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1

The narrow angle camera of the MPCS suite for the MarcoPolo ESA Mission: requirements and optical design solutions  

Microsoft Academic Search

Possible optical designs of a Narrow Angle Camera (NAC) suitable for being the high resolution channel of the MarcoPolo Camera System for the MarcoPolo ESA mission are presented. The MarcoPolo mission objective is the rendezvous with a Near Earth Asteroid in order to fully characterize the body, to land on the surface and to return to Earth a sample of

Vania da Deppo; Gabriele Cremonese; Giampiero Naletto

2010-01-01

2

Narrow band and wide angle hemispherical interference optical filter  

NASA Astrophysics Data System (ADS)

An optical interference filter has narrow linewidth and wide acceptance angle and includes a hemisphere coated to provide a narrow bandpass filter at a desired wavelength at normal incidence while other wavelengths at normal incidence are absorbed or reflected. A photodetector placed at the center of the hemisphere detects the desired wavelength only. Other wavelengths that are shorter than the wavelength of the filter are transmitted through the filter to be absorbed by a black absorbing surface around the photodetector. Thus, only the frequency of interest at normal incidence provides a representative signal at the detector.

Rieger, Harry

1989-07-01

3

Fast angle catching methods for a narrow beam system  

NASA Astrophysics Data System (ADS)

Compare with width antenna beam system, a narrow beam system need a faster angle catching method. In this paper, three kinds of methods are introduced: the first one is the delay autocorrelation method; the second one is cross correlation method; the last one is cycle spectrum correlation method. All these three methods need no data demodulation, so they can output angle value quickly. They have different advantages and disadvantages, and are used in different condition. Delay autocorrelation method is fit for mono-channel and mono-pulse angle tracking system. The received signal pass a delayer, then correlate with itself. A notable advantage of the method is that it has a very simple structure. But its performance is not very good when SNR is very low. Cross correlation method is only fit for double-channel and mono-pulse angle tracking system .But it can improve the output accuracy, reduce the influence of noise. Spectrum correlation method has perfect performance. But it needs much more resource. This paper introduces theories and performance of these three methods, especially in high dynamic and low SNR condition .Then it points out how to select a method in different condition according to their characters.

Zeng, Haibin; Huang, Ying; Li, Tao; You, Shasha

2012-12-01

4

Measurement of the chief ray angle of mobile phone camera  

NASA Astrophysics Data System (ADS)

The chief ray angle (CRA) of a mobile phone lens is related to the acceptance angle of the IR cutoff filter and micro lens array. The CRA of a lens need to be within an allowed value, otherwise image blurring or vignetting occurs. However, because of the compact size of mobile phone camera lenses, it is not easy to measure the CRA accurately. In this paper, we suggest a new method to measure the CRA of high-quality mobile phone camera lenses accurately using a laser beam as a light source and a plane mirror to collimate the beam in a double pass configuration. When the plane mirror is tilted to the same angle as the lens CRA, the spot center does not change, irrespective of the longitudinal position of the plane mirror. We manufactured the reference optics, which consisted of four spherical lenses, to verify our method. We found that our new CRA measurement method has 0.65° of measurement uncertainty for 15° CRA, which satisfies phone camera makers' requirements.

Yang, Ho-Soon; Jo, Yong-Geol; Kim, Gyu-Ug; Lee, Yun-Woo

2011-09-01

5

Planet Detection with SIM in Narrow Angle Mode  

NASA Astrophysics Data System (ADS)

The Space Interferometry Mission (SIM) will measure astrometric reflex motions of stars to unprecedented precision. This will make possible detection and characterization of the orbits of subJupiter-mass planetary companions around nearby solar-type stars. We report results of simulation of planet detection by the SIM instrument. We consider ensembles of stars observed in narrow-angle mode. Each star may have one or more companions. For various signal strengths, we determine (from analysis of a time series of simulated differential delay measurements over a five year observing campaign) the confidence level at which we can state that a companion exists. We determine threshold signal strength at which it is possible to identify the orbital periods present in the system and assign each companion unambiguously to its proper parent star. We determine threshold signal strengths at which it is possible to determine orbit parameters such as inclination, semi-major axis and period of each companion. These results are preliminary in nature and not to be taken as final description of the capability of the SIM instrument.

Catanzarite, J. H.; Unwin, S. C.; Shao, M.; Loiseau, S.; Pourbaix, D.; SIM Science Planning Team

1999-12-01

6

New comparative ultrasound biomicroscopic findings between fellow eyes of acute angle closure and glaucomatous eyes with narrow angle  

Microsoft Academic Search

Purpose: To compare morphometric features between fellow acute primary angle-closure (APAC) eyes and glaucomatous or suspect eyes with narrow angle (NA). Methods: Fellow eyes of 30 patients with unilateral APAC and 30 with NA were evaluated by ultrasound biomicroscopy (UBM) under light and dark conditions. UBM parameters such as anterior chamber depth (ACD), angle opening distance at 250 µm\\/500 µm

Rafael Vidal Mérula; Sebastião Cronemberger; Alberto Diniz Filho; Nassim Calixto

2008-01-01

7

Characterizing Geometric Distortion of the Lunar Reconnaissance Orbiter Wide Angle Camera  

NASA Astrophysics Data System (ADS)

Each month the Lunar Reconnaissance Orbiter (LRO) Wide Angle Camera (WAC) provides 100 m scale images of nearly the entire Moon, each month with different range of lighting conditions [1]. Pre-flight calibration efforts provided a baseline for correcting the geometric distortion present in the WAC. However, residual errors of 1-2 pixels existed with this original model. In-flight calibration enables the derivation of a precise correction for geometric distortion to provide sub-pixel map projection accuracy. For the in-flight calibration, we compared WAC images to high-resolution (0.5 - 2.0 meter scale) images provided by the Narrow Angle Camera (NAC). Since the NAC has very narrow field of view (2.86°) its geometric accuracy is well characterized. The additions of the WAC-derived 100 m/pixel digital terrain model (GLD100) [2] and refined ephemeris provided by LOLA [3] have improved our efforts to remove small distortion artifacts in the WAC camera model. Since the NAC field of view is always in the same cross-track location in the WAC frame, NAC and WAC images of the same regions, under similar lighting conditions, were map projected. Hundreds of NAC (truth image) and WAC images were then co-registered using an automatic registration algorithm in ISIS [4]. This output was fed into a second ISIS program (fplanemap) that converted the registration offsets to focal plane coordinates for the distorted (original) and undistorted (corrected location derived from the truth image) pixel [4]. With this dataset, offsets in the WAC distortion model were identified and accounted for with a new 2D Taylor series function that has been added to the existing radial model. This technique improves the accurate placement of each pixel across the sensor in target space. We have applied this correction to the 643 nm band and will derive the coefficients for the remaining bands. Once this study is complete, a new camera model, instrument kernel (IK), and frames kernel (FK) will be released though NAIF [5] and USGS.

Speyerer, E.; Wagner, R.; Robinson, M. S.; Becker, K. J.; Anderson, J.; Thomas, P. C.

2011-12-01

8

13. 22'X34' original vellum, VariableAngle Launcher, 'SIDEVIEW CAMERA CAR TRACK ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. 22'X34' original vellum, Variable-Angle Launcher, 'SIDEVIEW CAMERA CAR TRACK DETAILS' drawn at 1/4'=1'-0' (BUORD Sketch # 208078, PAPW 908). - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

9

10. 22'X34' original blueprint, VariableAngle Launcher, 'SIDE VIEW CAMERA CARSTEEL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. 22'X34' original blueprint, Variable-Angle Launcher, 'SIDE VIEW CAMERA CAR-STEEL FRAME AND AXLES' drawn at 1/2'=1'-0'. (BOURD Sketch # 209124). - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

10

93. 22'X34' original blueprint, VariableAngle Launcher, 'OVERHEAD CAMERA SUSPENSION SYSTEM, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

93. 22'X34' original blueprint, Variable-Angle Launcher, 'OVERHEAD CAMERA SUSPENSION SYSTEM, TOWER STAY CABLES' drawn at 3/4'=1'-0'. (BUORD Sketch # 208783). - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

11

92. 22'X34' original blueprint, VariableAngle Launcher, 'CAMERA CABLE TOWER PLAN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

92. 22'X34' original blueprint, Variable-Angle Launcher, 'CAMERA CABLE TOWER PLAN AND ELEVATION' drawn at 3/8'=1'0' (BUORD Sketch # 208580). - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

12

Characterizing the Geometric Distortion of the Lunar Reconnaissance Orbiter Wide Angle Camera  

NASA Astrophysics Data System (ADS)

The Wide Angle Camera (WAC) is currently acquiring synoptic views of nearly the entire Moon each month. In-flight calibration measurements and improved distortion models are improving the accuracy of map projected images.

Speyerer, E. J.; Wagner, R.; Robinson, M. S.; Becker, K.; Anderson, J.; Thomas, P.; Brylow, S.

2012-03-01

13

A single camera photogrammetry system for multi-angle fast localization of EEG electrodes.  

PubMed

Photogrammetry has become an effective method for the determination of electroencephalography (EEG) electrode positions in three dimensions (3D). Capturing multi-angle images of the electrodes on the head is a fundamental objective in the design of photogrammetry system for EEG localization. Methods in previous studies are all based on the use of either a rotating camera or multiple cameras, which are time-consuming or not cost-effective. This study aims to present a novel photogrammetry system that can realize simultaneous acquisition of multi-angle head images in a single camera position. Aligning two planar mirrors with the angle of 51.4°, seven views of the head with 25 electrodes are captured simultaneously by the digital camera placed in front of them. A complete set of algorithms for electrode recognition, matching, and 3D reconstruction is developed. It is found that the elapsed time of the whole localization procedure is about 3 min, and camera calibration computation takes about 1 min, after the measurement of calibration points. The positioning accuracy with the maximum error of 1.19 mm is acceptable. Experimental results demonstrate that the proposed system provides a fast and cost-effective method for the EEG positioning. PMID:21818532

Qian, Shuo; Sheng, Yang

2011-08-05

14

Cross-diffractive optical elements for wide angle geometric camera calibration.  

PubMed

Diffractive optical elements (DOEs) can generate multiple two-dimensional (2D) diffraction grids that can be used to calibrate cameras for photogrammetry. However, several factors limit the accuracy and the functionality of this technique. One of the most important is the DOE fabrication itself. A large DOE with wide 2D fan-out grids is very difficult and costly to develop. Consequently, the calibration is limited to small aperture cameras and/or limited angles. To overcome these problems, we present a low cost solution. We propose to use two large, commercially available, crossed phase DOEs that generate 15×15 equally spaced dots. As the DOEs are not perfect, the unwanted secondary diffractive orders are used as calibration targets to expand the calibration field of view. We show that the use of the primary and secondary diffractive orders provides a valuable calibration tool for wide angle aerial cameras. PMID:22179878

Thibault, Simon; Arfaoui, Aymen; Desaulniers, Pierre

2011-12-15

15

Camera Calibration for Miniature, Low-cost, Wide-angle Imaging Systems  

Microsoft Academic Search

This paper presents a new model and an extension to an existing algorithm for camera calibration. The main goal of the proposed approach is to cal- ibrate miniature, low-cost, wide-angle fisheye lenses. The model has been verified with a calibration implementation and was tested on real data. Ex- periments show that the proposed model improves the accuracy compared to the

Oliver Frank; Roman Katz; Christel-Loic Tisse; Hugh F. Durrant-Whyte

2007-01-01

16

OPTICAL FLOW NAVIGATION FOR AN OUTDOOR UAV USING A WIDE ANGLE MONO CAMERA AND DEM MATCHING  

Microsoft Academic Search

Visual navigation for low altitude unmanned aerial vehicles (UAV) shows many scientific and technical challenges in terms of navigation performances, complex 3D environment, high computational requirements for real-time image processing and very limited onboard mass and power resources. The current paper presents a concept of a visual navigation system, based on a wide angle mono camera as vision sensor and

V. Tchernykh; M. Beck; K. Janschek

17

The Effect of Mediated Camera Angle on Receiver Evaluations of Source Credibility, Dominance, Attraction and Homophily.  

ERIC Educational Resources Information Center

|Two hundred forty college undergraduates participated in a study of the effect of camera angle on an audience's perceptual judgments of source credibility, dominance, attraction, and homophily. The subjects were divided into four groups and each group was shown a videotape presentation in which sources had been videotaped according to one of four…

Beverly, Robert E.; Young, Thomas J.

18

A two camera video imaging system with application to parafoil angle of attack measurements  

NASA Astrophysics Data System (ADS)

This paper describes the development of a two-camera, video imaging system for the determination of three-dimensional spatial coordinates from stereo images. This system successfully measured angle of attack at several span-wise locations for large-scale parafoils tested in the NASA Ames 80- by 120-Foot Wind Tunnel. Measurement uncertainty for angle of attack was less than 0.6 deg. The stereo ranging system was the primary source for angle of attack measurements since inclinometers sewn into the fabric ribs of the parafoils had unknown angle offsets acquired during installation. This paper includes discussions of the basic theory and operation of the stereo ranging system, system measurement uncertainty, experimental set-up, calibration results, and test results. Planned improvements and enhancements to the system are also discussed.

Meyn, Larry A.; Bennett, Mark S.

1991-01-01

19

Asymmetric dual paraboloid reflector: improving system throughput by narrowing cone angles  

NASA Astrophysics Data System (ADS)

Wavien patented dual paraboloid reflector (DPR) system, while optimal in maximizing image brightness (equivalent to minimizing the image aberration) at the input of its light pipe, does not produce maximal lumen throughput at its output. The overall lumen throughput depends in large part on three factors: Fresnel losses and image aberration, both defined at the input face of the light pipe, and the light pipe's input dimensions. Fresnel losses can be reduced by narrowing the cone angles of the light cone incident on the light pipe, which in turn can be achieved by increasing the size and/or focal length of the second paraboloid reflector. Smaller cone angles also mean reduced tapering of the light pipe which translates into larger input sizes (as its output dimensions are fixed) and higher coupling efficiency. Unfortunately this gain in coupling efficiency comes at the expense of breaking the system symmetry, which destroys 1:1 imaging and leads to increased aberration and reduced brightness. Using a ray-tracing software an optimal point of operation can be reached and it is found that at least 10% increase in lumen throughput over the symmetric DPR system is achievable.

Ouyang, George; Li, Kenneth

2006-09-01

20

Large-angle pinhole gamma camera with depth-of-interaction detector for contamination monitoring  

NASA Astrophysics Data System (ADS)

The gamma camera system was designed for monitoring the medical fields such as a radiopharmaceutical preparation lab or a patient waiting room (after source injection) in the division of nuclear medicine. However, gamma cameras equipped with a large-angle pinhole collimator and a thick monolithic crystal suffer from the degradation of the spatial resolution at the periphery region due to parallax error by obliquely incident photons. To improve the uniformity of the spatial resolution across the field of view (FOV), we proposed a three-layer crystal detector with a maximum-likelihood position-estimation (MLPE) method, which can measure depth-of-interaction (DOI) information. The aim of this study was to develop and evaluate the performance of new detector experimentally. The proposed detector employed three layers of monolithic CsI(Tl) crystals, each of which is 50.0×50.0×2.0 mm3, and a large-angle pinhole collimator with an acceptance angle of 120°. The bottom surface of the third layer was directly coupled to an 8×8 channel position-sensitive photomultiplier tube (PSPMT, Hamamatsu H8500C). The PSPMT was read out using a resistive charge divider, which multiplexes 64 anodes into 8(X)+8(Y) channels. Gaussian-based MLPE method has been implemented using experimentally measured detector response functions (DRFs). Tc-99 m point source was imaged at different positions with and without DOI measurements. Experimental results showed that the spatial resolution was degraded gradually as the source moved from the center to the periphery of the FOV without DOI information but the DOI detector showed the marked improvement in the spatial resolution, especially at off-center by correcting the parallax error. In this paper, our new detector with DOI capability proved to characterize reliably the gamma event position with the high and uniform spatial resolution, so that the large-angle pinhole gamma camera could be a useful tool in contamination monitoring.

Baek, Cheol-Ha; Kim, Hyun-Il; Hwang, Ji Yeon; Jung An, Su; Kim, Kwang Hyun; Kwak, Sung-Woo; Chung, Yong Hyun

2011-08-01

21

Lunar Reconnaissance Orbiter Camera (LROC) Instrument Overview  

Microsoft Academic Search

The Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) and Narrow Angle Cameras (NACs) are on the NASA Lunar\\u000a Reconnaissance Orbiter (LRO). The WAC is a 7-color push-frame camera (100 and 400 m\\/pixel visible and UV, respectively), while\\u000a the two NACs are monochrome narrow-angle linescan imagers (0.5 m\\/pixel). The primary mission of LRO is to obtain measurements\\u000a of the Moon that

M. S. Robinson; S. M. Brylow; M. Tschimmel; D. Humm; S. J. Lawrence; P. C. Thomas; B. W. Denevi; E. Bowman-Cisneros; J. Zerr; M. A. Ravine; M. A. Caplinger; F. T. Ghaemi; J. A. Schaffner; M. C. Malin; P. Mahanti; A. Bartels; J. Anderson; T. N. Tran; E. M. Eliason; A. S. McEwen; E. Turtle; B. L. Jolliff; H. Hiesinger

2010-01-01

22

USGS HIGH-RESOLUTION TOPOMAPPING OF MARS WITH MARS ORBITER CAMERA NARROW-ANGLE IMAGES  

Microsoft Academic Search

We describe our initial experiences producing controlled digital elevation models (DEMs) of Mars with horizontal resolutions of ?10 m and vertical precisions of ?2 m. Such models are of intense interest at all phases of Mars exploration and scientific investigation, from the selection of safe landing sites to the quantitative analysis of the morphologic record of surface processes. Topomapping with

Randolph L. Kirk; Laurence A. Soderblom; Elpitha Howington-Kraus; Brent Archinal

2002-01-01

23

Possible association of glaucoma with pectinate ligament dysplasia and narrowing of the iridocorneal angle in Shiba Inu dogs in Japan.  

PubMed

The purpose of the study was to describe the shape of the pectinate ligament (PL) and to estimate the width of the iridocorneal angle (ICA) in glaucomatous and non-glaucomatous eye of Shiba Inu dogs in Japan. One hundred fourteen Shiba Inu dogs were presented to the Veterinary Medical Center at the University of Tokyo between June 1998 and June 2003. Among these, 46 dogs had glaucoma; the remaining 68 dogs were presented for routine vaccinations or heartworm testing and were used as a control population. Complete ophthalmic examination and gonioscopy were performed in all the dogs. PL and ICA were evaluated by gonioscopy and goniophotographs. Of the 46 dogs with glaucoma, 17 (37%) were affected bilaterally, and 29 (63%) were affected unilaterally. Of the 29 dogs with unilateral glaucoma, the ICA of the normotensive eye was slightly narrow in 2 eyes (7%), narrow in 12 eyes (41%), and closed in 15 eyes (52%). Among the normotensive control group, the ICA was open in 13 dogs (19%), slightly narrow in 29 (43%), narrow in 22 (32%), and closed in 4 (6%). In dogs with narrow and slightly narrow ICAs, the PLs were thickened, and in some cases, formed a solid sheet. The majority of dogs with glaucoma had changes in both ICA and PL. A narrow or slightly narrow ICA was also detected in the majority of normotensive control dogs. This study suggests that ICA narrowing and PL thickening is a common abnormality in Shiba Inu dogs in Japan and may predispose those dogs to glaucoma. PMID:16497230

Kato, Kumiko; Sasaki, Nobuo; Matsunaga, Satoru; Mochizuki, Manabu; Nishimura, Ryohei; Ogawa, Hiroyuki

24

An analytical image reconstruction algorithm to compensate for scattering angle broadening in Compton cameras.  

PubMed

Compton cameras have been developed for use in gamma-ray astronomy and nuclear medicine. Their defining merit is that they do not need collimators; however, on the demerit side, they need inversion procedures for image reconstruction, since a measured datum is proportional to the integration of incident gamma rays along a cone surface with the same Compton scattering angle. First, an iteration method was adopted for this task. Later, analytical methods were found under restricted conditions. Parra (2000 IEEE Trans. Nucl. Sci. 47 1543-50) deduced a purely analytical reconstruction algorithm for a complete set of scattering-projection data that include data at all the scattering angles. Tomitani and Hirasawa (2002 Phys. Med. Biol. 47 2129-45) found that by making a slight modification, Parra's algorithm could be extended to the scattering-projection data in limited scattering angles. However, their algorithm neglected the effects of practical problems that cause the degradation of spatial resolution. Sources of degradation were identified as noise in the energy signal of their front detector and the Doppler effect in the scattering process. In this paper, we first analyse the effects of these sources on the angular resolution of the scattering-projection data and then present a revised reconstruction algorithm in which these two factors are incorporated. Simulation studies on digital phantoms reveal that the algorithm can reconstruct images even when these two factors are included. PMID:12741498

Hirasawa, M; Tomitani, T

2003-04-21

25

Low sooting combustion of narrow-angle wall-guided sprays in an HSDI diesel engine with retarded injection timings  

Microsoft Academic Search

An optically accessible single-cylinder high speed direct-injection (HSDI) diesel engine was used to investigate the spray and combustion processes with narrow-angle wall-guided sprays. Influences of injection timings and injection pressure on combustion characteristics and emissions were studied. In-cylinder pressure was measured and used for heat release analysis. High-speed spray and combustion videos were captured. NOx emissions were measured in the

Tiegang Fang; Chia-fon F. Lee

2011-01-01

26

Development of a large-angle pinhole gamma camera with depth-of-interaction capability for small animal imaging  

NASA Astrophysics Data System (ADS)

A large-angle gamma camera was developed for imaging small animal models used in medical and biological research. The simulation study shows that a large field of view (FOV) system provides higher sensitivity with respect to a typical pinhole gamma cameras by reducing the distance between the pinhole and the object. However, this gamma camera suffers from the degradation of the spatial resolution at the periphery region due to parallax error by obliquely incident photons. We propose a new method to measure the depth of interaction (DOI) using three layers of monolithic scintillators to reduce the parallax error. The detector module consists of three layers of monolithic CsI(Tl) crystals with dimensions of 50.0 × 50.0 × 2.0 mm3, a Hamamatsu H8500 PSPMT and a large-angle pinhole collimator with an acceptance angle of 120°. The 3-dimensional event positions were determined by the maximum-likelihood position-estimation (MLPE) algorithm and the pre-generated look up table (LUT). The spatial resolution (FWHM) of a Co-57 point-like source was measured at different source position with the conventional method (Anger logic) and with DOI information. We proved that high sensitivity can be achieved without degradation of spatial resolution using a large-angle pinhole gamma camera: this system can be used as a small animal imaging tool.

Baek, C.-H.; An, S. J.; Kim, H.-I.; Choi, Y.; Chung, Y. H.

2012-01-01

27

Ultra-small-angle X-ray scattering to bridge the gap between visible light scattering and standard small-angle scattering cameras  

Microsoft Academic Search

This paper reports the performance of an ultra-small-angle X-ray scattering facility on beamline X23A3 at the National Synchrotron Light Source. Based on a Bonse-Hart double-crystal design, the instrument combines: continuously tunable optics with asymmetric first monochromator crystal, high-flux throughput, high-precision crystal rotators, independently-mounted reflecting crystals, photodiode detector and high-resolution X-ray video camera. This combination of features permits rapid small-angle X-ray

A. J. Allen; P. R. Jemian; D. R. Black; H. E. Burdette; R. D. Spal; S. Krueger; G. G. Long

1994-01-01

28

Automatic screening of narrow anterior chamber angle and angle-closure glaucoma based on slit-lamp image analysis by using support vector machine.  

PubMed

At present, Van Herick's method is a standard technique used to screen a Narrow Anterior Chamber Angle (NACA) and Angle-Closure Glaucoma (ACG). It can identify a patient who suffers from NACA and ACG by considering the width of peripheral anterior chamber depth (PACD) and corneal thickness. However, the screening result of this method often varies among ophthalmologists. So, an automatic screening of NACA and ACG based on slit-lamp image analysis by using Support Vector Machine (SVM) is proposed. SVM can automatically generate the classification model, which is used to classify the result as an angle-closure likely or an angle-closure unlikely. It shows that it can improve the accuracy of the screening result. To develop the classification model, the width of PACD and corneal thickness from many positions are measured and selected to be features. A statistic analysis is also used in the PACD and corneal thickness estimation in order to reduce the error from reflection on the cornea. In this study, it is found that the generated models are evaluated by using 5-fold cross validation and give a better result than the result classified by Van Herick's method. PMID:24111078

Theeraworn, C; Kongprawechnon, W; Kondo, T; Bunnun, P; Nishihara, A; Manassakorn, A

2013-07-01

29

A pipelined architecture for real-time correction of barrel distortion in wide-angle camera images  

Microsoft Academic Search

An efficient pipelined architecture for the real-time correction of barrel distortion in wide-angle camera images is presented in this paper. The distortion correction model is based on least-squares estimation to correct the nonlinear distortion in images. The model parameters include the expanded\\/corrected image size, the back-mapping coefficients, distortion center, and corrected center. The coordinate rotation digital computer (CORDIC) based hardware

Hau T. Ngo; Vijayan K. Asari

2005-01-01

30

Narrow angle light scatter in rabbit corneas after excimer laser surface ablation.  

PubMed

Corneal haze following excimer laser ablation is an adverse after-effect of photorefractive keratectomy (PRK) and is associated with the development of subepithelial opacities. The present work pertains to the measurement of light scattering in rabbit corneas following excimer laser treatment; to the microscopic analysis of the light-scattering corneal structures; and to the development of a mathematical model of light propagation through the post-laser treatment cornea. Photorefractive keratectomy (PRK-6D, 6 mm optical zone) followed by standard postoperative pharmaceutical treatment was performed on rabbit eyes. Animals were examined clinically on a weekly basis and sacrificed after the tenth postoperative week. Confocal microscope image sequences were acquired immediately before animal sacrifice. After the scatter measurement, the corneas were prepared for histopathological evaluation. The subepithelial structures observed using the confocal microscope correspond to refractive index (and therefore optical path difference (OPD) variation. This OPD distribution can be approximated with a fractal surface, band-pass filtered in the Fourier domain. The angular distribution of scattered light is characterised by a narrow forward peak of the order of 0.5 degrees full-width at half maximum (FWHM) in accordance with the sizes of the subepithelial structures (5-150 microm).The intensity of scattered light is correlated with the thickness of the subepithelial scar-tissue layer. PMID:19422569

Ginis, Harilaos; Pentari, Iro; de Brouwere, Dirk; Bouzoukis, Dimitris; Naoumidi, Irini; Pallikaris, Ioannis

2009-05-01

31

Angles  

NSDL National Science Digital Library

This set of eight interactive activities lets the user explore angles from many different perspectives. Activities include (1) visualizing the size of an angle; (2) examining objects that will stand or fall with right and non-right angles; (3) identifying obtuse, right, acute and straight angles; (4) guessing angle measures with different levels of precision; (5) exploring regular shapes and their angle measures; (6) studying angles in a fractal tree that is drawn with user inputs of the same angle measure between the branches at each stage; (7) exploring angle measures through firing a cannon (8) drawing with a Logo activity.

Edkins, Jo

2007-01-01

32

Monolithic SiC telescope of the OSIRIS Narrow-Angle Camera for the cometary mission ROSETTA  

Microsoft Academic Search

The international Rosetta mission, now planned by ESA to be launched in January 2003, will provide a unique opportunity to directly study the nucleus of comet 46P\\/Wirtanen and its activity from a heliocentric distance of 3.2 AU to the perihelion passage at 1.06 AU in July 2013. We describe here the design, the development and the performances of the telescope

Didier Castel; Bertrand Calvel; Philippe L. Lamy; Kjetil Dohlen; Michel Bougoin

1999-01-01

33

O2 atmospheric band measurements with WINDII: performance of a narrow-band filter/wide-angle Michelson combination in space  

NASA Astrophysics Data System (ADS)

Among the emissions viewed by the wind imaging interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS) are selected lines in the (0 - 0) transition of the O(subscript 2) atmospheric band. These lines are viewed simultaneously using a narrow band filter/wide- angle Michelson interferometer combination. The narrow band filter is used to separate the lines on the CCD (spectral-spatial scanning) and the Michelson used to modulate the emissions so that winds and rotational temperatures may be measured from the Doppler shifts and relative intensities of the lines. In this report this technique is outlined and the on-orbit behavior since launch summarized.

Ward, William E.; Gault, William A.; Shepherd, Gordon G.; Hersom, Charles H.; Tai, C. C.; Solheim, Brian H.

1994-09-01

34

CCD CAMERA CALIBRATION BASED ON THE SUN'S IMAGES  

Microsoft Academic Search

A Nikon D70s Digital camera with resolution of 6M, equipped with a narrow angle Nikkor 85 mm f\\/1.8D lens and suitable filters; was calibrated successfully, by two sets of the sun's images. Each set was taken while the camera's orientation was held unchanged for more than a hour. During this time the sun's image cross the camera's field of view

U. Ethrog

2006-01-01

35

Angles.  

National Technical Information Service (NTIS)

Shows the Brownstone Kids teaching others how to dance. Illustrates angles as they turn and sing 'Get the Angles.' The group goes to a community center for playing pool in 'Calling Shoots.' Discusses angles showing the 90-degree, 45-degree, and 180-degree...

1994-01-01

36

Angles  

NSDL National Science Digital Library

This Java applet enables students to investigate acute, obtuse, and right angles. The student decides to work with one or two transversals and a pair of parallel lines. Angle measure is given for one angle. The student answers a short series of questions about the size of other angles, identifying relationships such as vertical and adjacent angles and alternate interior and alternate exterior angles. In addition to automatically checking the student's answers, the applet can keep score of correct answers. From the activity page, What, How, and Why buttons open pages that explain the activity's purpose, function, and how the mathematics fits into the curriculum. Supplemental resources include lesson plans and a handout with a grid for showing the relationship between all possible angles that occur when parallel lines are cut by a transversal. Copyright 2005 Eisenhower National Clearinghouse

Foundation, Shodor E.

2004-01-01

37

7. VAL CAMERA CAR, DETAIL OF 'FLARE' OR TRAJECTORY CAMERA ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. VAL CAMERA CAR, DETAIL OF 'FLARE' OR TRAJECTORY CAMERA INSIDE CAMERA CAR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

38

2. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH CAMERA STATION ABOVE LOOKING WEST TAKEN FROM RESERVOIR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

39

The calibration of wide-angle lens cameras using perspective and non-perspective projections in the context of real-time tracking applications  

NASA Astrophysics Data System (ADS)

In most close-range photogrammetry applications, the cameras are modelled as imaging systems with perspective projection combined with the lens distortion correction as proposed by Brown in 1971. In the 1980s, the calibration of video cameras received considerable attention. This required compensation for further systematic effects caused by the digitization of the analogue image signal. Modelling the image process in that manner has become the widely-applied standard since then. To take advantage of the increased field of view of individual cameras, the use of wide angle as well as fisheye lenses became common in computer vision and close-range photogrammetry, again requiring appropriate modelling of the imaging process to ensure high accuracies. A.R.T. provides real-time tracking systems with infra-red cameras, which are in some cases equipped with short focal length lenses for the purpose of increased fields of view, resulting in larger trackable object volumes. Unfortunately the lens distortion of these cameras reaches magnitudes which can not be sufficiently modelled with the customary Brown model as - mainly at high excentricities such as image corners - the calculation of the correction is not applicable. Considerations to avoid modelling these lenses as fisheye projections led to an alternate and rather pragmatic approach, where the distortion model is extended by a fourth radial distortion coefficient. Due to numeric instabilities, a stepwise camera calibration is required to achieve convergence in the bundle adjustment process. This paper presents the modified lens distortion model, describes the stepwise calibration procedure and compares results in respect to the conventional approach. The results are also compared to the approach wherein the camera lens is modelled as a fisheye projection. The introduction of a fourth radial lens distortion parameter allows the correction of lens distortion effects over the full sensor area of wide angle lenses, which increases the usable field of view of that specific camera and therefore the size of the trackable observed object volume. The approaches with the extended lens distortion model and the fisheye projection were successfully implemented and tested, and are on target to become part of the A.R.T. product range.

Willneff, Jochen; Wenisch, Oliver

2011-06-01

40

Mars Global Surveyor Mars Orbiter Camera Image Gallery  

NSDL National Science Digital Library

This site from Malin Space Science Systems provides access to all of the images acquired by the Mars Orbiter Camera (MOC) during the Mars Global Surveyor mission through March 2005. MOC consists of several cameras: A narrow angle system that provides grayscale high resolution views of the planet's surface (typically, 1.5 to 12 meters/pixel), and red and blue wide angle cameras that provide daily global weather monitoring, context images to determine where the narrow angle views were actually acquired, and regional coverage to monitor variable surface features such as polar frost and wind streaks. Ancillary data for each image is provided and instructions regarding gallery usage are also available on the site.

Systems, Malin S.

41

3. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH THE VAL TO THE RIGHT, LOOKING NORTHEAST. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

42

1. VARIABLEANGLE LAUNCHER CAMERA CAR, VIEW OF CAMERA CAR AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. VARIABLE-ANGLE LAUNCHER CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH CAMERA STATION ABOVE LOOKING NORTH TAKEN FROM RESERVOIR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

43

A survey of Martian dust devil activity using Mars Global Surveyor Mars Orbiter Camera images  

Microsoft Academic Search

A survey of dust devils using the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) wide- and narrow-angle (WA and NA) images has been undertaken. The survey comprises two parts: (1) sampling of nine broad regions from September 1997 to July 2001 and (2) a focused seasonal monitoring of variability in the Amazonis region, an active dust devil site, from

Jenny A. Fisher; Mark I. Richardson; Claire E. Newman; Mark A. Szwast; Chelsea Graf; Shabari Basu; Shawn P. Ewald; Anthony D. Toigo; R. John Wilson

2005-01-01

44

The canopy camera - Treesearch  

Treesearch

Description: The canopy camera is a device of new design that takes wide-angle, ... vegetation canopies, cloud cover, topographic horizons, and similar subjects. Since the entire hemisphere is photographed in a single exposure, the resulting ...

45

LROC - Lunar Reconnaissance Orbiter Camera  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter Camera (LROC) is designed to address two of the prime LRO measurement requirements. 1) Assess meter and smaller-scale features to facilitate safety analysis for potential lunar landing sites near polar resources, and elsewhere on the Moon. 2) Acquire multi-temporal synoptic imaging of the poles every orbit to characterize the polar illumination environment (100 m scale), identifying regions of permanent shadow and permanent or near-permanent illumination over a full lunar year. The LROC consists of two narrow-angle camera components (NACs) to provide 0.5-m scale panchromatic images over a 5-km swath, a wide-angle camera component (WAC) to provide images at a scale of 100 and 400 m in seven color bands over a 100-km swath, and a common Sequence and Compressor System (SCS). In addition to acquiring the two LRO prime measurement sets, LROC will return six other high-value datasets that support LRO goals, the Robotic Lunar Exploration Program (RLEP), and basic lunar science. These additional datasets include: 3) meter-scale mapping of regions of permanent or near-permanent illumination of polar massifs; 4) multiple co-registered observations of portions of potential landing sites and elsewhere for derivation of high-resolution topography through stereogrammetric and photometric stereo analyses; 5) a global multispectral map in 7 wavelengths (300-680 nm) to characterize lunar resources, in particular ilmenite; 6) a global 100-m/pixel basemap with incidence angles (60-80°) favorable for morphologic interpretations; 7) sub-meter imaging of a variety of geologic units to characterize physical properties, variability of the regolith, and key science questions; and 8) meter-scale coverage overlapping with Apollo era Panoramic images (1-2 m/pixel) to document the number of small impacts since 1971-1972, to ascertain hazards for future surface operations and interplanetary travel.

Robinson, M. S.; Bowman-Cisneros, E.; Brylow, S. M.; Eliason, E.; Hiesinger, H.; Jolliff, B. L.; McEwen, A. S.; Malin, M. C.; Roberts, D.; Thomas, P. C.; Turtle, E.

2006-12-01

46

The calibration of wide-angle lens cameras using perspective and non-perspective projections in the context of real-time tracking applications  

Microsoft Academic Search

In most close-range photogrammetry applications, the cameras are modelled as imaging systems with perspective projection combined with the lens distortion correction as proposed by Brown in 1971. In the 1980s, the calibration of video cameras received considerable attention. This required compensation for further systematic effects caused by the digitization of the analogue image signal. Modelling the image process in that

Jochen Willneff; Oliver Wenisch

2011-01-01

47

How to Rotate a Camera  

Microsoft Academic Search

A procedure is proposed that, given any rotating device to support a camera, places the camera's center of projection to within a tenth of a millimeter from the axis of the rotating device, even with wide angle lenses with severe distortion. Results are experimentally validated by checking that all t he camera projection centers as computed through an off-the- shelf

Carlo Tomasi; John Zhang

1999-01-01

48

HIGH SPEED CAMERA  

DOEpatents

This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

Rogers, B.T. Jr.; Davis, W.C.

1957-12-17

49

8. VAL CAMERA CAR, CLOSEUP VIEW OF 'FLARE' OR TRAJECTORY ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VAL CAMERA CAR, CLOSE-UP VIEW OF 'FLARE' OR TRAJECTORY CAMERA ON SLIDING MOUNT. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

50

Critical Heat Flux in Inclined Rectangular Narrow Gaps  

SciTech Connect

In light of the TMI-2 accident, in which the reactor vessel lower head survived the attack by molten core material, the in-vessel retention strategy was suggested to benefit from cooling the debris through a gap between the lower head and the core material. The GAMMA 1D (Gap Apparatus Mitigating Melt Attack One Dimensional) tests were conducted to investigate the critical heat flux (CHF) in narrow gaps with varying surface orientations. The CHF in an inclined gap, especially in case of the downward-facing narrow gap, is dictated by bubble behavior because the departing bubbles are squeezed. The orientation angle affects the bubble layer and escape of the bubbles from the narrow gap. The test parameters include gap sizes of 1, 2, 5 and 10 mm and the open periphery, and the orientation angles range from the fully downward-facing (180o) to the vertical (90o) position. The 15 ×35 mm copper test section was electrically heated by the thin film resistor on the back. The heater assembly was installed to the tip of the rotating arm in the heated water pool at the atmospheric pressure. The bubble behavior was photographed utilizing a high-speed camera through the Pyrex glass spacer. It was observed that the CHF decreased as the surface inclination angle increased and as the gap size decreased in most of the cases. However, the opposing results were obtained at certain surface orientations and gap sizes. Transition angles, at which the CHF changed in a rapid slope, were also detected, which is consistent with the existing literature. A semi-empirical CHF correlation was developed for the inclined narrow rectangular channels through dimensional analysis. The correlation provides with best-estimate CHF values for realistically assessing the thermal margin to failure of the lower head during a severe accident involving relocation of the core material.

Jeong J. Kim; Yong H. Kim; Seong J. Kim; Sang W. Noh; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

2004-06-01

51

The DSLR Camera  

NASA Astrophysics Data System (ADS)

Cameras have developed significantly in the past decade; in particular, digital Single-Lens Reflex Cameras (DSLR) have appeared. As a consequence we can buy cameras of higher and higher pixel number, and mass production has resulted in the great reduction of prices. CMOS sensors used for imaging are increasingly sensitive, and the electronics in the cameras allows images to be taken with much less noise. The software background is developing in a similar way—intelligent programs are created for after-processing and other supplementary works. Nowadays we can find a digital camera in almost every household, most of these cameras are DSLR ones. These can be used very well for astronomical imaging, which is nicely demonstrated by the amount and quality of the spectacular astrophotos appearing in different publications. These examples also show how much post-processing software contributes to the rise in the standard of the pictures. To sum up, the DSLR camera serves as a cheap alternative for the CCD camera, with somewhat weaker technical characteristics. In the following, I will introduce how we can measure the main parameters (position angle and separation) of double stars, based on the methods, software and equipment I use. Others can easily apply these for their own circumstances.

Berkó, Ern?; Argyle, R. W.

52

Angles, Angles and More Angles!  

NSDL National Science Digital Library

Test Your Angle Knowledge! Angles Telescope Star Gazing Help diget to fill up his scrapbook of stars by using his telescope and pointting at each planet during the night! But make sure you hurry before the sun comes up! Shoot The Space Ship Angles Game Try and figure out which angle you need to use to shoot down the aliens spaceship! ...

Smith, Miss

2011-03-23

53

9. WEST SIDE OF EAST TOWER CAMERA POINTED STRAIGHT DOWN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. WEST SIDE OF EAST TOWER CAMERA POINTED STRAIGHT DOWN FOR THE BENEFIT OF ACROPHOBICS; NOTE EXTREMELY TURBULENT WATER FROM CURRENT - Tacoma Narrows Bridge, Spanning Narrows at State Route 16, Tacoma, Pierce County, WA

54

Cardiac cameras.  

PubMed

Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes. PMID:21440695

Travin, Mark I

2011-05-01

55

5. VAL CAMERA CAR, DETAIL OF HOIST AT SIDE OF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VAL CAMERA CAR, DETAIL OF HOIST AT SIDE OF BRIDGE AND ENGINE CAR ON TRACKS, LOOKING NORTHEAST. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

56

Electronic still camera  

NASA Astrophysics Data System (ADS)

A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

Holland, S. Douglas

1992-09-01

57

NASA's Lunar Reconnaissance Orbiter Cameras (LROC)  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter LRO mission is scheduled to launch in the fall of 2008 as part of NASA s Robotic Lunar Exploration Program and is the first spacecraft to be built as part of NASA s Vision for Space Exploration The orbiter will be equipped with seven scientific instrument packages one of which is LROC The Lunar Reconnaissance Orbiter Camera LROC has been designed to address two of LRO s primary measurement objectives landing site certification and monitoring of polar illumination In order to examine potential landing sites high-resolution images 0 5 m pixel will be used to assess meter-scale features near the pole and other regions on the lunar surface The LROC will also acquire 100 m pixel images of the polar regions of the Moon during each orbit for a year to identify areas of permanent shadow and permanent or near-permanent illumination In addition to these two main objectives the LROC team also plans to conduct meter-scale monitoring of polar regions under varying illumination angles acquire overlapping observations to enable derivation of meter-scale topography acquire global multispectral imaging to map ilmenite and other minerals derive a global morphology base map characterize regolith properties and determine current impact hazards by re-imaging areas covered by Apollo images to search for newly-formed impact craters The LROC is a modified version of the Mars Reconnaissance Orbiter s Context Camera and Mars Color Imager The LROC will be made up of four optical elements two identical narrow-angle telescopes

Robinson, M.; McEwen, A.; Eliason, E.; Joliff, B.; Hiesinger, H.; Malin, M.; Thomas, P.; Turtle, E.; Brylow, S.

58

CCD Camera  

DOEpatents

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

Roth, Roger R. (Minnetonka, MN)

1983-01-01

59

CCD Camera  

DOEpatents

A CCD camera capable of observing a moving object which has varying intensities of radiation emanating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other. 7 figs.

Roth, R.R.

1983-08-02

60

Curiosity's Cameras  

NASA Video Gallery

Curiosity is at Point Lake on Mars and will snap pictures to send home. Find out more about the rover's 17 cameras, including why some shoot in color and others others take black-and-white images.Credit: NASA/JPL-Caltech › Curiosity's mission site

Luis Espinoza

2013-06-13

61

Computing camera heading: A study  

NASA Astrophysics Data System (ADS)

An accurate estimate of the motion of a camera is a crucial first step for the 3D reconstruction of sites, objects, and buildings from video. Solutions to the camera heading problem can be readily applied to many areas, such as robotic navigation, surgical operation, video special effects, multimedia, and lately even in internet commerce. From image sequences of a real world scene, the problem is to calculate the directions of the camera translations. The presence of rotations makes this problem very hard. This is because rotations and translations can have similar effects on the images, and are thus hard to tell apart. However, the visual angles between the projection rays of point pairs are unaffected by rotations, and their changes over time contain sufficient information to determine the direction of camera translation. We developed a new formulation of the visual angle disparity approach, first introduced by Tomasi, to the camera heading problem. Our new derivation makes theoretical analysis possible. Most notably, a theorem is obtained that locates all possible singularities of the residual function for the underlying optimization problem. This allows identifying all computation trouble spots beforehand, and to design reliable and accurate computational optimization methods. A bootstrap-jackknife resampling method simultaneously reduces complexity and tolerates outliers well. Experiments with image sequences show accurate results when compared with the true camera motion as measured with mechanical devices.

