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1

Thermal Design of the Cassini Narrow Angle Camera  

NASA Technical Reports Server (NTRS)

The Narrow Angle Camera (NAC) is one of two cameras in the Imaging Science Subsystem (ISS) on the Cassini Spacecraft (S/C), the second camera is a Voyager-inherited Wide Angle Camera (WAC). Cassini is currently planned to be launched in October 1997 and will arrive at Saturn for a four year tour in June 2004. The Narrow Angle Optics are a Ritchey Chretien type Optics, has a focal length of 2000 mm, a relative aperture of f/10.5, a spectral range of 200 to 1100 nm, 24 filters, a pixel field of view of 6.0 microradian/pixel, and has a field of view of 3.5 x 3.5 degrees. The sensor is a Charged Couple Device (CCD), 1024 x 1024 pixels with a pixel size of 12 x 12 um, a full well greater than 50,000 e-, on chip processing of up to 800,000 e- pixel summation, a dark current of less than 0.1 e-/pixel/sec at operating temperature, and a charge transfer efficiency of 0.99999 at operating temperature...

Hoffman, Pamela

1994-01-01

2

High-resolution topomapping of candidate MER landing sites with Mars Orbiter Camera narrow-angle images  

Microsoft Academic Search

We analyzed narrow-angle Mars Orbiter Camera (MOC-NA) images to produce high-resolution digital elevation models (DEMs) in order to provide topographic and slope information needed to assess the safety of candidate landing sites for the Mars Exploration Rovers (MER) and to assess the accuracy of our results by a variety of tests. The mapping techniques developed also support geoscientific studies and

Randolph L. Kirk; Elpitha Howington-Kraus; Bonnie Redding; Donna Galuszka; Trent M. Hare; Brent A. Archinal; Laurence A. Soderblom; Janet M. Barrett

2003-01-01

3

Determination Of The Light Curve Of Rosetta Target Asteroid 2867 Steins With The Osiris Narrow Angle Camera Onboard Rosetta  

NASA Astrophysics Data System (ADS)

On its way to comet 67P/Churyumov-Gerasimenko, the European Space Agency's Rosetta spacecraft is going to fly by Asteroids 2867 Steins in Sept. 2008 and 21 Lutetia in July 2010. While 21 Lutetia is a large main belt asteroid with a long history of investigation, relatively little is known about 2867 Steins. In particular, knowledge of the rotation period and the orientation of the rotation axis are valuable for the flyby preparations. OSIRIS is the scientific camera system onboard Rosetta, consisting of a narrow angle camera (NAC) and a wide angle camera (WAC). In March 2006, the NAC observed 2867 Steins continuously for 24 hours, acquiring 238 images, with a clear filter. The camera performed flawlessly. The data obtained from spacecraft are unique in terms of continuous temporal coverage and phase angle. Indeed, the NAC observations were taken at a phase angle of 42 deg., compared to a maximum phase angle of 30 deg. when seen from Earth. The distance between Rosetta and 2867 Steins was 1.06 AU. The OSIRIS data show a double peaked light curve with an amplitude of 0.23 magnitudes and a synodic rotation period of 6.052 ± 0.035 hours, in good agreement with ground based data by Hicks et al. (2004, IAU Circular 8315) and Weissman et al. (2006, ACM Conference). The continuous observations over four rotations completely exclude the possibility of period ambiguities. There is no indication of deviation from a principal axis rotation state. The observations are being combined with Earth-based data sets to derive the orientation of the spin axis and pole position for 2867 Steins. We acknowledge funding from the national space agencies ASI, CNES, DLR, the Spanish Space Program (Ministerio de Educación y Ciencia), SNSB, and ESA.

Kueppers, Michael; Keller, H. U.; Hviid, S. F.; Mottola, S.; Fornasier, S.; Barbieri, C.; Barucci, A.; Gutiérrez, P.; Lamy, P.; OSIRIS Team

2006-09-01

4

Narrow Angle movie  

NASA Technical Reports Server (NTRS)

This brief three-frame movie of the Moon was made from three Cassini narrow-angle images as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. The purpose of this particular set of images was to calibrate the spectral response of the narrow-angle camera and to test its 'on-chip summing mode' data compression technique in flight. From left to right, they show the Moon in the green, blue and ultraviolet regions of the spectrum in 40, 60 and 80 millisecond exposures, respectively. All three images have been scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is the same in each image. The spatial scale in the blue and ultraviolet images is 1.4 miles per pixel (2.3 kilometers). The original scale in the green image (which was captured in the usual manner and then reduced in size by 2x2 pixel summing within the camera system) was 2.8 miles per pixel (4.6 kilometers). It has been enlarged for display to the same scale as the other two. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS) at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

1999-01-01

5

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

NASA Astrophysics Data System (ADS)

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 the asteroid soil. Science goals for the NAC are global mapping of the object, detailed investigations of the surface at high spatial resolution (order of millimeters), and deep examination of possible landing sites from a close distance. The instrument has a 3"/pixel scale factor, corresponding to 80 mm/px at 5 km from the surface, on a 1.75° × 1.75° FoV; imaging in 5 to 8 different spectral bands (panchromatic and broadband), in the range between 400 and 900 nm, is foreseen. Since the target is an extended low contrast object, to avoid image contrast degradation, only off-axis unobstructed optical layouts have been considered. Solutions with two mirrors plus a refractive corrector, or all-reflective three mirrors ones, have been studied, both allowing to reach good aberration balancing over all the field of view: the diffraction Ensquared Energy inside one pixel of the detector is of the order of 70%. To cope with the hazardous radiation environment in which the spacecraft will be immersed in during the mission, all the glasses selected for the design are rad-hard type.

da Deppo, Vania; Cremonese, Gabriele; Naletto, Giampiero

2010-07-01

6

High-resolution topomapping of candidate MER landing sites with Mars Orbiter Camera narrow-angle images  

USGS Publications Warehouse

We analyzed narrow-angle Mars Orbiter Camera (MOC-NA) images to produce high-resolution digital elevation models (DEMs) in order to provide topographic and slope information needed to assess the safety of candidate landing sites for the Mars Exploration Rovers (MER) and to assess the accuracy of our results by a variety of tests. The mapping techniques developed also support geoscientific studies and can be used with all present and planned Mars-orbiting scanner cameras. Photogrammetric analysis of MOC stereopairs yields DEMs with 3-pixel (typically 10 m) horizontal resolution, vertical precision consistent with ???0.22 pixel matching errors (typically a few meters), and slope errors of 1-3??. These DEMs are controlled to the Mars Orbiter Laser Altimeter (MOLA) global data set and consistent with it at the limits of resolution. Photoclinometry yields DEMs with single-pixel (typically ???3 m) horizontal resolution and submeter vertical precision. Where the surface albedo is uniform, the dominant error is 10-20% relative uncertainty in the amplitude of topography and slopes after "calibrating" photoclinometry against a stereo DEM to account for the influence of atmospheric haze. We mapped portions of seven candidate MER sites and the Mars Pathfinder site. Safety of the final four sites (Elysium, Gusev, Isidis, and Meridiani) was assessed by mission engineers by simulating landings on our DEMs of "hazard units" mapped in the sites, with results weighted by the probability of landing on those units; summary slope statistics show that most hazard units are smooth, with only small areas of etched terrain in Gusev crater posing a slope hazard.

Kirk, R. L.; Howington-Kraus, E.; Redding, B.; Galuszka, D.; Hare, T. M.; Archinal, B. A.; Soderblom, L. A.; Barrett, J. M.

2003-01-01

7

Fluorescence nanoscopy by polarization modulation and polarization angle narrowing.  

PubMed

When excited with rotating linear polarized light, differently oriented fluorescent dyes emit periodic signals peaking at different times. We show that measurement of the average orientation of fluorescent dyes attached to rigid sample structures mapped to regularly defined (50 nm)(2) image nanoareas can provide subdiffraction resolution (super resolution by polarization demodulation, SPoD). Because the polarization angle range for effective excitation of an oriented molecule is rather broad and unspecific, we narrowed this range by simultaneous irradiation with a second, de-excitation, beam possessing a polarization perpendicular to the excitation beam (excitation polarization angle narrowing, ExPAN). This shortened the periodic emission flashes, allowing better discrimination between molecules or nanoareas. Our method requires neither the generation of nanometric interference structures nor the use of switchable or blinking fluorescent probes. We applied the method to standard wide-field microscopy with camera detection and to two-photon scanning microscopy, imaging the fine structural details of neuronal spines. PMID:24705472

Hafi, Nour; Grunwald, Matthias; van den Heuvel, Laura S; Aspelmeier, Timo; Chen, Jian-Hua; Zagrebelsky, Marta; Schütte, Ole M; Steinem, Claudia; Korte, Martin; Munk, Axel; Walla, Peter J

2014-05-01

8

Constraints on bent beams in narrow angle tail radio sources  

SciTech Connect

The physics of bent radio luminous plasma beams is discussed and constraintson the momentum and energy flux are examined. Expressions for the bulk velocity,particle density, Mach number, and efficiency of conversion of bulk kinetic andinternal energy into radio luminosity are given. VLA data on the intensityratios of opposing jets in a sample of narrow angle tail (NAT) sources are usedto set an upper limit of 0.2c to the bulk velocity of the beams/plasmons. Within the context of models for NATs, order-of-magnitude constraints are placed on the bulk velocities, particle densities, efficiencies, and mass loss rates of the beams/ plasmons in 19 NATs.

O'Dea, C.P.

1985-08-01

9

Morphology and energetics of narrow angle tail radio sources  

SciTech Connect

Fifty-seven radio sources in the directions of clusters of galaxies were observed with the VLA with resolutions of approx.1-4''. Thirty-eight narrow angle tail (NAT) sources from these observations were combined with 13 from the literature to produce a representative sample of 51 NATs in the directions of Abell clusters. The global properties of this sample were investigated. Correlations between various parameters (i.e., optical rank, core and total power, width, length, galaxy velocity, distance from the cluster center, cluster richness, Bautz-Morgan type and Rood-Sastry type) were examined and discussed within the context of our current understanding of rich clusters of galaxies. The statistical results are in agreement with the hypothesis that the tailed morphology of these objects is due to the interaction of the radio plasma ejected by the moving galaxy with the intracluster medium.

