Time and space integrating acousto-optic folded spectrum processing for SETI

NASA Technical Reports Server (NTRS)

Wagner, K.; Psaltis, D.

1986-01-01

Time and space integrating folded spectrum techniques utilizing acousto-optic devices (AOD) as 1-D input transducers are investigated for a potential application as wideband, high resolution, large processing gain spectrum analyzers in the search for extra-terrestrial intelligence (SETI) program. The space integrating Fourier transform performed by a lens channels the coarse spectral components diffracted from an AOD onto an array of time integrating narrowband fine resolution spectrum analyzers. The pulsing action of a laser diode samples the interferometrically detected output, aliasing the fine resolution components to baseband, as required for the subsequent charge coupled devices (CCD) processing. The raster scan mechanism incorporated into the readout of the CCD detector array is used to unfold the 2-D transform, reproducing the desired high resolution Fourier transform of the input signal.

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

NASA Astrophysics Data System (ADS)

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.

Construction of a photochemical reactor combining a CCD spectrophotometer and a LED radiation source.

PubMed

Gombár, Melinda; Józsa, Éva; Braun, Mihály; Ősz, Katalin

2012-10-01

An inexpensive photoreactor using LED light sources and a fibre-optic CCD spectrophotometer as a detector was built by designing a special cell holder for standard 1.000 cm cuvettes. The use of this device was demonstrated by studying the aqueous photochemical reaction of 2,5-dichloro-1,4-benzoquinone. The developed method combines the highly quantitative data collection of CCD spectrophotometers with the possibility of illuminating the sample independently of the detecting light beam, which is a substantial improvement of the method using diode array spectrophotometers as photoreactors.

Degradation of optical components in space

NASA Technical Reports Server (NTRS)

Blue, M. D.

1993-01-01

This report concerns two types of optical components: multilayer filters and mirrors, and self-scanned imaging arrays using charge coupled device (CCD) readouts. For the filters and mirrors, contamination produces a strong reduction in transmittance in the ultraviolet spectral region, but has little or no effect in the visible and infrared spectral regions. Soft substrates containing halides are unsatisfactory as windows or substrates. Materials choice for dielectric layers should also reflect such considerations. Best performance is also found for the harder materials. Compaction of the layers and interlayer diffusion causes a blue shift in center wavelength and loss of throughput. For sensors using CCD's, shifts in gate voltage and reductions in transfer efficiency occur. Such effects in CCD's are in accord with expectations of the effects of the radiation dose on the device. Except for optical fiber, degradation of CCD's represents the only ionizing-radiation induced effect on the Long Duration Exposure Facility (LDEF) optical systems components that has been observed.

DQE analysis for CCD imaging arrays

NASA Astrophysics Data System (ADS)

Shaw, Rodney

1997-05-01

By consideration of the statistical interaction between exposure quanta and the mechanisms of image detection, the signal-to-noise limitations of a variety of image acquisition technologies are now well understood. However in spite of the growing fields of application for CCD imaging- arrays and the obvious advantages of their multi-level mode of quantum detection, only limited and largely empirical approaches have been made to quantify these advantages on an absolute basis. Here an extension is made of a previous model for noise-free sequential photon-counting to the more general case involving both count-noise and arbitrary separation functions between count levels. This allows a basic model to be developed for the DQE associated with devices which approximate to the CCD mode of operation, and conclusions to be made concerning the roles of the separation-function and count-noise in defining the departure from the ideal photon counter.

Integrated infrared detector arrays for low-background applications

NASA Technical Reports Server (NTRS)

Mccreight, C. R.; Goebel, J. H.

1982-01-01

Advanced infrared detector and detector array technology is being developed and characterized for future NASA space astronomy applications. Si:Bi charge-injection-device arrays have been obtained, and low-background sensitivities comparable to that of good discrete detectors have been measured. Intrinsic arrays are being assessed, and laboratory and telescope data have been collected on a monolithic InSb CCD array. For wavelengths longer than 30 microns, improved Ge:Ga detectors have been produced, and steps have been taken to prove the feasibility of an integrated extrinsic germanium array. Other integrated arrays and cryogenic components are also under investigation.

Characterization of Custom-Designed Charge-Coupled Devices for Applications to Gas and Aerosol Monitoring Sensorcraft Instrument

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Abedin, M. Nurul; Farnsworth, Glenn R.; Garcia, Christopher S.; Zawodny, Joseph M.

2005-01-01

Custom-designed charge-coupled devices (CCD) for Gas and Aerosols Monitoring Sensorcraft instrument were developed. These custom-designed CCD devices are linear arrays with pixel format of 512x1 elements and pixel size of 10x200 sq m. These devices were characterized at NASA Langley Research Center to achieve a full well capacity as high as 6,000,000 e-. This met the aircraft flight mission requirements in terms of signal-to-noise performance and maximum dynamic range. Characterization and analysis of the electrical and optical properties of the CCDs were carried out at room temperature. This includes measurements of photon transfer curves, gain coefficient histograms, read noise, and spectral response. Test results obtained on these devices successfully demonstrated the objectives of the aircraft flight mission. In this paper, we describe the characterization results and also discuss their applications to future mission.

Digital Mammography with a Mosaic of CCD-Arrays

NASA Technical Reports Server (NTRS)

Jalink, Antony, Jr. (Inventor); McAdoo, James A. (Inventor)

1996-01-01

The present invention relates generally to a mammography device and method and more particularly to a novel digital mammography device and method to detect microcalcifications of precancerous tissue. A digital mammography device uses a mosaic of electronic digital imaging arrays to scan an x-ray image. The mosaic of arrays is repositioned several times to expose different portions of the image, until the entire image is scanned. The data generated by the arrays during each exposure is stored in a computer. After the final exposure, the computer combines data of the several partial images to produce a composite of the original x-ray image. An aperture plate is used to reduce scatter and the overall exposure of the patient to x-rays. The novelty of this invention is that it provides a digital mammography device with large field coverage, high spatial resolution, scatter rejection, excellent contrast characteristics and lesion detectability under clinical conditions. This device also shields the patient from excessive radiation, can detect extremely small calcifications and allows manipulation and storage of the image.

Performance of 4x5120 Element Visible and 2x2560 Element Shortwave Infrared Multispectral Focal Planes

NASA Astrophysics Data System (ADS)

Tower, J. R.; Cope, A. D.; Pellion, L. E.; McCarthy, B. M.; Strong, R. T.; Kinnard, K. F.; Moldovan, A. G.; Levine, P. A.; Elabd, H.; Hoffman, D. M.

1985-12-01

Performance measurements of two Multispectral Linear Array focal planes are presented. Both pushbroom sensors have been developed for application in remote sensing instruments. A buttable, four-spectral-band, linear-format charge coupled device (CCD) and a but-table, two-spectral-band, linear-format, shortwave infrared charge coupled device (IRCCD) have been developed under NASA funding. These silicon integrated circuits may be butted end to end to provide very-high-resolution multispectral focal planes. The visible CCD is organized as four sensor lines of 1024 pixels each. Each line views the scene in a different spectral window defined by integral optical bandpass filters. A prototype focal plane with five devices, providing 4x5120-pixel resolution has been demonstrated. The high quantum efficiency of the backside-illuminated CCD technology provides excellent signal-to-noise performance and unusually high MTF across the entire visible and near-IR spectrum. The shortwave infrared (SWIR) sensor is organized as two line sensors of 512 detectors each. The SWIR (1-2.5 μm) spectral windows may be defined by bandpass filters placed in close proximity to the devices. The dual-band sensor consists of Schottky barrier detectors read out by CCD multiplexers. This monolithic sensor operates at 125°K with radiometric performance. A prototype five-device focal plane providing 2x2560 detectors has been demonstrated. The devices provide very high uniformity, and excellent MTF across the SWIR band.

Solid state television camera (CCD-buried channel)

NASA Technical Reports Server (NTRS)

1976-01-01

The development of an all solid state television camera, which uses a buried channel charge coupled device (CCD) as the image sensor, was undertaken. A 380 x 488 element CCD array is utilized to ensure compatibility with 525 line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (a) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (b) techniques for the elimination or suppression of CCD blemish effects, and (c) automatic light control and video gain control (i.e., ALC and AGC) techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a deliverable solid state TV camera which addressed the program requirements for a prototype qualifiable to space environment conditions.

Solid state television camera (CCD-buried channel), revision 1

NASA Technical Reports Server (NTRS)

1977-01-01

An all solid state television camera was designed which uses a buried channel charge coupled device (CCD) as the image sensor. A 380 x 488 element CCD array is utilized to ensure compatibility with 525-line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (1) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (2) techniques for the elimination or suppression of CCD blemish effects, and (3) automatic light control and video gain control techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a deliverable solid state TV camera which addressed the program requirements for a prototype qualifiable to space environment conditions.

Solid state, CCD-buried channel, television camera study and design

NASA Technical Reports Server (NTRS)

Hoagland, K. A.; Balopole, H.

1976-01-01

An investigation of an all solid state television camera design, which uses a buried channel charge-coupled device (CCD) as the image sensor, was undertaken. A 380 x 488 element CCD array was utilized to ensure compatibility with 525 line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (a) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (b) techniques for the elimination or suppression of CCD blemish effects, and (c) automatic light control and video gain control techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a design which addresses the program requirements for a deliverable solid state TV camera.

[Techniques for pixel response nonuniformity correction of CCD in interferential imaging spectrometer].

PubMed

Yao, Tao; Yin, Shi-Min; Xiangli, Bin; Lü, Qun-Bo

2010-06-01

Based on in-depth analysis of the relative radiation scaling theorem and acquired scaling data of pixel response nonuniformity correction of CCD (charge-coupled device) in spaceborne visible interferential imaging spectrometer, a pixel response nonuniformity correction method of CCD adapted to visible and infrared interferential imaging spectrometer system was studied out, and it availably resolved the engineering technical problem of nonuniformity correction in detector arrays for interferential imaging spectrometer system. The quantitative impact of CCD nonuniformity on interferogram correction and recovery spectrum accuracy was given simultaneously. Furthermore, an improved method with calibration and nonuniformity correction done after the instrument is successfully assembled was proposed. The method can save time and manpower. It can correct nonuniformity caused by other reasons in spectrometer system besides CCD itself's nonuniformity, can acquire recalibration data when working environment is changed, and can also more effectively improve the nonuniformity calibration accuracy of interferential imaging

Charge coupled devices

NASA Technical Reports Server (NTRS)

Walker, J. W.; Hornbeck, L. J.; Stubbs, D. P.

1977-01-01

The results are presented of a program to design, fabricate, and test CCD arrays suitable for operation in an electron-bombarded mode. These intensified charge coupled devices have potential application to astronomy as photon-counting arrays. The objectives of this program were to deliver arrays of 250 lines of 400 pixels each and some associated electronics. Some arrays were delivered on tube-compatible headers and some were delivered after incorporation in vacuum tubes. Delivery of these devices required considerable improvements to be made in the processing associated with intensified operation. These improvements resulted in a high yield in the thinning process, reproducible results in the accumulation process, elimination of a dark current source in the accumulation process, solution of a number of header related problems, and the identification of a remaining major source of dark current. Two systematic failure modes were identified and protective measures established. The effects of tube processing on the arrays in the delivered ICCDs were determined and are reported along with the characterization data on the arrays.

Line scanning system for direct digital chemiluminescence imaging of DNA sequencing blots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karger, A.E.; Weiss, R.; Gesteland, R.F.

A cryogenically cooled charge-coupled device (CCD) camera equipped with an area CCD array is used in a line scanning system for low-light-level imaging of chemiluminescent DNA sequencing blots. Operating the CCD camera in time-delayed integration (TDI) mode results in continuous data acquisition independent of the length of the CCD array. Scanning is possible with a resolution of 1.4 line pairs/mm at the 50% level of the modulation transfer function. High-sensitivity, low-light-level scanning of chemiluminescent direct-transfer electrophoresis (DTE) DNA sequencing blots is shown. The detection of DNA fragments on the blot involves DNA-DNA hybridization with oligonucleotide-alkaline phosphatase conjugate and 1,2-dioxetane-based chemiluminescence.more » The width of the scan allows the recording of up to four sequencing reactions (16 lanes) on one scan. The scan speed of 52 cm/h used for the sequencing blots corresponds to a data acquisition rate of 384 pixels/s. The chemiluminescence detection limit on the scanned images is 3.9 [times] 10[sup [minus]18] mol of plasmid DNA. A conditional median filter is described to remove spikes caused by cosmic ray events from the CCD images. 39 refs., 9 refs.« less

Multiport backside-illuminated CCD imagers for high-frame-rate camera applications

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Sauer, Donald J.; Hseuh, Fu-Lung; Shallcross, Frank V.; Taylor, Gordon C.; Meray, Grazyna M.; Tower, John R.; Harrison, Lorna J.; Lawler, William B.

1994-05-01

Two multiport, second-generation CCD imager designs have been fabricated and successfully tested. They are a 16-port 512 X 512 array and a 32-port 1024 X 1024 array. Both designs are back illuminated, have on-chip CDS, lateral blooming control, and use a split vertical frame transfer architecture with full frame storage. The 512 X 512 device has been operated at rates over 800 frames per second. The 1024 X 1024 device has been operated at rates over 300 frames per second. The major changes incorporated in the second-generation design are, reduction in gate length in the output area to give improved high-clock-rate performance, modified on-chip CDS circuitry for reduced noise, and optimized implants to improve performance of blooming control at lower clock amplitude. This paper discusses the imager design improvements and presents measured performance results at high and moderate frame rates. The design and performance of three moderate frame rate cameras are discussed.

SPECIAL ISSUE ON OPTICAL PROCESSING OF INFORMATION: Optoelectronic processors with scanning CCD photodetectors

NASA Astrophysics Data System (ADS)

Esepkina, N. A.; Lavrov, A. P.; Anan'ev, M. N.; Blagodarnyi, V. S.; Ivanov, S. I.; Mansyrev, M. I.; Molodyakov, S. A.

1995-10-01

Two new types of optoelectronic radio-signal processors were investigated. Charge-coupled device (CCD) photodetectors are used in these processors under continuous scanning conditions, i.e. in a time delay and storage mode. One of these processors is based on a CCD photodetector array with a reference-signal amplitude transparency and the other is an adaptive acousto-optical signal processor with linear frequency modulation. The processor with the transparency performs multichannel discrete—analogue convolution of an input signal with a corresponding kernel of the transformation determined by the transparency. If a light source is an array of light-emitting diodes of special (stripe) geometry, the optical stages of the processor can be made from optical fibre components and the whole processor then becomes a rigid 'sandwich' (a compact hybrid optoelectronic microcircuit). A report is given also of a study of a prototype processor with optical fibre components for the reception of signals from a system with antenna aperture synthesis, which forms a radio image of the Earth.

Fabricating a hybrid imaging device

NASA Technical Reports Server (NTRS)

Wadsworth, Mark (Inventor); Atlas, Gene (Inventor)

2003-01-01

A hybrid detector or imager includes two substrates fabricated under incompatible processes. An array of detectors, such as charged-coupled devices, are formed on the first substrate using a CCD fabrication process, such as a buried channel or peristaltic process. One or more charge-converting amplifiers are formed on a second substrate using a CMOS fabrication process. The two substrates are then bonded together to form a hybrid detector.

Development of an all-in-one gamma camera/CCD system for safeguard verification

NASA Astrophysics Data System (ADS)

Kim, Hyun-Il; An, Su Jung; Chung, Yong Hyun; Kwak, Sung-Woo

2014-12-01

For the purpose of monitoring and verifying efforts at safeguarding radioactive materials in various fields, a new all-in-one gamma camera/charged coupled device (CCD) system was developed. This combined system consists of a gamma camera, which gathers energy and position information on gamma-ray sources, and a CCD camera, which identifies the specific location in a monitored area. Therefore, 2-D image information and quantitative information regarding gamma-ray sources can be obtained using fused images. A gamma camera consists of a diverging collimator, a 22 × 22 array CsI(Na) pixelated scintillation crystal with a pixel size of 2 × 2 × 6 mm3 and Hamamatsu H8500 position-sensitive photomultiplier tube (PSPMT). The Basler scA640-70gc CCD camera, which delivers 70 frames per second at video graphics array (VGA) resolution, was employed. Performance testing was performed using a Co-57 point source 30 cm from the detector. The measured spatial resolution and sensitivity were 4.77 mm full width at half maximum (FWHM) and 7.78 cps/MBq, respectively. The energy resolution was 18% at 122 keV. These results demonstrate that the combined system has considerable potential for radiation monitoring.

Digital Mammography with a Mosaic of CCD Arrays

NASA Technical Reports Server (NTRS)

Jalink, Antony, Jr. (Inventor); McAdoo, James A. (Inventor)

1998-01-01

A digital mammography device uses a mosaic of electronic digital imaging arrays to scan an x-ray image is discussed. The mosaic of arrays is repositioned several times to expose different portions of the image, until the entire image is scanned. The data generated by the arrays during each exposure is stored in a computer. After the final exposure, the computer combines data of the several partial images to produce a composite of the original x-ray image. An aperture plate is used to reduce scatter and the overall exposure of the patient to x-rays.

Curved CCD detector devices and arrays for multispectral astrophysical applications and terrestrial stereo panoramic cameras

NASA Astrophysics Data System (ADS)

Swain, Pradyumna; Mark, David

2004-09-01

The emergence of curved CCD detectors as individual devices or as contoured mosaics assembled to match the curved focal planes of astronomical telescopes and terrestrial stereo panoramic cameras represents a major optical design advancement that greatly enhances the scientific potential of such instruments. In altering the primary detection surface within the telescope"s optical instrumentation system from flat to curved, and conforming the applied CCD"s shape precisely to the contour of the telescope"s curved focal plane, a major increase in the amount of transmittable light at various wavelengths through the system is achieved. This in turn enables multi-spectral ultra-sensitive imaging with much greater spatial resolution necessary for large and very large telescope applications, including those involving infrared image acquisition and spectroscopy, conducted over very wide fields of view. For earth-based and space-borne optical telescopes, the advent of curved CCD"s as the principle detectors provides a simplification of the telescope"s adjoining optics, reducing the number of optical elements and the occurrence of optical aberrations associated with large corrective optics used to conform to flat detectors. New astronomical experiments may be devised in the presence of curved CCD applications, in conjunction with large format cameras and curved mosaics, including three dimensional imaging spectroscopy conducted over multiple wavelengths simultaneously, wide field real-time stereoscopic tracking of remote objects within the solar system at high resolution, and deep field survey mapping of distant objects such as galaxies with much greater multi-band spatial precision over larger sky regions. Terrestrial stereo panoramic cameras equipped with arrays of curved CCD"s joined with associative wide field optics will require less optical glass and no mechanically moving parts to maintain continuous proper stereo convergence over wider perspective viewing fields than their flat CCD counterparts, lightening the cameras and enabling faster scanning and 3D integration of objects moving within a planetary terrain environment. Preliminary experiments conducted at the Sarnoff Corporation indicate the feasibility of curved CCD imagers with acceptable electro-optic integrity. Currently, we are in the process of evaluating the electro-optic performance of a curved wafer scale CCD imager. Detailed ray trace modeling and experimental electro-optical data performance obtained from the curved imager will be presented at the conference.

Fabricating a hybrid imaging device having non-destructive sense nodes

NASA Technical Reports Server (NTRS)

Wadsworth, Mark (Inventor); Atlas, Gene (Inventor)

2001-01-01

A hybrid detector or imager includes two substrates fabricated under incompatible processes. An array of detectors, such as charged-coupled devices, are formed on the first substrate using a CCD fabrication process, such as a buried channel or peristaltic process. One or more charge-converting amplifiers are formed on a second substrate using a CMOS fabrication process. The two substrates are then bonded together to form a hybrid detector.

X-Ray Diffraction Apparatus

NASA Technical Reports Server (NTRS)

Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

1996-01-01

An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.

Scientific, Back-Illuminated CCD Development for the Transiting Exoplanet Survey Satellite

NASA Technical Reports Server (NTRS)

Suntharalingam, V.; Ciampi, J.; Cooper, M. J.; Lambert, R. D.; O'Mara, D. M.; Prigozhin, I.; Young, D. J.; Warner, K.; Burke, B. E.

2015-01-01

We describe the development of the fully depleted, back illuminated charge coupled devices for the Transiting Exoplanet Survey Satellite, which includes a set of four wide angle telescopes, each having a 2x2 array of CCDs. The devices are fabricated on the newly upgraded 200-mm wafer line at Lincoln Laboratory. We discuss methods used to produce the devices and present early performance results from the 100- micron thick, 15x15-microns, 2k x 4k pixel frame transfer CCDs.

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

NASA Astrophysics Data System (ADS)

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.

The CAOS camera platform: ushering in a paradigm change in extreme dynamic range imager design

NASA Astrophysics Data System (ADS)

Riza, Nabeel A.

2017-02-01

Multi-pixel imaging devices such as CCD, CMOS and Focal Plane Array (FPA) photo-sensors dominate the imaging world. These Photo-Detector Array (PDA) devices certainly have their merits including increasingly high pixel counts and shrinking pixel sizes, nevertheless, they are also being hampered by limitations in instantaneous dynamic range, inter-pixel crosstalk, quantum full well capacity, signal-to-noise ratio, sensitivity, spectral flexibility, and in some cases, imager response time. Recently invented is the Coded Access Optical Sensor (CAOS) Camera platform that works in unison with current Photo-Detector Array (PDA) technology to counter fundamental limitations of PDA-based imagers while providing high enough imaging spatial resolution and pixel counts. Using for example the Texas Instruments (TI) Digital Micromirror Device (DMD) to engineer the CAOS camera platform, ushered in is a paradigm change in advanced imager design, particularly for extreme dynamic range applications.

Simultaneous Determination of Iron, Copper and Cobalt in Food Samples by CCD-diode Array Detection-Flow Injection Analysis with Partial Least Squares Calibration Model

NASA Astrophysics Data System (ADS)

Mi, Jiaping; Li, Yuanqian; Zhou, Xiaoli; Zheng, Bo; Zhou, Ying

2006-01-01

A flow injection-CCD diode array detection spectrophotometry with partial least squares (PLS) program for simultaneous determination of iron, copper and cobalt in food samples has been established. The method was based on the chromogenic reaction of the three metal ions and 2- (5-Bromo-2-pyridylazo)-5-diethylaminophenol, 5-Br-PADAP in acetic acid - sodium acetate buffer solution (pH5) with Triton X-100 and ascorbic acid. The overlapped spectra of the colored complexes were collected by charge-coupled device (CCD) - diode array detector and the multi-wavelength absorbance data was processed using partial least squares (PLS) algorithm. Optimum reaction conditions and parameters of flow injection analysis were investigated. The samples of tea, sesame, laver, millet, cornmeal, mung bean and soybean powder were determined by the proposed method. The average recoveries of spiked samples were 91.80%~100.9% for Iron, 92.50%~108.0% for Copper, 93.00%~110.5% for Cobalt, respectively with relative standard deviation (R.S.D) of 1.1%~12.1%. The sampling rate is 45 samples h-1. The determination results of the food samples were in good agreement between the proposed method and ICP-AES.

Method for Measurement of Multi-Degrees-of-Freedom Motion Parameters Based on Polydimethylsiloxane Cross-Coupling Diffraction Gratings.

PubMed

Duan, Junping; Zhu, Qiang; Qian, Kun; Guo, Hao; Zhang, Binzhen

2017-08-30

This work presents a multi-degrees-of-freedom motion parameter measurement method based on the use of cross-coupling diffraction gratings that were prepared on the two sides of a polydimethylsiloxane (PDMS) substrate using oxygen plasma processing technology. The laser beam that travels pass the cross-coupling optical grating would be diffracted into a two-dimensional spot array. The displacement and the gap size of the spot-array were functions of the movement of the laser source, as explained by the Fraunhofer diffraction effect. A 480 × 640 pixel charge-coupled device (CCD) was used to acquire images of the two-dimensional spot-array in real time. A proposed algorithm was then used to obtain the motion parameters. Using this method and the CCD described above, the resolutions of the displacement and the deflection angle were 0.18 μm and 0.0075 rad, respectively. Additionally, a CCD with a higher pixel count could improve the resolutions of the displacement and the deflection angle to sub-nanometer and micro-radian scales, respectively. Finally, the dynamic positions of hovering rotorcraft have been tracked and checked using the proposed method, which can be used to correct the craft's position and provide a method for aircraft stabilization in the sky.

Method for Measurement of Multi-Degrees-of-Freedom Motion Parameters Based on Polydimethylsiloxane Cross-Coupling Diffraction Gratings

NASA Astrophysics Data System (ADS)

Duan, Junping; Zhu, Qiang; Qian, Kun; Guo, Hao; Zhang, Binzhen

2017-08-01

This work presents a multi-degrees-of-freedom motion parameter measurement method based on the use of cross-coupling diffraction gratings that were prepared on the two sides of a polydimethylsiloxane (PDMS) substrate using oxygen plasma processing technology. The laser beam that travels pass the cross-coupling optical grating would be diffracted into a two-dimensional spot array. The displacement and the gap size of the spot-array were functions of the movement of the laser source, as explained by the Fraunhofer diffraction effect. A 480 × 640 pixel charge-coupled device (CCD) was used to acquire images of the two-dimensional spot-array in real time. A proposed algorithm was then used to obtain the motion parameters. Using this method and the CCD described above, the resolutions of the displacement and the deflection angle were 0.18 μm and 0.0075 rad, respectively. Additionally, a CCD with a higher pixel count could improve the resolutions of the displacement and the deflection angle to sub-nanometer and micro-radian scales, respectively. Finally, the dynamic positions of hovering rotorcraft have been tracked and checked using the proposed method, which can be used to correct the craft's position and provide a method for aircraft stabilization in the sky.

The development of a cryogenic over-pressure pump

NASA Astrophysics Data System (ADS)

Alvarez, M.; Cease, H.; Flaugher, B.; Flores, R.; Garcia, J.; Lathrop, A.; Ruiz, F.

2014-01-01

A cryogenic over-pressure pump (OPP) was tested in the prototype telescope liquid nitrogen (LN2) cooling system for the Dark Energy Survey (DES) Project. This OPP consists of a process cylinder (PC), gas generator, and solenoid operated valves (SOVs). It is a positive displacement pump that provided intermittent liquid nitrogen (LN2) flow to an array of charge couple devices (CCDs) for the prototype Dark Energy Camera (DECam). In theory, a heater submerged in liquid would generate the drive gas in a closed loop cooling system. The drive gas would be injected into the PC to displace that liquid volume. However, due to limitations of the prototype closed loop nitrogen system (CCD cooling system) for DECam, a quasiclosed-loop nitrogen system was created. During the test of the OPP, the CCD array was cooled to its designed set point temperature of 173K. It was maintained at that temperature via electrical heaters. The performance of the OPP was captured in pressure, temperature, and flow rate in the CCD LN2 cooling system at Fermi National Accelerator Laboratory (FNAL).

A Star Image Extractor for Small Satellites

NASA Astrophysics Data System (ADS)

Yamada, Yoshiyuki; Yamauchi, Masahiro; Gouda, Naoteru; Kobayashi, Yukiyasu; Tsujimoto, Takuji; Yano, Taihei; Suganuma, Masahiro; Nakasuka, Shinichi; Sako, Nobutada; Inamori, Takaya

We have developed a Star Image Extractor (SIE) which works as an on-board real-time image processor. It is a logic circuit written on an FPGA(Field Programmable Gate Array) device. It detects and extracts only an object data from raw image data. SIE will be required with the Nano-JASMINE 1) satellite. Nano-JASMINE is the small astrometry satellite that observes objects in our galaxy. It will be launched in 2010 and needs two years mission period. Nano-JASMINE observes an object with the TDI (Time Delayed Integration) observation mode. TDI is one of operation modes of CCD detector. Data is obtained, by rotating the imaging system including CCD at a rated synchronized with a vertical charge transfer of CCD. Obtained image data is sent through SIE to the Mission-controller.

Improved Line Tracing Methods for Removal of Bad Streaks Noise in CCD Line Array Image—A Case Study with GF-1 Images

PubMed Central

Wang, Bo; Bao, Jianwei; Wang, Shikui; Wang, Houjun; Sheng, Qinghong

2017-01-01

Remote sensing images could provide us with tremendous quantities of large-scale information. Noise artifacts (stripes), however, made the images inappropriate for vitalization and batch process. An effective restoration method would make images ready for further analysis. In this paper, a new method is proposed to correct the stripes and bad abnormal pixels in charge-coupled device (CCD) linear array images. The method involved a line tracing method, limiting the location of noise to a rectangular region, and corrected abnormal pixels with the Lagrange polynomial algorithm. The proposed detection and restoration method were applied to Gaofen-1 satellite (GF-1) images, and the performance of this method was evaluated by omission ratio and false detection ratio, which reached 0.6% and 0%, respectively. This method saved 55.9% of the time, compared with traditional method. PMID:28441754

Night Sky Weather Monitoring System Using Fish-Eye CCD

NASA Astrophysics Data System (ADS)

Tomida, Takayuki; Saito, Yasunori; Nakamura, Ryo; Yamazaki, Katsuya

Telescope Array (TA) is international joint experiment observing ultra-high energy cosmic rays. TA employs fluorescence detection technique to observe cosmic rays. In this technique, tho existence of cloud significantly affects quality of data. Therefore, cloud monitoring provides important information. We are developing two new methods for evaluating night sky weather with pictures taken by charge-coupled device (CCD) camera. One is evaluating the amount of cloud with pixels brightness. The other is counting the number of stars with contour detection technique. The results of these methods show clear correlation, and we concluded both the analyses are reasonable methods for weather monitoring. We discuss reliability of the star counting method.

Characterization of multiport solid state imagers at megahertz data rates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yates, G.J.; Pena, C.R.; Turko, B.T.

1994-08-01

Test results obtained from two recently developed multiport Charge-Coupled Devices (CCDs) operated at pixel rates in the 10-to-100 MHz range will be presented . The CCDs were evaluated in Los Alamos National Laboratory`s High Speed Solid State Imager Test Station (HSTS) which features PC-based programmable clock waveform generation (Tektronix DAS 9200) and synchronously clocked Digital Sampling Oscilloscopes (DSOs) (LeCroy 9424/9314 series) for CCD pixel data acquisition, analysis and storage. The HSTS also provided special designed optical pinhole array test patterns in the 5-to-50 micron diameter range for use with Xenon Strobe and pulsed laser light sources to simultaneously provide multiplemore » single-pixel illumination patterns to study CCD point-spread-function (PSF) and pixel smear characteristics. The two CCDs tested, EEV model CCD-13 and EG&G Reticon model HSO512J, are both 512 {times} 512 pixel arrays with eight (8) and sixteen (16) video output ports respectively. Both devices are generically Frame Transfer CCDs (FT CCDs) designed for parallel bi-directional vertical readout to augment their multiport design for increased pixel rates over common single port serial readout architecture. Although both CCDs were tested similarly, differences in their designs precluded normalization or any direct comparisons of test results. Rate dependent parameters investigated include S/N, PSF, and MTF. The performance observed for the two imagers at various pixel rates from selected typical output ports is discussed.« less

Effects of space-radiation damage and temperature on CCD noise for the Lyman FUSE mission

NASA Astrophysics Data System (ADS)

Murowinski, Richard G.; Gao, Linzhuang; Deen, Mohamed J.

1993-09-01

Charge coupled device (CCD) imaging arrays are becoming more frequently used in space vehicles and equipment, especially space-based astronomical telescopes. It is important to understand the effects of radiation on a CCD so that its performance degradation during mission lifetime can be predicted, and so that methods to prevent unacceptable performance degradation can be found. Much recent work by various groups has focused on the problems surrounding the loss of charge transfer efficiency and the increase in dark current and dark current spikes in CCDs. The use of a CCD as the fine error sensor in the Lyman Far Ultraviolet Spectroscopic Explorer (FUSE) is limited by its noise performance. In this work we attempt to understand some of the factors surrounding the noise degradation due to radiation in a space environment. Later, we demonstrate how low frequency noise can be used as a characterization tool for studying proton radiation damage in CCDs.

High precision computing with charge domain devices and a pseudo-spectral method therefor

NASA Technical Reports Server (NTRS)

Barhen, Jacob (Inventor); Toomarian, Nikzad (Inventor); Fijany, Amir (Inventor); Zak, Michail (Inventor)

1997-01-01

The present invention enhances the bit resolution of a CCD/CID MVM processor by storing each bit of each matrix element as a separate CCD charge packet. The bits of each input vector are separately multiplied by each bit of each matrix element in massive parallelism and the resulting products are combined appropriately to synthesize the correct product. In another aspect of the invention, such arrays are employed in a pseudo-spectral method of the invention, in which partial differential equations are solved by expressing each derivative analytically as matrices, and the state function is updated at each computation cycle by multiplying it by the matrices. The matrices are treated as synaptic arrays of a neural network and the state function vector elements are treated as neurons. In a further aspect of the invention, moving target detection is performed by driving the soliton equation with a vector of detector outputs. The neural architecture consists of two synaptic arrays corresponding to the two differential terms of the soliton-equation and an adder connected to the output thereof and to the output of the detector array to drive the soliton equation.

Composite x-ray image assembly for large-field digital mammography with one- and two-dimensional positioning of a focal plane array

NASA Technical Reports Server (NTRS)

Halama, G.; McAdoo, J.; Liu, H.

1998-01-01

To demonstrate the feasibility of a novel large-field digital mammography technique, a 1024 x 1024 pixel Loral charge-coupled device (CCD) focal plane array (FPA) was positioned in a mammographic field with one- and two-dimensional scan sequences to obtain 950 x 1800 pixel and 3600 x 3600 pixel composite images, respectively. These experiments verify that precise positioning of FPAs produced seamless composites and that the CCD mosaic concept has potential for high-resolution, large-field imaging. The proposed CCD mosaic concept resembles a checkerboard pattern with spacing left between the CCDs for the driver and readout electronics. To obtain a complete x-ray image, the mosaic must be repositioned four times, with an x-ray exposure at each position. To reduce the patient dose, a lead shield with appropriately patterned holes is placed between the x-ray source and the patient. The high-precision motorized translation stages and the fiber-coupled-scintillating-screen-CCD sensor assembly were placed in the position usually occupied by the film cassette. Because of the high mechanical precision, seamless composites were constructed from the subimages. This paper discusses the positioning, image alignment procedure, and composite image results. The paper only addresses the formation of a seamless composite image from subimages and will not consider the effects of the lead shield, multiple CCDs, or the speed of motion.

Enhanced radiation detectors using luminescent materials

DOEpatents

Vardeny, Zeev V.; Jeglinski, Stefan A.; Lane, Paul A.

2001-01-01

A radiation detecting device comprising a radiation sensing element, and a layer of luminescent material to expand the range of wavelengths over which the sensing element can efficiently detect radiation. The luminescent material being selected to absorb radiation at selected wavelengths, causing the luminescent material to luminesce, and the luminescent radiation being detected by the sensing element. Radiation sensing elements include photodiodes (singly and in arrays), CCD arrays, IR detectors and photomultiplier tubes. Luminescent materials include polymers, oligomers, copolymers and porphyrines, Luminescent layers include thin films, thicker layers, and liquid polymers.

NASA-Texas Planetary Program

NASA Technical Reports Server (NTRS)

Smith, H. J.

1984-01-01

Astronomical observations performed at the McDonald Observatory were summarized. Various spectra obtained from Jupiter, Uranus, Saturn, Neptune, Pluto, Titan, Iapetus, and sundry asteroids were described briefly. Spectra taken of various comets using an IDS (Intensified Dissector Scanner) spectrograph on a 2.7 m telescope were reviewed. The Octicon, a linear array of eight 1872-element Reticon arrays that was installed in the 2.7 m coude spectrograph at the observatory, was described. The 2.7 m coude scanner, 2.7 m coude CCD (charge coupled device), and 2.7 m radial velocity spectrometer were mentioned.

Comparing simulations and test data of a radiation damaged charge-coupled device for the Euclid mission

NASA Astrophysics Data System (ADS)

Skottfelt, Jesper; Hall, David J.; Gow, Jason P. D.; Murray, Neil J.; Holland, Andrew D.; Prod'homme, Thibaut

2017-04-01

The visible imager instrument on board the Euclid mission is a weak-lensing experiment that depends on very precise shape measurements of distant galaxies obtained by a large charge-coupled device (CCD) array. Due to the harsh radiative environment outside the Earth's atmosphere, it is anticipated that the CCDs over the mission lifetime will be degraded to an extent that these measurements will be possible only through the correction of radiation damage effects. We have therefore created a Monte Carlo model that simulates the physical processes taking place when transferring signals through a radiation-damaged CCD. The software is based on Shockley-Read-Hall theory and is made to mimic the physical properties in the CCD as closely as possible. The code runs on a single electrode level and takes the three-dimensional trap position, potential structure of the pixel, and multilevel clocking into account. A key element of the model is that it also takes device specific simulations of electron density as a direct input, thereby avoiding making any analytical assumptions about the size and density of the charge cloud. This paper illustrates how test data and simulated data can be compared in order to further our understanding of the positions and properties of the individual radiation-induced traps.

Signal detectability in diffusive media using phased arrays in conjunction with detector arrays.

PubMed

Kang, Dongyel; Kupinski, Matthew A

2011-06-20

We investigate Hotelling observer performance (i.e., signal detectability) of a phased array system for tasks of detecting small inhomogeneities and distinguishing adjacent abnormalities in uniform diffusive media. Unlike conventional phased array systems where a single detector is located on the interface between two sources, we consider a detector array, such as a CCD, on a phantom exit surface for calculating the Hotelling observer detectability. The signal detectability for adjacent small abnormalities (2 mm displacement) for the CCD-based phased array is related to the resolution of reconstructed images. Simulations show that acquiring high-dimensional data from a detector array in a phased array system dramatically improves the detectability for both tasks when compared to conventional single detector measurements, especially at low modulation frequencies. It is also observed in all studied cases that there exists the modulation frequency optimizing CCD-based phased array systems, where detectability for both tasks is consistently high. These results imply that the CCD-based phased array has the potential to achieve high resolution and signal detectability in tomographic diffusive imaging while operating at a very low modulation frequency. The effect of other configuration parameters, such as a detector pixel size, on the observer performance is also discussed.

3D morphology reconstruction using linear array CCD binocular stereo vision imaging system

NASA Astrophysics Data System (ADS)

Pan, Yu; Wang, Jinjiang

2018-01-01

Binocular vision imaging system, which has a small field of view, cannot reconstruct the 3-D shape of the dynamic object. We found a linear array CCD binocular vision imaging system, which uses different calibration and reconstruct methods. On the basis of the binocular vision imaging system, the linear array CCD binocular vision imaging systems which has a wider field of view can reconstruct the 3-D morphology of objects in continuous motion, and the results are accurate. This research mainly introduces the composition and principle of linear array CCD binocular vision imaging system, including the calibration, capture, matching and reconstruction of the imaging system. The system consists of two linear array cameras which were placed in special arrangements and a horizontal moving platform that can pick up objects. The internal and external parameters of the camera are obtained by calibrating in advance. And then using the camera to capture images of moving objects, the results are then matched and 3-D reconstructed. The linear array CCD binocular vision imaging systems can accurately measure the 3-D appearance of moving objects, this essay is of great significance to measure the 3-D morphology of moving objects.

Preliminary study of the reliability of imaging charge coupled devices

NASA Technical Reports Server (NTRS)

Beall, J. R.; Borenstein, M. D.; Homan, R. A.; Johnson, D. L.; Wilson, D. D.; Young, V. F.

1978-01-01

Imaging CCDs are capable of low light level response and high signal-to-noise ratios. In space applications they offer the user the ability to achieve extremely high resolution imaging with minimum circuitry in the photo sensor array. This work relates the CCD121H Fairchild device to the fundamentals of CCDs and the representative technologies. Several failure modes are described, construction is analyzed and test results are reported. In addition, the relationship of the device reliability to packaging principles is analyzed and test data presented. Finally, a test program is defined for more general reliability evaluation of CCDs.

Experimental research on femto-second laser damaging array CCD cameras

NASA Astrophysics Data System (ADS)

Shao, Junfeng; Guo, Jin; Wang, Ting-feng; Wang, Ming

2013-05-01

Charged Coupled Devices (CCD) are widely used in military and security applications, such as airborne and ship based surveillance, satellite reconnaissance and so on. Homeland security requires effective means to negate these advanced overseeing systems. Researches show that CCD based EO systems can be significantly dazzled or even damaged by high-repetition rate pulsed lasers. Here, we report femto - second laser interaction with CCD camera, which is probable of great importance in future. Femto - second laser is quite fresh new lasers, which has unique characteristics, such as extremely short pulse width (1 fs = 10-15 s), extremely high peak power (1 TW = 1012W), and especially its unique features when interacting with matters. Researches in femto second laser interaction with materials (metals, dielectrics) clearly indicate non-thermal effect dominates the process, which is of vast difference from that of long pulses interaction with matters. Firstly, the damage threshold test are performed with femto second laser acting on the CCD camera. An 800nm, 500μJ, 100fs laser pulse is used to irradiate interline CCD solid-state image sensor in the experiment. In order to focus laser energy onto tiny CCD active cells, an optical system of F/5.6 is used. A Sony production CCDs are chose as typical targets. The damage threshold is evaluated with multiple test data. Point damage, line damage and full array damage were observed when the irradiated pulse energy continuously increase during the experiment. The point damage threshold is found 151.2 mJ/cm2.The line damage threshold is found 508.2 mJ/cm2.The full-array damage threshold is found to be 5.91 J/cm2. Although the phenomenon is almost the same as that of nano laser interaction with CCD, these damage thresholds are substantially lower than that of data obtained from nano second laser interaction with CCD. Then at the same time, the electric features after different degrees of damage are tested with electronic multi meter. The resistance values between clock signal lines are measured. Contrasting the resistance values of the CCD before and after damage, it is found that the resistances decrease significantly between the vertical transfer clock signal lines values. The same results are found between the vertical transfer clock signal line and the earth electrode (ground).At last, the damage position and the damage mechanism were analyzed with above results and SEM morphological experiments. The point damage results in the laser destroying material, which shows no macro electro influence. The line damage is quite different from that of point damage, which shows deeper material corroding effect. More importantly, short circuits are found between vertical clock lines. The full array damage is even more severe than that of line damage starring with SEM, while no obvious different electrical features than that of line damage are found. Further researches are anticipated in femto second laser caused CCD damage mechanism with more advanced tools. This research is valuable in EO countermeasure and/or laser shielding applications.

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

PubMed

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

2013-03-10

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

Optical Readout System for Bi-Material Terahertz Sensors

DTIC Science & Technology

2011-09-01

CCD Charged-Coupled Device DFG Difference-Frequency Generation FOV Field of View FPA Focal Plane Array fps Frames Per Second FTIR Fourier ...techniques in the THz range may be classified as either coherent or incoherent. Basically, coherent detection measures the amplitude and phase of the field...using a lock-in amplifier. In a piezoresistive detector, two electrodes are connected to two deformable temperature–sensitive legs. Monitoring the

An LOD with improved breakdown voltage in full-frame CCD devices

NASA Astrophysics Data System (ADS)

Banghart, Edmund K.; Stevens, Eric G.; Doan, Hung Q.; Shepherd, John P.; Meisenzahl, Eric J.

2005-02-01

In full-frame image sensors, lateral overflow drain (LOD) structures are typically formed along the vertical CCD shift registers to provide a means for preventing charge blooming in the imager pixels. In a conventional LOD structure, the n-type LOD implant is made through the thin gate dielectric stack in the device active area and adjacent to the thick field oxidation that isolates the vertical CCD columns of the imager. In this paper, a novel LOD structure is described in which the n-type LOD impurities are placed directly under the field oxidation and are, therefore, electrically isolated from the gate electrodes. By reducing the electrical fields that cause breakdown at the silicon surface, this new structure permits a larger amount of n-type impurities to be implanted for the purpose of increasing the LOD conductivity. As a consequence of the improved conductance, the LOD width can be significantly reduced, enabling the design of higher resolution imaging arrays without sacrificing charge capacity in the pixels. Numerical simulations with MEDICI of the LOD leakage current are presented that identify the breakdown mechanism, while three-dimensional solutions to Poisson's equation are used to determine the charge capacity as a function of pixel dimension.

A curved surface micro-moiré method and its application in evaluating curved surface residual stress

NASA Astrophysics Data System (ADS)

Zhang, Hongye; Wu, Chenlong; Liu, Zhanwei; Xie, Huimin

2014-09-01

The moiré method is typically applied to the measurement of deformations of a flat surface while, for a curved surface, this method is rarely used other than for projection moiré or moiré interferometry. Here, a novel colour charge-coupled device (CCD) micro-moiré method has been developed, based on which a curved surface micro-moiré (CSMM) method is proposed with a colour CCD and optical microscope (OM). In the CSMM method, no additional reference grating is needed as a Bayer colour filter array (CFA) installed on the OM in front of the colour CCD image sensor performs this role. Micro-moiré fringes with high contrast are directly observed with the OM through the Bayer CFA under the special condition of observing a curved specimen grating. The principle of the CSMM method based on a colour CCD micro-moiré method and its application range and error analysis are all described in detail. In an experiment, the curved surface residual stress near a welded seam on a stainless steel tube was investigated using the CSMM method.

High-speed line-scan camera with digital time delay integration

NASA Astrophysics Data System (ADS)

Bodenstorfer, Ernst; Fürtler, Johannes; Brodersen, Jörg; Mayer, Konrad J.; Eckel, Christian; Gravogl, Klaus; Nachtnebel, Herbert

2007-02-01

Dealing with high-speed image acquisition and processing systems, the speed of operation is often limited by the amount of available light, due to short exposure times. Therefore, high-speed applications often use line-scan cameras, based on charge-coupled device (CCD) sensors with time delayed integration (TDI). Synchronous shift and accumulation of photoelectric charges on the CCD chip - according to the objects' movement - result in a longer effective exposure time without introducing additional motion blur. This paper presents a high-speed color line-scan camera based on a commercial complementary metal oxide semiconductor (CMOS) area image sensor with a Bayer filter matrix and a field programmable gate array (FPGA). The camera implements a digital equivalent to the TDI effect exploited with CCD cameras. The proposed design benefits from the high frame rates of CMOS sensors and from the possibility of arbitrarily addressing the rows of the sensor's pixel array. For the digital TDI just a small number of rows are read out from the area sensor which are then shifted and accumulated according to the movement of the inspected objects. This paper gives a detailed description of the digital TDI algorithm implemented on the FPGA. Relevant aspects for the practical application are discussed and key features of the camera are listed.

Defect detection in slab surface: a novel dual Charge-coupled Device imaging-based fuzzy connectedness strategy.

PubMed

Zhao, Liming; Ouyang, Qi; Chen, Dengfu; Udupa, Jayaram K; Wang, Huiqian; Zeng, Yuebin

2014-11-01

To provide an accurate surface defects inspection system and make the automation of robust image segmentation method a reality in routine production line, a general approach is presented for continuous casting slab (CC-slab) surface defects extraction and delineation. The applicability of the system is not tied to CC-slab exclusively. We combined the line array CCD (Charge-coupled Device) traditional scanning imaging (LS-imaging) and area array CCD laser three-dimensional (3D) scanning imaging (AL-imaging) strategies in designing the system. Its aim is to suppress the respective imaging system's limitations. In the system, the images acquired from the two CCD sensors are carefully aligned in space and in time by maximum mutual information-based full-fledged registration schema. Subsequently, the image information is fused from these two subsystems such as the unbroken 2D information in LS-imaging and 3D depressed information in AL-imaging. Finally, on the basis of the established dual scanning imaging system the region of interest (ROI) localization by seed specification was designed, and the delineation for ROI by iterative relative fuzzy connectedness (IRFC) algorithm was utilized to get a precise inspection result. Our method takes into account the complementary advantages in the two common machine vision (MV) systems and it performs competitively with the state-of-the-art as seen from the comparison of experimental results. For the first time, a joint imaging scanning strategy is proposed for CC-slab surface defect inspection that allows a feasible way of powerful ROI delineation strategies to be applied to the MV inspection field. Multi-ROI delineation by using IRFC in this research field may further improve the results.

Method and apparatus for acquisition and tracking of light sources in a transient event rich environment

NASA Technical Reports Server (NTRS)

Bolin, Kenneth (Inventor); Flynn, David (Inventor); Fowski, Walter (Inventor); Miklus, Kenneth (Inventor); Kissh, Frank (Inventor); Abreu, Rene (Inventor)

1993-01-01

A method and apparatus for tracking a light source in a transient event rich environment locks on to a light source incident on a field-of-view 1 of a charge-coupled-device (CCD) array 6, validates the permanence of said light source and transmits data relating to the brilliance and location of said light source if said light source is determined to be permanent.

Characterization of a fully depleted CCD on high-resistivity silicon

NASA Astrophysics Data System (ADS)

Stover, Richard J.; Wei, Mingzhi; Lee, Y.; Gilmore, David K.; Holland, S. E.; Groom, D. E.; Moses, William W.; Perlmutter, Saul; Goldhaber, G.; Pennypacker, C.; Wang, N. W.; Palaio, N.

1997-04-01

Most scientific CCD imagers are fabricated on 30-50 (Omega) - cm epitaxial silicon. When illuminated form the front side of the device they generally have low quantum efficiency in the blue region of the visible spectrum because of strong absorption in the polycrystalline silicon gates as well as poor quantum efficiency in the far red and near infrared region of the spectrum because of the shallow depletion depth of the low-resistivity silicon. To enhance the blue response of scientific CCDs they are often thinned and illuminated from the back side. While blue response is greatly enhanced by this process, it is expensive and it introduces additional problems for the red end of the spectrum. A typical thinned CCD is 15 to 25 micrometers thick, and at wavelengths beyond about 800 nm the absorption depth becomes comparable to the thickness of the device, leading to interference fringes from reflected light. Because these interference fringes are of high order, the spatial pattern of the fringes is extremely sensitive to small changes in the optical illumination of the detector. Calibration and removal of the effects of the fringes is one of the primary limitations on the performance of astronomical images taken at wavelengths of 800 nm or more. In this paper we present results from the characterization of a CCD which promises to address many of the problems of typical thinned CCDs. The CCD reported on here was fabricated at Lawrence Berkeley National Laboratory (LBNL) on a 10-12 K$OMega-cm n-type silicon substrate.THe CCD is a 200 by 200 15-micrometers square pixel array, and due to the very high resistivity of the starting material, the entire 300 micrometers substrate is depleted. Full depletion works because of the gettering technology developed at LBNL which keeps leakage current down. Both front-side illuminated and backside illuminated devices have been tested. We have measured quantum efficiency, read-noise, full-well, charge-transfer efficiency, and leakage current. We have also observed the effects of clocking waveform shapes on spurious charge generation. While these new CCDs promise to be a major advance in CD technology, they too have limitations such as charge spreading and cosmic-ray effects. These limitations have been characterized and are presented. Examples of astronomical observations obtained with the backside CCD on the 1-meter reflector at Lick Observatory are presented.

Space infrared telescope pointing control system. Infrared telescope tracking in the presence of target motion

NASA Technical Reports Server (NTRS)

Powell, J. D.; Schneider, J. B.

1986-01-01

The use of charge-coupled-devices, or CCD's, has been documented by a number of sources as an effective means of providing a measurement of spacecraft attitude with respect to the stars. A method exists of defocussing and interpolation of the resulting shape of a star image over a small subsection of a large CCD array. This yields an increase in the accuracy of the device by better than an order of magnitude over the case when the star image is focussed upon a single CCD pixel. This research examines the effect that image motion has upon the overall precision of this star sensor when applied to an orbiting infrared observatory. While CCD's collect energy within the visible spectrum of light, the targets of scientific interest may well have no appreciable visible emissions. Image motion has the effect of smearing the image of the star in the direction of motion during a particular sampling interval. The presence of image motion is incorporated into a Kalman filter for the system, and it is shown that the addition of a gyro command term is adequate to compensate for the effect of image motion in the measurement. The updated gyro model is included in this analysis, but has natural frequencies faster than the projected star tracker sample rate for dim stars. The system state equations are reduced by modelling gyro drift as a white noise process. There exists a tradeoff in selected star tracker sample time between the CCD, which has improved noise characteristics as sample time increases, and the gyro, which will potentially drift further between long attitude updates. A sample time which minimizes pointing estimation error exists for the random drift gyro model as well as for a random walk gyro model.

Smart photodetector arrays for error control in page-oriented optical memory

NASA Astrophysics Data System (ADS)

Schaffer, Maureen Elizabeth

1998-12-01

Page-oriented optical memories (POMs) have been proposed to meet high speed, high capacity storage requirements for input/output intensive computer applications. This technology offers the capability for storage and retrieval of optical data in two-dimensional pages resulting in high throughput data rates. Since currently measured raw bit error rates for these systems fall several orders of magnitude short of industry requirements for binary data storage, powerful error control codes must be adopted. These codes must be designed to take advantage of the two-dimensional memory output. In addition, POMs require an optoelectronic interface to transfer the optical data pages to one or more electronic host systems. Conventional charge coupled device (CCD) arrays can receive optical data in parallel, but the relatively slow serial electronic output of these devices creates a system bottleneck thereby eliminating the POM advantage of high transfer rates. Also, CCD arrays are "unintelligent" interfaces in that they offer little data processing capabilities. The optical data page can be received by two-dimensional arrays of "smart" photo-detector elements that replace conventional CCD arrays. These smart photodetector arrays (SPAs) can perform fast parallel data decoding and error control, thereby providing an efficient optoelectronic interface between the memory and the electronic computer. This approach optimizes the computer memory system by combining the massive parallelism and high speed of optics with the diverse functionality, low cost, and local interconnection efficiency of electronics. In this dissertation we examine the design of smart photodetector arrays for use as the optoelectronic interface for page-oriented optical memory. We review options and technologies for SPA fabrication, develop SPA requirements, and determine SPA scalability constraints with respect to pixel complexity, electrical power dissipation, and optical power limits. Next, we examine data modulation and error correction coding for the purpose of error control in the POM system. These techniques are adapted, where possible, for 2D data and evaluated as to their suitability for a SPA implementation in terms of BER, code rate, decoder time and pixel complexity. Our analysis shows that differential data modulation combined with relatively simple block codes known as array codes provide a powerful means to achieve the desired data transfer rates while reducing error rates to industry requirements. Finally, we demonstrate the first smart photodetector array designed to perform parallel error correction on an entire page of data and satisfy the sustained data rates of page-oriented optical memories. Our implementation integrates a monolithic PN photodiode array and differential input receiver for optoelectronic signal conversion with a cluster error correction code using 0.35-mum CMOS. This approach provides high sensitivity, low electrical power dissipation, and fast parallel correction of 2 x 2-bit cluster errors in an 8 x 8 bit code block to achieve corrected output data rates scalable to 102 Gbps in the current technology increasing to 1.88 Tbps in 0.1-mum CMOS.

Study of optimal wavefront sensing with elongated laser guide stars

NASA Astrophysics Data System (ADS)

Thomas, S. J.; Adkins, S.; Gavel, D.; Fusco, T.; Michau, V.

2008-06-01

Over the past decade, adaptive optics (AO) has become an established method for overcoming the effects of atmospheric turbulence on both astronomical imaging and spectroscopic observations. These systems are now beginning to make extensive use of laser guide star (LGS) techniques to improve performance and provide increased sky coverage. Sodium LGS AO employs one or more lasers at 589-nm wavelength to produce an artificial guide star through excitation of sodium atoms in the mesosphere (90 km altitude). Because of its dependence on the abundance and distribution of sodium atoms in the mesosphere, this approach has its own unique set of difficulties not seen with natural stars. The sodium layer exhibits time-dependent variations in density and altitude, and since it is at a finite range, the LGS images become elongated due to the thickness of the layer and the offset between the laser projection point and the subapertures of a Shack-Hartmann wavefront sensor (SHWFS). Elongation causes the LGS image to be spread out resulting in a decrease in the signal-to-noise ratio which, in turn, leads to an increase in SHWFS measurement error and therefore an increased error in wavefront phase reconstruction. To address the problem of elongation, and also to provide a higher level of readout performance and reduced readout noise, a new type of charge-coupled device (CCD) is now under development for Shack-Hartmann wavefront sensing called the polar coordinate CCD. In this device, discrete imaging arrays are provided in each SHWFS subaperture and the size, shape and orientation of each discrete imaging array are adjusted to optimally sample the LGS image. The device is referred to as the polar coordinate CCD because the location of each imager is defined by a polar coordinate system centred on the laser guide star projection point. This concept is especially suited to Extremely Large Telescopes (ELTs) where the effect of perspective elongation is a significant factor. In this paper, we evaluate the performance of centroiders based on this CCD geometry by evaluating the centroid error variance and also the linearity issues associated with LGS image sampling and truncation. We also describe how we will extend this work to address the problems presented by the time variability of the sodium layer and how this will impact SHWFS performance in LGS AO systems.

Flat field anomalies in an x-ray charge coupled device camera measured using a Manson x-ray source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haugh, M. J.; Schneider, M. B.

2008-10-15

The static x-ray imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the x rays produced by lasers hitting a gold foil target. The intensity distribution taken by the SXI camera during a NIF shot is used to determine how accurately NIF can aim laser beams. This is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The charge coupled device (CCD) chip is an x-ray sensitive silicon sensor, with a large format array (2kx2k), 24 {mu}m square pixels, and 15 {mu}mmore » thick. A multianode Manson x-ray source, operating up to 10 kV and 10 W, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/{delta}E{approx_equal}10. The x-ray beam intensity was measured using an x-ray photodiode that has an accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The x-ray beam provides full CCD illumination and is flat, within {+-}1% maximum to minimum. The spectral efficiency was measured at ten energy bands ranging from 930 to 8470 eV. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation occurred at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was not observable below 4 keV. We were also able to observe debris, damage, and surface defects on the CCD chip. The Manson source is a powerful tool for characterizing the imaging errors of an x-ray CCD imager. These errors are quite different from those found in a visible CCD imager.« less

A Compact Imaging Detector of Polarization and Spectral Content

NASA Technical Reports Server (NTRS)

Rust, D. M.; Kumar, A.; Thompson, K. E.

1993-01-01

A new type of image detector will simultaneously analyze the polarization of light at all picture elements in a scene. The integrated Dual Imaging Detector (IDID) consists of a polarizing beam splitter bonded to a charge-coupled device (CCD), with signal-analysis circuitry and analog-to-digital converters, all integrated on a silicon chip. The polarizing beam splitter can be either a Ronchi ruling, or an array of cylindrical lenslets, bonded to a birefringent wafer. The wafer, in turn, is bonded to the CCD so that light in the two orthogonal planes of polarization falls on adjacent pairs of pixels. The use of a high-index birefringent material, e.g., rutile, allows the IDID to operate at f-numbers as high as f/3.5. Other aspects of the detector are discussed.