Zhang, John Jiaxiang

2000-08-01

62

Camera Projector  

NSDL National Science Digital Library

In this activity (posted on March 14, 2011), learners follow the steps to construct a camera projector to explore lenses and refraction. First, learners use relatively simple materials to construct the projector. Then, learners discover that lenses project images upside down and backwards. They explore this phenomenon by creating their own slides (must be drawn upside down and backwards to appear normally). Use this activity to also introduce learners to spherical aberration and chromatic aberration.

Center, Oakland D.

2011-01-01

63

2. VAL CONCRETE 'A' FRAME STRUCTURE SHOWING CAMERA TOWER, PROJECTILE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VAL CONCRETE 'A' FRAME STRUCTURE SHOWING CAMERA TOWER, PROJECTILE LOADING DECK AND BREECH END OF LAUNCHER BRIDGE LOOKING SOUTH. - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

64

NSTX high-speed color camera as a low-resolution survey spectrometer  

NASA Astrophysics Data System (ADS)

NSTX has recently installed a high-speed 10-bit color camera having a wide-angle global view of the plasma. The camera is typically operated from 1.5 - 5 kHz depending on the desired spatial resolution. The high-speed aspect of the camera yields information on the overall plasma behavior, while the colors gives an indication of the dominant elements involved. For instance, neutral deuterium and helium are readily identified as a red and yellow glow respectively, and especially during the plasma fueling, their spectra can be easily discerned. With the introduction of lithium into NSTX, the camera readily reveals the orange glow from Li I and the bright green associated with the Li II state, depending on the local temperature. Narrow green filaments are often observed to spiral around the center stack or propagating along the last closed flux surface. Bright flares of Li are observed when the plasma interacts with material surfaces or even dust particles. Several methods of displaying the 10-bit color can be used to emphasize details of the discharges. Many example movies will be available to demonstrate the camera's capabilities.

Roquemore, A. L.; Bell, R. E.; Kaita, R.; Mueller, D.; Davis, W.; Maqueda, R. J.; Bush, C.

2008-11-01

65

LRO Camera Imaging of Constellation Sites  

NASA Astrophysics Data System (ADS)

One of the top priorities for Lunar Reconnaissance Orbiter Camera (LROC) imaging during the "exploration" phase of the mission is thorough coverage of 50 sites selected to represent a wide variety of terrain types and geologic features that are of interest for human exploration. These sites, which are broadly distributed around the Moon and include locations at or near both poles, will provide the Constellation Program with data for a set of targets that represent a diversity of scientific and resource opportunities, thus forming a basis for planning for scientific exploration, resource development, and mission operations including traverse and habitation zone planning. Identification of the Constellation targets is not intended to be a site-selection activity. Sites include volcanic terrains (surfaces with young and old basalt flows, pyroclastic deposits, vents, fissures, domes, low shields, rilles, wrinkle ridges, and lava tubes), impact craters and basins (crater floors, central peaks, terraces and walls; impact-melt and ejecta deposits, basin ring structures; and antipodal terrain), and contacts of geologic features in areas of complex geology. Sites at the poles represent different lighting conditions and include craters with areas of permanent shadow. Sites were also chosen that represent typical feldspathic highlands terrain, areas in the highlands with anomalous compositions, and unusual features such as magnetic anomalies. These sites were reviewed by the Lunar Exploration Analysis Group (LEAG). These sites all have considerable scientific and exploration interest and were derived from previous studies of potential lunar landing sites, supplemented with areas that capitalize on discoveries from recent orbital missions. Each site consists of nested regions of interest (ROI), including 10×10 km, 20×20 km, and 40×40 km areas. Within the 10×10 and 20×20 ROIs, the goal is to compile a set of narrow-angle-camera (NAC) observations for a controlled mosaic, photometric and geometric stereo, and images taken at low and high sun to enhance morphology and albedo, respectively. These data will provide the basis for topographic maps, digital elevation models, and slope and boulder hazard maps that could be used to establish landing or habitation zones. Within the 40×40 ROIs, images will be taken to achieve the best possible high-resolution mosaics. All ROIs will have wide-angle-camera context images covering the sites and surrounding areas. At the time of writing (prior to the end of the LRO commissioning phase), over 500 individual NAC frames have been acquired for 47 of the 50 sites. Because of the polar orbit, the majority of repeat coverage occurs for the polar and high latitude sites. Analysis of the environment for several representative Constellation site ROIs will be presented.

Gruener, J.; Jolliff, B. L.; Lawrence, S.; Robinson, M. S.; Plescia, J. B.; Wiseman, S. M.; Li, R.; Archinal, B. A.; Howington-Kraus, A. E.

2009-12-01

66

The DRAGO gamma camera  

SciTech Connect

In this work, we present the results of the experimental characterization of the DRAGO (DRift detector Array-based Gamma camera for Oncology), a detection system developed for high-spatial resolution gamma-ray imaging. This camera is based on a monolithic array of 77 silicon drift detectors (SDDs), with a total active area of 6.7 cm{sup 2}, coupled to a single 5-mm-thick CsI(Tl) scintillator crystal. The use of an array of SDDs provides a high quantum efficiency for the detection of the scintillation light together with a very low electronics noise. A very compact detection module based on the use of integrated readout circuits was developed. The performances achieved in gamma-ray imaging using this camera are reported here. When imaging a 0.2 mm collimated {sup 57}Co source (122 keV) over different points of the active area, a spatial resolution ranging from 0.25 to 0.5 mm was measured. The depth-of-interaction capability of the detector, thanks to the use of a Maximum Likelihood reconstruction algorithm, was also investigated by imaging a collimated beam tilted to an angle of 45 deg. with respect to the scintillator surface. Finally, the imager was characterized with in vivo measurements on mice, in a real preclinical environment.

Fiorini, C.; Gola, A.; Peloso, R.; Longoni, A. [Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milano 20133, Italy and INFN, Sezione di Milano, Milano 20133 (Italy); Lechner, P.; Soltau, H. [PNSensor GmbH and PNDetector GmbH, D-80803 Munich (Germany); Strueder, L. [Max Planck Institut Halbleiterlabor, D-81739 Munich (Germany); Ottobrini, L.; Martelli, C.; Lui, R. [Department of Biomedical Sciences and Technologies, University of Milan, Milano 20133, Italy and Centre of Molecular and Cellular Imaging-IMAGO, Milano (Italy); Madaschi, L. [Department of Medicine, Surgery, and Dentistry, University of Milan, Milano 20142 (Italy); Belloli, S. [IBFM-CNR, Istituto Scientifico Ospedale San Raffale, Milano 20132 (Italy)

2010-04-15

67

Pinhole Cameras: For Science, Art, and Fun!  

ERIC Educational Resources Information Center

|A pinhole camera is a camera without a lens. A tiny hole replaces the lens, and light is allowed to come in for short amount of time by means of a hand-operated shutter. The pinhole allows only a very narrow beam of light to enter, which reduces confusion due to scattered light on the film. This results in an image that is focused, reversed, and…

Button, Clare

2007-01-01

68

Caught on Camera.  

ERIC Educational Resources Information Center

|Describes the benefits of and rules to be followed when using surveillance cameras for school security. Discusses various camera models, including indoor and outdoor fixed position cameras, pan-tilt zoom cameras, and pinhole-lens cameras for covert surveillance. (EV)|

Milshtein, Amy

2002-01-01

69

Lobate Scarp Modeling with Lunar Reconnaissance Orbiter Camera Digital Terrain Models  

NASA Astrophysics Data System (ADS)

Lobate scarps are a type of contractional tectonic landform expressed on the Moon's surface in both highlands and maria. Typically only tens of meters in relief, these linear or curvilinear topographic rises are interpreted to be low-angle thrust fault scarps resulting from global radial contraction. Radial contraction of the Moon can be inferred from shortening across the population of lobate scarps and is estimated at ~100 m. However, the geometry and depth of the underlying faults and mechanical properties of the near-surface lunar crustal materials are not well constrained. The Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Cameras (NACs) acquire 0.5 to 2.0 m/pixel panchromatic images and digital terrain models (DTMs) with spatial resolutions of 2 m are derived from NAC stereo pairs. Topographic data are being used to constrain models of the lobate scarp thrust faults. DTMs are analyzed for relief and morphology of the Slipher (48.3°N, 160.6°E), Racah X-1 (10°S, 178°E), and Simpelius-1 (73.5°S, 13°E) scarps. Profiles are extracted, detrended, and compared along strike. LROC Wide Angle Camera (WAC) 100 m/pixel image mosaics and topography provide regional contexts. Using elastic dislocation modeling, the fault dip angles, depths, slip, and taper are each varied until the predicted surface displacement best fits the DTM profiles for each lobate scarp. Preliminary best-fit dip angles vary from 30-40°, maximum fault depths extend to several hundred meters, and the amount of slip varies from 10 to 30 meters for the three scarps. The modeled maximum depths suggest that the thrust faults are not deeply rooted.

Williams, N. R.; Watters, T. R.; Pritchard, M. E.; Banks, M. E.; Bell, J. F.; Robinson, M. S.; Tran, T.

2011-12-01

70

Integrated mobile radar-camera system in airport perimeter security  

Microsoft Academic Search

The paper presents the test results of a mobile system for the protection of large-area objects, which consists of a radar and thermal and visual cameras. Radar is used for early detection and localization of an intruder and the cameras with narrow field of view are used for identification and tracking of a moving object. The range evaluation of an

M. Zyczkowski; M. Szustakowski; W. Ciurapinski; R. Dulski; M. Kastek; P. Trzaskawka

2011-01-01

71

Narrow complex (supraventricular) tachycardias  

Microsoft Academic Search

Patients experiencing a narrow complex tachycardia are usually at a lower risk than those in whom a broad complex tachycardia occurs. Therefore, in the UK cardiologists are frequently involved in broad complex dysrhythmias at an early stage, while general physicians and general practitioners will often have greater involvement in the management of patients with narrow complex arrhythmias. We describe the

N W F Linton; S W Dubrey

2009-01-01

72

High-power, narrow-band, high-repetition-rate, 5.9 eV coherent light source using passive optical cavity for laser-based angle-resolved photoelectron spectroscopy.  

PubMed

We demonstrate a scheme for efficient generation of a 5.9 eV coherent light source with an average power of 23 mW, 0.34 meV linewidth, and 73 MHz repetition rate from a Ti: sapphire picosecond mode-locked laser with an output power of 1 W. Second-harmonic light is generated in a passive optical cavity by a BiB(3)O(6) crystal with a conversion efficiency as high as 67%. By focusing the second-harmonic light transmitted from the cavity into a ?-BaB(2)O(4) crystal, we obtain fourth-harmonic light at 5.9 eV. This light source offers stable operation for at least a week. We discuss the suitability of the laser light source for high-resolution angle-resolved photoelectron spectroscopy by comparing it with other sources (synchrotron radiation facilities and gas discharge lamp). PMID:23188317

Omachi, J; Yoshioka, K; Kuwata-Gonokami, M

2012-10-01

73

Scale factor in digital cameras  

NASA Astrophysics Data System (ADS)

For objects on a plane, a "scale factor" relates the physical dimensions of the objects to the corresponding dimensions in a camera image. This scale factor may be the only calibration parameter of importance in many test applications. The scale factor depends on the angular size of a pixel of the camera, and also on the range to the object plane. A measurement procedure is presented for the determination of scale factor to high precision, based on the translation of a large-area target by a precision translator. A correlation analysis of the images of a translated target against a reference image is used to extract image shifts and the scale factor. The precision of the measurement is limited by the translator accuracy, camera noise and various other secondary factors. This measurement depends on the target being translated in a plane perpendicular to the optic axis of the camera, so that the scale factor is constant during the translation. The method can be extended to inward-looking 3D camera networks and can, under suitable constraints, yield both scale factor and transcription angle.

Badali, Anthony P.; Zhang, Yahui; Carr, Peter; Thomas, Paul J.; Hornsey, Richard I.

2005-09-01

74

Compact 3D camera  

NASA Astrophysics Data System (ADS)

A new, miniaturized fringe projection system is presented which has a size and handling that approximates to common 2D cameras. The system is based on the fringe projection technique. A miniaturized fringe projector and camera are assembled into a housing of 21x20x11 cm size with a triangulation basis of 10 cm. The advantage of the small triangulation basis is the possibility to measure difficult objects with high gradients. Normally a small basis has the disadvantage of reduced sensitivity. We investigated in methods to compensate the reduced sensitivity via setup and enhanced evaluation methods. Special hardware issues are a high quality, bright light source (and components to handle the high luminous flux) as well as adapted optics to gain a large aperture angle and a focus scan unit to increase the usable measurement volume. Adaptable synthetic wavelengths and integration times were used to increase the measurement quality and allow robust measurements that are adaptable to the desired speed and accuracy. Algorithms were developed to generate automatic focus positions to completely cover extended measurement volumes. Principles, setup, measurement examples and applications are shown.

Bothe, Thorsten; Osten, Wolfgang; Gesierich, Achim; Jueptner, Werner P.

2002-06-01

75

Object tracking using multiple camera video streams  

NASA Astrophysics Data System (ADS)

Two synchronized cameras are utilized to obtain independent video streams to detect moving objects from two different viewing angles. The video frames are directly correlated in time. Moving objects in image frames from the two cameras are identified and tagged for tracking. One advantage of such a system involves overcoming effects of occlusions that could result in an object in partial or full view in one camera, when the same object is fully visible in another camera. Object registration is achieved by determining the location of common features in the moving object across simultaneous frames. Perspective differences are adjusted. Combining information from images from multiple cameras increases robustness of the tracking process. Motion tracking is achieved by determining anomalies caused by the objects' movement across frames in time in each and the combined video information. The path of each object is determined heuristically. Accuracy of detection is dependent on the speed of the object as well as variations in direction of motion. Fast cameras increase accuracy but limit the speed and complexity of the algorithm. Such an imaging system has applications in traffic analysis, surveillance and security, as well as object modeling from multi-view images. The system can easily be expanded by increasing the number of cameras such that there is an overlap between the scenes from at least two cameras in proximity. An object can then be tracked long distances or across multiple cameras continuously, applicable, for example, in wireless sensor networks for surveillance or navigation.

Mehrubeoglu, Mehrube; Rojas, Diego; McLauchlan, Lifford

2010-04-01

76

Three-dimensional camera  

NASA Astrophysics Data System (ADS)

Industrial- and multimedia applications need cost effective, compact and flexible 3D profiling instruments. In the talk we will show the principle of, applications for and results from a new miniaturized 3-D profiling system for macroscopic scenes. The system uses a compact housing and is usable like a camera with minimum stabilization like a tripod. The system is based on common fringe projection technique. Camera and projector are assembled with parallel optical axes having coplanar projection and imaging plane. Their axes distance is comparable to the human eyes distance altogether giving a complete system of 21x20x11 cm size and allowing to measure high gradient objects like the interior of tubes. The fringe projector uses a LCD which enables fast and flexible pattern projection. Camera and projector have a short focal length and a high system aperture as well as a large depth of focus. Thus, objects can be measured from a shorter distance compared to common systems (e.g. 1 m sized objects in 80 cm distance). Actually, objects with diameters up to 4 m can be profiled because the set-up allows working with completely opened aperture combined with bright lamps giving a big amount of available light and a high Signal to Noise Ratio. Normally a small basis has the disadvantage of reduced sensitivity. We investigated in methods to compensate the reduced sensitivity via setup and enhanced evaluation methods. For measurement we use synthetic wavelengths. The developed algorithms are completely adaptable concerning the users needs of speed and accuracy. The 3D camera is built from low cost components, robust, nearly handheld and delivers insights also into difficult technical objects like tubes and inside volumes. Besides the realized high resolution phase measurement the system calibration is an important task for usability. While calibrating with common photogrammetric models (which are typically used for actual fringe projection systems) problems were found that originate from the short focal length and the extreme opening angle of the system as well as the large depth of focus. The actual calibration method is outlined and current problems are shown. An improved calibration of the system is discussed for improved results in future.

Bothe, Thorsten; Gesierich, Achim; Legarda-Sáenz, Ricardo; Jüptner, Werner P. O.

2003-05-01

77

Electronic still camera  

Microsoft Academic Search

A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use

S. Douglas Holland

1992-01-01

78

Determining Camera Gain in Room Temperature Cameras  

SciTech Connect

James R. Janesick provides a method for determining the amplification of a CCD or CMOS camera when only access to the raw images is provided. However, the equation that is provided ignores the contribution of dark current. For CCD or CMOS cameras that are cooled well below room temperature, this is not a problem, however, the technique needs adjustment for use with room temperature cameras. This article describes the adjustment made to the equation, and a test of this method.

Joshua Cogliati

2010-12-01

79

Full Stokes polarization imaging camera  

NASA Astrophysics Data System (ADS)

Objective and background: We present a new version of Bossa Nova Technologies' passive polarization imaging camera. The previous version was performing live measurement of the Linear Stokes parameters (S0, S1, S2), and its derivatives. This new version presented in this paper performs live measurement of Full Stokes parameters, i.e. including the fourth parameter S3 related to the amount of circular polarization. Dedicated software was developed to provide live images of any Stokes related parameters such as the Degree Of Linear Polarization (DOLP), the Degree Of Circular Polarization (DOCP), the Angle Of Polarization (AOP). Results: We first we give a brief description of the camera and its technology. It is a Division Of Time Polarimeter using a custom ferroelectric liquid crystal cell. A description of the method used to calculate Data Reduction Matrix (DRM)5,9 linking intensity measurements and the Stokes parameters is given. The calibration was developed in order to maximize the condition number of the DRM. It also allows very efficient post processing of the images acquired. Complete evaluation of the precision of standard polarization parameters is described. We further present the standard features of the dedicated software that was developed to operate the camera. It provides live images of the Stokes vector components and the usual associated parameters. Finally some tests already conducted are presented. It includes indoor laboratory and outdoor measurements. This new camera will be a useful tool for many applications such as biomedical, remote sensing, metrology, material studies, and others.

Vedel, M.; Breugnot, S.; Lechocinski, N.

2011-09-01

80

FCam for multiple cameras  

NASA Astrophysics Data System (ADS)

The Frankencamera (FCam) architecture and API enables precise control over the camera in computational photography applications. We present an extension to FCam API for systems equipped with multiple cameras. The proposed extension allows for an enumeration of cameras and their corresponding properties, such as position or orientation. In addition, we explicitly support camera synchronization, either through hardware mechanisms or software primitives. If hardware synchronization is available, cameras can be grouped together under a concept of a multi-sensor. Otherwise, multiple camera streams are scheduled asynchronously and synchronized using our software control primitives.

Troccoli, Alejandro; Pajak, Dawid; Pulli, Kari

2012-02-01

81

Investigating the Pinhole Camera and Camera Obscura  

NSDL National Science Digital Library

In this activity, students explore the nature of light, including the fact that it travels in straight lines, by building and using two visual tools. The first is a simple pinhole camera--a box with a pinhole opening. The second is a camera obscura--a tool

Eichinger, John

2009-05-30

82

Interconnected network of cameras  

NASA Astrophysics Data System (ADS)

The real-time development of multi-camera systems is a great challenge. Synchronization and large data rates of the cameras adds to the complexity of these systems as well. The complexity of such system also increases as the number of their incorporating cameras increases. The customary approach to implementation of such system is a central type, where all the raw stream from the camera are first stored then processed for their target application. An alternative approach is to embed smart cameras to these systems instead of ordinary cameras with limited or no processing capability. Smart cameras with intra and inter camera processing capability and programmability at the software and hardware level will offer the right platform for distributed and parallel processing for multi- camera systems real-time application development. Inter camera processing requires the interconnection of smart cameras in a network arrangement. A novel hardware emulating platform is introduced for demonstrating the concept of the interconnected network of cameras. A methodology is demonstrated for the interconnection network of camera construction and analysis. A sample application is developed and demonstrated.

Hosseini Kamal, Mahdad; Afshari, Hossein; Leblebici, Yusuf; Schmid, Alexandre; Vandergheynst, Pierre

2013-02-01

83

Polarimetric performance of Si/CdTe semiconductor Compton camera  

NASA Astrophysics Data System (ADS)

A Compton camera has been developed based on Si and CdTe semiconductor detectors with high spatial and spectral resolution for hard X- and ?-ray astrophysics applications. A semiconductor Compton camera is also an excellent polarimeter due to its capability to precisely measure the Compton scattering azimuth angle, which is modulated by linear polarization. We assembled a prototype Compton camera and conducted a beam test using nearly 100% linearly polarized ?-rays at SPring-8.

Takeda, Shin'Ichiro; Odaka, Hirokazu; Katsuta, Junichiro; Ishikawa, Shin-Nosuke; Sugimoto, So-Ichiro; Koseki, Yuu; Watanabe, Shin; Sato, Goro; Kokubun, Motohide; Takahashi, Tadayuki; Nakazawa, Kazuhiro; Fukazawa, Yasushi; Tajima, Hiroyasu; Toyokawa, Hidenori

2010-10-01

84

Constrained space camera assembly  

DOEpatents

A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

Heckendorn, Frank M. (Aiken, SC); Anderson, Erin K. (Augusta, GA); Robinson, Casandra W. (Trenton, SC); Haynes, Harriet B. (Aiken, SC)

1999-01-01

85

Electronic Still Camera.  

National Technical Information Service (NTIS)

A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an e...

S. D. Holland

1992-01-01

86

Universal Camera Calibration with Automatic Distortion Model Selection  

Microsoft Academic Search

We present an optimized full scale automatic camera calibration approach which is both accurate and simple to implement. The method can be applied to a wide range of cameras equipped with normal, wide-angle, fish-eye, and telephoto lenses. The procedure does not require prior knowledge of any parameters. The method uses a simple planar calibration pattern which is observed from different

Vitaliy Orekhov; Besma R. Abidi; Christopher Broaddus; Mongi A. Abidi

2007-01-01

87

9. COMPLETED ROLLING CAMERA CAR ON RAILROAD TRACK AND BRIDGE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. COMPLETED ROLLING CAMERA CAR ON RAILROAD TRACK AND BRIDGE LOOKING WEST, APRIL 26, 1948. (ORIGINAL PHOTOGRAPH IN POSSESSION OF DAVE WILLIS, SAN DIEGO, CALIFORNIA.) - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

88

Stardust Imaging Camera  

Microsoft Academic Search

The Stardust spacecraft is carrying an Imaging Camera, primarily for 81P\\/Wild 2 approach navigation, but the camera also will provide valuable data for P\\/Wild 2 nucleus characterization and about its activity. During an engineering readiness test, the camera already has provided useful scientific data about an asteroid, 5535 Annefrank. The camera utilizes spare parts from Cassini and Voyager as well

Ray L. Newburn Jr; Shyam Bhaskaran; Thomas C. Duxbury; George Fraschetti; Tom Radey; Mark Schwochert

2003-01-01

89

The camera in space  

Microsoft Academic Search

Photography in the U.S. space program for engineering information, lunar mapping, science and applications (e.g., studies of astronomical phenomena, terrain and weather, and the lunar surface), and general purposes. After Gemini 9, each manned mission (Apollo, Skylab) had a documented, detailed photographic plan. Photographic equipment (including still cameras, variable-sequence cameras, lunar surface close-up stereo camera, and lunar mapping cameras) and

H. J. P. Arnold

1974-01-01

90

Using Geometric Constraints for Fisheye Camera Calibration  

Microsoft Academic Search

This paper presents a technique to linearly calibrate a fisheye camera using the fact that the distortion is in the radial direction (angle preservation on the X-Y plane). First, a linear equation based on this constraint is proposed for estimating intrinsic\\/extrinsic parameters. The skewness in the intrinsic parameters is assumed to be zero in this paper. Second, a pure rotation

Tzung-Hsien Ho; Christopher C. Davis; Stuart D. Milner

91

Omnifocus video camera  

NASA Astrophysics Data System (ADS)

The omnifocus video camera takes videos, in which objects at different distances are all in focus in a single video display. The omnifocus video camera consists of an array of color video cameras combined with a unique distance mapping camera called the Divcam. The color video cameras are all aimed at the same scene, but each is focused at a different distance. The Divcam provides real-time distance information for every pixel in the scene. A pixel selection utility uses the distance information to select individual pixels from the multiple video outputs focused at different distances, in order to generate the final single video display that is everywhere in focus. This paper presents principle of operation, design consideration, detailed construction, and over all performance of the omnifocus video camera. The major emphasis of the paper is the proof of concept, but the prototype has been developed enough to demonstrate the superiority of this video camera over a conventional video camera. The resolution of the prototype is high, capturing even fine details such as fingerprints in the image. Just as the movie camera was a significant advance over the still camera, the omnifocus video camera represents a significant advance over all-focus cameras for still images.

Iizuka, Keigo

2011-04-01

92

Those Nifty Digital Cameras!  

ERIC Educational Resources Information Center

Describes digital photography--an electronic imaging technology that merges computer capabilities with traditional photography--and its uses in education. Discusses how a filmless camera works, types of filmless cameras, advantages and disadvantages, and educational applications of the consumer digital cameras. (AEF)

Ekhaml, Leticia

1996-01-01

93

Tower Press Camera  

USGS Multimedia Gallery

"4x5" enclosure camera with Rangefinder and Wollensak Raptar lens serial #A18388, 62 mm, 1950s-60s. Manufactured by Busch Optical Manufacturing Company, Chicago, Illinois (also known as Busch Precision Camera Corporation). The company was famous for its versatile press cameras which featured an opti...

2009-07-22

94

Calibrating Distributed Camera Networks  

Microsoft Academic Search

Recent developments in wireless sensor networks have made feasible distributed camera networks, in which cameras and processing nodes may be spread over a wide geographical area, with no centralized processor and limited ability to communicate a large amount of information over long distances. This paper overviews distributed algorithms for the calibration of such camera networks- that is, the automatic estimation

Dhanya Devarajan; Zhaolin Cheng; Richard J. Radke

2008-01-01

95

Contrail study with ground-based cameras  

NASA Astrophysics Data System (ADS)

Photogrammetric methods and analysis results for contrails observed with wide-angle cameras are described. Four cameras of two different types (view angle < 90° or whole-sky imager) at the ground at various positions are used to track contrails and to derive their altitude, width, and horizontal speed. Camera models for both types are described to derive the observation angles for given image coordinates and their inverse. The models are calibrated with sightings of the Sun, the Moon and a few bright stars. The methods are applied and tested in a case study. Four persistent contrails crossing each other together with a short-lived one are observed with the cameras. Vertical and horizontal positions of the contrails are determined from the camera images to an accuracy of better than 200 m and horizontal speed to 0.2 m s-1. With this information, the aircraft causing the contrails are identified by comparison to traffic waypoint data. The observations are compared with synthetic camera pictures of contrails simulated with the contrail prediction model CoCiP, a Lagrangian model using air traffic movement data and numerical weather prediction (NWP) data as input. The results provide tests for the NWP and contrail models. The cameras show spreading and thickening contrails suggesting ice-supersaturation in the ambient air. The ice-supersaturated layer is found thicker and more humid in this case than predicted by the NWP model used. The simulated and observed contrail positions agree up to differences caused by uncertain wind data. The contrail widths, which depend on wake vortex spreading, ambient shear and turbulence, were partly wider than simulated.

Schumann, U.; Hempel, R.; Flentje, H.; Garhammer, M.; Graf, K.; Kox, S.; Lösslein, H.; Mayer, B.

2013-08-01

96

Classroom multispectral imaging using inexpensive digital cameras.  

NASA Astrophysics Data System (ADS)

The proliferation of increasingly cheap digital cameras in recent years means that it has become easier to exploit the broad wavelength sensitivity of their CCDs (360 - 1100 nm) for classroom-based teaching. With the right tools, it is possible to open children's eyes to the invisible world of UVA and near-IR radiation either side of our narrow visual band. The camera-filter combinations I describe can be used to explore the world of animal vision, looking for invisible markings on flowers, or in bird plumage, for example. In combination with a basic spectroscope (such as the Project-STAR handheld plastic spectrometer, 25), it is possible to investigate the range of human vision and camera sensitivity, and to explore the atomic and molecular absorption lines from the solar and terrestrial atmospheres. My principal use of the cameras has been to teach multispectral imaging of the kind used to determine remotely the composition of planetary surfaces. A range of camera options, from 50 circuit-board mounted CCDs up to $900 semi-pro infrared camera kits (including mobile phones along the way), and various UV-vis-IR filter options will be presented. Examples of multispectral images taken with these systems are used to illustrate the range of classroom topics that can be covered. Particular attention is given to learning about spectral reflectance curves and comparing images from Earth and Mars taken using the same filter combination that it used on the Mars Rovers.

Fortes, A. D.

2007-12-01

97

Development of the collimator response of gas slit camera of MAXI  

NASA Astrophysics Data System (ADS)

Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky scanner, which will be attached on Exposed Facility of Japanese Experiment Module dubbed "Kibo" of International Space Station (ISS). MAXI will be launched by the Space Shuttle or the Japanese H-IIA Transfer Vehicle (HTV) in 2008. MAXI carries two types of X-ray cameras: Solid-state Slit Camera (SSC) for 0.5-10 keV and Gas Slit Camera (GSC) for 2-30 keV bands. Both have long narrow fields of view (FOV) made by a slit and orthogonally arranged collimator plates (slats). The FOV will sweep almost the whole sky once every 96 minutes by utilizing the orbital motion of ISS. Then the light curve of an X-ray point source become triangular shape in one transit. In this paper, we present the actual triangular response of the GSC collimator, obtained by our calibration. In fact they are deformed by gaps between the slats, leaning angle of the slats, and the effective width of the slats. We are measuring these sizes by shooting X-ray beams into the detector behind the collimator. We summarize the calibration and present the first compilation of the data to make the GSC collimator response, which will be useful for public users.

Morii, Mikio; Matsuoka, Masaru; Ueno, Shiro; Tomida, Hiroshi; Katayama, Haruyoshi; Kawasaki, Kazuyoshi; Yokota, Takao; Kuramata, Naoyuki; Mihara, Tatehiro; Kohama, Mitsuhiro; Isobe, Naoki; Nakajima, Motoki; Tsunemi, Hiroshi; Miyata, Emi; Yoshida, Atsumasa; Yamaoka, Kazutaka; Tsuchiya, Yuichiro; Miyakawa, Takehiro; Kawai, Nobuyuki; Kataoka, Jun; Tanaka, Satoshi; Negoro, Hitoshi

2006-07-01

98

Automatic camera tracking for remote manipulators  

SciTech Connect

The problem of automatic camera tracking of mobile objects is addressed with specific reference to remote manipulators and using either fixed or mobile cameras. The technique uses a kinematic approach employing 4 x 4 coordinate transformation matrices to solve for the needed camera PAN and TILT angles. No vision feedback systems are used, as the required input data are obtained entirely from position sensors from the manipulator and the camera-positioning system. All hardware requirements are generally satisfied by currently available remote manipulator systems with a supervisory computer. The system discussed here implements linear plus on/off (bang-bang) closed-loop control with a +-2/sup 0/ deadband. The deadband area is desirable to avoid operator seasickness caused by continuous camera movement. Programming considerations for camera control, including operator interface options, are discussed. The example problem presented is based on an actual implementation using a PDP 11/34 computer, a TeleOperator Systems SM-229 manipulator, and an Oak Ridge National Laboratory (ORNL) camera-positioning system. 3 references, 6 figures, 2 tables.

Stoughton, R.S.; Martin, H.L.; Bentz, R.R.

1984-04-01

99

Automatic camera tracking for remote manipulators  

SciTech Connect

The problem of automatic camera tracking of mobile objects is addressed with specific reference to remote manipulators and using either fixed or mobile cameras. The technique uses a kinematic approach employing 4 x 4 coordinate transformation matrices to solve for the needed camera PAN and TILT angles. No vision feedback systems are used, as the required input data are obtained entirely from position sensors from the manipulator and the camera-positioning system. All hardware requirements are generally satisfied by currently available remote manipulator systems with a supervisory computer. The system discussed here implements linear plus on/off (bang-bang) closed-loop control with a +-2-deg deadband. The deadband area is desirable to avoid operator seasickness caused by continuous camera movement. Programming considerations for camera control, including operator interface options, are discussed. The example problem presented is based on an actual implementation using a PDP 11/34 computer, a TeleOperator Systems SM-229 manipulator, and an Oak Ridge National Laboratory (ORNL) camera-positioning system. 3 references, 6 figures, 2 tables.

Stoughton, R.S.; Martin, H.L.; Bentz, R.R.

1984-07-01

100

Narrow-complex tachycardia.  

PubMed

The term "narrow-complex tachycardia" is applied to a number of common and rare arrhythmias. Atrial fibrillation is the narrow-complex tachycardia most frequently seen in clinical practice. Sinus tachycardia is associated with underlying metabolic abnormalities, and paroxysmal atrial tachycardia most often results from digitalis toxicity. Multifocal atrial tachycardia usually occurs in older adults with chronic obstructive pulmonary disease. Atrioventricular nodal reentrant tachycardia is commonly found in otherwise healthy children and adolescents. The initial diagnosis should be reconsidered if drug therapy is unsuccessful, because differences in rhythm disturbances are often subtle. Radiofrequency catheter ablation is an effective treatment for atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia (Wolff-Parkinson-White syndrome) and the permanent form of junctional reentrant tachycardia. Catheter ablation should also be considered in difficult cases of atrial flutter, intra-atrial reentry and automatic atrial tachycardia. PMID:8116517

Giudici, M C; Gumpert, T J; Heathman, L L

1994-03-01

101

Tower Camera Handbook  

SciTech Connect

The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.

Moudry, D

2005-01-01

102

Angle performance on optima MDxt  

NASA Astrophysics Data System (ADS)

Angle control on medium current implanters is important due to the high angle-sensitivity of typical medium current implants, such as halo implants. On the Optima MDxt, beam-to-wafer angles are controlled in both the horizontal and vertical directions. In the horizontal direction, the beam angle is measured through six narrow slits, and any angle adjustment is made by electrostatically steering the beam, while cross-wafer beam parallelism is adjusted by changing the focus of the electrostatic parallelizing lens (P-lens). In the vertical direction, the beam angle is measured through a high aspect ratio mask, and any angle adjustment is made by slightly tilting the wafer platen prior to implant. A variety of tests were run to measure the accuracy and repeatability of Optima MDxt's angle control. SIMS profiles of a high energy, channeling sensitive condition show both the cross-wafer angle uniformity, along with the small-angle resolution of the system. Angle repeatability was quantified by running a channeling sensitive implant as a regular monitor over a seven month period and measuring the sheet resistance-to-angle sensitivity. Even though crystal cut error was not controlled for in this case, when attributing all Rs variation to angle changes, the overall angle repeatability was measured as 0.16° (1?). A separate angle repeatability test involved running a series of V-curves tests over a four month period using low crystal cut wafers selected from the same boule. The results of this test showed the angle repeatability to be <0.1° (1?).

David, Jonathan; Kamenitsa, Dennis

2012-11-01

103

Angle performance on optima MDxt  

SciTech Connect

Angle control on medium current implanters is important due to the high angle-sensitivity of typical medium current implants, such as halo implants. On the Optima MDxt, beam-to-wafer angles are controlled in both the horizontal and vertical directions. In the horizontal direction, the beam angle is measured through six narrow slits, and any angle adjustment is made by electrostatically steering the beam, while cross-wafer beam parallelism is adjusted by changing the focus of the electrostatic parallelizing lens (P-lens). In the vertical direction, the beam angle is measured through a high aspect ratio mask, and any angle adjustment is made by slightly tilting the wafer platen prior to implant. A variety of tests were run to measure the accuracy and repeatability of Optima MDxt's angle control. SIMS profiles of a high energy, channeling sensitive condition show both the cross-wafer angle uniformity, along with the small-angle resolution of the system. Angle repeatability was quantified by running a channeling sensitive implant as a regular monitor over a seven month period and measuring the sheet resistance-to-angle sensitivity. Even though crystal cut error was not controlled for in this case, when attributing all Rs variation to angle changes, the overall angle repeatability was measured as 0.16 Degree-Sign (1{sigma}). A separate angle repeatability test involved running a series of V-curves tests over a four month period using low crystal cut wafers selected from the same boule. The results of this test showed the angle repeatability to be <0.1 Degree-Sign (1{sigma}).

David, Jonathan; Kamenitsa, Dennis [Axcelis Technologies, Inc., 108 Cherry Hill Dr, Beverly, MA 01915 (United States)

2012-11-06

104

Angle Hunting  

NSDL National Science Digital Library

In this activity, learners use a hand-made protractor to measure angles they find in playground equipment. Learners will observe that angle measurements do not change with distance, because they are distance invariant, or constant. Note: The "Pocket Protractor" activity should be done ahead as a separate activity (see related resource), but a standard protractor can be used as a substitute.

Exploratorium

2010-01-01

105

The narrow pentaquark  

SciTech Connect

The experimental status of the pentaquark searches is briefly reviewed. Recent null results by the CLAS collaboration are commented, and new strong evidence of a very narrow {theta}+ resonance by the DIANA collaboration is presented. On the theory side, I revisit the argument against the existence of the pentaquark - that of Callan and Klebanov - and show that actually a strong resonance is predicted in that approach, however its width is grossly overestimated. A recent calculation gives 2 MeV for the pentaquark width, and this number is probably still an upper bound.

Diakonov, Dmitri [Petersburg Nuclear Physics Institute, Gatchina, 188 300, St. Petersburg (Russian Federation)

2007-02-27

106

Planar graphene-narrow-gap semiconductor-graphene heterostructure  

Microsoft Academic Search

A planar heterostructure composed of two graphene films between which a narrow-gap semiconductor ribbon is inserted was studied.\\u000a It was shown that the Klein paradox is absent when conical points of the graphene Brillouin zone are in the band gap of a\\u000a narrow-gap semiconductor. There is an energy range dependent on the angle of incidence, in which an above-barrier decaying

P. V. Ratnikov; A. P. Silin

2008-01-01

107

Planar Heterostructure Graphene -- Narrow-Gap Semiconductor -- Graphene  

Microsoft Academic Search

We investigate a planar heterostructure composed of two graphene films separated by a narrow-gap semiconductor ribbon. We show that there is no the Klein paradox when the Dirac points of the Brillouin zone of graphene are in a band gap of a narrow-gap semiconductor. There is the energy range depending on an angle of incidence, in which the above-barrier damped

P. V. Ratnikov; A. P. Silin

2008-01-01

108

Microchannel plate streak camera  

DOEpatents

An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (uv to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 keV x-rays.

Wang, C.L.

1984-09-28

109

Microchannel plate streak camera  

DOEpatents

An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras is disclosed. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1,000 KeV x-rays. 3 figs.

Wang, C.L.

1989-03-21

110

Microchannel plate streak camera  

DOEpatents

An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

Wang, Ching L. (Livermore, CA)

1989-01-01

111

Advantage of diverging radial type for mobile stereo camera  

NASA Astrophysics Data System (ADS)

Distortions in the perceived image characteristics for three different camera arrangements of parallel, converging, and diverging are different according to each focal length, focus distance, field of view angle, color, magnification, and camera aligning direction. The distortions in perceived image for the parallel and converging arrangements have been researched commercially available stereoscopic TV based on high speed LCD, shutter glasses, and mobile devices. However, the distortion in the perceived image for diverging arrangement is not well known. This paper discusses the distortion in perceived image characteristics of diverging type stereo camera according to the magnification determining the enlargement and reduction of a camera image, and they are compared with those of other camera arrangements such as parallel and converging types. Also, the distortion induces the image closer to the viewers for the diverging type while away for the converging. The inducement is more prominent as the camera distance between two component cameras of the stereo camera for the diverging type. Furthermore, the effect of diverging angle on disparity will be considered that the inter-camera distance can be made as small as possible.

Lee, Dong-Su; Mun, Sungchul; Park, Min-Chul; Son, Jung-Young

2013-05-01

112

FPA camera standardisation  

NASA Astrophysics Data System (ADS)

The temperature standardisation of an infrared camera is generally done with an internal black body. However, some cameras do not have such correction and some particular effects like Narcissus or other internal contributions disturb the measurements. The determination of the different contributions of the thermosignal given by the camera allows us to propose a procedure in order to obtain an absolute temperature with a precision of one degree.

Horny, N.

2003-04-01

113

VNIR hypersensor camera system  

NASA Astrophysics Data System (ADS)

The hypersensor camera operates with a unique multispectral imaging modality developed recently at Surface Optics Corporation. The Hypersensor camera is small, low cost, rugged, and solid state, using micro-optics and an array of spectral filters, which captures a complete multispectral cube of spatial and spectral data with every focal plane exposure. The prototype VNIR Hypersensor camera captures full cubes of 588x438 (spatial pixels) x 16 (spectral bands) at frame rates up to 60 Hz. This paper discusses the optical design of the Hypersensor camera, the measured performance, and the design and operation of a custom video-rate hyperspectral processor developed for this system.

Cavanaugh, David B.; Lorenz, James M.; Unwin, Nora; Dombrowski, Mark; Willson, Paul

2009-08-01

114

Ringfield lithographic camera  

DOEpatents

A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D.sub.source .apprxeq.0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry with an increased etendue for the camera system. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors.

Sweatt, William C. (Albuquerque, NM)

1998-01-01

115

LSST Camera Optics Design  

SciTech Connect

The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope mirrors to optimize performance. We discuss the rationale for the LSST camera optics design, describe the methodology for fabricating, coating, mounting and testing the lenses and filters, and present the results of detailed analyses demonstrating that the camera optics will meet their performance goals.

Riot, V J; Olivier, S; Bauman, B; Pratuch, S; Seppala, L; Gilmore, D; Ku, J; Nordby, M; Foss, M; Antilogus, P; Morgado, N

2012-05-24

116

Light Field Video Camera.  

National Technical Information Service (NTIS)

We present the Light Field Video Camera, an array of CMOS image sensors for video image based rendering applications. The device is designed to record a synchronized video dataset from over one hundred cameras to a hard disk array using as few as one PC p...

B. Wilburn M. Smulski K. Lee M. A. Horowitz

2000-01-01

117

Traffic camera system development  

Microsoft Academic Search

The intelligent transportation system has generated a strong need for the development of intelligent camera systems to meet the requirements of sophisticated applications, such as electronic toll collection (ETC), traffic violation detection and automatic parking lot control. In order to achieve the highest levels of accuracy in detection, these cameras must have high speed electronic shutters, high resolution, high frame

Toshi Hori

1997-01-01

118

Camera Operator and Videographer  

ERIC Educational Resources Information Center

Television, video, and motion picture camera operators produce images that tell a story, inform or entertain an audience, or record an event. They use various cameras to shoot a wide range of material, including television series, news and sporting events, music videos, motion pictures, documentaries, and training sessions. Those who film or…

Moore, Pam

2007-01-01

119

A Holographic Motion Picture Camera.  

National Technical Information Service (NTIS)

A holographic motion picture camera for producing three dimensional images was disclosed. The camera employs an elliptical optical system and a motion compensator is present in one of the beam paths; the compensator allows the camera to photograph fast mo...

R. L. Kurtz

1974-01-01

120

Estimating Angles  

NSDL National Science Digital Library

This Flash game for one or two players gives students practice in estimating the size of angles. A circle and a radius pointing in a random direction are given. The student activates a second sweeping radius, which can move in either direction, and tries to stop it at the specified measure. Three difficulty levels control the range of angle measures. Points are awarded based on closeness of the estimate. The Teachers' Notes page includes suggestions for implementation, discussion questions, ideas for extension and support.

2007-06-01

121

Critical Angle  

NSDL National Science Digital Library

This website from the Exploratorium provides a demonstration of total internal reflection. The activity uses a fish aquarium to illustrate how a transparent material like water can act as a reflector. The site provides a thorough description of what to do, an explanation of what is happening, including the critical angle, and examples of its applications to optical fibers.

2008-06-23

122

Camera for landing applications  

NASA Astrophysics Data System (ADS)

This paper describes the Enhanced Video System (EVS) camera, built by OPGAL as subcontractor of Kollsman Inc. The EVS contains a Head up Display built by Honeywell, a special design camera for landing applications, and the external window installed on the plane together with the electronic control box built by Kollsman. The special design camera for lending applications is the subject of this paper. The entire system was installed on a Gulfstream V plane and passed the FAA proof of concept during August and September 2000.

