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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.

  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. PMID:27191962

  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

    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

    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.

  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. 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.

  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. 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.

  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

    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.

  2. 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.

  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. 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.

  16. 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...

  17. 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...

  18. 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

  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

    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.

  7. 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

  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 sum...

  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. 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.

  16. 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.

  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

    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

    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.

  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. 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.

  13. 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)

  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. 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.

  1. 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.

  2. 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.

  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. 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.

  5. 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...

  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. 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...

  8. 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.

  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. 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.

  11. 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...

  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 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.

  2. 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.

  3. 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.

  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. 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...

  8. 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.

  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...

  11. Highly Stable, Large Format EUV Imager Project

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

  12. A novel approach to accurate portal dosimetry using CCD-camera based EPIDs

    A new method for portal dosimetry using CCD camera-based electronic portal imaging devices (CEPIDs) is demonstrated. Unlike previous approaches, it is not based on a priori assumptions concerning CEPID cross-talk characteristics. In this method, the nonsymmetrical and position-dependent cross-talk is determined by directly imaging a set of cross-talk kernels generated by small fields ('pencil beams') exploiting the high signal-to-noise ratio of a cooled CCD camera. Signal calibration is achieved by imaging two reference fields. Next, portal dose images (PDIs) can be derived from electronic portal dose images (EPIs), in a fast forward-calculating iterative deconvolution. To test the accuracy of these EPI-based PDIs, a comparison is made to PDIs obtained by scanning diode measurements. The method proved accurate to within 0.2±0.7% (1 SD), for on-axis symmetrical and asymmetrical fields with different field widths and homogeneous phantom thicknesses, off-axis Alderson thorax fields and a strongly modulated IMRT field. Hence, the proposed method allows for fast, accurate portal dosimetry. In addition, it is demonstrated that the CEPID cross-talk signal is not only induced by optical photon reflection and scatter within the CEPID structure, but also by high-energy back-scattered radiation from CEPID elements (mirror and housing) towards the fluorescent screen

  13. Which part of a CCD pixel is sensitive to the proton damage?

    A mesh experiment is, so far, the only practical technique to study charge-coupled devices (CCD) response with subpixel resolution. Since the Chandra ACIS was seriously damaged by low-energy protons in orbit, we undertook a mesh experiment with a relatively low-energy proton beam. The CCD used was designed for the Solid Slit Camera (SSC) employed by the Monitor of All-sky X-ray Image (MAXI) mission that is scheduled to be onboard the International Space Station in 2007. It consists of 1024x1024 pixels, each 24 μm square. Each pixel is equipped with a 'notch' structure in the center to make it radiation hard. A proton beam energy has been selected so that the protons passing through the mesh holes, 2 μm in diameter, will penetrate into the CCD chip and damage the transfer channel. At the beginning of the experiment, we used a low intensity proton beam and operated the CCD in proton count mode in order to precisely determine the mutual alignment between the mesh and the CCD. Then, we irradiated the CCD with a strong proton beam, which increased the charge transfer inefficiency (CTI) from 10-6 to 10-4. After the proton irradiation, we removed the mesh and measured the CTI with X-rays. In this way, we determined the CTI for individual pixels. We see that there is a high CTI region running through the center of the pixels from top to bottom. This corresponds to the notch region where the charge is transferred. Pixels whose notch structures are damaged show a CTI of ∼3x10-4 that is about three times worse than those damaged outside the notch regions. When the proton damages in the notch structure, the signal charges are easily trapped, resulting in a high CTI. Our results clearly show that the non-uniformity of the CTI is due to the notch structure. This result is consistent with other experiments showing the effectiveness of the notch structure

  14. Establishment and Optimization of Rigorous Geometric Model of Push-broom Camera Using TDI CCD Arranged in an Alternating Pattern

    MENG Weican

    2015-12-01

    Full Text Available Push-broom cameras using TDI CCD arranged in an alternating pattern are widely carried by typical high-resolution optical satellites in order to obtain high space resolution and enough strip width. For this kind of cameras, several TDI CCD are arranged in an alternating pattern in two lines on the focal plane and push-broom imaging mode is always adopted. Imaging principle and characteristic of this kind of camera is introduced. Exterior parameters of TDI CCD are modeled together based on their same values in any instant of time and an integrated geometric model is finally established. Error compensation methods are designed to remove exterior error and interior error based on this integrated geometric model. A series of tests are designed to verify models and methods proposed in this paper using original image of TH-1 Satellite HR Camera whose detectors are divided into 8 modules arranged in an alternating pattern. As the results, the imaging geometry of this kind of camera can be rigorously described by this integral geometrical model. The positioning accuracy can be obviously improved by our exterior error compensation method, however, different residual error would be remained for different TDI CCD. The positioning accuracy will not be obviously improved while systematic errors of different TDI CCD can be effectively removed by the interior error compensation method. 2 m positioning accuracy in X, Y and Z directions can be achieved and different systematic errors can be removed when both exterior and interior error were compensated. The same accuracy can be achieved in the other scenes when the calculated inner distortion parameters are adopted.

  15. LAIWO: a new wide-field CCD camera for Wise Observatory

    Baumeister, Harald; Afonso, Cristina; Marien, Karl-Heinz; Klein, Ralf

    2006-06-01

    LAIWO is a new CCD wide-field camera for the 40-inch Ritchey-Chretien telescope at Wise Observatory in Mitzpe Ramon/Israel. The telescope is identical to the 40-in. telescope at Las Campanas Observatory, Chile, which is described in [2]. LAIWO was designed and built at Max-Planck-Institute for Astronomy in Heidelberg, Germany. The scientific aim of the instrument is to detect Jupiter-sized extra-solar planets around I=14-15 magnitude stars with the transit method, which relies on the temporary drop in brightness of the parent star harboring the planet. LAIWO can observe a 1.4 x 1.4 degree field-of-view and has four CCDs with 4096*4096 pixels each The Fairchild Imaging CCDs have a pixel size of 15 microns. Since they are not 2-side buttable, they are arranged with spacings between the chips that is equal to the size of a single CCD minus a small overlap. The CCDs are cooled by liquid nitrogen to a temperature of about -100 °C. The four science CCDs and the guider CCD are mounted on a common cryogenic plate which can be adjusted in three degrees of freedom. Each of these detectors can also be adjusted independently by a similar mechanism. The instrument contains large shutter and filter mechanisms, both designed in a modular way for fast exchange and easy maintenance.

  16. Large area high-resolution CCD-based X-ray detector for macromolecular crystallography

    Pokric, M; Jorden, A R; Cox, M P; Marshall, A; Long, P G; Moon, K; Jerram, P A; Pool, P; Nave, C; Derbyshire, G E; Helliwell, J R

    2002-01-01

    An X-ray detector system for macromolecular crystallography based on a large area charge-coupled device (CCD) sensor has been developed as part of a large research and development programme for advanced X-ray sensor technology, funded by industry and the Particle Physics and Astronomy Research Council (PPARC) in the UK. The prototype detector consists of two large area three-sides buttable charge-coupled devices (CCD 46-62 EEV), where the single CCD area is 55.3 mmx41.5 mm. Overall detector imaging area is easily extendable to 85 mmx110 mm. The detector consists of an optically coupled X-ray sensitive phosphor, skewed fibre-optic studs and CCDs. The crystallographic measurement requirements at synchrotron sources are met through a high spatial resolution (2048x1536 pixel array), high dynamic range (approx 10 sup 5), a fast readout (approx 1 s), low noise (<10e sup -) and much reduced parallax error. Additionally, the prototype detector system has been optimised by increasing its efficiency at low X-ray ene...

  17. Design of measurement system for low illuminance CCD's key performance parameters

    Shao, Xiao-peng; Du, Juan; Wang, Yang

    2013-08-01

    As an important photovoltaic detector in the night vision imaging systems, some main performance parameters decide the properties of the low illuminance CCDs greatly including noise, quantum effects, dynamic range and dark current, and it is necessary to design a measurement system to measure the performance parameters of the low illuminance CCD. This article designs a set of low illuminance CCD chips' performance parameter measurement system, which is consisted of five parts including adjustable monochromatic light source, integrating sphere-darkroom, Dewar control chamber, main control circuit and the master computer software for automatic measurement. By persistent demonstration, the performance parameters measurement system which is focused on the low illuminance CCD proposed in this paper has the advantages of compact, good compatibility, theoretical measurement precision and fully automated measurement etc.The appropriate equipment and instruments are selected in this measurement system. And the connections of each subsystem are designed independently, which guarantees the tightness of the total system, eliminate the effects of stray light at the same time and improves the measurement accuracy of the system. Besides, this measurement system solves the generation of monochromatic light, and the measurement of low illuminance CCDs at a low temperature.

  18. The X-ray CCD camera of the MAXI experiment on the ISS/JEM

    Monitor of All-sky X-ray Image (MAXI), is the X-ray observatory on the Japanese experimental module (JEM) Exposed Facility (EF) on the International Space Station (ISS). MAXI is a slit scanning camera which consists of two kinds of X-ray detectors: one is a one-dimensional position-sensitive proportional counter with a total area of ∼5000 cm2, the Gas Slit Camera (GSC), and the other is an X-ray CCD array with a total area of ∼200 cm2, the Solid-state Slit Camera (SSC). The GSC subtends a field of view with an angular dimension of 1 deg. x180 deg. while the SSC subtends a field of view with an angular dimension of 1 deg. times a little less than 180 deg. . In the course of one station orbit, MAXI can scan almost the entire sky with a precision of 1 deg. and with an X-ray energy range of 0.5-30 keV. We have developed the engineering model of CCD chips and the analogue electronics for the SSC. The energy resolution of EM CCD for Mn Kα has a full-width at half-maximum of ≅182 eV. Readout noise is ≅11 e- rms

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

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

    2007-01-01

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

  20. The brighter-fatter effect and pixel correlations in CCD sensors

    We present evidence that spots imaged using astronomical CCDs do not exactly scale with flux: bright spots tend to be broader than faint ones, using the same illumination pattern. We measure that the linear size of spots or stars, of typical size 3 to 4 pixels FWHM, increase linearly with their flux by up to 2 % over the full CCD dynamic range. This brighter-fatter effect affects both deep-depleted and thinned CCD sensors. We propose that this effect is a direct consequence of the distortions of the drift electric field sourced by charges accumulated within the CCD during the exposure and experienced by forthcoming light-induced charges in the same exposure. The pixel boundaries then become slightly dynamical: overfilled pixels become increasingly smaller than their neighbors, so that bright star sizes, measured in number of pixels, appear larger than those of faint stars. This interpretation of the brighter-fatter effect implies that pixels in flat-fields should exhibit statistical correlations, sourced by Poisson fluctuations, that we indeed directly detect. We propose to use the measured correlations in flat-fields to derive how pixel boundaries shift under the influence of a given charge pattern, which allows us in turn to predict how star shapes evolve with flux. We show that, within the precision of our tests, we are able to quantitatively relate the correlations of flat-field pixels and the broadening of stars with flux. This physical model of the brighter-fatter effect also explains the commonly observed phenomenon that the spatial variance of CCD flat-fields increases less rapidly than their average

  1. CCD-based high resolution digital radiography system for non destructive evaluation

    Film radiography has long served the aerospace industry as a principal method for hardware flaw detection. Although excellent in performance, this method is extremely time consuming, labor intensive, costly, and is unsuitable for real time inspections. Modem digital radiographic systems overcome some of these difficulties but are also limited in terms of speed of operation due to persistence of the sensor and a problematic tradeoff between the X-ray detection efficiency and spatial resolution. We are developing an innovative X-ray imaging detector consisting of a novel microstructured CsI scintillator coupled to a fiberoptic taper-based CCD. Thin-film deposition techniques, previously developed to produce thin, structured CsI screens have been extended to fabricate CsI screens, up to 450 mg/cm2 (1,000 μm) in thickness. These sensors are suitable to provide high detection efficiency with high image quality for NDE applications. A prototype high energy imaging system was constructed by integrating these screens into a fiber-optic-based CCD camera. The performance was compared to that of the same system using a standard polycrystalline phosphor for NDE imaging applications. The experimental evaluations were carried out at Scientific Measurement Systems, Inc., Austin, TX

  2. Measurement of the AT and the CCD angle of macerated cadaver femora: a comparative study between CT and MRI measurements

    Purpose: To compare measurements of the real AT (femoral antetorsion) and CCD (caput-scollum-diaphysis) angle by computed tomography (CT) and magnetic resonance imaging (MRI) of hip specimen using direct measurements as reference standard, and to show that measurements by MRI can replace CT measurements and ma help avoiding X-ray exposition. Materials and methods: CT and MRI measurements were obtained on 25 in water-arrested macerated human femora. Postprocessing was done by 4 independent readers on a workstation using a dedicated 3D-software. Direct measurements of the real AT and the CCD angle were used as reference standard. The analysis included Student's test for paired values, interobserver variability using intra-class correlation coefficients (ICC), maximum and middle divergence of the angles, and Bland-Altman plots. Results: For determining AT and the CCD angle with CT and MRI, good correlation was found between the 4 readers and with measurements using the reference standard. ICCs were 0.97 and 0.90 for measuring AT and CCD angle with CT, and 0.95 and 0.71 for measurements with MRI, respectively. Mean divergence between CT measurements and those of the reference standard was 0.8 for AT and 0.7 for the CDD-angle. Mean divergence between MRI measurements and those of the reference standard was 0.3 for AT and -0.4 for the CCD-angle. Mean divergences between CT and MRI measurements of AT and CCD-angle were 0.5 . Neither systematic errors nor dependences on the qualitative size of the reference data were evident in the divergences of measurements. (orig.)

  3. Electronic portal imaging devices

    The topics discussed include, among others, the following: Role of portal imaging; Port films vs. EPID; Image guidance: Elekta volume view; Delivery verification; Automation tasks of portal imaging; Types of portal imaging (Fluorescent screen, mirror, and CCD camera-based imaging; Liquid ion chamber imaging; Amorpho-silicon portal imagers; Fluoroscopic portal imaging; Kodak CR reader; and Other types of portal imaging devices); QA of EPID; and Portal dosimetry (P.A.)

  4. PSF and MTF measurement methods for thick CCD sensor characterization

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

    2010-07-01

    Knowledge of the point spread function (PSF) of the sensors to be used in the Large Synoptic Survey Telescope (LSST) camera is essential for optimal extraction of subtle galaxy shape distortions caused by gravitational weak lensing. We have developed a number of techniques for measuring the PSF of candidate CCD sensors to be used in the LSST camera, each with its own strengths and weaknesses. The two main optical PSF measurement techniques that we use are the direct Virtual Knife Edge (VKE) scan as developed by Karcher, et al.1 and the indirect interference fringe method after Andersen and Sorensen2 that measures the modulation transfer function (MTF) directly. The PSF is derived from the MTF by Fourier transform. Other non-optical PSF measurement techniques that we employ include 55Fe x-ray cluster image size measurements and statistical distribution analysis, and cosmic ray muon track size measurements, but are not addressed here. The VKE technique utilizes a diffraction-limited spot produced by a Point-Projection Microscope (PPM) that is scanned across the sensor with sub-pixel resolution. This technique closely simulates the actual operating condition of the sensor in the telescope with the source spot size having an f/# close to the actual telescope design value. The interference fringe method uses a simple equal-optical-path Michelson-type interferometer with a single-mode fiber source that produces interference fringes with 100% contrast over a wide spatial frequency range sufficient to measure the MTF of the sensor directly. The merits of each measurement technique and results from the various measurement techniques on prototype LSST sensors are presented and compared.

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

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

  6. Multiple solutions of CCD equations for PPP model of benzene

    Podeszwa, R; Jankowski, K; Rubiniec, K; Podeszwa, Rafa{\\l}; Stolarczyk, Leszek Z.; Jankowski, Karol; Rubiniec, Krzysztof

    2002-01-01

    To gain some insight into the structure and physical significance of the multiple solutions to the coupled-cluster doubles (CCD) equations corresponding to the Pariser-Parr-Pople (PPP) model of cyclic polyenes, complete solutions to the CCD equations for the A^{-}_{1g} states of benzene are obtained by means of the homotopy method. By varying the value of the resonance integral beta from -5.0 eV to -0.5 eV, we cover the so-called weakly, moderately, and strongly correlated regimes of the model. For each value of beta 230 CCD solutions are obtained. It turned out, however, that only for a few solutions a correspondence with some physical states can be established. It has also been demonstrated that, unlike for the standard methods of solving CCD equations, some of the multiple solutions to the CCD equations can be attained by means of the iterative process based on Pulay's direct inversion in the iterative subspace (DIIS) approach.

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

    A CcdB homologue from V. fischeri was overexpressed in E. coli and purified. The free protein was crystallized, as were its complexes with fragments of E. coli and V. fischeri gyrase and with the F-plasmid CcdA C-terminal domain. The ccd toxin–antitoxin module from the Escherichia coli F plasmid has a homologue on the Vibrio fischeri integron. The homologue of the toxin (CcdBVfi) was crystallized in two different crystal forms. The first form belongs to space group I23 or I213, with unit-cell parameter a = 84.5 Å, and diffracts to 1.5 Å resolution. The second crystal form belongs to space group C2, with unit-cell parameters a = 58.5, b = 43.6, c = 37.5 Å, β = 110.0°, and diffracts to 1.7 Å resolution. The complex of CcdBVfi with the GyrA14Vfi fragment of V. fischeri gyrase crystallizes in space group P212121, with unit-cell parameters a = 53.5, b = 94.6, c = 58.1 Å, and diffracts to 2.2 Å resolution. The corresponding mixed complex with E. coli GyrA14Ec crystallizes in space group C2, with unit-cell parameters a = 130.1, b = 90.8, c = 58.1 Å, β = 102.6°, and diffracts to 1.95 Å. Finally, a complex between CcdBVfi and part of the F-plasmid antitoxin CcdAF crystallizes in space group P212121, with unit-cell parameters a = 46.9, b = 62.6, c = 82.0 Å, and diffracts to 1.9 Å resolution

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

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

    2007-04-01

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

  9. Pengembangan Metoda Deteksi Rintangan untuk Traktor tanpa Awak Menggunakan Kamera CCD

    Usman Ahmad; Desrial; Mudho Saksono

    2012-01-01

    For unmanned tractor guided by global positioning system, ability for eluding obstacles such as trees, big stone, cavity, bund, people, and other objects in the work area is very important in order not to stop the operation.Surrounding detection system using CCD camera makes it possible for unmanned tractor to detect obstacles in front of it realtime. However, with so many different objects that may captured by the camera, it will need a lot of image processing steps that takes a lot of time ...

  10. Research on the System Error Analysis and Compensation Method for the 3-D Profile Measurement with CCD Based on Linear Structure Lighting

    For the 3-D profile measurement with CCD, the calibration of CCD measurement system is still the focus of the researchers' attention. Firstly taking no account of some factors, such as the CCD lens aberration, image process error, etc., the principle error of the CCD calibration method constructing the coordinates mapping relation from image coordinates to space coordinates based on the polynomial fitting solution is analyzed through the experimental data in the paper. Then the paper analyzes the device error and operation error that is mainly from CCD lens aberration and image process. By measuring the standard geometry element, the error value can be picked up on the different depth position of field. After filtering the noise, the system error can be got, and can be used to compensate and amend the measurement result. The experimental result shows that with the system error compensation method, the measurable depth of field can be increased efficiently and the precision of the measurement result can be control within ±50um with common table of which the simple axis machine precision is 15um and open-loop control driven by the stepper motor, which can meet the profile measuring requirements well

  11. Improving the resolution in soft X-ray emission spectrometers through photon-counting using an Electron Multiplying CCD

    In 2007, a study of back-illuminated Charge-Coupled Devices (CCDs) for soft X-ray photon detection demonstrated the improvements that could be brought over more traditional micro-channel plate detectors for X-ray spectrometers based on diffraction gratings and position sensitive detectors. Whilst the spatial resolution was reported to be improved dramatically, an intrinsic limit of approximately 25 micrometers was found due to the spreading of the charge cloud generated in the CCD across several pixels. To overcome this resolution limit, it is necessary to move away from the current integrated imaging methods and consider a photon-counting approach, recording the photon interaction locations to the sub-pixel level. To make use of photon-counting techniques it is important that the individual events are separable. To maintain the throughput of the spectrometer for high intensity lines, higher frame rates and therefore higher readout speeds are required. With CCD based systems, the increased noise at high readout speeds can limit the photon-counting performance. The Electron-Multiplying CCD shares a similar architecture with the standard CCD but incorporates a gain register. This novel addition allows controllable gain to be applied to the signal before the read noise is introduced, therefore allowing individual events to be resolved above the noise even at much higher readout rates. In the past, the EM-CCD has only been available with imaging areas too small to be practical in soft X-ray emission spectrometers. The current drive for large area Electron-Multiplying CCDs is opening this technology to new photon-counting applications, requiring in-depth analysis of the processes and techniques involved. Early results indicate that through the introduction of photon-counting techniques the resolution in such systems can be dramatically improved.

  12. Radioactive Quality Evaluation and Cross Validation of Data from the HJ-1A/B Satellites’ CCD Sensors

    Xin Zhang

    2013-07-01

    Full Text Available Data from multiple sensors are frequently used in Earth science to gain a more complete understanding of spatial information changes. Higher quality and mutual consistency are prerequisites when multiple sensors are jointly used. The HJ-1A/B satellites successfully launched on 6 September 2008. There are four charge-coupled device (CCD sensors with uniform spatial resolutions and spectral range onboard the HJ-A/B satellites. Whether these data are keeping consistency is a major issue before they are used. This research aims to evaluate the data consistency and radioactive quality from the four CCDs. First, images of urban, desert, lake and ocean are chosen as the objects of evaluation. Second, objective evaluation variables, such as mean, variance and angular second moment, are used to identify image performance. Finally, a cross validation method are used to ensure the correlation of the data from the four HJ-1A/B CCDs and that which is gathered from the moderate resolution imaging spectro-radiometer (MODIS. The results show that the image quality of HJ-1A/B CCDs is stable, and the digital number distribution of CCD data is relatively low. In cross validation with MODIS, the root mean square errors of bands 1, 2 and 3 range from 0.055 to 0.065, and for band 4 it is 0.101. The data from HJ-1A/B CCD have better consistency.

  13. Backside illuminated CCD operating at 16,000,000 frames per second with sub-ten-photon sensitivity

    An ultra-high-speed and very high sensitivity video camera is developed. The highest frame rate reaches 16,000,000 frames per second (16 Mfps). The full well capacity is 22,000e- at frame rates up to 4 Mfps, and 8000e- at 16 Mfps. The pixel count is 165,072 (362x456) pixels. The total number of consecutive frames is 117, which can be doubled to 234 by interlaced imaging operation. The sensitivity is less than 10 photons/pixel. - Highlights: → A high-speed high-sensitivity CCD image sensor was developed. → It has a special structure processed on a wafer with p/n double epi-layers. → The highest frame rate is 16,000,000 fps for 165,000 (=456x362) pixels. → The CCM (EM-CCD) is mounted, which makes the sensitivity less than 10 photons/pixel.

  14. Shack-Fizeau interferometer and some methods to process their aspheric wavefront interferograms using a CCD detector

    Rivera, Mariano; Garcia, J.; Malacara, D.; Marroquin, Jose L.

    1996-02-01

    A Fizeau interferometer has been built to test aspherical and concave telescope mirrors. Results of one method used to evaluate the maximum number of fringes when the interferogram image is projected on a CCD device are mentioned. Some complementary techniques have been utilized to analyze interferograms using this kind of interferometer. A deterministic approach to the regularization term added by Marroquin and Rivera (1995) to the least-squares unwrapping technique is shown.

