际工程应用时常采用CCD来测量激光远场发散角.进一步介绍了使用CCD摄像法进行发散角测量所采用的系统软件设计,首次提出了采用图像处理的方法来捕捉脉冲激光光斑.%This paper demonstrated the basic parameters and characteristics of laser beam, and introduced the basic principles and the devices used in the CCD laser divergence angle measurement method. Using CCD to measure the beam spot can gain the two-dimensional scanned result in a real-time manager. As a result, CCD was always used to measure Far-field divergence angle of the laser beam in the real engineering applications. The paper also made a further introduction of software design in the measuring system using CCD camera method. Finally, it is the first time that by the image-processing method to acquire pulse laser spot is introduced.

  12. Radiation damage of the PCO Pixelfly VGA CCD camera of the BES system on KSTAR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Náfrádi, Gábor, E-mail: nafradi@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Kovácsik, Ákos, E-mail: kovacsik.akos@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Pór, Gábor, E-mail: por@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Lampert, Máté, E-mail: lampert.mate@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary); Un Nam, Yong, E-mail: yunam@nfri.re.kr [NFRI, 169-148 Gwahak-Ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of); Zoletnik, Sándor, E-mail: zoletnik.sandor@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary)

    2015-01-11

    A PCO Pixelfly VGA CCD camera which is part a of the Beam Emission Spectroscopy (BES) diagnostic system of the Korea Superconducting Tokamak Advanced Research (KSTAR) used for spatial calibrations, suffered from serious radiation damage, white pixel defects have been generated in it. The main goal of this work was to identify the origin of the radiation damage and to give solutions to avoid it. Monte Carlo N-Particle eXtended (MCNPX) model was built using Monte Carlo Modeling Interface Program (MCAM) and calculations were carried out to predict the neutron and gamma-ray fields in the camera position. Besides the MCNPX calculations pure gamma-ray irradiations of the CCD camera were carried out in the Training Reactor of BME. Before, during and after the irradiations numerous frames were taken with the camera with 5 s long exposure times. The evaluation of these frames showed that with the applied high gamma-ray dose (1.7 Gy) and dose rate levels (up to 2 Gy/h) the number of the white pixels did not increase. We have found that the origin of the white pixel generation was the neutron-induced thermal hopping of the electrons which means that in the future only neutron shielding is necessary around the CCD camera. Another solution could be to replace the CCD camera with a more radiation tolerant one for example with a suitable CMOS camera or apply both solutions simultaneously.

  13. Radiation damage of the PCO Pixelfly VGA CCD camera of the BES system on KSTAR tokamak

    Science.gov (United States)

    Náfrádi, Gábor; Kovácsik, Ákos; Pór, Gábor; Lampert, Máté; Un Nam, Yong; Zoletnik, Sándor

    2015-01-01

    A PCO Pixelfly VGA CCD camera which is part a of the Beam Emission Spectroscopy (BES) diagnostic system of the Korea Superconducting Tokamak Advanced Research (KSTAR) used for spatial calibrations, suffered from serious radiation damage, white pixel defects have been generated in it. The main goal of this work was to identify the origin of the radiation damage and to give solutions to avoid it. Monte Carlo N-Particle eXtended (MCNPX) model was built using Monte Carlo Modeling Interface Program (MCAM) and calculations were carried out to predict the neutron and gamma-ray fields in the camera position. Besides the MCNPX calculations pure gamma-ray irradiations of the CCD camera were carried out in the Training Reactor of BME. Before, during and after the irradiations numerous frames were taken with the camera with 5 s long exposure times. The evaluation of these frames showed that with the applied high gamma-ray dose (1.7 Gy) and dose rate levels (up to 2 Gy/h) the number of the white pixels did not increase. We have found that the origin of the white pixel generation was the neutron-induced thermal hopping of the electrons which means that in the future only neutron shielding is necessary around the CCD camera. Another solution could be to replace the CCD camera with a more radiation tolerant one for example with a suitable CMOS camera or apply both solutions simultaneously.

  14. Results of 194 Double Stars Measurements from Astrometric CCD Observations at the Nikolaev Observatory (Ukraine)

    Science.gov (United States)

    Bodryagin, Daniil; Bondarchuk, Larisa; Maigurova, Nadiia

    2016-04-01

    This paper presents the results of double stars measurements from CCD observations at the 50-cm telescope of the Nikolaev Observatory. The accurate positions at current epoch and proper motions were obtained for 194 WDS pairs. The position angles and separations were measured using REDUC software. The measures standard errors were 0.05" for separations and 0.2° for position angles.

  15. The study of interferometer spectrometer based on DSP and linear CCD

    Science.gov (United States)

    Kang, Hua; Peng, Yuexiang; Xu, Xinchen; Xing, Xiaoqiao

    2010-11-01

    In this paper, general theory of Fourier-transform spectrometer and polarization interferometer is presented. A new design is proposed for Fourier-transform spectrometer based on polarization interferometer with Wollaston prisms and linear CCD. Firstly, measured light is changed into linear polarization light by polarization plate. And then the light can be split into ordinary and extraordinary lights by going through one Wollaston prism. At last, after going through another Wollaston prism and analyzer, interfering fringes can be formed on linear CCD behind the analyzer. The linear CCD is driven by CPLD to output amplitude of interfering fringes and synchronous signals of frames and pixels respectively. DSP is used to collect interference pattern signals from CCD and the digital data of interfering fringes are processed by using 2048-point-FFT. Finally, optical spectrum of measured light can be display on LCD connected to DSP with RS232. The spectrometer will possess the features of firmness, portability and the ability of real-time analyzing. The work will provide a convenient and significant foundation for application of more high accuracy of Fourier-transform spectrometer.

  16. A Charge-Coupled Device CCD line-scan system for road luminance measurement.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1996-01-01

    The problems involved in measuring road luminance are discussed and a new measuring system described which is based on a line-scan Charge Coupled Device (CCD) configuration. It is designed for the assessment of average road surface luminance and degree of non-uniformity of road lighting. Additionall

  17. Determining the Spectral Resolution of a Charge-Coupled Device (CCD) Raman Instrument

    DEFF Research Database (Denmark)

    Liu, Chuan; Berg, Rolf W.

    2012-01-01

    A new method based on dispersion equations is described to express the spectral resolution of an applied charge-coupled device (CCD) Czerny-Turner Raman instrument entirely by means of one equation and principal factors determined by the actual setup. The factors involved are usual quantities suc...

  18. MiCPhot: A prime-focus multicolor CCD photometer on the 85-cm Telescope

    Institute of Scientific and Technical Information of China (English)

    Ai-Ying Zhou; Xiao-Jun Jiang; Yan-Ping Zhang; Jian-Yan Wei

    2009-01-01

    We describe a new BVRI multicolor CCD photometric system situated at the prime focus of the 85-cm telescope at the Xinglong Station of NAOC. Atmospheric extinction effects, photometric accuracy and color calibration dependence of the system are investigated. Additional attention was paid to giving observers guidance in estimating throughput, detection limit, signal-to-noise ratio and exposure time.

  19. Silvaco ATLAS model of ESA's Gaia satellite e2v CCD91-72 pixels

    CERN Document Server

    Seabroke, G M; Burt, D; Robbins, M S; 10.1117/12.856958

    2010-01-01

    The Gaia satellite is a high-precision astrometry, photometry and spectroscopic ESA cornerstone mission, currently scheduled for launch in 2012. Its primary science drivers are the composition, formation and evolution of the Galaxy. Gaia will achieve its unprecedented accuracy requirements with detailed calibration and correction for CCD radiation damage and CCD geometric distortion. In this paper, the third of the series, we present our 3D Silvaco ATLAS model of the Gaia e2v CCD91-72 pixel. We publish e2v's design model predictions for the capacities of one of Gaia's pixel features, the supplementary buried channel (SBC), for the first time. Kohley et al. (2009) measured the SBC capacities of a Gaia CCD to be an order of magnitude smaller than e2v's design. We have found the SBC doping widths that yield these measured SBC capacities. The widths are systematically 2 {\\mu}m offset to the nominal widths. These offsets appear to be uncalibrated systematic offsets in e2v photolithography, which could either be du...

  20. On the use of CCD area detectors for high-resolution specular X-ray reflectivity.

    Science.gov (United States)

    Fenter, P; Catalano, J G; Park, C; Zhang, Z

    2006-07-01

    The use and application of charge coupled device (CCD) area detectors for high-resolution specular X-ray reflectivity is discussed. Direct comparison of high-resolution specular X-ray reflectivity data measured with CCD area detectors and traditional X-ray scintillator ('point') detectors demonstrates that the use of CCD detectors leads to a substantial (approximately 30-fold) reduction in data acquisition rates because of the elimination of the need to scan the sample to distinguish signal from background. The angular resolution with a CCD detector is also improved by a factor of approximately 3. The ability to probe the large dynamic range inherent to high-resolution X-ray reflectivity data in the specular reflection geometry was demonstrated with measurements of the orthoclase (001)- and alpha-Al2O3 (012)-water interfaces, with measured reflectivity signals varying by a factor of approximately 10(6) without the use of any beam attenuators. Statistical errors in the reflectivity signal are also derived and directly compared with the repeatability of the measurements.

  1. Quantum efficiency measurement of the Transiting Exoplanet Survey Satellite (TESS) CCD detectors

    Science.gov (United States)

    Krishnamurthy, A.; Villasenor, J.; Thayer, C.; Kissel, S.; Ricker, G.; Seager, S.; Lyle, R.; Deline, A.; Morgan, E.; Sauerwein, T.; Vanderspek, R.

    2016-07-01

    Very precise on-ground characterization and calibration of TESS CCD detectors will significantly assist in the analysis of the science data from the mission. An accurate optical test bench with very high photometric stability has been developed to perform precise measurements of the absolute quantum efficiency. The setup consists of a vacuum dewar with a single MIT Lincoln Lab CCID-80 device mounted on a cold plate with the calibrated reference photodiode mounted next to the CCD. A very stable laser-driven light source is integrated with a closed-loop intensity stabilization unit to control variations of the light source down to a few parts-per-million when averaged over 60 s. Light from the stabilization unit enters a 20 inch integrating sphere. The output light from the sphere produces near-uniform illumination on the cold CCD and on the calibrated reference photodiode inside the dewar. The ratio of the CCD and photodiode signals provides the absolute quantum efficiency measurement. The design, key features, error analysis, and results from the test campaign are presented.

  2. Simulated aperture-photometry on CCD-frames for 67 southern galaxies in B and R

    NARCIS (Netherlands)

    Peletier, R. F.; Lauberts, A.; Valentijn, E. A.

    1989-01-01

    As part of a large project to calibrate all the Schmidt plates of the ESO Quick blue and the red survey, CCD-photometry in B and R has been obtained for galaxies on 67 different survey fields. On these frames synthetic-aperture photometry is applied in order to present the data in a way which makes

  3. Subnanometer Translation of Microelectromechanical Systems Measured by Discrete Fourier Analysis of CCD Images

    NARCIS (Netherlands)

    Yamahata, Christophe; Sarajlic, Edin; Krijnen, Gijs J.M.; Gijs, Martin A.M.

    2010-01-01

    Abstract—In-plane linear displacements of microelectromechanical systems are measured with subnanometer accuracy by observing the periodic micropatterns with a charge-coupled device camera attached to an optical microscope. The translation of the microstructure is retrieved from the video by phase-s

  4. Characterization of Electrically Active Defects in Si Using CCD Image Sensors

    Science.gov (United States)

    1978-02-01

    made of each slice using the elon -asoorbio aold developer described in Appendix D. The inagers were then thinned using the procedure at Appendix taor...investigated for use an diffusion or implantation musks . The use of high pressure thermal oxidation at lower temperatures my serve to reduoe the

  5. SlCCD7 controls strigolactone biosynthesis, shoot branching and mycorrhiza-induced apocarotenoid formation in tomato.

    NARCIS (Netherlands)

    Vogel, J.T.; Walter, M.H.; Giavalisco, P.; Lytovchenko, A.; Kohlen, W.; Charnikhova, T.; Simkin, A.J.; Goulet, C.; Strack, D.; Bouwmeester, H.J.; Fernie, A.R.; Klee, H.J.

    2010-01-01

    The regulation of shoot branching is an essential determinant of plant architecture, integrating multiple external and internal signals. One of the signaling pathways regulating branching involves the MAX (more axillary branches) genes. Two of the genes within this pathway, MAX3/CCD7 and MAX4/CCD8,

  6. A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry

    CERN Document Server

    Ferro, A Arellano; Jaimes, R Figuera; Giridhar, Sunetra; Kains, N; Kuppuswamy, K; Jørgensen, U G; Alsubai, K A; Andersen, J M; Bozza, V; Browne, P; Novati, S Calchi; Damerdji, Y; Diehl, C; Dominik, M; Dreizler, S; Elyiv, A; Giannini, E; Harpsøe, K; Hessman, F V; Hinse, T C; Hundertmark, M; Juncher, D; Kerins, E; Korhonen, H; Liebig, C; Mancini, L; Mathiasen, M; Penny, M T; Rabus, M; Rahvar, S; Ricci, D; Scarpetta, G; Skottfelt, J; Snodgrass, C; Southworth, J; Surdej, J; Tregloan-Reed, J; Vilela, C; Wertz, O

    2013-01-01

    We report CCD $V$ and $I$ time-series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precision better than 0.05 mag for stars brighter than $V \\sim 19.0$ mag, even in the crowded central regions of the cluster. The high photometric precision has resulted in the discovery of two new RRc stars, three eclipsing binaries, seven long-term variables and one field RRab star behind the cluster. A detailed identification chart and equatorial coordinates are given for all the variable stars in the field of our images of the cluster. Our data together with literature $V$-data obtained in 1994 and 1995 allowed us to refine considerably the periods for all RR Lyrae stars. The nature of the new variables is discussed. We argue that variable V12 is a cluster member and an Anomalous Cepheid. Secular period variations, double mode pulsations and/or the Blazhko-like modulations in some RRc variables are addressed. Through the light curve Fou...

  7. Laboratory characterization of a CCD camera system for retrieval of bi-directional reflectance distribution function

    Science.gov (United States)

    Nandy, Prabal; Thome, Kurtis J.; Biggar, Stuart F.

    1999-12-01

    The Remote Sensing Group of the Optical Science Center at the University of Arizona has developed a four-band, multi- spectral, wide-angle, imaging radiometer for the retrieval of the bi-directional reflectance distribution function (BRDF) for vicarious calibration applications. The system consists of a fisheye lens with four interference filters centered at 470 nm, 575 nm, 660 nm, and 835 nm for spectral selection and an astronomical grade 1024 X 1024-pixel, silicon CCD array. Data taken by the system fit in the array as a nominally 0.2 degree per pixel image. This imaging radiometer system has been used in support of the calibration of Landsat-5 and SPOT- satellite sensors. This paper presents the results of laboratory characterization of the system to determine linearity of the detector, point spread function (PSF) and polarization effects. The linearity study was done on detector array without the lens, using a spherical-integrating source with a 1.5-mm aperture. This aperture simulates a point source for distances larger than 60 cm. Data were collected as both a function of exposure time and distance from the source. The results of these measurements indicate that each detector of the array is linear to better than 0.5%. Assuming a quadratic response improves this fit to better than 0.1% over 88% of the upper end of the detector's dynamic range. The point spread function (PSF) of the lens system was measured using the sphere source and aperture with the full camera system operated at a distance of 700 mm from the source, thus the aperture subtends less than the field of view of one pixel. The PSF was measured for several field angles and the signal level was found to fall to less than 1% of the peak signal within 1.5-degrees (10 pixels) for the on-axis case. The effect of this PSF on the retrieval of modeled BRDFs is shown to be less than 0.2% out to view angles of 70 degrees. The final test presented is one to assess the polarization effects of the lens

  8. Dark signal correction for a lukecold frame transfer CCD. Application to the SODISM solar telescope on board the PICARD space mission

    CERN Document Server

    Hochedez, J -F; Hauchecorne, A; Meftah, M

    2013-01-01

    When Charge Coupled Devices are used for scientific observations, their dark signal is a hindrance. In their pristine state, most CCD pixels are `cool'; they exhibit low, quasi uniform dark current, which can be estimated and corrected for. In space, after having been hit by an energetic particle, pixels can turn `hot'. They start delivering excessive, less predictable, dark current. The hot pixels need therefore to be flagged so that subsequent analysis may ignore them. The image data of the PICARD SODISM solar telescope (Meftah et al. 2013) require dark signal correction and hot pixel identification. Its frame transfer E2V 42-80 CCD operates at -7{\\deg}C. Both image and memory zones thus accumulate dark current during, respectively, integration and readout time. These two components must be separated to estimate the dark signal for any observation. This is the purpose of the Dark Signal Model presented in this paper. The dark signal time series of every pixel is processed by the Unbalanced Haar Technique (F...

  9. Dynamic CT Perfusion Imaging for the Detection of Crossed Cerebellar Diaschisis in Acute Ischemic Stroke

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Young Wook; Kim, Seo Hyun; Lee, Ji Young; Whang, Kum; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub; Brain Reserch Group [Wonju Christian Hospital, Yonsei University Wonju University College of Medicine, Wonju (Korea, Republic of)

    2012-01-15

    Although the detection of crossed cerebellar diaschisis (CCD) by means of different imaging modalities is well described, little is known about its diagnosis by computed tomography perfusion (CTP) imaging. We investigated the detection rate of CCD by CTP imaging and the factors related to CCD on CTP images in patients with acute ischemic stroke. CT perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) obtained from 81 consecutive patients affected by an acute ischemic stroke were retrospectively reviewed. Whole-brain perfusion maps were obtained with a multichannel CT scanner using the toggling-table technique. The criteria for CCD was a unilateral supratentorial ischemic lesion and an accompanying decrease in perfusion of the contralateral cerebellar hemisphere on the basis of CTP maps by visual inspection without a set threshold. Maps were quantitatively analyzed in CCD positive cases. The criteria for CCD were fulfilled in 25 of the 81 cases (31%). Detection rates per CTP map were as follows: MTT (31%) > TTP (21%) > CBF (9%) > CBV (6%). Supratentorial ischemic volume, degree of perfusion reduction, and infratentorial asymmetry index correlated strongly (R, 0.555-0.870) and significantly (p < 0.05) with each other in CCD-positive cases. It is possible to detect CCD on all four of the CTP-based maps. Of these maps, MTT is most sensitive in detecting CCD. Our data indicate that CTP imaging is a valid tool for the diagnosis of CCD in patients affected by an acute hemispheric stroke.

  10. CCD Photometry Of The Extreme Mass Ratio Binary, TYC 1404-1687-1

    Science.gov (United States)

    Faulkner, Danny R.; Samec, Ron; Figg, Evan; Oliver, Bruce; Program, Astronomy; Jones University, Bob; VanHamme, Walter; Interational University, Florida

    2011-01-01

    We report our photometric analysis of the variable, TYC 1404-1687-1 (GSC 1404 1687, Cancer). The images were taken in December, 2008, March 2009 with NURO and 16 January 2009 via remote observing with SARA North. The UBVRI CCD photometry shows that TYC 1404-1687-1 has a totally eclipsing W UMa light curve, yet it has a shallow amplitude (AV 0.4 mag.). We studied the possibility the low amplitude was due to the presence of a third component: we began our analysis with 30% third light as determined from Binary Maker. Next, we performed a BVRI simultaneous WD synthetic light curve analysis. Surprisingly, we obtained two nearly identical sums of square solutions, one with a measurable but small third light component (0-2%) and another with no third light. We conclude that the solution does not require a third light. Our period study yielded 9 new times of minimum light, two from ROTSEI curves, JD Hel Min= 2452721.4226 and 2452728.3972, and the others from our observations: HJD Min I = 2454848.8844 ±0.0014, 2454901.8924 ±0.0006, 2454902.6903 ±0.0014, 2454904.6790 ±0.0058, HJD Min II = 2454823.9678 ±0.0017, 2454827.9618 ±0.0005, 2454901.6927 ±0.0005. Using these, we calculated the first precision ephemeris for this system, HJD Min I = 2454902.6912 ±0.0009 + 0.3985874 ±0.0000003 d*E. UBVRCIC standard magnitudes were determined. We find that the comparison star (GSC 1404 0119) is a late G-type dwarf while the check star (GSC 1404 0587) is a mid F-type dwarf. The binary is an F0V contact binary. We also performed a number of solutions (a q-search) which minimized at a mass ratio near 0.2. Our WD solution gave a fill-out of 45%. No spots are needed in the solution. So we find that TYC 1404-1687-1 is among the once rare, but growing number, of low amplitude-extreme mass ratio, totally eclipsing binaries.

  11. Perceptual evaluation of different image fusion schemes

    NARCIS (Netherlands)

    Toet, A.; Franken, E.M.