O'Dea, C.P.

1984-01-01

10

Associations between Narrow Angle and Adult Anthropometry: The Liwan Eye Study.  

PubMed

Abstract Purpose: To assess the associations between narrow angle and adult anthropometry. Methods: Chinese adults aged 50 years and older were recruited from a population-based survey in the Liwan District of Guangzhou, China. Narrow angle was defined as the posterior trabecular meshwork not visible under static gonioscopy in at least three quadrants (i.e. a circumference of at least 270°). Logistic regression models were used to examine the associations between narrow angle and anthropomorphic measures (height, weight and body mass index, BMI). Results: Among the 912 participants, lower weight, shorter height, and lower BMI were significantly associated with narrower angle width (tests for trend: mean angle width in degrees vs weight p?narrow angle. The crude association between height and narrow angle was largely attributable to a stronger association with age and sex. Lower BMI and weight remained significantly associated with narrow angle after adjustment for height, age, sex, axial ocular biometric measures and education. In analyses stratified by sex, the association between BMI and narrow angle was only observed in women. Conclusion: Lower BMI and weight were associated with significantly greater odds of narrow angle after adjusting for age, education, axial ocular biometric measures and height. The odds of narrow angle increased 7% per 1 unit decrease in BMI. This association was most evident in women. PMID:24707840

Jiang, Yuzhen; He, Mingguang; Friedman, David S; Khawaja, Anthony P; Lee, Pak Sang; Nolan, Winifred P; Yin, Qiuxia; Foster, Paul J

2014-06-01

11

Improved iris localization by using wide and narrow field of view cameras for iris recognition  

NASA Astrophysics Data System (ADS)

Biometrics is a method of identifying individuals by their physiological or behavioral characteristics. Among other biometric identifiers, iris recognition has been widely used for various applications that require a high level of security. When a conventional iris recognition camera is used, the size and position of the iris region in a captured image vary according to the X, Y positions of a user's eye and the Z distance between a user and the camera. Therefore, the searching area of the iris detection algorithm is increased, which can inevitably decrease both the detection speed and accuracy. To solve these problems, we propose a new method of iris localization that uses wide field of view (WFOV) and narrow field of view (NFOV) cameras. Our study is new as compared to previous studies in the following four ways. First, the device used in our research acquires three images, one each of the face and both irises, using one WFOV and two NFOV cameras simultaneously. The relation between the WFOV and NFOV cameras is determined by simple geometric transformation without complex calibration. Second, the Z distance (between a user's eye and the iris camera) is estimated based on the iris size in the WFOV image and anthropometric data of the size of the human iris. Third, the accuracy of the geometric transformation between the WFOV and NFOV cameras is enhanced by using multiple matrices of the transformation according to the Z distance. Fourth, the searching region for iris localization in the NFOV image is significantly reduced based on the detected iris region in the WFOV image and the matrix of geometric transformation corresponding to the estimated Z distance. Experimental results showed that the performance of the proposed iris localization method is better than that of conventional methods in terms of accuracy and processing time.

Kim, Yeong Gon; Shin, Kwang Yong; Park, Kang Ryoung

2013-10-01

12

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

13

12. 22'X34' original vellum, VariableAngle Launcher, 'SIDE VIEW CAMERA TRACK ...  

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

12. 22'X34' original vellum, Variable-Angle Launcher, 'SIDE VIEW CAMERA TRACK H-20 BRIDGE MODIFICATIONS' drawn at 3/16'=1'-0' and 1/2'1'-0'. (BUORD Sketch # 208784, PAPW 907). - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

14

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

15

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

16

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

17

Design and Construction of a Wide Angle Ophthalmoscope and Camera.  

National Technical Information Service (NTIS)

The purpose of the project was to design a camera capable of photographing the entire fundus of the eye in a single exposure. One of the main design problems was the 'haze' created over the central part of the retinal image by reflections from crystalline...

O. Pomerantzeff

1975-01-01

18

What are the benefits of having multiple camera angles?  

... zenith angles allowed by the scanner or push-broom design of the sensor. The accumulation of multiangular observations with such ... More detailed information is provided on the MISR web site Science Goals and Objectives page.   ...

2012-07-20

19

Wide-Angle, Reflective Strip-Imaging Camera  

NASA Technical Reports Server (NTRS)

Proposed camera images thin, striplike portion of field of view of 180 degrees wide. Hemispherical concave reflector forms image onto optical fibers, which transfers it to strip of photodetectors or spectrograph. Advantages include little geometric distortion, achromatism, and ease of athermalization. Uses include surveillance of clouds, coarse mapping of terrain, measurements of bidirectional reflectance distribution functions of aerosols, imaging spectrometry, oceanography, and exploration of planets.

Vaughan, Arthur H.

1992-01-01

20

Analytical image reconstruction of cone-beam projections from limited-angle Compton camera data  

Microsoft Academic Search

Since the integration of gamma-rays on a cone is measured with Compton cameras, some sort of image reconstruction method is necessary. Parra (2000) developed an analytical reconstruction algorithm based on a spherical harmonics expansion of projection data that covers the entire scattering-angle range. The measurable scattering angle range is limited due to the electrical noise of the detector and to

Takehiro Tomitani; Masahiko Hirasawa

2003-01-01

21

On-Orbit Geometric Calibration of the Lunar Reconnaissance Orbiter Wide Angle Camera  

NASA Astrophysics Data System (ADS)

Lunar Reconnaissance Orbiter (LRO) is equipped with a single Wide Angle Camera (WAC) [1] designed to collect monochromatic and multispectral observations of the lunar surface. Cartographically accurate image mosaics and stereo image based terrain models requires the position of each pixel in a given image be known to a corresponding point on the lunar surface with a high degree of accuracy and precision. The Lunar Reconnaissance Orbiter Camera (LROC) team initially characterized the WAC geometry prior to launch at the Malin Space Science Systems calibration facility. After lunar orbit insertion, the LROC team recognized spatially varying geometric offsets between color bands. These misregistrations made analysis of the color data problematic and showed that refinements to the pre-launch geometric analysis were necessary. The geometric parameters that define the WAC optical system were characterized from statistics gathered from co-registering over 84,000 image pairs. For each pair, we registered all five visible WAC bands to a precisely rectified Narrow Angle Camera (NAC) image (accuracy <15 m) [2] to compute key geometric parameters. In total, we registered 2,896 monochrome and 1,079 color WAC observations to nearly 34,000 NAC observations and collected over 13.7 million data points across the visible portion of the WAC CCD. Using the collected statistics, we refined the relative pointing (yaw, pitch and roll), effective focal length, principal point coordinates, and radial distortion coefficients. This large dataset also revealed spatial offsets between bands after orthorectification due to chromatic aberrations in the optical system. As white light enters the optical system, the light bends at different magnitudes as a function of wavelength, causing a single incident ray to disperse in a spectral spread of color [3,4]. This lateral chromatic aberration effect, also known as 'chromatic difference in magnification' [5] introduces variation to the effective focal length for each WAC band. Secondly, tangential distortions caused by minor decentering in the optical system altered the derived exterior orientation parameters for each 14-line WAC band. We computed the geometric parameter sets separately for each band to characterize the lateral chromatic aberrations and the decentering components in the WAC optical system. From this approach, we negated the need for additional tangential terms in the distortion model, thus reducing the number of computations during image orthorectification and therefore expediting the orthorectification process. We undertook a similar process for refining the geometry for the UV bands (321 and 360 nm), except we registered each UV bands to orthorectified visible bands of the same WAC observation (the visible bands have resolutions 4 times greater than the UV). The resulting 7-band camera model with refined geometric parameters enables map projection with sub-pixel accuracy. References: [1] Robinson et al. (2010) Space Sci. Rev. 150, 81-124 [2] Wagner et al. (2013) Lunar Sci Forum [3] Mahajan, V.N. (1998) Optical Imaging and Aberrations [4] Fiete, R.D. (2013), Manual of Photogrammetry, pp. 359-450 [5] Brown, D.C. (1966) Photometric Eng. 32, 444-462.

Speyerer, E. J.; Wagner, R.; Robinson, M. S.

2013-12-01

22

Narrow-angle tail radio sources and the distribution of galaxy orbits in Abell clusters  

SciTech Connect

The present data on the orientations of the tails with respect to the cluster centers of a sample of 70 narrow-angle-tail (NAT) radio sources in Abell clusters show the distribution of tail angles to be inconsistent with purely radial or circular orbits in all the samples, while being consistent with isotropic orbits in (1) the whole sample, (2) the sample of NATs far from the cluster center, and (3) the samples of morphologically regular Abell clusters. Evidence for very radial orbits is found, however, in the sample of NATs near the cluster center. If these results can be generalized to all cluster galaxies, then the presence of radial orbits near the center of Abell clusters suggests that violent relaxation may not have been fully effective even within the cores of the regular clusters. 93 references.

O'dea, C.P.; Sarazin, C.L.; Owen, F.N.

1987-05-01

23

Narrow-angle tail radio sources and the distribution of galaxy orbits in Abell clusters  

NASA Technical Reports Server (NTRS)

The present data on the orientations of the tails with respect to the cluster centers of a sample of 70 narrow-angle-tail (NAT) radio sources in Abell clusters show the distribution of tail angles to be inconsistent with purely radial or circular orbits in all the samples, while being consistent with isotropic orbits in (1) the whole sample, (2) the sample of NATs far from the cluster center, and (3) the samples of morphologically regular Abell clusters. Evidence for very radial orbits is found, however, in the sample of NATs near the cluster center. If these results can be generalized to all cluster galaxies, then the presence of radial orbits near the center of Abell clusters suggests that violent relaxation may not have been fully effective even within the cores of the regular clusters.

O'Dea, Christopher P.; Sarazin, Craig L.; Owen, Frazer N.

1987-01-01

24

Analytical image reconstruction of cone-beam projections from limited-angle Compton camera data  

Microsoft Academic Search

Since the integration of gamma-rays on a cone is measured with Compton cameras, some sort of image reconstruction method is necessary. Parra (2000) developed an analytical reconstruction algorithm based on a spherical-harmonics expansion of projection data that covers the entire scattering-angle range. The scattering-angle range is limited due to the electrical noise of the detector and due to the finite

Takehiro Tomitani; Masahiko Hirasawa

2002-01-01

25

Calibration of a trinocular system formed with wide angle lens cameras.  