Automated 3D-Printed Unibody Immunoarray for Chemiluminescence Detection of Cancer Biomarker Proteins

PubMed Central

Tang, C. K.; Vaze, A.; Rusling, J. F.

2017-01-01

A low cost three-dimensional (3D) printed clear plastic microfluidic device was fabricated for fast, low cost automated protein detection. The unibody device features three reagent reservoirs, an efficient 3D network for passive mixing, and an optically transparent detection chamber housing a glass capture antibody array for measuring chemiluminescence output with a CCD camera. Sandwich type assays were built onto the glass arrays using a multi-labeled detection antibody-polyHRP (HRP = horseradish peroxidase). Total assay time was ~30 min in a complete automated assay employing a programmable syringe pump so that the protocol required minimal operator intervention. The device was used for multiplexed detection of prostate cancer biomarker proteins prostate specific antigen (PSA) and platelet factor 4 (PF-4). Detection limits of 0.5 pg mL−1 were achieved for these proteins in diluted serum with log dynamic ranges of four orders of magnitude. Good accuracy vs ELISA was validated by analyzing human serum samples. This prototype device holds good promise for further development as a point-of-care cancer diagnostics tool. PMID:28067370

InSb arrays with CCD readout for 1.0- to 5.5-microns infrared applications

NASA Technical Reports Server (NTRS)

Phillips, J. D.; Scorso, J. B.; Thom, R. D.

1976-01-01

There were two approaches for fabricating indium antimonide (InSb) arrays with CCD readout discussed. The hybrid approach integrated InSb detectors and silicon CCDs in a modular assembly via an advanced interconnection technology. In the monolithic approach, the InSb infrared detectors and the CCD readout were integrated on the same InSb chip. Both approaches utilized intrinsic (band-to-band) photodetection with the attendant advantages over extrinsic detectors. The status of each of these detector readout concepts, with pertinent performance characteristics, was presented.

Isolation Mounting for Charge-Coupled Devices

NASA Technical Reports Server (NTRS)

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

1985-01-01

CCD's suspended by wires under tension. Remote thermoelectric cooling of charge coupled device allows vibration isolating mounting of CCD assembly alone, without having to suspend entire mass and bulk of thermoelectric module. Mounting hardware simple and light. Developed for charge-coupled devices (CCD's) in infrared telescope support adaptable to sensors in variety of environments, e.g., sensors in nuclear reactors, engine exhausts and plasma chambers.

An evaluation of an ICCD imager of dynamic range expansion technique and application of insitu procedures for life-time extension

NASA Technical Reports Server (NTRS)

Currie, D. G.

1982-01-01

Research toward practical implementation of the Intensified Charge Coupled Device (ICCD) as a photon-counting array detector for astronomy is reported. The first area of concentration was to determine the rate and extent of the lifetime limiting damage to the CCD caused by the impact of high energy electrons, and to find whether various methods of annealing the damage were productive. The second effort was to determine the performance of the ICCD in a photon-counting mode to produce extended dynamic range measurements. There are two main effects that appear as the practical results of the electron damage to the CCD. One is an increase in the leakage current, i.e., the normal thermal generation of charge carriers in the silicon that provides a background dark signal that adds to the light produced image. In an undamaged CCD, the leakage current is usually fairly uniform across the photosensitive area of the silicon chip, with the exception of various bright pixels which have an anomalous leakage current well above the overall level.

CCD sensors in synchrotron X-ray detectors

NASA Astrophysics Data System (ADS)

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

1988-04-01

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

A CCD experimental platform for large telescope in Antarctica based on FPGA

NASA Astrophysics Data System (ADS)

Zhu, Yuhua; Qi, Yongjun

2014-07-01

The CCD , as a detector , is one of the important components of astronomical telescopes. For a large telescope in Antarctica, a set of CCD detector system with large size, high sensitivity and low noise is indispensable. Because of the extremely low temperatures and unattended, system maintenance and software and hardware upgrade become hard problems. This paper introduces a general CCD controller experiment platform, using Field programmable gate array FPGA, which is, in fact, a large-scale field reconfigurable array. Taking the advantage of convenience to modify the system, construction of driving circuit, digital signal processing module, network communication interface, control algorithm validation, and remote reconfigurable module may realize. With the concept of integrated hardware and software, the paper discusses the key technology of building scientific CCD system suitable for the special work environment in Antarctica, focusing on the method of remote reconfiguration for controller via network and then offering a feasible hardware and software solution.

Advances in CCD detector technology for x-ray diffraction applications

NASA Astrophysics Data System (ADS)

Thorson, Timothy A.; Durst, Roger D.; Frankel, Dan; Bordwell, Rex L.; Camara, Jose R.; Leon-Guerrero, Edward; Onishi, Steven K.; Pang, Francis; Vu, Paul; Westbrook, Edwin M.

2004-01-01

Phosphor-coupled CCDs are established as one of the most successful technologies for x-ray diffraction. This application demands that the CCD simultaneously achieve both the highest possible sensitivity and high readout speeds. Recently, wafer-scale, back illuminated devices have become available which offer significantly higher quantum efficiency than conventional devices (the Fairchild Imaging CCD 486 BI). However, since back thinning significantly changes the electrical properties of the CCD the high speed operation of wafer-scale, back-illuminated devices is not well understood. Here we describe the operating characteristics (including noise, linearity, full well capacity and CTE) of the back-illuminated CCD 486 at readout speeds up to 4 MHz.

Design of multi-mode compatible image acquisition system for HD area array CCD

NASA Astrophysics Data System (ADS)

Wang, Chen; Sui, Xiubao

2014-11-01

Combining with the current development trend in video surveillance-digitization and high-definition, a multimode-compatible image acquisition system for HD area array CCD is designed. The hardware and software designs of the color video capture system of HD area array CCD KAI-02150 presented by Truesense Imaging company are analyzed, and the structure parameters of the HD area array CCD and the color video gathering principle of the acquisition system are introduced. Then, the CCD control sequence and the timing logic of the whole capture system are realized. The noises of the video signal (KTC noise and 1/f noise) are filtered by using the Correlated Double Sampling (CDS) technique to enhance the signal-to-noise ratio of the system. The compatible designs in both software and hardware for the two other image sensors of the same series: KAI-04050 and KAI-08050 are put forward; the effective pixels of these two HD image sensors are respectively as many as four million and eight million. A Field Programmable Gate Array (FPGA) is adopted as the key controller of the system to perform the modularization design from top to bottom, which realizes the hardware design by software and improves development efficiency. At last, the required time sequence driving is simulated accurately by the use of development platform of Quartus II 12.1 combining with VHDL. The result of the simulation indicates that the driving circuit is characterized by simple framework, low power consumption, and strong anti-interference ability, which meet the demand of miniaturization and high-definition for the current tendency.

Small-angle solution scattering using the mixed-mode pixel array detector.

PubMed

Koerner, Lucas J; Gillilan, Richard E; Green, Katherine S; Wang, Suntao; Gruner, Sol M

2011-03-01

Solution small-angle X-ray scattering (SAXS) measurements were obtained using a 128 × 128 pixel X-ray mixed-mode pixel array detector (MMPAD) with an 860 µs readout time. The MMPAD offers advantages for SAXS experiments: a pixel full-well of >2 × 10(7) 10 keV X-rays, a maximum flux rate of 10(8) X-rays pixel(-1) s(-1), and a sub-pixel point-spread function. Data from the MMPAD were quantitatively compared with data from a charge-coupled device (CCD) fiber-optically coupled to a phosphor screen. MMPAD solution SAXS data from lysozyme solutions were of equal or better quality than data captured by the CCD. The read-noise (normalized by pixel area) of the MMPAD was less than that of the CCD by an average factor of 3.0. Short sample-to-detector distances were required owing to the small MMPAD area (19.2 mm × 19.2 mm), and were revealed to be advantageous with respect to detector read-noise. As predicted by the Shannon sampling theory and confirmed by the acquisition of lysozyme solution SAXS curves, the MMPAD at short distances is capable of sufficiently sampling a solution SAXS curve for protein shape analysis. The readout speed of the MMPAD was demonstrated by continuously monitoring lysozyme sample evolution as radiation damage accumulated. These experiments prove that a small suitably configured MMPAD is appropriate for time-resolved solution scattering measurements.

Small-angle solution scattering using the mixed-mode pixel array detector

PubMed Central

Koerner, Lucas J.; Gillilan, Richard E.; Green, Katherine S.; Wang, Suntao; Gruner, Sol M.

2011-01-01

Solution small-angle X-ray scattering (SAXS) measurements were obtained using a 128 × 128 pixel X-ray mixed-mode pixel array detector (MMPAD) with an 860 µs readout time. The MMPAD offers advantages for SAXS experiments: a pixel full-well of >2 × 107 10 keV X-rays, a maximum flux rate of 108 X-rays pixel−1 s−1, and a sub-pixel point-spread function. Data from the MMPAD were quantitatively compared with data from a charge-coupled device (CCD) fiber-optically coupled to a phosphor screen. MMPAD solution SAXS data from lysozyme solutions were of equal or better quality than data captured by the CCD. The read-noise (normalized by pixel area) of the MMPAD was less than that of the CCD by an average factor of 3.0. Short sample-to-detector distances were required owing to the small MMPAD area (19.2 mm × 19.2 mm), and were revealed to be advantageous with respect to detector read-noise. As predicted by the Shannon sampling theory and confirmed by the acquisition of lysozyme solution SAXS curves, the MMPAD at short distances is capable of sufficiently sampling a solution SAXS curve for protein shape analysis. The readout speed of the MMPAD was demonstrated by continuously monitoring lysozyme sample evolution as radiation damage accumulated. These experiments prove that a small suitably configured MMPAD is appropriate for time-resolved solution scattering measurements. PMID:21335900

Development of InSb charge-coupled infrared imaging devices: Linear imager

NASA Technical Reports Server (NTRS)

Phillips, J. D.

1976-01-01

The following results were accomplished in the development of charge coupled infrared imaging devices: (1) a four-phase overlapping gate with 9 transfers (2-bits) and 1.0-mil gate lengths was successfully operated, (2) the measured transfer efficiency of 0.975 for this device is in excellent agreement with predictions for the reduced gate length device, (3) mask revisions of the channel stop metal on the 8582 mask have been carried out with the result being a large increase in the dc yield of the tested devices, (4) partial optical sensitivity to chopped blackbody radiation was observed for an 8582 9-bit imager, (5) analytical consideration of the modulation transfer function degradation caused by transfer inefficiency in the CCD registers was presented, and (6) for larger array lengths or for the insertion of isolated bits between sensors, improvements in InSb fabrication technology with corresponding decrease in the interface state density are required.

MMW/THz imaging using upconversion to visible, based on glow discharge detector array and CCD camera

NASA Astrophysics Data System (ADS)

Aharon, Avihai; Rozban, Daniel; Abramovich, Amir; Yitzhaky, Yitzhak; Kopeika, Natan S.

2017-10-01

An inexpensive upconverting MMW/THz imaging method is suggested here. The method is based on glow discharge detector (GDD) and silicon photodiode or simple CCD/CMOS camera. The GDD was previously found to be an excellent room-temperature MMW radiation detector by measuring its electrical current. The GDD is very inexpensive and it is advantageous due to its wide dynamic range, broad spectral range, room temperature operation, immunity to high power radiation, and more. An upconversion method is demonstrated here, which is based on measuring the visual light emitting from the GDD rather than its electrical current. The experimental setup simulates a setup that composed of a GDD array, MMW source, and a basic CCD/CMOS camera. The visual light emitting from the GDD array is directed to the CCD/CMOS camera and the change in the GDD light is measured using image processing algorithms. The combination of CMOS camera and GDD focal plane arrays can yield a faster, more sensitive, and very inexpensive MMW/THz camera, eliminating the complexity of the electronic circuits and the internal electronic noise of the GDD. Furthermore, three dimensional imaging systems based on scanning prohibited real time operation of such imaging systems. This is easily solved and is economically feasible using a GDD array. This array will enable us to acquire information on distance and magnitude from all the GDD pixels in the array simultaneously. The 3D image can be obtained using methods like frequency modulation continuous wave (FMCW) direct chirp modulation, and measuring the time of flight (TOF).

Comparing simulations and test data of a radiation damaged CCD for the Euclid mission

NASA Astrophysics Data System (ADS)

Skottfelt, Jesper; Hall, David; Gow, Jason; Murray, Neil; Holland, Andrew; Prod'homme, Thibaut

2016-07-01

The radiation damage effects from the harsh radiative environment outside the Earth's atmosphere can be a cause for concern for most space missions. With the science goals becoming ever more demanding, the requirements on the precision of the instruments on board these missions also increases, and it is therefore important to investigate how the radiation induced damage affects the Charge-Coupled Devices (CCDs) that most of these instruments rely on. The primary goal of the Euclid mission is to study the nature of dark matter and dark energy using weak lensing and baryonic acoustic oscillation techniques. The weak lensing technique depends on very precise shape measurements of distant galaxies obtained by a large CCD array. It is anticipated that over the 6 year nominal lifetime of mission, the CCDs will be degraded to an extent that these measurements will not be possible unless the radiation damage effects are corrected. We have therefore created a Monte Carlo model that simulates the physical processes taking place when transferring signal through a radiation damaged CCD. The software is based on Shockley-Read-Hall theory, and is made to mimic the physical properties in the CCD as close as possible. The code runs on a single electrode level and takes charge cloud size and density, three dimensional trap position, and multi-level clocking into account. A key element of the model is that it takes device specific simulations of electron density as a direct input, thereby avoiding to make any analytical assumptions about the size and density of the charge cloud. This paper illustrates how test data and simulated data can be compared in order to further our understanding of the positions and properties of the individual radiation-induced traps.

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

NASA Astrophysics Data System (ADS)

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.

Delta-Doped Back-Illuminated CMOS Imaging Arrays: Progress and Prospects

NASA Technical Reports Server (NTRS)

Hoenk, Michael E.; Jones, Todd J.; Dickie, Matthew R.; Greer, Frank; Cunningham, Thomas J.; Blazejewski, Edward; Nikzad, Shouleh

2009-01-01

In this paper, we report the latest results on our development of delta-doped, thinned, back-illuminated CMOS imaging arrays. As with charge-coupled devices, thinning and back-illumination are essential to the development of high performance CMOS imaging arrays. Problems with back surface passivation have emerged as critical to the prospects for incorporating CMOS imaging arrays into high performance scientific instruments, just as they did for CCDs over twenty years ago. In the early 1990's, JPL developed delta-doped CCDs, in which low temperature molecular beam epitaxy was used to form an ideal passivation layer on the silicon back surface. Comprising only a few nanometers of highly-doped epitaxial silicon, delta-doping achieves the stability and uniformity that are essential for high performance imaging and spectroscopy. Delta-doped CCDs were shown to have high, stable, and uniform quantum efficiency across the entire spectral range from the extreme ultraviolet through the near infrared. JPL has recently bump-bonded thinned, delta-doped CMOS imaging arrays to a CMOS readout, and demonstrated imaging. Delta-doped CMOS devices exhibit the high quantum efficiency that has become the standard for scientific-grade CCDs. Together with new circuit designs for low-noise readout currently under development, delta-doping expands the potential scientific applications of CMOS imaging arrays, and brings within reach important new capabilities, such as fast, high-sensitivity imaging with parallel readout and real-time signal processing. It remains to demonstrate manufacturability of delta-doped CMOS imaging arrays. To that end, JPL has acquired a new silicon MBE and ancillary equipment for delta-doping wafers up to 200mm in diameter, and is now developing processes for high-throughput, high yield delta-doping of fully-processed wafers with CCD and CMOS imaging devices.

[A capillary blood flow velocity detection system based on linear array charge-coupled devices].

PubMed

Zhou, Houming; Wang, Ruofeng; Dang, Qi; Yang, Li; Wang, Xiang

2017-12-01

In order to detect the flow characteristics of blood samples in the capillary, this paper introduces a blood flow velocity measurement system based on field-programmable gate array (FPGA), linear charge-coupled devices (CCD) and personal computer (PC) software structure. Based on the analysis of the TCD1703C and AD9826 device data sheets, Verilog HDL hardware description language was used to design and simulate the driver. Image signal acquisition and the extraction of the real-time edge information of the blood sample were carried out synchronously in the FPGA. Then a series of discrete displacement were performed in a differential operation to scan each of the blood samples displacement, so that the sample flow rate could be obtained. Finally, the feasibility of the blood flow velocity detection system was verified by simulation and debugging. After drawing the flow velocity curve and analyzing the velocity characteristics, the significance of measuring blood flow velocity is analyzed. The results show that the measurement of the system is less time-consuming and less complex than other flow rate monitoring schemes.

Range imaging laser radar

DOEpatents

Scott, Marion W.

1990-01-01

A laser source is operated continuously and modulated periodically (typicy sinusoidally). A receiver imposes another periodic modulation on the received optical signal, the modulated signal being detected by an array of detectors of the integrating type. Range to the target determined by measuring the phase shift of the intensity modulation on the received optical beam relative to a reference. The receiver comprises a photoemitter for converting the reflected, periodically modulated, return beam to an accordingly modulated electron stream. The electron stream is modulated by a local demodulation signal source and subsequently converted back to a photon stream by a detector. A charge coupled device (CCD) array then averages and samples the photon stream to provide an electrical signal in accordance with the photon stream.

Range imaging laser radar

DOEpatents

Scott, M.W.

1990-06-19

A laser source is operated continuously and modulated periodically (typically sinusoidally). A receiver imposes another periodic modulation on the received optical signal, the modulated signal being detected by an array of detectors of the integrating type. Range to the target determined by measuring the phase shift of the intensity modulation on the received optical beam relative to a reference. The receiver comprises a photoemitter for converting the reflected, periodically modulated, return beam to an accordingly modulated electron stream. The electron stream is modulated by a local demodulation signal source and subsequently converted back to a photon stream by a detector. A charge coupled device (CCD) array then averages and samples the photon stream to provide an electrical signal in accordance with the photon stream. 2 figs.

High-resolution CCD imaging alternatives

NASA Astrophysics Data System (ADS)

Brown, D. L.; Acker, D. E.

1992-08-01

High resolution CCD color cameras have recently stimulated the interest of a large number of potential end-users for a wide range of practical applications. Real-time High Definition Television (HDTV) systems are now being used or considered for use in applications ranging from entertainment program origination through digital image storage to medical and scientific research. HDTV generation of electronic images offers significant cost and time-saving advantages over the use of film in such applications. Further in still image systems electronic image capture is faster and more efficient than conventional image scanners. The CCD still camera can capture 3-dimensional objects into the computing environment directly without having to shoot a picture on film develop it and then scan the image into a computer. 2. EXTENDING CCD TECHNOLOGY BEYOND BROADCAST Most standard production CCD sensor chips are made for broadcast-compatible systems. One popular CCD and the basis for this discussion offers arrays of roughly 750 x 580 picture elements (pixels) or a total array of approximately 435 pixels (see Fig. 1). FOR. A has developed a technique to increase the number of available pixels for a given image compared to that produced by the standard CCD itself. Using an inter-lined CCD with an overall spatial structure several times larger than the photo-sensitive sensor areas each of the CCD sensors is shifted in two dimensions in order to fill in spatial gaps between adjacent sensors.

Real-time two-dimensional imaging of potassium ion distribution using an ion semiconductor sensor with charged coupled device technology.

PubMed

Hattori, Toshiaki; Masaki, Yoshitomo; Atsumi, Kazuya; Kato, Ryo; Sawada, Kazuaki

2010-01-01

Two-dimensional real-time observation of potassium ion distributions was achieved using an ion imaging device based on charge-coupled device (CCD) and metal-oxide semiconductor technologies, and an ion selective membrane. The CCD potassium ion image sensor was equipped with an array of 32 × 32 pixels (1024 pixels). It could record five frames per second with an area of 4.16 × 4.16 mm(2). Potassium ion images were produced instantly. The leaching of potassium ion from a 3.3 M KCl Ag/AgCl reference electrode was dynamically monitored in aqueous solution. The potassium ion selective membrane on the semiconductor consisted of plasticized poly(vinyl chloride) (PVC) with bis(benzo-15-crown-5). The addition of a polyhedral oligomeric silsesquioxane to the plasticized PVC membrane greatly improved adhesion of the membrane onto Si(3)N(4) of the semiconductor surface, and the potential response was stabilized. The potential response was linear from 10(-2) to 10(-5) M logarithmic concentration of potassium ion. The selectivity coefficients were K(K(+),Li(+))(pot) = 10(-2.85), K(K(+),Na(+))(pot) = 10(-2.30), K(K(+),Rb(+))(pot) =10(-1.16), and K(K(+),Cs(+))(pot) = 10(-2.05).

Method for Accurately Calibrating a Spectrometer Using Broadband Light

NASA Technical Reports Server (NTRS)

Simmons, Stephen; Youngquist, Robert

2011-01-01

A novel method has been developed for performing very fine calibration of a spectrometer. This process is particularly useful for modern miniature charge-coupled device (CCD) spectrometers where a typical factory wavelength calibration has been performed and a finer, more accurate calibration is desired. Typically, the factory calibration is done with a spectral line source that generates light at known wavelengths, allowing specific pixels in the CCD array to be assigned wavelength values. This method is good to about 1 nm across the spectrometer s wavelength range. This new method appears to be accurate to about 0.1 nm, a factor of ten improvement. White light is passed through an unbalanced Michelson interferometer, producing an optical signal with significant spectral variation. A simple theory can be developed to describe this spectral pattern, so by comparing the actual spectrometer output against this predicted pattern, errors in the wavelength assignment made by the spectrometer can be determined.

The readout and control system of the mid-size telescope prototype of the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Oya, I.; Anguner, O.; Behera, B.; Birsin, E.; Fuessling, M.; Melkumyan, D.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.; Cta Consortium,the

2014-06-01

The Cherenkov Telescope Array (CTA) is one of the major ground-based astronomy projects being pursued and will be the largest facility for ground-based y-ray observations ever built. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different type and size. A prototype for the Mid-Size Telescope (MST) with a diameter of 12 m has been installed in Berlin and is currently being commissioned. This prototype is composed of a mechanical structure, a drive system and mirror facets mounted with powered actuators to enable active control. Five Charge-Coupled Device (CCD) cameras, and a wide set of sensors allow the evaluation of the performance of the instrument. The design of the control software is following concepts and tools under evaluation within the CTA consortium in order to provide a realistic test-bed for the middleware: 1) The readout and control system for the MST prototype is implemented with the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) distributed control middleware; 2) the OPen Connectivity-Unified Architecture (OPC UA) is used for hardware access; 3) the document oriented MongoDB database is used for an efficient storage of CCD images, logging and alarm information: and 4) MySQL and MongoDB databases are used for archiving the slow control monitoring data and for storing the operation configuration parameters. In this contribution, the details of the implementation of the control system for the MST prototype telescope are described.

Research on Geometric Calibration of Spaceborne Linear Array Whiskbroom Camera

PubMed Central

Sheng, Qinghong; Wang, Qi; Xiao, Hui; Wang, Qing

2018-01-01

The geometric calibration of a spaceborne thermal-infrared camera with a high spatial resolution and wide coverage can set benchmarks for providing an accurate geographical coordinate for the retrieval of land surface temperature. The practice of using linear array whiskbroom Charge-Coupled Device (CCD) arrays to image the Earth can help get thermal-infrared images of a large breadth with high spatial resolutions. Focusing on the whiskbroom characteristics of equal time intervals and unequal angles, the present study proposes a spaceborne linear-array-scanning imaging geometric model, whilst calibrating temporal system parameters and whiskbroom angle parameters. With the help of the YG-14—China’s first satellite equipped with thermal-infrared cameras of high spatial resolution—China’s Anyang Imaging and Taiyuan Imaging are used to conduct an experiment of geometric calibration and a verification test, respectively. Results have shown that the plane positioning accuracy without ground control points (GCPs) is better than 30 pixels and the plane positioning accuracy with GCPs is better than 1 pixel. PMID:29337885

Time delay and integration array (TDI) using charge transfer device technology. Phase 2, volume 1: Technical

NASA Technical Reports Server (NTRS)

1977-01-01

The 20x9 TDI array was developed to meet the LANDSAT Thematic Mapper Requirements. This array is based upon a self-aligned, transparent gate, buried channel process. The process features: (1) buried channel, four phase, overlapping gate CCD's for high transfer efficiency without fat zero; (2) self-aligned transistors to minimize clock feedthrough and parasitic capacitance; and (3) transparent tin oxide electrode for high quantum efficiency with front surface irradiation. The requirements placed on the array and the performance achieved are summarized. This data is the result of flat field measurements only, no imaging or dynamic target measurements were made during this program. Measurements were performed with two different test stands. The bench test equipment fabricated for this program operated at the 8 micro sec line time and employed simple sampling of the gated MOSFET output video signal. The second stand employed Correlated Doubled Sampling (CDS) and operated at 79.2 micro sec line time.

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

NASA Astrophysics Data System (ADS)

Mori, Koji; Nishioka, Yusuke; Ohura, Satoshi; Koura, Yoshiaki; Yamauchi, Makoto; Nakajima, Hiroshi; Ueda, Shutaro; Kan, Hiroaki; Anabuki, Naohisa; Nagino, Ryo; Hayashida, Kiyoshi; Tsunemi, Hiroshi; Kohmura, Takayoshi; Ikeda, Shoma; Murakami, Hiroshi; Ozaki, Masanobu; Dotani, Tadayasu; Maeda, Yukie; Sagara, Kenshi

2013-12-01

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. 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.

Solar XUV Imaging and Non-dispersive Spectroscopy for Solar-C Enabled by Scientific CMOS APS Arrays

NASA Astrophysics Data System (ADS)

Stern, Robert A.; Lemen, J. R.; Shing, L.; Janesick, J.; Tower, J.

2009-05-01

Monolithic CMOS Advanced Pixel Sensor (APS) arrays are showing great promise as eventual replacements for the current workhorse of solar physics focal planes, the scientific CCD. CMOS APS devices have individually addressable pixels, increased radiation tolerance compared to CCDs, and require lower clock voltages, and thus lower power. However, commercially available CMOS chips, while suitable for use with intensifiers or fluorescent coatings, are generally not optimized for direct detection of EUV and X-ray photons. A high performance scientific CMOS array designed for these wavelengths will have significant new capabilities compared to CCDs, including the ability to read out small regions of the solar disk at high (sub sec) cadence, count single X-ray photons with Fano-limited energy resolution, and even operate at room temperature with good noise performance. Such capabilities will be crucial for future solar X-ray and EUV missions such as Solar-C. Sarnoff Corporation has developed scientific grade, monolithic CMOS arrays for X-ray imaging and photon counting. One prototype device, the "minimal" array, has 8 um pixels, is 15 to 25 um thick, is fabricated on high-resistivity ( 10 to 20 kohm-cm) Si wafers, and can be back-illuminated. These characteristics yield high quantum efficiency and high spatial resolution with minimal charge sharing among pixels, making it ideal for the detection of keV X-rays. When used with digital correlated double sampling, the array has demonstrated noise performance as low as 2 e, allowing single photon counting of X-rays over a range of temperatures. We report test results for this device in X-rays, and discuss the implications for future solar space missions.

Real-Time Label-Free Detection of Suspicious Powders Using Noncontact Optical Methods

DTIC Science & Technology

2013-11-05

energy in a small, 1 pound, low power consumption package; and 2) new technology resistive gate linear CCD array detectors developed by Hamamatsu Corp...as a wide range of possible interferent or confusant organic materials such as powdered sugar, granulate sugar, fruit pectin, flower, corn starch ...resolution, room temperature, resistive gate linear CCD array, the BRANE sensor SWAP decreases along with a decrease in sensitivity, but the information

The design and realization of a three-dimensional video system by means of a CCD array

NASA Astrophysics Data System (ADS)

Boizard, J. L.

1985-12-01

Design features and principles and initial tests of a prototype three-dimensional robot vision system based on a laser source and a CCD detector array is described. The use of a laser as a coherent illumination source permits the determination of the relief using one emitter since the location of the source is a known quantity with low distortion. The CCD signal detector array furnishes an acceptable signal/noise ratio and, when wired to an appropriate signal processing system, furnishes real-time data on the return signals, i.e., the characteristic points of an object being scanned. Signal processing involves integration of 29 kB of data per 100 samples, with sampling occurring at a rate of 5 MHz (the CCDs) and yielding an image every 12 msec. Algorithms for filtering errors from the data stream are discussed.

The study of surface acoustic wave charge transfer device

NASA Technical Reports Server (NTRS)

Papanicolaou, N.; Lin, H. C.

1978-01-01

A surface acoustic wave-charge transfer device, consisting of an n-type silicon substrate, a thermally grown silicon dioxide layer, and a sputtered film of piezoelectric zinc oxide is proposed as a means of circumventing problems associated with charge-coupled device (CCD) applications in memory, signal processing, and imaging. The proposed device creates traveling longitudinal electric fields in the silicon and replaces the multiphase clocks in CCD's. The traveling electric fields create potential wells which carry along charges stored there. These charges may be injected into the wells by light or by using a p-n junction as in conventional CCD's.

Integrated infrared detector arrays for low-background astronomy

NASA Technical Reports Server (NTRS)

Mccreight, C. R.

1979-01-01

Existing integrated infrared detector array technology is being evaluated under low-background conditions to determine its applicability in orbiting astronomical applications where extended integration times and photometric accuracy are of interest. Preliminary performance results of a 1 x 20 elements InSb CCD array under simulated astronomical conditions are presented. Using the findings of these tests, improved linear- and area-array technology will be developed for use in NASA programs such as the Shuttle Infrared Telescope Facility. For wavelengths less than 30 microns, extrinsic silicon and intrinsic arrays with CCD readout will be evaluated and improved as required, while multiplexed arrays of Ge:Ga for wavelengths in the range 30 to 120 microns will be developed as fundamental understanding of this material improves. Future efforts will include development of improved drive and readout circuitry, and consideration of alternate multiplexing schemes.

High resolution biomedical imaging system with direct detection of x-rays via a charge coupled device

DOEpatents

Atac, M.; McKay, T.A.

1998-04-21

An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD. 13 figs.

High resolution biomedical imaging system with direct detection of x-rays via a charge coupled device

DOEpatents

Atac, Muzaffer; McKay, Timothy A.

1998-01-01

An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD.

The future scientific CCD

NASA Technical Reports Server (NTRS)

Janesick, J. R.; Elliott, T.; Collins, S.; Marsh, H.; Blouke, M. M.

1984-01-01

Since the first introduction of charge-coupled devices (CCDs) in 1970, CCDs have been considered for applications related to memories, logic circuits, and the detection of visible radiation. It is pointed out, however, that the mass market orientation of CCD development has left largely untapped the enormous potential of these devices for advanced scientific instrumentation. The present paper has, therefore, the objective to introduce the CCD characteristics to the scientific community, taking into account prospects for further improvement. Attention is given to evaluation criteria, a summary of current CCDs, CCD performance characteristics, absolute calibration tools, quantum efficiency, aspects of charge collection, charge transfer efficiency, read noise, and predictions regarding the characteristics of the next generation of silicon scientific CCD imagers.

Jig Aligns Shadow Mask On CCD

NASA Technical Reports Server (NTRS)

Matus, Carlos V.

1989-01-01

Alignment viewed through microscope. Alignment jig positions shadow mask on charge-coupled device (CCD) so metal film deposited on it precisely. Allows CCD package to be inserted and removed without disturbing alignment of mask. Holds CCD packages securely and isolates it electrostatically while providing electrical contact to each of its pins. When alignment jig assembled with CCD, used to move mask under micrometer control.

Applications of charge-coupled device transversal filters to communication

NASA Technical Reports Server (NTRS)

Buss, D. D.; Bailey, W. H.; Brodersen, R. W.; Hewes, C. R.; Tasch, A. F., Jr.

1975-01-01

The paper discusses the computational power of state-of-the-art charged-coupled device (CCD) transversal filters in communications applications. Some of the performance limitations of CCD transversal filters are discussed, with attention given to time delay and bandwidth, imperfect charge transfer efficiency, weighting coefficient error, noise, and linearity. The application of CCD transversal filters to matched filtering, spectral filtering, and Fourier analysis is examined. Techniques for making programmable transversal filters are briefly outlined.

Intra-cavity upconversion to 631 nm of images illuminated by an eye-safe ASE source at 1550 nm.

PubMed

Torregrosa, A J; Maestre, H; Capmany, J

2015-11-15

We report an image wavelength upconversion system. The system mixes an incoming image at around 1550 nm (eye-safe region) illuminated by an amplified spontaneous emission (ASE) fiber source with a Gaussian beam at 1064 nm generated in a continuous-wave diode-pumped Nd(3+):GdVO(4) laser. Mixing takes place in a periodically poled lithium niobate (PPLN) crystal placed intra-cavity. The upconverted image obtained by sum-frequency mixing falls around the 631 nm red spectral region, well within the spectral response of standard silicon focal plane array bi-dimensional sensors, commonly used in charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) video cameras, and of most image intensifiers. The use of ASE illumination benefits from a noticeable increase in the field of view (FOV) that can be upconverted with regard to using coherent laser illumination. The upconverted power allows us to capture real-time video in a standard nonintensified CCD camera.

Study of digital charge coupled devices

NASA Technical Reports Server (NTRS)

Wilson, D. D.; Young, V. F.

1980-01-01

Charge coupled devices represent unique usage of the metal oxide semiconductor concept. These devices can sample an AC signal at the input, transfer charge proportional to this signal through the CCD shift register and then provide an output of the same frequency and shape as the input. The delay time between input and output is controlled by the CCD operating frequency and the number of stages in the shift resistor. This work is a reliability evaluation of the buried channel and surface channel CCD technologies. The constructions are analyzed, failure modes are described, and test results are reported.

Development of a Portable 3CCD Camera System for Multispectral Imaging of Biological Samples

PubMed Central

Lee, Hoyoung; Park, Soo Hyun; Noh, Sang Ha; Lim, Jongguk; Kim, Moon S.

2014-01-01

Recent studies have suggested the need for imaging devices capable of multispectral imaging beyond the visible region, to allow for quality and safety evaluations of agricultural commodities. Conventional multispectral imaging devices lack flexibility in spectral waveband selectivity for such applications. In this paper, a recently developed portable 3CCD camera with significant improvements over existing imaging devices is presented. A beam-splitter prism assembly for 3CCD was designed to accommodate three interference filters that can be easily changed for application-specific multispectral waveband selection in the 400 to 1000 nm region. We also designed and integrated electronic components on printed circuit boards with firmware programming, enabling parallel processing, synchronization, and independent control of the three CCD sensors, to ensure the transfer of data without significant delay or data loss due to buffering. The system can stream 30 frames (3-waveband images in each frame) per second. The potential utility of the 3CCD camera system was demonstrated in the laboratory for detecting defect spots on apples. PMID:25350510

A conceptual design study for a two-dimensional, electronically scanned thinned array radiometer

NASA Technical Reports Server (NTRS)

Mutton, Philip; Chromik, Christopher C.; Dixon, Iain; Statham, Richard B.; Stillwagen, Frederic H.; Vontheumer, Alfred E.; Sasamoto, Washito A.; Garn, Paul A.; Cosgrove, Patrick A.; Ganoe, George G.

1993-01-01

A conceptual design for the Two-Dimensional, Electronically Steered Thinned Array Radiometer (ESTAR) is described. This instrument is a synthetic aperture microwave radiometer that operates in the L-band frequency range for the measurement of soil moisture and ocean salinity. Two auxiliary instruments, an 8-12 micron, scanning infrared radiometer and a 0.4-1.0 micron, charge coupled device (CCD) video camera, are included to provided data for sea surface temperature measurements and spatial registration of targets respectively. The science requirements were defined by Goddard Space Flight Center. Instrument and the spacecraft configurations are described for missions using the Pegasus and Taurus launch vehicles. The analyses and design trades described include: estimations of size, mass and power, instrument viewing coverage, mechanical design trades, structural and thermal analyses, data and communications performance assessments, and cost estimation.

Integrated Dual Imaging Detector

NASA Technical Reports Server (NTRS)

Rust, David M.

1999-01-01

A new type of image detector was designed to simultaneously analyze the polarization of light at all picture elements in a scene. The integrated Dual Imaging detector (IDID) consists of a lenslet array and a polarizing beamsplitter bonded to a commercial charge coupled device (CCD). The IDID simplifies the design and operation of solar vector magnetographs and the imaging polarimeters and spectroscopic imagers used, for example, in atmosphere and solar research. When used in a solar telescope, the vector magnetic fields on the solar surface. Other applications include environmental monitoring, robot vision, and medical diagnoses (through the eye). Innovations in the IDID include (1) two interleaved imaging arrays (one for each polarization plane); (2) large dynamic range (well depth of 10(exp 5) electrons per pixel); (3) simultaneous readout and display of both images; and (4) laptop computer signal processing to produce polarization maps in field situations.

Development of nine-channel 10-micrometer (Hg, Cd)Te pushbroom IR/CCD system

NASA Technical Reports Server (NTRS)

White, W. J.; Wasa, S.

1977-01-01

The engineering development of the 9-channel detector array is documented. The development of the array demonstrates the feasibility of a self scanned multi-element infrared detector focal plane. Procedures for operating the array are outlined.

A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

NASA Technical Reports Server (NTRS)

Kimble, Randy A.; Pain, Bedabrata; Norton, Timothy J.; Haas, J. Patrick; Oegerle, William R. (Technical Monitor)

2002-01-01

Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest of by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

CCD charge collection efficiency and the photon transfer technique

NASA Technical Reports Server (NTRS)

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

1985-01-01

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

Software design of control system of CCD side-scatter lidar

NASA Astrophysics Data System (ADS)

Kuang, Zhiqiang; Liu, Dong; Deng, Qian; Zhang, Zhanye; Wang, Zhenzhu; Yu, Siqi; Tao, Zongming; Xie, Chenbo; Wang, Yingjian

2018-03-01

Because of the existence of blind zone and transition zone, the application of backscattering lidar in near-ground is limited. The side-scatter lidar equipped with the Charge Coupled Devices (CCD) can separate the transmitting and receiving devices to avoid the impact of the geometric factors which is exited in the backscattering lidar and, detect the more precise near-ground aerosol signals continuously. Theories of CCD side-scatter lidar and the design of control system are introduced. The visible control of laser and CCD and automatic data processing method of the side-scatter lidar are developed by using the software of Visual C #. The results which are compared with the calibration of the atmospheric aerosol lidar data show that signals from the CCD side- scatter lidar are convincible.

The OCA CCD Camera Controller

DTIC Science & Technology

1996-01-01

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

VizieR Online Data Catalog: MYStIX: the Chandra X-ray sources (Kuhn+, 2013)

NASA Astrophysics Data System (ADS)

Kuhn, M. A.; Getman, K. V.; Broos, P. S.; Townsley, L. K.; Feigelson, E. D.

2013-11-01

X-ray observations were made with the imaging array on the Advanced CCD Imaging Spectrometer (ACIS-I) on board the Chandra X-Ray Observatory. This array of four CCD detectors subtends 17'x17' on the sky. Data were acquired from the Chandra Data Archive from 2001 Jan to Mar 2008 for 10 MYStIX fields (Flame Nebula, RCW 36, NGC 2264, Rosette Nebula, Lagoon Nebula, NGC 2362, DR 21, RCW 38, Trifid Nebula and NGC 1893); see table1. (2 data files).

Event-Driven Random-Access-Windowing CCD Imaging System

NASA Technical Reports Server (NTRS)

Monacos, Steve; Portillo, Angel; Ortiz, Gerardo; Alexander, James; Lam, Raymond; Liu, William

2004-01-01

A charge-coupled-device (CCD) based high-speed imaging system, called a realtime, event-driven (RARE) camera, is undergoing development. This camera is capable of readout from multiple subwindows [also known as regions of interest (ROIs)] within the CCD field of view. Both the sizes and the locations of the ROIs can be controlled in real time and can be changed at the camera frame rate. The predecessor of this camera was described in High-Frame-Rate CCD Camera Having Subwindow Capability (NPO- 30564) NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 26. The architecture of the prior camera requires tight coupling between camera control logic and an external host computer that provides commands for camera operation and processes pixels from the camera. This tight coupling limits the attainable frame rate and functionality of the camera. The design of the present camera loosens this coupling to increase the achievable frame rate and functionality. From a host computer perspective, the readout operation in the prior camera was defined on a per-line basis; in this camera, it is defined on a per-ROI basis. In addition, the camera includes internal timing circuitry. This combination of features enables real-time, event-driven operation for adaptive control of the camera. Hence, this camera is well suited for applications requiring autonomous control of multiple ROIs to track multiple targets moving throughout the CCD field of view. Additionally, by eliminating the need for control intervention by the host computer during the pixel readout, the present design reduces ROI-readout times to attain higher frame rates. This camera (see figure) includes an imager card consisting of a commercial CCD imager and two signal-processor chips. The imager card converts transistor/ transistor-logic (TTL)-level signals from a field programmable gate array (FPGA) controller card. These signals are transmitted to the imager card via a low-voltage differential signaling (LVDS) cable assembly. The FPGA controller card is connected to the host computer via a standard peripheral component interface (PCI).

Stray light correction on array spectroradiometers for optical radiation risk assessment in the workplace.

PubMed

Barlier-Salsi, A

2014-12-01

The European directive 2006/25/EC requires the employer to assess and, if necessary, measure the levels of exposure to optical radiation in the workplace. Array spectroradiometers can measure optical radiation from various types of sources; however poor stray light rejection affects their accuracy. A stray light correction matrix, using a tunable laser, was developed at the National Institute of Standards and Technology (NIST). As tunable lasers are very expensive, the purpose of this study was to implement this method using only nine low power lasers; other elements of the correction matrix being completed by interpolation and extrapolation. The correction efficiency was evaluated by comparing CCD spectroradiometers with and without correction and a scanning double monochromator device as reference. Similar to findings recorded by NIST, these experiments show that it is possible to reduce the spectral stray light by one or two orders of magnitude. In terms of workplace risk assessment, this spectral stray light correction method helps determine exposure levels, with an acceptable degree of uncertainty, for the majority of workplace situations. The level of uncertainty depends upon the model of spectroradiometers used; the best results are obtained with CCD detectors having an enhanced spectral sensitivity in the UV range. Thus corrected spectroradiometers require a validation against a scanning double monochromator spectroradiometer before using them for risk assessment in the workplace.

Spectral analysis using the CCD Chirp Z-transform

NASA Technical Reports Server (NTRS)

Eversole, W. L.; Mayer, D. J.; Bosshart, P. W.; Dewit, M.; Howes, C. R.; Buss, D. D.

1978-01-01

The charge coupled device (CCD) Chirp Z transformation (CZT) spectral analysis techniques were reviewed and results on state-of-the-art CCD CZT technology are presented. The CZT algorithm was examined and the advantages of CCD implementation are discussed. The sliding CZT which is useful in many spectral analysis applications is described, and the performance limitations of the CZT are studied.

Three-dimensional charge coupled device

DOEpatents

Conder, Alan D.; Young, Bruce K. F.

1999-01-01

A monolithic three dimensional charged coupled device (3D-CCD) which utilizes the entire bulk of the semiconductor for charge generation, storage, and transfer. The 3D-CCD provides a vast improvement of current CCD architectures that use only the surface of the semiconductor substrate. The 3D-CCD is capable of developing a strong E-field throughout the depth of the semiconductor by using deep (buried) parallel (bulk) electrodes in the substrate material. Using backside illumination, the 3D-CCD architecture enables a single device to image photon energies from the visible, to the ultra-violet and soft x-ray, and out to higher energy x-rays of 30 keV and beyond. The buried or bulk electrodes are electrically connected to the surface electrodes, and an E-field parallel to the surface is established with the pixel in which the bulk electrodes are located. This E-field attracts charge to the bulk electrodes independent of depth and confines it within the pixel in which it is generated. Charge diffusion is greatly reduced because the E-field is strong due to the proximity of the bulk electrodes.

Process for fabricating a charge coupled device

DOEpatents

Conder, Alan D.; Young, Bruce K. F.

2002-01-01

A monolithic three dimensional charged coupled device (3D-CCD) which utilizes the entire bulk of the semiconductor for charge generation, storage, and transfer. The 3D-CCD provides a vast improvement of current CCD architectures that use only the surface of the semiconductor substrate. The 3D-CCD is capable of developing a strong E-field throughout the depth of the semiconductor by using deep (buried) parallel (bulk) electrodes in the substrate material. Using backside illumination, the 3D-CCD architecture enables a single device to image photon energies from the visible, to the ultra-violet and soft x-ray, and out to higher energy x-rays of 30 keV and beyond. The buried or bulk electrodes are electrically connected to the surface electrodes, and an E-field parallel to the surface is established with the pixel in which the bulk electrodes are located. This E-field attracts charge to the bulk electrodes independent of depth and confines it within the pixel in which it is generated. Charge diffusion is greatly reduced because the E-field is strong due to the proximity of the bulk electrodes.

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

PubMed

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

2016-03-01

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

Using a delta-doped CCD to determine the energy of a low-energy particle

NASA Technical Reports Server (NTRS)

Nikzad, Shouleh (Inventor); Croley, Donald R. (Inventor); Murphy, Gerald B. (Inventor)

2001-01-01

The back surface of a thinned charged-coupled device (CCD) is treated to eliminate the backside potential well that appears in a conventional thinned CCD during backside illumination. The backside of the CCD includes a delta layer of high-concentration dopant confined to less than one monolayer of the crystal semiconductor. The thinned, delta-doped CCD is used to determine the energy of a very low-energy particle that penetrates less than 1.0 nm into the CCD, such as a proton having energy less than 10 keV.

Delta-doped CCD's as low-energy particle detectors and imagers

NASA Technical Reports Server (NTRS)

Nikzad, Shouleh (Inventor); Hoenk, Michael E. (Inventor); Hecht, Michael H. (Inventor)

2002-01-01

The back surface of a thinned charged-coupled device (CCD) is treated to eliminate the backside potential well that appears in a conventional thinned CCD during backside illumination. The backside of the CCD includes a delta layer of high-concentration dopant confined to less than one monolayer of the crystal semiconductor. The thinned, delta-doped CCD is used to detect very low-energy particles that penetrate less than 1.0 nm into the CCD, including electrons having energies less than 1000 eV and protons having energies less than 10 keV.

Silicide Schottky Barrier For Back-Surface-Illuminated CCD

NASA Technical Reports Server (NTRS)

Hecht, Michael H.

1990-01-01

Quantum efficiency of back-surface-illuminated charge-coupled device (CCD) increased by coating back surface with thin layer of PtSi or IrSi on thin layer of SiO2. In its interaction with positively-doped bulk Si of CCD, silicide/oxide layer forms Schottky barrier that repels electrons, promoting accumulation of photogenerated charge carriers in front-side CCD potential wells. Physical principle responsible for improvement explained in "Metal Film Increases CCD Output" (NPO-16815).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynch, Bart D.; Kozelka, Jakub; Ranade, Manisha K.

In this study, we present three significant artifacts that have the potential to negatively impact the accuracy and precision of film dosimetry measurements made using GAFCHROMIC[reg] EBT radiochromic film when read out with CCD flatbed scanners. Films were scanned using three commonly employed instruments: a Macbeth TD932 spot densitometer, an Epson Expression 1680 CCD array scanner, and a Microtek ScanMaker i900 CCD array scanner. For the two scanners we assessed the variation in optical density (OD) of GAFCHROMIC EBT film with scanning bed position, angular rotation of the film with respect to the scan line direction, and temperature inside themore » scanner due to repeated scanning. Scanning uniform radiochromic films demonstrated a distinct bowing effect in profiles in the direction of the CCD array with a nonuniformity of up to 17%. Profiles along a direction orthogonal to the CCD array demonstrated a 7% variation. A strong angular dependence was found in measurements made with the flatbed scanners; the effect could not be reproduced with the spot densitometer. An IMRT quality assurance film was scanned twice rotating the film 90 deg. between the scans. For films scanned on the Epson scanner, up to 12% variation was observed in unirradiated EBT films rotated between 0 deg. and 90 deg. , which decreased to approximately 8% for EBT films irradiated to 300 cGy. Variations of up to 80% were observed for films scanned with the Microtek scanner. The scanners were found to significantly increase the film temperature with repeated scanning. Film temperature between 18 and 33 deg. C caused OD changes of approximately 7%. Considering these effects, we recommend adherence to a strict scanning protocol that includes: maintaining the orientation of films scanned on flatbed scanners, limiting scanning to the central portion of the scanner bed, and limiting the number of consecutive scans to minimize changes in OD caused by film heating.« less

Monolithic in-based III-V compound semiconductor focal plane array cell with single stage CCD output

NASA Technical Reports Server (NTRS)

Fossum, Eric R. (Inventor); Cunningham, Thomas J. (Inventor); Krabach, Timothy N. (Inventor); Staller, Craig O. (Inventor)

1994-01-01

A monolithic semiconductor imager includes an indium-based III-V compound semiconductor monolithic active layer of a first conductivity type, an array of plural focal plane cells on the active layer, each of the focal plane cells including a photogate over a top surface of the active layer, a readout circuit dedicated to the focal plane cell including plural transistors formed monolithically with the monolithic active layer and a single-stage charge coupled device formed monolithically with the active layer between the photogate and the readout circuit for transferring photo-generated charge accumulated beneath the photogate during an integration period to the readout circuit. The photogate includes thin epitaxial semiconductor layer of a second conductivity type overlying the active layer and an aperture electrode overlying a peripheral portion of the thin epitaxial semiconductor layer, the aperture electrode being connectable to a photogate bias voltage.

Advanced optical position sensors for magnetically suspended wind tunnel models

NASA Technical Reports Server (NTRS)

Lafleur, S.

1985-01-01

A major concern to aerodynamicists has been the corruption of wind tunnel test data by model support structures, such as stings or struts. A technique for magnetically suspending wind tunnel models was considered by Tournier and Laurenceau (1957) in order to overcome this problem. This technique is now implemented with the aid of a Large Magnetic Suspension and Balance System (LMSBS) and advanced position sensors for measuring model attitude and position within the test section. Two different optical position sensors are discussed, taking into account a device based on the use of linear CCD arrays, and a device utilizing area CID cameras. Current techniques in image processing have been employed to develop target tracking algorithms capable of subpixel resolution for the sensors. The algorithms are discussed in detail, and some preliminary test results are reported.

Performance evaluation of integrating detectors for near-infrared fluorescence molecular imaging

NASA Astrophysics Data System (ADS)

Zhu, Banghe; Rasmussen, John C.; Sevick-Muraca, Eva M.

2014-05-01

Although there has been a plethora of devices advanced for clinical translation, there has been no standards to compare and determine the optical device for fluorescence molecular imaging. In this work, we compare different CCD configurations using a solid phantom developed to mimic pM - fM concentrations of near-infrared fluorescent dyes in tissues. Our results show that intensified CCD systems (ICCDs) offer greater contrast at larger signal-tonoise ratios (SNRs) in comparison to their un-intensified CCD systems operated at clinically reasonable, sub-second acquisition times. Furthermore, we compared our investigational ICCD device to the commercial NOVADAQ SPY system, demonstrating different performance in both SNR and contrast.

A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

NASA Technical Reports Server (NTRS)

Kimble, Randy A.; Pain, B.; Norton, T. J.; Haas, P.; Fisher, Richard R. (Technical Monitor)

2001-01-01

Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution for the readout while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest or by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

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

NASA Astrophysics Data System (ADS)

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

2016-09-01

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

CCD research. [design, fabrication, and applications

NASA Technical Reports Server (NTRS)

Gassaway, J. D.

1976-01-01

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

Method for implementation of back-illuminated CMOS or CCD imagers

NASA Technical Reports Server (NTRS)

Pain, Bedabrata (Inventor)

2008-01-01

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

Enhancement of sun-tracking with optoelectronic devices

NASA Astrophysics Data System (ADS)

Wu, Jiunn-Chi

2015-09-01

Sun-tracking is one of the most challenging tasks in implementing CPV. In order to justify the additional complexity of sun-tracking, careful assessment of performance of CPV by monitoring the performance of sun-tracking is vital. Measurement of accuracy of sun-tracking is one of the important tasks in an outdoor test. This study examines techniques with three optoelectronic devices (i.e. position sensitive device (PSD), CCD and webcam). Outdoor measurements indicated that during sunny days (global horizontal insolation (GHI) > 700 W/m2), three devices recorded comparable tracking accuracy of 0.16˜0.3°. The method using a PSD has fastest sampling rate and is able to detect the sun's position without additional image processing. Yet, it cannot identify the sunlight effectively during low insolation. The techniques with a CCD and a webcam enhance the accuracy of centroid of sunlight via the optical lens and image processing. The image quality acquired using a webcam and a CCD is comparable but the webcam is more affordable than that of CCD because it can be assembled with consumer-graded products.

64 x 64 thresholding photodetector array for optical pattern recognition

NASA Astrophysics Data System (ADS)

Langenbacher, Harry; Chao, Tien-Hsin; Shaw, Timothy; Yu, Jeffrey W.

1993-10-01

A high performance 32 X 32 peak detector array is introduced. This detector consists of a 32 X 32 array of thresholding photo-transistor cells, manufactured with a standard MOSIS digital 2-micron CMOS process. A built-in thresholding function that is able to perform 1024 thresholding operations in parallel strongly distinguishes this chip from available CCD detectors. This high speed detector offers responses from one to 10 milliseconds that is much higher than the commercially available CCD detectors operating at a TV frame rate. The parallel multiple peaks thresholding detection capability makes it particularly suitable for optical correlator and optoelectronically implemented neural networks. The principle of operation, circuit design and the performance characteristics are described. Experimental demonstration of correlation peak detection is also provided. Recently, we have also designed and built an advanced version of a 64 X 64 thresholding photodetector array chip. Experimental investigation of using this chip for pattern recognition is ongoing.

CCD Detects Two Images In Quick Succession

NASA Technical Reports Server (NTRS)

Janesick, James R.; Collins, Andy

1996-01-01

Prototype special-purpose charge-coupled device (CCD) designed to detect two 1,024 x 1,024-pixel images in rapid succession. Readout performed slowly to minimize noise. CCD operated in synchronism with pulsed laser, stroboscope, or other pulsed source of light to form pairs of images of rapidly moving objects.

Results of the engineering run of the Coherent Neutrino Nucleus Interaction Experiment (CONNIE)

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A.; Bertou, X.; Bonifazi, C.; Butner, M.; Cancelo, G.; Castañeda Vázquez, A.; Cervantes Vergara, B.; Chavez, C. R.; Da Motta, H.; D'Olivo, J. C.; Dos Anjos, J.; Estrada, J.; Fernandez Moroni, G.; Ford, R.; Foguel, A.; Hernández Torres, K. P.; Izraelevitch, F.; Kavner, A.; Kilminster, B.; Kuk, K.; Lima, H. P., Jr.; Makler, M.; Molina, J.; Moreno-Granados, G.; Moro, J. M.; Paolini, E. E.; Sofo Haro, M.; Tiffenberg, J.; Trillaud, F.; Wagner, S.

2016-07-01

The CONNIE detector prototype is operating at a distance of 30 m from the core of a 3.8 GWth nuclear reactor with the goal of establishing Charge-Coupled Devices (CCD) as a new technology for the detection of coherent elastic neutrino-nucleus scattering. We report on the results of the engineering run with an active mass of 4 g of silicon. The CCD array is described, and the performance observed during the first year is discussed. A compact passive shield was deployed around the detector, producing an order of magnitude reduction in the background rate. The remaining background observed during the run was stable, and dominated by internal contamination in the detector packaging materials. The in-situ calibration of the detector using X-ray lines from fluorescence demonstrates good stability of the readout system. The event rates with the reactor ON and OFF are compared, and no excess is observed coming from nuclear fission at the power plant. The upper limit for the neutrino event rate is set two orders of magnitude above the expectations for the standard model. The results demonstrate the cryogenic CCD-based detector can be remotely operated at the reactor site with stable noise below 2 e- RMS and stable background rates. The success of the engineering test provides a clear path for the upgraded 100 g detector to be deployed during 2016.

Time-resolved spectroscopy using a chopper wheel as a fast shutter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Shicong; Wendt, Amy E.; Boffard, John B.

Widely available, small form-factor, fiber-coupled spectrometers typically have a minimum exposure time measured in milliseconds, and thus cannot be used directly for time-resolved measurements at the microsecond level. Spectroscopy at these faster time scales is typically done with an intensified charge coupled device (CCD) system where the image intensifier acts as a “fast” electronic shutter for the slower CCD array. In this paper, we describe simple modifications to a commercially available chopper wheel system to allow it to be used as a “fast” mechanical shutter for gating a fiber-coupled spectrometer to achieve microsecond-scale time-resolved optical measurements of a periodically pulsedmore » light source. With the chopper wheel synchronized to the pulsing of the light source, the time resolution can be set to a small fraction of the pulse period by using a chopper wheel with narrow slots separated by wide spokes. Different methods of synchronizing the chopper wheel and pulsing of the light sources are explored. The capability of the chopper wheel system is illustrated with time-resolved measurements of pulsed plasmas.« less

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

NASA Technical Reports Server (NTRS)

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

1993-01-01

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

Colorimetric Sensor Array for White Wine Tasting.

PubMed

Chung, Soo; Park, Tu San; Park, Soo Hyun; Kim, Joon Yong; Park, Seongmin; Son, Daesik; Bae, Young Min; Cho, Seong In

2015-07-24

A colorimetric sensor array was developed to characterize and quantify the taste of white wines. A charge-coupled device (CCD) camera captured images of the sensor array from 23 different white wine samples, and the change in the R, G, B color components from the control were analyzed by principal component analysis. Additionally, high performance liquid chromatography (HPLC) was used to analyze the chemical components of each wine sample responsible for its taste. A two-dimensional score plot was created with 23 data points. It revealed clusters created from the same type of grape, and trends of sweetness, sourness, and astringency were mapped. An artificial neural network model was developed to predict the degree of sweetness, sourness, and astringency of the white wines. The coefficients of determination (R2) for the HPLC results and the sweetness, sourness, and astringency were 0.96, 0.95, and 0.83, respectively. This research could provide a simple and low-cost but sensitive taste prediction system, and, by helping consumer selection, will be able to have a positive effect on the wine industry.