  15. Optimal DN encoding for CCD detectors

    Seaman, Robert L; Pence, William D

    2009-01-01

    Image compression has been a frequent topic of presentations at ADASS. Compression is often viewed as just a technique to fit more data into a smaller space. Rather, the packing of data - its "density" - affects every facet of local data handling, long distance data transport, and the end-to-end throughput of workflows. In short, compression is one aspect of proper data structuring. For example, with FITS tile compression the efficient representation of data is combined with an expressive logistical paradigm for its manipulation. A deeper question remains. Not just how best to represent the data, but which data to represent. CCDs are linear devices. What does this mean? One thing it does not mean is that the analog-to-digital conversion of pixels must be stored using linear data numbers (DN). An alternative strategy of using non- linear representations is presented, with one motivation being to magnify the efficiency of numerical compression algorithms such as Rice.

  16. CCD photometry of apparent dwarf galaxies in Fornax

    Blue and red CCD surface photometry of two apparent dwarf galaxies in the Fornax cluster region is presented. Luminosity profiles are derived and their form discussed. The fainter galaxy resembles an archetypal diffuse dwarf elliptical but the brighter of the pair is either an unusual red dwarf or a background galaxy in chance juxtaposition. (author)

  17. CCD photometry of the Globular Cluster NGC 6093

    Ruelas-Mayorga, A; Bernal-Herrera, C A; Nigoche-Netro, A; Echevarria, J; Garcia, A M

    2016-01-01

    In this paper we present photometric CCD observations of the globular cluster NGC 6093 (M80) in filters B, V , R and I. We produce the colour-magnitude diagrams for this object and obtain values for its metallicity [Fe/H], reddening E(V-B), E(V-I) and distance modulus (m - M)_0.

  18. Diagnostics of the CCD using the mesh experiment

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

    1999-01-01

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

  19. A New Technique for CCD Camera Auto-Calibration

    Xiaodong Zhang; Changku Sun; Zhixiong Wang; Wei Wei

    2003-01-01

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

  20. Pengembangan Metoda Deteksi Rintangan untuk Traktor tanpa Awak Menggunakan Kamera CCD

    Usman Ahmad

    2012-04-01

    Full Text Available For unmanned tractor guided by global positioning system, ability for eluding obstacles such as trees, big stone, cavity, bund, people, and other objects in the work area is very important in order not to stop the operation.Surrounding detection system using CCD camera makes it possible for unmanned tractor to detect obstacles in front of it realtime. However, with so many different objects that may captured by the camera, it will need a lot of image processing steps that takes a lot of time so it is no longer suitable for realtime detection in application. The proposed research is aimed to develop a simpler obstacle detection method by adding a red laser pointer to the CCD camera used to capture scene in front of the tractor. The red laser light that reflected by an obstacle gives an important information in the image, and the distance of the obstacle could be calculated based on phytagoras theory. The results showed that all obstacles with 1 m distance, 80% obstacles with 2 m distance, and 40% obstacles with 3 m distance could be detected. Obstacles with more than 3 m distances could not be detected due to weak laser light for the distances. The accuracy of distance prediction for all situation is 67.5%, which is still need improvements.

  1. Application of CCD measurement technique for wear on pantograph sliding plates

    Yang, Kai; Wang, Li; Gao, Xiaorong; Zhao, Quanke; Wang, Zeyong; Peng, Chaoyong

    2009-05-01

    Pantograph sliding plate is the most important electricity-collecting part in locomotive power supply system. Once the sliding plates are disabled, they will be severe dangerous for safety. The measurement for pantograph of 27.5KV is especially difficult. The article uses non-contact and online dynamic detection by utilizing CCD technique to solve the problem. The system will get all images of sliding plates after triggering by space arrangement of CCD cameras cooperated with flashlights. The precision of demarcate is guaranteed by special methods. It adopts directional edge search to get sliding plates, and connect the images of different CCDS. It also makes use of conditional Hough transformation to locate the wire. The wear on sliding plates will be given after complicated processing. The system is applicable to the detection for all kinds of pantographs by adding different arithmetic amends. At last the precision can achieve +/-0.5mm . At the same time a database is setup which can give the trend curve of wear, it can predict the limit time of the sliding plates.

  2. A Two-Colour CCD Survey of the North Celestial Cap: I. The Method

    Gorbikov, Evgeny; Afonso, Cristina

    2009-01-01

    We describe technical aspects of an astrometric and photometric survey of the North Celestial Cap (NCC), from the Pole (DEC=90 deg) to DEC=80 deg, in support of the TAUVEX mission. This region, at galactic latitudes from ~ 17 deg to ~ 37 deg, has poor coverage in modern CCD-based surveys. The observations are performed with the Wise Observatory one-meter reflector and with a new mosaic CCD camera (LAIWO) that images in the Johnson-Cousins R and I bands a one-square-degree field with subarcsec pixels. The images are treated using IRAF and SExtractor to produce a final catalogue of sources. The astrometry, based on the USNO-A2.0 catalogue, is good to ~ 1 arcsec and the photometry is good to ~ 0.1 mag for point sources brighter than R=20.0 or I=19.1 mag. The limiting magnitudes of the survey, defined at photometric errors smaller than 0.15 mag, are 20.6 mag (R) and 19.6 (I). We separate stars from non-stellar objects based on the object shapes in the R and I bands, attempting to reproduce the SDSS star/galaxy di...

  3. Investigation of temporal evolution and spatial distribution of dust creation events in DITS campaign using visible CCD cameras in Tore Supra

    Hong, Suk-Ho [Association EURATOM-CEA/Cadarache, IRFM/SIPP/GIPP, St. Paul les Durance 13108 (France)], E-mail: sukhhong@nfri.re.kr; Grisolia, Christian; Monier-Gabet, Pascale [Association EURATOM-CEA/Cadarache, IRFM/SIPP/GIPP, St. Paul les Durance 13108 (France)

    2009-06-15

    Images of wide-angle visible CCD cameras contain information on dust creation events (flaking) that occur during plasma operations. Due to the interaction with plasma, flakes entering into the plasma left straight line-like visible traces behind in the images. Analyzing these traces by image processing, the temporal evolution, spatial distribution, and statistics on dust creation events in DITS campaign in Tore Supra were obtained.

  4. Predicting Chandra CCD Degradation with the Chandra Radiation Model

    Minow, Joseph I.; Blackwell, William C.; DePasquale, Joseph M.; Grant, Catherine E.; O'Dell, Stephen L.; Plucinsky, Paul P.; Schwartz, Daniel A.; Spitzbart, Bradley D.; Wolk, Scott J.

    2008-01-01

    Not long after launch of the Chandra X-Ray Observatory, it was discovered that the Advanced CCD Imaging Spectrometer (ACIS) detector was rapidly degrading due to radiation. Analysis by Chandra personnel showed that this degradation was due to 10w energy protons (100 - 200 keV) that scattered down the optical path onto the focal plane. In response to this unexpected problem, the Chandra Team developed a radiation-protection program that has been used to manage the radiation damage to the CCDs. This program consists of multiple approaches - scheduled sating of the ACIS detector from the radiation environment during passage through radiation belts, real-time monitoring of space weather conditions, on-board monitoring of radiation environment levels, and the creation of a radiation environment model for use in computing proton flux and fluence at energies that damage the ACIS detector. This radiation mitigation program has been very successful. The initial precipitous increase in the CCDs' charge transfer inefficiency (CTI) resulting from proton damage has been slowed dramatically, with the front-illuminated CCDS having an increase in CTI of only 2.3% per year, allowing the ASIS detector's expected lifetime to exceed requirements. This paper concentrates on one aspect of the Chandra radiation mitigation program, the creation of the Chandra Radiation Model (CRM). Because of Chandra's highly elliptical orbit, the spacecraft spends most of its time outside of the trapped radiation belts that present the severest risks to the ACIS detector. However, there is still a proton flux environment that must be accounted for in all parts of Chandra's orbit. At the time of Chandra's launch there was no engineering model of the radiation environment that could be used in the outer regions of the spacecraft's orbit, so the CRM was developed to provide the flux environment of 100 - 200 keV protons in the outer magnetosphere, magnetosheath, and solar wind regions of geospace. This

  5. X-ray diagnostic study on the optimization of digital radiography in dentistry. Optimal exposure conditions for X-ray CCD sensor

    The purpose of this research is to reduce the patient dose by optimization of irradiation conditions of an X-ray CCD sensor in intra-oral digital radiography. The X-ray diagnosis was divided into two, high quality-of-image diagnosis and low quality-of-image diagnosis, and it optimized by using the exposure of necessary minimum for each. The image quality of CCD was evaluated using the signal-to-noise ratio (SNR) in order to estimate the influence of irradiation conditions. The dose based on CCD maker setting value was set up so that the highest quality of image might be obtained mostly. In low quality-of-image diagnosis, even if it reduced the dose to 13.2% of standard irradiation, SNR was 40% and interpretation was possible. In high quality-of-image diagnosis, even if it reduces the dose to 49% of standard irradiation, SNR remained 80% and there were few differences of the image with a standard. A study of the digital X-ray examination taken at the dental clinic showed high quality-of-image diagnosis was 69% and low quality-of-image one was 31%. When this optimization was performed, it was presumed that reduction of about 62% of the dose is possible. (author)

  6. Radiometric calibration of frame transfer CCD camera with uniform source system

    Zhou, Jiankang; Shi, Rongbao; Chen, Yuheng; Zhou, Yuying; Shen, Weimin

    2010-08-01

    This paper presents a radiometric calibration method based on visibility function and uniform source system. The uniform system is mainly comprised of an integrating sphere and a monitoring silicon detector. The current of the silicon detector with a visibility function filter corresponds to the luminance at the exit port of integrating sphere through standard luminance meter transfer. The radiance at the camera entrance pupil is calculated for different solar zenith angles and Earth surface albedos by the MODTRAN atmospheric code. To simplify the calibration process, the radiance at its entrance pupil is integrated by visibility function. The shift smear of the frame transfer CCD is removed by the radiometric calibration and the amending ratio factor is introduced in the retrieving methods. The imaging experiment verifies the reliability of the calibration method and retrieves good quality image.

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

    Shalaby, Mostafa; Hauri, Christoph P

    2015-01-01

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

  8. CCD SURFACE PHOTOMETRY OF THE LOW-LUMINOSITY RADIO GALAXIES CONTAINING RADIO JETS B-2-0034+25 AND B-2-0206+35

    GONZALEZSERRANO, JI; PEREZFOURNON, [No Value

    1991-01-01

    We present broad-band CCD imaging of the radio galaxies B2 0034+25 and B2 0206+36. Both galaxies are of low radio power and contain radio jets at the arcsec scale. The galaxies have close companions and the optical morphology suggests that they are interacting. The surface photometry method and its

  9. Measurement and analysis of image sensors

    Vitek, Stanislav

    2005-06-01

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

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

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

    2015-06-01

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

  11. Measurement of the soft X-ray response of P-channel back-illuminated CCD

    Ueda, Shutaro, E-mail: shutaro@ess.sci.osaka-u.ac.jp [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Hayashida, Kiyoshi; Nakajima, Hiroshi; Anabuki, Naohisa; Tsunemi, Hiroshi; Kan, Hiroaki [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Kohmura, Takayoshi; Ikeda, Shoma; Kaneko, Kenta; Watanabe, Tatsuo [Physics Department, Kogakuin University, 2665-1, Nakano, Hachioji 192-0015 (Japan); Mori, Koji [Department of Applied Physics, Faculty of Engineering, University of Miyazaki, 1-1 Gakuen Kibana-dai Nishi, Miyazaki 889-2192 (Japan); Nobukawa, Masayoshi [Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Murakami, Hiroshi; Sakata, Kazuya; Todoroki, Shotaro; Yagihashi, Nobuyoshi; Mizuno, Eiki [Department of Physics, Faculty of Science, Rikkyo University, 3-34-1, Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501 (Japan); Muramatsu, Masaharu; Suzuki, Hisanori; Takagi, Shin' ichiro [Solid State Division, Hamamatsu Photonics K.K., 1126-1 Ichino, Hamamatsu 435-8558 (Japan)

    2013-03-11

    P-channel charge-coupled devices (CCDs) made from N-type silicon wafers were originally developed for ground-based optical and near-infrared telescopes. The thick depletion layer of these CCDs provides the significant advantage of high quantum efficiency (QE) for hard X-rays. On the other hand, high QE for soft X-rays is obtained with back-illuminated (BI) and fully depleted CCDs in which only a thin dead layer exists on the surface of incidence. Thus, P-channel BI CCDs can be applicable as superior wide band X-ray detectors. We have developed such a device specifically for the Soft X-ray Imager (SXI) on board the X-ray astronomy satellite ASTRO-H, scheduled to be launched in 2014. We previously reported that the depletion layers of our CCDs, a prototype of SXI-CCDs, have a thickness of more than 200μm. In this paper, we report a novel soft X-ray response of P-channel BI CCDs. First, we irradiate fluorescent X-rays of O, F, Na, Al, Si and K to the SXI prototype. This experiment reveals that our CCD has a significant low-energy tail structure in the soft X-ray response. Since the intensity of the low-energy tail is larger for lower X-ray energies, the tail is originated on the CCD surface layer. Then, we fabricate a new type of CCDs by applying an alternative treatment to its surface layer. The soft X-ray response of the CCD is measured by irradiation of monochromatic X-rays from 0.25 keV to 1.8 keV in a synchrotron facility, KEK-PF. The intensity of the low-energy tail for 0.5 keV incident X-ray is one order of magnitude smaller than that for the previous CCD. The same treatment will be applied to the surface layer of the SXI flight model.

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

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

    2013-08-01

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

  13. Development of a CCD camera for an automated supernova search and observations of a supernova in NGC 5033

    The Berkeley supernova search uses an automated telescope along with a Charge Coupled Device (CCD) camera and a dedicated minicomputer to automatically scan galaxies for supernovae. The system is currently able to observe about 500 galaxies in a full night of observing. These images are stored on video tapes that are brought back to the lab the next day for analysis. This paper begins with a brief summary of the observational and theoretical understanding of supernovae. The design of the search system is discussed with an emphasis on its current operation. The development and performance of the CCD camera is described in detail, as well as the performance of the entire system. Finally, observations of a supernova in NGC 5033 are presented

  14. Characterization of a CCD array for Bragg spectroscopy

    Indelicato, P J; Gotta, D; Hennebach, M; Le Bigot, E O; Nelms, N; Simons, L M; Trassinelli, M; Bigot, Eric-Olivier Le; David, Christian; Gotta, Detlev; Hennebach, Maik; Indelicato, Paul; Nelms, Nick; Simons, Leopold M.; Trassinelli, Martino

    2006-01-01

    The average pixel distance as well as the relative orientation of an array of 6 CCD detectors have been measured with accuracies of about 0.5 nm and 50 $\\mu$rad, respectively. Such a precision satisfies the needs of modern crystal spectroscopy experiments in the field of exotic atoms and highly charged ions. Two different measurements have been performed by illuminating masks in front of the detector array by remote sources of radiation. In one case, an aluminum mask was irradiated with X-rays and in a second attempt, a nanometric quartz wafer was illuminated by a light bulb. Both methods gave consistent results with a smaller error for the optical method. In addition, the thermal expansion of the CCD detectors was characterized between -105 C and -40 C.

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

    The capability to measure bursts of neutron fluences and gamma/x-ray fluxes directly with charge coupled device (CCD) cameras while being able to distinguish between the video signals produced by these two types of radiation, even when they occur simultaneously, has been demonstrated. Volume and area measurements of transient radiation-induced pixel charge in English Electric Valve (EEV) Frame Transfer (FT) charge coupled devices (CCDs) from irradiation with pulsed neutrons (14 MeV) and Bremsstrahlung photons (4--12 MeV endpoint) are utilized to calibrate the devices as radiometric imaging sensors capable of distinguishing between the two types of ionizing radiation. Measurements indicate ∼.05 V/rad responsivity with ≥1 rad required for saturation from photon irradiation. Neutron-generated localized charge centers or ''peaks'' binned by area and amplitude as functions of fluence in the 105 to 107 n/cm2 range indicate smearing over ∼1 to 10% of CCD array with charge per pixel ranging between noise and saturation levels

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

    Schippers, J M; Luijk, P V

    2002-01-01

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

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

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

  18. Quantum efficiency measurements in the swept charge device CCD236

    The e2v technologies plc. CCD236 is a Swept Charge Device (SCD) designed as a large area (20 mm × 20 mm) soft X-ray detector for spectroscopy in the range 0.8 keV to 10 keV. It benefits from improvements in design over the previous generation, the e2v CCD54, such as: a 4 times increased detector area, a reduction in split X-ray events due to the 100 μm × 100 μm 'pixel' size, and improvements to radiation hardness. The CCD236 will be used in India's Chandrayaan-2 Large Soft X-ray Spectrometer (CLASS) instrument and China's Hard X-ray Modulation Telescope (HXMT). Measurements of the Quantum Efficiency (QE) have been obtained relative to a NIST calibrated photodiode over the energy range 0.2 keV to 1.9 keV, using the BESSY II X-ray synchrotron in Berlin. Two X-ray event counting methods are described and compared, and QE for soft X-ray interaction is reported. Uniformity of QE across the device is also investigated at energies between 0.52 keV and 1.5 keV in different areas of the detector. This work will enable the actual number of photons incident on the detectors to be calculated, thus ensuring that the CCD236 detectors provide valuable scientific data during use. By comparing the QE methods in this paper with the event processing techniques to be used with CLASS, an estimate of the instrument-specific QE for CLASS can be provided

  19. Building a CCD Spectrograph for Educational or Amateur Astronomy

    Kannappan, Sheila J.; Fabricant, Daniel G.; Hughes, Charles B.

    2002-01-01

    We discuss the design of an inexpensive, high-throughput CCD spectrograph for a small telescope. By using optical fibers to carry the light from the telescope focus to a table-top spectrograph, one can minimize the weight carried by the telescope and simplify the spectrograph design. We recently employed this approach in the construction of IntroSpec, an instrument built for the 16-inch Knowles Telescope on the Harvard College campus.

  20. A CCD fitted to the UV Prime spectrograph: Performance

    A CCD camera was fitted to the 3.6 m French-Canadian telescope in Hawai. Performance of the system and observations of elliptic galaxies (stellar content and galactic evolution in a cluster) and quasars (absorption lines in spectra) are reported. In spite of its resolution being only average, the extremely rapid optics of the UV spectrograph gives good signal to noise ratios enabling redshifts and velocity scatter to be calculated with an accuracy better than 30 km/sec

  1. Wavelength Calibration Accuracy for the STIS CCD and MAMA Modes

    Pascucci, Ilaria; Hodge, Phil; Proffitt, Charles R.; Ayres, T.

    2011-03-01

    Two calibration programs were carried out to determine the accuracy of the wavelength solutions for the most used STIS CCD and MAMA modes after Servicing Mission 4. We report here on the analysis of this dataset and show that the STIS wavelength solution has not changed after SM4. We also show that a typical accuracy for the absolute wavelength zero-points is 0.1 pixels while the relative wavelength accuracy is 0.2 pixels.

  2. Study of pixel area variations in fully depleted thick CCD

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

    Bellingham: SPIE, 2010 - (Holland, A.; Dorn, D.), 774206/1-774206/8. (Proceedings of the SPIE. 7742). ISBN 9780819482327. [High Energy, Optical, and Infrared Detectors for Astronomy /4./. San Diego (US), 27.06.2010-04.07.2010] R&D Projects: GA MŠk ME09052 Institutional research plan: CEZ:AV0Z10100502 Keywords : CCD * pixel size * charge diffusion Subject RIV: BF - Elementary Particles and High Energy Physics http://dx.doi.org/10.1117/12.856519

  3. High speed and high accuracy inspection of in-tray laser IC marking using line scan CCD with a new calibration model

    Lin, Chern-Sheng; Tsung Huang, Jui; Wei, Tzu-Chi; Yeh, Mau-Shiun; Chen, Der-Chin

    2011-02-01

    This study used a high-speed high-resolution line scan CCD, and a Delta motor drive module to provide position feedback in a laser marking system. Based on a novel algorithm, image processing of the high-speed CCD scan was allowed the accurate determination of the laser marking location. This system was calibrated using a template, and a novel 1-D calibration model of the line scan CCD was developed. The relevant position of each IC in the tray was obtained based on the calibration algorithm. Gain and offset calibration, sub-pixel calculation, and normalized checks were performed in this automatic optical inspection system. The total processing time for laser correction marking, scanning and identification was about 2˜2.5 s, the positioning accuracy was×9 μm, and the industrial specification and process capability index Cpk reached over 1.2.

  4. LED characterization for development of on-board calibration unit of CCD-based advanced wide-field sensor camera of Resourcesat-2A

    Chatterjee, Abhijit; Verma, Anurag

    2016-05-01

    The Advanced Wide Field Sensor (AWiFS) camera caters to high temporal resolution requirement of Resourcesat-2A mission with repeativity of 5 days. The AWiFS camera consists of four spectral bands, three in the visible and near IR and one in the short wave infrared. The imaging concept in VNIR bands is based on push broom scanning that uses linear array silicon charge coupled device (CCD) based Focal Plane Array (FPA). On-Board Calibration unit for these CCD based FPAs is used to monitor any degradation in FPA during entire mission life. Four LEDs are operated in constant current mode and 16 different light intensity levels are generated by electronically changing exposure of CCD throughout the calibration cycle. This paper describes experimental setup and characterization results of various flight model visible LEDs (λP=650nm) for development of On-Board Calibration unit of Advanced Wide Field Sensor (AWiFS) camera of RESOURCESAT-2A. Various LED configurations have been studied to meet dynamic range coverage of 6000 pixels silicon CCD based focal plane array from 20% to 60% of saturation during night pass of the satellite to identify degradation of detector elements. The paper also explains comparison of simulation and experimental results of CCD output profile at different LED combinations in constant current mode.

  5. SWNT Imaging Using Multispectral Image Processing

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

    2012-02-01

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

  6. Methode nouvelle pour la mesure CCD du diametre solaire avec un astrolabe. A new method for CCD measurements of the solar diameter with an astrolabe

    Sinceac, V.; Chollet, F.; Laclare, F.; Delmas, C.

