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Sample records for 000301c ccd imaging

  1. Hubble Space Telescope STIS Observations of GRB 000301C: CCD Imaging and Near-Ultraviolet MAMA Spectroscopy

    A. Smette; A.S. Fruchter; Th.R. Gull; K.C. Sahu; L. Petro; H. Ferguson; J. Rhoads; D.J. Lindler; R.A.M.J. Wijers

    2001-01-01

    We present Space Telescope Imaging Spectrograph observations of the optical transient (OT) counterpart of the gamma-ray burster GRB 000301C obtained 5 days after the burst, on 2000 March 6. CCD clear-aperture imaging reveals a R~=21.50+/-0.15 source with no apparent host galaxy. An 8000 s, 1150 Å

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

    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. ...

  3. HST\\/STIS observations of GRB000301C CCD imaging and NUV MAMA spectroscopy

    Smette, A; Gull, T R; Sahu, K C; Petro, L; Ferguson, H; Rhoads, J E; Lindler, D; Gibbons, R A; Hogg, D W; Kouveliotou, C; Livio, M; Macchetto, D; Metzger, M R; Pedersen, H; Pian, E; Thorsett, S E; Wijers, R A M J; Fynbo, J P U; Gorosabel, J; Hjorth, J; Jensen, B L; Levine, A; Smith, D A; Cline, T; Hurley, K; Trombka, J I

    2000-01-01

    We present HST/STIS observations of the optical counterpart (OT) of the gamma-ray burster GRB 000301C obtained on 2000 March 6, five days after the burst. CCD clear aperture imaging reveals a R ~ 21.50+/-0.15 source with no apparent host galaxy. An 8000 s, 1150 18 on the line-of-sight to the OT. This value is conservatively a lower limit to the GRB redshift. However, the facts that large N(HI) system are usually considered as progenitors of present day galaxies and that other OTs are found associated with star forming galaxies strongly suggest that it is the GRB redshift. In any case, this represents the largest direct redshift determination of a gamma-ray burster to date. Our data are compatible with an OT spectrum represented by a power-law with an intrinsic index \\alpha = 1.2((f_nu \\propto nu^-alpha) and no extinction in the host galaxy or with alpha = 0.5 and extinction by a SMC-like dust in the OT rest-frame with A_V = 0.15. The large N(HI) and the lack of detected host is similar to the situation for d...

  4. Intensified CCD Image Sensor①

    LIUJikun; ZHAOBaoyun

    1997-01-01

    Work has been done with extending the useful imaging and detection rage of CCD.This was accomplished through direct optical coupling and bonding of image intensifiers to the CCD.It has been shown that the useful range of a CCD may be extended two orders of magnitude using these techniques in coupling a microchannel plate image intensifier to the CCD array.All of these works were done with presently available CCD made by China

  5. CCD Imaging of KIC 8462852

    Lahey, Adam

    2016-06-01

    A particularly interesting star, KIC 8562852, recently became famous for its enigmatic dips in brightness. The interpretation broadcast by many popular media outlets was that the dips were caused by a megastructure built around the star by an intelligent civilization. The best scientific hypothesis relies on a natural phenomenon: the break-up of a comet orbiting the star. To further address this problem, we have measured the star for four months using BGSU’s 0.5m telescope and digital CCD camera, and we present the star’s brightness as a function of time. Using three very clear nights, we refined the brightness of four comparison stars which can be used by the local astronomical community to monitor the star’s brightness. These newly refined magnitudes should reduce the uncertainties in our brightness measurements; this error analysis is essential in determining the significance of any brightness deviations. An observed dip in brightness would confirm the comet hypothesis by establishing a cyclical pattern, or may serve as a basis for new understanding of variable stars. An additional element to the project involves creating CCD calibration images and a well-documented procedure for future use.

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

    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...

  7. Radiation effects on CCD image sensors

    In the past decade, the micro process technology has advanced and some elaborate semiconductor devices with many microscopic elements in a cell of about 10 μm x 10 μm can be successfully used as radiation detectors and related parts in the field of nuclear physics and engineering. A CCD image sensor, for example, effectively measures details of particle-beam profiles in accelerator applications. This paper describes radiation effects on CCD image sensors. Some CCD samples were irradiated with 60Co gamma-rays and DD and DT neutrons for the examination of the reliability of CCDs used in radiation environments. This paper shows experimental data on radiation effects on CCDs and then discusses the difference in the radiation effects between gamma-rays and neutrons. The following two radiation effects on CCDs are described. One is the transient effect, which is induced by the ionisation process of radiations and is not permanent but recoverable. A CCD responds to radiations as well as light and outputs pseudo signals induced by radiation reactions in the normal video signals during irradiation. The other is the permanent effect, which is caused by the generation of the defects. A CCD image sensor is easily influenced by the trapped holes produced by ionisation in the gate oxide. The defects cause the generation of the leakage current within the depletion region, the trapping of signal charge within the channel of the charge shift register, and the flat band voltage shift which affects the CCD operating bias. (author)

  8. Ghost Images in Schmidt CCD Photometry

    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.

  9. Large area CCD image sensors for space astronomy

    Schwarzschild, M.

    1979-01-01

    The Defense Advanced Research Projects Agency (DARPA) has a substantial program to develop a 2200 x 2200 pixel CCD (Charge Coupled Device) mosaic array made up of 400 individual CCD's, 110 x 110 pixels square. This type of image sensor appeared to have application in space and ground-based astronomy. Under this grant a CCD television camera system was built which was capable of operating an array of 4 CCD's to explore the suitability of the CCD's to explore the suitability of the CCD for astronomical applications. Two individual packaged CCD's were received and evaluated. Evaluation of the basic characteristics of the best individual chips was encouraging, but the manufacturer found that their yield in manufacturing this design is two low to supply sufficient CDD's for the DARPA mosaic array. The potential utility of large mosaic arrays in astronomy is still substantial and continued monitoring of the manufacturers progress in the coming year is recommended.

  10. Target Image Matching Algorithm Based on Binocular CCD Ranging

    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.

  11. Atmospheric correction of CBERS CCD images with MODIS data

    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.

  12. Based on line scan CCD print image detection system

    Zhang, Lifeng; Xie, Kai; Li, Tong

    2015-12-01

    In this paper, a new method based on machine vision is proposed for the defects of the traditional manual inspection of the quality of printed matter. With the aid of on line array CCD camera for image acquisition, using stepper motor as a sampling of drive circuit. Through improvement of driving circuit, to achieve the different size or precision image acquisition. In the terms of image processing, the standard image registration algorithm then, because of the characteristics of CCD-image acquisition, rigid body transformation is usually used in the registration, so as to achieve the detection of printed image.

  13. CCD image data acquisition system for optical astronomy.

    Bhat, P. N.; Patnaik, K.; Kembhavi, A. K.; Patnaik, A. R.; Prabhu, T. P.

    1990-11-01

    A complete image processing system based on a charge coupled device (CCD) has been developed at TIFR, Bombay, for use in optical astronomy. The system consists of a P-8600/B GEC CCD chip, a CCD controller, a VAX 11/725 mini-computer to carry out the image acquisition and display on a VS-11 monitor. All the necessary software and part of the hardware were developed locally, integrated together and installed at the Vainu Bappu Observatory at Kavalur. CCD as an imaging device and its advantages over the conventional photographic plate is briefly reviewed. The acquisition system is described in detail. The preliminary results are presented and the future research programme is outlined.

  14. CCD Astrophotography High-Quality Imaging from the Suburbs

    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. CCD image sensor induced error in PIV applications

    The readout procedure of charge-coupled device (CCD) cameras is known to generate some image degradation in different scientific imaging fields, especially in astrophysics. In the particular field of particle image velocimetry (PIV), widely extended in the scientific community, the readout procedure of the interline CCD sensor induces a bias in the registered position of particle images. This work proposes simple procedures to predict the magnitude of the associated measurement error. Generally, there are differences in the position bias for the different images of a certain particle at each PIV frame. This leads to a substantial bias error in the PIV velocity measurement (∼0.1 pixels). This is the order of magnitude that other typical PIV errors such as peak-locking may reach. Based on modern CCD technology and architecture, this work offers a description of the readout phenomenon and proposes a modeling for the CCD readout bias error magnitude. This bias, in turn, generates a velocity measurement bias error when there is an illumination difference between two successive PIV exposures. The model predictions match the experiments performed with two 12-bit-depth interline CCD cameras (MegaPlus ES 4.0/E incorporating the Kodak KAI-4000M CCD sensor with 4 megapixels). For different cameras, only two constant values are needed to fit the proposed calibration model and predict the error from the readout procedure. Tests by different researchers using different cameras would allow verification of the model, that can be used to optimize acquisition setups. Simple procedures to obtain these two calibration values are also described. (paper)

  16. Computer-aided analysis of CCD linear image sensors

    Prince, S. S.

    1976-01-01

    Special test equipment and techniques to collect and process image information from charge coupled devices (CCDs) by digital computer were reviewed. The video channel was traced from the CCD to the direct memory access bus of the Interdata Computer. Software was developed to evaluate and characterize a CCD for (1) dark signal versus temperature relationship, (2) calculation of temporal noise magnitude and noise shape for each pixel, (3) spatial noise into the video chain due to dark signal, (4) response versus illumination relationship (gamma), (5) response versus wavelength of illumination (spectral), (6) optimization of forcing functions, and (7) evaluation of an image viewed by a CCD. The basic software differences and specific examples of each program operating on real data are presented.

  17. Evaluation of a CCD-based tissue imaging system

    A digital tissue imaging system based on a cooled charge coupled device (CCD) has been developed at the Physics Department of the Institute of Cancer Research. The system images low energy X-ray emissions and β particle emissions from a variety of isotopes, with a position resolution approaching 20μm and sensitivity approaching 100%. Because of the frame-by-frame composite way in which images are constructed, the dynamic range of the system is 16 bit, limited only by the microcomputer used to acquire and store the images. Images have been obtained of isotope distributions in tissue with radioactivity levels which were too low to be detected using conventional technology. Room temperature operation of the CCD in the inverted mode has been investigated

  18. Programmable CCD imaging system for synchrotron radiation studies

    A real-time imaging system for x-ray detection has been developed. The CAMAC-based system has a Charge Coupled Device (CCD) as its active detection element. The electronics consist of a CAMAC-crate-based dedicated microprocessor coupled to arbitrary waveform generators, programmable timing, and ADC modules. The hardware flexibility achievable through this system enables one to use virtually any commercially available CCD. A dedicated CAMAC-based display driver allows for real-time imaging on a high-resolution color monitor. An optional front end consisting of a fiber-optic taper and a focusing optical lens system coupled to a phosphor screen allows for large area imaging. Further, programming flexibility, in which the detector can be used in different read-out modes, enables it to be exploited for time-resolved experiments. In one mode, sections of the CCD can be read-out with millisecond time-resolution and, in another, the use of the CCD as a storage device is exploited resulting in microsecond time-resolution. Three different CCDs with radically different read-out timings and waveforms have been tested: the TI 4849, a 39Ox584 pixel array; TC 215, a 1024x1O24 pixel array; and the TH 7883, a 576x384 pixel array. The TC 215 and TI 4849 are single-phase CCDs manufactured by Texas Instruments, and the TH 7883 is a four-phase device manufactured by Thomson-CSF. The CCD characterized for uniformity, charge transfer efficiency (CTE), linearity, and sensitivity is the TC215

  19. A luminescence imaging system based on a CCD camera

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

    1997-01-01

    Stimulated luminescence arising from naturally occurring minerals is likely to be spatially heterogeneous. Standard luminescence detection systems are unable to resolve this variability. Several research groups have attempted to use imaging photon detectors, or image intensifiers linked...... 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...

  20. A progressive scan CCD image sensor for high speed photography

    Strunk, S.J.; Winzenread, R.

    1995-12-31

    The authors have developed a second generation CCD image sensor for high speed motion analysis. The 2/3 inch format device is constructed on a 16 {micro}m square pixel pitch with 512(H) x 512(V) active elements. Design is based on a progressive scan interline transfer architecture with a vertical overflow drain for blooming and exposure control. Full resolution is achieved at 1,000 frames per second by use of eight parallel outputs operating at a data rate of 40 MHz per tap. Other performance parameters include dynamic range of 62 dB, less than 1% image lag, and very low smear. This work details the essential design features and reports results of the preliminary evaluation.

  1. A fast double shutter system for CCD image sensors

    A new fast shutter system for CCD sensor-based cameras is presented. This system is capable of providing for the first time short exposure times for two consecutive frames recorded in fast succession with high spatial resolutions. In addition, a third frame can be recorded with a long exposure time, this then corresponding to the well-known ‘double shutter’. Measurement techniques such as particle image velocimetry (PIV) will benefit from the new fast shutter when being used in bright environments. Using the optional third frame, advanced evaluation schemes can be implemented to measure acceleration, increase the dynamic range of the velocity measurements or reduce the number of false matches (ghost particles) in tomographic PIV or particle tracking. It will be shown that for double-frame applications this new shutter timing outperforms even the latest commercially available single-chip high-speed cameras. (paper)

  2. Large area CCD image sensors for scientific applications

    Blouke, M. M.; Heidtmann, D. L.; Corrie, B.; Lust, M. L.; Janesick, J. R.

    1985-01-01

    The designs of the 512 x 512 pixel and 2048 x 2048 pixel CCD sensors developed for scientific imaging are described. Both sensors are manufactured using the three phase, three level polysilicon gate technology, and the architecture of the chips is series-parallel-series. The components of the two different on-chip amplifiers are examined. The sensors are thinned and operated in the back side illumination mode to ensure the highest quantum efficiency. The performances of a number of front side illuminated devices and two thinned rear illuminated chips are evaluated. It is observed that the sensors equal or exceed their proposed charge transfer efficiency of 0.99999, the noise level of 2 e- and 20 e- at 50 kp/s, the quantum efficiency of 40 percent at 400 microns and 70 percent at 700 microns, and of the well capacity of greater than 500 ke-/pixel.

  3. VME image acquisition and processing using standard TV CCD cameras

    The ESRF has released the first version of a low-cost image acquisition and processing system based on a industrial VME board and commercial CCD TV cameras. The images from standard CCIR (625 lines) or EIA (525 lines) inputs are digitised with 8-bit dynamic range and stored in a general purpose frame buffer to be processed by the embedded firmware. They can also be transferred to a UNIX workstation through the network for display in a X11 window, or stored in a file for off-line processing with image analysis packages like KHOROS, IDL, etc. The front-end VME acquisition system can be controlled with a Graphic Users' Interface (GUI) based on X11/Motif running under UNIX. The first release of the system is in operation and allows one to observe and analyse beam spots around the accelerators. The system has been extended make it possible to position a micro sample (less than 10 μm2) not visible to the naked eye. This system is a general purpose image acquisition system which may have wider applications. ((orig.))

  4. System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor

    J. Misun; M. Chrenek; Sevcik, P; P. Kulla

    1993-01-01

    The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video signals, which are processed in the analog signal processor. The output signal is continually converted to 8-bit data words in A/D converter. This data words maybe transfer over a bus driver to the o...

  5. A luminescence imaging system based on a CCD camera

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

    1997-01-01

    spectrum, the CCD system is less sensitive than the standard bi-alkali photocathode photomultipliers that are commonly used. However, the CCD has a peak performance between 500 and 900 nm. and is more sensitive than the photomultiplier tube over this range. (C) 1997 Elsevier Science Ltd....

  6. 32-megapixel dual-color CCD imaging system

    Stubbs, Christopher W.; Marshall, Stuart; Cook, Kenneth H.; Hills, Robert F.; Noonan, Joseph; Akerlof, Carl W.; Alcock, Charles R.; Axelrod, Timothy S.; Bennett, D.; Dagley, K.; Freeman, K. C.; Griest, Kim; Park, Hye-Sook; Perlmutter, Saul; Peterson, Bruce A.; Quinn, Peter J.; Rodgers, A. W.; Sosin, C.; Sutherland, W. J.

    1993-07-01

    We have developed an astronomical imaging system that incorporates a total of eight 2048 X 2048 pixel CCDs into two focal planes, to allow simultaneous imaging in two colors. Each focal plane comprises four 'edge-buttable' detector arrays, on custom Kovar mounts. The clocking and bias voltage levels for each CCD are independently adjustable, but all the CCDs are operated synchronously. The sixteen analog outputs (two per chip) are measured at 16 bits with commercially available correlated double sampling A/D converters. The resulting 74 MBytes of data per frame are transferred over fiber optic links into dual-ported VME memory. The total readout time is just over one minute. We obtain read noise ranging from 6.5 e- to 10 e- for the various channels when digitizing at 34 Kpixels/sec, with full well depths (MPP mode) of approximately 100,000 e- per 15 micrometers X 15 micrometers pixel. This instrument is currently being used in a search of gravitational microlensing from compact objects in our Galactic halo, using the newly refurbished 1.3 m telescope at the Mt. Stromlo Observatory, Australia.

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

    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.

  8. Calibration to the image position of CCD camera and correction of q profile measurement

    Calibration to the image position of CCD camera used in the HL-1M tokamak has been carried out. Based on the calibration, the safety factor profile measured with the CCD camera during pellet injection is corrected. Points for attention are discussed, and some measures for improvement are proposed

  9. System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor

    J. Misun

    1993-11-01

    Full Text Available The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video signals, which are processed in the analog signal processor. The output signal is continually converted to 8-bit data words in A/D converter. This data words maybe transfer over a bus driver to the operation memory of personal computer, by setting one of the three work regimes of digital CCD camera. Some application possibilities and basic technical parameters of this system are given.

  10. A tilted fiber-optic plate coupled CCD detector for high resolution neutron imaging

    One of these efforts is that a tilted scintillator geometry and lens coupled CCD detector for neutron imaging system were used to improve spatial resolution in one dimension. The increased spatial resolution in one dimension was applied to fuel cell study. However, a lens coupled CCD detector has lower sensitivity than a fiber-optic plate coupled CCD detector due to light loss. In this research, a tilted detector using fiber-optic plate coupled CCD detector was developed to improve resolution and sensitivity. In addition, a tilted detector can prevent an image sensor from direct radiation damage. Neutron imaging has been used for fuel cell study, lithium ion battery study, and many scientific applications. High quality neutron imaging is demanded for more detailed studies of applications, and spatial resolution should be considered to get high quality neutron imaging. Therefore, there were many efforts to improve spatial resolution

  11. Researchers develop CCD image sensor with 20ns per row parallel readout time

    Bush, S

    2004-01-01

    "Scientists at the Rutherford Appleton Laboratory (RAL) in Oxfordshire have developed what they claim is the fastest CCD (charge-coupled device) image sensor, with a readout time which is 20ns per row" (1/2 page)

  12. Measurement of soft x-ray image by using CCD camera for long pulse discharge

    A soft x-ray imaging was made a CCD camera installed to a tangential port in LHD. The large number of pixels (1024x512) of with CCD gives a good spatial resolution of 1.8 mm. The tangential soft x-ray image is obtained during long pulse discharge on LHD with a time resolution of 0.5 s. The shift of x-ray emission profile is found for plasmas with different magnetic axes. (J.P.N.)

  13. The analysis of the imaging speed of the neutron digital radiography system based CCD

    The imaging speed is the main character of the neutron digital radiography system, and the calculating method of neutron digital radiography based CCD is put forward according to the characters of CCD and the principal of neutron digital radiography and optics. Then the imaging speed of neutron radiography system in SPRR-300 is calculated by the method. The experiment shows the counted value basically tallies with the measured value, then the calculating method is believable. (authors)

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

    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.

  15. The research and development of CCD-based slab continuous casting mold copper surface imaging system

    Wang, Xingdong; Zhang, Liugang; Xie, Haihua; Long, Liaosha; Yu, Wenyong

    2011-11-01

    An imaging system for the continuous casting mold copper surface is researched and developed, to replace the on-line manual measuring method, which is used to checking Copper defects such as wearing, scratches and coating loss and other phenomena. Method: The imaging system proposes a special optical loop formed by three Mirrors, selects light source, CCD camera and lens type, designs mechanical transmission system and installation platform. Result: the optical loop and light source can insure imaging large-format object in narrow space. The CCD camera and lens determine the accuracy of horizontal scanning, and the mechanical transmission system ensures accuracy of the vertical scan. The installation platform supplies base and platform for the system. Conclusions: CCD-based copper surface imaging system effectively prevent defects such as missed measuring and low efficiency, etc. It can automatically and accurately shoot copper surface images on-line, and supply basis for image processing, defects identification and copper changing in the late.

  16. Space station application of CCD image sensors for x-ray imaging

    Charge Coupled Device (CCD) type solid state image sensors are employed in a number of space based imaging experiments and will be the basis for a camera system to acquire x-ray diffraction images on board the Space Station. This paper will present the system engineering considerations that led to the selection of CCDs over other x-ray imaging technologies and the design of the camera system. This will include discussion of the special requirements imposed by the space environment and this x-ray crystallography mission. This systems engineering discussion will be followed by a summary of high spatial resolution CCDs that are candidates for this camera, what may become available in the future, and what improvements would make CCDs even more suited to such X-ray imaging applications on the ground as well as in space

  17. CCD imaging technology and the war on crime

    McNeill, Glenn E.