    2003-01-01

    Human scene recognition performance was tested with images of night-time outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3–5 mm) infrared (IR) camera. Fused imagery was

  12. 基于线阵CCD的尺寸测量装置数据采集系统设计%Data Acquisition System of Linear CCD object’s dimension measurement Device

    Institute of Scientific and Technical Information of China (English)

    崔岩; 吴国兴; 顾媛媛; 陆惠; 殷美琳

    2013-01-01

      Charge Coupled Device (CCD) is used in non-contacted measuring object’s dimension as a new photoelectric device, which can convert optical image of the part in the spatial domain into video signal in the time domain with the aid of the essential optical system and suitable driving circuit. Taking linear CCD image sensor TCD1251UD as example, this paper presents a linear CCD driver design with a Complicated Programmable Logical Devices FPGA, which makes integration time and frequency tuned simultaneously. Video signal processing and data acquisition from the output image signal of CCD were accomplished in this dissertation. The experiment shows that the timing driven pulses could meet the requirement of CCD, the data also could be obtained from the signal acquisition circuit.%  电荷耦合器件(CCD)作为一种新型的光电器件被广泛地应用于非接触测量物体尺寸。CCD通过必要的光学系统和适合的驱动电路完成光电转换,将物体在空间域分布的光学图像转换成一列按时间域分布的电脉冲信号。以线阵CCD图像传感器TCD1251UD为例,设计了视频信号预处理电路,并采用可编程逻辑器件FPGA实现积分时间和频率同时可调的CCD驱动程序,完成了对CCD输出信号的数据采集。实验结果证明时序脉冲能够驱动CCD完成光电转换功能,数据采集电路能够采集到需要的信号数据。

  13. A Simple Method Based on the Application of a CCD Camera as a Sensor to Detect Low Concentrations of Barium Sulfate in Suspension

    Directory of Open Access Journals (Sweden)

    Joao Francisco Cajaiba da Silva

    2011-01-01

    Full Text Available The development of a simple, rapid and low cost method based on video image analysis and aimed at the detection of low concentrations of precipitated barium sulfate is described. The proposed system is basically composed of a webcam with a CCD sensor and a conventional dichroic lamp. For this purpose, software for processing and analyzing the digital images based on the RGB (Red, Green and Blue color system was developed. The proposed method had shown very good repeatability and linearity and also presented higher sensitivity than the standard turbidimetric method. The developed method is presented as a simple alternative for future applications in the study of precipitations of inorganic salts and also for detecting the crystallization of organic compounds.

  14. “嫦娥二号”卫星CCD立体相机的关键技术%Key Technologies of CE-2 CCD Stereo Camera

    Institute of Scientific and Technical Information of China (English)

    赵葆常; 唐茜; 薛彬

    2013-01-01

    文章介绍了中国两次绕月探测中 CCD 立体相机所采用的技术与创新,并与国际同类相机所获取的图像进行了比较;在此基础上详细介绍了“嫦娥二号”(CE-2)卫星CCD立体相机的综合创新集成技术--“单镜头两视角同轨立体成像、时间延迟积分图像传感器(TDICCD)推扫、速高比补偿”,并从工程目标与科学目标出发进行探测灵敏度及成像动态范围的需求分析;根据需求分析确定了总体技术方案,包括光、机、电的优化设计以及对月探测中首次采用TDICCD的技术困难与对策;特别讨论了速高比补偿的方案及实施途径,并进行了在轨试验验证。文章最后分别给出了虹湾地区成像分辨率为1.3m以及全月面分辨率为7m 的代表性图像,图像清晰、层次丰富,显示出中国在对月立体成像技术上取得了显著进步。%The paper describes the CCD-stereo camera’s novel techniques used in China’s two around-lunar reconnaissances and compares similar images of lunar terrain obtained by foreign cameras. The paper also details CCD stereo-camera’s overall scheme, i.e. synthetically integrating techniques of“same orbit stereo-imaging with two sight angles, TDICCD pushing scan and velocity/height ratio compensation”. It in-cludes the requirement analysis of the sensibility and imaging dynamical range for the sake of engineering and science goals. The overall scheme is established on the basis of the requirement analysis, including the opti-mizing designs with optics, machine and electronics and imaging capability analysis for this scheme. The scheme can fulfill the mission goals. The paper introduces the technical difficulties with time-delay-integration CCD for lunar high resolution stereo-imaging and the countermeasures employed, especially discusses the scheme and way for velocity/height ratio compensation and gives the executed validation on orbit. Finally, it shows

  15. Development of low-noise CCD drive electronics for the world space observatory ultraviolet spectrograph subsystem

    Science.gov (United States)

    Salter, Mike; Clapp, Matthew; King, James; Morse, Tom; Mihalcea, Ionut; Waltham, Nick; Hayes-Thakore, Chris

    2016-07-01

    World Space Observatory Ultraviolet (WSO-UV) is a major Russian-led international collaboration to develop a large space-borne 1.7 m Ritchey-Chrétien telescope and instrumentation to study the universe at ultraviolet wavelengths between 115 nm and 320 nm, exceeding the current capabilities of ground-based instruments. The WSO Ultraviolet Spectrograph subsystem (WUVS) is led by the Institute of Astronomy of the Russian Academy of Sciences and consists of two high resolution spectrographs covering the Far-UV range of 115-176 nm and the Near-UV range of 174-310 nm, and a long-slit spectrograph covering the wavelength range of 115-305 nm. The custom-designed CCD sensors and cryostat assemblies are being provided by e2v technologies (UK). STFC RAL Space is providing the Camera Electronics Boxes (CEBs) which house the CCD drive electronics for each of the three WUVS channels. This paper presents the results of the detailed characterisation of the WUVS CCD drive electronics. The electronics include a novel high-performance video channel design that utilises Digital Correlated Double Sampling (DCDS) to enable low-noise readout of the CCD at a range of pixel frequencies, including a baseline requirement of less than 3 electrons rms readout noise for the combined CCD and electronics system at a readout rate of 50 kpixels/s. These results illustrate the performance of this new video architecture as part of a wider electronics sub-system that is designed for use in the space environment. In addition to the DCDS video channels, the CEB provides all the bias voltages and clocking waveforms required to operate the CCD and the system is fully programmable via a primary and redundant SpaceWire interface. The development of the CEB electronics design has undergone critical design review and the results presented were obtained using the engineering-grade electronics box. A variety of parameters and tests are included ranging from general system metrics, such as the power and mass

  16. Multicolour CCD Photometric Study of Galactic Star Clusters SAI 63 and SAI 75

    Indian Academy of Sciences (India)

    R. K. S. Yadav; S. I. Leonova; R. Sagar; E. V. Glushkova

    2014-06-01

    We present CCD photometric observations obtained in the field of open clusters SAI 63 and SAI 75. CCD optical data obtained for the first time for these clusters are used to derive the fundamental parameters of the clusters. Stellar surface density profile indicates that radii of SAI 63 and SAI 75 are ∼ 3'.5 and 2'.5 respectively. The reddenings ( - ) are 0.44 ± 0.05 and 0.34 ± 0.05 mag for SAI 63 and SAI 75 respectively while the corresponding distances are 2.2 ± 0.2 and 3.5 ± 0.3 kpc. An age of 450 ± 50 Myr for SAI 63 and 90 ± 10 Myr for SAI 75 is determined using the theoretical isochrones of Z = 0.019. Our analysis shows that reddening law is normal towards SAI 75.

  17. The multi-band CCD photometric investigation of short-period eclipsing binary V1044 Her

    Science.gov (United States)

    Lu, Hongpeng; Zhang, Liyun; Han, Xianming L.; Pi, Qingfeng; Wang, Daimei

    2016-10-01

    We present new CCD photometric observations of V1044 Her obtained on May 22, 23 and 24, 2015. From our data, we derived five new light curve minimum times. Combining our new results with previously available CCD light minimum times, we derived an updated ephemeris and discovered that the period of this binary system exhibits an oscillation. The cyclic variation may be caused by the light-time effect via the presence of a third body or magnetic activity cycle. We calculated the corresponding period of the third body to be 14.1 ± 1.4 years or magnetic cycle to be 12.2 ± 0.7 years. We analyzed our new asymmetric light curves to obtain photometric solutions and starspot parameters using the Wilson and Devinney program. The final results show that V1044 Her is a contact binary system with a degree of contact factor f = 3.220(± 0.002)%.

  18. Growth of delta-doped layers on silicon CCD/S for enhanced ultraviolet response

    Science.gov (United States)

    Hoenk, Michael E. (Inventor); Grunthaner, Paula J. (Inventor); Grunthaner, Frank J. (Inventor); Terhune, Robert W. (Inventor); Hecht, Michael H. (Inventor)

    1994-01-01

    The backside surface potential well of a backside-illuminated CCD is confined to within about half a nanometer of the surface by using molecular beam epitaxy (MBE) to grow a delta-doped silicon layer on the back surface. Delta-doping in an MBE process is achieved by temporarily interrupting the evaporated silicon source during MBE growth without interrupting the evaporated p+ dopant source (e.g., boron). This produces an extremely sharp dopant profile in which the dopant is confined to only a few atomic layers, creating an electric field high enough to confine the backside surface potential well to within half a nanometer of the surface. Because the probability of UV-generated electrons being trapped by such a narrow potential well is low, the internal quantum efficiency of the CCD is nearly 100% throughout the UV wavelength range. Furthermore, the quantum efficiency is quite stable.

  19. 双重美丽——富士第四代Super CCD

    Institute of Scientific and Technical Information of China (English)

    Macho

    2003-01-01

    富士公司是目前世界上仅有的几家具有CCD研发生产能力的厂商。在数码相机上,富士公司的Super CCD一直是其看家功夫。富士公司在数码相机生产上的发展是伴随着其独门绝技Super CCD而不断前进的。今年1月22日,富士公司又正式宣布了第四代Super CCD——超级CCD HR和超级CCD SR技术。

  20. White light single-shot interferometry with colour CCD camera for optical inspection of microsystems

    Science.gov (United States)

    Upputuri, Paul Kumar; Pramanik, Manojit; Nandigana, Krishna Mohan; Kothiyal, Mahendra Prasad

    2015-07-01

    White light interferometry is a well-established optical tool for surface metrology of reflective samples. In this work, we discuss a single-shot white light interferometer based on single-chip color CCD camera and Hilbert transformation. The approach makes the measurement dynamic, faster, easier and cost-effective for industrial applications. Here we acquire only one white light interferogram using colour CCD camera and then decompose into its individual components using software. We present a simple Hilbert transformation approach to remove the non-uniform bias associated with the interference signal. The phases at individual wavelengths are calculated using Hilbert transformation. The use of Hilbert transformation introduces phase error which depends on number of fringe cycles. We discuss these errors. Experimental results on reflective micro-scale-samples for surface profiling are presented.

  1. Puesta en marcha de un microdensitómetro automático basado en CCD

    Science.gov (United States)

    Calderón, J. H.; Bustos Fierro, I. H.

    We present the commisioning of a CCD-based microdensitometer intended to perform astrometric measurements of photographic plates. The work done consisted in the installation of a CCD camera, the modification of the motion system, the construction of a new illumination device, the adaptation of the electronics, and the development of software. The instrument is intended to be used for the astrometric measurement mainly of plates of the Astrographic Catalog and Carte du Ciel collections from Córdoba Observatory. In this phase of the project we counted with the collaboration of the Instituto Provincial de Enseñanza Media No 59, 25 de Mayo, Cruz Alta (Province of Córdoba). The origin and importance of such collaboration is commented.

  2. Non-contact Measurement of Damaged External Tapered Thread Based on Linear Array CCD

    Science.gov (United States)

    He, F. J.; Zhang, R. J.; Du, Z. J.; Cui, X. M.

    2006-10-01

    The non-contact measurement of external tapered thread based on linear array CCD is presented to decrease the measuring error caused by local damage area contrast to the measurement with mechanical gauges. The thread is scanned by linear array CCD and the signal is processed by first order difference to obtain thread contour. For the thread with damage on tooth flank and deformation on generating line, the Hough transform and weighted least squares are adopted to reduce the local defects and to set up fitted thread contour equations that can reflect the real dimension. Then the dimensions can be calculated based on these equations according to the definition. The paper also presents the method to evaluate the local damage. Experiment shows that the method is suitable for the measurement of damaged thread.

  3. SEARCHING FOR BULK MOTIONS IN THE INTRACLUSTER MEDIUM OF MASSIVE, MERGING CLUSTERS WITH CHANDRA CCD DATA

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ang; Yu, Heng; Tozzi, Paolo; Zhu, Zong-Hong, E-mail: yuheng@bnu.edu.cn, E-mail: zhuzh@bnu.edu.cn [Department of Astronomy, Beijing Normal University, Beijing, 100875 (China)

    2016-04-10

    We search for bulk motions in the intracluster medium (ICM) of massive clusters showing evidence of an ongoing or recent major merger with spatially resolved spectroscopy in Chandra CCD data. We identify a sample of six merging clusters with >150 ks Chandra exposure in the redshift range 0.1 < z < 0.3. By performing X-ray spectral analysis of projected ICM regions selected according to their surface brightness, we obtain the projected redshift maps for all of these clusters. After performing a robust analysis of the statistical and systematic uncertainties in the measured X-ray redshift z{sub X}, we check whether or not the global z{sub X} distribution differs from that expected when the ICM is at rest. We find evidence of significant bulk motions at more than 3σ in A2142 and A115, and less than 2σ in A2034 and A520. Focusing on single regions, we identify significant localized velocity differences in all of the merger clusters. We also perform the same analysis on two relaxed clusters with no signatures of recent mergers, finding no signs of bulk motions, as expected. Our results indicate that deep Chandra CCD data enable us to identify the presence of bulk motions at the level of v{sub BM} > 1000 km s{sup −1} in the ICM of massive merging clusters at 0.1 < z < 0.3. Although the CCD spectral resolution is not sufficient for a detailed analysis of the ICM dynamics, Chandra CCD data constitute a key diagnostic tool complementing X-ray bolometers on board future X-ray missions.

  4. CCD measurements of double and multiple stars at NAO Rozhen. III

    Directory of Open Access Journals (Sweden)

    Cvetković Z.

    2007-01-01

    Full Text Available Using the 2-m telescope of the Bulgarian National Astronomical Observatory at Rozhen, observations of 55 multiple stars were carried out during one night, December 16/17. 2006. This is the third series of CCD measurements of double and multiple stars carried out at Rozhen. In the paper we present the results for the position angle and separation for 49 multiple stars (67 pairs which could be measured. .

  5. CCD Measurements of Double and Multiple Stars at NAO Rozhen. IV

    Directory of Open Access Journals (Sweden)

    Boeva, S.

    2010-06-01

    Full Text Available Using the 2 m telescope of the Bulgarian National Astronomical Observatory at Rozhen observations of 30 double or multiple stars were carried out during two half nights on July 20and 21, 2009. This is the fourth series of measurements of CCD frames of double and multiple stars obtained at Rozhen. In this paper we present the results for the position angle and separation for 23 double and 5 multiple stars (35 pairs which could have been measured.

  6. Optical fiber sensors using hollow glass spheres and CCD spectrometer interrogator

    Science.gov (United States)

    Dakin, John P.; Ecke, Wolfgang; Schroeder, Kerstin; Reuter, Martin

    2009-10-01

    Hollow glass micro-spheres, firstly used to make fiber optic sensors for high hydrostatic pressure, have been interrogated using a high-resolution CCD-based spectrometer, to give far better precision than conventional spectrometric read out. It is found that these simple, low-cost micro-sensors have excellent sensitivity to both static and dynamic pressure, and have the advantage of being hermetically sealed. Many other application areas are foreseen for these low-cost sensors.

  7. Data Reduction and Control Software for Meteor Observing Stations Based on CCD Video Systems

    Science.gov (United States)

    Madiedo, J. M.; Trigo-Rodriguez, J. M.; Lyytinen, E.

    2011-01-01

    The SPanish Meteor Network (SPMN) is performing a continuous monitoring of meteor activity over Spain and neighbouring countries. The huge amount of data obtained by the 25 video observing stations that this network is currently operating made it necessary to develop new software packages to accomplish some tasks, such as data reduction and remote operation of autonomous systems based on high-sensitivity CCD video devices. The main characteristics of this software are described here.

  8. Superimposing of virtual graphics and real image based on 3D CAD information

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Proposes methods of transforming 3D CAD models into 2D graphics and recognizing 3D objects by features and superimposing VE built in computer onto real image taken by a CCD camera, and presents computer simulation results.

  9. The research on calibration methods of dual-CCD laser three-dimensional human face scanning system

    Science.gov (United States)

    Wang, Jinjiang; Chang, Tianyu; Ge, Baozhen; Tian, Qingguo; Yang, Fengting; Shi, Shendong

    2013-09-01

    In this paper, on the basis of considering the performance advantages of two-step method, we combines the stereo matching of binocular stereo vision with active laser scanning to calibrate the system. Above all, we select a reference camera coordinate system as the world coordinate system and unity the coordinates of two CCD cameras. And then obtain the new perspective projection matrix (PPM) of each camera after the epipolar rectification. By those, the corresponding epipolar equation of two cameras can be defined. So by utilizing the trigonometric parallax method, we can measure the space point position after distortion correction and achieve stereo matching calibration between two image points. Experiments verify that this method can improve accuracy and system stability is guaranteed. The stereo matching calibration has a simple process with low-cost, and simplifies regular maintenance work. It can acquire 3D coordinates only by planar checkerboard calibration without the need of designing specific standard target or using electronic theodolite. It is found that during the experiment two-step calibration error and lens distortion lead to the stratification of point cloud data. The proposed calibration method which combining active line laser scanning and binocular stereo vision has the both advantages of them. It has more flexible applicability. Theory analysis and experiment shows the method is reasonable.

  10. Developments of engineering model of the X-ray CCD camera of the MAXI experiment onboard the International Space Station

    CERN Document Server

    Miyata, E; Kamazuka, T; Akutsu, D; Kouno, H; Tsunemi, H; Matsuoka, M; Tomida, H; Ueno, S; Hamaguchi, K; Tanaka, I

    2002-01-01

    MAXI, Monitor of All-sky X-ray Image, is an X-ray observatory on the Japanese Experimental Module (JEM) Exposed Facility (EF) on the International Space Station (ISS). MAXI is a slit scanning camera which consists of two kinds of X-ray detectors: one is a one-dimensional position-sensitive proportional counter with a total area of approx 5000 cm sup 2 , the Gas Slit Camera (GSC), and the other is an X-ray CCD array with a total area approx 200 cm sup 2 , the Solid-state Slit Camera (SSC). The GSC subtends a field of view with an angular dimension of 1 deg. x180 deg. while the SSC subtends a field of view with an angular dimension of 1 deg. times a little less than 180 deg. . In the course of one station orbit, MAXI can scan almost the entire sky with a precision of 1 deg. and with an X-ray energy range 0.5-30 keV. We have developed an engineering model (EM) for all components of the SSC. Their performance test is underway. We have also developed several kinds of CCDs fabricated from different wafers. Since th...

  11. UB CCD Photometry of the Old, Metal-rich, Open Clusters NGC 6791, NGC 6819, and NGC 7142

    Science.gov (United States)

    Carraro, G.; Buzzoni, A.; Bertone, E.; Buson, L.

    2013-11-01

    We report on a UV-oriented imaging survey in the fields of the old, metal-rich open clusters NGC 6791, NGC 6819, and NGC 7142. With their super-solar metallicity and ages >~ 3-8 Gyr, these three clusters represent both very near and ideal stellar aggregates to match the distinctive properties of the evolved stellar populations, as in elliptical galaxies and bulges of spirals. Following a first discussion of NGC 6791 observations in an accompanying paper, here we complete our analysis, also presenting for NGC 6819 and NGC 7142 the first-ever U CCD photometry. The color-magnitude diagram of the three clusters is analyzed in detail, with special emphasis on the hot stellar component. We report, in this regard, one new extreme horizontal-branch star candidate in NGC 6791. For NGC 6819 and 7142, the stellar luminosity function clearly points to a looser radial distribution of faint lower main sequence stars, either as a consequence of cluster dynamical interaction with the Galaxy or as an effect of an increasing fraction of binary stars toward the cluster core, as also observed in NGC 6791. Compared to a reference theoretical model for the Galaxy disk, the analysis of the stellar field along the line of sight of each cluster indicates that a more centrally concentrated thick disk, on a scale length shorter than ~2.8 kpc, might better reconcile the lower observed fraction of bright field stars and their white-dwarf progeny.

  12. UB CCD PHOTOMETRY OF THE OLD, METAL-RICH, OPEN CLUSTERS NGC 6791, NGC 6819, AND NGC 7142

    Energy Technology Data Exchange (ETDEWEB)

    Carraro, G. [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 19 (Chile); Buzzoni, A. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Bertone, E. [INAOE-Instituto Nacional de Astrofísica Optica y Electrónica, Calle L.E. Erro 1, 72840 Tonantzintla, Puebla (Mexico); Buson, L., E-mail: gcarraro@eso.org, E-mail: alberto.buzzoni@oabo.inaf.it, E-mail: ebertone@inaoep.mx, E-mail: lucio.buson@oapd.inaf.it [INAF-Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy)

    2013-11-01

    We report on a UV-oriented imaging survey in the fields of the old, metal-rich open clusters NGC 6791, NGC 6819, and NGC 7142. With their super-solar metallicity and ages ∼> 3-8 Gyr, these three clusters represent both very near and ideal stellar aggregates to match the distinctive properties of the evolved stellar populations, as in elliptical galaxies and bulges of spirals. Following a first discussion of NGC 6791 observations in an accompanying paper, here we complete our analysis, also presenting for NGC 6819 and NGC 7142 the first-ever U CCD photometry. The color-magnitude diagram of the three clusters is analyzed in detail, with special emphasis on the hot stellar component. We report, in this regard, one new extreme horizontal-branch star candidate in NGC 6791. For NGC 6819 and 7142, the stellar luminosity function clearly points to a looser radial distribution of faint lower main sequence stars, either as a consequence of cluster dynamical interaction with the Galaxy or as an effect of an increasing fraction of binary stars toward the cluster core, as also observed in NGC 6791. Compared to a reference theoretical model for the Galaxy disk, the analysis of the stellar field along the line of sight of each cluster indicates that a more centrally concentrated thick disk, on a scale length shorter than ∼2.8 kpc, might better reconcile the lower observed fraction of bright field stars and their white-dwarf progeny.

  13. The CFHT Open Star Cluster Survey II -- Deep CCD Photometry of the Old Open Star Cluster NGC 6819

    CERN Document Server

    Singh-Kalirai, J; Fahlman, G G; Cuillandre, J C; Ventura, P; D'Antona, F; Bertin, E; Marconi, G; Durrell, P R; Kalirai, Jasonjot Singh; Richer, Harvey B.; Fahlman, Gregory G.; Cuillandre, Jean-Charles; Ventura, Paolo; Antona, Francesca D'; Bertin, Emmanuel; Marconi, Gianni; Durrell, Patrick R.