    1998-03-01

    Observing the Solar disk is a challenge and, as for the past visual observations, we have many results depending on observers and/or instruments. This was due to the differences in visual perceptions of the Sun's limb, instrumental errors and atmospheric disturbances. After a long series of visual observations at Calern Observatory, Francis Laclare felt the need for more impersonal and automatic measurements of the Solar diameter. After a series of analog CCD measurements (1989-1995), a digital data acquisition and processing was tested by the Paris Observatory group (F. Chollet and V. Sinceac) during the 1996 spring at Calern Observatory. Before starting a new continuous campaign of observations, to confirm eventual variations of the diameter and solar flatness, the aim is to find the best definition of the solar edge. The test campaign was spent comparing different solutions that were tried on two different astrolabes at Calern Observatory: The ``classical'' one, outfitted with eleven zerodur ceramic prisms (S astrolabe), that has been used for twenty years in the Laclare series and on the other hand an instrument equipped with a varying angle prism (V astrolabe) enabling many measurements (385 in 1996) for perfecting the know how. This article focusses on acquisition techniques and their feasibility. Two procedures were tried: The first one used alternately the direct and reflected images (separated using a revolving shutter in front of the objective) and the second one mathematically sorts out both components inside the computer (an image being a two-dimensionral array of numbers). According to the principle of the astrolabe, the measured quantity is the exact time crossing the parallel of altitude (defined by the prism angle) by the Sun's edge, i.e. the time of merging of the two images of the Sun in the focal plane of the telescope where the CCD matrix stands. Here comes the definition of the Solar edge for one frame as the collection of the inflect points on

  7. CCD[charge-coupled device]-based synchrotron x-ray detector for protein crystallography: Performance projected from an experiment

    The intense x radiation from a synchrotron source could, with a suitable detector, provide a complete set of diffraction images from a protein crystal before the crystal is damaged by radiation (2 to 3 min). An area detector consisting of a 40 mm dia. x-ray fluorescing phosphor, coupled with an image intensifier and lens to a CCD image sensor, was developed to determine the effectiveness of such a detector in protein crystallography. The detector was used in an experiment with a rotating anode x-ray generator. Diffraction patterns from a lysozyme crystal obtained with this detector are compared to those obtained with film. The two images appear to be virtually identical. The flux of 104 x-ray photons/s was observed on the detector at the rotating anode generator. At the 6-GeV synchrotron being designed at Argonne, the flux on an 80 x 80 mm2 detector is expected to be >109 photons/s. The projected design of such a synchrotron detector shows that a diffraction-peak count >106 could be obtained in ∼0.5 s. With an additional ∼0.5 s readout time of a 512 x 512 pixel CCD, the data acquisition time per frame would be ∼1 s so that ninety 10 diffraction images could be obtained, with approximately 1% precision, in less than 3 min

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

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

    2011-08-01

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

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

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

    2007-01-01

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

  10. Advantages of the CCD camera measurements for profile and wear of cutting tools

    In our paper we prepared an evaluating study of which conclusions draw mainly two directions for our fields of research. On the one hand, this means the measuring of fix, standing workpieces, on the other hand this means geometrical measurement of moving tools. The first case seems to be solved in many respects (in general cases), but the second one is not completely worked out according to the relevant literature. The monitoring of tool wear, the determination of geometrical parameters (this is mainly in case of gear-generating tools) is not really widespread yet, mainly, if optical parameters have influence on the evaluating procedure (e.g. examination of profiles of grinding wheels). We show the elaboration of a process for the practical application of measuring techniques performed by image processing CCD cameras on the basis of wearing criteria of different cutting tools (drilling tool, turning tool). We have made a profile and cutting tool wear measuring program

  11. Evolution of the Chandra CCD Spectra of SNR 1987A: Probing the Reflected-Shock Picture

    Zhekov, Svetozar A; McCray, Richard; Racusin, Judith L; Burrows, David N

    2010-01-01

    We continue to explore the validity of the reflected shock structure (RSS) picture in SNR 1987A that was proposed in our previous analyses of the X-ray emission from this object. We used an improved version of our RSS model in a global analysis of 14 CCD spectra from the monitoring program with Chandra. In the framework of the RSS picture, we are able to match both the expansion velocity curve deduced from the analysis of the X-ray images and light curve. Using a simplified analysis, we also show that the X-rays and the non-thermal radio emission may originate from the same shock structure (the blast wave). We believe that using the RSS model in the analysis of grating data from the Chandra monitoring program of SNR 1987A that cover a long enough time interval, will allow us to build a more realistic physical picture and model of SNR 1987A.

  12. A reflectance model for non-contact mapping of venous oxygen saturation using a CCD camera

    Li, Jun; Dunmire, Barbrina; Beach, Kirk W.; Leotta, Daniel F.

    2013-11-01

    A method of non-contact mapping of venous oxygen saturation (SvO2) is presented. A CCD camera is used to image skin tissue illuminated alternately by a red (660 nm) and an infrared (800 nm) LED light source. Low cuff pressures of 30-40 mmHg are applied to induce a venous blood volume change with negligible change in the arterial blood volume. A hybrid model combining the Beer-Lambert law and the light diffusion model is developed and used to convert the change in the light intensity to the change in skin tissue absorption coefficient. A simulation study incorporating the full light diffusion model is used to verify the hybrid model and to correct a calculation bias. SvO2 in the fingers, palm, and forearm for five volunteers are presented and compared with results in the published literature. Two-dimensional maps of venous oxygen saturation are given for the three anatomical regions.

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

    Liu, Chuan; Berg, Rolf W.

    2012-01-01

    A new method based on dispersion equations is described to express the spectral resolution of an applied charge-coupled device (CCD) Czerny-Turner Raman instrument entirely by means of one equation and principal factors determined by the actual setup. The factors involved are usual quantities such...... spectral resolution of the Raman instrument. An essential feature of the new method is a proposed way to compensate for non-ideality (diffractions, aberrations, etc.) by use of a hyperbola model function to describe the relationship between the width of the entrance slit and the image signal width on the...... 1332.4 cm(-1) diamond Raman fundamental band, excited with two quite different wavelengths (a deep ultraviolet 257.3 nm laser line and a visible green 514.5 nm line). A low pressure mercury line at 265.2042 nm also was applied to give further verification of the given expression. A useful method to...

  14. Development of the X-ray CCD camera for the MAXI mission

    Monitor of All-sky X-ray Image (MAXI) is an astrophysical payload for the Japanese Experiment Module (Kibo) on the International Space Station (ISS). MAXI is designed for full-sky monitoring in the 0.5-30keV X-ray band. The Solid-state Slit Camera (SSC) is the X-ray CCD Camera for the MAXI mission. We have developed an engineering model (EM) of the SSC. Combined with the EM electronics, we achieved low readout noise (∼5e-rms) and good energy resolution (150eV at 5.9keV). We also examine the energy scale and the energy resolution as a function of energy using our calibration system. From these results, we conclude that the performance of the SSC-EM almost fulfills our requirements and that the final performance goals will be obtained in the flight model

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

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

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

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

  17. Preliminary evaluation of charge-coupled device (CCD) multispectral analysis in ophthalmology

    The work described was originally aimed at providing a new diagnostic technique for the early detection of malignant ocular tumors through their spectral signature. The instrument developed comprises a modified fundus camera, a Charge-coupled device (CCD) camera and a 16 bit microcomputer equipped with floopy disk drives and a 512 x 512 x 8-bit display device. The system allows the recording of digitized fundus or iris reflectance pictures in eight spectral bands between 500 and 1100 nm. After calibration and preprocessing of the data, a multispectral analysis is performed by means of a VAX computer. The image processing methods are described and their ability to characterize pigmented lesions or other ocular anatomical features through their spectral signature is evaluated

  18. Case study of atmospheric correction on CCD data of HJ-1 satellite based on 6S model

    In this study, atmospheric radiative transfer model 6S was used to simulate the radioactive transfer process in the surface-atmosphere-sensor. An algorithm based on the look-up table (LUT) founded by 6S model was used to correct (HJ-1) CCD image pixel by pixel. Then, the effect of atmospheric correction on CCD data of HJ-1 satellite was analyzed in terms of the spectral curves and evaluated against the measured reflectance acquired during HJ-1B satellite overpass, finally, the normalized difference vegetation index (NDVI) before and after atmospheric correction were compared. The results showed: (1) Atmospheric correction on CCD data of HJ-1 satellite can reduce the ''increase'' effect of the atmosphere. (2) Apparent reflectance are higher than those of surface reflectance corrected by 6S model in band1∼band3, but they are lower in the near-infrared band; the surface reflectance values corrected agree with the measured reflectance values well. (3)The NDVI increases significantly after atmospheric correction, which indicates the atmospheric correction can highlight the vegetation information

  19. Assessment of total suspended sediment concentrations in Poyang Lake using HJ-1A/1B CCD imagery

    YU Zhifeng; CHEN Xiaoling; ZHOU Bin; TIAN Liqiao; YUAN Xiaohong; FENG Lian

    2012-01-01

    We explored the potential of the environment and disaster monitoring and forecasting small satellite constellations (HJ-1A/1B satellites) charge-coupled device (CCD) imagery (spatial resolution of 30 m,revisit time of 2 days) in the monitoring of total suspended sediment (TSS) concentrations in dynamic water bodies using Poyang Lake,the largest freshwater lake in China,as an example.Field surveys conducted during October 17-26,2009 showed a wide range of TSS concentration (3-524 mg/L).Atmospheric correction was implemented using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) module in ENVI with the aid of aerosol information retrieved from concurrent Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) surveys,which worked well at the CCD bands with relatively high reflectance.A practical exponential retrieval algorithm was created between satellite remote sensing reflectance and in-situ measured TSS concentration.The retrieved results for the whole water area matched the in-situ data well at most stations.The retrieval errors may be related to the problem of scale matching and mixed pixel.In three selected subregions of Poyang Lake,the distribution trend of retrieved TSS was consistent with that of the field investigation.It was shown that HJ-1A/1B CCD imagery can be used to estimate TSS concentrations in Poyang Lake over synoptic scales after applying an appropriate atmospheric correction method and retrieval algorithm.

  20. High frame rate imaging based photometry

    Harpsøe, Kennet Bomann West; Jørgensen, U. G.; Andersen, M. I.;

    2012-01-01

    the output from an EMCCD is not normally distributed. Also, the readout process generates spurious charges in any CCD, but in EMCCD data, these charges are visible as opposed to the conventional CCD. Furthermore we aim to eliminate the photon waste associated with lucky imaging by combining this...

  1. Developments of engineering model of the X-ray CCD camera of the MAXI experiment onboard the International Space Station

    MAXI, Monitor of All-sky X-ray Image, is an X-ray observatory on the Japanese Experimental Module (JEM) Exposed Facility (EF) on the International Space Station (ISS). MAXI is a slit scanning camera which consists of two kinds of X-ray detectors: one is a one-dimensional position-sensitive proportional counter with a total area of ∼5000 cm2, the Gas Slit Camera (GSC), and the other is an X-ray CCD array with a total area ∼200 cm2, the Solid-state Slit Camera (SSC). The GSC subtends a field of view with an angular dimension of 1 deg. x180 deg. while the SSC subtends a field of view with an angular dimension of 1 deg. times a little less than 180 deg. . In the course of one station orbit, MAXI can scan almost the entire sky with a precision of 1 deg. and with an X-ray energy range 0.5-30 keV. We have developed an engineering model (EM) for all components of the SSC. Their performance test is underway. We have also developed several kinds of CCDs fabricated from different wafers. Since the thermal condition of the ISS is not suitable for the CCD operation, the operating temperature of the CCD is estimated to be -85 deg. to -50 deg. C at the end of mission life. We therefore carefully need to choose CCD considering not only detection efficiency and readout noise but also the dark current. Here we report the current status of the EM of the SSC and the X-ray responsivity of CCDs

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

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

    2015-08-01

    The limitations of satellite data acquisition mean that there is a lack of satellite data with high spatial and temporal resolutions for environmental process monitoring. In this study, we address this problem by applying the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) and the Spatial and Temporal Data Fusion Approach (STDFA) to combine Huanjing satellite charge coupled device (HJ CCD), Gaofen satellite no. 1 wide field of view camera (GF-1 WFV) and Moderate Resolution Imaging Spectroradiometer (MODIS) data to generate daily high spatial resolution synthetic data for land surface process monitoring. Actual HJ CCD and GF-1 WFV data were used to evaluate the precision of the synthetic images using the correlation analysis method. Our method was tested and validated for two study areas in Xinjiang Province, China. The results show that both the ESTARFM and STDFA can be applied to combine HJ CCD and MODIS reflectance data, and GF-1 WFV and MODIS reflectance data, to generate synthetic HJ CCD data and synthetic GF-1 WFV data that closely match actual data with correlation coefficients (r) greater than 0.8989 and 0.8643, respectively. Synthetic red- and near infrared (NIR)-band data generated by ESTARFM are more suitable for the calculation of Normalized Different Vegetation Index (NDVI) than the data generated by STDFA. PMID:26308017

  3. Small field CCD astrometry with a long focus reflector telescope

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

    2002-01-01

    Se muestra la utilización del método de ajuste en bloque para la medición de posiciones astromètricas a partir de un mosaico de imágenes CCD directas tomadas con un telescopio reflector de distancia focal larga. Las observaciones cubren una región de aproximadamente 25 x 25 en torno al cúmulo abierto Rup21. Como catálogo de referencia se empleó el Catálogo Tycho-2. Se analiza el error interno de las posiciones medidas, y se estima el error externo a partir de la comparación ...

  4. Use of RTS2 for LSST multiple channel CCD characterisation

    Kubánek, Petr; Prouza, Michael; Kotov, I.; O´Connor, P.; Doherty, P.; Frank, J.

    Bellingham: SPIE, 2012 - (Radziwill, N.; Chiozzi, G.), 84512T/1-84512T/12. (Proceedings of the SPIE. 8451). ISBN 9780819491527. ISSN 0277-786X. [ Software and Cyberinfrastructure for Astronomy II. Amsterdam (NL), 01.07.2012-04.07.2012] R&D Projects: GA MŠk ME09052; GA MŠk 7E12064 EU Projects: European Commission(XE) 283783 - GLORIA Institutional research plan: CEZ:AV0Z10100502 Keywords : observatory software * CCD testing * LSST Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  5. Radiation Hardness of CCD Vertex Detectors for the ILC

    Sopczak, Andre; Bekhouche, Khaled; Bowdery, Chris; Damerell, Chris; Davies, Gavin; Dehimi, Lakhdar; Greenshaw, Tim; Koziel, Michal; Stefanov, Konstantin; Woolliscroft, Tim; Worm, Steve

    2006-01-01

    Results of detailed simulations of the charge transfer inefficiency of a prototype CCD chip are reported. The effect of radiation damage in a particle detector operating at a future accelerator is studied by examining two electron trap levels, 0.17 eV and 0.44 eV below the bottom of the conduction band. Good agreement is found between simulations using the ISE-TCAD DESSIS program and an analytical model for the 0.17 eV level. Optimum operation is predicted to be at about 250 K where the effec...

  6. CCD - observations of optical jets and extensions in galaxies

    A survey of galaxies with jet-like features has been undertaken in order to allow a statistical approach to the optical jet phenomenon. Sixty peculiar galaxies have been observed in different colours, using the standard B and V filters and the g, r, i, and z filters, a set of broad-band filters which cover the wavelength range of the CCD response (4000A-1μ). Preliminary results of five jet galaxies (M87, 3C273, 3C120, IC1182, PKS0521-36) are reported. New information on the morphology of the optical jets in these objects has been obtained. (G.J.P.)

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

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

    2010-01-01

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

  8. CCD camera full range pH sensor array.

    Safavi, A; Maleki, N; Rostamzadeh, A; Maesum, S

    2007-01-15

    Changes in colors of an array of optical sensors that responds in full pH range were recorded using a CCD camera. The data of the camera were transferred to the computer through a capture card. Simple software was written to read the specific color of each sensor. In order to associate sensor array responses with pH values, a number of different mathematics and chemometrics methods were investigated and compared. The results show that the use of "Microsoft Excel's Solver" provides results which are in very good agreement with those obtained with chemometric methods such as artificial neural network (ANN) and partial least square (PLS) methods. PMID:19071333

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

    Seabroke, G. M.; Prod'Homme, T.; Hopkinson, G.; Burt, D.; Robbins, M.; Holland, A.

    2011-02-01

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

  10. CCD-Delta a and BVR photometry of NGC 7296

    Netopil, M; Maitzen, H M; Claret, A; Pavlovski, K; Tamajo, E

    2005-01-01

    The first CCD photometric investigation of the open cluster NGC 7296 up to now was performed within the narrow band Delta a photometric system, which enables us to detect peculiar objects. A deeper investigation of that cluster followed, using the standard BVR-Bessel filter set. The age and E(B-V) was determined independently to log t= 8.0 and 0.15 respectively by using Delta a and broadband photometry. In total five Be/Ae objects and two metal-weak stars showing significant negative Delta a-values as well as one classical chemically peculiar star could be identified within that intermediate age open cluster.

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

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

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

  12. Wide field CCD photometry of the globular cluster M92

    Lee, K H; Fahlman, G G; Lee, M G; Lee, Kang Hwan; Lee, Hyung Mok; Fahlman, Gregory G.; Lee, Myung Gyoon

    2003-01-01

    We present wide field CCD photometry of a galactic globular cluster M92 obtained in the V and I bands with the CFH12K mosaic CCD at the Canada-France-Hawaii Telescope. A well-defined color-magnitude diagram is derived down to 5 magnitudes fainter than the cluster main sequence turn-off. After removing the background contribution, we obtain luminosity and mass functions, surface density profiles, and the surface number density maps of the stars belonging to the cluster. The surface density profile of all stars shows that the cluster's halo extends at least out to ~30' from the cluster center in agreement with previous study, but the profile of faint stars at the very outer region of the cluster shows a different gradient compared with that of bright stars. For a mass function of the cluster, we find that the inner region of the cluster has x = 1.2+-0.2, whereas the outer region has x = 1.8 +-0.3, clearly indicating a mass segregation of the cluster. An estimate of the photometric mass of the cluster implies th...

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

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

    2012-01-01

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

  14. AGN Search From Multicolor CCD Photometric Observations of Faint ROSAT X-ray Sources in a One Square Degree Field

    Xue, Suijian; Zhou, Xu; Zhang, H.

    We present the optical identifications of 75 X-ray sources in a 1 sq. deg. overlapping region, T329 of BATC sky survey with a medium deep ROSAT survey (Molthagen et al. 1997), based on multi-color CCD imaging observations made for the T329 utilizing BAO 60/90 cm Schmidt telescope with 15 intermediate-band filters covering the wavelength range 3360-9745 AA. These X-ray sources are relatively faint (CR MOFS) of SAO 6m telescope, which will help to form a complete, X-ray flux limited AGN sample in a 1 square degree field.

  15. The in-flight spectroscopic performance of the Swift XRT CCD camera

    Osborne, J. P.; Beardmore, A. P.; Godet, O.; Abbey, A. F.; Goad, M. R.; Page, K. L.; Wells, A. A.; Angelini, L; Burrows, D. N.; S. Campana; Chincarini, G.; Citterio, O.; Cusumano, G.; Giommi, P.; Hill, J.E.

    2005-01-01

    The Swift X-ray Telescope (XRT) focal plane camera is a front-illuminated MOS CCD, providing a spectral response kernel of 144 eV FWHM at 6.5 keV. We describe the CCD calibration program based on celestial and on-board calibration sources, relevant in-flight experiences, and developments in the CCD response model. We illustrate how the revised response model describes the calibration sources well. Loss of temperature control motivated a laboratory program to re-optimize the CCD substrate volt...

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

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

    2016-01-01

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

  17. CCD soft X-ray observations of the Puppis a supernova remnant

    Berthiaume, G. D.; Burrows, D. N.; Garmire, G. P.; Nousek, J. A.

    1994-01-01

    We present the first images and spectra of an astronomical object, other than the Sun, acquired with a charge coupled device (CCD) imaging X-ray spectrometer. During a 230 s sounding rocket observation, we have acquired moderate-resolution spectra and moderate-resolution images of a portion of the Pup A supernova remnant (SNR). Based on these data, we conclude that the X-ray spectrum of Pup A is inconsistent with any single-temperature equilibrium or nonequilibrium plasma model. We find evidence for variations in the emitting plasma on scales as small as 5.0 min and as large as 30.0 min. The spatial structure of the spectral variations in the remnant is found to be inconsistent with the standard Sedov model for the evolution of a SRN into a homogeneous interstellar medium (ISM). We suggest that the remnant is expanding into a region of the ISM having a density of approximately 1 cm(exp -3) with inhomogeneities on the order of 50%. We have found evidence for the presence of a knot of plasma enriched in neon, but require more data to be conclusive.

  18. Measurement of the AT and the CCD angle of macerated cadaver femora: a comparative study between CT and MRI measurements; Die Bestimmung des AT- und CCD-Winkels am mazerierten Leichenfemur - Eine Vergleichsstudie zwischen CT- und MRT-Messung und Direktmessung am Praeparat

    Nuss, V.; Herber, S.; Kreitner, K.-F.; Thelen, M. [Universitaetsklinik Mainz (Germany). Klinik und Poliklinik fuer Radiologie; Kuellmer, K. [Universitaetsklinik Mainz (Germany). Klinik fuer Orthopaedie

    2003-10-01

    Purpose: To compare measurements of the real AT (femoral antetorsion) and CCD (caput-scollum-diaphysis) angle by computed tomography (CT) and magnetic resonance imaging (MRI) of hip specimen using direct measurements as reference standard, and to show that measurements by MRI can replace CT measurements and ma help avoiding X-ray exposition. Materials and methods: CT and MRI measurements were obtained on 25 in water-arrested macerated human femora. Postprocessing was done by 4 independent readers on a workstation using a dedicated 3D-software. Direct measurements of the real AT and the CCD angle were used as reference standard. The analysis included Student's test for paired values, interobserver variability using intra-class correlation coefficients (ICC), maximum and middle divergence of the angles, and Bland-Altman plots. Results: For determining AT and the CCD angle with CT and MRI, good correlation was found between the 4 readers and with measurements using the reference standard. ICCs were 0.97 and 0.90 for measuring AT and CCD angle with CT, and 0.95 and 0.71 for measurements with MRI, respectively. Mean divergence between CT measurements and those of the reference standard was 0.8 for AT and 0.7 for the CDD-angle. Mean divergence between MRI measurements and those of the reference standard was 0.3 for AT and -0.4 for the CCD-angle. Mean divergences between CT and MRI measurements of AT and CCD-angle were 0.5 . Neither systematic errors nor dependences on the qualitative size of the reference data were evident in the divergences of measurements. (orig.) [German] Ziel: Messung des reellen Femurantetorsions (AT)- und Caput-Collum-Diaphysenwinkels (CCD-Winkels) im computer (CT)- und magnetresonanz (MR)-tomographischen Bild sowie Direktmessungen am Praeparat im Vergleich. Es soll gezeigt werden, dass die mit einer Strahlenexposition verbundene computertomographische durch die roentgenstrahlenfreie MR-tomographische Messung ersetzt werden kann. Material und

  19. A three-band semi-analytical model for deriving total suspended sediment concentration from HJ-1A/CCD data in turbid coastal waters

    Chen, Jun; Cui, Tingwei; Qiu, Zhongfeng; Lin, Changsong

    2014-07-01

    The accurate assessment of total suspended sediment (TSM) concentration in coastal waters by means of remote sensing is quite challenging, due to the optical complexity and significant variability of these waters. In this study, three-band semi-analytical TSM retrieval (TSTM) model with HJ-1A/CCD spectral bands was developed for the retrieval of TSM concentration from turbid coastal waters. This model was calibrated and validated by means of one calibration dataset and three independent validation datasets obtained from three different turbid waters. It was found that the TSTM model may be used to retrieve accurate TSM concentration data from highly turbid waters without the spectral slope of the model requiring further optimization. Finally, the TSM concentration data were quantified from the HJ-1A/CCD images after atmospheric correction using the dark-object subtraction technique. Upon comparing the model-derived and field-measured TSM concentration data, it was observed that the TSTM model produced <29% uncertainty in deriving TSM concentration from the HJ-1A/CCD data. These findings imply that the TSTM model may be used for the quantitative monitoring of TSM concentration in coastal waters, provided that the atmospheric correction scheme for the HJ-1A/CCD imagery is available.

  20. Photometric characteristics of the Vega 1 and Vega 2 CCD cameras for the observation of Comet Halley.

    Abergel, A; Bertaux, J L; Avanessov, G A; Tarnopolsky, V I; Zhukov, B S

    1987-10-15

    The first pictures of the nucleus of Comet Halley were returned from the CCD TV system (TVS) placed onboard the two Soviet spacecraft Vega 1 and 2. Comet Halley was observed from 4 to 11 Mar. 1986, and ~1500 images were transmitted to the earth. The raw data are given in digital numbers which must be converted into units of brightness. After a brief description of the experiment, the on-ground calibration tests are discussed. Many images were registered and processed to obtain standard correcting images and absolute calibration. Photometric performance could also be checked during flight with observations of Jupiter; in-flight and on-ground performances are compared. PMID:20523385

  1. CCD photometry of the distant young open cluster NGC 7510

    CCD observations in B, V and I passbands have been used to generate deep V, (B-V) and V,(V-I) colour-magnitude diagrams for the open cluster NGC 7510. The sample consists of 592 stars reaching down to V=21 mag. There appears to be non-uniform extinction over the face of the cluster with the value of colour excess, E(B-V), ranging from 1.0 to 1.3 mag. The law of interstellar extinction in the direction of the cluster is found to be normal. A broad main sequence is clearly visible in both colour-magnitude diagrams. From the bluest part of the colour-magnitude diagrams, the true distance modulus to the cluster has been estimated as 12.5±0.3 mag and an upper limit of 10 Myr has been assigned for the cluster age. (author)

  2. CCD camera automatic calibration technology and ellipse recognition algorithm

    Changku Sun; Xiaodong Zhang; Yunxia Qu

    2005-01-01

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

  3. Rotational properties of asteroids: CCD observations of nine small asteroids

    Birlan, M.; Barucci, M. A.; Angeli, C. A.; Doressoundiram, A.; De Sanctis, M. C.