    1992-08-01

    Linear array based CCD technology has been successfully used in the development of an Automatic Currency Reader/Comparator (ACR/C) system. The ACR/C system is designed to provide a method for tracking US currency in the organized crime and drug trafficking environments where large amounts of cash are involved in illegal transactions and money laundering activities. United States currency notes can be uniquely identified by the combination of the denomination serial number and series year. The ACR/C system processes notes at five notes per second using a custom transport a stationary linear array and optical character recognition (OCR) techniques to make such identifications. In this way large sums of money can be " marked" (using the system to read and store their identifiers) and then circulated within various crime networks. The system can later be used to read and compare confiscated notes to the known sets of identifiers from the " marked" set to document a trail of criminal activities. With the ACR/C law enforcement agencies can efficiently identify currency without actually marking it. This provides an undetectable means for making each note individually traceable and facilitates record keeping for providing evidence in a court of law. In addition when multiple systems are used in conjunction with a central data base the system can be used to track currency geographically. 1.

  18. Experience with 800 x 800 virtual phase and 500 x 500 three-phase CCD imagers

    Hlivak, R. J.; Henry, J. P.; Pilcher, C. B.

    1984-01-01

    A description of the Galileo/Institute for Astronomy charge-coupled device (CCD) imaging system and its initial operation has been presented previously. Originally designed to operate a 500 x 500 backside illuminated three-phase CCD, the system has been modified to allow use of either the 500 x 500 sensor or the TI 800 x 800 virtual phase CCD. The modifications for the operation of the virtual phase CCD and current system performance with each type of sensor are discussed. A description is given of the implementation of various techniques discovered at the Jet Propulsion Laboratory that improve imager performance. These techniques include tri-level clocking of the virtual phase CCD to eliminate spurious charge generation in the serial register, the use of ultraviolet light flood with the backside thinned 500 x 500 three-phase device to dramatically improve the quantum efficiency in the blue, and the practical elimination of deferred charge in the three-phase device. Results of astronomical observations with each sensor are presented.

  19. A Lossy Method for Compressing Raw CCD Images

    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.

  20. Fast neutron fields imaging with a CCD-based luminescent detector

    The paper considers some questions concerned with the development of an imaging system based on a CCD-detector for visualising fast neutron fields. From those the most important are: development of fast neutron screens, detector resistance to irradiation fields, and feasibility of fast neutron radiography and tomography at various neutron sources

  1. Fast neutron fields imaging with a CCD-based luminescent detector

    Mikerov, V

    1999-01-01

    The paper considers some questions concerned with the development of an imaging system based on a CCD-detector for visualising fast neutron fields. From those the most important are: development of fast neutron screens, detector resistance to irradiation fields, and feasibility of fast neutron radiography and tomography at various neutron sources.

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

    Luo, Tong-Ding; Li, Bin-Kang; Yang, Shao-Hua; Guo, Ming-An; Yan, Ming

    2016-06-01

    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.

  3. A Lossy Method for Compressing Raw CCD Images

    Watson, A M

    2002-01-01

    This paper describes a lossy method for compressing raw images produced by CCDs or similar devices. The method is very simple: lossy quantization followed by lossless compression using general-purpose compression tools such as gzip and bzip2. A key feature of the method is that compressed images can be converted to FITS files simply by decompressing with gunzip or bunzip2, and this is a significant advantage for distributing compressed files. The degree of quantization is chosen to eliminate low-order bits that over-sample the noise, contain no information, and are difficult or impossible to compress. The method is lossy but gives guarantees on the maximum absolute difference, the expected mean difference, and the expected RMS difference between the compressed and original images; these guarantees make it suitable for use on raw images. The method consistently compresses images to roughly 1/5 of their original size with a quantization such that no value changes by more than 1/2 of a standard deviation in the ...

  4. Contrast reduction in digital images due to x-ray induced damage to a TV camera's CCD image receptor

    The CCD image receptor in a monochrome TV camera was irradiated in the dark with a single-phase 80 kVp narrow beam carrying an additional 0.5 mm Al filter. It was found that the CCD responded to the x-rays with a transient signal which would reach a maximum value at about 70 mR per image frame. The signal's contrast would reach a maximum of about 7%, but was detectable at much lower exposure rates. Continuous irradiation of the CCD image receptor created a 'lesion' at the point of incidence that remained after the x-ray beam was switched off. This signal seemed to be due to permanent damage to the CCD and could be detected after a cumulative exposure of less than 20 R. It was shown that such damage could be created much more effectively if the TV camera was switched off rather than on and the maximum contrast was achieved with about 75 R and 220 R respectively. The maximum contrast achieved was about 8%. Further increase in the cumulative exposure of a particular location on the CCD image receptor was not investigated but it seemed reasonable that much higher contrast values could be reached if irradiation was continued. The latter damage described here was found to persist for at least several weeks and hence it will probably prevent any normal use of the TV camera in the future. (author)

  5. A pnCCD-based, fast direct single electron imaging camera for TEM and STEM

    We report on a new camera that is based on a pnCCD sensor for applications in scanning transmission electron microscopy. Emerging new microscopy techniques demand improved detectors with regards to readout rate, sensitivity and radiation hardness, especially in scanning mode. The pnCCD is a 2D imaging sensor that meets these requirements. Its intrinsic radiation hardness permits direct detection of electrons. The pnCCD is read out at a rate of 1,150 frames per second with an image area of 264 x 264 pixel. In binning or windowing modes, the readout rate is increased almost linearly, for example to 4000 frames per second at 4× binning (264 x 66 pixel). Single electrons with energies from 300 keV down to 5 keV can be distinguished due to the high sensitivity of the detector. Three applications in scanning transmission electron microscopy are highlighted to demonstrate that the pnCCD satisfies experimental requirements, especially fast recording of 2D images. In the first application, 65536 2D diffraction patterns were recorded in 70 s. STEM images corresponding to intensities of various diffraction peaks were reconstructed. For the second application, the microscope was operated in a Lorentz-like mode. Magnetic domains were imaged in an area of 256 x 256 sample points in less than 37 seconds for a total of 65536 images each with 264 x 132 pixels. Due to information provided by the two-dimensional images, not only the amplitude but also the direction of the magnetic field could be determined. In the third application, millisecond images of a semiconductor nanostructure were recorded to determine the lattice strain in the sample. A speed-up in measurement time by a factor of 200 could be achieved compared to a previously used camera system

  6. A pnCCD-based, fast direct single electron imaging camera for TEM and STEM

    Ryll, H.; Simson, M.; Hartmann, R.; Holl, P.; Huth, M.; Ihle, S.; Kondo, Y.; Kotula, P.; Liebel, A.; Müller-Caspary, K.; Rosenauer, A.; Sagawa, R.; Schmidt, J.; Soltau, H.; Strüder, L.

    2016-04-01

    We report on a new camera that is based on a pnCCD sensor for applications in scanning transmission electron microscopy. Emerging new microscopy techniques demand improved detectors with regards to readout rate, sensitivity and radiation hardness, especially in scanning mode. The pnCCD is a 2D imaging sensor that meets these requirements. Its intrinsic radiation hardness permits direct detection of electrons. The pnCCD is read out at a rate of 1,150 frames per second with an image area of 264 x 264 pixel. In binning or windowing modes, the readout rate is increased almost linearly, for example to 4000 frames per second at 4× binning (264 x 66 pixel). Single electrons with energies from 300 keV down to 5 keV can be distinguished due to the high sensitivity of the detector. Three applications in scanning transmission electron microscopy are highlighted to demonstrate that the pnCCD satisfies experimental requirements, especially fast recording of 2D images. In the first application, 65536 2D diffraction patterns were recorded in 70 s. STEM images corresponding to intensities of various diffraction peaks were reconstructed. For the second application, the microscope was operated in a Lorentz-like mode. Magnetic domains were imaged in an area of 256 x 256 sample points in less than 37 seconds for a total of 65536 images each with 264 x 132 pixels. Due to information provided by the two-dimensional images, not only the amplitude but also the direction of the magnetic field could be determined. In the third application, millisecond images of a semiconductor nanostructure were recorded to determine the lattice strain in the sample. A speed-up in measurement time by a factor of 200 could be achieved compared to a previously used camera system.

  7. CCD sensors.

    O. S. Neuimin; S. M. Dyachenko

    2010-01-01

    The principle of action, the basic parameters, the application CCD and achievements of the leading companies in their improved performance are considered. Methods of color image acquisition existing today are described. The table of parameters of modern image sensors which are used in modern technics are made.

  8. CCD sensors.

    O. S. Neuimin

    2010-10-01

    Full Text Available The principle of action, the basic parameters, the application CCD and achievements of the leading companies in their improved performance are considered. Methods of color image acquisition existing today are described. The table of parameters of modern image sensors which are used in modern technics are made.

  9. Electro-optical testing of fully depleted CCD image sensors for the Large Synoptic Survey Telescope camera

    Doherty, Peter Edward; Antilogus, Pierre; Astier, Pierre; Chiang, James; Gilmore, D. Kirk; Guyonnet, Augustin; Huang, Dajun; Kelly, Heather; Kotov, Ivan; Kubanek, Petr; Nomerotski, Andrei; O’Connor, Paul; Rasmussen, Andrew; Riot, Vincent J.; Stubbs, Christopher William

    2014-01-01

    The LSST Camera science sensor array will incorporate 189 large format Charge Coupled Device (CCD) image sensors. Each CCD will include over 16 million pixels and will be divided into 16 equally sized segments and each segment will be read through a separate output amplifier. The science goals of the project require CCD sensors with state of the art performance in many aspects. The broad survey wavelength coverage requires fully depleted, 100 micrometer thick, high resistivity, bulk silicon a...

  10. Dynamic monitoring of lake based on HJ-CCD Images: a case study of Poyang Lake

    Liu, Dong; Huang, Haiqing; Gong, Fang; Zhu, Qiankun; Yang, Xuefei

    2014-11-01

    Lake ecological environment is changing, driving by natural and human factors, and in turn influence people's living and producing. Therefore, dynamic monitoring of lake based on remote sensing technologies will play an important role to the disaster prevention and reduction work of lakes. In this paper, we expounded a series of work to realized monitor Poyang Lake dynamically by using HJ-CCD images. First, we did pretreatment to all HJ-CCD images, which mainly contain geometric correction, atmospheric correlation, image clipping, etc. Then, based on different features between water and non-water in different index layers, we extracted the covered area by water in different times from the corresponding HJ-CCD images, and we also extracted the true area through visual interpretation method. After that, by combining the water boundaries and DEM, we also estimated water level and water capacity in different times. Results of our work showed that the mean absolute error of water area extracted through remote technologies is 5.57%. The relationship of remote sensing areas and visual interpretation areas could be described as Strue = 0.8757*Sinterp + 110.24, with R2 = 0.9807. Besides, there was obvious relationship between water area and water capacity of Poyang Lake too, and the relations can be described with linear function. Based on such results, we can realize the dynamic estimation of Poyang Lake's area and capacity from daily gotten HJ-CCD image which covers the District of Poyang Lake. In other words, the results of this paper can provide decision basis for Poyang Lake's real-time, dynamic, economic monitoring.

  11. NIR area array CCD-based singlet oxygen luminescence imaging for photodynamic therapy

    In this work, a near-infrared CCD-based singlet oxygen luminescence two-dimensional imaging method is proposed to detect singlet oxygen by its 1270nm luminescence. Two-dimensional singlet oxygen images with its near-infrared luminescence during photosensitization could be obtained with a CCD integration time of 1s, without scanning. The data presented shows a linear relationship between the singlet oxygen luminescence intensity and sample concentration. This method provides a detection sensitivity of 0.00189mg/ml (Hematoporphyrin monomethyl Ether dissolved in ethanol) and a spatial resolution better than 100μm. We applied this method in vivo to demonstrate its potential in monitoring photodynamic therapy.

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

    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...

  13. CCD Camera

    Roth, Roger R.

    1983-01-01

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

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

    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.

  15. A position sensitive detector using an interline transfer imaging CCD at standard TV rate and room temperature

    This paper shows the possibility of using an interline transfer (and floating gate) imaging CCD as X-ray and charged particle detector, running at standard TV rate (7.16 MHz) and room temperature (296 K). Experimental tests have been made using a Fairchild CCD 222 with exposures to 55Fe, 90Sr, 241Am radiation sources. The CCD is linked to a personal computer through a video processor and the events are filtered and analyzed by digital image processing. The rms noise has been measured as a function of the temperature obtaining about 87 electrons/pixel at 296 K. (orig.)

  16. Application of fast CCD drift scanning to speckle imaging of binary stars

    Fors, O; Nuñez, J

    2004-01-01

    A new application of a fast CCD drift scanning technique that allows us to perform speckle imaging of binary stars is presented. For each observation, an arbitrary number of speckle frames is periodically stored on a computer disk, each with an appropriate exposure time given both atmospheric and instrumental considerations. The CCD charge is shifted towards the serial register and read out sufficiently rapidly to avoid an excessive amount of interframe dead time. Four well-known binary systems (ADS 755, ADS 2616, ADS 3711 and ADS 16836) are observed in to show the feasibility of the proposed technique. Bispectral data analysis and power spectrum fitting is carried out for each observation, yielding relative astrometry and photometry. A new approach for self-calibrating this analysis is also presented and validated. The proposed scheme does not require any additional electronic or optical hardware, so it should allow most small professional observatories and advanced amateurs to enjoy the benefits of diffract...

  17. A new method of CCD dark current correction via extracting the dark Information from scientific images

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

    2014-07-01

    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°C, resulting in a high dark current level of about 3e-/pix/sec, even comparable to the sky brightness (10e-/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 scientific images. We have applied this method to the AST3 data, and demonstrated that it can reduce the noise to a level roughly as low as the photon noise of the sky brightness, solving the high noise problem and improving the photometric precision. This method will also be helpful for other projects that suffer from similar issues.

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

    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...

  19. Design of Frame-transferred Surface Array CCD Imaging System for Dark Objects

    Zhang, Yu-heng; Yan, Yi-hua

    2016-01-01

    In order to realize the requirement of low-noise observations of dark objects in deep-space explorations, the design method for a simple and stable space camera imaging system is proposed in this paper. Based on the back-illuminated frame-transferred surface array CCD (CCD47-20AIMO) produced by the British E2V company, the circuitry design is given for the every part of the system. In which the applications of the correlated double-sampling analog-digital converter (AD) and the synchronous dynamic random access memory (SDRAM) can effectively suppress the correlated noise in the image signal. In addition, a drive control method favorable to the adjustment of exposure time is proposed, in the light-sensing stage it provides the exposure time with an independent and adjustable time delay to make the imaging system satisfy the requirement of long exposure time setting. The imaging system adopts the Cyclone III-series EP3C25Q240C8 field programable gate array produced by the Altera company as the kernel control device, and the drives are programmed in modules according to the function of the every device, in favor of transplantation. The simulative and experimental results indicate that the drive circuitry works normally, and that the system design can satisfy the preset requirement.

  20. Design for the correction system of the real time nonuniformity of large area-array CCD image

    Wang, Yan; Li, Chunmei; Lei, Ning

    2012-10-01

    With the robust thriving of aviation cameras and remote sensing technology, the linear-array CCD (charge-coupled device) and area CCD have developed toward large area CCD, which has a broad coverage and avoids the difficulty in jointing small area CCDs in addition to improving time resolution. However, due to the high amount of pixels and channels of large area CCD, photo-response non-uniformity (PRNU) is severe. In this paper, a real time non-uniformity correction system is introduced for a sort of large area full frame transfer CCD. First, the correction algorithm is elaborated according to CCD's working principle. Secondly, due to the high number of pixels and correction coefficient, ordinary chip memory cannot meet the requirement. The combination of external flash memory and DDR described in the paper satisfies large capacity memory and rapid real time correction. The methods and measurement steps for obtaining correction factors are provided simultaneously. At the end, an imaging test is made. The non-uniformity of the image is reduced to 0.38 % from the pre-correction 2.96 %, achieving an obvious reduction of non-uniformity. The result shows that the real time non-uniformity correction system can meet the demands of large area-array CCD.

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

    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.

  2. Controlled charge extraction—antiblooming capabilities in pnCCD imaging sensors

    Blooming in a CCD occurs when the signal charges accumulating in a pixel exceed the pixel saturation level and spill over into adjacent pixels. They start to spill over the weakest threshold in the electric potential of the pixel structure resulting in a degradation of the spatial information. With antiblooming mechanisms, the spatial resolution of the incoming photons can be preserved, but the intensity information is lost in the overflowing pixels. For imaging experiments, relying on a precise image structure, the preservation of the spatial resolution at the expense of precise intensity information is a workable compromise. In contrast to insulated gate CCDs, notably MOSCCDs, the potential wells of the pixel array of a pnCCD are created by p+n junctions, allowing direct electric access to the pixel structure. This allows to directly drain off charges from the pixels and to define a drain level by applying the appropriate operation voltages. Charge packets from 1 000 to more than one billion signal electrons per readout frame were generated without observing a spillover into adjacent pixels. As soon as the saturation level of the pixel is reached, the excess charge carriers are removed through charge drains exclusively created with the modification of the electric potential of the pnCCD by the operation voltages. No additional antiblooming structures were implemented in the device and the pixel full well capacity of approximately 300 000 electrons in standard operation mode was preserved. A physical model of the antiblooming mechanism of pnCCDs with a pixel size of 75μm×75μm was established by two-dimensional numerical device simulations and verified by experiments

  3. Inner FoV Stitching of Spaceborne TDI CCD Images Based on Sensor Geometry and Projection Plane in Object Space

    Xinming Tang

    2014-07-01

    Full Text Available High-quality inner FoV (Field of View stitching is currently a prerequisite step for photogrammetric processing and application of image data acquired by spaceborne TDI CCD cameras. After reviewing the technical development in the issue, we present an inner FoV stitching method based on sensor geometry and projection plane in object space, in which the geometric sensor model of spaceborne TDI CCD images is used to establish image point correspondence between the stitched image and the TDI CCD images, using an object-space projection plane as the intermediary. In this study, first, the rigorous geometric sensor model of the TDI CCD images is constructed. Second, principle and implementation of the stitching method are described. Third, panchromatic high-resolution (HR images of ZY-1 02C satellite and triple linear-array images of ZY-3 satellite are utilized to validate the correctness and feasibility of the method. Fourth, the stitching precision and geometric quality of the generated stitched images are evaluated. All the stitched images reached the sub-pixel level in precision. In addition, the geometric models of the stitched images can be constructed with zero loss in geometric precision. Experimental results demonstrate the advantages of the method for having small image distortion when on-orbit geometric calibration of satellite sensors is available. Overall, the new method provide a novel solution for inner FoV stitching of spaceborne TDI CCD images, in which all the sub-images are projected to the object space based on the sensor geometry, performing indirect image geometric rectification along and across the target trajectory. At present, this method has been successfully applied in the daily processing system for ZY-1 02C and ZY-3 satellites.

  4. Development of a programmable CCD detector for imaging, real time studies and other synchrotron radiation applications

    A new CCD detector has been developed. The working of CCD and programmable detector is detailed in this thesis. The flexibility of the system allows the use of CCDs from different manufactures. The vacuum chamber of the detector is made of a beryllium window for experiments using X-radiation or of a quartz window coupled to a focusing optic system. Its temporal resolution is 2 microseconds with a X-radiation imaging. Images with a high spatial resolution have been obtained with the focusing system having a set of optical lenses and filters. The first X-ray diffraction experiments in the range of milliseconds and microseconds for the study of semiconductor heterostructures have been performed at X16 beam line at NSLS (National Synchrotron Light Source) with the detector illuminated by X-rays. For the first time, a X-ray beam, horizontally focused has been used to record a X-ray diffraction spectra on a 2-D detector. Finally, a X-ray diffraction method has been used to study the first steps of the crystallisation of Fe80B20 amorphous metallic alloy at X6 beam line at NSLS

  5. X-ray CCD image sensor with a thick depletion region

    To develop a solid-state image sensor for high energy X-ray above 1 -- 2 keV, basic studies have been made on the CCD (charge coupled device) with a thick depletion region. A method of super-imposing a high DC bias voltage on low voltage signal pulses was newly proposed. The characteristics of both SCCD and BCCD were investigated, and their ability as X-ray sensors was compared. It was found that a depletion region of 60 μm thick was able to be obtained with ordinary doping density of 1020/m3, and that even thicker over 1 mm depletion region was able to be obtained with doping density of about 1018/m3, and a high bias voltage above 1 kV was able to be applied. It is suggested that the CCD image sensors for 8 keV or 24 keV X-ray can be realized since the absorption length of these X-ray in Si is about 60 μm and 1 mm, respectively. As for the characteristics other than the depletion thickness, the BCCD is preferable to SCCD for the present purpose because of lower noise and dark current. As for the transfer method, the frame-transfer method is recommended. (Aoki, K.)