Colorimetric Sensor Array for White Wine Tasting

PubMed Central

Chung, Soo; Park, Tu San; Park, Soo Hyun; Kim, Joon Yong; Park, Seongmin; Son, Daesik; Bae, Young Min; Cho, Seong In

2015-01-01

A colorimetric sensor array was developed to characterize and quantify the taste of white wines. A charge-coupled device (CCD) camera captured images of the sensor array from 23 different white wine samples, and the change in the R, G, B color components from the control were analyzed by principal component analysis. Additionally, high performance liquid chromatography (HPLC) was used to analyze the chemical components of each wine sample responsible for its taste. A two-dimensional score plot was created with 23 data points. It revealed clusters created from the same type of grape, and trends of sweetness, sourness, and astringency were mapped. An artificial neural network model was developed to predict the degree of sweetness, sourness, and astringency of the white wines. The coefficients of determination (R2) for the HPLC results and the sweetness, sourness, and astringency were 0.96, 0.95, and 0.83, respectively. This research could provide a simple and low-cost but sensitive taste prediction system, and, by helping consumer selection, will be able to have a positive effect on the wine industry. PMID:26213946

Fabrication and investigation of the bionic curved visual microlens array films

NASA Astrophysics Data System (ADS)

Kuo, Wen-Kai; Lin, Syuan-You; Hsu, Sheng-Wei; Yu, Hsin Her

2017-04-01

The compound eyes of insects are smaller, lighter, and have a wider field of view and high sensitivity to moving targets. In recent years, these advantages have attracted many researchers to develop minimized optical devices. In this study, a high performance microlens was fabricated, mimicking the biological visual feature. Polystyrene (PS) microspheres were synthesized by dispersion polymerization first, and then a close-packed monolayer of PS microspheres was assembled by the Langmuir-Blodgett (LB) deposition method. Following this, a 2D polydimethylsiloxane (PDMS) concave mold was fabricated by a soft lithography technique. Different aperture sizes of poly(methyl methacrylate) (PMMA) curved microlens array replicated films were prepared using traditional Chinese medicine cupping tool with a temperature-controllable hot plate, which eliminated the need for inconvenient metal modeling. The optical performance of the curved microlens films were evaluated by a system of optical microscopy (OM) and a home-made image capture charge-coupled device (CCD). The field of view (FOV) and the light intensity distribution of the curved microlens array were also investigated. We found that a broader field of view corresponded to a smaller aperture size of the curved microlens films, as the convex heights of the films are identical. The resolution of the curved microlens films was not affected by their aperture sizes, but was determined by their interommatidial angle and the diameter of the microlens.

Remote media vision-based computer input device

NASA Astrophysics Data System (ADS)

Arabnia, Hamid R.; Chen, Ching-Yi

1991-11-01

In this paper, we introduce a vision-based computer input device which has been built at the University of Georgia. The user of this system gives commands to the computer without touching any physical device. The system receives input through a CCD camera; it is PC- based and is built on top of the DOS operating system. The major components of the input device are: a monitor, an image capturing board, a CCD camera, and some software (developed by use). These are interfaced with a standard PC running under the DOS operating system.

Online detecting system of roller wear based on laser-linear array CCD technology

NASA Astrophysics Data System (ADS)

Guo, Yuan

2010-10-01

Roller is an important metallurgy tool in the rolling mill. And the surface of a roller affects the quantity of the rolling product directly. After using a period of time, roller must be repaired or replaced. Examining the profile of a working roller between the intervals of rolling is called online detecting for roller wear. The study of online detecting roller wear is very important for selecting the grinding time in reason, reducing the exchanging times of rollers, improving the quality of the product and realizing online grinding rollers. By applying the laser-linear array CCD detective technology, a method for online non-touch detecting roller wear was brought forward. The principle, composition and the operation process of the linear array CCD detecting system were expatiated. And an error compensation algorithm is exactly calculated to offset the shift of the roller axis in this measurement system. So the stability and the accuracy were improved remarkably. The experiment proves that the accuracy of the detecting system reaches to the demand of practical production process. It can provide a new method of high speed and high accuracy online detecting for roller wear.

Single-Shot Spectrally Resolved UV Rayleigh Scattering Measurements in High Speed Flow

NASA Technical Reports Server (NTRS)

Seasholtz, Richard G.

1996-01-01

A single-shot UV molecular Rayleigh scattering technique to measure velocity in high speed flow is described. The beam from an injection-seeded, frequency quadrupled Nd:YAG laser (266 nm) is focused to a line in a free air jet with velocities up to Mach 1.3. Rayleigh scattered light is imaged through a planar mirror Fabry-Perot interferometer onto a Charged Coupled Device (CCD) array detector. Some laser light is also simultaneously imaged through the Fabry-Perot to provide a frequency reference. Two velocity measurements are obtained from each image. Multiple-pulse data are also given. The Rayleigh scattering velocity data show good agreement with velocities calculated from isentropic flow relations.

The SMILE Soft X-ray Imager (SXI) CCD design and development

NASA Astrophysics Data System (ADS)

Soman, M. R.; Hall, D. J.; Holland, A. D.; Burgon, R.; Buggey, T.; Skottfelt, J.; Sembay, S.; Drumm, P.; Thornhill, J.; Read, A.; Sykes, J.; Walton, D.; Branduardi-Raymont, G.; Kennedy, T.; Raab, W.; Verhoeve, P.; Agnolon, D.; Woffinden, C.

2018-01-01

SMILE, the Solar wind Magnetosphere Ionosphere Link Explorer, is a joint science mission between the European Space Agency and the Chinese Academy of Sciences. The spacecraft will be uniquely equipped to study the interaction between the Earth's magnetosphere-ionosphere system and the solar wind on a global scale. SMILE's instruments will explore this science through imaging of the solar wind charge exchange soft X-ray emission from the dayside magnetosheath, simultaneous imaging of the UV northern aurora and in-situ monitoring of the solar wind and magnetosheath plasma and magnetic field conditions. The Soft X-ray Imager (SXI) is the instrument being designed to observe X-ray photons emitted by the solar wind charge exchange process at photon energies between 200 eV and 2000 eV . X-rays will be collected using a focal plane array of two custom-designed CCDs, each consisting of 18 μm square pixels in a 4510 by 4510 array. SMILE will be placed in a highly elliptical polar orbit, passing in and out of the Earth's radiation belts every 48 hours. Radiation damage accumulated in the CCDs during the mission's nominal 3-year lifetime will degrade their performance (such as through decreases in charge transfer efficiency), negatively impacting the instrument's ability to detect low energy X-rays incident on the regions of the CCD image area furthest from the detector outputs. The design of the SMILE-SXI CCDs is presented here, including features and operating methods for mitigating the effects of radiation damage and expected end of life CCD performance. Measurements with a PLATO device that has not been designed for soft X-ray signal levels indicate a temperature-dependent transfer efficiency performance varying between 5×10-5 and 9×10-4 at expected End of Life for 5.9 keV photons, giving an initial set of measurements from which to extrapolate the performance of the SXI CCDs.

Ion profiling in an ambient drift tube-ion mobility spectrometer using a high pixel density linear array detector IonCCD.

PubMed

Davila, Stephen J; Hadjar, Omar; Eiceman, Gary A

2013-07-16

A linear pixel-based detector array, the IonCCD, is characterized for use under ambient conditions with thermal (<1 eV) positive ions derived from purified air and a 10 mCi (63)Ni foil. The IonCCD combined with a drift tube-ion mobility spectrometer permitted the direct detection of gas phase ions at atmospheric pressure and confirmed a limit of detection of 3000 ions/pixel/frame established previously in both the keV (1-2 keV) and the hyper-thermal (10-40 eV) regimes. Results demonstrate the "broad-band" application of the IonCCD over 10(5) orders in ion energy and over 10(10) in operating pressure. The Faraday detector of a drift tube for an ion mobility spectrometer was replaced with the IonCCD providing images of ion profiles over the cross-section of the drift tube. Patterns in the ion profiles were developed in the drift tube cross-section by control of electric fields between wires of Bradbury Nielson and Tyndall Powell shutter designs at distances of 1-8 cm from the detector. Results showed that ion beams formed in wire sets, retained their shape with limited mixing by diffusion and Coulombic repulsion. Beam broadening determined as 95 μm/cm for hydrated protons in air with moisture of ~10 ppmv. These findings suggest a value of the IonCCD in further studies of ion motion and diffusion of thermalized ions, enhancing computational results from simulation programs, and in the design or operation of ion mobility spectrometers.

The control system of the 12-m medium-size telescope prototype: a test-ground for the CTA array control

NASA Astrophysics Data System (ADS)

Oya, I.; Anguner, E. A.; Behera, B.; Birsin, E.; Fuessling, M.; Lindemann, R.; Melkumyan, D.; Schlenstedt, S.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.

2014-07-01

The Cherenkov Telescope Array (CTA) will be the next generation ground-based very-high energy -ray observatory. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different sizes and types and in addition numerous auxiliary devices. In order to provide a test-ground for the CTA array control, the steering software of the 12-m medium size telescope (MST) prototype deployed in Berlin has been implemented using the tools and design concepts under consideration to be used for the control of the CTA array. The prototype control system is implemented based on the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) control middleware, with components implemented in Java, C++ and Python. The interfacing to the hardware is standardized via the Object Linking and Embedding for Process Control Unified Architecture (OPC UA). In order to access the OPC UA servers from the ACS framework in a common way, a library has been developed that allows to tie the OPC UA server nodes, methods and events to the equivalents in ACS components. The front-end of the archive system is able to identify the deployed components and to perform the sampling of the monitoring points of each component following time and value change triggers according to the selected configurations. The back-end of the archive system of the prototype is composed by two different databases: MySQL and MongoDB. MySQL has been selected as storage of the system configurations, while MongoDB is used to have an efficient storage of device monitoring data, CCD images, logging and alarm information. In this contribution, the details and conclusions on the implementation of the control software of the MST prototype are presented.

Establishing Information Security Systems via Optical Imaging

DTIC Science & Technology

2015-08-11

SLM, spatial light modulator; BSC, non - polarizing beam splitter cube; CCD, charge-coupled device. In computational ghost imaging, a series of...Laser Object Computer Fig. 5. A schematic setup for the proposed method using holography: BSC, Beam splitter cube; CCD, Charge-coupled device. The...interference between reference and object beams . (a) (e) (d) (c) (b) Distribution Code A: Approved for public release, distribution is unlimited

Nonlinear time dependence of dark current in charge-coupled devices

NASA Astrophysics Data System (ADS)

Dunlap, Justin C.; Bodegom, Erik; Widenhorn, Ralf

2011-03-01

It is generally assumed that charge-coupled device (CCD) imagers produce a linear response of dark current versus exposure time except near saturation. We found a large number of pixels with nonlinear dark current response to exposure time to be present in two scientific CCD imagers. These pixels are found to exhibit distinguishable behavior with other analogous pixels and therefore can be characterized in groupings. Data from two Kodak CCD sensors are presented for exposure times from a few seconds up to two hours. Linear behavior is traditionally taken for granted when carrying out dark current correction and as a result, pixels with nonlinear behavior will be corrected inaccurately.

New low noise CCD cameras for Pi-of-the-Sky project

NASA Astrophysics Data System (ADS)

Kasprowicz, G.; Czyrkowski, H.; Dabrowski, R.; Dominik, W.; Mankiewicz, L.; Pozniak, K.; Romaniuk, R.; Sitek, P.; Sokolowski, M.; Sulej, R.; Uzycki, J.; Wrochna, G.

2006-10-01

Modern research trends require observation of fainter and fainter astronomical objects on large areas of the sky. This implies usage of systems with high temporal and optical resolution with computer based data acquisition and processing. Therefore Charge Coupled Devices (CCD) became so popular. They offer quick picture conversion with much better quality than film based technologies. This work is theoretical and practical study of the CCD based picture acquisition system. The system was optimized for "Pi of The Sky" project. But it can be adapted to another professional astronomical researches. The work includes issue of picture conversion, signal acquisition, data transfer and mechanical construction of the device.

Measured and calculated K-fluorescence effects on the MTF of an amorphous-selenium based CCD x-ray detector.

PubMed

Hunter, David M; Belev, George; Kasap, Safa; Yaffe, Martin J

2012-02-01

Theoretical reasoning suggests that direct conversion digital x-ray detectors based upon photoconductive amorphous-selenium (a-Se) could attain very high values of the MTF (modulation transfer function) at spatial frequencies well beyond 20 cycles mm(-1). One of the fundamental factors affecting resolution loss, particularly at x-ray energies just above the K-edge of selenium (12.66 keV), is the K-fluorescence reabsorption mechanism, wherein energy can be deposited in the detector at locations laterally displaced from the initial x-ray interaction site. This paper compares measured MTF changes above and below the Se K-edge of a CCD based a-Se x-ray detector with theoretical expectations. A prototype 25 μm sampling pitch (Nyquist frequency = 20 cycles mm(-1), 200 μm thick a-Se layer based x-ray detector, utilizing a specialized CCD readout device (200 × 400 area array), was used to make edge images with monochromatic x-rays above and below the K-edge of Se. A vacuum double crystal monochromator, exposed to polychromatic x-rays from a synchrotron, formed the monochromatic x-ray source. The monochromaticity of the x-rays was 99% or better. The presampling MTF was determined using the slanted edge method. The theory modeling the MTF performance of the detector includes the basic x-ray interaction physics in the a-Se layer as well as effects related to the operation of the CCD and charge trapping at a blocking layer present at the CCD/a-Se interface. The MTF performance of the prototype a-Se CCD was reduced from the theoretical value prescribed by the basic Se x-ray interaction physics, principally by the presence of a blocking layer. Nevertheless, the K-fluorescence reduction in the MTF was observed, approximately as predicted by theory. For the CCD prototype detector, at five cycles mm(-1), there was a 14% reduction of the MTF, from a value of 0.7 below the K-edge of Se, to 0.6 just above the K-edge. The MTF of an a-Se x-ray detector has been measured using monochromatic x-rays above and below the K-edge of selenium. The MTF is poorer above the K-edge by an amount consistent with theoretical expectations.

Angular sensitivity of modeled scientific silicon charge-coupled devices to initial electron direction

NASA Astrophysics Data System (ADS)

Plimley, Brian; Coffer, Amy; Zhang, Yigong; Vetter, Kai

2016-08-01

Previously, scientific silicon charge-coupled devices (CCDs) with 10.5-μm pixel pitch and a thick (650 μm), fully depleted bulk have been used to measure gamma-ray-induced fast electrons and demonstrate electron track Compton imaging. A model of the response of this CCD was also developed and benchmarked to experiment using Monte Carlo electron tracks. We now examine the trade-off in pixel pitch and electronic noise. We extend our CCD response model to different pixel pitch and readout noise per pixel, including pixel pitch of 2.5 μm, 5 μm, 10.5 μm, 20 μm, and 40 μm, and readout noise from 0 eV/pixel to 2 keV/pixel for 10.5 μm pixel pitch. The CCD images generated by this model using simulated electron tracks are processed by our trajectory reconstruction algorithm. The performance of the reconstruction algorithm defines the expected angular sensitivity as a function of electron energy, CCD pixel pitch, and readout noise per pixel. Results show that our existing pixel pitch of 10.5 μm is near optimal for our approach, because smaller pixels add little new information but are subject to greater statistical noise. In addition, we measured the readout noise per pixel for two different device temperatures in order to estimate the effect of temperature on the reconstruction algorithm performance, although the readout is not optimized for higher temperatures. The noise in our device at 240 K increases the FWHM of angular measurement error by no more than a factor of 2, from 26° to 49° FWHM for electrons between 425 keV and 480 keV. Therefore, a CCD could be used for electron-track-based imaging in a Peltier-cooled device.

Scanning Miniature Microscopes without Lenses

NASA Technical Reports Server (NTRS)

Wang, Yu

2009-01-01

The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the nonpolarizing beam splitter were replaced by a polarizing one, then the specimen would be illuminated by s-polarized light. Upon reflection from the specimen, some of the s-polarized light would become p-polarized. Only the p-polarized light would contribute to the image on the CCD; in other words, the image would contain information on the polarization rotating characteristic of the specimen.

An ultrahigh-speed color video camera operating at 1,000,000 fps with 288 frame memories

NASA Astrophysics Data System (ADS)

Kitamura, K.; Arai, T.; Yonai, J.; Hayashida, T.; Kurita, T.; Maruyama, H.; Namiki, J.; Yanagi, T.; Yoshida, T.; van Kuijk, H.; Bosiers, Jan T.; Saita, A.; Kanayama, S.; Hatade, K.; Kitagawa, S.; Etoh, T. Goji

2008-11-01

We developed an ultrahigh-speed color video camera that operates at 1,000,000 fps (frames per second) and had capacity to store 288 frame memories. In 2005, we developed an ultrahigh-speed, high-sensitivity portable color camera with a 300,000-pixel single CCD (ISIS-V4: In-situ Storage Image Sensor, Version 4). Its ultrahigh-speed shooting capability of 1,000,000 fps was made possible by directly connecting CCD storages, which record video images, to the photodiodes of individual pixels. The number of consecutive frames was 144. However, longer capture times were demanded when the camera was used during imaging experiments and for some television programs. To increase ultrahigh-speed capture times, we used a beam splitter and two ultrahigh-speed 300,000-pixel CCDs. The beam splitter was placed behind the pick up lens. One CCD was located at each of the two outputs of the beam splitter. The CCD driving unit was developed to separately drive two CCDs, and the recording period of the two CCDs was sequentially switched. This increased the recording capacity to 288 images, an increase of a factor of two over that of conventional ultrahigh-speed camera. A problem with the camera was that the incident light on each CCD was reduced by a factor of two by using the beam splitter. To improve the light sensitivity, we developed a microlens array for use with the ultrahigh-speed CCDs. We simulated the operation of the microlens array in order to optimize its shape and then fabricated it using stamping technology. Using this microlens increased the light sensitivity of the CCDs by an approximate factor of two. By using a beam splitter in conjunction with the microlens array, it was possible to make an ultrahigh-speed color video camera that has 288 frame memories but without decreasing the camera's light sensitivity.

CCD radiation damage in ESA Cosmic Visions missions: assessment and mitigation

NASA Astrophysics Data System (ADS)

Lumb, David H.

2009-08-01

Charge Coupled Device (CCD) imagers have been widely used in space-borne astronomical instruments. A frequent concern has been the radiation damage effects on the CCD charge transfer properties. We review some methods for assessing the Charge Transfer Inefficiency (CTI) in CCDs. Techniques to minimise degradation using background charge injection and p-channel CCD architectures are discussed. A critical review of the claims for p-channel architectures is presented. The performance advantage for p-channel CCD performance is shown to be lower than claimed previously. Finally we present some projections for the performance in the context of some future ESA missions.

A novel biosensor array with a wheel-like pattern for glucose, lactate and choline based on electrochemiluminescence imaging.

PubMed

Zhou, Zhenyu; Xu, Linru; Wu, Suozhu; Su, Bin

2014-10-07

Electrochemiluminescence (ECL) imaging provides a superior approach to achieve array detection because of its ability for ultrasensitive multiplex analysis. In this paper, we reported a novel ECL imaging biosensor array modified with an enzyme/carbon nanotubes/chitosan composite film for the determination of glucose, choline and lactate. The biosensor array was constructed by integrating a patterned indium tin oxide (ITO) glass plate with six perforated poly(dimethylsiloxane) (PDMS) covers. ECL is generated by the electrochemical reaction between luminol and hydrogen peroxide that is produced by the enzyme catalysed oxidation of different substrates with molecular oxygen, and ECL images were captured by a charge-coupled device (CCD) camera. The separated electrochemical micro-cells enabled simultaneous assay of six samples at different concentrations. From the established calibration curves, the detection limits were 14 μM for glucose, 40 μM for lactate and 97 μM for choline, respectively. Moreover, multicomponent assays and cross reactivity were also studied, both of which were satisfied for the analysis. This biosensing platform based on ECL imaging shows many distinct advantages, including miniaturization, low cost, and multi-functionalization. We believe that this novel ECL imaging biosensor platform will have potential applications in clinical diagnostics, medicine and food inspection.

A compressive-sensing Fourier-transform on-chip Raman spectrometer

NASA Astrophysics Data System (ADS)

Podmore, Hugh; Scott, Alan; Lee, Regina

2018-02-01

We demonstrate a novel compressive sensing Fourier-transform spectrometer (FTS) for snapshot Raman spectroscopy in a compact format. The on-chip FTS consists of a set of planar-waveguide Mach-Zehnder interferometers (MZIs) arrayed on a photonic chip, effecting a discrete Fourier-transform of the input spectrum. Incoherence between the sampling domain (time), and the spectral domain (frequency) permits compressive sensing retrieval using undersampled interferograms for sparse spectra such as Raman emission. In our fabricated device we retain our chosen bandwidth and resolution while reducing the number of MZIs, e.g. the size of the interferogram, to 1/4th critical sampling. This architecture simultaneously reduces chip footprint and concentrates the interferogram in fewer pixels to improve the signal to noise ratio. Our device collects interferogram samples simultaneously, therefore a time-gated detector may be used to separate Raman peaks from sample fluorescence. A challenge for FTS waveguide spectrometers is to achieve multi-aperture high throughput broadband coupling to a large number of single-mode waveguides. A multi-aperture design allows one to increase the bandwidth and spectral resolution without sacrificing optical throughput. In this device, multi-aperture coupling is achieved using an array of microlenses bonded to the surface of the chip, and aligned with a grid of vertically illuminated waveguide apertures. The microlens array accepts a collimated beam with near 100% fill-factor, and the resulting spherical wavefronts are coupled into the single-mode waveguides using 45& mirrors etched into the waveguide layer via focused ion-beam (FIB). The interferogram from the waveguide outputs is imaged using a CCD, and inverted via l1-norm minimization to correctly retrieve a sparse input spectrum.

Development and Characterization of a Chromotomosynthetic Hyperspectral Imaging System

DTIC Science & Technology

2013-03-01

being taken piece-by-piece with photons not collected simultaneously in all spatial or spectral regions, rejecting energy that could contribute to the...alone define the spatial sampling resolution of the system. Incident photons excite the photocathode, which causes a release of electrons that are...create the photons that are incident on the CCD. The fiberoptic coupling between the photocathode and CCD array introduces a FWHM blur with

Final Report, January 1991 - July 1992

NASA Astrophysics Data System (ADS)

Ferrara, Jon

1992-07-01

This report covers final schedules, expenses and billings, monthly reports, testing, and deliveries for this contract. The goal of the detector development program for the Solar and Heliospheric Spacecraft (SOHO) EUV Imaging Telescope (EIT) is an Extreme UltraViolet (EUV) CCD (Change Collecting Device) camera. As a part of the CCD screening effort, the quantum efficiency (QE) of a prototype CCD has been measured in the NRL EUV laboratory over the wavelength range of 256 to 735 Angstroms. A simplified model has been applied to these QE measurements to illustrate the relevant physical processes that determine the performance of the detector. The charge transfer efficiency (CTE) characteristics of the Tektronix 1024 X 1024 CCD being developed for STIS/SOHO space imaging applications have been characterized at different signal levels, operating conditions, and temperatures using a variety of test methods. A number of CCD's have been manufactured using processing techniques developed to improve CTE, and test results on these devices will be used in determining the final chip design. In this paper, we discuss the CTE test methods used and present the results and conclusions of these tests.

Next generation of pnCCDs for X-ray spectroscopy and imaging

NASA Astrophysics Data System (ADS)

Meidinger, Norbert; Andritschke, Robert; Hälker, Olaf; Hartmann, Robert; Herrmann, Sven; Holl, Peter; Lutz, Gerhard; Kimmel, Nils; Schaller, Gerhard; Schnecke, Martina; Schopper, Florian; Soltau, Heike; Strüder, Lothar

2006-11-01

A special type of charge-coupled device, the pnCCD, has been developed in the nineties as focal-plane detector for the X-ray astronomy mission XMM-Newton of the European Space Agency. The pnCCD detector has been in operation since the satellite launch in 1999. It is performing up to date spectroscopy of X-rays in combination with imaging and high time resolution. The excellent performance of the flight camera is still maintained; in particular, the energy resolution has been nearly constant since launch. In order to satisfy the requirements of future X-ray astronomy missions as well as those of ground-based experiments, a new type of pnCCD has been developed. The ‘frame store pnCCD’ shows various optimizations in device design and fabrication process. Devices with up to 256×512 pixels have been fabricated in 2004 and recently tested. Simultaneously, a programmable analog signal processor for the readout of the CCD signals, the DUO CAMEX, has been developed. The readout noise of the new detector has a value of 2 electrons ENC which is less than half of the figure of the XMM-Newton pnCCD. We measured an energy resolution that is close to the theoretical limit given by the Fano noise. In particular the low-energy response of the new devices was substantially improved. The quantum efficiency for X-rays is at least 90% in the entire energy band from 0.3 keV up to 11 keV. This is due to the ultra-thin photon entrance window as well as the full depletion of the 450 μm thick back-illuminated pnCCD. The position resolution is better than the pixel sizes of 75 μm×75 μm or 51 μm×51 μm because the signal charge is spread over up to four pixels which allows a more accurate event position determination. ‘Out of time’ events are substantially reduced to the order of 0.1% by operating the pnCCD in frame store mode. Higher operating temperatures, e.g. -20 °C, are possible due to the smaller thermally generated dark-current level of the new devices and the operation at higher frame rates. Low power consumption applications like for the ROSITA X-ray astronomy mission with low frame rates of, e.g. 20 images/s, as well as high frame rate applications, e.g. 200 images/s, are possible with the same device.

Radiation-hardened backside-illuminated 512 x 512 charge-coupled device

NASA Astrophysics Data System (ADS)

Bates, Philip A.; Levine, Peter A.; Sauer, Donald J.; Hsueh, Fu-Lung; Shallcross, Frank V.; Smeltzer, Ronald K.; Meray, Grazyna M.; Taylor, Gordon C.; Tower, John R.

1995-04-01

A four-port 512 X 512 charge coupled device (CCD) imager hardened against proton displacement damage and total dose degradation has been fabricated and tested. The device is based upon an established thinned, backside illuminated, triple polysilicon, buried channel CCD process technology. The technology includes buried blooming drains. A three step approach has been taken to hardening the device. The first phase addressed hardening against proton displacement damage. The second phase addressed hardening against both proton displacement damage and total dose degradation. The third phase addresses final optimization of the design. Test results from the first and second phase efforts are presented. Plans for the third phase are discussed.

Design and fabrication of an angle-scanning based platform for the construction of surface plasmon resonance biosensor

NASA Astrophysics Data System (ADS)

Hu, Jiandong; Cao, Baiqiong; Wang, Shun; Li, Jianwei; Wei, Wensong; Zhao, Yuanyuan; Hu, Xinran; Zhu, Juanhua; Jiang, Min; Sun, Xiaohui; Chen, Ruipeng; Ma, Liuzheng

2016-03-01

A sensing system for an angle-scanning optical surface-plasmon-resonance (SPR) based biosensor has been designed with a laser line generator in which a P polarizer is embedded to utilize as an excitation source for producing the surface plasmon wave. In this system, the emitting beam from the laser line generator is controlled to realize the angle-scanning using a variable speed direct current (DC) motor. The light beam reflected from the prism deposited with a 50 nm Au film is then captured using the area CCD array which was controlled by a personal computer (PC) via a universal serial bus (USB) interface. The photoelectric signals from the high speed digital camera (an area CCD array) were converted by a 16 bit A/D converter before it transferred to the PC. One of the advantages of this SPR biosensing platform is greatly demonstrated by the label-free and real-time bio-molecular analysis without moving the area CCD array by following the laser line generator. It also could provide a low-cost surface plasmon resonance platform to improve the detection range in the measurement of bioanalytes. The SPR curve displayed on the PC screen promptly is formed by the effective data from the image on the area CCD array and the sensing responses of the platform to bulk refractive indices were calibrated using various concentrations of ethanol solution. These ethanol concentrations indicated with volumetric fraction of 5%, 10%, 15%, 20%, and 25%, respectively, were experimented to validate the performance of the angle-scanning optic SPR biosensing platform. As a result, the SPR sensor was capable to detect a change in the refractive index of the ethanol solution with the relative high linearity at the correlation coefficient of 0.9842. This greatly enhanced detection range is obtained from the position relationship between the laser line generator and the right-angle prism to allow direct quantification of the samples over a wide range of concentrations.

SCP -- A Simple CCD Processing Package

NASA Astrophysics Data System (ADS)

Lewis, J. R.

This note describes a small set of programs, written at RGO, which deal with basic CCD frame processing (e.g. bias subtraction, flat fielding, trimming etc.). The need to process large numbers of CCD frames from devices such as FOS or ISIS in order to extract spectra has prompted the writing of routines which will do the basic hack-work with a minimal amount of interaction from the user. Although they were written with spectral data in mind, there are no ``spectrum-specific'' features in the software which means they can be applied to any CCD data.

Scientific grade CCDs from EG & G Reticon

NASA Technical Reports Server (NTRS)

Cizdziel, Philip J.

1990-01-01

The design and performance of three scientific grade CCDs are summarized: a 1200 x 400 astronomical array of 27 x 27 sq micron pixels, a 512 x 512 scientific array of 27 x 27 sq micron pixels and a 404 x 64 VNIR array of 52 x 52 sq micron pixels. Each of the arrays is fabricated using a four phase, double poly, buried n-channel, multi-pinned phase CCD process. Performance data for each sensor is presented.

Nonlinear optical cryptosystem based on joint Fresnel transform correlator under vector wave illumination

NASA Astrophysics Data System (ADS)

Xueju, Shen; Chao, Lin; Xiao, Zou; Jianjun, Cai

2015-05-01

We present a nonlinear optical cryptosystem with multi-dimensional keys including phase, polarization and diffraction distance. To make full use of the degrees of freedom that optical processing offers, an elaborately designed vector wave with both a space-variant phase and locally linear polarization is generated with a common-path interferometer for illumination. The joint transform correlator in the Fresnel domain, implemented with a double optical wedge, is utilized as the encryption framework which provides an additional key known as the Fresnel diffraction distance. Two nonlinear operations imposed on the recorded joint Fresnel power distribution (JFPD) by a charge coupled device (CCD) are adopted. The first one is the division of power distribution of the reference window random function which is previously proposed by researchers and can improve the quality of the decrypted image. The second one is the recording of a hybrid JFPD using a micro-polarizers array with orthogonal and random transmissive axes attached to the CCD. Then the hybrid JFPD is further scrambled by substituting random noise for partial power distribution. The two nonlinear operations break the linearity of this cryptosystem and provide ultra security. We verify our proposal using a quick response code for noise-free recovery.

Microtomography with photon counting detectors: improving the quality of tomographic reconstruction by voxel-space oversampling

NASA Astrophysics Data System (ADS)

Dudak, J.; Zemlicka, J.; Karch, J.; Hermanova, Z.; Kvacek, J.; Krejci, F.

2017-01-01

Photon counting detectors Timepix are known for their unique properties enabling X-ray imaging with extremely high contrast-to-noise ratio. Their applicability has been recently further improved since a dedicated technique for assembling large area Timepix detector arrays was introduced. Despite the fact that the sensitive area of Timepix detectors has been significantly increased, the pixel pitch is kept unchanged (55 microns). This value is much larger compared to widely used and popular X-ray imaging cameras utilizing scintillation crystals and CCD-based read-out. On the other hand, photon counting detectors provide steeper point-spread function. Therefore, with given effective pixel size of an acquired radiography, Timepix detectors provide higher spatial resolution than X-ray cameras with scintillation-based devices unless the image is affected by penumbral blur. In this paper we take an advance of steep PSF of photon counting detectors and test the possibility to improve the quality of computed tomography reconstruction using finer sampling of reconstructed voxel space. The achieved results are presented in comparison with data acquired under the same conditions using a commercially available state-of-the-art CCD X-ray camera.

Improved Scanners for Microscopic Hyperspectral Imaging

NASA Technical Reports Server (NTRS)

Mao, Chengye

2009-01-01

Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version, the window would be a slit, the CCD would contain a one-dimensional array of pixels, and the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion. The image built up by scanning in this case would be an ordinary (non-spectral) image. In another version, the optics of which are depicted in the lower part of the figure, the spatial window would be a slit, the CCD would contain a two-dimensional array of pixels, the slit image would be refocused onto the CCD by a relay-lens pair consisting of a collimating and a focusing lens, and a prism-gratingprism optical spectrometer would be placed between the collimating and focusing lenses. Consequently, the image on the CCD would be spatially resolved along the slit axis and spectrally resolved along the axis perpendicular to the slit. As in the first-mentioned version, the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion.

Development of an Integrated Countermeasure Device for Long Duration Space Flight and Exploration Missions

NASA Technical Reports Server (NTRS)

Lee, S. M. C.; Streeper, T.; Spiering, B. A.; Loehr, J. A.; Guilliams, M. E.; Bloomberg, J. J.; Mulavara, A. P.; Cavanagh, P. R.; Lang, T.

2010-01-01

Musculoskeletal, cardiovascular, and sensorimotor deconditioning have been observed consistently in astronauts and cosmonauts following long-duration spaceflight. Studies in bed rest, a spaceflight analog, have shown that high intensity resistive or aerobic exercise attenuates or prevents musculoskeletal and cardiovascular deconditioning, respectively, but complete protection has not been achieved during spaceflight. Exercise countermeasure hardware used during earlier International Space Station (ISS) missions included a cycle ergometer, a treadmill, and the interim resistive exercise device (iRED). Effectiveness of the countermeasures may have been diminished by limited loading characteristics of the iRED as well as speed restrictions and subject harness discomfort during treadmill exercise. The Advanced Resistive Exercise Device (ARED) and the second generation treadmill were designed to address many of the limitations of their predecessors, and anecdotal reports from ISS crews suggest that their conditioning is better preserved since the new hardware was delivered in 2009. However, several countermeasure devices to protect different physiologic systems will not be practical during exploration missions when the available volume and mass will be severely restricted. The combined countermeasure device (CCD) integrates a suite of hardware into one device intended to prevent spaceflight-induced musculoskeletal, cardiovascular, and sensorimotor deconditioning. The CCD includes pneumatic loading devices with attached cables for resistive exercise, a cycle for aerobic exercise, and a 6 degree of freedom motion platform for balance training. In a proof of concept test, ambulatory untrained subjects increased muscle strength (58%) as well as aerobic capacity (26%) after 12-weeks of exercise training with the CCD (without balance training), improvements comparable to those observed with traditional exercise training. These preliminary results suggest that this CCD can concurrently improve musculoskeletal and cardiovascular conditioning in ambulatory subjects, but further work is required to validate its use as countermeasure to spaceflight-induced deconditioning.

Vision communications based on LED array and imaging sensor

NASA Astrophysics Data System (ADS)

Yoo, Jong-Ho; Jung, Sung-Yoon

2012-11-01

In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

Optical and dark characterization of the PLATO CCD at ESA

NASA Astrophysics Data System (ADS)

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

2016-07-01

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

Considerations on Circuit Design and Data Acquisition of a Portable Surface Plasmon Resonance Biosensing System.

PubMed

Chang, Keke; Chen, Ruipeng; Wang, Shun; Li, Jianwei; Hu, Xinran; Liang, Hao; Cao, Baiqiong; Sun, Xiaohui; Ma, Liuzheng; Zhu, Juanhua; Jiang, Min; Hu, Jiandong

2015-08-19

The aim of this study was to develop a circuit for an inexpensive portable biosensing system based on surface plasmon resonance spectroscopy. This portable biosensing system designed for field use is characterized by a special structure which consists of a microfluidic cell incorporating a right angle prism functionalized with a biomolecular identification membrane, a laser line generator and a data acquisition circuit board. The data structure, data memory capacity and a line charge-coupled device (CCD) array with a driving circuit for collecting the photoelectric signals are intensively focused on and the high performance analog-to-digital (A/D) converter is comprehensively evaluated. The interface circuit and the photoelectric signal amplifier circuit are first studied to obtain the weak signals from the line CCD array in this experiment. Quantitative measurements for validating the sensitivity of the biosensing system were implemented using ethanol solutions of various concentrations indicated by volume fractions of 5%, 8%, 15%, 20%, 25%, and 30%, respectively, without a biomembrane immobilized on the surface of the SPR sensor. The experiments demonstrated that it is possible to detect a change in the refractive index of an ethanol solution with a sensitivity of 4.99838 × 10(5) ΔRU/RI in terms of the changes in delta response unit with refractive index using this SPR biosensing system, whereby the theoretical limit of detection of 3.3537 × 10(-5) refractive index unit (RIU) and a high linearity at the correlation coefficient of 0.98065. The results obtained from a series of tests confirmed the practicality of this cost-effective portable SPR biosensing system.

Enhanced performance CCD output amplifier

DOEpatents

Dunham, Mark E.; Morley, David W.

1996-01-01

A low-noise FET amplifier is connected to amplify output charge from a che coupled device (CCD). The FET has its gate connected to the CCD in common source configuration for receiving the output charge signal from the CCD and output an intermediate signal at a drain of the FET. An intermediate amplifier is connected to the drain of the FET for receiving the intermediate signal and outputting a low-noise signal functionally related to the output charge signal from the CCD. The amplifier is preferably connected as a virtual ground to the FET drain. The inherent shunt capacitance of the FET is selected to be at least equal to the sum of the remaining capacitances.

Scientific CCD technology at JPL

NASA Technical Reports Server (NTRS)

Janesick, J.; Collins, S. A.; Fossum, E. R.

1991-01-01

Charge-coupled devices (CCD's) were recognized for their potential as an imaging technology almost immediately following their conception in 1970. Twenty years later, they are firmly established as the technology of choice for visible imaging. While consumer applications of CCD's, especially the emerging home video camera market, dominated manufacturing activity, the scientific market for CCD imagers has become significant. Activity of the Jet Propulsion Laboratory and its industrial partners in the area of CCD imagers for space scientific instruments is described. Requirements for scientific imagers are significantly different from those needed for home video cameras, and are described. An imager for an instrument on the CRAF/Cassini mission is described in detail to highlight achieved levels of performance.

Total ionizing dose effect and damage mechanism on saturation output voltage of charge coupled device

NASA Astrophysics Data System (ADS)

Wen, Lin; Li, Yu-dong; Guo, Qi; Wang, Chao-min

2018-02-01

Total ionizing dose effect is a major threat to space applications of CCD, which leads to the decrease of CCD saturation output voltage and the increase of dark signal. This paper investigated CCD and its readout circuit for experimental samples of different channel width to length ratio of MOSFET, and readout circuit amplifier, and CCD. The irradiation source was 60Co- gamma ray. through testing the parameters degradation of MOSFET and amplifier degradation, the generation and annealing law of irradiation induced defects in MOS single tube are analyzed. Combined with the radiation effect of amplifier and CCD, The correlation of radiation damage of the MOSFET and the readout circuit amplifier and CCD parameter degradation is established. Finally, this paper reveals the physical mechanism of ionizing radiation damage of the readout circuit. The research results provide a scientific basis for the selection of anti-radiation technology and structure optimization of domestic CCD.

Development of Measurement Device of Working Radius of Crane Based on Single CCD Camera and Laser Range Finder

NASA Astrophysics Data System (ADS)

Nara, Shunsuke; Takahashi, Satoru

In this paper, what we want to do is to develop an observation device to measure the working radius of a crane truck. The device has a single CCD camera, a laser range finder and two AC servo motors. First, in order to measure the working radius, we need to consider algorithm of a crane hook recognition. Then, we attach the cross mark on the crane hook. Namely, instead of the crane hook, we try to recognize the cross mark. Further, for the observation device, we construct PI control system with an extended Kalman filter to track the moving cross mark. Through experiments, we show the usefulness of our device including new control system of mark tracking.

Soft X-ray and XUV imaging with a charge-coupled device /CCD/-based detector

NASA Technical Reports Server (NTRS)

Loter, N. G.; Burstein, P.; Krieger, A.; Ross, D.; Harrison, D.; Michels, D. J.

1981-01-01

A soft X-ray/XUV imaging camera which uses a thinned, back-illuminated, all-buried channel RCA CCD for radiation sensing has been built and tested. The camera is a slow-scan device which makes possible frame integration if necessary. The detection characteristics of the device have been tested over the 15-1500 eV range. The response was linear with exposure up to 0.2-0.4 erg/sq cm; saturation occurred at greater exposures. Attention is given to attempts to resolve single photons with energies of 1.5 keV.

The application of charge-coupled device processors in automatic-control systems

NASA Technical Reports Server (NTRS)

Mcvey, E. S.; Parrish, E. A., Jr.

1977-01-01

The application of charge-coupled device (CCD) processors to automatic-control systems is suggested. CCD processors are a new form of semiconductor component with the unique ability to process sampled signals on an analog basis. Specific implementations of controllers are suggested for linear time-invariant, time-varying, and nonlinear systems. Typical processing time should be only a few microseconds. This form of technology may become competitive with microprocessors and minicomputers in addition to supplementing them.

LSI arrays for space stations

NASA Technical Reports Server (NTRS)

Gassaway, J. D.

1976-01-01

Two approaches have been taken to study CCD's and some of their fundamental limitations. First a numerical analysis approach has been developed to solve the coupled transport and Poisson's equation for a thorough analysis of charge transfer in a CCD structure. The approach is formulated by treating the minority carriers as a surface distribution at the Si-SiO2 interface and setting up coupled difference equations for the charge and the potential. The SOR method is proposed for solving the two dimensional Poisson's equation for the potential. Methods are suggested for handling the discontinuities to improve convergence. Second, CCD shift registers were fabricated with parameters which should allow complete charge transfer independent of the transfer electrode gap width. A test instrument was designed and constructed which can be used to test this, or any similar, three phase CCD shift register.

Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

NASA Astrophysics Data System (ADS)

Prele, D.

2015-08-01

As we have seen for digital camera market and a sensor resolution increasing to "megapixels", all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, "simple" and "efficient" techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described.

Initial results from a cryogenic proton irradiation of a p-channel CCD

NASA Astrophysics Data System (ADS)

Gow, J. P. D.; Wood, D.; Burt, D.; Hall, D. J.; Dryer, B.; Holland, A. D.; Murray, N. J.

2015-08-01

The displacement damage hardness that can be achieved using p-channel charge coupled devices (CCD) was originally demonstrated in 1997 and since then a number of other studies have demonstrated an improved tolerance to radiationinduced CTI when compared to n-channel CCDs. A number of recent studies have also shown that the temperature history of the device after the irradiation impacts the performance of the detector, linked to the mobility of defects at different temperatures. This study describes the initial results from an e2v technologies p-channel CCD204 irradiated at 153 K with a 10 MeV equivalent proton fluences of 1.24×109 and 1.24×1011 protons.cm-2. The number of defects identified using trap pumping, dark current and cosmetic quality immediately after irradiation and over a period of 150 hours after the irradiation with the device held at 153 K and then after different periods of time at room temperature are described. The device also exhibited a flatband voltage shift of around 30 mV per krad, determined by the reduction in full well capacity.

Colostomy, management and quality of life for the patient.

PubMed

Swan, Elaine

The aim of this article is to describe the development and use of a new and unique continence control device (CCD). The Vitala TM CCD is a pouchless ostomy device that seals against the stoma and prevents the passage of stool, while allowing the release and deodorization of flatus. This will enable many end-colostomates to control their effluent. It is the first non-invasive product to temporarily meet the colostomate's need of faecal continence. The reasons why people receive stomas and the different products available for their management will be explored in this article. Issues with regard to quality of life and the patient experience are discussed in the context of results from a VitalaTM CCD phase III 12-hour study. Two short case studies are also presented to illustrate how VitalaTM CCD can be used by ostomates experiencing functional and/or psychological problems to improve quality of life by allowing them to regain continence for up to 12 hours.

Methods of dark signal determination for CCD array spectroradiometers used in solar UVR measurements.

PubMed

Baczynska, K A; Khazova, M

2015-02-01

The methods of the dark signal determination by direct contemporaneous measurements using a light spectrum and modelling of the dark signal based on the dark signal characterisation data were discussed. These techniques were tested with two charge-couple detectors (CCD) array spectroradiometers used in solar UVR measurements. The sensitivity of both instruments was significantly reduced when shutters were used; the measured signal varied by up to 12% depending on the orientation of the shutter. The shutters should be permanently attached to the SSR, so that the orientation cannot be changed to prevent an increase in uncertainty. The method of using blind pixels from the optically inactive part of the CCD array in a light spectrum could be used to derive the dark signal with some limitations for integration times <10 s for the QE65000. An alternative method of deriving the dark signal from light measurements using out-of-range pixels has been proved impossible due to out-of-range stray light in both instruments. The dark signal was characterised for the range of integration times and ambient temperatures of 15-35°C. Based on these data, the model of the dark signal was developed so that a single value of the dark signal can be subtracted over the whole spectral range if the instrument temperature is known. © Crown copyright 2014.

Compression of CCD raw images for digital still cameras

NASA Astrophysics Data System (ADS)

Sriram, Parthasarathy; Sudharsanan, Subramania

2005-03-01

Lossless compression of raw CCD images captured using color filter arrays has several benefits. The benefits include improved storage capacity, reduced memory bandwidth, and lower power consumption for digital still camera processors. The paper discusses the benefits in detail and proposes the use of a computationally efficient block adaptive scheme for lossless compression. Experimental results are provided that indicate that the scheme performs well for CCD raw images attaining compression factors of more than two. The block adaptive method also compares favorably with JPEG-LS. A discussion is provided indicating how the proposed lossless coding scheme can be incorporated into digital still camera processors enabling lower memory bandwidth and storage requirements.

A Framework for Propagation of Uncertainties in the Kepler Data Analysis Pipeline

NASA Technical Reports Server (NTRS)

Clarke, Bruce D.; Allen, Christopher; Bryson, Stephen T.; Caldwell, Douglas A.; Chandrasekaran, Hema; Cote, Miles T.; Girouard, Forrest; Jenkins, Jon M.; Klaus, Todd C.; Li, Jie;

Distributed optical microsensors for hydrogen leak detection and related applications

NASA Astrophysics Data System (ADS)

Hunter, Scott R.; Patton, James F.; Sepaniak, Michael J.; Datskos, Panos G.; Smith, D. Barton

2010-04-01

Significant advances have recently been made to develop optically interrogated microsensor based chemical sensors with specific application to hydrogen vapor sensing and leak detection in the hydrogen economy. We have developed functionalized polymer-film and palladium/silver alloy coated microcantilever arrays with nanomechanical sensing for this application. The uniqueness of this approach is in the use of independent component analysis (ICA) and the classification techniques of neural networks to analyze the signals produced by an array of microcantilever sensors. This analysis identifies and quantifies the amount of hydrogen and other trace gases physisorbed on the arrays. Selectivity is achieved by using arrays of functionalized sensors with a moderate distribution of specificity among the sensing elements. The device consists of an array of beam-shaped transducers with molecular recognition phases (MRPs) applied to one surface of the transducers. Bending moments on the individual transducers can be detected by illuminating them with a laser or an LED and then reading the reflected light with an optical position sensitive detector (PSD) such as a CCD. Judicious selection of MRPs for the array provides multiple isolated interaction surfaces for sensing the environment. When a particular chemical agent binds to a transducer, the effective surface stresses of its modified and uncoated sides change unequally and the transducer begins to bend. The extent of bending depends upon the specific interactions between the microcantilever's MRP and the analyte. Thus, the readout of a multi-MRP array is a complex multidimensional signal that can be analyzed to deconvolve a multicomponent gas mixture. The use of this sensing and analysis technique in unattended networked arrays of sensors for various monitoring and surveillance applications is discussed.

CCDs in the Mechanics Lab--A Competitive Alternative? (Part I).

ERIC Educational Resources Information Center

Pinto, Fabrizio

1995-01-01

Reports on the implementation of a relatively low-cost, versatile, and intuitive system to teach basic mechanics based on the use of a Charge-Coupled Device (CCD) camera and inexpensive image-processing and analysis software. Discusses strengths and limitations of CCD imaging technologies. (JRH)

Autonomous Low Earth Orbit Satellite and Orbital Debris Tracking Using Mid Aperture COTS Optical Trackers

NASA Astrophysics Data System (ADS)

Ehrhorn, B.; Azari, D.

Low Earth Orbit (LEO) and Orbital Debris tracking have become considerably important with regard to Space Situational Awareness (SSA). This paper discusses the capabilities of autonomous LEO and Orbital Debris Tracking Systems using commercially available (mid aperture 20-24 inch) telescopes, tracking gimbals, and CCD imagers. RC Optical Systems has been developing autonomous satellite trackers that allow for unattended acquisition, imaging, and orbital determination of LEOs using low cost COTS equipment. The test setup from which we are gathering data consists of an RC Optical Systems Professional Series Elevation over Azimuth Gimbal with field de-rotation, RC Optical Systems 20 inch Ritchey-Chretien Telescope coupled to an e2v CCD42-40 CCD array, and 77mm f/4 tracking lens coupled to a KAF-0402ME CCD array. Central to success of LEO acquisition and open loop tracking is accurate modeling of Gimbal and telescope misalignments and flexures. Using pro-TPoint and a simple automated mapping routine we have modeled our primary telescope to achieve pointing and tracking accuracies within a population standard deviation of 1.3 arc-sec (which is 1.1 arc-sec RMS). Once modeled, a mobile system can easily and quickly be calibrated to the sky using a simple 6-10 star map to solve for axis tilt and collimation coefficients. Acquisition of LEO satellites is accomplished through the use of a wide field imager. Using a 77mm f/4 lens and 765 x 510 x 9mu CCD array yields a 1.28 x 0.85 degree field of view in our test setup. Accurate boresite within the acquisition array is maintained throughout the full range of motion through differential tpoint modeling of the main and acquisition imagers. Satellite identification is accomplished by detecting a stationary centroid as a point source and differentiating from the background of streaked stars in a single frame. We found 100% detection rate of LEO with radar cross sections (RCS) of > 0.5 meter*meter within the acquisition array, and approximately 90% within 0.25 degrees of center. Tests of open loop tracking revealed a vast majority of satellites remain within the main detector area of 0.19 x 0.19 degrees after initial centering. Once acquired, the satellite is centered within the main imager via automated adjustment of the epoch and inclination using non-linear least square fit. Thereafter, real time satellite position is sequentially determined and recorded using the main imaging array. Real time determination of the SGP4 Keplerian elements are solved using non-linear least squares regression. The tracking propagator is periodically updated to reflect the solved Keplerian elements in order to maintain the satellite position near image center. These processes are accomplished without the need for user intervention. Unattended fully autonomous LEO satellite tracking and orbital determination simply requires scheduling of appropriate targets and scripted command of the tracking system.

The Prediction and Observation of the 1997 July 18 Stellar Occultation by Triton: More Evidence for Distortion and Increasing Pressure in Triton's Atmosphere

NASA Technical Reports Server (NTRS)

Elliot, J. L.; Person, M. J.; McDonald, S. W.; Buie, M. W.; Dunham, E. W.; Millis, R. L.; Nye, R. A.; Olkin, C. B.; Wasserman, L. H.; Young, L. A.

2000-01-01

We used CCD (charge coupled device) astrometric data to predict where the occultation path of the star Tr 176 was located, on July 18, 1997. It could be seen from northern Australia and the southern section of North America. We set up an array of portable and mixed telescopes which had high-speed photometric equipment to observe the occultation. Goals included the following: (1) mapping the central flash; (2) obtaining light curves for the signal-to-noise ratio; (3) acquiring light curves from Triton's disk. We combined these with data from others to find the radius and geometry of the half-light surface of the atmosphere, as well as the equivalent-isothermal temperature latitudes below the occultation on Triton.

Internal reflection sensors with high angular resolution

NASA Astrophysics Data System (ADS)

Shavirin, I.; Strelkov, O.; Vetskous, A.; Norton-Wayne, L.; Harwood, R.

1996-07-01

We discuss the use of total internal reflection for the production of sensors with high angular resolution. These sensors are intended for measurement of the angle between a sensor's axis and the direction to a source of radiation or reflecting object. Sensors of this type are used in controlling the position of machine parts in robotics and industry, orienting space vehicles and astronomic devices in relation to the Sun, and as autocollimators for checking angles of deviation. This kind of sensor was used in the Apollo space vehicle some 20 years ago. Using photodetectors with linear and area CCD arrays has opened up new application possibilities for appropriately designed sensors. A generalized methodology is presented applicable to a wide range of tasks. Some modifications that can improve the performance of the basic design are described.

Image intensification; Proceedings of the Meeting, Los Angeles, CA, Jan. 17, 18, 1989

NASA Astrophysics Data System (ADS)

Csorba, Illes P.

Various papers on image intensification are presented. Individual topics discussed include: status of high-speed optical detector technologies, super second generation imge intensifier, gated image intensifiers and applications, resistive-anode position-sensing photomultiplier tube operational modeling, undersea imaging and target detection with gated image intensifier tubes, image intensifier modules for use with commercially available solid state cameras, specifying the components of an intensified solid state television camera, superconducting IR focal plane arrays, one-inch TV camera tube with very high resolution capacity, CCD-Digicon detector system performance parameters, high-resolution X-ray imaging device, high-output technology microchannel plate, preconditioning of microchannel plate stacks, recent advances in small-pore microchannel plate technology, performance of long-life curved channel microchannel plates, low-noise microchannel plates, development of a quartz envelope heater.

A system design of data acquisition and processing for side-scatter lidar

NASA Astrophysics Data System (ADS)

Zhang, ZhanYe; Xie, ChenBo; Wang, ZhenZhu; Kuang, ZhiQiang; Deng, Qian; Tao, ZongMing; Liu, Dong; Wang, Yingjian

2018-03-01

A system for collecting data of Side-Scatter lidar based on Charge Coupled Device (CCD),is designed and implemented. The system of data acquisition is based on Microsoft. Net structure and the language of C# is used to call dynamic link library (DLL) of CCD for realization of the real-time data acquisition and processing. The software stores data as txt file for post data acquisition and analysis. The system has ability to operate CCD device in all-day, automatic, continuous and high frequency data acquisition and processing conditions, which will catch 24-hour information of the atmospheric scatter's light intensity and retrieve the spatial and temporal properties of aerosol particles. The experimental result shows that the system is convenient to observe the aerosol optical characteristics near surface.

Breast Biopsy System

NASA Technical Reports Server (NTRS)

1994-01-01

Charge Coupled Devices (CCDs) are high technology silicon chips that connect light directly into electronic or digital images, which can be manipulated or enhanced by computers. When Goddard Space Flight Center (GSFC) scientists realized that existing CCD technology could not meet scientific requirements for the Hubble Space Telescope Imagining Spectrograph, GSFC contracted with Scientific Imaging Technologies, Inc. (SITe) to develop an advanced CCD. SITe then applied many of the NASA-driven enhancements to the manufacture of CCDs for digital mammography. The resulting device images breast tissue more clearly and efficiently. The LORAD Stereo Guide Breast Biopsy system incorporates SITe's CCD as part of a digital camera system that is replacing surgical biopsy in many cases. Known as stereotactic needle biopsy, it is performed under local anesthesia with a needle and saves women time, pain, scarring, radiation exposure and money.

Using confidence intervals to evaluate the focus alignment of spectrograph detector arrays.

PubMed

Sawyer, Travis W; Hawkins, Kyle S; Damento, Michael

2017-06-20

High-resolution spectrographs extract detailed spectral information of a sample and are frequently used in astronomy, laser-induced breakdown spectroscopy, and Raman spectroscopy. These instruments employ dispersive elements such as prisms and diffraction gratings to spatially separate different wavelengths of light, which are then detected by a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) detector array. Precise alignment along the optical axis (focus position) of the detector array is critical to maximize the instrumental resolution; however, traditional approaches of scanning the detector through focus lack a quantitative measure of precision, limiting the repeatability and relying on one's experience. Here we propose a method to evaluate the focus alignment of spectrograph detector arrays by establishing confidence intervals to measure the alignment precision. We show that propagation of uncertainty can be used to estimate the variance in an alignment, thus providing a quantitative and repeatable means to evaluate the precision and confidence of an alignment. We test the approach by aligning the detector array of a prototype miniature echelle spectrograph. The results indicate that the procedure effectively quantifies alignment precision, enabling one to objectively determine when an alignment has reached an acceptable level. This quantitative approach also provides a foundation for further optimization, including automated alignment. Furthermore, the procedure introduced here can be extended to other alignment techniques that rely on numerically fitting data to a model, providing a general framework for evaluating the precision of alignment methods.

A matter of collection and detection for intraoperative and noninvasive near-infrared fluorescence molecular imaging: To see or not to see?

PubMed Central

Zhu, Banghe; Rasmussen, John C.; Sevick-Muraca, Eva M.

2014-01-01

Purpose: Although fluorescence molecular imaging is rapidly evolving as a new combinational drug/device technology platform for molecularly guided surgery and noninvasive imaging, there remains no performance standards for efficient translation of “first-in-humans” fluorescent imaging agents using these devices. Methods: The authors employed a stable, solid phantom designed to exaggerate the confounding effects of tissue light scattering and to mimic low concentrations (nM–pM) of near-infrared fluorescent dyes expected clinically for molecular imaging in order to evaluate and compare the commonly used charge coupled device (CCD) camera systems employed in preclinical studies and in human investigational studies. Results: The results show that intensified CCD systems offer greater contrast with larger signal-to-noise ratios in comparison to their unintensified CCD systems operated at clinically reasonable, subsecond acquisition times. Conclusions: Camera imaging performance could impact the success of future “first-in-humans” near-infrared fluorescence imaging agent studies. PMID:24506637

A matter of collection and detection for intraoperative and noninvasive near-infrared fluorescence molecular imaging: To see or not to see?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Banghe; Rasmussen, John C.; Sevick-Muraca, Eva M., E-mail: Eva.Sevick@uth.tmc.edu

2014-02-15

Purpose: Although fluorescence molecular imaging is rapidly evolving as a new combinational drug/device technology platform for molecularly guided surgery and noninvasive imaging, there remains no performance standards for efficient translation of “first-in-humans” fluorescent imaging agents using these devices. Methods: The authors employed a stable, solid phantom designed to exaggerate the confounding effects of tissue light scattering and to mimic low concentrations (nM–pM) of near-infrared fluorescent dyes expected clinically for molecular imaging in order to evaluate and compare the commonly used charge coupled device (CCD) camera systems employed in preclinical studies and in human investigational studies. Results: The results show thatmore » intensified CCD systems offer greater contrast with larger signal-to-noise ratios in comparison to their unintensified CCD systems operated at clinically reasonable, subsecond acquisition times. Conclusions: Camera imaging performance could impact the success of future “first-in-humans” near-infrared fluorescence imaging agent studies.« less

6 x 6-cm fully depleted pn-junction CCD for high-resolution spectroscopy in the 0.1- to 15-keV photon energy range

NASA Astrophysics Data System (ADS)

von Zanthier, Christoph; Holl, Peter; Kemmer, Josef; Lechner, Peter; Maier, B.; Soltau, Heike; Stoetter, R.; Braeuninger, Heinrich W.; Dennerl, Konrad; Haberl, Frank; Hartmann, R.; Hartner, Gisela D.; Hippmann, H.; Kastelic, E.; Kink, W.; Krause, N.; Meidinger, Norbert; Metzner, G.; Pfeffermann, Elmar; Popp, M.; Reppin, Claus; Stoetter, Diana; Strueder, Lothar; Truemper, Joachim; Weber, U.; Carathanassis, D.; Engelhard, S.; Gebhart, Th.; Hauff, D.; Lutz, G.; Richter, R. H.; Seitz, H.; Solc, P.; Bihler, Edgar; Boettcher, H.; Kendziorra, Eckhard; Kraemer, J.; Pflueger, Bernhard; Staubert, Ruediger

1998-04-01

The concept and performance of the fully depleted pn- junction CCD system, developed for the European XMM- and the German ABRIXAS-satellite missions for soft x-ray imaging and spectroscopy in the 0.1 keV to 15 keV photon range, is presented. The 58 mm X 60 mm large pn-CCD array uses pn- junctions for registers and for the backside instead of MOS registers. This concept naturally allows to fully deplete the detector volume to make it an efficient detector to photons with energies up to 15 keV. For high detection efficiency in the soft x-ray region down to 100 eV, an ultrathin pn-CCD backside deadlayer has been realized. Each pn-CCD-channel is equipped with an on-chip JFET amplifier which, in combination with the CAMEX-amplifier and multiplexing chip, facilitates parallel readout with a pixel read rate of 3 MHz and an electronic noise floor of ENC < e-. With the complete parallel readout, very fast pn-CCD readout modi can be implemented in the system which allow for high resolution photon spectroscopy of even the brightest x-ray sources in the sky.