Grimberg, Ernest

2001-08-01

123

Structured light camera calibration  

NASA Astrophysics Data System (ADS)

Structured light camera which is being designed with the joined effort of Institute of Radioelectronics and Institute of Optoelectronics (both being large units of the Warsaw University of Technology within the Faculty of Electronics and Information Technology) combines various hardware and software contemporary technologies. In hardware it is integration of a high speed stripe projector and a stripe camera together with a standard high definition video camera. In software it is supported by sophisticated calibration techniques which enable development of advanced application such as real time 3D viewer of moving objects with the free viewpoint or 3D modeller for still objects.

Garbat, P.; Skarbek, W.; Tomaszewski, M.

2013-03-01

124

Ringfield lithographic camera  

DOEpatents

A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D{sub source} {approx_equal} 0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors. 11 figs.

Sweatt, W.C.

1998-09-08

125

Periodic disc packings generated by random deposition in narrow channels  

Microsoft Academic Search

Periodic structures have been found to be characteristic of two-dimensional Visscher-Bolsterli disc packings in narrow channels. The effective period d is related to the disc diameter, d0, and the channel width, w, by d ? ma'dd0 and ?d? ? adw, where ad ? 2?tg (?)? (? is the angle of inclination of bonds between contacting discs in large w ?

P. Meakin; R. Jullien

1991-01-01

126

Aircraft Altitude Estimation Using Un-calibrated Onboard Cameras  

NASA Astrophysics Data System (ADS)

In the present study, implementation and study of aircraft altitude estimation using un-calibrated onboard camera is obtained. A camera model has been implemented to simulate the test data. From the results, it was observed that the rounding nature of pixel coordinates creates fluctuations around the true vanishing point (VP) angle and height computations. These fluctuations were smoothened using a Kalman filter based state estimator. The effects of camera tilt and focal length on VP angle and height computations were also studied. It is concluded that the camera should be perpendicular to the runway for there to be no effect of the focal length on the height computation. It is being planned to apply this algorithm for real time imaging data along with Integrated Enhanced Synthetic Vision (IESVS) on HANSA aircraft.

Naidu, V. P. S.; Mukherjee, J.

2012-10-01

127

Effects of incidence angle on observations of equilibrium crater diameter  

NASA Astrophysics Data System (ADS)

Determining the equilibrium crater diameter for a crater population is important in lunar regolith depth estimates as the equilibrium diameter represents the steady-state between the formation of new craters and the removal of older craters [1]. [2] hypothesized that the number of craters identified in an image is dependent on the incidence angle and showed that for three different young mare regions, fewer craters are visible at lower incidence angles, affecting reliable estimates of the equilibrium diameter of the counted crater population. [3] disputed this hypothesis and the presence of an equilibrium crater population in the data from [2]. Testing the hypothesis from [2], we chose four Apollo Metric images of the same area with different incidence angles to examine the effects of resolution on apparent equilibrium diameter estimates. We selected a 100 km2 area centered at 27.3°N, 18.2°W in Mare Imbrium east of Lambert crater with data at 87°, 82°, 71°, and 50° incidence angles, and scan resolutions of 6.6 to 7.6 m/pixel. To compare the craters visible at different illuminations, we resampled the images to 10 m/pixel and employed three individuals to count craters. The cumulative histograms for the four Apollo Metric frames exhibit the effects of different incidence angles on reliably counting craters. Current results show that the crater counts for the 82° incidence angle image are the most consistent between different observers, finding a production function slope of -4.1 and an apparent equilibrium diameter of 200 m. Deviation from the small crater trends (equilibrium population?) and the production function slope observed at 82° incidence is found at the higher (87°) and lower (71°, 50°) incidence angles. We attribute some of this deviation to the effects of incidence angle on crater detection; at crater diameters >~300 m, we find similar production functions, an observation consistent with our identification of these large craters in all four illuminations. However, the small crater trends vary significantly among observations at different illuminations. An important question is whether the small crater slope and rollover we observe are representative of the equilibrium crater population or whether these observations are due to resolution limits of the images, a too-small count area, or shadow effects (e.g., loss of small craters in the shadows of larger craters). To test if the observed rollover in the cumulative histograms is due to resolution effects or to the observation of the equilibrium crater population, we will use substantially higher resolution images. Images from the Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (resolution increasing during the nominal mission from ~1.5 to ~0.5 m/pixel) at incidence angles ranging from 50° to 87°, focusing on higher incidences (70° to 87°), will be used to maximize the identification of small craters. [1] L. A. Soderblom (1970) JGR, 75, 2655. [2] B. B. Wilcox et al. (2005) Meteoritics & Plan. Sci., 40, 695. [3] V. R. Oberbeck (2008) Meteoritics & Plan. Sci., 43, 815.

Ostrach, L. R.; Denevi, B. W.; Hastings, A.; Koeber, S.; Robinson, M. S.; Thomas, P. C.; Tran, T. N.

2009-12-01

128

The MKID Camera  

NASA Astrophysics Data System (ADS)

The MKID Camera project is a collaborative effort of Caltech, JPL, the University of Colorado, and UC Santa Barbara to develop a large-format, multi-color millimeter and submillimeter-wavelength camera for astronomy using microwave kinetic inductance detectors (MKIDs). These are superconducting, micro-resonators fabricated from thin aluminum and niobium films. We couple the MKIDs to multi-slot antennas and measure the change in surface impedance produced by photon-induced breaking of Cooper pairs. The readout is almost entirely at room temperature and can be highly multiplexed; in principle hundreds or even thousands of resonators could be read out on a single feedline. The camera will have 576 spatial pixels that image simultaneously in four bands at 750, 850, 1100 and 1300 microns. It is scheduled for deployment at the Caltech Submillimeter Observatory in the summer of 2010. We present an overview of the camera design and readout and describe the current status of testing and fabrication.

Maloney, P. R.; Czakon, N. G.; Day, P. K.; Duan, R.; Gao, J.; Glenn, J.; Golwala, S.; Hollister, M.; Leduc, H. G.; Mazin, B.; Noroozian, O.; Nguyen, H. T.; Sayers, J.; Schlaerth, J.; Vaillancourt, J. E.; Vayonakis, A.; Wilson, P.; Zmuidzinas, J.

2009-12-01

129

The people's camera  

NASA Astrophysics Data System (ADS)

Taxpayer-funded scientific research carries with it the responsibility to communicate to the general public its relevance in an accessible, open and inspirational manner. The HiRISE project that steers a camera on Mars admirably achieves this aim.

2010-03-01

130

Fire Surveillance System Using an Omnidirectional Camera for Remote Monitoring  

Microsoft Academic Search

This paper proposes new video-based fire surveillance and remote monitoring system for real-life application. Most previous video-based fire detection systems using color information and temporal variations of pixels produce frequent false alarms due to the use of many heuristic features. Plus, they need several cameras to overcome the dead angle problem of a normal CCD camera. Thus, to overcome these

ByoungChul Ko; Hyun-Jae Hwang; In-Gyu Lee; Jae-Yeal Nam

2008-01-01

131

Neutron cameras for ITER  

SciTech Connect

Neutron cameras with horizontal and vertical views have been designed for ITER, based on systems used on JET and TFTR. The cameras consist of fan-shaped arrays of collimated flight tubes, with suitably chosen detectors situated outside the biological shield. The sight lines view the ITER plasma through slots in the shield blanket and penetrate the vacuum vessel, cryostat, and biological shield through stainless steel windows. This paper analyzes the expected performance of several neutron camera arrangements for ITER. In addition to the reference designs, the authors examine proposed compact cameras, in which neutron fluxes are inferred from {sup 16}N decay gammas in dedicated flowing water loops, and conventional cameras with fewer sight lines and more limited fields of view than in the reference designs. It is shown that the spatial sampling provided by the reference designs is sufficient to satisfy target measurement requirements and that some reduction in field of view may be permissible. The accuracy of measurements with {sup 16}N-based compact cameras is not yet established, and they fail to satisfy requirements for parameter range and time resolution by large margins.

Johnson, L.C.; Barnes, C.W.; Batistoni, P. [ITER San Diego Joint Work Site, La Jolla, CA (United States)] [and others

1998-12-31

132

Multichannel camera calibration  

NASA Astrophysics Data System (ADS)

For the latest computer vision applications, it becomes more and more popular to take advantage of multichannel cameras (RGB cameras, etc.) to obtain not only gray values but also color information of pixels. The currently most common approach for multichannel camera calibration is the straightforward application of methods developed for calibration of single channel cameras. These conventional calibration methods may give quite poor performances including color fringes and displacement of features, especially for high-resolution multichannel cameras. In order to suppress the undesired effects, a novel multichannel camera calibration approach is introduced and evaluated in this paper. This approach considers each single channel individually and involves different transversal chromatic aberration models. In comparison to the standard approach, the proposed approach provides more accurate calibration results in most cases and should lead subsequently to more reliable estimation results for computer vision issues. Moreover, besides the existing transversal chromatic aberration (TCA) model, further TCA models and correction methods are introduced which are superior to the existing ones. Since the proposed approach is based on the most popular calibration routine, only minimal modifications have to be made to the existing approaches to obtain the improved calibration quality.

Li, Wei; Klein, Julie

2013-01-01

133

The WHIRC near-IR Camera  

NASA Astrophysics Data System (ADS)

WHIRC is a near-IR (0.9-2.5 micron) camera for the WIYN 3.5m telescope. WHIRC frequently delivers seeing limited performance of approximately 0.5-0.6" FWHM. When the seeing is very good, applying tip-tilt first-order AO corrections with the WIYN-Tip-Tilt-Module(WTTM) can produce near diffraction-limited images (0.20") in the Ks band. A suite of broad and narrow-band filters are available. These capabilities have seen WHIRC rapidly become one of the most popular and productive instruments on WIYN.

Rajagopal, Jayadev

2013-06-01

134

Mars Exploration Rover Engineering Cameras  

Microsoft Academic Search

NASA's Mars Exploration Rover (MER) Mission will place a total of 20 cameras (10 per rover) onto the surface of Mars in early 2004. Fourteen of the 20 cameras are designated as engineering cameras and will support the operation of the vehicles on the Martian surface. Images returned from the engineering cameras will also be of significant importance to the

J. N. Maki; J. F. Bell; K. E. Herkenhoff; S. W. Squyres; A. Kiely; M. Klimesh; M. Schwochert; T. Litwin; R. Willson; A. Johnson; M. Maimone; E. Baumgartner; A. Collins; M. Wadsworth; S. T. Elliot; A. Dingizian; D. Brown; E. C. Hagerott; L. Scherr; R. Deen; D. Alexander; J. Lorre

2003-01-01

135

Camera Calibration Using Line Correspondences  

Microsoft Academic Search

In this paper, a method of determining the essential matrix for uncalibrated cameras is given, based on line matches in three images. The three cameras may have different unknown calibrations, and the essential matrices corresponding to each of the three pairs of cameras may be determined. Determination of the essential matrix for uncalibrated cameras is important, forming the basis for

Richard I. Hartley

1993-01-01

136

Cinematic Camera as Videogame Cliché  

Microsoft Academic Search

Because the videogame camera is not an optical camera, it can be programmed to represent a potentially infinite number of perspectives beyond the classic, representational linear perspective. However, an ongoing collusion of the optical camera and the videogame camera leads videogame designs to favor cinematic visual patterns. Classic videogames show a strong tradition of non-optical, non-cinematic perspectives and prove the

David Thomas; Gary Haussmann

137

Viewing angle control mode using nematic bistability.  

PubMed

As an approach using bistable nematic liquid crystals, we present a liquid crystal display with viewing angle control using two stable states, splay and 180 degrees-twist at pi cell, with three terminal electrode structures. The splay state is controlled by in-plane switching for a wide viewing angle (WVA), while the 180 degrees-twist state is operated by vertical switching for a narrow viewing angle (NVA). With this bistable mode, we fabricated viewing angle-controlled LCDs without additional optical components. PMID:18542350

Gwag, Jin Seog; Lee, You-Jin; Kim, Myung-Eun; Kim, Jae-Hoon; Kim, Jae Chang; Yoon, Tae-Hoon

2008-02-18

138

ROSAT wide field camera mirrors.  

PubMed

The ROSAT wide field camera (WFC) is an XUV telescope operating in the 12-250-eV energy band. The mirror system utilizes Wolter-Schwarzschild type I (WS I) grazing incidence optics with a focal length of 525 mm, comprised of three nested aluminum shells with an outermost diameter of 576 mm providing a geometric aperture area of 456 cm(2). The reflecting surfaces are electroless nickel plated and coated with gold to enhance their reflectivity in the XUV. The mirrors have undergone full aperture optical testing, narrow beam XUV testing, and full aperture XUV testing. Measurements of the reflectivity are compared to theoretical values derived from the optical constants of gold in the XUV range. Analysis of the focused distribution is used to estimate the surface roughness and figuring errors of the polished surfaces. The results are compared to the mechanical metrology data collected during manufacture of the shells and the power spectral density of the reflecting surfaces is found to have a power-law form. PMID:20531591

Willingale, R

1988-04-15

139

Rosat wide field camera mirrors  

NASA Astrophysics Data System (ADS)

The Rosat wide field camera is an XUV telescope operating in the 12-250-eV energy band. The mirror system utilizes Wolter-Schwarzschild type I grazing incidence optics with a focal length of 525 mm, comprised of three nested aluminum shells with an outermost diameter of 576 mm which provide a geometric aperture area of 456 sq cm. The reflecting surfaces are coated with gold to enchance their reflectivity in the XUV. The mirrors have undergone full aperture optical testing, narrow beam XUV testing, and full aperture XUV testing. Measurements of the reflectivity are compared to theoretical values derived from the optical constants of gold in the XUV range. Analysis of the focused distribution is used to estimate the surface roughness and figuring errors of the polished surfaces. The results are compared to the mechanical metrology data collected during manufacture of the shells, and the power spectral density of the reflecting surfaces is found to have a power-law form.

Willingale, R.

1988-04-01

140

The multifocus plenoptic camera  

NASA Astrophysics Data System (ADS)

The focused plenoptic camera is based on the Lippmann sensor: an array of microlenses focused on the pixels of a conventional image sensor. This device samples the radiance, or plenoptic function, as an array of cameras with large depth of field, focused at a certain plane in front of the microlenses. For the purpose of digital refocusing (which is one of the important applications) the depth of field needs to be large, but there are fundamental optical limitations to this. The solution of the above problem is to use and array of interleaved microlenses of different focal lengths, focused at two or more different planes. In this way a focused image can be constructed at any depth of focus, and a really wide range of digital refocusing can be achieved. This paper presents our theory and results of implementing such camera. Real world images are demonstrating the extended capabilities, and limitations are discussed.

Georgiev, Todor; Lumsdaine, Andrew

2012-01-01

141

Narrow tetraquarks at large N  

NASA Astrophysics Data System (ADS)

Following a recent suggestion by Weinberg, we use the large-N expansion in QCD to discuss the decay amplitudes of tetraquarks into ordinary mesons as well as their mixing properties. We find that the flavor structure of the tetraquark is a crucial ingredient to determine both this mixing as well as the decays. Although in some cases tetraquarks should be expected to be as narrow as ordinary mesons, they may get to be even narrower, depending on this flavor structure.

Knecht, Marc; Peris, Santiago

2013-08-01

142

Make a Pinhole Camera  

ERIC Educational Resources Information Center

|On Earth, using ordinary visible light, one can create a single image of light recorded over time. Of course a movie or video is light recorded over time, but it is a series of instantaneous snapshots, rather than light and time both recorded on the same medium. A pinhole camera, which is simple to make out of ordinary materials and using…

Fisher, Diane K.; Novati, Alexander

2009-01-01

143

Jack & the Video Camera  

ERIC Educational Resources Information Center

|This article narrates how the use of video camera has transformed the life of Jack Williams, a 10-year-old boy from Colorado Springs, Colorado, who has autism. The way autism affected Jack was unique. For the first nine years of his life, Jack remained in his world, alone. Functionally non-verbal and with motor skill problems that affected his…

Charlan, Nathan

2010-01-01

144

Communities, Cameras, and Conservation  

ERIC Educational Resources Information Center

|Communities, Cameras, and Conservation (CCC) is the most exciting and valuable program the author has seen in her 30 years of teaching field science courses. In this citizen science project, students and community volunteers collect data on mountain lions ("Puma concolor") at four natural areas and public parks along the Front Range of Colorado.…

Patterson, Barbara

2012-01-01

145

A smart fast camera  

NASA Astrophysics Data System (ADS)

It is generally believed that very fast cameras imaging large Fields of View translate into huge optomechanics and mosaics of very large contiguous CCDs. It has already been suggested that seeing limited imaging cameras for telescopes whose diameters are larger than 20m are considered virtually impossible for a reasonable cost. We show here that, using existing technology and at a moderate price, one can build a Smart Fast Camera, a device that placed on aberrated Field of View, including those of slow focal ratios, is able to provide imaging at an equivalent focal ratio as low as F/1, with a size that is identical to the large focal ratio focal plane size. The design allows for easy correction of aberrations over the Field of View. It has low weight and size with respect to any focal reducer or prime focus station of the same performance. It can be applied to existing 8m-class telescopes to provide a wide field fast focal plane or to achieve seeing-limited imaging on Extremely Large Telescopes. As it offers inherently fast read-out in a massive parallel mode, the SFC can be used as a pupil or focal plane camera for pupil-plane or Shack-Hartmann wavefront sensing for 30-100m class telescopes.

Ragazzoni, Roberto; Arcidiacono, Carmelo; Diolaiti, Emiliano; Farinato, Jacopo; Moore, Anna M.; Soci, Roberto

2004-09-01

146

The LSST Camera Overview  

SciTech Connect

The LSST camera is a wide-field optical (0.35-1um) imager designed to provide a 3.5 degree FOV with better than 0.2 arcsecond sampling. The detector format will be a circular mosaic providing approximately 3.2 Gigapixels per image. The camera includes a filter mechanism and, shuttering capability. It is positioned in the middle of the telescope where cross-sectional area is constrained by optical vignetting and heat dissipation must be controlled to limit thermal gradients in the optical beam. The fast, f/1.2 beam will require tight tolerances on the focal plane mechanical assembly. The focal plane array operates at a temperature of approximately -100 C to achieve desired detector performance. The focal plane array is contained within an evacuated cryostat, which incorporates detector front-end electronics and thermal control. The cryostat lens serves as an entrance window and vacuum seal for the cryostat. Similarly, the camera body lens serves as an entrance window and gas seal for the camera housing, which is filled with a suitable gas to provide the operating environment for the shutter and filter change mechanisms. The filter carousel can accommodate 5 filters, each 75 cm in diameter, for rapid exchange without external intervention.

Gilmore, Kirk; Kahn, Steven A.; Nordby, Martin; Burke, David; O'Connor, Paul; Oliver, John; Radeka, Veljko; Schalk, Terry; Schindler, Rafe; /SLAC

2007-01-10

147

The Beagle 2 stereo camera system  

NASA Astrophysics Data System (ADS)

The stereo camera system (SCS) was designed to provide wide-angle multi-spectral stereo imaging of the Beagle 2 landing site. Based on the Space-X micro-cameras, the primary objective was to construct a digital elevation model of the area in reach of the lander's robot arm. The SCS technical specifications and scientific objectives are described; these included panoramic 3-colour imaging to characterise the landing site; multi-spectral imaging to study the mineralogy of rocks and soils beyond the reach of the arm and solar observations to measure water vapour absorption and the atmospheric dust optical density. Also envisaged were stellar observations to determine the lander location and orientation, multi-spectral observations of Phobos & Deimos and observations of the landing site to monitor temporal changes.

Griffiths, A. D.; Coates, A. J.; Josset, J.-L.; Paar, G.; Hofmann, B.; Pullan, D.; Rüffer, P.; Sims, M. R.; Pillinger, C. T.

2005-12-01

148

Data on Separation and Position Angle of Binary Star Systems  

Microsoft Academic Search

Data on separation and position angle of binary star systems Abstract: We report on data gathered for the measurement of separation and position angle of binary stars. The coupling of a CCD camera to a telescope allows us to use a precise simple and straightforward method for such measurements. We use the 31 inch National Undergraduate Research Observatory (NURO) Telescope

Rafael J. Muller; D. C. Centeno; L. Rivera-Rivera; J. C. Cersosimo; K. Morales; K. Ramos; E. Franco; V. Miranda; V. Maldonado

2009-01-01

149

Quality criterion for digital still camera  

NASA Astrophysics Data System (ADS)

The main quality requirements for a digital still camera are color capturing accuracy, low noise level, and quantum efficiency. Different consumers assign different priorities to the listed parameters, and camera designers need clearly formulated methods for their evaluation. While there are procedures providing noise level and quantum efficiency estimation, there are no effective means for color capturing accuracy estimation. Introduced in this paper criterion allows to fill this gap. Luther-Ives condition for correct color reproduction system became known in the beginning of the last century. However, since no detector system satisfies Luther-Ives condition, there are always stimuli that are distinctly different for an observer, but which detectors are unable to distinguish. To estimate conformity of a detector set with Luther-Ives condition and calculate a measure of discrepancy, an angle between detector sensor sensitivity and Cohen's Fundamental Color Space may be used. In this paper, the divergence angle is calculated for some typical CCD sensors and a demonstration provided on how this angle might be reduced with a corrective filter. In addition, it is shown that with a specific corrective filter Foveon sensors turn into a detector system with a good Luther-Ives condition compliance.

Bezryadin, Sergey

2007-03-01

150

Camera data sheet for pictorial electronic still cameras  

Microsoft Academic Search

A data sheet is presented outlining the performance and characteristics of a Kodak DCS 200mi camera. In addition to providing information on this camera, the format and content of the data sheet could serve as a guide in the organization and display of pertinent information on electronic still cameras in general. Such data sheets are already common in silver halide

Sabine Susstrunk; Jack M. Holm

1995-01-01

151

Relative Position Estimation Using Airport Image from a Camera of Missile-borne  

Microsoft Academic Search

In vision aided terminal inertial navigation system, the camera always attaches rigidly, or straps down, to the body of missile. Because the pitch angle of the missile usually is not constant and varies with time, the optical axis of the camera is not vertical. Then the rectangular border of the runway stripe in horizontal land plane is projected as trapezoid

Dongxue Yue; Xinsheng Huang; Hongli Tan; Qingwei Yang

2007-01-01

152

A wide-angle scanning optical antenna  

Microsoft Academic Search

The design of a modified Rinehart metal dome antenna with a dielectric ring lens at the output edge is discussed. This antenna provides wide-angle scanning of a narrow beam. The dome shape, which provides perfect focus in the plane of scan, is determined by solving an integral equation. The dielectric lens focuses in the plane perpendicular to the plane scan,

E. C. Dufort; H. Uyeda

1983-01-01

153

The gonial angle stripper: an instrument for the treatment of prominent gonial angle.  

PubMed

In the Orient, a prominent gonial angle, so-called benign masseteric hypertrophy, is rather common and considered unattractive. Therefore, its surgical correction is one of the most popular forms of facial skeletal contouring. For accurate and safe osteotomy of the mandibular angle region, a gonial angle stripper was specially invented. It has a small projection that will ease identification of the osteotomy line in a narrow operative field. The tool has been clinically used in eight patients to prove its usefulness, especially for a posteriorly developed mandibular angle. PMID:7880065

Kyutoku, S; Yanagida, A; Kusumoto, K; Ogawa, Y

1994-12-01

154

Depth perception with a rotationally symmetric coded camera  

Microsoft Academic Search

A novel design of a phase coded depth-sensing camera is presented. A rotational symmetric phase mask is designed to discriminate the point spread functions (PSF) from different scene distances. The depth information can then be computationally obtained from a single captured photograph through a phase coded lens. The PSF must be carefully optimized at off-axis angles in order to create

Chuan-Chung Chang; Yung-Lin Chen; Chir-Weei Chang; Cheng-Chung Lee

2009-01-01

155

Camera Phone Based Presentation Control  

Microsoft Academic Search

Due to the recent progress of technology, camera phones are becoming an indispensable part of our daily life. Their functions are no longer limited to pure voice communications. Instead camera phones can be used for many additional functions such as taking pictures or listening to music. This project aims to explore the possibility of converting a camera phone to an

Carolyn Hafernik; Faculty Mentor; John Canny; Jingtao Wang

156

Narrow bandpass widely tunable Fabry-Perot filter  

Microsoft Academic Search

This paper presents the results of the analysis and experimental characterization of a narrow bandpass optical filter based on the Fabry-Perot interferometer configuration with a variable spacing between the mirrors allowing for a relatively wide spectral tunability. Such a filter with a high-throughput bandpass and sufficiently large aperture and acceptance angle is of practical interest for a high-resolution spectral measurements

Vladimir B. Markov; Anatoly I. Khizhnyak; Vladimir Goren; William B. Cook

2005-01-01

157

Limits on neutrino oscillations in the Fermilab narrow band beam  

SciTech Connect

A search for neutrino oscillations was made using the Fermilab narrow-band neutrino beam and the 15 ft. bubble chamber. No positive signal for neutrino oscillations was observed. Limits were obtained for mixing angles and neutrino mass differences for nu/sub ..mu../ ..-->.. nu/sub e/, nu/sub ..mu../ ..-->.. nu/sub tau/, nu/sub e/ ..-->.. nu/sub e/. 5 refs.

Brucker, E.B.; Jacques, P.F.; Kalelkar, M.; Koller, E.L.; Plano, R.J.; Stamer, P.E.; Baker, N.J.; Connolly, P.L.; Kahn, S.A.; Murtagh, M.J.

1986-01-01

158

Combustion pinhole camera system  

DOEpatents

A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor. 2 figs.

Witte, A.B.

1984-02-21

159

NSTX Tangential Divertor Camera  

SciTech Connect

Strong magnetic field shear around the divertor x-point is numerically predicted to lead to strong spatial asymmetries in turbulence driven particle fluxes. To visualize the turbulence and associated impurity line emission near the lower x-point region, a new tangential observation port has been recently installed on NSTX. A reentrant sapphire window with a moveable in-vessel mirror images the divertor region from the center stack out to R 80 cm and views the x-point for most plasma configurations. A coherent fiber optic bundle transmits the image through a remotely selected filter to a fast camera, for example a 40500 frames/sec Photron CCD camera. A gas puffer located in the lower inboard divertor will localize the turbulence in the region near the x-point. Edge fluid and turbulent codes UEDGE and BOUT will be used to interpret impurity and deuterium emission fluctuation measurements in the divertor.

A.L. Roquemore; Ted Biewer; D. Johnson; S.J. Zweben; Nobuhiro Nishino; V.A. Soukhanovskii

2004-07-16

160

Combustion pinhole camera system  

DOEpatents

A pinhole camera system utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

Witte, Arvel B. (Rolling Hills, CA)

1984-02-21

161

Accurate camera calibration method specialized for virtual studios  

NASA Astrophysics Data System (ADS)

Virtual studio is a popular technology for TV programs, that makes possible to synchronize computer graphics (CG) to realshot image in camera motion. Normally, the geometrical matching accuracy between CG and realshot image is not expected so much on real-time system, we sometimes compromise on directions, not to come out the problem. So we developed the hybrid camera calibration method and CG generating system to achieve the accurate geometrical matching of CG and realshot on virtual studio. Our calibration method is intended for the camera system on platform and tripod with rotary encoder, that can measure pan/tilt angles. To solve the camera model and initial pose, we enhanced the bundle adjustment algorithm to fit the camera model, using pan/tilt data as known parameters, and optimizing all other parameters invariant against pan/tilt value. This initialization yields high accurate camera position and orientation consistent with any pan/tilt values. Also we created CG generator implemented the lens distortion function with GPU programming. By applying the lens distortion parameters obtained by camera calibration process, we could get fair compositing results.

Okubo, Hidehiko; Yamanouchi, Yuko; Mitsumine, Hideki; Fukaya, Takashi; Inoue, Seiki

2008-02-01

162

Gamma ray camera  

DOEpatents

A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

Perez-Mendez, V.

1997-01-21

163

Gamma ray camera  

DOEpatents

A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

Perez-Mendez, Victor (Berkeley, CA)

1997-01-01

164

[Drugs and closed-angle glaucoma risk].  

PubMed

Closed-angle glaucomas arise among predisposed patients (narrow iridocorneal angle) in response to various stimuli. Most of the attacks are of iatrogenic origin: all the topical and systemic mydriatic drugs can provoke an angle closure glaucoma attack. Dangerous active ingredients with closed-angle glaucoma are active substances with anticholinergic activity (peripheral action, central action, with anticholinergic side-effects), active ingredients with sympathomimetic alpha activity (alpha 1, alpha and beta with indirect effects), and the active ingredients with parasympathomimetic activity (anticholinesterases). The proprietary medicine, whether or not they are included in the French dictionary Vidal((R)), are classified according to the administration route and their different indications. The closed-angle glaucoma risk after administration of these drugs is noted in the items'contraindications and precautions in the summary of the product characteristics enclosed in the marketing authorization. PMID:11965126

Pozzi, D; Giraud, C; Callanquin, M

2002-01-01

165

Synthetic Doppler spectroscopy and curvilinear camera diagnostics in the ERO code  

NASA Astrophysics Data System (ADS)

We present a set of new synthetic diagnostics, recently implemented in the ERO code, that were developed to facilitate direct comparisons between experiments and modeling of tokamak scrape-off-layer plasmas. The diagnostics calculate the spectroscopic Doppler shift and Doppler broadening of impurity lines of interest for any line of sight, and they also generate camera images from arbitrary viewing angles allowing for curvilinear (e.g., wide-angle or fisheye) lenses. The synthetic camera diagnostics can either replicate the distortions caused by curvilinear lenses or create a rectilinear synthetic camera image and correct the curvilinear distortions in the experimental image. Comparison to experimental data is presented.

Makkonen, T.; Groth, M.; Airila, M. I.; Dux, R.; Janzer, A.; Kurki-Suonio, T.; Lunt, T.; Mueller, H. W.; Puetterich, T.; Viezzer, E.

2013-08-01

166

Characterization of Previously Unidentified Lunar Pyroclastic Deposits using Lunar Reconnaissance Orbiter Camera (LROC) Data  

NASA Astrophysics Data System (ADS)

We used a Lunar Reconnaissance Orbiter Cameras (LROC) global monochrome Wide Angle Camera (WAC) mosaic to conduct a survey of the Moon to search for previously unidentified pyroclastic deposits. Promising locations were examined in detail using LROC multispectral WAC mosaics, high-resolution LROC Narrow Angle Camera (NAC) images, and Clementine multispectral (ultraviolet-visible, or UVVIS) data. Out of 47 potential deposits chosen for closer examination, 13 were selected as probable newly identified pyroclastic deposits. Potential pyroclastic deposits were generally found in settings similar to previously identified deposits, including areas within or near mare deposits adjacent to highlands, within floor-fractured craters, and along fissures in mare deposits. A significant new finding is the discovery of localized pyroclastic deposits within floor-fractured craters Anderson E & F on the lunar farside, isolated from other known similar deposits. These appear to be Alphonsus-type deposits erupted from a series of small vents aligned with the fracture system, suggesting their origin in volatile-rich vulcanian-style eruptions containing relatively small amounts of juvenile material. The presence of such volcanic features on the lunar farside outside of the major basins such as Moscoviense, Orientale, and South Pole - Aitken indicates that magma ascent and eruption have occurred even in the central farside highlands, despite the thicker farside crust. However, this is the only such occurrence that we have located, and it appears to represent an endpoint in the continuum of eruption styles where the eruption was just barely able to reach the surface but could not transport enough magma to the surface to form an effusive deposit. Many of the 47 potential locations screened were eliminated from consideration based on inconclusive evidence regarding their mode of emplacement. Additional optical imaging, or analyses of other data sets such as radar, imaging spectroscopy, or thermal inertia, could result in identification of additional pyroclastic deposits, especially lighter-toned deposits. However, our search also confirms that most major regional and localized pyroclastic deposits have likely been identified on the Moon down to ~100 m/pix resolution, and that additional newly identified pyroclastic deposits are likely to be either isolated small deposits or additional portions of discontinuous, patchy deposits. Based on the locations where we identified previously unidentified pyroclastic deposits, the greatest potential for identification of additional pyroclastic deposits is likely to be in regions with other volcanic constructs associated with mare deposits, highland locations along the margins of maria, and smaller floor-fractured craters that have not yet been thoroughly imaged at higher resolution, particularly on the farside (such as Anderson E & F).

Gustafson, O.; Bell, J. F.; Gaddis, L. R.; Hawke, B. R.; Giguere, T.

2011-12-01

167

Axi-vision camera: a three-dimensional camera  

NASA Astrophysics Data System (ADS)

A novel 3D camera named Axi-vision camera was developed. IT can acquire both color and distance information of objects. An intensity-modulated light illuminates objects and the camera with an ultra-fast shutter captures the light reflected from the scene. The distance information is obtained from two images of the same scene taken under linearly increasing and decreasing illuminations. The camera does not require scanning, multiple camera units, or complicated computations. It is possible to acquire distance information for each pixel of a TV image at real time. The operational features and technical specifications of the camera were investigated. The application to TV program production, such as replacing the image of an object at a particular distance by another, was demonstrated. A new 3D display system is also proposed, developed and demonstrated.

Kawakita, Masahiro; Iizuka, Keigo; Aida, Tahito; Kikuchi, Hiroshi; Fujikake, Hideo; Yonai, Jun; Takizawa, Kuniharu

2000-03-01

168

Phoenix Robotic Arm Camera  

NASA Astrophysics Data System (ADS)

The Phoenix Robotic Arm Camera (RAC) is a variable-focus color camera mounted to the Robotic Arm (RA) of the Phoenix Mars Lander. It is designed to acquire both close-up images of the Martian surface and microscopic images (down to a scale of 23 ?m/pixel) of material collected in the RA scoop. The mounting position at the end of the Robotic Arm allows the RAC to be actively positioned for imaging of targets not easily seen by the Stereo Surface Imager (SSI), such as excavated trench walls and targets under the Lander structure. Color information is acquired by illuminating the target with red, green, and blue light-emitting diodes. Digital terrain models (DTM) can be generated from RAC images acquired from different view points. This can provide high-resolution stereo information about fine details of the trench walls. The large stereo baseline possible with the arm can also provide a far-field DTM. The primary science objectives of the RAC are the search for subsurface soil/ice layering at the landing site and the characterization of scoop samples prior to delivery to other instruments on board Phoenix. The RAC shall also provide low-resolution panoramas in support of SSI activities and acquire images of the Lander deck for instrument and Lander check out. The camera design was inherited from the unsuccessful Mars Polar Lander mission (1999) and further developed for the (canceled) Mars Surveyor 2001 Lander (MSL01). Extensive testing and partial recalibration qualified the MSL01 RAC flight model for integration into the Phoenix science payload.

Keller, H. U.; Goetz, W.; Hartwig, H.; Hviid, S. F.; Kramm, R.; Markiewicz, W. J.; Reynolds, R.; Shinohara, C.; Smith, P.; Tanner, R.; Woida, P.; Woida, R.; Bos, B. J.; Lemmon, M. T.

2008-10-01

169

Adaptive compressive sensing camera  

NASA Astrophysics Data System (ADS)

We have embedded Adaptive Compressive Sensing (ACS) algorithm on Charge-Coupled-Device (CCD) camera based on the simplest concept that each pixel is a charge bucket, and the charges comes from Einstein photoelectric conversion effect. Applying the manufactory design principle, we only allow altering each working component at a minimum one step. We then simulated what would be such a camera can do for real world persistent surveillance taking into account of diurnal, all weather, and seasonal variations. The data storage has saved immensely, and the order of magnitude of saving is inversely proportional to target angular speed. We did design two new components of CCD camera. Due to the matured CMOS (Complementary metal-oxide-semiconductor) technology, the on-chip Sample and Hold (SAH) circuitry can be designed for a dual Photon Detector (PD) analog circuitry for changedetection that predicts skipping or going forward at a sufficient sampling frame rate. For an admitted frame, there is a purely random sparse matrix [?] which is implemented at each bucket pixel level the charge transport bias voltage toward its neighborhood buckets or not, and if not, it goes to the ground drainage. Since the snapshot image is not a video, we could not apply the usual MPEG video compression and Hoffman entropy codec as well as powerful WaveNet Wrapper on sensor level. We shall compare (i) Pre-Processing FFT and a threshold of significant Fourier mode components and inverse FFT to check PSNR; (ii) Post-Processing image recovery will be selectively done by CDT&D adaptive version of linear programming at L1 minimization and L2 similarity. For (ii) we need to determine in new frames selection by SAH circuitry (i) the degree of information (d.o.i) K(t) dictates the purely random linear sparse combination of measurement data a la [?]M,N M(t) = K(t) Log N(t).

Hsu, Charles; Hsu, Ming K.; Cha, Jae; Iwamura, Tomo; Landa, Joseph; Nguyen, Charles; Szu, Harold

2013-05-01

170

Smithsonian Widefield Infrared Camera  

NASA Astrophysics Data System (ADS)

The Smithsonian Widefield Infrared Camera (SWIRC) is a Y -, J-, and H-band imager for the f/5 MMT. Proposed in May 2003 and commissioned in June 2004, the goal of the instrument was to deliver quickly a wide field-of-view instrument with minimal optical elements and hence high throughput. The trade-off; was to sacrifice K-band capability by not having an internal, cold Lyot stop. We describe SWIRC's design and capabilities, and discuss lessons learned from the thermal design and the detector mount, all of which have been incorporated into the upcoming MMT & Magellan Infrared Spectrograph.

Brown, Warren R.; McLeod, Brian A.; Geary, John C.; Bowsher, Emily C.

2008-08-01

171

Neutron imaging camera  

NASA Astrophysics Data System (ADS)

The Neutron Imaging Camera (NIC) is based on the Three-dimensional Track Imager (3_DTI) technology developed at GSFC for gamma-ray astrophysics applications. The 3-DTI, a large volume time-projection chamber, provides accurate, ~0.4 mm resolution, 3-D tracking of charged particles. The incident direction of fast neutrons, En > 0.5 MeV, are reconstructed from the momenta and energies of the proton and triton fragments resulting from 3He(n,p)3H interactions in the 3-DTI volume. The performance of the NIC from laboratory is presented.

Hunter, S. D.; de Nolfo, G. A.; Barbier, L. M.; Link, J. T.; Son, S.; Floyd, S. R.; Guardala, N.; Skopec, M.; Stark, B.

2008-05-01

172

6.RP Security Camera  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: A shop owner wants to prevent shoplifting. He decides to install a security camera on the ceiling of his shop. Below is a picture of the shop floor pla...

173

The influence of tilt angle on the acoustic target strength of the Japanese common squid (Todarodes pacificus)  

Microsoft Academic Search

To measure the influence of changes in tilt angle on the acoustic target strength (TS) of the Japanese common squid (Todarodes pacificus), we conducted a series of experiments to estimate TS in relation to tilt angle and swimming angle. Swimming angle was measured in a seawater tank using two infrared, underwater cameras under dark conditions. Ex situ measurements of TS

Donhyug Kang; Tohru Mukai; Kohji Iida; Doojin Hwang; Jung-Goo Myoung

2005-01-01

174

2000 FPS digital airborne camera  

NASA Astrophysics Data System (ADS)

For many years 16 mm film cameras have been used in severe environments. These film cameras are used on Hy-G automotive sleds, airborne weapon testing, range tracking, and other hazardous environments. The companies and government agencies using these cameras are in need of replacing them with a more cost-effective solution. Film-based cameras still produce the best resolving capability. However, film development time, chemical disposal, non-optimal lighting conditions, recurring media cost, and faster digital analysis are factors influencing the desire for a 16 mm film camera replacement. This paper will describe a new imager from Kodak that has been designed to replace 16 mm high- speed film cameras. Also included is a detailed configuration, operational scenario, and cost analysis of Kodak's imager for airborne applications.

Balch, Kris S.

1998-11-01

175

91. 22'X34' original blueprint, VariableAngle Launcher, 'CONNECTING BRIDGE, REAR VIEW ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

91. 22'X34' original blueprint, Variable-Angle Launcher, 'CONNECTING BRIDGE, REAR VIEW CAMERA HOUSE ASSEMBLY' drawn at 3/8=1'-0', 3'=1'-0'. (BUORD Sketch # 209042). - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

176

PAU camera: detectors characterization  

NASA Astrophysics Data System (ADS)

The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

Casas, Ricard; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Jiménez, Jorge; Maiorino, Marino; Pío, Cristóbal; Sevilla, Ignacio; de Vicente, Juan

2012-07-01

177

Stereoscopic camera design  

NASA Astrophysics Data System (ADS)

It is clear from the literature that the majority of work in stereoscopic imaging is directed towards the development of modern stereoscopic displays. As costs come down, wider public interest in this technology is expected to increase. This new technology would require new methods of image formation. Advances in stereo computer graphics will of course lead to the creation of new stereo computer games, graphics in films etc. However, the consumer would also like to see real-world stereoscopic images, pictures of family, holiday snaps etc. Such scenery would have wide ranges of depth to accommodate and would need also to cope with moving objects, such as cars, and in particular other people. Thus, the consumer acceptance of auto/stereoscopic displays and 3D in general would be greatly enhanced by the existence of a quality stereoscopic camera. This paper will cover an analysis of existing stereoscopic camera designs and show that they can be categorized into four different types, with inherent advantages and disadvantages. A recommendation is then made with regard to 3D consumer still and video photography. The paper will go on to discuss this recommendation and describe its advantages and how it can be realized in practice.

Montgomery, David J.; Jones, Christopher K.; Stewart, James N.; Smith, Alan

2002-05-01

178

The LSST camera instrument model  

NASA Astrophysics Data System (ADS)

The design of the Large Synoptic Survey Telescope (LSST) requires a camera system of unprecedented size and complexity. Achieving the science goals of the LSST project, through design, fabrication, integration, and operation, requires a thorough understanding of the camera performance. Essential to this effort is the camera modeling which defines the effects of a large number of potential mechanical, optical, electronic or sensor variations which can only be captured with sophisticated instrument modeling that incorporates all of the crucial parameters. This paper presents the ongoing development of LSST camera instrument modeling and details the parametric issues and attendant analysis involved with this modeling.

Gilmore, D. Kirk K.; Kahn, Steven; Hascall, Pat; Ku, John; O'Connor, Paul; Rasmussen, Andrew; Riot, Vincent; Singal, Jack

2012-09-01

179

A video camera system for multispectral sensing  

NASA Astrophysics Data System (ADS)

A brief description is given of a 4-band video data acquisition system designed to operate with one recorder in narrow spectral bands in the visible and near IR spectrum. It is designed to utilize four black and white solid-state cameras, a custom-built multiplexer, one 3/4 or 1/2 inch tape recorder, and a small black and white monitor. The acquired imagery can be played back as is in rapid-band sequencing for viewing or the individual bands can be displayed in 'freeze frame' mode for digitization and computer image processing. The first flight using ultricon tube (f = 8 mm) cameras at three diferent altitudes was conducted in October 1984 north of Toronto. The results given here describe digital analysis at 256 x 256 pixel resolution of two sets of 4-band video taken with 40 nm bandpass filters centered at 550 nm, 650 nm, 700 nm, and 800 nm wavelengths, one set taken at 305 m, and the other at 610 m altitude.

King, D.; Vlcek, J.; Shemilt, S.

180

Matched tandem etalon camera - MATEC - and its application to auroral observations  

Microsoft Academic Search

The matched tandem etalon camera employs a Fabry-Perot interferometer (FP) in the photographic mode for the spatial resolution over all angles up to 7 deg from normal. An interference filter and an appropriate field lens isolate a single order of 0.1 A resolution, which is recorded simultaneously at all angles in the field of view by array detection. Thus the

E. R. Young; K. C. Clark

1980-01-01

181

Digital synchroballistic schlieren camera for high-speed photography of bullets and rocket sleds  

NASA Astrophysics Data System (ADS)

A high-speed digital streak camera designed for simultaneous high-resolution color photography and focusing schlieren imaging is described. The camera uses a computer-controlled galvanometer scanner to achieve synchroballistic imaging through a narrow slit. Full color 20 megapixel images of a rocket sled moving at 480 m/s and of projectiles fired at around 400 m/s were captured, with high-resolution schlieren imaging in the latter cases, using conventional photographic flash illumination. The streak camera can achieve a line rate for streak imaging of up to 2.4 million lines/s.