  6. Development of proton CT imaging system using plastic scintillator and CCD camera.

    Tanaka, Sodai; Nishio, Teiji; Matsushita, Keiichiro; Tsuneda, Masato; Kabuki, Shigeto; Uesaka, Mitsuru

    2016-06-01

    A proton computed tomography (pCT) imaging system was constructed for evaluation of the error of an x-ray CT (xCT)-to-WEL (water-equivalent length) conversion in treatment planning for proton therapy. In this system, the scintillation light integrated along the beam direction is obtained by photography using the CCD camera, which enables fast and easy data acquisition. The light intensity is converted to the range of the proton beam using a light-to-range conversion table made beforehand, and a pCT image is reconstructed. An experiment for demonstration of the pCT system was performed using a 70 MeV proton beam provided by the AVF930 cyclotron at the National Institute of Radiological Sciences. Three-dimensional pCT images were reconstructed from the experimental data. A thin structure of approximately 1 mm was clearly observed, with spatial resolution of pCT images at the same level as that of xCT images. The pCT images of various substances were reconstructed to evaluate the pixel value of pCT images. The image quality was investigated with regard to deterioration including multiple Coulomb scattering. PMID:27191962

  7. Development of proton CT imaging system using plastic scintillator and CCD camera

    Tanaka, Sodai; Nishio, Teiji; Matsushita, Keiichiro; Tsuneda, Masato; Kabuki, Shigeto; Uesaka, Mitsuru

    2016-06-01

    A proton computed tomography (pCT) imaging system was constructed for evaluation of the error of an x-ray CT (xCT)-to-WEL (water-equivalent length) conversion in treatment planning for proton therapy. In this system, the scintillation light integrated along the beam direction is obtained by photography using the CCD camera, which enables fast and easy data acquisition. The light intensity is converted to the range of the proton beam using a light-to-range conversion table made beforehand, and a pCT image is reconstructed. An experiment for demonstration of the pCT system was performed using a 70 MeV proton beam provided by the AVF930 cyclotron at the National Institute of Radiological Sciences. Three-dimensional pCT images were reconstructed from the experimental data. A thin structure of approximately 1 mm was clearly observed, with spatial resolution of pCT images at the same level as that of xCT images. The pCT images of various substances were reconstructed to evaluate the pixel value of pCT images. The image quality was investigated with regard to deterioration including multiple Coulomb scattering.

  8. Performance of a slow-scan CCD camera for macromolecular imaging in a 400 kV electron cryomicroscope.

    Sherman, M B; Brink, J; Chiu, W

    1996-04-01

    The feasibility and limitations of a 1024 x 1024 slow-scan charge-coupled device (CCD) camera were evaluated for imaging in a 400kV electron cryomicroscope. Catalase crystals and amorphous carbon film were used as test specimens. Using catalase crystals, it was found that the finite (24 microns) pixel size of the slow-scan CCD camera governs the ultimate resolution in the acquired images. For instance, spot-scan images of ice-embedded catalase crystals showed resolutions of 8 A and 4 A at effective magnifications of 67,000 x and 132,000 x, respectively. Using an amorphous carbon film, the damping effect of the modulation transfer function (MTF) of the slow-scan CCD camera on the specimen's Fourier spectrum relative to that of the photographic film was evaluated. The MTF of the slow-scan CCD camera fell off more rapidly compared to that of the photographic film and reached the value of 0.2 at the Nyquist frequency. Despite this attenuation, the signal-to-noise ratio of the CCD data, as determined from reflections of negatively-stained catalase crystals, was found to decrease to approximately 50% of that of photographic film data. The phases computed from images of the same negatively-stained catalase crystals recorded consecutively on both the slow-scan CCD camera and photographic film were found to be comparable to each other within 12 degrees. Ways of minimizing the effect of the MTF of the slow-scan CCD camera on the acquired images are also presented. PMID:8858867

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

    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.

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

    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.

  11. Quantification winter wheat LAI with HJ-1CCD image features over multiple growing seasons

    Li, Xinchuan; Zhang, Youjing; Luo, Juhua; Jin, Xiuliang; Xu, Ying; Yang, Wenzhi

    2016-02-01

    Remote sensing images are widely used to map leaf area index (LAI) continuously over landscape. The objective of this study is to explore the ideal image features from Chinese HJ-1 A/B CCD images for estimating winter wheat LAI in Beijing. Image features were extracted from such images over four seasons of winter wheat growth, including five vegetation indices (VIs), principal components (PC), tasseled cap transformations (TCT) and texture parameters. The LAI was significantly correlated with the near-infrared reflectance band, five VIs [normalized difference vegetation index, enhanced vegetation index (EVI), modified nonlinear vegetation index (MNLI), optimization of soil-adjusted vegetation index, and ratio vegetation index], the first principal component (PC1) and the second TCT component (TCT2). However, these image features cannot significantly improve the estimation accuracy of winter wheat LAI in conjunction with eight texture measures. To determine the few ideal features with the best estimation accuracy, partial least squares regression (PLSR) and variable importance in projection (VIP) were applied to predict LAI values. Four remote sensing features (TCT2, PC1, MNLI and EVI) were chosen based on VIP values. The result of leave-one-out cross-validation demonstrated that the PLSR model based on these four features produced better result than the ten features' model, throughout the whole growing season. The results of this study suggest that selecting a few ideal image features is sufficient for LAI estimation.

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

    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.

  13. Texas Instruments /TI/ 800 x 800 charge-coupled device /CCD/ image sensor

    Blouke, M. M.; Hall, J. E.; Cowens, M. W.; Janesick, J. R.

    1981-01-01

    Very-large area high-performance CCD image sensors with 800 x 800 pixel format have been successfully fabricated and operated on the basis of a three-level polysilicon gate technology. They are thinned to 8 microns over the entire 12.2 x 12.2 mm active area, and are used in the rear illumination mode. The light transfer characteristic has a gamma value of 1.000 + or - 0.002 over most of the dynamic range. Analysis of the noise behavior shows that the device SNR is shot-noise-limited over most of the dynamic range. Simple on-chip signal processing can be performed using an integration well to noiselessly collect signal charge from multiple pixels prior to reading out the charge. A UV-sensitive phosphor has been applied to the chip, yielding a device capable of imaging at wavelengths from the vacuum UV to the near IR.

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

    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.

  15. Reducing Scattered Light in CCD Images at the CTIO 0.9m Telescope

    Barnaby, D.; Rauscher, B. J.

    1998-12-01

    We have been studying luminous halos around spiral galaxies in very deep near-infrared K-band images (limiting surface brightness =24 mag arcsec(-2) ; lambda_ {c} = 2.35 mu m). Following our successful detection of a halo around the southern spiral galaxy ESO 240-G11 (Rauscher et al. 1998), we collected optical CCD images of candidate galaxies at the Cerro Tololo Interamerican Observatory (CTIO) 0.9 m telescope from 17-21 Sept 1998. Because light scattered by the telescope can mask or mimic faint, extended emission, we took precautions to minimize stray and scattered light. To assess the amount of scattered light, we collected images of the telescope pupil using a pinhole camera, which we constructed by laying a sheet of aluminum foil, perforated with a submillimeter hole, 19 mm in front of the CCD. These images showed that the telescope did scatter light on the order of a few percent over a radius of about 2 arcminutes. Supressing this extraneous light was highly desirable, since halo surface brightness can be baffles. One baffle consisted of a 0.95 m diameter tube added as an extension to the telescope, which has a closed-tube design. The other 2 baffles were diaphragms mounted between the primary baffle (the ``chimney'') and the shutter. These baffles effectively eliminated the largest sources of scattered light, which appear to be the edge of the secondary baffle and the inner surface of the chimney (Figure 1, http:// astro.uchicago.edu/home/web/barnaby/sctrdlite98.html). In this paper, we quantify the reduction in scattered light and examine the most useful location to add baffles to this telescope. Acknowledgements. We thank the CTIO Telescope Operations staff for their help in constructing and installing the baffles. We also thank support astronomer Nick Suntzeff for suggesting the pinhole tests. Rauscher, B. J. et al. 1998, ApJ, 506, 116

  16. CCD和CMOS图像传感器性能比较%Character Comparison of CCD and CMOS Image Sensor

    黄美玲; 张伯珩; 边川平; 李露瑶; 达选福

    2007-01-01

    简单介绍了CCD(电荷耦合器件)与CMOS图像传感器的结构,并对二者的性能特点进行了比较.对他们的现状和发展趋势进行了分析,说明了CCD图像传感器和CMOS图像传感器之间存在的长期竞争.%The structure of CCD(charge-coupled device)and CMOS image sensors is introduced, followed by comparison of their performances. Then it analyses their actualities and development trend; finally it forecasts that there is a long term competition between CMOS image sensor and CCD image sensor.

  17. CCD drift-scan imaging lunar occultations a feasible approach for sub-meter class telescopes

    Fors, O; Richichi, A

    2001-01-01

    A CCD drift-scanning technique for lunar occultation (LO) observations is presented. While this approach has been addressed before by Sturmann (1994) for the case of large telescopes, the technical validity has never been discussed for sub-meter class telescopes. In contrast to Sturmann's scheme, the proposed technique places the CCD in the image plane of the telescope. This does not represent a problem in the case of small telescopes, where the practical angular resolution attainable by LO is not limited by aperture smoothing. Photon-generated charge is read out at millisecond rate on a column-per-column basis, as the diffraction pattern of the occulted star is being tracked. Two LO events (SAO 79031 and SAO 77911) were observed to demonstrate the feasibility of the method. Data analysis was carried out and no angular diameter the observed stars were resolved. We show, however, that the technique could be useful for close binary detections with small telescopes. A discussion of the limiting resolution and ma...

  18. Development of three-wavelength CCD image pyrometer used for the temperature field measurements of continuous casting billets

    This paper develops an imaging based three-color pyrometer for the monitoring of temperature distribution in a continuous casting billet. A novel optical device, together with an embedded electronic system, is designed to sequentially collect a dark image and three thermal images with specified wavelengths on a same monochromatic charge-coupled-device (CCD). The three thermal images provide the basis for the determination of target temperature, while the dark image is used to online eliminate the dark noise of CCD with a differential method. This image pyrometer is not only independent of target emissivity but also overcomes the dissimilarity of measuring accuracy between the micro-sensors of CCD resulted from the non-uniformity of pixels’ intensity response and the vignetting of optical system. Furthermore, a precise two-color temperature field measuring model on the CCD pyrometer is established, based on which a self-adaptive light-integration mechanism is presented. Compared with the traditional fixed light-integration method, the measuring range of the pyrometer is greatly extended and its sensitivity in low temperature segment is improved. The test results in a steel factory demonstrate that the pyrometer is capable of meeting the requirement of surface temperature measurements about casting billets. Reliability and accuracy of measurement results are also discussed herein

  19. An adaptive threshold method for improving astrometry of space debris CCD images

    Sun, Rong-yu; Zhao, Chang-yin

    2014-06-01

    Optical survey is a main technique for observing space debris, and precisely measuring the positions of space debris is of great importance. Due to several factors, e.g. the angle object normal to the observer, the shape as well as the attitude of the object, the variations of observed characteristics for low earth orbital space debris are distinct. When we look at optical CCD images of observed objects, the size and brightness are varying, hence it’s difficult to decide the threshold during centroid measurement and precise astrometry. Traditionally the threshold is given empirically and constantly in data reduction, and obviously it’s not suitable for data reduction of space debris. Here we offer a solution to provide the threshold. Our method assumes that the PSF (point spread function) is Gaussian and estimates the signal flux by a directly two-dimensional Gaussian fit, then a cubic spline interpolation is performed to divide each initial pixel into several sub-pixels, at last the threshold is determined by the estimation of signal flux and the sub-pixels above threshold are separated to estimate the centroid. A trail observation of the fast spinning satellite Ajisai is made and the CCD frames are obtained to test our algorithm. The calibration precision of various threshold is obtained through the comparison between the observed equatorial position and the reference one, the latter are obtained from the precise ephemeris of the satellite. The results indicate that our method reduces the total errors of measurements, it works effectively in improving the centering precision of space debris images.

  20. New results from an imaging CCD used as a position sensitive detector at standard TV rate and room temperature

    This paper shows new and improved results, with respect to previous work, regarding the use of an area imaging CCD (Fairchild CCD 222 running at standard TV rate and at 296 K) as X-ray and charged particle detector. A more dedicated video processor is used and as a consequence single pixel signals, revealing X-rays from a 55Fe source and β-rays from a 106Ru source, can be processed, on the basis of the dark average response and of the rms noise of each pixel. Tests are reported concerning the correlation of the signals with the dark current pattern and with the low light level illumination. (orig.)

  1. Development of automatic data extraction technique from visible CCD images for in-vessel dust study in Tore Supra

    In-vessel dusts will be an important issue in next generation fusion devices. They affect not only plasma operations but also safety limits. A new image processing technique for in-vessel dust research is developed in Tore Supra (TS). This paper describes the image processing technique for in-vessel dust study based on simple standard image processing techniques. The technique is intended to use visible standard RGB CCD cameras at a standard frame rate already installed in TS. Studying the traces of straight line-like dust trajectories appearing in the CCD images during the plasma shots, the temporal evolution and the spatial locations of dust creation events (DCEs) can be monitored. Building a database of DCEs, information on the short/long term behavior of in-vessel dusts are obtained. Analyzing the database, statistics on DCEs can be found. Finally, DCEs during 22 ohmic discharges in 2006 CIMES campaign in TS are illustrated as an example.

  2. Development of automatic data extraction technique from visible CCD images for in-vessel dust study in Tore Supra

    Hong, Suk-Ho [National Fusion Research Institute, 113 Gwahangno, YuSung-Gu, DaeJeon 305-333 (Korea, Republic of); Grisolia, Christian; Monier-Garbet, Pascale [Association EURATOM-CEA/DSM/IRFM/SIPP, CEA Cadarache, 13108 St. Paul les Durance (France)], E-mail: sukhhong@nfri.re.kr

    2009-07-15

    In-vessel dusts will be an important issue in next generation fusion devices. They affect not only plasma operations but also safety limits. A new image processing technique for in-vessel dust research is developed in Tore Supra (TS). This paper describes the image processing technique for in-vessel dust study based on simple standard image processing techniques. The technique is intended to use visible standard RGB CCD cameras at a standard frame rate already installed in TS. Studying the traces of straight line-like dust trajectories appearing in the CCD images during the plasma shots, the temporal evolution and the spatial locations of dust creation events (DCEs) can be monitored. Building a database of DCEs, information on the short/long term behavior of in-vessel dusts are obtained. Analyzing the database, statistics on DCEs can be found. Finally, DCEs during 22 ohmic discharges in 2006 CIMES campaign in TS are illustrated as an example.

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

    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...

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

    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

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

    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

    2015-01-01

    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 vegetati...

  6. Application of four CCD image sensors in radiation imaging system%多CCD图象传感器在辐射成象系统中的应用

    田慧; 王义; 杜宏亮

    2001-01-01

    多CCD图象传感器辐射成象系统采用当前最先进的光电成象器件,高速、高分辨率图象采集卡和现代数字图象处理技术,可以直接得到弹道过程的四个时刻的四幅数字X射线图象。概述多CCD图象传感器辐射成象系统的组成和原理,详细论述多CCD图象传感器的应用技术。%In order to present the images immediately during operation and acquire digitized images for further image manipulation and process,CCD image sensors radiation imaging system is developed.The system adopts the hardhitting photoelectric imaging devices,high speed and high resolution image collection,and recent digit image processing technique.Composite part and schematic of four CCD image sensors radiation imaging system is summarized,and research for CCD image sensors application technique is in extanso introduced.

  7. Image Quality of Digital Direct Flat-Panel Mammography Versus an Indirect Small-Field CCD Technique Using a High-Contrast Phantom

    Kathrin Barbara Krug

    2011-01-01

    Full Text Available Objective. To compare the detection of microcalcifications on mammograms of an anthropomorphic breast phantom acquired by a direct digital flat-panel detector mammography system (FPM versus a stereotactic breast biopsy system utilizing CCD (charge-coupled device technology with either a 1024 or 512 acquisition matrix (1024 CCD and 512 CCD. Materials and Methods. Randomly distributed silica beads (diameter 100–1400 m and anthropomorphic scatter bodies were applied to 48 transparent films. The test specimens were radiographed on a direct digital FPM and by the indirect 1024 CCD and 512 CCD techniques. Four radiologists rated the monitor-displayed images independently of each other in random order. Results. The rate of correct positive readings for the “number of detectable microcalcifications” for silica beads of 100–199 m in diameter was 54.2%, 50.0% and 45.8% by FPM, 1024 CCD and 512 CCD, respectively. The inter-rater variability was most pronounced for silica beads of 100–199 m in diameter. The greatest agreement with the gold standard was observed for beads >400 m in diameter across all methods. Conclusion. Stereotactic spot images taken by 1024 matrix CCD technique are diagnostically equivalent to direct digital flat-panel mammograms for visualizing simulated microcalcifications >400 m in diameter.

  8. Comparative evolution of various CCD image sensors hardening techniques with ionizing radiation

    This paper reviews various techniques to harden Charged Coupled Device (CCD) sensors and the results after irradiation of three Thomson n buried channel CCDs having a different degree of hardening. It describes the major irradiation effects on CCD performances and it makes a comparison of the results between the different hardening levels. It shows good results on dark voltage after ionizing radiation for TH 7863M device hardened both by design and by operating conditions (MPP mode) with respect to the standard device TH 7863A. The irradiations were performed with 60Co or X-ray (10 keV) sources on devices in operating mode. (author). 3 refs., 8 figs

  9. Photometric correction and reflectance calculation for lunar images from the Chang'E-1 CCD stereo camera.

    Chen, Chao; Qin, Qiming; Chen, Li; Zheng, Hong; Fa, Wenzhe; Ghulam, Abduwasit; Zhang, Chengye

    2015-12-01

    Photometric correction and reflectance calculation are two important processes in the scientific analysis and application of Chang'E-1 (CE-1) charge-coupled device (CCD) stereo camera data. In this paper, the methods of photometric correction and reflectance calculation were developed. On the one hand, in considering the specificity of datasets acquired by the CE-1 CCD stereo camera, photometric correction was conducted based on the digital number value directly using the revised Lommel-Seeliger factor. On the other hand, on the basis of laboratory-measured bidirectional reflectances, the relative reflectance was then calculated using the empirical linear model. The presented approach can be used to identify landing sites, obtain global images, and produce topographic maps of the lunar surface. PMID:26831395

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

    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.

  11. Images processing in hostile nuclear environments. Experimental CCD cameras tests results for robotic operations

    This paper describes succinctly the hostile aspect of nuclear environment for visual sensors and transmissions. It approaches the new field of nuclear Robotic and its constraints about vision process. Tolerance tests of CCD cameras in gamma radiations environment are displayed: - gamma dosimetry measures, - electrical measurement process, - views during testing, - degradations and better tolerance hypothesis

  12. CCD linear image sensor ILX511 arrangment for a technical spectrometer

    Bartoněk, L.; Keprt, Jiří; Vlček, Martin

    2003-01-01

    Roč. 33, 2-3 (2003), s. 548-553. ISSN 0078-5466 Institutional research plan: CEZ:AV0Z1010921 Keywords : CCD linear sensor ILX511 * enhanced parallel port (EPP able IEEE1284) * A/D converter AD9280 Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.221, year: 2003

  13. PIV camera response to high frequency signal: comparison of CCD and CMOS cameras using particle image simulation

    We present a quantitative comparison between FlowMaster3 CCD and Phantom V9.1 CMOS cameras’ response in the scope of application to particle image velocimetry (PIV). First, the subpixel response is characterized using a specifically designed set-up. The crosstalk between adjacent pixels for the two cameras is then estimated and compared. Then, the camera response is experimentally characterized using particle image simulation. Based on a three-point Gaussian peak fitting, the bias and RMS errors between locations of simulated and real images for the two cameras are accurately calculated using a homemade program. The results show that, although the pixel response is not perfect, the optical crosstalk between adjacent pixels stays relatively low and the accuracy of the position determination of an ideal PIV particle image is much better than expected. (paper)

  14. Advanced CCD camera developments

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

    1994-11-15

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

  15. A new and efficient transient noise analysis technique for simulation of CCD image sensors or particle detectors

    CCD image sensors or switched capacitor circuits used for particle detectors have a certain noise level affecting the resolution of the detector. A new noise simulation technique for these devices is presented that has been implemented in the circuit simulator ELDO. The approach is particularly useful for noise simulation in analog sampling circuits. Comparison between simulations and experimental results has been made and is shown for a 1.5 μ CMOS current mode amplifier designed for high-rate particle detectors. (R.P.) 5 refs., 7 figs

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

    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.

  17. 3D time-of-flight distance measurement with custom solid-state image sensors in CMOS/CCD-technology

    Lange, Robert

    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...

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

    Fulvio Rinaudo; Roberto Chiabrando; Dario Piatti; Filiberto Chiabrando

    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 tre...