    2001-01-01

    We present analysis of deep CCD photometry for the very rich, old open star cluster NGC 6819. These CFH12K data results represent the first of nineteen open star clusters which were imaged as a part of the CFHT Open Star Cluster Survey. We find a tight, very rich, main-sequence and turn-off consisting of over 2900 cluster stars in the V, B-V color-magnitude diagram (CMD). Main-sequence fitting of the un-evolved cluster stars with the Hyades star cluster yields a distance modulus of (m-M)v = 12.30 +/- 0.12, for a reddening of E(B-V) = 0.10. These values are consistent with a newly calculated theoretical stellar isochrone of age 2.5 Gyrs, which we take to be the age of the cluster. Detailed star counts indicate a much larger cluster extent (R = 9.5' +/- 1.0'), by a factor of ~2 over some previous estimates. Incompleteness tests confirm a slightly negatively sloped luminosity function extending to faint (V ~ 23) magnitudes which is indicative of a dynamically evolved cluster. Further luminosity function and mass...

  14. CCD Photometry of the globular cluster NGC 5466. RR Lyrae light curve decomposition and the distance scale

    CERN Document Server

    Ferro, A Arellano; Giridhar, Sunetra; Bramich, D M

    2007-01-01

    We report the results of CCD V and r photometry of the globular cluster NGC 5466. The difference image analysis technique adopted in this work has resulted in accurate time series photometry even in crowded regions of the cluster enabling us to discover five probably semi-regular variables. We present new photometry of three previously known eclipsing binaries and six SX Phe stars. The light curves of the RR Lyrae stars have been decomposed in their Fourier harmonics and their fundamental physical parameters have been estimated using semi-empirical calibrations. The zero points of the metallicity, luminosity and temperature scales are discussed and our Fourier results are transformed accordingly. The average iron abundance and distance to the Sun derived from individual RR Lyrae stars, indicate values of [Fe/H]=-1.91 +- 0.19 and D = 16.0 +- 0.6 kpc, or a true distance modulus of 16.02 +- 0.09 mag, for the parent cluster. These values are respectively in the Zinn & West metallicity scale and in agreement w...

  15. Cooling System for a Frame-Store PN-CCD Detector for Low Background Application

    CERN Document Server

    Pereira, H; Santos Silva, P; Kuster, M; Lang, P

    2012-01-01

    The astroparticle physics experiment CERN Axion Solar Telescope (CAST) aims to detect hypothetical axions or axion-like particles produced in the Sun by the Primakoff process. A Large Hadron Collider (LHC) prototype superconducting dipole magnet provides a 9 T transverse magnetic field for the conversion of axions into detectable X-ray photons. These photons are detected with an X-ray telescope and a novel type of frame-store CCD detector built from radio-pure materials, installed in the optics focal plane. A novel type of cooling system has been designed and built based on krypton-filled cryogenic heat pipes, made out of oxygen-free radiopure copper, and a Stirling cryocooler as cold source. The heat pipes provide an efficient thermal coupling between the cryocooler and the CCD which is kept at stable temperatures between 150 and 230 K within an accuracy of 0.1 K. A graded-Z radiation shield, also serving as a gas cold-trap operated at 120 K, is implemented to reduce the surface contamination of the CCD wind...

  16. Precise CCD positions of Himalia using Gaia DR1 in 2015-2016

    Science.gov (United States)

    Peng, H. W.; Peng, Q. Y.; Wang, N.

    2017-01-01

    In order to obtain high precision CCD positions of Himalia, the sixth Jovian satellite, a total of 598 CCD observations have been obtained during the years 2015-2016. The observations were made by using the 2.4 m and 1 m telescopes administered by Yunnan Observatories over 27 nights. Several factors which would influence the positional precision of Himalia were analyzed, including the reference star catalogue used, the geometric distortion and the phase effect. By taking advantage of its unprecedented positional precision, the recently released catalogue Gaia DR1 was chosen to match reference stars in the CCD frames of both Himalia and open clusters which were observed for deriving the geometric distortion. The latest version of SOFA library was used to calculate the positions of reference stars. The theoretical positions of Himalia were retrieved from the Jet Propulsion Laboratory Horizons System which includes the satellite ephemeris JUP300, while the positions of Jupiter were based on the planetary ephemeris DE431. Our results showed that the means of observed minus computed (O-C) residuals are 0.071 and -0.001 arcsec in right ascension and declination, respectively. Their standard deviations are estimated at about 0.03 arcsec in each direction.

  17. Preliminary results of CCD observations of Himalia at Yunnan Observatories in 2015

    CERN Document Server

    Peng, H W; Peng, Q Y

    2016-01-01

    In order to study the potential in high precision CCD astrometry of irregular satellites, we have made experimental observations for Himalia, the sixth and irregular satellite of Jupiter. A total of 185 CCD observations were obtained by using the 2.4 m telescope and 1 m telescope at Yunnan Observatories over ten nights. Preliminary analysis for the observations were made, including the geometric distortion, the atmospheric refraction, and also the phase effect. All positions of Himalia are measured relative to the reference stars from the catalogue UCAC4 in each CCD field of view. The theoretical positions of Himalia were retrieved from the IMCCE, while the positions of Jupiter were obtained based on the planetary theory INPOP13C. The results show that the mean (O-C) (observed minus computed) residuals are -0.004 and -0.002 arcsec in right ascension and declination, respectively. The standard deviation of (O-C) residuals are estimated at about 0.04 arcsec in each direction.

  18. Development of the analog ASIC for multi-channel readout X-ray CCD camera

    CERN Document Server

    Nakajima, Hiroshi; Idehara, Toshihiro; Anabuki, Naohisa; Tsunemi, Hiroshi; Doty, John P; Ikeda, Hirokazu; Katayama, Haruyoshi; Kitamura, Hisashi; Uchihori, Yukio; 10.1016/j.nima.2010.12.174

    2011-01-01

    We report on the performance of an analog application-specific integrated circuit (ASIC) developed aiming for the front-end electronics of the X-ray CCDcamera system onboard the next X-ray astronomical satellite, ASTRO-H. It has four identical channels that simultaneously process the CCD signals. Distinctive capability of analog-to-digital conversion enables us to construct a CCD camera body that outputs only digital signals. As the result of the front-end electronics test, it works properly with low input noise of =<30 uV at the pixel rate below 100 kHz. The power consumption is sufficiently low of about 150 mW/chip. The input signal range of 720 mV covers the effective energy range of the typical X-ray photon counting CCD (up to 20 keV). The integrated non-linearity is 0.2% that is similar as those of the conventional CCDs in orbit. We also performed a radiation tolerance test against the total ionizing dose (TID) effect and the single event effect. The irradiation test using 60Co and proton beam showed ...

  19. Functional Expression of Aquaporin-2 Tagged with Photoconvertible Fluorescent Protein in mpkCCD Cells

    Directory of Open Access Journals (Sweden)

    Kay-Pong Yip

    2015-05-01

    Full Text Available Background: Vasopressin induced trafficking of aquaporin-2 (AQP2 containing vesicles has been studied in kidney cell lines using conventional fluorescent proteins as tags. However, trafficking of fluorescent tagged AQP2, which resembles the vectorial translocation of native AQP2 from cytoplasm to apical membrane has not been demonstrated at real time. Using a photoconvertible fluorescent protein tag on AQP2 might allow the simultaneous tracking of two separate populations of AQP2 vesicle after subcellular local photoconversion. Methods: A spacer was used to link a photoconvertible fluorescent protein (mEos2 to the amino-terminus of AQP2. The DNA constructs were expressed in mpkCCD cells. The trafficking of chimeric protein was visualized with high speed confocal microscopy in 4 dimensions. Results: Chimeric AQP2 expressed in mpkCCD cell conferred osmotic water permeability to the cells. Subcellular photoconversion with a 405 nm laser pulse converted green chimeras to red chimeras locally. Forskolin stimulation triggered chimeric AQP2 to translocate from acidic organelles to apical plasma membrane. By serendipity, the rate of apical accumulation was found to increase when mEos2 was tagged to the carboxyl-terminus in at least one of the AQP2 molecules within the tetramer. Conclusion: Functional photoconvertible chimeric AQP2 was successfully expressed in mpkCCD cells, in which forskolin induced apical trafficking and accumulation of chimeric AQP2. The proof-of-concept to monitor two populations of AQP2 vesicle simultaneously was demonstrated.

  20. The role of the potato (Solanum tuberosum) CCD8 gene in stolon and tuber development.

    Science.gov (United States)

    Pasare, Stefania A; Ducreux, Laurence J M; Morris, Wayne L; Campbell, Raymond; Sharma, Sanjeev K; Roumeliotis, Efstathios; Kohlen, Wouter; van der Krol, Sander; Bramley, Peter M; Roberts, Alison G; Fraser, Paul D; Taylor, Mark A

    2013-06-01

    · Strigolactones (SLs) are a class of phytohormones controlling shoot branching. In potato (Solanum tuberosum), tubers develop from underground stolons, diageotropic stems which originate from basal stem nodes. As the degree of stolon branching influences the number and size distribution of tubers, it was considered timely to investigate the effects of SL production on potato development and tuber life cycle. · Transgenic potato plants were generated in which the CAROTENOID CLEAVAGE DIOXYGENASE8 (CCD8) gene, key in the SL biosynthetic pathway, was silenced by RNA interference (RNAi). · The resulting CCD8-RNAi potato plants showed significantly more lateral and main branches than control plants, reduced stolon formation, together with a dwarfing phenotype and a lack of flowering in the most severely affected lines. New tubers were formed from sessile buds of the mother tubers. The apical buds of newly formed transgenic tubers grew out as shoots when exposed to light. In addition, we found that CCD8 transcript levels were rapidly downregulated in tuber buds by the application of sprout-inducing treatments. · These results suggest that SLs could have an effect, solely or in combination with other phytohormones, in the morphology of potato plants and also in controlling stolon development and maintaining tuber dormancy.

  1. Imagers for digital still photography

    Science.gov (United States)

    Bosiers, Jan; Dillen, Bart; Draijer, Cees; Manoury, Erik-Jan; Meessen, Louis; Peters, Inge

    2006-04-01

    This paper gives an overview of the requirements for, and current state-of-the-art of, CCD and CMOS imagers for use in digital still photography. Four market segments will be reviewed: mobile imaging, consumer "point-and-shoot cameras", consumer digital SLR cameras and high-end professional camera systems. The paper will also present some challenges and innovations with respect to packaging, testing, and system integration.

  2. System design and demonstration of a CCD-based solar spectroradiometer

    Science.gov (United States)

    Zielinskie, David Alphonse

    The Atmospheric Remote Sensing Lab at the University of Arizona's Electrical and Computer Engineering Department has been involved with the study and measurement of atmospheric gases and aerosols for many years. The research has been conducted using instruments designed and constructed by the lab. This dissertation presents a system design for the next step in the evolution of spectroradiometers designed by the Atmospheric Remote Sensing Lab. The design draws upon the lessons learned from previous generations of radiometers and from the requirements of ongoing research. The proposed spectroradiometer uses an inexpensive CCD as the detector and takes advantage of modern processors and re-programmable CPLDs. The new design employs an embedded DSP in a novel way; it provides high level control over the CCD detector, receives serial ADC data and communicates with a Host computer. Through the use of one of the serial channels, the DSP identifies when to accumulate charge in the CCD and when to dump it. This controlled sampling allows charge to accumulate from adjacent cells internal to the CCD, improving the SNR in regions of poor spectral transmission. Since the charge accumulate/reset is controlled by the DSP through software, the sequence is programmable using the host computer interface and can be dynamically re-programmed to accommodate changing atmospheric conditions. A re-programmable CPLD isolates the DSP from the detector hardware and provides low level control of the detector assembly. The CPLD accepts high level commands from the DSP and generates the low level clocks and control signals used by the CCD and ADC. This capability permits the CPLD to be re-programmed to accommodate various CCDs and ADCs available today and in the future without altering the Host communication, control or analysis software. The capabilities of the instrument can be altered by downloading new software to the embedded DSP. Provisions have been made to download software or

  3. The Research of Quality Assessment and Ecological Monitoring for the H J-CCD and Landsat TM Omage%环境卫星CCD与Landsat TM影像质量及生态监测应用比对研究——以青海湖区域为例

    Institute of Scientific and Technical Information of China (English)

    杨永顺; 董贵华; 赵旭东; 王勇; 张晓明; 葛劲松

    2011-01-01

    针对环境卫星CCD影像,结合影像质量评价、专题制图、土地利用/覆被解译以及常用植被指数构建,以青海湖区域为例,与Landsat TM影像进行比对研究.结果表明,在与TM影像质量评价参数比较中,TM影像较优,而环境卫星影像具有很大的改善空间;在对地物判译中,环境卫星影像色彩稍暗淡,但对大多数地物解译判读的边界更清晰;环境卫星覆盖度大,区域制图的优势非常明显;生态监测定量遥感常用的植被指数比较中两种数据大致相同.%The area of Qinghaihu lake was selected as the typical area for the research of HJ-CCD image and Landsat TM image.The statistical comparison of image quality was that TM image with much better information capacity, texture, etc. However, the image quality of HJ-CCD can be improved greatly by image enhancement processing. For the ability of thematic mapping and monitoring land use/cover change, HJ-CCD image was better. HJ-CCD image had the same ability in constructing usual vegetation index of ecological monitoring as TM image.

  4. A multiple CCD X-ray detector and its first operation with synchrotron radiation X-ray beam

    CERN Document Server

    Suzuki, M; Kumasaka, T; Sato, K; Toyokawa, H; Aries, I F; Jerram, P A; Ueki, T

    1999-01-01

    A 4x4 array structure of 16 identical CCD X-ray detector modules, called the multiple CCD X-ray detector system (MCCDX), was submitted to its first synchrotron radiation experiment at the protein crystallography station of the RIKEN beamline (BL45XU) at the SPring-8 facility. An X-ray diffraction pattern of cholesterol powder was specifically taken in order to investigate the overall system performance.

  5. 高分辨率大面阵CCD相机高帧频设计及其非均匀性的校正%High-resolution large area CCD camera frame rate design and its non-uniformity correction

    Institute of Scientific and Technical Information of China (English)

    任航

    2013-01-01

    Using high-resolution full frame area array CCD FTF5066M as aerial image sensor of the camera, its frame rate is generally not more than 1 fps, which can not meet the high frame rate applications. Firstly, the full frame area array CCDFTF5066M drive circuit was introduced in this paper, and it was also been improved. Using CCD four output amplifiers to output at the same time, the highest frame rate reached 3.4 fps. Secondly, the timing of the CCD driver, front-end processing circuit, DC bias circuit, interface circuit of the four outputs were designed. The improved driver circuit could meet the application requirements of various aerial camera. Then the full frame area array CCDFTF5066M non-uniformity was analyzed, and a non-uniform response detection system was established. Using this system, the array CCD5066M's non-uniformity between the four quadrants and each pixel was tested separately. On the basis of CCD linear responsivity, two correction algorithm was proposed to correct the non-uniformity. At last, by correcting, the four quadrants's standard deviation of response sensitivity was reduced to the original's 1/13. Through the re-shoting of the identify rate board, it can seen that the array CCD's non-uniformity has been improved obviously.%  目前采用高分辨率全帧面阵CCD FTF5066M 作图像传感器的航拍相机帧频一般不超过1 fps,为了满足高帧频应用,文中首先介绍了全帧型面阵CCDFTF5066M的基本驱动电路,并对其进行了改进,利用CCD 4个输出放大器进行同时输出,使最高帧频达到了3.4 fps,介绍了4路输出时CCD驱动时序、前端处理电路、直流偏置电路、接口电路等的设计,改进后的驱动电路能满足多种航拍相机的应用要求。然后对全帧型面阵CCDFTF5066M的非均匀性进行了分析,并建立了一种响应非均匀性检测系统。利用该系统分别对面阵CCD5066M的4个象限之间的非均匀性和每个像元之间的非均匀

  6. Multiport solid-state imager characterization at variable pixel rates

    Science.gov (United States)

    Yates, George J.; Albright, Kevin L.; Turko, Bojan T.

    1993-10-01

    The imaging performance of an 8-port Full Frame Transfer Charge Coupled Device (FFT CCD) as a function of several parameters including pixel clock rate is presented. The device, model CCD-13, manufactured by English Electric Valve (EEV), is a 512 X 512 pixel array designed with four individual programmable bidirectional serial registers and eight output amplifiers permitting simultaneous readout of eight segments (128 horizontal X 256 vertical pixels) of the array. The imager was evaluated in Los Alamos National Laboratory's High-Speed Solid-State Imager Test Station at true pixel rates as high as 50 MHz for effective imager pixel rates approaching 400 MHz from multiporting. Key response characteristics measured include absolute responsivity, Charge-Transfer-Efficiency (CTE), dynamic range, resolution, signal-to-noise ratio, and electronic and optical crosstalk among the eight video channels. Preliminary test results and data obtained from the CCD-13 are presented and the versatility/capabilities of the test station are reviewed.

  7. Pocket pumped image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kotov, I.V., E-mail: kotov@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973 (United States); O' Connor, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Murray, N. [Centre for Electronic Imaging, Open University, Milton Keynes, MK7 6AA (United Kingdom)

    2015-07-01

    The pocket pumping technique is used to detect small electron trap sites. These traps, if present, degrade CCD charge transfer efficiency. To reveal traps in the active area, a CCD is illuminated with a flat field and, before image is read out, accumulated charges are moved back and forth number of times in parallel direction. As charges are moved over a trap, an electron is removed from the original pocket and re-emitted in the following pocket. As process repeats one pocket gets depleted and the neighboring pocket gets excess of charges. As a result a “dipole” signal appears on the otherwise flat background level. The amplitude of the dipole signal depends on the trap pumping efficiency. This paper is focused on trap identification technique and particularly on new methods developed for this purpose. The sensor with bad segments was deliberately chosen for algorithms development and to demonstrate sensitivity and power of new methods in uncovering sensor defects.

  8. Dynamic, Large-Magnitude CCD Changes in the Atlantic During the Middle Eocene Climatic Optimum

    Science.gov (United States)

    Kordesch, W.; Bohaty, S. M.; Palike, H.; Wilson, P. A.; Edgar, K. M.; Agnini, C.; Westerhold, T.; Roehl, U.

    2015-12-01

    The Middle Eocene Climatic Optimum (MECO; ~40.1 Ma) is a transient global warming event that abruptly reversed the long-term Eocene cooling trend. The primary driving mechanism(s) must be linked to a CO2 increase; however, geochemical modeling experiments show that prevailing hypotheses are incompatible with the paleoclimate record. To further examine changes in deep-sea carbonate burial, we identify the MECO for the first time at ODP Site 929 (Equatorial Atlantic; ~3935 m paleodepth) and present new lithological and geochemical data for this site, including benthic foraminiferal stable isotopes (δ18O and δ13C), XRF scanning data, and an orbitally tuned age model. We combine these records with data from a suite of Atlantic sites to form a depth transect between ~2-4 km (DSDP Site 523, ODP Site 1260 and 1263, IODP Site U1404) representing the first detailed record of carbonate dissolution in the Atlantic spanning the MECO. This compilation reveals dissolution at water depths as shallow as ~2 km (>1 km shallower than previous estimates) with multiple and discrete short-lived (<100 kyr) phases of carbonate compensation depth (CCD) shoaling during and after the event. Careful reevaluation of the Pacific CCD records combined with new results suggests similar short-term variability and magnitude of shoaling globally. These data provide new constraints on carbon release history during the MECO and, potentially, the forcing mechanisms for warming. The transient CCD shoaling events indicate multiple pulses of carbon input and acidification decoupled from deep-sea δ18O and δ13C records, indicating that these events must not have been driven directly by changes in temperature or carbon burial/storage - potentially reconciling some of the data-model discrepancies.

  9. PIV系统CCD相机位移调整机构的设计%Design of CCD Camera Displacement Adjusting Mechanism for PIV System

    Institute of Scientific and Technical Information of China (English)

    王成军; 江平

    2014-01-01

    In order to have a higher reliability,accuracy and stability in flow field test for 2D Particle Image Velocimetry (PIV) system,the CCD camera displacement adjusting mechanism was designed,according to the PIV system requirements and the function of flow field test working environment,then the structural design thought,composition,and capable functions achieved and its charac-teristics were expounded.Through the use of the mechanism for the flow field test,the result shows that using of the CCD camera dis-placement adjusting mechanism,can very well satisfy the job needs of PIV system in flow field test,while makes the whole system more simple,stable and efficient,and further makes flow field test results more reliable and accurate.%为使PIV (Particle Image Velocimetry)系统在流场测试中具有更高的可靠性、准确性和稳定性,根据PIV流场试验对CCD相机安装要求和工作环境的需求,设计了CCD相机位移调整机构,并阐述了该机构的设计思路、组成、能实现的功能及其特点。通过使用该机构进行流场试验,结果表明:采用该CCD相机位移调整机构,能很好地满足PIV系统在流场测试试验中的工作需要,使整个系统更加简单、稳定、高效,进而使流场测试结果更加可靠、准确。

  10. 基于场景坏点检测的面阵CCD暗电流估计方法%Dark-Current Calculation Method of Area CCD Based on Bad Pixels Detection in the Scene

    Institute of Scientific and Technical Information of China (English)

    程宣; 赵慧洁

    2012-01-01

    Bad pixels in the area CCD detector are used as temperature sensor, to estimate the CCD temperature, and to establish the function model between the CCD temperature and the dark current. In order to make the result insensitive to noise; mean filtering method is used to estimate the CCD temperature in the image of the real scene. After extraction of the CCD temperature of the real scene, the dark current of area can be estimated. Based on analysis of the method, using the real dark current as standard, the result of the dark current estimation has been validated. The experiment shows that the estimation of the dark current is very exact in both different integration time and large dynamic range conditions with the rate of error under 0.4%. Furthermore, it is not sensitive to the noise within the images. The method uses the character of the image to estimate dark current, so it is not necessary to collect the dark-current data, and the image acquisition time can be saved. Therefore, this method is very suitable to the low-cost CCD imaging system without temperature control for real-time image acquisition in hyper-spectral imaging or astronomical observation fields.%利用CCD中的部分坏点作为温度敏感器,提取CCD温度估计值,建立温度估计值与暗电流的函数模型,并结合均值滤波的方法,在真实场景图像中提取CCD温度估计值,实现了面阵CCD的暗电流估计.在方法分析的基础上,以真实的暗电流数据为基准参考,对暗电流的估计结果进行了比对实验.实验结果表明,在不同的积分时间及大动态范围的成像条件下暗电流的估计结果十分准确,偏差小于0.4%,并且具有一定的抗噪性.该方法利用场景本身的特征信息对拍摄时刻的暗电流进行估计,不需要额外采集暗电流数据,节省了图像采集时间,十分适合于积分时间较长的高光谱成像或天文观测领域,采用无温度控制的低成本CCD成像探测系统进行实时图像采集.