Heat dissipation schemes in QCLs monitored by CCD thermoreflectance (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pierscinski, Kamil; Pierścińska, Dorota; Morawiec, Magdalena; Gutowski, Piotr; Karbownik, Piotr; Serebrennikova, Olga; Bugajski, Maciej

2017-02-01

In this paper we present the development of the instrumentation for accurate evaluation of the thermal characteristics of quantum cascade lasers based on CCD thermoreflectance (CCD TR). This method allows rapid thermal characterization of QCLs, as the registration of high-resolution map of the whole device facet lasts only several seconds. The capabilities of the CCD TR are used to study temperature dissipation schemes in different designs of QCLs. We report on the investigation of thermal performance of QCLs developed at the Institute of Electron Technology, with an emphasis on the influence of different material system, processing technology and device designs. We investigate and compare AlInAs/InGaAs/InP QCLs (lattice matched and strain compensated) of different architectures, i.e., double trench and buried heterostructure (BH) in terms of thermal management. Experimental results are in very good agreement with numerical predictions of heat dissipation in various device constructions. Numerical model is based on FEM model solved by commercial software package. The model assumes anisotropic thermal conductivity in the AR layers as well as the temperature dependence of thermal conductivities of all materials in the project. We have observed experimentally improvement of thermal properties of devices based on InP materials, especially for buried heterostructure type. The use of buried heterostructure enhanced the lateral heat dissipation from the active region of QCLs. The BH structure and epilayer-down bonding help dissipate the heat generated from active core of the QCL.

High-Voltage Clock Driver for Photon-Counting CCD Characterization

NASA Technical Reports Server (NTRS)

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.

Design of a CCD Camera for Space Surveillance

DTIC Science & Technology

2016-03-05

Laboratory fabricated CCID-51M, a 2048x1024 pixel Charge Couple Device (CCD) imager. [1] The mission objective is to observe and detect satellites in...phased to transfer the charge to the outputs. An electronic shutter is created by having an equal area of pixels covered by an opaque metal mask. The...Figure 4 CDS Timing Diagram By design the CCD readout rate is 400 KHz. This rate was chosen so reading the 2E6 pixels from one output is less than

Development of CCD imaging sensors for space applications, phase 1

NASA Technical Reports Server (NTRS)

Antcliffe, G. A.

1975-01-01

The results of an experimental investigation to develop a large area charge coupled device (CCD) imager for space photography applications are described. Details of the design and processing required to achieve 400 X 400 imagers are presented together with a discussion of the optical characterization techniques developed for this program. A discussion of several aspects of large CCD performance is given with detailed test reports. The areas covered include dark current, uniformity of optical response, square wave amplitude response, spectral responsivity and dynamic range.

MOS Circuitry Would Detect Low-Energy Charged Particles

NASA Technical Reports Server (NTRS)

Sinha, Mahadeva; Wadsworth, Mark

2003-01-01

Metal oxide semiconductor (MOS) circuits for measuring spatially varying intensities of beams of low-energy charged particles have been developed. These circuits are intended especially for use in measuring fluxes of ions with spatial resolution along the focal planes of mass spectrometers. Unlike prior mass spectrometer focal-plane detectors, these MOS circuits would not be based on ion-induced generation of electrons, and photons; instead, they would be based on direct detection of the electric charges of the ions. Hence, there would be no need for microchannel plates (for ion-to-electron conversion), phosphors (for electron-to-photon conversion), and photodetectors (for final detection) -- components that degrade spatial resolution and contribute to complexity and size. The developmental circuits are based on linear arrays of charge-coupled devices (CCDs) with associated readout circuitry (see figure). They resemble linear CCD photodetector arrays, except that instead of a photodetector, each pixel contains a capacitive charge sensor. The capacitor in each sensor comprises two electrodes (typically made of aluminum) separated by a layer of insulating material. The exposed electrode captures ions and accumulates their electric charges during signal-integration periods.

Laser Scanning In Inspection

NASA Astrophysics Data System (ADS)

West, Patricia; Baker, Lionel R.

1989-03-01

This paper is a review of the applications of laser scanning in inspection. The reasons for the choice of a laser in flying spot scanning and the optical properties of a laser beam which are of value in a scanning instrument will be given. The many methods of scanning laser beams in both one and two dimensions will be described. The use of one dimensional laser scanners for automatic surface inspection for transmitting and reflective products will be covered in detail, with particular emphasis on light collection techniques. On-line inspection applications which will be mentioned include: photographic film web, metal strip products, paper web, glass sheet, car body paint surfaces and internal cylinder bores. Two dimensional laser scanning is employed in applications where increased resolution, increased depth of focus, and better contrast are required compared with conventional vidicon TV or solid state array cameras. Such examples as special microscope laser scanning systems and a TV compatible system for use in restricted areas of a nuclear reactor will be described. The technical and economic benefits and limitations of laser scanning video systems will be compared with conventional TV and CCD array devices.

Design considerations for imaging charge-coupled device

NASA Astrophysics Data System (ADS)

1981-04-01

The image dissector tube, which was formerly used as detector in star trackers, will be replaced by solid state imaging devices. The technology advances of charge transfer devices, like the charge-coupled device (CCD) and the charge-injection device (CID) have made their application to star trackers an immediate reality. The Air Force in 1979 funded an American Aerospace company to develop an imaging CCD (ICCD) star sensor for the Multimission Attitude Determination and Autonomous Navigation (MADAN) system. The MADAN system is a technology development for a strapdown attitude and navigation system which can be used on all Air Force 3-axis stabilized satellites. The system will be autonomous and will provide real-time satellite attitude and position information. The star sensor accuracy provides an overall MADAN attitude accuracy of 2 arcsec for star rates up to 300 arcsec/sec. The ICCD is basically an integrating device. Its pixel resolution in not yet satisfactory for precision applications.

A CMOS In-Pixel CTIA High Sensitivity Fluorescence Imager.

PubMed

Murari, Kartikeya; Etienne-Cummings, Ralph; Thakor, Nitish; Cauwenberghs, Gert

2011-10-01

Traditionally, charge coupled device (CCD) based image sensors have held sway over the field of biomedical imaging. Complementary metal oxide semiconductor (CMOS) based imagers so far lack sensitivity leading to poor low-light imaging. Certain applications including our work on animal-mountable systems for imaging in awake and unrestrained rodents require the high sensitivity and image quality of CCDs and the low power consumption, flexibility and compactness of CMOS imagers. We present a 132×124 high sensitivity imager array with a 20.1 μm pixel pitch fabricated in a standard 0.5 μ CMOS process. The chip incorporates n-well/p-sub photodiodes, capacitive transimpedance amplifier (CTIA) based in-pixel amplification, pixel scanners and delta differencing circuits. The 5-transistor all-nMOS pixel interfaces with peripheral pMOS transistors for column-parallel CTIA. At 70 fps, the array has a minimum detectable signal of 4 nW/cm(2) at a wavelength of 450 nm while consuming 718 μA from a 3.3 V supply. Peak signal to noise ratio (SNR) was 44 dB at an incident intensity of 1 μW/cm(2). Implementing 4×4 binning allowed the frame rate to be increased to 675 fps. Alternately, sensitivity could be increased to detect about 0.8 nW/cm(2) while maintaining 70 fps. The chip was used to image single cell fluorescence at 28 fps with an average SNR of 32 dB. For comparison, a cooled CCD camera imaged the same cell at 20 fps with an average SNR of 33.2 dB under the same illumination while consuming over a watt.

A CMOS In-Pixel CTIA High Sensitivity Fluorescence Imager

PubMed Central

Murari, Kartikeya; Etienne-Cummings, Ralph; Thakor, Nitish; Cauwenberghs, Gert

2012-01-01

Traditionally, charge coupled device (CCD) based image sensors have held sway over the field of biomedical imaging. Complementary metal oxide semiconductor (CMOS) based imagers so far lack sensitivity leading to poor low-light imaging. Certain applications including our work on animal-mountable systems for imaging in awake and unrestrained rodents require the high sensitivity and image quality of CCDs and the low power consumption, flexibility and compactness of CMOS imagers. We present a 132×124 high sensitivity imager array with a 20.1 μm pixel pitch fabricated in a standard 0.5 μ CMOS process. The chip incorporates n-well/p-sub photodiodes, capacitive transimpedance amplifier (CTIA) based in-pixel amplification, pixel scanners and delta differencing circuits. The 5-transistor all-nMOS pixel interfaces with peripheral pMOS transistors for column-parallel CTIA. At 70 fps, the array has a minimum detectable signal of 4 nW/cm2 at a wavelength of 450 nm while consuming 718 μA from a 3.3 V supply. Peak signal to noise ratio (SNR) was 44 dB at an incident intensity of 1 μW/cm2. Implementing 4×4 binning allowed the frame rate to be increased to 675 fps. Alternately, sensitivity could be increased to detect about 0.8 nW/cm2 while maintaining 70 fps. The chip was used to image single cell fluorescence at 28 fps with an average SNR of 32 dB. For comparison, a cooled CCD camera imaged the same cell at 20 fps with an average SNR of 33.2 dB under the same illumination while consuming over a watt. PMID:23136624

Optical cell monitoring system for underwater targets

NASA Astrophysics Data System (ADS)

Moon, SangJun; Manzur, Fahim; Manzur, Tariq; Demirci, Utkan

2008-10-01

We demonstrate a cell based detection system that could be used for monitoring an underwater target volume and environment using a microfluidic chip and charge-coupled-device (CCD). This technique allows us to capture specific cells and enumerate these cells on a large area on a microchip. The microfluidic chip and a lens-less imaging platform were then merged to monitor cell populations and morphologies as a system that may find use in distributed sensor networks. The chip, featuring surface chemistry and automatic cell imaging, was fabricated from a cover glass slide, double sided adhesive film and a transparent Polymethlymetacrylate (PMMA) slab. The optically clear chip allows detecting cells with a CCD sensor. These chips were fabricated with a laser cutter without the use of photolithography. We utilized CD4+ cells that are captured on the floor of a microfluidic chip due to the ability to address specific target cells using antibody-antigen binding. Captured CD4+ cells were imaged with a fluorescence microscope to verify the chip specificity and efficiency. We achieved 70.2 +/- 6.5% capturing efficiency and 88.8 +/- 5.4% specificity for CD4+ T lymphocytes (n = 9 devices). Bright field images of the captured cells in the 24 mm × 4 mm × 50 μm microfluidic chip were obtained with the CCD sensor in one second. We achieved an inexpensive system that rapidly captures cells and images them using a lens-less CCD system. This microfluidic device can be modified for use in single cell detection utilizing a cheap light-emitting diode (LED) chip instead of a wide range CCD system.

An acoustic charge transport imager for high definition television applications

NASA Technical Reports Server (NTRS)

Hunt, W. D.; Brennan, K. F.; Summers, C. J.

1994-01-01

The primary goal of this research is to develop a solid-state television (HDTV) imager chip operating at a frame rate of about 170 frames/sec at 2 Megapixels/frame. This imager will offer an order of magnitude improvements in speed over CCD designs and will allow for monolithic imagers operating from the IR to UV. The technical approach of the project focuses on the development of the three basic components of the imager and their subsequent integration. The camera chip can be divided into three distinct functions: (1) image capture via an array of avalanche photodiodes (APD's); (2) charge collection, storage, and overflow control via a charge transfer transistor device (CTD); and (3) charge readout via an array of acoustic charge transport (ACT) channels. The use of APD's allows for front end gain at low noise and low operating voltages while the ACT readout enables concomitant high speed and high charge transfer efficiency. Currently work is progressing towards the optimization of each of these component devices. In addition to the development of each of the three distinct components, work towards their integration and manufacturability is also progressing. The component designs are considered not only to meet individual specifications but to provide overall system level performance suitable for HDTV operation upon integration. The ultimate manufacturability and reliability of the chip constrains the design as well. The progress made during this period is described in detail.

Design and Calibration of a Novel Bio-Inspired Pixelated Polarized Light Compass.

PubMed

Han, Guoliang; Hu, Xiaoping; Lian, Junxiang; He, Xiaofeng; Zhang, Lilian; Wang, Yujie; Dong, Fengliang

2017-11-14

Animals, such as Savannah sparrows and North American monarch butterflies, are able to obtain compass information from skylight polarization patterns to help them navigate effectively and robustly. Inspired by excellent navigation ability of animals, this paper proposes a novel image-based polarized light compass, which has the advantages of having a small size and being light weight. Firstly, the polarized light compass, which is composed of a Charge Coupled Device (CCD) camera, a pixelated polarizer array and a wide-angle lens, is introduced. Secondly, the measurement method of a skylight polarization pattern and the orientation method based on a single scattering Rayleigh model are presented. Thirdly, the error model of the sensor, mainly including the response error of CCD pixels and the installation error of the pixelated polarizer, is established. A calibration method based on iterative least squares estimation is proposed. In the outdoor environment, the skylight polarization pattern can be measured in real time by our sensor. The orientation accuracy of the sensor increases with the decrease of the solar elevation angle, and the standard deviation of orientation error is 0 . 15 ∘ at sunset. Results of outdoor experiments show that the proposed polarization navigation sensor can be used for outdoor autonomous navigation.

Design and Calibration of a Novel Bio-Inspired Pixelated Polarized Light Compass

PubMed Central

Hu, Xiaoping; Lian, Junxiang; He, Xiaofeng; Zhang, Lilian; Wang, Yujie; Dong, Fengliang

2017-01-01

Animals, such as Savannah sparrows and North American monarch butterflies, are able to obtain compass information from skylight polarization patterns to help them navigate effectively and robustly. Inspired by excellent navigation ability of animals, this paper proposes a novel image-based polarized light compass, which has the advantages of having a small size and being light weight. Firstly, the polarized light compass, which is composed of a Charge Coupled Device (CCD) camera, a pixelated polarizer array and a wide-angle lens, is introduced. Secondly, the measurement method of a skylight polarization pattern and the orientation method based on a single scattering Rayleigh model are presented. Thirdly, the error model of the sensor, mainly including the response error of CCD pixels and the installation error of the pixelated polarizer, is established. A calibration method based on iterative least squares estimation is proposed. In the outdoor environment, the skylight polarization pattern can be measured in real time by our sensor. The orientation accuracy of the sensor increases with the decrease of the solar elevation angle, and the standard deviation of orientation error is 0.15∘ at sunset. Results of outdoor experiments show that the proposed polarization navigation sensor can be used for outdoor autonomous navigation. PMID:29135927

Accurate measurement of chest compression depth using impulse-radio ultra-wideband sensor on a mattress

PubMed Central

Kim, Yeomyung

2017-01-01

Objective We developed a new chest compression depth (CCD) measuring technology using radar and impulse-radio ultra-wideband (IR-UWB) sensor. This study was performed to determine its accuracy on a soft surface. Methods Four trials, trial 1: chest compressions on the floor using an accelerometer device; trial 2: chest compressions on the floor using an IR-UWB sensor; trial 3: chest compressions on a foam mattress using an accelerometer device; trial 4: chest compressions on a foam mattress using an IR-UWB sensor, were performed in a random order. In all the trials, a cardiopulmonary resuscitation provider delivered 50 uninterrupted chest compressions to a manikin. Results The CCD measured by the manikin and the device were as follows: 57.42 ± 2.23 and 53.92 ± 2.92 mm, respectively in trial 1 (p < 0.001); 56.29 ± 1.96 and 54.16 ± 3.90 mm, respectively in trial 2 (p < 0.001); 55.61 ± 1.57 and 103.48 ± 10.48 mm, respectively in trial 3 (p < 0.001); 57.14 ± 3.99 and 55.51 ± 3.39 mm, respectively in trial 4 (p = 0.012). The gaps between the CCD measured by the manikin and the devices (accelerometer device vs. IR-UWB sensor) on the floor were not different (3.50 ± 2.08 mm vs. 3.15 ± 2.27 mm, respectively, p = 0.136). However, the gaps were significantly different on the foam mattress (48.53 ± 5.65 mm vs. 4.10 ± 2.47 mm, p < 0.001). Conclusion The IR-UWB sensor could measure the CCD accurately both on the floor and on the foam mattress. PMID:28854262

Accurate measurement of chest compression depth using impulse-radio ultra-wideband sensor on a mattress.

PubMed

Yu, Byung Gyu; Oh, Je Hyeok; Kim, Yeomyung; Kim, Tae Wook

2017-01-01

We developed a new chest compression depth (CCD) measuring technology using radar and impulse-radio ultra-wideband (IR-UWB) sensor. This study was performed to determine its accuracy on a soft surface. Four trials, trial 1: chest compressions on the floor using an accelerometer device; trial 2: chest compressions on the floor using an IR-UWB sensor; trial 3: chest compressions on a foam mattress using an accelerometer device; trial 4: chest compressions on a foam mattress using an IR-UWB sensor, were performed in a random order. In all the trials, a cardiopulmonary resuscitation provider delivered 50 uninterrupted chest compressions to a manikin. The CCD measured by the manikin and the device were as follows: 57.42 ± 2.23 and 53.92 ± 2.92 mm, respectively in trial 1 (p < 0.001); 56.29 ± 1.96 and 54.16 ± 3.90 mm, respectively in trial 2 (p < 0.001); 55.61 ± 1.57 and 103.48 ± 10.48 mm, respectively in trial 3 (p < 0.001); 57.14 ± 3.99 and 55.51 ± 3.39 mm, respectively in trial 4 (p = 0.012). The gaps between the CCD measured by the manikin and the devices (accelerometer device vs. IR-UWB sensor) on the floor were not different (3.50 ± 2.08 mm vs. 3.15 ± 2.27 mm, respectively, p = 0.136). However, the gaps were significantly different on the foam mattress (48.53 ± 5.65 mm vs. 4.10 ± 2.47 mm, p < 0.001). The IR-UWB sensor could measure the CCD accurately both on the floor and on the foam mattress.

Quantification of in vitro produced wear sites on composite resins using contact profilometry and CCD microscopy: a methodological investigation.

PubMed

Koottathape, Natthavoot; Takahashi, Hidekazu; Finger, Wernerj; Kanehira, Masafumi; Iwasaki, Naohiko; Aoyagi, Yujin

2012-06-01

Although attritive and abrasive wear of recent composite resins has been substantially reduced, in vitro wear testing with reasonably simulating devices and quantitative determination of resulting wear is still needed. Three-dimensional scanning methods are frequently used for this purpose. The aim of this trial was to compare maximum depth of wear and volume loss of composite samples, evaluated with a contact profilometer and a non-contact CCD camera imaging system, respectively. Twenty-three random composite specimens with wear traces produced in a ball-on-disc sliding device, using poppy seed slurry and PMMA suspension as third-body media, were evaluated with the contact profilometer (TalyScan 150, Taylor Hobson LTD, Leicester, UK) and with the digital CCD microscope (VHX1000, KEYENCE, Osaka, Japan). The target parameters were maximum depth of the wear and volume loss.Results - The individual time of measurement needed with the non-contact CCD method was almost three hours less than that with the contact method. Both, maximum depth of wear and volume loss data, recorded with the two methods were linearly correlated (r(2) > 0.97; p < 0.01). The contact scanning method and the non-contact CCD method are equally suitable for determination of maximum depth of wear and volume loss of abraded composite resins.

Fabrication of Robust, Flat, Thinned, UV-Imaging CCDs

NASA Technical Reports Server (NTRS)

Grunthaner, Paula; Elliott, Stythe; Jones, Todd; Nikzad, Shouleh

2004-01-01

An improved process that includes a high-temperature bonding subprocess has been developed to enable the fabrication of robust, flat, silicon-based charge-coupled devices (CCDs) for imaging in ultraviolet (UV) light and/or for detecting low-energy charged particles. The CCDs in question are devices on which CCD circuitry has already been formed and have been thinned for backsurface illumination. These CCDs may be delta doped, and aspects of this type of CCD have been described in several prior articles in NASA Tech Briefs. Unlike prior low-temperature bonding subprocesses based on the use of epoxies or waxes, the high-temperature bonding subprocess is compatible with the deltadoping process as well as with other CCD-fabrication processes. The present improved process and its bonding, thinning, and delta-doping subprocesses, are characterized as postfabrication processes because they are undertaken after the fabrication of CCD circuitry on the front side of a full-thickness silicon substrate. In a typical case, it is necessary to reduce the thickness of the CCD to between 10 and 20 m in order to take advantage of back-side illumination and in order to perform delta doping and/or other back-side treatment to enhance the quantum efficiency. In the prior approach to the fabrication of back-side-illuminated CCDs, the thinning subprocess turned each CCD into a free-standing membrane that was fragile and tended to become wrinkled. In the present improved process, prior to thinning and delta doping, a CCD is bonded on its front side to a silicon substrate that has been prefabricated to include cutouts to accommodate subsequent electrical connections to bonding pads on the CCD circuitry. The substrate provides structural support to increase ruggedness and maintain flatness. At the beginning of this process, the back side of a CCD as fabricated on a full-thickness substrate is polished. Silicon nitride is deposited on the back side, opposite the bonding pads on the front side, in order to define a relatively thick frame. The portion of the CCD not covered by the frame is the portion to be thinned by etching.

Charge-coupled-device X-ray detector performance model

NASA Technical Reports Server (NTRS)

Bautz, M. W.; Berman, G. E.; Doty, J. P.; Ricker, G. R.

1987-01-01

A model that predicts the performance characteristics of CCD detectors being developed for use in X-ray imaging is presented. The model accounts for the interactions of both X-rays and charged particles with the CCD and simulates the transport and loss of charge in the detector. Predicted performance parameters include detective and net quantum efficiencies, split-event probability, and a parameter characterizing the effective thickness presented by the detector to cosmic-ray protons. The predicted performance of two CCDs of different epitaxial layer thicknesses is compared. The model predicts that in each device incomplete recovery of the charge liberated by a photon of energy between 0.1 and 10 keV is very likely to be accompanied by charge splitting between adjacent pixels. The implications of the model predictions for CCD data processing algorithms are briefly discussed.

Design of a multispectral, wedge filter, remote-sensing instrument incorporating a multiport, thinned, CCD area array

NASA Astrophysics Data System (ADS)

Demro, James C.; Hartshorne, Richard; Woody, Loren M.; Levine, Peter A.; Tower, John R.

1995-06-01

The next generation Wedge Imaging Spectrometer (WIS) instruments currently in integration at Hughes SBRD incorporate advanced features to increase operation flexibility for remotely sensed hyperspectral imagery collection and use. These features include: a) multiple linear wedge filters to tailor the spectral bands to the scene phenomenology; b) simple, replaceable fore-optics to allow different spatial resolutions and coverages; c) data acquisition system (DAS) that collects the full data stream simultaneously from both WIS instruments (VNIR and SWIR/MWIR), stores the data in a RAID storage, and provides for down-loading of the data to MO disks; the WIS DAS also allows selection of the spectral band sets to be stored; d) high-performance VNIR camera subsystem based upon a 512 X 512 CCD area array and associated electronics.

Novel instrumentation of multispectral imaging technology for detecting tissue abnormity

NASA Astrophysics Data System (ADS)

Yi, Dingrong; Kong, Linghua

2012-10-01

Multispectral imaging is becoming a powerful tool in a wide range of biological and clinical studies by adding spectral, spatial and temporal dimensions to visualize tissue abnormity and the underlying biological processes. A conventional spectral imaging system includes two physically separated major components: a band-passing selection device (such as liquid crystal tunable filter and diffraction grating) and a scientific-grade monochromatic camera, and is expensive and bulky. Recently micro-arrayed narrow-band optical mosaic filter was invented and successfully fabricated to reduce the size and cost of multispectral imaging devices in order to meet the clinical requirement for medical diagnostic imaging applications. However the challenging issue of how to integrate and place the micro filter mosaic chip to the targeting focal plane, i.e., the imaging sensor, of an off-shelf CMOS/CCD camera is not reported anywhere. This paper presents the methods and results of integrating such a miniaturized filter with off-shelf CMOS imaging sensors to produce handheld real-time multispectral imaging devices for the application of early stage pressure ulcer (ESPU) detection. Unlike conventional multispectral imaging devices which are bulky and expensive, the resulting handheld real-time multispectral ESPU detector can produce multiple images at different center wavelengths with a single shot, therefore eliminates the image registration procedure required by traditional multispectral imaging technologies.

Development of Multiple-Element Flame Emission Spectrometer Using CCD Detection

ERIC Educational Resources Information Center

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,…

Design Method For Ultra-High Resolution Linear CCD Imagers

NASA Astrophysics Data System (ADS)

Sheu, Larry S.; Truong, Thanh; Yuzuki, Larry; Elhatem, Abdul; Kadekodi, Narayan

1984-11-01

This paper presents the design method to achieve ultra-high resolution linear imagers. This method utilizes advanced design rules and novel staggered bilinear photo sensor arrays with quadrilinear shift registers. Design constraint in the detector arrays and shift registers are analyzed. Imager architecture to achieve ultra-high resolution is presented. The characteristics of MTF, aliasing, speed, transfer efficiency and fine photolithography requirements associated with this architecture are also discussed. A CCD imager with advanced 1.5 um minimum feature size was fabricated. It is intended as a test vehicle for the next generation small sampling pitch ultra-high resolution CCD imager. Standard double-poly, two-phase shift registers were fabricated at an 8 um pitch using the advanced design rules. A special process step that blocked the source-drain implant from the shift register area was invented. This guaranteed excellent performance of the shift registers regardless of the small poly overlaps. A charge transfer efficiency of better than 0.99995 and maximum transfer speed of 8 MHz were achieved. The imager showed excellent performance. The dark current was less than 0.2 mV/ms, saturation 250 mV, adjacent photoresponse non-uniformity ± 4% and responsivity 0.7 V/ μJ/cm2 for the 8 μm x 6 μm photosensor size. The MTF was 0.6 at 62.5 cycles/mm. These results confirm the feasibility of the next generation ultra-high resolution CCD imagers.

Automatic detection of recoil-proton tracks and background rejection criteria in liquid scintillator-micro-capillary-array fast neutron spectrometer

NASA Astrophysics Data System (ADS)

Mor, Ilan; Vartsky, David; Dangendorf, Volker; Tittelmeier, Kai.; Weierganz, Mathias; Goldberg, Mark Benjamin; Bar, Doron; Brandis, Michal

2018-06-01

We describe an analysis procedure for automatic unambiguous detection of fast-neutron-induced recoil proton tracks in a micro-capillary array filled with organic liquid scintillator. The detector is viewed by an intensified CCD camera. This imaging neutron detector possesses the capability to perform high position-resolution (few tens of μm), energy-dispersive transmission-imaging using ns-pulsed beams. However, when operated with CW or DC beams, it also features medium-quality spectroscopic capabilities for incident neutrons in the energy range 2-20 MeV. In addition to the recoil proton events which display a continuous extended track structure, the raw images exhibit complex ion-tracks from nuclear interactions of fast-neutrons in the scintillator, capillaries quartz-matrix and CCD. Moreover, as expected, one also observes a multitude of isolated scintillation spots of varying intensity (henceforth denoted "blobs") that originate from several different sources, such as: fragmented proton tracks, gamma-rays, heavy-ion reactions as well as events and noise that occur in the image-intensifier and CCD. In order to identify the continuous-track recoil proton events and distinguish them from all these background events, a rapid, computerized and automatic track-recognition-procedure was developed. Based on an appropriately weighted analysis of track parameters such as: length, width, area and overall light intensity, the method is capable of distinguishing a single continuous-track recoil proton from typically surrounding several thousands of background events that are found in each CCD frame.

Vacuum compatible miniature CCD camera head

DOEpatents

Conder, Alan D.

2000-01-01

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

Large Format CMOS-based Detectors for Diffraction Studies

NASA Astrophysics Data System (ADS)

Thompson, A. C.; Nix, J. C.; Achterkirchen, T. G.; Westbrook, E. M.

2013-03-01

Complementary Metal Oxide Semiconductor (CMOS) devices are rapidly replacing CCD devices in many commercial and medical applications. Recent developments in CMOS fabrication have improved their radiation hardness, device linearity, readout noise and thermal noise, making them suitable for x-ray crystallography detectors. Large-format (e.g. 10 cm × 15 cm) CMOS devices with a pixel size of 100 μm × 100 μm are now becoming available that can be butted together on three sides so that very large area detector can be made with no dead regions. Like CCD systems our CMOS systems use a GdOS:Tb scintillator plate to convert stopping x-rays into visible light which is then transferred with a fiber-optic plate to the sensitive surface of the CMOS sensor. The amount of light per x-ray on the sensor is much higher in the CMOS system than a CCD system because the fiber optic plate is only 3 mm thick while on a CCD system it is highly tapered and much longer. A CMOS sensor is an active pixel matrix such that every pixel is controlled and readout independently of all other pixels. This allows these devices to be readout while the sensor is collecting charge in all the other pixels. For x-ray diffraction detectors this is a major advantage since image frames can be collected continuously at up 20 Hz while the crystal is rotated. A complete diffraction dataset can be collected over five times faster than with CCD systems with lower radiation exposure to the crystal. In addition, since the data is taken fine-phi slice mode the 3D angular position of diffraction peaks is improved. We have developed a cooled 6 sensor CMOS detector with an active area of 28.2 × 29.5 cm with 100 μm × 100 μm pixels and a readout rate of 20 Hz. The detective quantum efficiency exceeds 60% over the range 8-12 keV. One, two and twelve sensor systems are also being developed for a variety of scientific applications. Since the sensors are butt able on three sides, even larger systems could be built at reasonable cost.

A 128K-bit CCD buffer memory system

NASA Technical Reports Server (NTRS)

Siemens, K. H.; Wallace, R. W.; Robinson, C. R.

1976-01-01

A prototype system was implemented to demonstrate that CCD's can be applied advantageously to the problem of low power digital storage and particularly to the problem of interfacing widely varying data rates. 8K-bit CCD shift register memories were used to construct a feasibility model 128K-bit buffer memory system. Peak power dissipation during a data transfer is less than 7 W., while idle power is approximately 5.4 W. The system features automatic data input synchronization with the recirculating CCD memory block start address. Descriptions are provided of both the buffer memory system and a custom tester that was used to exercise the memory. The testing procedures and testing results are discussed. Suggestions are provided for further development with regards to the utilization of advanced versions of CCD memory devices to both simplified and expanded memory system applications.

A novel reflectometer for relative reflectance measurements of CCDs

NASA Astrophysics Data System (ADS)

Hart, Murdock; Barkhouser, Robert H.; Gunn, James E.; Smee, Stephen A.

2016-07-01

The high quantum efficiencies (QE) of backside illuminated charge coupled devices (CCD) has ushered in the age of the large scale astronomical survey. The QE of these devices can be greater than 90%, and is dependent upon the operating temperature, device thickness, backside charging mechanisms, and anti-reflection (AR) coatings. But at optical wavelengths the QE is well approximated as one minus the reflectance, thus the measurement of the backside reflectivity of these devices provides a second independent measure of their QE. We have designed and constructed a novel instrument to measure the relative specular reflectance of CCD detectors, with a significant portion of this device being constructed using a 3D fused deposition model (FDM) printer. This device implements both a monitor and measurement photodiode to simultaneously collect in- cident and reflected measurements reducing errors introduced by the relative reflectance calibration process. While most relative reflectometers are highly dependent upon a precisely repeatable target distance for accurate measurements, we have implemented a method of measurement which minimizes these errors. Using the reflectometer we have measured the reflectance of two types of Hamamatsu CCD detectors. The first device is a Hamamatsu 2k x 4k backside illuminated high resistivity p-type silicon detector which has been optimized to operate in the blue from 380 nm - 650 nm. The second detector being a 2k x 4k backside illuminated high resistivity p-type silicon detector optimized for use in the red from 640 nm - 960 nm. We have not only been able to measure the reflectance of these devices as a function of wavelength we have also sampled the reflectance as a function of position on the device, and found a reflection gradient across these devices.

NEUTRON RADIATION DAMAGE IN CCD CAMERAS AT JOINT EUROPEAN TORUS (JET).

PubMed

Milocco, Alberto; Conroy, Sean; Popovichev, Sergey; Sergienko, Gennady; Huber, Alexander

2017-10-26

The neutron and gamma radiations in large fusion reactors are responsible for damage to charged couple device (CCD) cameras deployed for applied diagnostics. Based on the ASTM guide E722-09, the 'equivalent 1 MeV neutron fluence in silicon' was calculated for a set of CCD cameras at the Joint European Torus. Such evaluations would be useful to good practice in the operation of the video systems. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Discovery of Spatial and Spectral Structure in the X-Ray Emission from the Crab Nebula

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.; Hester, J. Jeff; Tennant, Allyn F.; Elsner, Ronald F.; Schulz, Norbert S.; Marshall, Herman L.; Karovska, Margarita; Nichols, Joy S.; Swartz, Douglas A.; Kolodziejczak, Jeffery J.

2000-01-01

The Chandra X-Ray Observatory observed the Crab Nebula and pulsar during orbital calibration. Zeroth-order images with the High-Energy Transmission Grating (HETG) readout by the Advanced Charge Coupled Devices (CCD) Imaging Spectrometer spectroscopy array (ACIS-S) show a striking richness of X-ray structure at a resolution comparable to that of the best ground-based visible-light observations. The HETG-ACIS-S images reveal, for the first time, an X-ray inner ring within the X-ray torus, the suggestion of a hollow-tube structure for the torus, and X-ray knots along the inner ring and (perhaps) along the inward extension of the X-ray jet. Although complicated by instrumental effects and the brightness of the Crab Nebula, the spectrometric analysis shows systematic variations of the X-ray spectrum throughout the nebula.

Maturing CCD Photon-Counting Technology for Space Flight

NASA Technical Reports Server (NTRS)

Mallik, Udayan; Lyon, Richard; Petrone, Peter; McElwain, Michael; Benford, Dominic; Clampin, Mark; Hicks, Brian

2015-01-01

This paper discusses charge blooming and starlight saturation - two potential technical problems - when using an Electron Multiplying Charge Coupled Device (EMCCD) type detector in a high-contrast instrument for imaging exoplanets. These problems especially affect an interferometric type coronagraph - coronagraphs that do not use a mask to physically block starlight in the science channel of the instrument. These problems are presented using images taken with a commercial Princeton Instrument EMCCD camera in the Goddard Space Flight Center's (GSFC), Interferometric Coronagraph facility. In addition, this paper discusses techniques to overcome such problems. This paper also discusses the development and architecture of a Field Programmable Gate Array and Digital-to-Analog Converter based shaped clock controller for a photon-counting EMCCD camera. The discussion contained here will inform high-contrast imaging groups in their work with EMCCD detectors.

[Analysis of H2S/PH3/NH3/AsH3/Cl2 by Full-Spectral Flame Photometric Detector].

PubMed

Ding, Zhi-jun; Wang, Pu-hong; Li, Zhi-jun; Du, Bin; Guo, Lei; Yu, Jian-hua

2015-07-01

Flame photometric analysis technology has been proven to be a rapid and sensitive method for sulfur and phosphorus detection. It has been widely used in environmental inspections, pesticide detection, industrial and agricultural production. By improving the design of the traditional flame photometric detector, using grating and CCD sensor array as a photoelectric conversion device, the types of compounds that can be detected were expanded. Instead of a single point of characteristic spectral lines, full spectral information has been used for qualitative and quantitative analysis of H2S, PH3, NH3, AsH3 and Cl2. Combined with chemometric method, flame photometric analysis technology is expected to become an alternative fast, real-time on-site detection technology to simultaneously detect multiple toxic and harmful gases.

Adjustment of multi-CCD-chip-color-camera heads

NASA Astrophysics Data System (ADS)

Guyenot, Volker; Tittelbach, Guenther; Palme, Martin

1999-09-01

The principle of beam-splitter-multi-chip cameras consists in splitting an image into differential multiple images of different spectral ranges and in distributing these onto separate black and white CCD-sensors. The resulting electrical signals from the chips are recombined to produce a high quality color picture on the monitor. Because this principle guarantees higher resolution and sensitivity in comparison to conventional single-chip camera heads, the greater effort is acceptable. Furthermore, multi-chip cameras obtain the compete spectral information for each individual object point while single-chip system must rely on interpolation. In a joint project, Fraunhofer IOF and STRACON GmbH and in future COBRA electronic GmbH develop methods for designing the optics and dichroitic mirror system of such prism color beam splitter devices. Additionally, techniques and equipment for the alignment and assembly of color beam splitter-multi-CCD-devices on the basis of gluing with UV-curable adhesives have been developed, too.

Charged Coupled Device Debris Telescope Observations of the Geosynchronous Orbital Debris Environment - Observing Year: 1998

NASA Technical Reports Server (NTRS)

Jarvis, K. S.; Thumm, T. L.; Matney, M. J.; Jorgensen, K.; Stansbery, E. G.; Africano, J. L.; Sydney, P. F.; Mulrooney, M. K.

2002-01-01

NASA has been using the charged coupled device (CCD) debris telescope (CDT)--a transportable 32-cm Schmidt telescope located near Cloudcroft, New Mexico-to help characterize the debris environment in geosynchronous Earth orbit (GEO). The CDT is equipped with a SITe 512 x 512 CCD camera whose 24 m2 (12.5 arc sec) pixels produce a 1.7 x 1.7-deg field of view. The CDT system can therefore detect l7th-magnitude objects in a 20-sec integration corresponding to an approx. 0.6-m diameter, 0.20 albedo object at 36,000 km. The telescope pointing and CCD operation are computer controlled to collect data automatically for an entire night. The CDT has collected more than 1500 hrs of data since November 1997. This report describes the collection and analysis of 58 nights (approx. 420 hrs) of data acquired in 1998.

VizieR Online Data Catalog: Observation of six NSVS eclipsing binaries (Dimitrov+, 2015)

NASA Astrophysics Data System (ADS)

Dimitrov, D. P.; Kjurkchieva, D. P.

2017-11-01

We managed to separate a sample of about 40 ultrashort-period candidates from the Northern Sky Variability Survey (NSVS, Wozniak et al. 2004AJ....127.2436W) appropriate for follow-up observations at Rozhen observatory (δ>-10°). Follow-up CCD photometry of the targets in the VRI bands was carried out with the three telescopes of the Rozhen National Astronomical Observatory. The 2-m RCC telescope is equipped with a VersArray CCD camera (1340x1300 pixels, 20 μm/pixel, field of 5.35x5.25 arcmin2). The 60-cm Cassegrain telescope is equipped with a FLI PL09000 CCD camera (3056x3056 pixels, 12 μm/pixel, field of 17.1x17.1 arcmin2). The 50/70 cm Schmidt telescope has a field of view (FoV) of around 1° and is equipped with a FLI PL 16803 CCD camera, 4096x4096 pixels, 9 μm/pixel size. (4 data files).

Research and development in optical biosensors for determination of toxic environmental pollutants

NASA Astrophysics Data System (ADS)

Tsargorodska, Anna

The detection of pollutants (such as toxins, heavy metal ions, and pesticides) in water and food plays an important role in human health and safety regulations. Different optical biosensing techniques enabling the monitoring of these compounds were chosen for this study. Low molecular weight (LMW) environmental toxins, such as simazine, atrazine, nonylphenol and T-2 mycotoxin were registered with the methods of surface plasmon resonance (SPR) and the recently developed total internal reflection ellipsometry (TIRE). The immune assay approach was exploited for in situ registration of the above toxins with specific antibodies immobilized onto a gold surface via a polyelectrolyte layer using electrostatic self-assembly (ESA) technique. TIRE showed a higher sensitivity than the SPR technique. The obtained responses of the TIRE method were higher than estimated for the immune binding of single molecules of nonylphenol or T-2 mycotoxin. The mechanism of the binding of large aggregates of these toxins to respective antibodies was suggested as a possible reason for this. The formation of large molecular aggregates of toxin molecules on the surface was later proven by the AFM study.The prototype of the portable sensor array device for water pollution monitoring was based on a SiO[2]/Si[3]n[4] planar waveguide with a sensing window coated with ESA film containing pH sensitive organic chromophore molecules and different enzymes (namely, urease, acetyl- and butyryl-cholinesterase) adsorbed on a disposable nylon membrane. The sensor was capable of registration of enzyme reactions as well as their inhibition by traces of some typical water pollutants, such as heavy metal ions Cd[2+], Pb[2+], and Ni[2+], and pesticides imidacloprid and DVDP over a wide range of concentrations (from 1000 ppb down to 0.1 ppb). A portable prototype sensor array device comprises a fan-beam laser diode, a semi-cylindrical lens, a planar waveguide with a three-channel cell attached, and a CCD array photodetector. Dedicated software was developed for CCD image processing and further data analysis with an artificial neural network.The large internal surface area within a small volume, efficient room-temperature visible photoluminescence and biocompatibility of porous silicon (PS) has stimulated recent interest in its applications for sensor development. The method of spectroscopic ellipsometry was applied to study in situ the adsorption of bovine serum albumin (BSA) into PS. The porosity and amount of adsorbed BSA were determined by fitting the ellipsometric data to the Bruggeman effective medium approximation model. The presence of intermediate adsorbed layers of polyelectrolytes was found to increase protein adsorption.

Periodicity analysis on cat-eye reflected beam profiles of optical detectors

NASA Astrophysics Data System (ADS)

Gong, Mali; He, Sifeng

2017-05-01

The cat-eye effect reflected beam profiles of most optical detectors have a certain characteristic of periodicity, which is caused by array arrangement of sensors at their optical focal planes. It is the first time to find and prove that the reflected beam profile becomes several periodic spots at the reflected propagation distance corresponding to half the imaging distance of a CCD camera. Furthermore, the spatial cycle of these spots is approximately constant, independent of the CCD camera's imaging distance, which is related only to the focal length and pixel size of the CCD sensor. Thus, we can obtain the imaging distance and intrinsic parameters of the optical detector by analyzing its cat-eye reflected beam profiles. This conclusion can be applied in the field of non-cooperative cat-eye target recognition.

CCD developments for particle colliders

NASA Astrophysics Data System (ADS)

Stefanov, Konstantin D.

2006-09-01

Charge Coupled Devices (CCDs) have been successfully used in several high-energy physics experiments over the last 20 years. Their small pixel size and excellent precision provide superb tool for studying of short-lived particles and understanding the nature at fundamental level. Over the last years the Linear Collider Flavour Identification (LCFI) collaboration has developed Column-Parallel CCDs (CPCCD) and CMOS readout chips to be used for the vertex detector at the International Linear Collider (ILC). The CPCCDs are very fast devices capable of satisfying the challenging requirements imposed by the beam structure of the superconducting accelerator. First set of prototype devices have been designed, manufactured and successfully tested, with second-generation chips on the way. Another idea for CCD-based device, the In-situ Storage Image Sensor (ISIS) is also under development and the first prototype is in production.

CCD-based vertex detector for ILC

NASA Astrophysics Data System (ADS)

Stefanov, Konstantin D.

2006-12-01

Charge Coupled Devices (CCDs) have been successfully used in several high-energy physics experiments over the last 20 years. Their small pixel size and excellent precision provide a superb tool for studying of short-lived particles and understanding the nature at fundamental level. Over the last few years the Linear Collider Flavour Identification (LCFI) collaboration has developed Column-Parallel CCDs (CPCCD) and CMOS readout chips, to be used for the vertex detector at the International Linear Collider (ILC). The CPCCDs are very fast devices capable of satisfying the challenging requirements imposed by the beam structure of the superconducting accelerator. The first set of prototype devices have been successfully designed, manufactured and tested, with second generation chips on the way. Another idea for CCD-based device, the In-situ Storage Image Sensor (ISIS) is also under development and the first prototype has been manufactured.

A webcam in Bayer-mode as a light beam profiler for the near infra-red

PubMed Central

Langer, Gregor; Hochreiner, Armin; Burgholzer, Peter; Berer, Thomas

2013-01-01

Beam profiles are commonly measured with complementary metal oxide semiconductors (CMOS) or charge coupled devices (CCD). The devices are fast and reliable but expensive. By making use of the fact that the Bayer-filter in commercial webcams is transparent in the near infra-red (>800 nm) and their CCD chips are sensitive up to about 1100 nm, we demonstrate a cheap and simple way to measure laser beam profiles with a resolution down to around ±1 μm, which is close to the resolution of the knife-edge technique. PMID:23645943

A webcam in Bayer-mode as a light beam profiler for the near infra-red.

PubMed

Langer, Gregor; Hochreiner, Armin; Burgholzer, Peter; Berer, Thomas

2013-05-01

Beam profiles are commonly measured with complementary metal oxide semiconductors (CMOS) or charge coupled devices (CCD). The devices are fast and reliable but expensive. By making use of the fact that the Bayer-filter in commercial webcams is transparent in the near infra-red (>800 nm) and their CCD chips are sensitive up to about 1100 nm, we demonstrate a cheap and simple way to measure laser beam profiles with a resolution down to around ±1 μm, which is close to the resolution of the knife-edge technique.

Method and apparatus for ultra-high-sensitivity, incremental and absolute optical encoding

NASA Technical Reports Server (NTRS)

Leviton, Douglas B. (Inventor)

1999-01-01

An absolute optical linear or rotary encoder which encodes the motion of an object (3) with increased resolution and encoding range and decreased sensitivity to damage to the scale includes a scale (5), which moves with the object and is illuminated by a light source (11). The scale carries a pattern (9) which is imaged by a microscope optical system (13) on a CCD array (17) in a camera head (15). The pattern includes both fiducial markings (31) which are identical for each period of the pattern and code areas (33) which include binary codings of numbers identifying the individual periods of the pattern. The image of the pattern formed on the CCD array is analyzed by an image processor (23) to locate the fiducial marking, decode the information encoded in the code area, and thereby determine the position of the object.

Development of Residual Gas Profile Monitors at GSI

NASA Astrophysics Data System (ADS)

Giacomini, T.; Barabin, S.; Forck, P.; Liakin, D.; Skachkov, V.

2004-11-01

Beam profile measurements at modern ion synchrotrons and storage rings require high timing performances on a turn-by-turn basis. High spatial resolutions are essential for cold beams and beamwidth measurings. The currently used RGM supported very interesting measurements and applications. Due to the readout technology the spatial and time resolution is limited. To meet the expanded demands a more comprehensive device is under development. It will be an all-purpose residual gas monitor to cover the wide range of beam currents and transversal particle distributions. Due to the fast profile detection it will operate on primary electrons after residual gas ionization. A magnetic field of 100 mT binds them to the ionization point inside 0.1-mm orbits. The high-resolution mode will be read out by a digital CCD camera with an upstream MCP-phosphor screen assembly. It is planned to read out the fast turn-by-turn mode by an array of 100 photodiodes with a resolution of 1 mm. Every photodiode is equipped with an amplifier-digitizer device providing a frame rate of ˜ 10 MSamples/s.

Printed circuit board for a CCD camera head

DOEpatents

Conder, Alan D.

2002-01-01

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

Radiation-tolerant imaging device

DOEpatents

Colella, N.J.; Kimbrough, J.R.

1996-11-19

A barrier at a uniform depth for an entire wafer is used to produce imaging devices less susceptible to noise pulses produced by the passage of ionizing radiation. The barrier prevents charge created in the bulk silicon of a CCD detector or a semiconductor logic or memory device from entering the collection volume of each pixel in the imaging device. The charge barrier is a physical barrier, a potential barrier, or a combination of both. The physical barrier is formed by an SiO{sub 2} insulator. The potential barrier is formed by increasing the concentration of majority carriers (holes) to combine with the electron`s generated by the ionizing radiation. A manufacturer of CCD imaging devices can produce radiation-tolerant devices by merely changing the wafer type fed into his process stream from a standard wafer to one possessing a barrier beneath its surface, thus introducing a very small added cost to his production cost. An effective barrier type is an SiO{sub 2} layer. 7 figs.

Radiation-tolerant imaging device

DOEpatents

Colella, Nicholas J.; Kimbrough, Joseph R.

1996-01-01

A barrier at a uniform depth for an entire wafer is used to produce imaging devices less susceptible to noise pulses produced by the passage of ionizing radiation. The barrier prevents charge created in the bulk silicon of a CCD detector or a semiconductor logic or memory device from entering the collection volume of each pixel in the imaging device. The charge barrier is a physical barrier, a potential barrier, or a combination of both. The physical barrier is formed by an SiO.sub.2 insulator. The potential barrier is formed by increasing the concentration of majority carriers (holes) to combine with the electron's generated by the ionizing radiation. A manufacturer of CCD imaging devices can produce radiation-tolerant devices by merely changing the wafer type fed into his process stream from a standard wafer to one possessing a barrier beneath its surface, thus introducing a very small added cost to his production cost. An effective barrier type is an SiO.sub.2 layer.

A 5- μ m pitch charge-coupled device optimized for resonant inelastic soft X-ray scattering

DOE PAGES

Andresen, N. C.; Denes, P.; Goldschmidt, A.; ...

2017-08-08

Here, we have developed a charge-coupled device (CCD) with 5 μm × 45 μm pixels on high-resistivity silicon. The fully depleted 200 μm-thick silicon detector is back-illuminated through a 10 nm-thick in situ doped polysilicon window and is thus highly efficient for soft through > 8 keV hard X-rays. The device described here is a 1.5 megapixel CCD with 2496 × 620 pixels. The pixel and camera geometry was optimized for Resonant Inelastic X-ray Scattering (RIXS) and is particularly advantageous for spectrometers with limited arm lengths. In this article, we describe the device architecture, construction and operation, and its performancemore » during tests at the Advance Light Source (ALS) 8.0.1 RIXS beamline. The improved spectroscopic performance, when compared with a current standard commercial camera, is demonstrated with a ~280 eV (C K) X-ray beam on a graphite sample. Readout noise is typically 3-6 electrons and the point spread function for soft C K X-rays in the 5 μm direction is 4.0 μm ± 0.2 μm. Finally, the measured quantum efficiency of the CCD is greater than 75% in the range from 200 eV to 1 keV.« less

A 5-μm pitch charge-coupled device optimized for resonant inelastic soft X-ray scattering

NASA Astrophysics Data System (ADS)

Andresen, N. C.; Denes, P.; Goldschmidt, A.; Joseph, J.; Karcher, A.; Tindall, C. S.

2017-08-01

We have developed a charge-coupled device (CCD) with 5 μm × 45 μm pixels on high-resistivity silicon. The fully depleted 200 μm-thick silicon detector is back-illuminated through a 10 nm-thick in situ doped polysilicon window and is thus highly efficient for soft through >8 keV hard X-rays. The device described here is a 1.5 megapixel CCD with 2496 × 620 pixels. The pixel and camera geometry was optimized for Resonant Inelastic X-ray Scattering (RIXS) and is particularly advantageous for spectrometers with limited arm lengths. In this article, we describe the device architecture, construction and operation, and its performance during tests at the Advance Light Source (ALS) 8.0.1 RIXS beamline. The improved spectroscopic performance, when compared with a current standard commercial camera, is demonstrated with a ˜280 eV (CK) X-ray beam on a graphite sample. Readout noise is typically 3-6 electrons and the point spread function for soft CK X-rays in the 5 μm direction is 4.0 μm ± 0.2 μm. The measured quantum efficiency of the CCD is greater than 75% in the range from 200 eV to 1 keV.

A 5-μm pitch charge-coupled device optimized for resonant inelastic soft X-ray scattering.

PubMed

Andresen, N C; Denes, P; Goldschmidt, A; Joseph, J; Karcher, A; Tindall, C S

2017-08-01

We have developed a charge-coupled device (CCD) with 5 μm × 45 μm pixels on high-resistivity silicon. The fully depleted 200 μm-thick silicon detector is back-illuminated through a 10 nm-thick in situ doped polysilicon window and is thus highly efficient for soft through >8 keV hard X-rays. The device described here is a 1.5 megapixel CCD with 2496 × 620 pixels. The pixel and camera geometry was optimized for Resonant Inelastic X-ray Scattering (RIXS) and is particularly advantageous for spectrometers with limited arm lengths. In this article, we describe the device architecture, construction and operation, and its performance during tests at the Advance Light Source (ALS) 8.0.1 RIXS beamline. The improved spectroscopic performance, when compared with a current standard commercial camera, is demonstrated with a ∼280 eV (C K ) X-ray beam on a graphite sample. Readout noise is typically 3-6 electrons and the point spread function for soft C K X-rays in the 5 μm direction is 4.0 μm ± 0.2 μm. The measured quantum efficiency of the CCD is greater than 75% in the range from 200 eV to 1 keV.

Development of an integrated countermeasure device for use in long-duration spaceflight

NASA Astrophysics Data System (ADS)

Streeper, T.; Cavanagh, P. R.; Hanson, A. M.; Carpenter, R. D.; Saeed, I.; Kornak, J.; Frassetto, L.; Grodsinsky, C.; Funk, J.; Lee, S. M. C.; Spiering, B. A.; Bloomberg, J.; Mulavara, A.; Sibonga, J.; Lang, T.

2011-06-01

Prolonged weightlessness is associated with declines in musculoskeletal, cardiovascular, and sensorimotor health. Consequently, in-flight countermeasures are required to preserve astronaut health. We developed and tested a novel exercise countermeasure device (CCD) for use in spaceflight with the aim of preserving musculoskeletal and cardiovascular health along with an incorporated balance training component. Additionally, the CCD features a compact footprint, and a low power requirement. Methods: After design and development of the CCD, we carried out a training study to test its ability to improve cardiovascular and muscular fitness in healthy volunteers. Fourteen male and female subjects (41.4±9.0 years, 69.5±15.4 kg) completed 12 weeks (3 sessions per week) of concurrent strength and endurance training on the CCD. All training was conducted with the subject in orthostasis. When configured for spaceflight, subjects will be fixed to the device via a vest with loop attachments secured to subject load devices. Subjects were tested at baseline and after 12 weeks for 1-repetition max leg press strength (1RM), peak oxygen consumption (VO 2peak), and isokinetic joint torque (ISO) at the hip, knee, and ankle. Additionally, we evaluated subjects after 6 weeks of training for changes in VO 2peak and 1RM. Results: VO 2peak and 1RM improved after 6 weeks, with additional improvements after 12 weeks (1.95±0.5, 2.28±0.5, 2.47±0.6 L min -1, and 131.2±63.9,182.8±75.0, 207.0±75.0 kg) for baseline, 6 weeks, and 12 weeks, respectively. ISO for hip adduction, adduction, and ankle plantar flexion improved after 12 weeks of training (70.3±39.5, 76.8±39.2, and 55.7±21.7 N m vs. 86.1±37.3, 85.1±34.3, and 62.1±26.4 N m, respectively). No changes were observed for ISO during hip flexion, knee extension, or knee flexion. Conclusions: The CCD is effective at improving cardiovascular fitness and isotonic leg strength in healthy adults. Further, the improvement in hip adductor and abductor torque provides support that the CCD may provide additional protection for the preservation of bone health at the hip.

Cross delay line sensor characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owens, Israel J; Remelius, Dennis K; Tiee, Joe J

There exists a wealth of information in the scientific literature on the physical properties and device characterization procedures for complementary metal oxide semiconductor (CMOS), charge coupled device (CCD) and avalanche photodiode (APD) format detectors. Numerous papers and books have also treated photocathode operation in the context of photomultiplier tube (PMT) operation for either non imaging applications or limited night vision capability. However, much less information has been reported in the literature about the characterization procedures and properties of photocathode detectors with novel cross delay line (XDL) anode structures. These allow one to detect single photons and create images by recordingmore » space and time coordinate (X, Y & T) information. In this paper, we report on the physical characteristics and performance of a cross delay line anode sensor with an enhanced near infrared wavelength response photocathode and high dynamic range micro channel plate (MCP) gain (> 10{sup 6}) multiplier stage. Measurement procedures and results including the device dark event rate (DER), pulse height distribution, quantum and electronic device efficiency (QE & DQE) and spatial resolution per effective pixel region in a 25 mm sensor array are presented. The overall knowledge and information obtained from XDL sensor characterization allow us to optimize device performance and assess capability. These device performance properties and capabilities make XDL detectors ideal for remote sensing field applications that require single photon detection, imaging, sub nano-second timing response, high spatial resolution (10's of microns) and large effective image format.« less

New light-amplifier-based detector designs for high spatial resolution and high sensitivity CBCT mammography and fluoroscopy

PubMed Central

Rudin, Stephen; Kuhls, Andrew T.; Yadava, Girijesh K.; Josan, Gaurav C.; Wu, Ye; Chityala, Ravishankar N.; Rangwala, Hussain S.; Ciprian Ionita, N.; Hoffmann, Kenneth R.; Bednarek, Daniel R.

2011-01-01

New cone-beam computed tomographic (CBCT) mammography system designs are presented where the detectors provide high spatial resolution, high sensitivity, low noise, wide dynamic range, negligible lag and high frame rates similar to features required for high performance fluoroscopy detectors. The x-ray detectors consist of a phosphor coupled by a fiber-optic taper to either a high gain image light amplifier (LA) then CCD camera or to an electron multiplying CCD. When a square-array of such detectors is used, a field-of-view (FOV) to 20 × 20 cm can be obtained where the images have pixel-resolution of 100 µm or better. To achieve practical CBCT mammography scan-times, 30 fps may be acquired with quantum limited (noise free) performance below 0.2 µR detector exposure per frame. Because of the flexible voltage controlled gain of the LA’s and EMCCDs, large detector dynamic range is also achievable. Features of such detector systems with arrays of either generation 2 (Gen 2) or 3 (Gen 3) LAs optically coupled to CCD cameras or arrays of EMCCDs coupled directly are compared. Quantum accounting analysis is done for a variety of such designs where either the lowest number of information carriers off the LA photo-cathode or electrons released in the EMCCDs per x-ray absorbed in the phosphor are large enough to imply no quantum sink for the design. These new LA- or EMCCD-based systems could lead to vastly improved CBCT mammography, ROI-CT, or fluoroscopy performance compared to systems using flat panels. PMID:21297904

New light-amplifier-based detector designs for high spatial resolution and high sensitivity CBCT mammography and fluoroscopy

NASA Astrophysics Data System (ADS)

Rudin, Stephen; Kuhls, Andrew T.; Yadava, Girijesh K.; Josan, Gaurav C.; Wu, Ye; Chityala, Ravishankar N.; Rangwala, Hussain S.; Ionita, N. Ciprian; Hoffmann, Kenneth R.; Bednarek, Daniel R.