  19. Imaging the Moon II: Webcam CCD Observations and Analysis (a Two-Week Lab for Non-Majors)

    Sato, T.

    2014-07-01

    Imaging the Moon 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, a common household object adapted for astronomical work, the lab now uses webcams as film photography has evolved into an obscure specialty technology and increasing numbers of students have little familiarity with it. The printed circuit board with the CCD is harvested from a commercial 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. They learn to keep a schedule and work 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.

  20. A high resolution Small Field Of View (SFOV) gamma camera: a columnar scintillator coated CCD imager for medical applications

    We describe a high resolution, small field of view (SFOV), Charge Coupled Device (CCD) based camera for imaging small volumes of radionuclide uptake in tissues. The Mini Gamma Ray Camera (MGRC) is a collimated, scintillator-coated, low cost, high performance imager using low noise CCDs. The prototype MGRC has a 600 μm thick layer of columnar CsI(Tl) and operates in photon counting mode using a thermoelectric cooler to achieve an operating temperature of - 10deg C. Collimation was performed using a pin hole collimator. We have measured the spatial resolution, energy resolution and efficiency using a number of radioisotope sources including 140 keV gamma-rays from 99mTc in a specially designed phantom. We also describe our first imaging of a volunteer patient.

  1. Measurement of cathode surface temperature using the method of CCD imaging in arc discharge

    2006-01-01

    A two-wavelength pyrometry device using ordinary array CCD (charge coupled device) to collect the radiation data in the horizontal and vertical directions has been developed for measuring the cathode surface temperature during the arc discharge. Analyses of experimental results show that the device can make the measurement of the cathode surface temperature feasible. The cathode surface temperatures measured are lower than the melting point of tungsten (3653 K), and the arc current, cathode diameter, and the cathode length are the main influencing factors of the cathode surface temperature.

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

    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.

  3. Spatial resolution limit study of a CCD camera and scintillator based neutron imaging system according to MTF determination and analysis

    Spatial resolution limit is a very important parameter of an imaging system that should be taken into consideration before examination of any object. The objectives of this work are the determination of a neutron imaging system's response in terms of spatial resolution. The proposed procedure is based on establishment of the Modulation Transfer Function (MTF). The imaging system being studied is based on a high sensitivity CCD neutron camera (2×10−5 lx at f1.4). The neutron beam used is from the horizontal beam port (H.6) of the Algerian Es-Salam research reactor. Our contribution is on the MTF determination by proposing an accurate edge identification method and a line spread function undersampling problem-resolving procedure. These methods and procedure are integrated into a MatLab code. The methods, procedures and approaches proposed in this work are available for any other neutron imaging system and allow for judging the ability of a neutron imaging system to produce spatial (internal details) properties of any object under examination. - Highlights: ► Determination of spatial response of a neutron imaging system. ► Ability of a neutron imaging system to reproduce spatial properties of any object. ► Spatial resolution limits measurement using MTF with the slanted edge method. ► Accurate edge identification and line spread function sampling improvement. ► Development of a MatLab code to compute automatically the MTF.

  4. An analysis of CCD images of the coma of Comet Halley. Final report, October 1989-September 1990

    The analysis of selected CCD images of the coma of comet P/Halley is presented. The images were taken using specially designed filters that isolate regions of a comet's spectrum such that only sunlight which has been scattered by the dust in the coma is recorded. The modeling analysis objective is to make use of the skills developed in the development of Monte Carlo particle trajectory models for the distributions of gas species in cometary comae and to use those models as a basis for a new dust coma model. This model will include a self-consistant picture of the time-dependent dusty-gas dynamics of the inner coma and the three-dimensional time-dependent trajectories of the dust particles under the influence of solar gravity and solar radiation pressure in the outer coma. The model is intended to be used as a tool to analyze selected images from the two sets of CCD images with the hope that it will help the understanding of the effects of a number of important processes on the spatial morphology of the observed dust coma. The processes of importance to the observed dust coma include: (1) the dust particle size distribution function; (2) the terminal velocities of various sized dust particles in the inner coma; (3) the radiation scattering properties of dust particles, which are important both in terms of the observe scattered radiation and the radiation pressure acceleration on dust particles; (4) the fragmentation and/or vaporization of dust particles; and (5) the relative importance of CHON and silicate dust particles as they contribute both to the dusty-gasdynamics in the inner coma (that produce the dust particle terminal velocities) and to the observed spatial morphology on the outer dust coma

  5. Design of a hardware/software FPGA-based driver system for a large area high resolution CCD image sensor

    Chen, Ying; Xu, Wanpeng; Zhao, Rongsheng; Chen, Xiangning

    2014-09-01

    A hardware/software field programmable gate array (FPGA)-based driver system was proposed and demonstrated for the KAF-39000 large area high resolution charge coupled device (CCD). The requirements of the KAF-39000 driver system were analyzed. The structure of "microprocessor with application specific integrated circuit (ASIC) chips" was implemented to design the driver system. The system test results showed that dual channels of imaging analog data were obtained with a frame rate of 0.87 frame/s. The frequencies of horizontal timing and vertical timing were 22.9 MHz and 28.7 kHz, respectively, which almost reached the theoretical value of 24 MHz and 30 kHz, respectively.

  6. Electronic intraoral dental x-ray imaging system employing a direct sensing CCD array

    A commercial prototype intraoral radiography system has been developed that can provide digital x-ray images for diagnosis. The system consists of an intraoral detector head, an intermediate drive electronics package, a main drive electronics package and a PC-based digital image management system. The system has the potential to replace the use of dental film in intraoral radiographic examinations. High-resolution images are acquired, then displayed on a CRT within seconds of image acquisition

  7. Electronic intraoral dental x-ray imaging system employing a direct-sensing CCD array

    Cox, John D.; Langford, D. S.; Williams, Donald W.

    1993-12-01

    A commercial prototype intraoral radiography system has been developed that can provide digital x-ray images for diagnosis. The system consists of an intraoral detector head, an intermediate drive electronics package, a main drive electronics package, and a PC-based digital image management system. The system has the potential to replace the use of dental film in intraoral radiographic examinations. High-resolution images are acquired, then displayed on a CRT within seconds of image acquisition.

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

    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. Intra-Oral X-Ray Fluoroscopy With Image Intensifier And CCD. A new imagery for a new dentistry.

    Le Denmat, D.; Bonifay, P.; Camus, Jean P.; Bouchier, Guy; Roville, J. C.

    1989-05-01

    At present, many dental acts involve operations carried out without visual monitoring, for example in mouth surgery or during the course of a dental root canal treatment. While this kind of operation is in progress, the dental surgeon is guided by his tactile sense alone. Only the traditional pre and post-operative radiographic examinations are possible. Waiting for a least ten minutes is the time required for these radiographs. This article describes a new material giving the dentist the means of a real time visual monitoring for the intervention being carried out. The device implemented in our laboratory is a dental fluoroscopy set with low level X-ray doses, small field, suitable resolution, and primarily usable for kinetic images acquisition. This dental fluoroscopic device consists of : - a special X-ray generator (low exposure and collimated flow), - a fiber optics bundle and its X-ray / visible converter, - an image intensifier associated to a charge coupled device (CCD), - and finally, a digital processing device for image treatment and display. A preliminary/ dosimetric study completes this work.

  10. CCD microscopy-image analysis by Group for Intelligent Systems GIS

    Jovanović Aleksandar B.

    2003-01-01

    Full Text Available BACKGROUND: Classic microscopy does not allow dealing with visual and photographic phenomena, observation of the distinctions where they are needed, or carrying out of any image processing other than cutting. Digital imaging provided more detailed and distinctive insights, and formed the basis for the development of the image processing tools and techniques that transcended in potential and power all initial expectations. The purpose of this article is to present our achievements in this area. METHODS: The starting point is that the matrix. Digital image is a discrete approximation of the continuous two-argument function. Analogue original is a fair basis to start building good mathematical representations of present objects structures, features, which are then subjected to calculations transformations and analyses that could precisely match the predefined aims. These analyses are: Photomorphology 3D model with morphometrics and full 3D navigation, mathematical representations of granular forms in images, object contours, mathematical representations of chromosomes with mathematical definition of similarity, automatic procedures, such as pattern normalizations, matching, classifications, which leads to broader application of Artificial Intelligence methodology. RESULTS: We developed a method and a complex software environment for microscopic imaging, with many tools and algorithms that proved to be useful in genetics, pathology, and oncology. The presented method is prepared and available for further generalizations and automatization, easily bridging to intelligent systems. CONCLUSION: Microscopic imaging is powerful new high-tech domain of great assistance in biomedical research and medical practice that is revolutionizing real time diagnostic methods and potential, matching the power of molecular biology techniques. Being the pioneers in the microscopic imaging, we are pleased that it is exponentially expanding to the general benefit.

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

    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.

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

    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.

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

    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. PMID:26465131

  14. CCD detectors for spectroscopy and imaging of x-rays with the eROSITA space telescope

    Meidinger, N.; Andritschke, R.; Ebermayer, S.; Elbs, J.; Hälker, O.; Hartmann, R.; Herrmann, S.; Kimmel, N.; Predehl, P.; Schächner, G.; Soltau, H.; Strüder, L.; Tiedemann, L.

    2009-08-01

    A special type of CCD, the so-called PNCCD, was originally developed for the focal plane camera of the XMMNewton space telescope. After the satellite launch in 1999, the MPI Halbleiterlabor continued the detector development for various ground-based applications. Finally, a new X-ray PNCCD was designed again for a space telescope named eROSITA. The space telescope will be equipped with an array of seven parallel oriented X-ray mirror systems of Wolter-I type and seven cameras, placed in their foci. This instrumentation will permit the exploration of the X-ray universe in the energy band from 0.3 keV up to 10 keV with a time resolution of 50 ms for a full image comprising 384 x 384 pixels. eROSITA will be accommodated on the new Russian Spectrum-RG satellite. The mission was already approved by the responsible German and Russian space agencies. The detector development is focussed to fulfil the scientific specifications for detector performance under the constraints of all the mechanical, power, thermal and radiation hardness issues for space instrumentation. This considers also the recent change of the satellite's orbit. The Lagrange point L2 was decided as new destination of the satellite instead of a low-Earth orbit (LEO). We present a detailed description of the detector system and the current development status. The most recent test results are reported here. Essential steps for completion of the seven focal plane detectors until satellite launch in 2012 will be itemized.

  15. Performance evaluation of CCD- and mobile-phone-based near-infrared fluorescence imaging systems with molded and 3D-printed phantoms

    Wang, Bohan; Ghassemi, Pejhman; Wang, Jianting; Wang, Quanzeng; Chen, Yu; Pfefer, Joshua

    2016-03-01

    Increasing numbers of devices are emerging which involve biophotonic imaging on a mobile platform. Therefore, effective test methods are needed to ensure that these devices provide a high level of image quality. We have developed novel phantoms for performance assessment of near infrared fluorescence (NIRF) imaging devices. Resin molding and 3D printing techniques were applied for phantom fabrication. Comparisons between two imaging approaches - a CCD-based scientific camera and an NIR-enabled mobile phone - were made based on evaluation of the contrast transfer function and penetration depth. Optical properties of the phantoms were evaluated, including absorption and scattering spectra and fluorescence excitation-emission matrices. The potential viability of contrastenhanced biological NIRF imaging with a mobile phone is demonstrated, and color-channel-specific variations in image quality are documented. Our results provide evidence of the utility of novel phantom-based test methods for quantifying image quality in emerging NIRF devices.

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

    Fynbo, J P U; Thomsen, B; Hjorth, J; Gorosabel, J; Andersen, M I; Egholm, M P; Holland, S; Jensen, B L; Pedersen, H; Weidinger, M

    2002-01-01

    We report on the results of deep narrow-band Ly-alpha, U and I imaging of the fields of two GRBs at z=2.04 (GRB 000301C and GRB 000926). We find that the host galaxy of GRB 000926 is an extended, strong Ly-alpha emitter with a rest-frame equivalent width of 71+20-15 AA. The galaxy consists of two main components and several fainter knots. GRB 000926 occurred in the western component, whereas most of the Ly-alpha luminosity (about 65%) originates in the eastern component. Using archival HST images of the host galaxy we measure the spectral slopes (f_lambda prop. to lambda^beta) of the two components to beta = -2.4+-0.3 (east) and -1.4+-0.2 (west). This implies that both components contain at most small amounts of dust, consistent with the observed strong Ly-alpha emission. The western component has a slightly redder V-I colour than the eastern component, suggesting the presence of at least some dust. We do not detect the host galaxy of GRB 000301C in neither Ly-alpha emission nor in U and I-band images. We inf...

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

    Fynbo, J.P.U.; Møller, Per; Thomsen, Bente; Hjorth, J.; Gorosabel, J.; Andersen, M.I.; Egholm, M.P.; Jensen, B.L.; Pedersen, H.; Weidinger, M.

    2002-01-01

    spectral slopes (f(lambda) proportional to lambda(beta)) of the two components to beta = 2.4 +/- 0.3 (east)and -1.4 +/- 0.2 (west). This implies that both components contain at most small amounts of dust, consistent with the observed strong Lyalpha emission. The western component has a slightly redder V...... - I colour than the eastern component, suggesting the presence of at least some dust. We do not detect the host galaxy of GRB 000301C in neither Lyalpha emission nor in U and I broad-band images. The strongest limit comes from combining the narrow and U-band imaging where we infer a limit of U...... are candidate Lyalpha emitting galaxies in the environment of the host galaxies. Based on these detections we conclude that GRB 000926 occurred in one of the strongest centres of star formation within several Mpc, whereas GRB 000301C occurred in an intrinsically very faint galaxy far from being the...

  18. Real-time detection of DNA hybridization on microarray using a CCD-based imaging system equipped with a rotated microlens array disk.

    Mogi, Takeyuki; Hatakeyama, Keiichi; Taguchi, Tomoyuki; Wake, Hitoshi; Tanaami, Takeo; Hosokawa, Masahito; Tanaka, Tsuyoshi; Matsunaga, Tadashi

    2011-01-15

    This work describes a novel charge-coupled device (CCD)-based imaging system (MB Biochip Reader™) for real-time detection of DNA hybridization to DNA microarrays. The MB Biochip Reader™ consisted of a laser light source (532 nm), a microlens array for generation of a multi-beam laser, and a CCD for 2-D signal imaging. The MB Biochip Reader™ with a rotated microlens array, allowed large-field imaging (6.2 mm × 7.6 mm with 6.45 μm resolution) with fast time-resolution at 0.2 s without speckle noise. Furthermore, real-time detection of DNA hybridization, which is sufficient to obtain accurate data from tens of thousands of array element per field, was successfully performed without the need for laser scanning. The performance of the MB Biochip Reader™ for DNA microarray imaging was similar to the commercially available photomultiplier tube (PMT)-based microarray scanner, ScanArray Lite. The system potentially could be applied toward real-time analysis in many other fluorescent techniques in addition to real-time DNA microarray analysis. PMID:20951567

  19. 快中子照相 CCD 成像系统反射镜组件设计%Design of the optical reflector stricture in a fast neutron radiography CCD imaging system

    周广星; 高明辉; 孙宝玉

    2014-01-01

    Considering the stiffness , strength and thermal dimensional stability of the reflector structure in a fast neutron radiography CCD imaging system ,we propose a four-point back support scheme .Finite element method is applied to analyze both the static and dynamic features of the supporting structure such as stiffness and the stability of thermal dimension .The results show that the surface figure accuracy of the reflector mirror (PV) is less λ/10 ,RMS is less then λ/50(λ=400) , and the modal analysis verifies the stiffness of the structure .%基于反射镜组件的刚度、强度和热尺寸稳定性,采用背部4点支撑方案设计了反射镜组件。对反射镜组件进行的静、动态刚度及热尺寸稳定性分析结果表明,反射镜在重力载荷和4℃温升载荷及温度和重力耦合变形下,面形精度达到PV≤λ/10,RM S≤λ/50(λ=400 nm )。模态分析结果证明该结构有足够的动态刚度。

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

    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.

  1. Dark signal correction for a lukecold frame-transfer CCD. New method and application to the solar imager of the PICARD space mission

    Hochedez, J.-F.; Timmermans, C.; Hauchecorne, A.; Meftah, M.

    2014-01-01

    Context. Astrophysical observations must be corrected for their imperfections of instrumental origin. When charge-coupled devices (CCDs) are used, their dark signal is one such hindrance. In their pristine state, most CCD pixels are cool, that is, they exhibit a 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, viz. they start delivering excessive, less predictable, dark current. The hot pixels therefore need to be flagged so that a subsequent analysis may ignore them. Aims: The image data of the PICARD-SODISM solar telescope require dark signal correction and hot pixel identification. Its E2V 42-80 CCD operates at -7.2 °C and has a frame-transfer architecture. Both image and memory zones thus accumulate dark current during integration and readout time, respectively. These two components must be separated in order to estimate the dark signal for any given observation. This is the main purpose of the dark signal model presented in this paper. Methods: The dark signal time-series of every pixel was processed by the unbalanced Haar technique to timestamp when its dark signal changed significantly. In-between these instants, the two components were assumed to be constant, and a robust linear regression, with respect to integration time, provides first estimates and a quality coefficient. The latter serves to assign definitive estimates for this pixel and that period. Results: Our model is part of the SODISM Level 1 data production scheme. To confirm its reliability, we verified on dark frames that it leaves a negligible residual bias (5 e-) and generates a small rms error (25 e- rms). We also examined the distribution of the image zone dark current. The cool pixel level is found to be 4.0 e- pxl-1 s-1, in agreement with the predicted value. The emergence rate of hot pixels was investigated as well. It yields a threshold criterion at 50 e- pxl-1 s-1. The growth rate

  2. Characteristic analysis on the thermal noise of infrared CCD

    Zhang, Rong-zhu; Yu, Xing; Liu, Guo-dong

    2014-09-01

    1.064 μm, 1.319 μm and 10.6 μm laser were used to irradiate silicon-based HgCdTe CCD image system. The temperature distribution of detector induced by infrared laser irradiating in the experiment above was simulated. The influence of temperature on photoelectric parameters of HgCdTe CCD was calculated. A CCD physical model of crosstalk saturation was built and the response characteristic of CCD under the influence of thermal noise was analyzed. Result indicated that the rise of temperature induced by laser irradiating little influenced imaging effect of CCD.

  3. High-power white LED-based system incorporating a CCD Offner imaging spectrometer for real-time fluorescence qPCR measurements

    An optical system for qPCR fluorescence measurements which incorporates high-power white LEDs, PMMA plastic lenses and an Offner multichannel (imaging) CCD-based spectrometer has been developed and validated. The optical system can detect twenty reaction vessels in an asynchronous manner and up to seven different fluorescent dyes (7 plex) at 1 nM dye concentrations in each of the reaction vessels. Furthermore, PCR curves obtained using the optical measurement system for a genomic deoxyribonucleic acid (DNA) template containing HEX and Texas Red fluorescent probes (fluorophores) are discussed. The spectral resolution, dynamic range and repeatability of the measurement system are < 15 nm, > 3 decades and < 1% CV, respectively. (paper)

  4. CCD imaging space correction based on electronic image stabilization technology%基于电子稳像技术的CCD成像空间校正方法研究

    马心儒; 邹丽新; 汤荣生; 顾济华; 徐婷婷; 尹楠

    2012-01-01

    On the basis of the research on the phenomenon of image's three-color dislocation appeared in the application of the color linear arrary CCD, a CCD imaging space correction method based on the technology of electronic image stabilization is proposed. This method contains several key steps including the separation of colour images, the extraction of feature points, the matching of feature points, the estimation of location parameters and the compensation of images. The experimental results show that this method can solve CCD colour disorder and improve the image quality.%针对彩色线阵CCD应用时,出现的成像三色错位问题进行了研究,提出了基于电子稳像技术的CCD成像空间校正方法.与传统方法相比,该方法引入了电子稳像技术的思想,巧妙运用帧间运动的处理手段解决了帧内运动的问题.首先对线阵CCD得到的图像进行彩色图像分离,再通过特征点提取,特征点匹配,错位参数估计,图像补偿,彩色图像合成等过程,最终获得校正后的彩色图像.仿真实验表明,该方法能有效解决三色错位问题,改善图像质量.

  5. Use of a speckle reduction technique to improve the reconstruction image quality of CCD-based optical computed tomography scanner

    This study proposed a speckle reduction technique (SRT) that employs a rotating diffuser in the parallel beam optical computed tomography (CT). Results showed that the mean and standard deviation of the gray level are 89.79±4.53 and 89.16±2.88 for reconstruction images without SRT and with SRT, respectively. The proposed SRT effectively removed ring artifacts. In addition, two image processing techniques, namely, the mean and Wiener filters, were also used to improve the reconstructed images. The image processing technique alone effectively reduced ring artifacts, but some fluctuations were still observed in the line profiles of the reconstructed images. Results proved that the proposed SRT is a simple method that is easily implemented to improve image quality for parallel beam optical CT. The combination of SRT and image filters was suggested to achieve the best image reconstruction quality through the full removal of ring artifacts. - Highlights: • Speckle reduction technique is effective to remove ring artifacts. • The fluctuation in reconstruction image can be reduced using speckle reduction technique. • The image processing technique can reduce the ring artifacts effectively, but few fluctuations can still be observed in line profiles. • The combination speckle reduction technique and image filters can achieve the best quality of reconstruction image

  6. CCD Luminescence Camera

    Janesick, James R.; Elliott, Tom

    1987-01-01

    New diagnostic tool used to understand performance and failures of microelectronic devices. Microscope integrated to low-noise charge-coupled-device (CCD) camera to produce new instrument for analyzing performance and failures of microelectronics devices that emit infrared light during operation. CCD camera also used to indentify very clearly parts that have failed where luminescence typically found.