Buckner, Benjamin D.; L'Esperance, Drew

2013-08-01

182

CPAPIR: a wide-field infrared camera for the Observatoire du Mont Megantic  

NASA Astrophysics Data System (ADS)

CPAPIR is a wide-field infrared camera for use at the Observatoire du mont Megantic and CTIO 1.5 m telescopes. The camera will be primarily a survey instrument with a half-degree field of view, making it one of the most efficient of its kind. CPAPIR will provide broad and narrow band filters within its 0.8 to 2.5 ?m bandpass. The camera is based on a Hawaii-2 2048x2048 HgCdTe detector.

Artigau, Etienne; Doyon, Rene; Vallee, Philippe; Riopel, Martin; Nadeau, Daniel

2004-09-01

183

LRO Camera Imaging of Potential Landing Sites in the South Pole-Aitken Basin  

NASA Astrophysics Data System (ADS)

We show results of WAC (Wide Angle Camera) and NAC (Narrow Angle Camera) imaging of candidate landing sites within the South Pole-Aitken (SPA) basin of the Moon obtained by the Lunar Reconnaissance Orbiter during the first full year of operation. These images enable a greatly improved delineation of geologic units, determination of unit thicknesses and stratigraphy, and detailed surface characterization that has not been possible with previous data. WAC imaging encompasses the entire SPA basin, located within an area ranging from ~ 130-250 degrees east longitude and ~15 degrees south latitude to the South Pole, at different incidence angles, with the specific range of incidence dependent on latitude. The WAC images show morphology and surface detail at better than 100 m per pixel, with spatial coverage and quality unmatched by previous data sets. NAC images reveal details at the sub-meter pixel scale that enable new ways to evaluate the origins and stratigraphy of deposits. Key among new results is the capability to discern extents of ancient volcanic deposits that are covered by later crater ejecta (cryptomare) [see Petro et al., this conference] using new, complementary color data from Kaguya and Chandrayaan-1. Digital topographic models derived from WAC and NAC geometric stereo coverage show broad intercrater-plains areas where slopes are acceptably low for high-probability safe landing [see Archinal et al., this conference]. NAC images allow mapping and measurement of small, fresh craters that excavated boulders and thus provide information on surface roughness and depth to bedrock beneath regolith and plains deposits. We use these data to estimate deposit thickness in areas of interest for landing and potential sample collection to better understand the possible provenance of samples. Also, small regions marked by fresh impact craters and their associated boulder fields are readily identified by their bright ejecta patterns and marked as lander keep-out zones. We will show examples of LROC data including those for Constellation sites on the SPA rim and interior, a site between Bose and Alder Craters, sites east of Bhabha Crater, and sites on and near the “Mafic Mound” [see Pieters et al., this conference]. Together the LROC data and complementary products provide essential information for ensuring identification of safe landing and sampling sites within SPA basin that has never before been available for a planetary mission.

Jolliff, B. L.; Wiseman, S. M.; Gibson, K. E.; Lauber, C.; Robinson, M.; Gaddis, L. R.; Scholten, F.; Oberst, J.; LROC Science; Operations Team

2010-12-01

184

Multiresolution stereoscopic immersive communication using a set of four cameras  

NASA Astrophysics Data System (ADS)

In projection-based virtual reality systems, such as the CAVE, users can observe immersive stereoscopic images. To date, most of the images, projected onto the screens, are synthesized form polygonal models, which represent the virtual world, This is because the resolution and the viewing angle of a real time are not enough for such large screen systems. In this paper, the authors propose a novel approach to avoid the problem by exploiting the human visual systems. In the proposed system, the resolution of the center of view is very high, while that of the rest is not so high. The authors constructed a four-camera system, in which the pairs of NTSC cameras are prepared for both left and right eyes. Four video streams are combined into one video stream and captured by a graphics computer. Wide-angle multi-resolution images are synthesized in real-time from the combined video stream. Thus, we can observe the wide- angle stereoscopic video, while the resolution of the center of view is high enough. Moreover, this paper proposed another configuration of the four-camera system. Experimental results show that we can observe three levels of viewing angle and resolution by the stereoscopic effects, while images for each eye has just two levels. The discontinuities in the multi-resolution images are effectively suppressed by this new lens configuration.

Naemura, Takeshi; Sugita, Kaoru; Takano, Takahide; Harashima, Hiroshi

2000-05-01

185

Digital All-sky cameras VI: Camera design  

NASA Astrophysics Data System (ADS)

In this sixth paper about the development of a digital All-sky camera the final design is described. The camera is based on a Canon EOS 350D, Sigma 4.5mm/F2.8 EX DC fisheye lens and a LC-TEC liquid crystal optical chopper.

Bettonvil, F.

2011-01-01

186

The Advanced Camera for the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

The JHU and Ball Aerospace Advanced Camera for the HST will have a high throughput, wide field (200'' times 200''), optical and I-band camera which is critically sampled at 1000 nm, a high resolution optical and near-UV camera critically sampled at 500 nm, and a high throughput, far-UV camera. The AC's survey capability will be optimized for optical and NIR studies of the early Universe. The optimization is achieved by combining a novel, three-mirror optical design for the wide field camera with high reflectivity optical and NIR mirror and window coatings, a large format CCD optimized for the NIR, and a camera orientation chosen to minimize the time required to move to an adjacent field and begin a new exposure. The AC will increase HST's capability for surveys and discovery in the NIR by at least a factor of 10. We will use ~ 350 CVZ orbits to take contiguous deep V- and I-band WFC images of 0.7 square degrees of sky to investigate the formation and evolution of galaxies and clusters of galaxies, and the nature and large scale distribution of dark matter. In the second survey, we will use Surface Brightness Fluctuations in deep WFC I-band images of early type galaxies to map large scale flow. We will use narrow band and polarimetric HRC and WFC images to address QSOs and AGNs, our second major science area. The cornerstone of our approach to building the AC within the cost and schedule constraints set out in the NASA AO is reliance on STIS design and technology. The detectors and electronics for the far-UV and high resolution cameras are STIS design, and, in fact, may be STIS flight spares. Approximately 80% of the AC electronics modules and mechanisms are ``build to print'' from STIS drawings.

Ford, H.; Broadhurst, T.; Feldman, P.; Bartko, F.; Bely, P.; Brown, R.; Burrows, C.; Clampin, M.; Crocker, J.; Hartig, G.; Postman, M.; Sparks, W.; White, R.; Cheng, E.; Kimble, R.; Neff, S.; Illingworth, G.; Lesser, M.; Miley, G.; Woodruff, R.

1995-05-01

187

Bayesian Multi-Camera Surveillance  

Microsoft Academic Search

The task of multi-camera surveillance is to re- construct the paths taken by all moving objects that are temporarily visible from multiple non-overlapping cameras. We present a Bayesian formalization of this task, where the optimal solution is the set of object paths with the highest posterior probability given the observed data. We show how to eciently approximate the maximum a

Vera Kettnaker; Ramin Zabih

1999-01-01

188

Bridging the Gaps between Cameras  

Microsoft Academic Search

The paper investigates the unsupervised learning of a model of activity for a multi-camera surveillance network that can be created from a large set of observations. This enables the learning algorithm to establish links between camera views associated with an activity. The learning algorithm operates in a correspondence-free manner, exploiting the statistical consistency of the observation data. The derived model

Dimitrios Makris; Tim Ellis; James Black

2004-01-01

189

The "All Sky Camera Network"  

ERIC Educational Resources Information Center

|In 2001, the "All Sky Camera Network" came to life as an outreach program to connect the Denver Museum of Nature and Science (DMNS) exhibit "Space Odyssey" with Colorado schools. The network is comprised of cameras placed strategically at schools throughout Colorado to capture fireballs--rare events that produce meteorites. Meteorites have great…

Caldwell, Andy

2005-01-01

190

Quantitative Approach to Camera Fixation.  

National Technical Information Service (NTIS)

The paper deals with quantitative aspects of camera fixation for a static scene. In general, when the camera undergoes translation and rotation, there is an infinite number of points that produce equal optical flow for any instantaneous point in time. Usi...

D. Raviv

1990-01-01

191

An Educational PET Camera Model  

ERIC Educational Resources Information Center

|Positron emission tomography (PET) cameras are now in widespread use in hospitals. A model of a PET camera has been installed in Stockholm House of Science and is used to explain the principles of PET to school pupils as described here.|

Johansson, K. E.; Nilsson, Ch.; Tegner, P. E.

2006-01-01

192

Radiation camera motion correction system  

DOEpatents

The device determines the ratio of the intensity of radiation received by a radiation camera from two separate portions of the object. A correction signal is developed to maintain this ratio at a substantially constant value and this correction signal is combined with the camera signal to correct for object motion. (Official Gazette)

Hoffer, P.B.

1973-12-18

193

Wide-angle imaging system with fiberoptic components providing angle-dependent virtual material stops  

NASA Astrophysics Data System (ADS)

A strip imaging wide angle optical system is provided. The optical system is provided with a 'virtual' material stop to avoid aberrational effects inherent in wide angle optical systems. The optical system includes a spherical mirror section for receiving light from a 180 deg strip or arc of a target image. Light received by the spherical mirror section is reflected to a frustoconical mirror section for subsequent rereflection to a row of optical fibers. Each optical fiber transmits a portion of the received light to a detector. The optical system exploits the narrow cone of acceptance associated with optical fibers to substantially eliminate vignetting effects inherent in wide angle systems. Further, the optical system exploits the narrow cone of acceptance of the optical fibers to substantially limit spherical aberration. The optical system is ideally suited for any application wherein a 180 deg strip image need be detected, and is particularly well adapted for use in hostile environments such as in planetary exploration.

Vaughan, Arthur H.

1993-11-01

194

Swept Narrow Band Random on Random.  

National Technical Information Service (NTIS)

The implementation of swept narrow band random on random on the HP5451C Fourier Analyzer System and the HP5427A Vibration Control System is discussed. Up to five narrow bands of a dynamically changing narrow band random spectrum can be super-imposed on a ...

F. T. Mercer

1980-01-01

195

Narrow band gap amorphous silicon semiconductors  

Microsoft Academic Search

Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises

A. Madan; A. H. Mahan

1985-01-01

196

Developments towards a filter wheel hyperspectral camera for planetary exploration  

NASA Astrophysics Data System (ADS)

The benefits of hyperspectral imaging in remote sensing applications are well established and it is now routinely exploited in terrestrial applications. However the restrictions imposed on mass and power consumption and the extreme operating conditions encountered in extra-terrestrial environments have limited its widespread use for planetary exploration. Instead multispectral camera systems with typically 10-12 discrete filters are employed, providing only coarse spectral information. By exploiting the properties of interference filters off axis it is possible to obtain additional spectral information. Recent advances in filter technology have made it possible to develop a simple and lightweight wide angle hyperspectral camera employing a filter wheel. The theory of operation and early test results from a prototype camera system are presented.

Gunn, M.; Langstaff, D. P.; Barnes, D.

2011-10-01

197

Water-Soluble Narrow Line Radicals for Dynamic Nuclear Polarization  

PubMed Central

The synthesis of air-stable highly water-soluble organic radicals containing a 1,3-bisdiphenylene-2-phenylallyl (BDPA) core is reported. A sulfonated derivative, SA-BDPA, retains the narrow EPR linewidth (<30 MHz at 5 T) of the parent BDPA in highly concentrated glycerol/water solutions (40 mM), which enables its use as polarizing agent for solid effect dynamic nuclear polarization (SE DNP). Sensitivity enhancement of 110 was obtained in high field magic-angle-spinning nuclear magnetic resonance (MAS NMR) experiments. The ease of synthesis and high maximum enhancements obtained with the BDPA-based radicals constitute a major advance over the trityl-type narrow line polarization agents.

Haze, Olesya; Corzilius, Bjorn; Smith, Albert A.; Griffin, Robert G.; Swager, Timothy M.

2012-01-01

198

Global Environmental Monitoring With Theeos Multi-angle Imaging Spectroradiometer (MISR)  

Microsoft Academic Search

The MISR instrument will provide a unique opportunity for studying the ecology and climate of the Earth through the acquisition of systematic, global multi-angle imagery in reflected sunlight. MISR employs nine cameras: A nadir camera and two banks of four cameras each pointed forward and aftward along the spacecraft ground track to image the Earth at f30.7, f45.6, f60.0, and

D. J. Diner; C. J. Bruegge; J. V. Martonchik; G. W. Bothwell; L. E. Hovland; K. L. Jones

1991-01-01

199

Camera evidence: visibility analysis through a multicamera viewpoint  

NASA Astrophysics Data System (ADS)

A major criterion in the design of backhoes (and other heavy machinery) is the ability of the operator to see all critical portions of the vehicle and the surrounding environment. Computer graphics provides a method for analyzing this ability prior to the building of full-scale wooden models. By placing the computer graphic camera at the operator's eyepoint, designers can detect poor placement of supports, blind spots, etc. In this type of analysis, the camera becomes an active, yet somewhat imperfect, participant in our understanding of what an operator of the backhoe 'sees'. In order to simulate a backhoe operator's vision from within a cab, one needs to expand the angle of view of the camera to mimic unfocused, peripheral vision. A traditional wide-angle lens creates extreme distortions that are not present in 'natural' vision, and is therefore hardly an adequate representation. The solution we arrived at uses seven cameras fanned out horizontally in order to capture a relatively undistorted 155 degree angle of view. In addition, another camera displays and numerically analyzes the percentage of the loader bucket visible and blocked. These two views are presented simultaneously in order to address both the 'naturalistic' and quantitative needs of the designers, as well as to point to the incompleteness of any one representation of a scene. In the next phase of this project we will bring this type of analysis into a machine environment more conducive to interactivity: a backhoe simulator with levers to control the vehicle and bucket positions, viewed through a virtual reality environment.

Bajuk, Mark

1992-06-01

200

Auto-preview camera orientation for environment perception on a mobile robot  

NASA Astrophysics Data System (ADS)

Using wide-angle or omnidirectional camera lenses to increase a mobile robot's field of view introduces nonlinearity in the image due to the 'fish-eye' effect. This complicates distance perception, and increases image processing overhead. Using multiple cameras avoids the fish-eye complications, but involves using more electrical and processing power to interface them to a computer. Being able to control the orientation of a single camera, both of these disadvantages are minimized while still allowing the robot to preview a wider area. In addition, controlling the orientation allows the robot to optimize its environment perception by only looking where the most useful information can be discovered. In this paper, a technique is presented that creates a two dimensional map of objects of interest surrounding a mobile robot equipped with a panning camera on a telescoping shaft. Before attempting to negotiate a difficult path planning situation, the robot takes snapshots at different camera heights and pan angles and then produces a single map of the surrounding area. Distance perception is performed by making calibration measurements of the camera and applying coordinate transformations to project the camera's findings into the vehicle's coordinate frame. To test the system, obstacles and lines were placed to form a chicane. Several snapshots were taken with different camera orientations, and the information from each were stitched together to yield a very useful map of the surrounding area for the robot to use to plan a path through the chicane.

Radovnikovich, Micho; Vempaty, Pavan K.; Cheok, Ka C.

2010-01-01

201

21 CFR 892.1110 - Positron camera.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Positron camera. 892.1110 Section 892.1110 Food...Diagnostic Devices § 892.1110 Positron camera. (a) Identification. A positron camera is a device intended to image the...

2013-04-01

202

Observation of Planetary Motion Using a Digital Camera  

ERIC Educational Resources Information Center

|A digital SLR camera with a standard lens (50 mm focal length, f/1.4) on a fixed tripod is used to obtain photographs of the sky which contain stars up to 8[superscript m] apparent magnitude. The angle of view is large enough to ensure visual identification of the photograph with a large sky region in a stellar map. The resolution is sufficient…

Meyn, Jan-Peter

2008-01-01

203

Interline transfer CCD camera  

DOEpatents

An interline CCD sensing device for use in a camera system, includes an imaging area sensitive to impinging light, for generating charges corresponding to the intensity of the impinging light. Sixteen independent registers R1 - R16 sequentially receive the interline data from the imaging area, corresponding to the generated charges. Sixteen output amplifiers S1 - S16 and sixteen ports P1 - P16 for sequentially transferring the interline data, one pixel at a time, in order to supply a desired image transfer speed. The imaging area is segmented into sixteen independent imaging segments A1 - A16, each of which corresponds to one register, on output amplifier, and one output port. Each one of the imaging segments A1 - A16 includes an array of rows and columns of pixels. Each pixel includes a photogate area, an interline CCD channel area, and an anti-blooming area. The anti-blooming area is, in turn, divided into an anti-blooming barrier and an anti-blooming drain.

Prokop, M.S.; McCurnin, T.W.; Stump, C.J.; Stradling, G.L.

1993-12-31

204

New narrow baryons and dibaryons observed in inelastic pp scattering  

SciTech Connect

Several narrow exotic baryonic states have been recently observed at 1004, 1044, and possibly at 1094 MeV, from the study of pp{yields}p{pi}{sup +}X reaction at different energies (T{sub p}=1520, 1805 and 2100 MeV) and angles from 0 deg. up to 17 deg. (lab.). The small widths: a few MeV, indicate a possible interpretation within multiquark baryons or baryonic resonances. A phenomonological mass formula for two clusters of quarks, predicts masses, quite close to the experimental ones.

Tatischeff, B.; Willis, N.; Comets, M. P.; Courtat, P.; Gacougnolle, R.; Le Bornee, Y.; Loireleux, E.; Reide, F. [Institut de Physique Nucleaire, CNRS/IN2P3, 91406 Orsay Cedex (France); Yonnet, J.; Boivin, M. [Laboratoire National Saturne, CEA/DSM CNRS/IN2P3, 91191 Gif-sur-Yvette Cedex (France)

1998-05-29

205

Computing Epipolar Geometry from Unsynchronized Cameras  

NASA Astrophysics Data System (ADS)

Recently, many application systems have been developed by using a large number of cameras. If 3D points are observed from synchronized cameras, the multiple view geometry of these cameras can be computed and the 3D reconstruction of the scene is available. Thus, the synchronization of multiple cameras is essential. In this paper, we propose a method for synchronizing multiple cameras and for computing the epipolar geometry from uncalibrated and unsynchronized cameras. In particular we using affine invariance to match the frame numbers of camera images for finding the synchronization. The proposed method is tested by using real image sequences taken from uncalibrated and unsynchronized cameras.

Piao, Ying; Sato, Jun

206

Polarizing aperture stereoscopic cinema camera  

NASA Astrophysics Data System (ADS)

The art of stereoscopic cinematography has been held back because of the lack of a convenient way to reduce the stereo camera lenses' interaxial to less than the distance between the eyes. This article describes a unified stereoscopic camera and lens design that allows for varying the interaxial separation to small values using a unique electro-optical polarizing aperture design for imaging left and right perspective views onto a large single digital sensor, the size of the standard 35 mm frame, with the means to select left and right image information. Even with the added stereoscopic capability, the appearance of existing camera bodies will be unaltered.

Lipton, Lenny

2012-07-01

207

BLAST autonomous daytime star cameras  

NASA Astrophysics Data System (ADS)

We have developed two redundant daytime star cameras to provide the fine pointing solution for the balloon-borne submillimeter telescope, BLAST. The cameras are capable of providing a reconstructed pointing solution with an absolute accuracy < 5". They are sensitive to stars down to magnitudes ~ 9 in daytime float conditions. Each camera combines a 1 megapixel CCD with a 200mm f/2 lens to image a 2° × 2.5° field of the sky. The instruments are autonomous. An internal computer controls the temperature, adjusts the focus, and determines a real-time pointing solution at 1 Hz. The mechanical details and flight performance of these instruments are presented.

Rex, Marie; Chapin, Edward; Devlin, Mark J.; Gundersen, Joshua; Klein, Jeff; Pascale, Enzo; Wiebe, Donald

2006-07-01

208

Three-dimensional Camera Phone  

NASA Astrophysics Data System (ADS)

An inexpensive technique for realizing a three-dimensional (3D) camera phone display is presented. Light from the liquid-crystal screen of a camera phone is linearly polarized, and its direction of polarization is easily manipulated by a cellophane sheet used as a half-waveplate. The novel 3D camera phone display is made possible solely by optical components without resorting to computation, so that the 3D image is displayed in real time. Quality of the original image is not sacrificed in the process of converting it into a 3D image.

Iizuka, Keigo

2004-12-01

209

Three-dimensional camera phone.  

PubMed

An inexpensive technique for realizing a three-dimensional (3D) camera phone display is presented. Light from the liquid-crystal screen of a camera phone is linearly polarized, and its direction of polarization is easily manipulated by a cellophane sheet used as a half-waveplate. The novel 3D camera phone display is made possible solely by optical components without resorting to computation, so that the 3D image is displayed in real time. Quality of the original image is not sacrificed in the process of converting it into a 3D image. PMID:15619839

Iizuka, Keigo

2004-12-01

210

Tracking with the Giotto Camera  

NASA Astrophysics Data System (ADS)

The principle of operation of the Giotto Camera is presented. The onboard computer of the camera system is introduced and the principle of the tracking procedure is explained. The test environment for the S/W-development of the onboard computer is outlined. The data generated by the tracking system during the Halley flyby are analyzed. It became evident that the tracking system operated flawlessly. The observed anomalies could be traced to the pointing mechanisms. The operational capability of the camera tracking system is not questionable and hence does not object the planned reactivation.

Krahn, Edgar; Michalik, H.; Rueffer, P.; Gliem, F.; Volk, K.

1990-06-01

211

Speckle Camera Imaging of the Planet Pluto  

NASA Astrophysics Data System (ADS)

We have obtained optical wavelength (692 nm and 880 nm) speckle imaging of the planet Pluto and its largest moon Charon. Using our DSSI speckle camera attached to the Gemini North 8 m telescope, we collected high resolution imaging with an angular resolution of ˜20 mas, a value at the Gemini-N telescope diffraction limit. We have produced for this binary system the first speckle reconstructed images, from which we can measure not only the orbital separation and position angle for Charon, but also the diameters of the two bodies. Our measurements of these parameters agree, within the uncertainties, with the current best values for Pluto and Charon. The Gemini-N speckle observations of Pluto are presented to illustrate the capabilities of our instrument and the robust production of high accuracy, high spatial resolution reconstructed images. We hope our results will suggest additional applications of high resolution speckle imaging for other objects within our solar system and beyond.

Howell, Steve B.; Horch, Elliott P.; Everett, Mark E.; Ciardi, David R.

2012-10-01

212

Bio-inspired fluidic lens surgical camera for MIS.  

PubMed

We report a new type of surgical camera that will greatly improve minimally invasive surgery (MIS). The key enabling technology for this camera is a unique type of lens-bio-inspired fluidic lens, which is a bio-mimetic lens that can change its curvature, just like the way human crystalline lens can accommodate. Because of its curvature changing capability, it is now possible to design a new regime of optical systems where auto-focusing and optical zoom can be performed without moving the lens positions, as is done in typical cameras. Hence, miniaturized imaging system with high functionality can be achieved with such technology. MIS is a surgical technique where small incisions are made on the abdominal wall as opposed to a large cut in open surgery. This type of surgery ensures faster patient recovery. The key tool for MIS is its surgical camera, or laparoscope. Traditional laparoscope is long and rigid and limits the field of view. To further advance MIS technology, we utilized bio-inspired fluidic lens to design a highly versatile imager that is small, can change its field of view or zoom optically, works in low light conditions, and varies the viewing angles. The surgical camera prototype is small (total track<17 mm), possesses 3X optical zoom, operates with light emitting diode (LED) lighting, among many other unique features. PMID:19965017

Tsai, Frank S; Johnson, Daniel; Cho, Sung Hwan; Qiao, Wen; Arianpour, Ashkan; Lo, Yu-Hwa

2009-01-01

213

Fast camera objective designs for spectrograph of Mont Megantique telescope  

NASA Astrophysics Data System (ADS)

All-reflective optics is conventionally required for extended spectral region observations in astronomical spectrograph. But the spatial resolution is usually not good enough while the large-size CCD will be used for observation in all-reflective optics. In this paper, all-refractive optics has been investigated to design a fast (F/1.55) and wide angle camera objective for large spectral coverage, from UV to VIS and up to NIR, when a large-size CCD is used on the focal plane of the spectrograph of Mont Megantique telescope. The case of achromatic and apochromatic condition has been investigated for axial and lateral color controls. The new proposed solutions have been optimized from two to three different glass combinations in order to have higher throughputs for large spectral coverage, especially in UV region. The used components have been minimized to reduce the light inherent lost. The monochromatic aberrations have been corrected and controlled by using optimized lens bending and shapes to make the camera have the CCD pixel resolution. Ray tracing results displayed the good optical performance of the camera to cover from 350 nm to 1000 nm spectral region with high resolution. The broadband AR coating, enhanced on UV region, will be used on each surface of the lenses in the camera. Final throughputs for the designed camera has been estimated and given in the paper.

Thibault, Simon; Wang, Min

2004-02-01

214

Focal Plane Metrology for the LSST Camera  

SciTech Connect

Meeting the science goals for the Large Synoptic Survey Telescope (LSST) translates into a demanding set of imaging performance requirements for the optical system over a wide (3.5{sup o}) field of view. In turn, meeting those imaging requirements necessitates maintaining precise control of the focal plane surface (10 {micro}m P-V) over the entire field of view (640 mm diameter) at the operating temperature (T {approx} -100 C) and over the operational elevation angle range. We briefly describe the hierarchical design approach for the LSST Camera focal plane and the baseline design for assembling the flat focal plane at room temperature. Preliminary results of gravity load and thermal distortion calculations are provided, and early metrological verification of candidate materials under cold thermal conditions are presented. A detailed, generalized method for stitching together sparse metrology data originating from differential, non-contact metrological data acquisition spanning multiple (non-continuous) sensor surfaces making up the focal plane, is described and demonstrated. Finally, we describe some in situ alignment verification alternatives, some of which may be integrated into the camera's focal plane.

A Rasmussen, Andrew P.; Hale, Layton; Kim, Peter; Lee, Eric; Perl, Martin; Schindler, Rafe; Takacs, Peter; Thurston, Timothy; /SLAC

2007-01-10

215

Cryogenic Detectors (Narrow Field Instruments)  

NASA Astrophysics Data System (ADS)

Two cryogenic imaging spectrometer arrays are currently considered as focal plane instruments for XEUS. The narrow field imager 1 (NFI 1) will cover the energy range from 0.05 to 3 keV with an energy resolution of 2 eV, or better, at 500 eV. A second narrow field imager (NFI 2) covers the energy range from 1 to 15 keV with an energy resolution of 2 eV (at 1 keV) and 5 eV (at 7 keV), creating some overlap with part of the NFI 1 energy window. Both narrow field imagers have a 0.5 arcmin field of view. Their imaging capabilities are matched to the XEUS optics of 2 to 5 arcsec leading to 1 arcsec pixels. The detector arrays will be cooled by a closed cycle system comprising a mechanical cooler with a base temperature of 2.5 K and either a low temperature 3He sorption pump providing the very low temperature stage and/or an Adiabatic Demagnetization Refrigerator (ADR). The ADR cooler is explicitly needed to cool the NFI 2 array. The narrow field imager 1} Currently a 48 times 48 element array of superconducting tunnel junctions (STJ) is envisaged. Its operating temperature is in the range between 30 and 350 mK. Small, single Ta STJs (20-50 mum on a side) have shown 3.5 eV (FWHM) resolution at E = 525 eV and small arrays have been successfully demonstrated (6 times 6 pixels), or are currently tested (10 times 12 pixels). Alternatively, a prototype Distributed Read-Out Imaging Device (DROID), consisting of a linear superconducting Ta absorber of 20 times 100 mum2, including a 20 times 20 mum STJ for readout at either end, has shown a measured energy resolution of 2.4 eV (FWHM) at E = 500 eV. Simulations involving the diffusion properties as well as loss and tunnel rates have shown that the performance can be further improved by slight modifications in the geometry, and that the size of the DROIDS can be increased to 0.5-1.0 mm without loss in energy resolution. The relatively large areas and good energy resolution compared to single STJs make DROIDS good candidates for the basic elements of the NFI 1 detector array. With a DROID-based array of 48 times 10 elements covering the NFI 1 field of view of 0.5 arcmin, the number of signal wires would already be reduced by a factor 2.4 compared to a 48 times 48 array of single pixels. While the present prototype DROIDS are still covered with a 480 nm thick SiOx insulation layer, this layer could easily be reduced in thickness or omitted. The detection efficiency of such a device with a 500 nm thick Ta absorber would be >80% in the energy range of 100-3000eV, without any disturbing contributions from other layers as in single STJs. Further developments involve devices of lower Tc-superconductors for better energy resolution and faster diffusion (e.g. Mo). The narrow field imager 2 The NFI 2 will consist of an array of 32 times 32 detector pixels. Each detector is a microcalorimeter which consists of a a superconducting to normal phase transition edge thermometer (transition edge sensor, TES) with an operating temperature of 100 mK, and an absorber which allows a detection efficiency of >90% and a filling factor of the focal plane in excess of 90%. Single pixel microcalorimeters with a Ti/Au TES have already shown an energy resolution of 3.9 eV at 5.89 keV in combination with a thermal response time of 100 mus. These results imply that they the high-energy requirement for XEUS can be met, in terms of energy resolution and response time. It has been demonstrated that bismuth can be applied as absorber material without impeding on the detector performance. Bi increases the stopping power in excess of 90 % and allows for a high filling factor since the absorber is can be modeled in the shape of a mushroom, allowing that the wiring to the detector and the thermal support structure are placed under the hat of the mushroom. In order to realize the NFI 2 detector array, there are two major development areas. Firstly, there is the development of micromachined Si and SiN structures that will provide proper cooling for each of the pixels and the production of small membranes to support the

Hoevers, H.; Verhoeve, P.

216

Vision Sensors and Cameras  

NASA Astrophysics Data System (ADS)

Silicon charge-coupled-device (CCD) imagers have been and are a specialty market ruled by a few companies for decades. Based on CMOS technologies, active-pixel sensors (APS) began to appear in 1990 at the 1 ?m technology node. These pixels allow random access, global shutters, and they are compatible with focal-plane imaging systems combining sensing and first-level image processing. The progress towards smaller features and towards ultra-low leakage currents has provided reduced dark currents and ?m-size pixels. All chips offer Mega-pixel resolution, and many have very high sensitivities equivalent to ASA 12.800. As a result, HDTV video cameras will become a commodity. Because charge-integration sensors suffer from a limited dynamic range, significant processing effort is spent on multiple exposure and piece-wise analog-digital conversion to reach ranges >10,000:1. The fundamental alternative is log-converting pixels with an eye-like response. This offers a range of almost a million to 1, constant contrast sensitivity and constant colors, important features in professional, technical and medical applications. 3D retino-morphic stacking of sensing and processing on top of each other is being revisited with sub-100 nm CMOS circuits and with TSV technology. With sensor outputs directly on top of neurons, neural focal-plane processing will regain momentum, and new levels of intelligent vision will be achieved. The industry push towards thinned wafers and TSV enables backside-illuminated and other pixels with a 100% fill-factor. 3D vision, which relies on stereo or on time-of-flight, high-speed circuitry, will also benefit from scaled-down CMOS technologies both because of their size as well as their higher speed.

Hoefflinger, Bernd

217

Adaptive DOF for plenoptic cameras  

NASA Astrophysics Data System (ADS)

Plenoptic cameras promise to provide arbitrary re-focusing through a scene after the capture. In practice, however, the refocusing range is limited by the depth of field (DOF) of the plenoptic camera. For the focused plenoptic camera, this range is given by the range of object distances for which the microimages are in focus. We propose a technique of recording light fields with an adaptive depth of focus. Between multiple exposures { or multiple recordings of the light field { the distance between the microlens array (MLA) and the image sensor is adjusted. The depth and quality of focus is chosen by changing the number of exposures and the spacing of the MLA movements. In contrast to traditional cameras, extending the DOF does not necessarily lead to an all-in-focus image. Instead, the refocus range is extended. There is full creative control about the focus depth; images with shallow or selective focus can be generated.

Oberdörster, Alexander; Lensch, Hendrik P. A.

2013-03-01

218

An Inexpensive Digital Infrared Camera  

ERIC Educational Resources Information Center

|Details are given for the conversion of an inexpensive webcam to a camera specifically sensitive to the near infrared (700-1000 nm). Some experiments and practical applications are suggested and illustrated. (Contains 9 figures.)|

Mills, Allan

2012-01-01

219

Astronomy and the camera obscura  

NASA Astrophysics Data System (ADS)

The camera obscura (from Latin meaning darkened chamber) is a simple optical device with a long history. In the form considered here, it can be traced back to 1550. It had its heyday during the Victorian era when it was to be found at the seaside as a tourist attraction or sideshow. It was also used as an artist's drawing aid and, in 1620, the famous astronomer-mathematician, Johannes Kepler used a small tent camera obscura to trace the scenery.

Feist, M.

2000-02-01

220

Vibration detection and calibration method used to remote sensing optical camera  

NASA Astrophysics Data System (ADS)

In order to obtain sharp remote sensing images, the image stabilization technology of space camera and the remote sensing image restoration technology are usually used now. Vibration detection is the key to realize these technologies: an image stabilization system needs the displacement vector derived from vibration detection to drive the compensation mechanism; and the remote sensing image restoration technology needs the vibration displacement vector to construct the point spread function (PSF). Vibration detection not only can be used to improve image quality of panchromatic camera, infrared cameras and other optical camera, also is motion compensation basis of satellite radar equipment. In this paper we have constructed a vibration measuring method based on Fiber optic gyro (FOG). FOG is a device sensitive to angular velocity or angular displacement. High-precision FOG can be used to measure the jitter angle of the optic axis of a space camera fixed on satellite platform. According to the measured data, the vibration displacement vector of the imaging plane can be calculated. Consequently the vibration data provide a basis for image stabilization of space camera and restoration of remote sensing images. We simulated the vibration of a space camera by using a piezoelectric ceramic deflection platform, and calibrated vibration measurement by using laser beam and a high-speed linear array camera. We compared the feedback output of the deflection platform, the FOG measured data and the calibrated data of the linear array camera, and obtained a calibration accuracy better than 1.5 ?rad.

Li, Qi; Dong, Wende; Xu, Zhihai; Feng, Huajun

2013-09-01

221

Depth encoding of point-of-interaction in thick scintillation cameras  

Microsoft Academic Search

Scintillation cameras of thick NaI(Tl) crystals without collimators have been used in the field of gamma ray astronomy, positron camera and PET. In such cases, gamma rays enter into a crystal at various angles, so that the depth of interaction causes position errors in two-dimensional position encoding. In principle, the light distribution inside the crystal depends on the depth of

T. Tomitanil; Y. Futamil; Y. Izeki; S. Kouda; T. Nishio; T. Murakamil; A. Kitagawal; M. Kanazawa; E. Urakabe; M. Shinbo; T. Kanai

1999-01-01

222

A Video Monitoring Model with a Distributed Camera System for the Smart Space  

Microsoft Academic Search

\\u000a The developed model of video monitoring based on distributed camera system is intended for automation of registration of meeting\\u000a participants. The problem of detecting position of participants simultaneously attended in the room and their faces is solved\\u000a by joint use of wide-angle, omni-directional and PTZ cameras located on walls and ceiling of the room, as well as implementation\\u000a of face

Alexander L. Ronzhin; Maria Prischepa; Alexey Karpov

2010-01-01

223

Fundus camera guided photoacoustic ophthalmoscopy.  

PubMed

Abstract Purpose: To demonstrate the feasibility of fundus camera guided photoacoustic ophthalmoscopy (PAOM) system and its multimodal imaging capabilities. Methods: We integrated PAOM and a fundus camera consisting of a white-light illuminator and a high-sensitivity, high-speed CCD. The fundus camera captures both retinal anatomy and PAOM illumination at the same time to provide a real-time feedback when we position the PAOM illuminating light. We applied the integrated system to image rat eyes in vivo and used full-spectrum, visible (VIS), and near infrared (NIR) illuminations in fundus photography. Results: Both albino and pigmented rat eyes were imaged in vivo. During alignment, different trajectories of PAOM laser scanning were successfully visualized by the fundus camera, which reduced the PAOM alignment time from several minutes to 30?s. In albino eyes, in addition to retinal vessels, main choroidal vessels were observed using VIS-illumination, which is similar to PAOM images. In pigmented eyes, the radial striations of retinal nerve fiber layer were visualized by fundus photography using full-spectrum illumination; meanwhile, PAOM imaged both retinal vessels and the retinal pigmented epithelium melanin distribution. Conclusions: The results demonstrated that PAOM can be well-integrated with fundus camera without affecting its functionality. The fundus camera guidance is faster and easier comparing with our previous work. The integrated system also set the stage for the next-step verification between oximetry methods based on PAOM and fundus photography. PMID:24131226

Liu, Tan; Li, Hao; Song, Wei; Jiao, Shuliang; Zhang, Hao F

2013-07-25

224

Angles of Reflection  

NSDL National Science Digital Library

This interactive simulation shows what happens to light when it hits a mirror. The simluation allows the user to change the angle of the incoming or incident light wave and see the corresponding reflected angle.

Davidson, Michael W.; Tchourioukanov, Kirill I.

2006-06-15

225

Overview and design of the Canarias infrared camera experiment (CIRCE)  

NASA Astrophysics Data System (ADS)

We report on the design status of the Canarias InfraRed Camera Experiment (CIRCE), a near-infrared visitor instrument for the 10.4-meter Gran Telescopio Canarias (GTC). Besides functioning as a 1-2.5 micron imager, CIRCE will have the capacity for narrow-band imaging, low- and moderate- resolution grism spectroscopy, and imaging polarimetry. Other design features include fully cryogenic filter, slit, and grism wheels, high-speed photometry modes, and broad-band imaging in J, H, and Ks filters. We anticipate that a myriad of scientific projects will benefit from CIRCE's unique combination of capabilities.

Edwards, Michelle L.; Marin-Franch, Antonio; Eikenberry, Stephen S.; Rodgers, Michael; Julian, Jeff; Hanna, Kevin; Packham, Chris

2004-09-01

226

Status of the Canarias InfraRed Camera Experiment (CIRCE)  

NASA Astrophysics Data System (ADS)

We report on the design status of the Canarias InfraRed Camera Experiment (CIRCE), a near-infrared visitor instrument for the 10.4 meter Gran Telescopio Canarias (GTC). In addition to functioning as a 1-2.5 micron imager, CIRCE will have the capacity for narrow-band imaging, low- and moderate- resolution grism spectroscopy, and polarimetry. CIRCE's all-reflective aspheric optical design offers excellent throughput and image quality. We present an analysis of the optical layout, an overview of the software development and the progress of the opto- and cryo-mechanical design and manufacture.

Edwards, M. L.; Eikenberry, S. S.; Marin-Franch, A.; Charcos-Llorens, M.; Rodgers, M.; Julian, J.; Raines, S. N.; Packham, C.

2007-06-01

227

CIRCE: The Canarias InfraRed Camera Experiment  

Microsoft Academic Search

\\u000a The Canarias InfraRed Camera Experiment (CIRCE) is a near-infrared (1–2.5 ?m) instrument for the Gran Telescopio Canarias\\u000a (GTC) 10.4 m telescope. CIRCE has an off-axis aspheric all-reflective optical system that offers both excellent throughput\\u000a and image quality. Observational modes include broad\\/narrow band imaging and low-resolution spectroscopy. High time-resolution\\u000a data acquisition and polarimetry are available in both cases. We present an

M. V. Charcos-Llorens; A. J. Cenarro; M. L. Edwards; S. S. Eikenberry; K. T. Hanna; J. Julian; N. M. Lasso Cabrera; A. Marín-Franch; C. Packham; S. N. Raines; M. Rodgers; F. Varosi

2010-01-01

228

A fast focal-reducing camera for CCD imaging  

NASA Astrophysics Data System (ADS)

This paper describes the design and performance of the OREAD focal-reducing camera, constructed for use at the Cassegrain focus of the Michigan-Dartmouth-MIT Observatory McGraw-Hill 1.3-meter telescope. OREAD is an all-refractive optical system providing a 50-mm collimated beam suitable for commercially available narrow-band filters or grisms. Its collimator and field lens are custom-made to decrease the severe coma which would otherwise be present at the extremities of its 30-arc-min field. When used with a CCD such as the TI 800 x 800, OREAD provides a field of view of 0.1 square degree at 1.5 arcsec/pixel. The focal ratio of OREAD of f/1.63 allows sky-limited narrow-band images to be obtained with exposures of only moderate duration. In an Appendix, some limitations inherent in coarsely sampled data obtained with CCDs are examined.

Aldering, Gregory S.; Bothun, Gregory D.

1991-12-01

229

Dynamics of an oscillating bubble in a narrow gap  

NASA Astrophysics Data System (ADS)

The complex dynamics of a single bubble of a few millimeters in size oscillating inside a narrow fluid-filled gap between two parallel plates is studied using high-speed videography. Two synchronized high-speed cameras were used to observe both the side and front views of the bubble. The front-view images show bubble expansion and collapse with the formation of concentric dark and bright rings. The simultaneous recordings reveal the mechanism behind these rings. The side-view images reveal two different types of collapse behavior of the bubble including a previously unreported collapse phenomenon that is observed as the gap width is changed. At narrow widths, the bubble collapses towards the center of the gap; when the width is increased, the bubble splits before collapsing towards the walls. The bubble dynamics is also observed to be unaffected by the hydrophobic or hydrophilic nature of the plate surface due to the presence of a thin film of liquid between each of the plates and the bubble throughout the bubble lifetime. It is revealed that such systems do not behave as quasi-two-dimensional systems; three-dimensional effects are important.

Azam, Fahad Ibn; Karri, Badarinath; Ohl, Siew-Wan; Klaseboer, Evert; Khoo, Boo Cheong

2013-10-01

230

Aspect and Deviation Angle.  

National Technical Information Service (NTIS)

The purpose of this paper is twofold: first, an attempt is made to define aspect angle and deviation angle in a logical and acceptable manner; second, a graphical calculator is supplied in the hope that it will make the calculation of these angles so simp...

T. A. Croft

1964-01-01

231

Video camera count of burrow?dwelling fairy prions, sooty shearwaters, and tuatara on Takapourewa (Stephens Island), New Zealand  

Microsoft Academic Search

Video camera technology is an increasingly common tool in the study of burrow?dwelling animals. A camera used to observe the inhabitants of narrow burrows on Takapourewa (Cook Strait, New Zealand) is described. Population densities (animals per m) of up to 1.1 for fairy prions {Pachyptila turtur), 0.06 for sooty shearwaters (Puffinus griseus), and 0.15 for tuatara (Sphenodon punctatus) were estimated

T. J. Markwell

1997-01-01

232

StartleCam: A Cybernetic Wearable Camera  

Microsoft Academic Search

StartleCam is a wearable video camera, computer, and sensing system, which enables the camera to be controlled via both conscious and preconscious events involving the wearer. Traditionally, a wearer consciously hits record on the video camera, or runs a computer script to trigger the camera according to some pre-specified frequency. The sys- tem described here offers an additional option: images

Jennifer Healey; Rosalind W. Picard

1998-01-01

233

A testbed for wide-field, high-resolution, gigapixel-class cameras.  