    1996-06-01

    The observational programme on small asteroids (diameter less than about 50 km) is continued to enlarge the available dataset of small asteroids. The results are presented of CCD observations of nine small asteroids ( D≤23 km), performed in France with the 1.2 m telescope at Haute Provence Observatory and with the 2 m telescope at Pic du Midi Observatory. A total of 27 single night lightcurves for nine asteroids were obtained. All the objects were observed for the first time and rotational periods have been determined for all of the observed asteroids: 1992 Galvarino ( Psyn = 7 h.004), 2419 Moldavia ( Psyn = 2 h.412), 2921 Sophocles ( Psyn = 4 h.778), 3247 Di Martino ( Psyn = 5 h.445), 3623 Chaplin ( Psyn = 8 h.361), 3986 Rozhkovskij ( Psyn = 4 h.26), 4436 1983 EX ( Psyn = 6 h.656), 5046 1981 DQ ( Psyn = 6 h.050) and 1992 YG3 ( Psyn = 8 h.91).

  4. Optimal CCD readout by digital correlated double sampling

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

    2015-01-01

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

  5. Method to implement the CCD timing generator based on FPGA

    Li, Binhua; Song, Qian; He, Chun; Jin, Jianhui; He, Lin

    2010-07-01

    With the advance of the PFPA technology, the design methodology of digital systems is changing. In recent years we develop a method to implement the CCD timing generator based on FPGA and VHDL. This paper presents the principles and implementation skills of the method. Taking a developed camera as an example, we introduce the structure, input and output clocks/signals of a timing generator implemented in the camera. The generator is composed of a top module and a bottom module. The bottom one is made up of 4 sub-modules which correspond to 4 different operation modes. The modules are implemented by 5 VHDL programs. Frame charts of the architecture of these programs are shown in the paper. We also describe implementation steps of the timing generator in Quartus II, and the interconnections between the generator and a Nios soft core processor which is the controller of this generator. Some test results are presented in the end.

  6. CCD identification and classification of 5 GHz radio sources

    Deep CCD exposures of the optical fields of 19 previously unidentified 5 GHz sources have revealed 10 new optical counterparts, 2 marginal identifications, and 4 ''empty fields''; 3 sources are probably radio galaxies where no exact coincidence of the optical and radio positions is expected and only a tentative identification is given. The new optical counterparts are classified as stellar or extended (i.e. as galaxy) according to their optical appaearance. Two flatspectrum radio sources previously identified as galaxies are re-classified as stellar objects with neighbouring galaxies. The results support the view that, down to a limiting red magnitude of 23m, practically all strong 5 GHz sources can be identified and that, even among the optically faintest objects, flat-spectrum radio sources usually have a stellar intensity profile while many steep-spectrum sources are extended

  7. CCD polarimetry and photometry of 5 GHz radio sources

    Fugmann, W.; Meisenheimer, K.

    1988-11-01

    We present CCD polarimetry of the optical counterparts of 48 radio sources selected from 5 GHz surveys. 37 sources were observed polarimetrically for the first time, 22 of which were fainter than R = 19/sup m/. One object, the blazar PKS 0219-164, was monitored continuously for almost a month. Based on polarization, we discovered 9 new blazars and a further 6 new probable blazars. Among the 38 sources with distinct polarimetric properties, the blazar detection rate is almost 50%. Much lower blazar detection rates reported in previous surveys of radio-loud quasars are mainly due to the contribution of quasars with steep radio spectra. Photometric and polarimetric observations of optically quiet compact radio sources (OQCRSs) indicate that many of these objects are blazars. Frequently, we found evidence of a galaxy contributing to the optical spectrum of an OQCRS. 0500+01 is the quasar with the steepest optical spectrum ever observed.

  8. CCD polarimetry and photometry of 5 GHz radio sources

    We present CCD polarimetry of the optical counterparts of 48 radio sources selected from 5 GHz surveys. 37 sources were observed polarimetrically for the first time, 22 of which were fainter than R = 19m. One object, the blazar PKS 0219-164, was monitored continuously for almost a month. Based on polarization, we discovered 9 new blazars and a further 6 new probable blazars. Among the 38 sources with distinct polarimetric properties, the blazar detection rate is almost 50%. Much lower blazar detection rates reported in previous surveys of radio-loud quasars are mainly due to the contribution of quasars with steep radio spectra. Photometric and polarimetric observations of optically quiet compact radio sources (OQCRSs) indicate that many of these objects are blazars. Frequently, we found evidence of a galaxy contributing to the optical spectrum of an OQCRS. 0500+01 is the quasar with the steepest optical spectrum ever observed

  9. CCD identification and classification of 5 GHz radio sources

    Fugmann, W. Meisenheimer, K.; Roeser, H.J.

    1988-10-01

    Deep CCD exposures of the optical fields of 19 previously unidentified 5 GHz sources have revealed 10 new optical counterparts, 2 marginal identifications, and 4 ''empty fields''; 3 sources are probably radio galaxies where no exact coincidence of the optical and radio positions is expected and only a tentative identification is given. The new optical counterparts are classified as stellar or extended (i.e. as galaxy) according to their optical appaearance. Two flatspectrum radio sources previously identified as galaxies are re-classified as stellar objects with neighbouring galaxies. The results support the view that, down to a limiting red magnitude of 23/sup m/, practically all strong 5 GHz sources can be identified and that, even among the optically faintest objects, flat-spectrum radio sources usually have a stellar intensity profile while many steep-spectrum sources are extended.

  10. CCD observations of the polarization of the Crab Nebula

    CCD observations are used to map the intensity distribution and polarization of the optical synchrotron radiation of the Crab Nebula. The data indicate that the Crab Nebula has a large-scale magnetic field in which major variations generally occur over regions with sizes larger than 10 arcsec (0.1 pc). However, in the vicinity of the Crab pulsar, the polarization shows structure on a scale of a few arcsec. Evidence is found for a narrow depolarized channel extending from the pulsar to the region of the optical wisps in the synchrotron nebula. The results also confirm previous studies which show that the magnetic vectors of polarization are predominantly oriented parallel to the edges of the dark bays in the outer regions of the visible synchrotron nebulosity. This supports the suggestion that these regions of the Nebula are wrapped in magnetic field lines, and are therefore deficient in electrons capable of emitting synchrotron radiation. 33 refs

  11. Beam profile monitor using alumina screen and CCD camera

    A pair of beam profile monitors using alumina ceramic screens (Al2O3) and CCD cameras has been developed for diagnosis of a linac beam at the 1.3 GeV electron synchrotron of the Institute for Nuclear Study, the University of Tokyo (INS-ES). Since both the light decay-time of the screen and a shutter speed of the camera are relatively short, about 10 msec or less and 1 msec, respectively, this system is able to measure the beam profile for each pulse of the linac beam operated at a repetition rate of 21.5 Hz. Detailed analysis of the beam profile is made using the stored data on the personal computer. On the other hand, a light spot on the screen is displayed directly on a monitor display. (author)

  12. A tasseled cap transformation for CBERS-02B CCD data

    Li SHENG; Jing-feng HUANG; Xiao-lu TANG

    2011-01-01

    The tasseled cap transformation of remote sensing data has been widely used in agriculture,forest,ecology,and landscape.In this paper,tasseled cap transformation coefficients appropriate for data from a new sensor (China & Brazil Earth Resource Satellite (CBERS-02B)) are presented.The first three components after transformation captured 98% of the four-band variance,and represent the physical characteristics of brightness (coefficients:0.509,0.431,0.330,and 0.668),greenness (coefficients:-0.494,-0.318,-0.324,and 0.741),and blueness (coefficients:0.581,-0.070,-0.811,and 0.003),respectively.We hope these results will enhance the application of CBERS-02B charge-coupled device (CCD) data in the areas of agriculture,forest,ecology,and landscape.

  13. White-light interference fringe detection using color CCD camera

    Buchta, Zdeněk; Jedlička, Petr; Matějka, Milan; Kolařík, Vladimír; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej

    Los Alamitos : IEEE, 2009, 5308093: 1-5. ISBN 978-1-4244-3918-8. [Africon 2009. Nairobi (KE), 23.09.2009-25.09.2009] R&D Projects: GA MŠk(CZ) LC06007; GA MŠk 2C06012; GA AV ČR KAN311610701; GA MPO 2A-1TP1/127; GA MPO FT-TA3/133; GA MPO 2A-3TP1/113; GA ČR GA102/07/1179; GA ČR GP102/09/P293; GA ČR GP102/09/P630; GA ČR GA102/09/1276 Institutional research plan: CEZ:AV0Z20650511 Keywords : white- light source * phase-crossing algorithm * gauge block * color CCD camera Subject RIV: BH - Optics, Masers, Lasers

  14. CCD photometry of the sparse halo cluster E3

    New photometry in B and V for the sparse halo cluster E3 has been obtained with the prime-focus CCD camera at the CTIO 4-m telescope. The principal sequences are better defined than in the previous color-magnitude (C-M) diagrams, but the large scatter of evolved stars above the turnoff remains. The C-M morphology, inferred old age, and position in the halo definitely indicate that E3 is a globular cluster. Evidence for possible main-sequence binaries appears in the C-M diagram in the form of a sequence parallel to the cluster main sequence and three-quarters of a magnitude above it. The luminosity function drops off sharply, about 2.5 mag below the turnoff, supporting the suggestion by van den Bergh, Demers, and Kunkel (1980), that the cluster is severely truncated by tidal forces. 34 references

  15. A low-cost, CCD solid state star tracker

    Chmielowski, M.; Wynne, D.

    1992-01-01

    Applied Research Corporation (ARC) has developed an engineering model of a multi-star CCD-based tracker for space applications requiring radiation hardness, high reliability and low power consumption. The engineering unit compared favorably in functional performance tests to the standard NASA single-star tracker. Characteristics of the ARC star tracker are: field of view = 10 deg x 7.5 deg, sensitivity range of -1 to +5 star magnitude, NEA = 3 in x 3 in, linearity = 5 in x 5 in, and power consumption of 1-3 W (operating mode dependent). The software is upgradable through a remote link. The hardware-limited acquisition rate is 1-5 Hz for stars of +2 to +5 magnitude and 10-30 Hz for -1 to +2 magnitude stars. Mechanical and electrical interfaces are identical to the standard NASA star tracker.

  16. Clinical ultraviolet dosimetry with a CCD monochromator array spectroradiometer

    Coleman, Andrew; Sarkany, Robert; Walker, Susan

    2008-09-01

    Single monochromator charge-coupled device (CCD) array spectroradiometers have the advantage of ease of use and speed compared with double grating instruments. Their inherently inferior stray-light rejection, however, can critically affect their accuracy in phototherapy and research-related dosimetry applications. This paper shows that without adequate correction the HR4000 (Ocean Optics Inc., Dunedin, USA) array device can overestimate the CIE erythema-weighted irradiance of common phototherapy sources and solar simulator beams by over 100%. A software stray-light correction (Ylianttila et al 2005 Photochem. Photobiol. 81 333-41), using the measured slit function of the HR4000, has been applied to spectra acquired from sources used in phototherapy and photobiology (PUVA, UV21, TL01 and solar simulator). The resulting corrected erythema-weighted irradiance measurements from the HR4000 are within 10% of those from a DM150 double grating spectroradiometer (Bentham Instruments Ltd, Reading, UK). A simple model is considered for combining estimates of measurement uncertainties. The importance of exposure bracketing to improve the dynamic range of the HR4000 is illustrated, along with the difficulty in making direct comparison of spectral values between two instruments due to wavelength scale uncertainties. Comparison with a double grating instrument in a solar simulator beam is examined here as a basis for validating CCD array device measurements. The study demonstrates that the HR4000 array spectroradiometer can provide an adequate level of accuracy for common phototherapy and photobiology applications only where a suitable stray-light correction is carefully applied and where the instrument's effective dynamic range is improved.

  17. Optimal CCD readout by digital correlated double sampling

    Alessandri, C.; Abusleme, A.; Guzman, D.; Passalacqua, I.; Alvarez-Fontecilla, E.; Guarini, M.

    2016-01-01

    Digital correlated double sampling (DCDS), a readout technique for charge-coupled devices (CCD), is gaining popularity in astronomical applications. By using an oversampling ADC and a digital filter, a DCDS system can achieve a better performance than traditional analogue readout techniques at the expense of a more complex system analysis. Several attempts to analyse and optimize a DCDS system have been reported, but most of the work presented in the literature has been experimental. Some approximate analytical tools have been presented for independent parameters of the system, but the overall performance and trade-offs have not been yet modelled. Furthermore, there is disagreement among experimental results that cannot be explained by the analytical tools available. In this work, a theoretical analysis of a generic DCDS readout system is presented, including key aspects such as the signal conditioning stage, the ADC resolution, the sampling frequency and the digital filter implementation. By using a time-domain noise model, the effect of the digital filter is properly modelled as a discrete-time process, thus avoiding the imprecision of continuous-time approximations that have been used so far. As a result, an accurate, closed-form expression for the signal-to-noise ratio at the output of the readout system is reached. This expression can be easily optimized in order to meet a set of specifications for a given CCD, thus providing a systematic design methodology for an optimal readout system. Simulated results are presented to validate the theory, obtained with both time- and frequency-domain noise generation models for completeness.

  18. Proton radiation damage experiment on P-Channel CCD for an X-ray CCD camera onboard the ASTRO-H satellite

    We report on a proton radiation damage experiment on P-channel CCD newly developed for an X-ray CCD camera onboard the ASTRO-H satellite. The device was exposed up to 109 protons cm−2 at 6.7 MeV. The charge transfer inefficiency (CTI) was measured as a function of radiation dose. In comparison with the CTI currently measured in the CCD camera onboard the Suzaku satellite for 6 years, we confirmed that the new type of P-channel CCD is radiation tolerant enough for space use. We also confirmed that a charge-injection technique and lowering the operating temperature efficiently work to reduce the CTI for our device. A comparison with other P-channel CCD experiments is also discussed. -- Author-Highlights: •We performed a proton radiation damage experiment on a new P-channel CCD. •The device was exposed up to 109 protons cm−2 at 6.7 MeV. •We confirmed that it is radiation tolerant enough for space use. •We confirmed that a charge-injection technique reduces the CTI. •We confirmed that lowering the operating temperature also reduces the CTI

  19. Images

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

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

    Afanasieva, I V

    2016-01-01

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

  1. Charge diffusion measurement in fully depleted CCD using X-rays

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

    2012-01-01

    Roč. 695, Dec (2012), s. 296-297. ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100502 Keywords : CCD * charge diffusion * CCD X-ray detectors Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.142, year: 2012

  2. Technology advancement of the CCD201-20 EMCCD for the WFIRST coronagraph instrument: sensor characterization and radiation damage

    Harding, Leon K.; Demers, Richard T.; Hoenk, Michael; Peddada, Pavani; Nemati, Bijan; Cherng, Michael; Michaels, Darren; Neat, Leo S.; Loc, Anthony; Bush, Nathan; Hall, David; Murray, Neil; Gow, Jason; Burgon, Ross; Holland, Andrew; Reinheimer, Alice; Jorden, Paul R.; Jordan, Douglas

    2016-01-01

    The Wide Field InfraRed Survey Telescope-Astrophysics Focused Telescope Asset (WFIRST-AFTA) mission is a 2.4-m class space telescope that will be used across a swath of astrophysical research domains. JPL will provide a high-contrast imaging coronagraph instrument-one of two major astronomical instruments. In order to achieve the low noise performance required to detect planets under extremely low flux conditions, the electron multiplying charge-coupled device (EMCCD) has been baselined for both of the coronagraph's sensors-the imaging camera and integral field spectrograph. JPL has established an EMCCD test laboratory in order to advance EMCCD maturity to technology readiness level-6. This plan incorporates full sensor characterization, including read noise, dark current, and clock-induced charge. In addition, by considering the unique challenges of the WFIRST space environment, degradation to the sensor's charge transfer efficiency will be assessed, as a result of damage from high-energy particles such as protons, electrons, and cosmic rays. Science-grade CCD201-20 EMCCDs have been irradiated to a proton fluence that reflects the projected WFIRST orbit. Performance degradation due to radiation displacement damage is reported, which is the first such study for a CCD201-20 that replicates the WFIRST conditions. In addition, techniques intended to identify and mitigate radiation-induced electron trapping, such as trap pumping, custom clocking, and thermal cycling, are discussed.

  3. On-ground characterization of the Euclid low noise CCD273 sensor for precise galaxy shape measurements

    The VISible imaging instrument VIS is one of two instruments on board the Euclid telescope. The focal plane consists of 36 CCD273-84 sensors manufactured by the e2v technologies. The sensors are designed to provide a maximum charge transfer efficiency (CTE) to minimize distortions to source shapes. Each sensor undergoes a rigorous on-ground electro-optical testing at several stages of the mission to ensure that strict requirements are met before the launch of the spacecraft. This paper summarizes the commissioning of the Euclid CCD273 testing facility at the Mullard Space Science Laboratory (MSSL), the lead institute for VIS . The testing bench supports the measurements of the point spread function (PSF), system noise and the flat field evaluation. Accurate spot measurements are extremely important for the precise modelling and general understanding of an instrument's PSF . We show the preliminary results of the optical characterization of the pre-development devices with a special interest in the measurements of the PSF at different illumination levels and in the VIS spectral range of 550–900 nm. Additionally, the influence of the on-ground testing environment and a dedicated readout electronics on the obtained images is taken into consideration

  4. Dynamic monitoring of water petroleum substance using HJ-1/CCD remote sensing data

    The experiment data used in this paper include CDOM(Chromophoric dissolved organic matter) absorption coefficient, water apparent optical properties and petroleum pollution concentration, which were obtained in May 2008, August 2009 and June 2010 respectively at Liaohe Oilfield in Panjin city, Liaoning province of China. A model between CDOM absorption coefficient and petroleum pollution concentration was developed, and then was applied to eight HJ-1CCD remote sense images obtained from 2009 to 2011, to produce multi-period temporal and spatial distribution maps of petroleum concentration in costal waters. Based on these thematic maps, the dynamic monitoring of petroleum pollution concentration distribution was done. The results showed that (1)There was a decreasing trend of petroleum concentration from costal waters to open sea, which manifest itself as an approximately zonal distribution;(2) due to low precipitation in May and June every year, the concentration of petroleum keeps in a relatively high value state; (3) in September, the concentration of petroleum decreases dramatically as pre increases, most of the area below 0.29 mg/L; (4) compared with that in the same period, the concentration of petroleum in April 2010 is apparently higher than in April 2011, and among the images in September from 2009 to 2011,the highest concentration of petroleum appears in 2010, and the lowest in 2009

  5. High-Voltage Clock Driver for Photon-Counting CCD Characterization

    Baker, Robert

    2013-01-01

    A document discusses the CCD97 from e2v technologies as it is being evaluated at Goddard Space Flight Center's Detector Characterization Laboratory (DCL) for possible use in ultra-low background noise space astronomy applications, such as Terrestrial Planet Finder Coronagraph (TPF-C). The CCD97 includes a photoncounting mode where the equivalent output noise is less than one electron. Use of this mode requires a clock signal at a voltage level greater than the level achievable by the existing CCD (charge-coupled-device) electronics. A high-voltage waveform generator has been developed in code 660/601 to support the CCD97 evaluation. The unit generates required clock waveforms at voltage levels from -20 to +50 V. It deals with standard and arbitrary waveforms and supports pixel rates from 50 to 500 kHz. The system is designed to interface with existing Leach CCD electronics.

  6. From the Sensor to Color Images

    Losson, Olivier; Dinet, Eric

    2012-01-01

    This chapter deals with the acquisition of colour images by mono-CCD colour cameras. These devices acquire only one colour component at each pixel through the CFA (Colour Filter Array) that covers the CCD sensor. A procedure - called demosaicing - is necessary to estimate the other two missing colour components at each pixel to obtain a colour image. A mathematical formalization for demosaicing is proposed, before we present some of the methods in the demosaicing literature, as well as the po...

  7. Follow the yellow-orange rabbit: a CCD optimized for wavefront sensing a pulsed sodium laser guide star

    Beletic, James W.

    2004-09-01

    Most large telescopes are now implementing sodium laser guide star (LGS) adaptive optics (AO) systems. Most of these systems plan to use the Shack-Hartmann approach for wavefront sensing. In these systems, the laser spots that are imaged in the Shack-Hartmann subapertures suffer spot elongation due to the 10 km extent of the sodium layer. The spot elongation extends radially from the projection point, and increases linearly with the distance the subaperture is separated from the laser. For 8-meter class telescopes with laser projection behind the secondary mirror, the spot elongation is ~1 arc sec at the edge of the pupil, and does not significantly affect the performance of the AO system. However, for the coming generation of extremely large telescopes, sodium LGS spot elongation will significantly degrade the quality of wavefront measurement. Attention should now be given to the development of technologies that can reduce or eliminate the spot elongation problem. The laser spot elongation can be greatly reduced by projecting the sodium laser in a series of short (1-3 µsec) pulses. The Lawrence Livermore National Laboratory (LLNL) has been funded to develop a pulsed fiber laser. In parallel, a new kind of wavefront sensor detector must be developed to properly sense the pulsed laser return. In this paper, we present our project that will develop a novel CCD which is optimized for sensing the return from a pulsed sodium LGS. Our CCD design uses custom pixel morphology that aligns the pixels of each subaperture with the radial extension of the LGS spot. This pixel geometry will allow each subaperture to follow the yellow-orange rabbit (i.e. the 589 nm laser pulse) as it traverses the sodium layer, providing optimal sampling of a limited number of detected photons. This CCD will attain photon-noise limited performance at high frame rates, using MOSFET amplifiers that exist today (2-3 electrons noise). However, we seek even lower noise amplifiers, and as part of

  8. Characterization of a parallel-beam CCD optical-CT apparatus for 3D radiation dosimetry

    Krstajic, Nikola; Doran, Simon J.

    2007-07-01

    3D measurement of optical attenuation is of interest in a variety of fields of biomedical importance, including spectrophotometry, optical projection tomography (OPT) and analysis of 3D radiation dosimeters. Accurate, precise and economical 3D measurements of optical density (OD) are a crucial step in enabling 3D radiation dosimeters to enter wider use in clinics. Polymer gels and Fricke gels, as well as dosimeters not based around gels, have been characterized for 3D dosimetry over the last two decades. A separate problem is the verification of the best readout method. A number of different imaging modalities (magnetic resonance imaging (MRI), optical CT, x-ray CT and ultrasound) have been suggested for the readout of information from 3D dosimeters. To date only MRI and laser-based optical CT have been characterized in detail. This paper describes some initial steps we have taken in establishing charge coupled device (CCD)-based optical CT as a viable alternative to MRI for readout of 3D radiation dosimeters. The main advantage of CCD-based optical CT over traditional laser-based optical CT is a speed increase of at least an order of magnitude, while the simplicity of its architecture would lend itself to cheaper implementation than both MRI and laser-based optical CT if the camera itself were inexpensive enough. Specifically, we study the following aspects of optical metrology, using high quality test targets: (i) calibration and quality of absorbance measurements and the camera requirements for 3D dosimetry; (ii) the modulation transfer function (MTF) of individual projections; (iii) signal-to-noise ratio (SNR) in the projection and reconstruction domains; (iv) distortion in the projection domain, depth-of-field (DOF) and telecentricity. The principal results for our current apparatus are as follows: (i) SNR of optical absorbance in projections is better than 120:1 for uniform phantoms in absorbance range 0.3 to 1.6 (and better than 200:1 for absorbances 1.0 to

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

    Yong Pang

    2016-05-01

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

  10. Laboratory x-ray CCD camera electronics: a test bed for the Swift X-Ray Telescope

    Hill, Joanne E.; Zugger, Michael E.; Shoemaker, Jason; Witherite, Mark E.; Koch, T. Scott; Chou, Lester L.; Case, Traci; Burrows, David N.