  7. Wide Dynamic Range CCD Camera

    Younse, J. M.; Gove, R. J.; Penz, P. A.; Russell, D. E.

    1984-11-01

    A liquid crystal attenuator (LCA) operated as a variable neutral density filter has been attached to a charge-coupled device (CCD) imager to extend the dynamic range of a solid-state TV camera by an order of magnitude. Many applications are best served by a camera with a dynamic range of several thousand. For example, outside security systems must operate unattended with "dawn-to-dusk" lighting conditions. Although this can be achieved with available auto-iris lens assemblies, more elegant solutions which provide the small size, low power, high reliability advantages of solid state technology are now available. This paper will describe one such unique way of achieving these dynamic ranges using standard optics by making the CCD imager's glass cover a controllable neutral density filter. The liquid crystal attenuator's structure and theoretical properties for this application will be described along with measured transmittance. A small integrated TV camera which utilizes a "virtual-phase" CCD sensor coupled to a LCA will be described and test results for a number of the camera's optical and electrical parameters will be given. These include the following camera parameters: dynamic range, Modulation Transfer Function (MTF), spectral response, and uniformity. Also described will be circuitry which senses the ambient scene illuminance and automatically provides feedback signals to appropriately adjust the transmittance of the LCA. Finally, image photographs using this camera, under various scene illuminations, will be shown.

  8. Testing fully depleted CCD

    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.

  9. Single-spin CCD

    Baart, T. A.; Shafiei, M.; Fujita, T.; Reichl, C.; Wegscheider, W.; Vandersypen, L. M. K.

    2016-04-01

    Spin-based electronics or spintronics relies on the ability to store, transport and manipulate electron spin polarization with great precision. In its ultimate limit, information is stored in the spin state of a single electron, at which point quantum information processing also becomes a possibility. Here, we demonstrate the manipulation, transport and readout of individual electron spins in a linear array of three semiconductor quantum dots. First, we demonstrate single-shot readout of three spins with fidelities of 97% on average, using an approach analogous to the operation of a charge-coupled device (CCD). Next, we perform site-selective control of the three spins, thereby writing the content of each pixel of this ‘single-spin charge-coupled device’. Finally, we show that shuttling an electron back and forth in the array hundreds of times, covering a cumulative distance of 80 μm, has negligible influence on its spin projection. Extrapolating these results to the case of much larger arrays points at a diverse range of potential applications, from quantum information to imaging and sensing.

  10. Assessment of Total Suspended Sediment Distribution under Varying Tidal Conditions in Deep Bay: Initial Results from HJ-1A/1B Satellite CCD Images

    Liqiao Tian

    2014-10-01

    Full Text Available Using Deep Bay in China as an example, an effective method for the retrieval of total suspended sediment (TSS concentration using HJ-1A/1B satellite images is proposed. The factors driving the variation of the TSS spatial distribution are also discussed. Two field surveys, conducted on August 29 and October 26, 2012, showed that there was a strong linear relationship (R2 = 0.9623 between field-surveyed OBS (optical backscatter measurements (5-31NTU and laboratory-analyzed TSS concentrations (9.89–35.58 mg/L. The COST image-based atmospheric correction procedure and the pseudo-invariant features (PIF method were combined to remove the atmospheric effects from the total radiance measurements obtained with different CCDs onboard the HJ-1A/1B satellites. Then, a simple and practical retrieval model was established based on the relationship between the satellite-corrected reflectance band ratio of band 3 and band 2 (Rrs3/Rrs2 and in-situ TSS measurements. The R2 of the regression relationship was 0.807, and the mean relative error (MRE was 12.78%, as determined through in-situ data validation. Finally, the influences of tide cycles, wind factors (direction and speed and other factors on the variation of the TSS spatial pattern observed from HJ-1A/1B satellite images from September through November of 2008 are discussed. The results show that HJ-1A/1B satellite CCD images can be used to estimate TSS concentrations under different tides in the study area over synoptic scales without using simultaneous in-situ atmospheric parameters and spectrum data. These findings provide strong informational support for numerical simulation studies on the combined influence of tide cycles and other associated hydrologic elements in Deep Bay.

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

    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

  12. What X-ray images and CCD energy resolution can tell us about the physics of ICM

    Churazov, E.

    2016-06-01

    X-ray images and moderate-resolution energy spectra provide us with a wealth of data on the global properties of galaxy clusters. Additional information is recored in small scale surface brightness and spectral perturbations. We argue that statistical analysis of many small fluctuations in different X-ray energy bands offers a convenient way of characterizing the nature of perturbations and reveals important clues on the ICM physics and on the AGN feedback process.

  13. CCD characterization for a range of color cameras

    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

  14. Cooled 2-CCD acquisition system applied in SPR imaging%制冷双CCD采集系统在SPR成像中的应用

    张玮; 邓焱; 王大千; 丁丽丽; 余兴龙

    2011-01-01

    SPR双分差动干涉成像检测法既可实现高通量,又可提高折射率分辨率,能满足蛋白质组学和药物发现与开发的迫切需要.然而,如何高灵敏度获取干涉图像信号却是面临的技术难题.展示了一种制冷双CCD同时曝光采集系统,可同时采集2帧相位差为180.的干涉图像,解算后得到反映传感表面上发生生物分子相互作用时引起的折射率变化分布,经解析得到生物分子的特征参数.制冷CCD使暗电流噪声显著减小,有效提高检测分辨率;利用FPGA产生CCD控制信号,保证双CCD同时曝光,避免分时采集中光源光强波动引起的误差.以盐水为试剂,对系统的分辨率进行了检测,实验结果表明,该采集系统具有低噪声,无相移误差及效率高等优点,使SPR检测系统的分辨率达到2xl0-6 RIU,满足了要求.%Double-difference SPR interferometric imaging method with the advantages of high-throughput and high-resolution is potentially to be applied in proteomics and drug discovery. However, acquiring high quality interfero-metric images is still a challenging task. This paper presents a cooled 2-CCD acquisition system with simultaneous exposure, which can acquire two imterferometric images of the sensor surface with 180° phase difference simultane-ously. Then the refractive index changes on the sensor surface can be calculated, and the biomolecular interaction state and information can be extracted. Cooled CCDs can decrease dark current noise and improve resolution. FPGA chip is used to generate the signals to control the CCDs and makes sure that two CCDs can be exposed at the same time, which avoids the intensity fluctuation of LD laser. The resolution was tested in salt-water experiments and the results show that 2 ×10-6 refractive index resolution (unit; RIU) in SPR imaging can be achieved using this low-noise, efficient CCD acquisition system.

  15. Back-illuminated, fully-depleted CCD image sensors for use in optical and near-IR astronomy

    Charge-coupled devices (CCDs) of novel design have been fabricated at Lawrence Berkeley National Laboratory (LBNL), and the first large-format science-grade chips for astronomical imaging are now being characterized at Lick Observatory. They are made on 300-μm thick n-type high-resistivity (∼10 000 Ω cm) silicon wafers, using a technology developed at LBNL to fabricate low-leakage silicon microstrip detectors for high-energy physics. A bias voltage applied via a transparent contact on the back side fully depletes the substrate, making the entire volume photosensitive and ensuring that charge reaches the potential wells with minimal lateral diffusion. The development of a thin, transparent back-side contact compatible with fully depleted operation permits blue response comparable to that obtained with thinned CCDs. Since the entire region is active, high quantum efficiency is maintained to nearly λ=1000 nm, above which the silicon band gap effectively truncates photoproduction. Early characterization results indicate a charge transfer efficiency >0.999995, readout noise 4 e's at -132 deg. C, full well capacity >300 000 e's, and quantum efficiency >85% at λ=900 nm

  16. A quadrant-CCD star tracker

    Clampin, M.; Durrance, S. T.; Barkhouser, R.; Golimowski, D. A.; Wald, A.; Fastie, W. G.; Heidtmann, D. L.; Blouke, Morley M.; Westphal, James A.; Janesick, James R.

    1990-01-01

    The characteristics of a quadrant-CCD designed for pointing and tracking are discussed with reference to its use in an adaptive optics program. The quadrant-CCD is used to correct stellar image motion proceeding from atmospheric turbulence by means of a system in which a sensor measures the image offset and sends data to a high-speed tip/tilt mirror. The design and control of the device are detailed, including four 100-micron-square pixels, the quadrant architecture, controller electronics, and data acquisition computer and interface. The transfer function is set forth in the x and y directions, and transfer curves are shown. A laboratory simulation of random image motion was conducted to evaluate the performance of the quadrant-CCD as an image motion sensor, and the experimental results are presented. The suitability of the quadrant-CCD for space-based pointing and tracking uses is demonstrated by this test and two earlier theoretical studies. Some future developments which improve performance capabilities are mentioned.

  17. 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

    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

  18. CCD characterization and measurements automation

    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 55Fe data analysis. 55Fe data are used to measure gain, charge transfer efficiency and charge diffusion. Examples of express analysis results are presented and discussed.

  19. Air Quality Monitoring Using CCD/ CMOS Devices

    Low, Khee Lam; Joanna, Tan Choay Ee; Sim, Keat; Jafri, Mohd Zubir Mat; and, Khiruddin Abdullah

    2010-01-01

    In this chapter, we showed a method for measuring of the air quality index by using the CCD/CMOS sensor. We showed two examples to obtain index values by using webcam and CCTV. Both devices provided a high correlation between the measured and estimated PM10. So, the imaging method is capable to measure PM10 values in the environment. Futher application can be conducted using different devices.

  20. CCD video information acquisition technology based on image pattern%基于图象模式的CCD视频信息采集技术

    王汉兵; 黄涛; 雷磊; 周永平; 陈世纯

    2011-01-01

    以某型反坦克导弹CCD观测器测试系统的研制为背景,结合典型CCD观测器的性能及工作原理,对观测器的核心输出信号即视频信息的提取及关键软硬件设计进行了较为深入的研究,运用数字处理和视频采集技术,给出测角精度、抗干扰能力和灵敏度的分析处理方法.系统技术先进,操作界面友好,分析直观,工作可靠,很好地满足使用要求.%This study is one department of CCD observer test system development for a certain type of anti -tank missile. According to the performance and working principle of typical CCD observer, the authors deeply researched the extraction of core output signals, namely video information, and the key software and hardware design of observer. A method for processing and analyzing angle measurement accuracy, anti -jamming capability and sensitivity was provided through digital processing and video capture technology. Such system commendably satisfies the requirements for application with advanced technology, user-friendly interface, intiutive analysis and reliable function.

  1. Remote sensing of atmospheric PM2.5 from high spatial resolution image of Chinese environmental satellite HJ-1/ CCD data

    Due to lack of the middle infrared wavelength, it is difficult to employ the classic dark target method to retrieve aerosol optical depth (AOD) from Chinese Environmental satellite HJ1-CCD data. Therefore, focusing on extracting weak information from mixed satellite signals of atmosphere and land surface, we developed the Multi-wavelength, Multi-sensor, Multi-day (3M) approach in order to utilize maximally the observation information, and with the consideration of a prior knowledge, e.g. the surface property changes quickly with location but slowly with time. We present the AOD retrieval algorithm based on HJ1-CCD blue and green bands, based on the look-up table approach constructed using 6S radiative transfer model to provide the simultaneous determination of AOD and the ground reflectance. The aerosol and particle size information obtained from ground-based sun-sky radiometer are then used to estimate PM2.5 on the surface level, while air humidity and height of planetary boundary layer from reanalysis data are employed to improve the correlation between AOD and PM2.5. Validation of the retrieval results with different spatial resolutions (300, 500 and 1000 m), are also performed by comparison with ground-based measurements at three sites of North China regions

  2. Analysis of Image Sensor Technology Patent: Analysis of Key Patentin CCD Image Sensor Technology%图像传感器技术的专利状况分析——CCD图像传感器技术的重点专利分析

    杨隆鑫; 侯冠华; 左恬源

    2012-01-01

    图像传感器主要分为感光耦合元件(CCD)和互补式金属氧化物半导体有源像素传感器(CMOS)两种,其中感光耦合元件因诸多优点,其技术以及产业应用最为成熟.针对CCD图像传感器技术领域的专利文献,对该领域的重点专利进行了技术研究和分析,揭示了这些重点专利的技术要点.%Image sensors are mainly divided into Charged Coupled Device (CCD) and Complementary Metal-Oxide Semiconductor (CMOS), where in the technology and industry of CCD are the most mature . In this paper, the important patents of the field are studied and analyzed, and the technical points of these important patents are shown based on the patents of the field of the image sensor of CCD.

  3. Medical x-ray-sensitive array based on CCD

    Gnedenko, Valeri G.; Krasnjuk, Andrey A.; Larionov, Sergei V.; Phainberg, Evgeni M.; Shilin, Victor A.; Skrylev, Alexander S.; Stenin, Vladimir J.

    1996-04-01

    The achievements of CCD technology allow to design X-ray sensitive solid-state images for various medicine applications. The first medical systems have been created for using in dental practice and diagnosis. This radiovisiographic method allows to reduce X-ray exposure by 80%, except any films and provide paralleled diagnosis capacities which revolutionize every day practice. In the future a mosaic scanner with CCD chips will be used for detecting breast cancer.

  4. A microprocessor-controlled CCD star tracker

    Salomon, P. M.; Goss, W. C.

    1976-01-01

    The STELLAR (Star Tracker for Economical Long Life Attitude Reference) utilizes an image sensing Charge-Coupled Device (CCD) operating under microprocessor control. This approach results in a new type of high-accuracy star tracker which can be adapted to a wide variety of different space flight applications through software changes only. The STELLAR determines two-axis star positions by computing the element and the interelement interpolated centroid positions of the star images. As many as 10 stars may be tracked simultaneously, providing significantly increased stability and accuracy. A detailed description of the STELLAR is presented along with measurements of system performance obtained from an operating breadboard model.

  5. SCREEN photometric property detection system based on area CCD

    Yan, Fu-cai; Ye, Wei; Xu, Yu; Wang, Chao; Zhang, Yu-wei

    2011-08-01

    The photometric property detection of screen display is crucial for screen display quality test. Traditional photometry detection technologies were based on photoelectric sensors such as silicon photocell, photo-electric multiplier and CdS, which can detect only some isolated points. To break the limitation of randomness, incompleteness and detection accuracy in current technologies, we designed a screen photometric detection system based on area CCD. The system consists of photometric image sensor, photometric image acquisition hardware and photometric image analyzing software. The photometric image sensor, which adopts optical lens, optical filters and area CCD, adapts its spectrum response property to fit the spectrum luminous efficiency curve V (λ) by adjusting the thickness and quantity of appropriate optical filters. photometric image acquisition hardware adopts the DSP as a core processor to drive the area CCD, to sample, acquire , process and save the image from image sensor, to transmit the image to computer. For real-time performance of transmitting, the hardware system adopts the transmission protocol of USB2.0. The uploaded image will be processed by photometric image analyzing software, and then displayed in real time with detection results. The screen photometric detection technology based on area CCD can detect specifications of the whole screen such as luminance, contrast, onoff ratio and uniformity, breaks the limitation of randomness and incompleteness in current detection technology, exactly and fully reflects the integrated display quality of the whole screen. According to the test results, the accuracy of this system has reached the accuracy level one in China.

  6. An introduction to some imperfections of CCD sensors

    CCD sensors do not deliver a perfect image of the light they receive. Beyond the well known linear image smearing due to diffusion of charges during their drift towards the pixel wells, non-linear effects are at play in these sensors. We now have ample evidence for both a flux-dependent and static image distortions, especially but not only, on deep-depleted CCDs. For large surveys relying on CCD sensors, these effects should now be taken into account when reducing data. We present here a summary of current results on sensor characterization and mitigation methods

  7. An introduction to some imperfections of CCD sensors

    Astier, Pierre

    2015-01-01

    CCD sensors do not deliver a perfect image of the light they receive. Beyond the well known linear image smearing due to diffusion of charges during their drift towards the pixel wells, non-linear effects are at play in these sensors. We now have ample evidence for both a flux- dependent and static image distortions, especially but not only, on deep-depleted CCDs. For large surveys relying on CCD sensors, these effects should now be taken into account when reducing data. We present here a sum...

  8. An introduction to some imperfections of CCD sensors

    Astier, Pierre

    2015-01-01

    CCD sensors do not deliver a perfect image of the light they receive. Beyond the well known linear image smearing due to diffusion of charges during their drift towards the pixel wells, non-linear effects are at play in these sensors. We now have ample evidence for both a flux- dependent and static image distortions, especially but not only, on deep-depleted CCDs. For large surveys relying on CCD sensors, these effects should now be taken into account when reducing data. We present here a summary of current results on sensor characterization and mitigation methods.

  9. 基于PXIE总线的高速CCD数字图像采集系统设计%Design of High-speed CCD Digital Image Collecting System Based on PXIE Bus

    霍志; 刁节涛; 李清江; 邢金岭; 刘海军

    2011-01-01

    A design scheme of high-speed image collecting system based on PXIE bus and Camera Link protocol is proposed to realize the high-speed CCD (capacitive coupled device) digital image acquisition transmission. The interface circuit of the Camera Link protocol is designed. The designs of video data signal interface, the control signals interface and the serial communication signal interface are implemented. The Xilinx Virtex-5 LX50T FPGA is used as the transmission control device of PXIE bus, and IP core is developed to reduce the difficulty of the peripheral circuit design. The DMA (direct memory access) method is innovately adopted to optimize the transmission speed of PXIE. The results show that, while PXIE is configured with 8-channet, the read data rate is up to 1504 MB/s, the write data rate is up to 1490 MB/s, which meet the requirements of high-speed CCD data transmission.%为实现高速电容耦合器件(CCD)数字图像采集传输,提出一种基于PXIE总线和Camera Link协议的高速图像来集系统设计方案.设计了Camera Link硬件接口电路,实现了视频数据信号的接口设计、控制信号的接口设计、串行通信信号接口设计;同时采用Xilinx公司的Virtex 5 LX50T型FPGA作为PXIE传输控制器,并对IP核进行了开发,减少了外围电路设计难度.创新性地运用直接内存访问的工作方式对PXIE传输速度进行优化.实验结果表明,PXIE配I.为8通道时,读取数据速率达到1 504 MB/s,写入速率达到了1 490 MB/s,可以满足高速CCD数据的传输要求.

  10. Design of Self-tracking Robot Based on Analog CCD Sensor and Image Correction%基于模拟CCD传感器和图像矫正的自循迹机器人设计

    赵思蕊; 吴亚东; 杨文超; 蒋宏宇

    2015-01-01

    设计了一种基于模拟CCD图像传感器和图像透视矫正算法的自动循迹机器人。分别完成了机器人的总体设计和软硬件设计。该循迹机器人以32位单片机MK60DN512ZVLQ10为主控制器,采用模拟CCD摄像头获取黑色引导线信息,并转化为有效的舵机和电机控制量。为提高控制精度,利用PID控制算法实现机器人的闭环控制。由于采集的图像存在梯形失真,所以利用图像透视变换对原始图像校正,实现机器人精确的循迹。测试结果表明:该循迹机器人对场地适应性强,具有低成本、低功耗等优点,在核辐射和高压电等特殊环境下有很大的使用价值。%A self-tracking robot has been designed based on analog CCD image sensor and image per-spective correction. The overall design as well as hardware/software design is completed. The tracking ro-bot uses the MK60 DN512 ZVLQ10 as main controller and collects the black guide line image information using analog CCD camera,the image information is converted to effective steering gear and motor control. In order to improve control accuracy,using the PID control algorithm to realize the closed-loop control of the robot. Due to the collection of image is trapezoidal distortion,perspective transformation is used to correct the original image and realize accurate tracking of robot. Result of the test indicates that the track-ing robot which has strong adaptability is strong and has the advantages of low cost,low power consump-tion,it has great value in the special environment such as radiation,high voltage,etc.

  11. Riprese CCD della chioma interna della cometa Ikeya-Zhang

    Comolli, Lorenzo

    2003-03-01

    During the period of maximum brightness of comet Ikeya-Zhang we acquired many unsaturated CCD images thanks to a period of good weather. The series of images of about 2 weeks can be animated so that changes in the inner coma are made evident. Elaborations with Larson-Sekanina filter and masking filters evidence details like concentric halos, jets and shells.