  11. Fotometría de imágenes CCD insuficientemente muestreadas

    Science.gov (United States)

    Ostrov, P. G.

    Se enfrenta el problema de la fotometría de imágenes CCD con una escala inadecuada (fwhm menor o igual que el tamaño de un pixel) y psf fuertemente variable con la posición. Se analiza, en particular, la aplicabilidad de una táctica propuesta por Massey, consistente en eliminar las vecinas débiles (utilizando una psf rudimentaria) para luego efectuar una fotometría de apertura sobre las estrellas brillantes. Se determina, mediante experimentos numéricos, la precisión alcanzada mediante esta técnica.

  12. DISTANCE MEASURING MODELING AND ERROR ANALYSIS OF DUAL CCD VISION SYSTEM SIMULATING HUMAN EYES AND NECK

    Institute of Scientific and Technical Information of China (English)

    Wang Xuanyin; Xiao Baoping; Pan Feng

    2003-01-01

    A dual-CCD simulating human eyes and neck (DSHEN) vision system is put forward. Its structure and principle are introduced. The DSHEN vision system can perform some movements simulating human eyes and neck by means of four rotating joints, and realize precise object recognizing and distance measuring in all orientations. The mathematic model of the DSHEN vision system is built, and its movement equation is solved. The coordinate error and measure precision affected by the movement parameters are analyzed by means of intersection measuring method. So a theoretic foundation for further research on automatic object recognizing and precise target tracking is provided.

  13. CCD surface photometry of radio galaxies: Pt. 1. FR class I and II sources

    Energy Technology Data Exchange (ETDEWEB)

    Owen, F.N.; Laing, R.A.

    1989-05-01

    CCD surface photometry of 47 radio galaxies in the R-band is reported. The goal of the programme is to study the relationship of the properties of the parent galaxies to the radio structure and, in particular, to look for differences between Fanaroff and Riley (FR) class I and II sources. In order to clarify some ambiguous cases in the FR classification, we define Classical Double, Twin Jet and Fat Double sources. We describe our definitions of these three classes and their relation to the FR classification. (author).

  14. The overlapping plates method applied to CCD observations of 243 Ida

    Science.gov (United States)

    Owen, W. M., Jr.; Yeomans, D. K.

    1994-01-01

    The overlapping plates method has been applied to crossing-point Charge Coupled Device (CCD) observations of minor planet 243 Ida to produce absolute position measurements precise to better than 0.1 sec and differential position measurements precise to better than 0.06 sec. Although these observations numbered only 17 out of the 520 that produced the final ground-based Ida ephemeris for the Galileo spacecraft flyby, their inclusion decreased Ida's downtrack error from 78 to 60 km and its out-of-plane error from 58 to 44 km.

  15. A study on using image serving technology for high precision mechanical positioning

    Science.gov (United States)

    Lin, Chuen-Horng; Hsiao, Muh-Don; Lai, Kuo-Jung

    2016-12-01

    This paper focused on using image server technology for high precision mechanical positioning. Rapid and precise positioning systems depend on the correct positions of CCD (Charge Coupled Device) video cameras, as well as on pattern matching modes. This study deals with four different positions captured by an automatic detection system employing a CCD video camera. According to a variety of hybrid image registration systems, this study proposes an entire set of methods for achieving optimal hybrid pattern matching. First, the four different position detections captured by the CCD video camera in low-resolution were examined. Next, the original position detection was carried out in high-resolution, in order to derive a precise set of CCD video camera positions. The fiducial mark (FM) was then divided into two types in the optimal option for pattern matching: the "fiducial mark" and "non-fiducial mark", which were then used for sampling. The automatic detection method is able to achieve the first pattern matching detection for recognized images. Unrecognized images or images that cannot have an FM were subjected to fine pattern matching detection. When it is not possible to find more than one FM after the proposed detection method, this suggests that the position of the CCD video camera should be reset. In this paper, the results of the experiment regarding the CCD camera precision location and the segmentation of fiducial patterns or insignificant fiducial patterns can detect and segment more unique areas and areas with unique features.

  16. Image upconversion, a low noise infrared sensor?

    DEFF Research Database (Denmark)

    for detection of infrared images. Silicon cameras have much smaller intrinsic noise than their IR counter part- some models even offer near single photon detection capability. We demonstrate that an ordinary CCD camera combined with a low noise upconversion has superior noise characteristics when compared...

  17. Image upconversion - a low noise infrared sensor?

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    for detection of infrared images. Silicon cameras have much smaller intrinsic noise than their IR counter part- some models even offer near single photon detection capability. We demonstrate that an ordinary CCD camera combined with a low noise upconversion has superior noise characteristics when compared...

  18. Active imaging system with Faraday filter

    Science.gov (United States)

    Snyder, James J.

    1993-01-01

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  19. Dosimetry with a fluoroscopic electronic portal imaging device

    NARCIS (Netherlands)

    K.L. Pasma (Kasper)

    1999-01-01

    textabstractechniques for dosimetric verification of radiotherapy treatments using a CCD camera based fluoroscopic electronic portal imaging device (EPID) are described. The dosimetric characteristics of the EPID were investigated and a method was developed to derive portal dose images (PDIs) from m

  20. 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.

  1. Agricultural produce grading and sorting system using color CCD and new color identification algorithm

    Science.gov (United States)

    Wang, Dongsheng; Zou, Jizuo; Yang, Yunping; Dong, Jianhua; Zhang, Yuanxiang

    1996-10-01

    A high-speed automatic agricultural produce grading and sorting system using color CCD and new color identification algorithm has been developed. In a typical application, the system can sort almonds into tow output grades according to their color. Almonds ar rich in 18 kinds of amino acids and 13 kinds of micro minerals and vitamins and can be made into almond drink. In order to ensure the drink quality, almonds must be sorted carefully before being made into a drink. Using this system, almonds can be sorted into two grades: up to grade and below grade almonds or foreign materials. A color CCD inspects the almonds passing on a conveyor of rotating rollers, a color identification algorithm grades almonds and distinguishes foreign materials from almonds. Employing an elaborately designed mechanism, the below grade almonds and foreign materials can be removed effectively from the raw almonds. This system can be easily adapted for inspecting and sorting other kinds of agricultural produce such as peanuts, beans tomatoes and so on.

  2. Methods of dark signal determination for CCD array spectroradiometers used in solar UVR measurements.

    Science.gov (United States)

    Baczynska, K A; Khazova, M

    2015-02-01

    The methods of the dark signal determination by direct contemporaneous measurements using a light spectrum and modelling of the dark signal based on the dark signal characterisation data were discussed. These techniques were tested with two charge-couple detectors (CCD) array spectroradiometers used in solar UVR measurements. The sensitivity of both instruments was significantly reduced when shutters were used; the measured signal varied by up to 12% depending on the orientation of the shutter. The shutters should be permanently attached to the SSR, so that the orientation cannot be changed to prevent an increase in uncertainty. The method of using blind pixels from the optically inactive part of the CCD array in a light spectrum could be used to derive the dark signal with some limitations for integration times dark signal from light measurements using out-of-range pixels has been proved impossible due to out-of-range stray light in both instruments. The dark signal was characterised for the range of integration times and ambient temperatures of 15-35°C. Based on these data, the model of the dark signal was developed so that a single value of the dark signal can be subtracted over the whole spectral range if the instrument temperature is known.

  3. A uvbyCaHbeta CCD Analysis of the Open Cluster Standard, NGC 752

    CERN Document Server

    Twarog, B A; Deliyannis, C P; Thomas, D T

    2015-01-01

    Precision uvbyCaHbeta photometry of the nearby old open cluster, NGC 752, is presented. The mosaic of CCD fields covers an area ~42' on a side with internal precision at the 0.005 to 0.010 mag level for the majority of stars down to V~15. The CCD photometry is tied to the standard system using an extensive set of published photoelectric observations adopted as secondary standards within the cluster. Multicolor indices are used to eliminate as nonmembers a large fraction of the low probability proper-motion members near the faint end of the main sequence, while identifying 24 potential dwarf members between V=15.0 and 16.5, eight of which have been noted before from Vilnius photometry. From 68 highly probable F dwarf members, we derive a reddening estimate of E(b-y)= 0.025 +/- 0.003 (E(B-V) = 0.034 +/- 0.004), where the error includes the internal photometric uncertainty and the systematic error arising from the choice of the standard (b-y), Hbeta relation. With reddening fixed, [Fe/H] is derived from the F dw...

  4. Proton radiation damage assessment of a CCD for use in a Ultraviolet and Visible Spectrometer

    Science.gov (United States)

    Gow, J. P. D.; Mason, J.; Leese, M.; Hathi, B.; Patel, M.

    2017-01-01

    This paper describes the radiation environment and radiation damage analysis performed for the Nadir and Occultation for MArs Discovery (NOMAD) Ultraviolet and Visible Spectrometer (UVIS) channel launched onboard the ExoMars Trace Gas Orbiter (TGO) in 2016. The aim of the instrument is to map the temporal and spatial variation of trace gases such as ozone and dust/cloud aerosols in the atmosphere of Mars. The instrument consists of a set of two miniature telescope viewing optics which allow for selective input onto the optical bench, where an e2v technologies CCD30-11 will be used as the detector. A Geometry Description Markup Language model of the spacecraft and instrument box was created and through the use of ESA's SPace ENVironment Information System (SPENVIS) an estimate of the 10 MeV equivalent proton fluence was made at a number of radiation sensitive regions within NOMAD, including that of the CCD30-11 which is the focus of this paper. The end of life 10 MeV equivalent proton fluence at the charge coupled device was estimated to be 4.7 × 109 protons.cm-2 three devices were irradiated at different levels up a 10 MeV equivalent fluence of 9.4 × 109 protons.cm-2. The dark current, charge transfer inefficiency, charge storage, and cosmetic quality of the devices was investigated pre- and post-irradiation, determining that the devices will continue to provide excellent science throughout the mission.

  5. Development of photoelectric balanced car based on the linear CCD sensor

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2016-01-01

    Full Text Available The smart car is designed based on Freescale’s MC9S12XS128 and a linear CCD camera. The linear CCD collects the road information and sends it to MCU through the operational amplifier. The PID control algorithm, the proportional–integral–derivative control algorithm, is adopted synthetically to control the smart car. First, the smart car’s inclination and angular velocity are detect through the accelerometers and gyro sensors, then the PD control algorithm, the proportional–derivative control algorithm, is employed to make the smart car have the ability of two-wheeled self-balancing. Second, the speed of wheel obtained by the encoder is fed back to the MCU by way of pulse signal, then the PI control algorithm, the proportional–integral control algorithm, is employed to make the speed of smart car reach the set point in the shortest possible time and stabilize at the set point. Finally, the PD control algorithm is used to regulate the smart car’s turning angle to make the smart car respond quickly while the smart car is passing the curve path. The smart car can realize the self-balancing control of two wheels and track automatically the black and while lines to march.

  6. Flat-Field Calibration of CCD Detector for Long TraceProfilers

    Energy Technology Data Exchange (ETDEWEB)

    Kirschman, Jonathan L.; Domning, Edward E.; Franck, Keith D.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R.; Morrison,Gregory Y.; Smith, Brian V.; Warwick, Tony; Yashchuk, Valeriy V.

    2007-07-31

    The next generation of synchrotrons and free electron lasersrequires x-ray optical systems with extremely high-performance,generally, of diffraction limited quality. Fabrication and use of suchoptics requires highly accurate metrology. In the present paper, wediscuss a way to improve the performance of the Long Trace Profiler(LTP), a slope measuring instrument widely used at synchrotron facilitiesto characterize x-ray optics at high-spatial-wavelengths fromapproximately 2 mm to 1 m. One of the major sources of LTP systematicerror is the detector. For optimal functionality, the detector has topossess the smallest possible pixel size/spacing, a fast method ofshuttering, and minimal non-uniformity of pixel-to-pixel photoresponse.While the first two requirements are determined by choice of detector,the non-uniformity of photoresponse of typical detectors such as CCDcameras is around 2-3 percent. We describe a flat-field calibration setupspecially developed for calibration of CCD camera photo-response and darkcurrent with an accuracy of better than 0.5 percent. Such accuracy isadequate for use of a camera as a detector for an LTP with performance of~;0.1 microradian (rms). We also present the design details of thecalibration system and results of calibration of a DALSA CCD camera usedfor upgrading our LTP-II instrument at the ALS Optical MetrologyLaboratory.

  7. Front- vs. back-illuminated CCD cameras for photometric surveys: a noise budget analysis

    CERN Document Server

    Crouzet, Nicolas; Fressin, Francois; Blazit, Alain

    2008-01-01

    Exoplanetary transit and stellar oscillation surveys require a very high precision photometry. The instrumental noise has therefore to be minimized. First, we perform a semi-analytical model of different noise sources. We show that the noise due the CCD electrodes can be overcome using a Gaussian PSF (Point Spread Function) of full width half maximum larger than 1.6 pixels. We also find that for a PSF size of a few pixels, the photometric aperture has to be at least 2.5 times larger than the PSF full width half maximum. Then, we compare a front- with a back-illuminated CCD through a Monte-Carlo simulation. Both cameras give the same results for a PSF full width half maximum larger than 1.5 pixels. All these simulations are applied to the A STEP (Antarctica Search for Transiting Extrasolar Planets) project. As a result, we choose a front-illuminated camera for A STEP because of its better resolution and lower price, and we will use a PSF larger than 1.6 pixels.

  8. UBVI CCD Photometry of the Open Clusters NGC 4609 and Hogg 15

    Science.gov (United States)

    Kook, Seung-Hwa; Sung, Hwankyung; Bessell, M. S.

    2010-10-01

    {UBVI CCD photometry is obtained for the open clusters NGC 4609 and Hogg 15 in Crux. For NGC 4609, CCD data are presented for the first time. From new photometry we derive the reddening, distance modulus and age of each cluster - NGC 4609 : E(B-V) = 0.37 ± 0.03, V_0 - M_V = 10.60 ± 0.08, log τ= 7.7 ± 0.1; Hogg 15 : E(B-V) = 1.13 ± 0.11, V_0 - M_V = 12.50 ± 0.15, log τ ≲ 6.6. The young age of Hogg 15 strongly implies that WR 47 is a member of the cluster. We also determine the mass function of these clusters and obtain a slope Γ = -1.2 (± 0.3) for NGC 4609 which is normal and a somewhat shallow slope (Γ = -0.95 ± 0.5) for Hogg 15.

  9. 推扫式线阵TDI CCD扫描调制传递函数分析%Scanning modulation transfer function analysis of push-broom linear TDI CCD

    Institute of Scientific and Technical Information of China (English)

    杨永明; 李昕阳; 赵嘉鑫

    2011-01-01

    根据线阵TDI CCD离散采样的特点,以采样间距内成像调制度均值为基础,构建了推扫成像模式下线阵TDI CCD扫描方向的调制传递函数.该调制传递函数的数值分析表明:对于像元为10μm的线阵TDI CCD,行转移驱动时钟相数为4,3或2时,Nyquist频率处调制传递函数值分别为0.363,0.333或0.255;行频误差为1%及3%时,不同积分级数下调制传递函数变化曲线表明,增大行频误差及增加积分级数将使调制传递函数值减小,图像分辨率降低.成像实验结果符合所构建调制传递函数的定量分析结论.%Scanning modulation transfer function (MTF) for linear time-delay integration (TDD charge coupled device (CCD) using push-broom imaging mode was established. The MTF which took the discrete sampling characteristics of linear TDI CCD into account, was based on the imaging modulation mean within sampling interval. The numerical analysis of the proposed MTF indicated that the value of MTF at Nyquist frequency for linear TDI CCD with 10 fim pixel size was 0. 363, 0. 333 and 0. 255 respectively, when the number of row transfer phase clocks was 4, 3 and 2. When the row frequency error was 1% or 3%, the changes of MTF curves with different integration numbers implied that increasing the row frequency error and the integration number could decrease the value of MTF and reduce the image resolution. The results of imaging experiment agree with the quantity analysis of the proposed MTF.

  10. Point spread function and centroiding accuracy measurements with the JET-X mirror and MOS CCD detector of the Swift gamma ray burst explorer's X-ray telescope

    Science.gov (United States)

    Ambrosi, R. M.; Abbey, A. F.; Hutchinson, I. B.; Willingale, R.; Wells, A.; Short, A. D. T.; Campana, S.; Citterio, O.; Tagliaferri, G.; Burkert, W.; Brauninger, H.

    2002-08-01

    The optical components of the Swift X-ray telescope (XRT) are already developed items. They are the flight spare X-ray mirror from the JET-X/Spectrum-X program and an MOS CCD (CCD22) of the type currently operating in orbit as part of the EPIC focal plane camera on XMM-Newton (SPIE 4140 (2000) 64). The JET-X mirrors were first calibrated at the Max Plank Institute for Extraterrestrial Physics' (MPE) Panter facility, Garching, Germany in 1996 (SPIE 2805 (1996) 56; SPIE 3114 (1997) 392). Half-energy widths of 16arcsec at 1.5keV were confirmed for the two flight mirrors and the flight spare. The calibration of the flight spare was repeated at Panter in July 2000 in order to establish whether any changes had occurred during the 4yr that the mirror had been in storage at the OAB, Milan, Italy. The results reported in this paper confirm that the resolution of the JET-X mirrors has remained stable over this storage period. In an extension of this test program, the flight spare EPIC camera was installed at the focus of the JET-X mirror to simulate the optical system of the Swift XRT. Tolerances in the mirror focal length, the on-axis and off-axis point spread functions were measured and calibration data sets were used to obtain centroid positions of X-ray point sources. The results confirmed Swift's ability to determine the centroid positions of sources at 100mCrab brightness to better than 1arcsec and provided a calibration of the centroiding process as a function of source flux and off-axis angle. The presence of background events in the image frame introduced errors in the centroiding process and this was accounted for by reducing the sampling area used for the centroiding algorithm.

  11. Different Turbidity Fast Detection Technology Based on CCD%基于CCD的多浊度快速检测技术

    Institute of Scientific and Technical Information of China (English)

    王清泉; 李旭宇; 张茂林

    2013-01-01

    Due to high optical sensitivity and fast image response of CCD,this paper proposed a research combined with the theory of color recognizing for liquid different turbidity fast detection. Through the analysis of light transmission theory and principles of CCD sensor, self-made experiment platform were used to measure the turbidity of multiple sets of formazine standard solution of different turbidity values. The experimental data were proceed used the curve fitting of least squares method. Meanwhile, the measured data of WGZ - 2 turbidity instrument for formazine standard solution of different turbidity values were listed. The math-ematic relationship was achieved between turbidity value and RGB experimental. The system used this method have small errors and good stability in the measurement process. Thus it has good prospect in microbial detection industry.%针对CCD光电灵敏度高和图像响应快的特点,结合颜色识别理论提出一种基于CCD的液体多浊度快速检测方法.通过光透射理论和CCD传感原理分析,自制实验平台对多组标准福尔马肼浊度液进行测量,采用最小二乘法对数据作曲线拟合;同时,对比列出了WGZ-2型浊度仪对标准液测量的数据.通过实验数据分析得出了浊度与RGB值的数学对应关系式,系统采用该方法在测量过程中产生误差小、稳定性好,并取得了良好的效果.在微生物细菌检测行业有较好的应用前景.

  12. Estimating forest aboveground biomass using HJ-1 Satellite CCD and ICESat GLAS waveform data

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The ecosystem in northeastern China and the Russian Far East is a hotspot of scientific research into the global carbon balance.Forest aboveground biomass(AGB) is an important component in the land surface carbon cycle.In this study,using forest inventory data and forest distribution data,the AGB was estimated for forest in Daxinganlin in northeastern China by combining charge-coupled device(CCD) data from the Small Satellite for Disaster and Environment Monitoring and Forecast(HJ-1) and Geoscience Laser Altimeter System(GLAS) waveform data from the Ice,Cloud and land Elevation Satellite(ICESat).The forest AGB prediction models were separately developed for different forest types in the research area at GLAS footprint level from GLAS waveform parameters and field survey plot biomass in the Changqing(CQ) Forest Center,which was calculated from forest inventory data.The resulted statistical regression models have a R2=0.68 for conifer and R2=0.71 for broadleaf forests.These models were used to estimate biomass for all GLAS footprints of forest located in the study area.All GLAS footprint biomass coupled with various spectral reflectivity parameters and vegetation indices derived from HJ-1 satellite CCD data were used in multiple regression analyses to establish biomass prediction models(R2=0.55 and R2=0.52 for needle and broadleaf respectively).Then the models were used to produce a forest AGB map for the whole study area using the HJ-1 data.Biomass data obtained from forest inventory data of the Zhuanglin(ZL) Forest Center were used as independent field measurements to validate the AGB estimated from HJ-1 CCD data(R2=0.71).About 80% of biomass samples had an error less than 20 t ha-1,and the mean error of all validation samples is 5.74 t ha-1.The pixel-level biomass map was then stratified into different biomass levels to illustrate the AGB spatial distribution pattern in this area.It was found that HJ-1 wide-swath data and GLAS waveform data can be combined to

  13. The Al sub x Ga sub 1 sub - sub x As X-ray imaging detector

    CERN Document Server

    Pozela, K; Dileenas, A; Jasutis, V; Dapkus, L; Jucienee, V

    2001-01-01

    An X-ray imaging detector based on the graded-gap Al sub x Ga sub 1 sub - sub x As structures with the CCD camera as an image read-out tool is investigated. High X-ray - light conversion efficiency and X-ray image spatial resolution better than 20 line/mm are obtained.