PubMed

To obtain 3D information of large areas, wide angle lens cameras are used to reduce the number of cameras as much as possible. However, since images are high distorted, errors in point correspondences increase and 3D information could be erroneous. To increase the number of data from images and to improve the 3D information, trinocular sensors are used. In this paper a calibration method for a trinocular sensor formed with wide angle lens cameras is proposed. First pixels locations in the images are corrected using a set of constraints which define the image formation in a trinocular system. When pixels location are corrected, lens distortion and trifocal tensor is computed. PMID:23262716

Ricolfe-Viala, Carlos; Sanchez-Salmeron, Antonio-Jose; Valera, Angel

2012-12-01

26

Narrow basis angle doubles secret key in the BB84 protocol  

NASA Astrophysics Data System (ADS)

We consider a modified version of the BB84 quantum key distribution protocol in which the angle between two different bases is less than ?/4. We show that the channel parameter estimate becomes the same as the original protocol with sufficiently transmitted qubits. On the other hand, the statistical correlation between bits transmitted in one basis and those received in the other basis becomes stronger as the angle between two bases becomes narrower. If the angle is very small, the statistical correlation between bits transmitted in one basis and those received in the other basis is as strong as those received in the same basis as the transmitting basis, which means that the modified protocol can generate almost twice as long secret key as in the original protocol, provided that Alice and Bob choose two different bases with almost the same probability. We also point out that the reverse reconciliation often gives a different amount of secret key to the direct reconciliation over Pauli channels with our modified protocol.

Matsumoto, Ryutaroh; Watanabe, Shun

2010-04-01

27

An algorithm of calculating the scanning start angle and the scanning angle of linear array CCD panoramic aerial camera  

NASA Astrophysics Data System (ADS)

The scanning start angle (SSA), the scanning angle (SA) and the target slope angle (SA) are important parameters of Linear Array CCD Panoramic Aerial Camera. This paper analyzes the relationship of them and suggests that the current method of calculating SA is very difficult to be realized in engineering. It proposes an algorithm of calculating SSA and SA according to TSA. Its main characteristics are, with achieving the overlap rate as a premise, to calculate SSA and SA reasonably and to try to put the target into the middle of swath coverage, making the coverage as wide as possible. The algorithm is very simple and is easy to be realized in engineering. The paper gives us the relationship graph between TSA and SA.

Zhou, Gang; Zhai, Lin-Pei

2006-11-01

28

Abell 119: Cluster Mergers and the Origin of Narrow-Angle-Tail Radio Galaxies  

NASA Astrophysics Data System (ADS)

Abell 119 has two parallel Narrow-Angle-Tail (NAT) radio galaxies projected near its center. Although the dynamic state of the cluster has been uncertain, our short Chandra image showed a central cold front and possible north merger shock, which suggest the cluster is near core passage in a merger. A longer Chandra observation will be used to derive the merger kinematics from the cold front and merger shock. We will determine if the NAT-ICM relative motion is due to galaxy orbits or the cluster merger, which are the two main theories. We will look for interactions between the NATs and the intracluster gas, and see if the NATs have displaced the ICM. We will determine if the large Faraday rotations of the NATs are due to a dense sheath around them or to a large intracluster magnetic field.

Sarazin, Craig

2006-09-01

29

Narrow Angle Wide Spectral Range Radiometer Design FEANICS/REEFS Radiometer Design Report  

NASA Technical Reports Server (NTRS)

A critical measurement for the Radiative Enhancement Effects on Flame Spread (REEFS) microgravity combustion experiment is the net radiative flux emitted from the gases and from the solid fuel bed. These quantities are measured using a set of narrow angle, wide spectral range radiometers. The radiometers are required to have an angular field of view of 1.2 degrees and measure over the spectral range of 0.6 to 30 microns, which presents a challenging design effort. This report details the design of this radiometer system including field of view, radiometer response, radiometric calculations, temperature effects, error sources, baffling and amplifiers. This report presents some radiometer specific data but does not present any REEFS experiment data.

Camperchioli, William

2005-01-01

30

Narrow-angle tail radio sources and evidence for radial orbits in Abell clusters  

NASA Technical Reports Server (NTRS)

Published observational data on the tail orientations (TOs) of 60 narrow-angle-tail (NAT) radio sources in Abell clusters of galaxies are analyzed statistically using a maximum-likelihood approach. The results are presented in a table, and it is found that the observed TO distributions in the whole sample and in subsamples of morphologically regular NATs and NATs with pericentric distances d greater than 500 kpc are consistent with isotropic orbits, whereas the TOs for NATs with d less than 500 kpc are consistent with highly radial orbits. If radial orbits were observed near the centers of other types of cluster galaxies as well, it could be inferred that violent relaxation during cluster formation was incomplete, and that clusters form by spherical collapse and secondary infall, as proposed by Gunn (1977).

O'Dea, Christopher P.; Owen, Frazer N.; Sarazin, Craig L.

1986-01-01

31

Numerical Simulations of Narrow Angle Tailed Radio Sources : The Jones and Owen Model  

NASA Astrophysics Data System (ADS)

In previous work, Balsara and Norman (1992), we had focussed on simulating narrow angle tailed radio sources as fluid beams that are bent by the ram pressure of a cross flowing ICM. This allowed a comparison with several observable attributes of NAT sources. In particular we were able to make estimates of bending rate, beam profile, radial evolution and formation and interspacing of knots. The previous work suffered from the fact that the ISM of the host galaxy was not represented. In this work we remove that restriction by representing the host galaxy's ISM self-consistently using the prescription given in Balsara, Livio and O'Dea (1994). We then run jets through it and compare with observations.

Norman, Michael L.; Balsara, Dinshaw; O'Dea, Chris

1994-05-01

32

Real-Time Adjusting of Yaw Angle of Space Camera Based on General Image-Quality Equation  

Microsoft Academic Search

A Strategy of Real-Time Adjusting of Yaw Angle (SRTAYA) of space camera was proposed base on General Image-Quality Equation (GIQE). During space camera imaging, yaw angle which is caused by rotation of the earth and the gesture changing of satellite impacts integral aspect of TDI (Time Delay and Integration) CCD (Charge Couple Device), so that the image quality degrades. For

Jinling Wang; Xiaojun He; Shuyan Xu

2009-01-01

33

Generating target path for tracing a line before missing the traced line of dead angle of camera  

Microsoft Academic Search

In this paper, the problem that a robot misses traced line due to its dead angle during a line trace task is focused. When a vehicle traces a line on the floor, it usually uses a camera image in real-times. However, it is difficult to trace a line when the line is hidden in the dead angle of a camera,

T. Kawano; M. Hara; M. Sugisaka

2006-01-01

34

A Generic Camera Model and Calibration Method for Conventional, Wide-Angle, and Fish-Eye Lenses  

Microsoft Academic Search

Fish-eye lenses are convenient in such applications where a very wide angle of view is needed but their use for measurement purposes has been limited by the lack of an accurate, generic, and easy-to-use calibration procedure. We hence propose a generic camera model, which is suitable for sh-e ye lens cameras as well as for conventional and wide-angle lens cameras,

Juho Kannala; Sami S. Brandt

2006-01-01

35

Narrowed Aortoseptal Angle Is Related to Increased Central Blood Pressure and Aortic Pressure Wave Reflection.  

PubMed

The left ventricular (LV) aortoseptal angle (ASA) decreases with age, and is associated with basal septal hypertrophy (septal bulge). Enhanced arterial pressure wave reflection is known to impact LV hypertrophy. We assessed whether ASA is related to central blood pressure (BP) and augmentation index (AI), a measure of the reflected pressure wave. We studied 75 subjects (age 62 ± 16 years; 66% female) who were referred for transthoracic echocardiography and had radial artery applanation tonometry within 24 h. Peripheral systolic BP (P-SBP), peripheral diastolic BP (P-DBP), and peripheral pulse pressure (P-PP) were obtained by sphygmomanometry. Central BPs (C-SBP, C-DBP, C-PP) and AI were derived from applanation tonometry. AI was corrected for heart rate (AI75). The basal septal wall thickness (SWT), mid SWT and ASA were measured using the parasternal long axis echocardiographic view. Mean ASA and AI75 were 117 ± 11° and 22 ± 11%, respectively. ASA correlated with AI75 (r = -0.31, p ? 0.01), C-SBP (r = -0.24, p = 0.04), C-PP (r = -0.29, p = 0.01), but only showed a trend towards significance with P-SBP (r = -0.2, p = 0.09) and P-PP (r = -0.21, p = 0.08). Interestingly, C-PP was correlated with basal SWT (r = 0.27, p = 0.02) but not with mid SWT (r = 0.19, p = 0.11). On multivariate linear regression analysis, adjusted for age, gender, weight, and mean arterial pressure, AI75 was an independent predictor of ASA (p = 0.02). Our results suggest that a narrowed ASA is related to increased pressure wave reflection and higher central BP. Further studies are needed to determine whether narrowed LV ASA is a cause or consequence of enhanced wave reflection and whether other factors are involved. PMID:22969773

Olafiranye, Oladipupo; Ibrahim, Mediha; Kamran, Haroon; Venner-Jones, Kinda; McFarlane, Samy I; Salciccioli, Louis; Lazar, Jason M

2012-08-01

36

Narrow Angle Diversity using ACTS Ka-band Signal with Two USAT Ground Stations  

NASA Technical Reports Server (NTRS)

Two ultra small aperture terminal (USAT) ground stations, separated by 1.2 km in a narrow angle diversity configuration, received a continuous Ka-band tone sent from Cleveland Link Evaluation Terminal (LET). The signal was transmitted to the USAT ground stations via NASA's Advanced Communications Technology Satellite (ACTS) steerable beam. Received signal power at the two sites was measured and analyzed. A dedicated datalogger at each site recorded time-of-tip data from tipping bucket rain gauges, providing rain amount and instantaneous rain rate. WSR-88D data was also obtained for the collection period. Eleven events with ground-to-satellite slant-path precipitation and resultant signal attenuation were observed during the data collection period. Fade magnitude and duration were compared at the two sites and diversity gain was calculated. These results exceeded standard diversity gain model predictions by several decibels. Rain statistics from tipping bucket data and from radar data were also compared to signal attenuation. The nature of Florida's subtropical rainfall, specifically its impact on signal attenuation at the sites, was addressed.