  12. Colorized linear CCD data acquisition system with automatic exposure control

    Li, Xiaofan; Sui, Xiubao

    2014-11-01

    Colorized linear cameras deliver superb color fidelity at the fastest line rates in the industrial inspection. It's RGB trilinear sensor eliminates image artifacts by placing a separate row of pixels for each color on a single sensor. It's advanced design minimizes distance between rows to minimize image artifacts due to synchronization. In this paper, the high-speed colorized linear CCD data acquisition system was designed take advantages of the linear CCD sensor μpd3728. The hardware and software design of the system based on FPGA is introduced and the design of the functional modules is performed. The all system is composed of CCD driver module, data buffering module, data processing module and computer interface module. The image data was transferred to computer by Camera link interface. The system which automatically adjusts the exposure time of linear CCD, is realized with a new method. The integral time of CCD can be controlled by the program. The method can automatically adjust the integration time for different illumination intensity under controlling of FPGA, and respond quickly to brightness changes. The data acquisition system is also offering programmable gains and offsets for each color. The quality of image can be improved after calibration in FPGA. The design has high expansibility and application value. It can be used in many application situations.

  13. 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

    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...

  14. BUNDLE ADJUSTMENTS CCD CAMERA CALIBRATION BASED ON COLLINEARITY EQUATION

    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.

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

    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.

  16. Streak Camera Performance with Large-Format CCD Readout

    The ICF program at Livermore has a large inventory of optical streak cameras that were built in the 1970s and 1980s. The cameras include micro-channel plate image-intensifier tubes (IIT) that provide signal amplification and early lens-coupled CCD readouts. Today, these cameras are still very functional, but some replacement parts such as the original streak tube, CCD, and IIT are scarce and obsolete. This article describes recent efforts to improve the performance of these cameras using today's advanced CCD readout technologies. Very sensitive, large-format CCD arrays with efficient fiber-optic input faceplates are now available for direct coupling with the streak tube. Measurements of camera performance characteristics including linearity, spatial and temporal resolution, line-spread function, contrast transfer ratio (CTR), and dynamic range have been made for several different camera configurations: CCD coupled directly to the streak tube, CCD directly coupled to the IIT, and the original configuration with a smaller CCD lens coupled to the IIT output. Spatial resolution (limiting visual) with and without the IIT is 8 and 20 lp/mm, respectively, for photocathode current density up to 25% of the Child-Langmuir (C-L) space-charge limit. Temporal resolution (fwhm) deteriorates by about 20% when the cathode current density reaches 10% of the C-L space charge limit. Streak tube operation with large average tube current was observed by illuminating the entire slit region through a Ronchi ruling and measuring the CTR. Sensitivity (CCD electrons per streak tube photoelectron) for the various configurations ranged from 7.5 to 2,700 with read noise of 7.5 to 10.5 electrons. Optimum spatial resolution is achieved when the IIT is removed. Maximum dynamic range requires a configuration where a single photoelectron from the photocathode produces a signal that is 3 to 5 times the read noise

  17. Quantitative retrieval model of suspended sediment concentration in estuary based on HJ-1 CCD image%近海水体悬浮物HJ-1号小卫星CCD定量反演研究

    肖艳芳; 赵文吉; 朱琳

    2012-01-01

    基于H J-1号小卫星CCD数据,开展近海水体悬浮物含量监测研究.采用邻近清洁水体和同日MODIS气溶胶产品的方法对CCD辐亮度数据进行较精准的大气校正;利用得到的水体遥感反射率,结合地面准同步实测悬浮物含量数据建立悬浮物反演模型,获得研究区悬浮物的空间分布.模型的相关系数R2为0.849,平均误差为33.0%,反演结果较为理想.结果表明,HJ-1号小卫星作为中国首个灾害监测小卫星星座,能够实现定量反演近海水体的悬浮物含量,对中国近海水体水质的监测和治理具有重要意义.%On the basis of HJ-1 CCD image, remote sensing detection of suspended sediment concentration in estuary was carried out. A method using clean water nearby and the aerosol product relevant to the moderate resolution imaging spectroradiometer (MODIS) data was adopted to carry out the accurate atmospheric correction. The calculated water reflectance and the measured suspended sediment concentration was used to establish the quantitative retrieval model and get the spatial distribution for suspended sediment concentration in study area. The R2 of this model was 0.849, the mean error was 33.0%, and the result was satisfactory. The study showed that HJ-1 CCD image could be applied to detect the suspended sediment concentration in estuary.

  18. 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

    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.

  19. CCD characterization and measurements automation

    Kotov, I.V.; Frank, J.; Kotov, A.I.; Kubánek, Petr; O´Connor, P.; Prouza, Michael; Radeka, V.; Takacs, P.

    2012-01-01

    Roč. 695, Dec (2012), 188-192. ISSN 0168-9002 R&D Projects: GA MŠk ME09052 Institutional research plan: CEZ:AV0Z10100502 Keywords : CCD * characterization * test automation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.142, year: 2012

  20. Stable vacuum UV CCD detectors designed for space flight experiments

    Socker, Dennis G.; Marchywka, Mike; Taylor, G. C.; Levine, P.; Rios, R.; Shallcross, F.; Hughes, G.

    1993-01-01

    Thinned, backside-illuminated, p-channel CCD images are under development which can exploit the surface potential in VUV applications, yielding enhanced quantum efficiency to wavelengths as short as 1100 A. The current goal is production of large-format, 5-micron pixel imagers for spectrographic and imaging VUV spaceflight experiments. Model predictions of the effect of device design on quantum efficiency, well capacity, and crosstalk are presented for such 5-micron-approaching pixel sizes.

  1. One method for HJ-1-A HSI and CCD data fusion

    HJ-1-A satellite, developed by China independently, was equipped with two sensors of Hyper Spectral Imager (HSI) and multispectral sensor (CCD). In this paper, we examine the benefits of combining data from CCD data (high-spatial-resolution, low-spectral-resolution image) with HSI data (low -spatial-resolution, high -spectral-resolution image). Due to the same imaging time and similar spectral regime, the CCD and HSI data can be registered with each other well, and the difference between CCD and HSI data mainly is systematic bias. The approach we have been investigating compares the spectral information present in the multispectral image to the spectral content in the hyperspectral image, and derives a set of equations to approximately acquire the systematic bias between the two sensors. The systematic bias is then applied to the interpolated high-spectral CCD image to produce a fused product. This fused image has the spectral resolution of the hyperspectral image (HSI) and the spatial resolution of the multispectral image (CCD). It is capable of full exploitation as a hyperspectral image. We evaluate this technique using the data of Honghe wetland and show both good spectral and visual fidelity. An analysis of SAM classification test case shows good result when compared to original image. All in all, the approach we developed here provides a means for fusing data from HJ-1-A satellite to produce a spatial-resolution-enhanced hyperspectral data cube that can be further analyzed by spectral classification and detection algorithms

  2. 面向遥感图像无损压缩的CCD噪声抑制方法研究%Study on Suppression Method of CCD Noise for Lossless Compression of Remote Sensing Images

    吴强; 王智勇; 郭兴杰

    2011-01-01

    The noise generated by Charge-Coupled Device (CCD) will limit transmission efficiency of the remote sensing im age data transmitted from the satellite to the earth. Therefore, in order to efficiently suppress CCD noise and increase lossless compression ratio of the remote sensing images,an anisotropic diffusion method based on estimation of noise standard deviation is proposed. Firstly, based on the results of image homogeneity measurement and edge extraction, an automatic estimation method of noise standard deviation is proposed. Then, empirically linear regression model between noise standard deviation and gradient threshold of the conduction coefficient in conventional anisotropic diffusion is extracted using simulated noisy images. Based on results of noise estimation and homogeneity measurement, a noise-driven anisotropic diffusion method , which could adaptively modify conduction coefficient value and iteration number,is finally proposed. Also, Beijing-1 multispectral images and standard test images are used to assess noise estimation and noise suppression methods. The experimental results show that compared with other existing anisotropic diffusion methods,the proposed method not only achieves a better quality of image restoration but also efficiently increases lossless compression ratio of multispectral images. Furthermore, the proposed method will provide a novel thought for future development of onboard data processing system.%CCD在成像过程中所产生的噪声会限制星地间遥感图像数据的传输效率.因此,为有效抑制CCD噪声并提高遥感图像的无损压缩比,本文提出了一种基于图像噪声标准差估计的各向异性扩散方法.首先,结合图像同质性测度和边缘提取结果提出一种遥感图像噪声标准差的自动化估计方法.而后,通过噪声模拟的方式拟合出图像噪声标准差与经典式各向异性扩散方程传导系数中梯度阈值的线性关系.基于图像噪声标准差估

  3. High-sensitivity CCD-based x-ray detector

    The detector is designed for imaging measurements requiring relatively high sensitivity and high spatial resolution. The detector can discriminate single X-ray photons, yet has the wide dynamic range (∼10000:1) associated with integrating detectors. A GdO2S2 phosphor screen converts the incoming X-ray image into an optical image. The optical image is coupled (without demagnification) to the CCD image sensor using a fiber optic faceplate. The CCD (Philips Semiconductors) has an area of 4.9 x 8.6 cm with 4000 x 7000 12 μm pixels. A single 12 keV X-ray photon produces a signal of 100 e-. With 2 x 2 pixel binning, the total noise per 24 μm pixel in a 100 s image is ∼30 e-, the detective quantum efficiency is >0.6 at 1 X-ray photon per pixel, and the full image can be read out in <4 s. The spatial resolution is 50 μm. The CCD readout system is fully computer-controlled, allowing flexible operation in time-resolved experiments. The detector has been characterized using visible-light images, X-ray images and time-resolved muscle diffraction measurements.

  4. The SXI: CCD camera onboard the NeXT mission

    Tsunemi, Hiroshi; Tsuru, Takeshi Go; Dotani, Tadayasu; Hayashida, Kiyoshi; Bautz, Marshall W.

    2008-07-01

    The Soft X-ray Imager (SXI) is the X-ray CCD camera on board the NeXT mission that is to be launched around 2013. We are going to employ the CCD chips developed at Hamamatsu Photonics, K.K. We have been developing two types of the CCD: an N-channel chip and a P-channel chip. The effective area of the detector system will be 5-6 cm square with a depletion layer of 100-200μm. The P-channel chip will have thicker depletion layer that makes it easy to develop it to back-illuminated type CCD. It will need a year or so for us to reach the final conclusion which type will be available. Based on the Suzaku experience, we will incorporate the charge injection gate so that we can reduce the proton damage. Furthermore, we will employ a mechanical cooler to keep the CCD working temperature down to -120°C in spite that NeXT will be in the low earth orbit. We can expect the radiation damage on our system very small. The CCD will have an Al coat on the chip to prevent optical photons from entering. This also eliminates the vacuum-tight chamber and the door-opening mechanism. We are planning to employ a custom-made analog ASIC that will reduce the power consumption and the size. The ASIC may speed up the frame-time if we can use a multi-node CCD. With using the focal length of 6m, the SXI will fully function with the optics around 20" resolution. We will report the current plan of the SXI in detail.

  5. Ground-Based CCD Astrometry with Wide Field Imagers. I. [Observations just a few years apart allow decontamination of field objects from members in two Globular clusters.

    Anderson, J; Bellini, A; Piotto, G; Yadav, R S; Anderson, Jay; Bedin, Luigi R.; Bellini, Andrea; Piotto, Giampaolo; Yadav, Ramakant Singh

    2006-01-01

    This paper is the first of a series of papers in which we will apply the methods we have developed for high-precision astrometry (and photometry) with the Hubble Space Telescope to the case of wide-field ground-based images. In particular, we adapt the software originally developed for WFPC2 to ground-based, wide field images from the WFI at the ESO 2.2m telescope. In this paper, we describe in details the new software, we characterize the WFI geometric distortion, discuss the adopted local transformation approach for proper-motion measurements, and apply the new technique to two-epoch archive data of the two closest Galactic globular clusters: NGC 6121 (M4) and NGC 6397. The results of this exercise are more than encouraging. We find that we can achieve a precision of ~7 mas (in each coordinate) in a single exposure for a well-exposed star, which allows a very good cluster-field separation in both M4, and NGC 6397, with a temporal baseline of only 2.8, and 3.1 years, respectively.

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

    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. PMID:27296309

  7. 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

    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

  8. Resolved CCD Photometry of Pluto and Charon

    Highly resolved CCD images of Pluto and Charon near maximum separation are measured with point spread function fitting techniques to determine independent magnitudes and an accurate separation for Pluto and Charon. A measured separation of 0.923 + or - 0.005 arcsec at a position angle of 173.3 + or - 0.3 deg on June 18, 1987 UT produced a value of 19558.0 + or - 153.0 km for the radius of Charon's orbit. An apparent B magnitude of 14.877 + or - 0.009 and (B-I) color of 1.770 + or - 0.015 are determined for Pluto, while Charon is fainter with B = 18.826 + or - 0.011 and slightly bluer with (B-I) = 1.632 + or - 0.018. 18 references

  9. Monitoring spatial distribution of armyworm disaster on maize with multi-temporal HJ-CCD images%利用多时相HJ-CCD遥感影像监测玉米粘虫灾情空间分布

    杨粉团; 顾晓鹤; 李刚; 曹庆军; 姜晓莉; 王纪华※

    2013-01-01

      Insect infestation is one of the major biological disasters in crop production. To identify an insect-damaged area and to obtain its spatial distribution are important for agricultural disaster monitoring. These data are usually obtained through field investigation, collation, and summary. As an alternative, the remote sensing of insect infestation has advantages of large range, time savings, labor savings, and high speed. In summer of 2012, an outbreak of oriental armyworm (Mythimna seperata Walker) occurred in a vast area of northeast China. In order to examine the potential of remote sensing technique in monitoring such a migratory, fulminant, and devastating agricultural pest, several data processing and analysis procedures were carried out to assess the spatial distribution of oriental armyworm and its severity level, as follows. 1)Cornfield acreage was extracted in the study area using a decision tree classifier based on NDVI and single-band reflectance that was derived from multi-temporal HJ-1A/1B CCD images over the growing season of maize. 2) Based on field measurements, the pest severity level was associated with leaf biomass from several ground agronomic parameters;the aim was to find a certain remote sensing variable and its quantitative model with the ground agronomic parameter to monitor the oriental armyworm disaster severity level. 3) The relationship between vegetation indices that were derived from three temporal HJ-CCD satellite images on three different phases and agronomic parameters were established based on numerical analysis. 4) Using the relationship between agronomic parameters and oriental armyworm disaster severity level, it is possible to use remote sensing data to obtain the spatial distribution of oriental armyworm. The results showed that the leaf biomass was significantly correlated with oriental armyworm severity level (R2=0.905, n=51). Therefore, it is feasible to use leaf biomass as a surrogate of the hazard grade of

  10. 2048 pixel front illuminated linear CCD for spectroscopy

    Wang, Chao-min; Liu, Chang-ju; Zheng, Yu; Li, Ping

    2009-07-01

    The charge couple device(CCD) used in spectroscopy requests good response to the wave bands between 190-1000 nm. The common measure to carry out UV response is phosphor coatings or back illuminated. Among them, phosphors are wavelength converters that convert short-wavelength light into the visible spectral region. This technology needs adding special process which not only raises cost, reduces yield, but also reduces the resolution of the image. Back illuminated is reducing CCD thickness to 15um which is thinner than the normal paper by mechanical polishing and chemical corrosion after completing the front processes of CCD. This technology needs special instrument, complex process , and the yield is also low. Both phosphor coatings and back illuminated have some disadvantages such as low space resolution, complex process, low yield, high cost etc. The CCD of traditional structure has no response to the wavelength less than 350nm, the reason is that the length of UV penetrating through Si is shallow, the penetrating length is only 6.5nm of 300nm UV, the shorter wavelength UV, the shallower penetrating length. The junction depth of normal CCD process is above 200nm, some realize shallow junction through molecular beam epitaxy, but the instrument is expensive and the cost is high. The photosensitive area of normal structure CCD adopting portrait P-N junction, light incidences from N area, N area can't be completely depleted because of the restrict of physics, photon can't arrive depletion area directly. On the basis of thorough analysis traditional UV CCD, horizontal P-N junction structure of Photosensitive area is put forward, whose depletion can reach the surface, the photon falls depletion area directly, which can effectively carry out the absorption of the UV light and the collection of photoelectron. As the latent absorption of Si3N4 to UV with less than 248nm wavelength, the Si3N4 passivation on the photosensitive area is take out. The improved 2048 elements

  11. CCD Color Camera Characterization for Image Measurements

    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

  12. CCD flux measurement system Prohermes

    Kroger-Vodde, A. [University of Almeria, Plataforma Solar de Almeria (Spain); Hollander, A. [German Aerospace Center, Plataforma de Almeria, Head of Engineering (Spain)

    1999-03-01

    At the Plataforma Solar de Almeria (PSA) a new, PC based, 14 bit CCD video flux measurement system, called PROHERMES, has been introduced to improve the precision of data acquisition and includes with Optimas a flexible, more user friendly, easy adaptable software environment. The hardware and software is described. Macros have been created to meet the special requirements of the tasks at the PSA. As an example for a macro, the program flow structure is given for the acquisition of the moving-bar sequence to measure the performance of receivers like in the REFOS project. The results are exported to Excel. The comparison with the former measurement system HERMES II concludes the new system as an important progress. Future efforts will focus on the further automation of flux measurements and heliostat controls. (authors)

  13. CCD-based thermoreflectance microscopy: principles and applications

    CCD-based thermoreflectance microscopy has emerged as a high resolution, non-contact imaging technique for thermal profiling and performance and reliability analysis of numerous electronic and optoelectronic devices at the micro-scale. This thermography technique, which is based on measuring the relative change in reflectivity of the device surface as a function of change in temperature, provides high-resolution thermal images that are useful for hot spot detection and failure analysis, mapping of temperature distribution, measurement of thermal transient, optical characterization of photonic devices and measurement of thermal conductivity in thin films. In this paper we review the basic physical principle behind thermoreflectance as a thermography tool, discuss the experimental setup, resolutions achieved, signal processing procedures and calibration techniques, and review the current applications of CCD-based thermoreflectance microscopy in various devices. (topical review)

  14. CCD Readout Electronics for the Subaru Prime Focus Spectrograph

    Hope, Stephen C.; Gunn, James E.; 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 4...

  15. Robotic CCD microscope for enhanced crystal recognition

    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.

  16. Status Of Sofradir IR-CCD Detectors

    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.

  17. Cryostat and CCD for MEGARA at GTC

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

    2012-09-01

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

  18. CCD Photometry of bright stars using objective wire mesh

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

    2014-06-01

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

  19. CCD Photometry of bright stars using objective wire mesh

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

  20. Development of the x-ray CCD for SXI on board ASTRO-H

    Ueda, Shutaro; Hayashida, Kiyoshi; Nakajima, Hiroshi; Anabuki, Naohisa; Uchida, Hiroyuki; Tsunemi, Hiroshi; Fujikawa, Mari; Mori, Hideki; Kohmura, Takayoshi; Watanabe, Tatsuo; Kawai, Kohei; Ikeda, Shoma; Kaneko, Kenta; Sakata, Kazuya; Todoroki, Shotaro; Mizuno, Hideki; Yagihashi, Nobuyoshi; Dotani, Tadayasu; Ozaki, Masanobu; Tsuru, Takeshi Go; Muramatsu, Masaharu; Suzuki, Hisanori; Takagi, Shin'ichiro

    2011-09-01

    We report on the development of the X-ray CCD for the soft X-ray imager (SXI) onboard ASTRO-H. SXI CCDs are P-channel, back-illuminated type manufactured by Hamamatsu Photonics K. K. Experiments with prototype CCD for the SXI shows the device has a depletion layer as thick as 200μm, high efficiency for hard X-rays. By irradiating soft X-rays to the prototype CCD for the SXI. At the same time, we found a significant low energy tail in the soft X-ray response of the SXI prototype CCD. We thus made several small size CCD chips with different treatment in processing the surface layers. CCDs with one of the surface layers treatment show a low energy tail of which intensity is one order of magnitude smaller than that of the original SXI prototype CCD for 0.5keV X-ray incidence. The same treatment will be applied to the flight model CCDs of the SXI. We also performed experiments to inject charge with the SXI prototype CCD, which is needed to mitigate the radiation damage in the orbit. We investigated the operation conditions of the charge injection. Using the potential equilibration method, charges are injected in each column homogeneously, though the amount of the charge must be larger than 20ke-.

  1. Discriminação de variedades de citros em imagens CCD/CBERS-2 Discrimination of citrus varieties using CCD/CBERS-2 satellite imagery

    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.

  2. New trends in developments of CCD arrays

    Timofeev, V. O.

    2005-06-01

    Currently the number of foreign companies manufacturing the charge-coupled devices (CCD) comes to many tens, and manufacture of CCDs for different applications exceeds 10 million pieces per year. With the purpose to provide competition ability of our CCDs our enterprise has concentrated efforts on the manufacture of customized CCDs designed either for military or civilian applications. The main trends in the CCD developments are presented.