  14. Comparative study of ionization chamber detectors vis-a-vis a CCD detector for dispersive XAS measurement in transmission geometry

    Energy Technology Data Exchange (ETDEWEB)

    Poswal, A. K.; Agrawal, A.; Bhattachryya, D.; Jha, S. N.; Sahoo, N. K. [Applied Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai -400 085 (India)

    2013-02-05

    We have designed and fabricated parallel plate ionization chamber detectors and voltage vs. current characteristics (V-I curve) of the detectors were recorded with synchrotron radiation to qualify for use in X-ray Absorption Spectroscopy (XAS) measurements. After qualifying the ionization chambers, the detectors were used in the dispersive EXAFS beamline (BL-08) at INDUS-2 SRS in Turbo-XAS geometry. Using the same setup and under the same setting, XAS spectra were also recorded with a CCD detector and the observation on relative performance of the ionization chamber vis-a-vis the CCD detector is presented in this paper.

  15. 富士FinePix F200 EXR Super CCD EXR传感器、全手动功能

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    富士首款搭载图像传感器Super CCD EXR的相机FinePix F200 EXR面世,它采用1/1.6英寸1200万有效像素的Super CCD EXR和完全重新设计的EXR图像处理引擎,能够提供更生动的降噪效果以及更加丰富宽广的画面动态范围。

  16. Design of CCD Video Signal Process Circuit%CCD视频信号处理电路设计

    Institute of Scientific and Technical Information of China (English)

    程鹏飞; 顾明剑; 王模昌

    2006-01-01

    针对e2v公司的CCD67 Back Iluminated NIMO型CCD,设计其视频信号处理电路,包括:前置放大电路、相关双采样(CDS)电路以及低通滤波电路等.实验结果表明,设计的CCD视频信号处理电路能够达到去除噪声、提取有用信号的目的.

  17. Preparation of flame retardant wool using zirconium acetate optimized by CCD

    Energy Technology Data Exchange (ETDEWEB)

    Forouharshad, M., E-mail: Forouharmahdi@gmail.com [Textile Department, Islamic Azad University South Tehran Branch, Tehran (Iran, Islamic Republic of); Montazer, M., E-mail: tex5mm@aut.ac.ir [Textile Department, Amirkabir University of Technology, Center of Excellence in Textile, Tehran (Iran, Islamic Republic of); Moghadam, M.B. [Associate Professor, Department of Statistics, Allameh-Tabataba' i University, Tehran (Iran, Islamic Republic of); Saligheh, O. [Textile Department, Islamic Azad University South Tehran Branch, Young Researchers Club, Tehran (Iran, Islamic Republic of)

    2011-06-10

    Highlights: {yields} We investigate effect of ZrAc and formic acid on the flame retardancy of wool fabric. {yields} The response surface methodology uses for the experimental plan. {yields} The thermal degradation studies by thermal analysis, LOI and vertical flame test. {yields} The fabric surfaces observe by SEM. {yields} Results show an increase in the decomposition temperature, residual mass and LOI. - Abstract: The thermal degradation of wool treated with the flame retardant synergistic system, zirconium acetate, citric acid and formic acid, was studied by thermal analysis, mass loss, limited oxygen index (LOI) and vertical flame test. The surfaces of the wool samples were observed by SEM. The treated wool samples show an increase in the temperature of decomposition, residual mass and LOI in comparison with the untreated wool. The central composite design (CCD) was used for the experimental plan with four variables on the results of flame retardancy. Statistical analysis confirms the optimum conditions obtained by the experimental results.

  18. Spallation Process of Thermally Grown Oxides by In-Situ CCD Monitoring Technique

    Institute of Scientific and Technical Information of China (English)

    QI Yu-hong; Philippe Lours; Yannick Le Maoult

    2009-01-01

    In cooling process of Fe-Cr-AI alloy oxidized at 1 300 ℃, the effect of cooling speed and exposure time on oxide spalled area fraction and successive variety of the spalled region were studied by investigating evolvement of the thermally grown oxide using in-situ CCD monitoring technique. The results showed that oxide spallation can be re-strained by controlling cooling speed and the critical temperature drop of spallation initiation which is closely related to the oxide thickness or exposure time, and the spallation process of a little region may be described in more detail as two routes:from the oxide/substrate interface micro-decohesion, micro-buckles, buckle spreading, buckle crack to spallation and from the interface micro-decohesion, micro-buckles, buckle crack and spallation to the residual oxide decohesion and spallation.

  19. Software development for studies of diffuse scattering using CCD-detectors and synchrotron radiation sources

    CERN Document Server

    Paulmann, C; Bismayer, U

    2001-01-01

    A graphical-user-interface based software system was developed to cover advanced data processing requirements which arise from studies of diffuse scattering in disordered minerals using synchrotron radiation sources and CCD-detectors. The software includes interfaces to standard applications, procedures for numerical processing of large data sets, corrections for sample external scattering and detector-specific distortions, different scaling options to correct the data set against the varying primary beam intensity as well as procedures to reconstruct arbitrary slices in reciprocal space on a regular grid. The software system was successfully applied in studies of diffuse scattering in disordered REE-doped germanates, phase-transition studies of synthetic titanite and studies of the thermal recrystallization behaviour of radiation-damaged (metamict) minerals.

  20. BroCam: a versatile PC-based CCD camera system

    Science.gov (United States)

    Klougart, Jens

    1995-03-01

    At the Copenhagen University, we have developed a compact CCD camera system for single and mosaic CCDs. The camera control and data acquisition is performed by a 486 type PC via a frame buffer located in one ISA-bus slot, communicating to the camera electronics on two optical fibers. The PC can run as well special purpose DOS programs, as in a more general mode under LINUX, a UNIX similar operating system. In the latter mode, standard software packages, such as SAOimage and Gnuplot, are utilized extensively thereby reducing the amount of camera specific software. At the same time the observer feels at ease with the system in an IRAF-like environment. Finally, the LINUX version enables the camera to be remotely controlled.

  1. 富士“Super CCD EXR”传感器

    Institute of Scientific and Technical Information of China (English)

    谢晴

    2008-01-01

    9月23日,富士发布了全新CCD图像传感器“Super CCD EXR”,它在增加CCD像素密度的同时,高效地控制了图像的噪点并且优化了图像的感光度,通过“自然影像技术”保证了超高画质。“自然影像技术”是一套基于那些资深摄影师的拍摄理念,基于那些曾经陶醉于使用如“Velvia”、“PROVIA”等富士专业反转胶片的专业影像工作者的理念的数码影像处理技术。

  2. White light interferometer with color CCD for 3D-surface profiling of microsystems

    Science.gov (United States)

    Upputuri, Paul K.; Pramanik, Manojit; Nandigana, Krishna M.; Kothiyal, Mahendra P.

    2015-03-01

    White light interferometry (WLI) is a state-of-the-art technique for high resolution full-filed 3-D surface profiling of Microsystems. However, the WLI is rather slow, because the number of frames to be recorded and evaluated is large compared to the single wavelength phase shifting interferometry. In this paper, we combine white light interferometer with a single-chip color CCD camera which makes the measurement faster, simpler, and cost-effective. The red-bluegreen (RGB) color interferogram stored in a computer is then decomposed into its individual components and corresponding phase maps for red, green, and blue components are calculated independently. The usefulness of the technique is demonstrated on reflective micro-scale-samples.

  3. Observation of fine particle aggregating behavior induced by high intensity conditioning using high speed CCD

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The aggregating behavior between bubbles and particles induced by high intensity conditioning (HIC) was studied using high speed CCD technique. Bubble size measurement was conducted, and the attachment behavior between bubbles and particles in HIC cell and flotation cell were observed. The results show that in HIC cell, high intensity conditioning creates an advantage environment for the formation of small size bubble due to hydrodynamic cavitations, and these fine bubbles have high probability of bubble-particle collision,which will enhance fine particle flotation. The bubble-particle attachment experiments indicate that in high intensity conditioning cell, a lot of fine bubbles are produced in situ on the surface of fine particles, and most of fine particles are aggregated under the bridging action of fine bubbles. The observation of bubble-particle interaction in flotation cell illustrates that aggregates created by HIC can be loaded more easily by big air bubble in flotation cell than those created by normal conditioning.

  4. VizieR Online Data Catalog: CCD UBV photometry of close visual doubles (Nakos+ 1997)

    Science.gov (United States)

    Nakos, T.; Sinachopoulos, D.; van Dessel, E.

    1996-11-01

    We present V magnitudes, (B-V) and (U-B) colours of close visual double star components, and their differences as well as separations and position angles of 40 visual double stars. The common properties of the members of this sample are the small angular separation ρ, which is less than 7", and the common spectral type of the primaries, which are of G-type. The observations made with the Bessel U, B and V filters, while the astrometry was performed in the V filter only. For the observations, the CCD camera attached to the Cassegrain focus of the 90 cm Dutch telescope, at La Silla, Chile, had been used. From the analysis of the data we concluded that from the sample of the fourty double stars observed seven proved to be physical pairs, while the rest must have common origin components. (3 data files).

  5. Observaciones CCD de los cúmulos abiertos Melotte 105, Ruprecht~75 y Pismis 7

    Science.gov (United States)

    Ahumada, J.; Lapasset, E.

    Se presentan los resultados preliminares de observaciones CCD en cinco colores (UBVRI) de campos de ~2,5' de radio centrados en los cúmulos abiertos Melotte 105, Ruprecht 75 y Pismis 7. Los datos fueron adquiridos en abril de 1996 con el telescopio de 60 cm de la Universidad de Toronto en Las Campanas (Chile), y el detector PM512 en su modo directo. Se muestran los diagramas color-magnitud y color-color preliminares de los cúmulos. Mediante criterios fotométricos se hace una selección de los posibles miembros. También se determinan enrojecimientos, distancias y edades de los cúmulos.

  6. Fotometría CCD en el campo del cúmulo abierto Ruprecht 58

    Science.gov (United States)

    Giorgi, E. E.; Vázquez, R. A.; Seggewiss, W.; Ostrov, P.; Solivella, G. R.

    La región de Vela-Puppis contiene varios cúmulos cuyo estudio puede brindarnos información acerca de la cinemática y el estado evolutivo de la población estelar en las zonas externas del disco galáctico. A través de observaciones CCD en los filtros UBV en el campo del cúmulo abierto Ruprecht 58 (α2000= 8h 14m 41s, δ2000=-31o 57'), se han determinado por primera vez los parámetros fundamentales de este cúmulo tales como distancia, enrojecimiento y edad. Se analiza también la estructura de su secuencia principal y la presencia de gigantes y binarias.

  7. Stroboscopic fluorescence lifetime imaging.

    Science.gov (United States)

    Holton, Mark D; Silvestre, Oscar R; Errington, Rachel J; Smith, Paul J; Matthews, Daniel R; Rees, Paul; Summers, Huw D

    2009-03-30

    We report a fluorescence lifetime imaging technique that uses the time integrated response to a periodic optical excitation, eliminating the need for time resolution in detection. A Dirac pulse train of variable period is used to probe the frequency response of the total fluorescence per pulse leading to a frequency roll-off that is dependent on the relaxation rate of the fluorophores. The technique is validated by demonstrating wide-field, realtime, lifetime imaging of the endocytosis of inorganic quantum dots by a cancer cell line. Surface charging of the dots in the intra-cellular environment produces a switch in the fluorescence lifetime from approximately 40 ns to technique offers lifetime based imaging at video rates with standard CCD cameras and has application in probing millisecond cell dynamics and in high throughput imaging assays.

  8. Glas Spacecraft Attitude Determination Using CCD Star Tracker and 3-AXIS Gyros

    Science.gov (United States)

    Bae, Sungkoo

    The main purpose of the Geoscience Laser Altimeter System (GLAS) is to determine the mass balance of the polar ice-sheets and their contributions to global sea level change. For the mission, the required accuracy for the laser altimeter height measurements is 10 cm. In this case, the direction in which the altimeter beam is pointing relative to the Terrestrial Reference Frame must be known to an accuracy of 1.5 arcseconds assuming the average slope of the ice-sheet surface is one degree. The laser pointing direction will be determined relative to the star field measured by a star tracker in the GLAS spacecraft (ICESAT). Thus, the specification of one arcsecond pointing accuracy requires that the spacecraft attitude determination has comparable accuracy. A Charge Coupled Device (CCD) star tracker and gyros will be installed in an optical bench of ICESAT to determine the spacecraft attitude. Each star position measurement from the CCD star tracker contains approximately five arcseconds position uncertainty depending on the magnitude of the observed stars. Furthermore, gyro output accuracy is corrupted by measurement noise and bias. The main purpose of this dissertation was to investigate the ability to determine the attitude to better than one arcsecond (1σ) using developed estimation algorithms. Extended Kalman Filters and a Batch method were developed and used to estimate the simulated GLAS attitude. The determined attitude showed that the root sum square of roll and pitch errors, which directly affect the laser beam pointing error, reduced to about 0.5 arcsecond (1σ), far better than one arcsecond. In order to support the study result, actual attitude data obtained from the X-ray Timing Explorer spacecraft, were processed with some of algorithms developed for this research. As a part of the generation of the measurement data, a star identification algorithm was developed.

  9. Design Study of An Automtic Forest Fire Monitoring System based on CCD Cameras and ArcObjects%基于CCD摄像机和ArcObjects的森林火灾自动监测系统的设计研究

    Institute of Scientific and Technical Information of China (English)

    窦长娥; 费鲜芸

    2011-01-01

    通过安装在监控地点的CCD摄像机,借助卫星遥感技术、图像处理技术以及网络通讯设施,结合ArcObjects组件开发方式,在探讨森林火灾自动监测系统总体框架的基础上,对系统数据库和核心模块功能进行分析设计,建立基于CCD摄像机和ArcObjects的森林火灾自动监测系统,解决了传统的以人工实地为主的监测方式,采用CCD摄像机视频监控,结合图像处理技术和人工智能技术,提高了视频监控系统的能力.%The system database and core module function were designed based on the discussion of the general framework of the Automatic Forest Fire Monitoring System (AFFMS) by using CCD cameras which were installed in monitoring spots, ArcObjects technologies, satellite remote sensing technology, image processing technology and network communication function. The automated monitoring system for forest fire disaster based on CCD camera and ArcObjects were set up to solve the traditional artificial field observation method. Using CCD camera video monitoring, and combining with image process technology and artificial intelligence technology, the ability of video monitoring system was enhanced.

  10. Hologram production and representation for corrected image

    Science.gov (United States)

    Jiao, Gui Chao; Zhang, Rui; Su, Xue Mei

    2015-12-01

    In this paper, a CCD sensor device is used to record the distorted homemade grid images which are taken by a wide angle camera. The distorted images are corrected by using methods of position calibration and correction of gray with vc++ 6.0 and opencv software. Holography graphes for the corrected pictures are produced. The clearly reproduced images are obtained where Fresnel algorithm is used in graph processing by reducing the object and reference light from Fresnel diffraction to delete zero-order part of the reproduced images. The investigation is useful in optical information processing and image encryption transmission.

  11. Gradient Index in Wear Debris Image Collection

    Institute of Scientific and Technical Information of China (English)

    LVZhi-yong; GAOHui-liang; YANXin-ping

    2004-01-01

    In order to solve a problem of oil on-line monitoring, this instrument adopts a prinripium of self-focus lens of Gradieat index fiber( GRIN Len) to design optics system and magnetic circuit. For the magnetic circuit, the monitor can catch particle wear debris in oil. And for the optics circuit. GRIN Len can transfer image of debris to apparatus of gather image, e . g, CCD and camera. And the image of debris is transferred to computer for analyzing seize and physiognomy of debris. The character of the monitor is of micro weight, micro volume andcurve imaging And it is directly pluged into oil to catch image of wear particles.

  12. Imaging an atomic beam using fluorescence

    Institute of Scientific and Technical Information of China (English)

    Ming He(何明); Jin Wang(王谨); Mingsheng Zhan(詹明生)

    2003-01-01

    A fluorescence detection scheme is applied to image an atomic beam. Using two laser diodes as the sources of detection light and pumping light respectively, the fluorescence image of the atomic beam is then observed by a commercial CCD-camera, which is corresponding to the atomic state and velocity distribution. The detection scheme has a great utilization in the experiments of cold atoms and atomic optics.

  13. State-of-the-art imaging arrays and their applications; Proceedings of the Meeting, San Diego, CA, August 21-23, 1984

    Science.gov (United States)

    Prettyjohns, K. N.

    1984-01-01

    Visible and X-ray imaging arrays are considered, taking into account the future scientific CCD, high sensitivity charge-coupled device (CCD) imagers for television, an analysis of the vertical charge transfer efficiency of a 'line transfer' color image sensor, techniques for operating CCDs in very high speed framing mode, a wide dynamic range CCD camera, recent innovations in CID (Charge Injection Device) cameras, and the design and development of a 1024x1024 visible imager. Other topics explored are related to infrared imaging arrays, techniques for array testing and characterization, new applications and instruments, and imaging arrays in astronomy. Attention is given to the advent of three-dimensional imaging array architectures, a television compatible portable IR-CCD camera system, a method for measuring the modulation transfer function of CCDs using laser speckle, an expedient approach to focal plane testing, a CCD-based parallel analog processor, integrated detector array technology for infrared astronomy, and a star mapper using a linear CCD array.

  14. Bistatic SAR: Imagery & Image Products.

    Energy Technology Data Exchange (ETDEWEB)

    Yocky, David A.; Wahl, Daniel E.; Jakowatz, Charles V,

    2014-10-01

    While typical SAR imaging employs a co-located (monostatic) RADAR transmitter and receiver, bistatic SAR imaging separates the transmitter and receiver locations. The transmitter and receiver geometry determines if the scattered signal is back scatter, forward scatter, or side scatter. The monostatic SAR image is backscatter. Therefore, depending on the transmitter/receiver collection geometry, the captured imagery may be quite different that that sensed at the monostatic SAR. This document presents imagery and image products formed from captured signals during the validation stage of the bistatic SAR research. Image quality and image characteristics are discussed first. Then image products such as two-color multi-view (2CMV) and coherent change detection (CCD) are presented.

  15. Digital image processing in neutron radiography

    CERN Document Server

    Körner, S

    2000-01-01

    automated neutron tomography facility has been built at the Atominstitut with this detector. Digital Image Processing: Due to special detector properties of the CCD-camera NR detector, a standard image processing procedure has been developed that always has to be applied, when the CCD-detector is used. It consists of the following steps: white spot correction - dark frame correction and flat field correction. Radiation, which hits the CCD-chip causes an overflow of one or several pixels, which appears in the image as white spots. These disturbing spots have to be removed by means of digital image processing. Several filters have been tested, but the results were insufficient. Therefore, a new threshold-median-mean value filter was designed and a proper code was written in IDL (interactive data language). The new filter removes white spots very well by hardly blurring the images. A dark frame is an image made with closed camera shutter. It contains undesired detector signal caused by read out noise and dark cu...

  16. Israeli acute paralysis virus: epidemiology, pathogenesis and implications for honey bee health and Colony Collapse Disorder (CCD)

    Science.gov (United States)

    Israeli acute paralysis virus (IAPV) is a widespread RNA virus that was linked with honey bee Colony Collapse Disorder (CCD), the sudden and massive die-off of honey bee colonies in the U.S. in 2006-2007. Here we describe the transmission, prevalence and genetic diversity of IAPV, host transcripti...

  17. Identification and characterization of a novel gene, TrCCD1, and its possible function in hyphal growth and conidiospore development of Trichoderma reesei.

    Science.gov (United States)

    Zhong, Yao Hua; Wang, Tian Hong; Wang, Xiao Li; Zhang, Guang Tao; Yu, Hai Na

    2009-03-01

    To investigate genes with essential functions during hyphal growth or sporulation in the asexual filamentous fungus Trichoderma reesei, we screened a collection of T-DNA insertion mutants and identified the genomic integration events. Two mutants with abnormal phenotypes, named as ccdO and ccdP, were found to have independent T-DNA insertions into a putative TrCCD1 gene locus, the product of which has significant homology to carotenoid cleavage dioxygenases (CCDs). Compared to the parental strain, both mutants tended to produce slow-growing hyphae and had a more than 50% reduction in colony growth rate. Simultaneously, the hyphae of the growing mutants formed wilting tip while the parental strain elongated straightly. To the effect of the TrCCD1 mutation on the conidiospore development, less spores were formed in the mutants than in the parental strain. In addition, disruption of TrCCD1 resulted in another phenotype characterized by a remarkable enhancement in the total carotenoid content. When the wild-type TrCCD1 gene was reintroduced into the ccd mutants, the abnormal phenotypes were rescued. These results suggest that TrCCD1 is involved in carotenoid metabolism and likely required for hyphal growth and conidiospore development in filamentous fungi T. reesei.

  18. Near infrared thermography by CCD cameras and application to first wall components of Tore Supra tokamak; Thermographie proche infrarouge par cameras CCD et application aux composants de premiere paroi du tokamak Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, F.