PubMed

The high resolution and wide field of view (FOV) of the AWARE (Advanced Wide FOV Architectures for Image Reconstruction and Exploitation) gigapixel class cameras present new challenges in calibration, mechanical testing, and optical performance evaluation. The AWARE system integrates an array of micro-cameras in a multiscale design to achieve gigapixel sampling at video rates. Alignment and optical testing of the micro-cameras is vital in compositing engines, which require pixel-level accurate mappings over the entire array of cameras. A testbed has been developed to automatically calibrate and measure the optical performance of the entire camera array. This testbed utilizes translation and rotation stages to project a ray into any micro-camera of the AWARE system. A spatial light modulator is projected through a telescope to form an arbitrary object space pattern at infinity. This collimated source is then reflected by an elevation stage mirror for pointing through the aperture of the objective into the micro-optics and eventually the detector of the micro-camera. Different targets can be projected with the spatial light modulator for measuring the modulation transfer function (MTF) of the system, fiducials in the overlap regions for registration and compositing, distortion mapping, illumination profiles, thermal stability, and focus calibration. The mathematics of the testbed mechanics are derived for finding the positions of the stages to achieve a particular incident angle into the camera, along with calibration steps for alignment of the camera and testbed coordinate axes. Measurement results for the AWARE-2 gigapixel camera are presented for MTF, focus calibration, illumination profile, fiducial mapping across the micro-camera for registration and distortion correction, thermal stability, and alignment of the camera on the testbed. PMID:23742532

Kittle, David S; Marks, Daniel L; Son, Hui S; Kim, Jungsang; Brady, David J

2013-05-01

234

Elliptical cavity resonators for dual-mode narrow-band filters  

Microsoft Academic Search

A novel cavity resonator with elliptical cross section is proposed in order to realize dual-mode narrow-band filters without tuning and coupling elements. The absence of any discontinuity inside the cavities significantly enhances the unloaded Q, the ability to operate with higher power levels, and the ease of manufacturing. Proper choice of the ellipticity and of the inclination angle controls the

Luciano Accatino; Giorgio Bertin; Mauro Mongiardo

1997-01-01

235

30. TACOMA NARROWS BRIDGE, LOOKING EAST THROUGH TOLL LANES, 29 ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. TACOMA NARROWS BRIDGE, LOOKING EAST THROUGH TOLL LANES, 29 AUGUST 1940. (ELDRIDGE, CLARK H. TACOMA NARROWS BRIDGE, TACOMA, WASHINGTON, FINAL REPORT ON DESIGN AND CONSTRUCTION, 1941) - Tacoma Narrows Bridge, Spanning Narrows at State Route 16, Tacoma, Pierce County, WA

236

31. TACOMA NARROWS BRIDGE, LOOKING WEST ACROSS TOLL PLAZA, 29 ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. TACOMA NARROWS BRIDGE, LOOKING WEST ACROSS TOLL PLAZA, 29 AUGUST 1940. (ELDRIDGE, CLARK M. TACOMA NARROWS BRIDGE, TACOMA, WASHINGTON, FINAL REPORT ON DESIGN AND CONSTRUCTION, 1941) - Tacoma Narrows Bridge, Spanning Narrows at State Route 16, Tacoma, Pierce County, WA

237

Cylindrical holographic radar camera  

NASA Astrophysics Data System (ADS)

A novel personnel surveillance system has been developed to rapidly obtain 360 degree, full-body images of humans for the detection and identification of concealed threats. Detectable threats include weapons fabricated with metal, plastic, and ceramic, as well as explosive solids and liquids. This new system uses a cylindrical mechanical scanner to move a seven-foot, 384 element, Ka band (26 - 30 GHz) array circumferentially around a person in four to seven seconds. Low power millimeter-waves, which are nonionizing and not harmful to humans, are employed because they readily penetrate clothing barriers and reflect from concealed threats. The reflected waves provide information that is reconstructed into 3-D cylindrical holographic images with high-speed, digital signal processing (DSP) boards. This system is capable of displaying in an animation format eight, sixteen, thirty-two or sixty-four image frames at various aspect angles around the person under surveillance. This new prototype surveillance system is operational and is presently under laboratory testing and evaluation.

McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.

1998-12-01

238

LED camera light with a compact wide-range zoom  

NASA Astrophysics Data System (ADS)

A design concept for an extremely compact zoom optics which is suitable for illumination applications is presented. Such optics is especially useful for camera or flash lights as the illuminated area can be adjusted according to the picture content of the photo or film camera. The principle of the design is as follows: Collimated light passes through two lenses, each with a freeform surface. The freeform surfaces face each other and fit into one another perfectly. When the two lenses are merged together, they basically represent a coplanar plate: The cone angle entering the merged lenses does not change while passing them. When the plates are separated, the light is scattered at the freeform surfaces. Due to the smooth characteristics of the freeform surfaces shape, the cone angle can be adjusted continuously with the distance of the zoom lenses. The distance of the zoom lenses, which is necessary for maximum angle widening, is dependent on the size of the structures of the freeform surfaces and can be reduced to the sub-millimeter range. The compactness of the resulting device is a major advantage of the design concept. The principle of operation of the design could be shown by the construction of a prototype. It features a LED light source and a zoom range of 5° to 30° (cone angle). The luminous flux of the device is approx. 650 lm.

Hartwig, Ulrich; Rehn, Henning

2010-08-01

239

Projectile entry angle determination.  

PubMed

Small angles of projectile entry are difficult to determine in two-dimensional targets or in three-dimensional targets where internal deflection has taken place. This results from the fact that small errors in measurement lead to large errors in the calculation of the sine function used in the estimation of the angular projection of a circle onto an inclined plane at angles of less than 20 degrees from the normal. The use of a bullet tip scale, constructed to the dimensions of the entering projectile, allows a significantly more accurate determination of small angles of entry in targets not subject to stretching. A comparison of the relative error inherent in calculating entry angle using the sine function and measuring the angle using the bullet tip scale demonstrates the suitability of using the tip scale at angles less than 20 degrees and the sine function at entry angles greater than 20 degrees. PMID:3944581

Cashman, P J

1986-01-01

240

Surveillance camera scheduling: a virtual vision approach  

Microsoft Academic Search

ABSTRACT We present a surveillance system, comprising wide field-of-view (FOV) passive cameras and pan\\/tilt\\/zoom (PTZ) active cameras, which automatically captures and labels high-resolution videos of pedestrians as they move,through a designated area. A wide-FOV stationary camera can track multiple pedestrians, while any PTZ active camera can capture high-quality videos of a single pedestrian at a time. We propose a multi-camera

Faisal Z. Qureshi; Demetri Terzopoulos

2006-01-01

241

A matrix CCD camera for astronomical observations  

NASA Astrophysics Data System (ADS)

A CCD camera based on a liquid-nitrogen-cooled virtual-phase buried-channel CCD matrix is described. High-resolution spectra of stars obtained at the 2.6-m reflector with this camera are presented. The comparison of the spectra taken with the new camera and with the CCD-2000 camera at the same telescope shows that the new camera is more sensitive within the entire spectral range from 3940 to 10,830 A.

Beriozin, V. Yu.; Zuyev, A. G.; Kiryan, G. V.; Rybakov, M. I.; Khvilivitsky, A. T.; Ilyin, I. V.; Petrov, P. P.; Savanov, I. S.; Scherbakov, A. G.

1991-10-01

242

Narrow Spikes Detection From Distorted Signals  

Microsoft Academic Search

In the present paper is presented a method for on-line narrow spike detention from distorted signals. The method consists of successive derivations of the distorted signal till the only event remains significant in the sequence. A study for narrow spike form influence in detection will be performs.

C. Donciu; M. Cretu; S. Hanganu; E. Lunca

243

Polarized Thermal Emission from Narrow Tungsten Filaments  

Microsoft Academic Search

FROM experimental work carried out by Fresnel many years ago and a theoretical investigation made by K. Schwarzschild1, it is well known that light transmitted through a narrow slit is more or less polarized. Though conditions are rather different in the case of thermal emission from a narrow filament the idea has occurred to me that polarized emission may be

Yngve Öhman

1961-01-01

244

Do narrow {Sigma}-hypernuclear states exist?  

SciTech Connect

Reports of narrow states in {Sigma}-hypernucleus production have appeared from time to time. The present experiment is a repeat of the first and seemingly most definitive such experiment, that on a target of {sup 9}Be, but with much better statistics. No narrow states were observed.

Chrien, R.E.

1995-12-31

245

Generic Substitution of Narrow Therapeutic Index Drugs  

Microsoft Academic Search

Controversy regarding generic substitution of narrow therapeutic index drugs, especially antiepileptic drugs, has become a big debate lately. Some states are considering passing laws that will restrict the generic substitution of these narrow therapeutic index drugs. In fact, some states have already modified their laws to limit switching and generic substitution of these medications, requiring patient and prescriber consent before

Mays Putrus

246

INT prime focus mosaic camera  

NASA Astrophysics Data System (ADS)

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

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

1996-03-01

247

The Clementine longwave infrared camera  

SciTech Connect

The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. The longwave-infrared (LWIR) camera supplemented the UV/Visible and near-infrared mapping cameras providing limited strip coverage of the moon, giving insight to the thermal properties of the soils. This camera provided {approximately}100 m spatial resolution at 400 km periselene, and a 7 km across-track swath. This 2.1 kg camera using a 128 x 128 Mercury-Cadmium-Telluride (MCT) FPA viewed thermal emission of the lunar surface and lunar horizon in the 8.0 to 9.5 {micro}m wavelength region. A description of this light-weight, low power LWIR camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

Priest, R.E.; Lewis, I.T.; Sewall, N.R.; Park, H.S.; Shannon, M.J.; Ledebuhr, A.G.; Pleasance, L.D. [Lawrence Livermore National Lab., CA (United States); Massie, M.A. [Pacific Advanced Technology, Solvang, CA (United States); Metschuleit, K. [Amber/A Raytheon Co., Goleta, CA (United States)

1995-04-01

248

Development of filter exchangeable 3CCD camera for multispectral imaging acquisition  

NASA Astrophysics Data System (ADS)

There are a lot of methods to acquire multispectral images. Dynamic band selective and area-scan multispectral camera has not developed yet. This research focused on development of a filter exchangeable 3CCD camera which is modified from the conventional 3CCD camera. The camera consists of F-mounted lens, image splitter without dichroic coating, three bandpass filters, three image sensors, filer exchangeable frame and electric circuit for parallel image signal processing. In addition firmware and application software have developed. Remarkable improvements compared to a conventional 3CCD camera are its redesigned image splitter and filter exchangeable frame. Computer simulation is required to visualize a pathway of ray inside of prism when redesigning image splitter. Then the dimensions of splitter are determined by computer simulation which has options of BK7 glass and non-dichroic coating. These properties have been considered to obtain full wavelength rays on all film planes. The image splitter is verified by two line lasers with narrow waveband. The filter exchangeable frame is designed to make swap bandpass filters without displacement change of image sensors on film plane. The developed 3CCD camera is evaluated to application of detection to scab and bruise on Fuji apple. As a result, filter exchangeable 3CCD camera could give meaningful functionality for various multispectral applications which need to exchange bandpass filter.

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

2012-05-01

249

The IAC's Near Infrared Camera  

NASA Astrophysics Data System (ADS)

Here we report the main characteristics of the recently acquired near infrared camera. It is based on a 256x256 HgCdTe Nicmos-3 array, sensitive from 1 mu m to 2.5mu m. The pixel size is 40mu mx40mu m, adequate for the spatial and spectral scales at the different telescopes operating at the observatories of La Palma and Tenerife. The cooling system operates with LN2 with a hold time larger than 20 hours. The camera will be used for photometric, spectroscopic and spectropolarimetric observations.

Collados, M.; Joven, E.; Fuentes, F. J.; Diaz, J. J.; Gonzalez Escalera, V.; Bonet, J. A.; Vazquez, M.

250

Microcomputer controlled Isocon camera system  

SciTech Connect

An Isocon camera system is described which uses an 8080 microcomputer system for its control. Horizontal synchronized operational power supplies are used with a DAC for each channel of control. Each control function is entered by way of a key-board and software. Video information is digitized by a fast ADC and serialized to a low nibble and high nibble. Performance of the camera in terms of SNR and limiting resolution are discussed as well as block diagrams showing how the system was constructed.

Dunbar, D.L.

1980-02-27

251

Camera calibration approach based on adaptive active target  

NASA Astrophysics Data System (ADS)

Aiming at calibrating camera on site, where the lighting condition is hardly controlled and the quality of target images would be declined when the angle between camera and target changes, an adaptive active target is designed and the camera calibration approach based on the target is proposed. The active adaptive target in which LEDs are embedded is flat, providing active feature point. Therefore the brightness of the feature point can be modified via adjusting the electricity, judging from the threshold of image feature criteria. In order to extract features of the image accurately, the concept of subpixel-precise thresholding is also proposed. It converts the discrete representation of the digital image to continuous function by bilinear interpolation, and the sub-pixel contours are acquired by the intersection of the continuous function and the appropriate selection of threshold. According to analysis of the relationship between the features of the image and the brightness of the target, the area ratio of convex hulls and the grey value variance are adopted as the criteria. Result of experiments revealed that the adaptive active target accommodates well to the changing of the illumination in the environment, the camera calibration approach based on adaptive active target can obtain high level of accuracy and fit perfectly for image targeting in various industrial sites.

Zhang, Yalin; Zhou, Fuqiang; Deng, Peng

2011-12-01

252

Study of laser reflection of infrared cameras with germanium optics  

NASA Astrophysics Data System (ADS)

Infrared cameras are widely used in today"s battlefield for surveillance purpose. Because of retroreflection, an incident laser beam entering the camera optics results in a beam reflecting back to the direction of the laser source. An IR detector positioned close to the laser source can then detect the reflected beam. This effect can reveal the location of the cameras and thus increases the risk of covert operations. In the present work, the characteristics of the retroreflection is studied. It is found that the reflection intensity is high when the incident beam enters through the middle part of the lenses while it is low and the beam is diverged when entering through the outer part of the lenses. The reflection is symmetric when the incident beam is normal to the lenses while asymmetric when it is incident with an angle to the lenses. In order to study the potential effects on retroreflection of modified camera optics, IR low index slides (ZnSe and KCl with refractive indices of 2.49 and 1.54, respectively) with different thicknesses (2mm, 4mm and 6mm) are placed in the optical system. The result shows that the focal point of the lenses is changed by the addition of the slide but the optical paths of the reflection remain unchanged. The relationship between the different slides and beam intensity is also studied.

Chiu, Patrio; Shih, Ishiang; Shi, S.; Laou, Philips

2003-09-01

253

Multiple Sensor Camera for Enhanced Video Capturing  

NASA Astrophysics Data System (ADS)

A resolution of camera has been drastically improved under a current request for high-quality digital images. For example, digital still camera has several mega pixels. Although a video camera has the higher frame-rate, the resolution of a video camera is lower than that of still camera. Thus, the high-resolution is incompatible with the high frame rate of ordinary cameras in market. It is difficult to solve this problem by a single sensor, since it comes from physical limitation of the pixel transfer rate. In this paper, we propose a multi-sensor camera for capturing a resolution and frame-rate enhanced video. Common multi-CCDs camera, such as 3CCD color camera, has same CCD for capturing different spectral information. Our approach is to use different spatio-temporal resolution sensors in a single camera cabinet for capturing higher resolution and frame-rate information separately. We build a prototype camera which can capture high-resolution (2588×1958 pixels, 3.75 fps) and high frame-rate (500×500, 90 fps) videos. We also proposed the calibration method for the camera. As one of the application of the camera, we demonstrate an enhanced video (2128×1952 pixels, 90 fps) generated from the captured videos for showing the utility of the camera.

Nagahara, Hajime; Kanki, Yoshinori; Iwai, Yoshio; Yachida, Masahiko

254

Exploring the Moon at High-Resolution: First Results From the Lunar Reconnaissance Orbiter Camera (LROC)  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter (LRO) spacecraft was launched on an Atlas V 401 rocket from the Cape Canaveral Air Force Station Launch Complex 41 on June 18, 2009. After spending four days in Earth-Moon transit, the spacecraft entered a three month commissioning phase in an elliptical 30×200 km orbit. On September 15, 2009, LRO began its planned one-year nominal mapping mission in a quasi-circular 50 km orbit. A multi-year extended mission in a fixed 30×200 km orbit is optional. The Lunar Reconnaissance Orbiter Camera (LROC) consists of a Wide Angle Camera (WAC) and two Narrow Angle Cameras (NACs). The WAC is a 7-color push-frame camera, which images the Moon at 100 and 400 m/pixel in the visible and UV, respectively, while the two NACs are monochrome narrow-angle linescan imagers with 0.5 m/pixel spatial resolution. LROC was specifically designed to address two of the primary LRO mission requirements and six other key science objectives, including 1) assessment of meter-and smaller-scale features in order to select safe sites for potential lunar landings near polar resources and elsewhere on the Moon; 2) acquire multi-temporal synoptic 100 m/pixel images of the poles during every orbit to unambiguously identify regions of permanent shadow and permanent or near permanent illumination; 3) meter-scale mapping of regions with permanent or near-permanent illumination of polar massifs; 4) repeat observations of potential landing sites and other regions to derive high resolution topography; 5) global multispectral observations in seven wavelengths to characterize lunar resources, particularly ilmenite; 6) a global 100-m/pixel basemap with incidence angles (60° -80° ) favorable for morphological interpretations; 7) sub-meter imaging of a variety of geologic units to characterize their physical properties, the variability of the regolith, and other key science questions; 8) meter-scale coverage overlapping with Apollo-era panoramic images (1-2 m/pixel) to document the number of small impacts since 1971-1972. LROC allows us to determine the recent impact rate of bolides in the size range of 0.5 to 10 meters, which is currently not well known. Determining the impact rate at these sizes enables engineering remediation measures for future surface operations and interplanetary travel. The WAC has imaged nearly the entire Moon in seven wavelengths. A preliminary global WAC stereo-based topographic model is in preparation [1] and global color processing is underway [2]. As the mission progresses repeat global coverage will be obtained as lighting conditions change providing a robust photometric dataset. The NACs are revealing a wealth of morpho-logic features at the meter scale providing the engineering and science constraints needed to support future lunar exploration. All of the Apollo landing sites have been imaged, as well as the majority of robotic landing and impact sites. Through the use of off-nadir slews a collection of stereo pairs is being acquired that enable 5-m scale topographic mapping [3-7]. Impact mor-phologies (terraces, impact melt, rays, etc) are preserved in exquisite detail at all Copernican craters and are enabling new studies of impact mechanics and crater size-frequency distribution measurements [8-12]. Other topical studies including, for example, lunar pyroclastics, domes, and tectonics are underway [e.g., 10-17]. The first PDS data release of LROC data will be in March 2010, and will include all images from the commissioning phase and the first 3 months of the mapping phase. [1] Scholten et al. (2010) 41st LPSC, #2111; [2] Denevi et al. (2010a) 41st LPSC, #2263; [3] Beyer et al. (2010) 41st LPSC, #2678; [4] Archinal et al. (2010) 41st LPSC, #2609; [5] Mattson et al. (2010) 41st LPSC, #1871; [6] Tran et al. (2010) 41st LPSC, #2515; [7] Oberst et al. (2010) 41st LPSC, #2051; [8] Bray et al. (2010) 41st LPSC, #2371; [9] Denevi et al. (2010b) 41st LPSC, #2582; [10] Hiesinger et al. (2010a) 41st LPSC, #2278; [11] Hiesinger et al. (2010b) 41st LPSC, #2304; [12] van der Bogert et al. (2010) 41st LPSC, #2165;

Robinson, Mark; Hiesinger, Harald; McEwen, Alfred; Jolliff, Brad; Thomas, Peter C.; Turtle, Elizabeth; Eliason, Eric; Malin, Mike; Ravine, A.; Bowman-Cisneros, Ernest

255

Overview of Neutrino Mixing Models and Their Mixing Angle Predictions  

SciTech Connect

An overview of neutrino-mixing models is presented with emphasis on the types of horizontal flavor and vertical family symmetries that have been invoked. Distributions for the mixing angles of many models are displayed. Ways to differentiate among the models and to narrow the list of viable models are discussed.

Albright, Carl H. [Department of Physics, Northern Illinois University, DeKalb, IL 60115 (United States) and Theoretical Physics Department, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

2010-03-30

256

ERICA PLUS: compact MWIR camera with 20x step zoom optics and advanced processing  

NASA Astrophysics Data System (ADS)

The development of a compact and high performance MWIR step zoom camera based on the 640x480 staring focal plane array (FPA) is described. The camera has a 20 magnification step zoom ranging between 24°x20° for the wide field of view up to 1.2° x 1° for the narrow field of view and an aperture of F#4. The processing electronics is based on a flexible and expandable architecture. Special emphasis is spent on the solutions adopted for the design of this high zoom ratio and fast optics FLIR and on the electronic architecture and algorithms for image processing. An overview of the performance is given.

Porta, A.; Romagnoli, M.; Lavacchini, P.; Olivieri, M.; Torrini, D.

2007-11-01

257

Recent advances in digital camera optics  

NASA Astrophysics Data System (ADS)

The digital camera market has extremely expanded in the last ten years. The zoom lens for digital camera is especially the key determining factor of the camera body size and image quality. Its technologies have been based on several analog technological progresses including the method of aspherical lens manufacturing and the mechanism of image stabilization. Panasonic is one of the pioneers of both technologies. I will introduce the previous trend in optics of zoom lens as well as original optical technologies of Panasonic digital camera "LUMIX", and in addition optics in 3D camera system. Besides, I would like to suppose the future trend in digital cameras.

Ishiguro, Keizo

2012-10-01

258

Improving the accuracy of the SO2 camera  

NASA Astrophysics Data System (ADS)

The SO2 Camera is a novel technique to measure column densities and fluxes of SO2 emitted by volcanoes using solar radiation scattered in the atmosphere as a light source. The instrument is based on two interference band-pass filters and a UV-sensitive CCD sensor. A filter centered around 315 nm is used to measure the optical density of SO2in the plume, whereas a second filter, centered around 330 nm, corrects the effects of aerosol scattering and therefore makes the technique applicable to volcanic plumes containing aerosols. The ability to deliver spatially resolved images of volcanic SO2 distributions at a frame rate of the order of 1 Hz makes the SO2 camera a very promising technique for monitoring the evolution of volcanic plumes, the quantitative determination of SO2 emissions and flux measurements. This poster explains the measurement principle and how to evaluate data measured with the SO2camera. Several issues that can influence the measurement are addressed. For one, the change in light path through the stratosphere with changing solar zenith angle changes the spectral distribution measured on the earth's surface. As the absorption of SO2 is highly dependent on the wavelength of light, these changes can influence the measured column densities. Secondly, as the camera uses scattered solar radiation as a light source, we have to take radiative transfer effects in account. The path between the sun and the instrument is not fixed, as effects like multiple scattering or 'radiative dilution' can occur and lead to an underestimation or overestimation of the SO2 column density. Recommendations for correcting the individual effects during data analysis are given. Aside from the above-mentioned intrinsic effects, there are several choices in the technical setup of the SO2 camera which are discussed. A general description of the instrument's set-up and the camera control software are given. Finally, several measurement examples are shown and possibilities to combine SO2 camera measurements with other remote sensing techniques are explored. For example, a co-located DOAS system was used to accurately calibrate the SO2-camera data in real time and to correct for the radiative transfer effects.

Lübcke, Peter; Kern, Christoph; Vogel, Leif; Kick, Felix; Wöhrbach, Markus; Platt, Ulrich

2010-05-01

259

A prospective randomised study on narrow-band imaging versus conventional colonoscopy for adenoma detection: does narrow-band imaging induce a learning effect?  

Microsoft Academic Search

Background and aims:Colonoscopy is an established method of colorectal cancer screening, but has an adenoma miss rate of 10–20%. Detection rates are expected to improve with optimised visualisation methods. This prospective randomised study evaluated narrow-band imaging (NBI), a new technique that may enhance image contrast in colon adenoma detection.Methods:Eligible patients presenting for diagnostic colonoscopy were randomly assigned to undergo wide-angle

A Adler; H Pohl; I S Papanikolaou; H Abou-Rebyeh; G Schachschal; W Veltzke-Schlieker; A C Khalifa; E Setka; M Koch; B Wiedenmann; T Rösch

2008-01-01

260

Camera response estimation. Radiometric calibration  

Microsoft Academic Search

Real time vision requires accurate information about the environment that is to be processed. The quality of the acquired images depends on many factors, such as weather and lighting conditions (sun, rain, snow, fog, mist), entering and going out of tunnels, shadows, cars headlights. This paper presents a new approach for assessing the response of a digital camera as a

Mihai Negru; Sergiu Nedevschi

2009-01-01

261

OSIRIS camera barrel optomechanical design  

NASA Astrophysics Data System (ADS)

A Camera Barrel, located in the OSIRIS imager/spectrograph for the Gran Telescopio Canarias (GTC), is described in this article. The barrel design has been developed by the Institute for Astronomy of the University of Mexico (IA-UNAM), in collaboration with the Institute for Astrophysics of Canarias (IAC), Spain. The barrel is being manufactured by the Engineering Center for Industrial Development (CIDESI) at Queretaro, Mexico. The Camera Barrel includes a set of eight lenses (three doublets and two singlets), with their respective supports and cells, as well as two subsystems: the Focusing Unit, which is a mechanism that modifies the first doublet relative position; and the Passive Displacement Unit (PDU), which uses the third doublet as thermal compensator to maintain the camera focal length and image quality when the ambient temperature changes. This article includes a brief description of the scientific instrument; describes the design criteria related with performance justification; and summarizes the specifications related with misalignment errors and generated stresses. The Camera Barrel components are described and analytical calculations, FEA simulations and error budgets are also included.

Farah, Alejandro; Tejada, Carlos; Gonzalez, Jesus; Cobos, Francisco J.; Sanchez, Beatriz; Fuentes, Javier; Ruiz, Elfego

2004-09-01

262

Measuring Distances Using Digital Cameras  

ERIC Educational Resources Information Center

|This paper presents a generic method of calculating accurate horizontal and vertical object distances from digital images taken with any digital camera and lens combination, where the object plane is parallel to the image plane or tilted in the vertical plane. This method was developed for a project investigating the size, density and spatial…

Kendal, Dave

2007-01-01

263

Automatic camera effects system (ACES)  

Microsoft Academic Search

The need to achieve realism in theatrical motion pictures with miniature models requires precise positioning, close tolerances, and a high degree of repeatability. A particular movement of the camera and the subject(s) may be repeated several times to create mattes or other special effects involving multiple exposures. Traditionally, miniatures photography has been performed \\

Steven N. Crane; R. David Snyder

1980-01-01

264

Camera assisted multimodal user interaction  

NASA Astrophysics Data System (ADS)

Since more processing power, new sensing and display technologies are already available in mobile devices, there has been increased interest in building systems to communicate via different modalities such as speech, gesture, expression, and touch. In context identification based user interfaces, these independent modalities are combined to create new ways how the users interact with hand-helds. While these are unlikely to completely replace traditional interfaces, they will considerably enrich and improve the user experience and task performance. We demonstrate a set of novel user interface concepts that rely on built-in multiple sensors of modern mobile devices for recognizing the context and sequences of actions. In particular, we use the camera to detect whether the user is watching the device, for instance, to make the decision to turn on the display backlight. In our approach the motion sensors are first employed for detecting the handling of the device. Then, based on ambient illumination information provided by a light sensor, the cameras are turned on. The frontal camera is used for face detection, while the back camera provides for supplemental contextual information. The subsequent applications triggered by the context can be, for example, image capturing, or bar code reading.

Hannuksela, Jari; Silvén, Olli; Ronkainen, Sami; Alenius, Sakari; Vehviläinen, Markku

2010-02-01

265

Artificial compound eye zoom camera  

Microsoft Academic Search

We demonstrate a highly compact image capturing system with variable field of view but without any mechanically moving parts. The camera combines an ultra-thin artificial apposition compound eye with one variable focal length liquid lens. The change of optical power of the liquid lens when applying a voltage results in a change of the magnification of the microlens array imaging

Jacques Duparré; Frank Wippermann; Peter Dannberg; Andreas Bräuer

2008-01-01

266

Micromap Camera for Display Systems.  

National Technical Information Service (NTIS)

The report covers the engineer design tests of a precision copy camera designed for the production of high-precision film chips or continuous filmstrips ranging in size from 35 mm by 60 mm up to 9 by 9 inches. This report evaluates the resolution, distort...

E. K. Woods

1971-01-01

267

Automated thermoplastic holographic camera development  

Microsoft Academic Search

The development of an automated thermoplastic holographic camera, which gives reproducible results from cycle to cycle and from sample to sample, is reported. The thermoplastic device has a conventional sandwich geometry consisting of a thin transparent conductor, a thin layer of organic photoconductor, and a thermoplastic layer with a softening temperature of roughly 70 C. A major innovation of the

T. C. Lee; J. Skogen; R. Schulze; E. Bernal; G. J. Lin; T. Daehlin; M. Campbell

1980-01-01

268

Binarising Camera Images for OCR  

Microsoft Academic Search

In this paper we describe a new binarisation method de- signed specifically for OCR of low quality camera images: Background Surface Thresholding or BST. This method is robust to lighting variations and produces images with very little noise and consistent stroke width. BST computes a \\

Mauritius Seeger; Christopher R. Dance

2001-01-01

269

Close-Range Camera Calibration  

Microsoft Academic Search

For highest accuracies it is necessary in close range photogrammetryto account for the variation of lens distortion within the photographic field. Atheory to accomplish this is developed along with a practical method for calibratingradial and decentering distortion of close-range cameras. This method, theanalytical plumb line method, is applied in an experimental investigation leadingto confirmation of the validity of the theoretical

Duane C. Brown

1971-01-01

270

Reading challenging barcodes with cameras  

Microsoft Academic Search

Current camera-based barcode readers do not work well when the image has low resolution, is out of focus, or is motion-blurred. One main reason is that virtually all existing algorithms perform some sort of binarization, either by gray scale thresholding or by finding the bar edges. We propose a new approach to barcode reading that never needs to binarize the

Orazio Gallo; Roberto Manduchi

2009-01-01

271

Resolution limitations and optimization of the LLNL streak camera focus  

NASA Astrophysics Data System (ADS)

The RCA C73435 image tube is biased at voltages far from its original design in the Lawrence Livermore National Laboratory (LLNL) ultrafast (10 ps) streak camera. Its output resolution at streak camera operating potentials has been measured as a function of input slit width, incident-light wavelength, and focus-grid voltage. The temporal resolution is insensitive to focus-grid voltage for a narrow (100 micron) input slit, but is very sensitive to focus-grid voltage for a wide (2 mm) input slit. At the optimum wide-slit focus voltage, temporal resolution is insensitive to slit width. Spatial resolution is nearly independent of focus-grid voltage for values that give good temporal resolution. Both temporal and spatial resolution depend on the incident-light wavelength. Data for 1.06 micron light show significantly better focusing than for 0.53 micron light. Streak camera operation is simulated with a computer program that calculates photoelectron trajectories. Electron ray tracing describes all of the observed effects of slit width, incident-light wavelength, and focus-grid voltage on output resolution.

Lerche, R. A.; Griffith, R. L.

1987-09-01

272

In-flight calibration of the Dawn Framing Camera  

NASA Astrophysics Data System (ADS)

We present a method for calibrating images acquired by the Dawn Framing Camera (FC) that is based on the results of an in-flight calibration campaign performed during the cruise from Earth to Vesta. We describe this campaign and the data analysis in full. Both the primary camera FC2 and the backup camera FC1 are radiometrically and geometrically calibrated through observations of standard stars, star fields, and Solar System objects. The calibration in each spectral filter is accurate to within a few percent for point sources. Geometric distortion, small by design, is characterized with high accuracy. Dark current, monitored on a regular basis, is very low at flight operational temperatures. Out-of-field stray light was characterized using the Sun as a stray light source. In-field stray light is confirmed in narrow-band filter images of Vesta. Its magnitude and distribution are scene-dependent, and expected to contribute significantly to images of extended objects. Description of a method for in-field stray light correction is deferred to a follow-up paper, as is a discussion of the closely related topic of flat-fielding.

Schröder, S. E.; Maue, T.; Gutiérrez Marqués, P.; Mottola, S.; Aye, K. M.; Sierks, H.; Keller, H. U.; Nathues, A.

2013-11-01

273

Depth perception with a rotationally symmetric coded camera  

NASA Astrophysics Data System (ADS)

A novel design of a phase coded depth-sensing camera is presented. A rotational symmetric phase mask is designed to discriminate the point spread functions (PSF) from different scene distances. The depth information can then be computationally obtained from a single captured photograph through a phase coded lens. The PSF must be carefully optimized at off-axis angles in order to create a restored image which is sharp over the required field of view. In this paper, a phase coded depth camera with a focal length 10.82mm, sensor size 2mm and F-number 5 is designed. Simulation data is exchanged between Matlab and Zemax for co-optimization of optical coding and digital decoding process. The simulation result shows that coarse depth information is investigated for object distance from 513 mm to 1000 mm.

Chang, Chuan-Chung; Chen, Yung-Lin; Chang, Chir-Weei; Lee, Cheng-Chung

2009-08-01

274

Analysis and protection of stray light for the space camera at geosynchronous orbit  

NASA Astrophysics Data System (ADS)

Stray light is the general term for all non-normal transmission of light in the optical system. The influence of stray light is different according to optical system's structure. Large area array camera at geosynchronous orbit is facing more serious influence of stray light, especially for the small incident angle of sunlight on the system. It is in dire need of a detailed analysis of stray light of the basic shape of the optical system .In the paper, the influence on the camera used in space from stray light and the necessity to eliminate stray light are presented. The definition of the stray light coefficient and PST(point source transmittance) is briefed. In Tracepro, analysis of the impact of sunlight incident was made at different angles on the space camera, in the case of stray light factor for the quantitative evaluation. The design principle of the inside and outside hood is presented for the R-C (Ritchey Chretien) optical system. On this basis, in order to reduce stray light interference for the space camera, the primary and secondary mirror's hoods were designed. Finally, when the incidence angle of sunlight is more than 3° incidence on the space camera, the coefficient of stray light is less than 2%. It meets the engineering requirements.

Jin, Xiaorui; Lin, Li

2012-11-01

275

SunAngle Calculator  

NSDL National Science Digital Library

SunAngle is an on-line tool that calculates solar angles and related information for a given location, date, and time. It computes the declination of the Sun, sunrise and sunset times, azimuth of the Sun, solar time and more. Complete instructions and definitions of variables are included.

Gronbeck, Christopher

276

Adaptive angle tracking  

Microsoft Academic Search

Angle tracking with phased array antennas in an external noise environment was studied. While the results of this study are applicable generally to arrays of sensors for measuring the angle of arrival of incident radiation, the emphasis in the simulation portion of the study was placed on radar arrays operating in a jamming environment. This problem is important in a

L. E. Brennan; I. S. Reed

1975-01-01

277

Polygon Angle Applet  

NSDL National Science Digital Library

This interactive Java applet supports the investigation of the relationship between the number of vertices of a polygon and its interior angle sum. Learners choose and locate the vertices, the angle measures are displayed, and then the student can drag the measures into a circle to see them summed relative to 360 degrees.

Exner, Nicholas

2000-05-31

278

Optical parametrization of an aerial multispectral camera.  

National Technical Information Service (NTIS)

This work presents a parametric study of an aerial multispectral camera produced with the aid of small cameras. The effects of the filter, spectrum of light, image motion and vibrations to the resolving power, contrast transfer function and resolution of ...

R. Silvennoinen

1989-01-01

279

Advanced Low Altitude Panoramic Camera System.  

National Technical Information Service (NTIS)

An engineering design study program was performed to investigate new camera concepts and configurations for an Advanced Low Altitude Panoramic (ALAP) camera. The effort was divided into two phases. The initial phase was concerned with conceptual studies o...

S. Kaye A. Magill

1976-01-01

280

National Dry Store Laser Scanning Camera,  

National Technical Information Service (NTIS)

A laser scanning camera was designed and constructed suitable for use in the proposed 'National Dry Store'. Designed to be installed in the 'Container Handling Machine (CHM)', the camera is required to provide information for automatic alignment of the CH...

R. S. Adrain J. H. Bach A. Clothier G. Jervis-Hunter R. Glanville

1987-01-01

281

Quadrotor control using dual camera visual feedback  

Microsoft Academic Search

In this paper, a vision-based stabilization and output tracking control method for a four-rotor helicopter has been proposed. A novel 2 camera method has been described for estimating the full 6 DOF pose of the heli- copter. This two camera system is consisting of a pan-tilt ground camera and an onboard camera. The pose estimation algorithm is compared in simulation

Erdinç Altug; James P. Ostrowski; Camillo J. Taylor

2003-01-01

282

Preliminary Mapping of Permanently Shadowed and Sunlit Regions Using the Lunar Reconnaissance Orbiter Camera (LROC)  

NASA Astrophysics Data System (ADS)

The spin axis of the Moon is tilted by only 1.5° (compared with the Earth's 23.5°), leaving some areas near the poles in permanent shadow while other nearby regions remain sunlit for a majority of the year. Theory, radar data, neutron measurements, and Lunar CRater Observation and Sensing Satellite (LCROSS) observations suggest that volatiles may be present in the cold traps created inside these permanently shadowed regions. While areas of near permanent illumination are prime locations for future lunar outposts due to benign thermal conditions and near constant solar power. The Lunar Reconnaissance Orbiter (LRO) has two imaging systems that provide medium and high resolution views of the poles. During almost every orbit the LROC Wide Angle Camera (WAC) acquires images at 100 m/pixel of the polar region (80° to 90° north and south latitude). In addition, the LROC Narrow Angle Camera (NAC) targets selected regions of interest at 0.7 to 1.5 m/pixel [Robinson et al., 2010]. During the first 11 months of the nominal mission, LROC acquired almost 6,000 WAC images and over 7,300 NAC images of the polar region (i.e., within 2° of pole). By analyzing this time series of WAC and NAC images, regions of permanent shadow and permanent, or near-permanent illumination can be quantified. The LROC Team is producing several reduced data products that graphically illustrate the illumination conditions of the polar regions. Illumination movie sequences are being produced that show how the lighting conditions change over a calendar year. Each frame of the movie sequence is a polar stereographic projected WAC image showing the lighting conditions at that moment. With the WAC’s wide field of view (~100 km at an altitude of 50 km), each frame has repeat coverage between 88° and 90° at each pole. The same WAC images are also being used to develop multi-temporal illumination maps that show the percent each 100 m × 100 m area is illuminated over a period of time. These maps are derived by stacking all the WAC frames, selecting a threshold to determine if the surface is illuminated, and summing the resulting binary images. In addition, mosaics of NAC images are also being produced for regions of interest at a scale of 0.7 to 1.5 m/pixel. The mosaics produced so far have revealed small illuminated surfaces on the tens of meters scale that were previously thought to be shadowed during that time. The LROC dataset of the polar regions complements previous illumination analysis of Clementine images [Bussey et al., 1999], Kaguya topography [Bussey et al., 2010], and the current efforts underway by the Lunar Orbiter Laser Altimeter (LOLA) Team [Mazarico et al., 2010] and provide an important new dataset for science and exploration. References: Bussey et al. (1999), Illumination conditions at the lunar south pole, Geophysical Research Letters, 26(9), 1187-1190. Bussey et al. (2010), Illumination conditions of the south pole of the Moon derived from Kaguya topography, Icarus, 208, 558-564. Mazarico et al. (2010), Illumination of the lunar poles from the Lunar Orbiter Laser Altimeter (LOLA) Topography Data, paper presented at 41st LPSC, Houston, TX. Robinson et al. (2010), Lunar Reconnaissance Orbiter Camera (LROC) Instrument Overview, Space Sci Rev, 150, 81-124.

Speyerer, E.; Koeber, S.; Robinson, M. S.

2010-12-01

283

Future Planetary Surface Imager Development by the Beagle 2 Stereo Camera System Team  

NASA Astrophysics Data System (ADS)

The Stereo Camera System provided Beagle 2 with wide-angle multi-spectral stereo imaging (IFOV=0.043°). The SCS team plans to build on this design heritage to provide improved stereo capabilities to the Pasteur payload of the Aurora ExoMars rover.

Griffiths, A. D.; Coates, A. J.; Josset, J.-L.; Paar, G.

2004-03-01

284

Recovery of Intrinsic and Extrinsic Camera Parameters Using Perspective Views of Rectangles  

Microsoft Academic Search

This paper concerns the recovery of intrinsic and extrinsic camera parameters using perspective views of rectangles. Several algorithms are described. The intrinsic parameters (aspect ratio, effective focal length, and the principal point) are determined in closed-form using a minimum of four views. The recovery of the intrinsic parameters and the rotation angles is independent of the size of the rectangles.

T. N. Tan; G. D. Sullivan; K. D. Baker

285

Riser angle control apparatus and method  

SciTech Connect

A riser angle control apparatus and method is described for use with a floating vessel having well drilling equipment, including an elongated riser having upper elements connected to the floating vessel by vessel connection means, and first flexible coupling means located adjacent the vessel connection means, the riser extending down from the vessel connection means to a point adjacent the ocean floor. The improvement described here consists of riser angle control apparatus comprising: second flexible coupling means operatively engaged with a portion of the upper elements of the riser below the first flexible coupling means, liquid phase of the pumpable waste or increase the specific gravity thereof; and adsorbents, in order to minimize convergence of the salt cavern by narrowing the difference between the specific gravity of the salt cavern walls and the specific gravity of the liquid phase of the pumpable waste by converting the liquid phase to a paste-like or solid consistency.

Dension, E.B.

1986-03-18

286

16 CFR 501.1 - Camera film.  

Code of Federal Regulations, 2013 CFR

...Practices 1 2013-01-01 2013-01-01 false Camera film. 501.1 Section 501.1 Commercial Practices...REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is...

2013-01-01

287

21 CFR 886.1120 - Ophthalmic camera.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Ophthalmic camera. 886.1120 Section 886.1120 Food...Diagnostic Devices § 886.1120 Ophthalmic camera. (a) Identification. An ophthalmic camera is an AC-powered device intended to...

2013-04-01

288

On Photometric Aspects of Catadioptric Cameras  

Microsoft Academic Search

Several imaging systems called catadioptric cameras have been developed that use a combination of lenses and mirrors to obtain wide fields of view. Geometric aspects have been well studied. This paper focuses on photometric aspects of catadioptric cameras. We discuss how geometric distortion of images of catadioptric cameras resulting from curvature of the mirror affects image irradiance. We show that

Takayuki Okatani; Koichiro Deguchi

2001-01-01

289

Calibration of Cameras with Radially Symmetric Distortion  

Microsoft Academic Search

We present algorithms for plane-based calibration of general radially distorted cameras. By this we understand cameras that have a distortion center and an optical axis such that the projection rays of pixels lying on a circle centered on the distortion center, form a right viewing cone centered on the optical axis. The camera is said to have a single viewpoint

Jean-philippe Tardif; Peter F. Sturm; Martin Trudeau; Sébastien Roy

2009-01-01

290

Observing Exoplanet Transits with Digital SLR Cameras  

NASA Astrophysics Data System (ADS)

Using a digital single lens reflex (DSLR) camera, I observed a transit of exoplanet HD 189733 in order to determine the feasibility of using these types of cameras for high-precision photometry. The results were scientifically useful, showing that even though the camera is not explicitly designed for scientific applications, it can nevertheless produce high-quality differential photometry.

Littlefield, C.

2010-12-01

291

Calibration of an Outdoor Active Camera System  

Microsoft Academic Search

A parametric camera model and calibration procedures are developed for an outdoor active camera system with pan, tilt and zoom control. Unlike traditional methods, active camera motion plays a key role in the calibration process, and no special laboratory setups are required. Intrinsic pa- rameters are estimated automatically by fitting parametric models to the optic flow induced by rotating and

Robert T. Collins; Yanghai Tsin

1999-01-01

292

Characterization of the LBNL PEM camera  

Microsoft Academic Search

We present the tomographic images and performance measurements of the LBNL positron emission mammography (PEM) camera, a specially designed positron emission tomography (PET) camera that utilizes PET detector modules with depth of interaction measurement capability to achieve both high sensitivity and high resolution for breast cancer detection. The camera currently consists of 24 detector modules positioned as four detector banks

G.-C. Wang; J. S. Huber; W. W. Moses; J. Qi; W.-S. Choong

2006-01-01

293

An auto-focusing CCD camera mount  

NASA Astrophysics Data System (ADS)

The traditional methods of focusing a CCD camera are either time consuming, difficult or, more importantly, indecisive. This paper describes a device designed to allow the observer to be confident that the camera will always be properly focused by sensing a selected star image and automatically adjusting the camera's focal position.

Arbour, R. W.