Kalu, A.; Emrich, C.; Ventre, J.; Wilson, W.; Acosta, R.

1998-01-01

37

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

38

Using a TDI camera in vibration conditions with nonzero viewing angles for surface inspection  

NASA Astrophysics Data System (ADS)

A variety of time delay and integration (TDI) arrays have been developed. The TDI image sensor offers significant improvement in performance over a linear CCD-sensor with respect to sensitivity. This is particularly significant in low light level operation since the effective exposure time is increased by a factor which is equal to the number of the TDI stages in the sensor. Our previous work has indicated that the TDI camera can be used with viewing angles up to 30 degrees from the surface normal. The effects caused by vibration of the viewed surface become critical when using a TDI camera at non-zero viewing angles.FOr this reason, a study was made on the vibration effects. This paper reports this study, concentrating ont he relation between the vibration of the inspected surface and the sharpness of the image. The contrast perceived by the TDI camera as a function of the vibration amplitude and frequency is measured. The measurements are performed using a special test pattern in a dynamic situation. The results based on the contrast modulation function (CMF) in the vertical and horizontal directions are reported. A hypothesis of the effect of vibration on the CMF was formulated as a rule, which was then tested with measured data. Tentative result support the hypothesis.

Miettinen, Jari; Ailisto, Heikki J.

1997-08-01

39

Optical design of the wide angle camera for the Rosetta mission.  

PubMed

The final optical design of the Wide Angle Camera for the Rosetta mission to the P/Wirtanen comet is described. This camera is an F/5.6 telescope with a rather large 12 degrees x 12 degrees field of view. To satisfy the scientific requirements for spatial resolution, contrast capability, and spectral coverage, a two-mirror, off-axis, and unobstructed optical design, believed to be novel, has been adopted. This configuration has been simulated with a ray-tracing code, showing that theoretically more than 80% of the collimated beam energy falls within a single pixel (20" x 20") over the whole camera field of view and that the possible contrast ratio is smaller than 1/1000. Moreover, this novel optical design is rather simple from a mechanical point of view and is compact and relatively easy to align. All these characteristics make this type of camera rather flexible and also suitable for other space missions with similar performance requirements. PMID:11900025

Naletto, Giampiero; Da, Deppo Vania; Pelizzo, Maria Guglielmina; Ragazzoni, Roberto; Marchetti, Enrico

2002-03-01

40

The faster the narrower: characteristic bulk velocities and jet opening angles of gamma-ray bursts  

NASA Astrophysics Data System (ADS)

The jet opening angle ?jet and the bulk Lorentz factor ?0 are crucial parameters for the computation of the energetics of gamma-ray bursts (GRBs). From the ˜30 GRBs with measured ?jet or ?0 it is known that (i) the real energetic E?, obtained by correcting the isotropic equivalent energy Eiso for the collimation factor ˜ ?2jet, is clustered around 1050-1051 erg and it is correlated with the peak energy Ep of the prompt emission and (ii) the comoving frame E'p and E'? are clustered around typical values. Current estimates of ?0 and ?jet are based on incomplete data samples and their observed distributions could be subject to biases. Through a population synthesis code we investigate whether different assumed intrinsic distributions of ?0 and ?jet can reproduce a set of observational constraints. Assuming that all bursts have the same E'p and E'? in the comoving frame, we find that ?0 and ?jet cannot be distributed as single power laws. The best agreement between our simulation and the available data is obtained assuming (a) log-normal distributions for ?jet and ?0 and (b) an intrinsic relation between the peak values of their distributions, i.e. ?jet2.5?0 = const. On average, larger values of ?0 (i.e. the `faster' bursts) correspond to smaller values of ?jet (i.e. the `narrower'). We predict that ˜6 per cent of the bursts that point to us should not show any jet break in their afterglow light curve since they have sin ?jet < 1/?0. Finally, we estimate that the local rate of GRBs is ˜0.3 per cent of all local Type Ib/c supernova (SNIb/c) and ˜4.3 per cent of local hypernovae, i.e. SNIb/c with broad lines.

Ghirlanda, G.; Ghisellini, G.; Salvaterra, R.; Nava, L.; Burlon, D.; Tagliaferri, G.; Campana, S.; D'Avanzo, P.; Melandri, A.

2013-01-01

41

Comparison of Scheimpflug imaging and spectral domain anterior segment optical coherence tomography for detection of narrow anterior chamber angles  

PubMed Central

Purpose To compare the performance of anterior chamber volume (ACV) and anterior chamber depth (ACD) obtained using Scheimpflug imaging with angle opening distance (AOD500) and trabecular-iris space area (TISA500) obtained using spectral domain anterior segment optical coherence tomography (SD-ASOCT) in detecting narrow angles classified using gonioscopy. Methods In this prospective, cross-sectional observational study, 265 eyes of 265 consecutive patients underwent sequential Scheimpflug imaging, SD-ASOCT imaging, and gonioscopy. Correlations between gonioscopy grading, ACV, ACD, AOD500, and TISA500 were evaluated. Area under receiver operating characteristic curve (AUC), sensitivity, specificity, and likelihood ratios (LRs) were calculated to assess the performance of ACV, ACD, AOD500, and TISA500 in detecting narrow angles (defined as Shaffer grade ?1 in all quadrants). SD-ASOCT images were obtained at the nasal and temporal quadrants only. Results Twenty-eight eyes (10.6%) were classified as narrow angles on gonioscopy. ACV correlated with gonioscopy grading (P<0.001) for temporal (r=0.204), superior (r=0.251), nasal (r=0.213), and inferior (r=0.236) quadrants. ACV correlated with TISA500 for nasal (r=0.135, P=0.029) and temporal (P=0.160, P=0.009) quadrants and also with AOD500 for nasal (r=0.498, P<0.001) and temporal (r=0.517, P<0.001) quadrants. For detection of narrow angles, ACV (AUC=0.935; 95% confidence interval (CI) =0.898–0.961) performed similar to ACD (AUC=0.88, P=0.06) and significantly better than AOD500 nasal (AUC=0.761, P=0.001), AOD500 temporal (AUC=0.808, P<0.001), TISA500 nasal (AUC=0.756, P<0.001), and TISA500 temporal (AUC=0.738, P<0.001). Using a cutoff of 113?mm3, ACV had 90% sensitivity and 88% specificity for detecting narrow angles. Positive and negative LRs for ACV were 8.63 (95% CI=7.4–10.0) and 0.11 (95% CI=0.03–0.4), respectively. Conclusions ACV measurements using Scheimpflug imaging outperformed AOD500 and TISA500 using SD-ASOCT for detecting narrow angles.

Grewal, D S; Brar, G S; Jain, R; Grewal, S P S

2011-01-01

42

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

43

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

44

Small-angle approximation to the transfer of narrow laser beams in anisotropic scattering media  

NASA Technical Reports Server (NTRS)

The broadening and the signal power detected of a laser beam traversing an anisotropic scattering medium were examined using the small-angle approximation to the radiative transfer equation in which photons suffering large-angle deflections are neglected. To obtain tractable answers, simple Gaussian and non-Gaussian functions for the scattering phase functions are assumed. Two other approximate approaches employed in the field to further simplify the small-angle approximation solutions are described, and the results obtained by one of them are compared with those obtained using small-angle approximation. An exact method for obtaining the contribution of each higher order scattering to the radiance field is examined but no results are presented.

Box, M. A.; Deepak, A.

1981-01-01

45

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

2013-01-01

46

Narrow-band hybrid pulsed laser/EMAT system for noncontact ultrasonic inspection using angled shear waves  

SciTech Connect

Angled, shear wave ultrasonic testing using piezoelectric transducers has been used in industry for years to inspect the plate welds of steel vessels. This method`s reliance on viscous surface couplants limits its reproducibility as well as its applicability for testing surfaces at elevated temperatures. In this work, a pulsed laser/meander line EMAT (electromagnetic acoustic transducer) system was demonstrated to perform testing using vertically polarized, angled, shear waves. This capability was augmented with a narrow-bandwidth laser excitation technique to increase signal-to-noise ratio. The system was tested on both aluminum and steel plates containing saw cuts to mimic cracks. Finally, a steel weld specimen with known defects was tested with good results.

Oursler, D.A.; Wagner, J.W. [Johns Hopkins Univ., Baltimore, MD (United States). Center for Nondestructive Evaluation

1995-05-01

47

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

48

ITER CODAC interface for the visible and infra-red wide angle viewing cameras  

Microsoft Academic Search

The amount of data generated by the infra-red and visible cameras at ITER is expected to be considerably larger than most diagnostics. ITER will have 12 infra-red cameras plus 12 visible cameras in four different equatorial port plugs. Each of the ports will have a Plant System Host (PSH) that will provide a standard image of the plant system to

André Neto; Carlos Silva; Jorge Sousa; Horácio Fernandes; Carlos Hidalgo; Jose Luis De Pablos; Sophie Salasca; Jean-Marcel Travère; Jonathan B. Lister

2009-01-01

49

Numerical simulations of the bending of narrow-angle-tail radio jets by ram pressure or pressure gradients  

SciTech Connect

Three-dimensional numerical hydrodynamic simulations are used to study the bending of radio jets. The simulations are compared with observations of jets in narrow-angle-tail radio sources. Two mechanisms for the observed bending are considered: direct bending of quasi-continuous jets by ram pressure from intergalactic gas and bending by pressure gradients in the interstellar gas of the host galaxy, the pressure gradients themselves being the result of ram pressure by intergalactic gas. It is shown that the pressure gradients are much less effective in bending jets, implying that the jets have roughly 30 times lower momentum fluxes if they are bent by this mechanism. Ram-pressure bending produces jets with kidney-shaped cross sections; when observed from the side, these jets appear to have diffuse extensions on the downstream side. On the other hand, pressure-gradient bending causes the jets to be densest near their upstream side. 31 references.