2006-03-01

New cone-beam computed tomographic (CBCT) mammography system designs are presented where the detectors provide high spatial resolution, high sensitivity, low noise, wide dynamic range, negligible lag and high frame rates similar to features required for high performance fluoroscopy detectors. The x-ray detectors consist of a phosphor coupled by a fiber-optic taper to either a high gain image light amplifier (LA) then CCD camera or to an electron multiplying CCD. When a square-array of such detectors is used, a field-of-view (FOV) to 20 x 20 cm can be obtained where the images have pixel-resolution of 100 μm or better. To achieve practical CBCT mammography scan-times, 30 fps may be acquired with quantum limited (noise free) performance below 0.2 μR detector exposure per frame. Because of the flexible voltage controlled gain of the LA's and EMCCDs, large detector dynamic range is also achievable. Features of such detector systems with arrays of either generation 2 (Gen 2) or 3 (Gen 3) LAs optically coupled to CCD cameras or arrays of EMCCDs coupled directly are compared. Quantum accounting analysis is done for a variety of such designs where either the lowest number of information carriers off the LA photo-cathode or electrons released in the EMCCDs per x-ray absorbed in the phosphor are large enough to imply no quantum sink for the design. These new LA- or EMCCD-based systems could lead to vastly improved CBCT mammography, ROI-CT, or fluoroscopy performance compared to systems using flat panels.

Spectral analysis using CCDs

NASA Technical Reports Server (NTRS)

Hewes, C. R.; Brodersen, R. W.; De Wit, M.; Buss, D. D.

1976-01-01

Charge-coupled devices (CCDs) are ideally suited for performing sampled-data transversal filtering operations in the analog domain. Two algorithms have been identified for performing spectral analysis in which the bulk of the computation can be performed in a CCD transversal filter; the chirp z-transform and the prime transform. CCD implementation of both these transform algorithms is presented together with performance data and applications.

pnCCD for photon detection from near-infrared to X-rays

NASA Astrophysics Data System (ADS)

Meidinger, Norbert; Andritschke, Robert; Hartmann, Robert; Herrmann, Sven; Holl, Peter; Lutz, Gerhard; Strüder, Lothar

2006-09-01

A pnCCD is a special type of charge-coupled device developed for spectroscopy and imaging of X-rays with high time resolution and quantum efficiency. Its most famous application is the operation on the XMM-Newton satellite, an X-ray astronomy mission that was launched by the European space agency in 1999. The excellent performance of the focal plane camera has been maintained for more than 6 years in orbit. The energy resolution in particular has shown hardly any degradation since launch. In order to satisfy the requirements of future X-ray astronomy missions as well as those of ground-based experiments, a new type of pnCCD has been developed. This ‘frame-store pnCCD’ shows an enhanced performance compared to the XMM-Newton type of pnCCD. Now, more options in device design and operation are available to tailor the detector to its respective application. Part of this concept is a programmable analog signal processor, which has been developed for the readout of the CCD signals. The electronic noise of the new detector has a value of only 2 electrons equivalent noise charge (ENC), which is less than half of the figure achieved for the XMM-Newton-type pnCCD. The energy resolution for the Mn-Kα line at 5.9 keV is approximately 130 eV FWHM. We have close to 100% quantum efficiency for both low- and high-energy photon detection (e.g. the C-K line at 277 eV, and the Ge-Kα line at 10 keV, respectively). Very high frame rates of 1000 images/s have been achieved due to the ultra-fast readout accomplished by the parallel architecture of the pnCCD and the analog signal processor. Excellent spectroscopic performance is shown even at the relatively high operating temperature of -25 °C that can be achieved by a Peltier cooler. The applications of the low-noise and fast pnCCD detector are not limited to the detection of X-rays. With an anti-reflective coating deposited on the photon entrance window, we achieve high quantum efficiency also for near-infrared and optical photons. A novel type of pnCCD is in preparation, which allows single optical photon counting. This feature is accomplished by implementation of an avalanche-type amplifier in the pnCCD concept.

Fixed mount wavefront sensor

DOEpatents

Neal, Daniel R.

2000-01-01

A rigid mount and method of mounting for a wavefront sensor. A wavefront dissector, such as a lenslet array, is rigidly mounted at a fixed distance relative to an imager, such as a CCD camera, without need for a relay imaging lens therebetween.

Scientific and technical collaboration between Russian and Ukranian researchers and manufacturers on the development of astronomical instruments equipped with advanced detection services

NASA Astrophysics Data System (ADS)

Vishnevsky, G. I.; Galyatkin, I. A.; Zhuk, A. A.; Iblyaminova, A. F.; Kossov, V. G.; Levko, G. V.; Nesterov, V. K.; Rivkind, V. L.; Rogalev, Yu. N.; Smirnov, A. V.; Gumerov, R. I.; Bikmaev, I. F.; Pinigin, G. I.; Shulga, A. V.; Kovalchyk, A. V.; Protsyuk, Yu. I.; Malevinsky, S. V.; Abrosimov, V. M.; Mironenko, V. N.; Savchenko, V. V.; Ivaschenko, Yu. N.; Andruk, V. M.; Dalinenko, I. N.; Vydrevich, M. G.

2003-01-01

The paper presents the possibilities and a list of tasks that are solved by collaboration between research and production companies, and astronomical observatories of Russia and Ukraine in the field of development, modernization and equipping of various telescopes (the AMC, RTT-150, Zeiss-600 and quantum-optical system Sazhen-S types) with advanced charge-coupled device (CCD) cameras. CCD imagers and ditital CCD cameras designed and manufactured by the "Electron-Optronic" Research & Production Company, St Petersburg, to equip astronomical telescopes and scientific instruments are described.

ESA's CCD test bench for the PLATO mission

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

Trap pumping schemes for the Euclid CCD273 detector: characterisation of electrodes and defects

NASA Astrophysics Data System (ADS)

Skottfelt, J.; Hall, D. J.; Dryer, B.; Bush, N.; Campa, J.; Gow, J. P. D.; Holland, A. D.; Jordan, D.; Burt, D.

2017-12-01

The VISible imager instrument (VIS) on board the Euclid mission will deliver high resolution shape measurements of galaxies down to very faint limits (R ~ 25 at 10σ) in a large part of the sky, in order to infer the distribution of dark matter in the Universe. To help mitigate radiation damage effects that will accumulate in the detectors over the mission lifetime, the properties of the radiation induced traps needs to be known with as high precision as possible. For this purpose the trap pumping method will be employed as part of the in-orbit calibration routines. Using trap pumping it is possible to identify and characterise single traps in a Charge-Coupled Device (CCD), thus providing information such as the density, emission time constants and sub-pixel positions of the traps in the detectors. This paper presents the trap pumping algorithms used for the radiation testing campaign of the CCD273 detectors, performed by the Centre for Electronic Imaging (CEI) at the Open University, that will be used for the VIS instrument. The CCD273 is a four-phase device with uneven phase widths, which complicates the trap pumping analysis. However, we find that by optimising the trap pumping algorithms and analysis routines, it is possible to obtain sub-pixel and even sub-phase positional information about the traps. Further, by comparing trap pumping data with simulations, it is possible to gain more information about the effective electrode widths of the device.

15 CFR 740.19 - Consumer Communications Devices (CCD).

Code of Federal Regulations, 2010 CFR

2010-01-01

...; (11) Memory devices classified under ECCN 5A992 or designated EAR99; (12) “Information security... 5D992 or designated EAR99; (13) Digital cameras and memory cards classified under ECCN 5A992 or...

An acoustic charge transport imager for high definition television applications

NASA Technical Reports Server (NTRS)

Hunt, W. D.; Brennan, Kevin F.

1994-01-01

The primary goal of this research is to develop a solid-state high definition television (HDTV) imager chip operating at a frame rate of about 170 frames/sec at 2 Megapixels per frame. This imager offers an order of magnitude improvement in speed over CCD designs and will allow for monolithic imagers operating from the IR to the UV. The technical approach of the project focuses on the development of the three basic components of the imager and their integration. The imager chip can be divided into three distinct components: (1) image capture via an array of avalanche photodiodes (APD's), (2) charge collection, storage and overflow control via a charge transfer transistor device (CTD), and (3) charge readout via an array of acoustic charge transport (ACT) channels. The use of APD's allows for front end gain at low noise and low operating voltages while the ACT readout enables concomitant high speed and high charge transfer efficiency. Currently work is progressing towards the development of manufacturable designs for each of these component devices. In addition to the development of each of the three distinct components, work towards their integration is also progressing. The component designs are considered not only to meet individual specifications but to provide overall system level performance suitable for HDTV operation upon integration. The ultimate manufacturability and reliability of the chip constrains the design as well. The progress made during this period is described in detail in Sections 2-4.

A low cost surface plasmon resonance biosensor using a laser line generator

NASA Astrophysics Data System (ADS)

Chen, Ruipeng; Wang, Manping; Wang, Shun; Liang, Hao; Hu, Xinran; Sun, Xiaohui; Zhu, Juanhua; Ma, Liuzheng; Jiang, Min; Hu, Jiandong; Li, Jianwei

2015-08-01

Due to the instrument designed by using a common surface plasmon resonance biosensor is extremely expensive, we established a portable and cost-effective surface plasmon resonance biosensing system. It is mainly composed of laser line generator, P-polarizer, customized prism, microfluidic cell, and line Charge Coupled Device (CCD) array. Microprocessor PIC24FJ128GA006 with embedded A/D converter, communication interface circuit and photoelectric signal amplifier circuit are used to obtain the weak signals from the biosensing system. Moreover, the line CCD module is checked and optimized on the number of pixels, pixels dimension, output amplifier and the timing diagram. The micro-flow cell is made of stainless steel with a high thermal conductivity, and the microprocessor based Proportional-Integral-Derivative (PID) temperature-controlled algorithm was designed to keep the constant temperature (25 °C) of the sample solutions. Correspondingly, the data algorithms designed especially to this biosensing system including amplitude-limiting filtering algorithm, data normalization and curve plotting were programmed efficiently. To validate the performance of the biosensor, ethanol solution samples at the concentrations of 5%, 7.5%, 10%, 12.5% and 15% in volumetric fractions were used, respectively. The fitting equation ΔRU = - 752987.265 + 570237.348 × RI with the R-Square of 0.97344 was established by delta response units (ΔRUs) to refractive indexes (RI). The maximum relative standard deviation (RSD) of 4.8% was obtained.

Real-time Full-spectral Imaging and Affinity Measurements from 50 Microfluidic Channels using Nanohole Surface Plasmon Resonance†

PubMed Central

Lee, Si Hoon; Lindquist, Nathan C.; Wittenberg, Nathan J.; Jordan, Luke R.; Oh, Sang-Hyun

2012-01-01

With recent advances in high-throughput proteomics and systems biology, there is a growing demand for new instruments that can precisely quantify a wide range of receptor-ligand binding kinetics in a high-throughput fashion. Here we demonstrate a surface plasmon resonance (SPR) imaging spectroscopy instrument capable of extracting binding kinetics and affinities from 50 parallel microfluidic channels simultaneously. The instrument utilizes large-area (~cm2) metallic nanohole arrays as SPR sensing substrates and combines a broadband light source, a high-resolution imaging spectrometer and a low-noise CCD camera to extract spectral information from every channel in real time with a refractive index resolution of 7.7 × 10−6. To demonstrate the utility of our instrument for quantifying a wide range of biomolecular interactions, each parallel microfluidic channel is coated with a biomimetic supported lipid membrane containing ganglioside (GM1) receptors. The binding kinetics of cholera toxin b (CTX-b) to GM1 are then measured in a single experiment from 50 channels. By combining the highly parallel microfluidic device with large-area periodic nanohole array chips, our SPR imaging spectrometer system enables high-throughput, label-free, real-time SPR biosensing, and its full-spectral imaging capability combined with nanohole arrays could enable integration of SPR imaging with concurrent surface-enhanced Raman spectroscopy. PMID:22895607

Measurements of 42 Wide CPM Pairs with a CCD

NASA Astrophysics Data System (ADS)

Harshaw, Richard

2015-11-01

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

Integrative Multi-Spectral Sensor Device for Far-Infrared and Visible Light Fusion

NASA Astrophysics Data System (ADS)

Qiao, Tiezhu; Chen, Lulu; Pang, Yusong; Yan, Gaowei

2018-06-01

Infrared and visible light image fusion technology is a hot spot in the research of multi-sensor fusion technology in recent years. Existing infrared and visible light fusion technologies need to register before fusion because of using two cameras. However, the application effect of the registration technology has yet to be improved. Hence, a novel integrative multi-spectral sensor device is proposed for infrared and visible light fusion, and by using the beam splitter prism, the coaxial light incident from the same lens is projected to the infrared charge coupled device (CCD) and visible light CCD, respectively. In this paper, the imaging mechanism of the proposed sensor device is studied with the process of the signals acquisition and fusion. The simulation experiment, which involves the entire process of the optic system, signal acquisition, and signal fusion, is constructed based on imaging effect model. Additionally, the quality evaluation index is adopted to analyze the simulation result. The experimental results demonstrate that the proposed sensor device is effective and feasible.

Detection systems for mass spectrometry imaging: a perspective on novel developments with a focus on active pixel detectors.

PubMed

Jungmann, Julia H; Heeren, Ron M A

2013-01-15

Instrumental developments for imaging and individual particle detection for biomolecular mass spectrometry (imaging) and fundamental atomic and molecular physics studies are reviewed. Ion-counting detectors, array detection systems and high mass detectors for mass spectrometry (imaging) are treated. State-of-the-art detection systems for multi-dimensional ion, electron and photon detection are highlighted. Their application and performance in three different imaging modes--integrated, selected and spectral image detection--are described. Electro-optical and microchannel-plate-based systems are contrasted. The analytical capabilities of solid-state pixel detectors--both charge coupled device (CCD) and complementary metal oxide semiconductor (CMOS) chips--are introduced. The Medipix/Timepix detector family is described as an example of a CMOS hybrid active pixel sensor. Alternative imaging methods for particle detection and their potential for future applications are investigated. Copyright © 2012 John Wiley & Sons, Ltd.

Electronic pictures from charged-coupled devices

NASA Technical Reports Server (NTRS)

Mccann, D. H.; Turly, A. P.; White, M.

1979-01-01

Imaging system uses charge-coupled devices (CCD's) to generate TV-like pictures with high resolution, sensitivity, and signal-to-noise ratio. It combines detectors for five spectral bands as well as processing and control circuitry all on single silicon chip.

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

NASA Technical Reports Server (NTRS)

Jones, J. A.

1983-01-01

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

Study the performance of star sensor influenced by space radiation damage of image sensor

NASA Astrophysics Data System (ADS)

Feng, Jie; Li, Yudong; Wen, Lin; Guo, Qi; Zhang, Xingyao

2018-03-01

Star sensor is an essential component of spacecraft attitude control system. Spatial radiation can cause star sensor performance degradation, abnormal work, attitude measurement accuracy and reliability reduction. Many studies have already been dedicated to the radiation effect on Charge-Coupled Device(CCD) image sensor, but fewer studies focus on the radiation effect of star sensor. The innovation of this paper is to study the radiation effects from the device level to the system level. The influence of the degradation of CCD image sensor radiation sensitive parameters on the performance parameters of star sensor is studied in this paper. The correlation among the radiation effect of proton, the non-uniformity noise of CCD image sensor and the performance parameter of star sensor is analyzed. This paper establishes a foundation for the study of error prediction and correction technology of star sensor on-orbit attitude measurement, and provides some theoretical basis for the design of high performance star sensor.

VizieR Online Data Catalog: Photometry of multiple stars at NAOR&ASV in 2015 (Cvetkovic+, 2017)

NASA Astrophysics Data System (ADS)

Cvetkovic, Z.; Pavlovic, R.; Boeva, S.

2018-05-01

This is the ninth series of CCD observations of double and multiple stars, obtained at the Bulgarian National Astronomical Observatory at Rozhen (NAOR) over five nights. As previously, the CCD camera VersArray 1300B was used, which was attached to the 2 m telescope. For each double or multiple star, five CCD frames in the Johnson B filter and five frames in the Johnson V filter were taken, which enabled us to determine the magnitude difference for these filters. In 2015 at the Astronomical Station at Vidojevica (ASV), over a total of 23 nights, observations were carried out by using the 60 cm telescope with a Cassegrain optical system. This is the fourth observational series at ASV since the work started there in 2011. In the observations we used the Apogee Alta U42 CCD camera whose characteristics can be found in the paper by Cvetkovic et al. (2016, J/AJ/151/58). Every pair was observed five times in the Cousins/Bessel B filter and five times in the Cousins/Bessel V one. (3 data files).

Modeling the impact of preflushing on CTE in proton irradiated CCD-based detectors

NASA Astrophysics Data System (ADS)

Philbrick, R. H.

2002-04-01

A software model is described that performs a "real world" simulation of the operation of several types of charge-coupled device (CCD)-based detectors in order to accurately predict the impact that high-energy proton radiation has on image distortion and modulation transfer function (MTF). The model was written primarily to predict the effectiveness of vertical preflushing on the custom full frame CCD-based detectors intended for use on the proposed Kepler Discovery mission, but it is capable of simulating many other types of CCD detectors and operating modes as well. The model keeps track of the occupancy of all phosphorous-silicon (P-V), divacancy (V-V) and oxygen-silicon (O-V) defect centers under every CCD electrode over the entire detector area. The integrated image is read out by simulating every electrode-to-electrode charge transfer in both the vertical and horizontal CCD registers. A signal level dependency on the capture and emission of signal is included and the current state of each electrode (e.g., barrier or storage) is considered when distributing integrated and emitted signal. Options for performing preflushing, preflashing, and including mini-channels are available on both the vertical and horizontal CCD registers. In addition, dark signal generation and image transfer smear can be selectively enabled or disabled. A comparison of the charge transfer efficiency (CTE) data measured on the Hubble space telescope imaging spectrometer (STIS) CCD with the CTE extracted from model simulations of the STIS CCD show good agreement.

Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD

DOE PAGES

Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; ...

2017-09-26

Here, we have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068 e - rms/pixel. This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime.more » Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while future astronomical applications may include direct imaging and spectroscopy of exoplanets.« less

Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD

NASA Astrophysics Data System (ADS)

Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; Essig, Rouven; Guardincerri, Yann; Holland, Steve; Volansky, Tomer; Yu, Tien-Tien

2017-09-01

We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068 e- rms /pixel . This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime. Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while future astronomical applications may include direct imaging and spectroscopy of exoplanets.

Single-Electron and Single-Photon Sensitivity with a Silicon Skipper CCD.

PubMed

Tiffenberg, Javier; Sofo-Haro, Miguel; Drlica-Wagner, Alex; Essig, Rouven; Guardincerri, Yann; Holland, Steve; Volansky, Tomer; Yu, Tien-Tien

2017-09-29

We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level of 0.068  e^{-} rms/pixel. This is the first time that discrete subelectron readout noise has been achieved reproducible over millions of pixels on a stable, large-area detector. This enables the contemporaneous, discrete, and quantized measurement of charge in pixels, irrespective of whether they contain zero electrons or thousands of electrons. Thus, the resulting CCD detector is an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime. Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while future astronomical applications may include direct imaging and spectroscopy of exoplanets.

Spectroscopic Studies of the Electronic Structure of Metal-Semiconductor and Vacuum-Semiconductor Interfaces.

DTIC Science & Technology

1982-12-31

interfaces which are of importance in such semi- conductor devices as MOSFETS, CCD devices, photovoltaic devices, DD I jAN 73 1473 EDITION OF INOV 66 if...interfaces is interesting for the study of electrolytic cells . Our photoemission study reveals for the first time how the electronic structure of water

Cryostat and CCD for MEGARA at GTC

NASA Astrophysics Data System (ADS)

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.

Spectroscopy and CCD-photography of extended red emission in reflection nebulae

NASA Technical Reports Server (NTRS)

Witt, A. N.; Schild, R. E.

1986-01-01

Recent spectrographic studies of extended red emission (ERE) seen in the 0.6 to 0.9 micron spectral region in many reflection nebulae have shown fluorescence by amorphous hydrogenated carbon to be the most probable cause of the ERE. Spectrographic observations were performed on the nebulae NGC 2023 and NGC 7023, using the intensified Reticon scanner (IRS) of Kitt Peak National Observatory on the N0-2 0.9 mm telescope. Charge coupled device (CCD) images of NGC2023 and NGC 7023 were obtained with the CfA CCD detector on the 0.6 mm telescope of the Whipple Observatory. Results are discussed.

High-speed high-resolution epifluorescence imaging system using CCD sensor and digital storage for neurobiological research

NASA Astrophysics Data System (ADS)

Takashima, Ichiro; Kajiwara, Riichi; Murano, Kiyo; Iijima, Toshio; Morinaka, Yasuhiro; Komobuchi, Hiroyoshi

2001-04-01

We have designed and built a high-speed CCD imaging system for monitoring neural activity in an exposed animal cortex stained with a voltage-sensitive dye. Two types of custom-made CCD sensors were developed for this system. The type I chip has a resolution of 2664 (H) X 1200 (V) pixels and a wide imaging area of 28.1 X 13.8 mm, while the type II chip has 1776 X 1626 pixels and an active imaging area of 20.4 X 18.7 mm. The CCD arrays were constructed with multiple output amplifiers in order to accelerate the readout rate. The two chips were divided into either 24 (I) or 16 (II) distinct areas that were driven in parallel. The parallel CCD outputs were digitized by 12-bit A/D converters and then stored in the frame memory. The frame memory was constructed with synchronous DRAM modules, which provided a capacity of 128 MB per channel. On-chip and on-memory binning methods were incorporated into the system, e.g., this enabled us to capture 444 X 200 pixel-images for periods of 36 seconds at a rate of 500 frames/second. This system was successfully used to visualize neural activity in the cortices of rats, guinea pigs, and monkeys.

Effectiveness study of UNL's pneumatic crack/joint preparation device.

DOT National Transportation Integrated Search

2014-03-01

The aim of this project was to evaluate the effectiveness of the crack cleaning device (CCD) for improving the current crack/joint preparation practices and for possible adoption as a standard in Nebraska Department of Roads (NDOR). Through the colla...

IDSAC-IUCAA digital sampler array controller

NASA Astrophysics Data System (ADS)

Chattopadhyay, Sabyasachi; Chordia, Pravin; Ramaprakash, A. N.; Burse, Mahesh P.; Joshi, Bhushan; Chillal, Kalpesh

2016-07-01

In order to run the large format detector arrays and mosaics that are required by most astronomical instruments, readout electronic controllers are required which can process multiple CCD outputs simultaneously at high speeds and low noise levels. These CCD controllers need to be modular and configurable, should be able to run multiple detector types to cater to a wide variety of requirements. IUCAA Digital Sampler Array Controller (IDSAC), is a generic CCD Controller based on a fully scalable architecture which is adequately flexible and powerful enough to control a wide variety of detectors used in ground based astronomy. The controller has a modular backplane architecture that consists of Single Board Controller Cards (SBCs) and can control up to 5 CCDs (mosaic or independent). Each Single Board Controller (SBC) has all the resources to a run Single large format CCD having up to four outputs. All SBCs are identical and are easily interchangeable without needing any reconfiguration. A four channel video processor on each SBC can process up to four output CCDs with or without dummy outputs at 0.5 Megapixels/Sec/Channel with 16 bit resolution. Each SBC has a USB 2.0 interface which can be connected to a host computer via optional USB to Fibre converters. The SBC uses a reconfigurable hardware (FPGA) as a Master Controller. IDSAC offers Digital Correlated Double Sampling (DCDS) to eliminate thermal kTC noise. CDS performed in Digital domain (DCDS) has several advantages over its analog counterpart, such as - less electronics, faster readout and easier post processing. It is also flexible with sampling rate and pixel throughput while maintaining the core circuit topology intact. Noise characterization of the IDSAC CDS signal chain has been performed by analytical modelling and practical measurements. Various types of noise such as white, pink, power supply, bias etc. has been considered while creating an analytical noise model tool to predict noise of a controller system like IDSAC. Several tests are performed to measure the actual noise of IDSAC. The theoretical calculation matches very well with practical measurements within 10% accuracy.

Experimental research on thermal conductive fillers for CCD module in space borne optical remote sensor

NASA Astrophysics Data System (ADS)

Zeng, Yi; Han, Xue-bing; Yang, Dong-shang; Gui, Li-jia; Zhao, Xiao-xiang; Si, Fu-qi

2016-03-01

A space-borne differential optical absorption spectrometer is a high precision aerospace optical remote sensor. It obtains the hyper-spectral，high spatial resolution radiation information by using the spectrometer with CCD（Charge Coupled Device）array detectors. Since a few CCDs are used as the key detector, the performance of the entire instrument is greatly affected by working condition of CCDs. The temperature of CCD modules has a great impact on the instrument measurement accuracy. It requires strict temperature control. The selection of the thermal conductive filler sticking CCD to the radiator is important in the CCD thermal design. Besides，due tothe complex and compact structure, it needs to take into account the anti-pollution of the optical system. Therefore, it puts forward high requirements on the selection of the conductive filler. In this paper, according to the structure characteristics of the CCD modules and the distribution of heat consumption, the thermal analysis tool I-DEAS/TMG is utilized to compute and simulate the temperature level of the CCD modules, while filling in thermal grease and thermal pad respectively. The temperature distribution of CCD heat dissipation in typical operating conditions is obtained. In addition, the heat balance test was carried out under the condition of two kinds of thermal conductive fillers. The thermal control of CCD was tested under various conditions, and the results were compared with the results of thermal analysis. The results show that there are some differences in thermal performance between the two kinds of thermal conductive fillers. Although they both can meet the thermal performance requirements of the instrument, either would be chosen taking account of other conditions and requirements such as anti-pollution and insulation. The content and results of this paper will be a good reference for the thermal design of the CCD in the aerospace optical payload.

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

NASA Astrophysics Data System (ADS)

Seabroke, G. M.; Holland, A. D.; Burt, D.; Robbins, M. S.

2009-08-01

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 results will fit into Gaia's overall radiation calibration strategy. In this paper, the second of the series, we present our first results using Silvaco's physics-based, engineering software: the ATLAS device simulation framework. Inputting a doping profile, pixel geometry and materials into ATLAS and comparing the results to other simulations reveals that ATLAS has a free parameter, fixed oxide charge, that needs to be calibrated. ATLAS is successfully benchmarked against other simulations and measurements of a test device, identifying how to use it to model Gaia pixels and highlighting the affect of different doping approximations.

Development of Cell Phone Application for Blood Glucose Self-Monitoring Based on ISO/IEEE 11073 and HL7 CCD.

PubMed

Park, Hyun Sang; Cho, Hune; Kim, Hwa Sun

2015-04-01

The objectives of this research were to develop and evaluate a cell phone application based on the standard protocol for personal health devices and the standard information model for personal health records to support effective blood glucose management and standardized service for patients with diabetes. An application was developed for Android 4.0.3. In addition, an IEEE 11073 Manager, Medical Device Encoding Rule, and Bluetooth Health Device Profile Connector were developed for standardized health communication with a glucometer, and a Continuity of Care Document (CCD) Composer and CCD Parser were developed for CCD document exchange. The developed application was evaluated by five healthcare professionals and 87 users through a questionnaire comprising the following variables: usage intention, effort expectancy, social influence, facilitating condition, perceived risk, and voluntariness. As a result of the evaluation of usability, it was confirmed that the developed application is useful for blood glucose self-monitoring by diabetic patients. In particular, the healthcare professionals stated their own views that the application is useful to observe the trends in blood glucose change through the automatic function which records a blood glucose level measured using Bluetooth function, and the function which checks accumulated records of blood glucose levels. Also, a result of the evaluation of usage intention was 3.52 ± 0.42 out of 5 points. The application developed by our research team was confirmed by the verification of healthcare professionals that accurate feedback can be provided to healthcare professionals during the management of diabetic patients or education for glucose management.

Development of Cell Phone Application for Blood Glucose Self-Monitoring Based on ISO/IEEE 11073 and HL7 CCD

PubMed Central

Park, Hyun Sang; Cho, Hune

2015-01-01

Objectives The objectives of this research were to develop and evaluate a cell phone application based on the standard protocol for personal health devices and the standard information model for personal health records to support effective blood glucose management and standardized service for patients with diabetes. Methods An application was developed for Android 4.0.3. In addition, an IEEE 11073 Manager, Medical Device Encoding Rule, and Bluetooth Health Device Profile Connector were developed for standardized health communication with a glucometer, and a Continuity of Care Document (CCD) Composer and CCD Parser were developed for CCD document exchange. The developed application was evaluated by five healthcare professionals and 87 users through a questionnaire comprising the following variables: usage intention, effort expectancy, social influence, facilitating condition, perceived risk, and voluntariness. Results As a result of the evaluation of usability, it was confirmed that the developed application is useful for blood glucose self-monitoring by diabetic patients. In particular, the healthcare professionals stated their own views that the application is useful to observe the trends in blood glucose change through the automatic function which records a blood glucose level measured using Bluetooth function, and the function which checks accumulated records of blood glucose levels. Also, a result of the evaluation of usage intention was 3.52 ± 0.42 out of 5 points. Conclusions The application developed by our research team was confirmed by the verification of healthcare professionals that accurate feedback can be provided to healthcare professionals during the management of diabetic patients or education for glucose management. PMID:25995960

Fast noninvasive eye-tracking and eye-gaze determination for biomedical and remote monitoring applications

NASA Astrophysics Data System (ADS)

Talukder, Ashit; Morookian, John M.; Monacos, Steve P.; Lam, Raymond K.; Lebaw, C.; Bond, A.

2004-04-01

Eyetracking is one of the latest technologies that has shown potential in several areas including human-computer interaction for people with and without disabilities, and for noninvasive monitoring, detection, and even diagnosis of physiological and neurological problems in individuals. Current non-invasive eyetracking methods achieve a 30 Hz rate with possibly low accuracy in gaze estimation, that is insufficient for many applications. We propose a new non-invasive visual eyetracking system that is capable of operating at speeds as high as 6-12 KHz. A new CCD video camera and hardware architecture is used, and a novel fast image processing algorithm leverages specific features of the input CCD camera to yield a real-time eyetracking system. A field programmable gate array (FPGA) is used to control the CCD camera and execute the image processing operations. Initial results show the excellent performance of our system under severe head motion and low contrast conditions.

Aerosol mobility imaging for rapid size distribution measurements

DOEpatents

Wang, Jian; Hering, Susanne Vera; Spielman, Steven Russel; Kuang, Chongai

2016-07-19

A parallel plate dimensional electrical mobility separator and laminar flow water condensation provide rapid, mobility-based particle sizing at concentrations typical of the remote atmosphere. Particles are separated spatially within the electrical mobility separator, enlarged through water condensation, and imaged onto a CCD array. The mobility separation distributes particles in accordance with their size. The condensation enlarges size-separated particles by water condensation while they are still within the gap of the mobility drift tube. Once enlarged the particles are illuminated by a laser. At a pre-selected frequency, typically 10 Hz, the position of all of the individual particles illuminated by the laser are captured by CCD camera. This instantly records the particle number concentration at each position. Because the position is directly related to the particle size (or mobility), the particle size spectra is derived from the images recorded by the CCD.

Specialized CCDs for high-frame-rate visible imaging and UV imaging applications

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Taylor, Gordon C.; Shallcross, Frank V.; Tower, John R.; Lawler, William B.; Harrison, Lorna J.; Socker, Dennis G.; Marchywka, Mike

1993-11-01

This paper reports recent progress by the authors in two distinct charge coupled device (CCD) technology areas. The first technology area is high frame rate, multi-port, frame transfer imagers. A 16-port, 512 X 512, split frame transfer imager and a 32-port, 1024 X 1024, split frame transfer imager are described. The thinned, backside illuminated devices feature on-chip correlated double sampling, buried blooming drains, and a room temperature dark current of less than 50 pA/cm2, without surface accumulation. The second technology area is vacuum ultraviolet (UV) frame transfer imagers. A developmental 1024 X 640 frame transfer imager with 20% quantum efficiency at 140 nm is described. The device is fabricated in a p-channel CCD process, thinned for backside illumination, and utilizes special packaging to achieve stable UV response.

Development of advanced diagnostics for characterization of burning droplets in microgravity

NASA Technical Reports Server (NTRS)

Sankar, Subramanian; Buermann, Dale H.; Bachalo, William D.

1995-01-01

Diagnostic techniques currently used for microgravity research are generally not as advanced as those used in earth based gravity experiments. Diagnostic techniques for measuring the instantaneous radial temperature profile (or temperature gradients) within the burning droplet do not exist. Over the past few years, Aerometrics has been researching and developing a rainbow thermometric technique for measuring the droplet temperatures of burning droplets. This technique has recently been integrated with the phase Doppler interferometric technique to yield a diagnostic instrument that can be used to simultaneously measure the size, velocity, and temperature of burning droplets in complex spray flames. Also, the rainbow thermometric technique has been recently integrated with a point-diffraction interferometric technique for measuring the instantaneous gas phase temperature field surrounding a burning droplet. These research programs, apart from being very successful, have also helped us identify other innovative techniques for the characterization of burning droplets. For example, new techniques have been identified for measuring the instantaneous regression rate of burning droplets. Also, there is the possibility of extracting the instantaneous radial temperature distribution or the temperature gradients within a droplet during transient heating. What is important is that these diagnostic techniques have the potential for making use of inexpensive, light-weight, and rugged devices such as diode lasers and linear CCD arrays. As a result, they can be easily packaged for incorporation into microgravity drop-test and flight-test facilities. Furthermore, with the use of linear CCD arrays, data rates as high as 10-100 kHz can be easily achieved. This data rate is orders of magnitude higher than what is currently achievable. In this research and development program, a compact and rugged diagnostic system will be developed that can be used to measure instantaneous fuel droplet diameter, droplet regression rate, and the droplet internal temperature profiles or gradients at very high data rates in microgravity experiments.

Mid-infrared photodetectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guyot-Sionnest, Philippe; Keuleyan, Sean E.; Lhuillier, Emmanuel

2016-04-19

Nanoparticles, methods of manufacture, devices comprising the nanoparticles, methods of their manufacture, and methods of their use are provided herein. The nanoparticles and devices having photoabsorptions in the range of 1.7 .mu.m to 12 .mu.m and can be used as photoconductors, photodiodes, phototransistors, charge-coupled devices (CCD), luminescent probes, lasers, thermal imagers, night-vision systems, and/or photodetectors.

Cat-eye effect reflected beam profiles of an optical system with sensor array.

PubMed

Gong, Mali; He, Sifeng; Guo, Rui; Wang, Wei

2016-06-01

In this paper, we propose an applicable propagation model for Gaussian beams passing through any cat-eye target instead of traditional simplification consisting of only a mirror placed at the focal plane of a lens. According to the model, the cat-eye effect of CCD cameras affected by defocus is numerically simulated. An excellent agreement of experiment results with theoretical analysis is obtained. It is found that the reflectivity distribution at the focal plane of the cat-eye optical lens has great influence on the results, while the cat-eye effect reflected beam profiles of CCD cameras show obvious periodicity.

Improving signal to noise in labeled biological specimens using energy-filtered TEM of sections with a drift correction strategy and a direct detection device.

PubMed

Ramachandra, Ranjan; Bouwer, James C; Mackey, Mason R; Bushong, Eric; Peltier, Steven T; Xuong, Nguyen-Huu; Ellisman, Mark H

2014-06-01

Energy filtered transmission electron microscopy techniques are regularly used to build elemental maps of spatially distributed nanoparticles in materials and biological specimens. When working with thick biological sections, electron energy loss spectroscopy techniques involving core-loss electrons often require exposures exceeding several minutes to provide sufficient signal to noise. Image quality with these long exposures is often compromised by specimen drift, which results in blurring and reduced resolution. To mitigate drift artifacts, a series of short exposure images can be acquired, aligned, and merged to form a single image. For samples where the target elements have extremely low signal yields, the use of charge coupled device (CCD)-based detectors for this purpose can be problematic. At short acquisition times, the images produced by CCDs can be noisy and may contain fixed pattern artifacts that impact subsequent correlative alignment. Here we report on the use of direct electron detection devices (DDD's) to increase the signal to noise as compared with CCD's. A 3× improvement in signal is reported with a DDD versus a comparably formatted CCD, with equivalent dose on each detector. With the fast rolling-readout design of the DDD, the duty cycle provides a major benefit, as there is no dead time between successive frames.

A reagentless real-time method for the multiparameter analysis of nanoparticles as a potential 'trigger' device

NASA Astrophysics Data System (ADS)

Carr, Bob; Knowles, John; Warren, Jeremy

2008-10-01

We describe the continuing development of a laser-based, light scattering detector system capable of detecting and analysing liquid-borne nanoparticles. Using a finely focussed and specially configured laser beam to illuminate a suspension of nanoparticles in a small (250ul) sample and videoing the Brownian motion of each and every particle in the detection zone should allow individual but simultaneous detection and measurement of particle size, scattered light intensity, electrophoretic mobility and, where applicable, shape asymmetry. This real-time, multi-parameter analysis capability offers the prospect of reagentlessly differentiating between different particle types within a complex sample of potentially high and variable background. Employing relatively low powered (50-100mW) laser diode modules and low resolution CCD arrays, each component could be run off battery power, allowing distributed/remote or personal deployment. Voltages needed for electrophoresis measurement s would be similarly low (e.g. 20V, low current) and 30second videos (exported at mobile/cell phone download speeds) analysed remotely. The potential of such low-cost technology as a field-deployable grid of remote, battery powered and reagentless, multi-parameter sensors for use as trigger devices is discussed.

BATMAN: MOS Spectroscopy on Demand

NASA Astrophysics Data System (ADS)

Molinari, E.; Zamkotsian, F.; Moschetti, M.; Spano, P.; Boschin, W.; Cosentino, R.; Ghedina, A.; González, M.; Pérez, H.; Lanzoni, P.; Ramarijaona, H.; Riva, M.; Zerbi, F.; Nicastro, L.; Valenziano, L.; Di Marcantonio, P.; Coretti, I.; Cirami, R.

2016-10-01

Multi-Object Spectrographs (MOS) are the major instruments for studying primary galaxies and remote and faint objects. Current object selection systems are limited and/or difficult to implement in next generation MOS for space and ground-based telescopes. A promising solution is the use of MOEMS devices such as micromirror arrays, which allow the remote control of the multi-slit configuration in real time. TNG is hosting a novelty project for real-time, on-demand MOS masks based on MOEMS programmable slits. We are developing a 2048×1080 Digital-Micromirror-Device-based (DMD) MOS instrument to be mounted on the Galileo telescope, called BATMAN. It is a two-arm instrument designed for providing in parallel imaging and spectroscopic capabilities. With a field of view of 6.8×3.6 arcmin and a plate scale of 0.2 arcsec per micromirror, this astronomical setup can be used to investigate the formation and evolution of galaxies. The wavelength range is in the visible and the spectral resolution is R=560 for a 1 arcsec object, and the two arms will have 2k × 4k CCD detectors. ROBIN, a BATMAN demonstrator, has been designed, realized and integrated. We plan to have BATMAN first light by mid-2016.

Design and performance of the SLD vertex detector: a 307 Mpixel tracking system

NASA Astrophysics Data System (ADS)

Abe, K.; Arodzero, A.; Baltay, C.; Brau, J. E.; Breidenbach, M.; Burrows, P. N.; Chou, A. S.; Crawford, G.; Damerell, C. J. S.; Dervan, P. J.; Dong, D. N.; Emmet, W.; English, R. L.; Etzion, E.; Foss, M.; Frey, R.; Haller, G.; Hasuko, K.; Hertzbach, S. S.; Hoeflich, J.; Huffer, M. E.; Jackson, D. J.; Jaros, J. A.; Kelsey, J.; Lee, I.; Lia, V.; Lintern, A. L.; Liu, M. X.; Manly, S. L.; Masuda, H.; McKemey, A. K.; Moore, T. B.; Nichols, A.; Nagamine, T.; Oishi, N.; Osborne, L. S.; Russell, J. J.; Ross, D.; Serbo, V. V.; Sinev, N. B.; Sinnott, J.; Skarpaas, K. Viii; Smy, M. B.; Snyder, J. A.; Strauss, M. G.; Dong, S.; Suekane, F.; Taylor, F. E.; Trandafir, A. I.; Usher, T.; Verdier, R.; Watts, S. J.; Weiss, E. R.; Yashima, J.; Yuta, H.; Zapalac, G.

1997-02-01

This paper describes the design, construction, and initial operation of SLD's upgraded vertex detector which comprises 96 two-dimensional charge-coupled devices (CCDs) with a total of 307 Mpixel. Each pixel functions as an independent particle detecting element, providing space point measurements of charged particle tracks with a typical precision of 4 μm in each co-ordinate. The CCDs are arranged in three concentric cylinders just outside the beam-pipe which surrounds the e +e - collision point of the SLAC Linear Collider (SLC). The detector is a powerful tool for distinguishing displaced vertex tracks, produced by decay in flight of heavy flavour hadrons or tau leptons, from tracks produced at the primary event vertex. The requirements for this detector include a very low mass structure (to minimize multiple scattering) both for mechanical support and to provide signal paths for the CCDs; operation at low temperature with a high degree of mechanical stability; and high speed CCD readout, signal processing, and data sparsification. The lessons learned in achieving these goals should be useful for the construction of large arrays of CCDs or active pixel devices in the future in a number of areas of science and technology.

Fast Confocal Raman Imaging Using a 2-D Multifocal Array for Parallel Hyperspectral Detection.

PubMed

Kong, Lingbo; Navas-Moreno, Maria; Chan, James W

2016-01-19

We present the development of a novel confocal hyperspectral Raman microscope capable of imaging at speeds up to 100 times faster than conventional point-scan Raman microscopy under high noise conditions. The microscope utilizes scanning galvomirrors to generate a two-dimensional (2-D) multifocal array at the sample plane, generating Raman signals simultaneously at each focus of the array pattern. The signals are combined into a single beam and delivered through a confocal pinhole before being focused through the slit of a spectrometer. To separate the signals from each row of the array, a synchronized scan mirror placed in front of the spectrometer slit positions the Raman signals onto different pixel rows of the detector. We devised an approach to deconvolve the superimposed signals and retrieve the individual spectra at each focal position within a given row. The galvomirrors were programmed to scan different focal arrays following Hadamard encoding patterns. A key feature of the Hadamard detection is the reconstruction of individual spectra with improved signal-to-noise ratio. Using polystyrene beads as test samples, we demonstrated not only that our system images faster than a conventional point-scan method but that it is especially advantageous under noisy conditions, such as when the CCD detector operates at fast read-out rates and high temperatures. This is the first demonstration of multifocal confocal Raman imaging in which parallel spectral detection is implemented along both axes of the CCD detector chip. We envision this novel 2-D multifocal spectral detection technique can be used to develop faster imaging spontaneous Raman microscopes with lower cost detectors.

Constraining neutrinos as background to wimp-nucleon dark matter particle searches for DaMIC: CCD physics analysis and electronics development

NASA Astrophysics Data System (ADS)

Butner, Melissa Jean

The DaMIC (Dark Matter in CCDs) experiment searches for dark matter particles using charge coupled devices (CCDs) operated at a low detection threshold of ˜40 eV electron equivalent energy (eVee). A multiplexor board is tested for DAMIC100+ which has the ability to control up to 16 CCDs at one time allowing for the selection of a single CCD for readout while leaving all others static and maintaining sub-electron noise. A dark matter limit is produced using the results of physics data taken with the DAMIC experiment. Next, the contribution from neutrino-nucleus coherent scattering is investigated using data from the Coherent Neutrino Nucleus Interaction Experiment (CONnuIE) using the same CCD technology. The results are used to explore the performance of CCD detectors that ultimately will limit the ability to differentiate incident solar and atmospheric neutrinos from dark matter particles.

Postirradiation behavior of p-channel charge-coupled devices irradiated at 153 K

NASA Astrophysics Data System (ADS)

Gow, Jason P. D.; Wood, Daniel; Murray, Neil J.; Burt, David; Hall, David J.; Dryer, Ben; Holland, Andrew D.

2016-04-01

The displacement damage hardness that can be achieved using p-channel charge-coupled devices (CCD) was originally demonstrated in 1997, and since then a number of other studies have demonstrated an improved tolerance to radiation-induced charge transfer inefficiency when compared to n-channel CCDs. A number of recent studies have also shown that the temperature history of the device after the irradiation impacts the performance of the detector, linked to the mobility of defects at different temperatures. The initial results from an e2v technologies p-channel CCD204 irradiated at 153 K with 10-MeV equivalent proton fluences of 1.24×109 and 1.24×1011 protons cm-2 is described. The dark current, cosmetic quality, and the number of defects identified using trap pumping immediately were monitored after the irradiation for a period of 150 h with the device held at 153 K and then after different periods of time at room temperature. The device also exhibited a flatband voltage shift of around 30 mV/krad, determined by the reduction in full well capacity.

Multilayered microelectronic device package with an integral window

DOEpatents

Peterson, Kenneth A.; Watson, Robert D.

2003-01-01

An apparatus for packaging of microelectronic devices is disclosed, wherein the package includes an integral window. The microelectronic device can be a semiconductor chip, a CCD chip, a CMOS chip, a VCSEL chip, a laser diode, a MEMS device, or a IMEMS device. The package can comprise, for example, a cofired ceramic frame or body. The package has an internal stepped structure made of a plurality of plates, with apertures, which are patterned with metallized conductive circuit traces. The microelectronic device can be flip-chip bonded on the plate to these traces, and oriented so that the light-sensitive side is optically accessible through the window. A cover lid can be attached to the opposite side of the package. The result is a compact, low-profile package, having an integral window that can be hermetically-sealed. The package body can be formed by low-temperature cofired ceramic (LTCC) or high-temperature cofired ceramic (HTCC) multilayer processes with the window being simultaneously joined (e.g. cofired) to the package body during LTCC or HTCC processing. Multiple chips can be located within a single package, according to some embodiments. The cover lid can include a window. The apparatus is particularly suited for packaging of MEMS devices, since the number of handling steps is greatly reduced, thereby reducing the potential for contamination. The integral window can further include a lens for optically transforming light passing through the window. The package can include an array of binary optic lenslets made integral with the window. The package can include an electrically-switched optical modulator, such as a lithium niobate window attached to the package, for providing a very fast electrically-operated shutter.

Proton radiation damage assessment of a CCD for use in a Ultraviolet and Visible Spectrometer

NASA Astrophysics Data System (ADS)

Gow, J. P. D.; Mason, J.; Leese, M.; Hathi, B.; Patel, M.

2017-01-01

This paper describes the radiation environment and radiation damage analysis performed for the Nadir and Occultation for MArs Discovery (NOMAD) Ultraviolet and Visible Spectrometer (UVIS) channel launched onboard the ExoMars Trace Gas Orbiter (TGO) in 2016. The aim of the instrument is to map the temporal and spatial variation of trace gases such as ozone and dust/cloud aerosols in the atmosphere of Mars. The instrument consists of a set of two miniature telescope viewing optics which allow for selective input onto the optical bench, where an e2v technologies CCD30-11 will be used as the detector. A Geometry Description Markup Language model of the spacecraft and instrument box was created and through the use of ESA's SPace ENVironment Information System (SPENVIS) an estimate of the 10 MeV equivalent proton fluence was made at a number of radiation sensitive regions within NOMAD, including that of the CCD30-11 which is the focus of this paper. The end of life 10 MeV equivalent proton fluence at the charge coupled device was estimated to be 4.7 × 109 protons.cm-2 three devices were irradiated at different levels up a 10 MeV equivalent fluence of 9.4 × 109 protons.cm-2. The dark current, charge transfer inefficiency, charge storage, and cosmetic quality of the devices was investigated pre- and post-irradiation, determining that the devices will continue to provide excellent science throughout the mission.

Combining shearography and interferometric fringe projection in a single device for complete control of industrial applications

NASA Astrophysics Data System (ADS)

Blain, Pascal; Michel, Fabrice; Piron, Pierre; Renotte, Yvon; Habraken, Serge

2013-08-01

Noncontact optical measurement methods are essential tools in many industrial and research domains. A family of new noncontact optical measurement methods based on the polarization states splitting technique and monochromatic light projection as a way to overcome ambient lighting for in-situ measurement has been developed. Recent works on a birefringent element, a Savart plate, allow one to build a more flexible and robust interferometer. This interferometer is a multipurpose metrological device. On one hand the interferometer can be set in front of a charge-coupled device (CCD) camera. This optical measurement system is called a shearography interferometer and allows one to measure microdisplacements between two states of the studied object under coherent lighting. On the other hand, by producing and shifting multiple sinusoidal Young's interference patterns with this interferometer, and using a CCD camera, it is possible to build a three-dimensional structured light profilometer.

Combining Charge Couple Devices and Rate Sensors for the Feedforward Control System of a Charge Coupled Device Tracking Loop.

PubMed

Tang, Tao; Tian, Jing; Zhong, Daijun; Fu, Chengyu

2016-06-25

A rate feed forward control-based sensor fusion is proposed to improve the closed-loop performance for a charge couple device (CCD) tracking loop. The target trajectory is recovered by combining line of sight (LOS) errors from the CCD and the angular rate from a fiber-optic gyroscope (FOG). A Kalman filter based on the Singer acceleration model utilizes the reconstructive target trajectory to estimate the target velocity. Different from classical feed forward control, additive feedback loops are inevitably added to the original control loops due to the fact some closed-loop information is used. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability. The bandwidth of the Kalman filter is the major factor affecting the control stability and close-loop performance. Both simulations and experiments are provided to demonstrate the benefits of the proposed algorithm.

Active pixel sensor array as a detector for electron microscopy.

PubMed

Milazzo, Anna-Clare; Leblanc, Philippe; Duttweiler, Fred; Jin, Liang; Bouwer, James C; Peltier, Steve; Ellisman, Mark; Bieser, Fred; Matis, Howard S; Wieman, Howard; Denes, Peter; Kleinfelder, Stuart; Xuong, Nguyen-Huu

2005-09-01

A new high-resolution recording device for transmission electron microscopy (TEM) is urgently needed. Neither film nor CCD cameras are systems that allow for efficient 3-D high-resolution particle reconstruction. We tested an active pixel sensor (APS) array as a replacement device at 200, 300, and 400 keV using a JEOL JEM-2000 FX II and a JEM-4000 EX electron microscope. For this experiment, we used an APS prototype with an area of 64 x 64 pixels of 20 microm x 20 microm pixel pitch. Single-electron events were measured by using very low beam intensity. The histogram of the incident electron energy deposited in the sensor shows a Landau distribution at low energies, as well as unexpected events at higher absorbed energies. After careful study, we concluded that backscattering in the silicon substrate and re-entering the sensitive epitaxial layer a second time with much lower speed caused the unexpected events. Exhaustive simulation experiments confirmed the existence of these back-scattered electrons. For the APS to be usable, the back-scattered electron events must be eliminated, perhaps by thinning the substrate to less than 30 microm. By using experimental data taken with an APS chip with a standard silicon substrate (300 microm) and adjusting the results to take into account the effect of a thinned silicon substrate (30 microm), we found an estimate of the signal-to-noise ratio for a back-thinned detector in the energy range of 200-400 keV was about 10:1 and an estimate for the spatial resolution was about 10 microm.

Infrared imaging of subcutaneous veins.

PubMed

Zharov, Vladimir P; Ferguson, Scott; Eidt, John F; Howard, Paul C; Fink, Louis M; Waner, Milton

2004-01-01

Imaging of subcutaneous veins is important in many applications, such as gaining venous access and vascular surgery. Despite a long history of medical infrared (IR) photography and imaging, this technique is not widely used for this purpose. Here we revisited and explored the capability of near-IR imaging to visualize subcutaneous structures, with a focus on diagnostics of superficial veins. An IR device comprising a head-mounted IR LED array (880 nm), a small conventional CCD camera (Toshiba Ik-mui, Tokyo, Japan), virtual-reality optics, polarizers, filters, and diffusers was used in vivo to obtain images of different subcutaneous structures. The same device was used to estimate the IR image quality as a function of wavelength produced by a tunable xenon lamp-based monochrometer in the range of 500-1,000 nm and continuous-wave Nd:YAG (1.06 microm) and diode (805 nm) lasers. The various modes of optical illumination were compared in vivo. Contrast of the IR images in the reflectance mode was measured in the near-IR spectral range of 650-1,060 nm. Using the LED array, various IR images were obtained in vivo, including images of vein structure in a pigmented, fatty forearm, varicose leg veins, and vascular lesions of the tongue. Imaging in the near-IR range (880-930 nm) provides relatively good contrast of subcutaneous veins, underscoring its value for diagnosis. This technique has the potential for the diagnosis of varicose veins with a diameter of 0.5-2 mm at a depth of 1-3 mm, guidance of venous access, podiatry, phlebotomy, injection sclerotherapy, and control of laser interstitial therapy. Copyright 2004 Wiley-Liss, Inc.

A Vision-Based Motion Sensor for Undergraduate Laboratories.

ERIC Educational Resources Information Center

Salumbides, Edcel John; Maristela, Joyce; Uy, Alfredson; Karremans, Kees

2002-01-01

Introduces an alternative method to determine the mechanics of a moving object that uses computer vision algorithms with a charge-coupled device (CCD) camera as a recording device. Presents two experiments, pendulum motion and terminal velocity, to compare results of the alternative and conventional methods. (YDS)

Ultrahigh-frame CCD imagers

NASA Astrophysics Data System (ADS)

Lowrance, John L.; Mastrocola, V. J.; Renda, George F.; Swain, Pradyumna K.; Kabra, R.; Bhaskaran, Mahalingham; Tower, John R.; Levine, Peter A.

2004-02-01

This paper describes the architecture, process technology, and performance of a family of high burst rate CCDs. These imagers employ high speed, low lag photo-detectors with local storage at each photo-detector to achieve image capture at rates greater than 106 frames per second. One imager has a 64 x 64 pixel array with 12 frames of storage. A second imager has a 80 x 160 array with 28 frames of storage, and the third imager has a 64 x 64 pixel array with 300 frames of storage. Application areas include capture of rapid mechanical motion, optical wavefront sensing, fluid cavitation research, combustion studies, plasma research and wind-tunnel-based gas dynamics research.

A portable array biosensor for food safety

NASA Astrophysics Data System (ADS)

Golden, Joel P.; Ngundi, Miriam M.; Shriver-Lake, Lisa C.; Taitt, Chris R.; Ligler, Frances S.

2004-11-01

An array biosensor developed for simultaneous analysis of multiple samples has been utilized to develop assays for toxins and pathogens in a variety of foods. The biochemical component of the multi-analyte biosensor consists of a patterned array of biological recognition elements immobilized on the surface of a planar waveguide. A fluorescence assay is performed on the patterned surface, yielding an array of fluorescent spots, the locations of which are used to identify what analyte is present. Signal transduction is accomplished by means of a diode laser for fluorescence excitation, optical filters and a CCD camera for image capture. A laptop computer controls the miniaturized fluidics system and image capture. Results for four mycotoxin competition assays in buffer and food samples are presented.

Replacing a technology - The Large Space Telescope and CCDs

NASA Astrophysics Data System (ADS)

Smith, R. W.; Tatarewicz, J. H.

1985-07-01

The technological improvements, design choices and mission goals which led to the inclusion of CCD detectors in the wide field camera of the Large Space Telescope (LST) to be launched by the STS are recounted. Consideration of CCD detectors began before CCDs had seen wide astronomical applications. During planning for the ST, in the 1960s, photographic methods and a vidicon were considered, and seemed feasible provided that periodic manual maintenance could be performed. The invention of CCDs was first reported in 1970 and by 1973 the CCDs were receiving significant attention as potential detectors instead of a vidicon, which retained its own technological challenges. The CCD format gained new emphasis when success was achieved in developments for planetary-imaging spacecraft. The rapidity of progress in CCD capabilities, coupled with the continued shortcomings of the vidicon, resulted in a finalized choice for a CCD device by 1977. The decision was also prompted by continuing commercial and military interest in CCDs, which was spurring the development of the technology and improving the sensitivities and reliability while lowering the costs.

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

NASA Astrophysics Data System (ADS)

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

2016-07-01

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

Readout of the UFFO Slewing Mirror Telescope to detect UV/optical photons from Gamma-Ray Bursts

NASA Astrophysics Data System (ADS)

Kim, J. E.; Lim, H.; Nam, J. W.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A. J.; Chen, P.; Choi, H. S.; Grossan, B.; Huang, M. A.; Jeong, S.; Jung, A.; Kim, M. B.; Kim, S.-W.; Lee, J.; Linder, E. V.; Liu, T.-C.; Na, G. W.; Panasyuk, M. I.; Park, I. H.; Ripa, J.; Reglero, V.; Smoot, G. F.; Svertilov, S.; Vedenkin, N.; Yashin, I.

2013-07-01

The Slewing Mirror Telescope (SMT) was proposed for rapid response to prompt UV/optical photons from Gamma-Ray Bursts (GRBs). The SMT is a key component of the Ultra-Fast Flash Observatory (UFFO)-pathfinder, which will be launched aboard the Lomonosov spacecraft at the end of 2013. The SMT utilizes a motorized mirror that slews rapidly forward to its target within a second after triggering by an X-ray coded mask camera, which makes unnecessary a reorientation of the entire spacecraft. Subsequent measurement of the UV/optical is accomplished by a 10 cm aperture Ritchey-Chrètien telescope and the focal plane detector of Intensified Charge-Coupled Device (ICCD). The ICCD is sensitive to UV/optical photons of 200-650 nm in wavelength by using a UV-enhanced S20 photocathode and amplifies photoelectrons at a gain of 104-106 in double Micro-Channel Plates. These photons are read out by a Kodak KAI-0340 interline CCD sensor and a CCD Signal Processor with 10-bit Analog-to-Digital Converter. Various control clocks for CCD readout are implemented using a Field Programmable Gate Array (FPGA). The SMT readout is in charge of not only data acquisition, storage and transfer, but also control of the slewing mirror, the ICCD high voltage adjustments, power distribution, and system monitoring by interfacing to the UFFO-pathfinder. These functions are realized in the FPGA to minimize power consumption and to enhance processing time. The SMT readout electronics are designed and built to meet the spacecraft's constraints of power consumption, mass, and volume. The entire system is integrated with the SMT optics, as is the UFFO-pathfinder. The system has been tested and satisfies the conditions of launch and those of operation in space: those associated with shock and vibration and those associated with thermal and vacuum, respectively. In this paper, we present the SMT readout electronics: the design, construction, and performance, as well as the results of space environment test.