1994-08-01

294

Performance evaluation of the UCL Compton camera  

Microsoft Academic Search

An ongoing project is being carried out to develop a High Purity Germanium (HPGe) Compton camera for medical applications. The Compton camera offers many potential advantages over other imaging modalities used in nuclear medicine. These advantages include a wide field of view, the ability to reconstruct 3D images without tomography, and the fact that the camera can have a portable

Mashari A. Alnaaimi; Gary J. Royle; Walid Ghoggali; Robert D. Speller

2010-01-01

295

An Introduction to Distributed Smart Cameras  

Microsoft Academic Search

Distributed smart cameras (DSCs) are real-time distributed embedded systems that perform computer vision using multiple cameras. This new approach has emerged thanks to a confluence of simultaneous advances in four key disciplines: computer vision, image sensors, embedded computing, and sensor networks. Processing images in a network of distributed smart cameras introduces several complications. However, we believe that the problems DSCs

Bernhard Rinner; Wayne Wolf

2008-01-01

296

Camera Self-Calibration: Theory and Experiments  

Microsoft Academic Search

The problem of finding the internal orientation of a camera (camera calibration) is extremely important for practical applications. In this paper a complete method for calibrating a camera is presented. In contrast with existing methods it does not require a calibration object with a known 3D shape. The new method requires only point matches from image sequences. It is shown,

Olivier D. Faugeras; Quang-tuan Luong; Stephen J. Maybank

1992-01-01

297

The emission of narrow-band Jovian kilometric radiation  

NASA Astrophysics Data System (ADS)

A model based on the nonlinear coupling of electrostatic plasma waves is proposed to explain the emission of the narrow-band Jovian kilometric radiation (nKOM) observed by the Voyager spacecraft. It is shown that upper-hybrid branch electrostatic waves propagating through the inhomogeneities in the outer periphery of the Io plasma torus can attain the proper geometry for localized upconversion interactions leading to pump depletion. Plasma waves propagating into a weak density gradient and reflected at the critical layer interact with the incident waves leading to the electromagnetic emission, which is beamed at large angles with respect to the background magnetic field. In general, both L-O and R-X mode waves can be generated. The observed power and net polarization (L-O) are consistent with pump depletion of electrostatic waves at a level of about 10 mV/m. A possible excitation mechanism for the electrostatic waves is also discussed.

Fung, S. F.; Papadopoulos, K.

1987-08-01

298

A new method of meteor trajectory determination applied to multiple unsynchronized video cameras  

NASA Astrophysics Data System (ADS)

A new approach has been formulated to solve for the straight line trajectory of a meteor through the atmosphere when given multiple camera views of the meteor's luminous track. Using a motion propagation model in three-dimensional space plus time, and iteratively solving for all free model parameters simultaneously, one can obtain a fully coupled solution to the apparent radiant direction, three-dimensional begin position, atmospheric entry speed, deceleration terms, and timing offsets when using data from unsynchronized video cameras. A Monte Carlo component adds empirical error estimation for each of the key model parameters computed. This multi-parameter fitting method extends the allowable collection geometries for meteor trajectory estimation to lower convergence angles between camera-meteor-camera lines of sight and smaller site separation distances.

Gural, P. S.

2012-01-01

299

A new method of meteor trajectory determination applied to multiple unsynchronized video cameras  

NASA Astrophysics Data System (ADS)

A new approach has been formulated to solve for the straight line trajectory of a meteor through the atmosphere when given multiple camera views of the meteor's luminous track. Using a motion propagation model in 3-D space plus time, and iteratively solving for all free model parameters simultaneously, one can obtain a fully coupled solution to the apparent radiant direction, 3-D begin position, atmospheric entry speed, deceleration terms, and timing offsets when using data from unsynchronized video cameras. A Monte Carlo component adds empirical error estimation for each of the key model parameters computed. This multiparameter fitting method extends the allowable collection geometries for meteor trajectory estimation to lower convergence angles between camera-meteor-camera lines of sight and smaller site separation distances.

Gural, Peter S.

2012-08-01

300

Sentinel node detection in an animal study: evaluation of a new portable gamma camera.  

PubMed

We tested the capacity of a newly developed portable gamma camera to precisely locate sentinel nodes by injecting a radiotracer. Two sets of experiments were performed on eight pigs under general anesthesia. 99mTc-Nanocolloid and dye complex was injected in the submuscular layer of the small bowel in the first set and subcutaneously in the knee region in the second set of experiments. Image acquisition of the sentinel nodes was performed with the Camera placed at various angles. A mosaic of images was obtained encompassing the injection sites, lymphatic pathways, and sentinel lymph nodes. Three-dimensional visualizations were obtained, allowing the precise location and complete excision of these nodes. The use of the portable gamma camera allowed the rapid visualization of the lymphatic pathways leading from the injection sites to the sentinel nodes and precise location of these nodes. The Camera was also useful to verify the complete removal of the labeled target tissues. PMID:17972472

Kopelman, Doron; Blevis, Ira; Iosilevsky, Galina; Hatoum, Ossama A; Zaretzki, Assaf; Shofti, Rona; Salmon, Tal; Israel, Ora; Hashmonai, Moshe

301

Spectrally narrowed edge emission from leaky waveguide modes in organic light-emitting diodes  

SciTech Connect

A dramatic spectral line narrowing of the edge emission at room temperature from tris(quinolinolate) Al (Alq{sub 3}), N,N{prime}-diphenyl-N,N{prime}-bis(1-naphthylphenyl)-1,1{prime}-biphenyl-4,4{prime}-diamine (NPD), 4,4{prime}-bis(2,2{prime}-diphenyl-vinyl)-,1{prime}-biphenyl (DPVBi), and some guest-host small molecular organic light-emitting diodes (OLEDs), fabricated on indium tin oxide (ITO)-coated glass, is described. In all but the DPVBi OLEDs, the narrowed emission band emerges above a threshold thickness of the emitting layer, and narrows down to a full width at half maximum of only 5-10 nm. The results demonstrate that this narrowed emission is due to irregular waveguide modes that leak from the ITO to the glass substrate at a grazing angle. While measurements of variable stripe length l devices exhibit an apparent weak optical gain 0 {le} g {le} 1.86 cm{sup -1}, there is no observable threshold current or bias associated with this spectral narrowing. In addition, in the phosphorescent guest-host OLEDs, there is no decrease in the emission decay time of the narrowed edge emission relative to the broad surface emission. It is suspected that the apparent weak optical gain is due to misalignment of the axis of the waveguided mode and the axis of the collection lens of the probe.

Gan, Zhengqing; Tian, Yun; Lynch, David W.; Kang, Ji-hun; Park, Q-Han; and Shinar, Joseph

2009-11-03

302

Combustion pinhole-camera system  

DOEpatents

A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

Witte, A.B.

1982-05-19

303

Simulation and assessment of stray light effects in infrared cameras using non-sequential ray tracing  

NASA Astrophysics Data System (ADS)

In this article, we have evaluated the stray light effects in infrared cameras operating in the 3–5 ?m waveband having cooled focal plane array detectors. A non-sequential ray tracing method is used to model the multiple reflections from polished lens surfaces as well as diffused scattering from rough mechanical surfaces inside the camera housing. The flux signature on the detector surface due to the self-emission of in-band radiation from the lenses and camera housing is calculated. The flux signature due to sources beyond the nominal field-of-view of the camera is also calculated. Light splitting into multiple diffraction orders from diffractive lens surfaces is taken into account both in the transmission and the reflection paths. The wavelength and angle dependent reflection coefficient of the anti-reflection coatings on the polished lens surfaces is taken into account. The effect of local heating of camera mounts on the stray light signature on the detector surface is also evaluated. The results show that using the non-sequential ray tracing method, useful predictions can be made for the stray light signature in the infrared cameras. Such calculations can be used to identify areas in the camera housing which need to be temperature stabilized to reduce their detrimental stray-light signature.

Pravdivtsev, A. V.; Akram, M. N.

2013-09-01

304

Advanced camera image data acquisition system for Pi-of-the-Sky  

NASA Astrophysics Data System (ADS)

The paper describes a new generation of high performance, remote control, CCD cameras designed for astronomical applications. A completely new camera PCB was designed, manufactured, tested and commissioned. The CCD chip was positioned in a different way than previously resulting in better performance of the astronomical video data acquisition system. The camera was built using a low-noise, 4Mpixel CCD circuit by STA. The electronic circuit of the camera is highly parameterized and reconfigurable, as well as modular in comparison with the solution of first generation, due to application of open software solutions and FPGA circuit, Altera Cyclone EP1C6. New algorithms were implemented into the FPGA chip. There were used the following advanced electronic circuit in the camera system: microcontroller CY7C68013a (core 8051) by Cypress, image processor AD9826 by Analog Devices, GigEth interface RTL8169s by Realtec, memory SDRAM AT45DB642 by Atmel, CPU typr microprocessor ARM926EJ-S AT91SAM9260 by ARM and Atmel. Software solutions for the camera and its remote control, as well as image data acquisition are based only on the open source platform. There were used the following image interfaces ISI and API V4L2, data bus AMBA, AHB, INDI protocol. The camera will be replicated in 20 pieces and is designed for continuous on-line, wide angle observations of the sky in the research program Pi-of-the-Sky.

Kwiatkowski, Maciej; Kasprowicz, Grzegorz; Pozniak, Krzysztof; Romaniuk, Ryszard; Wrochna, Grzegorz

2008-11-01

305

Rosat wide field camera mirrors  

Microsoft Academic Search

The Rosat wide field camera is an XUV telescope operating in the 12-250-eV energy band. The mirror system utilizes Wolter-Schwarzschild type I grazing incidence optics with a focal length of 525 mm, comprised of three nested aluminum shells with an outermost diameter of 576 mm which provide a geometric aperture area of 456 sq cm. The reflecting surfaces are coated

R. Willingale

1988-01-01

306

The Advanced Camera for Surveys  

NSDL National Science Digital Library

The Johns Hopkins University describes the Advanced Camera for Surveys (ACS), which was installed in the Hubble Space Telescope in 2002 to "detect light from the ultraviolet to the near infrared." Users can view a photo gallery of the filters, detectors, optical bench, astronomers, and other aspects of ACS optical and mechanical components. While some parts of the website are restricted, scientists can find abstracts and full-text scientific papers, explanations of calibration, the coronagraph and other instruments, and press releases.

307

Artificial compound eye zoom camera.  

PubMed

We demonstrate a highly compact image capturing system with variable field of view but without any mechanically moving parts. The camera combines an ultra-thin artificial apposition compound eye with one variable focal length liquid lens. The change of optical power of the liquid lens when applying a voltage results in a change of the magnification of the microlens array imaging system. However, its effect on focusing of the individual microlenses can be neglected due to their small focal length. PMID:19029582

Duparré, Jacques; Wippermann, Frank; Dannberg, Peter; Bräuer, Andreas

2008-11-21

308

Cooling the dark energy camera instrument  

SciTech Connect

DECam, camera for the Dark Energy Survey (DES), is undergoing general design and component testing. For an overview see DePoy, et al in these proceedings. For a description of the imager, see Cease, et al in these proceedings. The CCD instrument will be mounted at the prime focus of the CTIO Blanco 4m telescope. The instrument temperature will be 173K with a heat load of 113W. In similar applications, cooling CCD instruments at the prime focus has been accomplished by three general methods. Liquid nitrogen reservoirs have been constructed to operate in any orientation, pulse tube cryocoolers have been used when tilt angles are limited and Joule-Thompson or Stirling cryocoolers have been used with smaller heat loads. Gifford-MacMahon cooling has been used at the Cassegrain but not at the prime focus. For DES, the combined requirements of high heat load, temperature stability, low vibration, operation in any orientation, liquid nitrogen cost and limited space available led to the design of a pumped, closed loop, circulating nitrogen system. At zenith the instrument will be twelve meters above the pump/cryocooler station. This cooling system expected to have a 10,000 hour maintenance interval. This paper will describe the engineering basis including the thermal model, unbalanced forces, cooldown time, the single and two-phase flow model.

Schmitt, R.L.; Cease, H.; /Fermilab; DePoy, D.; /Ohio State U.; Diehl, H.T.; Estrada, J.; Flaugher, B.; /Fermilab; Kuhlmann, S.; /Ohio State U.; Onal, Birce; Stefanik, A.; /Fermilab

2008-06-01

309

Cooling the Dark Energy Camera instrument  

NASA Astrophysics Data System (ADS)

DECam, camera for the Dark Energy Survey (DES), is undergoing general design and component testing. For an overview see DePoy, et al in these proceedings. For a description of the imager, see Cease, et al in these proceedings. The CCD instrument will be mounted at the prime focus of the CTIO Blanco 4m telescope. The instrument temperature will be 173K with a heat load of 113W. In similar applications, cooling CCD instruments at the prime focus has been accomplished by three general methods. Liquid nitrogen reservoirs have been constructed to operate in any orientation, pulse tube cryocoolers have been used when tilt angles are limited and Joule-Thompson or Stirling cryocoolers have been used with smaller heat loads. Gifford-MacMahon cooling has been used at the Cassegrain but not at the prime focus. For DES, the combined requirements of high heat load, temperature stability, low vibration, operation in any orientation, liquid nitrogen cost and limited space available led to the design of a pumped, closed loop, circulating nitrogen system. At zenith the instrument will be twelve meters above the pump/cryocooler station. This cooling system expected to have a 10,000 hour maintenance interval. This paper will describe the engineering basis including the thermal model, unbalanced forces, cooldown time, the single and two-phase flow model.

Schmitt, R. L.; Cease, H.; DePoy, D.; Diehl, H. T.; Estrada, J.; Flaugher, B.; Kuhlmann, S.; Onal, Birce; Stefanik, A.

2008-08-01

310

Unassisted 3D camera calibration  

NASA Astrophysics Data System (ADS)

With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

2012-02-01

311

Measurement of the surface wavelength distribution of narrow-band radiation by a colorimetric method  

SciTech Connect

A method is suggested for determining the wavelength of narrow-band light from a digital photograph of a radiating surface. The digital camera used should be appropriately calibrated. The accuracy of the wavelength measurement is better than 1 nm. The method was tested on the yellow doublet of mercury spectrum and on the adjacent continuum of the incandescent lamp radiation spectrum. By means of the method suggested the homogeneity of holographic sensor swelling was studied in stationary and transient cases. (laser applications and other topics in quantum electronics)

Kraiskii, A V; Mironova, T V; Sultanov, T T [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2010-09-10

312

High speed 512 [times] 512 camera system  

SciTech Connect

Lawrence Livermore National Laboratory has been involved in the design of high speed solid state camera systems for over a decade. The latest camera system designed by the laboratory utilizes the CCD-13 multiport 512 [times] 5l2 CCD array, manufactured by English Electric Valve. Simultaneous readout from each port at a 20 MHz pixel rate allows this camera system to achieve up to 500 frames per second. A first goneration camera system was designed by LLNL to provide data on the CCD-13, and as proof of principle for the camera system electronics. The results of the tests involving this camera will be presented in this report. A second generation camera system has been designed which incorporates the knowledge gained from these tests, and is currently being manufactured. This system should be available for testing in September '92.

Conder, A.

1992-07-01

313

High speed 512 {times} 512 camera system  

SciTech Connect

Lawrence Livermore National Laboratory has been involved in the design of high speed solid state camera systems for over a decade. The latest camera system designed by the laboratory utilizes the CCD-13 multiport 512 {times} 5l2 CCD array, manufactured by English Electric Valve. Simultaneous readout from each port at a 20 MHz pixel rate allows this camera system to achieve up to 500 frames per second. A first goneration camera system was designed by LLNL to provide data on the CCD-13, and as proof of principle for the camera system electronics. The results of the tests involving this camera will be presented in this report. A second generation camera system has been designed which incorporates the knowledge gained from these tests, and is currently being manufactured. This system should be available for testing in September `92.

Conder, A.

1992-07-01

314

Congenital narrowing of the cervical spinal canal.  

PubMed Central

The clinical and laboratory findings in six patients with congenital narrowing of the cervical spinal canal and neurological symptoms are described. A variable age of onset and an entirely male occurrence were found. Signs and symptoms of spinal cord dysfunction predominated in all but one patient. Symptoms were produced in five patients by increased physical activity alone. Congenital narrowing of the cervical spinal canal may result in cord compression without a history of injury and occasionally without evidence of significant bony degenerative changes. The clinical features may be distinguishable from those found in cervical spondylosis without congenital narrowing. Intermittent claudication of the cervical spinal cord appears to be an important feature of this syndrome. Surgery improved four out of five people.

Kessler, J T

1975-01-01

315

Correction of calculation method for boresight on aerial remote sensing camera  

NASA Astrophysics Data System (ADS)

The boresight of the aerial remote sensing camera (ARSC) need to be elicited to the reference coordinate system of the satellite after the assemblage of the whole satellite. Because it is difficult to aim the boresight after finish fixing the camera to the satellite, the boresight must be elicited by a cube before the fixing. So the cube coordinate system can be transited to the reference coordinate system. The boresight of the camera is measured by a theodolite. The orientation of the boresight can be solved through measuring four angles of the CCD, the top left corner, the bottom left corner, the top right corner, and the bottom right corner, and then the spatial angle of the boresight can be solved. According to the traditional methods of the data processing after boresight measuring, the limitation has been analyzed by using the Mat lab software. The trace of motion of the theodolite is provided, while it is rotating horizontally with a vertical angle around the vertical axis and rotating vertically with a horizontal angle around the horizontal axis. Based on the vector combination theory, the normalized vector of the boresight can be obtained, so the spatial angle of the boresight can also be calculated. At last, this paper shows two applications in factual measuring.

Xing, Hui; Mu, Sheng-bo; Chen, Jia-yi

2012-10-01

316

A Narrow-band Survey of Protostellar Shock Activity  

NASA Astrophysics Data System (ADS)

Energetic outflows are a ubiquitous signpost of star formation, observed in young stars of all masses. In studies of the early stages of star formation, we strive both to understand the mechanical and chemical properties of gas within an outflow, and to characterize outflow interactions with the dense clouds in which they are embedded. To develop a complete model of the interactions between protostar, outflow, and natal molecular cloud, surveys of entire star forming clouds as well as detailed studies of individual outflows are required. We have conducted a near-infrared protostellar shock survey of 35 star-forming regions in the Galaxy, including both isolated, individual outflows as well as larger molecular clouds containing multiple outflows. We imaged these regions in near-infrared narrow-band emission lines of molecular hydrogen, [FeII], and Paschen beta with the refurbished 2MASS camera on the Steward Observatory 61-inch Kuiper telescope. In addition, we have obtained moderate resolution (R=3500) near-infrared spectra (using TripleSpec at the Apache Point Observatory) for some of the individual outflows. We use the complementary near-infrared spectroscopic and imaging data to characterize the physical properties of each outflow, including excitation temperatures, emission line velocities, and energetics, and to describe the feedback these outflows may have on their natal clouds.

Drosback, Meredith M.; Indebetouw, R.

2011-01-01

317

On the absolute calibration of SO2 cameras  

NASA Astrophysics Data System (ADS)

Sulphur dioxide emission rate measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 300 and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. One important step for correct SO2 emission rate measurements that can be compared with other measurement techniques is a correct calibration. This requires conversion from the measured optical density to the desired SO2 column density (CD). The conversion factor is most commonly determined by inserting quartz cells (cuvettes) with known amounts of SO2 into the light path. Another calibration method uses an additional narrow field-of-view Differential Optical Absorption Spectroscopy system (NFOV-DOAS), which measures the column density simultaneously in a small area of the camera's field-of-view. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different, calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (I-DOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an I-DOAS to verify the calibration curve over the spatial extent of the image. The results show that calibration cells, while working fine in some cases, can lead to an overestimation of the SO2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration, radiative transfer effects (e.g. light dilution, multiple scattering) can significantly influence the results of both instrument types. The measurements presented in this work were taken at Popocatépetl, Mexico, between 1 March 2011 and 4 March 2011. Average SO2 emission rates between 4.00 and 14.34 kg s-1 were observed.

Lübcke, P.; Bobrowski, N.; Illing, S.; Kern, C.; Alvarez Nieves, J. M.; Vogel, L.; Zielcke, J.; Delgado Granados, H.; Platt, U.

2013-03-01

318

On the absolute calibration of SO2 cameras  

NASA Astrophysics Data System (ADS)

Sulphur dioxide emission flux measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 305 nm and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. While this approach is simple and delivers valuable insights into the two-dimensional SO2 distribution, absolute calibration has proven to be difficult. An accurate calibration of the SO2 camera (i.e., conversion from optical density to SO2 column density, CD) is crucial to obtain correct SO2 CDs and flux measurements that are comparable to other measurement techniques and can be used for volcanological applications. The most common approach for calibrating SO2 camera measurements is based on inserting quartz cells (cuvettes) containing known amounts of SO2 into the light path. It has been found, however, that reflections from the windows of the calibration cell can considerably affect the signal measured by the camera. Another possibility for calibration relies on performing simultaneous measurements in a small area of the camera's field-of-view (FOV) by a narrow-field-of-view Differential Optical Absorption Spectroscopy (NFOV-DOAS) system. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (IDOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an IDOAS to verify the calibration curve over the spatial extend of the image. Our results show that calibration cells can lead to an overestimation of the SO2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration, radiative transfer effects (e.g. light dilution, multiple scattering) can significantly influence the results of both instrument types. These effects can lead to an even more significant overestimation or, depending on the measurement conditions, an underestimation of the true CD. Previous investigations found that possible errors can be more than an order of magnitude. However, the spectral information from the DOAS measurements allows to correct for these radiative transfer effects. The measurement presented in this work were taken at Popocatépetl, Mexico, between 1 March 2011 and 4 March 2011. Average SO2 emission rates between 4.00 kg s-1 and 14.34 kg s-1 were observed.

Lübcke, P.; Bobrowski, N.; Illing, S.; Kern, C.; Alvarez Nieves, J. M.; Vogel, L.; Zielcke, J.; Delgado Granados, H.; Platt, U.

2012-09-01

319

Contact Angle Measurements Using a Simplified Experimental Setup  

ERIC Educational Resources Information Center

|A basic and affordable experimental apparatus is described that measures the static contact angle of a liquid drop in contact with a solid. The image of the drop is made with a simple digital camera by taking a picture that is magnified by an optical lens. The profile of the drop is then processed with ImageJ free software. The ImageJ contact…

Lamour, Guillaume; Hamraoui, Ahmed; Buvailo, Andrii; Xing, Yangjun; Keuleyan, Sean; Prakash, Vivek; Eftekhari-Bafrooei, Ali; Borguet, Eric

2010-01-01

320

Modulatable narrow-linewidth semiconductor lasers  

SciTech Connect

We find that using the technique of optical feedback locking, to narrow semiconductor linewidths, does not sacrifice the ability to modulate the laser's frequency via the injection current. The frequency of a laser is stabilized to a separate Fabry--Perot reference cavity using resonant optical feedback and can be modulated efficiently at frequencies related by rational fractions to the free-spectral range of the reference cavity. This system can provide an array of narrow-linewidth, frequency-stable laser lines and shows promise for applications in frequency-division-multiplexed coherent communications, as well as laser frequency control and precision measurement systems.

Hollberg, L.; Ohtsu, M.

1988-09-12

321

Low-frequency ionospheric sounding with Narrow Bipolar Event lightning radio emissions: energy-reflectivity spectrum  

NASA Astrophysics Data System (ADS)

We analyze data on radio-reflection from the D-region of the lower ionosphere, retrieving the energy-reflection coefficient in the frequency range ~5 95 kHz. The data are the same as developed for a recent study of ionospheric-reflection height, and are based on recordings of powerful (multi-Gigawatt) radio emissions from a type of narrow (~10 ?s) lightning discharge known as "Narrow Bipolar Events". The sequential appearance of first the groundwave signal, and then the ionospheric single-hop reflection signal, permits us to construct the energy-reflection ratio. We infer the energy reflection's statistical variation with solar zenith angle, angle-of-incidence, frequency, and propagation azimuth. There is also a marginally-significant response of the energy reflectivity to solar X-ray flux density. Finally, we review the relationship of our results to previous published reports.

Jacobson, A. R.; Holzworth, R.; Shao, X.-M.

2008-06-01

322

Variance-reduction normalization technique for a compton camera system  

NASA Astrophysics Data System (ADS)

For an artifact-free dataset, pre-processing (known as normalization) is needed to correct inherent non-uniformity of detection property in the Compton camera which consists of scattering and absorbing detectors. The detection efficiency depends on the non-uniform detection efficiency of the scattering and absorbing detectors, different incidence angles onto the detector surfaces, and the geometry of the two detectors. The correction factor for each detected position pair which is referred to as the normalization coefficient, is expressed as a product of factors representing the various variations. The variance-reduction technique (VRT) for a Compton camera (a normalization method) was studied. For the VRT, the Compton list-mode data of a planar uniform source of 140 keV was generated from a GATE simulation tool. The projection data of a cylindrical software phantom were normalized with normalization coefficients determined from the non-uniformity map, and then reconstructed by an ordered subset expectation maximization algorithm. The coefficient of variations and percent errors of the 3-D reconstructed images showed that the VRT applied to the Compton camera provides an enhanced image quality and the increased recovery rate of uniformity in the reconstructed image.

Kim, S. M.; Lee, J. S.; Kim, J. H.; Seo, H.; Kim, C. H.; Lee, C. S.; Lee, S. J.; Lee, M. C.; Lee, D. S.

2011-01-01

323

A 3D camera for improved facial recognition  

NASA Astrophysics Data System (ADS)

We describe a camera capable of recording 3D images of objects. It does this by projecting thousands of spots onto an object and then measuring the range to each spot by determining the parallax from a single frame. A second frame can be captured to record a conventional image, which can then be projected onto the surface mesh to form a rendered skin. The camera is able of locating the images of the spots to a precision of better than one tenth of a pixel, and from this it can determine range to an accuracy of less than 1 mm at 1 meter. The data can be recorded as a set of two images, and is reconstructed by forming a 'wire mesh' of range points and morphing the 2 D image over this structure. The camera can be used to record the images of faces and reconstruct the shape of the face, which allows viewing of the face from various angles. This allows images to be more critically inspected for the purpose of identifying individuals. Multiple images can be stitched together to create full panoramic images of head sized objects that can be viewed from any direction. The system is being tested with a graph matching system capable of fast and accurate shape comparisons for facial recognition. It can also be used with "models" of heads and faces to provide a means of obtaining biometric data.

Lewin, Andrew; Orchard, David A.; Scott, Andrew M.; Walton, Nicholas A.; Austin, Jim

2004-12-01

324

Digital cameras with designs inspired by the arthropod eye.  

PubMed

In arthropods, evolution has created a remarkably sophisticated class of imaging systems, with a wide-angle field of view, low aberrations, high acuity to motion and an infinite depth of field. A challenge in building digital cameras with the hemispherical, compound apposition layouts of arthropod eyes is that essential design requirements cannot be met with existing planar sensor technologies or conventional optics. Here we present materials, mechanics and integration schemes that afford scalable pathways to working, arthropod-inspired cameras with nearly full hemispherical shapes (about 160 degrees). Their surfaces are densely populated by imaging elements (artificial ommatidia), which are comparable in number (180) to those of the eyes of fire ants (Solenopsis fugax) and bark beetles (Hylastes nigrinus). The devices combine elastomeric compound optical elements with deformable arrays of thin silicon photodetectors into integrated sheets that can be elastically transformed from the planar geometries in which they are fabricated to hemispherical shapes for integration into apposition cameras. Our imaging results and quantitative ray-tracing-based simulations illustrate key features of operation. These general strategies seem to be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes). PMID:23636401

Song, Young Min; Xie, Yizhu; Malyarchuk, Viktor; Xiao, Jianliang; Jung, Inhwa; Choi, Ki-Joong; Liu, Zhuangjian; Park, Hyunsung; Lu, Chaofeng; Kim, Rak-Hwan; Li, Rui; Crozier, Kenneth B; Huang, Yonggang; Rogers, John A

2013-05-01

325

Actual properties of CCD cameras  

NASA Astrophysics Data System (ADS)

The information approach was applied to a determination of the actual properties of CCD-cameras. This approach is very useful when we have to establish from spectrograms, interferograms, holograms or other recorded data a set of functions that describe how the object under investigation behaves in space and time. Moreover this approach allows the actual properties of the measuring device be taken into account in order to determine the lower bound of experimental errors both before and after the measurement and to check how much use is made of the information that is contained in the recorded data. One of the best professional-quality CCD-cameras (ST-7I, Santa Barbara Instrument Group) was chosen for experimental investigation. Both the transfer (spread) function and the frequency-contrast function of this CCD-camera were determined experimentally and the optical channel fluctuation noise and the signal-to-noise ratio were measured as well. It has been shown that due to light scattering in the semiconductor base of the CCD matrix the amplitudes of high spatial frequency components of the image are reduced; the smaller the frequency of the light, the smaller are the amplitudes of the spatial frequency components of the output image. It has been ascertained that the relative error of the recorded image can be as small as one percent if the whole of the dynamic range is used (the full well capacity is equal to 40,000e) and if the highest spatial frequency of the image is small enough. But if the highest spatial frequency of the image fc is limited by pixel steps ? (? approximately equals 1/2 fc ), the relative error increases due to contrast reduction of the high spatial frequency and the relative error of the reconstructed input intensity distribution of the image more than doubles. This experimental result is very close to that derived from the calculated output image information. These experimental and simulation results are illustrated by recently obtained data.

Kryzhko, V. V.; Pergament, Michael M.; Pergament, M. M.; Simonov, V. V.; Wolferz, A. A.

2003-07-01

326

Research of sub-pixel sub-division location algorithm for spot center of digital aerial survey camera image  

NASA Astrophysics Data System (ADS)

So far, the geometric laboratory calibration system of optical aerial survey camera has been well established, while there is not a perfect system for digital aerial survey camera and the calibration of digital camera has not been included in the metrological verification system. In order to make the photogrammetry project rule-based, it's imperative to establish geometric laboratory calibration system of digital survey camera. Exact measuring angle method is the most common method to calibrate the camera in lab. The sub-pixel sub-division location of spot center for point-source image of digital camera is one of the key techniques to calibrate the camera based on the exact measuring angle method in lab. A novel location algorithm is proposed on account of the realities of the lab system. First, the Gauss filter is introduced to reduce the noise from the stray light and so on. Then the integration of iterative threshold segmentation and seed region growing is adopted to identify the general location of the spot. Thirdly, using the bilinear interpolation, the pixels used to estimate the location are increased. Finally, we use the proposed improved moment method to determinate the precise centroid location of the digital image. Experimental results show that the spots are identified with 93 percent accuracy and the centroid accuracy is superior to 1/40 of a pixel and improves about 2 to 4 times than other algorithms, which indicates that the proposed method is effective, convenient and precision.

Yu, Xiu-juan; Pang, Xu-feng; Fang, Ai-ping; Qi, Wei-jun

2013-08-01

327

Making Oatmeal Box Pinhole Cameras  

NSDL National Science Digital Library

This web site provides step-by-step directions for constructing a pinhole camera out of an oatmeal box and other common household items. Each step is supplemented with photos to show exactly how to build the apparatus so that it will actually take pictures. Also included are detailed procedures for shooting the photographs and developing them in an amateur darkroom. **NOTE: If performing this activity with children, follow safety procedures for using the photo developing agent. SEE THIS LINK for safety information on Kodak Dektol: http://www2.itap.purdue.edu/msds/docs/9735.pdf

Woodruff, Stewart

2009-05-28

328

Calibration of CCD video cameras  

NASA Astrophysics Data System (ADS)

By implementation of CCD video cameras with matrix array sensors in an analytical plotter, a hardware and software system for digital on-line image correlation to be used for conventional photogrammetric measurement was established. Geometric and radiometric calibration of the system is described. Connection of the CCD matrix sensors to the coordinate system of the analytical plotter is highlighted. For geometric and radiometric real time corrections for each pixel, methods for the determination of pixel by pixel or at least of regional correction parameters are discussed.

Guelch, E.

1986-11-01

329

Electrocardiographic manifestations: narrow QRS complex tachycardias  

Microsoft Academic Search

Narrow QRS complex tachycardia is a common dysrhythmia in Emergency Medicine practice. Diagnosis and mechanism often can be made by 12-lead electrocardiographic (EKG) analysis but may subsequently require electrophysiologic testing. The clinical manifestations are varied and dependent upon heart rate, prior cardiac disease, and general physiologic status. Patient management is directed towards the etiology and mechanism of the dysrhythmia and

Marc L Pollack; William J Brady; Theodore C Chan

2003-01-01

330

Adsorbate layering in narrow-pore materials  

Microsoft Academic Search

The conditions of layering of adsorbate molecules in porous systems with characteristic sizes of from 1 to 50 100 nm are discussed. The porous systems contain both very narrow pores, in which interaction potentials of pore walls overlap, and comparatively broad pores without overlapping of surface potentials. Three pore size intervals are distinguished. In the first interval, no adsorbate layering

Yu. K. Tovbin

2008-01-01

331

Narrow-Band Nonlinear Sea Waves  

Microsoft Academic Search

Probabilistic description of nonlinear waves with a narrow-band spectrum is simplified to a form in which each realization of the surface displacement becomes an amplitude-modulated Stokes wave with a mean frequency and random phase. Under appropriate conditions this simplification provides a convenient yet rigorous means of describing nonlinear effects on sea surface properties in a semiclosed or closed form. In

M. Aziz Tayfun

1980-01-01

332

New completeness results for lazy conditional narrowing  

Microsoft Academic Search

We show the completeness of the lazy conditional narrowing calculus (LCNC) with leftmost selection for the class of deterministic conditional rewrite systems (CTRSs). Deterministic CTRSs permit extra variables in the right-hand sides and conditions of their rewrite rules. From the completeness proof we obtain several insights to make the calculus more deterministic. Furthermore, and similar to the refinements developed for

Mircea Marin; Aart Middeldorp

2004-01-01

333

Progressive Retropalatal Narrowing Preceding Obstructive Apnea  

Microsoft Academic Search

Pharyngeal occlusion during obstructive apnea is thought to be an inspiratory-related event; however, occlusion also occurs in the absence of negative intrathoracic pressure. We hypothesized that inspira- tory-related pharyngeal occlusion would be preceded by significant expiratory narrowing. Eight sleeping patients with obstructive apnea were studied. Pharyngeal caliber, airflow, and esophageal pressure (Pes) were simultaneously monitored during three to four consecutive

MARY J. MORRELL; YASEEN ARABI; BRIAN ZAHN; M. SAFWAN

1998-01-01

334

Helium II flow through narrow pore filters  

Microsoft Academic Search

Studies of helium II flow through the narrow pore filters of cylindrical shapes, fabricated by compacting under pressure fine powders of aluminium oxide (0·05 µm), nickel and chromium (1 µm), have been made by measuring the volume flow rates in a two bath arrangement. The “easy” direction mass flow rates are in general agreement with the Gorter Mellink description, but

S. Kasthurirengan; S. Jacob; R. Karunanithi; G. Manjunath

1990-01-01

335

Navigation in partially unknown, narrow, cluttered space  

Microsoft Academic Search

Navigation of non-circular mobile robots in narrow, cluttered, partially unknown environments is considered. The paper introduces a planner capable of planning paths in these environments, while taking specific kinematic constraints and user defined optimality criteria into account. The planning is based on a graph, built and maintained in a variable, explicit configuration space representation of robot and workspace

M. Strobel

1999-01-01

336

From Reduction Machines To Narrowing Machines  

Microsoft Academic Search

Narrowing, the evaluation mechanism of functional logic languages, can be seen as a generalizationof reduction, the evaluation mechanism of purely functional languages. The unidirectionalpattern matching, which is used for parameter passing in functional languages, is simplyreplaced by the bidirectional unification known from logic programming languages. We showin this paper, how to extend a reduction machine, that has been designed for

Rita Loogen; RWTH Aachen

1991-01-01

337

Narrow Feshbach Dance of Two Trapped Atoms  

NASA Astrophysics Data System (ADS)

Near a narrow Feshbach resonance (with magnetic field width 10 mG or smaller) the ultra-cold atom interactions acquire an effective range that can be comparable to the average inter-particle distance. Although requiring a more accurate magnetic field control than their broad counterparts, the narrow Feshbach resonances can free cold atom physics from its straightjacket of the contact interaction paradigm. The finite-range effects can give rise to roton features in the phonon dispersion of dilute Bose-Einstein condensates (BEC's) and BEC's can support a ground state with modulated density patterns that breaks translational symmetry. We show that the finite range interaction is the consequence of the time-delay in atom-atom collisions. The narrow regime is also the parameter region in which the interacting atoms can spend a significant fraction of their time in the spin-rearranged (also called ``closed'') channel. To study the interaction physics we describe two atoms in a harmonic trap, interacting near a narrow resonance. We find the fraction of time that the atoms spend in the closed channel at fixed magnetic field and we study the time evolution of this system under conditions of a time-varying magnetic field.

Lopez Valdez, Nicolas; Timmermans, Eddy; Tsai, Shan-Wen

2012-06-01

338

of Intelligent Wheelchair in Narrow Spaces  

Microsoft Academic Search

Research on intelligent wheelchair, which is a kind of home welfare tools and can help the handicapped and elderly people to obtain more independent spaces, is attracting more and more attentions. This paper focuses on the problem of operation difficulty of intelligent wheelchair in narrow spaces and presents a kind of navigation strategy based on geometrical analysis. The running conditions

Tao Lu; Kui Yuan; Wei Zou; Huosheng Hu

339

Status of the Canarias InfraRed Camera Experiment (CIRCE)  

NASA Astrophysics Data System (ADS)

We report on the design status of the Canarias InfraRed Camera Experiment (CIRCE), a near-infrared visitor instrument for the Gran Telescopio Canarias (GTC). Besides functioning as a 1-2.5 ? m imager, CIRCE will have the capacity for narrow band imaging, low and moderate resolution grism spectroscopy, and imaging polarimetry. Other design features include fully cryogenic filter, slit, and grism wheels, high-speed photometry modes, and broad-band imaging in J, H, and Ks filters. We anticipate that a myriad of scientific projects will benefit from CIRCE's unique combination of capabilities, which will also compliment the EMIR instrument. We will preview one such research project currently in progress: the search for and identification of very massive stars in our Galaxy.

Edwards, M. L.; Eikenberry, S. S.; Marin-Franch, A.; Rodgers, M.; Julian, J.; Hanna, K.

2005-12-01

340

What's the Angle?  

NSDL National Science Digital Library

This activity helps learners understand how the angle of the Sun affects temperatures around the globe. After experimenting with a heat lamp and thermometers at differing angles, learners apply what they learned to explain temperature variations on Earth. The printable six-page handout includes a series of inquiry-based questions to get learners thinking about what they already know about temperature patterns, detailed experiment directions, and a worksheet that helps learners use the experiment results to gain a deeper understanding of seasonal temperature changes and why Antarctica is always cold.

History, American M.; University, Rice

2002-01-01

341

Polarization characteristics of the backscattering signal during pulsed sounding of the ocean with a narrow light beam  

Microsoft Academic Search

The problem of determining the polarized radiation field in a stratified absorbing medium with highly anisotropic scattering illuminated by a nonstationary narrow collimated beam is considered. Expressions for the backscattering signal polarization characteristics are obtained in the small-angle approximation. The influence of the optical characteristics of the medium and of the sounding geometry on the time dependence of the degree

A. P. Vasil'Kov; T. V. Kondranin; E. V. Miasnikov

1988-01-01

342

Lens assemblies for multispectral camera  

NASA Astrophysics Data System (ADS)

In the framework of a contract with the Indian Space Research Organization (ISRO), MATRA DEFENSE - DOD/UAO have developed, produced and tested 36 types LISS 1 - LISS 2 lenses and 12 LISS 3 lenses equipped with their interferential filters. These lenses are intended to form the optical systems of multispectral imaging sensors aboard Indian earth observation satellites IRS 1A, 1B, 1C, and 1D. It should be noted that the multispectrum cameras of the IRS 1A - 1B satellite have been in operation for two years and have given very satisfactory results according to ISRO. Each of these multispectrum LISS 3 cameras consists of lenses, each working in a different spectral bandwidth (B2: 520 - 590 nm; B3: 620 - 680 nm; B4: 770 - 860 nm; B5: 1550 - 1700 nm). In order to superimpose the images of each spectral band without digital processing, the image formats (60 mm) of the lenses are registered better that 2 micrometers and remain as such throughout all the environmental tests. Similarly, due to the absence of precise thermal control aboard the satellite, the lenses are as athermal as possible.

Lepretre, Francois

1994-09-01

343

Multi-camera track-before-detect  

Microsoft Academic Search

We present a novel multi-camera multi-target fusion and tracking algorithm for noisy data. Information fusion is an important step towards robust multi-camera tracking and allows us to reduce the effect of projection and parallax errors as well as of the sensor noise. Input data from each camera view are projected on a top-view through multi-level homographic transformations. These projected planes

Murtaza Taj; Andrea Cavallaro

2009-01-01

344

The Mars Science Laboratory Engineering Cameras  

NASA Astrophysics Data System (ADS)

NASA's Mars Science Laboratory (MSL) Rover is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover cameras described in Maki et al. (J. Geophys. Res. 108(E12): 8071, 2003). Images returned from the engineering cameras will be used to navigate the rover on the Martian surface, deploy the rover robotic arm, and ingest samples into the rover sample processing system. The Navigation cameras (Navcams) are mounted to a pan/tilt mast and have a 45-degree square field of view (FOV) with a pixel scale of 0.82 mrad/pixel. The Hazard Avoidance Cameras (Hazcams) are body-mounted to the rover chassis in the front and rear of the vehicle and have a 124-degree square FOV with a pixel scale of 2.1 mrad/pixel. All of the cameras utilize a 1024×1024 pixel detector and red/near IR bandpass filters centered at 650 nm. The MSL engineering cameras are grouped into two sets of six: one set of cameras is connected to rover computer "A" and the other set is connected to rover computer "B". The Navcams and Front Hazcams each provide similar views from either computer. The Rear Hazcams provide different views from the two computers due to the different mounting locations of the "A" and "B" Rear Hazcams. This paper provides a brief description of the engineering camera properties, the locations of the cameras on the vehicle, and camera usage for surface operations.

Maki, J.; Thiessen, D.; Pourangi, A.; Kobzeff, P.; Litwin, T.; Scherr, L.; Elliott, S.; Dingizian, A.; Maimone, M.

2012-09-01

345

A CCD based focal spot camera.  

PubMed

Rapid, quantative assessment of x-radiation source intensity distributions would be useful in several areas of radiation physics. A simple x-ray sensitive CCD based camera for the measurement of focal spot and radiation beam intensity profiles has been constructed. Focal spot images recorded with the CCD camera and radiographic emulsion are compared and the advantage of the CCD camera in rapidly recording true radiation intensity distributions is demonstrated. PMID:7708858

Speller, R D; Martínez-Dávalos, A; Farquharson, M

1995-02-01

346

Casting and Angling.  

ERIC Educational Resources Information Center

|As part of a series of books and pamphlets on outdoor education, this manual consists of easy-to-follow instructions for fishing activities dealing with casting and angling. The manual may be used as a part of the regular physical education program in schools and colleges or as a club activity for the accomplished weekend fisherman or the…

Smith, Julian W.

347

Wide Angle SAR Imaging  

Microsoft Academic Search

ABSTRACT We consider imaging strategies for synthetic aperture radar data collections that span a wide angular aperture. Most traditional radar imaging techniques are predicated on the assumption of isotropic point scattering mechanisms, which does not hold for wide apertures. We investigate point scattering center images for narrowband, wide angle data, and consider the effect of limited persistence on the resulting

Randolph L. Moses; Lee C. Potter; Mujdat Cetin

348

Multiple LED camera for dynamic photoelasticity  

NASA Astrophysics Data System (ADS)

Dynamic photoelasticity involves the high-speed recording of rapidly moving fringe patterns in synchronization with loading. Cranz Schardin cameras are routinely utilized in the recording of dynamic photoelastic patterns. There are no moving components in these cameras, making the setup simple and attractive. A multiple LED camera based on the Cranz Schardin format is presented. High-speed instant polaroid film is used for recording the photoelastic fringes. Low cost, simplicity in the experimental setup, and rapid repeatability are the advantages of the camera.

Asundi, A.; Sajan, M. R.

1995-05-01

349

Intelligent thermal imaging camera with network interface  

NASA Astrophysics Data System (ADS)

In recent years, a significant increase in usage of thermal imagining cameras can be observed in both public and commercial sector, due to the lower cost and expanding availability of uncooled microbolometer infrared radiation detectors. Devices present on the market vary in their parameters and output interfaces. However, all these thermographic cameras are only a source of an image, which is then analyzed in external image processing unit. There is no possibility to run users dedicated image processing algorithms by thermal imaging camera itself. This paper presents a concept of realization, architecture and hardware implementation of "Intelligent thermal imaging camera with network interface" utilizing modern technologies, standards and approach in one single device.

Sielewicz, Krzysztof M.; Kasprowicz, Grzegorz; Po?niak, Krzysztof T.; Romaniuk, R. S.