    1996-06-07

    In the Tokamak TORE-SUPRA, the plasma facing components absorbs and evacuate (active cooling) high power fluxes (up to 10 MW/m{sup 2}). Their thermal behavior study is essential for the success of controlled thermonuclear fusion line. The first part is devoted to the study of power deposition on the TORE-SUPRA actively cooled limiters. A model of power deposition on one of the limiters is developed. It takes into account the magnetic topology and a description of the plasma edge. The model is validated with experimental calorimetric data obtained during a series of shots. This will allow to compare the surface temperature measurements with the predicted ones. The main purpose of this thesis was to evaluate and develop a new temperature measurement system. It works in the near infrared range (890 nm) and is designed to complete the existing thermographic diagnostic of TORE-SUPRA. By using the radiation laws (for a blackbody and the plasma) and the laboratory calibration one can estimate the surface temperature of the observed object. We evaluate the performances and limits of such a device in the harsh conditions encountered in a Tokamak environment. On the one hand, in a quasi ideal situation, this analysis shows that the range of measurements is 600 deg. C to 2500 deg. C. On the other hand, when one takes into account of the plasma radiation (with an averaged central plasma density of 6.10{sup 19} m{sup -3}), we find that the minimum surface temperature rise to 900 deg. C instead of 700 deg. C. In the near future, according to the development of IR-CCD cameras working in the near infrared range up to 2 micrometers, we will be able to keep the good spatial resolution with an improved lower limit for the temperature down to 150 deg. C. The last section deals with a number of computer tools to process the images obtained from experiments on TORE-SUPRA. A pattern recognition application was developed to detect a complex plasma iso-intensity structure. 87 refs.

  19. Aerosol mobility imaging for rapid size distribution measurements

    Science.gov (United States)

    Wang, Jian; Hering, Susanne Vera; Spielman, Steven Russel; Kuang, Chongai

    2016-07-19

    A parallel plate dimensional electrical mobility separator and laminar flow water condensation provide rapid, mobility-based particle sizing at concentrations typical of the remote atmosphere. Particles are separated spatially within the electrical mobility separator, enlarged through water condensation, and imaged onto a CCD array. The mobility separation distributes particles in accordance with their size. The condensation enlarges size-separated particles by water condensation while they are still within the gap of the mobility drift tube. Once enlarged the particles are illuminated by a laser. At a pre-selected frequency, typically 10 Hz, the position of all of the individual particles illuminated by the laser are captured by CCD camera. This instantly records the particle number concentration at each position. Because the position is directly related to the particle size (or mobility), the particle size spectra is derived from the images recorded by the CCD.

  20. Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range

    Science.gov (United States)

    Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

    2013-12-01

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 μm from the current 24 μm spatial resolution (FWHM). The 400 eV-1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 μm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these

  1. Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range

    Energy Technology Data Exchange (ETDEWEB)

    Soman, M.R., E-mail: m.r.soman@open.ac.uk [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Hall, D.J.; Tutt, J.H.; Murray, N.J.; Holland, A.D. [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Schmitt, T.; Raabe, J.; Schmitt, B. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2013-12-11

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 µm from the current 24 µm spatial resolution (FWHM). The 400 eV–1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 µm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these

  2. Quantitative imaging of turbulent and reacting flows

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.H. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing excitation/detection strategies which provide for a quantitative measure of particular flowfield scalars. The standard camera used for the study is an intensified CCD array operated in a conventional video format. The design of the system was based on detailed modeling of signal and image transfer properties of fast UV imaging lenses, image intensifiers and CCD detector arrays. While this system is suitable for direct scalar imaging, derived quantities (e.g. temperature or velocity images) require an exceptionally wide dynamic range imaging detector. To apply these diagnostics to reacting flows also requires a very fast shuttered camera. The authors have developed and successfully tested a new type of gated low-light level detector. This system relies on fast switching of proximity focused image-diode which is direct fiber-optic coupled to a cooled CCD array. Tests on this new detector show significant improvements in detection limit, dynamic range and spatial resolution as compared to microchannel plate intensified arrays.

  3. Ultrafast Imaging using Spectral Resonance Modulation.

    Science.gov (United States)

    Huang, Eric; Ma, Qian; Liu, Zhaowei

    2016-04-28

    CCD cameras are ubiquitous in research labs, industry, and hospitals for a huge variety of applications, but there are many dynamic processes in nature that unfold too quickly to be captured. Although tradeoffs can be made between exposure time, sensitivity, and area of interest, ultimately the speed limit of a CCD camera is constrained by the electronic readout rate of the sensors. One potential way to improve the imaging speed is with compressive sensing (CS), a technique that allows for a reduction in the number of measurements needed to record an image. However, most CS imaging methods require spatial light modulators (SLMs), which are subject to mechanical speed limitations. Here, we demonstrate an etalon array based SLM without any moving elements that is unconstrained by either mechanical or electronic speed limitations. This novel spectral resonance modulator (SRM) shows great potential in an ultrafast compressive single pixel camera.

  4. Compact pnCCD-based X-ray camera with high spatial and energy resolution: a color X-ray camera.

    Science.gov (United States)

    Scharf, O; Ihle, S; Ordavo, I; Arkadiev, V; Bjeoumikhov, A; Bjeoumikhova, S; Buzanich, G; Gubzhokov, R; Günther, A; Hartmann, R; Kühbacher, M; Lang, M; Langhoff, N; Liebel, A; Radtke, M; Reinholz, U; Riesemeier, H; Soltau, H; Strüder, L; Thünemann, A F; Wedell, R

    2011-04-01

    For many applications there is a requirement for nondestructive analytical investigation of the elemental distribution in a sample. With the improvement of X-ray optics and spectroscopic X-ray imagers, full field X-ray fluorescence (FF-XRF) methods are feasible. A new device for high-resolution X-ray imaging, an energy and spatial resolving X-ray camera, is presented. The basic idea behind this so-called "color X-ray camera" (CXC) is to combine an energy dispersive array detector for X-rays, in this case a pnCCD, with polycapillary optics. Imaging is achieved using multiframe recording of the energy and the point of impact of single photons. The camera was tested using a laboratory 30 μm microfocus X-ray tube and synchrotron radiation from BESSY II at the BAMline facility. These experiments demonstrate the suitability of the camera for X-ray fluorescence analytics. The camera simultaneously records 69,696 spectra with an energy resolution of 152 eV for manganese K(α) with a spatial resolution of 50 μm over an imaging area of 12.7 × 12.7 mm(2). It is sensitive to photons in the energy region between 3 and 40 keV, limited by a 50 μm beryllium window, and the sensitive thickness of 450 μm of the chip. Online preview of the sample is possible as the software updates the sums of the counts for certain energy channel ranges during the measurement and displays 2-D false-color maps as well as spectra of selected regions. The complete data cube of 264 × 264 spectra is saved for further qualitative and quantitative processing.

  5. Imaging with a small number of photons

    CERN Document Server

    Morris, Peter A; Bell, Jessica; Boyd, Robert W; Padgett, Miles J

    2014-01-01

    Low-light-level imaging techniques have application in many diverse fields, ranging from biological sciences to security. We demonstrate a single-photon imaging system based on a time-gated inten- sified CCD (ICCD) camera in which the image of an object can be inferred from very few detected photons. We show that a ghost-imaging configuration, where the image is obtained from photons that have never interacted with the object, is a useful approach for obtaining images with high signal-to-noise ratios. The use of heralded single-photons ensures that the background counts can be virtually eliminated from the recorded images. By applying techniques of compressed sensing and associated image reconstruction, we obtain high-quality images of the object from raw data comprised of fewer than one detected photon per image pixel.

  6. Improving the ability of image sensors to detect faint stars and moving objects using image deconvolution techniques.

    Science.gov (United States)

    Fors, Octavi; Núñez, Jorge; Otazu, Xavier; Prades, Albert; Cardinal, Robert D

    2010-01-01

    In this paper we show how the techniques of image deconvolution can increase the ability of image sensors as, for example, CCD imagers, to detect faint stars or faint orbital objects (small satellites and space debris). In the case of faint stars, we show that this benefit is equivalent to double the quantum efficiency of the used image sensor or to increase the effective telescope aperture by more than 30% without decreasing the astrometric precision or introducing artificial bias. In the case of orbital objects, the deconvolution technique can double the signal-to-noise ratio of the image, which helps to discover and control dangerous objects as space debris or lost satellites. The benefits obtained using CCD detectors can be extrapolated to any kind of image sensors.

  7. Partially light-controlled imager based on liquid crystal plate and image intensifier for aurora and airglow measurement.

    Science.gov (United States)

    Tang, Yuanhe; Cao, Xiangang; Liu, Hanchen; Shepherd, G G; Liu, Shulin; Gao, Haiyang; Yang, Xusan; Wu, Yong; Wang, Shuiwei

    2012-04-20

    In order to obtain information both of aurora and airglow in one image by the same detector, a PLCI based on liquid crystal plate LCP and super second-generation image intensifier SSGII is proposed in this research. The detection thresholds of the CCD for aurora and airglow are calculated. For the detectable illumination range of 10(4)-10(-2) lx, the corresponding electron count is 1.57×10(5) - 0.2 for every pixel of CCD. The structure and work principle of the PLCI are described. An LC is introduced in the front of CCD to decrease the intensities of aurora in overexposure areas by means of controlling transmittances pixel by pixel, while an image intensifier is set between the LC and CCD to increase the intensity of the weak airglow. The modulation transfer function MTF of this system is calculated as 0.391 at a Nyquist frequency of 15 lp/mm. The curve of transmittance with regard to gray level for the LC is obtained by calibration experiment. Based on the design principle, the prototype is made and used to take photos of objects under strong light greater than 2×10(5) lx. The clear details of [symbols: see text] presented in the image indicate that the PLCI can greatly improve the imaging quality. The theoretical calculations and experiment results prove that this device can extend the dynamic range and it provides a more effective method for upper atmospheric wind measurement.

  8. Assessment of suspended sediment concentration at the Hangzhou Bay using HJ CCD imagery%杭州湾HJ CCD影像悬浮泥沙遥感定量反演

    Institute of Scientific and Technical Information of China (English)

    刘王兵; 于之锋; 周斌; 蒋锦刚; 潘玉良; 凌在盈

    2013-01-01

    This research explored the potential of the use of the CCD image of the HJ satellite to derive Suspended Sediment Concentrations (SSC) of dynamic water bodies at Hangzhou Bay,which is a typical turbid water body in China.Through the analysis on the correlation between Remote Sensing Reflectance (RTS) and SSC,two apparent reflectance peaks at approximately 690 and 830 nm have been found in the third and fourth bands,respectively.The result also shows that a good correlation exists between Rrs and SSC when the wavelength is more than 700 nm.Based on the measured correlation between SSC and Rrs,the retrieval model is established using the ratio of band4 and band3 as remote sensing factor,and the model determination coefficient of 0.90 is reached.Through the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived Aerosol Optical Depth (AOD) data,which are calculated from the Near Infrared-Short Wave Infrared (NIR-SWIR) atmospheric correction,the atmospheric correction of HJ CCD imagery is realized.The correction-relative errors of the third and fourth bands are 5.54% and 6.97%,respectively.The result demonstrates that the relative error of SSC derived from HJ CCD imagery is 7.12%,and SSC at Hangzhou Bay,which also has significant internal diversity,is much higher than that in the entrance of the Yangtze River.This research demonstrated that HJ CCD imagery can be used to evaluate SSC at Hangzhou Bay,if the appropriate atmospheric correction method and retrieval algorithm are used.%利用环境小卫星CCD(HJ CCD)影像对杭州湾悬浮泥沙浓度(SSC)进行了反演研究.通过对杭州湾水体遥感反射率(Rrs)与SSC进行相关性分析发现,在690nm和830nm左右出现显著的反射峰,分别位于HJCCD影像的第3和第4波段范围内;大于700nm波长处的Rrs与SSC相关性较好.基于实测Rrs和SSC之间的相关关系,利用第4和第3波段比值作为遥感因子建立SSC反演模型,模型决定系数达到0.90.借鉴近红外-短

  9. A Bayesian Super-Resolution Approach to Demosaicing of Blurred Images

    OpenAIRE

    Molina Rafael; Katsaggelos Aggelos K; Vega Miguel

    2006-01-01

    Most of the available digital color cameras use a single image sensor with a color filter array (CFA) in acquiring an image. In order to produce a visible color image, a demosaicing process must be applied, which produces undesirable artifacts. An additional problem appears when the observed color image is also blurred. This paper addresses the problem of deconvolving color images observed with a single coupled charged device (CCD) from the super-resolution point of view. Utilizing the Bayes...

  10. Far ultraviolet auroral imager

    Institute of Scientific and Technical Information of China (English)

    FU LiPing; WANG YongMei; WANG YingJian; ZHANG ZhongMou; LU JianGong

    2009-01-01

    Reviewing the technology development of imaging the global FUV auroral morphology,we introduce a space-based FUV auroral imager prototype developed by the Center for Space Science and Applied Research(CSSAR).It is designed to obtain continuous observations on the temporal and spatial morphology of the aurora which occupies highly elliptical high-altitude near-polar orbits.Primarily composed of a telescope system,image intensifier system,CCD,and collection and control system,the instrument works in the spectral region from 140-190 nm in the field of view 25°×25°,and the spatial resolution is better than 0.1°.

  11. Far ultraviolet auroral imager

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Reviewing the technology development of imaging the global FUV auroral morphology,we introduce a space-based FUV auroral imager prototype developed by the Center for Space Science and Applied Research(CSSAR).It is designed to obtain continuous observations on the temporal and spatial morphology of the aurora which occupies highly elliptical high-altitude near-polar orbits.Primarily composed of a telescope system,image intensifier system,CCD,and collection and control system,the instrument works in the spectral region from 140―190 nm in the field of view 25°×25°,and the spatial resolution is better than 0.1°.

  12. High-Procession Eye Tracking Using Fundus Images

    Science.gov (United States)

    Mulligan, Jeffrey B.

    1996-01-01

    Fundus images provide high optical gain for eye movement tracking, i.e. large image displacements occur as a result of small eye rotations. Subpixel registration techniques can provide resolution better than 1 arc minute using images acquired with a CCD camera. Ocular torsion may also be estimated, with a precision of approximately 0.1 degree. This talk will discuss the software algorithms used to attain this performance.

  13. Note: thermal imaging enhancement algorithm for gas turbine aerothermal characterization.

    Science.gov (United States)

    Beer, S K; Lawson, S A

    2013-08-01

    An algorithm was developed to convert radiation intensity images acquired using a black and white CCD camera to thermal images without requiring knowledge of incident background radiation. This unique infrared (IR) thermography method was developed to determine aerothermal characteristics of advanced cooling concepts for gas turbine cooling application. Compared to IR imaging systems traditionally used for gas turbine temperature monitoring, the system developed for the current study is relatively inexpensive and does not require calibration with surface mounted thermocouples.

  14. Two-dimensional X-ray imaging using plastic scintillating fiber array

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Due to its low cost,flexibility and convenience for long distance dala transfer,plastic scintillation fiber (PSF)have been increasingly used in building detectors or sensors for detecting various radiations and imaging.In this work,the performance of using PSF coupled with charge-coupled devices(CCD)to build are adetectors for 2D X-ray imaging is studied.We describe the experimental setup and show the obtained images from CCD.Modulation Transfer Function(MTF)of the PSF array is also presented and compared to earlier reports.

  15. High-resolution two-dimensional image upconversion of incoherent light

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2010-01-01

    We consider a technique for high-resolution image upconversion of thermal light. Experimentally, we demonstrate cw upconversion with a resolution of more than 200 × 1000 pixels of thermally illuminated objects. This is the first demonstration (to our knowledge) of high-resolution cw image...... upconversion. The upconversion method promises an alternative route to high-quantum-efficiency all-optical imaging in the mid-IR wavelength region and beyond using standard CCD cameras. A particular advantage of CCD cameras compared to state-of-the-art thermal cameras is the possibility to tailor and tune...

  16. A Practical Solution for 77 K Fluorescence Measurements Based on LED Excitation and CCD Array Detector.

    Directory of Open Access Journals (Sweden)

    Jacob Lamb

    Full Text Available The fluorescence emission spectrum of photosynthetic microorganisms at liquid nitrogen temperature (77 K provides important insights into the organization of the photosynthetic machinery of bacteria and eukaryotes, which cannot be observed at room temperature. Conventionally, to obtain such spectra, a large and costly table-top fluorometer is required. Recently portable, reliable, and largely maintenance-free instruments have become available that can be utilized to accomplish a wide variety of spectroscopy-based measurements in photosynthesis research. In this report, we show how to build such an instrument in order to record 77K fluorescence spectra. This instrument consists of a low power monochromatic light-emitting diode (LED, and a portable CCD array based spectrometer. The optical components are coupled together using a fiber optic cable, and a custom made housing that also supports a dewar flask. We demonstrate that this instrument facilitates the reliable determination of chlorophyll fluorescence emission spectra for the cyanobacterium Synechocystis sp. PCC 6803, and the green alga Chlamydomonas reinhardtii.

  17. CCD SDSS gr photometry of poorly studied star clusters in the Large Magellanic Cloud

    CERN Document Server

    Piatti, Andres E

    2014-01-01

    We present for the first time CCD SDSS gr photometry, obtained at the Gemini South telescope with the GMOS attached, of stars in the field of the poorly studied star clusters NGC1768, HS85, SL676, NGC2107, NGC2190, and SL866, which are distributed in the main body of the Large Magellanic Cloud. We applied a subtraction procedure to statistically clean the cluster CMDs from field star contamination. In order to disentangle cluster features from those belonging to their surrounding fields, we applied a subtraction procedure which makes use of variable cells to reproduce the field star Color-Magnitude Diagrams (CMDs) as closely as possible. We then traced their stellar density radial profiles from star counts performed over the cleaned field stars dataset and derived their radii. Using the cleaned cluster CMDs, we estimated ages and metallicities from matching theoretical isochrones computed for the SDSS system. The studied star clusters have ages from 0.1 up to 2.0 Gyr and are of slightly metal-poor metal conte...

  18. Three Years of Mira Variable CCD Photometry: What Has Been Learned?

    CERN Document Server

    Mais, D E; Stencel, R E

    2007-01-01

    The subject of micro-variability among Mira stars has received increased attention since DeLaverny et al. (1998) reported short-term brightness variations in 15 percent of the 250 Mira or Long Period Variable stars surveyed using the broadband 340 to 890 nm Hp filter on the HIPPARCOS satellite. The abrupt variations reported ranged 0.2 to 1.1 magnitudes, on time-scales between 2 to 100 hours, with a preponderance found nearer Mira minimum light phases. However, the HIPPARCOS sampling frequency was extremely sparse and required confirmation because of potentially important atmospheric dynamics and dust-formation physics that could be revealed. We report on Mira light curve sub-structure based on new CCD V and R band data, augmenting the known light curves of Hipparcos-selected long period variables [LPVs], and interpret same in terms of [1] interior structure, [2] atmospheric structure change, and/or [3] formation of circumstellar [CS] structure. We propose that the alleged micro-variability among Miras is lar...

  19. CCD UBVRI PHOTOMETRY OF THE GALACTIC OPEN CLUSTERS: BE 89, RU 135, AND BE 10

    Directory of Open Access Journals (Sweden)

    Inci Akkaya

    2010-01-01

    Full Text Available Presentamos los parámetros fundamentales de enrojecimiento, metalicidad, edad y distancia de los cúmulos abiertos poco estudiados Be 89, Ru 135 y Be 10, derivados de la fotometría CCD UBVRI. Los enrojecimientos interestelares se midieron en el diagrama color-color, y las metalicidades fotométricas se derivaron del exceso de ultravioleta de las estrellas tipo F. Las distancias y edades se obtuvieron ajustando isocronas a las secuencias observadas en cinco diagramas colormagnitud diferentes. Los promedios ponderados de los módulos de distancia y distancias heliocéntricas [(V0 ¿ MV , d(kpc] son: (11.m 90 ± 0.m 06, 2.4 ± 0.06 para Be 89, (9.m 58 ± 0.m 07, 0.81 ± 0.03 para Ru 135 y (11.m 16 ± 0.m 06, 1.7 ± 0.05 para Be 10, mientras que los promedios ponderados para las edades [log(A,A(Gyr] son: (9.58 ± 0.06, 3.8 ± 0.6 para Be 89, (9.58 ± 0.06, 3.8 ± 0.7 para Ru 135 y (9.06 ± 0.05, 1.08 ± 0.08 para Be 10.

  20. Validation of Noninvasive MOEMS-Assisted Measurement System Based on CCD Sensor for Radial Pulse Analysis

    Directory of Open Access Journals (Sweden)

    Rolanas Dauksevicius

    2013-04-01

    Full Text Available Examination of wrist radial pulse is a noninvasive diagnostic method, which occupies a very important position in Traditional Chinese Medicine. It is based on manual palpation and therefore relies largely on the practitioner’s subjective technical skills and judgment. Consequently, it lacks reliability and consistency, which limits practical applications in clinical medicine. Thus, quantifiable characterization of the wrist pulse diagnosis method is a prerequisite for its further development and widespread use. This paper reports application of a noninvasive CCD sensor-based hybrid measurement system for radial pulse signal analysis. First, artery wall deformations caused by the blood flow are calibrated with a laser triangulation displacement sensor, following by the measurement of the deformations with projection moiré method. Different input pressures and fluids of various viscosities are used in the assembled artificial blood flow system in order to test the performance of laser triangulation technique with detection sensitivity enhancement through microfabricated retroreflective optical element placed on a synthetic vascular graft. Subsequently, the applicability of double-exposure whole-field projection moiré technique for registration of blood flow pulses is considered: a computational model and representative example are provided, followed by in vitro experiment performed on a vascular graft with artificial skin atop, which validates the suitability of the technique for characterization of skin surface deformations caused by the radial pulsation.

  1. New CCD photometry for the extreme lower mass-ratio binary AW Ursae Majoris

    Science.gov (United States)

    Yang, Yuangui

    2008-04-01

    This paper presents charge-couple device (CCD) photometric observations for the eclipsing binary AW UMa. The V-band light curve in 2007 was analyzed using the 2003 version of the Wilson Devinney code. It is confirmed that AW UMa is a total eclipsing binary with a higher degree of contact f=80.2% and a lower mass ratio of q=0.076. From the ( O- C) curve, the orbital period shows a continuous period decrease at a rate of dP/ dt=-2.05×10-7 d yr-1. The long-term period decrease suggested that AW UMa is undergoing the mass transfer from the primary component to the secondary one, accompanied by angular momentum loss due to mass outflow L 2. Weak evidence indicates that there exists a cyclic variation with a period of 17.6 yr and a small amplitude of A=0. d 0019, which may be attributed to the light-time effect via the third body. If the existence of an additional body is true, it may remove a great amount of angular momentum from the central system. For this kind of contact binary, as the orbital period decreases, the shrinking of the inner and outer critical Roche lobes will cause the contact degree f to increase. Finally, this kind of binary will merge into a single rapid-rotation star.