Pixel detectors for x-ray imaging spectroscopy in space

NASA Astrophysics Data System (ADS)

Treis, J.; Andritschke, R.; Hartmann, R.; Herrmann, S.; Holl, P.; Lauf, T.; Lechner, P.; Lutz, G.; Meidinger, N.; Porro, M.; Richter, R. H.; Schopper, F.; Soltau, H.; Strüder, L.

2009-03-01

Pixelated semiconductor detectors for X-ray imaging spectroscopy are foreseen as key components of the payload of various future space missions exploring the x-ray sky. Located on the platform of the new Spectrum-Roentgen-Gamma satellite, the eROSITA (extended Roentgen Survey with an Imaging Telescope Array) instrument will perform an imaging all-sky survey up to an X-ray energy of 10 keV with unprecedented spectral and angular resolution. The instrument will consist of seven parallel oriented mirror modules each having its own pnCCD camera in the focus. The satellite born X-ray observatory SIMBOL-X will be the first mission to use formation-flying techniques to implement an X-ray telescope with an unprecedented focal length of around 20 m. The detector instrumentation consists of separate high- and low energy detectors, a monolithic 128 × 128 DEPFET macropixel array and a pixellated CdZTe detector respectively, making energy band between 0.5 to 80 keV accessible. A similar concept is proposed for the next generation X-ray observatory IXO. Finally, the MIXS (Mercury Imaging X-ray Spectrometer) instrument on the European Mercury exploration mission BepiColombo will use DEPFET macropixel arrays together with a small X-ray telescope to perform a spatially resolved planetary XRF analysis of Mercury's crust. Here, the mission concepts and their scientific targets are briefly discussed, and the resulting requirements on the detector devices together with the implementation strategies are shown.

CCDiode: an optimal detector for laser confocal microscopes

NASA Astrophysics Data System (ADS)

Pawley, James B.; Blouke, Morley M.; Janesick, James R.

1996-04-01

The laser confocal microscope (LCM) is now an established research tool in biology and materials science. In biological applications, it is usually employed to detect the location of fluorescent market molecules and, under these conditions, signal levels from bright areas are often < 20 photons/pixel (from the specimen, assuming a standard 512 X 768, 1 sec. scan). Although this data rate limits the speed at which information can be derived from the specimen, saturation of the fluorophor, photobleaching of the dye, and phototoxicity prevent it being increased. Currently, most LCMs use photomultiplier tubes (PMT, QE equals 1 - 30% 400 - 900 nm). By contrast, rear-illuminated, scientific charge-coupled devices (CCD) now routinely readout the signal from square sensors approximately 30 micrometers on a side with a QE of 80 - 90%, a noise of only +/- 3 e-/pix and with no multiplicative noise. For this reason, in 1989, one of us (JJ) developed a rear-illuminated, single-channel Si sensor, called the Turbodiode, employing some of the sophisticated readout techniques used to measure charge in a scientific CCD. We are now extending this work to a device in which a single 36 X 36 micrometers sensor is read out through a low-noise FET charge amplifier with a reset circuit and then passed to a correlated, double-sampling digitizer. To maintain the desired +/- 3 e noise level at the relatively high data rate of 1 MHz, our new device utilizes 64 separate readout amplifier/digitizer systems, operating in sequence. The resulting detector is more compact, efficient and reliable than the PMT it replaces but as its sensitive area is smaller than that of a PMT, it will require auxiliary optics when used with any LCM having a large (mm) pinhole. As the signal light is parallel, a simple lens mounted axially and with the CCDiode at its focus would suffice. Future versions may use 3 X 3 or 5 X 5 arrays of sensors to `track' the confocal spot as it is deflected by inhomogeneities of the specimen, change its effective size or shape or detect system misalignment.

Multi-modal diffuse optical techniques for breast cancer neoadjuvant chemotherapy monitoring (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cochran, Jeffrey M.; Busch, David R.; Ban, Han Y.; Kavuri, Venkaiah C.; Schweiger, Martin J.; Arridge, Simon R.; Yodh, Arjun G.

2017-02-01

We present high spatial density, multi-modal, parallel-plate Diffuse Optical Tomography (DOT) imaging systems for the purpose of breast tumor detection. One hybrid instrument provides time domain (TD) and continuous wave (CW) DOT at 64 source fiber positions. The TD diffuse optical spectroscopy with PMT- detection produces low-resolution images of absolute tissue scattering and absorption while the spatially dense array of CCD-coupled detector fibers (108 detectors) provides higher-resolution CW images of relative tissue optical properties. Reconstruction of the tissue optical properties, along with total hemoglobin concentration and tissue oxygen saturation, is performed using the TOAST software suite. Comparison of the spatially-dense DOT images and MR images allows for a robust validation of DOT against an accepted clinical modality. Additionally, the structural information from co-registered MR images is used as a spatial prior to improve the quality of the functional optical images and provide more accurate quantification of the optical and hemodynamic properties of tumors. We also present an optical-only imaging system that provides frequency domain (FD) DOT at 209 source positions with full CCD detection and incorporates optical fringe projection profilometry to determine the breast boundary. This profilometry serves as a spatial constraint, improving the quality of the DOT reconstructions while retaining the benefits of an optical-only device. We present initial images from both human subjects and phantoms to display the utility of high spatial density data and multi-modal information in DOT reconstruction with the two systems.

Ultraviolet downconverting phosphor for use with silicon CCD imagers

NASA Technical Reports Server (NTRS)

Blouke, M. M.; Cowens, M. W.; Hall, J. E.; Westphal, J. A.; Christensen, A. B.

1980-01-01

The properties and application of a UV downconverting phosphor (coronene) to silicon charge coupled devices are discussed. Measurements of the absorption spectrum have been extended to below 1000 A, and preliminary results indicate the existence of useful response to at least 584 A. The average conversion efficiency of coronene was measured to be approximately 20% at 2537 A. Imagery at 3650 A using a backside illuminated 800 x 800 CCD coated with coronene is presented.

Optical sample-position sensing for electrostatic levitation

NASA Technical Reports Server (NTRS)

Sridharan, G.; Chung, S.; Elleman, D.; Whim, W. K.

1989-01-01

A comparative study is conducted for optical position-sensing techniques applicable to micro-G conditions sample-levitation systems. CCD sensors are compared with one- and two-dimensional position detectors used in electrostatic particle levitation. In principle, the CCD camera method can be improved from current resolution levels of 200 microns through the incorporation of a higher-pixel device and more complex digital signal processor interface. Nevertheless, the one-dimensional position detectors exhibited superior, better-than-one-micron resolution.

A computational approach to real-time image processing for serial time-encoded amplified microscopy

NASA Astrophysics Data System (ADS)

Oikawa, Minoru; Hiyama, Daisuke; Hirayama, Ryuji; Hasegawa, Satoki; Endo, Yutaka; Sugie, Takahisa; Tsumura, Norimichi; Kuroshima, Mai; Maki, Masanori; Okada, Genki; Lei, Cheng; Ozeki, Yasuyuki; Goda, Keisuke; Shimobaba, Tomoyoshi

2016-03-01

High-speed imaging is an indispensable technique, particularly for identifying or analyzing fast-moving objects. The serial time-encoded amplified microscopy (STEAM) technique was proposed to enable us to capture images with a frame rate 1,000 times faster than using conventional methods such as CCD (charge-coupled device) cameras. The application of this high-speed STEAM imaging technique to a real-time system, such as flow cytometry for a cell-sorting system, requires successively processing a large number of captured images with high throughput in real time. We are now developing a high-speed flow cytometer system including a STEAM camera. In this paper, we describe our approach to processing these large amounts of image data in real time. We use an analog-to-digital converter that has up to 7.0G samples/s and 8-bit resolution for capturing the output voltage signal that involves grayscale images from the STEAM camera. Therefore the direct data output from the STEAM camera generates 7.0G byte/s continuously. We provided a field-programmable gate array (FPGA) device as a digital signal pre-processor for image reconstruction and finding objects in a microfluidic channel with high data rates in real time. We also utilized graphics processing unit (GPU) devices for accelerating the calculation speed of identification of the reconstructed images. We built our prototype system, which including a STEAM camera, a FPGA device and a GPU device, and evaluated its performance in real-time identification of small particles (beads), as virtual biological cells, owing through a microfluidic channel.

Low cost charged-coupled device (CCD) based detectors for Shiga toxins activity analysis

USDA-ARS?s Scientific Manuscript database

To improve food safety there is a need to develop simple, low-cost sensitive devices for detection of foodborne pathogens and their toxins. We describe a simple and relatively low-cost webcam-based detector which can be used for various optical detection modalities, including fluorescence, chemilumi...

Solution processed integrated pixel element for an imaging device

NASA Astrophysics Data System (ADS)

Swathi, K.; Narayan, K. S.

2016-09-01

We demonstrate the implementation of a solid state circuit/structure comprising of a high performing polymer field effect transistor (PFET) utilizing an oxide layer in conjunction with a self-assembled monolayer (SAM) as the dielectric and a bulk-heterostructure based organic photodiode as a CMOS-like pixel element for an imaging sensor. Practical usage of functional organic photon detectors requires on chip components for image capture and signal transfer as in the CMOS/CCD architecture rather than simple photodiode arrays in order to increase speed and sensitivity of the sensor. The availability of high performing PFETs with low operating voltage and photodiodes with high sensitivity provides the necessary prerequisite to implement a CMOS type image sensing device structure based on organic electronic devices. Solution processing routes in organic electronics offers relatively facile procedures to integrate these components, combined with unique features of large-area, form factor and multiple optical attributes. We utilize the inherent property of a binary mixture in a blend to phase-separate vertically and create a graded junction for effective photocurrent response. The implemented design enables photocharge generation along with on chip charge to voltage conversion with performance parameters comparable to traditional counterparts. Charge integration analysis for the passive pixel element using 2D TCAD simulations is also presented to evaluate the different processes that take place in the monolithic structure.

Multiple-target tracking implementation in the ebCMOS camera system: the LUSIPHER prototype

NASA Astrophysics Data System (ADS)

Doan, Quang Tuyen; Barbier, Remi; Dominjon, Agnes; Cajgfinger, Thomas; Guerin, Cyrille

2012-06-01

The domain of the low light imaging systems progresses very fast, thanks to detection and electronic multiplication technology evolution, such as the emCCD (electron multiplying CCD) or the ebCMOS (electron bombarded CMOS). We present an ebCMOS camera system that is able to track every 2 ms more than 2000 targets with a mean number of photons per target lower than two. The point light sources (targets) are spots generated by a microlens array (Shack-Hartmann) used in adaptive optics. The Multiple-Target-Tracking designed and implemented on a rugged workstation is described. The results and the performances of the system on the identification and tracking are presented and discussed.

Visible and shortwave infrared focal planes for remote sensing instruments

NASA Astrophysics Data System (ADS)

Tower, J. R.; McCarthy, B. M.; Pellon, L. E.; Strong, R. T.; Elabd, H.

1984-01-01

The development of solid-state sensor technology for multispectral linear array (MLA) instruments is described. A buttable four-spectral-band linear-format CCD and a buttable two-spectral band linear-format short-wave IR CCD have been designed, and first samples have been demonstrated. In addition, first-sample four-band interference filters have been fabricated, and hybrid packaging technology is being developed. Based on this development work, the design and construction of focal planes for a Shuttle sortie MLA instrument have begun. This work involves a visible and near-IR focal plane with 2048 pixels x 4 spectral bands and a short-wave IR focal plane with 1024 pixels x 2 spectral bands.

Puesta en marcha de un microdensitómetro automático basado en CCD

NASA Astrophysics Data System (ADS)

Calderón, J. H.; Bustos Fierro, I. H.

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

Investigation of solar active regions at high resolution by balloon flights of the solar optical universal polarimeter, extended definition phase

NASA Technical Reports Server (NTRS)

Tarbell, Theodore D.

1993-01-01

Technical studies of the feasibility of balloon flights of the former Spacelab instrument, the Solar Optical Universal Polarimeter, with a modern charge-coupled device (CCD) camera, to study the structure and evolution of solar active regions at high resolution, are reviewed. In particular, different CCD cameras were used at ground-based solar observatories with the SOUP filter, to evaluate their performance and collect high resolution images. High resolution movies of the photosphere and chromosphere were successfully obtained using four different CCD cameras. Some of this data was collected in coordinated observations with the Yohkoh satellite during May-July, 1992, and they are being analyzed scientifically along with simultaneous X-ray observations.

Development of a CCD based solar speckle imaging system

NASA Astrophysics Data System (ADS)

Nisenson, Peter; Stachnik, Robert V.; Noyes, Robert W.

1986-02-01

A program to develop software and hardware for the purpose of obtaining high angular resolution images of the solar surface is described. The program included the procurement of a Charge Coupled Devices imaging system; an extensive laboratory and remote site testing of the camera system; the development of a software package for speckle image reconstruction which was eventually installed and tested at the Sacramento Peak Observatory; and experiments of the CCD system (coupled to an image intensifier) for low light level, narrow spectral band solar imaging.

Data Reduction and Control Software for Meteor Observing Stations Based on CCD Video Systems

NASA Technical Reports Server (NTRS)

Madiedo, J. M.; Trigo-Rodriguez, J. M.; Lyytinen, E.

2011-01-01

The SPanish Meteor Network (SPMN) is performing a continuous monitoring of meteor activity over Spain and neighbouring countries. The huge amount of data obtained by the 25 video observing stations that this network is currently operating made it necessary to develop new software packages to accomplish some tasks, such as data reduction and remote operation of autonomous systems based on high-sensitivity CCD video devices. The main characteristics of this software are described here.

Binary/Analog CCD Correlator Development.

DTIC Science & Technology

1981-07-01

architecture , design and performance of a general purpose, 1,024-stage, programmable transversal filter implemented in CCD/NMOS technology is described. The device features programmability of the reference signal, the filter length and weighting coefficient resolution. Off-ship circuitry is minimized by incorporating both analog and digital support circuitry, on-chip. This results in a monolithic analog signal processing system that has the flexibility to be operated in nine programmable configurations, from 1,024-stages by 1-bit, to 128-stages by 8-bits. The versatility

Scientific charge-coupled devices

NASA Technical Reports Server (NTRS)

Janesick, James R.; Elliott, Tom; Collins, Stewart; Blouke, Morley M.; Freeman, Jack

1987-01-01

The charge-coupled device dominates an ever-increasing variety of scientific imaging and spectroscopy applications. Recent experience indicates, however, that the full potential of CCD performance lies well beyond that realized in devices currently available.Test data suggest that major improvements are feasible in spectral response, charge collection, charge transfer, and readout noise. These properties, their measurement in existing CCDs, and their potential for future improvement are discussed in this paper.

Calibrating Images from the MINERVA Cameras

NASA Astrophysics Data System (ADS)

Mercedes Colón, Ana

2016-01-01

The MINiature Exoplanet Radial Velocity Array (MINERVA) consists of an array of robotic telescopes located on Mount Hopkins, Arizona with the purpose of performing transit photometry and spectroscopy to find Earth-like planets around Sun-like stars. In order to make photometric observations, it is necessary to perform calibrations on the CCD cameras of the telescopes to take into account possible instrument error on the data. In this project, we developed a pipeline that takes optical images, calibrates them using sky flats, darks, and biases to generate a transit light curve.

Diffraction mode terahertz tomography

DOEpatents

Ferguson, Bradley; Wang, Shaohong; Zhang, Xi-Cheng

2006-10-31

A method of obtaining a series of images of a three-dimensional object. The method includes the steps of transmitting pulsed terahertz (THz) radiation through the entire object from a plurality of angles, optically detecting changes in the transmitted THz radiation using pulsed laser radiation, and constructing a plurality of imaged slices of the three-dimensional object using the detected changes in the transmitted THz radiation. The THz radiation is transmitted through the object as a two-dimensional array of parallel rays. The optical detection is an array of detectors such as a CCD sensor.

Performance characteristics of a low-cost, field-deployable miniature CCD spectrometer

PubMed Central

Coles, Simon; Nimmo, Malcolm; Worsfold, Paul J.

2000-01-01

Miniature spectrometers incorporating array detectors are becoming a viable, low-cost option for field and process deployments. The performance characteristics of one such instrument are reported and compared with those of a conventional benchtop instrument. The parameters investigated were wavelength repeatability, photometric linearity, instrumental noise (photometric precision) and instrumental drift. PMID:18924863

A novel approach of an absolute coding pattern based on Hamiltonian graph

NASA Astrophysics Data System (ADS)

Wang, Ya'nan; Wang, Huawei; Hao, Fusheng; Liu, Liqiang

2017-02-01

In this paper, a novel approach of an optical type absolute rotary encoder coding pattern is presented. The concept is based on the principle of the absolute encoder to find out a unique sequence that ensures an unambiguous shaft position of any angular. We design a single-ring and a n-by-2 matrix absolute encoder coding pattern by using the variations of Hamiltonian graph principle. 12 encoding bits is used in the single-ring by a linear array CCD to achieve an 1080-position cycle encoding. Besides, a 2-by-2 matrix is used as an unit in the 2-track disk to achieve a 16-bits encoding pattern by using an area array CCD sensor (as a sample). Finally, a higher resolution can be gained by an electronic subdivision of the signals. Compared with the conventional gray or binary code pattern (for a 2n resolution), this new pattern has a higher resolution (2n*n) with less coding tracks, which means the new pattern can lead to a smaller encoder, which is essential in the industrial production.

Development and use of an L3CCD high-cadence imaging system for Optical Astronomy

NASA Astrophysics Data System (ADS)

Sheehan, Brendan J.; Butler, Raymond F.

2008-02-01

A high cadence imaging system, based on a Low Light Level CCD (L3CCD) camera, has been developed for photometric and polarimetric applications. The camera system is an iXon DV-887 from Andor Technology, which uses a CCD97 L3CCD detector from E2V technologies. This is a back illuminated device, giving it an extended blue response, and has an active area of 512×512 pixels. The camera system allows frame-rates ranging from 30 fps (full frame) to 425 fps (windowed & binned frame). We outline the system design, concentrating on the calibration and control of the L3CCD camera. The L3CCD detector can be either triggered directly by a GPS timeserver/frequency generator or be internally triggered. A central PC remotely controls the camera computer system and timeserver. The data is saved as standard `FITS' files. The large data loads associated with high frame rates, leads to issues with gathering and storing the data effectively. To overcome such problems, a specific data management approach is used, and a Python/PYRAF data reduction pipeline was written for the Linux environment. This uses calibration data collected either on-site, or from lab based measurements, and enables a fast and reliable method for reducing images. To date, the system has been used twice on the 1.5 m Cassini Telescope in Loiano (Italy) we present the reduction methods and observations made.

Injection of a coaxial-gun-produced magnetized plasma into a background helicon plasma

NASA Astrophysics Data System (ADS)

Zhang, Yue; Lynn, Alan; Gilmore, Mark; Hsu, Scott

2014-10-01

A compact coaxial plasma gun is employed for experimental investigation of plasma bubble relaxation into a lower density background plasma. Experiments are being conducted in the linear device HelCat at UNM. The gun is powered by a 120-uF ignitron-switched capacitor bank, which is operated in a range of 5 to 10 kV and 100 kA. Multiple diagnostics are employed to investigate the plasma relaxation process. Magnetized argon plasma bubbles with velocities 1.2Cs, densities 1020 m-3 and electron temperature 13eV have been achieved. The background helicon plasma has density 1013 m-3, magnetic field from 200 to 500 Gauss and electron temperature 1eV. Several distinct operational regimes with qualitatively different dynamics are identified by fast CCD camera images. Additionally a B-dot probe array has been employed to measure the spatial toroidal and poloidal magnetic flux evolution to identify plasma bubble configurations. Experimental data and analysis will be presented.

A New Instrument for Measurement of the Solar Aureole Radiance Distribution from Unstable Platforms

NASA Technical Reports Server (NTRS)

Ritter, Joseph M.; Voss, Kenneth J.

1999-01-01

A novel imaging solar aureole radiometer, which can obtain absolute radiometric measurements of the solar aureole when operated on an unstable platform is described. A CCD array is used to image the aureole, while a neutral density occulter on a long pole blocks the direct solar radiation. This ensures accurate direction registration as the sun appears in acquired images, and the total circumsolar region is measured simultaneously. The imaging nature of this instrument along with a special triggering device permit acquisition of the circumsolar sky radiance within 7.5 degrees of the center of the solar disk, and within 1 degree of the edge of the solar disk. This innovation makes possible for the first time, reliable and accurate radiometric measurements of the solar aureole from unstable mobile platforms such as ships. This allows determination small angle atmospheric scattering. The instrument has been used in field studies of atmospheric aerosols and will be used in satellite validation and calibration campaigns.

Performance of an extended dynamic range time delay integration charge coupled device (XDR TDI CCD) for high-intrascene dynamic range scanning

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Dawson, Robin M.; Andrews, James T.; Bhaskaran, Mahalingham; Furst, David; Hsueh, Fu-Lung; Meray, Grazyna M.; Sudol, Thomas M.; Swain, Pradyumna K.; Tower, John R.

2003-05-01

Many applications, such as industrial inspection and overhead reconnaissance benefit from line scanning architectures where time delay integration (TDI) significantly improves sensitivity. CCDs are particularly well suited to the TDI architecture since charge is transferred virtually noiselessly down the column. Sarnoff's TDI CCDs have demonstrated extremely high speeds where a 7200 x 64, 8 um pixel device with 120 output ports demonstrated a vertical line transfer rate greater than 800 kHz. The most recent addition to Sarnoff's TDI technology is the implementation of extended dynamic range (XDR) in high speed, back illuminated TDI CCDs. The optical, intrascene dynamic range can be adjusted in the design of the imager with measured dynamic ranges exceeding 2,000,000:1 with no degradation in low light performance. The device provides a piecewise linear response to light where multiple slopes and break points can be set during the CCD design. A description of the device architecture and measured results from fabricated XDR TDI CCDs are presented.

Event-driven charge-coupled device design and applications therefor

NASA Technical Reports Server (NTRS)

Doty, John P. (Inventor); Ricker, Jr., George R. (Inventor); Burke, Barry E. (Inventor); Prigozhin, Gregory Y. (Inventor)

2005-01-01

An event-driven X-ray CCD imager device uses a floating-gate amplifier or other non-destructive readout device to non-destructively sense a charge level in a charge packet associated with a pixel. The output of the floating-gate amplifier is used to identify each pixel that has a charge level above a predetermined threshold. If the charge level is above a predetermined threshold the charge in the triggering charge packet and in the charge packets from neighboring pixels need to be measured accurately. A charge delay register is included in the event-driven X-ray CCD imager device to enable recovery of the charge packets from neighboring pixels for accurate measurement. When a charge packet reaches the end of the charge delay register, control logic either dumps the charge packet, or steers the charge packet to a charge FIFO to preserve it if the charge packet is determined to be a packet that needs accurate measurement. A floating-diffusion amplifier or other low-noise output stage device, which converts charge level to a voltage level with high precision, provides final measurement of the charge packets. The voltage level is eventually digitized by a high linearity ADC.

The USNO Astrometry Department

Science.gov Websites

and methods, such as large scale CCD measuring devices, speckle and radio interferometry, are being the observational programs are published in the Naval Observatory Publications and in refereed

Growth of a delta-doped silicon layer by molecular beam epitaxy on a charge-coupled device for reflection-limited ultraviolet quantum efficiency

NASA Technical Reports Server (NTRS)

Hoenk, Michael E.; Grunthaner, Paula J.; Grunthaner, Frank J.; Terhune, R. W.; Fattahi, Masoud; Tseng, Hsin-Fu

1992-01-01

Low-temperature silicon molecular beam epitaxy is used to grow a delta-doped silicon layer on a fully processed charge-coupled device (CCD). The measured quantum efficiency of the delta-doped backside-thinned CCD is in agreement with the reflection limit for light incident on the back surface in the spectral range of 260-600 nm. The 2.5 nm silicon layer, grown at 450 C, contained a boron delta-layer with surface density of about 2 x 10 exp 14/sq cm. Passivation of the surface was done by steam oxidation of a nominally undoped 1.5 nm Si cap layer. The UV quantum efficiency was found to be uniform and stable with respect to thermal cycling and illumination conditions.

A goggle navigation system for cancer resection surgery

NASA Astrophysics Data System (ADS)

Xu, Junbin; Shao, Pengfei; Yue, Ting; Zhang, Shiwu; Ding, Houzhu; Wang, Jinkun; Xu, Ronald

2014-02-01

We describe a portable fluorescence goggle navigation system for cancer margin assessment during oncologic surgeries. The system consists of a computer, a head mount display (HMD) device, a near infrared (NIR) CCD camera, a miniature CMOS camera, and a 780 nm laser diode excitation light source. The fluorescence and the background images of the surgical scene are acquired by the CCD camera and the CMOS camera respectively, co-registered, and displayed on the HMD device in real-time. The spatial resolution and the co-registration deviation of the goggle navigation system are evaluated quantitatively. The technical feasibility of the proposed goggle system is tested in an ex vivo tumor model. Our experiments demonstrate the feasibility of using a goggle navigation system for intraoperative margin detection and surgical guidance.

Image Information Obtained Using a Charge-Coupled Device (CCD) Camera During an Immersion Liquid Evaporation Process for Measuring the Refractive Index of Solid Particles.

PubMed

Niskanen, Ilpo; Sutinen, Veijo; Thungström, Göran; Räty, Jukka

2018-06-01

The refractive index is a fundamental physical property of a medium, which can be used for the identification and purity issues of all media. Here we describe a refractive index measurement technique to determine simultaneously the refractive index of different solid particles by monitoring the transmittance of light from a suspension using a charge-coupled device (CCD) camera. An important feature of the measurement is the liquid evaporation process for the refractive index matching of the solid particle and the immersion liquid; this was realized by using a pair of volatile and non-volatile immersion liquids. In this study, refractive indices of calcium fluoride (CaF 2 ) and barium fluoride (BaF 2 ) were determined using the proposed method.

DAMIC at SNOLAB

DOE PAGES

Chavarria, Alvaro E.; Tiffenberg, Javier; Aguilar-Arevalo, Alexis; ...

2015-03-24

We introduce the fully-depleted charge-coupled device (CCD) as a particle detector. We demonstrate its low energy threshold operation, capable of detecting ionizing energy depositions in a single pixel down to 50 eV ee. We present results of energy calibrations from 0.3 keV ee to 60 ke Vee, showing that the CCD is a fully active detector with uniform energy response throughout the silicon target, good resolution (Fano ~0.16), and remarkable linear response to electron energy depositions. We show the capability of the CCD to localize the depth of particle interactions within the silicon target. We discuss the mode of operationmore » and unique imaging capabilities of the CCD, and how they may be exploited to characterize and suppress backgrounds. We present the first results from the deployment of 250 μm thick CCDs in SNOLAB, a prototype for the upcoming DAMIC100. DAMIC100 will have a target mass of 0.1 kg and should be able to directly test the CDMS-Si signal within a year of operation.« less

Laser pulse detection method and apparatus

NASA Technical Reports Server (NTRS)

Goss, W.; Janesick, J. R. (Inventor)

1984-01-01

A sensor is described for detecting the difference in phase of a pair of returned light pulse components, such as two components of a light pulse of an optical gyro. In an optic gyro, the two light components have passed in opposite directions through a coil of optical fiber, with the difference in phase of the returned light components determining the intensity of light shining on the sensor. The sensor includes a CCD (charge coupled device) that receives the pair of returned light components to generate a charge proportional to the number of photons in the received light. The amount of the charge represents the phase difference between the two light components. At a time after the transmission of the light pulse and before the expected time of arrival of the interfering light components, charge accumulating in the CCD as a result of reflections from components in the system, are repeatedly removed from the CCD, by transferring out charges in the CCD and dumping these charges.

Novel low-cost vision-sensing technology with controllable of exposal time for welding

NASA Astrophysics Data System (ADS)

Zhang, Wenzeng; Wang, Bin; Chen, Nian; Cao, Yipeng

2005-02-01

In the process of robot Welding, position of welding seam and welding pool shape is detected by CCD camera for quality control and seam tracking in real-time. It is difficult to always get a clear welding image in some welding methods, such as TIG welding. A novel idea that the exposal time of CCD camera is automatically controlled by arc voltage or arc luminance is proposed to get clear welding image. A set of special device and circuits are added to a common industrial CCD camera in order to flexibly control the CCD to start or close exposal by control of the internal clearing signal of the accumulated charge. Two special vision sensors according to the idea are developed. Their exposal grabbing can be triggered respectively by the arc voltage and the variety of the arc luminance. Two prototypes have been designed and manufactured. Experiments show that they can stably grab clear welding images at appointed moment, which is a basic for the feedback control of automatic welding.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. J. Haugh and M. B. Schneider

2008-10-31

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

Solid state high resolution multi-spectral imager CCD test phase

NASA Technical Reports Server (NTRS)

1973-01-01

The program consisted of measuring the performance characteristics of charge coupled linear imaging devices, and a study defining a multispectral imaging system employing advanced solid state photodetection techniques.

Focal plane alignment and detector characterization for the Subaru prime focus spectrograph

NASA Astrophysics Data System (ADS)

Hart, Murdock; Barkhouser, Robert H.; Carr, Michael; Golebiowski, Mirek; Gunn, James E.; Hope, Stephen C.; Smee, Stephen A.

2014-07-01

We describe the infrastructure being developed to align and characterize the detectors for the Subaru Measure- ment of Images and Redshifts (SuMIRe) Prime Focus Spectrograph (PFS). PFS will employ four three-channel spectrographs with an operating wavelength range of 3800 °A to 12600 °A. Each spectrograph will be comprised of two visible channels and one near infrared (NIR) channel, where each channel will use a separate Schmidt camera to image the captured spectra onto their respective detectors. In the visible channels, Hamamatsu 2k × 4k CCDs will be mounted in pairs to create a single 4k × 4k detector, while the NIR channel will use a single Teledyne 4k × 4k H4RG HgCdTe device. The fast f/1.1 optics of the Schmidt cameras will give a shallow depth of focus necessitating an optimization of the focal plane array flatness. The minimum departure from flatness of the focal plane array for the visible channels is set the by the CCD flatness, typically 10 μm peak-to-valley. We will adjust the coplanarity for a pair of CCDs such that the flatness of the array is consistent with the flatness of the detectors themselves. To achieve this we will use an optical non-contact measurement system to measure surface flatness and coplanarity at both ambient and operating temperatures, and use shims to adjust the coplanarity of the CCDs. We will characterize the performance of the detectors for PFS consistent with the scientific goals for the project. To this end we will measure the gain, linearity, full well, quantum efficiency (QE), charge diffusion, charge transfer inefficiency (CTI), and noise properties of these devices. We also desire to better understand the non-linearity of the photon transfer curve for the CCDs, and the charge persistence/reciprocity problems of the HgCdTe devices. To enable the metrology and characterization of these detectors we are building two test cryostats nearly identical in design. The first test cryostat will primarily be used for the coplanarity measurements and sub- pixel illumination testing, and the second will be dedicated to performance characterization requiring at field illumination. In this paper we will describe the design of the test cryostats. We will also describe the system we have built for measuring focal plane array flatness, and examine the precision and error with which it operates. Finally we will detail the methods by which we plan to characterize the performance of the detectors for PFS, and provide preliminary results.

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

ERIC Educational Resources Information Center

Santillo, Michael F.

2009-01-01

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…

Fast Neural Solution Of A Nonlinear Wave Equation

NASA Technical Reports Server (NTRS)

Barhen, Jacob; Toomarian, Nikzad

1996-01-01

Neural algorithm for simulation of class of nonlinear wave phenomena devised. Numerically solves special one-dimensional case of Korteweg-deVries equation. Intended to be executed rapidly by neural network implemented as charge-coupled-device/charge-injection device, very-large-scale integrated-circuit analog data processor of type described in "CCD/CID Processors Would Offer Greater Precision" (NPO-18972).

Improving depth estimation from a plenoptic camera by patterned illumination

NASA Astrophysics Data System (ADS)

Marshall, Richard J.; Meah, Chris J.; Turola, Massimo; Claridge, Ela; Robinson, Alex; Bongs, Kai; Gruppetta, Steve; Styles, Iain B.

2015-05-01

Plenoptic (light-field) imaging is a technique that allows a simple CCD-based imaging device to acquire both spatially and angularly resolved information about the "light-field" from a scene. It requires a microlens array to be placed between the objective lens and the sensor of the imaging device1 and the images under each microlens (which typically span many pixels) can be computationally post-processed to shift perspective, digital refocus, extend the depth of field, manipulate the aperture synthetically and generate a depth map from a single image. Some of these capabilities are rigid functions that do not depend upon the scene and work by manipulating and combining a well-defined set of pixels in the raw image. However, depth mapping requires specific features in the scene to be identified and registered between consecutive microimages. This process requires that the image has sufficient features for the registration, and in the absence of such features the algorithms become less reliable and incorrect depths are generated. The aim of this study is to investigate the generation of depth-maps from light-field images of scenes with insufficient features for accurate registration, using projected patterns to impose a texture on the scene that provides sufficient landmarks for the registration methods.

Calibration Device Designed for proof ring used in SCC Experiment

NASA Astrophysics Data System (ADS)

Hu, X. Y.; Kang, Z. Y.; Yu, Y. L.

2017-11-01

In this paper, a calibration device for proof ring used in SCC (Stress Corrosion Cracking) experiment was designed. A compact size loading device was developed to replace traditional force standard machine or a long screw nut. The deformation of the proof ring was measured by a CCD (Charge-Coupled Device) during the calibration instead of digital caliper or a dial gauge. The calibration device was verified at laboratory that the precision of force loading is ±0.1% and the precision of deformation measurement is ±0.002mm.

Upwelling Radiance at 976 nm Measured from Space Using a CCD Camera

NASA Technical Reports Server (NTRS)

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

2015-01-01

The Optical Payload for Lasercomm Science (OPALS) Flight System on-board the International Space Station uses a charge coupled device (CCD) camera for receiving a beacon laser from Earth. Relative measurements of the background contributed by upwelling radiance under diverse illumination conditions and varying 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.

C2D8: An eight channel CCD readout electronics dedicated to low energy neutron detection

NASA Astrophysics Data System (ADS)

Bourrion, O.; Clement, B.; Tourres, D.; Pignol, G.; Xi, Y.; Rebreyend, D.; Nesvizhevsky, V. V.

2018-02-01

Position-sensitive detectors for cold and ultra-cold neutrons (UCN) are in use in fundamental research. In particular, measuring the properties of the quantum states of bouncing neutrons requires micro-metric spatial resolution. To this end, a Charge Coupled Device (CCD) coated with a thin conversion layer that allows a real time detection of neutron hits is under development at LPSC. In this paper, we present the design and performance of a dedicated electronic board designed to read-out eight CCDs simultaneously and operating under vacuum.

Automatic target detection using binary template matching

NASA Astrophysics Data System (ADS)

Jun, Dong-San; Sun, Sun-Gu; Park, HyunWook

2005-03-01

This paper presents a new automatic target detection (ATD) algorithm to detect targets such as battle tanks and armored personal carriers in ground-to-ground scenarios. Whereas most ATD algorithms were developed for forward-looking infrared (FLIR) images, we have developed an ATD algorithm for charge-coupled device (CCD) images, which have superior quality to FLIR images in daylight. The proposed algorithm uses fast binary template matching with an adaptive binarization, which is robust to various light conditions in CCD images and saves computation time. Experimental results show that the proposed method has good detection performance.

CCD image sensor induced error in PIV applications

NASA Astrophysics Data System (ADS)

Legrand, M.; Nogueira, J.; Vargas, A. A.; Ventas, R.; Rodríguez-Hidalgo, M. C.

2014-06-01

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.

Development of an Integrated Countermeasure Device for Use in Long-Duration Space Flight

NASA Technical Reports Server (NTRS)

Streeper, Tim; Cavanagh, Peter R.; Hanson, Andrea M.; Carpenter, Dana; Saeed, Isra; Kornak, John; Frassetto, Lynda; Grodsinsky, Carlos; Funk, Justin; Lee, Stuart M. C.;

High-voltage compatible, full-depleted CCD

DOEpatents

Holland, Stephen Edward

2007-09-18

A charge coupled device for detecting electromagnetic and particle radiation is described. The device includes a high-resistivity semiconductor substrate, buried channel regions, gate electrode circuitry, and amplifier circuitry. For good spatial resolution and high performance, especially when operated at high voltages with full or nearly full depletion of the substrate, the device can also include a guard ring positioned near channel regions, a biased channel stop, and a biased polysilicon electrode over the channel stop.

Analysis of crystalline lens coloration using a black and white charge-coupled device camera.

PubMed

Sakamoto, Y; Sasaki, K; Kojima, M

1994-01-01

To analyze lens coloration in vivo, we used a new type of Scheimpflug camera that is a black and white type of charge-coupled device (CCD) camera. A new methodology was proposed. Scheimpflug images of the lens were taken three times through red (R), green (G), and blue (B) filters, respectively. Three images corresponding with the R, G, and B channels were combined into one image on the cathode-ray tube (CRT) display. The spectral transmittance of the tricolor filters and the spectral sensitivity of the CCD camera were used to correct the scattering-light intensity of each image. Coloration of the lens was expressed on a CIE standard chromaticity diagram. The lens coloration of seven eyes analyzed by this method showed values almost the same as those obtained by the previous method using color film.

Design and Fabrication of High-Efficiency CMOS/CCD Imagers

NASA Technical Reports Server (NTRS)

Pain, Bedabrata

2007-01-01

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

Space and power efficient hybrid counters array

DOEpatents

Gara, Alan G [Mount Kisco, NY; Salapura, Valentina [Chappaqua, NY

2009-05-12

A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

Space and power efficient hybrid counters array

DOEpatents

Gara, Alan G.; Salapura, Valentina

2010-03-30

A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

NGS2: a focal plane array upgrade for the GeMS multiple tip-tilt wavefront sensor

NASA Astrophysics Data System (ADS)

Rigaut, François; Price, Ian; d'Orgeville, Céline; Bennet, Francis; Herrald, Nick; Paulin, Nicolas; Uhlendorf, Kristina; Garrel, Vincent; Sivo, Gaetano; Montes, Vanessa; Trujillo, Chad

2016-07-01

NGS2 is an upgrade for the multi-natural guide star tip-tilt & plate scale wavefront sensor for GeMS (Gemini Multi-Conjugate Adaptive Optics system). It uses a single Nüvü HNü-512 Electron-Multiplied CCD array that spans the entire GeMS wavefront sensor focal plane. Multiple small regions-of-interest are used to enable frame rates up to 800Hz. This set up will improve the optical throughput with respect to the current wavefront sensor, as well as streamline acquisition and allow for distortion compensation.

Coordinated garbage collection for raid array of solid state disks

DOEpatents

Dillow, David A; Ki, Youngjae; Oral, Hakki S; Shipman, Galen M; Wang, Feiyi

2014-04-29

An optimized redundant array of solid state devices may include an array of one or more optimized solid-state devices and a controller coupled to the solid-state devices for managing the solid-state devices. The controller may be configured to globally coordinate the garbage collection activities of each of said optimized solid-state devices, for instance, to minimize the degraded performance time and increase the optimal performance time of the entire array of devices.

Fifty Years of Lightning Observations from Space

NASA Astrophysics Data System (ADS)

Christian, H. J., Jr.

2017-12-01

Some of the earliest satellites, starting with OSO (1965), ARIEL (1967), and RAE (1968), detected lightning using either optical and RF sensors, although that was not their intent. One of the earliest instruments designed to detect lightning was the PBE (1977). The use of space to study lightning activity has exploded since these early days. The advent of focal-plane imaging arrays made it possible to develop high performance optical lightning sensors. Prior to the use of charged-coupled devices (CCD), most space-based lightning sensors used only a few photo-diodes, which limited the location accuracy and detection efficiency (DE) of the instruments. With CCDs, one can limit the field of view of each detector (pixel), and thus improve the signal to noise ratio over single-detectors that summed the light reflected from many clouds with the lightning produced by a single cloud. This pixelization enabled daytime DE to increase from a few percent to close to 90%. The OTD (1995), and the LIS (1997), were the first lightning sensors to utilize focal-plane arrays. Together they detected global lightning activity for more than twenty years, providing the first detailed information on the distribution of global lightning and its variability. The FORTE satellite was launched shortly after LIS, and became the first dedicated satellite to simultaneously measure RF and optical lightning emissions. It too used a CCD focal plane to detect and locate lightning. In November 2016, the GLM became the first lightning instrument in geostationary orbit. Shortly thereafter, China placed its GLI in orbit. Lightning sensors in geostationary orbit significantly increase the value of space-based observations. For the first time, lightning activity can be monitored continuously, over large areas of the Earth with high, uniform DE and location accuracy. In addition to observing standard lightning, a number of sensors have been placed in orbit to detect transient luminous events and tropospheric gamma-ray flashes. A lineal history of space-based lightning observations will be presented as well as a discussion of the scientific contributions made possible by these instruments. In addition, relative merits of space versus ground measurements will be addressed, as well as an effort to demonstrate the complementary nature of the two approaches.

Principles for new optical techniques in medical diagnostics for mHealth applications

NASA Astrophysics Data System (ADS)

Balsam, Joshua Michael

Medical diagnostics is a critical element of effective medical treatment. However, many modern and emerging diagnostic technologies are not affordable or compatible with the needs and conditions found in low-income and middle-income countries and regions. Resource-poor areas require low-cost, robust, easy-to-use, and portable diagnostics devices compatible with telemedicine (i.e. mHealth) that can be adapted to meet diverse medical needs. Many suitable devices will need to be based on optical technologies, which are used for many types of biological analyses. This dissertation describes the fabrication and detection principles for several low-cost optical technologies for mHealth applications including: (1) a webcam based multi-wavelength fluorescence plate reader, (2) a lens-free optical detector used for the detection of Botulinum A neurotoxin activity, (3) a low cost micro-array reader that allows the performance of typical fluorescence based assays demonstrated for the detection of the toxin staphylococcal enterotoxin (SEB), and (4) a wide-field flow cytometer for high throughput detection of fluorescently labeled rare cells. This dissertation discusses how these technologies can be harnessed using readily available consumer electronics components such as webcams, cell phones, CCD cameras, LEDs, and laser diodes. There are challenges in developing devices with sufficient sensitivity and specificity, and approaches are presented to overcoming these challenges to create optical detectors that can serve as low cost medical diagnostics in resource-poor settings for mHealth.

Fiber-MZI-based FBG sensor interrogation: comparative study with a CCD spectrometer.

PubMed

Das, Bhargab; Chandra, Vikash

2016-10-10

We present an experimental comparative study of the two most commonly used fiber Bragg grating (FBG) sensor interrogation techniques: a charge-coupled device (CCD) spectrometer and a fiber Mach-Zehnder interferometer (F-MZI). Although the interferometric interrogation technique is historically known to offer the highest sensitivity measurements, very little information exists regarding how it compares with the current commercially available spectral-characteristics-based interrogation systems. It is experimentally established here that the performance of a modern-day CCD spectrometer interrogator is very close to a F-MZI interrogator with the capability of measuring Bragg wavelength shifts with sub-picometer-level accuracy. The results presented in this research study can further be used as a guideline for choosing between the two FBG sensor interrogator types for small-amplitude dynamic perturbation measurements down to nano-level strain.

Dosimetry of heavy ions by use of CCD detectors

NASA Technical Reports Server (NTRS)

Schott, J. U.

1994-01-01

The design and the atomic composition of Charge Coupled Devices (CCD's) make them unique for investigations of single energetic particle events. As detector system for ionizing particles they detect single particles with local resolution and near real time particle tracking. In combination with its properties as optical sensor, particle transversals of single particles are to be correlated to any objects attached to the light sensitive surface of the sensor by simple imaging of their shadow and subsequent image analysis of both, optical image and particle effects, observed in affected pixels. With biological objects it is possible for the first time to investigate effects of single heavy ions in tissue or extinguished organs of metabolizing (i.e. moving) systems with a local resolution better than 15 microns. Calibration data for particle detection in CCD's are presented for low energetic protons and heavy ions.

Producing CCD imaging sensor with flashed backside metal film

NASA Technical Reports Server (NTRS)

Janesick, James R. (Inventor)

1988-01-01

A backside illuminated CCD imaging sensor for reading out image charges from wells of the array of pixels is significantly improved for blue, UV, far UV and low energy x-ray wavelengths (1-5000.ANG.) by so overthinning the backside as to place the depletion edge at the surface and depositing a thin transparent metal film of about 10.ANG. on a native-quality oxide film of less than about 30.ANG. grown on the thinned backside. The metal is selected to have a higher work function than that of the semiconductor to so bend the energy bands (at the interface of the semiconductor material and the oxide film) as to eliminate wells that would otherwise trap minority carriers. A bias voltage may be applied to extend the frontside depletion edge to the interface of the semiconductor material with the oxide film in the event there is not sufficient thinning. This metal film (flash gate), which improves and stabilizes the quantum efficiency of a CCD imaging sensor, will also improve the QE of any p-n junction photodetector.

CCD imaging sensor with flashed backside metal film

NASA Technical Reports Server (NTRS)

Janesick, James R. (Inventor)

1991-01-01

A backside illuminated CCD imaging sensor for reading out image charges from wells of the array of pixels is significantly improved for blue, UV, far UV and low energy x-ray wavelengths (1-5000.ANG.) by so overthinning the backside as to place the depletion edge at the surface and depositing a thin transparent metal film of about 10.ANG. on a native-quality oxide film of less than about 30.ANG. grown on the thinned backside. The metal is selected to have a higher work function than that of the semiconductor to so bend the energy bands (at the interface of the semiconductor material and the oxide film) as to eliminate wells that would otherwise trap minority carriers. A bias voltage may be applied to extend the frontside depletion edge to the interface of the semiconductor material with the oxide film in the event there is not sufficient thinning. This metal film (flash gate), which improves and stabilizes the quantum efficiency of a CCD imaging sensor, will also improve the QE of any p-n junction photodetector.

Analysis of Dark Current in BRITE Nanostellite CCD Sensors †

PubMed Central

Popowicz, Adam

2018-01-01

The BRightest Target Explorer (BRITE) is the pioneering nanosatellite mission dedicated for photometric observations of the brightest stars in the sky. The BRITE charge coupled device (CCD) sensors are poorly shielded against extensive flux of energetic particles which constantly induce defects in the silicon lattice. In this paper we investigate the temporal evolution of the generation of the dark current in the BRITE CCDs over almost four years after launch. Utilizing several steps of image processing and employing normalization of the results, it was possible to obtain useful information about the progress of thermal activity in the sensors. The outcomes show a clear and consistent linear increase of induced damage despite the fact that only about 0.14% of CCD pixels were probed. By performing the analysis of temperature dependencies of the dark current, we identified the observed defects as phosphorus-vacancy (PV) pairs, which are common in proton irradiated CCD matrices. Moreover, the Meyer-Neldel empirical rule was confirmed in our dark current data, yielding EMN=24.8 meV for proton-induced PV defects. PMID:29415471

Particle displacement tracking applied to air flows

NASA Technical Reports Server (NTRS)

Wernet, Mark P.

1991-01-01

Electronic Particle Image Velocimeter (PIV) techniques offer many advantages over conventional photographic PIV methods such as fast turn around times and simplified data reduction. A new all electronic PIV technique was developed which can measure high speed gas velocities. The Particle Displacement Tracking (PDT) technique employs a single cw laser, small seed particles (1 micron), and a single intensified, gated CCD array frame camera to provide a simple and fast method of obtaining two-dimensional velocity vector maps with unambiguous direction determination. Use of a single CCD camera eliminates registration difficulties encountered when multiple cameras are used to obtain velocity magnitude and direction information. An 80386 PC equipped with a large memory buffer frame-grabber board provides all of the data acquisition and data reduction operations. No array processors of other numerical processing hardware are required. Full video resolution (640x480 pixel) is maintained in the acquired images, providing high resolution video frames of the recorded particle images. The time between data acquisition to display of the velocity vector map is less than 40 sec. The new electronic PDT technique is demonstrated on an air nozzle flow with velocities less than 150 m/s.

Design of a Day/Night Star Camera System

NASA Technical Reports Server (NTRS)

Alexander, Cheryl; Swift, Wesley; Ghosh, Kajal; Ramsey, Brian

1999-01-01

This paper describes the design of a camera system capable of acquiring stars during both the day and night cycles of a high altitude balloon flight (35-42 km). The camera system will be filtered to operate in the R band (590-810 nm). Simulations have been run using MODTRAN atmospheric code to determine the worse case sky brightness at 35 km. With a daytime sky brightness of 2(exp -05) W/sq cm/str/um in the R band, the sensitivity of the camera system will allow acquisition of at least 1-2 stars/sq degree at star magnitude limits of 8.25-9.00. The system will have an F2.8, 64.3 mm diameter lens and a 1340X1037 CCD array digitized to 12 bits. The CCD array is comprised of 6.8 X 6.8 micron pixels with a well depth of 45,000 electrons and a quantum efficiency of 0.525 at 700 nm. The camera's field of view will be 6.33 sq degree and provide attitude knowledge to 8 arcsec or better. A test flight of the system is scheduled for fall 1999.

Memory device for two-dimensional radiant energy array computers

NASA Technical Reports Server (NTRS)

Schaefer, D. H.; Strong, J. P., III (Inventor)

1977-01-01

A memory device for two dimensional radiant energy array computers was developed, in which the memory device stores digital information in an input array of radiant energy digital signals that are characterized by ordered rows and columns. The memory device contains a radiant energy logic storing device having a pair of input surface locations for receiving a pair of separate radiant energy digital signal arrays and an output surface location adapted to transmit a radiant energy digital signal array. A regenerative feedback device that couples one of the input surface locations to the output surface location in a manner for causing regenerative feedback is also included

Attenuator And Conditioner

DOEpatents

Anderson, Gene R.; Armendariz, Marcelino G.; Carson, Richard F.; Bryan, Robert P.; Duckett, III, Edwin B.; Kemme, Shanalyn Adair; McCormick, Frederick B.; Peterson, David W.

2006-04-04

An apparatus and method of attenuating and/or conditioning optical energy for an optical transmitter, receiver or transceiver module is disclosed. An apparatus for attenuating the optical output of an optoelectronic connector including: a mounting surface; an array of optoelectronic devices having at least a first end; an array of optical elements having at least a first end; the first end of the array of optical elements optically aligned with the first end of the array of optoelectronic devices; an optical path extending from the first end of the array of optoelectronic devices and ending at a second end of the array of optical elements; and an attenuator in the optical path for attenuating the optical energy emitted from the array of optoelectronic devices. Alternatively, a conditioner may be adapted in the optical path for conditioning the optical energy emitted from the array of optoelectronic devices.

Two-dimensional radiant energy array computers and computing devices

NASA Technical Reports Server (NTRS)

Schaefer, D. H.; Strong, J. P., III (Inventor)

1976-01-01

Two dimensional digital computers and computer devices operate in parallel on rectangular arrays of digital radiant energy optical signal elements which are arranged in ordered rows and columns. Logic gate devices receive two input arrays and provide an output array having digital states dependent only on the digital states of the signal elements of the two input arrays at corresponding row and column positions. The logic devices include an array of photoconductors responsive to at least one of the input arrays for either selectively accelerating electrons to a phosphor output surface, applying potentials to an electroluminescent output layer, exciting an array of discrete radiant energy sources, or exciting a liquid crystal to influence crystal transparency or reflectivity.

Fabrication and Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

NASA Technical Reports Server (NTRS)

Chervenak, James A.; Adams, James S.; Bandler, Simon R.; Busch, Sara E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, Jan-Patrick;

Astigmatism correction of a non-imaging double spectrometer fitted with a 2D array detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yaney, P.P.; Ernst, S.L.; Blackshire, J.

1992-12-01

A SPEX 1401 double spectrometer was adapted for a liquid nitrogen cooled CCD detector to permit both spectral and spatial analysis of ceramic specimens in a laser Raman microprobe system. The exit image of the spectrometer suffers from astigmatism due to off-axis spherical mirrors. A cylindrical lens was added before the CCD to correct for the astigmatism. The spectrometer and several lenses were modeled using an optical ray tracing program to characterize the astigmatism and to optimize the locations of the lens and the detector. The astigmatism and the spot pattern sizes determined by the model were in good agreementmore » with he observed performance of the modified spectrometer-detector system. Typical spot patterns fell within the 23 {mu}m square pixel size.« less

Recent CCD Images of Hubble's Variable Nebula (NGC 2261)

NASA Astrophysics Data System (ADS)

Meisel, D.; Dykstra, W.; Schulitz, F.

1992-05-01

Four CCD exposures of Hubble's Variable Nebula were taken with the RIT Kodak KF-4200 array using the 0.6m Hawaii telescope at Mauna Kea. The field of view was 5' x 7' of arc with a resolution of 0.3" per pixel. The effective wavelengths were v 5300A, r 6200A, i 8000A and ii 9000A. Preliminary image processing has been done on Macintosh IIfxs and LCs using NIH Image1.44b20 and has revealed considerable detail in the dust cloud, but no obvious obscuration features as seen at past epochs. Final image processing is continuing on Sun workstations using IRAF and SAO Image. Differences of structure between the wavelength bands and comparisons between images at other epochs, CO maps, and polarimetry will be discussed.

SU-E-T-161: SOBP Beam Analysis Using Light Output of Scintillation Plate Acquired by CCD Camera.

PubMed

Cho, S; Lee, S; Shin, J; Min, B; Chung, K; Shin, D; Lim, Y; Park, S

2012-06-01

To analyze Bragg-peak beams in SOBP (spread-out Bragg-peak) beam using CCD (charge-coupled device) camera - scintillation screen system. We separated each Bragg-peak beam using light output of high sensitivity scintillation material acquired by CCD camera and compared with Bragg-peak beams calculated by Monte Carlo simulation. In this study, CCD camera - scintillation screen system was constructed with a high sensitivity scintillation plate (Gd2O2S:Tb) and a right-angled prismatic PMMA phantom, and a Marlin F-201B, EEE-1394 CCD camera. SOBP beam irradiated by the double scattering mode of a PROTEUS 235 proton therapy machine in NCC is 8 cm width, 13 g/cm 2 range. The gain, dose rate and current of this beam is 50, 2 Gy/min and 70 nA, respectively. Also, we simulated the light output of scintillation plate for SOBP beam using Geant4 toolkit. We evaluated the light output of high sensitivity scintillation plate according to intergration time (0.1 - 1.0 sec). The images of CCD camera during the shortest intergration time (0.1 sec) were acquired automatically and randomly, respectively. Bragg-peak beams in SOBP beam were analyzed by the acquired images. Then, the SOBP beam used in this study was calculated by Geant4 toolkit and Bragg-peak beams in SOBP beam were obtained by ROOT program. The SOBP beam consists of 13 Bragg-peak beams. The results of experiment were compared with that of simulation. We analyzed Bragg-peak beams in SOBP beam using light output of scintillation plate acquired by CCD camera and compared with that of Geant4 simulation. We are going to study SOBP beam analysis using more effective the image acquisition technique. © 2012 American Association of Physicists in Medicine.

Shack-Hartmann Phasing of Segmented Telescopes: Systematic Effects from Lenslet Arrays

NASA Technical Reports Server (NTRS)

Troy, Mitchell; Chanan, Gary; Roberts, Jennifer

2010-01-01

The segments in the Keck telescopes are routinely phased using a Shack-Hartmann wavefront sensor with sub-apertures that span adjacent segments. However, one potential limitation to the absolute accuracy of this technique is that it relies on a lenslet array (or a single lens plus a prism array) to form the subimages. These optics have the potential to introduce wavefront errors and stray reflections at the subaperture level that will bias the phasing measurement. We present laboratory data to quantify this effect, using measured errors from Keck and two other lenslet arrays. In addition, as part of the design of the Thirty Meter Telescope Alignment and Phasing System we present a preliminary investigation of a lenslet-free approach that relies on Fresnel diffraction to form the subimages at the CCD. Such a technique has several advantages, including the elimination of lenslet aberrations.

QUALITY ASSESSMENT OF CONFOCAL MICROSCOPY SLIDE-BASED SYSTEMS: INSTABLITY

EPA Science Inventory

Background: All slide-based fluorescence cytometry detections systems basically include an excitation light source, intermediate optics, and a detection device (CCD or PMT). Occasionally, this equipment becomes unstable, generating unreliable and inferior data. Methods: A num...

An Efficient Image Compressor for Charge Coupled Devices Camera

PubMed Central

Li, Jin; Xing, Fei; You, Zheng

2014-01-01

Recently, the discrete wavelet transforms- (DWT-) based compressor, such as JPEG2000 and CCSDS-IDC, is widely seen as the state of the art compression scheme for charge coupled devices (CCD) camera. However, CCD images project on the DWT basis to produce a large number of large amplitude high-frequency coefficients because these images have a large number of complex texture and contour information, which are disadvantage for the later coding. In this paper, we proposed a low-complexity posttransform coupled with compressing sensing (PT-CS) compression approach for remote sensing image. First, the DWT is applied to the remote sensing image. Then, a pair base posttransform is applied to the DWT coefficients. The pair base are DCT base and Hadamard base, which can be used on the high and low bit-rate, respectively. The best posttransform is selected by the l p-norm-based approach. The posttransform is considered as the sparse representation stage of CS. The posttransform coefficients are resampled by sensing measurement matrix. Experimental results on on-board CCD camera images show that the proposed approach significantly outperforms the CCSDS-IDC-based coder, and its performance is comparable to that of the JPEG2000 at low bit rate and it does not have the high excessive implementation complexity of JPEG2000. PMID:25114977

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

NASA Astrophysics Data System (ADS)

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.

A design of optical modulation system with pixel-level modulation accuracy

NASA Astrophysics Data System (ADS)

Zheng, Shiwei; Qu, Xinghua; Feng, Wei; Liang, Baoqiu

2018-01-01

Vision measurement has been widely used in the field of dimensional measurement and surface metrology. However, traditional methods of vision measurement have many limits such as low dynamic range and poor reconfigurability. The optical modulation system before image formation has the advantage of high dynamic range, high accuracy and more flexibility, and the modulation accuracy is the key parameter which determines the accuracy and effectiveness of optical modulation system. In this paper, an optical modulation system with pixel level accuracy is designed and built based on multi-points reflective imaging theory and digital micromirror device (DMD). The system consisted of digital micromirror device, CCD camera and lens. Firstly we achieved accurate pixel-to-pixel correspondence between the DMD mirrors and the CCD pixels by moire fringe and an image processing of sampling and interpolation. Then we built three coordinate systems and calculated the mathematic relationship between the coordinate of digital micro-mirror and CCD pixels using a checkerboard pattern. A verification experiment proves that the correspondence error is less than 0.5 pixel. The results show that the modulation accuracy of system meets the requirements of modulation. Furthermore, the high reflecting edge of a metal circular piece can be detected using the system, which proves the effectiveness of the optical modulation system.