2011-06-01

350

Advantages of improved timing accuracy in PET cameras using LSOscintillator  

SciTech Connect

PET scanners based on LSO have the potential forsignificantly better coincidence timing resolution than the 6 ns fwhmtypically achieved with BGO. This study analyzes the performanceenhancements made possible by improved timing as a function of thecoincidence time resolution. If 500 ps fwhm coincidence timing resolutioncan be achieved in a complete PET camera, the following four benefits canbe realized for whole-body FDG imaging: 1) The random event rate can bereduced by using a narrower coincidence timing window, increasing thepeak NECR by~;50 percent. 2) Using time-of-flight in the reconstructionalgorithm will reduce the noise variance by a factor of 5. 3) Emissionand transmission data can be acquired simultaneously, reducing the totalscan time. 4) Axial blurring can be reduced by using time-of-flight todetermine the correct axial plane that each event originated from. Whiletime-of-flight was extensively studied in the 1980's, practical factorslimited its effectiveness at that time and little attention has been paidto timing in PET since then. As these potential improvements aresubstantial and the advent of LSO PET cameras gives us the means toobtain them without other sacrifices, efforts to improve PET timingshould resume after their long dormancy.

Moses, William W.

2002-12-02

351

Calibration of a wide angle stereoscopic system.  

PubMed

Inaccuracies in the calibration of a stereoscopic system appear with errors in point correspondences between both images and inexact points localization in each image. Errors increase if the stereoscopic system is composed of wide angle lens cameras. We propose a technique where detected points in both images are corrected before estimating the fundamental matrix and the lens distortion models. Since points are corrected first, errors in point correspondences and point localization are avoided. To correct point location in both images, geometrical and epipolar constraints are imposed in a nonlinear minimization problem. Geometrical constraints define the point localization in relation to its neighbors in the same image, and eipolar constraints represent the location of one point referred to its corresponding point in the other image. PMID:21847161

Ricolfe-Viala, Carlos; Sanchez-Salmeron, Antonio-Jose; Martinez-Berti, Enrique

2011-08-15

352

Attitudes Toward Red Light Camera Enforcement In Cities With Camera Programs  

Microsoft Academic Search

Objective: To obtain information on attitudes and experiences related to red light camera enforcement in cities with camera programs and in Houston, Texas, where cameras were removed after voters rejected the program in November 2010.Methods: Telephone surveys were conducted with 3,111 drivers in 14 large cities (population greater than 200,000) with long-standing red light camera programs and 300 drivers in

Anne T. McCartt; Angela H. Eichelberger

2011-01-01

353

Target detection against narrow band noise backgrounds.  

PubMed

We studied the detectability of narrow band random noise targets embedded in narrow band random noise backgrounds as a function of differences in center frequency, spatial frequency bandwidth and orientation bandwidth between target and the immediately adjacent background. Unlike most target detection experiments the targets were not added to the background; they replaced the underlying background texture. Simulations showed that target detection probabilities could be accounted for by a simple transformation on the summed outputs of a two layer filter model similar to the complex channels model proposed by Graham, Beck and Sutter (Graham, N., Beck, J., & Sutter, A. (1992). Vision Research, 32, 719-743). Subsequently, the model was tested on the detection of camouflaged vehicle targets with encouraging results. PMID:10343801

Cannon, M W; Reese, G J; Fullenkamp, S C

1999-06-01

354

Current Propagation in Narrow Bipolar Pulses  

NASA Astrophysics Data System (ADS)

We model the observed electric fields of a particular narrow bipolar pulse (NBP) published in Eack [2004]. We assume an exponential growth of current carriers due to a runaway breakdown avalanche and show that this leads to a corresponding increase in current. With specific input values for discharge altitude, length, current, and propagation velocity, the model does a good job of reproducing the observed near and far electric field. The ability of the model to reproduce the observed electric fields is an indication that our assumptions concerning the runaway avalanche may be correct, and this indication is further strengthened by the inability of the simple transmission line model to reproduce simultaneously both the near and far electric fields. Eack, K. B. (2004), Electrical characteristics of narrow bipolar events, Geophys. Res. Lett., 31, L20102, doi:10.1029/2004/GL021117.

Watson, S. S.; Marshall, T. C.

2005-12-01

355

Normal Q-angle in an adult Nigerian population.  

PubMed

The Q-angle has been studied among the adult Caucasian population with the establishment of reference values. Scientists are beginning to accept the concept of different human races. Physical variability exists between various African ethnic groups and Caucasians as exemplified by differences in anatomic features such as a flat nose compared with a pointed nose, wide rather than narrow faces, and straight rather than curly hair. Therefore, we cannot assume the same Q-angle values will be applicable to Africans and Caucasians. We established a baseline reference value for normal Q-angles among asymptomatic Nigerian adults. The Q-angles of the left and right knees were measured using a goniometer in 477 Nigerian adults (354 males; 123 females) in the supine and standing positions. The mean Q-angles for men were 10.7 degrees +/- 2.2 degrees in the supine position and 12.3 degrees +/- 2.2 degrees in the standing position in the right knee. The left knee Q-angles in men were 10.5 degrees +/- 2.6 degrees in the supine position and 11.7 degrees +/- 2.8 degrees in the standing position. In women, the mean Q-angles for the right knee were 21 degrees +/- 4.8 degrees in the supine position and 22.8 degrees +/- 4.7 degrees in the standing position. The mean Q-angles for the left knee in women were 20.9 degrees +/- 4.6 degrees in the supine position and 22.7 degrees +/- 4.6 degrees in the standing position. We observed a difference in Q-angles in the supine and standing positions for all participants. The Q-angle in adult Nigerian men is comparable to that of adult Caucasian men, but the Q-angle of Nigerian women is greater than that of their Caucasian counterparts. PMID:19034592

Omololu, Bade B; Ogunlade, Olusegun S; Gopaldasani, Vinod K

2008-11-26

356

Ship intelligent autopilot in narrow water  

Microsoft Academic Search

An on-line trained neurofuzzy control scheme is proposed for ship autopilot in narrow water. Due to the large inertia and relatively slow responses of the ship, a single input multi-output control strategy is developed. This specialized learning neurofuzzy controller uses the back-propagation gradient descent method to update the parameters of the network through time. With a relatively modest amount of

Zhuo Yongqiang; G. E. Hearn

2008-01-01

357

Adsorbate layering in narrow-pore materials  

Microsoft Academic Search

The conditions of layering of adsorbate molecules in porous systems with characteristic sizes of from 1 to 50–100 nm are discussed.\\u000a The porous systems contain both very narrow pores, in which interaction potentials of pore walls overlap, and comparatively\\u000a broad pores without overlapping of surface potentials. Three pore size intervals are distinguished. In the first interval,\\u000a no adsorbate layering occurs,

Yu. K. Tovbin

2008-01-01

358

Narrow bandwidth tunable optical parametric generator  

NASA Astrophysics Data System (ADS)

The output of a periodically poled lithium niobate (PPLN) optical parametric generator (OPG) is filtered using an off axis Fabry-Perot etalon. The filtered output is then parametrically amplified in the same PPLN crystal resulting in a tunable narrow-band infrared source. The PPLN OPG is pumped with a10 nsec pulse duration, 1.064 ?m singlefrequency pump laser, with an output signal and idler determined by the PPLN periodicity. The polarization of the pump laser is rotated so that only a portion of it is phase matched on the first pass through the PPLN crystal. The portion that is phase matched generates a signal that is directed to an off-axis Fabry-Perot etalon, which, in the off-axis configuration has a narrow bandwidth reflection. The pump beam is transmitted through a quarter wave plate and reflected with a mirror so that when passed back through the PPLN crystal, its polarization is rotated 90 degrees with respect to the input. Hence the portion of the pump not phase matched on the first pass is now phase matched for the second pass. The reflected and filtered signal is co-aligned with the pump resulting in a narrow bandwidth amplified signal. This system is capable of generating narrow bandwidth over the tuning range of the PPLN crystal and is only restricted by the etalon reflectivity range. We demonstrate tunability in the 1.4 ?m -1.6 ?m signal range (3.0 ?m-4.4 ?m idler range), which is restricted by our etalon reflectivity.

Dolasinski, Brian; Powers, Peter

2013-03-01

359

Narrowing Mossbauer Spectra by spinning magnetic field  

Microsoft Academic Search

In our work, we study numerically a possibility of Mossbauer line narrowing from the point of view of its experimental realization. Numerical simulation of the 14.4 keV 57Fe nuclear transition is based on Floquet-state perturbation theory for the RF modulation of the Mossbauer resonance. A model includes pairs of nuclei coupled to each other by dipole-dipole interaction, driven by the

Petr Anisimov; Olga Kocharovskaya; Yury Rostovtsev

2004-01-01

360

Decay Modes of Narrow Molecular Resonances  

NASA Astrophysics Data System (ADS)

The heavy-ion radiative capture reactions 12C(12C,?)24Mg and 12C(16O,?)28Si have been performed on and off resonance at TRIUMF using the Dragon separator and its associated BGO array. The decay of the studied narrow resonances has been shown to proceed predominantly through quasi-bound doorway states which cluster and deformed configurations would have a large overlap with the entry resonance states.

Courtin, S.; Haas, F.; Salsac, M.-D.; Lebhertz, D.; Michalon, A.; Beck, C.; Rousseau, M.; Zafra, A. Sanchez I.; Jenkins, D. G.; Glover, R. G.; Kent, P. E.; Hutcheon, D.; Davis, C.; Pearson, J. E.; Dragon Collaboration

2006-08-01

361

Electromechanical Model of Electrically Actuated Narrow Microbeams  

Microsoft Academic Search

A consistent one-dimensional distributed electromechanical model of an electrically actuated narrow microbeam with width\\/height between 0.5–2.0 is derived, and the needed pull-in parameters are extracted with different methods. The model accounts for the position-dependent electrostatic loading, the fringing field effects due to both the finite width and the finite thickness of a microbeam, the mid-plane stretching, the mechanical distributed stiffness,

Romesh C. Batra; Maurizio Porfiri; Davide Spinello

2006-01-01

362

Electrical Conductivity in Narrow Energy Bands  

Microsoft Academic Search

The electrical conductivity for a system of electrons described by the single-band Hubbard Hamiltonian is studied. An expression for the electrical conductivity that is applicable in the narrow-band regime, i.e., the bandwidth Delta, much smaller than intra-atomic Coulomb repulsion I is derived. It is shown that the conductivity vanishes at T=0 to first order in DeltaI for one electron per

Robert A. Bari; David Adler; Robert V. Lange

1970-01-01

363

Narrow-band microwave filter design  

Microsoft Academic Search

In this article, Dishal's concepts, EM simulation, and the port-tuning concept are combined as a powerful procedure for narrow-band filter design. When applied to an EM-based filter prototype, port tuning gives a direct indication of the magnitude and direction of the tunings needed to correct coupling errors and resonator frequency errors. An EM-based filter prototype potentially captures all the physics

Daniel G. Swanson

2007-01-01

364

New Method of Color Television Camera System Composition, Ccu-Less Color TV Camera.  

National Technical Information Service (NTIS)

The composition, means of reducing the size and weight, and the remote control method of the CCU-less camera are outlined, along with the color viewfinder. Block diagrams are presented on the standard compact 3P color camera and the CCU-less color camera....

K. Wakui E. Sawamura H. Marubayashi

1973-01-01

365

Robust Multi-View Camera Calibration for Wide-Baseline Camera Networks  

Microsoft Academic Search

Real-world camera networks are often characterized by very wide baselines covering a wide range of viewpoints. We describe a method not only calibrating each camera se- quence added to the system automatically, but also taking advantage of multi-view correspondences to make the en- tire calibration framework more robust. Novel camera se- quences can be seamlessly integrated into the system at

Jens Puwein; Remo Ziegler; Julia Vogel; Marc Pollefeys

2011-01-01

366

Approximations to camera sensor noise  

NASA Astrophysics Data System (ADS)

Noise is present in all image sensor data. Poisson distribution is said to model the stochastic nature of the photon arrival process, while it is common to approximate readout/thermal noise by additive white Gaussian noise (AWGN). Other sources of signal-dependent noise such as Fano and quantization also contribute to the overall noise profile. Question remains, however, about how best to model the combined sensor noise. Though additive Gaussian noise with signal-dependent noise variance (SD-AWGN) and Poisson corruption are two widely used models to approximate the actual sensor noise distribution, the justification given to these types of models are based on limited evidence. The goal of this paper is to provide a more comprehensive characterization of random noise. We concluded by presenting concrete evidence that Poisson model is a better approximation to real camera model than SD-AWGN. We suggest further modification to Poisson that may improve the noise model.

Jin, Xiaodan; Hirakawa, Keigo

2013-02-01

367

Reading Challenging Barcodes with Cameras  

PubMed Central

Current camera-based barcode readers do not work well when the image has low resolution, is out of focus, or is motion-blurred. One main reason is that virtually all existing algorithms perform some sort of binarization, either by gray scale thresholding or by finding the bar edges. We propose a new approach to barcode reading that never needs to binarize the image. Instead, we use deformable barcode digit models in a maximum likelihood setting. We show that the particular nature of these models enables efficient integration over the space of deformations. Global optimization over all digits is then performed using dynamic programming. Experiments with challenging UPC-A barcode images show substantial improvement over other state-of-the-art algorithms.

Gallo, Orazio; Manduchi, Roberto

2010-01-01

368

Illumination box and camera system  

DOEpatents

A hand portable, field-deployable thin-layer chromatography (TLC) unit and a hand portable, battery-operated unit for development, illumination, and data acquisition of the TLC plates contain many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit includes a solvent tank, a holder for TLC plates, and a variety of tool chambers for storing TLC plates, solvent, and pipettes. After processing in the TLC unit, a TLC plate is positioned in a collapsible illumination box, where the box and a CCD camera are optically aligned for optimal pixel resolution of the CCD images of the TLC plate. The TLC system includes an improved development chamber for chemical development of TLC plates that prevents solvent overflow.

Haas, Jeffrey S. (San Ramon, CA); Kelly, Fredrick R. (Modesto, CA); Bushman, John F. (Oakley, CA); Wiefel, Michael H. (La Honda, CA); Jensen, Wayne A. (Livermore, CA); Klunder, Gregory L. (Oakland, CA)

2002-01-01

369

A theory of self-calibration of a moving camera  

Microsoft Academic Search

There is a close connection between the calibration of a single camera and the epipolar transformation obtained when the camera undergoes a displacement. The epipolar transformation imposes two algebraic constraints on the camera calibration. If two epipolar transformations, arising from different camera displacements, are available then the compatible camera calibrations are parameterized by an algebraic curve of genus four. The

Stephen J. Maybank; Olivier D. Faugeras

1992-01-01

370

Camera Sensor network localization using FPGA  

Microsoft Academic Search

Camera networks are important in a video surveillance system. Many surveillance systems research has been done; most of it utilizes a general purpose computer. However, the latest trend is to use small, task specific and low power computer to process and control the system; in another word using embedded systems. This paper presents a camera network localization algorithm to be

Lina Noaman Elkhatib; Fawnizu Azmadi Hussin; Patrick Sebastian

2010-01-01

371

Real-World Interaction with Camera Phones  

Microsoft Academic Search

With the integration of cameras, mobile phones have evolved into networked personal image capture devices. Camera-phones can perform image processing tasks on the device itself and use the result as an additional means of user input and a source of context data. In this paper we present a system that turns such phones into mobile sen- sors for 2-dimensional visual

Michael Rohs

2004-01-01

372

Camera Jig for Underwater Stereoscopic Photography.  

National Technical Information Service (NTIS)

A portable camera jig for use by divers in making close-up, stereoscopic photographs of underwater surfaces with a single lens camera includes in combination with a sheet metal frame, a clear water box for operation in turbid water and that will permit il...

J. Millteman C. O. Warrell R. S. Peterson

1979-01-01

373

Mercuric Iodide X-Ray Camera.  

National Technical Information Service (NTIS)

A prototype x-ray camera utilizing a 1.5- by 1.5-in., 1024-element, thin mercuric iodide detector array has been tested and evaluated. The microprocessor-based camera is portable and operates at room temperature. Events can be localized within 1 to 2 mm a...

B. E. Patt A. Del Duca R. Dolin C. Ortale

1985-01-01

374

Recon .gurable High Resolution Network Camera  

Microsoft Academic Search

We present the result of development of the reconfigurable high resolution network camera (Proakis and Manolakis, 1989). The design goal was not just to build an end user product, but also to create both flexible and compact development platform suitable for experimenting with image processing and compression algorithms. To make this possible, Elphel model 313 camera has embedded computer running

Andrey Filippov

2003-01-01

375

Using a digital camera to study motion  

Microsoft Academic Search

A digital camera can easily be used to make a video record of a range of motions and interactions of objects - shm, free-fall and collisions, both elastic and inelastic. The video record allows measurements of displacement and time, and hence calculation of velocities, and practice with the standard formulas for motions and collisions. The camera extends the range of

Andrew J. McNeil; Steven Daniel

376

Photo annotation on a camera phone  

Microsoft Academic Search

In this paper we describe a system that allows users to annotate digital photos at the time of capture. The system uses camera phones with a lightweight client application and a server to store the images and metadata and assists the user in annotation on the camera phone by providing guesses about the location and content of the photos. By

Anita Wilhelm; Yuri Takhteyev; Risto Sarvas; Nancy A. Van House; Marc Davis

2004-01-01

377

Using vanishing points for camera calibration  

Microsoft Academic Search

In this article a new method for the calibration of a vision system which consists of two (or more) cameras is presented. The proposed method, which uses simple properties of vanishing points, is divided into two steps. In the first step, the intrinsic parameters of each camera, that is, the focal length and the location of the intersection between the

Bruno Caprile; Vincent Torre

1990-01-01

378

Sampling efficiency in digital camera performance standards  

Microsoft Academic Search

One of the first ISO digital camera standards to address image microstructure was ISO 12233, which introduced the SFR, spatial frequency response, based on the analysis of edge features in digital images. The SFR, whether derived from edges or periodic signals, describes the capture of image detail as a function of spatial frequency. Often during camera testing, however, there is

Peter D. Burns; Don Williams

2008-01-01

379

The streak camera system in HLS  

NASA Astrophysics Data System (ADS)

HLS (Hefei Light Source) is an 800MeV electron storage ring in National Synchrotron Radiation Laboratory. To measure electron bunch for Synchrotron Radiation and to understand the machine behavior during the operation, the streak camera system has been built in HLS storage ring on April 2006. The streak camera system mainly consists of the synchrotron light extracting optics setup and OPTOSCOPE the streak camera. The light extracting optics setup consists of the light extracting path and the optics imaging system. The OPTOSCOPE the streak camera consists of a camera main unit with input optics, a remote control unit, a CCD camera readout unit, a power supply unit, a Personal Computer with a frame grabber interface card and ARP-Optoscope software package. The streak camera system operates with synchroscan sweep mode or dual time base sweep mode. Controlling the streak camera and image acquisition is made by the ARP-Optoscope software. At present, the system is used to measure the bunch length and the bunch interval in HLS storage ring. Some typical results of the measurement are given.

Wang, J. G.; Sun, B. G.; Cao, Y.; Wang, B. Y.

2007-01-01

380

Spiraling Approach for Angles-Only Navigation within On-Orbit Servicing Missions  

Microsoft Academic Search

\\u000a On-Orbit Servicing missions possess a navigation problem for the transition from absolute to relative navigation when only\\u000a using camera based relative navigation. This gap can be covered by the concept of angles-only navigation. To avoid singularities\\u000a in angles-only navigation specifically trajectory profiles are designed. In this context the concept of the spiraling approach\\u000a is proposed. The spiraling approach results from

J. Spurmann

381

Calibration Plans for the Multi-angle Imaging SpectroRadiometer (MISR)  

Microsoft Academic Search

The EOS Multi-angle Imaging SpectroRadiometer (MISR) will study the ecology and climate of the Earth through acquisition of global multi-angle imagery. The MISR employs nine discrete cameras, each a push-broom imager. Of these, four point forward, four point aft and one views the nadir. Absolute radiometric calibration will be obtained pre-flight using high quantum efficiency (HQE) detectors and an integrating

C. J. Bruegge; V. G. Duval; N. L. Chrien; D. J. Diner

1993-01-01

382

Angle-resolved scattering spectroscopy of explosives using an external cavity quantum cascade laser  

SciTech Connect

Investigation of angle-resolved scattering from solid explosives residues on a car door for non-contact sensing geometries. Illumination with a mid-infrared external cavity quantum cascade laser tuning between 7 and 8 microns was detected both with a sensitive single point detector and a hyperspectral imaging camera. Spectral scattering phenomena were discussed and possibilities for hyperspectral imaging at large scattering angles were outlined.

Suter, Jonathan D.; Bernacki, Bruce E.; Phillips, Mark C.

2012-04-01

383

Narrow-K-band Observations of the GJ 1214 System  

NASA Astrophysics Data System (ADS)

GJ 1214 is a nearby M dwarf star that hosts a transiting super-Earth-size planet, making this system an excellent target for atmospheric studies. Most studies find that the transmission spectrum of GJ 1214b is flat, which favors either a high mean molecular weight or cloudy/hazy hydrogen (H) rich atmosphere model. Photometry at short wavelengths (<0.7 ?m) and in the K band can discriminate the most between these different atmosphere models for GJ 1214b, but current observations do not have sufficiently high precision. We present photometry of seven transits of GJ 1214b through a narrow K-band (2.141 ?m) filter with the Wide Field Camera on the 3.8 m United Kingdom Infrared Telescope. Our photometric precision is typically 1.7 × 10-3 (for a single transit), comparable with other ground-based observations of GJ 1214b. We measure a planet-star radius ratio of 0.1158 ± 0.0013, which, along with other studies, also supports a flat transmission spectrum for GJ 1214b. Since this does not exclude a scenario where GJ 1214b has an H-rich envelope with heavy elements that are sequestered below a cloud/haze layer, we compare K-band observations with models of H2 collision-induced absorption in an atmosphere for a range of temperatures. While we find no evidence for deviation from a flat spectrum (slope s = 0.0016 ± 0.0038), an H2-dominated upper atmosphere (<60 mbar) cannot be excluded. More precise observations at <0.7 ?m and in the K band, as well as a uniform analysis of all published data, would be useful for establishing more robust limits on atmosphere models for GJ 1214b.

Colón, Knicole D.; Gaidos, Eric

2013-10-01

384

Methods for spectral characterization of multispectral cameras  

NASA Astrophysics Data System (ADS)

High fidelity color image acquisition requires an accurate characterization of the camera's spectral sensitivity curves to perform color calibration or spectral estimation. Several methods have been proposed to perform this task; these include characterizations via test charts, narrowband filters and methods utilizing a monochromator. In most publications, RGB cameras are characterized. In this paper, we describe the characterization of the spectral sensitivity curves of a multispectral camera featuring seven optical bandpass filters. We show two different methods for the calibration using a monochromator - either by measuring the grayscale sensor of the camera and the filters separately or by characterizing the multispectral camera as a complete system. A comparison of both methods validates the measurement results. We furthermore develop different reconstruction methods (maximum value method, principal eigenvector method, linear or Wiener estimation). We perform also simulations of the characterization process to evaluate the methods and show the impact of the bandwidth of the monochromator stimuli on the reconstruction.

Klein, Julie; Brauers, Johannes; Aach, Til

2011-01-01

385

Camera calibration based on paraxial raytracing  

NASA Astrophysics Data System (ADS)

Traditional camera calibration is based on the pinhole model, which is an approximation algorithm using untrue geometrical assumptions and giving a single lumped result for the multiple optical elements in a camera. To provide an alternative method of camera calibration, we extend the traditional 2×2 matrix-based paraxial raytracing method to 6×6 in order to trace paraxial rays by using the first-order Taylor series expansion of Snell’s laws. Then we establish the geometric relationship between images and objects. Compared with the Snell’s Law camera calibration model of our previous work, the paraxial model offers explicit analytical sensitivity analysis for the mathematical manipulation of problematical conditions. Compared with the existing pinhole model, the proposed method, in addition to five intrinsic and six extrinsic parameters, gives the position parameters of each optical element of the camera system.

Lu, C.-H.; Lin, P. D.; Sung, C.-K.

2009-02-01

386

Be Foil "Filter Knee Imaging" NSTX Plasma with Fast Soft X-ray Camera  

SciTech Connect

A fast soft x-ray (SXR) pinhole camera has been implemented on the National Spherical Torus Experiment (NSTX). This paper presents observations and describes the Be foil Filter Knee Imaging (FKI) technique for reconstructions of a m/n=1/1 mode on NSTX. The SXR camera has a wide-angle (28{sup o}) field of view of the plasma. The camera images nearly the entire diameter of the plasma and a comparable region in the vertical direction. SXR photons pass through a beryllium foil and are imaged by a pinhole onto a P47 scintillator deposited on a fiber optic faceplate. An electrostatic image intensifier demagnifies the visible image by 6:1 to match it to the size of the charge-coupled device (CCD) chip. A pair of lenses couples the image to the CCD chip.

B.C. Stratton; S. von Goeler; D. Stutman; K. Tritz; L.E. Zakharov

2005-08-08

387

Fast soft x-ray camera observation of fast and slow reconnection events on NSTX  

NASA Astrophysics Data System (ADS)

Reconnection events on the National Spherical Torus Experiment (NSTX) are studied using data from a new soft x-ray camera diagnostic. The camera has a wide-angle tangential view of the plasma and can capture 300 images per discharge at rates up to 500000 frames per second. Two classes of m=n=1 reconnection events are seen: events such as sawteeth and internal reconnection events (IREs) characterized by rapid (˜200 ?s) reconnection, and events in which reconnection occurs on a much slower time scale (tens of ms) with a similar spatial structure. The mode evolution is reconstructed from the fast soft x-ray camera data. Nonlinear resistive MHD modeling with the M3D code and PEST code stability analysis is used to predict the growth rates and island structures of the fast and slow events, with the goal of understanding the conditions which lead to the two types of events.

Stratton, Brentley

2005-10-01

388

1024 x 768 XGA uncooled camera core achieves new levels of performance in a small package  

NASA Astrophysics Data System (ADS)

An uncooled XGA camera core has been developed for multiple thermal imaging applications that require longer detection range and wider fields of view. The design challenge is to maintain high performance while optimizing for size, weight, and power (SWAP). Utilizing a combination of low power electronic designs, proprietary calibration methods, and a new 17?m pitch high performance amorphous silicon (ASi) microbolometer, a rugged multi-purpose SWAP-optimized XGA camera core has been designed. The result is a camera core that has been shown to deliver far better detection range and angle-of-view performance than previous uncooled solutions with frame rates of 30 Hz in XGA mode and 60 Hz in VGA mode.

Alicandro, C. J.; Demarco, R. W.

2011-05-01

389

Optimum Projection Angle for Attaining Maximum Distance in a Soccer Punt Kick  

PubMed Central

To produce the greatest horizontal distance in a punt kick the ball must be projected at an appropriate angle. Here, we investigated the optimum projection angle that maximises the distance attained in a punt kick by a soccer goalkeeper. Two male players performed many maximum-effort kicks using projection angles of between 10° and 90°. The kicks were recorded by a video camera at 100 Hz and a 2 D biomechanical analysis was conducted to obtain measures of the projection velocity, projection angle, projection height, ball spin rate, and foot velocity at impact. The player’s optimum projection angle was calculated by substituting mathematical equations for the relationships between the projection variables into the equations for the aerodynamic flight of a soccer ball. The calculated optimum projection angles were in agreement with the player’s preferred projection angles (40° and 44°). In projectile sports even a small dependence of projection velocity on projection angle is sufficient to produce a substantial shift in the optimum projection angle away from 45°. In the punt kicks studied here, the optimum projection angle was close to 45° because the projection velocity of the ball remained almost constant across all projection angles. This result is in contrast to throwing and jumping for maximum distance, where the projection velocity the athlete is able to achieve decreases substantially with increasing projection angle and so the optimum projection angle is well below 45°. Key points The optimum projection angle that maximizes the distance of a punt kick by a soccer goalkeeper is about 45°. The optimum projection angle is close to 45° because the projection velocity of the ball is almost the same at all projection angles. This result is in contrast to throwing and jumping for maximum distance, where the optimum projection angle is well below 45° because the projection velocity the athlete is able to achieve decreases substantially with increasing projection angle.

Linthorne, Nicholas P.; Patel, Dipesh S.

2011-01-01

390

The European Photon Imaging Camera on XMM-Newton: The MOS cameras : The MOS cameras  

NASA Astrophysics Data System (ADS)

The EPIC focal plane imaging spectrometers on XMM-Newton use CCDs to record the images and spectra of celestial X-ray sources focused by the three X-ray mirrors. There is one camera at the focus of each mirror; two of the cameras contain seven MOS CCDs, while the third uses twelve PN CCDs, defining a circular field of view of 30' diameter in each case. The CCDs were specially developed for EPIC, and combine high quality imaging with spectral resolution close to the Fano limit. A filter wheel carrying three kinds of X-ray transparent light blocking filter, a fully closed, and a fully open position, is fitted to each EPIC instrument. The CCDs are cooled passively and are under full closed loop thermal control. A radio-active source is fitted for internal calibration. Data are processed on-board to save telemetry by removing cosmic ray tracks, and generating X-ray event files; a variety of different instrument modes are available to increase the dynamic range of the instrument and to enable fast timing. The instruments were calibrated using laboratory X-ray beams, and synchrotron generated monochromatic X-ray beams before launch; in-orbit calibration makes use of a variety of celestial X-ray targets. The current calibration is better than 10% over the entire energy range of 0.2 to 10 keV. All three instruments survived launch and are performing nominally in orbit. In particular full field-of-view coverage is available, all electronic modes work, and the energy resolution is close to pre-launch values. Radiation damage is well within pre-launch predictions and does not yet impact on the energy resolution. The scientific results from EPIC amply fulfil pre-launch expectations.

Turner, M. J. L.; Abbey, A.; Arnaud, M.; Balasini, M.; Barbera, M.; Belsole, E.; Bennie, P. J.; Bernard, J. P.; Bignami, G. F.; Boer, M.; Briel, U.; Butler, I.; Cara, C.; Chabaud, C.; Cole, R.; Collura, A.; Conte, M.; Cros, A.; Denby, M.; Dhez, P.; Di Coco, G.; Dowson, J.; Ferrando, P.; Ghizzardi, S.; Gianotti, F.; Goodall, C. V.; Gretton, L.; Griffiths, R. G.; Hainaut, O.; Hochedez, J. F.; Holland, A. D.; Jourdain, E.; Kendziorra, E.; Lagostina, A.; Laine, R.; La Palombara, N.; Lortholary, M.; Lumb, D.; Marty, P.; Molendi, S.; Pigot, C.; Poindron, E.; Pounds, K. A.; Reeves, J. N.; Reppin, C.; Rothenflug, R.; Salvetat, P.; Sauvageot, J. L.; Schmitt, D.; Sembay, S.; Short, A. D. T.; Spragg, J.; Stephen, J.; Strüder, L.; Tiengo, A.; Trifoglio, M.; Trümper, J.; Vercellone, S.; Vigroux, L.; Villa, G.; Ward, M. J.; Whitehead, S.; Zonca, E.

2001-01-01

391

Polymer-networked liquid crystal cell for omni-directional viewing-angle switching  

NASA Astrophysics Data System (ADS)

A novel method for switching the viewing-angle of a liquid crystal display is proposed by using a polymernetworked liquid crystal cell in combination with a collimated backlight system. The bright state for a wide viewing-angle is obtained aligning liquid crystals randomly in polymer-networked structure, which diffuses a collimated backlight. The liquid crystals homogeneous-aligned by in-plane switching are operated as the bright state for a narrow viewing-angle since a collimated backlight passes through the liquid crystal layer intactly. It is demonstrated experimentally that the viewing-angle can be controlled omni-directionally without an additional panel or an additional backlight system.

Yoon, Tae-Hoon; Baek, Jong-In; Kim, Ki-Han; Kim, Jae-Chang

2010-02-01

392

Limbus Impact on Off-angle Iris Degradation  

SciTech Connect

The accuracy of iris recognition depends on the quality of data capture and is negatively affected by several factors such as angle, occlusion, and dilation. Off-angle iris recognition is a new research focus in biometrics that tries to address several issues including corneal refraction, complex 3D iris texture, and blur. In this paper, we present an additional significant challenge that degrades the performance of the off-angle iris recognition systems, called the limbus effect . The limbus is the region at the border of the cornea where the cornea joins the sclera. The limbus is a semitransparent tissue that occludes a side portion of the iris plane. The amount of occluded iris texture on the side nearest the camera increases as the image acquisition angle increases. Without considering the role of the limbus effect, it is difficult to design an accurate off-angle iris recognition system. To the best of our knowledge, this is the first work that investigates the limbus effect in detail from a biometrics perspective. Based on results from real images and simulated experiments with real iris texture, the limbus effect increases the hamming distance score between frontal and off-angle iris images ranging from 0.05 to 0.2 depending upon the limbus height.

Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

2013-01-01

393

Matched tandem etalon camera - MATEC - and its application to auroral observations  

NASA Astrophysics Data System (ADS)

The matched tandem etalon camera employs a Fabry-Perot interferometer (FP) in the photographic mode for the spatial resolution over all angles up to 7 deg from normal. An interference filter and an appropriate field lens isolate a single order of 0.1 A resolution, which is recorded simultaneously at all angles in the field of view by array detection. Thus the resolution and luminosity of the MATEC camera are those of the FP. The MATEC pilot model has a ratio of free spectral range to linewidth of 400 and utilizes intensified photographic detection. In a system applied to auroral measurements the MATEC views a semiconical sky mirror to provide a simulatenous dimension of spatial resolution in the N-S meridian combined with the dimension of spectral resolution. Stellar features and cloud and ground reflections are more easily identified than by any scanning photometer.

Young, E. R.; Clark, K. C.

1980-08-01

394

Dependence of camera lens induced radial distortion and circle of confusion on object position  

NASA Astrophysics Data System (ADS)

Our work presents a theoretical description of camera lens radial distortion and its dependence on the change of the object position with respect to the optical system. We derived approximate formulas within the validity of the third-order aberration theory, which make possible to calculate the changes of lens distortion and the circle of confusion in dependence on the change of the object from the camera lens. These formulas consider a wide angle bundle of rays for calculation of the image point. We also prove that the elimination of distortion by tracing the principal ray does not warrant the removal of distortion of the optical system for the wide angle bundle of rays.

Miks, Antonin; Novak, Jiri

2012-06-01

395

The Hyperspectral Stereo Camera Project  

NASA Astrophysics Data System (ADS)

The MSSL Hyperspectral Stereo Camera (HSC) is developed from Beagle2 stereo camera heritage. Replaceing filter wheels with liquid crystal tuneable filters (LCTF) turns each eye into a compact hyperspectral imager. Hyperspectral imaging is defined here as acquiring 10s-100s of images in 10-20 nm spectral bands. Combined together these bands form an image `cube' (with wavelength as the third dimension) allowing a detailed spectrum to be extracted at any pixel position. A LCTF is conceptually similar to the Fabry-Perot tuneable filter design but instead of physical separation, the variable refractive index of the liquid crystal etalons is used to define the wavelength of interest. For 10 nm bandwidths, LCTFs are available covering the 400-720 nm and 650-1100 nm ranges. The resulting benefits include reduced imager mechanical complexity, no limitation on the number of filter wavelengths available and the ability to change the wavelengths of interest in response to new findings as the mission proceeds. LCTFs are currently commercially available from two US companies - Scientific Solutions Inc. and Cambridge Research Inc. (CRI). CRI distribute the `Varispec' LCTFs used in the HSC. Currently, in Earth orbit hyperspectral imagers can prospect for minerals, detect camouflaged military equipment and determine the species and state of health of crops. Therefore, we believe this instrument shows great promise for a wide range of investigations in the planetary science domain (below). MSSL will integrate and test at representative Martian temperatures the HSC development model (to determine power requirements to prevent the liquid crystals freezing). Additionally, a full radiometric calibration is required to determine the HSC sensitivity. The second phase of the project is to demonstrate (in a ground based lab) the benefit of much higher spectral resolution to the following Martian scientific investigations: - Determination of the mineralogy of rocks and soil - Detection of water vapour due to its absorption of sun light at 935 nm - The measurement of the dust optical density as a function of wavelength - Determination of the solar spectrum at the surface as a function of time of day - The search for putative biological pigments (i.e. chlorophyll and carotenoids) The detector for this proposal is a commercial low noise CCD imaging chip providing sufficient SNR to detect the 10s of ppm of water vapour present in the Martian atmosphere.

Griffiths, A. D.; Coates, A. J.

2006-12-01

396

Anomalous Wakefields in Ultra-Narrow Plasmas  

NASA Astrophysics Data System (ADS)

The properties of relativistic non-linear plasma wakes excited by lasers or particle beams in an ultra-narrow plasma (radius less than the plasma skin depth and the displacement amplitude of plasma electrons in the wake) are described. The restoring force on the oscillating electrons is reduced compared to oscillations in a homogeneous plasma resulting in a wave frequency that can be several times smaller than that of the usual wake at the plasma frequency. The circumstance described here arises commonly in current laser wakefield experiments with tightly focused lasers that self-ionize a gas in the low plasma density or resonant laser wakefield regime.

Tarik, K.; Katsouleas, T.; Muggli, P.; Mori, W. B.; Gordon, D.

2001-10-01

397

Gain Narrowing in Few-Atom Systems  

SciTech Connect

Using a density matrix approach, we study the simplest systems that display both gain and feedback: clusters of 2 to 5 atoms, one of which is pumped. The other atoms supply feedback through multiple scattering of light. We show that, if the atoms are in each other's near field, the system exhibits large gain narrowing and spectral mode redistribution. The observed phenomena are more pronounced if the feedback is enhanced. Our system is to our knowledge the simplest exactly solvable microscopic system which shows the approach to laser oscillation.

Savels, Tom [FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ, Amsterdam (Netherlands); Mosk, Allard P. [Complex Photonic Systems, MESA Research Institute, University of Twente, Post Office Box 217, 7500 AE Enschede (Netherlands); Lagendijk, Ad [FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ, Amsterdam (Netherlands); Complex Photonic Systems, MESA Research Institute, University of Twente, Post Office Box 217, 7500 AE Enschede (Netherlands)

2007-03-09

398

Dusty Outflows in Narrow-Line Regions  

NASA Astrophysics Data System (ADS)

When spectra of the narrow-line regions (NLR) of Seyfert Galaxies are examined, the emission-line ratios show a remarkable similarity, which is hard to understand with current models. What makes this similarity so remarkable is that it holds even over large distance and kinematical scales. In fact, recent observations show NLR outflows reaching 3000km/s in a typical Seyfert 2, NGC 1068. Here, we put forward a new model of the physical conditions in the NLR, which may explain both the similarity in line emission and these amazing outflows: radiation pressure dominated, dusty, photoablating clouds.

Groves, B. A.; Dopita, M. A.

2003-01-01

399

Quantum Hall effect in narrow Coulomb channels  

NASA Astrophysics Data System (ADS)

Proposed is a scenario for the development of magnetic-field-induced electron states (MESs) in finite charged systems. These states arise due to incomplete screening of external electrostatic fields governing the electron density distribution and therefore exist within a certain static skin layer of width ? along the edge of a two-dimensional (2D) charged system (either classical or degenerate). In the magnetic field normal to the 2D system the electrons in the skin layer are dragged along the MES orbits by the Lorentz force in both classical and degenerate 2D systems. Details of the ? scenario for MESs in the narrow-channel quantum Hall effect problem are reported.

Nazin, S.; Shikin, V.

2011-10-01

400

Narrowing the gap in childhood immunization disparities.  

PubMed

The reduction of health disparities among all people in the United States is a national health priority. Although immunization rates have improved in the past 20 years, disparities continue to exist among ethnic and racial groups, across different socioeconomic classes, and in different geographic locations. Pediatric health care providers can play a key role in helping to narrow the gap in immunization coverage rates, thus reducing disparities. The purpose of this article is to (1) provide a review of the literature on disparities in immunization rates of children and adolescents, (2) provide suggestions for intervention to minimize immunization disparities, and (3) set an agenda for future research in this area. PMID:16295153

Niederhauser, Victoria P; Stark, Mariailiana

401

Techniques for Optimising Data From Thermal Imaging Cameras on Active Volcanoes and Implications for Modelling Lava Flows  

Microsoft Academic Search

Following a systematic series of laboratory experiments using different thermal imaging cameras, it is now possible to determine surface temperatures of volcanic rocks in the laboratory over a range of temperatures and viewing angles with a precision of 0.8%. Extracting useful temperature data in the field is more challenging. Current methods of dealing with pixel integrated temperatures make assumptions that

H. Pinkerton; M. Ball; M. James; K. Cashman

2005-01-01

402

Phase resolved electroluminescence measurements in thin films of low density polyethylene using a charge coupled device camera  

Microsoft Academic Search

Electroluminescence (EL) produced by a commercially available additive free low density polyethylene film has been investigated under a 50 Hz AC electrical stress. The spatial distribution, spectral characteristics and the phase angle relationship of EL with respect to the 50 Hz applied AC voltage were studied using a sensitive Peltier cooled charge-couple device (CCD) camera. The experimental results from several

S. J. Dodd; P. L. Lewin; K. I. Wong

2006-01-01

403

Using the Separation of Double Stars to Obtain the Plate Scale of a Telescope with a CCD Camera Attached  

Microsoft Academic Search

A new CCD Camera was coupled to the NURO telescope in March 2006. We used the separation of selected binary stars in the Washington Double Star Catalog to calculate the new plate scale. The value of the plate scale obtained was, within the error bar, in agreement with the design (theoretical) value. We also report the position angle and separation

R. J. Muller; J. C. Cersosimo; D. Centeno; V. Miranda; L. Rivera-Rivera; E. Franco; K. Morales

2008-01-01

404

Shapes and Angles  

NSDL National Science Digital Library

In this activity (page 7 of PDF), learners will identify the general two-dimensional geometric shape of the uppermost cross section of an impact crater. They will also draw connections between the general two-dimensional geometric shape of an impact crater and the projectile's angle of impact. There are two versions of this activity: Challenge, where students construct a launcher and create their own craters; and Non-Challenge where students analyze pictures of craters. The Moon Math: Craters! guide follows a 5E approach, applying concepts of geometry, modeling, data analysis to the NASA lunar spacecraft mission, LCROSS.

Nasa

2012-05-08

405

Angles and Area  

NSDL National Science Digital Library

In this activity (page 10 of PDF), learners approximate the area of the uppermost cross section of an impact crater using a variety of square grids. They conclude which angle of impact results in the greatest area. There are two versions of this activity: Challenge, where students construct a launcher and create their own craters; and Non-Challenge where students analyze pictures of craters. Includes a pre-lesson activity (p54). The Moon Math: Craters! guide follows a 5E approach, applying concepts of geometry, modeling, data analysis to the NASA lunar spacecraft mission, LCROSS.

Nasa

2012-05-08

406

Opposed bubbly jets at different impact angles: Jet structure and bubble properties  

Microsoft Academic Search

The structure of two colliding water jets containing small gas bubbles is studied experimentally. The effects of the separation distance between jets, as well as the orientation angle, on the spatial distribution of bubbles have been considered. Results on the global structure of the final jet and bubble properties have been obtained using a high-speed video camera, and measurements of

Francesc Suñol; Ricard González-Cinca

2010-01-01

407

A novel digital shearography with wide angle of view for nondestructive inspection  

NASA Astrophysics Data System (ADS)

Digital shearography is widely accepted in non-destructive inspection of honeycomb sandwich structures due to its advantages of validity, non-contact, simple setup and robustness. In digital shearography, Michelson shear interferometer (MSI) is a dominant shearing device because it is easy to change the shearing amount and direction. However, the conventional digital shearography based on MSI suffers from the small angle of view which limits its employments in full field inspection of a big size sample at a short working distance. A novel structure digital shearography with wide angle of view introduced in this paper is developed to overcome the disadvantage. In the new shearography optical arrangement, the image lens is separated with the camera and locates at the front of system. A 4f imaging system is used to transmit the image of object from the imaging lens to the camera. The shearing device, MSI, locates between the imaging lens and camera. The angle of view in this shearography has no limit to the setup but it is based on several parameters, such as the focus length of the imaging lens and the size of the imaging device inside the camera. Thus wide angle of view can be easily achieved by changing those parameters. Using this novel digital shearography, full field inspection of the big size honeycomb sandwich structure can be rapidly conducted at a short working distance.