  2. Deep, Wide-field CCD Photometry for the Open Cluster NGC3532

    CERN Document Server

    Clem, James L; Hoard, D W; Wachter, Stefanie

    2011-01-01

    We present the results of a deep, wide-field CCD survey for the open cluster NGC~3532. Our new $BV(RI)_{c}$ photometry effectively covers a one square degree area and reaches an unprecedented depth of $V\\sim21$ to reveal that NGC~3532 is a rich open cluster that harbors a large number of faint, low-mass stars. We employ a number of methods to reduce the impact of field star contamination in the cluster color-magnitude diagrams, including supplementing our photometry with $JHK_{s}$ data from the 2MASS catalog. These efforts allow us to define a robust sample of candidate main sequence stars suitable for a purely empirical determination of the cluster's parameters by comparing them to the well-established Hyades main sequence. Our results confirm previous findings that NGC~3532 lies fairly near to the Sun [$(m-M)_0=8.46\\pm0.05$; $492^{+12}_{-11}$~pc] and has an extremely low reddening for its location near the Galactic plane [$E(B-V)=0.028\\pm0.006$]. Moreover, an age of $\\sim300$\\,Myr has been derived for the c...

  3. A CCD photometric study of the newly discovered contact binary ASAS 134738+0410.1

    CERN Document Server

    Deb, Sukanta; Seshadri, T R; Gupta, Ranjan

    2010-01-01

    We present a CCD photometric study of the star with ASAS ID 134738 + 0410.1 using V band observations obtained from the $IUCAA$ Girawali Observatory (IGO) 2-metre telescope, India. The star was selected from the $\\delta$ Scuti database of All Sky Automated Survey (ASAS) (Pojmanski 2002). Our analysis reveals that the star is not a $\\delta$ Scuti variable but is in fact a W UMa type contact binary with an orbital period of 0.2853067 day. Two new times of primary and secondary minima were determined from the observed data. A preliminary solution obtained using the Wilson-Devinney light curve modelling technique indicates that the star is more likely a partially-eclipsing W UMa type contact binary. However, the determination of actual subtype of this binary is quite impossible from the photometry alone, as the observed light curve can fitted for both A- and W-type solutions. The exact classification of this binary needs to be determined from high resolution spectroscopy.

  4. High-resolution CCD spectra of stars in globular clusters. I - Oxygen in M13

    Science.gov (United States)

    Leep, E. M.; Wallerstein, G.; Oke, J. B.

    1986-01-01

    High-resolution (0.3 A) CCD spectra obtained at the 200 in. coude spectrograph have been analyzed for the abundances of O, Sc, Fe, and La in four stars in the globular cluster M13. Fe/H abundance is found to be = -1.6, as found by many other observers of this cluster. For three stars O/Fe abundance is found to be = +0.3 + or - 0.1, which is similar to O/Fe ratios in other globular clusters and metal-poor field stars. For star II-67, no oxygen line is visible at 6300 A and O/Fe abundance is found to be not greater than -0.4 (for a high carbon content) and not greater than -0.7 (for a low carbon content). The latter is more likely to be correct. Two possible explanations of the oxygen deficiency in II-67 are discussed: primordial deficiency, and CNO cycling at or above a temperature of 25,000,000 K.

  5. Multicolor CCD Photometry and Period Analysis of Three Pulsating Variable Stars

    Science.gov (United States)

    Alton, K. B.

    2014-06-01

    Multicolor CCD photometry of three pulsating variable stars, RR Leo, TYC 790-1124-1, and V337 Ori has lead to period solutions using Fourier methods on light curves acquired at UnderOak Observatory (UO). New photometric data from RR Leo largely corroborate findings previously reported for this well studied RRab variable. An O-C diagram period analysis using a rich historical record of time-of-maximum light data produced an updated quadratic ephemeris for RR Leo. Although not compelling, underlying sinusoidal variability in the quadratic residuals suggest that this intrinsic variable may also have a gravitationally bound cohort. Light curves from the poorly studied HADS variable TYC 790-1124-1 were remarkably symmetrical; this behavior was observed during a single campaign in 2011 which lasted only one month. Fortunately, starting nearly a decade ago photometric data were also captured by the ASAS survey between 2002 and 2009; the combined results reveal that the fundamental period and light curve shape for TYC 790-1124-1 has substantively remained unchanged. V337 Ori has only been studied by two other investigative groups within the past three years; their results and the two most prominent pulsation frequencies at 4.96877 and 6.72 c/d detected in the UO light curves are in good agreement. Notably this HADS exhibits significant cycle-to-cycle amplitude variability which may be related to these and other pulsation modes not detected in the present study.

  6. CCD photometry of the globular cluster M15: RR lyrae fourier decomposition and physical parameters

    Directory of Open Access Journals (Sweden)

    A. Arellano Ferro

    2006-01-01

    Full Text Available Se reportan los resultados de la fotometría CCD a través de los filtros V y R de 33 estrellas RR Lyrae conocidas en M15. Los períodos de algunas variables han sido recalculados y se dan nuevas efemérides. El efecto Blazhko, reportado previamente para V12 no ha sido detectado. Con la técnica de descomposición de Fourier de las curvas de luz, se han estimado los parámetros físicos de las variables de tipos RRab y RRc. El cúmulo es del tipo Oosterhoff II y los valores determinados para el contenido de hierro y la distancia son: [Fe/H]= 1:98 0:24 y d = 8:67 0:41 kpc, respectivamente. Los valores medios de los parámetros físicos de las estrellas RR Lyrae colocan al cúmulo correctamente en las secuencias tipo de Oosterhoff –metalicidad y metalicidad– temperatura efectiva, válidas para cúmulos globulares. Se han encontrado evidencias de evolución, desde la Rama Horizontal de Edad Cero, de las estrellas RRc pero no de las RRab.

  7. CCD UBV Photometry and Kinematics of the Open Cluster NGC 225

    CERN Document Server

    Bilir, S; Yontan, T; Guver, T; Bakis, V; Ak, T; Ak, S; Paunzen, E; Eker, Z

    2016-01-01

    We present the results of CCD $UBV$ photometric and spectroscopic observations of the open cluster NGC 225. In order to determine the structural parameters of NGC 225, we calculated the stellar density profile in the cluster's field. We estimated the probabilities of the stars being physical members of the cluster using the existing astrometric data. The most likely members of the cluster were used in the determination of the astrophysical parameters of the cluster. We calculated the mean radial velocity of the cluster as $V_{r}=-8.3\\pm 5.0$ km s$^{-1}$ from the optical spectra of eight stars in the cluster's field. Using the U-B vs B-V two-colour diagram and UV excesses of the F-G type main-sequence stars, the reddening and metallicity of NGC 225 were inferred as $E(B-V)=0.151\\pm 0.047$ mag and $[Fe/H]=-0.11\\pm 0.01$ dex, respectively. We fitted the colour-magnitude diagrams of NGC 225 with the PARSEC isochrones and derived the distance modulus, distance and age of the cluster as $\\mu_{V}=9.3\\pm 0.07$ mag, d...

  8. The Blazhko behaviour of RR Geminorum I - CCD photometric results in 2004

    CERN Document Server

    Jurcsik, J; Varadi, M; Szeidl, B; Washuettl, A; Weber, M; Dekany, I; Hurta, Z; Lakatos, B; Posztobanyi, K; Szing, A; Vida, K; Hurta, Zs.

    2004-01-01

    Extended CCD monitoring of RR Gem revealed that it is a Blazhko type RRab star with the shortest Blazhko period (7.23d) and smallest modulation amplitude (Delta Mmax<0.1 mag) currently known. The short period of the modulation cycle enabled us to obtain complete phase coverage of the pulsation at each phase of the modulation. This is the first multicolour observation of a Blazhko star which is extended enough to define accurate mean magnitudes and colours of the variable at different Blazhko phases. Small, but real, changes in the intensity mean colours at different Blazhko phases have been detected. The Fourier analysis of the light curves shows that, in spite of the mmag and smaller order of the amplitudes, the triplet structure is noticeable up to about the 14th harmonic. The modulation is concentrated to a very narrow, 0.2 phase range of the pulsation, centred on the supposed onset of the H emission during rising light. These observational results raise further complications for theoretical explanation...

  9. Research on detecting heterogeneous fibre from cotton based on linear CCD camera

    Science.gov (United States)

    Zhang, Xian-bin; Cao, Bing; Zhang, Xin-peng; Shi, Wei

    2009-07-01

    The heterogeneous fibre in cotton make a great impact on production of cotton textile, it will have a bad effect on the quality of product, thereby affect economic benefits and market competitive ability of corporation. So the detecting and eliminating of heterogeneous fibre is particular important to improve machining technics of cotton, advance the quality of cotton textile and reduce production cost. There are favorable market value and future development for this technology. An optical detecting system obtains the widespread application. In this system, we use a linear CCD camera to scan the running cotton, then the video signals are put into computer and processed according to the difference of grayscale, if there is heterogeneous fibre in cotton, the computer will send an order to drive the gas nozzle to eliminate the heterogeneous fibre. In the paper, we adopt monochrome LED array as the new detecting light source, it's lamp flicker, stability of luminous intensity, lumens depreciation and useful life are all superior to fluorescence light. We analyse the reflection spectrum of cotton and various heterogeneous fibre first, then select appropriate frequency of the light source, we finally adopt violet LED array as the new detecting light source. The whole hardware structure and software design are introduced in this paper.

  10. Comparison of CCD, CMOS and Hybrid Pixel x-ray detectors: detection principle and data quality

    Science.gov (United States)

    Allé, P.; Wenger, E.; Dahaoui, S.; Schaniel, D.; Lecomte, C.

    2016-06-01

    We compare, from a crystallographic point of view, the data quality obtained using laboratory x-ray diffractometers equipped with a Molybdenum micro-source using different detector types: CCD, CMOS and XPAD hybrid pixel. First we give an overview of the working principle of these different detector types with a focus on their principal differences and their impact on the data quality. Then, using the example of an organic crystal, a comparison between the detector systems concerning the raw data statistics, the refinement agreement factors, the deformation electron density maps, and the residual density after multipolar refinement is presented. It is found that the data quality obtained with the XPAD detector is the best, even though the detection efficiency at the Mo energy (17.5 keV) is only 37% due to the Si-sensor layer thickness of 300 μm. Finally, we discuss the latest x-ray detector developments with an emphasis on the sensor material, where replacing Si by another material such as GaAs would yield detection efficiencies close to 100%, up to energies of 40 keV for hybrid pixel detectors.

  11. CCD BVRI and 2MASS photometry of the poorly studied open cluster NGC 6631

    Directory of Open Access Journals (Sweden)

    A.L. Tadross

    2014-12-01

    Full Text Available Here we have obtained the BVRI CCD photometry down to a limiting magnitude of V∼20 for the southern poorly studied open cluster NGC 6631. It is observed from the 1.88 m Telescope of Kottamia Observatory in Egypt. About 3300 stars have been observed in an area of ∼10′×10′ around the cluster center. The main photometric parameters have been estimated and compared with the results that determined for the cluster using JHKs 2MASS photometric database. The cluster’s diameter is estimated to be 10 arcmin; the reddening E(B-V=0.68 ± 0.10 mag, E(J-H=0.21 ± 0.10 mag, the true modulus (m-Mo=12.16 ± 0.10 mag, which corresponds to a distance of 2700 ± 125 pc and age of 500 ± 50 Myr.

  12. Research on Pixel Sensitivity Nonuniformity and Treatment Method of CCD%CCD 像元灵敏度非均匀性及处理方法研究

    Institute of Scientific and Technical Information of China (English)

    郭雨蓉; 李小波; 王锴磊; 崔桂利; 赵天承

    2014-01-01

    The principle of causing the pixel response nonuniformity of CCD and the problems of CCD application are researched .An improved normalization algorithm is used by the method .Because of the arts and crafts , every pixel of charge coupled device has a different sensitivity .This problem can be solved by this algorithm . And the source error can be reduced effectively .It has a great significance to improve the measurement accuracy of CCD .%研究了CCD像元灵敏度非均匀性产生的原理和给CCD应用带来的问题。采用改进的归一化算法对CCD像元灵敏度进行修正,解决了CCD图像传感器由于加工工艺造成的各像元光电灵敏度具有差异的问题。该方法有效的减小了CCD的原始误差,对提高CCD测量准确度具有重要意义。

  13. Charge-Transfer CMOS Image Sensors: Device and Radiation Aspects

    NARCIS (Netherlands)

    Ramachandra Rao, P.

    2009-01-01

    The aim of this thesis was twofold: investigating the effect of ionizing radiation on 4-T CMOS image sensors and the possibility of realizing a CCD like sensor in standard 0.18-μm CMOS technology (for medical applications). Both the aims are complementary; borrowing and lending many aspects of radia

  14. Infrared hyperspectral upconversion imaging using spatial object translation

    DEFF Research Database (Denmark)

    Kehlet, Louis Martinus; Sanders, Nicolai Højer; Tidemand-Lichtenberg, Peter;

    2015-01-01

    In this paper hyperspectral imaging in the mid-infrared wavelength region is realised using nonlinear frequency upconversion. The infrared light is converted to the near-infrared region for detection with a Si-based CCD camera. The object is translated in a predefined grid by motorized actuators...

  15. New target carotenoids for CCD4 enzymes are revealed with the characterization of a novel stress-induced carotenoid cleavage dioxygenase gene from Crocus sativus.

    Science.gov (United States)

    Rubio-Moraga, Angela; Rambla, José Luis; Fernández-de-Carmen, Asun; Trapero-Mozos, Almudena; Ahrazem, Oussama; Orzáez, Diego; Granell, Antonio; Gómez-Gómez, Lourdes

    2014-11-01

    Apocarotenoid compounds play diverse communication functions in plants, some of them being as hormones, pigments and volatiles. Apocarotenoids are the result of enzymatic cleavage of carotenoids catalyzed by carotenoid cleavage dioxygenase (CCD). The CCD4 family is the largest family of plant CCDs, only present in flowering plants, suggesting a functional diversification associated to the adaptation for specific physiological capacities unique to them. In saffron, two CCD4 genes have been previously isolated from the stigma tissue and related with the generation of specific volatiles involved in the attraction of pollinators. The aim of this study was to identify additional CCD4 members associated with the generation of other carotenoid-derived volatiles during the development of the stigma. The expression of CsCCD4c appears to be restricted to the stigma tissue in saffron and other Crocus species and was correlated with the generation of megastigma-4,6,8-triene. Further, CsCCD4c was up-regulated by wounding, heat, and osmotic stress, suggesting an involvement of its apocarotenoid products in the adaptation of saffron to environmental stresses. The enzymatic activity of CsCCD4c was determined in vivo in Escherichia coli and subsequently in Nicotiana benthamiana by analyzing carotenoids by HPLC-DAD and the volatile products by GC/MS. β-Carotene was shown to be the preferred substrate, being cleaved at the 9,10 (9',10') bonds and generating β-ionone, although β-cyclocitral resulting from a 7,8 (7',8') cleavage activity was also detected at lower levels. Lutein, neoxanthin and violaxanthin levels in Nicotiana leaves were markedly reduced when CsCCD4c is over expressed, suggesting that CsCCD4c recognizes these carotenoids as substrates.

  16. Insights into the formation of carlactone from in-depth analysis of the CCD8-catalyzed reactions

    KAUST Repository

    Bruno, Mark

    2017-02-10

    Strigolactones (SLs) are a new class of phytohormones synthesized from carotenoids via carlactone. The complex structure of carlactone is not easily deducible from its precursor, a cis-configured β-carotene cleavage product, and is thus formed via a poorly understood series of reactions and molecular rearrangements, all catalyzed by only one enzyme, the carotenoid cleavage dioxygenase 8 (CCD8). Moreover, the reactions leading to carlactone are expected to form a second, yet unidentified product. In this study, we used (13) C and (18) O-labelling to shed light on the reactions catalyzed by CCD8. The characterization of the resulting carlactone by LC-MS and NMR, and the identification of the assumed, less accessible second product allowed us to formulate a minimal reaction mechanism for carlactone generation. This article is protected by copyright. All rights reserved.

  17. Real time monitoring of coating status for microsphere target with digital image difference method

    Institute of Scientific and Technical Information of China (English)

    Baixuan Shi(施柏煊); Xiao Huang(黄晓); Caifeng Li(李彩凤)

    2003-01-01

    Digital image difference method monitorring coating status of microsphere targets automatically is sug-gested. A CCD micro-imaging system is developed for monitoring the status of bouncing and adherencebetween microspheres and the bouncing pan. A new bouncing pan with multiple holes is adopted formicrosphere coating to enhance the microsphere coating efficiency.

  18. Diseño, construcción y uso de una cámara CCD para observaciones astronómicas

    OpenAIRE

    Roca Molina, Felipe

    2014-01-01

    En este proyecto se presenta la construcción de una cámara CCD (dispositivo de carga acoplada) para su uso posterior en aplicaciones astronómicas siguiendo y adaptando las indicaciones del texto The CCD Camera Cookbook (Berry et al., 1994). Se explica el funcionamiento de una cámara CCD a nivel sencillo particularizada para el chip TC211 de la casa Texas Instuments. Se ha diseñado y construido las placas necesarias y se ha realizado un amplio estudio del funcionamiento de la...

  19. The Solar Neighborhood XXIII CCD Photometric Distance Estimates of SCR Targets -- 77 M Dwarf Systems within 25 Parsecs

    OpenAIRE

    Winters, Jennifer G.; Henry, Todd J.; Jao, Wei-Chun; Subasavage, John P.; Finch, Charlie T.; Hambly, Nigel C.

    2010-01-01

    We present CCD photometric distance estimates of 100 SCR (SuperCOSMOS RECONS) systems with $\\mu$ $\\geq$ 0$\\farcs$18/yr, 28 of which are new discoveries previously unpublished in this series of papers. These distances are estimated using a combination of new $VRI$ photometry acquired at CTIO and $JHK$ magnitudes extracted from 2MASS. The estimates are improvements over those determined using photographic plate $BRI$ magnitudes from SuperCOSMOS plus $JHK$, as presented in the original discovery...

  20. Tests of a new CCD-camera based neutron radiography detector system at the reactor stations in Munich and Vienna

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, E.; Pleinert, H. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Schillinger, B. [Technische Univ. Muenchen (Germany); Koerner, S. [Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria)

    1997-09-01

    The performance of the new neutron radiography detector designed at PSI with a cooled high sensitive CCD-camera was investigated under real neutronic conditions at three beam ports of two reactor stations. Different converter screens were applied for which the sensitivity and the modulation transfer function (MTF) could be obtained. The results are very encouraging concerning the utilization of this detector system as standard tool at the radiography stations at the spallation source SINQ. (author) 3 figs., 5 refs.

  1. Rice Fields Mapping in Fragmented Area Using Multi-Temporal HJ-1A/B CCD Images

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2015-03-01

    Full Text Available Rice is one of the most important crops in the world; meanwhile, the rice field is also an important contributor to greenhouse gas methane emission. Therefore, it is important to get an accurate estimation of rice acreage for both food production and climate change related studies. The eastern plain region is one of the major single-cropped rice (SCR growing areas in China. Subjected to the topography and intensified human activities, the rice fields are generally fragmented and irregular. How remote sensing can meet this challenge to accurately estimate the acreage of the rice in this region using medium-resolution imagery is the topic of this study. In this study, the applicability of the Chinese HJ-1A/B satellites and a two-band enhanced vegetation index (EVI2 was investigated. Field campaigns were carried out during the rice growing season and ground-truth data were collected for classification accuracy assessments in 2012. A stepwise classification strategy utilizing the EVI2 signatures during key phenology stages, i.e., the transplanting and the vegetative to reproductive transition phases, of the SCR was proposed, and the overall classification accuracy was 91.7%. The influence of the mixed pixel and boundary effects to classification accuracy was also investigated. This work demonstrates that the Chinese HJ-1A/B data are suitable data source to estimating SCR cropping area under complex land cover composition.

  2. 面阵探测器 KAI-04022驱动电路设计与实现∗%Design and implementation of area array-CCD KAI-04022 driving circuit

    Institute of Scientific and Technical Information of China (English)

    马天翔

    2015-01-01

    The operating principle of the interline image CCD sensor KAI-04022 was introduced.Due to the characteris-tics of the chip itself,the driving circuit was designed.The driving signal was divided into two level signals and three lev-el signals according to the number of signal level state.The two level signal output was realized by using the diode clam-ping circuit and MOSFET driver.The three level signals were realized through the driving signal result from AFE chip AD9920A.Under the offset current supplied by the voltage-controlled constant current source circuit,the weak driving signal was amplified output through the non-inverting emitter follower circuit composed by the current feedback ampli-fier.Ultimately,the driving was supplied for the CCD.The experimental results show that when the pixel clock was 40 MHz,the rising edge of the driving signal was 4 ns and the amplitude was 4.2 V.The two rising edges of the three level driving signal were both 50 ns.And the voltage pulse signal,whose amplitude was 48 V and pulse width was 4 μs,was produced by the electronic shutter circuit based on the substrate voltage.The signal produced by every driving circuit met the requirements and was able to supply the driving for the interline CCD.%介绍了行间转移 CCD 芯片 KAI-04022的工作原理,根据芯片自身的特点设计了驱动电路。首先,按照信号电平状态多少把驱动信号分为两电平信号和三电平信号两种类型,利用二极管钳位电路和 MOSFET 驱动器实现两电平信号的输出,而三电平信号的实现是利用 AFE 芯片 AD9920A 产生弱驱动能力信号,此信号在压控恒流源电路提供的偏置电流作用下,经过电流型反馈放大器组成的同相射随电路放大输出,为 CCD 芯片提供驱动。实验结果表明,像素时钟为40 MHz 时,水平驱动信号的上升沿为4 ns,幅度为4.2 V,三电平驱动信号的2个上升沿均为50 ns,电子快门信号发生电路能够在基底电压

  3. Images of the laser entrance hole from the static x-ray imager at NIF.

    Science.gov (United States)

    Schneider, M B; Jones, O S; Meezan, N B; Milovich, J L; Town, R P; Alvarez, S S; Beeler, R G; Bradley, D K; Celeste, J R; Dixit, S N; Edwards, M J; Haugh, M J; Kalantar, D H; Kline, J L; Kyrala, G A; Landen, O L; MacGowan, B J; Michel, P; Moody, J D; Oberhelman, S K; Piston, K W; Pivovaroff, M J; Suter, L J; Teruya, A T; Thomas, C A; Vernon, S P; Warrick, A L; Widmann, K; Wood, R D; Young, B K

    2010-10-01

    The static x-ray imager at the National Ignition Facility is a pinhole camera using a CCD detector to obtain images of Hohlraum wall x-ray drive illumination patterns seen through the laser entrance hole (LEH). Carefully chosen filters, combined with the CCD response, allow recording images in the x-ray range of 3-5 keV with 60 μm spatial resolution. The routines used to obtain the apparent size of the backlit LEH and the location and intensity of beam spots are discussed and compared to predictions. A new soft x-ray channel centered at 870 eV (near the x-ray peak of a 300 eV temperature ignition Hohlraum) is discussed.