An investigation of potential applications of OP-SAPS: Operational sampled analog processors

NASA Technical Reports Server (NTRS)

Parrish, E. A.; Mcvey, E. S.

1976-01-01

The impact of charge-coupled device (CCD) processors on future instrumentation was investigated. The CCD devices studied process sampled analog data and are referred to as OP-SAPS - operational sampled analog processors. Preliminary studies into various architectural configurations for systems composed of OP-SAPS show that they have potential in such diverse applications as pattern recognition and automatic control. It appears probable that OP-SAPS may be used to construct computing structures which can serve as special peripherals to large-scale computer complexes used in real time flight simulation. The research was limited to the following benchmark programs: (1) face recognition, (2) voice command and control, (3) terrain classification, and (4) terrain identification. A small amount of effort was spent on examining a method by which OP-SAPS may be used to decrease the limiting ground sampling distance encountered in remote sensing from satellites.

Low power, compact charge coupled device signal processing system

NASA Technical Reports Server (NTRS)

Bosshart, P. W.; Buss, D. D.; Eversole, W. L.; Hewes, C. R.; Mayer, D. J.

1980-01-01

A variety of charged coupled devices (CCDs) for performing programmable correlation for preprocessing environmental sensor data preparatory to its transmission to the ground were developed. A total of two separate ICs were developed and a third was evaluated. The first IC was a CCD chirp z transform IC capable of performing a 32 point DFT at frequencies to 1 MHz. All on chip circuitry operated as designed with the exception of the limited dynamic range caused by a fixed pattern noise due to interactions between the digital and analog circuits. The second IC developed was a 64 stage CCD analog/analog correlator for performing time domain correlation. Multiplier errors were found to be less than 1 percent at designed signal levels and less than 0.3 percent at the measured smaller levels. A prototype IC for performing time domain correlation was also evaluated.

PRESBYOPIA OPTOMETRY METHOD BASED ON DIOPTER REGULATION AND CHARGE COUPLE DEVICE IMAGING TECHNOLOGY.

PubMed

Zhao, Q; Wu, X X; Zhou, J; Wang, X; Liu, R F; Gao, J

2015-01-01

With the development of photoelectric technology and single-chip microcomputer technology, objective optometry, also known as automatic optometry, is becoming precise. This paper proposed a presbyopia optometry method based on diopter regulation and Charge Couple Device (CCD) imaging technology and, in the meantime, designed a light path that could measure the system. This method projects a test figure to the eye ground and then the reflected image from the eye ground is detected by CCD. The image is then automatically identified by computer and the far point and near point diopters are determined to calculate lens parameter. This is a fully automatic objective optometry method which eliminates subjective factors of the tested subject. Furthermore, it can acquire the lens parameter of presbyopia accurately and quickly and can be used to measure the lens parameter of hyperopia, myopia and astigmatism.

Scintillation imaging of tritium radioactivity distribution during tritiated thymidine uptake by PC12 cells using a melt-on scintillator.

PubMed

Irikura, Namiko; Miyoshi, Hirokazu; Shinohara, Yasuo

2017-02-01

A scintillation image of tritium fixed in a melt-on scintillator was obtained using a charged-coupled device (CCD) imager, and a linear relationship was observed between the intensity of the scintillation image and the radioactivity of tritium. In a [ 3 H]thymidine uptake experiment, a linear correlation between the intensity of the CCD image and the dilution ratio of cells was confirmed. Scintillation imaging has the potential for use in direct observation of tritium radioactivity distribution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of RCA thinned buried channel charge-coupled devices /CCDs/ for scientific applications

NASA Technical Reports Server (NTRS)

Zucchino, P.; Long, D.; Lowrance, J. L.; Renda, G.; Crawshaw, D. D.; Battson, D. F.

1981-01-01

An experimental version of a thinned illuminated buried-channel 512 x 320 pixel CCD with reduced amplifier input capacitance has been produced which is characterized by lower readout noise. Changes made to the amplifier are discussed, and readout noise measurements obtained by several different techniques are presented. The single energetic electron response of the CCD in the electron-bombarded mode and the single 5.9 keV X-ray pulse height distribution are reported. Results are also given on the dark current versus temperature and the spatial frequency response as a function of signal level.

Proximal caries detection: Sirona Sidexis versus Kodak Ektaspeed Plus.

PubMed

Khan, Emad A; Tyndall, Donald A; Ludlow, John B; Caplan, Daniel

2005-01-01

This study compared the accuracy of intraoral film and a charge-coupled device (CCD) receptor for proximal caries detection. Four observers evaluated images of the proximal surfaces of 40 extracted posterior teeth. The presence or absence of caries was scored using a five-point confidence scale. The actual status of each surface was determined from ground section histology. Responses were evaluated by means of receiver operating characteristic (ROC) analysis. Areas under ROC curves (Az) were assessed through a paired t-test. The performance of the CCD-based intraoral sensor was not different statistically from Ektaspeed Plus film in detecting proximal caries.

Modeling of organic solar cell using response surface methodology

NASA Astrophysics Data System (ADS)

Suliman, Rajab; Mitul, Abu Farzan; Mohammad, Lal; Djira, Gemechis; Pan, Yunpeng; Qiao, Qiquan

Polymer solar cells have drawn much attention during the past few decades due to their low manufacturing cost and incompatibility for flexible substrates. In solution-processed organic solar cells, the optimal thickness, annealing temperature, and morphology are key components to achieving high efficiency. In this work, response surface methodology (RSM) is used to find optimal fabrication conditions for polymer solar cells. In order to optimize cell efficiency, the central composite design (CCD) with three independent variables polymer concentration, polymer-fullerene ratio, and active layer spinning speed was used. Optimal device performance was achieved using 10.25 mg/ml polymer concentration, 0.42 polymer-fullerene ratio, and 1624 rpm of active layer spinning speed. The predicted response (the efficiency) at the optimum stationary point was found to be 5.23% for the Poly(diketopyrrolopyrrole-terthiophene) (PDPP3T)/PC60BM solar cells. Moreover, 97% of the variation in the device performance was explained by the best model. Finally, the experimental results are consistent with the CCD prediction, which proves that this is a promising and appropriate model for optimum device performance and fabrication conditions.

Ocean View

NASA Technical Reports Server (NTRS)

1999-01-01

Analytical Spectral Devices was able to commercialize the "engine" of SeaSpec. The Dual CCD developed for SeaSpec is used in our FieldSpecO Dual UV/VNIR/CCD. This product is very popular for coastal research. It allows for a small suitcase sized spectrometer to be placed in a boat and the attached fiber optic cable can be lowered 30 feet below the surface allowing researchers to perform the same studies as SeaSpec just not at the deep-water depths. Most of the people who inquire about SeaSpec end up purchasing a FieldSpec Dual CCD.SeaSpec was designed to withstand harsh marine environments and depths up to 200 m. While it meets these requirements it is the only instrument of its kind and we consider it a prototype. The first version was released in April 1997. It was tested, we made modification and returned the product in March 1998.

Deflection Measurements of a Thermally Simulated Nuclear Core Using a High-Resolution CCD-Camera

NASA Technical Reports Server (NTRS)

Stanojev, B. J.; Houts, M.

2004-01-01

Space fission systems under consideration for near-term missions all use compact. fast-spectrum reactor cores. Reactor dimensional change with increasing temperature, which affects neutron leakage. is the dominant source of reactivity feedback in these systems. Accurately measuring core dimensional changes during realistic non-nuclear testing is therefore necessary in predicting the system nuclear equivalent behavior. This paper discusses one key technique being evaluated for measuring such changes. The proposed technique is to use a Charged Couple Device (CCD) sensor to obtain deformation readings of electrically heated prototypic reactor core geometry. This paper introduces a technique by which a single high spatial resolution CCD camera is used to measure core deformation in Real-Time (RT). Initial system checkout results are presented along with a discussion on how additional cameras could be used to achieve a three- dimensional deformation profile of the core during test.

X-Ray Spectroscopy of Optically Bright Planets using the Chandra Observatory

NASA Technical Reports Server (NTRS)

Ford, P. G.; Elsner, R. F.

2005-01-01

Since its launch in July 1999, Chandra's Advanced CCD Imaging Spectrometer (ACIS) has observed several planets (Venus, Mars, Jupiter and Saturn) and 6 comets. At 0.5 arc-second spatial resolution, ACIS detects individual x-ray photons with good quantum efficiency (25% at 0.6 KeV) and energy resolution (20% FWHM at 0.6 KeV). However, the ACIS CCDs are also sensitive to optical and near-infrared light, which is absorbed by optical blocking filters (OBFs) that eliminate optical contamination from all but the brightest extended sources, e.g., planets. .Jupiter at opposition subseconds approx.45 arc-seconds (90 CCD pixels.) Since Chandra is incapable of tracking a moving target, the planet takes 10 - 20 kiloseconds to move across the most sensitive ACIS CCD, after which the observatory must be re-pointed. Meanwhile, the OBF covering that CCD adds an opt,ical signal equivalent to approx.110 eV to each pixel that lies within thc outline of the Jovian disk. This has three consequences: (1) the observatory must be pointed away from Jupiter while CCD bias maps are constructed; (2) most x-rays from within the optical image will be misidentified as charged-particle background and ignored; and (3) those x-rays that are reported will bc assigned anomalously high energies. The same also applies to thc other planets, but is less serious since they are either dimmer at optical wavelengths, or they show less apparent motion across the sky, permitting reduced CCD exposure times: the optical contamination from Saturn acids approx.15 eV per pixel, and from Mars and Venus approx.31 eV. After analyzing a series of short .Jupiter observations in December 2000, ACIS parameters were optimized for the February 2003 opposition. CCD bias maps were constructed while Chandra pointed away from Jupiter, and the subsequent observations employed on-board software to ignore any pixel that contained less charge than that expected from optical leakage. In addition, ACIS was commanded to report 5 x 5 arrays of pixel values surrounding each x-ray event, and the outlying values were employed during ground processing to correct for the optical contamination.

Revolutionary visible and infrared sensor detectors for the most advanced astronomical AO systems

NASA Astrophysics Data System (ADS)

Feautrier, Philippe; Gach, Jean-Luc; Guieu, Sylvain; Downing, Mark; Jorden, Paul; Rothman, Johan; de Borniol, Eric D.; Balard, Philippe; Stadler, Eric; Guillaume, Christian; Boutolleau, David; Coussement, Jérome; Kolb, Johann; Hubin, Norbert; Derelle, Sophie; Robert, Clélia; Tanchon, Julien; Trollier, Thierry; Ravex, Alain; Zins, Gérard; Kern, Pierre; Moulin, Thibaut; Rochat, Sylvain; Delpoulbé, Alain; Lebouqun, Jean-Baptiste

2014-07-01

We report in this paper decisive advance on the detector development for the astronomical applications that require very fast operation. Since the CCD220 and OCAM2 major success, new detector developments started in Europe either for visible and IR wavelengths. Funded by ESO and the FP7 Opticon European network, the NGSD CMOS device is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with strong ESO involvement. The NGSD will be a 880x840 pixels CMOS detector with a readout noise of 3 e (goal 1e) at 700 Hz frame rate and providing digital outputs. A camera development, based on this CMOS device and also funded by the Opticon European network, is ongoing. Another major AO wavefront sensing detector development concerns IR detectors based on Avalanche Photodiode (e- APD) arrays within the RAPID project. Developed by the SOFRADIR and CEA/LETI manufacturers, the latter offers a 320x255 8 outputs 30 microns IR array, sensitive from 0.4 to 3 microns, with less than 2 e readout noise at 1600 fps. A rectangular window can also be programmed to speed up even more the frame rate when the full frame readout is not required. The high QE response, in the range of 70%, is almost flat over this wavelength range. Advanced packaging with miniature cryostat using pulse tube cryocoolers was developed in the frame of this programme in order to allow use on this detector in any type of environment. The characterization results of this device are presented here. Readout noise as low as 1.7 e at 1600 fps has been measured with a 3 microns wavelength cut-off chip and a multiplication gain of 14 obtained with a limited photodiode polarization of 8V. This device also exhibits excellent linearity, lower than 1%. The pulse tube cooling allows smart and easy cooling down to 55 K. Vibrations investigations using centroiding and FFT measurements were performed proving that the miniature pulse tube does not induce measurable vibrations to the optical bench, allowing use of this cooled device without liquid nitrogen in very demanding environmental conditions. A successful test of this device was performed on sky on the PIONIER 4 telescopes beam combiner on the VLTi at ESOParanal in June 2014. First Light Imaging, which will commercialize a camera system using also APD infrared arrays in its proprietary wavefront sensor camera platform. These programs are held with several partners, among them are the French astronomical laboratories (LAM, OHP, IPAG), the detector manufacturers (e2v technologies, Sofradir, CEA/LETI) and other partners (ESO, ONERA, IAC, GTC, First Light Imaging). Funding is: Opticon FP7 from European Commission, ESO, CNRS and Université de Provence, Sofradir, ONERA, CEA/LETI the French FUI (DGCIS), the FOCUS Labex and OSEO.

Solar Polarimetry: Proceedings of the National Solar Observatory/ Sacramento Peak Summer Workshop 11th Held in Sunspot, New Mexico on 27-31 August 1990

DTIC Science & Technology

1991-01-01

test at Arosa A,,t rphys- ical Observatory of the ETH Zdrich. Two beam splitters are positioned behind the mcdulat(r parkac’e if three CCD array sensors...data obtained with the Horizontal Telescope of the Arosa Astrophysical Observatory (HAT). The latter consist of simultaneous recordings of the Stokes

Investigation of MHD Instabilities in Jets and Bubbles Using a Compact Coaxial Plasma Gun in a Background Magnetized Plasma

NASA Astrophysics Data System (ADS)

Zhang, Y.; Fisher, D. M.; Wallace, B.; Gilmore, M.; Hsu, S. C.

2016-10-01

A compact coaxial plasma gun is employed for experimental investigation of launching plasma into a lower density background magnetized plasma. Experiments are being conducted in the linear device HelCat at UNM. Four distinct operational regimes with qualitatively different dynamics are identified by fast CCD camera images. For regime I plasma jet formation, a global helical magnetic configuration is determined by a B-dot probe array data. Also the m =1 kink instability is observed and verified. Furthermore, when the jet is propagating into background magnetic field, a longer length and lifetime jet is formed. Axial shear flow caused by the background magnetic tension force contributes to the increased stability of the jet body. In regime II, a spheromak-like plasma bubble formation is identified when the gun plasma is injected into vacuum. In contrast, when the bubble propagates into a background magnetic field, the closed magnetic field configuration does not hold anymore and a lateral side, Reilgh-Taylor instability develops. Detailed experimental data and analysis will be presented for these cases.

Experimental investigation of plasma relaxation using a compact coaxial magnetized plasma gun in a background plasma

NASA Astrophysics Data System (ADS)

Zhang, Yue; Lynn, Alan; Gilmore, Mark; Hsu, Scott; University of New Mexico Collaboration; Los Alamos National Laboratory Collaboration

2013-10-01

A compact coaxial plasma gun is employed for experimental studies of plasma relaxation in a low density background plasma. Experiments are being conducted in the linear HelCat device at UNM. These studies will advance the knowledge of basic plasma physics in the areas of magnetic relaxation and space and astrophysical plasmas, including the evolution of active galactic jets/radio lobes within the intergalactic medium. The gun is powered by a 120pF ignitron-switched capacitor bank which is operated in a range of 5-10 kV and ~100 kA. Multiple diagnostics are employed to investigate plasma relaxation process. Magnetized Argon plasma bubbles with velocities ~1.2Cs and densities ~1020 m-3 have been achieved. Different distinct regimes of operation with qualitatively different dynamics are identified by fast CCD camera images, with the parameter determining the operation regime. Additionally, a B-dot probe array is employed to measure the spatial toroidal and poloidal magnetic flux evolution to identify detached plasma bubble configurations. Experimental data and analysis will be presented.

Explosives detection and identification using surface plasmon-coupled emission

NASA Astrophysics Data System (ADS)

Ja, Shiou-Jyh

2012-06-01

To fight against the explosives-related threats in defense and homeland security applications, a smarter sensing device that not only detects but differentiates multiple true threats from false positives caused by environmental interferents is essential. A new optical detection system is proposed to address these issues by using the temporal and spectroscopic information generated by the surface plasmon coupling emission (SPCE) effect. Innovative SPCE optics have been designed using Zemax software to project the fluorescence signal into clear "rainbow rings" on a CCD with subnanometer wavelength resolution. The spectroscopic change of the fluorescence signal and the time history of such changes due to the presence of a certain explosive analyte are unique and can be used to identify explosives. Thanks to high optical efficiency, reporter depositions as small as 160-μm in diameter can generate a sufficient signal, allowing a dense array of different reporters to be interrogated with wavelength multiplexing and detect a wide range of explosives. We have demonstrated detection and classification of explosives, such as TNT, NT, NM, RDX, PETN, and AN, with two sensing materials in a prototype.

Efficient single-pixel multispectral imaging via non-mechanical spatio-spectral modulation.

PubMed

Li, Ziwei; Suo, Jinli; Hu, Xuemei; Deng, Chao; Fan, Jingtao; Dai, Qionghai

2017-01-27

Combining spectral imaging with compressive sensing (CS) enables efficient data acquisition by fully utilizing the intrinsic redundancies in natural images. Current compressive multispectral imagers, which are mostly based on array sensors (e.g, CCD or CMOS), suffer from limited spectral range and relatively low photon efficiency. To address these issues, this paper reports a multispectral imaging scheme with a single-pixel detector. Inspired by the spatial resolution redundancy of current spatial light modulators (SLMs) relative to the target reconstruction, we design an all-optical spectral splitting device to spatially split the light emitted from the object into several counterparts with different spectrums. Separated spectral channels are spatially modulated simultaneously with individual codes by an SLM. This no-moving-part modulation ensures a stable and fast system, and the spatial multiplexing ensures an efficient acquisition. A proof-of-concept setup is built and validated for 8-channel multispectral imaging within 420~720 nm wavelength range on both macro and micro objects, showing a potential for efficient multispectral imager in macroscopic and biomedical applications.

Design of automatic leveling and centering system of theodolite

NASA Astrophysics Data System (ADS)

Liu, Chun-tong; He, Zhen-Xin; Huang, Xian-xiang; Zhan, Ying

2012-09-01

To realize the theodolite automation and improve the azimuth Angle measurement instrument, the theodolite automatic leveling and centering system with the function of leveling error compensation is designed, which includes the system solution, key components selection, the mechanical structure of leveling and centering, and system software solution. The redesigned leveling feet are driven by the DC servo motor; and the electronic control center device is installed. Using high precision of tilt sensors as horizontal skew detection sensors ensures the effectiveness of the leveling error compensation. Aiming round mark center is located using digital image processing through surface array CCD; and leveling measurement precision can reach the pixel level, which makes the theodolite accurate centering possible. Finally, experiments are conducted using the automatic leveling and centering system of the theodolite. The results show the leveling and centering system can realize automatic operation with high centering accuracy of 0.04mm.The measurement precision of the orientation angle after leveling error compensation is improved, compared with that of in the traditional method. Automatic leveling and centering system of theodolite can satisfy the requirements of the measuring precision and its automation.

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

PubMed

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

2015-08-20

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

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

PubMed Central

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

2015-01-01

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

Intraoral radiology in general dental practices - a comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction.

PubMed

Anissi, H D; Geibel, M A

2014-08-01

The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. ► Responsible use of digital intraoral radiology results in a significant dose reduction in everyday practice. ► The ALARA principle is only achieved by strict implementation of dose-reducing methods. ► The efforts to use dose-reducing devices must be increased. © Georg Thieme Verlag KG Stuttgart · New York.

Astrometric Calibration and Performance of the Dark Energy Camera

DOE PAGES

Bernstein, G. M.; Armstrong, R.; Plazas, A. A.; ...

2017-05-30

We characterize the ability of the Dark Energy Camera (DECam) to perform relative astrometry across its 500 Mpix, 3more » $deg^2$ science field of view, and across 4 years of operation. This is done using internal comparisons of $~ 4 x 10^7$ measurements of high-S/N stellar images obtained in repeat visits to fields of moderate stellar density, with the telescope dithered to move the sources around the array. An empirical astrometric model includes terms for: optical distortions; stray electric fields in the CCD detectors; chromatic terms in the instrumental and atmospheric optics; shifts in CCD relative positions of up to $$\\approx 10 \\mu m$$ when the DECam temperature cycles; and low-order distortions to each exposure from changes in atmospheric refraction and telescope alignment. Errors in this astrometric model are dominated by stochastic variations with typical amplitudes of 10-30 mas (in a 30 s exposure) and $$5^{\\prime}-10^{\\prime}$$ arcmin coherence length, plausibly attributed to Kolmogorov-spectrum atmospheric turbulence. The size of these atmospheric distortions is not closely related to the seeing. Given an astrometric reference catalog at density $$\\approx 0.7$$ $$arcmin^{-2}$$, e.g. from Gaia, the typical atmospheric distortions can be interpolated to $$\\approx$$ 7 mas RMS accuracy (for 30 s exposures) with $$1^{\\prime}$$ arcmin coherence length for residual errors. Remaining detectable error contributors are 2-4 mas RMS from unmodelled stray electric fields in the devices, and another 2-4 mas RMS from focal plane shifts between camera thermal cycles. Thus the astrometric solution for a single DECam exposure is accurate to 3-6 mas ( $$\\approx$$ 0.02 pixels, or $$\\approx$$ 300 nm) on the focal plane, plus the stochastic atmospheric distortion.« less

Compact programmable photonic variable delay devices

NASA Technical Reports Server (NTRS)

Yao, X. Steve (Inventor)

1999-01-01

Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the ladder experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, an index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines/cm.sup.2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

Photonic variable delay devices based on optical birefringence

NASA Technical Reports Server (NTRS)

Yao, X. Steve (Inventor)

2005-01-01

Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the ladder experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, an index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines/cm2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

Collision management utilizing CCD and remote sensing technology

NASA Technical Reports Server (NTRS)

Mcdaniel, Harvey E., Jr.

1995-01-01

With the threat of damage to aerospace systems (space station, shuttle, hypersonic a/c, solar power satellites, loss of life, etc.) from collision with debris (manmade/artificial), there exists an opportunity for the design of a novel system (collision avoidance) to be incorporated into the overall design. While incorporating techniques from ccd and remote sensing technologies, an integrated system utilized in the infrared/visible spectrum for detection, tracking, localization, and maneuvering from doppler shift measurements is achievable. Other analysis such as impact assessment, station keeping, chemical, and optical tracking/fire control solutions are possible through this system. Utilizing modified field programmable gated arrays (software reconfiguring the hardware) the mission and mission effectiveness can be varied. This paper outlines the theoretical operation of a prototype system as it applies to collision avoidance (to be followed up by research).

Very-large-area CCD image sensors: concept and cost-effective research

NASA Astrophysics Data System (ADS)

Bogaart, E. W.; Peters, I. M.; Kleimann, A. C.; Manoury, E. J. P.; Klaassens, W.; de Laat, W. T. F. M.; Draijer, C.; Frost, R.; Bosiers, J. T.

2009-01-01

A new-generation full-frame 36x48 mm2 48Mp CCD image sensor with vertical anti-blooming for professional digital still camera applications is developed by means of the so-called building block concept. The 48Mp devices are formed by stitching 1kx1k building blocks with 6.0 µm pixel pitch in 6x8 (hxv) format. This concept allows us to design four large-area (48Mp) and sixty-two basic (1Mp) devices per 6" wafer. The basic image sensor is relatively small in order to obtain data from many devices. Evaluation of the basic parameters such as the image pixel and on-chip amplifier provides us statistical data using a limited number of wafers. Whereas the large-area devices are evaluated for aspects typical to large-sensor operation and performance, such as the charge transport efficiency. Combined with the usability of multi-layer reticles, the sensor development is cost effective for prototyping. Optimisation of the sensor design and technology has resulted in a pixel charge capacity of 58 ke- and significantly reduced readout noise (12 electrons at 25 MHz pixel rate, after CDS). Hence, a dynamic range of 73 dB is obtained. Microlens and stack optimisation resulted in an excellent angular response that meets with the wide-angle photography demands.

Quadrilinear CCD sensors for the multispectral channel of spaceborne imagers

NASA Astrophysics Data System (ADS)

Materne, Alex; Gili, Bruno; Laubier, David; Gimenez, Thierry

2001-12-01

The PLEIADES-HR Earth Observation satellites will combine a high resolution panchromatic channel -- 0.7 m at nadir -- and a multispectral channel allowing a 2.8 m resolution. This paper presents the main specifications, design and performances of a 52 microns pitch quadrilinear CCD sensor developed by ATMEL under CNES contract, for the multispectral channel of the PLEIADES-HR instrument. The monolithic CCD device includes four lines of 1500 pixels, each line dedicated to a narrow spectral band within blue to near infra red spectrum. The design of the photodiodes and CCD registers, with larger size than those developed up to now for CNES spaceborne imagers, needed some specific structures to break the large equipotential areas where charge do not flow properly. Results are presented on the options which were experimented to improve sensitivity, maintain transfer efficiency and reduce power dissipation. The four spectral bands are achieved by four stripe filters made by SAGEM-REOSC PRODUCTS on a glass substrate, to be assembled on the sensor window. Line to line spacing on the silicon die takes into account the results of straylight analysis. A mineral layer, with high optical absorption performances is deposited between photosensitive lines to further reduce straylight.

Arrayed waveguide Sagnac interferometer.

PubMed

Capmany, José; Muñoz, Pascual; Sales, Salvador; Pastor, Daniel; Ortega, Beatriz; Martinez, Alfonso

2003-02-01

We present a novel device, an arrayed waveguide Sagnac interferometer, that combines the flexibility of arrayed waveguides and the wide application range of fiber or integrated optics Sagnac loops. We form the device by closing an array of wavelength-selective light paths provided by two arrayed waveguides with a single 2 x 2 coupler in a Sagnac configuration. The equations that describe the device's operation in general conditions are derived. A preliminary experimental demonstration is provided of a fiber prototype in passive operation that shows good agreement with the expected theoretical performance. Potential applications of the device in nonlinear operation are outlined and discussed.

High Efficient Ultra-Thin Flat Optics Based on Dielectric Metasurfaces

NASA Astrophysics Data System (ADS)

Ozdemir, Aytekin

Metasurfaces which emerged as two-dimensional counterparts of metamaterials, facilitate the realization of arbitrary phase distributions using large arrays with subwavelength and ultra-thin features. Even if metasurfaces are ultra-thin, they still effectively manipulate the phase, amplitude, and polarization of light in transmission or reflection mode. In contrast, conventional optical components are bulky, and they lose their functionality at sub-wavelength scales, which requires conceptually new types of nanoscale optical devices. On the other hand, as the optical systems shrink in size day by day, conventional bulky optical components will have tighter alignment and fabrication tolerances. Since metasurfaces can be fabricated lithographically, alignment can be done during lithographic fabrication, thus eliminating the need for post-fabrication alignments. In this work, various types of metasurface applications are thoroughly investigated for robust wavefront engineering with enhanced characteristics in terms of broad bandwidth, high efficiency and active tunability, while beneficial for application. Plasmonic metasurfaces are not compatible with the CMOS process flow, and, additionally their high absorption and ohmic loss is problematic in transmission based applications. Dielectric metasurfaces, however, offer a strong magnetic response at optical frequencies, and thus they can offer great opportunities for interacting not only with the electric component of a light field, but also with its magnetic component. They show great potential to enable practical device functionalities at optical frequencies, which motivates us to explore them one step further on wavefront engineering and imaging sensor platforms. Therefore, we proposed an efficient ultra-thin flat metalens at near-infrared regime constituted by silicon nanodisks which can support both electric and magnetic dipolar Mie-type resonances. These two dipole resonances can be overlapped at the same frequency by varying the geometric parameters of silicon nanodisks. Having two resonance mechanisms at the same frequency allows us to achieve full (0-2?) phase shift on the transmitted beam. To enable the miniaturization of pixel size for achieving high-resolution, planar, compact-size focal plane arrays (FPAs), we also present and explore the metasurface lens array-based FPAs. The investigated dielectric metasurface lens arrays achieved high focusing efficiency with superior optical crosstalk performance. We see a magnificent application prospect for metasurfaces in enhancing the fill factor and reducing the pixel size of FPAs and CCD, CMOS imaging sensors as well. Moreover, it is of paramount importance to design metasurfaces possessing tunable properties. Thus, we also propose a tunable beam steering device by combining phase manipulating metasurfaces concept and liquid crystals. Tunability feature is implemented by nematic liquid crystals infiltrated into nano holes in SiO2. Using electrically tunable nematic liquid crystals, dynamic beam steering is achieved.

Smartwatch feedback device for high-quality chest compressions by a single rescuer during infant cardiac arrest: a randomized, controlled simulation study.

PubMed

Lee, Juncheol; Song, Yeongtak; Oh, Jaehoon; Chee, Youngjoon; Ahn, Chiwon; Shin, Hyungoo; Kang, Hyunggoo; Lim, Tae Ho

2018-02-12

According to the guidelines, rescuers should provide chest compressions (CC) ∼1.5 inches (40 mm) for infants. Feedback devices could help rescuers perform CC with adequate rates (CCR) and depths (CCD). However, there is no CC feedback device for infant cardiopulmonary resuscitation (CPR). We suggest a smartwatch-based CC feedback application for infant CPR. We created a smartwatch-based CC feedback application. This application provides feedback on CCD and CCR by colour and text for infant CPR. To evaluate the application, 30 participants were divided randomly into two groups on the basis of whether CC was performed with or without the assistance of the smartwatch application. Both groups performed continuous CC-only CPR for 2 min on an infant mannequin placed on a firm table. We collected CC parameters from the mannequin, including the proportion of correct depth, CCR, CCD and the proportion of correct decompression depth. Demographics between the two groups were not significantly different. The median (interquartile range) proportion of correct depth was 99 (97-100) with feedback compared with 83 (58-97) without feedback (P=0.002). The CCR and proportion of correct decompression depth were not significantly different between the two groups (P=0.482 and 0.089). The CCD of the feedback group was significantly deeper than that of the control group [feedback vs. 41.2 (39.8-41.7) mm vs. 38.6 (36.1-39.6) mm; P=0.004]. Rescuers who receive feedback of CC parameters from a smartwatch could perform adequate CC during infant CPR.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

SONTRAC: A High Efficiency Solar Neutron Telescope

NASA Astrophysics Data System (ADS)

Wunderer, C. B.; Macri, J.; McConnell, M. L.; Ryan, J. M.; Baltgalvis, J.; Holslin, D.; Polichar, A.; Jenkins, T.

1997-05-01

Solar flare neutron emission between 20 and 100 MeV comes from a portion of the energetic proton spectrum that is poorly sampled by both nuclear-line and pion- decay gamma rays. SONTRAC is a new generation solar neutron telescope/spectrometer consisting of densely packed, alternating orthogonal layers of scintillating plastic fibers. The fibers in both dimensions are viewed by image intensifiers and CCD cameras. Incident neutrons scatter off hydrogen in the plastic scintillator. The resulting ionizing proton tracks can be reconstructed in three dimensions using the two planar CCD track images. Two neutron-proton scatters provide sufficient information to reconstruct the energy and direction of the incident neutron. Photomultiplier tubes view the other sides of the fiber scintillator array. The signals from the PMTs are used to give an additional measure of the proton energies and to provide a trigger for the CCD cameras. Recent technological advances have allowed us to construct an affordable working prototype instrument that consists of all the essential technical elements mentioned above. We will present images of tracks produced by minimum ionizing muons and energetic neutrons. We will also present efficiency estimates for SONTRAC's ability to detect and measure gamma rays above 10 MeV.

Undersampled digital holographic interferometry

NASA Astrophysics Data System (ADS)

Halaq, H.; Demoli, N.; Sović, I.; Šariri, K.; Torzynski, M.; Vukičević, D.

2008-04-01

In digital holography, primary holographic fringes are recorded using a matricial CCD sensor. Because of the low spatial resolution of currently available CCD arrays, the angle between the reference and object beams must be limited to a few degrees. Namely, due to the digitization involved, the Shannon's criterion imposes that the Nyquist sampling frequency be at least twice the highest signal frequency. This means that, in the case of the recording of an interference fringe pattern by a CCD sensor, the inter-fringe distance must be larger than twice the pixel period. This in turn limits the angle between the object and the reference beams. If this angle, in a practical holographic interferometry measuring setup, cannot be limited to the required value, aliasing will occur in the reconstructed image. In this work, we demonstrate that the low spatial frequency metrology data could nevertheless be efficiently extracted by careful choice of twofold, and even threefold, undersampling of the object field. By combining the time-averaged recording with subtraction digital holography method, we present results for a loudspeaker membrane interferometric study obtained under strong aliasing conditions. High-contrast fringes, as a consequence of the vibration modes of the membrane, are obtained.

Advances in detector technologies for visible and infrared wavefront sensing

NASA Astrophysics Data System (ADS)

Feautrier, Philippe; Gach, Jean-Luc; Downing, Mark; Jorden, Paul; Kolb, Johann; Rothman, Johan; Fusco, Thierry; Balard, Philippe; Stadler, Eric; Guillaume, Christian; Boutolleau, David; Destefanis, Gérard; Lhermet, Nicolas; Pacaud, Olivier; Vuillermet, Michel; Kerlain, Alexandre; Hubin, Norbert; Reyes, Javier; Kasper, Markus; Ivert, Olaf; Suske, Wolfgang; Walker, Andrew; Skegg, Michael; Derelle, Sophie; Deschamps, Joel; Robert, Clélia; Vedrenne, Nicolas; Chazalet, Frédéric; Tanchon, Julien; Trollier, Thierry; Ravex, Alain; Zins, Gérard; Kern, Pierre; Moulin, Thibaut; Preis, Olivier

2012-07-01

The purpose of this paper is to give an overview of the state of the art wavefront sensor detectors developments held in Europe for the last decade. The success of the next generation of instruments for 8 to 40-m class telescopes will depend on the ability of Adaptive Optics (AO) systems to provide excellent image quality and stability. This will be achieved by increasing the sampling, wavelength range and correction quality of the wave front error in both spatial and time domains. The modern generation of AO wavefront sensor detectors development started in the late nineties with the CCD50 detector fabricated by e2v technologies under ESO contract for the ESO NACO AO system. With a 128x128 pixels format, this 8 outputs CCD offered a 500 Hz frame rate with a readout noise of 7e-. A major breakthrough has been achieved with the recent development by e2v technologies of the CCD220. This 240x240 pixels 8 outputs EMCCD (CCD with internal multiplication) has been jointly funded by ESO and Europe under the FP6 programme. The CCD220 and the OCAM2 camera that operates the detector are now the most sensitive system in the world for advanced adaptive optics systems, offering less than 0.2 e readout noise at a frame rate of 1500 Hz with negligible dark current. Extremely easy to operate, OCAM2 only needs a 24 V power supply and a modest water cooling circuit. This system, commercialized by First Light Imaging, is extensively described in this paper. An upgrade of OCAM2 is foreseen to boost its frame rate to 2 kHz, opening the window of XAO wavefront sensing for the ELT using 4 synchronized cameras and pyramid wavefront sensing. Since this major success, new developments started in Europe. One is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with ESO involvement. The spot elongation from a LGS Shack Hartman wavefront sensor necessitates an increase of the pixel format. Two detectors are currently developed by e2v. The NGSD will be a 880x840 pixels CMOS detector with a readout noise of 3 e (goal 1e) at 700 Hz frame rate. The LGSD is a scaling of the NGSD with 1760x1680 pixels and 3 e readout noise (goal 1e) at 700 Hz (goal 1000 Hz) frame rate. New technologies will be developed for that purpose: advanced CMOS pixel architecture, CMOS back thinned and back illuminated device for very high QE, full digital outputs with signal digital conversion on chip. In addition, the CMOS technology is extremely robust in a telescope environment. Both detectors will be used on the European ELT but also interest potentially all giant telescopes under development. Additional developments also started for wavefront sensing in the infrared based on a new technological breakthrough using ultra low noise Avalanche Photodiode (APD) arrays within the RAPID project. Developed by the SOFRADIR and CEA/LETI manufacturers, the latter will offer a 320x240 8 outputs 30 microns IR array, sensitive from 0.4 to 3.2 microns, with 2 e readout noise at 1500 Hz frame rate. The high QE response is almost flat over this wavelength range. Advanced packaging with miniature cryostat using liquid nitrogen free pulse tube cryocoolers is currently developed for this programme in order to allow use on this detector in any type of environment. First results of this project are detailed here. These programs are held with several partners, among them are the French astronomical laboratories (LAM, OHP, IPAG), the detector manufacturers (e2v technologies, Sofradir, CEA/LETI) and other partners (ESO, ONERA, IAC, GTC). Funding is: Opticon FP6 and FP7 from European Commission, ESO, CNRS and Université de Provence, Sofradir, ONERA, CEA/LETI and the French FUI (DGCIS).

CdS nanorods/organic hybrid LED array and the piezo-phototronic effect of the device for pressure mapping.

PubMed

Bao, Rongrong; Wang, Chunfeng; Dong, Lin; Shen, Changyu; Zhao, Kun; Pan, Caofeng

2016-04-21

As widely applied in light-emitting diodes and optical devices, CdS has attracted the attention of many researchers due to its nonlinear properties and piezo-electronic effect. Here, we demonstrate a LED array composed of PSS and CdS nanorods and research the piezo-photonic effect of the array device. The emission intensity of the device depends on the electron-hole recombination at the interface of the p-n junction which can be adjusted using the piezo-phototronic effect and can be used to map the pressure applied on the surface of the device with spatial resolution as high as 1.5 μm. A flexible LED device array has been prepared using a CdS nanorod array on a Au/Cr/kapton substrate. This device may be used in the field of strain mapping using its high pressure spatial-resolution and flexibility.

Microgravity

NASA Image and Video Library

1991-04-03

The USML-1 Glovebox (GBX) is a multi-user facility supporting 16 experiments in fluid dynamics, combustion sciences, crystal growth, and technology demonstration. The GBX has an enclosed working space which minimizes the contamination risks to both Spacelab and experiment samples. The GBX supports four charge-coupled device (CCD) cameras (two of which may be operated simultaneously) with three black-and-white and three color camera CCD heads available. The GBX also has a backlight panel, a 35 mm camera, and a stereomicroscope that offers high-magnification viewing of experiment samples. Video data can also be downlinked in real-time. The GBX also provides electrical power for experiment hardware, a time-temperature display, and cleaning supplies.

Microgravity

NASA Image and Video Library

1995-08-29

The USML-1 Glovebox (GBX) is a multi-user facility supporting 16 experiments in fluid dynamics, combustion sciences, crystal growth, and technology demonstration. The GBX has an enclosed working space which minimizes the contamination risks to both Spacelab and experiment samples. The GBX supports four charge-coupled device (CCD) cameras (two of which may be operated simultaneously) with three black-and-white and three color camera CCD heads available. The GBX also has a backlight panel, a 35 mm camera, and a stereomicroscope that offers high-magnification viewing of experiment samples. Video data can also be downlinked in real-time. The GBX also provides electrical power for experiment hardware, a time-temperature display, and cleaning supplies.

Brazil's remote sensing activities in the Eighties

NASA Technical Reports Server (NTRS)

Raupp, M. A.; Pereiradacunha, R.; Novaes, R. A.

1985-01-01

Most of the remote sensing activities in Brazil have been conducted by the Institute for Space Research (INPE). This report describes briefly INPE's activities in remote sensing in the last years. INPE has been engaged in research (e.g., radiance studies), development (e.g., CCD-scanners, image processing devices) and applications (e.g., crop survey, land use, mineral resources, etc.) of remote sensing. INPE is also responsible for the operation (data reception and processing) of the LANDSATs and meteorological satellites. Data acquisition activities include the development of CCD-Camera to be deployed on board the space shuttle and the construction of a remote sensing satellite.

Flash Photolysis Experiment of o-Methyl Red as a Function of pH: A Low-Cost Experiment for the Undergraduate Physical Chemistry Lab

ERIC Educational Resources Information Center

Larsen, Molly C.; Perkins, Russell J.

2016-01-01

A low-cost, time-resolved spectroscopy experiment appropriate for third year physical chemistry students is presented. Students excite o-methyl red in basic solutions with a laser pointer and use a modular spectrometer with a CCD array detector to monitor the transient spectra as the higher-energy cis conformer of the molecule converts back to the…

Testing fully depleted CCD

NASA Astrophysics Data System (ADS)

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.

Research on detecting heterogeneous fibre from cotton based on linear CCD camera

NASA Astrophysics Data System (ADS)

Zhang, Xian-bin; Cao, Bing; Zhang, Xin-peng; Shi, Wei

2009-07-01

The heterogeneous fibre in cotton make a great impact on production of cotton textile, it will have a bad effect on the quality of product, thereby affect economic benefits and market competitive ability of corporation. So the detecting and eliminating of heterogeneous fibre is particular important to improve machining technics of cotton, advance the quality of cotton textile and reduce production cost. There are favorable market value and future development for this technology. An optical detecting system obtains the widespread application. In this system, we use a linear CCD camera to scan the running cotton, then the video signals are put into computer and processed according to the difference of grayscale, if there is heterogeneous fibre in cotton, the computer will send an order to drive the gas nozzle to eliminate the heterogeneous fibre. In the paper, we adopt monochrome LED array as the new detecting light source, it's lamp flicker, stability of luminous intensity, lumens depreciation and useful life are all superior to fluorescence light. We analyse the reflection spectrum of cotton and various heterogeneous fibre first, then select appropriate frequency of the light source, we finally adopt violet LED array as the new detecting light source. The whole hardware structure and software design are introduced in this paper.

Spectral domain optical coherence tomography with dual-balanced detection

NASA Astrophysics Data System (ADS)

Bo, En; Liu, Xinyu; Chen, Si; Luo, Yuemei; Wang, Nanshuo; Wang, Xianghong; Liu, Linbo

2016-03-01

We developed a spectral domain optical coherence tomography (SD-OCT) system employing dual-balanced detection (DBD) for direct current term suppression and SNR enhancement, especially for auto-autocorrelation artifacts reduction. The DBD was achieved by using a beam splitter to building a free-space Michelson interferometer, which generated two interferometric spectra with a phase difference of π. These two phase-opposed spectra were guided to the spectrometer through two single mode fibers of the 8 fiber v-groove array and acquired by ultizing the upper two lines of a three-line CCD camera. We rotated this fiber v-groove array by 1.35 degrees to focus two spectra onto the first and second line of the CCD camera. Two spectra were aligned by optimum spectrum matching algorithm. By subtracting one spectrum from the other, this dual-balanced detection system achieved a direct current term suppression of ~30 dB, SNR enhancement of ~3 dB, and auto-autocorrelation artifacts reduction of ~10 dB experimentally. Finally we respectively validated the feasibility and performance of dual-balanced detection by imaging a glass plate and swine corneal tissue ex vivo. The quality of images obtained using dual-balanced detection was significantly improved with regard to the conventional single-detection (SD) images.

CCD imaging technology and the war on crime

NASA Astrophysics Data System (ADS)

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.

NICOLAU: compact unit for photometric characterization of automotive lighting from near-field measurements

NASA Astrophysics Data System (ADS)

Royo, Santiago; Arranz, Maria J.; Arasa, Josep; Cattoen, Michel; Bosch, Thierry

2005-02-01

The present works depicts a measurement technique intended to enhance the characterization procedures of the photometric emissions of automotive headlamps, with potential applications to any light source emission, either automotive or non-automotive. A CCD array with a precisely characterized optical system is used for sampling the luminance field of the headlamp just a few centimetres in front of it, by combining deflectometric techniques (yielding the direction of the light beams) and photometric techniques (yielding the energy travelling in each direction). The CCD array scans the measurement plane using a self-developed mechanical unit and electronics, and then image-processing techniques are used for obtaining the photometric behaviour of the headlamp in any given plane, in particular in the plane and positions required by current normative, but also on the road, on traffic signs, etc. An overview of the construction of the system, of the considered principle of measurement, and of the main calibrations performed on the unit is presented. First results concerning relative measurements are presented compared both to reference data from a photometric tunnel and from a plane placed 5m away from the source. Preliminary results for the absolute photometric calibration of the system are also presented for different illumination beams of different headlamps (driving and passing beam).

Solid-state curved focal plane arrays

NASA Technical Reports Server (NTRS)

Jones, Todd (Inventor); Nikzad, Shouleh (Inventor); Hoenk, Michael (Inventor)

2010-01-01

The present invention relates to curved focal plane arrays. More specifically, the present invention relates to a system and method for making solid-state curved focal plane arrays from standard and high-purity devices that may be matched to a given optical system. There are two ways to make a curved focal plane arrays starting with the fully fabricated device. One way, is to thin the device and conform it to a curvature. A second way, is to back-illuminate a thick device without making a thinned membrane. The thick device is a special class of devices; for example devices fabricated with high purity silicon. One surface of the device (the non VLSI fabricated surface, also referred to as the back surface) can be polished to form a curved surface.

Carbon Nanotube Electrode Arrays For Enhanced Chemical and Biological Sensing

NASA Technical Reports Server (NTRS)

Han, Jie

2003-01-01

Applications of carbon nanotubes for ultra-sensitive electrical sensing of chemical and biological species have been a major focus in NASA Ames Center for Nanotechnology. Great progress has been made toward controlled growth and chemical functionalization of vertically aligned carbon nanotube arrays and integration into micro-fabricated chip devices. Carbon nanotube electrode arrays devices have been used for sub-attomole detection of DNA molecules. Interdigitated carbon nanotubes arrays devices have been applied to sub ppb (part per billion) level chemical sensing for many molecules at room temperature. Stability and reliability have also been addressed in our device development. These results show order of magnitude improvement in device performance, size and power consumption as compared to micro devices, promising applications of carbon nanotube electrode arrays for clinical molecular diagnostics, personal medical testing and monitoring, and environmental monitoring.

High-resolution x-ray imaging using a structured scintillator.

PubMed

Hormozan, Yashar; Sychugov, Ilya; Linnros, Jan

2016-02-01

In this study, the authors introduce a new generation of finely structured scintillators with a very high spatial resolution (a few micrometers) compared to conventional scintillators, yet maintaining a thick absorbing layer for improved detectivity. Their concept is based on a 2D array of high aspect ratio pores which are fabricated by ICP etching, with spacings (pitches) of a few micrometers, on silicon and oxidation of the pore walls. The pores were subsequently filled by melting of powdered CsI(Tl), as the scintillating agent. In order to couple the secondary emitted photons of the back of the scintillator array to a CCD device, having a larger pixel size than the pore pitch, an open optical microscope with adjustable magnification was designed and implemented. By imaging a sharp edge, the authors were able to calculate the modulation transfer function (MTF) of this finely structured scintillator. The x-ray images of individually resolved pores suggest that they have been almost uniformly filled, and the MTF measurements show the feasibility of a few microns spatial resolution imaging, as set by the scintillator pore size. Compared to existing techniques utilizing CsI needles as a structured scintillator, their results imply an almost sevenfold improvement in resolution. Finally, high resolution images, taken by their detector, are presented. The presented work successfully shows the functionality of their detector concept for high resolution imaging and further fabrication developments are most likely to result in higher quantum efficiencies.

Betacam: a commercial approach to β-autoradiography

NASA Astrophysics Data System (ADS)

Cabello, J.; Holland, A.; Holland, K.; Bailey, A.; Kitchen, I.; Wells, K.

2009-02-01

Autoradiography is a well established imaging modality in Biology and Medicine. This aims to measure the location and concentration of labelled molecules within thin tissue sections. The brain is the most anatomically complex organ and identification of neuroanatomical structures is still a challenge particularly when small animals are used for pre-clinical trials. High spatial resolution and high sensitivity are therefore necessary. This work shows the performance and ability of a prototype commercial system, based on a Charged-Couple Device (CCD), to accurately obtain detailed functional information in brain Autoradiography. The sample is placed in contact with the detector enabling direct detection of β- particles in silicon, and the system is run in a range of quasi-room temperatures (17-22 °C) under stable conditions by using a precision temperature controller. Direct detection of β- particles with low energy down to ~5 keV from 3[H] is possible using this room temperature approach. The CCD used in this work is an E2V CCD47-20 frame-transfer device which removes the image smear arising in conventional full-frame imaging devices. The temporal stability of the system has been analyzed by exposing a set of 14[C] calibrated microscales for different periods of time, and measuring the stability of the resultant sensitivity and background noise. The thermal performance of the system has also been analyzed in order to demonstrate its capability of working in other life science applications, where higher working temperatures are required. Once the performance of the system was studied, a set of experiments with biological samples, labelled with typical β- radioisotopes, such as 3[H], has been carried out to demonstrate its application in life sciences.

A Tracking Sun Photometer Without Moving Parts

NASA Technical Reports Server (NTRS)

Strawa, Anthony W.

2012-01-01

This innovation is small, lightweight, and consumes very little electricity as it measures the solar energy attenuated by gases and aerosol particles in the atmosphere. A Sun photometer is commonly used on the Earth's surface, as well as on aircraft, to determine the solar energy attenuated by aerosol particles in the atmosphere and their distribution of sizes. This information is used to determine the spatial and temporal distribution of gases and aerosols in the atmosphere, as well as their distribution sizes. The design for this Sun photometer uses a combination of unique optics and a charge coupled device (CCD) array to eliminate moving parts and make the instrument more reliable. It could be selfcalibrating throughout the year. Data products would be down-welling flux, the direct-diffuse flux ratio, column abundance of gas phase constituents, aerosol optical depth at multiple-wavelengths, phase functions, cloud statistics, and an estimate of the representative size of atmospheric particles. These measurements can be used to obtain an estimate of aerosol size distribution, refractive index, and particle shape. Incident light is received at a light-reflecting (inner) surface, which is a truncated paraboloid. Light arriving from a hemispheric field of view (solid angle 2 steradians) enters the reflecting optic at an entrance aperture at, or adjacent to, the focus of the paraboloid, and is captured by the optic. Most of this light is reflected from an inner surface. The light proceeds substantially parallel to the paraboloid axis, and is detected by an array detector located near an exit aperture. Each of the entrance and exit apertures is formed by the intersection of the paraboloid with a plane substantially perpendicular to the paraboloid axis. Incident (non-reflected) light from a source of limited extent (the Sun) illuminates a limited area on the detector array. Both direct and diffuse illumination may be reflected, or not reflected, before being received on the detector array. As the Sun traverses a path in the sky over some time interval, the track of the Sun can be traced on the detector array. A suitably modified Sun photometer might be used to study the dynamics of an environment on another planet or satellite with an atmosphere.

Manycore Performance-Portability: Kokkos Multidimensional Array Library

DOE PAGES

Edwards, H. Carter; Sunderland, Daniel; Porter, Vicki; ...

2012-01-01

Large, complex scientific and engineering application code have a significant investment in computational kernels to implement their mathematical models. Porting these computational kernels to the collection of modern manycore accelerator devices is a major challenge in that these devices have diverse programming models, application programming interfaces (APIs), and performance requirements. The Kokkos Array programming model provides library-based approach to implement computational kernels that are performance-portable to CPU-multicore and GPGPU accelerator devices. This programming model is based upon three fundamental concepts: (1) manycore compute devices each with its own memory space, (2) data parallel kernels and (3) multidimensional arrays. Kernel executionmore » performance is, especially for NVIDIA® devices, extremely dependent on data access patterns. Optimal data access pattern can be different for different manycore devices – potentially leading to different implementations of computational kernels specialized for different devices. The Kokkos Array programming model supports performance-portable kernels by (1) separating data access patterns from computational kernels through a multidimensional array API and (2) introduce device-specific data access mappings when a kernel is compiled. An implementation of Kokkos Array is available through Trilinos [Trilinos website, http://trilinos.sandia.gov/, August 2011].« less

Applications of a pnCCD detector coupled to columnar structure CsI(Tl) scintillator system in ultra high energy X-ray Laue diffraction

NASA Astrophysics Data System (ADS)

Shokr, M.; Schlosser, D.; Abboud, A.; Algashi, A.; Tosson, A.; Conka, T.; Hartmann, R.; Klaus, M.; Genzel, C.; Strüder, L.; Pietsch, U.

2017-12-01

Most charge coupled devices (CCDs) are made of silicon (Si) with typical active layer thicknesses of several microns. In case of a pnCCD detector the sensitive Si thickness is 450 μm. However, for silicon based detectors the quantum efficiency for hard X-rays drops significantly for photon energies above 10 keV . This drawback can be overcome by combining a pixelated silicon-based detector system with a columnar scintillator. Here we report on the characterization of a low noise, fully depleted 128×128 pixels pnCCD detector with 75×75 μm2 pixel size coupled to a 700 μm thick columnar CsI(Tl) scintillator in the photon range between 1 keV to 130 keV . The excellent performance of the detection system in the hard X-ray range is demonstrated in a Laue type X-ray diffraction experiment performed at EDDI beamline of the BESSY II synchrotron taken at a set of several GaAs single crystals irradiated by white synchrotron radiation. With the columnar structure of the scintillator, the position resolution of the whole system reaches a value of less than one pixel. Using the presented detector system and considering the functional relation between indirect and direct photon events Laue diffraction peaks with X-ray energies up to 120 keV were efficiently detected. As one of possible applications of the combined CsI-pnCCD system we demonstrate that the accuracy of X-ray structure factors extracted from Laue diffraction peaks can be significantly improved in hard X-ray range using the combined CsI(Tl)-pnCCD system compared to a bare pnCCD.

Application of the CCD Fabry-Perot Annular Summing Technique to Thermospheric O(1)D.

NASA Astrophysics Data System (ADS)

Coakley, Monica Marie

1995-01-01

This work will detail the verification of the advantages of the Fabry-Perot charge coupled device (CCD) annular summing technique, the development of the technique for analysis of daysky spectra, and the implications of the resulting spectra for neutral temperature and wind measurements in the daysky thermosphere. The daysky spectral feature of interest is the bright (1 kilo-Rayleigh) thermospheric (OI) emission at 6300 A which had been observed in the nightsky in order to determine winds and temperatures in the vicinity of the altitude of 250 km. In the daysky, the emission line sits on top of a bright Rayleigh scattered continuum background which significantly complicates the observation. With a triple etalon Fabry-Perot spectrometer, the continuum background can be reduced while maintaining high throughput and high resolution. The inclusion of a CCD camera results in significant savings in integration time over the two more standard scanning photomultiplier systems that have made the same wind and temperature measurements in the past. A comparable CCD system can experience an order of magnitude savings in integration time over a PMT system. Laboratory and field tests which address the advantages and limitations of both the Fabry-Perot CCD annular summing technique and the daysky CCD imaging are included in Chap. 2 and Chap. 3. With a sufficiently large throughput associated with the spectrometer and a CCD detector, rapid observations (~4 minute integrations) can be made. Extraction of the line width and line center from the daysky near-continuum background is complicated compared to the nightsky case, but possible. Methods of fitting the line are included in Chap. 4. The daysky O ^1D temperatures are consistent with a lower average emission height than predicted by models. The data and models are discussed in Chap. 5. Although some discrepancies exist between resulting temperatures and models, the observations indicate the potential for other direct measurements of bright neutral species in the daysky as well as the potential for twenty-four hour coverage.

Lasercom system architecture with reduced complexity

NASA Technical Reports Server (NTRS)

Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homayoon (Inventor)

1994-01-01

Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention, a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides the means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

LaserCom System Architecture With Reduced Complexity

NASA Technical Reports Server (NTRS)

Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homa-Yoon (Inventor)

1996-01-01

Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

Eliminating "Hotspots" in Digital Image Processing

NASA Technical Reports Server (NTRS)

Salomon, P. M.

1984-01-01

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

Stroboscopic Imaging Interferometer for MEMS Performance Measurement

DTIC Science & Technology

2007-07-15

Optical Iocusing L.aser Fiber Optics I) c 0 Mim er Collimator - C d Microcope lcam. indo Cold Objcclive Splitte FingerCCD "Mount irnro MEMS PicL zStack...Electronics and Photonics Laboratory: Microelectronics, VLSI reliability, failure analysis, solid-state device physics, compound semiconductors

Detector for CheMin

NASA Image and Video Library

2012-10-30

This charged couple device CCD is part of the CheMin instrument on NASA Curiosity rover. When CheMin directs X-rays at a sample of soil, this imager, which is the size of a postage stamp, detects both the position and energy of each X-ray photon.

A new clocking method for a charge coupled device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umezu, Rika; Kitamoto, Shunji, E-mail: kitamoto@rikkyo.ac.jp; Murakami, Hiroshi

2014-07-15

We propose and demonstrate a new clocking method for a charge-coupled device (CCD). When a CCD is used for a photon counting detector of X-rays, its weak point is a limitation of its counting rate, because high counting rate makes non-negligible pile-up of photons. In astronomical usage, this pile-up is especially severe for an observation of a bright point-like object. One typical idea to reduce the pile-up is a parallel sum (P-sum) mode. This mode completely loses one-dimensional information. Our new clocking method, panning mode, provides complementary properties between the normal mode and the P-sum mode. We performed a simplemore » simulation in order to investigate a pile-up probability and compared the simulated result and actual obtained event rates. Using this simulation and the experimental results, we compared the pile-up tolerance of various clocking modes including our new method and also compared their other characteristics.« less

Ground-Based Fabry-Perot Interferometry of the Terrestrial Nightglow with a Bare Charge-Coupled Device: Remote Field Site Deployment

NASA Technical Reports Server (NTRS)

Niciejewski, Rick; Killeen, Timothy L.; Turnbull, Matthew

1994-01-01

The application of Fabry-Perot interferometers (FPIs) to the study of upper atmosphere thermodynamics has largely been restricted by the very low light levels in the terrestrial airglow as well as the limited range in wavelength of photomultiplier tube (PMT) technology. During the past decade, the development of the scientific grade charge-coupled device (CCD) has progressed to the stage in which this detector has become the logical replacement for the PMT. Small fast microcomputers have made it possible to "upgrade" our remote field sites with bare CCDs and not only retain the previous capabilities of the existing FPls but expand the data coverage in both temporal and wavelength domains. The problems encountered and the solutions applied to the deployment of a bare CCD, with data acquisition and image reduction techniques, are discussed. Sample geophysical data determined from the FPI fringe profiles are shown for our stations at Peach Mountain, Michigan, and Watson Lake, Yukon Territory.

Imaging with organic indicators and high-speed charge-coupled device cameras in neurons: some applications where these classic techniques have advantages.