    2000-12-01

    The Penn State University Department of Astronomy and Astrophysics has been active in the design of X-ray CCD cameras for astronomy for over two decades, including sounding rocket systems, the CUBIC instrument on the SAC-B satellite and the ACIS camera on the Chandra satellite. Currently the group is designing and building an X-ray telescope (XRT), which will comprise part of the Swift Gamma-Ray Burst Explorer satellite. The Swift satellite, selected in October 1999 as one of two winners of NASA Explorer contracts, will -- within one minute -- detect, locate, and observe gamma-ray bursts simultaneously in the optical, ultraviolet, X-ray, and gamma- ray wavelengths using three co-aligned telescopes. The XRT electronics is required to read out the telescope's CCD sensor in a number of different ways depending on the observing mode selected. Immediately after the satellite re-orients to observe a newly detected burst, the XRT will enter an imaging mode to determine the exact position of the burst. The location will then be transmitted to the ground, and the XRT will autonomously enter other modes as the X-ray intensity of the burst waxes and wanes. This paper will discuss the electronics for a laboratory X-ray CCD camera, which serves as a test bed for development of the Swift XRT camera. It will also touch upon the preliminary design of the flight camera, which is closely related. A major challenge is achieving performance and reliability goals within the cost constraints of an Explorer mission.

  11. An intensified CCD detector using the phosphor TPB. [for Coronal Diagnostic Spectrometer experiment on Solar Heliospheric Observatory satellite

    Thompson, William T.; Swartz, Marvin; Poland, Arthur I.

    1990-01-01

    The Research Amplifying Imaging Detector consists of a microchannel plate image intensifier with a thin coating (3500-10,000 A) of the phosphor tetraphenyl-butadiene (TPB) on the entrance window to convert EUV radiation to visible, and coupled via a lens to a CCD detector. This design allows great flexibility in selecting the pixel size and field of view, with a simple mechanical design. The phosphor appears to be quite rugged, with no degradation having appeared during several months of testing both in and out of vacuum. Tests have been made at visible and EUV (304 A) wavelengths of the following performance aspects: EUV spectral sensitivity, spatial resolution (both of components and of the system as a whole), noise, linearity, and dynamic range. An improved detector for the Coronal Diagnostic Spectrometer experiment on the Solar Heliospheric Observatory satellite is being presently designed.

  12. Exploring effect of segmentation scale on orient-based crop identification using HJ CCD data in Northeast China

    Crop identification and acreage estimation with remote sensing were the main issues for crop production estimation. Object-oriented classification has been involved in crop extraction from high spatial resolution images. However, different imagery segmentation scales for object-oriented classification always yield quite different crop identification accuracy. In this paper, multi-scale image segmentation was conducted to carry out crop identification using HJ CCD imagery in Red Star Farm in Heilongjiang province. Corn, soybean and wheat were identified as the final crop classes. Crop identification features at different segmentation scale were generated. Crop separability based on different feature-combinations was evaluated using class separation distance. Nearest Neighbour classifier (NN) was then used for crop identification. The results showed that the best segmentation scale was 8, and the overall crop identification accuracy was about 0.969 at that scale

  13. Electron tubes and image intensifiers; Proceedings of the Meeting, San Jose, CA, Feb. 10, 11, 1992

    Johnson, C.B.; Laprade, B.N. (Litton Electron Devices, Tempe, AZ (United States) Galileo Electro-Optics Corp., Sturbridge, MA (United States))

    1992-01-01

    Various papers on electron tubes and image intensifiers are presented. Individual topics addressed include: high-performance LLTV CCD camera for nighttime pilotage, characterization and modelling of microchannel-plate intensified-CCD SNR variations with image size, high-resolution vidicon-based readout system for photon-counting streak camera applications, advancement in microchannel-plate technology, and fractal multifiber microchannel plates.

  14. Electron tubes and image intensifiers; Proceedings of the Meeting, San Jose, CA, Feb. 10, 11, 1992

    Johnson, C. B.; Laprade, Bruce N.

    Various papers on electron tubes and image intensifiers are presented. Individual topics addressed include: high-performance LLTV CCD camera for nighttime pilotage, characterization and modelling of microchannel-plate intensified-CCD SNR variations with image size, high-resolution vidicon-based readout system for photon-counting streak camera applications, advancement in microchannel-plate technology, and fractal multifiber microchannel plates.

  15. Perfecting the Photometric Calibration of the ACS CCD Cameras

    Bohlin, Ralph C

    2016-01-01

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

  16. CCD UBV photometry of the open cluster NGC 6819

    Ak, T; Yontan, T; Bilir, S; Guver, T; Ak, S; Urgup, H; Paunzen, E

    2016-01-01

    We present the results of CCD UBV observations of the open cluster NGC 6819. We calculated the stellar density profile in the cluster's field to determine the structural parameters of NGC 6819. Using the existing astrometric data, we calculated the probabilities of the stars being physical members of the cluster, and used these objects in the determination of the astrophysical parameters of NGC 6819. We inferred the reddening and metallicity of the cluster as $E(B-V)=0.130\\pm0.035$ mag and $[Fe/H]=+0.051\\pm 0.020$ dex, respectively, using the U-B vs B-V two-colour diagram and UV excesses of the F-G type main-sequence stars. We fit the colour-magnitude diagrams of NGC6819 with the PARSEC isochrones and derived the distance modula, distance and age of the cluster as $\\mu_{V}=12.22\\pm 0.10$ mag, $d=2309\\pm106$ pc and $t=2.4\\pm0.2$ Gyr, respectively. The parameters of the galactic orbit estimated for NGC 6819 indicate that the cluster is orbiting in a slightly eccentric orbit of $e=0.06$ with a period of $P_{orb}...

  17. Background Studies for the pn-CCD Detector of CAST

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into photons with energies up to around 10 keV via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in conjunction with an X-ray mirror optics is one of the three detectors used in CAST to register the expected photon signal. Since this signal is very rare a detailed study of the detector background has been undertaken with the aim to understand and further reduce the background level of the detector. The analysis is based on measured data taken during the data taking period of 2003 and 2004 of CAST and on Monte Carlo simulations of background with different origin. The background study performed for this detector show that the level of background (8.00±0.07)x10-5 counts cm-2 s-1 keV-1 between 1 and 7 keV is dominated by the external gamma background due to natural activities at the experimental site, while radioactive impurities in the detector itself and cosmic neutrons contribute with a smaller fraction

  18. The carotenoid cleavage dioxygenase CCD2 catalysing the synthesis of crocetin in spring crocuses and saffron is a plastidial enzyme.

    Ahrazem, Oussama; Rubio-Moraga, Angela; Berman, Judit; Capell, Teresa; Christou, Paul; Zhu, Changfu; Gómez-Gómez, Lourdes

    2016-01-01

    The apocarotenoid crocetin and its glycosylated derivatives, crocins, confer the red colour to saffron. Crocetin biosynthesis in saffron is catalysed by the carotenoid cleavage dioxygenase CCD2 (AIG94929). No homologues have been identified in other plant species due to the very limited presence of crocetin and its derivatives in the plant kingdom. Spring Crocus species with yellow flowers accumulate crocins in the stigma and tepals. Four carotenoid CCDs, namely CaCCD1, CaCCD2 and CaCCD4a/b and CaCCD4c were first cloned and characterized. CaCCD2 was localized in plastids, and a longer CCD2 version, CsCCD2L, was also localized in this compartment. The activity of CaCCD2 was assessed in Escherichia coli and in a stable rice gene function characterization system, demonstrating the production of crocetin in both systems. The expression of all isolated CCDs was evaluated in stigma and tepals at three key developmental stages in relation with apocarotenoid accumulation. CaCCD2 expression parallels crocin accumulation, but C14 apocarotenoids most likely are associated to the CaCCD1 activity in Crocus ancyrensis flowers. The specific CCD2 localization and its membrane interaction will contribute to the development of a better understanding of the mechanism of crocetin biosynthesis and regulation in the chromoplast. PMID:26377696

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

    Afanasieva, I V

    2015-01-01

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

  20. The in-flight spectroscopic performance of the Swift XRT CCD camera during 2006-2007

    Godet, O.; Beardmore, A. P.; Abbey, A. F.; Osborne, J. P.; Page, K. L.; Tyler, L.; Burrows, D. N.; Evans, P.; Starling, R.; Wells, A. A.; Angelini, L; S. Campana; Chincarini, G.; Citterio, O.; Cusumano, G.

    2007-01-01

    The Swift X-ray Telescope focal plane camera is a front-illuminated MOS CCD, providing a spectral response kernel of 135 eV FWHM at 5.9 keV as measured before launch. We describe the CCD calibration program based on celestial and on-board calibration sources, relevant in-flight experiences, and developments in the CCD response model. We illustrate how the revised response model describes the calibration sources well. Comparison of observed spectra with models folded through the instrument res...

  1. The in-flight spectroscopic calibration of the Swift XRT CCD camera

    The Swift X-ray Telescope (XRT) focal plane camera houses a front-illuminated MOS CCD, providing a spectral response of 145 eV FWHM at 5.9 keV. We describe the status of the CCD X-ray spectral redistribution matrices, which are made using a Monte-Carlo simulation technique based on physical models of the CCD response. We emphasize how the model has been refined following in-flight experience with celestial and on-board calibration sources. Residuals less than 10% are typically observed for astrophysical sources

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

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

    2016-01-01

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

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

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

    2006-01-01

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

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

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

    2014-01-01

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

  5. CCD Photometry of the Globular Cluster NGC 4833 and Extinction Near the Galactic Plane

    Melbourne, J; Layden, A; Martins, D H; Melbourne, Jason; Sarajedini, Ata; Layden, Andrew; Martins, Donald H.

    2000-01-01

    We present CCD photometry for the Galactic globular cluster NGC 4833. Our BVI color magnitude diagrams (CMD) extend from above the red giant branch (RGB) tip to several magnitudes below the main sequence turnoff. The principal sequences of the cluster show the effects of differential reddening. We have created a local extinction map, consistent with IRAS and COBE/DIRBE dust maps of the region. We use our map to correct the colors and magnitudes of each star to the value at the cluster center. The cluster horizontal branch (HB) is predominately blueward of the instability strip with 13 confirmed RR Lyrae variables and 5 additional RR Lyrae candidates. Using the 11 confirmed RR Lyraes measured on our images, and the differential reddening corrected photometry we calculate V(HB) = 15.56 +/- 0.063. We have used the simultaneous reddening and metallicity method of Sarajedini (1994) to find the mean reddening of the cluster E(B-V) = 0.32 +/- 0.03, and the mean metallicity [Fe/H] = -1.83 +/- 0.14. As for the age of ...

  6. Design and test of a high resolution plastic scintillating fiber detector with intensified CCD readout

    We present the design of a particle detector involving a coherent array of 100 000 plastic scintillating microfibers, with an individual core diameter around 50 micrometers, and an intensified bidimensional CCD array. We investigate both theoretically and experimentally the use of polystyrene based scintillators in optical multimodal fibers. The isotropic excitation of modes and the characteristics of energy transfers between the polystyrene matrix and the added fluorescent dyes are of particular interest. An experimental approach is proposed and applied to the development of a new binary scintillator. In order to study the transmission of the signal from the interaction area to the output face, we specify the loss factors, the resolution and the signal to noise ratio within the fiber array. The low light level at the output face of the detector leads us to use image intensifiers in photon counting mode. This requires a detailed analysis of resolutions, gain, noise and detectivity concepts. We propose to describe these strongly correlated notions by the moment generation formalism. Thus, a previous modelisation of the photoelectronic devices allows us to evaluate the performance of the readout chain. A complete detector has been assembled and tested on a high energy hadron beam; the measurements are in good agreement with the modelisation

  7. ASTROS - A sub-arcsec CCD star tracker

    Stanton, R. H.; Alexander, J. W.; Dennison, E. W.; Glavich, T. A.; Salomon, P. M.

    1984-01-01

    The design and application of ASTROS (Advanced Star and Target Reference Optical Sensor) are described, with emphasis on performance test results acquired with a prototype system. The ASTROS tracker provides extremely precise measurements of star image coordinates as inputs to the Image Motion Compensation (IMC) system used to stabilize the science instrument focal planes. Performance levels achieved are dramatic improvements over the levels achieved with image dissector designs with comparable fields of view.

  8. Infrared upconversion hyperspectral imaging

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

    2015-01-01

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

  9. VizieR Online Data Catalog: NGC 6811 CCD UBVRI photometry (Yontan+, 2015)

    Yontan, T.; Bilir, S.; Bostanc, Z. F.; Ak, T.; Karaali, S.; Guver, T.; Ak, S.; Duran, S.; Paunzen, E.

    2015-09-01

    CCD UBVRI observations of NGC 6811 were carried out on 18th July 2012 using the 1m Ritchey-Chretien telescope (T100) located at the TUBITAK National Observatory (TUG) in Bakirlitepe, Antalya/Turkey. (1 data file).

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

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

  11. JAstroCam - A New Tool for Data Gathering with CCD

    Budyn, M.; Zola, S.; Wojcik, K.

    2010-12-01

    We present a new acquisition program for observations with CCD. The code is written in the JAVA language, currently supports Photometrics S300, SBIG, APOGEE and Andor CCDs. New hardware support can be extended by adding plugins for either a new type of CCD or a filter wheel. The software is capable of performing an on-line reduction of frames coming in real time either on non-processed or reduced for bias/dark/flat frames.

  12. Improved astrometry of space debris with image restoration

    In order to implement an observing strategy, image degradation that occurs during optical observation of space debris is ineluctable and has distinct characteristics. Image restoration is presented as a way to remove the influence of degradation in CCD images of space debris, based on assumed PSF models with the same FWHM as images of the object. In the process of image restoration, the maximum entropy method is adopted. The results of reduction using observed raw CCD images indicate that the precision in estimating positions of objects is improved and the effects of degradation are reduced. Improving the astrometry of space debris using image restoration is effective and feasible. (research papers)

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

    Camila Aparecida Cotrim

    2010-01-01

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

  14. Electron-bombarded CCD detectors for ultraviolet atmospheric remote sensing

    Carruthers, G. R.; Opal, C. B.

    1983-01-01

    Electronic image sensors based on charge coupled devices operated in electron-bombarded mode, yielding real-time, remote-readout, photon-limited UV imaging capability are being developed. The sensors also incorporate fast-focal-ratio Schmidt optics and opaque photocathodes, giving nearly the ultimate possible diffuse-source sensitivity. They can be used for direct imagery of atmospheric emission phenomena, and for imaging spectrography with moderate spatial and spectral resolution. The current state of instrument development, laboratory results, planned future developments and proposed applications of the sensors in space flight instrumentation is described.

  15. Influence of scattered light on accurate CCD flat fielding --- necessity of modifying baffles of some existent reflectors

    Yao, B. A.; Zhang, C. S.; Sheng, C. J.; Peng, Y. L.

    2005-07-01

    This paper is the continuation of paper [1]. In this paper we further show that the difference between twilight flat field and night sky exposure is mainly due to the existence of scattered light. Like Grundahl and Sorensen, we also made the pinhole images of the 1.56m at the Shanghai Observatory and the 63cm of the Nanjing University to show the existence of scattered light intuitively. Both the 1.56m and the 63cm reflectors have normal designed baffles. Therefore it is the common weakness of all standard designed reflectors having only two baffles mounted in front of the primary and secondary mirrors which are not enough to protect the CCD cameras from scattered light in getting accurate flat fields. It is of great importance to modify the primary mirror baffle of all similar reflectors in order to get more accurate flat fielding.

  16. Computerized measurement of mammographic display image quality

    Chakraborty, Dev P.; Sivarudrappa, Mahesh; Roehrig, Hans

    1999-05-01

    Since the video monitor is widely believed to be the weak link in the imaging chain, it is critical, to include it in the total image quality evaluation. Yet, most physical measurements of mammographic image quality are presently limited to making measurements on the digital matrix, not the displayed image. A method is described to quantitatively measure image quality of mammographic monitors using ACR phantom-based test patterns. The image of the test pattern is digitized using a charge coupled device (CCD) camera, and the resulting image file is analyzed by an existing phantom analysis method (Computer Analysis of Mammography Phantom Images, CAMPI). The new method is called CCD-CAMPI and it yields the Signal-to-Noise-Ratio (SNR) for an arbitrary target shape (e.g., speck, mass or fiber). In this work we show the feasibility of this idea for speck targets. Also performed were physical image quality characterization of the monitor (so-called Fourier measures) and analysis by another template matching method due to Tapiovaara and Wagner (TW) which is closely related to CAMPI. The methods were applied to a MegaScan monitor. Test patterns containing a complete speck group superposed on a noiseless background were displayed on the monitor and a series of CCD images were acquired. These images were subjected to CCD-CAMPI and TW analyses. It was found that the SNR values for the CCD-CAMPI method tracked those of the TW method, although the latter measurements were considerably less precise. The TW SNR measure was also about 25% larger than the CCD-CAMPI determination. These differences could be understood from the manner in which the two methods evaluate the noise. Overall accuracy of the CAMPI SNR determination was 4.1% for single images when expressed as a coefficient of variance. While the SNR measures are predictable from the Fourier measures the number of images and effort required is prohibitive and it is not suited to Quality Control (QC). Unlike the Fourier

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

    Chiu, I-Non; Liu, Jiayi

    2016-01-01

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

  18. Maximum-likelihood scintillation detection for EM-CCD based gamma cameras

    Gamma cameras based on charge-coupled devices (CCDs) coupled to continuous scintillation crystals can combine a good detection efficiency with high spatial resolutions with the aid of advanced scintillation detection algorithms. A previously developed analytical multi-scale algorithm (MSA) models the depth-dependent light distribution but does not take statistics into account. Here we present and validate a novel statistical maximum-likelihood algorithm (MLA) that combines a realistic light distribution model with an experimentally validated statistical model. The MLA was tested for an electron multiplying CCD optically coupled to CsI(Tl) scintillators of different thicknesses. For 99mTc imaging, the spatial resolution (for perpendicular and oblique incidence), energy resolution and signal-to-background counts ratio (SBR) obtained with the MLA were compared with those of the MSA. Compared to the MSA, the MLA improves the energy resolution by more than a factor of 1.6 and the SBR is enhanced by more than a factor of 1.3. For oblique incidence (approximately 450), the depth-of-interaction corrected spatial resolution is improved by a factor of at least 1.1, while for perpendicular incidence the MLA resolution does not consistently differ significantly from the MSA result for all tested scintillator thicknesses. For the thickest scintillator (3 mm, interaction probability 66% at 141 keV) a spatial resolution (perpendicular incidence) of 147 μm full width at half maximum (FWHM) was obtained with an energy resolution of 35.2% FWHM. These results of the MLA were achieved without prior calibration of scintillations as is needed for many statistical scintillation detection algorithms. We conclude that the MLA significantly improves the gamma camera performance compared to the MSA.

  19. Development of a large format charge-coupled device (CCD) for applications in X-ray astronomy

    We report on the development of a charge-coupled device (CCD) for astronomical X-ray detection. Characteristics, performance and use of various CCD chips are described. Sizes range from a front-illuminated 2.5cmx2.5cm square chip for the MAXI mission with a depletion layer thickness of 70μm to a back-illuminated 3cmx6cm rectangular p-channel CCD with 200μm depletion thickness which exhibits improved quantum efficiency at low energy (below 0.5 keV). Combining the CCD with a scintillator deposit (SD-CCD) expands the effective energy range up to 100 keV. We describe the use of the SD-CCD in a balloon experiment

  20. FPGA-based flexible CCD control system for X-ray astronomy payloads

    We have developed a Field Programmable Gate Array (FPGA)-based Charge Coupled Device (CCD) data acquisition system, which will be used in the focal plane of Soft X-ray Telescope (SXT) on India's first multi-wavelength astronomy satellite-ASTROSAT. The use of FPGA allows a flexible system that can be used for driving almost all types of CCDs with very little modifications. It can generate clocks up to 1 MHz with adjustable phase. CCD biases and clock amplitudes can be generated and uploaded very easily. Electronic noise is reduced by reading the CCD when FPGA is at its minimum activity. CCD22, a MOS CCD developed in Europe, was biased and clocked by using this system. Each pixel is read at 6 μs intervals. The energy resolution of 55Fe at Kα peak has a full-width at half-maximum of ∼153 eV and the readout noise of our system is ∼8e- rms.

  1. The invention and early history of the CCD

    As the first practical solid-state imaging device, the invention of the Charge Coupled Device has profoundly affected image sensing technology. They are used in a wide range of applications as both area and linear imaging devices starting with the replacement of imaging tubes used in commercial TV cameras and camcorders. The rapid increase of their use in digital cameras has initiated the demise of film photography and created vast new markets with great economic benefit for many. Other uses include a wide variety of scientific, surveillance and scanning applications. The inception of the device at Bell Labs by Willard S. Boyle and George E. Smith in 1969 was strongly influenced by several unique factors existing both within Bell Labs and the current world state of technology. These factors and their relevance will be discussed along with the train of thought leading to the invention. Early experimental devices and their initial applications were vigorously pursued and will be described. Current applications will be mentioned.

  2. Panoramska radiologija s pomoću CCD: čimbenici izobličenja slike uz konture njenog odabranog sloja

    Farman, T. T.; Farman, A.G.; Kelly, M S.; Firriolo, F.J.; Yanacey, J.M; Stewart, A.V.

    1998-01-01

    Svrha: Svrha ove studije bila je odrediti svojstva čimbenika izobličenja kontura razlučivanja odabranog sloja slike ortopantomografa OP 100®Instrumentarium Imaging, Tuusula, Finland) kombiniranog sa senzorom vrste CCD (charge-coupled device) tipa (Trophy Radiologie, Vincennes, France). Materijal i metode: Upotrebom mreže kojom se određuje razlučivanje postavljene u razmacima uzduž iskustveno ustanovljenih putanja projekcijskog snopa, konture sloja slike proizvodene ortopantomografom OP 100® m...

  3. Beam profile analysis using the CCD camera with cameralink in the SPring-8 booster ring and beam transport line

    We had measured a beam position and beam size by the analog video camera system with the fluorescence plate in the SPring-8 booster ring and beam transport line. It was difficult to estimate the seasonal change of the beam position and size quantitatively. We started building up the digital beam profile acquisition system which used a digital CCD camera with the external trigger synchronous capturing function in 2007. In the accelerator parameter tuning between operation cycles, it is necessary to understand the change of a beam orbit and shape from latest cycle quickly in limited tuning time. Thus, we need both information of real-time picture images for visual confirmation and computing real-time analysis results of beam position and size. In this case, the LED light for reading the scale on the fluorescence plate becomes a background noise for a calculation of the beam profile analysis. We improved the analysis program of beam position and size in order to separates the LED light and beam light from a captured image. By this improvement, the reproducibility and adjustment accuracy of orbital steering have been improved. We will report the program flow and the details from an image capture to a beam profile analysis. (author)

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

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

    2012-12-01

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

  5. Ion-molecule calculation of the abundance ratio of CCD to CCH in dense interstellar clouds

    Laboratory measurements and calculations have been performed to determine the abundance ratio of the deuterated ethynyl radical (CCD) to the normal radical (CCH) which can be achieved in dense interstellar clouds via isotopic fractionation in the C2H2(+) (HD)=C2HD(+)(H2) system of reactions. According to this limited treatment, the CCD/CCH abundance ratio which can be attained is in the range 0.02-0.03 for the Orion molecular cloud and 0.0l-0.02 for TMC-1. These ranges of numbers are in reasonable agreement with the observed values in Orion and TMC-1. However, the analysis of the CCD/CCH abundance ratio is complicated via the presence of competing fractionation mechanisms, especially in the low-temperature source TMC-1. 28 references

  6. A fast CCD vertex detector for the future linear collider: some recent developments

    Gillman, A R

    2001-01-01

    Experiments at a future e sup + e sup - linear collider will require a high-performance vertex detector to identify heavy quarks in multi-jet final states. The SLD experiment at SLAC has successfully demonstrated that charge-coupled devices (CCDs) are ideal candidates for this role, offering excellent two-dimensional spatial resolution with extremely low mass.This paper discusses recent R and D studies aimed at further reducing the vertex detector material budget and significantly increasing the CCD readout speed, in order to extend the physics reach of the future linear collider. A radical new CCD architecture is described, which would enable a CCD-based vertex detector to be used in the extremely challenging environment of the superconducting TESLA collider.