  3. Computer-aided diagnosis of pneumoconiosis abnormalities extracted from chest radiographs scanned with a CCD scanner

    This paper presents a computer-aided diagnosis for pneumoconiosis radiographs obtained with a common charge-coupled devices (CCD) scanner. Since the current computer-aided diagnosis systems of pneumoconiosis are not practical for medical doctors due to high costs of usage for a special scanner, we propose a novel system which measures abnormalities of pneumoconiosis from lung images obtained with a common CCD scanner. Experimental results of discriminations between normal and abnormal cases for 56 right-lung images including 6 standard pneumoconiosis images have shown that the proposed abnormalities are well extracted according to the standards of pneumoconiosis categories. (author)

  4. First results with he pn-CCD detector system for the XMM satellite mission

    The pn-CCD is a novel CCD type which is developed for fast X-ray imaging and spectroscopy for the X-ray Multi Mirror (XMM) satellite emission. Each 200x64 pixel large pn-CCD unit with a sensitive area of 3x1 cm2 is a fully depleted detector. Full depletion allows for high photon detection efficiency (>90% in the energy range of 500 eV-10 keV), for a small input capacitance necessary for low noise signal measurements and for backward illumination. For good time resolution and low noise performance each of the 64 CCD channels is terminated with an integrated input-JFET for signal amplification. With the use of the CMOS Amplifier and Multiplexing Chip (CAMEX64B) it is possible to read out the 64 CCD channels in parallel before they are multiplexed and sent to an ADC. For the first time the system of a 64 channel pn-CCD together with CAMEX64B readout, ADC conversion and data acquisition and storage has been brought into operation. First images of an 55Fe X-ray source are presented and discussed. (orig.)

  5. High-speed optical shutter coupled to fast-readout CCD camera

    Yates, George J.; Pena, Claudine R.; McDonald, Thomas E., Jr.; Gallegos, Robert A.; Numkena, Dustin M.; Turko, Bojan T.; Ziska, George; Millaud, Jacques E.; Diaz, Rick; Buckley, John; Anthony, Glen; Araki, Takae; Larson, Eric D.

    1999-04-01

    A high frame rate optically shuttered CCD camera for radiometric imaging of transient optical phenomena has been designed and several prototypes fabricated, which are now in evaluation phase. the camera design incorporates stripline geometry image intensifiers for ultra fast image shutters capable of 200ps exposures. The intensifiers are fiber optically coupled to a multiport CCD capable of 75 MHz pixel clocking to achieve 4KHz frame rate for 512 X 512 pixels from simultaneous readout of 16 individual segments of the CCD array. The intensifier, Philips XX1412MH/E03 is generically a Generation II proximity-focused micro channel plate intensifier (MCPII) redesigned for high speed gating by Los Alamos National Laboratory and manufactured by Philips Components. The CCD is a Reticon HSO512 split storage with bi-direcitonal vertical readout architecture. The camera main frame is designed utilizing a multilayer motherboard for transporting CCD video signals and clocks via imbedded stripline buses designed for 100MHz operation. The MCPII gate duration and gain variables are controlled and measured in real time and up-dated for data logging each frame, with 10-bit resolution, selectable either locally or by computer. The camera provides both analog and 10-bit digital video. The camera's architecture, salient design characteristics, and current test data depicting resolution, dynamic range, shutter sequences, and image reconstruction will be presented and discussed.

  6. CCD readout electronics for the Subaru Prime Focus Spectrograph

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

    2014-07-01

    The following paper details the design for the CCD readout electronics for the Subaru Telescope Prime Focus Spectrograph (PFS). PFS is designed to gather spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm to 1260 nm. 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 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 × 4k, 15 μm pixel, detector format. The two visible cameras use a pair of Hamamatsu 2k × 4k CCDs with readout provided by custom electronics, while the NIR camera uses a single Teledyne HgCdTe 4k × 4k detector and Teledyne's 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 interface to the Subaru messaging hub and controls other peripheral devices associated with the camera, while the FPGA is used to generate the necessary clocks and transfer image data from the CCDs. The FEE board sets clock biases, substrate bias, and CDS offsets. It also monitors bias voltages, offset voltages, power rail voltage, substrate voltage and CCD temperature. The board translates LVDS clock signals to biased clocks and returns digitized analog data via LVDS. Monitoring and control messages are sent from the BEE to the FEE using a standard serial interface. The Pre-amplifier board resides behind the detectors and acts as an interface to the two Hamamatsu CCDs. The Pre-amplifier passes clocks and biases to the CCDs, and analog CCD data is buffered and amplified prior to being returned to the FEE. In this paper we describe the

  7. A Simple Illustrative Model of a Charge-Coupled Device (CCD)

    Santillo, Michael F.

    2009-10-01

    Many students (as well as the general public) use modern technology without an understanding of how these devices actually work. They are what scientists refer to in the laboratory as "black boxes." Students often wonder how physics relates to the technology used in the real world and are interested in such applications. An example of one such "black box" is the charge-coupled device (CCD), an electronic imaging sensor invented in 1970 by Bell Labs researchers Willard Boyle and George Smith. Astronomers first embraced CCD technology in the early 1980s because CCDs are very light sensitive, consume low amounts of power, and generate digital images quickly. More than three decades later, CCDs have become ubiquitous, as they are found in consumer digital cameras, scanners, photocopiers, medical imaging devices and spectroscopic detectors. This paper presents a model of a CCD "chip" that can be easily adapted as a classroom demonstration.

  8. The development of high-speed 100 fps CCD camera

    This paper describes the development of a high-speed CCD digital camera system. The system has been designed to use CCDs from various manufacturers with minimal modifications. The first camera built on this design utilizes a Thomson 512 x 512 pixel CCD as its sensor, which is read out from two parallel outputs at a speed of 15 MHz/pixel/output. The data undergo correlated double sampling after which it is digitized into 12 bits. The throughput of the system translates into 60 MB/second, which is either stored directly in a PC or transferred to a custom-designed VXI module. The PC data acquisition version of the camera can collect sustained data in real time that is limited to the memory installed in the PC. The VXI version of the camera, also controlled by a PC, stores 512 MB of real-time data before it must be read out to the PC disk storage. The uncooled CCD can be used either with lenses for visible light imaging or with a phosphor screen for X-ray imaging. This camera has been tested with a phosphor screen coupled to a fiber-optic face plate for high-resolution, high-speed X-ray imaging. The camera is controlled through a custom event-driven user-friendly Windows package. The pixel clock speed can be changed from 1 to 15 MHz. The noise was measured to be 1.05 bits at a 13.3 MHz pixel clock. This paper will describe the electronics, software, and characterizations that have been performed using both visible and X-ray photons. (orig.)

  9. Digital X-ray detector based on a CCD matrix

    The application of charge-coupled devices (CCD) as position-sensitive detectors for X-ray radiation is discussed. The experimental scheme contains a videotransmission camera to detect pulsed X-ray radiation and Vektor analog-to-digital converters and computer interface. It is shown that the sensitivity range of a K1200TsM1 matrix to bremsstrahlung with an average energy of 75 keV is 2.7·10-8-0.8·10-6 J/cm2. The spatial resolution of the resultant X-ray image is discussed. 5 refs., 5 figs

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

    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.

  11. Analysis of the Imaging Speed of the CCD Based Neutron Digital Radiography System%基于CCD的中子数字照相系统成像速度分析

    唐彬; 李西安; 霍合勇; 薛斌

    2007-01-01

    成像速度是中子冷阴极放电器(CCD)数字照相系统的主要性能参数.根据中子数字照相的原理、光学成像的基本关系式和CCD的特性,提出了一种基于CCD的中子数字照相系统的成像速度理论推算方法,对SPRR-300中子数字照相系统成像速度进行了计算,并与试验结果相比较证明,理论计算与试验基本吻合,计算方法可信.

  12. Subpixel characterization of a PIV-CCD camera using a laser spot

    We present a simple method for charge-coupled device (CCD; or CMOS) sensor characterization by using a subpixel laser spot. This method is used to measure the variations in sensitivity of the 2D sensor array systems equipped with a microlens array. The experimental results show that there is variation in the sensitivity for each position on the CCD of the camera, and the pixel optical center error with respect to the geometrical center is in the range of one-tenth that of a pixel. The disparity observed is attributed to the coherence of the laser light used that generates interference at the scale of the pixel. This may have significant consequences for coherent light imaging using CCD (or CMOS) such as particle image velocimetry. (paper)

  13. The development of large-aperture test system of infrared camera and visible CCD camera

    Li, Yingwen; Geng, Anbing; Wang, Bo; Wang, Haitao; Wu, Yanying

    2015-10-01

    Infrared camera and CCD camera dual-band imaging system is used in many equipment and application widely. If it is tested using the traditional infrared camera test system and visible CCD test system, 2 times of installation and alignment are needed in the test procedure. The large-aperture test system of infrared camera and visible CCD camera uses the common large-aperture reflection collimator, target wheel, frame-grabber, computer which reduces the cost and the time of installation and alignment. Multiple-frame averaging algorithm is used to reduce the influence of random noise. Athermal optical design is adopted to reduce the change of focal length location change of collimator when the environmental temperature is changing, and the image quality of the collimator of large field of view and test accuracy are also improved. Its performance is the same as that of the exotic congener and is much cheaper. It will have a good market.

  14. Protein diffraction experiments with Atlas CCD detector

    Dohnálek, Jan; Kovaľ, Tomáš; Dušek, Michal

    2008-01-01

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

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

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

    2009-01-01

    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

  16. Characterization of a pnCCD for applications with synchrotron radiation

    In this work we study the response of a pnCCD by means of X-ray spectroscopy in the energy range between 6 keV and 20 keV and by Laue diffraction techniques. The analyses include measurements of characteristic detector parameters like energy resolution, count rate capability and effects of different gain settings. The limit of a single photon counting operation in white beam X-ray diffraction experiments is discussed with regard to the occurrence of pile-up events, for which the energy information about individual photons is lost. In case of monochromatic illumination the pnCCD can be used as a fast conventional CCD with a charge handling capacity (CHC) of about 300,000 electrons per pixel. If the CHC is exceeded, any surplus charge will spill to neighboring pixels perpendicular to the transfer direction due to electrostatic repulsion. The possibilities of increasing the number of storable electrons are investigated for different voltage settings by exposing a single pixel with X-rays generated by a microfocus X-ray source. The pixel binning mode is tested as an alternative approach that enables a pnCCD operation with significantly shorter readout times. -- Highlights: ► The pnCCD acts as a four-dimensional detector for white X-rays. ► Its performance for applications with synchrotron radiation is investigated. ► The pnCCD can be used for single photon counting and photon integration. ► The operation mode depends on the local frequencies of pile-up events. The pnCCD can be optimized for X-ray spectroscopy and X-ray imaging

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

    Baltay, C.; Snyder, J. A.; Andrews, P.; Emmet, W.; Schaefer, B.; Sinnott, J.; Bailyn, C.; de Coppi, P.; Oemler, A.; Sabbey, C. N.; Sofia, S.; van Altena, W.; Vivas, A. K.; Abad, C; Briceno, C.

    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 ...

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

    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.

  19. THE CCD PHOTOMETRIC OBSERVATIONS OF COMET C/1995 O1 (HALE-BOPP)

    Zhou Hongnan; Huang Keliang; Wang Yu; Zhou Qinglin

    2000-01-01

    The CCD photometric observation of secular periodic comet C/1995 O1 (Hale-Bopp) was carried out at the Sheshan Station of Shanghai Observatory of China. We obtained 23 CCD images on 1996 March 11, April 22 and May 22. We derived the magnitude of the cometary nucleus in V, R bands, and estimated the lower limits of cometary mass and size. The results show that the diameter of nucleus ≈ 5 ~ 10km, which corresponds to a mass of 2 × 1012~ 3 × 1013 kg for different parameters when the bulk density is assumed to 1000 kg·m-3.

  20. Research of fiber position measurement by multi CCD cameras

    Zhou, Zengxiang; Hu, Hongzhuan; Wang, Jianping; Zhai, Chao; Chu, Jiaru; Liu, Zhigang

    2014-07-01

    Parallel controlled fiber positioner as an efficiency observation system, has been used in LAMOST for four years, and will be proposed in ngCFHT and rebuilt telescope Mayall. The fiber positioner research group in USTC have designed a new generation prototype by a close-packed module robotic positioner mechanisms. The prototype includes about 150 groups fiber positioning module plugged in 1 meter diameter honeycombed focal plane. Each module has 37 12mm diameter fiber positioners. Furthermore the new system promotes the accuracy from 40 um in LAMOST to 10um in MSDESI. That's a new challenge for measurement. Close-loop control system are to be used in new system. The CCD camera captures the photo of fiber tip position covered the focal plane, calculates the precise position information and feeds back to control system. After the positioner rotated several loops, the accuracy of all positioners will be confined to less than 10um. We report our component development and performance measurement program of new measuring system by using multi CCD cameras. With the stereo vision and image processing method, we precisely measure the 3-demension position of fiber tip carried by fiber positioner. Finally we present baseline parameters for the fiber positioner measurement as a reference of next generation survey telescope design.

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

    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.

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

    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.

  3. CCD Readout Electronics for the Subaru Prime Focus Spectrograph

    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...

  4. Cryostat and CCD for MEGARA at GTC

    Castillo Domínguez, E.; Ferrusca Rodríguez, D.; Tulloch, S.; Velázquez, M.; E. Carrasco; Gallego Maestro, Jesús; Gil De Paz, Armando; F. M. Sánchez; Vílchez, J. M.

    2012-01-01

    MEGARA (Multi-Espectrografo en GTC de Alta Resolucion para Astronomia) is the new integral field unit (IFU) and multi-object spectrograph (MOS) instrument for the GTC. The spectrograph subsystems include the pseudo-slit, the shutter, the collimator with a focusing mechanism, pupil elements on a volume phase holographic grating (VPH) wheel and the camera joined to the cryostat through the last lens, with a CCD detector inside. In this paper we describe the full preliminary design of the cryost...

  5. Measuring flying object velocity with CCD sensors

    Ricny, Vaclav; Mikulec, Jiri

    1994-06-01

    An autonomous optoelectronic method of measuring the flying objects track velocity vector (TVV) using digital signal two-line CCD sensors has been developed and simulated at the Department of Radioelectronics at the Faculty of Electrical Engineering of the Technical University of Brno, Czech Republic. The principle of the method, the computer simulation of measuring device operations, the application of statistic estimates for the precision of values measured, and the presentation of the results achieved are described.

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

    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.

  7. Design of CCD driver for quartz horizontal pendulum tiltmeter based on CPLD

    Zhan, Weiwei; Lu, Haiyan; Cai, Li; Wang, Xiu; Yang, Zhenyu

    2015-02-01

    In order to improve the resolution and conversion speed of photoelectric transducer, a high sensitive and low dark current CCD image sensor TCD1711DG was used in SQ-70D digital quartz horizontal pendulum tiltmeter. The timing chart of CCD has fixed state transition and rigorous timing requirements at typical pulse frequency. Then, a method of controlling the pulse state transition was developed by synchronous counting. The driver was carried out by using Verilog HDL based on CPLD. Simulation and experimental results indicated that the driver designed by this method was simple and stable enough to meet the timing requirements of TCD1711DG. Furthermore, integration time of the CCD could be revised flexibly by setting controlled variable QINT which improved the adaptability of the tiltmeter to different lighting levels.

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

    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. A study of a multi-pinned phase CCD detector for use as a star tracker

    Friedman, Scott D.

    1994-01-01

    This grant has supported studies of the use of charge coupled devices (CCD's) in star trackers in a number of different areas. Among the tasks we have pursued are the following: (1) radiation modeling and the increase in noise equivalent angle as a result of exposure to protons and bremsstrahlung gamma rays; (2) the development of pattern matching software to identify field locations from a CCD image and a pre-existing map of the local area; (3) observations of various stellar fields from the 24 inch telescope at the Offit Observatory at JHU, primarily to test the pattern matching software (these included crowded fields as well as moving objects, like comets); and (4) tracking of very faint objects to determine the faint limit of the CCD system.

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

    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. A Low Noise, High QE, Large Format CCD Camera System for the NASA MIGHTI Instrument

    Hancock, J. J.; Cardon, J.; Watson, M.; Cook, J.; Whiteley, M.; Beukers, J.; Englert, C. R.; Brown, C. M.; Harlander, J.

    2015-12-01

    The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument is part of the NASA Ionspheric Connection Explorer (ICON) mission designed to uncover the mysteries of the extreme variability of the Earth's ionosphere. MIGHTI consists of two identical units positioned to observe the Earth's low latitude thermosphere from perpendicular viewing directions. The MIGHTI instrument is a spatial heterodyne spectrometer and requires a low noise, high QE, large format camera system to detect slight phase changes in the fringe patterns which reveal the neutral wind velocity. The MIGHTI camera system uses a single control electronics box to operate two identical CCD camera heads and communicate with the ICON payload electronics. The control electronics are carefully designed for a low noise implementation of CCD biases, clocking, and CCD output digitization. The camera heads consist of a 2k by 2K, back-illuminated, frame transfer CCD provided by e2v. The CCD's are both TEC cooled and have butcher-block filters mounted in close proximity of the active area. The CCDs are nominally operated in binned mode, the control electronics register settings provide flexibility for binning and gain control. An engineering model of the camera system has been assembled and tested. The EM camera system characterization meets all performance requirements. Performance highlights include a measured read noise of 5.7 electrons and dark current of 0.01 electronics/pixel/second. The camera system design and characterization results will be presented.

  12. The University of Hawaii Institute for Astronomy CCD camera control system

    Jim, K. T. C.; Yamada, H. T.; Luppino, G. A.; Hlivak, R. J.

    1992-01-01

    The University of Hawaii Institute for Astronomy CCD Camera Control System consists of a NeXT workstation, a graphical user interface, and a fiber optics communications interface which is connected to a San Diego State University CCD controller. The UH system employs the NeXT-resident Motorola DSP 56001 as a real time hardware controller. The DSP 56001 is interfaced to the Mach-based UNIX of the NeXT workstation by DMA and multithreading. Since the SDSU controller also uses the DPS 56001, the NeXT is used as a development platform for the embedded control software. The fiber optic interface links the two DSP 56001's through their Synchronous Serial Interfaces. The user interface is based on the NeXTStep windowing system. It is easy to use and features real-time display of image data and control over all camera functions. Both Loral and Tektronix 2048 x 2048 CCD's have been driven at full readout speeds, and the system is intended to be capable of simultaneous readout of four such CCD's. The total hardware package is compact enough to be quite portable and has been used on five different telescopes on Mauna Kea. The complete CCD control system can be assembled for a very low cost. The hardware and software of the control system has proven to be quite reliable, well adapted to the needs of astronomers, and extensible to increasingly complicated control requirements.

  13. Ground-based observations of uranus and neptune using CCD instruments

    The author verifies that with the help of charge-coupled devices (CCD) great progress is being made in ground-based astronomical observations, including the study of the remote giant planets Uranus and Neptune. In reading the CCD the top row of pixels (potential wells) is moved into the sequential (shift) reading register; after this each row (line) of pixels moves its electrons upward (in each column) until the bottom row is cleared. This process is repeated for each row until the device is interrogated sequentially. The use of CCD detectors for purposes of image acquisition and spectroscopy has already found wide popularity at astronomical observatories, and soon it will spread to space research. The first known attempts to use CCD to obtain astronomical images was made by the author and his colleagues in April 1976. The result was the first observations of structure on the dark disk of Uranus. In general, the more refined the mathematical provision, the more information can be extracted from the images or spectra

  14. X-ray apparatus with scintillator and charge-coupled devices (CCD) sensor for dental radiography

    The apparatus includes an X-ray source coupled with a receiver both being placed on a support which can rotate about a vertical axis. The receiver comprises a slit receiving incident X-rays which are collected by a charge-coupled device (CCD) sensor via a scintillator screen. The sensor consists of an array of X-ray detectors which generate the X-ray image line by line. The image is transferred to an output amplifier and processed so that each element of the image is digitized and stored in a memory unit. The receiver also includes a mobile part which can be moved with the speed of a radiography film. The advantage of this technology is to enable panoramic images of objects using CCD detectors which can be adapted to existing apparatus. (authors). 2 figs

  15. Calibration Tests of Industrial and Scientific CCD Cameras

    Shortis, M. R.; Burner, A. W.; Snow, W. L.; Goad, W. K.

    1991-01-01

    Small format, medium resolution CCD cameras are at present widely used for industrial metrology applications. Large format, high resolution CCD cameras are primarily in use for scientific applications, but in due course should increase both the range of applications and the object space accuracy achievable by close range measurement. Slow scan, cooled scientific CCD cameras provide the additional benefit of additional quantisation levels which enables improved radiometric resolution. The calibration of all types of CCD cameras is necessary in order to characterize the geometry of the sensors and lenses. A number of different types of CCD cameras have been calibrated a the NASA Langley Research Center using self calibration and a small test object. The results of these calibration tests will be described, with particular emphasis on the differences between standard CCD video cameras and scientific slow scan CCD cameras.

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

    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.