Soker, N.; Sarazin, C.L.; O'Dea, C.P.

1988-04-01

50

Wide-angle narrow-bandpass optical detection system optimally designed to have a large signal-to-noise ratio.  

PubMed

A method for achieving optimal design of a wide-angle narrow-bandpass optical detection system composed of a spherical interference filter and a circular photodetector is introduced. It was found that there is an optimal photodetector diameter that maximizes the signal-to-noise ratio (SNR) for a given filter configuration. We show how to optimize optical detection systems based on spherical interference filters for all the important parameters simultaneously. The SNR values of these systems are compared with the SNR values of spherical-step-filter-based detection systems. When large silicon photodetectors are used, the two systems have equal SNR values so that the more economical step-filter systems are preferable. The results given here in the near-infrared region can be used for the optimization of any configuration of a detection system based on a spherical interference filter and a silicon photodetector working at the same wavelength range, without further calculations. PMID:18337966

Schweitzer, N; Arieli, Y

2000-02-20

51

A New Lunar Atlas: Mapping the Moon with the Wide Angle Camera  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter (LRO) spacecraft launched in June 2009 and began systematically mapping the lunar surface and providing a priceless dataset for the planetary science community and future mission planners. From 20 September 2009 to 11 December 2011, the spacecraft was in a nominal 50 km polar orbit, except for two one-month long periods when a series of spacecraft maneuvers enabled low attitude flyovers (as low as 22 km) of key exploration and scientifically interesting targets. One of the instruments, the Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) [1], captured nearly continuous synoptic views of the illuminated lunar surface. The WAC is a 7-band (321, 360, 415, 566, 604, 643, 689 nm) push frame imager with field of view of 60° in color mode and 90° in monochrome mode. This broad field of view enables the WAC to reimage nearly 50% (at the equator where the orbit tracks our spaced the furthest) of the terrain it imaged in the previous orbit. The visible bands of map projected WAC images have a pixel scale of 100 m, while UV bands have a pixel scale of 400 m due to 4x4 pixel on-chip binning that increases signal-to-noise. The nearly circular polar orbit and short (two hour) orbital periods enable seamless mosaics of broad areas of the surface with uniform lighting and resolution. In March of 2011, the LROC team released the first version of the global monochrome (643nm) morphologic map [2], which was comprised of 15,000 WAC images collected over three periods. With the over 130,000 WAC images collected while the spacecraft was in the 50 km orbit, a new set of mosaics are being produced by the LROC Team and will be released to the Planetary Data Systems. These new maps include an updated morphologic map with an improved set of images (limiting illumination variations and gores due to off-nadir observation of other instruments) and a new photometric correction derived from the LROC WAC dataset. In addition, a higher sun (lower incidence angle) mosaic will also be released. This map has minimal shadows and highlights albedo differences. In addition, seamless regional WAC mosaics acquired under multiple lighting geometries (Sunlight coming from the East, overhead, and West) will also be produced for key areas of interest. These new maps use the latest terrain model (LROC WAC GLD100) [3], updated spacecraft ephemeris provided by the LOLA team [4], and improved WAC distortion model [5] to provide accurate placement of each WAC pixel on the lunar surface. References: [1] Robinson et al. (2010) Space Sci. Rev. [2] Speyerer et al. (2011) LPSC, #2387. [3] Scholten et al. (2012) JGR. [4] Mazarico et al. (2012) J. of Geodesy [5] Speyerer et al. (2012) ISPRS Congress.

Speyerer, E.; Robinson, M. S.; Boyd, A.; Sato, H.

2012-12-01

52

Copernican craters: Early results from the Lunar Reconnaissance Orbiter Camera  

Microsoft Academic Search

The youngest (Copernican) craters on the Moon provide the best examples of original crater morphology and a record of the impact flux over the last ~1 Ga in the Earth-Moon system. The LRO Narrow Angle Cameras (NAC) provide 50 cm pixels from an altitude of 50 km. With changing incidence angle, global access, and very high data rates, these cameras

A. S. McEwen; H. Hiesinger; P. C. Thomas; M. S. Robinson; C. van der Bogert; L. Ostrach; J. B. Plescia; V. J. Bray; L. L. Tornabene

2009-01-01

53

Angle-of-incidence effects in the spectral performance of the infrared array camera of the Spitzer Space Telescope  

Microsoft Academic Search

The Infrared Array Camera (IRAC) on board the Spitzer Space Telescope uses two dichroic beamsplitters, four interference filters, and four detector arrays to acquire images in four different channels with nominal wavelengths of 3.6, 4.5, 5.8, and 8 mum for channels 1 through 4 respectively. A ray-tracing analysis of the IRAC optical system indicates a distribution of angles that is

Manuel A. Quijada; Catherine T. Marx; Richard G. Arendt; Samuel H. Moseley

2004-01-01

54

Horizontal parallax distortion in toed-in camera with wide-angle lens for mobile device  

NASA Astrophysics Data System (ADS)

An effect of the toed-in camera configuration is keystone distortion, which causes vertical and horizontal parallax in the stereoscopic image. The horizontal parallax is the source of the depth plane curvature. However, if the stereoscopic image captured by the toed-in camera system with fish-eye lens is displayed on mobile device, it is uncomfortable to view because the horizontal parallax contains horizontal parallax distortion occurred by the wide field of view of the lenses. Therefore, in this paper, we propose a novel correction method of the horizontal parallax distortion, which is one of the keystone distortions, in a toed-in camera with fish-eye lenses for mobile device. We have experimented to attest the proposed method. In experiment, we used two charge coupled device cameras, whose field of view is 48.48°. In addition, the captured stereoscopic image was corrected for the barrel distortion and the horizontal parallax distortion. Therefore, the proposed method provides correcting of the horizontal parallax distortion from a toed-in camera system in order that the users can enjoy three-dimensional effects without the visual fatigue. Additionally, the proposed method is able to apply to toed-in camera consisting of any kinds of cameras.

Kang, Hoonjong; Hur, Namho; Lee, Seunghyun; Yoshikawa, Hiroshi

2008-03-01

55

Observations of Comet 9P\\/Tempel 1 around the Deep Impact event by the OSIRIS cameras onboard Rosetta  

Microsoft Academic Search

The OSIRIS cameras on the Rosetta spacecraft observed Comet 9P\\/Tempel 1 from 5 days before to 10 days after it was hit by the Deep Impact projectile. The Narrow Angle Camera (NAC) monitored the cometary dust in 5 different filters. The Wide Angle Camera (WAC) observed through

Horst Uwe Keller; Michael Küppers; Sonia Fornasier; Pedro J. Gutiérrez; Stubbe F. Hviid; Laurent Jorda; Jörg Knollenberg; Stephen C. Lowry; Miriam Rengel; Ivano Bertini; Rainer Kramm; Ekkehard Kührt; Luisa-Maria Lara; Holger Sierks; Cesare Barbieri; Philippe Lamy; Hans Rickman; Rafael Rodrigo; Michael F. A'Hearn; Björn J. R. Davidsson; Marco Fulle; Fritz Gliem; Olivier Groussin; José J. Lopez Moreno; Francesco Marzari; Angel Sanz; Camino Bajo de Huétor; Chung Li; G. Galilei

2006-01-01

56

Narrow bandpass layered synthetic microstructure-based pinhole camera to image a tokamak plasma in H-like carbon emission at 34 A  

SciTech Connect

The layered synthetic microstructure (LSM) technology has made two-dimensional soft x-ray imaging of a tokamak plasma in a single impurity spectral line emission feasible. The curved LSM is used both as an optical filter, with a bandpass in the range of interest on the order of 1.5 A, and as a focusing optic. A detailed design of a narrow bandpass curved LSM-based pinhole camera, which will image the the region from the scrape-off layer 26 cm into the plasma in the DIII-D tokamak plasma in C VI Lyman {alpha} emission at 34 A, will be presented.

Regan, S.P.; Huang, L.K.; Finkenthal, M.; Moos, H.W. (The Johns Hopkins University, Baltimore, Maryland 21218 (United States))

1992-10-01

57

Angles  

NSDL National Science Digital Library

Play these games to determine the best angles for success! Alien Angles Set the angle to rescue the alien. Space Angles Target the angle to shoot the alien spaceship. Mini Golf Knowing the angles will help you get the ball in the hole. ...

Clark, Mr

2012-10-31

58

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

59

Miniature Wide-Angle Lens for Small-Pixel Electronic Camera  

NASA Technical Reports Server (NTRS)

A proposed wideangle lens is shown that would be especially well suited for an electronic camera in which the focal plane is occupied by an image sensor that has small pixels. The design of the lens is intended to satisfy requirements for compactness, high image quality, and reasonably low cost, while addressing issues peculiar to the operation of small-pixel image sensors. Hence, this design is expected to enable the development of a new generation of compact, high-performance electronic cameras. The lens example shown has a 60 degree field of view and a relative aperture (f-number) of 3.2. The main issues affecting the design are also shown.

Mouroulils, Pantazis; Blazejewski, Edward

2009-01-01

60

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

61

Lunar Reconnaissance Orbiter Camera (LROC) instrument overview  

USGS Publications Warehouse

The Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) and Narrow Angle Cameras (NACs) are on the NASA Lunar Reconnaissance Orbiter (LRO). The WAC is a 7-color push-frame camera (100 and 400 m/pixel visible and UV, respectively), while the two NACs are monochrome narrow-angle linescan imagers (0.5 m/pixel). The primary mission of LRO is to obtain measurements of the Moon that will enable future lunar human exploration. The overarching goals of the LROC investigation include landing site identification and certification, mapping of permanently polar shadowed and sunlit regions, meter-scale mapping of polar regions, global multispectral imaging, a global morphology base map, characterization of regolith properties, and determination of current impact hazards.

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

2010-01-01

62

On an assessment of surface roughness estimates from lunar laser altimetry pulse-widths for the Moon from LOLA using LROC narrow-angle stereo DTMs.  