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

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

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

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

    2006-11-01

    Film dosimetry is commonly performed by using linear CCD array transmission optical densitometers. However, these devices suffer from a variation in response along the detector array. If not properly corrected for, this nonuniformity may lead to significant overestimations of the measured dose as one approaches regions close to the edges of the scanning region. In this note, we present measurements of the spatial response of an AGFA Arcus II document scanner used for radiochromic film dosimetry. Results and methods presented in this work can be generalized to other CCD based transmission scanners used for film dosimetry employing either radiochromic or radiographic films. PMID:17153378

  9. Design and implementation of high sensitive CCD on gallium arsenide based miniaturized spectrometer

    Zheng, Jiamin; Shen, Jianhua; Guo, Fangmin

    2013-08-01

    In this paper, a method on how to design and implement a miniaturized spectrometer with low-light-level (LLL) CCD on GaAs is introduced. The optical system uses a blazed grating as the dispersive element and a 1×64 CCD on GaAs as the sensor. We apply a highly integrated Cortex-M4 MCU (STM32F407), to build the data acquisition and analysis unit, providing Wi-Fi interface to communicate with the PC software. It can complete the tasks like data acquisition, digital filtering, spectral display, network communication, human-computer interaction etc.

  10. Influences of CCD nonlinear response on measurement of propagation factor M2 of a laser beam

    In this paper, we analyze the influence of the nonlinear optoelectronic response on the measurement of the beam propagation factor M2 at different laser wavelengths. According to our theoretical investigation, the size of a laser beam with a standard Gaussian distribution will be estimated as larger than the real value when the response of a commercial non-calibrated CCD camera has a nonlinear relation to the recorded signal intensity. It has been demonstrated that the measurement accuracy in M2 becomes considerably worse by using such a CCD camera. The conclusion is thought to be useful for evaluation of the laser features in both research activities and industrial applications

  11. Characterization and performance of hyper Suprime-Cam CCD

    Kamata, Yukiko; Miyazaki, Satoshi; Nakaya, Hidehiko; Suzuki, Hisanori; Miyazaki, Yasuhito; Muramatsu, Masaharu

    2010-07-01

    Hyper Suprime-Cam (HSC) is a second-generation wide field imaging camera for Subaru telescope with 10 times wider field of view (FOV) compared with Suprime-Cam (SC) currently being used. HSC makes the survey speed considerably faster than SC, while maintaining the high image quality of SC. The 1.5 degrees in diameter FOV is covered with 116 of 2K × 4K fully depleted back-illuminated CCDs with 15 μm pixels developed by HAMAMATSU Photonics K. K. and National Astronomical Observatory of Japan (NAOJ). The CCDs for HSC are designed to have higher quantum efficiency than those for SC in a wider range in the visible wavelengths, especially in the blue region. We at NAOJ have started acceptance inspection of the CCDs being delivered from HAMAMATSU. We used the X-ray source of 55Fe and the LED to measure charge transfer efficiency, readout noise, linearity, and full-well capacity of 33 CCDs. In addition, we measured the quantum efficiency of 7 CCDs. We confirmed all the CCDs have good performances and quality. In this paper, we report the results from the acceptance inspection and characterization of these CCDs.

  12. Perceptual evaluation of different image fusion schemes

    Toet, A.; IJspeert, J.K.

    2001-01-01

    Human perceptual performance was tested with images of nighttime outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3-5 μm) infrared (IR) camera. Fused imagery was produce

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

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

    2010-01-01

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

  14. Research on Double CCD Dimensional Metrology Applying in Large Forge Piece

    Hu, C H; Xiong, Z [College of Electrical Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2006-10-15

    As development of computer vision, stereoscopic vision sensors have been used more and more widely, and double CCD vision sensor with its simplicity of operator, highaccuracy and high-efficiency has been used in many spheres. It can be used in dimensional metrology of large forge piece, which greatly improves the efficiency and accuracy of large forge piece measurement.

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

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

    2009-01-01

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

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

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

    1989-01-01

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

  17. Lensless CCD-based fluorometer using a micromachined optical Soller collimator

    Balsam, Joshua; Ossandon, Miguel; Kostov, Yordan; Bruck, Hugh Alan; Rasooly, Avraham

    2011-01-01

    In this paper, we describe a simple charge-coupled device (CCD) based lensless fluorometer with sensitivity in the range of current ELISA plate readers. In our lensfree fluorometer, a multi-wavelength LED light source was used for fluorophore excitation. To collimate the light, we developed a simple

  18. Opinion rating of comparison photographs of television pictures from CCD cameras under irradiation

    As part of the development of a general method of testing the effects of gamma radiation on CCD television cameras, this is a report of an experimental study on the optimisation of still photographic representation of video pictures recorded before and during camera irradiation. (author)

  19. Research on Double CCD Dimensional Metrology Applying in Large Forge Piece

    As development of computer vision, stereoscopic vision sensors have been used more and more widely, and double CCD vision sensor with its simplicity of operator, highaccuracy and high-efficiency has been used in many spheres. It can be used in dimensional metrology of large forge piece, which greatly improves the efficiency and accuracy of large forge piece measurement

  20. Development of Multiple-Element Flame Emission Spectrometer Using CCD Detection

    Seney, Caryn S.; Sinclair, Karen V.; Bright, Robin M.; Momoh, Paul O.; Bozeman, Amelia D.

    2005-01-01

    The full wavelength coverage of charge coupled device (CCD) detector when coupled with an echelle spectrography, the system allows for simultaneously multiple element spectroscopy to be performed. The multiple-element flame spectrometer was built and characterized through the analysis of environmentally significant elements such as Ca, K, Na, Cu,…

  1. Acceleration through a Holistic Support Model: An Implementation and Outcomes Analysis of FastStart@CCD

    Edgecombe, Nikki; Jaggars, Shanna Smith; Baker, Elaine DeLott; Bailey, Thomas

    2013-01-01

    Originally designed for students who test into at least two levels of developmental education in a particular subject area, FastStart is a compressed course program model launched in 2005 at the Community College of Denver (CCD). The program combines multiple semester-length courses into a single intensive semester, while providing case…

  2. Absolute spectral calibration of an intensified CCD camera using twin beams

    Haderka, O.; Peřina Jr., J.; Michálek, Václav; Hamar, Martin

    2014-01-01

    Roč. 31, č. 10 (2014), B1-B7. ISSN 0740-3224 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : spectral calibration * intensified CCD camera * twin beams * photon pairs Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.970, year: 2014

  3. White-light fringe detection based on novel light-source and colour CCD camera

    Buchta, Zdeněk; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej

    Brno : CMI, 2010. M05. [NanoScale 2010 - 9th Seminar on Quantitative Microscopy (QM) and 5th Seminar on Nanoscale Calibration Standards and Methods. 27.10.2010-29.10.2010, Brno] Institutional research plan: CEZ:AV0Z20650511 Keywords : low-coherence interferometry * fringe analysis * CCD camera Subject RIV: BH - Optics, Masers, Lasers

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

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

    2010-01-01

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

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

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

    2015-01-11

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

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

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

    2013-01-01

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

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

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

    2013-01-01

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

  8. WIYN OPEN CLUSTER STUDY LII: WIDE-FIELD CCD PHOTOMETRY OF THE OLD OPEN CLUSTER NGC 6819

    We present a comprehensive photometric study of the old open cluster, NGC 6819, using 1° × 1° field VI MOSAIC CCD imaging taken with the WIYN 0.9 m telescope. The resultant color-magnitude diagram (CMD) shows a well-developed main sequence (MS) extending from V ∼ 14.5 mag down to our photometric limit of V ∼ 21 mag. Fitting theoretical isochrones with the adopted values of the reddening and metallicity (E(B – V) = 0.14, [Fe/H] = +0.09 dex) to the observed CMD yields a distance modulus of (m – M)0 = 11.93 ± 0.10 and an age of ∼2.6 Gyr for NGC 6819. Our wide-field imaging reveals that NGC 6819 is larger in areal extent (R = 13') than previously thought. The wide field also benefits our estimate of the degree of field star contamination, and ultimately yields improved measurements of the structural parameters (rc = 2.'80, rt = 38.'2, and rh = 7') and tidal mass of the cluster (M tid = 3542.4 M ☉). The flattened luminosity and mass functions indicate that NGC 6819 has experienced mass segregation as a result of its dynamical evolution. Our variability study of the cluster blue straggler star (BSS) population using the Welch-Stetson variability index (I WS) has revealed a number of variable BSS candidates.

  9. Modelling and testing the x-ray performance of CCD and CMOS APS detectors using numerical finite element simulations

    Weatherill, Daniel P.; Stefanov, Konstantin D.; Greig, Thomas A.; Holland, Andrew D.

    2014-07-01

    Pixellated monolithic silicon detectors operated in a photon-counting regime are useful in spectroscopic imaging applications. Since a high energy incident photon may produce many excess free carriers upon absorption, both energy and spatial information can be recovered by resolving each interaction event. The performance of these devices in terms of both the energy and spatial resolution is in large part determined by the amount of diffusion which occurs during the collection of the charge cloud by the pixels. Past efforts to predict the X-ray performance of imaging sensors have used either analytical solutions to the diffusion equation or simplified monte carlo electron transport models. These methods are computationally attractive and highly useful but may be complemented using more physically detailed models based on TCAD simulations of the devices. Here we present initial results from a model which employs a full transient numerical solution of the classical semiconductor equations to model charge collection in device pixels under stimulation from initially Gaussian photogenerated charge clouds, using commercial TCAD software. Realistic device geometries and doping are included. By mapping the pixel response to different initial interaction positions and charge cloud sizes, the charge splitting behaviour of the model sensor under various illuminations and operating conditions is investigated. Experimental validation of the model is presented from an e2v CCD30-11 device under varying substrate bias, illuminated using an Fe-55 source.

  10. Compact MEMS/NEMS characterization platform using a DVD optical pick-up unit with optical imaging function

    Liao, Hsien-Shun; Hwang, Ing-Shouh; Chen, Ching-Hsiu;

    2013-01-01

    In this work, we present a compact, simple and efficient platform for Micro-electromechanical systems (MEMS)/Nano-electromechanical systems (NEMS) characterization. In this platform, a CCD camera is combined with a DVD optical pick-up unit (OPU). The CCD camera captures optical image of MEMS/NEMS...... of MEMS/NEMS cantilevers and strings are characterized....

  11. HJ-1-A/B optical satellite image geometric correction

    Small satellite constellation of environment and disaster's monitoring and predicting (shorted for HJ-1) is not a mapping satellite, and its parameters of attitude and orbit cannot satisfy the requirement of geometric correction using strict imaging model. On the other hand, due to the 12000 CCD detectors and large overlay of multispectral payload named CCD carried by HJ-1 satellite, the error caused by CCD distortion cannot be ignored. Aiming at these problems of HJ-1, this paper proposes a strict orbit model algorithm based on Ground Control Point (GCP) and collinear condition equations. Through the robust estimation of parameters, this algorithm can effectively set up imaging geometric model of CCD, and satisfy the requirement of high precision geometric correction

  12. Robust laser sources for ultrafast imaging systems

    Wei, Xiaoming; 韦小明

    2015-01-01

    Optical imaging has not unleashed its full potential for a better temporal resolution, which is in great demand for the studies of high-speed dynamical phenomena. Traditional imagers incorporated with CCD/CMOS electronic sensors are fundamentally limited by their on-chip storage and readout speed. Time-stretch imaging, on the other hand, has been proved to be a promising imaging modality for high throughput screening and transient dynamics observation. However, it has suffered greatly from th...

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

    de Sena, Rodrigo Caciano; Soares, Matheus; Pereira, Maria Luiza Oliveira; da Silva, Rogério Cruz Domingues; do Rosário, Francisca Ferreira; da Silva, Joao Francisco Cajaiba

    2011-01-01

    The development of a simple, rapid and low cost method based on video image analysis and aimed at the detection of low concentrations of precipitated barium sulfate is described. The proposed system is basically composed of a webcam with a CCD sensor and a conventional dichroic lamp. For this purpose, software for processing and analyzing the digital images based on the RGB (Red, Green and Blue) color system was developed. The proposed method had shown very good repeatability and linearity and also presented higher sensitivity than the standard turbidimetric method. The developed method is presented as a simple alternative for future applications in the study of precipitations of inorganic salts and also for detecting the crystallization of organic compounds. PMID:22346607

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

    Joao Francisco Cajaiba da Silva

    2011-01-01

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

  15. Superimposing of virtual graphics and real image based on 3D CAD information

    2000-01-01

    Proposes methods of transforming 3D CAD models into 2D graphics and recognizing 3D objects by features and superimposing VE built in computer onto real image taken by a CCD camera, and presents computer simulation results.

  16. Imagers for digital still photography

    Bosiers, Jan; Dillen, Bart; Draijer, Cees; Manoury, Erik-Jan; Meessen, Louis; Peters, Inge

    2006-04-01

    This paper gives an overview of the requirements for, and current state-of-the-art of, CCD and CMOS imagers for use in digital still photography. Four market segments will be reviewed: mobile imaging, consumer "point-and-shoot cameras", consumer digital SLR cameras and high-end professional camera systems. The paper will also present some challenges and innovations with respect to packaging, testing, and system integration.

  17. Development of a 300,000-pixel ultrahigh-speed high-sensitivity CCD

    Ohtake, H.; Hayashida, T.; Kitamura, K.; Arai, T.; Yonai, J.; Tanioka, K.; Maruyama, H.; Etoh, T. Goji; Poggemann, D.; Ruckelshausen, A.; van Kuijk, H.; Bosiers, Jan T.

    2006-02-01

    We are developing an ultrahigh-speed, high-sensitivity broadcast camera that is capable of capturing clear, smooth slow-motion videos even where lighting is limited, such as at professional baseball games played at night. In earlier work, we developed an ultrahigh-speed broadcast color camera1) using three 80,000-pixel ultrahigh-speed, highsensitivity CCDs2). This camera had about ten times the sensitivity of standard high-speed cameras, and enabled an entirely new style of presentation for sports broadcasts and science programs. Most notably, increasing the pixel count is crucially important for applying ultrahigh-speed, high-sensitivity CCDs to HDTV broadcasting. This paper provides a summary of our experimental development aimed at improving the resolution of CCD even further: a new ultrahigh-speed high-sensitivity CCD that increases the pixel count four-fold to 300,000 pixels.

  18. CCD Photometry of NGC 2482 and Five Previously Unobserved Open Star Clusters

    Krisciunas, Kevin; Dias, Wilton

    2014-01-01

    We present BV and u'g'r'i' CCD photometry of the central region of NGC 2482. We also present BVu'g' CCD photometry of five clusters that have been poorly studied in the past: Ruprecht 42, Ruprecht 51, Ruprecht 153, Ruprecht 154; and AH03 J0748-26.9, which to our knowledge has not been studied before. Using a global optimization technique that eliminates much of the subjectivity previously inherent in main sequence fitting studies, we obtain values of the distances, ages, and metallicities of the clusters, with robust estimates of the uncertainties of these fundamental parameters. Four of our clusters are less than ~1.3 kpc beyond the Sun's distance from the Galactic Center and have essentially solar metallicity. The metallicities of those clusters more distant from the Galactic Center are consistent with a 0.3 dex step to lower [Fe/H] found in other studies.

  19. VXD3: The SLD vertex detector upgrade based on a 307 Mpixel CCD system

    The SLD Collaboration is building a new CCD vertex detector (VXD3) comprising 96 3.2 Mpixel CCDs of 13 cm2 each for a total of 307 million pixels. This system is an upgrade of the Pioneering CCD vertex detector VXD2 which has operated in SLD since 1992. The CCDs of VXD3 are mounted on beryllium ladders in three cylinders, providing three space point measurements along each track of about 5 microns resolution in all three coordinates. The design and construction of VXD3 builds on three years of successful performance of VXD2. Significant improvements are achieved with VXD3 in impact parameters resolution (about a factor of two) and acceptance (∼20%) through optimized geometry and reduced material. New readout electronics have been developed for this system. This new vertex detector will be installed in late 1995 for the future runs of SLD

  20. Brayton Isotope Power System. Phase I. (Ground demonstration system) Configuration Control Document (CCD)

    The configuration control document (CCD) defines the BIPS-GDS configuration. The GDS configuration is similar to a conceptual flight system design, referred to as the BIPS-FS, which is discussed in App. I. The BIPS is being developed by ERDA as a 500 to 2000 W(e), 7-y life, space power system utilizing a closed Brayton cycle gas turbine engine to convert thermal energy (from an isotope heat source) to electrical energy at a net efficiency exceeding 25 percent. The CCD relates to Phase I of an ERDA Program to qualify a dynamic system for launch in the early 1980's. Phase I is a 35-month effort to provide an FS conceptual design and GDS design, fabrication, and test. The baseline is a 7-year life, 450-pound, 4800 W(t), 1300 W(e) system which will use two multihundred watt (MHW) isotope heat sources being developed

  1. Brayton Isotope Power System. Phase I. (Ground demonstration system) Configuration Control Document (CCD)

    1976-03-15

    The configuration control document (CCD) defines the BIPS-GDS configuration. The GDS configuration is similar to a conceptual flight system design, referred to as the BIPS-FS, which is discussed in App. I. The BIPS is being developed by ERDA as a 500 to 2000 W(e), 7-y life, space power system utilizing a closed Brayton cycle gas turbine engine to convert thermal energy (from an isotope heat source) to electrical energy at a net efficiency exceeding 25 percent. The CCD relates to Phase I of an ERDA Program to qualify a dynamic system for launch in the early 1980's. Phase I is a 35-month effort to provide an FS conceptual design and GDS design, fabrication, and test. The baseline is a 7-year life, 450-pound, 4800 W(t), 1300 W(e) system which will use two multihundred watt (MHW) isotope heat sources being developed.

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

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

    2014-06-01

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

  3. Near-infrared Raman spectroscopy using a diode laser and CCD detector for tissue diagnostics

    This paper surveys the possibility to observe high-quality NIR Raman spectra of both fluorescent and non-fluorescent samples with the use of a diode laser, a fibre optic sample, a single spectrometer and a charge-coupled device (CCD) detector. A shifted excitation difference technique was implemented for removing the broad-band fluorescence emission from Raman spectra of the highly fluorescent samples. Raman spectra of 1.4-dioxane, toluene, rhodamine 6G, and HITCI in the 640 to 1840 cm-1 spectral region and 1.4-dioxane and toluene in the 400 to 3400 cm-1 spectral region have been recorded. The results open the field of sensitive tissue characterisation and the possibility of optical biopsy in vivo by using NIR Raman spectroscopy with fibre optic sampling, a single spectrometer, and a CCD detector

  4. EUV transmission of Optical Blocking Filter and Optical Blocking Layer for Soft X-ray Imager (SXI) onboard Astro-H

    渡辺, 辰雄; Watanabe, Tatsuo; 幸村, 孝由; Kohmura, Takayoshi; 北本, 俊二; Kitamoto, Shunji; 村上, 弘志; Murakami, Hiroshi; 竹中, 恵理; Takenaka, Eri; 長崎, 健太; Nagasaki, Kenta; 東, 慶一; Higashi, Keiichi; 吉田, 正樹

    2010-01-01

    We have developed the X-ray CCD camera system for the Soft X-ray Imager (SXI) which will be launched as focal plane detectors of X-ray telescope onboard the Japanese 6th X-ray astronomical satellite, Astro-H. The X-ray CCD is back-illuminated (BI) CCD which has an Optical Blocking Layer (OBL) directly coating its X-ray illumination surface with Aluminum-Polyimide-Aluminum instead of Optical Blocking Filter (OBF). The X-ray CCD is affected by large doses of extreme ultraviolet (EUV) radiation ...

  5. A method for distinguishing between static and dynamic X-ray exposure of a personal TL-badge using the CCD camera TL reader

    This paper reports initial attempts to apply a thermoluminescent (TL) reader with CCD camera to identify cases of static and dynamic exposure of personal dosemeters to doses relevant for radiation protection. Standard MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P) TL pellets with diameter of 4.5 mm and thickness of 0.9 mm were used in a standard DOSACUS/RADOS personal dosimetry badge (holder). Pb, Cu and Al filters were installed instead of the standard Al 264 mg cm-2 filters used in the RADOS badge. The badges were exposed statically and dynamically to X-rays ranging from 28 keV (molybdenum anode) to 125 keV (tungsten anode) and to 137Cs (662 keV) gamma rays. The absorbed doses (in tissue) ranged from 20 to 100 mSv. Detectors were readout in the CCD reader and 2-D images were collected. The results obtained indicated that it was possible to identify the static, front exposure of the personal dosemeters equipped with Cu filter for doses >20 mGy for X-rays up to 125 keV. (authors)

  6. Novel plasma torch diagnostic method based on multiple exposition CCD and correlation analysis

    Šonský, Jiří; Něnička, Václav

    2006-01-01

    Roč. 56, - (2006), B1371-B1376. ISSN 0011-4626. [Symposium on Plasma Physics and Technology /22./. Prague, 26.06.2006-29.06.2006] R&D Projects: GA ČR(CZ) GA202/04/1341 Institutional research plan: CEZ:AV0Z20570509 Keywords : plasma torch * CCD * correlation analysis Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

  7. CCD Measurements of Double and Multiple Stars at NAO Rozhen. IV

    Boeva, S.

    2010-06-01

    Full Text Available Using the 2 m telescope of the Bulgarian National Astronomical Observatory at Rozhen observations of 30 double or multiple stars were carried out during two half nights on July 20and 21, 2009. This is the fourth series of measurements of CCD frames of double and multiple stars obtained at Rozhen. In this paper we present the results for the position angle and separation for 23 double and 5 multiple stars (35 pairs which could have been measured.

  8. Discriminative Channel Selection Method for the Recognition of Anticipation related Potentials from CCD estimated Cortical Activity

    Garipelli, Gangadhar; Chavarriaga, Ricardo; Cincotti, Febo; Babiloni, Fabio; Millán, José Del R

    2009-01-01

    Recognition of brain states and subject's intention from electroencephalogram (EEG) is a challenging problem for brain-computer interaction. Signals recorded from each of EEG electrodes represent noisy spatio-temporal overlapping of activity arising from very diverse brain regions. However, un-mixing methods such as Cortical Current Density (CCD) can be used for estimating activity of different brain regions. These methods not only improve spatial resolution but also signal to noise ratio, h...