  4. The flight test of a grazing incidence relay optics telescope for solar X-ray astronomy utilizing a thinned, back-illuminated CCD detector

    Science.gov (United States)

    Moses, J. Daniel; Davis, John M.

    1988-01-01

    The new AS&E Ultrahigh Resolution Soft X-ray Solar Research Rocket Payload has been successfully flown twice on Black Brant IX Sounding Rockets from White Sands Missile Range. These flights, conducted on 15 August 1987 and 11 December 1987, provided the first test of the new payload which consists of 3.8X magnifying hyperboloid-hyperboloid grazing incidence relay optic used in conjunction with an existing Wolter-I primary mirror. An RCA SID 500 series CCD detector was utilized in a thinned, back-illuminated configuration for recording the images. The 5.4 m effective focal length of the compound optics system resulted in a plate scale of 1 arc second per pixel which is comparable to the inherent resolution of the primary mirror. These flights represent the first use in X-ray astronomy of either of these two new technologies. These observations are presented with comparison to laboratory measurements and theoretical expectations of the instrument performance.

  5. HiPERCAM: A high-speed, quintuple-beam CCD camera for the study of rapid variability in the Universe

    CERN Document Server

    Dhillon, V S; Bezawada, N; Black, M; Dixon, S; Gamble, T; Henry, D; Kerry, P; Littlefair, S P; Lunney, D W; Morris, T; Osborn, J; Wilson, R W

    2016-01-01

    HiPERCAM is a high-speed camera for the study of rapid variability in the Universe. The project is funded by a 3.5MEuro European Research Council Advanced Grant. HiPERCAM builds on the success of our previous instrument, ULTRACAM, with very significant improvements in performance thanks to the use of the latest technologies. HiPERCAM will use 4 dichroic beamsplitters to image simultaneously in 5 optical channels covering the u'g'r'i'z' bands. Frame rates of over 1000 per second will be achievable using an ESO CCD controller (NGC), with every frame GPS timestamped. The detectors are custom-made, frame-transfer CCDs from e2v, with 4 low-noise (2.5e-) outputs, mounted in small thermoelectrically-cooled heads operated at 180 K, resulting in virtually no dark current. The two reddest CCDs will be deep-depletion devices with anti-etaloning, providing high quantum efficiencies across the red part of the spectrum with no fringing. The instrument will also incorporate scintillation noise correction via the conjugate-p...

  6. HAMC2 ASTROMETRY AND PHOTOMETRY CALIBRATION AND COMPARISON OF ITS DATA WITH THOSE OF OTHER MODERN CCD CATALOGUES

    Directory of Open Access Journals (Sweden)

    J. L. Muiños

    2008-01-01

    Full Text Available El segundo Cat logo Meridiano Hispano-Argentino (HAMC2 consta de m s de 12.500.000 de posiciones y magnitudes de estrellas m s brillantes que la magnitud V=16.5 y con declinaciones comprendidas entre -30 y 0 . Est calculado a partir de las observaciones CCD del C rculo Meridiano Automatico de San Fernando (CMASF instalado en la actualidad en el Observatorio Carlos U. Cesco (CUC en San Juan (Argentina. El CMASF es operado conjuntamente por el Real Instituto y Observatorio de la Armada (ROA de Espa a, propietario del instrumento, y el Observatorio Astron mico F lix Aguilar (OAFA de la Universidad Nacional de San Juan (Argentina, al que pertenece el CUC. La publicaci n del cat logo est prevista para el primer semestre de 2008. En esta comunicaci n presentamos los trabajos llevados a cabo para la formaci n del HAMC2, la calibraci n del sensor de su c mara CCD y nalmente la comparaci n de sus resultados astrometricos y fotom tricos con otros cat logos CCD actuales con el n de detectar y eliminar posibles errores sistem ticos.

  7. A matter of collection and detection for intraoperative and noninvasive near-infrared fluorescence molecular imaging: To see or not to see?

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Banghe; Rasmussen, John C.; Sevick-Muraca, Eva M., E-mail: Eva.Sevick@uth.tmc.edu [Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, Texas 77030 (United States)

    2014-02-15

    Purpose: Although fluorescence molecular imaging is rapidly evolving as a new combinational drug/device technology platform for molecularly guided surgery and noninvasive imaging, there remains no performance standards for efficient translation of “first-in-humans” fluorescent imaging agents using these devices. Methods: The authors employed a stable, solid phantom designed to exaggerate the confounding effects of tissue light scattering and to mimic low concentrations (nM–pM) of near-infrared fluorescent dyes expected clinically for molecular imaging in order to evaluate and compare the commonly used charge coupled device (CCD) camera systems employed in preclinical studies and in human investigational studies. Results: The results show that intensified CCD systems offer greater contrast with larger signal-to-noise ratios in comparison to their unintensified CCD systems operated at clinically reasonable, subsecond acquisition times. Conclusions: Camera imaging performance could impact the success of future “first-in-humans” near-infrared fluorescence imaging agent studies.

  8. 基于结构光和单CCD相机的物体表面三维测量%A New Method of Automatic Measurement for 3D Surface by Using Structured Light,Single CCD Camera

    Institute of Scientific and Technical Information of China (English)

    牟元英; 徐春斌

    2001-01-01

    Non-contact automatic measurement for 3D surface is one of central tasks of computer vision.Arounding this task ,a new method of automatic measurement for 3D surface by using structured light 、single CCD camera and double orientations techniques is proposed in this paper.The stereo coordinates of 3D surface can be obtained through a sequence monocular images without determining the relative position between camera (CCD) and structured light projector.%非接触式物体表面三维自动测量是计算机视觉领域的中心任务之一,围绕这个问题,提出了一种利用结构光,单CCD相机和双定向技术实现物体表面三维自动测量的新方法。采用该方法,无需测定相机和结构光光截面之间的相对位置,在单目序列影像上就可测量出物体表面的三维坐标。

  9. 彩色CCD比色测温的灰度值融合处理方法研究%An Intensity Fusion Method Applied To Color CCD-based Colorimetric Temperature Measurement

    Institute of Scientific and Technical Information of China (English)

    李进军

    2012-01-01

    设计了基于两个彩色CCD通道的比色测温系统,提出了用于比色测温时彩色CCD的R、G、B亮度(灰度)值融合处理方法,解决了在不同快门下利用两个通道的灰度值进行比色测温计算的问题;黑体炉实验结果表明,与常用的基于面阵CCD的简化比色测温方法相比较,基于两个彩色CCD通道的比色测温方法系统虽稍显复杂,但由于采用了经融合处理后的亮度值进行比色测量计算使得测温精度较高.%This paper designs a colorimetric temperature measurement method based on two color CCD. And presents an effective method applied to Colorimetric Temperature Measurement, which uses the intensity of the tuo CCD Camera images under different shutter. The experiment demonstrates that compared with the traditional methods, the simplified Dichromatic method , the proposed method obtained higher accuracy in the Temprature Measurement.

  10. On Relativistic Disk Spectroscopy in Compact Objects with X-ray CCD Cameras

    Science.gov (United States)

    Miller, J. M.; D'Aì, A.; Bautz, M. W.; Bhattacharyya, S.; Burrows, D. N.; Cackett, E. M.; Fabian, A. C.; Freyberg, M. J.; Haberl, F.; Kennea, J.; Nowak, M. A.; Reis, R. C.; Strohmayer, T. E.; Tsujimoto, M.

    2010-12-01

    X-ray charge-coupled devices (CCDs) are the workhorse detectors of modern X-ray astronomy. Typically covering the 0.3-10.0 keV energy range, CCDs are able to detect photoelectric absorption edges and K shell lines from most abundant metals. New CCDs also offer resolutions of 30-50 (E/ΔE), which is sufficient to detect lines in hot plasmas and to resolve many lines shaped by dynamical processes in accretion flows. The spectral capabilities of X-ray CCDs have been particularly important in detecting relativistic emission lines from the inner disks around accreting neutron stars and black holes. One drawback of X-ray CCDs is that spectra can be distorted by photon "pile-up," wherein two or more photons may be registered as a single event during one frame time. We have conducted a large number of simulations using a statistical model of photon pile-up to assess its impacts on relativistic disk line and continuum spectra from stellar-mass black holes and neutron stars. The simulations cover the range of current X-ray CCD spectrometers and operational modes typically used to observe neutron stars and black holes in X-ray binaries. Our results suggest that severe photon pile-up acts to falsely narrow emission lines, leading to falsely large disk radii and falsely low spin values. In contrast, our simulations suggest that disk continua affected by severe pile-up are measured to have falsely low flux values, leading to falsely small radii and falsely high spin values. The results of these simulations and existing data appear to suggest that relativistic disk spectroscopy is generally robust against pile-up when this effect is modest.

  11. CCD imagery, uvbyβ Photometry, and the Physical Parameters of Haffner 19

    Directory of Open Access Journals (Sweden)

    M. A. Moreno Corral

    2002-01-01

    Full Text Available Se presenta fotometría UBV(RIc de 334 estrellas del cúmulo Haffner 19 que complementa y amplía la existente, extendiéndola hasta la magnitud mλ = 19 (λ = U,B, V,R, I. Usando los diagramas (V, B−V , (V, V −I, (I, R−I, (U − B, B−V y (V −R, V −I resultantes, se establece la pertenencia de 102 estrellas, triplicando la información hasta ahora publicada. Esa fotometría permitió clasificar espectralmente 33 estrellas, confirmando la juventud de 29 (15 B0–B1 y 14 B2–B9. Para confirmar independientemente la distancia y enrojecimiento del cúmulo, se hizo fotometría fotoeléctrica uvbyβ de 6 estrellas brillantes. Se estudia imágenes CCD de banda angosta en Hα, [NII] y [SII], que revelan la presencia de una esfera de Strömgren en el cúmulo. Nuestros datos fotométricos, analizados usando 4 métodos diferentes, indican enrojecimiento homogéneo EB−V = 0.42 0.01 para Haffner 19, adem´as permiten establecer una distancia de 5.2 0.4 kpc, y restringen el intervalo de edad entre 106 y 3.7 106 a, con 2 106 a como el valor mías probable, lo que no permite deducir en forma confiable su metalicidad. Finalmente se presentan por separado las velocidades radiales de Haffner 18ab, Haffner 19 y NGC2467, las que indican que los dos últimos se hallan a la misma distancia.

  12. Energy dependent charge spread function in a dedicated synchrotron beam pnCCD detector

    Energy Technology Data Exchange (ETDEWEB)

    Yousef, Hazem

    2011-05-20

    A scan on the pixel edges is the method which is used to resolve the electron cloud size in the pixel array of the pnCCD detector. The EDR synchrotron radiation in BESSY is the source of the X-ray photons which are used in the scans. The radius of the electron cloud as a function of the impinging photon energy is analyzed. The angle of incidence of the X-ray beam is employed in the measurements. The measurements are validated by the numerical simulation models. The inclined X-ray track leads to distribute the electron clouds in a certain number of pixels according to the incident angle of the X-ray beam. The pixels detect different electron clouds according to their generation position in the detector bulk. A collimated X-ray beam of 12.14 keV is used in the measurements with 30 and 40 entrance angles. It is shown that the two factors that leads to expand the electron clouds namely the diffusion and the mutual electrostatic repulsion can be separated from the measured electron clouds. It is noticed as well that the influence of the mutual electrostatic repulsion dominates the cloud expansion over the diffusion process in the collection time of the detector. The perpendicular X-ray track leads to determine the average radius of the electron cloud per photon energy. The results show that the size of the electron clouds (RMS) in the energy range of [5.0-21.6] keV is smaller than the pixel size. (orig.)

  13. Imaging charge-coupled devices for deep-space surveillance

    Science.gov (United States)

    Streuber, D. W., Jr.; Bailis, E. I.

    1980-01-01

    The Ground-Based Electro-Optical Deep Space Surveillance (GEODSS) system will employ a SIT vidicon camera to detect satellites. Imaging charge-coupled devices (CCDs) are being evaluated as a means to improve GEODSS capability. This paper presents performance models and uses them to evaluate currently available CCDs and to determine the characteristics of the ideal CCD array for GEODSS. The analysis includes an approach for determining the CCD pixel size which maximizes signal-to-noise ratio; this approach can be used in many applications. The impact of response nonuniformity and a simple compensation method are also discussed. The combination of a suitable CCD array, response nonuniformity compensation, and moving target indicator (MTI) processing is expected to substantially increase the detection and search rate capability of the GEODSS system.

  14. The VTTVIS line imaging spectrometer - principles, error sources, and calibration

    DEFF Research Database (Denmark)

    Jørgensen, R.N.

    2002-01-01

    work describing the basic principles, potential error sources, and/or adjustment and calibration procedures. This report fulfils the need for such documentationwith special focus on the system at KVL. The PGP based system has several severe error sources, which should be removed prior any analysis....... Most of the random noise sources can be minimised by carefully selecting high-grade components especially withconcern to the camera. Systematic error sources like CCD fixed pattern noise (FPN), CCD photoresponse nonuniformity (PRNU), CCD charge transfer efficiency (CTE), slit width variations, changes...... in off-axis transmission efficiencies, diffractionefficiencies, and image distortion have a significant impact on the instrument performance. Procedures removing or minimising these systematic error sources are developed and described for the system build at KVL but can be generalised to other PGP...

  15. Inhibition of phosphatidylinositol 3-kinase stimulates activity of the small-conductance K channel in the CCD.

    Science.gov (United States)

    Li, Dimin; Wei, Yuan; Babilonia, Elisa; Wang, Zhijian; Wang, Wen-Hui

    2006-04-01

    We used Western blotting to examine the expression of phosphatidylinositol 3-kinase (PI3K) in the renal cortex and outer medulla and employed the patch-clamp technique to study the effect of PI3K on the ROMK-like small-conductance K (SK) channels in the cortical collecting duct (CCD). Low K intake increased the expression of the 110-kDa alpha-subunit (p110alpha) of PI3K compared with rats on a normal-K diet. Because low K intake increases superoxide levels (2), the possibility that increases in superoxide anions may be responsible for the effect of low K intake on the expression of PI3K is supported by finding that addition of H(2)O(2) stimulates the expression of p110alpha in M1 cells. Inhibition of PI3K with either wortmannin or LY-294002 significantly increased channel activity in the CCD from rats on a K-deficient (KD) diet or on a normal-K diet. The stimulatory effect of wortmannin on ROMK channel activity cannot be mimicked by inhibition of phospholipase C with U-73122. This suggests that the effect of inhibiting PI3K was not the result of increasing the phosphatidylinositol 4,5-bisphosphate level. Moreover, application of the exogenous phosphatidylinositol 3,4,5-trisphosphate analog had no effect on channel activity in excised patches. Because low K intake has been shown to increase the activity of protein tyrosine kinase (PTK), we explored the role of the interaction between PTK and PI3K in the regulation of the SK channel activity. Inhibition of PTK increased SK channel activity in the CCD from rats on a KD diet. However, addition of wortmannin did not further increase ROMK channel activity. Also, the effect of wortmannin was abolished by treatment of CCD with phalloidin. We conclude that PI3K is involved in mediating the effect of low K intake on ROMK channel activity in the CCD and that the effect of PI3K on SK channels requires the involvement of PTK and the cytoskeleton.

  16. Flow Measurements Using Particle Image Velocimetry in the Ultra Compact Combustor

    Science.gov (United States)

    2009-12-01

    potassium dihydrogen phosphate (KDP) crystal doubling the frequency to 532nm. This phenomenon, known as second harmonic generation, is a non-linear...taking pairs of images. The FlowSense 4M cameras have an image buffer of interlaced pixels allowing it to take a second picture before the camera...camera. Then, the image is quickly transferred to a storage buffer , allowing the CCD to be exposed to the second image. After the second exposure

  17. Evaluation of Mobile Phone Performance for Near-Infrared Fluorescence Imaging.

    Science.gov (United States)

    Ghassemi, Pejhman; Wang, Bohan; Wang, Jianting; Wang, Quanzeng; Chen, Yu; Pfefer, T Joshua

    2016-08-19

    We have investigated the potential for contrast-enhanced near-infrared fluorescence imaging of tissue on a mobile phone platform. CCD- and phone-based cameras were used to image molded and 3Dprinted tissue phantoms, and an ex vivo animal model. Quantitative and qualitative evaluations of image quality demonstrate the viability of this approach and elucidate variations in performance due to wavelength, pixel color and image processing.

  18. Million-frame-per-second CCD camera with 16 frames of storage

    Science.gov (United States)

    Howard, Nathan E.; Gardner, David W.; Snyder, Donald R.

    1997-12-01

    Ultrafast imaging is an important need for the development, control, and evaluation of modern air-deliverable weapons systems. Recent advances in optical imaging such as speckle interferometry can potentially improve DoD capability to deliver munitions and armaments to targets at long ranges, and under adverse seeing conditions. Moderate density arrays of at least 100 by 100 pixels and frame rates of at least 1 MHz are required. Ultrafast imaging is also required for flow field optical image analysis for hypersonic propulsion systems. Silicon Mountain Design (SMD) has built such an imager so that high quality images can be obtained for relatively low cost. The SMD-64k1M camera is capable of imaging 1,000,000 frames per second using a 256 by 256 array with the ability to store 16 frames with true 12 bits of dynamic range. This camera allows researchers to capture multiple high speed events using solid state technology housed in a 53 cubic inch package. A brief technical overview of the imager and results are presented in this paper.

  19. Overexpression of Crocus carotenoid cleavage dioxygenase, CsCCD4b, in Arabidopsis imparts tolerance to dehydration, salt and oxidative stresses by modulating ROS machinery.

    Science.gov (United States)

    Baba, Shoib Ahmad; Jain, Deepti; Abbas, Nazia; Ashraf, Nasheeman

    2015-09-15

    Apocarotenoids modulate vital physiological and developmental processes in plants. These molecules are formed by the cleavage of carotenoids, a reaction catalyzed by a family of enzymes called carotenoid cleavage dioxygenases (CCDs). Apocarotenoids like β-ionone and β-cyclocitral have been reported to act as stress signal molecules during high light stress in many plant species. In Crocus sativus, these two apocarotenoids are formed by enzymatic cleavage of β-carotene at 9, 10 and 7, 8 bonds by CsCCD4 enzymes. In the present study three isoforms of CsCCD4 were subjected to molecular modeling and docking analysis to determine their substrate specificity and all the three isoforms displayed high substrate specificity for β-carotene. Further, expression of these three CsCCD4 isoforms investigated in response to various stresses revealed that CsCCD4a and CsCCD4b exhibit enhanced expression in response to dehydration, salt and methylviologen, providing a clue towards their role in mediating plant defense response. This was confirmed by overexpressing CsCCD4b in Arabidopsis. The transgenic plants developed longer roots and possessed higher number of lateral roots. Further, overexpression of CsCCD4b imparted enhanced tolerance to salt, dehydration and oxidative stresses as was evidenced by higher survival rate, increased relative root length and biomass in transgenic plants as compared to wild type. Transgenic plants also displayed higher activity and expression of reactive oxygen species (ROS) metabolizing enzymes. This indicates that β-ionone and β-cyclocitral which are enzymatic products of CsCCD4b may act as stress signals and mediate reprogramming of stress responsive genes which ultimately leads to plant defense.

  20. CMOS Imaging Sensor Technology for Aerial Mapping Cameras

    Science.gov (United States)

    Neumann, Klaus; Welzenbach, Martin; Timm, Martin

    2016-06-01

    In June 2015 Leica Geosystems launched the first large format aerial mapping camera using CMOS sensor technology, the Leica DMC III. This paper describes the motivation to change from CCD sensor technology to CMOS for the development of this new aerial mapping camera. In 2002 the DMC first generation was developed by Z/I Imaging. It was the first large format digital frame sensor designed for mapping applications. In 2009 Z/I Imaging designed the DMC II which was the first digital aerial mapping camera using a single ultra large CCD sensor to avoid stitching of smaller CCDs. The DMC III is now the third generation of large format frame sensor developed by Z/I Imaging and Leica Geosystems for the DMC camera family. It is an evolution of the DMC II using the same system design with one large monolithic PAN sensor and four multi spectral camera heads for R,G, B and NIR. For the first time a 391 Megapixel large CMOS sensor had been used as PAN chromatic sensor, which is an industry record. Along with CMOS technology goes a range of technical benefits. The dynamic range of the CMOS sensor is approx. twice the range of a comparable CCD sensor and the signal to noise ratio is significantly better than with CCDs. Finally results from the first DMC III customer installations and test flights will be presented and compared with other CCD based aerial sensors.