NASA Astrophysics Data System (ADS)

Neumann et al. [1] proposed that laser altimetry pulse-widths could be employed to derive "within-footprint" surface roughness as opposed to surface roughness estimated from between laser altimetry pierce-points such as the example for Mars [2] and more recently from the 4-pointed star-shaped LOLA (Lunar reconnaissance Orbiter Laser Altimeter) onboard the NASA-LRO [3]. Since 2009, the LOLA has been collecting extensive global laser altimetry data with a 5m footprint and ?25m between the 5 points in a star-shape. In order to assess how accurately surface roughness (defined as simple RMS after slope correction) derived from LROC matches with surface roughness derived from LOLA footprints, publicly released LROC-NA (LRO Camera Narrow Angle) 1m Digital Terrain Models (DTMs) were employed to measure the surface roughness directly within each 5m footprint. A set of 20 LROC-NA DTMs were examined. Initially the match-up between the LOLA and LROC-NA orthorectified images (ORIs) is assessed visually to ensure that the co-registration is better than the LOLA footprint resolution. For each LOLA footprint, the pulse-width geolocation is then retrieved and this is used to "cookie-cut" the surface roughness and slopes derived from the LROC-NA DTMs. The investigation which includes data from a variety of different landforms shows little, if any correlation between surface roughness estimated from DTMs with LOLA pulse-widths at sub-footprint scale. In fact there is only any perceptible correlation between LOLA and LROC-DTMs at baselines of 40-60m for surface roughness and 20m for slopes. [1] Neumann et al. Mars Orbiter Laser Altimeter pulse width measurements and footprint-scale roughness. Geophysical Research Letters (2003) vol. 30 (11), paper 1561. DOI: 10.1029/2003GL017048 [2] Kreslavsky and Head. Kilometer-scale roughness of Mars: results from MOLA data analysis. J Geophys Res (2000) vol. 105 (E11) pp. 26695-26711. [3] Rosenburg et al. Global surface slopes and roughness of the Moon from the Lunar Orbiter Laser Altimeter. Journal of Geophysical Research (2011) vol. 116, paper E02001. DOI: 10.1029/2010JE003716 [4] Chin et al. Lunar Reconnaissance Orbiter Overview: The Instrument Suite and Mission. Space Science Reviews (2007) vol. 129 (4) pp. 391-419

Muller, Jan-Peter; Poole, William

2013-04-01

63

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

64

Performance Study of a Wide-Angle Camera for Atmospheric Cerenkov Telescopes  

SciTech Connect

With the next generation of Atmospheric Cerenkov Telescopes (ACT) well on their way, effort has being shifted now towards a further improvement of the capabilities of these instruments. These next generation experiments have improved up to an order of magnitude their sensitivity over their first generation counterparts, and have extended the energy coverage down to about 50 GeV. However, it is not clear whether the same approach is optimal for energies above 1 TeV, and with clear evidence of high energy emission above this energy from several astrophysical sources, we believe that this energy range could be further exploited. Many of our physics goals, such as, limits on quantum gravity or spectral variability and features of the high energy emission from AGNs, would benefit from an increase of sensitivity in this direction. Here, we investigate a possible way of increasing the collection area of ACTs above 1 TeV by using a wide-field-of-view ({approx} 10 deg.) camera. Both, the scientific motivation and preliminary Monte Carlo studies of the performance of such a detector, are discussed and presented here.

Calle, I. de la; Biller, S.D. [University of Oxford, Department of Physics, Denys Wilkinson Building, Oxford, OX1 3RH (United Kingdom)

2005-02-21

65

Theoretical demonstration of DBR-assisted super-periodic photonic-crystal light-emitting diodes with narrow divergence angles  

NASA Astrophysics Data System (ADS)

Highly-directive light-emitting diodes showing high extraction efficiency are designed and demonstrated based on a two-dimensional super-periodic photonic-crystal structure. With this specific design, a super-periodic photonic-crystal structure can generate a highly directional beam by satisfying the multiple-resonance conditions of distributed Bragg reflectors and the topmost slab. Dependence of the power efficiency on the thickness of the topmost slab and the etching depth of the photonic-crystal holes is then analyzed by the three-dimensional finite-difference time-domain method. From subsequent analyses, it has been determined that >80% of the extracted power could be funneled into a small divergence angle of 30°.

Lim, Chan M.; Song, G. Hugh

2010-04-01

66

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

67

6. VAL CAMERA CAR, DETAIL OF COMMUNICATION EQUIPMENT INSIDE CAMERA ...  

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

6. VAL CAMERA CAR, DETAIL OF COMMUNICATION EQUIPMENT INSIDE CAMERA CAR WITH CAMERA MOUNT IN FOREGROUND. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

68

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

69

SWAX - a dual-detector camera for simultaneous small- and wide-angle X-ray diffraction in polymer and liquid crystal research  

Microsoft Academic Search

The design, construction and performance of a new X-ray camera allowing simultaneous sampling of diffraction data both in the small- and in the wide-angle range are described. The instrument employs line collimation and contains two position-sensitive gas detectors covering distance ranges of 10-1000, and 3.4-4.9 Å, respectively, which are regions of strong interest in studies on polymer and liquid crystal

Peter Laggner; Hannes Mio

1992-01-01

70

The rate and causes of lunar space weathering: Insights from Lunar Reconnaissance Orbiter Wide Angle Camera ultraviolet observations  

NASA Astrophysics Data System (ADS)

Lunar Reconnaissance Orbiter Wide Angle Camera global ultraviolet and visible imaging provides a unique opportunity to examine the rate and causes of space weathering on the Moon. Silicates typically have a strong decrease in reflectance toward UV wavelengths (<~450 nm) due to strong bands at 250 nm and in the far UV. Metallic iron is relatively spectrally neutral, and laboratory spectra suggest that its addition to mature soils in the form of submicroscopic iron (also known as nanophase iron) flattens silicate spectra, significantly reducing spectral slope in the ultraviolet. Reflectance at ultraviolet wavelengths may be especially sensitive to the surface coatings that form due to exposure to space weathering because scattering from the surfaces of grains contributes a larger fraction to the reflectance spectrum at short wavelengths. We find that the UV slope (as measured by the 320/415 nm ratio) is a more sensitive measure of maturity than indexes based on visible and near-infrared wavelengths. Only the youngest features (less than ~100 Ma) retain a UV slope that is distinct from mature soils of the same composition. No craters >20 km have UV slopes that approach those observed in laboratory spectra of fresh lunar materials (powdered lunar rocks). While the 320/415 nm ratio increases by ~18% from powdered rocks to mature soils in laboratory samples, Giordano Bruno, the freshest large crater, only shows a 3% difference between fresh and mature materials. At the resolution of our UV data (400 m/pixel), we observe some small (<5 km) craters that show a ~14% difference in 320/415 nm ratio from their mature surroundings. UV observations show that Reiner Gamma has had significantly lower levels of space weathering than any of the Copernican craters we examined, and was the only region we found with a UV slope that approached laboratory values for fresh powdered rock samples. This is consistent with the hypothesis that its high albedo is due to magnetic shielding from solar wind sputtering effects. Furthermore the observation that all Copernican craters we examined show some degree of space weathering and the extreme immaturity of Reiner Gamma materials show that space weathering of the surface and the resultant modification of UV spectra proceeds at a fast rate and is dominated by solar wind sputtering. Comparisons of the UV trends on other airless bodies (i.e., asteroids and Mercury) may prove fruitful for understanding the relative rates and causes of space weathering across the inner solar system.

Denevi, B. W.; Robinson, M. S.; Sato, H.; Hapke, B. W.; McEwen, A. S.; Hawke, B. R.

2011-12-01

71

Angle-of-Incidence Efiects in the Spectral Performance of the Infrared Array Camera of the Spitzer Space Telescope  

Microsoft Academic Search

The Infrared Array Camera (IRAC) on board the Spitzer Space Telescope uses two dichroic beamsplitters, four interference fllters, and four detector arrays to acquire images in four difierent channels with nominal wavelengths of 3.6, 4.5, 5.8, and 8 \\

Manuel A. Quijada; Catherine Trout Marx; Richard G. Arendt; S. Harvey Moseley

72

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

73

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

74

9. VIEW OF CAMERA STATIONS UNDER CONSTRUCTION INCLUDING CAMERA CAR ...  

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

9. VIEW OF CAMERA STATIONS UNDER CONSTRUCTION INCLUDING CAMERA CAR ON RAILROAD TRACK AND FIXED CAMERA STATION 1400 (BUILDING NO. 42021) ABOVE, ADJACENT TO STATE HIGHWAY 39, LOOKING WEST, March 23, 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Camera Stations, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

75

Exploring the Moon with the Lunar Reconnaissance Orbiter Camera  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter Camera (LROC) consists of three imaging systems: a Wide Angle Camera (WAC) and two Narrow Angle Cameras (NACs). Since entering lunar orbit in June of 2009, LROC has collected over 700,000 images. A subset of WAC images were reduced into a global morphologic basemap, a near-global digital elevation model, and multitemporal movie sequences that characterize illumination conditions of the polar regions. In addition, NAC observations were reduced to meter scale maps and digital elevation models of select regions of interest. These Reduced Data Record (RDR) products were publicly released through NASA's Planetary Data System to aid scientists and engineers in planning future lunar missions and addressing key science questions.

Robinson, M. S.; Speyerer, E. J.; Boyd, A.; Waller, D.; Wagner, R. V.; Burns, K. N.

2012-08-01

76

Is Perceptual Narrowing Too Narrow?  

ERIC Educational Resources Information Center

There is a growing list of examples illustrating that infants are transitioning from having earlier abilities that appear more "universal," "broadly tuned," or "unconstrained" to having later abilities that appear more "specialized," "narrowly tuned," or "constrained." Perceptual narrowing, a well-known phenomenon related to face, speech, and…

Cashon, Cara H.; Denicola, Christopher A.