  9. The research on calibration methods of dual-CCD laser three-dimensional human face scanning system

    Wang, Jinjiang; Chang, Tianyu; Ge, Baozhen; Tian, Qingguo; Yang, Fengting; Shi, Shendong

    2013-09-01

    In this paper, on the basis of considering the performance advantages of two-step method, we combines the stereo matching of binocular stereo vision with active laser scanning to calibrate the system. Above all, we select a reference camera coordinate system as the world coordinate system and unity the coordinates of two CCD cameras. And then obtain the new perspective projection matrix (PPM) of each camera after the epipolar rectification. By those, the corresponding epipolar equation of two cameras can be defined. So by utilizing the trigonometric parallax method, we can measure the space point position after distortion correction and achieve stereo matching calibration between two image points. Experiments verify that this method can improve accuracy and system stability is guaranteed. The stereo matching calibration has a simple process with low-cost, and simplifies regular maintenance work. It can acquire 3D coordinates only by planar checkerboard calibration without the need of designing specific standard target or using electronic theodolite. It is found that during the experiment two-step calibration error and lens distortion lead to the stratification of point cloud data. The proposed calibration method which combining active line laser scanning and binocular stereo vision has the both advantages of them. It has more flexible applicability. Theory analysis and experiment shows the method is reasonable.

  10. The CFHT Open Star Cluster Survey II -- Deep CCD Photometry of the Old Open Star Cluster NGC 6819

    Singh-Kalirai, J; Fahlman, G G; Cuillandre, J C; Ventura, P; D'Antona, F; Bertin, E; Marconi, G; Durrell, P R; Kalirai, Jasonjot Singh; Richer, Harvey B.; Fahlman, Gregory G.; Cuillandre, Jean-Charles; Ventura, Paolo; Antona, Francesca D'; Bertin, Emmanuel; Marconi, Gianni; Durrell, Patrick R.

    2001-01-01

    We present analysis of deep CCD photometry for the very rich, old open star cluster NGC 6819. These CFH12K data results represent the first of nineteen open star clusters which were imaged as a part of the CFHT Open Star Cluster Survey. We find a tight, very rich, main-sequence and turn-off consisting of over 2900 cluster stars in the V, B-V color-magnitude diagram (CMD). Main-sequence fitting of the un-evolved cluster stars with the Hyades star cluster yields a distance modulus of (m-M)v = 12.30 +/- 0.12, for a reddening of E(B-V) = 0.10. These values are consistent with a newly calculated theoretical stellar isochrone of age 2.5 Gyrs, which we take to be the age of the cluster. Detailed star counts indicate a much larger cluster extent (R = 9.5' +/- 1.0'), by a factor of ~2 over some previous estimates. Incompleteness tests confirm a slightly negatively sloped luminosity function extending to faint (V ~ 23) magnitudes which is indicative of a dynamically evolved cluster. Further luminosity function and mass...

  11. Direct measurement of sub-pixel structure of the EPIC MOS CCD on-board the XMM/NEWTON satellite

    We have used a mesh experiment in order to measure the sub-pixel structure of the EPIC MOS CCDs on-board the XMM/NEWTON satellite. The EPIC MOS CCDs have 40 μm-square pixels which have an open electrode structure in order to improve the detection efficiency for low-energy X-rays. We obtained restored pixel images for various X-ray event grades (e.g. split-pixel events, single pixel events, etc.) at various X-ray energies. We confirmed that the open electrode structure results in a distorted horizontal pixel boundary. The open electrode region generates both single pixel events and vertically split events, but no horizontally split events. Because the single pixel events usually show the best energy resolution, we discuss a method of increasing the fraction of single pixel events from the open electrode region. Furthermore, we have directly measured the thickness of the electrodes and dead-layers by comparing spectra from the open electrode region with those from the other regions: electrodes, electrode finger and channel stop. We can say that EPIC MOS CCDs are more radiation hard than front-illumination chips of ACIS on-board Chandra X-ray Observatory because of their extra absorption thickness above the charge transfer channel. We calculated the mean pixel response and found that our estimation has a good agreement with that of the ground calibration of EPIC MOS CCD

  12. Compact and fully automated system for monitoring photodynamic therapy, based on two LEDs and a single CCD

    Kleshnin, M. S.; Fiks, I. I.; Plekhanov, V. I.; Gamayunov, S. V.; Turchin, I. V.

    2015-11-01

    Photodynamic therapy is one of the most promising methods for the treatment of oncological, inflammatory and degenerative diseases of the skin. This technique is based on light irradiation of a photosensitizer that has been injected into the patient’s body prior to the procedure, with determination of the efficacy of treatment requiring proper assessment of the drug concentration in the tissue lesion and the extent of sensitizer photobleaching during irradiation. We have developed a compact and low cost device based on a fluorescence imaging for localizing the tumor in the patient’s body, tracking the position of the tissue lesion during involuntary movements of the patient, estimating accumulation of the sensitizer in the tumor relative to the surrounding tissues and monitoring photobleaching of the sensitizer during laser irradiation. The system that has been created is compatible with any therapeutic laser and includes a single CCD camera and two LEDs, one in the excitation band and the other in the emission band of the ‘Photoditazin’ sensitizer. In this letter we also present the test results of the device in model experiments and in preliminary clinical trials. The results obtained clearly show the efficacy of the system for monitoring sensitizer photobleaching during photodynamic therapy.

  13. UB CCD PHOTOMETRY OF THE OLD, METAL-RICH, OPEN CLUSTERS NGC 6791, NGC 6819, AND NGC 7142

    Carraro, G. [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 19 (Chile); Buzzoni, A. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Bertone, E. [INAOE-Instituto Nacional de Astrofísica Optica y Electrónica, Calle L.E. Erro 1, 72840 Tonantzintla, Puebla (Mexico); Buson, L., E-mail: gcarraro@eso.org, E-mail: alberto.buzzoni@oabo.inaf.it, E-mail: ebertone@inaoep.mx, E-mail: lucio.buson@oapd.inaf.it [INAF-Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy)

    2013-11-01

    We report on a UV-oriented imaging survey in the fields of the old, metal-rich open clusters NGC 6791, NGC 6819, and NGC 7142. With their super-solar metallicity and ages ∼> 3-8 Gyr, these three clusters represent both very near and ideal stellar aggregates to match the distinctive properties of the evolved stellar populations, as in elliptical galaxies and bulges of spirals. Following a first discussion of NGC 6791 observations in an accompanying paper, here we complete our analysis, also presenting for NGC 6819 and NGC 7142 the first-ever U CCD photometry. The color-magnitude diagram of the three clusters is analyzed in detail, with special emphasis on the hot stellar component. We report, in this regard, one new extreme horizontal-branch star candidate in NGC 6791. For NGC 6819 and 7142, the stellar luminosity function clearly points to a looser radial distribution of faint lower main sequence stars, either as a consequence of cluster dynamical interaction with the Galaxy or as an effect of an increasing fraction of binary stars toward the cluster core, as also observed in NGC 6791. Compared to a reference theoretical model for the Galaxy disk, the analysis of the stellar field along the line of sight of each cluster indicates that a more centrally concentrated thick disk, on a scale length shorter than ∼2.8 kpc, might better reconcile the lower observed fraction of bright field stars and their white-dwarf progeny.

  14. Washington CCD Photometry of the Globular Cluster System of the Giant Elliptical Galaxy M60 in Virgo

    Lee, Myung Gyoon; Kim, Eunhyeuk; Hwang, Ho Seong; Kim, Sang Chul; Geisler, Doug

    2008-01-01

    We present a photometric study of the globular clusters in the giant elliptical galaxy M60 in the Virgo cluster, based on deep, relatively wide field Washington CT_1 CCD images. The color-magnitude diagram reveals a significant population of globular clusters in M60, and a large number of young luminous clusters in NGC 4647, a small companion spiral galaxy north-west of M60. The color distribution of the globular clusters in M60 is clearly bimodal, with a blue peak at (C-T_1)=1.37, and a red peak at (C-T_1)=1.87. We derive two new transformation relations between the (C-T_1)_0 color and [Fe/H] using the data for the globular clusters in our Galaxy and M49. Using these relations we derive the metallicity distribution of the globular clusters in M60, which is also bimodal: a dominant metal-poor component with center at [Fe/H]=-1.2, and a weaker metal-rich component with center at [Fe/H]=-0.2. The radial number density profile of the globular clusters is more extended than that of the stellar halo, and the radia...

  15. UB CCD PHOTOMETRY OF THE OLD, METAL-RICH, OPEN CLUSTERS NGC 6791, NGC 6819, AND NGC 7142

    We report on a UV-oriented imaging survey in the fields of the old, metal-rich open clusters NGC 6791, NGC 6819, and NGC 7142. With their super-solar metallicity and ages ∼> 3-8 Gyr, these three clusters represent both very near and ideal stellar aggregates to match the distinctive properties of the evolved stellar populations, as in elliptical galaxies and bulges of spirals. Following a first discussion of NGC 6791 observations in an accompanying paper, here we complete our analysis, also presenting for NGC 6819 and NGC 7142 the first-ever U CCD photometry. The color-magnitude diagram of the three clusters is analyzed in detail, with special emphasis on the hot stellar component. We report, in this regard, one new extreme horizontal-branch star candidate in NGC 6791. For NGC 6819 and 7142, the stellar luminosity function clearly points to a looser radial distribution of faint lower main sequence stars, either as a consequence of cluster dynamical interaction with the Galaxy or as an effect of an increasing fraction of binary stars toward the cluster core, as also observed in NGC 6791. Compared to a reference theoretical model for the Galaxy disk, the analysis of the stellar field along the line of sight of each cluster indicates that a more centrally concentrated thick disk, on a scale length shorter than ∼2.8 kpc, might better reconcile the lower observed fraction of bright field stars and their white-dwarf progeny

  16. A simple, low-cost, versatile CCD spectrometer for plasma spectroscopy

    The authors have constructed a simple, low-cost CCD spectrometer capable of both high resolution (Δλ ≤ 0.015 nm) and large bandpass (110 nm with Δλ ∼0.3 nm). These two modes of operation provide two broad areas of capability for plasma spectroscopy. The first major application is measurement of emission line broadening; the second is emission line surveys from the ultraviolet to the near infrared. Measurements have been made on a low-temperature plasma produced by a miniature electrostatic plasma source and the high-temperature plasma in the MST Reversed-Field Pinch. The spectrometer is a modified Jarrell-Ash 0.5 m Ebert-Fastie monochromator. Light is coupled into the entrance slit with a fused silica fiber optic bundle. The exposure time (2 ms minimum) is controlled by a fast electromechanical shutter. The exit plane detector is a compact and robust CCD detector developed for amateur astronomy by Santa Barbara Instrument Group. The CCD detector is controlled and read out by a Macintosh reg-sign computer. This spectrometer is sophisticated enough to serve well in a research laboratory, yet is simple and inexpensive enough to be affordable for instructional use

  17. The ARGOS wavefront sensor pnCCD camera for an ELT: characteristics, limitations and applications

    de Xivry, G. Orban; Ihle, S.; Ziegleder, J.; Barl, L.; Hartmann, R.; Rabien, S.; Soltau, H.; Strueder, L.

    2011-09-01

    From low-order to high-order AO, future wave front sensors on ELTs require large, fast, and low-noise detectors with high quantum efficiency and low dark current. While a detector for a high-order Shack-Hartmann WFS does not exist yet, the current CCD technology pushed to its limits already provides several solutions for the ELT AO detector requirements. One of these devices is the new WFS pnCCD camera of ARGOS, the Ground-Layer Adaptive Optics system (GLAO) for LUCIFER at LBT. Indeed, with its 264x264 pixels, 48 mu m pixel size and 1kHz frame rate, this camera provides a technological solution to different needs of the AO systems for ELTs, such as low-order but as well possibly higher order correction using pyramid wavefront sensing. In this contribution, we present the newly developped WFS pnCCD camera of ARGOS and how it fulfills future detector needs of AO on ELTs.

  18. Flat-Field Calibration of CCD Detector for Long Trace Profilers

    The next generation of synchrotrons and free electron lasers requires x-ray optical systems with extremely high-performance, generally, of diffraction limited quality. Fabrication and use of such optics requires highly accurate metrology. In the present paper, we discuss a way to improve the performance of the Long Trace Profiler (LTP), a slope measuring instrument widely used at synchrotron facilities to characterize x-ray optics at high-spatial-wavelengths from approximately 2 mm to 1 m. One of the major sources of LTP systematic error is the detector. For optimal functionality, the detector has to possess the smallest possible pixel size/spacing, a fast method of shuttering, and minimal non-uniformity of pixel-to-pixel photoresponse. While the first two requirements are determined by choice of detector, the non-uniformity of photoresponse of typical detectors such as CCD cameras is around 2-3 percent. We describe a flat-field calibration setup specially developed for calibration of CCD camera photo-response and dark current with an accuracy of better than 0.5 percent. Such accuracy is adequate for use of a camera as a detector for an LTP with performance of ∼0.1 microradian (rms). We also present the design details of the calibration system and results of calibration of a DALSA CCD camera used for upgrading our LTP-II instrument at the ALS Optical Metrology Laboratory

  19. Development of the analog ASIC for multi-channel readout X-ray CCD camera

    Nakajima, Hiroshi; Idehara, Toshihiro; Anabuki, Naohisa; Tsunemi, Hiroshi; Doty, John P; Ikeda, Hirokazu; Katayama, Haruyoshi; Kitamura, Hisashi; Uchihori, Yukio; 10.1016/j.nima.2010.12.174

    2011-01-01

    We report on the performance of an analog application-specific integrated circuit (ASIC) developed aiming for the front-end electronics of the X-ray CCDcamera system onboard the next X-ray astronomical satellite, ASTRO-H. It has four identical channels that simultaneously process the CCD signals. Distinctive capability of analog-to-digital conversion enables us to construct a CCD camera body that outputs only digital signals. As the result of the front-end electronics test, it works properly with low input noise of =<30 uV at the pixel rate below 100 kHz. The power consumption is sufficiently low of about 150 mW/chip. The input signal range of 720 mV covers the effective energy range of the typical X-ray photon counting CCD (up to 20 keV). The integrated non-linearity is 0.2% that is similar as those of the conventional CCDs in orbit. We also performed a radiation tolerance test against the total ionizing dose (TID) effect and the single event effect. The irradiation test using 60Co and proton beam showed ...

  20. Cooling System for a Frame-Store PN-CCD Detector for Low Background Application

    Pereira, H; Santos Silva, P; Kuster, M; Lang, P

    2012-01-01

    The astroparticle physics experiment CERN Axion Solar Telescope (CAST) aims to detect hypothetical axions or axion-like particles produced in the Sun by the Primakoff process. A Large Hadron Collider (LHC) prototype superconducting dipole magnet provides a 9 T transverse magnetic field for the conversion of axions into detectable X-ray photons. These photons are detected with an X-ray telescope and a novel type of frame-store CCD detector built from radio-pure materials, installed in the optics focal plane. A novel type of cooling system has been designed and built based on krypton-filled cryogenic heat pipes, made out of oxygen-free radiopure copper, and a Stirling cryocooler as cold source. The heat pipes provide an efficient thermal coupling between the cryocooler and the CCD which is kept at stable temperatures between 150 and 230 K within an accuracy of 0.1 K. A graded-Z radiation shield, also serving as a gas cold-trap operated at 120 K, is implemented to reduce the surface contamination of the CCD wind...

  1. Preliminary results of CCD observations of Himalia at Yunnan Observatories in 2015

    Peng, H W; Peng, Q Y

    2016-01-01

    In order to study the potential in high precision CCD astrometry of irregular satellites, we have made experimental observations for Himalia, the sixth and irregular satellite of Jupiter. A total of 185 CCD observations were obtained by using the 2.4 m telescope and 1 m telescope at Yunnan Observatories over ten nights. Preliminary analysis for the observations were made, including the geometric distortion, the atmospheric refraction, and also the phase effect. All positions of Himalia are measured relative to the reference stars from the catalogue UCAC4 in each CCD field of view. The theoretical positions of Himalia were retrieved from the IMCCE, while the positions of Jupiter were obtained based on the planetary theory INPOP13C. The results show that the mean (O-C) (observed minus computed) residuals are -0.004 and -0.002 arcsec in right ascension and declination, respectively. The standard deviation of (O-C) residuals are estimated at about 0.04 arcsec in each direction.

  2. 微光像传感器技术的最新进展%New Development of Low Light Level Imaging Sensor Technology

    田金生

    2013-01-01

    Based on the review of the development course, status of LLL image sensor, and tracking the development path of LLL image sensor in the near 10 years, this paper proposes the determination principle of a new generation of LLL image sensor and development direction. It also focuses on the latest progress of LLL image sensor including the CCD/CMOS with pre-intensified stage, such as the ICCD/CMOS and the EBCCD/COMS, solid-state LLL CCD/CMOS image sensor, CCD/CMOS hybrid image sensor, EMCCD, and InGaAs short wave infrared image sensor.%在回顾微光像传感器的发展历程、现状和跟踪最近10年的发展轨迹的基础上,提出了确定新一代微光像传感器的原则和发展方向。并重点介绍了微光像传感器的最新进展。包括,带有前置增强级的CCD/CMOS,如增强CCD/CMOS、电子轰击CCD/COMS。固体微光CCD/CMOS、CCD和CMOS混合微光像传感器、电子倍增CCD,铟镓砷短波红外微光像传感器。

  3. Measurement of the ionization produced by sub-keV silicon nuclear recoils in a CCD dark matter detector

    Chavarria, A. E.; Collar, J. I.; Pena, J.; Privitera, P.; Robinson, A E; Scholz, B.; Sengul, C.; Zhou, J.; Estrada, J.; Izraelevitch, F.; Tiffenberg, J.; Neto, J. R. T. de Mello(Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil); Machado, D. Torres

    2016-01-01

    We report a measurement of the ionization efficiency of silicon nuclei recoiling with sub-keV kinetic energy in the bulk silicon of a charge-coupled device (CCD). Nuclear recoils were produced by low-energy neutrons ($

  4. Pocket pumped image analysis

    Kotov, I.V., E-mail: kotov@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973 (United States); O' Connor, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Murray, N. [Centre for Electronic Imaging, Open University, Milton Keynes, MK7 6AA (United Kingdom)

    2015-07-01

    The pocket pumping technique is used to detect small electron trap sites. These traps, if present, degrade CCD charge transfer efficiency. To reveal traps in the active area, a CCD is illuminated with a flat field and, before image is read out, accumulated charges are moved back and forth number of times in parallel direction. As charges are moved over a trap, an electron is removed from the original pocket and re-emitted in the following pocket. As process repeats one pocket gets depleted and the neighboring pocket gets excess of charges. As a result a “dipole” signal appears on the otherwise flat background level. The amplitude of the dipole signal depends on the trap pumping efficiency. This paper is focused on trap identification technique and particularly on new methods developed for this purpose. The sensor with bad segments was deliberately chosen for algorithms development and to demonstrate sensitivity and power of new methods in uncovering sensor defects.

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

    Yong Pang; Zengyuan Li; Hongbo Ju; Hao Lu; Wen Jia; Lin Si; Ying Guo; Qingwang Liu; Shiming Li; Luxia Liu; Binbin Xie; Bingxiang Tan; Yuanyong Dian

    2016-01-01

    We describe the design, implementation and performance of a novel airborne system, which integrates commercial waveform LiDAR, CCD (Charge-Coupled Device) camera and hyperspectral sensors into a common platform system. CAF’s (The Chinese Academy of Forestry) LiCHy (LiDAR, CCD and Hyperspectral) Airborne Observation System is a unique system that permits simultaneous measurements of vegetation vertical structure, horizontal pattern, and foliar spectra from different view angles at very high sp...

  6. A multiple CCD X-ray detector and its first operation with synchrotron radiation X-ray beam

    Suzuki, M; Kumasaka, T; Sato, K; Toyokawa, H; Aries, I F; Jerram, P A; Ueki, T

    1999-01-01

    A 4x4 array structure of 16 identical CCD X-ray detector modules, called the multiple CCD X-ray detector system (MCCDX), was submitted to its first synchrotron radiation experiment at the protein crystallography station of the RIKEN beamline (BL45XU) at the SPring-8 facility. An X-ray diffraction pattern of cholesterol powder was specifically taken in order to investigate the overall system performance.

  7. The Design of Wire Diameter Measuring System Based on CCD Sensor%基于CCD动态传感器的线径测量系统设计

    彭泽州

    2011-01-01

    提出一种基于89S52单片机和线阵CCD传感器μPD3570D测量物体线径的方法,详细论述了线径测量系统的工作原理,即通过单片机对被遮挡像元计数得到待测物体的线径,并介绍了该测量系统的软硬件设计.%A method of measuring wire diameter was presented based on MCU 89S52 and linear CCD sensor μPD3570D. The principle of the system was that the wire diameter was measured through counting shielded image elements by MCU. The designs of software and hardware of the measuring system were introduced.

  8. A concept for the readout of multichannel detectors by using analog signal transmission via optical fibres coupled to a fast CCD

    Recent developments in the field of electro-optical components allowed one to transform fast analog electrical signals into fast light pulses in a wide dynamic range and to send them via optical fibres over relatively long distances with very low time dispersion and amplitude losses. Here we propose to use the analog signal fibre transmission technique in combination with fast CCDs for the data acquisition of multichannel detectors as, for example, for the read out of imaging cameras of atmospheric Cherenkov telescopes. Hundreds of signal channels can be read out by using commercially available single CCD module in fast gated mode. The latter can provide high amplitude resolution and an acquisition rate of up to a few hundred Hz. Such a system can provide significantly lower costs compared to traditionally used amplitude digitizing systems

  9. Calibration of the photometric method of heavy ion charge measurements in emulsion using a CCD camera

    A previously developed method of heavy ion charge measurements in emulsion has been significantly improved. The charge measurements are based on analysis of photometric profiles of the particle tracks in emulsion. These profiles are obtained using a CCD camera mounted on an optical microscope. So far, the manual charge determination by delta ray counting had to be used for calibration of the photometric method. In this paper a complete procedure for calibration of the photometric method is shown, without resorting to the manual method

  10. White-light fringe detection based on a novel light source and colour CCD camera

    Buchta, Zdeněk; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej

    2011-01-01

    Roč. 22, č. 9 (2011), 094031:1-6. ISSN 0957-0233 R&D Projects: GA ČR GP102/09/P293; GA ČR GP102/09/P630; GA MPO 2A-1TP1/127; GA MŠk(CZ) LC06007; GA MŠk ED0017/01/01 Institutional research plan: CEZ:AV0Z20650511 Keywords : low-coherence interferometry * phase-crossing algorithm * CCD camera * gauge block Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.494, year: 2011

  11. Upwelling radiance at 976 nm measured from space using the OPALS CCD camera on the ISS

    Biswas, Abhijit; Kovalik, Joseph M.; Oaida, Bogdan V.; Abrahamson, Matthew; Wright, Malcolm W.

    2015-03-01

    The Optical Payload for Lasercomm Science (OPALS) Flight System on-board the International Space Station uses a charge coupled device (CCD) camera to detect a beacon laser from Earth. Relative measurements of the background contributed by upwelling radiance under diverse illumination conditions and varying surface terrain is presented. In some cases clouds in the field-of-view allowed a comparison of terrestrial and cloud-top upwelling radiance. In this paper we will report these measurements and examine the extent of agreement with atmospheric model predictions.

  12. Calibration of the photometric method of heavy ion charge measurements in emulsion using a CCD camera

    Kudzia, D; Wilczynski, H

    2002-01-01

    A previously developed method of heavy ion charge measurements in emulsion has been significantly improved. The charge measurements are based on analysis of photometric profiles of the particle tracks in emulsion. These profiles are obtained using a CCD camera mounted on an optical microscope. So far, the manual charge determination by delta ray counting had to be used for calibration of the photometric method. In this paper a complete procedure for calibration of the photometric method is shown, without resorting to the manual method.