PubMed

Ross, William N; Miyazaki, Kenichi; Popovic, Marko A; Zecevic, Dejan

2015-04-01

Dynamic calcium and voltage imaging is a major tool in modern cellular neuroscience. Since the beginning of their use over 40 years ago, there have been major improvements in indicators, microscopes, imaging systems, and computers. While cutting edge research has trended toward the use of genetically encoded calcium or voltage indicators, two-photon microscopes, and in vivo preparations, it is worth noting that some questions still may be best approached using more classical methodologies and preparations. In this review, we highlight a few examples in neurons where the combination of charge-coupled device (CCD) imaging and classical organic indicators has revealed information that has so far been more informative than results using the more modern systems. These experiments take advantage of the high frame rates, sensitivity, and spatial integration of the best CCD cameras. These cameras can respond to the faster kinetics of organic voltage and calcium indicators, which closely reflect the fast dynamics of the underlying cellular events.

A CCD-based reader combined with CdS quantum dot-labeled lateral flow strips for ultrasensitive quantitative detection of CagA

NASA Astrophysics Data System (ADS)

Gui, Chen; Wang, Kan; Li, Chao; Dai, Xuan; Cui, Daxiang

2014-02-01

Immunochromatographic assays are widely used to detect many analytes. CagA is proved to be associated closely with initiation of gastric carcinoma. Here, we reported that a charge-coupled device (CCD)-based test strip reader combined with CdS quantum dot-labeled lateral flow strips for quantitative detection of CagA was developed, which used 365-nm ultraviolet LED as the excitation light source, and captured the test strip images through an acquisition module. Then, the captured image was transferred to the computer and was processed by a software system. A revised weighted threshold histogram equalization (WTHE) image processing algorithm was applied to analyze the result. CdS quantum dot-labeled lateral flow strips for detection of CagA were prepared. One hundred sera samples from clinical patients with gastric cancer and healthy people were prepared for detection, which demonstrated that the device could realize rapid, stable, and point-of-care detection, with a sensitivity of 20 pg/mL.

Analysis of mutations in oral poliovirus vaccine by hybridization with generic oligonucleotide microchips.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Proudnikov, D.; Kirillov, E.; Chumakov, K.

2000-01-01

This paper describes use of a new technology of hybridization with a micro-array of immobilized oligonucleotides for detection and quantification of neurovirulent mutants in Oral Poliovirus Vaccine (OPV). We used a micro-array consisting of three-dimensional gel-elements containing all possible hexamers (total of 4096 probes). Hybridization of fluorescently labelled viral cDNA samples with such microchips resulted in a pattern of spots that was registered and quantified by a computer-linked CCD camera, so that the sequence of the original cDNA could be deduced. The method could reliably identify single point mutations, since each of them affected fluorescence intensity of 12 micro-array elements.more » Micro-array hybridization of DNA mixtures with varying contents of point mutants demonstrated that the method can detect as little as 10% of revertants in a population of vaccine virus. This new technology should be useful for quality control of live viral vaccines, as well as for other applications requiring identification and quantification of point mutations.« less

Miniaturized high throughput detection system for capillary array electrophoresis on chip with integrated light emitting diode array as addressed ring-shaped light source.

PubMed

Ren, Kangning; Liang, Qionglin; Mu, Xuan; Luo, Guoan; Wang, Yiming

2009-03-07

A novel miniaturized, portable fluorescence detection system for capillary array electrophoresis (CAE) on a microfluidic chip was developed, consisting of a scanning light-emitting diode (LED) light source and a single point photoelectric sensor. Without charge coupled detector (CCD), lens, fibers and moving parts, the system was extremely simplified. Pulsed driving of the LED significantly increased the sensitivity, and greatly reduced the power consumption and photobleaching effect. The highly integrated system was robust and easy to use. All the advantages realized the concept of a portable micro-total analysis system (micro-TAS), which could work on a single universal serial bus (USB) port. Compared with traditional CAE detecting systems, the current system could scan the radial capillary array with high scanning rate. An 8-channel CAE of fluorescein isothiocyanate (FITC) labeled arginine (Arg) on chip was demonstrated with this system, resulting in a limit of detection (LOD) of 640 amol.

Validating Phasing and Geometry of Large Focal Plane Arrays

NASA Technical Reports Server (NTRS)

Standley, Shaun P.; Gautier, Thomas N.; Caldwell, Douglas A.; Rabbette, Maura

2011-01-01

The Kepler Mission is designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-sized and smaller planets in or near the habitable zone. The Kepler photometer is an array of 42 CCDs (charge-coupled devices) in the focal plane of a 95-cm Schmidt camera onboard the Kepler spacecraft. Each 50x25-mm CCD has 2,200 x 1,024 pixels. The CCDs accumulate photons and are read out every six seconds to prevent saturation. The data is integrated for 30 minutes, and then the pixel data is transferred to onboard storage. The data is subsequently encoded and transmitted to the ground. During End-to-End Information System (EEIS) testing of the Kepler Mission System (KMS), there was a need to verify that the pixels requested by the science team operationally were correctly collected, encoded, compressed, stored, and transmitted by the FS, and subsequently received, decoded, uncompressed, and displayed by the Ground Segment (GS) without the outputs of any CCD modules being flipped, mirrored, or otherwise corrupted during the extensive FS and GS processing. This would normally be done by projecting an image on the focal plane array (FPA), collecting the data in a flight-like way, and making a comparison between the original data and the data reconstructed by the science data system. Projecting a focused image onto the FPA through the telescope would normally involve using a collimator suspended over the telescope opening. There were several problems with this approach: the collimation equipment is elaborate and expensive; as conceived, it could only illuminate a limited section of the FPA (.25 percent) during a given test; the telescope cover would have to be deployed during testing to allow the image to be projected into the telescope; the equipment was bulky and difficult to situate in temperature-controlled environments; and given all the above, test setup, execution, and repeatability were significant concerns. Instead of using this complicated approach of projecting an optical image on the FPA, the Kepler project developed a method using known defect features in the CCDs to verify proper collection and reassembly of the pixels, thereby avoiding the costs and risks of the optical projection approach. The CCDs composing the Kepler FPA, as all CCDs, had minor defects. At ambient temperature, some pixels look far brighter than they should. These ghot h pixels have a higher rate of charge leakage than the others due to manufacturing variations. They are usually stable over time, and appear at temperatures above 5 oC. The hot pixels on the Kepler FPA were mapped before photometer assembly during module testing. Selected hot pixels were used as target gstars h for the purposes of EEIS testing. gDead h pixels are permanently off, producing a permanently black pixel. These can also be used if there is some illumination of the FPA. During EEIS testing, Dark Current Full Frame Images (FFIs) taken at room temperature were used to create the hot pixel maps for all 84 Kepler photometer CCD channels. Data from two separate nights were used to create two hot pixel maps per channel, which were cross-correlated to remove cosmic ray events which appear to be hot pixels. These hot pixel maps obtained during EEIS testing were compared to the maps made during module testing to verify that the end-to-end data flow was correct.

The Development of the Spanish Fireball Network Using a New All-Sky CCD System

NASA Astrophysics Data System (ADS)

Trigo-Rodríguez, J. M.; Castro-Tirado, A. J.; Llorca, J.; Fabregat, J.; Martínez, V. J.; Reglero, V.; Jelínek, M.; Kubánek, P.; Mateo, T.; Postigo, A. De Ugarte

2004-12-01

We have developed an all-sky charge coupled devices (CCD) automatic system for detecting meteors and fireballs that will be operative in four stations in Spain during 2005. The cameras were developed following the BOOTES-1 prototype installed at the El Arenosillo Observatory in 2002, which is based on a CCD detector of 4096 × 4096 pixels with a fish-eye lens that provides an all-sky image with enough resolution to make accurate astrometric measurements. Since late 2004, a couple of cameras at two of the four stations operate for 30 s in alternate exposures, allowing 100% time coverage. The stellar limiting magnitude of the images is +10 in the zenith, and +8 below ~ 65° of zenithal angle. As a result, the images provide enough comparison stars to make astrometric measurements of faint meteors and fireballs with an accuracy of ~ 2°arcminutes. Using this prototype, four automatic all-sky CCD stations have been developed, two in Andalusia and two in the Valencian Community, to start full operation of the Spanish Fireball Network. In addition to all-sky coverage, we are developing a fireball spectroscopy program using medium field lenses with additional CCD cameras. Here we present the first images obtained from the El Arenosillo and La Mayora stations in Andalusia during their first months of activity. The detection of the Jan 27, 2003 superbolide of ± 17 ± 1 absolute magnitude that overflew Algeria and Morocco is an example of the detection capability of our prototype.

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

NASA Astrophysics Data System (ADS)

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.

Label-free immunosensor based on gold nanoparticle silver enhancement.

PubMed

Yang, Minghui; Wang, Cunchang

2009-02-01

A label-free immunosensor for the sensitive detection of human immunoglobulin G (IgG) was prepared based on gold nanoparticle-silver enhancement detection with a simple charge-coupled device (CCD) detector. The gold nanoparticles, which were used as nuclei for the deposit of metallic silver and also for the adsorption of antibodies, were immobilized into wells of a 9-well chip. With the addition of silver enhancement buffer, metallic silver will deposit onto gold nanoparticles, causing darkness that can be optically measured by the CCD camera and quantified using ImageJ software. When antibody was immobilized onto the gold nanoparticles and antigen was captured, the formed immunocomplex resulted in a decrease of the darkness and the intensity of the darkness was in line with IgG concentrations from 0.05 to 10 ng/ml. The CCD detector is simple and portable, and the reported method has many desirable merits such as sensitivity and accuracy, making it a promising technique for protein detection.

The Extended Range X-Ray Telescope center director's discretionary fund report

NASA Technical Reports Server (NTRS)

Hoover, R. B.; Cumings, N. P.; Hildner, E.; Moore, R. L.; Tandberg-Hanssen, E. A.

1985-01-01

An Extended Range X-Ray Telescope (ERXRT) of high sensitivity and spatial resolution capable of functioning over a broad region of the X-ray/XUV portion of the spectrum has been designed and analyzed. This system has been configured around the glancing-incidence Wolter Type I X-ray mirror system which was flown on the Skylab Apollo Telescope Mount as ATM Experiment S-056. Enhanced sensitivity over a vastly broader spectral range can be realized by the utilization of a thinned, back-illuminated, buried-channel Charge Coupled Device (CCD) as the X-ray/XUV detector rather than photographic film. However, to maintain the high spatial resolution inherent in the X-ray optics when a CCD of 30 micron pixel size is used, it is necessary to increase the telescope plate scale. This can be accomplished by use of a glancing-incidence X-ray microscope to enlarge and re-focus the primary image onto the focal surface of the CCD.

VizieR Online Data Catalog: Proper motions and photometry of stars in NGC 3201 (Sariya+, 2017)

NASA Astrophysics Data System (ADS)

Sariya, D. P.; Jiang, I.-G.; Yadav, R. K. S.

2017-07-01

To determine the PMs of the stars in this work, we used archive images (http://archive.eso.org/eso/esoarchivemain.html) from observations made with the 2.2m ESO/MPI telescope at La Silla, Chile. This telescope contains a mosaic camera called the Wide-Field Imager (WFI), consisting of 4*2 (i.e., 8 CCD chips). Since each CCD has an array of 2048*4096 pixels, WFI ultimately produces images with a 34*33arcmin2 field of view. The observational run of the first epoch contains two images in B,V and I bands, each with 240s exposure time observed on 1999 December 05. In the second epoch, we have 35 images with 40s exposure time each in V filter observed during the period of 2014 April 02-05. Thus the epoch gap between the data is ~14.3 years. (2 data files).

Ultrafast Imaging using Spectral Resonance Modulation

NASA Astrophysics Data System (ADS)

Huang, Eric; Ma, Qian; Liu, Zhaowei

2016-04-01

CCD cameras are ubiquitous in research labs, industry, and hospitals for a huge variety of applications, but there are many dynamic processes in nature that unfold too quickly to be captured. Although tradeoffs can be made between exposure time, sensitivity, and area of interest, ultimately the speed limit of a CCD camera is constrained by the electronic readout rate of the sensors. One potential way to improve the imaging speed is with compressive sensing (CS), a technique that allows for a reduction in the number of measurements needed to record an image. However, most CS imaging methods require spatial light modulators (SLMs), which are subject to mechanical speed limitations. Here, we demonstrate an etalon array based SLM without any moving elements that is unconstrained by either mechanical or electronic speed limitations. This novel spectral resonance modulator (SRM) shows great potential in an ultrafast compressive single pixel camera.

Rocket and laboratory studies in astronomy

NASA Technical Reports Server (NTRS)

Feldman, P. D.

1993-01-01

This report covers the period from September 1, 1992 to August 31, 1993. During the reporting period we launched the Faint Object Telescope to measure absolute fluxes of two hot dwarf stars in the spectral range below 1200 A. Although all systems worked normally, a higher than anticipated pressure in the detector led to ion-feedback that masked the useable data from the source. We have identified the source of the problem and are preparing for a reflight in the Fall of 1993. Our laboratory program for the evaluation of the ultraviolet performance of charge-coupled-detector (CCD) arrays continued with the aim of including a UV-sensitive CCD in a payload to be flown in 1994, and we have begun the assembly of this payload. Work has continued on the analysis of data from previous rocket experiments and from the UVX experiment which flew on STS-61C in January 1986.

History highlights and future trends of infrared sensors

NASA Astrophysics Data System (ADS)

Corsi, Carlo

2010-10-01

Infrared (IR) technologies (materials, devices and systems) represent an area of excellence in science and technology and, even if they have been generally confined to a selected scientific community, they have achieved technological and scientific highlights constituting 'innovation drivers' for neighbouring disciplines, especially in the sensors field. The development of IR sensors, initially linked to astronomical observations, since World War II and for many years has been fostered essentially by defence applications, particularly thermo-vision and, later on, smart vision and detection, for surveillance and warning. Only in the last few decades, the impact of silicon technology has changed the development of IR detectors dramatically, with the advent of integrated signal read-outs and the opening of civilian markets (EO communications, biomedical, environmental, transport and energy applications). The history of infrared sensors contains examples of real breakthroughs, particularly true in the case of focal plane arrays that first appeared in the late 1970s, when the superiority of bi-dimensional arrays for most applications pushed the development of technologies providing the highest number of pixels. An impressive impulse was given to the development of FPA arrays by integration with charge coupled devices (CCD), with strong competition from different technologies (high-efficiency photon sensors, Schottky diodes, multi-quantum wells and, later on, room temperature microbolometers/cantilevers). This breakthrough allowed the development of high performance IR systems of small size, light weight and low cost - and therefore suitable for civil applications - thanks to the elimination of the mechanical scanning system and the progressive reduction of cooling requirements (up to the advent of microbolometers, capable of working at room temperature). In particular, the elimination of cryogenic cooling allowed the development and commercialisation of IR Smart Sensors; strategic components for important areas like transport, environment, territory control and security. Infrared history is showing oscillations and variations in raw materials, technology processes and in device design and characteristics. Various technologies oscillating between the two main detection techniques (photon and bolometer effects) have been developed and evaluated as the best ones, depending on the system use as well as expectable performances. Analysis of the 'waving change' in the history of IR sensor technologies is given with the fundamental theory of the various approaches. Highlights of the main historical IR developments and their impact and use in civil and military applications is shown and correlated with the leading technology of silicon microelectronics: scientific and economic comparisons are given and emerging technologies and forecasting of future developments are outlined.

Findings toward the miniaturization of a laser speckle contrast device for skin roughness measurements

NASA Astrophysics Data System (ADS)

Louie, Daniel C.; Tchvialeva, Lioudmilla; Zeng, Haishan; Lee, Tim K.

2017-02-01

Skin roughness is an important parameter in the characterization of skin and skin lesions, particularly for the purposes of skin cancer detection. Our group had previously constructed a laser speckle device that can detect the roughness in microrelief of the skin. This paper reports on findings made for the further miniaturization of our existing portably-sized device. These findings include the feasibility of adopting a laser diode without temperature control, and the use of a single CCD camera for detection. The coherence length of a laser is a crucial criterion for speckle measurements as it must be within a specific range. The coherence length of a commercial grade 405 nm laser diode was found to be of an appropriate length. Also, after a short warm-up period the coherence length of the laser was found to remain relatively stable, even without temperature control. Although the laser's temperature change during operation may affect its power output and the shape of its spectrum, these are only minor factors in speckle contrast measurements. Our second finding covers a calibration curve to relate speckle measurements to roughness using only parallel polarization from one CCD camera. This was created using experimental data from skin phantoms and tested on in-vivo skin. These improvements are important steps forward in the ongoing development of the laser speckle device, especially towards a clinical device to measure skin roughness and evaluate skin lesions.

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

NASA Astrophysics Data System (ADS)

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.

Soft x-ray pinhole imaging diagnostics for compact toroid plasmas

NASA Astrophysics Data System (ADS)

Crawford, E. A.; Taggart, D. P.; Bailey, A. D., III

1990-10-01

Soft x-ray pinhole imaging has recently become established as a valuable diagnostic for visualization of field reversed configuration (FRC) plasmas in the TRX-2, FRX-C/LSM devices. Gated MCP image converter devices with CsI cathodes and Be filters with a peak response around 11 nm wavelength are used for exposure durations ranging from a few tenths up to several microseconds. Results of experiments with single and Chevron channel plates are discussed along with estimates of linear exposure limitations with both film and CCD cameras as recording media. Plans for multiframe devices on the FRX-C/LSM and the LSX devices are also discussed.

Sealed symmetric multilayered microelectronic device package with integral windows

DOEpatents

Peterson, Kenneth A.; Watson, Robert D.

2002-01-01

A sealed symmetric multilayered package with integral windows for housing one or more microelectronic devices. The devices can be a semiconductor chip, a CCD chip, a CMOS chip, a VCSEL chip, a laser diode, a MEMS device, or a IMEMS device. The multilayered package can be formed of a low-temperature cofired ceramic (LTCC) or high-temperature cofired ceramic (HTCC) multilayer processes with the windows being simultaneously joined (e.g. cofired) to the package body during LTCC or HTCC processing. The microelectronic devices can be flip-chip bonded and oriented so that the light-sensitive sides are optically accessible through the windows. The result is a compact, low-profile, sealed symmetric package, having integral windows that can be hermetically-sealed.

3D imaging LADAR with linear array devices: laser, detector and ROIC

NASA Astrophysics Data System (ADS)

Kameyama, Shumpei; Imaki, Masaharu; Tamagawa, Yasuhisa; Akino, Yosuke; Hirai, Akihito; Ishimura, Eitaro; Hirano, Yoshihito

2009-07-01

This paper introduces the recent development of 3D imaging LADAR (LAser Detection And Ranging) in Mitsubishi Electric Corporation. The system consists of in-house-made key devices which are linear array: the laser, the detector and the ROIC (Read-Out Integrated Circuit). The laser transmitter is the high power and compact planar waveguide array laser at the wavelength of 1.5 micron. The detector array consists of the low excess noise Avalanche Photo Diode (APD) using the InAlAs multiplication layer. The analog ROIC array, which is fabricated in the SiGe- BiCMOS process, includes the Trans-Impedance Amplifiers (TIA), the peak intensity detectors, the Time-Of-Flight (TOF) detectors, and the multiplexers for read-out. This device has the feature in its detection ability for the small signal by optimizing the peak intensity detection circuit. By combining these devices with the one dimensional fast scanner, the real-time 3D range image can be obtained. After the explanations about the key devices, some 3D imaging results are demonstrated using the single element key devices. The imaging using the developed array devices is planned in the near future.

The design and development of low- and high-voltage ASICs for space-borne CCD cameras

NASA Astrophysics Data System (ADS)

Waltham, N.; Morrissey, Q.; Clapp, M.; Bell, S.; Jones, L.; Torbet, M.

2017-12-01

The CCD remains the pre-eminent visible and UV wavelength image sensor in space science, Earth and planetary remote sensing. However, the design of space-qualified CCD readout electronics is a significant challenge with requirements for low-volume, low-mass, low-power, high-reliability and tolerance to space radiation. Space-qualified components are frequently unavailable and up-screened commercial components seldom meet project or international space agency requirements. In this paper, we describe an alternative approach of designing and space-qualifying a series of low- and high-voltage mixed-signal application-specific integrated circuits (ASICs), the ongoing development of two low-voltage ASICs with successful flight heritage, and two new high-voltage designs. A challenging sub-system of any CCD camera is the video processing and digitisation electronics. We describe recent developments to improve performance and tolerance to radiation-induced single event latchup of a CCD video processing ASIC originally developed for NASA's Solar Terrestrial Relations Observatory and Solar Dynamics Observatory. We also describe a programme to develop two high-voltage ASICs to address the challenges presented with generating a CCD's bias voltages and drive clocks. A 0.35 μm, 50 V tolerant, CMOS process has been used to combine standard low-voltage 3.3 V transistors with high-voltage 50 V diffused MOSFET transistors that enable output buffers to drive CCD bias drains, gates and clock electrodes directly. We describe a CCD bias voltage generator ASIC that provides 24 independent and programmable 0-32 V outputs. Each channel incorporates a 10-bit digital-to-analogue converter, provides current drive of up to 20 mA into loads of 10 μF, and includes current-limiting and short-circuit protection. An on-chip telemetry system with a 12-bit analogue-to-digital converter enables the outputs and multiple off-chip camera voltages to be monitored. The ASIC can drive one or more CCDs and replaces the many discrete components required in current cameras. We also describe a CCD clock driver ASIC that provides six independent and programmable drivers with high-current capacity. The device enables various CCD clock parameters to be programmed independently, for example the clock-low and clock-high voltage levels, and the clock-rise and clock-fall times, allowing configuration for serial clock frequencies in the range 0.1-2 MHz and image clock frequencies in the range 10-100 kHz. Finally, we demonstrate the impact and importance of this technology for the development of compact, high-performance and low-power integrated focal plane electronics.

How do I convert the numbers stored in the files to physical quantities?

Atmospheric Science Data Center

2014-12-08

At Level 1A, the 14 most significant bits (MSB) directly represent the raw digital count from the camera's Charge-Coupled Device (CCD). The 2 least significant bits (LSB) of the 16-bit data values are data quality indicators (DQI). A...

Double emulsions from a capillary array injection microfluidic device.

PubMed

Shang, Luoran; Cheng, Yao; Wang, Jie; Ding, Haibo; Rong, Fei; Zhao, Yuanjin; Gu, Zhongze

2014-09-21

A facile microfluidic device was developed by inserting an annular capillary array into a collection channel for single-step emulsification of double emulsions. By inserting multiple inner-phase solutions into the capillary array, multicomponent double emulsions or microcapsules with inner droplets of different content could also be obtained from the device.

CHARGING OF DEVICES BY MICROWAVE POWER BEAMING

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A. (Inventor)

2005-01-01

A system for providing wireless, charging power and/or primary power to electronic/electrical devices is described whereby microwave energy is employed. Microwave energy is focused by a power transmitter comprising one or more adaptively-phased microwave array emitters onto a device to be charged. Rectennas within the device to be charged receive and rectify the microwave energy and use it for battery charging and/or for primary power. A locator signal generated by the device to be charged is analyzed by the system to determine the location of the device to be charged relative to the microwave array emitters, permitting thc microwave energy to be directly specifically towards the device to be charged. Backscatter detectors respond to backscatter energy reflected off of any obstacle between the device to be charged and the microwave array emitters. Power to any obstructed microwave array emitter is reduced until the obstruction is removed. Optionally, data can be modulated onto microwave energy beams produced by the array emitter and demodulated by the device, thereby providing means of data communication from the power transmitter to the device. Similarly, data can be modulated onto the locator signal and demodulated in the power transmitter, thereby providing means of data communication from the device to the power transmitter.

CCD Astrometric Measurements of Double Stars BAL 746, BPM 342, KU 92, and STF 897

NASA Astrophysics Data System (ADS)

Smith, Schuyler

2017-07-01

Double stars WDS 06589-0106 (BAL 746), WDS 06579+1430 (BPM 342), WDS 07006+0921 (KU 92), and WDS 06224+2640 (STF 897) were measured as part of a science fair project for the 2016 Greater San Diego Science and Engineering Fair. The goal was to measure the separation and position angles of stars by using a telescope with a charge-coupled device (CCD) on the iTelescope network. Five images were taken of each of the stars. These images were plate solved with Visual PinPoint and measured using Aladin Sky Atlas. Measurements for all five doubles compare well to the more recent values in the Washington Double Star Catalog.

MTF measurement of LCDs by a linear CCD imager: I. Monochrome case

NASA Astrophysics Data System (ADS)

Kim, Tae-hee; Choe, O. S.; Lee, Yun Woo; Cho, Hyun-Mo; Lee, In Won

1997-11-01

We construct the modulation transfer function (MTF) measurement system of a LCD using a linear charge-coupled device (CCD) imager. The MTF used in optical system can not describe in the effect of both resolution and contrast on the image quality of display. Thus we present the new measurement method based on the transmission property of a LCD. While controlling contrast and brightness levels, the MTF is measured. From the result, we show that the method is useful for describing of the image quality. A ne measurement method and its condition are described. To demonstrate validity, the method is applied for comparison of the performance of two different LCDs.

Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

NASA Technical Reports Server (NTRS)

Chervenak, J. A.; Adams, J. A.; Bandler, S. B.; Busch, S. E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, J. P.;

Digital solar edge tracker for the Halogen Occultation Experiment

NASA Technical Reports Server (NTRS)

Mauldin, L. E., III; Moore, A. S.; Stump, C. W.; Mayo, L. S.

1987-01-01

The optical and electronic design of the Halogen Occultation Experiment (Haloe) elevation sun sensor is described. The Haloe instrument is a gas-correlation radiometer now being developed at NASA Langley for the Upper Atmosphere Research Satellite. The system uses a Galilean telescope to form a solar image on a linear silicon photodiode array. The array is a self-scanned monolithic CCD. The addresses of both solar edges imaged on the array are used by the control/pointing system to scan the Haloe science instantaneous field of view (IFOV) across the vertical solar diameter during instrument calibration and then to maintain the science IFOV 4 arcmin below the top edge during the science data occultation event. Vertical resolution of 16 arcsec and a radiometric dynamic range of 100 are achieved at the 700-nm operating wavelength. The design provides for loss of individual photodiode elements without loss of angular tracking capability.

Reconfigurable Optical Elements Based on Single and Coupled Microdisk Resonators with Quantum DOT Active Media

DTIC Science & Technology

2012-06-29

of active-passive integrated polymer waveguides. The active waveguides consist of CdSe quantum dots dispersed in SU8 . Bottom panel shows CCD images...successfully demonstrated (i) incorporation of CdSe QDs into polymer and dielectric host and realization of devices such as active waveguides, microdisk...the significant outcomes of the program: • Successful incorporation of CdSe QDs into polymer and dielectric host and realization of devices such as

Modified modular imaging system designed for a sounding rocket experiment

NASA Astrophysics Data System (ADS)

Veach, Todd J.; Scowen, Paul A.; Beasley, Matthew; Nikzad, Shouleh

2012-09-01

We present the design and system calibration results from the fabrication of a charge-coupled device (CCD) based imaging system designed using a modified modular imager cell (MIC) used in an ultraviolet sounding rocket mission. The heart of the imaging system is the MIC, which provides the video pre-amplifier circuitry and CCD clock level filtering. The MIC is designed with standard four-layer FR4 printed circuit board (PCB) with surface mount and through-hole components for ease of testing and lower fabrication cost. The imager is a 3.5k by 3.5k LBNL p-channel CCD with enhanced quantum efficiency response in the UV using delta-doping technology at JPL. The recently released PCIe/104 Small-Cam CCD controller from Astronomical Research Cameras, Inc (ARC) performs readout of the detector. The PCIe/104 Small-Cam system has the same capabilities as its larger PCI brethren, but in a smaller form factor, which makes it ideally suited for sub-orbital ballistic missions. The overall control is then accomplished using a PCIe/104 computer from RTD Embedded Technologies, Inc. The design, fabrication, and testing was done at the Laboratory for Astronomical and Space Instrumentation (LASI) at Arizona State University. Integration and flight calibration are to be completed at the University of Colorado Boulder before integration into CHESS.

Wafer-size free-standing single-crystalline graphene device arrays

NASA Astrophysics Data System (ADS)

Li, Peng; Jing, Gaoshan; Zhang, Bo; Sando, Shota; Cui, Tianhong

2014-08-01

We report an approach of wafer-scale addressable single-crystalline graphene (SCG) arrays growth by using pre-patterned seeds to control the nucleation. The growth mechanism and superb properties of SCG were studied. Large array of free-standing SCG devices were realized. Characterization of SCG as nano switches shows excellent performance with life time (>22 000 times) two orders longer than that of other graphene nano switches reported so far. This work not only shows the possibility of producing wafer-scale high quality SCG device arrays but also explores the superb performance of SCG as nano devices.

Aligning Arrays of Lenses and Single-Mode Optical Fibers

NASA Technical Reports Server (NTRS)

Liu, Duncan

2004-01-01

A procedure now under development is intended to enable the precise alignment of sheet arrays of microscopic lenses with the end faces of a coherent bundle of as many as 1,000 single-mode optical fibers packed closely in a regular array (see Figure 1). In the original application that prompted this development, the precise assembly of lenses and optical fibers serves as a single-mode spatial filter for a visible-light nulling interferometer. The precision of alignment must be sufficient to limit any remaining wavefront error to a root-mean-square value of less than 1/10 of a wavelength of light. This wavefront-error limit translates to requirements to (1) ensure uniformity of both the lens and fiber arrays, (2) ensure that the lateral distance from the central axis of each lens and the corresponding optical fiber is no more than a fraction of a micron, (3) angularly align the lens-sheet planes and the fiber-bundle end faces to within a few arc seconds, and (4) axially align the lenses and the fiber-bundle end faces to within tens of microns of the focal distance. Figure 2 depicts the apparatus used in the alignment procedure. The beam of light from a Zygo (or equivalent) interferometer is first compressed by a ratio of 20:1 so that upon its return to the interferometer, the beam will be magnified enough to enable measurement of wavefront quality. The apparatus includes relay lenses that enable imaging of the arrays of microscopic lenses in a charge-coupled-device (CCD) camera that is part of the interferometer. One of the arrays of microscopic lenses is mounted on a 6-axis stage, in proximity to the front face of the bundle of optical fibers. The bundle is mounted on a separate stage. A mirror is attached to the back face of the bundle of optical fibers for retroreflection of light. When a microscopic lens and a fiber are aligned with each other, the affected portion of the light is reflected back by the mirror, recollimated by the microscopic lens, transmitted through the relay lenses and the beam compressor/expander, then split so that half goes to a detector and half to the interferometer. The output of the detector is used as a feedback control signal for the six-axis stage to effect alignment.

High-performance ultra-low power VLSI analog processor for data compression

NASA Technical Reports Server (NTRS)

Tawel, Raoul (Inventor)

1996-01-01

An apparatus for data compression employing a parallel analog processor. The apparatus includes an array of processor cells with N columns and M rows wherein the processor cells have an input device, memory device, and processor device. The input device is used for inputting a series of input vectors. Each input vector is simultaneously input into each column of the array of processor cells in a pre-determined sequential order. An input vector is made up of M components, ones of which are input into ones of M processor cells making up a column of the array. The memory device is used for providing ones of M components of a codebook vector to ones of the processor cells making up a column of the array. A different codebook vector is provided to each of the N columns of the array. The processor device is used for simultaneously comparing the components of each input vector to corresponding components of each codebook vector, and for outputting a signal representative of the closeness between the compared vector components. A combination device is used to combine the signal output from each processor cell in each column of the array and to output a combined signal. A closeness determination device is then used for determining which codebook vector is closest to an input vector from the combined signals, and for outputting a codebook vector index indicating which of the N codebook vectors was the closest to each input vector input into the array.

Ladder-structured photonic variable delay device

NASA Technical Reports Server (NTRS)

Yao, X. Steve (Inventor)

1998-01-01

An ladder-structured variable delay device for providing variable true time delay to multiple optical beams simultaneously. The device comprises multiple basic units stacked on top of each other resembling a ladder. Each basic unit comprises a polarization sensitive corner reflector formed by two polarization beamsplitters and a polarization rotator array placed parallel to the hypotenuse of the corner reflector. Controlling an array element of the polarization rotator array causes an optical beam passing through the array element to either go up to a basic unit above it or reflect back towards output. The beams going higher on the ladder experience longer optical path delay. Finally, the ladder-structured variable device can be cascaded with another multi-channel delay device to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

Transiting Exoplanet Survey Satellite (TESS) Briefing

NASA Image and Video Library

2018-03-28

George Ricker, TESS principal investigator, MIT Kavli Institute for Astrophysics and Space Research, is seen during a media briefing holding one of the wafers from which the Transiting Exoplanet Survey Satellite (TESS) camera charge coupled device (CCD) were fabricated, Wednesday, March 28, 2018 at NASA Headquarters in Washington. Photo Credit: (NASA/Bill Ingalls)

The detection of soft X-rays with charged coupled detectors

NASA Technical Reports Server (NTRS)

Burstein, P.; Davis, John M.

1989-01-01

The characteristics of an ideal soft X-ray imaging detector are enumerated. Of recent technical developments the CCD or charge coupled device goes furthest to meeting these requirements. Several properties of CCDs are described with reference to experimental work and their application to practical instruments is reviewed.

Stereo optical guidance system for control of industrial robots

NASA Technical Reports Server (NTRS)

Powell, Bradley W. (Inventor); Rodgers, Mike H. (Inventor)

1992-01-01

A device for the generation of basic electrical signals which are supplied to a computerized processing complex for the operation of industrial robots. The system includes a stereo mirror arrangement for the projection of views from opposite sides of a visible indicia formed on a workpiece. The views are projected onto independent halves of the retina of a single camera. The camera retina is of the CCD (charge-coupled-device) type and is therefore capable of providing signals in response to the image projected thereupon. These signals are then processed for control of industrial robots or similar devices.

Human eye-inspired soft optoelectronic device using high-density MoS2-graphene curved image sensor array.

PubMed

Choi, Changsoon; Choi, Moon Kee; Liu, Siyi; Kim, Min Sung; Park, Ok Kyu; Im, Changkyun; Kim, Jaemin; Qin, Xiaoliang; Lee, Gil Ju; Cho, Kyoung Won; Kim, Myungbin; Joh, Eehyung; Lee, Jongha; Son, Donghee; Kwon, Seung-Hae; Jeon, Noo Li; Song, Young Min; Lu, Nanshu; Kim, Dae-Hyeong

2017-11-21

Soft bioelectronic devices provide new opportunities for next-generation implantable devices owing to their soft mechanical nature that leads to minimal tissue damages and immune responses. However, a soft form of the implantable optoelectronic device for optical sensing and retinal stimulation has not been developed yet because of the bulkiness and rigidity of conventional imaging modules and their composing materials. Here, we describe a high-density and hemispherically curved image sensor array that leverages the atomically thin MoS 2 -graphene heterostructure and strain-releasing device designs. The hemispherically curved image sensor array exhibits infrared blindness and successfully acquires pixelated optical signals. We corroborate the validity of the proposed soft materials and ultrathin device designs through theoretical modeling and finite element analysis. Then, we propose the ultrathin hemispherically curved image sensor array as a promising imaging element in the soft retinal implant. The CurvIS array is applied as a human eye-inspired soft implantable optoelectronic device that can detect optical signals and apply programmed electrical stimulation to optic nerves with minimum mechanical side effects to the retina.

In-situ device integration of large-area patterned organic nanowire arrays for high-performance optical sensors

PubMed Central

Wu, Yiming; Zhang, Xiujuan; Pan, Huanhuan; Deng, Wei; Zhang, Xiaohong; Zhang, Xiwei; Jie, Jiansheng

2013-01-01

Single-crystalline organic nanowires (NWs) are important building blocks for future low-cost and efficient nano-optoelectronic devices due to their extraordinary properties. However, it remains a critical challenge to achieve large-scale organic NW array assembly and device integration. Herein, we demonstrate a feasible one-step method for large-area patterned growth of cross-aligned single-crystalline organic NW arrays and their in-situ device integration for optical image sensors. The integrated image sensor circuitry contained a 10 × 10 pixel array in an area of 1.3 × 1.3 mm2, showing high spatial resolution, excellent stability and reproducibility. More importantly, 100% of the pixels successfully operated at a high response speed and relatively small pixel-to-pixel variation. The high yield and high spatial resolution of the operational pixels, along with the high integration level of the device, clearly demonstrate the great potential of the one-step organic NW array growth and device construction approach for large-scale optoelectronic device integration. PMID:24287887

Spreading devices into a 2-D module layout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koplow, Jeffrey P.; Gupta, Vipin P.; Nielson, Gregory N.

An apparatus, method, and system, the apparatus including a receiving member dimensioned to receive an array of microelectronic devices; and a linkage member coupled to the receiving member, the linkage member configured to move the receiving member in at least two dimensions so as to modify a spacing between the electronic devices within the array of microelectronic devices received by the receiving member. The method including coupling an array of microelectronic devices to an expansion assembly; and expanding the expansion assembly so as to expand the array of microelectronic devices in at least two directions within a single plane. Themore » system including a support member; an expansion assembly coupled to the support member, the expansion assembly having a plurality of receiving members configured to move in at least two dimensions within a single plane; and a plurality of microelectronic devices coupled to each of the plurality of receiving members.« less

Feasibility study of hidden flow imaging based on laser speckle technique using multiperspectives contrast images

NASA Astrophysics Data System (ADS)

Abookasis, David; Moshe, Tomer

2014-11-01

This paper demonstrates the insertion of lens array in the front of a CCD camera in a laser speckle imaging (LSI) like-technique to acquire multiple speckle reflectance projections for imaging blood flow in an intact biological tissue. In some of LSI applications, flow imaging is obtained by thinning or removing of the upper tissue layers to access blood vessels. In contrast, with the proposed approach flow imaging can be achieved while the tissue is intact. In the system, each lens from an hexagonal lens array observed the sample from slightly different perspectives and captured with a CCD camera. In the computer, these multiview raw images are converted to speckled contrast maps. Then, a self-deconvolution shift-and-add algorithm is employed for processing yields high contrast flow information. The method is experimentally validated first with a plastic tube filled with scattering liquid running at different controlled flow rates hidden in a biological tissue and then extensively tested for imaging of cerebral blood flow in an intact rodent head experience different conditions. A total of fifteen mice were used in the experiments divided randomly into three groups as follows: Group 1 (n=5) consisted of injured mice experience hypoxic ischemic brain injury monitored for ~40 min. Group 2 (n=5) injured mice experience anoxic brain injury monitored up to 20 min. Group 3 (n=5) experience functional activation monitored up to ~35 min. To increase tissue transparency and the penetration depth of photons through head tissue layers, an optical clearing method was employed. To our knowledge, this work presents for the first time the use of lens array in LSI scheme.

Principal components analysis of the photoresponse nonuniformity of a matrix detector.

PubMed

Ferrero, Alejandro; Alda, Javier; Campos, Joaquín; López-Alonso, Jose Manuel; Pons, Alicia

2007-01-01

The principal component analysis is used to identify and quantify spatial distributions of relative photoresponse as a function of the exposure time for a visible CCD array. The analysis shows a simple way to define an invariant photoresponse nonuniformity and compare it with the definition of this invariant pattern as the one obtained for long exposure times. Experimental data of radiant exposure from levels of irradiance obtained in a stable and well-controlled environment are used.

JASMINE data analysis

NASA Astrophysics Data System (ADS)

Yamada, Y.; Gouda, N.; Yano, T.; Kobayashi, Y.; Niwa, Y.; Niwa

2008-07-01

Japan Astrometry Satellite Mission for Infrared Exploration (JASMINE) aims to construct a map of the Galactic bulge with a 10 μas accuracy. We use z-band CCD or K-band array detector to avoid dust absorption, and observe about 10 × 20 degrees area around the Galactic bulge region. In this poster, we show the observation strategy, reduction scheme, and error budget. We also show the basic design of the software for the end-to-end simulation of JASMINE, named JASMINE Simulator.

Real-time tricolor phase measuring profilometry based on CCD sensitivity calibration

NASA Astrophysics Data System (ADS)

Zhu, Lin; Cao, Yiping; He, Dawu; Chen, Cheng

2017-02-01

A real-time tricolor phase measuring profilometry (RTPMP) based on charge coupled device (CCD) sensitivity calibration is proposed. Only one colour fringe pattern whose red (R), green (G) and blue (B) components are, respectively, coded as three sinusoidal phase-shifting gratings with an equivalent shifting phase of 2π/3 is needed and sent to an appointed flash memory on a specialized digital light projector (SDLP). A specialized time-division multiplexing timing sequence actively controls the SDLP to project the fringe patterns in R, G and B channels sequentially onto the measured object in one over seventy-two of a second and meanwhile actively controls a high frame rate monochrome CCD camera to capture the corresponding deformed patterns synchronously with the SDLP. So the sufficient information for reconstructing the three-dimensional (3D) shape in one over twenty-four of a second is obtained. Due to the different spectral sensitivity of the CCD camera to RGB lights, the captured deformed patterns from R, G and B channels cannot share the same peak and valley, which will lead to lower accuracy or even failing to reconstruct the 3D shape. So a deformed pattern amending method based on CCD sensitivity calibration is developed to guarantee the accurate 3D reconstruction. The experimental results verify the feasibility of the proposed RTPMP method. The proposed RTPMP method can obtain the 3D shape at over the video frame rate of 24 frames per second, avoid the colour crosstalk completely and be effective for measuring real-time changing object.

Low-cost, high-performance and efficiency computational photometer design

NASA Astrophysics Data System (ADS)

Siewert, Sam B.; Shihadeh, Jeries; Myers, Randall; Khandhar, Jay; Ivanov, Vitaly

2014-05-01

Researchers at the University of Alaska Anchorage and University of Colorado Boulder have built a low cost high performance and efficiency drop-in-place Computational Photometer (CP) to test in field applications ranging from port security and safety monitoring to environmental compliance monitoring and surveying. The CP integrates off-the-shelf visible spectrum cameras with near to long wavelength infrared detectors and high resolution digital snapshots in a single device. The proof of concept combines three or more detectors into a single multichannel imaging system that can time correlate read-out, capture, and image process all of the channels concurrently with high performance and energy efficiency. The dual-channel continuous read-out is combined with a third high definition digital snapshot capability and has been designed using an FPGA (Field Programmable Gate Array) to capture, decimate, down-convert, re-encode, and transform images from two standard definition CCD (Charge Coupled Device) cameras at 30Hz. The continuous stereo vision can be time correlated to megapixel high definition snapshots. This proof of concept has been fabricated as a fourlayer PCB (Printed Circuit Board) suitable for use in education and research for low cost high efficiency field monitoring applications that need multispectral and three dimensional imaging capabilities. Initial testing is in progress and includes field testing in ports, potential test flights in un-manned aerial systems, and future planned missions to image harsh environments in the arctic including volcanic plumes, ice formation, and arctic marine life.

A multiprojection noncontact fluorescence tomography setup for imaging arbitrary geometries

NASA Astrophysics Data System (ADS)

Meyer, H.; Garofalakis, A.; Zacharakis, G.; Economou, E. N.; Mamalaki, C.; Kioussis, D.; Ntziachristos, V.; Ripoll, J.

2005-04-01

Optical imaging and tomography in tissues can facilitate the quantitative study of several important chromophores and fluorophores in-vivo. Due to this fact, there has been great interest in developing imaging systems offering quantitative information on the location and concentration of chromophores and fluorescent probes. However, most imaging systems currently used in research make use of fiber technology for delivery and detection, which restricts the size of the photon collecting arrays leading to insufficient spatial sampling and field of view. To enable large data sets and full 360o angular measurements, we developed a novel imaging system that enables 3D imaging of fluorescent signals in bodies of arbitrary shapes in a non-contact geometry in combination with a 3D surface reconstruction algorithm. The system consists of a rotating subject holder and a lens coupled Charge Coupled Device (CCD) camera in combination with a fiber coupled laser scanning device. An Argon ion laser is used as the source and different filters are used for the detection of various fluorophores or fluorescing proteins. With this new setup a large measurements dataset can be achieved while the use of inversion models give a high capacity for quantitative 3D reconstruction of fluorochrome distributions as well as high spatial resolution. The system is currently being tested in the observation of the distribution of Green Fluorescent Protein (GFP) expressing T-lymphocytes in order to study the function of the immune system in a murine model.

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

NASA Astrophysics Data System (ADS)

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

2000-12-01

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

Robotic apparatuses, systems and methods

NASA Technical Reports Server (NTRS)

Ross, William P. (Inventor); Hoburg, James F. (Inventor); Fromme, Christopher (Inventor); Bares, John (Inventor); DeLouis, Mark (Inventor)

2004-01-01

A mobile device for traversing a ferromagnetic surface. The device includes a frame and at least one surface contacting device attached to the frame. The device also includes a Halbach magnet array attached to the frame, wherein the Halbach magnet array provides a magnetic force to maintain the surface contacting device substantially into contact with the ferromagnetic surface.

Elliptically polarizing adjustable phase insertion device

DOEpatents

Carr, Roger

1995-01-01

An insertion device for extracting polarized electromagnetic energy from a beam of particles is disclosed. The insertion device includes four linear arrays of magnets which are aligned with the particle beam. The magnetic field strength to which the particles are subjected is adjusted by altering the relative alignment of the arrays in a direction parallel to that of the particle beam. Both the energy and polarization of the extracted energy may be varied by moving the relevant arrays parallel to the beam direction. The present invention requires a substantially simpler and more economical superstructure than insertion devices in which the magnetic field strength is altered by changing the gap between arrays of magnets.

Joint services electronics program

NASA Astrophysics Data System (ADS)

Flynn, George W.; Osgood, Richard M., Jr.

1988-05-01

Several milestones have been reached in GaAs research. The first active GaAs device, a 1 micrometer channel width MESFET, has been made at Columbia. This device is a basic building block in the GaAs CCD program. GaAs surface studies have also born fruit. UV light has been found to oxidize rapidly the surface of GaAs in an UHV environment containing traces of water vapor and O2. The mechanism appears to be related to the generation of hot photocarriers.

Absolute calibration of a charge-coupled device camera with twin beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meda, A.; Ruo-Berchera, I., E-mail: i.ruoberchera@inrim.it; Degiovanni, I. P.

2014-09-08

We report on the absolute calibration of a Charge-Coupled Device (CCD) camera by exploiting quantum correlation. This method exploits a certain number of spatial pairwise quantum correlated modes produced by spontaneous parametric-down-conversion. We develop a measurement model accounting for all the uncertainty contributions, and we reach the relative uncertainty of 0.3% in low photon flux regime. This represents a significant step forward for the characterization of (scientific) CCDs used in mesoscopic light regime.

Speech Envelope Normalization, a Method to Improve SNR and Suppress Noise in Present and Future Radio Systems.

DTIC Science & Technology

1982-12-01

GRA&IT--4 I DTIC TAB U:.r.nnoincee Distr±iatic !/ KAvnilr,1.llty Codes AvRUJ and/or Dist S pecial 1 AN 𔄃 . .. ACKNOWLEDGEMENTS The success of the...evaluated. Two different approaches emerged, one employing cascaded active all-pass networks, and the other using a charged coupled device sampled data delay...Wideband 900 Phase-Shifters 38 * 5.2 Samples Data Direct Hilbert Transforms 43 5.3 Charge Coupled Device (CCD) Implementation 45 5.4 Digital

Orbits and emission spectra from the 2014 Camelopardalids

NASA Astrophysics Data System (ADS)

Madiedo, José M.; Trigo-Rodríguez, Josep M.; Zamorano, Jaime; Izquierdo, Jaime; de Miguel, Alejandro Sánchez; Ocaña, Francisco; Ortiz, José L.; Espartero, Francisco; Morillas, Lorenzo G.; Cardeñosa, David; Moreno-Ibáñez, Manuel; Urzáiz, Marta

2014-12-01

We have analysed the meteor activity associated with meteoroids of fresh dust trails of Comet 209P/LINEAR, which produced an outburst of the Camelopardalid meteor shower (IAU code #451, CAM) in 2014 May. With this aim, we have employed an array of high-sensitivity CCD video devices and spectrographs deployed at 10 meteor observing stations in Spain in the framework of the Spanish Meteor Network. Additional meteoroid flux data were obtained by means of two forward-scatter radio systems. The observed peak zenithal hourly rate was much lower than expected, of around 20 meteors h-1. Despite of the small meteor flux in the optical range, we have obtained precise atmospheric trajectory, radiant and orbital information for 11 meteor and fireball events associated with this stream. The ablation behaviour and low tensile strength calculated for these particles reveal that Camelopardalid meteoroids are very fragile, mostly pristine aggregates with strength similar to that of the Orionids and the Leonids. The mineral grains seem to be glued together by a volatile phase. We also present and discuss two unique emission spectra produced by two Camelopardalid bright meteors. These suggest a non-chondritic nature for these particles, which exhibit Fe depletion in their composition.

NASA Tech Briefs, January 2004

NASA Technical Reports Server (NTRS)

2004-01-01

Topics covered include: Multisensor Instrument for Real-Time Biological Monitoring; Sensor for Monitoring Nanodevice-Fabrication Plasmas; Backed Bending Actuator; Compact Optoelectronic Compass; Micro Sun Sensor for Spacecraft; Passive IFF: Autonomous Nonintrusive Rapid Identification of Friendly Assets; Finned-Ladder Slow-Wave Circuit for a TWT; Directional Radio-Frequency Identification Tag Reader; Integrated Solar-Energy-Harvesting and -Storage Device; Event-Driven Random-Access-Windowing CCD Imaging System; Stroboscope Controller for Imaging Helicopter Rotors; Software for Checking State-charts; Program Predicts Broadband Noise from a Turbofan Engine; Protocol for a Delay-Tolerant Data-Communication Network; Software Implements a Space-Mission File-Transfer Protocol; Making Carbon-Nanotube Arrays Using Block Copolymers: Part 2; Modular Rake of Pitot Probes; Preloading To Accelerate Slow-Crack-Growth Testing; Miniature Blimps for Surveillance and Collection of Samples; Hybrid Automotive Engine Using Ethanol-Burning Miller Cycle; Fabricating Blazed Diffraction Gratings by X-Ray Lithography; Freeze-Tolerant Condensers; The StarLight Space Interferometer; Champagne Heat Pump; Controllable Sonar Lenses and Prisms Based on ERFs; Measuring Gravitation Using Polarization Spectroscopy; Serial-Turbo-Trellis-Coded Modulation with Rate-1 Inner Code; Enhanced Software for Scheduling Space-Shuttle Processing; Bayesian-Augmented Identification of Stars in a Narrow View; Spacecraft Orbits for Earth/Mars-Lander Radio Relay; and Self-Inflatable/Self-Rigidizable Reflectarray Antenna.

Multilayered Microelectronic Device Package With An Integral Window

DOEpatents

Peterson, Kenneth A.; Watson, Robert D.

2004-10-26

A microelectronic package with an integral window mounted in a recessed lip for housing a microelectronic device. The device can be a semiconductor chip, a CCD chip, a CMOS chip, a VCSEL chip, a laser diode, a MEMS device, or a IMEMS device. The package can be formed of a low temperature co-fired ceramic (LTCC) or high temperature cofired ceramic (HTCC) multilayered material, with the integral window being simultaneously joined (e.g. co-fired) to the package body during LTCC or HTCC processing. The microelectronic device can be flip-chip bonded and oriented so that a light-sensitive side is optically accessible through the window. The result is a compact, low profile package, having an integral window mounted in a recessed lip, that can be hermetically sealed.

Fisher information matrix for branching processes with application to electron-multiplying charge-coupled devices

PubMed Central

Chao, Jerry; Ward, E. Sally; Ober, Raimund J.

2012-01-01

The high quantum efficiency of the charge-coupled device (CCD) has rendered it the imaging technology of choice in diverse applications. However, under extremely low light conditions where few photons are detected from the imaged object, the CCD becomes unsuitable as its readout noise can easily overwhelm the weak signal. An intended solution to this problem is the electron-multiplying charge-coupled device (EMCCD), which stochastically amplifies the acquired signal to drown out the readout noise. Here, we develop the theory for calculating the Fisher information content of the amplified signal, which is modeled as the output of a branching process. Specifically, Fisher information expressions are obtained for a general and a geometric model of amplification, as well as for two approximations of the amplified signal. All expressions pertain to the important scenario of a Poisson-distributed initial signal, which is characteristic of physical processes such as photon detection. To facilitate the investigation of different data models, a “noise coefficient” is introduced which allows the analysis and comparison of Fisher information via a scalar quantity. We apply our results to the problem of estimating the location of a point source from its image, as observed through an optical microscope and detected by an EMCCD. PMID:23049166

Bi-level microelectronic device package with an integral window

DOEpatents

Peterson, Kenneth A.; Watson, Robert D.

2004-01-06

A package with an integral window for housing a microelectronic device. The integral window is bonded directly to the package without having a separate layer of adhesive material disposed in-between the window and the package. The device can be a semiconductor chip, CCD chip, CMOS chip, VCSEL chip, laser diode, MEMS device, or IMEMS device. The multilayered package can be formed of a LTCC or HTCC cofired ceramic material, with the integral window being simultaneously joined to the package during LTCC or HTCC processing. The microelectronic device can be flip-chip bonded so that the light-sensitive side is optically accessible through the window. The package has at least two levels of circuits for making electrical interconnections to a pair of microelectronic devices. The result is a compact, low-profile package having an integral window that is hermetically sealed to the package prior to mounting and interconnecting the microelectronic device(s).

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

NASA Astrophysics Data System (ADS)

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 double sampler; a digitally controlled variable gain amplifier and a 16-bit A/D converter which can help improve the data quality. And the acquired digital signals are transmitted into the computer via USB 2.0 data port. Our spectrometer with SHINERS technology can acquire the Raman spectrum signals efficiently in long time integration and weak signal environment, and the size of our system is well controlled for portable application.

The optical design of GMOX: a next-generation instrument concept for Gemini

NASA Astrophysics Data System (ADS)

Barkhouser, Robert; Robberto, Massimo; Smee, Stephen A.; Ninkov, Zoran; Gennaro, Mario; Heckman, Timothy

2016-08-01

We present the optical design of GMOX, the Gemini Multi-Object eXtra-wide-band spectrograph. GMOX was selected as part of the Gemini Instrument Feasibility Study to develop capabilities and requirements for the next facility instrument (Gen4#3) for the observatory. We envision GMOX covering the entire optical/near-IR wavelength range accessible from the ground, from 3500 Å in the U band up to 2.4 μm in the K band, with nominal resolving power R≃5,000. To maximize efficiency, the bandpass is split into three spectrograph arms - blue, red, and near-infrared - with the near-infrared arm further split into three channels covering the Y+J, H, and K bands. At the heart of each arm is a Digital Micromirror Device (DMD) serving as a programmable slit array. This technology will enable GMOX to simultaneously acquire hundreds of spectra of faint sources in crowded fields with unparalleled spatial resolution, optimally adapting to both seeing-limited and diffraction limited conditions provided by ALTAIR and GeMS at Gemini North and South, respectively. Fed by GeMS at f/33, GMOX can synthesize slits as small as 40 mas (corresponding to a single HST/WFC3 CCD pixel) over its entire 85"x45" field of view. With either ALTAIR or the native telescope focal ratio of f/16, both the slit and field sizes double. In this paper we discuss the conceptual optical design of GMOX including, for each arm: the pre-slit optics, DMD slit array, off-axis Schmidt collimator, VPH grating, and refractive spectrograph and slit-viewing cameras.

All-optical framing photography based on hyperspectral imaging method

NASA Astrophysics Data System (ADS)

Liu, Shouxian; Li, Yu; Li, Zeren; Chen, Guanghua; Peng, Qixian; Lei, Jiangbo; Liu, Jun; Yuan, Shuyun

2017-02-01

We propose and experimentally demonstrate a new all optical-framing photography that uses hyperspectral imaging methods to record a chirped pulse's temporal-spatial information. This proposed method consists of three parts: (1) a chirped laser pulse encodes temporal phenomena onto wavelengths; (2) a lenslet array generates a series of integral pupil images;(3) a dispersive device disperses the integral images at void space of image sensor. Compared with Ultrafast All-Optical Framing Technology(Daniel Frayer,2013,2014) and Sequentially Time All-Optical Mapping Photography( Nakagawa 2014, 2015), our method is convenient to adjust the temporal resolution and to flexibly increase the numbers of frames. Theoretically, the temporal resolution of our scheme is limited by the amount of dispersion that is added to a Fourier transform limited femtosecond laser pulse. Correspondingly, the optimal number of frames is decided by the ratio of the observational time window to the temporal resolution, and the effective pixels of each frame are mostly limited by the dimensions M×N of the lenslet array. For example, if a 40fs Fourier transform limited femtosecond pulse is stretched to 10ps, a CCD camera with 2048×3072 pixels can record 15 framing images with temporal resolution of 650fs and image size of 100×100 pixels. As spectrometer structure, our recording part has another advantage that not only amplitude images but also frequency domain interferograms can be imaged. Therefore, it is comparatively easy to capture fast dynamics in the refractive index change of materials. A further dynamic experiment is being conducted.

[Research of dual-photoelastic-modulator-based beat frequency modulation and Fourier-Bessel transform imaging spectrometer].

PubMed

Wang, Zhi-Bin; Zhang, Rui; Wang, Yao-Li; Huang, Yan-Fei; Chen, You-Hua; Wang, Li-Fu; Yang, Qiang

2014-02-01

As the existing photoelastic-modulator(PEM) modulating frequency in the tens of kHz to hundreds of kHz between, leading to frequency of modulated interference signal is higher, so ordinary array detector cannot effectively caprure interference signal..A new beat frequency modulation method based on dual-photoelastic-modulator (Dual-PEM) and Fourier-Bessel transform is proposed as an key component of dual-photoelastic-modulator-based imaging spectrometer (Dual-PEM-IS) combined with charge coupled device (CCD). The dual-PEM are operated as an electro-optic circular retardance modulator, Operating the PEMs at slightly different resonant frequencies w1 and w2 respectively, generates a differential signal at a much lower heterodyne frequency that modulates the incident light. This method not only retains the advantages of the existing PEM, but also the frequency of modulated photocurrent decreased by 2-3 orders of magnitude (10-500 Hz) and can be detected by common array detector, and the incident light spectra can be obtained by Fourier-Bessel transform of low frequency component in the modulated signal. The method makes the PEM has the dual capability of imaging and spectral measurement. The basic principle is introduced, the basic equations is derived, and the feasibility is verified through the corresponding numerical simulation and experiment. This method has' potential applications in imaging spectrometer technology, and analysis of the effect of deviation of the optical path difference. This work provides the necessary theoretical basis for remote sensing of new Dual-PEM-IS and for engineering implementation of spectra inversion.