2011-01-01

77

Wide Angle Movie  

NASA Technical Reports Server (NTRS)

This brief movie illustrates the passage of the Moon through the Saturn-bound Cassini spacecraft's wide-angle camera field of view as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. From beginning to end of the sequence, 25 wide-angle images (with a spatial image scale of about 14 miles per pixel (about 23 kilometers)were taken over the course of 7 and 1/2 minutes through a series of narrow and broadband spectral filters and polarizers, ranging from the violet to the near-infrared regions of the spectrum, to calibrate the spectral response of the wide-angle camera. The exposure times range from 5 milliseconds to 1.5 seconds. Two of the exposures were smeared and have been discarded and replaced with nearby images to make a smooth movie sequence. All images were scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is approximately the same in every image. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS)at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

1999-01-01

78

Optimum camera placement considering camera specification for security monitoring  

Microsoft Academic Search

Abstract—We,present,an optimum,camera,placement,algo- rithm. We,are motivated,by,the fact that the installation of security cameras,is increasing rapidly. From the system cost point of view, it is desirable to observe all the area of interest by the smallest number,of cameras. We propose,a method,for deciding optimum,camera,placement,automatically,considering,camera specification such as visual distance, visual angle, and resolution. Moreover, to reduce the number of cameras, we divide the

Kenichi Yabuta; Hitoshi Kitazawa

2008-01-01

79

RECON 6: A real-time, wide-angle, solid-state reconnaissance camera system for high-speed, low-altitude aircraft  

NASA Technical Reports Server (NTRS)

The maturity of self-scanned, solid-state, multielement photosensors makes the realization of "real time" reconnaissance photography viable and practical. A system built around these sensors which can be constructed to satisfy the requirements of the tactical reconnaissance scenario is described. The concept chosen is the push broom strip camera system -- RECON 6 -- which represents the least complex and most economical approach for an electronic camera capable of providing a high level of performance over a 140 deg wide, continuous swath at altitudes from 200 to 3,000 feet and at minimum loss in resolution at higher altitudes.

Labinger, R. L.

1976-01-01

80

Camera Obscura  

NSDL National Science Digital Library

Before photography was invented there was the camera obscura, useful for studying the sun, as an aid to artists, and for general entertainment. What is a camera obscura and how does it work ??? Camera = Latin for room Obscura = Latin for dark But what is a Camera Obscura? The Magic Mirror of Life What is a camera obscura? A French drawing camera with supplies A French drawing camera with supplies Drawing Camera Obscuras with Lens at the top Drawing Camera Obscuras with Lens at the top Read the first three paragraphs of this article. Under the portion Early Observations and Use in Astronomy you will find the answers to the ...

Engelman, Mr.

2008-10-28

81

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

82

Camera Animation  

NSDL National Science Digital Library

A general discussion of the use of cameras in computer animation. This section includes principles of traditional film techniques and suggestions for the use of a camera during an architectural walkthrough. This section includes html pages, images and one video.

2011-01-30

83

Camera Optics.  

ERIC Educational Resources Information Center

The camera presents an excellent way to illustrate principles of geometrical optics. Basic camera optics of the single-lens reflex camera are discussed, including interchangeable lenses and accessories available to most owners. Several experiments are described and results compared with theoretical predictions or manufacturer specifications.…

Ruiz, Michael J.

1982-01-01

84

The PAU Camera  

NASA Astrophysics Data System (ADS)

The PAU Camera (PAUCam) is a wide-field camera designed to be mounted at the William Herschel Telescope (WHT) prime focus, located at the Observatorio del Roque de los Muchachos in the island of La Palma (Canary Islands).Its primary function is to carry out a cosmological survey, the PAU Survey, covering an area of several hundred square degrees of sky. Its purpose is to determine positions and distances using photometric redshift techniques. To achieve accurate photo-z's, PAUCam will be equipped with 40 narrow-band filters covering the range from 450 to850 nm, and six broad-band filters, those of the SDSS system plus the Y band. To fully cover the focal plane delivered by the telescope optics, 18 CCDs 2k x 4k are needed. The pixels are square of 15 ? m size. The optical characteristics of the prime focus corrector deliver a field-of-view where eight of these CCDs will have an illumination of more than 95% covering a field of 40 arc minutes. The rest of the CCDs will occupy the vignetted region extending the field diameter to one degree. Two of the CCDs will be devoted to auto-guiding.This camera have some innovative features. Firstly, both the broad-band and the narrow-band filters will be placed in mobile trays, hosting 16 such filters at most. Those are located inside the cryostat at few millimeters in front of the CCDs when observing. Secondly, a pressurized liquid nitrogen tank outside the camera will feed a boiler inside the cryostat with a controlled massflow. The read-out electronics will use the Monsoon architecture, originally developed by NOAO, modified and manufactured by our team in the frame of the DECam project (the camera used in the DES Survey).PAUCam will also be available to the astronomical community of the WHT.

Casas, R.; Ballester, O.; Cardiel-Sas, L.; Carretero, J.; Castander, F. J.; Castilla, J.; Crocce, M.; de Vicente, J.; Delfino, M.; Fernández, E.; Fosalba, P.; García-Bellido, J.; Gaztañaga, E.; Grañena, F.; Jiménez, J.; Madrid, F.; Maiorino, M.; Martí, P.; Miquel, R.; Neissner, C.; Ponce, R.; Sánchez, E.; Serrano, S.; Sevilla, I.; Tonello, N.; Troyano, I.

2011-11-01

85

Networked video surveillance using multiple omnidirectional cameras  

Microsoft Academic Search

Remote surveillance is widely utilized in banks, shops, offices, at home and so on. In most conventional remote surveillance systems, fixed or active cameras with a narrow field of view are generally used in order to acquire an image of the remote site. This paper proposes a new networked surveillance system. The proposed surveillance system, which uses multiple omnidirectional cameras

Shinji Morita; Kazumasa Yamazawa; Naokazu Yokoya

2003-01-01

86

Space Camera  

NASA Technical Reports Server (NTRS)

Nikon's F3 35mm camera was specially modified for use by Space Shuttle astronauts. The modification work produced a spinoff lubricant. Because lubricants in space have a tendency to migrate within the camera, Nikon conducted extensive development to produce nonmigratory lubricants; variations of these lubricants are used in the commercial F3, giving it better performance than conventional lubricants. Another spinoff is the coreless motor which allows the F3 to shoot 140 rolls of film on one set of batteries.

1983-01-01

87

Characterization of light output from narrow sodium iodide detectors  

Microsoft Academic Search

The use of narrow scintillators in imaging devices raises the question of whether there is enough light output that can yield reasonable energy and spatial resolutions. Compared to scintillation within large-area detectors (such as those used in conventional gamma cameras), scintillation photons within narrow detectors are expected to undergo more reflections because of the proximity of the detector surfaces. In

C. E. Ordonez; W. Chang; J. Liu; D. L. Gunter

1996-01-01

88

Simulation of light output from narrow sodium iodide detectors  

Microsoft Academic Search

The use of narrow scintillators in imaging devices raises the question of whether there is enough light output that can yield reasonable energy and spatial resolutions. Compared to scintillation within large-area detectors (such as those used in conventional gamma cameras), scintillation photons within narrow detectors are expected to undergo more reflections because of the proximity of the detector surfaces. In

Caesar E. Ordonez; Wei Chang; Jingai Liu; Donald L. Gunter

1997-01-01

89

Mapping the Apollo 17 landing site area based on Lunar Reconnaissance Orbiter Camera images and Apollo surface photography  

NASA Astrophysics Data System (ADS)

Newly acquired high resolution Lunar Reconnaissance Orbiter Camera (LROC) images allow accurate determination of the coordinates of Apollo hardware, sampling stations, and photographic viewpoints. In particular, the positions from where the Apollo 17 astronauts recorded panoramic image series, at the so-called “traverse stations”, were precisely determined for traverse path reconstruction. We analyzed observations made in Apollo surface photography as well as orthorectified orbital images (0.5 m/pixel) and Digital Terrain Models (DTMs) (1.5 m/pixel and 100 m/pixel) derived from LROC Narrow Angle Camera (NAC) and Wide Angle Camera (WAC) images. Key features captured in the Apollo panoramic sequences were identified in LROC NAC orthoimages. Angular directions of these features were measured in the panoramic images and fitted to the NAC orthoimage by applying least squares techniques. As a result, we obtained the surface panoramic camera positions to within 50 cm. At the same time, the camera orientations, North azimuth angles and distances to nearby features of interest were also determined. Here, initial results are shown for traverse station 1 (northwest of Steno Crater) as well as the Apollo Lunar Surface Experiment Package (ALSEP) area.

Haase, I.; Oberst, J.; Scholten, F.; Wählisch, M.; Gläser, P.; Karachevtseva, I.; Robinson, M. S.

2012-05-01

90

Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)  

NASA Astrophysics Data System (ADS)

The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

Roberts, W. T.

91

Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)  

NASA Astrophysics Data System (ADS)

The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

Roberts, B.

1986-01-01

92

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

93

Infrared Camera  

NASA Technical Reports Server (NTRS)

A sensitive infrared camera that observes the blazing plumes from the Space Shuttle or expendable rocket lift-offs is capable of scanning for fires, monitoring the environment and providing medical imaging. The hand-held camera uses highly sensitive arrays in infrared photodetectors known as quantum well infrared photo detectors (QWIPS). QWIPS were developed by the Jet Propulsion Laboratory's Center for Space Microelectronics Technology in partnership with Amber, a Raytheon company. In October 1996, QWIP detectors pointed out hot spots of the destructive fires speeding through Malibu, California. Night vision, early warning systems, navigation, flight control systems, weather monitoring, security and surveillance are among the duties for which the camera is suited. Medical applications are also expected.

1997-01-01

94

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.

95

Security Cameras  

NSDL National Science Digital Library

Using the real world example of security cameras, this lesson has students explore properties of polygons. Using this example, students will be able to discover a formula as related to polygons. An activity sheet and student questions are included. This material is intended for students from grades 9-12 and should require 1 class period to complete.

2010-12-16

96

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

97

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

98

Camera Calibration.  

National Technical Information Service (NTIS)

Given an image that has been scaled both horizontally and vertically (possibly with different scale factors in the two directions), we determine the camera position and orientation, as well as the scale factors for sampling in the u and v axes of the imag...

I. Rigoutsos C. M. Brown

1986-01-01

99

Nikon Camera  

NASA Technical Reports Server (NTRS)

Nikon FM compact has simplification feature derived from cameras designed for easy, yet accurate use in a weightless environment. Innovation is a plastic-cushioned advance lever which advances the film and simultaneously switches on a built in light meter. With a turn of the lens aperture ring, a glowing signal in viewfinder confirms correct exposure.