  13. Measurement of charge of heavy ions in emulsion using a CCD camera

    Kudzia, D; Dabrowska, A; Deines-Jones, P; Holynski, R; Olszewski, A; Nilsen, B S; Sen-Gupta, K; Szarska, M; Trzupek, A; Waddington, C J; Wefel, J P; Wilczynska, B; Wilczynski, H; Wolter, W; Wosiek, B; Wozniak, K

    1999-01-01

    A system has been developed for semi-automated determination of the charges of heavy ions recorded in nuclear emulsions. The profiles of various heavy ion tracks in emulsion, both accelerator beam ions and fragments of heavy projectiles, were obtained with a CCD camera mounted on a microscope. The dependence of track profiles on illumination, emulsion grain size and density, background in emulsion, and track geometry was analyzed. Charges of the fragments of heavy projectiles were estimated independently by the delta ray counting method. A calibration of both width and height of track profiles against ion charges was made with ions of known charges ranging from helium to gold nuclei. (author)

  14. Measurement of charge of heavy ions in emulsion using a CCD camera

    A system has been developed for semi-automated determination of the charges of heavy ions recorded in nuclear emulsions. The profiles of various heavy ion tracks in emulsion, both accelerator beam ions and fragments of heavy projectiles, were obtained with a CCD camera mounted on a microscope. The dependence of track profiles on illumination, emulsion grain size and density, background in emulsion, and track geometry was analyzed. Charges of the fragments of heavy projectiles were estimated independently by the delta ray counting method. A calibration of both width and height of track profiles against ion charges was made with ions of known charges ranging from helium to gold nuclei. (author)

  15. Non-contact and Automatic Measurement of 2D Size with CCD Matrix and Computer System

    ZHANG Ye; WANG Wen-sheng; GUO Yang-xue; SONG Hui-ying

    2003-01-01

    A measurement system with the CCD matrix and computer system is designed to test the 2D size of any shape workpieces automatically. In addition, the system adopts the method of the relative measurement which increases the precision and the velocity.More importantly,the precision can't be changed with the conditions of the temperature and air pressure.The experiments show that the relative precision of 0.002 9 and the absolute precision of 2.97 μm are obtained. The instrument may be used in the product line and make the testing on line possible.

  16. THE BROAD-BAND CCD PHOTOMETRY AND DUST PRODUCTION RATES OF COMET HALE-BOPP

    Huang Keliang; Hu Jingyao; Zhou Hongnan

    2000-01-01

    Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp are reported. Using the photometric results, the dust production rate, radius and mass of nucleus of comet Hale-Bopp are estimated as follows: dM/dt~1.5×105 kgs-1, Rn~35.5km, and Mn~5.65×1016kg.

  17. The broad-band CCD photometry and dust production rates of comet Hale-Bopp

    黄克谅; 胡景耀; 周洪楠

    2000-01-01

    Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60 cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp are reported. Using the photometric results, the dust production rate, radius and mass of nucleus of comet Hale-Bopp are estimated as follows: dM/df ~ 1.5 × 105 kgs-1, Rn~35.5 km, and Mn~5.65×1016 kg.

  18. The broad-band CCD photometry and dust production rates of comet Hale-Bopp

    2000-01-01

    Based upon broad-band CCD observation data of comet Hale-Bopp obtained by a 60 cm telescope at Xinglong Station of Beijing Astronomical Observatory during March-August, 1996, the photometric results of comet Hale-Bopp are reported. Using the photometric results, the dust production rate, radius and mass of nucleus of comet Hale-Bopp are estimated as follows: dM/dt~1.5×105 kgs-1, Rn~35.5 km, and Mn~5.65×1016 kg.

  19. Alignment method for 50 m distance using laser and CCD camera

    The interference pattern of laser light on the CCD device is suppressed by removing the cover glass in front of the device. The reference plane of the quadrupole magnets after division and restoration becomes unreliable for six years. The measurement tool for mechanical center of the multipole magnet is useful for checking the alignment. Few magnets of which reference planes were unreliable were aligned by using this tool. This also can measure the twist between the poles. It is quite important for the suppression of light fluctuation to choose pipe material. Temperature gradient refracts the light more in the pipe. Copper pipe is better than the paper one. (author)

  20. Application of CCD-camera for size measuring of electron ring by means of synchrotron radiation

    The method is described and the results of measuring of electron ring density distribution are presented. A TV-camera on the basis of a CCD matrix is used as a sensing element. The camera is connected through the interface unit in CAMAC standard with the SM-4 computer. The time exposition of radiaiton is realized by using an electro-optic sutter in the time interval from 0.01 to 1 ms at an operation voltage of 1 kV. 5 refs

  1. Globular clusters in the magellanic clouds; 1, BV CCD-photometry for 11 clusters

    Corsi, C E

    1994-01-01

    We present BV CCD-data for 11 intermediate-age LMC clusters; the main conclusions are: 1. in the (V_to, V_cl,m) and (V-to, (V_to-V_cl,m)) planes the models yield a good overall description of the data; 2. with the current sample, it is impossible to firmly choose between "classical" and "overshooting" models; 3. the separation in colour between the MS band and the Red He-burning Clump is smaller than predicted by theoretical tracks; 4. the existence of the so-called "RGB phase-transition (Renzini and Buzzoni 1986) seems to be confirmed.

  2. Background study for the pn-CCD detector of CERN Axion Solar Telescope

    Cebrián, S.; Rodríguez, A; M. Kuster(Technische Universität Darmstadt); Beltrán, B; Carmona, J.M.; H Gómez; Hartmann, R.; Irastorza, I. G.; R. Kotthaus; Luzón, G.; MORALES, J., CRUZ, D., DELGADO, P., LIZANA, M., LÓPEZ, V.; de Solórzano, A. Ortiz(Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009, Zaragoza, Spain); Ruz, J.; Strüder, L.; Villar, J. A.

    2007-01-01

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into photons with energies up to around 10 keV via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in conjunction with an X-ray mirror optics is one of the three detectors used in CAST to register the expected photon signal. Since this signal is very rare and different background components...

  3. Surface Diagnostics using Low-Coherence Interferometry and Colour Single CCD Camera

    Buchta, Zdeněk; Mikel, Břetislav; Lazar, Josef; Číp, Ondřej

    Ottawa : International ASET, 2010, 517: 1-6. ISBN 978-0-9867183-0-4. [Nanotechnology: Fundamentals and Applications. Ottawa (CA), 04.08.2010-06.08.2010] R&D Projects: GA ČR GP102/09/P293; GA ČR GP102/09/P630; GA MPO 2A-1TP1/127; GA MŠk ED0017/01/01; GA MŠk(CZ) LC06007 Institutional research plan: CEZ:AV0Z20650511 Keywords : low-coherence interferometry * surface diagnostics * CCD camera * white- light fringe analysis Subject RIV: BH - Optics, Masers, Lasers

  4. RR Lyrae variables in the globular cluster M3 (NGC5272). I. BVI CCD photometry

    Carretta, E.; Cacciari, C.; Ferraro, F. R.; Pecci, F. Fusi; Tessicini, G.

    1998-01-01

    New BVI CCD photometry is presented for 60 RR Lyrae variables in the globular cluster M3. Light curves have been constructed and ephemerides have been (re)-derived for all of them. Four stars (i.e. V29, V136, V155 and V209), although recognized as variables, had no previous period determinations. Also, the period derived for V129 is significantly different from the one published by Sawyer-Hogg (1973). Light curve parameters, i.e. mean magnitudes, amplitudes and rise-times, have been derived. ...

  5. DISTANCE MEASURING MODELING AND ERROR ANALYSIS OF DUAL CCD VISION SYSTEM SIMULATING HUMAN EYES AND NECK

    Wang Xuanyin; Xiao Baoping; Pan Feng

    2003-01-01

    A dual-CCD simulating human eyes and neck (DSHEN) vision system is put forward. Its structure and principle are introduced. The DSHEN vision system can perform some movements simulating human eyes and neck by means of four rotating joints, and realize precise object recognizing and distance measuring in all orientations. The mathematic model of the DSHEN vision system is built, and its movement equation is solved. The coordinate error and measure precision affected by the movement parameters are analyzed by means of intersection measuring method. So a theoretic foundation for further research on automatic object recognizing and precise target tracking is provided.

  6. Observation of Einstein-Podolsky-Rosen type correlations with an electron multiplying CCD camera

    Edgar, Matthew P; Izdebski, Frauke; Warburton, Ryan E; Leach, Jonathan; Agnew, Megan; Buller, Gerald S; Boyd, Robert W; Padgett, Miles J

    2012-01-01

    The light produced by parametric down-conversion shows strong spatial entanglement that leads to violations of EPR criteria for separability. Historically, such studies have been performed by scanning a single-element, single-photon detector across a detection plane. Here we show that modern electron-multiplying CCD cameras can measure correlations in both position and momentum across a multi-pixel field of view. This capability allows us to observe entanglement of around 2500 spatial states and demonstrate EPR-type correlations by more than two orders of magnitude. More generally, our work shows that such cameras can lead to important new capabilities in quantum optics and quantum information science.

  7. Reconstruction of Daily 30 m Data from HJ CCD, GF-1 WFV, Landsat, and MODIS Data for Crop Monitoring

    Mingquan Wu

    2015-12-01

    Full Text Available With the recent launch of new satellites and the developments of spatiotemporal data fusion methods, we are entering an era of high spatiotemporal resolution remote-sensing analysis. This study proposed a method to reconstruct daily 30 m remote-sensing data for monitoring crop types and phenology in two study areas located in Xinjiang Province, China. First, the Spatial and Temporal Data Fusion Approach (STDFA was used to reconstruct the time series high spatiotemporal resolution data from the Huanjing satellite charge coupled device (HJ CCD, Gaofen satellite no. 1 wide field-of-view camera (GF-1 WFV, Landsat, and Moderate Resolution Imaging Spectroradiometer (MODIS data. Then, the reconstructed time series were applied to extract crop phenology using a Hybrid Piecewise Logistic Model (HPLM. In addition, the onset date of greenness increase (OGI and greenness decrease (OGD were also calculated using the simulated phenology. Finally, crop types were mapped using the phenology information. The results show that the reconstructed high spatiotemporal data had a high quality with a proportion of good observations (PGQ higher than 0.95 and the HPLM approach can simulate time series Normalized Different Vegetation Index (NDVI very well with R2 ranging from 0.635 to 0.952 in Luntai and 0.719 to 0.991 in Bole, respectively. The reconstructed high spatiotemporal data were able to extract crop phenology in single crop fields, which provided a very detailed pattern relative to that from time series MODIS data. Moreover, the crop types can be classified using the reconstructed time series high spatiotemporal data with overall accuracy equal to 0.91 in Luntai and 0.95 in Bole, which is 0.028 and 0.046 higher than those obtained by using multi-temporal Landsat NDVI data.

  8. Front- vs. back-illuminated CCD cameras for photometric surveys: a noise budget analysis

    Crouzet, Nicolas; Fressin, Francois; Blazit, Alain

    2008-01-01

    Exoplanetary transit and stellar oscillation surveys require a very high precision photometry. The instrumental noise has therefore to be minimized. First, we perform a semi-analytical model of different noise sources. We show that the noise due the CCD electrodes can be overcome using a Gaussian PSF (Point Spread Function) of full width half maximum larger than 1.6 pixels. We also find that for a PSF size of a few pixels, the photometric aperture has to be at least 2.5 times larger than the PSF full width half maximum. Then, we compare a front- with a back-illuminated CCD through a Monte-Carlo simulation. Both cameras give the same results for a PSF full width half maximum larger than 1.5 pixels. All these simulations are applied to the A STEP (Antarctica Search for Transiting Extrasolar Planets) project. As a result, we choose a front-illuminated camera for A STEP because of its better resolution and lower price, and we will use a PSF larger than 1.6 pixels.

  9. A directional fast neutron detector using scintillating fibers and an intensified CCD camera system

    We have been developing and testing a scintillating fiber detector (SFD) for use as a fast neutron sensor which can discriminate against neutrons entering at angles non-parallel to the fiber axis (''directionality''). The detector/convertor component is a fiber bundle constructed of plastic scintillating fibers each measuring 10 cm long and either 0.3 mm or 0.5 mm in diameter. Extensive Monte Carlo simulations were made to optimize the bundle response to a range of fast neutron energies and to intense fluxes of high energy gamma-rays. The bundle is coupled to a set of gamma-ray insenitive electro-optic intensifiers whose output is viewed by a CCD camera directly coupled to the intensifiers. Two types of CCD cameras were utilized: 1) a standard, interline RS-170 camera with electronic shuttering and 2) a high-speed (up to 850 frame/s) field-transfer camera. Measurements of the neutron detection efficiency and directionality were made using 14 MeV neutrons, and the response to gamma-rays was performed using intense fluxes from radioisotopic sources (up to 20 R/h). Recently, the detector was constructed and tested using a large 10 cm by 10 cm square fiber bundle coupled to a 10 cm diameter GEN I intensifier tube. We present a description of the various detector systems and report the results of experimental tests. ((orig.))

  10. Charge transfer inefficiency in the pre- and post-irradiated Swept Charge Device CCD236

    This paper describes the mapping of spectral response of an e2v technologies Swept Charge Device (SCD) CCD236 pre and post irradiation with a 10 MeV equivalent proton fluence of 5.0 × 108 protons cm−2. The CCD236 is a large area (4.4 cm2) X-ray detector which will be used in India's Chandrayaan-2 Large Soft X-ray Spectrometer (CLASS) and China's Hard X-ray Modulation Telescope (HXMT). To enable the suppression of surface dark current, clocking is performed continuously resulting in a linear readout. As such the flat field illumination used to measure any change in spectral response over a conventional Charge-Coupled Devices (CCDs) is not possible. An alternative masking technique has been used to expose pinpoint regions of the device to Mn-Kα and Mn-Kβ X-rays, enabling a local map of spectral response to be built up over the device. This novel approach allows for an estimation of the Charge Transfer Inefficiency (CTI) of the device to be made by allowing the creation of a CTI scatter plot similar to that typically observed in conventional CCDs

  11. Evaluation of the fully-depleted back-illuminated CCD for Subaru Suprime-Cam

    Kamata, Yukiko; Miyazaki, Satoshi; Nakaya, Hidehiko; Tsuru, Takeshi G.; Tsunemi, Hiroshi; Miyata, Emi; Muramatsu, Masaharu; Suzuki, Hisanori; Miyaguchi, Kazuhisa

    2008-07-01

    In order to improve the quantum efficiency (QE) at longer wavelength, we have developed fully-depleted backilluminated CCDs in collaboration with Hamamatsu Photonics K.K (HPK). Recently, HPK delivered 10 CCDs for Subaru Prime Focus Camera (Suprime-Cam). These CCDs are made on N-type, high resistivity silicon wafers. Each CCD has a 200 μm thick depletion layer. The CCD format is four-side buttable, 2k × 4k, 15 μm square pixels with 4 low noise output amplifiers. The characteristics of the CCDs have been tested in the laboratory before they are installed into Suprime-Cam dewar. These CCDs have excellent performance; readout noise 0.999995, and full-well ~ 180,000 e-. The QE of λ = 1 μm was 40 % at -100°C. All CCDs have good cosmetics. Surface flatness is ~ 25 μm peak to value (P-V). The specification was acceptable. We are also developing CCDs for Hype Suprime-Cam (HSC), the next generation instrument for Subaru Telescope. HPK optimized back side process and has developed blue enhanced CCDs for HSC.

  12. A uvbyCaHbeta CCD Analysis of the Open Cluster Standard, NGC 752

    Twarog, B A; Deliyannis, C P; Thomas, D T

    2015-01-01

    Precision uvbyCaHbeta photometry of the nearby old open cluster, NGC 752, is presented. The mosaic of CCD fields covers an area ~42' on a side with internal precision at the 0.005 to 0.010 mag level for the majority of stars down to V~15. The CCD photometry is tied to the standard system using an extensive set of published photoelectric observations adopted as secondary standards within the cluster. Multicolor indices are used to eliminate as nonmembers a large fraction of the low probability proper-motion members near the faint end of the main sequence, while identifying 24 potential dwarf members between V=15.0 and 16.5, eight of which have been noted before from Vilnius photometry. From 68 highly probable F dwarf members, we derive a reddening estimate of E(b-y)= 0.025 +/- 0.003 (E(B-V) = 0.034 +/- 0.004), where the error includes the internal photometric uncertainty and the systematic error arising from the choice of the standard (b-y), Hbeta relation. With reddening fixed, [Fe/H] is derived from the F dw...

  13. Flat-Field Calibration of CCD Detector for Long TraceProfilers

    Kirschman, Jonathan L.; Domning, Edward E.; Franck, Keith D.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R.; Morrison,Gregory Y.; Smith, Brian V.; Warwick, Tony; Yashchuk, Valeriy V.

    2007-07-31

    The next generation of synchrotrons and free electron lasersrequires x-ray optical systems with extremely high-performance,generally, of diffraction limited quality. Fabrication and use of suchoptics requires highly accurate metrology. In the present paper, wediscuss a way to improve the performance of the Long Trace Profiler(LTP), a slope measuring instrument widely used at synchrotron facilitiesto characterize x-ray optics at high-spatial-wavelengths fromapproximately 2 mm to 1 m. One of the major sources of LTP systematicerror is the detector. For optimal functionality, the detector has topossess the smallest possible pixel size/spacing, a fast method ofshuttering, and minimal non-uniformity of pixel-to-pixel photoresponse.While the first two requirements are determined by choice of detector,the non-uniformity of photoresponse of typical detectors such as CCDcameras is around 2-3 percent. We describe a flat-field calibration setupspecially developed for calibration of CCD camera photo-response and darkcurrent with an accuracy of better than 0.5 percent. Such accuracy isadequate for use of a camera as a detector for an LTP with performance of~;0.1 microradian (rms). We also present the design details of thecalibration system and results of calibration of a DALSA CCD camera usedfor upgrading our LTP-II instrument at the ALS Optical MetrologyLaboratory.

  14. Automatic calibration system for analog instruments based on DSP and CCD sensor

    Lan, Jinhui; Wei, Xiangqin; Bai, Zhenlong

    2008-12-01

    Currently, the calibration work of analog measurement instruments is mainly completed by manual and there are many problems waiting for being solved. In this paper, an automatic calibration system (ACS) based on Digital Signal Processor (DSP) and Charge Coupled Device (CCD) sensor is developed and a real-time calibration algorithm is presented. In the ACS, TI DM643 DSP processes the data received by CCD sensor and the outcome is displayed on Liquid Crystal Display (LCD) screen. For the algorithm, pointer region is firstly extracted for improving calibration speed. And then a math model of the pointer is built to thin the pointer and determine the instrument's reading. Through numbers of experiments, the time of once reading is no more than 20 milliseconds while it needs several seconds if it is done manually. At the same time, the error of the instrument's reading satisfies the request of the instruments. It is proven that the automatic calibration system can effectively accomplish the calibration work of the analog measurement instruments.

  15. The X-ray mirror telescope and the pn-CCD detector of CAST

    Kuster, M; Englhauser, J; Franz, J; Friedrich, P; Hartmann, R; Kang, D; Kotthaus, R; Lutz, Gerhard; Moralez, J; Serber, W; Strüder, L

    2004-01-01

    The Cern Axion Solar Telescope - CAST - uses a prototype 9 Tesla LHC superconducting dipole magnet to search for a hypothetical pseudoscalar particle, the axion, which was proposed by theory in the 1980s to solve the strong CP problem and which could be a dark matter candidate. In CAST a strong magnetic field is used to convert the solar axions to detectable photons via inverse Primakoff effect. The resulting X-rays are thermally distributed in the energy range of 1-7 keV and can be observed with conventional X-ray detectors. The most sensitive detector system of CAST is a pn-CCD detector originally developed for XMM-Newton combined with a Wolter I type X-ray mirror system. The combination of a focusing X-ray optics and a state of the art pn-CCD detector which combines high quantum efficiency, good spacial and energy resolution, and low background improves the sensitivity of the CAST experiment such that for the first time the axion photon coupling constant can be probed beyond the best astrophysical constrai...

  16. CCD Photometric Study of the Contact Binary TX Cnc in the Young Open Cluster NGC 2632

    Liang, Liu; Soonthornthum, BOONRUCKSAR; Liying, Zhu; Jiajia, He; Yuan, J -Z

    2011-01-01

    TX Cnc is a member of the young open cluster NGC 2632. In the present paper, four CCD epochs of light minimum and a complete V light curve of TX Cnc are presented. A period investigation based on all available photoelectric or CCD data showed that it is found to be superimposed on a long-term increase ($dP/dt=+3.97\\times{10^{-8}}$\\,days/year), and a weak evidence suggests that it includes a small-amplitude period oscillation ($A_3=0.^{d}0028$; $T_3=26.6\\,years$). The light curves in the V band obtained in 2004 were analyzed with the 2003 version of the W-D code. It was shown that TX Cnc is an overcontact binary system with a degree of contact factor $f=24.8%(\\pm0.9%)$. The absolute parameters of the system were calculated: $M_1=1.319\\pm0.007M_{\\odot}$, $M_2=0.600\\pm0.01M_{\\odot}$; $R_1=1.28\\pm0.19R_{\\odot}$, $R_2=0.91\\pm0.13R_{\\odot}$. TX Cnc may be on the TRO-controlled stage of the evolutionary scheme proposed by Qian (2001a, b; 2003a), and may contains an invisible tertiary component ($m_3\\approx0.097M_{\\o...

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

    S. A. Chernouss

    2008-05-01

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

  18. Improving the ability of image sensors to detect faint stars and moving objects using image deconvolution techniques

    Octavi Fors; Jorge Núñez; Xavier Otazu; Albert Prades; Cardinal, Robert D.

    2010-01-01

    In this paper we show how the techniques of image deconvolution can increase the ability of image sensors as, for example, CCD imagers, to detect faint stars or faint orbital objects (small satellites and space debris). In the case of faint stars, we show that this benefit is equivalent to double the quantum efficiency of the used image sensor or to increase the effective telescope aperture by more than 30% without decreasing the astrometric precision or introducing artificial bias. In the ca...

  19. Soft x-ray imager (SXI) onboard ASTRO-H

    Tsunemi, Hiroshi; Hayashida, Kiyoshi; Tsuru, Takeshi Go; Dotani, Tadayasu; Hiraga, Junko S.; Anabuki, Naohisa; Bamba, Aya; Hatsukade, Isamu; Kohmura, Takayoshi; Mori, Koji; Murakami, Hiroshi; Nakajima, Hiroshi; Ozaki, Masanobu; Uchida, Hiroyuki; Yamauchi, Makoto

    2010-07-01

    We are designing an X-ray CCD camera (SXI) for ASTRO-H, including many new items. We have developed the CCD, CCD-NeXT4, that is a P-channel type CCD. It has a thick depletion layer of 200μm with an imaging area of 30mm square. Since it is back-illuminated, it has a good low energy response and is robust against the impact of micro-meteorites. We will employ 4 chips to cover the area of 60mm square. A mechanical rather than peltier cooler will be employed so that we can cool the CCD to -120°C. We will also introduce an analog ASIC that is placed very close to the CCD. It performs well, having a similar noise level to that assembled by using individual parts used on SUZAKU. We also employ a modulated X-ray source (MXS), that improves the accuracy of the calibration. The SXI will have one of the largest SΩ among various satellites.

  20. Improvement in the light sensitivity of the ultrahigh-speed high-sensitivity CCD with a microlens array

    Hayashida, T.,; Yonai, J.; Kitamura, K.; Arai, T.; Kurita, T.; Tanioka, K.; Maruyama, H.; Etoh, T. Goji; Kitagawa, S.; Hatade, K.; Yamaguchi, T.; Takeuchi, H.; Iida, K.

    2008-02-01

    We are advancing the development of ultrahigh-speed, high-sensitivity CCDs for broadcast use that are capable of capturing smooth slow-motion videos in vivid colors even where lighting is limited, such as at professional baseball games played at night. We have already developed a 300,000 pixel, ultrahigh-speed CCD, and a single CCD color camera that has been used for sports broadcasts and science programs using this CCD. However, there are cases where even higher sensitivity is required, such as when using a telephoto lens during a baseball broadcast or a high-magnification microscope during science programs. This paper provides a summary of our experimental development aimed at further increasing the sensitivity of CCDs using the light-collecting effects of a microlens array.