Wu, Sijin; Yang, Lianxiang

2010-12-01

408

Real time measurement of crystal growth by glancing angle scattering of fast ions  

Microsoft Academic Search

We have constructed a new system for real time measurements of crystal growth by glancing angle scattering of fast ions. The system is composed of a microchannel plate, a fluorescence screen and a CCD video camera in order to measure the dynamical change in the angular distribution of the scattered ions during crystal growth. Initial stage of epitaxial growth of

Y. Fujii; K. Toba; K. Narumi; K. Kimura; M. Mannami

1993-01-01

409

33 CFR 162.240 - Tongass Narrows, Alaska; navigation.  

Code of Federal Regulations, 2011 CFR

... 2013-07-01 2013-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation...WATERWAYS NAVIGATION REGULATIONS § 162.240 Tongass Narrows, Alaska; navigation. (a) Definitions. The term...

2013-07-01

410

Development of gamma ray imaging cameras  

NASA Astrophysics Data System (ADS)

In January 1990, the Department of Energy initiated this project with the objective to develop the technology for general purpose, portable gamma ray imaging cameras useful to the nuclear industry. The ultimate goal of this R&D initiative is to develop the analog to the color television camera where the camera would respond to gamma rays instead of visible photons. The two-dimensional real-time image would be displayed and indicate the geometric location of the radiation relative to the camera's orientation, while the brightness and 'color' would indicate the intensity and energy of the radiation and, hence, identify the emitting isotope. There is a strong motivation for developing such a device for applications within the nuclear industry, for both high- and low-level waste repositories, for environmental restoration problems, and for space and fusion applications. At present, there are no general purpose radiation cameras capable of producing spectral images for such practical applications. At the time of this writing, work on this project has been underway for almost 18 months. Substantial progress has been made in the project's two primary areas: mechanically-collimated (MCC) and electronically-collimated camera (ECC) designs. We present developments covering the mechanically-collimated design, and then discuss the efforts on the electronically-collimated camera. The renewal proposal addresses the continuing R&D efforts for the third year effort.

Wehe, D. K.; Knoll, G. F.

1992-05-01

411

Development of gamma ray imaging cameras  

SciTech Connect

In January 1990, the Department of Energy initiated this project with the objective to develop the technology for general purpose, portable gamma ray imaging cameras useful to the nuclear industry. The ultimate goal of this R D initiative is to develop the analog to the color television camera where the camera would respond to gamma rays instead of visible photons. The two-dimensional real-time image would be displayed would indicate the geometric location of the radiation relative to the camera's orientation, while the brightness and color'' would indicate the intensity and energy of the radiation (and hence identify the emitting isotope). There is a strong motivation for developing such a device for applications within the nuclear industry, for both high- and low-level waste repositories, for environmental restoration problems, and for space and fusion applications. At present, there are no general purpose radiation cameras capable of producing spectral images for such practical applications. At the time of this writing, work on this project has been underway for almost 18 months. Substantial progress has been made in the project's two primary areas: mechanically-collimated (MCC) and electronically-collimated camera (ECC) designs. We present developments covering the mechanically-collimated design, and then discuss the efforts on the electronically-collimated camera. The renewal proposal addresses the continuing R D efforts for the third year effort. 8 refs.

Wehe, D.K.; Knoll, G.F.

1992-05-28

412

Camera calibration method based on bundle adjustment  

NASA Astrophysics Data System (ADS)

Camera calibration is the most important step for stereovision measuring system, which affects the accuracy and stability of the measuring system directly. In order to compute the intrinsic and extrinsic parameters of camera, at least seven feature points should be extracted from the calibration board, and the world coordinates of these points should be consistent with their camera coordinates. In this paper, a special planar board utilizing the circular blobs of different sizes is used, and the correspondence between world and image coordinates of these feature points could be built automatically. Based on an existing algorithm that is used for single camera calibration, the intrinsic and lens radial distortion parameters can be computed with several image pairs of the planar board that are captured by two cameras in different orientations as well as the initial orientation and location of cameras. In order to improve the accuracy of object reconstruction, the bundle adjustment algorithm is further used to optimize the orientation and location of camera. Experiment results demonstrate the efficiency of proposed method.

Sui, Liansheng; Zhang, Ting

2009-12-01

413

Creation of the ? angle standard for the flat angle measurements  

NASA Astrophysics Data System (ADS)

Angle measurements are based mainly on multiangle prisms - polygons with autocollimators, rotary encoders fo high accuracy and circular scales as the standards of the flat angle. Traceability of angle measurements is based on the standard of the plane angle - prism (polygon) calibrated at an appropriate accuracy. Some metrological institutions have established their special test benches (comparators) equipped with circular scales or rotary encoders of high accuracy and polygons with autocollimators for angle calibration purposes. Nevertheless, the standard (etalon) of plane angle - polygon has many restrictions for the transfer of angle unit - radian (rad) and other units of angle. It depends on the number of angles formed by the flat sides of the polygon that is restricted by technological and metrological difficulties related to the production and accuracy determination of the polygon. A possibility to create the standard of the angle equal to ? rad or half the circle or the full angle is proposed. It can be created by the circular scale with the rotation axis of very high accuracy and two precision reading instruments, usually, photoelectric microscopes (PM), placed on the opposite sides of the circular scale using the special alignment steps. A great variety of angle units and values can be measured and its traceability ensured by applying the third PM on the scale. Calibration of the circular scale itself and other scale or rotary encoder as well is possible using the proposed method with an implementation of ? rad as the primary standard angle. The method proposed enables to assure a traceability of angle measurements at every laboratory having appropriate environment and reading instruments of appropriate accuracy together with a rotary table with the rotation axis of high accuracy - rotation trajectory (runout) being in the range of 0.05 ?m. Short information about the multipurpose angle measurement test bench developed is presented.

Giniotis, V.; Rybokas, M.

2010-07-01

414

Development Status of Multiangle SpectroPolarimetric Imager (MSPI) Prototype Cameras  

Microsoft Academic Search

We have been developing the Multiangle SpectroPolarimetric Imager (MSPI) as a candidate for the multi- directional, multi-wavelength, polarimetric imager identified by Earth Sciences Decadal Survey as one component of the Aerosol-Cloud-Ecosystem (ACE) mission. MSPI is conceptually similar to the Terra Multi- angle Imaging SpectroRadiometer (MISR), but contains a new camera design that widens the spectral range, increases the swath width,

D. J. Diner; A. Davis; S. Geier; B. Hancock; N. Raouf; C. Wrigley; M. A. Bull; V. M. Jovanovic; B. E. Rheingans; G. Saghri; R. A. Chipman; A. Mahler; S. McClain

2008-01-01

415

Observations of Mars and its satellites by the Mars Imaging Camera (MIC) on Planet-B  

Microsoft Academic Search

We present the specifications of the Mars Imaging Camera (MIC) on the Planet-B spin-stabilized spacecraft, and key scientific objectives of MIC observations. A non-sun-synchronous orbit of Planet-B with a large eccentricity of about 0.87 around Mars provides the opportunities (1) to observe the same region of Mars at various times of day and various solar phase angles with spatial resolution

Tadashi Mukai; Tokuhide Akabane; Tatsuaki Hashimoto; Hiroshi Ishimoto; Sho Sasaki; A. Inada; Anthony Toigo; Masato Nakamura; Yutaka Abe; Kei Kurita; Takeshi Imamura

1998-01-01

416

Modeling of a slanted-hole collimator in a compact endo-cavity gamma camera.  

NASA Astrophysics Data System (ADS)

Having the ability to take an accurate 3D image of a tumor greatly helps doctors diagnose it and then create a treatment plan for a patient. One way to accomplish molecular imaging is to inject a radioactive tracer into a patient and then measure the gamma rays emitted from regions with high-uptake of the tracer, viz., the cancerous tissues. In large, expensive PET- or SPECT-imaging systems, the 3D imaging easily is accomplished by rotating the gamma-ray detectors and then employing software to reconstruct the 3D images from the multiple 2D projections at different angles of view. However, this method is impractical in a very compact imaging system due to anatomical considerations, e.g., the transrectal gamma camera under development at Brookhaven National Laboratory (BNL) for detection of intra-prostatic tumors. The camera uses pixilated cadmium zinc telluride (CdZnTe or CZT) detectors with matched parallel-hole collimator. Our research investigated the possibility of using a collimator with slanted holes to create 3D pictures of a radioactive source. The underlying concept is to take 2D projection images at different angles of view by adjusting the slant angle of the collimator, then using the 2D projection images to reconstruct the 3D image. To do this, we first simulated the response of a pixilated CZT detector to radiation sources placed in the field of view of the camera. Then, we formulated an algorithm to use the simulation results as prior knowledge and estimate the distribution of a shaped source from its 2D projection images. From the results of the simulation, we measured the spatial resolution of the camera as ~7-mm at a depth of 13.85-mm when using a detector with 2.46-mm pixel pitch and a collimator with 60° slant angle.

Kamuda, Mark; Cui, Yonggang; Lall, Terry; Ionson, Jim; Camarda, Giuseppe S.; Hossain, Anwar; Yang, Ge; Roy, Utpal N.; James, Ralph B.

2013-09-01

417

Angle closure in younger patients  

Microsoft Academic Search

PurposeAngle-closure glaucoma is rare in children and young adults; only scattered cases associated with specific clinical entities have been reported. We evaluated the findings in patients aged 40 or younger with angle closure in our database.

Robert Ritch; Brian M Chang; Jeffrey M Liebmann

2003-01-01

418

The effect of viewing angle on wrist posture estimation from photographic images using novice raters.  

PubMed

Observational assessment of wrist posture using photographic methods is theoretically affected by camera view angle. A study was conducted to investigate whether wrist flexion/extension and radial/ulnar deviation postures were estimated differently by raters depending on the viewing angle and compared to predictions using a quantitative 2D model of parallax. Novice raters (n=26) estimated joint angles from images of wrist postures photographed from ten different viewing angles. Results indicated that ideal views, orthogonal to the plane of motion, produced more accurate estimates of posture compared to non-ideal views. The neutral (0°) posture was estimated the most accurately even at different viewing angles. Raters were more accurate than model predictions. Findings demonstrate a need for more systematic methods for collecting and analyzing photographic data for observational studies of posture. Renewed caution in interpreting existing studies of wrist posture where viewing angle was not controlled is advised. PMID:21296336

Lau, Michael H; Armstrong, Thomas J

2011-02-05

419

Development of narrow gap welding technology for extremely thick steel  

NASA Astrophysics Data System (ADS)

In the field of extremely thick steel, various narrow gap welding methods were developed on the basis of former welding methods and are used in practice. It is important to develop and improve automatic narrow gap welding, J edge preparation by gas cutting, the prevention of welding defects, wires for narrow gap welding and so on in order to expand the scope of application of the method. Narrow gap welding technologies are described, based on new concepts developed by Nippon Steel Corporation.

Imai, K.; Saito, T.; Okumura, M.

420

Variable angle correlation spectroscopy  

SciTech Connect

In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with {sup 13}C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system.

Lee, Y.K. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States). Chemical Biodynamics Div.

1994-05-01

421

Narrow field electromagnetic sensor system and method  

DOEpatents

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments. 12 figs.

McEwan, T.E.

1996-11-19

422

Narrow field electromagnetic sensor system and method  

DOEpatents

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments.

McEwan, Thomas E. (Livermore, CA)

1996-01-01

423

First Data from the Fermilab Drift Scan Camera  

NASA Astrophysics Data System (ADS)

The Fermilab Drift Scan Camera contains a single Tektronix/SITe 2048(2) CCD and serves as a prototype for the Sloan Digital Sky Survey. The camera is on the 41'' reflector at Yerkes Observatory. We have completed a section of a great circle survey near the celestial equator, 8h long and 20(') wide, using four filters which approximate the colors V, R, I, and z(') . The last color, z(') , is centered at 9250 Angstroms with FWHM of 1450 Angstroms, and will be used in the Sloan Digital Sky Survey. The effective exposure time of 80 seconds gives a limiting magnitude of 20 in I. By tuning the detection parameters (# connected pixels, and significance above sky) we detect low surface brightness objects (central surface brightness of 21 mag/arcsec(2) in I) and reject noise. We measure isophotal magnitude to a surface brightness of 24.5 mag/arcsec(2) in I, aperture magnitude, radial profiles, and weighted moments in each color. The object finding and measuring software is specific to the Drift Scan Camera, although the ``framework'' software (FITS i/o, storing object parameters, etc.) and commercial object oriented database (Versant) are those used by the Sloan Digital Sky Survey. Thus, tools for data analysis which we develop let us see how to handle the similar, but significantly more volumnious, Sloan Digital Sky Survey data. The photometric calibration is from Landolt standard stars, and we then compare to objects in the HST Guide Star Catalog to check the photometry and calibrate the astrometry. Repeated scans on sections of the survey check the calibrations. These data allow us to study the global properties of stars and galaxies in the 40 square degrees of our survey, free from systematic biases inherent in large-angle photographic surveys.

Stoughton, Chris; Annis, Jim; Kent, Steve; Kron, Richard; Loveday, Jonathan; McKay, Tim; Newberg, Heidi

1994-05-01

424

Interface circuit design and control system programming for an EMCCD camera based on Camera Link  

NASA Astrophysics Data System (ADS)

This paper presents an appropriate solution for self-developed EMCCD cameras based on Camera Link. A new interface circuit used to connect an embedded processor Nios II to the serial communication port of Camera Link in the camera is designed, and a simplified structure diagram is shown. To implement functions of the circuit, in the hardware design, it is necessary to add a universal serial communication component to the Nios II when building the processor and its peripheral components in the Altera SOPC development environment. In the software design, we use C language to write a UART interrupt response routine for instructions and data receiving and transmitting, and a camera control program in the slave computer (Nios II), employ a Sapera LT development library and VC++ to write a serial communication routine, a camera control and image acquisition program in the host computer. The developed camera can be controlled by the host PC, the camera status can return to the PC, and a huge amount of image data can be uploaded at a high speed through a Camera Link cable. A flow chart of the serial communication and camera control program in Nios II is given, and two operating interfaces in the PC are shown. Some design and application skills are described in detail. The test results indicate that the interface circuit and the control programs that we have developed are feasible and reliable.

Li, Bin-hua; Rao, Xiao-hui; Yan, Jia; Li, Da-lun; Zhang, Yi-gong

2013-08-01

425

2. Photocopied July 1971 from photostat Jordan Narrows Folder #1, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Photocopied July 1971 from photostat Jordan Narrows Folder #1, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. JORDAN NARROWS STATION. PLAN AND SECTION. - Salt Lake City Water & Electrical Power Company, Jordan Narrows Hydroelectric Plant, Jordan River, Riverton, Salt Lake County, UT

426

MRI of surgically created pulmonary artery narrowing in the dog  

Microsoft Academic Search

Narrowing of the pulmonary arteries was created surgically in twelve dogs. In six of the dogs the narrowing was central (main pulmonary artery), and in the remaining six the narrowing was located peripherally at the hilar level of the right pulmonary artery beyond the pericardial reflection. MRI and angiography were performed in all dogs. MRI clearly delineated the site of

R. J. Hernandez; A. P. Rocchini; E. L. Bove; T. L. Chenevert; B. Gubin

1989-01-01

427

Modified plenoptic camera for phase and amplitude wavefront sensing  

NASA Astrophysics Data System (ADS)

Shack-Hartmann sensors have been widely applied in wavefront sensing. However, they are limited to measuring slightly distorted wavefronts whose local tilt doesn't surpass the numerical aperture of its micro-lens array and cross talk of incident waves on the mrcro-lens array should be strictly avoided. In medium to strong turbulence cases of optic communication, where large jitter in angle of arrival and local interference caused by break-up of beam are common phenomena, Shack-Hartmann sensors no longer serve as effective tools in revealing distortions in a signal wave. Our design of a modified Plenoptic Camera shows great potential in observing and extracting useful information from severely disturbed wavefronts. Furthermore, by separating complex interference patterns into several minor interference cases, it may also be capable of telling regional phase difference of coherently illuminated objects.

Wu, Chensheng; Davis, Christopher C.

2013-09-01

428

Imaging performance of a multiwire proportional-chamber positron camera  

SciTech Connect

A new design - fully three-dimensional - Positron Camera is presented, made of six MultiWire Proportional Chamber modules arranged to form the lateral surface of a hexagonal prism. A true coincidence rate of 56000 c/s is expected with an equal accidental rate for a 400 ..mu..Ci activity uniformly distributed in a approx. 3 l water phantom. A detailed Monte Carlo program has been used to investigate the dependence of the spatial resolution on the geometrical and physical parameters. A spatial resolution of 4.8 mm FWHM has been obtained for a /sup 18/F point-like source in a 10 cm radius water phantom. The main properties of the limited angle reconstruction algorithms are described in relation to the proposed detector geometry.

Perez-Mandez, V.; Del Guerra, A.; Nelson, W.R.; Tam, K.C.

1982-08-01

429

A single camera roentgen stereophotogrammetry method for static displacement analysis.  

PubMed

A new method to quantify motion or deformation of bony structures has been developed, since quantification is often difficult due to overlaying tissue, and the currently used roentgen stereophotogrammetry method requires significant investment. In our method, a single stationary roentgen source is used, as opposed to the usual two, which, in combination with a fixed radiogram cassette holder, forms a camera with constant interior orientation. By rotating the experimental object, it is possible to achieve a sufficient angle between the various viewing directions, enabling photogrammetric calculations. The photogrammetric procedure was performed on digitised radiograms and involved template matching to increase accuracy. Co-ordinates of spherical markers in the head of a bird (Rhea americana), were calculated with an accuracy of 0.12mm. When these co-ordinates were used in a deformation analysis, relocations of about 0.5mm could be accurately determined. PMID:10807998

Gussekloo, S W; Janssen, B A; George Vosselman, M; Bout, R G

2000-06-01

430

Observation of ultra-narrow band plasmon induced transparency based on large-area hybrid plasmon-waveguide systems  

NASA Astrophysics Data System (ADS)

We report the observation of an ultra-narrow band plasmon induced transparency resonance which is realized in a large area hybrid plasmon-waveguide system consisting of a gold nanowire array embedded in a slab waveguide. Due to the destructive interference between optical modes supported by the hybrid system, an ultra-narrow plasmon induced transparency resonance with a bandwidth of 8 nm at the wavelength of 966 nm was obtained (i.e., ~1/120 of the peak wavelength at the incident angle of 60°). The group velocity is estimated to be ~76, which is promising for miniaturized slow-light components.

Zhang, Jing; Bai, Wenli; Cai, Likang; Xu, Yun; Song, Guofeng; Gan, Qiaoqiang

2011-10-01

431

Refinement in aesthetic contouring of the prominent mandibular angle.  

PubMed

Oriental women, in general, greatly desire a more delicate and feminine facial shape. This can be obtained by contouring the prominent mandibular angles that give a strong, masculine image. Western authors regarded masseteric muscular hypertrophy the main cause of a square facial appearance, so they usually corrected it by partially excising the masseter muscle. In the authors' view, a square facial appearance in the Oriental is not due to masseteric hypertrophy but to a posterior projection and lateral flaring of the mandibular angle. However, it is sometimes difficult to make the square face narrow and ovoid by using only the conventional curved-angle osteotomy. We divided patients, whose chief complaint was a square facial appearance, into three groups after clinical, photographic, and radiographic evaluation. We applied different contouring methods to each of the three groups and obtained cosmetically improved facial appearance in both lateral and frontal views. PMID:7976763

Baek, S M; Baek, R M; Shin, M S

1994-01-01

432

New design of a gamma camera detector with reduced edge effect for breast imaging  

NASA Astrophysics Data System (ADS)

In recent years, there has been a growing interest in developing small gamma cameras dedicated to breast imaging. We designed a new detector with trapezoidal shape to expand the field of view (FOV) of camera without increasing its dimensions. To find optimal parameters, images of point sources at the edge area as functions of the angle and optical treatment of crystal side surface were simulated by using a DETECT2000. Our detector employs monolithic CsI(Tl) with dimensions of 48.0×48.0×6.0 mm coupled to an array of photo-sensors. Side surfaces of crystal were treated with three different surface finishes: black absorber, metal reflector and white reflector. The trapezoidal angle varied from 45° to 90° in steps of 15°. Gamma events were generated on 15 evenly spaced points with 1.0 mm spacing in the X-axis starting 1.0 mm away from the side surface. Ten thousand gamma events were simulated at each location and images were formed by calculating the Anger-logic. The results demonstrated that all the 15 points could be identified only for the crystal with trapezoidal shape having 45° angle and white reflector on the side surface. In conclusion, our new detector proved to be a reliable design to expand the FOV of small gamma camera for breast imaging.

Yeon Hwang, Ji; Lee, Seung-Jae; Baek, Cheol-Ha; Hyun Kim, Kwang; Hyun Chung, Yong

2011-05-01

433

Keyboard before Head Tracking Depresses User Success in Remote Camera Control  

NASA Astrophysics Data System (ADS)

In remote mining, operators of complex machinery have more tasks or devices to control than they have hands. For example, operating a rock breaker requires two handed joystick control to position and fire the jackhammer, leaving the camera control to either automatic control or require the operator to switch between controls. We modelled such a teleoperated setting by performing experiments using a simple physical game analogue, being a half size table soccer game with two handles. The complex camera angles of the mining application were modelled by obscuring the direct view of the play area and the use of a Pan-Tilt-Zoom (PTZ) camera. The camera control was via either a keyboard or via head tracking using two different sets of head gestures called “head motion” and “head flicking” for turning camera motion on/off. Our results show that the head motion control was able to provide a comparable performance to using a keyboard, while head flicking was significantly worse. In addition, the sequence of use of the three control methods is highly significant. It appears that use of the keyboard first depresses successful use of the head tracking methods, with significantly better results when one of the head tracking methods was used first. Analysis of the qualitative survey data collected supports that the worst (by performance) method was disliked by participants. Surprisingly, use of that worst method as the first control method significantly enhanced performance using the other two control methods.

Zhu, Dingyun; Gedeon, Tom; Taylor, Ken

434

The Panoramic Camera (PanCam) Instrument for the ESA ExoMars Rover  

NASA Astrophysics Data System (ADS)

The recently approved ExoMars rover is the first element of the ESA Aurora programme and is slated to deliver the Pasteur exobiology payload to Mars by 2013. The 0.7 kg Panoramic Camera will provide multispectral stereo images with 65° field-of- view (1.1 mrad/pixel) and high resolution (85 µrad/pixel) monoscopic "zoom" images with 5° field-of-view. The stereo Wide Angle Cameras (WAC) are based on Beagle 2 Stereo Camera System heritage. The Panoramic Camera instrument is designed to fulfil the digital terrain mapping requirements of the mission as well as providing multispectral geological imaging, colour and stereo panoramic images, solar images for water vapour abundance and dust optical depth measurements and to observe retrieved subsurface samples before ingestion into the rest of the Pasteur payload. Additionally the High Resolution Camera (HRC) can be used for high resolution imaging of interesting targets detected in the WAC panoramas and of inaccessible locations on crater or valley walls.

Griffiths, A.; Coates, A.; Jaumann, R.; Michaelis, H.; Paar, G.; Barnes, D.; Josset, J.

435

High speed web printing inspection with multiple linear cameras  

NASA Astrophysics Data System (ADS)

Purpose: To detect the defects during the high speed process of web printing, such as smudges, doctor streaks, pin holes, character misprints, foreign matters, hazing, wrinkles, etc., which are the main infecting factors to the quality of printing presswork. Methods: A set of novel machine vision system is used to detect the defects. This system consists of distributed data processing with multiple linear cameras, effective anti-blooming illumination design and fast image processing algorithm with blob searching. Also, pattern matching adapted to paper tension and snake-moving are emphasized. Results: Experimental results verify the speed, reliability and accuracy of the proposed system, by which most of the main defects are inspected at real time under the speed of 300 m/min. Conclusions: High speed quality inspection of large-size web requires multiple linear cameras to construct distributed data processing system. Also material characters of the printings should also be stressed to design proper optical structure, so that tiny web defects can be inspected with variably angles of illumination.

Shi, Hui; Yu, Wenyong

2011-11-01

436

Narrow-band holographic optical filter using thick efficient holographic gratings  

NASA Astrophysics Data System (ADS)

RL Associates in conjunction with Hybrid Technologies is developing a narrow linewidth optical filter employing extremely thick volume holographic diffraction gratings. The gratings are written in MEMPLEX, a new holographic materia invented by Laser Photonics Technology, Inc. and licensed to Hybrid Technologies. MEMPLEX has the following characteristics: (1) Excellent optical clarity, (2) Preparable at any thickness up to 10 mm, (3) Large dynamic range for plane wave holograms, (4) Hard, freestanding, stable, polishable and coatable. We have written and characterized numerous gratings in 1.8 mm thick samples to study the effect of writing geometry on the spectral linewidth and field-of-view of a single grating in the reflection geometry. We have succeeded in writing some very efficient gratings at 15 degrees internal write angles with external slant angles of 5 degrees. These gratings exhibit linewidths of < 0.2 nm and diffraction efficiencies of better than 70 percent. The measured angular acceptance of these gratings ranges from 0.1 to 0.24 degrees. We have also written some initial angle multiplexed gratings which include 3 efficient gratings in the same volume in an attempt to increase the angular acceptance. In this manner we hope to achieve a highly efficient optical filter with extremely narrow spectral linewidth and wide angular acceptance. Filters based on thick volume holograms show great promise in Lidar applications and should result in superior S/N ratios.

Billmers, Richard I.; Billmers, Elizabeth J.; Burzynski, Ryszard; Weibel, John F.; Heverley, L. H.; Casstevens, Martin K.; Curran, Thomas P.; Contarino, V. Michael

2002-06-01

437

Clementine High Resolution Camera Mosaicking Project  

NASA Astrophysics Data System (ADS)

This report constitutes the final report for NASA Contract NASW-5054. This project processed Clementine I high resolution images of the Moon, mosaicked these images together, and created a 22-disk set of compact disk read-only memory (CD-ROM) volumes. The mosaics were produced through semi-automated registration and calibration of the high resolution (HiRes) camera's data against the geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic produced by the US Geological Survey (USGS). The HiRes mosaics were compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution nadir-looking observations. The images were spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel for sub-polar mosaics (below 80 deg. latitude) and using the stereographic projection at a scale of 30 m/pixel for polar mosaics. Only images with emission angles less than approximately 50 were used. Images from non-mapping cross-track slews, which tended to have large SPICE errors, were generally omitted. The locations of the resulting image population were found to be offset from the UV/Vis basemap by up to 13 km (0.4 deg.). Geometric control was taken from the 100 m/pixel global and 150 m/pixel polar USGS Clementine Basemap Mosaics compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Radiometric calibration was achieved by removing the image nonuniformity dominated by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap, that approximately transform the 8-bit HiRes data to photometric units. The sub-polar mosaics are divided into tiles that cover approximately 1.75 deg. of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. Polar mosaics are tiled into squares 2250 pixels on a side, which spans approximately 2.2 deg. Two mosaics are provided for each pole: one corresponding to data acquired while periapsis was in the south, the other while periapsis was in the north. The CD-ROMs also contain ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files.

1998-10-01

438

Water-soluble narrow-line radicals for dynamic nuclear polarization.  

PubMed

The synthesis of air-stable, highly water-soluble organic radicals containing a 1,3-bis(diphenylene)-2-phenylallyl (BDPA) core is reported. A sulfonated derivative, SA-BDPA, retains the narrow electron paramagnetic resonance linewidth (<30 MHz at 5 T) of the parent BDPA in highly concentrated glycerol/water solutions (40 mM), which enables its use as polarizing agent for solid effect dynamic nuclear polarization (SE DNP). A sensitivity enhancement of 110 was obtained in high-field magic-angle-spinning (MAS) NMR experiments. The ease of synthesis and high maximum enhancements obtained with the BDPA-based radicals constitute a major advance over the trityl-type narrow-line polarization agents. PMID:22917088

Haze, Olesya; Corzilius, Björn; Smith, Albert A; Griffin, Robert G; Swager, Timothy M

2012-08-23

439

Evidence of recent thrust faulting on the Moon revealed by the Lunar Reconnaissance Orbiter Camera.  

PubMed

Lunar Reconnaissance Orbiter Camera images reveal previously undetected lobate thrust-fault scarps and associated meter-scale secondary tectonic landforms that include narrow extensional troughs or graben, splay faults, and multiple low-relief terraces. Lobate scarps are among the youngest landforms on the Moon, based on their generally crisp appearance, lack of superposed large-diameter impact craters, and the existence of crosscut small-diameter impact craters. Identification of previously known scarps was limited to high-resolution Apollo Panoramic Camera images confined to the equatorial zone. Fourteen lobate scarps were identified, seven of which are at latitudes greater than +/-60 degrees, indicating that the thrust faults are globally distributed. This detection, coupled with the very young apparent age of the faults, suggests global late-stage contraction of the Moon. PMID:20724632

Watters, Thomas R; Robinson, Mark S; Beyer, Ross A; Banks, Maria E; Bell, James F; Pritchard, Matthew E; Hiesinger, Harald; van der Bogert, Carolyn H; Thomas, Peter C; Turtle, Elizabeth P; Williams, Nathan R

2010-08-20

440

Distributed Smart Cameras for Aging in Place.  

National Technical Information Service (NTIS)

This paper describes the design and preliminary implementation of two distributed smart camera applications: a fall detector and an object finder. These functions are part of a novel suite of applications being developed to address aging in place health c...

A. Hanson A. Williams D. Xie R. Grupen S. Ou

2006-01-01

441

EOD Facilities Manual. Camera Calibration Laboratory Capabilities.  

National Technical Information Service (NTIS)

The tests and equipment are described for measuring the exact performance characteristics of camera systems for earth resources, space, and other applications. The tests discussed include: modulation transfer function, field irradiance, veiling glare, T-n...

1972-01-01

442

Distributed Smart Cameras for Aging in Place  

Microsoft Academic Search

This paper describes the design and preliminary imple- mentation of two distributed smart camera applications: a fall detector and an object finder. These functions are part of a novel suite of applications being developed to address \\

Adam Williams; Dan Xie; Shichao Ou; Roderic Grupen; Allen Hanson; Edward Riseman

443

Recording Images Using a Simple Pinhole Camera  

NSDL National Science Digital Library

In this lesson, students develop and expand their observational skills and technological understanding by building and operating a pinhole camera. The interdisciplinary connections are in the realm of application in this motivating activity. The lesson pr

Eichinger, John

2009-05-30

444

Selecting the Right Camera for Your Desktop.  

ERIC Educational Resources Information Center

|Provides an overview of camera options and selection criteria for desktop videoconferencing. Key factors in image quality are discussed, including lighting, resolution, and signal-to-noise ratio; and steps to improve image quality are suggested. (LRW)|

Rhodes, John

1997-01-01

445

Vacuum compatible miniature CCD camera head  

DOEpatents

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.

Conder, Alan D. (Tracy, CA)

2000-01-01

446

Neutron Streak Camera Electron Gun Design.  

National Technical Information Service (NTIS)

Representative values for electrode voltages, time compensation, and transmission efficiency are obtained by computer simulation for a preliminary design of an electron gun to be used in a neutron streak camera application. The calculations indicate a tim...

E. R. Close J. S. Colonias

1984-01-01

447

X-Ray Shawdowgraph Camera Design  

SciTech Connect

An imagining camera that is used with X-Ray radiography systems in high explosive experiments has been built and fielded. The camera uses a 40mm diameter Micro-Channel Plate Itensifier (MCPI) for optical gain and photographic film for image recording. In the normal location of the X-ray film pack, a scintillating screen is placed instead. The camera system views the screen and records the image. The sensitivity of the MCPI to light makes the camera design sensitive to small details that a film pack does not need to consider. The X-ray image recording system was designed and bulit for situations where the film pack of the X-ray shadowgraph is not retrievable after the experiment. The system has been used in a number of experiments.

Edward J. McCrea; Michael J. Doman; Randy A. Rohde

1999-01-01

448

Innovative camera system developed for Sprint vehicle  

SciTech Connect

A new inspection system for the Sprint 101 ROV eliminates parallax errors because all three camera modules use a single lens for viewing. Parallax is the apparent displacement of an object when it is viewed from two points not in the same line of sight. The central camera is a Pentax 35-mm single lens reflex with a 28-mm lens. It comes with 250-shot film cassettes, an automatic film wind-on, and a data chamber display. An optical transfer assembly on the stills camera viewfinder transmits the image to one of the two video camera modules. The video picture transmitted to the surface is exactly the same as the stills photo. The surface operator can adjust the focus by viewing the video display.

Not Available

1985-04-01

449

The CCD cameras of RATS project.  

NASA Astrophysics Data System (ADS)

We report on the characteristics and the performances of the CCD cameras that will be used by the project RATS (RAdial velocity and Transit Search) that is an italian-ESA collaboration whose main goal is the search of extrasolar planet using the transit method. We describe the characteristics of the variuos cameras and the first tests at the Asiago Schmidt telescope at Cima Ekar.

Scuderi, S.; Claudi, R. U.; Favata, F.; Bonanno, G.; Bruno, P.; Cosentino, R.; Belluso, M.; Calí, A.; Timpanaro, M. C.; Chiomento, V.; Farisato, G.; Frigo, A.; Gianesini, G.; Traverso, L.; Rebeschini, M.; Strazzabosco, D.

450

Free-Viewpoint Video from Depth Cameras  

Microsoft Academic Search

Depth cameras, which provide color and depth in- formation per pixel at video rates, offer exciting new opportunities in computer graphics. We address the challenge of supporting free-viewpoint video of dynamic 3D scenes using live data captured and streamed from widely-spaced viewpoints by a hand- ful of synchronized depth cameras. We introduce the concept of the depth hull, which is

Alexander Bogomjakov; Craig Gotsman; Marcus Magnor

451

The FourStar Infrared Camera  

Microsoft Academic Search

The FourStar infrared camera is a 1.0-2.5 mum (JHKs) near infrared camera for the Magellan Baade 6.5 m Telescope at Las Campanas Observatory (Chile). It is being built by Carnegie Observatories for use by the Magellan Consortium and is scheduled for completion in June 2009. The instrument uses four Rockwell HAWAII-2RG 2048 X 2048 imaging arrays in a close-packed arrangement

David C. Murphy; R. Barkhouser; R. Hammond; D. Kelson; J. Marshall; P. McCarthy; J. Orndorff; E. Persson; G. Scharfstein; S. Shectman; S. Smee; A. Uomoto

2007-01-01

452

A Multiple Kerr-Cell Camera  

Microsoft Academic Search

The need for new ultra-high speed photographic techniques in studies of brief transient phenomena has led to the development of a multiple Kerr-cell camera designed to take a sequence of three photographs at submicrosecond exposure times. This camera uses shutters of the electro-optical type utilizing the Kerr effect in nitrobenzene. Pulsing networks for the Kerr cells and synchronizing networks for

A. M. Zarem; F. R. Marshall

1950-01-01

453

Multi-people tracking across multiple cameras  

Microsoft Academic Search

Multi-target tracking (MTT) is an active and challenging research topic. Many different approaches to MTT problem exist, yet there are still few satisfactory methods of solving multi-target occlusion problem, which often appears in multi-target tracking task. The application of multi cameras in most existing researches for multi-target occlusion requires camera calibration parameters in advance, which is not practical in the

V. Rudakova P. Wang S. Saha Faouzi Alaya Cheikh

2012-01-01

454

Multi­people tracking across multiple cameras  

Microsoft Academic Search

Multi-target tracking (MTT) is an active and challenging research topic. Many different approaches to MTT problem exist, yet there are still few satisfactory methods of solving multi-target occlusion problem, which often appears in multi-target tracking task. The application of multi cameras in most existing researches for multi-target occlusion requires camera calibration parameters in advance, which is not practical in the

Faouzi Alaya Cheikh; Sajib Kumar Saha; Victoria Rudakova; Peng Wang

455

Efficient, causal camera tracking in unprepared environments  

Microsoft Academic Search

This paper addresses the problem of tracking the 3D pose of a camera in space, using the images it acquires while moving freely in unmodeled, arbitrary environments. A novel feature-based approach for camera tracking is proposed, intended to facilitate tracking in on-line, time-critical applications such as video see-through augmented reality. In contrast to several existing methods which are designed to

Manolis I. A. Lourakis; Antonis A. Argyros

2005-01-01

456

Results With the Neutron Scatter Camera  

Microsoft Academic Search

We describe the design, calibration, and measurements made with the neutron scatter camera. Neutron scatter camera design allows for the determination of the direction and energy of incident neutrons by measuring the position, recoil energy, and time-of-flight (TOF) between elastic scatters in two liquid scintillator cells. The detector response and sensitive energy range (0.5-10 MeV) has been determined by detailed

Nicholas Mascarenhas; James Brennan; Kevin Krenz; Peter Marleau; Stanley Mrowka

2009-01-01

457

Production of narrow weakly divergent beams  

SciTech Connect

Experimental results are presented from an ultrasonic field study of piezoelectric transducers on whose operating surfaces there has been created an acoustic-pressure distribution in the form of a Bessel function of the first kind and zero order. The transducers were comprised of a system of ring electrodes on both sides of a piezoelectric plate. It was established that a transducer having on its operating surface an acoustic pressure distribution according to the Bessel function used will form throughout the irradiated zone the narrowest weakly divergent beam and will produce the greatest signal amplitude. The larger the number of ring-electrode pairs disposed on its surface and the larger its diameter, the narrower will be the main lobe of the directivity pattern it forms and the lower will be the level of its side lobes.

Karpel'son, A.E.

1989-02-01

458

Bioequivalence and narrow therapeutic index drugs.  

PubMed

Every prescription written for a generic drug requires an act of faith by the prescriber that any one of the several available products will be therapeutically equivalent to the innovator (brand name) products. Concerns about this act of faith have been expressed for many years, particularly in the wake of the generic scandals that occurred in 1989-1990, and especially relative to the drugs with a narrow therapeutic range. We contend that these drugs are actually the least likely to pose problems in ensuring therapeutic equivalence, but that new criteria must be established for bioequivalence because the present system is wasteful and is stifling innovation in the industry. We propose four suggestions to the scientific and regulatory communities that we believe could assist in modifying the process such that innovation is encouraged and practitioners are reassured relative to the appropriateness of using generic drugs. PMID:7479195

Benet, L Z; Goyan, J E

459

Synchrotron studies of narrow band materials  

SciTech Connect

Objective was to determine the single-particle electronic structure of selected narrow band materials in order to understand the relation between their electronic structures and novel low energy properties, such as mixed valence, heavy Fermions, Kondo effect, insulator-metal transitions, non-Fermi liquid behavior, and high-temperature superconductivity. This program supports photoemission spectroscopy (PES) at various synchrotrons. The progress is reported under the following section titles: ZSA (Zaanen-Sawatzky-Allen) systematics and I-M transitions in 3d transition metal oxides, insulator-metal transitions in superconducting cuprates, Fermi liquid and non-Fermi liquid behavior in angular resolved PES lineshapes, heavy-Fermion and non-Fermi liquid 5f electron systems, and Kondo insulators.

Allen, J.W.

1993-01-01

460

Isolating prompt photons with narrow cones  

NASA Astrophysics Data System (ADS)

We discuss the isolation of prompt photons in hadronic collisions by means of narrow isolation cones and the QCD computation of the corresponding cross sections. We reconsider the occurence of large perturbative terms with logarithmic dependence on the cone size and their impact on the fragmentation scale dependence. We cure the apparent perturbative violation of unitarity for small cone sizes, which had been noticed earlier in next-to-leading-order (NLO) calculations, by resumming the leading logarithmic dependence on the cone size. We discuss possible implications regarding the implementation of some hollow cone variants of the cone criterion, which simulate the experimental difficulty to impose isolation inside the region filled by the electromagnetic shower that develops in the calorimeter.

Catani, S.; Fontannaz, M.; Guillet, J. Ph.; Pilon, E.

2013-09-01

461

Narrow QRS complex tachycardia presenting as palpitation.  

PubMed

Atrial fibrillation is the most common sustained cardiac arrhythmia. The rhythm in atrial fibrillation is irregular. Correct interpretation of the electrocardiogram (ECG) is essential. Atrial flutter can present as regular or irregular narrow QRS complex tachycardia. Knowledge of the ECG features of atrial flutter will help to differentiate it from paroxysmal supraventricular tachycardia. The treatment strategy in atrial fibrillation should focus on rhythm control vs. rate control, and anticoagulation should be started based on the calculated risk of systemic embolisation. Atrial flutter is a unique arrhythmia that has similar management strategies to those of atrial fibrillation; however, radiofrequency ablation is increasingly preferred due to its higher rate of efficacy and safety compared to pharmacological therapy. PMID:21808955

Singh, D; Teo, S G; Kireyev, D; Poh, K K

2011-07-01

462

Spectral narrowing induced by discrete frequency fluctuations  

NASA Astrophysics Data System (ADS)

We study an ensemble of two level systems coupled to an environment that randomly modulates their resonant frequency. We use Poissonian statistics for the random frequency jumps and derive a closed-from formula for the spectrum in terms of the inhomogeneous frequency distribution and the Poisson rate constant. We show that for a Gaussian distribution our result asymptotically reproduces the results of the well known Kubo model. Our formula holds for any frequency distribution. In particular we calculate the spectrum of atoms in a 3D trap harmonic trap and show that motional narrowing naturally emerges. We experimentally measure this spectrum with optically trapped ^87Rb atoms and obtain a good agreement to our theory without fitting parameters. Our theory apply to a wide range of systems such as atomic ensembles, nuclear magnetic resonance spectroscopy, single molecule spectroscopy and the line-shape of lasers.

Sagi, Yoav; Pugatch, Rami; Almog, Ido; Davidson, Nir

2010-03-01

463

Robotic chair at steep and narrow stairways  

NASA Astrophysics Data System (ADS)

A robotic chair is developed to support mobility of elderly and disabled people living in the house where steep and narrow stairways are installed. In order to deal with such mobility problem the developed robotic chair has a compact original configuration. The robotic chair vertically moves by actuation of electric cylinders and horizontally moves by push-pull operation given by a care-giver. In order to navigate safely every action of the chair is checked by the operator. Up-and-down motions of the robotic chair on the stairway are executed through combinations of motor and cylinder actuations. Performance of the robotic chair was evaluated through two kinds of experiments. The excellent ability of the robotic chair could be confirmed through these experiments.

Imazato, Masahiro; Yamaguchi, Masahiro; Moromugi, Shunji; Ishimatsu, Takakazu

2007-12-01

464

Domain wall resistance in narrow Permalloy wires  

NASA Astrophysics Data System (ADS)

Experiments by several other groups have observed the contribution of domain walls to the resistance of a ferromagnet. Some of these experiments, including work done by our group[1] have shown that in narrow Ni wires the resistance of a domain wall can be negative. In this talk we present the new studies of the wall resistance in Permalloy (Ni(90)Fe(10)). Our results showed that the resistance decreases markedly during the magnetization reversal. We show that this decrease is due to a combination of coherent rotation and a negative wall resistance. We are able to separate these two effects and estimate the resistance of a single wall. [1] K. Hong and N. Giordano, J. Phys. Cond. Matter 10, L401 (1998), B. Cetin and N. Giordano, Mat. Sci. and Eng. B84, 133 (2001).

Cetin, B.; Giordano, N.

2004-03-01

465

Domain wall resistance in narrow ferromagnetic wires  

NASA Astrophysics Data System (ADS)

Recent experiments by several groups have observed the contribution to the resistance of domain walls in ferromagnets. Some of these experiments, including work by our group [1] have found that the domain wall resistance can be negative. That is, the resistance of a sample containing domain walls can be lower than the same sample without walls. We report new results for the domain wall resistance of very narrow (widths as small as 20 nm) Ni wires. By simultaneous application of magnetic fields parallel and perpendicular to the axis of the wire, we have observed abrupt steps in the resistance which appear to be due to the field induced nucleation of individual domain walls. Our results for the wall resistance are compared with other experiments and with various theoretical proposals. [1] K. Hong and N. Giordano, J. Phys. Cond. Matter 10, L401 (1998). Supported by NSF grant DMR-9970708.

Cetin, B.; Giordano, N.

2001-03-01