  17. CCD development for the Dark Energy Spectroscopic Instrument

    We describe research and development efforts directed towards the production of 4 k × 4 k, 15 μm-pixel, fully depleted CCDs for the Dark Energy Spectroscopic Instrument (DESI). The requirements for DESI include the spectroscopic characterization of large numbers of faint galaxies at high redshift. The identification of the type and the determination of the redshift of the targeted galaxies require the use of thick, fully depleted CCDs with high quantum efficiency at near-infrared wavelengths. We describe our work to improve the CCD performance in terms of quantum efficiency and read noise. We also discuss efforts to reduce the level of image-distortion effects that have been observed on previous CCDs that are due to resistivity striations in the starting silicon and periodic errors in the photomasks used to produce the CCDs

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

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

    2009-05-01

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

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

    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.

  20. Use of a C.C.D. array in an X-ray pinhole camera

    X-ray imaging adapted to the laser-matter interaction experiments consits in recording plasma images from its X-ray emission; those phenomena have between 100 ps and some nanoseconds duration. When we only need spatial information on 1-10 keV X-ray emission, the most simple imaging device is the pinhole camera; the two dimension image of the plasma is temporally integrated by an X-ray sensitive detector. Until now, X-ray film was used. Its operation and processing were long and tedious, so we replaced it by a television camera built around a Charge Coupled device (C.C.D.). This camera is directly integrated in the pinhole camera. The X-ray detection is made by the silicon substrat of a C.C.D. without input window working in the vacuum of the experiment chamber; a compact camera head (40 mm diameter, 120 mm length) located near the C.C.D. (1 to 2 cm) makes the charge voltage conversion and the signal amplification. The immediate operation of images is done by an image acquisition and processing unit after digitizing the video signal on 8 bits. From measurements made on a continuous X-ray source (5,4 keV) we could point out the fact that a THOMSON-CSF THX 31135 CCD is 10 times more sensitive than the X-ray SB2 KODAK film that we use in pinhole cameras. The dynamic range measured in these conditions was about 300. The first experimental results obtained on a pulsed X-ray source are presented

  1. CCD developed for scientific application by Hamamatsu

    Miyaguchi, K; Dezaki, J; Yamamoto, K

    1999-01-01

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

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

    Uesugi, K.; Hoshino, M.; Yagi, N

    2010-01-01

    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...

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

    Lens- and fiber-coupled X-ray detectors with identical CCD chips were compared in their performance in high-resolution computed tomography experiments. 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

  4. Full-field sensitivity and its time-dependence for the STIS CCD and MAMAs

    Roman-Duval, Julia; Proffitt, Charles

    2013-07-01

    The three STIS detectors - CCD, NUV-MAMA, FUV-MAMA - are subject to temperature- and time-dependent sensitivity changes. These temporal sensitivity variations are cal- ibrated as part of routine calibration monitoring programs, and corrected for in the standard CALSTIS pipeline. In order to determine whether the correction algorithms, developed based on spectroscopic observations prior to the 2004 failure of STIS, are adequate for pre- and post-SM4 STIS imaging data, we examine the photometry of stan- dard stellar fields (NGC5139 for the CCD, NGC6681 for the MAMAs) obtained between 1997 and 2012 as part of the routine full-field sensitivity calibration programs. For the CCD, we include a correction for CTE effects. We find statistically significant residual temporal variations in the full-field sensitivity of 0.5 mmag/year, 0.04 mmag/year, and 0.54 mmag/year for the CCD, NUV-MAMA, and FUV-MAMA respectively. However, these residual trends are small: they do not incur flux changes exceeding 1% over a 15 year time period.

  5. Programmable Clock Waveform Generation for CCD Readout

    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.

  6. The Brighter-Fatter and other sensor effects in CCD simulations for precision astronomy

    Upcoming and current large astronomical survey experiments often seek to constrain cosmological parameters via measurements of subtle effects such as weak lensing, which can only be measured statistically. In these cases, instrumental effects in the image plane CCDs need to be accounted and/or corrected for in measurement algorithms. Otherwise, the systematic errors induced in the measurements might overwhelm the size of the desired effects. Lateral electric fields in the bulk of the CCDs caused by field shaping potentials or space charge build up as the electrons in the image are acquired can cause lateral deflections of the electrons drifting in the CCD bulk. Here, I report on the LSST effort to model these effects on a photon-by-photon basis by the use of a Monte Carlo technique. The eventual goal of this work is to produce a CCD model validated by laboratory data which can then be used to evaluate its effects on weak lensing science

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

    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.

  8. Application of Model Derived Charge Transfer Inefficiency Corrections to STIS Photometric CCD Data

    Bristow, Paul

    2003-01-01

    The STECF Calibration Enhancement effort for the Space Telescope Imaging Spectrograph (STIS) aims to improve data calibration via the application of physical modelling techniques. As part of this effort we have developed a model of the STIS CCD readout process. The model itself is described in some detail in earlier ISRs. Here we consider the application to STIS photometric data. We demonstrate that this approach can successfully remove the trails typically seen in CTE affected data and go on...

  9. Application of Model Derived Charge Transfer Inefficiency Corrections to STIS Spectroscopic CCD Data

    Bristow, Paul

    2003-01-01

    The ST-ECF Calibration Enhancement effort for the Space Telescope Imaging Spectrograph (STIS) aims to improve data calibration via the application of physical modelling techniques. As part of this effort we have developed a model of the STIS CCD readout process. The model itself is described in some detail in earlier ISRs. Here we consider the application to STIS spectroscopic data. We find good agreement between the simulation derived corrections and empirical corrections for a range of back...

  10. EL Sistema CCD de Tonantzintla. Pruebas Y Planes Futuros

    Cardona, O.; Chavira, E.; Furenlid, L.; Iriarte, B.

    1987-05-01

    We present results of the laboratory tests of the CCD camera system recently acquired by INAOE, also the theoretical and observational performance of the instrument with the one meter telescope of UNAM. The system has a TI 4849 CCD with 390 >c 584 pixels. We will present the future plans of its use in the new 2.1 m telescope at Cananea, onora.

  11. Pixel-Based CTI Corrections for HST/STIS CCD Data

    Biretta, John A.; Lockwood, Sean A.; Debes, John H.

    2016-01-01

    The Space Telescope Imaging Spectrograph (STIS) team at STScI has created stand-alone automated software to apply Charge Transfer Inefficiency (CTI) corrections to STIS CCD data. CTI results from radiation damage to the CCD detector during its many years in the space environment on-board the Hubble Space Telescope (HST). The software will remove trails and other image artifacts caused by CTI, and will help correct target fluxes and positions to their proper values. The software script (stis_cti v1.0) uses a pixel-based correction algorithm, and will correct both images and spectra. It automatically generates CTI corrected dark reference files, applies CTI corrections to the science data, and outputs the usual CALSTIS products with CTI corrections applied. Currently only the most common observation modes are supported -- full-frame, non-binned data, taken with the default CCD amplifier; future enhancements may include sub-array data. It is available free to the community for download and use. Further information can be found at www.stsci.edu/hst/stis/software/analyzing/scripts/pixel_based_CTI.

  12. Recording of radiation-induced optical density changes in doped agarose gels with a CCD camera

    Full text: Spatially resolved dose measurement with iron-doped agarose gels is continuing to be investigated for applications in radiotherapy dosimetry. It has previously been proposed to use optical methods, rather than MRI, for dose measurement with such gels and this has been investigated using a spectrophotometer (Appleby A and Leghrouz A, Med Phys, 18:309-312, 1991). We have previously studied the use of a pencil beam laser for such optical density measurement of gels and are currently investigating charge-coupled devices (CCD) camera imaging for the same purpose but with the advantages of higher data acquisition rates and potentially greater spatial resolution. The gels used in these studies were poured, irradiated and optically analysed in Perspex casts providing gel sections 1 cm thick and up to 20 cm x 30 cm in dimension. The gels were also infused with a metal indicator dye (xylenol orange) to render the radiation induced oxidation of the iron in the gel sensitive to optical radiation, specifically in the green spectral region. Data acquisition with the CCD camera involved illumination of the irradiated gel section with a diffuse white light source, with the light from the plane of the gel section focussed to the CCD array with a manual zoom lens. The light was also filtered with a green colour glass filter to maximise the contrast between unirradiated and irradiated gels. The CCD camera (EG and G Reticon MC4013) featured a 1024 x 1024 pixel array and was interfaced to a PC via a frame grabber acquisition board with 8 bit resolution. The performance of the gel dosimeter was appraised in mapping of physical and dynamic wedged 6 MV X-ray fields. The results from the CCD camera detection system were compared with both ionisation chamber data and laser based optical density measurements of the gels. Cross beam profiles were extracted from each measurement system at a particular depth (eg. 2.3 cm for the physical wedge field) for direct comparison. A

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

    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∼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 dose

  14. Experiment research on laser disturbing CCD detectors%激光干扰CCD系统的实验研究

    刘延武

    2011-01-01

    为了验证激光辐照CCD系统的干扰效果,进行了视场内和视场外He-Ne激光干扰面阵CCD探测器系统的实验研究,测得了像元饱和阈值和局部受辐照时的CCD饱和功率街度阈值.使用Matlab编程处理了视场内干扰图像,得到了激光入射能量与CCD饱和面积比的关系曲线,并对实验中出现的光饱和串音现象进行了理论分析.对视场外干扰图像进行计算机处理,得到了激光入射角度与CCD饱和面积比的关系曲线.实验结果表明:激光干扰CCD成像制导武器是可行的.%in order to verify disturbance effect on CCD detectors irradiated by laser, eexperiment research on He - Ne laser disturbing CCD detectors was accomplished from inside and outside the field of view.Pixel saturation threshold was measured.CCD saturation power density threshold was also measured.Disturbance image from inside the field of view was processed using the Matlab programming.The curve was described.The curve is changed by laser incident energy and CCD saturation area ratio.Crosstalk phenomenon of light - saturated was analyzed in theory.Disturbance image from outside the field of view was processed with computer.The curve was described.The curve is changed by laser incident angle and CCD saturation area ratio.The experiment result shows that laser disturbing CCD imaging guidance weapons is feasible.

  15. Fotometria CCD della cometa Hale-Bopp.

    Mikuz, H.; Dintinjana, B.

    1999-10-01

    This contribution is based on the authors' five-year program of CCD photometry of faint comets, performed mainly with 20-cm and 36-cm telescopes, V filter and two CCDs. Recent apparition of comet Hale-Bopp proved to be an excellent opportunity to test the observing method, instrumentation and software even on a very bright comet. The authors found that their V observations of faint comets tend to be systematically fainter by 0.5 - 1 magnitude in spite of the fact that the CCDs record systematically more coma than human eye. The authors explained this with the fact that the human eye and V filter passbands are not the same and have thus different response to C2 which is the main emission from the coma. Additional troubles may appear with bright comets that have prominent inner tails, composed mainly of dust particles. In case of comet Hale-Bopp, it is shown that by carefully choosing the aperture radius, the resulting total V magnitudes are in good agreement with total values of experienced visual observers.

  16. CCD UBVRI photometry of NGC 6811

    Yontan, T; Bostancı, Z F; Ak, T; Karaali, S; Güver, T; Ak, S; Duran, S; Paunzen, E

    2014-01-01

    We present the results of CCD UBVRI observations of the open cluster NGC 6811 obtained on 18th July 2012 with the 1m telescope at the T\\"UB\\.ITAK National Observatory (TUG). Using these photometric results, we determine the structural and astrophysical parameters of the cluster. The mean photometric uncertainties are better than 0.02 mag in the V magnitude and B-V, V-R, and V-I colour indices to about 0.03 mag for U-B among stars brighter than magnitude V=18. Cluster member stars were separated from the field stars using the Galaxia model of Sharma et al. (2011) together with other techniques. The core radius of the cluster is found to be $r_{c}$=3.60 arcmin. The astrophysical parameters were determined simultaneously via Bayesian statistics using the colour-magnitude diagrams V versus B-V, V versus V-I, V versus V-R, and V versus R-I of the cluster. The resulting most likely parameters were further confirmed using independent methods, removing any possible degeneracies. The colour excess, distance modulus, m...

  17. Structural and Thermodynamic Characterization of Vibrio fischeri CcdB*

    De Jonge, Natalie; Hohlweg, Walter; Garcia-Pino, Abel; Respondek, Michal; Buts, Lieven; Haesaerts, Sarah; Lah, Jurij; Zangger, Klaus; Loris, Remy

    2010-01-01

    CcdBVfi from Vibrio fischeri is a member of the CcdB family of toxins that poison covalent gyrase-DNA complexes. In solution CcdBVfi is a dimer that unfolds to the corresponding monomeric components in a two-state fashion. In the unfolded state, the monomer retains a partial secondary structure. This observation correlates well with the crystal and NMR structures of the protein, which show a dimer with a hydrophobic core crossing the dimer interface. In contrast to its F plasmid homologue, CcdBVfi possesses a rigid dimer interface, and the apparent relative rotations of the two subunits are due to structural plasticity of the monomer. CcdBVfi shows a number of non-conservative substitutions compared with the F plasmid protein in both the CcdA and the gyrase binding sites. Although variation in the CcdA interaction site likely determines toxin-antitoxin specificity, substitutions in the gyrase-interacting region may have more profound functional implications. PMID:19959472

  18. Structural and thermodynamic characterization of Vibrio fischeri CcdB.

    De Jonge, Natalie; Hohlweg, Walter; Garcia-Pino, Abel; Respondek, Michal; Buts, Lieven; Haesaerts, Sarah; Lah, Jurij; Zangger, Klaus; Loris, Remy

    2010-02-19

    CcdB(Vfi) from Vibrio fischeri is a member of the CcdB family of toxins that poison covalent gyrase-DNA complexes. In solution CcdB(Vfi) is a dimer that unfolds to the corresponding monomeric components in a two-state fashion. In the unfolded state, the monomer retains a partial secondary structure. This observation correlates well with the crystal and NMR structures of the protein, which show a dimer with a hydrophobic core crossing the dimer interface. In contrast to its F plasmid homologue, CcdB(Vfi) possesses a rigid dimer interface, and the apparent relative rotations of the two subunits are due to structural plasticity of the monomer. CcdB(Vfi) shows a number of non-conservative substitutions compared with the F plasmid protein in both the CcdA and the gyrase binding sites. Although variation in the CcdA interaction site likely determines toxin-antitoxin specificity, substitutions in the gyrase-interacting region may have more profound functional implications. PMID:19959472

  19. Development of the X-ray CCD in Japan

    We review the progress of X-ray charge-coupled device (CCD) development and related issues in Japan. They are summarized into the following topics: (1) We demonstrated, for the first time, that a CCD could detect X-ray polarization, by studying the event profiles generated from individual X-ray photons. This is based on the fact that a photoelectron is preferentially injected in the direction of X-ray polarization. (2) Before developing a CCD with a thick depletion layer, we modified a CCD for optical use by removing the absorption layer. This made it possible to detect emission lines from Ge-L (53 eV) in detail. (3) A mesh experiment was introduced to measure the quantum efficiency (QE) in detail within a pixel. We could directly measure the thickness of the gates and their overlaps with each other. This experimentally revealed how the X-ray event grades were produced within a pixel. (4) As an application of the mesh experiment, we could also measure the shape of the charge cloud generated by an X-ray photon. Once we know the charge-cloud shape, we can precisely determine the point of interaction of the X-ray photon within a pixel. This makes the position resolution of the CCD much better than the pixel size. (5) So far, we have developed X-ray astronomy satellites, ASCA, ASTRO-E2 and MAXI, equipped with CCD cameras. CCD cameras on ASCA and ASTRO-E2 were developed through collaborative work with MIT. A future Japanese satellite, NeXT, will also be equipped with a CCD camera. We will design the CCD such that it can function simultaneously with a high-energy detector in order to cover a wide energy range

  20. CCD [charge-coupled device] sensors in synchrotron x-ray detectors

    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 cm2 can be imaged on a 2 cm2 CCD. With a conversion efficiency of ∼1 CCD electron/x-ray photon, a peak saturation capacity of >106 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 x 106 pixels/s and the shift rate in the parallel registers is 106 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 the rate of ∼1 frame/s or a complete 3-dimensional data set from a single crystal in ∼2 min. 16 refs., 16 figs., 2 tabs

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

    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.

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

    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.

  3. A Simple Approach of CCD Camera Calibration for Optical Diagnostics Instrumentation

    Cha, Soyoung Stephen; Leslie, Fred W.; Ramachandran, Narayanan; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Solid State array sensors are ubiquitous nowadays for obtaining gross field images in numerous scientific and engineering applications including optical diagnostics and instrumentation. Linear responses of these sensors are often required as in interferometry, light scattering and attenuation measurements, and photometry. In most applications, the linearity is usually taken to be granted without thorough quantitative assessment or correction through calibration. Upper-grade CCD cameras of high price may offer better linearity: however, they also require linearity checking and correction if necessary. Intermediate- or low-grade CCD cameras are more likely to need calibration for linearity . Here, we present two very simple approaches: one for quickly checking camera linearity without any additional setup and one for precisely correcting nonlinear sensor responses. It is believed that after calibration, those sensors of intermediate or low grade can function as effectively as their expensive counterpart.

  4. A new approach to modelling radiation noise in CCD's

    The energy depositions reported by Monte Carlo electron-photon irradiation transport codes are subject to a random error due to the finite number of particle histories used to generate the results. These statistical variations, normally a nuisance, may also be identified with the real radiation noise effects experienced by CCD pixels in persistent radiation environments. This paper explores the practicability of such radiation noise modelling by applying the ACCEPT code from the ITS suite to the case of a shielded CCD exposed to an electron flux. The results are compared with those obtained in a subsequent electron irradiation of the CCD by a Van de Graaff accelerator

  5. The Spectrum of Quantum Dots Film for UV CCD

    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.

  6. Astrometric CCD observations of the third and the fourth moons of Uranus with the normal astrograph at the Pulkovo observatory

    Dement'eva, A. A.

    2015-09-01

    The results of astrometric CCD observations of two major moons of Uranus (Oberon and Titania) with the Normal Astrograph ( D/F = 0.33 m/3.5 m; CCD S2C with a FOV of 18' × 16') at the Pulkovo Observatory are presented. The observations were conducted in 2008-2011. The CCD image reduction is based on the Turner method with a reference to the UCAC3 catalogue system. The (O-C) values are calculated with the use of the MULTI-SAT server for the ephemerides of planetary moons. The obtained equatorial coordinates are compared to two modern theories of planetary motion: INPOP10 + Lainey (2008) and DE421/LE421 + Lainey (2008). The observations agree well with both theories.

  7. Testing thinned, backside illuminated CCD area image sensors

    Root, G.

    1976-01-01

    Test techniques were developed making use of computer processing of the video data. The results of testing device noise and nonuniformity were obtained. Read-out noise levels of 25 to 50 electrons rms and uncorrected nonuniformity of response of about 1 to 3% were measured. A simple technique for linearly correcting nonuniformity was described and examples given. The technique was shown to be successful in reducing nonuniformity to the level of random noise.

  8. Plasma Jet Imaging by CCD Technology in Rapid Mold Manufacturing

    2002-01-01

    Plasma spraying is an important enabling technology i n near-net-shaped process as well as many high-performance coating applicatio ns. Recently, it is being applied to rapid mould manufacturing to reduce develop ment time and manufacturing cost. In this process, inputted powders are heated a nd accelerated by plasma jet, and impinge on master pattern or prototype to form ing a thick coating. Mould will be fabricated after backed-up with consolidated material and other post-treatments. Amongst numerous fa...

  9. Follow-up study of children with cerebral coordination disturbance (CCD, Vojta).

    Imamura, S; Sakuma, K; Takahashi, T

    1983-01-01

    713 children (from newborn to 12-month-old) with delayed motor development were carefully examined and classified into normal, very light cerebral coordination disturbance (CCD, Vojta), light CCD, moderate CCD, severe CCD, suspected cerebral palsy (CP) and other diseases at their first visit, and were followed up carefully. Finally, 89.0% of very light CCD, 71.4% of light CCD, 56.0% of moderate CCD and 30.0% of severe CCD developed into normal. 59.5% of moderate CCD and 45.5% of severe CCD among children who were given Vojta's physiotherapy developed into normal. The classification of cases with delayed motor development into very light, light, moderate and severe CCD based on the extent of abnormality in their postural reflexes is useful and well correlated with their prognosis. Treatment by Vojta's method seems to be efficient and helpful for young children with delayed motor development. PMID:6614390

  10. In-process automatic wavelength calibration for CCD-spectrometers

    Mirapeix Serrano, Jesús María; Cobo García, Adolfo; Cubillas de Cos, Ana María; Conde Portilla, Olga María; López Higuera, José Miguel

    2008-01-01

    In CCD-spectrometers, the relation between the CCD-pixel number and the associated wavelength is established by means of a calibration polynomial, whose coefficients are typically obtained using a calibration lamp with known emission line wavelengths and a regression procedure. A recalculation of this polynomial has to be performed periodically, as the pixel number versus wavelength relation can change with ambient temperature variations or modifications in the optics attached to the spectrom...