1980-01-01

100

Initial Results of 3D Topographic Mapping Using Lunar Reconnaissance Orbiter Camera (LROC) Stereo Imagery  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter (LRO), launched June 18, 2009, carries the Lunar Reconnaissance Orbiter Camera (LROC) as one of seven remote sensing instruments on board. The camera system is equipped with a Wide Angle Camera (WAC) and two Narrow Angle Cameras (NAC) for systematic lunar surface mapping and detailed site characterization for potential landing site selection and resource identification. The LROC WAC is a pushframe camera with five 14-line by 704-sample framelets for visible light bands and two 16-line by 512-sample (summed 4x to 4 by 128) UV bands. The WAC can also acquire monochrome images with a 14-line by 1024-sample format. At the nominal 50-km orbit the visible bands ground scale is 75-m/pixel and the UV 383-m/pixel. Overlapping WAC images from adjacent orbits can be used to map topography at a scale of a few hundred meters. The two panchromatic NAC cameras are pushbroom imaging sensors each with a Cassegrain telescope of a 700-mm focal length. The two NAC cameras are aligned with a small overlap in the cross-track direction so that they cover a 5-km swath with a combined field-of-view (FOV) of 5.6°. At an altitude of 50-km, the NAC can provide panchromatic images from its 5,000-pixel linear CCD at a ground scale of 0.5-m/pixel. Calibration of the cameras was performed by using precision collimator measurements to determine the camera principal points and radial lens distortion. The orientation of the two NAC cameras is estimated by a boresight calibration using double and triple overlapping NAC images of the lunar surface. The resulting calibration results are incorporated into a photogrammetric bundle adjustment (BA), which models the LROC camera imaging geometry, in order to refine the exterior orientation (EO) parameters initially retrieved from the SPICE kernels. Consequently, the improved EO parameters can significantly enhance the quality of topographic products derived from LROC NAC imagery. In addition, an analysis of the spacecraft jitter effect is performed by measuring lunar surface features in the NAC CCD overlapping strip in the image space and object space. Topographic and cartographic data processing results and products derived from LROC NAC and WAC stereo imagery using different software systems from several participating institutions of the LROC team will be presented, including results of calibration, bundle adjustment, jitter analysis, DEM, orthophoto, and cartographic maps.

Li, R.; Oberst, J.; McEwen, A. S.; Archinal, B. A.; Beyer, R. A.; Thomas, P. C.; Chen, Y.; Hwangbo, J.; Lawver, J. D.; Scholten, F.; Mattson, S. S.; Howington-Kraus, A. E.; Robinson, M. S.

2009-12-01

101

Calibration of the Lunar Reconnaissance Orbiter Camera  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter Camera (LROC) onboard the NASA Lunar Reconnaissance Orbiter (LRO) spacecraft consists of three cameras: the Wide-Angle Camera (WAC) and two identical Narrow Angle Cameras (NAC-L, NAC-R). The WAC is push-frame imager with 5 visible wavelength filters (415 to 680 nm) at a spatial resolution of 100 m/pixel and 2 UV filters (315 and 360 nm) with a resolution of 400 m/pixel. In addition to the multicolor imaging the WAC can operate in monochrome mode to provide a global large- incidence angle basemap and a time-lapse movie of the illumination conditions at both poles. The WAC has a highly linear response, a read noise of 72 e- and a full well capacity of 47,200 e-. The signal-to-noise ratio in each band is 140 in the worst case. There are no out-of-band leaks and the spectral response of each filter is well characterized. Each NAC is a monochrome pushbroom scanner, providing images with a resolution of 50 cm/pixel from a 50-km orbit. A single NAC image has a swath width of 2.5 km and a length of up to 26 km. The NACs are mounted to acquire side-by-side imaging for a combined swath width of 5 km. The NAC is designed to fully characterize future human and robotic landing sites in terms of topography and hazard risks. The North and South poles will be mapped on a 1-meter-scale poleward of 85.5° latitude. Stereo coverage can be provided by pointing the NACs off-nadir. The NACs are also highly linear. Read noise is 71 e- for NAC-L and 74 e- for NAC-R and the full well capacity is 248,500 e- for NAC-L and 262,500 e- for NAC- R. The focal lengths are 699.6 mm for NAC-L and 701.6 mm for NAC-R; the system MTF is 28% for NAC-L and 26% for NAC-R. The signal-to-noise ratio is at least 46 (terminator scene) and can be higher than 200 (high sun scene). Both NACs exhibit a straylight feature, which is caused by out-of-field sources and is of a magnitude of 1-3%. However, as this feature is well understood it can be greatly reduced during ground processing. All three cameras were calibrated in the laboratory under ambient conditions. Future thermal vacuum tests will characterize critical behaviors across the full range of lunar operating temperatures. In-flight tests will check for changes in response after launch and provide key data for meeting the requirements of 1% relative and 10% absolute radiometric calibration.

Tschimmel, M.; Robinson, M. S.; Humm, D. C.; Denevi, B. W.; Lawrence, S. J.; Brylow, S.; Ravine, M.; Ghaemi, T.

2008-12-01

102

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

103

Angle Performance on Optima XE  

NASA Astrophysics Data System (ADS)

Angle control on high energy implanters is important due to shrinking device dimensions, and sensitivity to channeling at high beam energies. On Optima XE, beam-to-wafer angles are controlled in both the horizontal and vertical directions. In the horizontal direction, the beam angle is measured through a series of narrow slits, and any angle adjustment is made by steering the beam with the corrector magnet. 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 during implant. Using a sensitive channeling condition, we were able to quantify the angle repeatability of Optima XE. By quantifying the sheet resistance sensitivity to both horizontal and vertical angle variation, the total angle variation was calculated as 0.04° (1?). Implants were run over a five week period, with all of the wafers selected from a single boule, in order to control for any crystal cut variation.

David, Jonathan; Satoh, Shu

2011-01-01

104

The High Resolution Stereo Camera (HRSC) for Mars 96: Results of Outdoor Tests  

NASA Astrophysics Data System (ADS)

The High Resolution Stereo Camera (HRSC) is one of the principal orbiter payload instruments for the Russian Mars 96 Mission to be launched in November this year. The pushbroom scanner is equipped with a single 175 mm lens and 9 linear CCD arrays (5 panchromatic and 4 narrow-band color filters) mounted in parallel providing nadir, forward, and backward looking viewing conditions for each line, respectively. In orbit, images will be acquired line by line as the spacecraft moves. The goal is to obtain large-scale high-resolution (10- 15m/pixel) multispectral stereo images at different phase angles. In spring 1995, the flight hard-ware was tested at the prime manufacturer's facility near Lake Constance (Germany) in order to verify the geometric and radiometric performance of the camera as well as the software developed for HRSC ground data processing. It was demonstrated that instrument and processing software met or exceeded their design goals.

Hauber, E.; Oberst, J.; Flohrer, J.; Sebastian, I.; Zhang, W.; Robinson, C. A.; Jaumann, R.; Neukum, G.

1996-03-01

105

Viewing angle changeable display  

NASA Astrophysics Data System (ADS)

Viewing angle changeable display can change the display viewing angle as needed: In the public place the display could have a narrow viewing angle for privacy, while in the private place the displays could have a wide viewing angle for the convenience of the operation and better viewing experience. This article propose a novel adjustable optical transmission device to realize the viewing angle changes for LCD by using the principle of guest- host effect of liquid crystal. The major technology is to insert a special equipment between the backlight and the LCD, through which the backlight will display either parallel or scattered features to get an either narrow or wide viewing angle. The equipment is an adjustable transmission cell (ATC) which is actually a black G-H LC cell. This ATC is the main focus of our invention. The ATC consists of a polarizer sheet and a special guest-host liquid crystal device filled with the two-phase dye (called as GH-LC in this report), to achieve the viewing angle change in the LCD. When an electrical field charges to the ATC, only the so-called near-axis lights can pass through the ATC within a relatively small angle, while the other scattered lights are absorbed sequentially by GH-LC and the polarizer sheet. On the other hand, when there is no electrical charge to the ATC, the cell behaves like a normal polarizer; and the scattered light can pass through the cell and polarizer in a normal way. This paper describes the principle and structure of the device, applies the electric field on the sample to observe the electro-optical properties, combine the theoretical and experimental research, getting the viewing angle effects of the display.

Leng, Jinbi; Huang, Ziqiang; Yang, Wenjun; Chen, Xiaoxi

2010-05-01

106

11. COMPLETED FIXED CAMERA STATION 1700 (BUILDING NO. 42022) LOOKING ...  

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

11. COMPLETED FIXED CAMERA STATION 1700 (BUILDING NO. 42022) LOOKING WEST SHOWING WINDOW OPENING FOR CAMERA, March 31, 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Camera Stations, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

107

A Novel Method for the Distortion Modification of Camera Lens  

Microsoft Academic Search

Lens distortion is one of the main factors affecting camera calibration. To improve the accuracy of calibrating camera, a new approach to modify the lens distortion is proposed. Based on Brown model and pinhole imaging principle, the measurement model of the incident angle is built. The sensibilities of different distortion coefficients in the expression of incident angle are analyzed using

Minghua Pan; Guoli Zhu

2010-01-01

108

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

109

Cydonia: Wide Angle Color Image  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

Although the resolution of the MOC wide angle cameras is too low to tell much about the geomorphology of the Cydonia region, the images from the red and blue wide angle cameras provide us with two types of information that is of interest in their own right: color and stereoscopic data. Above are a color view and a stereoscopic anaglyph rendition of Geodesy Campaign images acquired by MGS MOC in May 1999. To view the stereo image, you need red/blue '3-D' glasses.

2000-01-01

110

Multispectral calibration to enhance the metrology performance of C-mount camera systems  

NASA Astrophysics Data System (ADS)

Low cost monochrome camera systems based on CMOS sensors and C-mount lenses have been successfully applied to a wide variety of metrology tasks. For high accuracy work such cameras are typically equipped with ring lights to image retro-reflective targets as high contrast image features. Whilst algorithms for target image measurement and lens modelling are highly advanced, including separate RGB channel lens distortion correction, target image circularity compensation and a wide variety of detection and centroiding approaches, less effort has been directed towards optimising physical target image quality by considering optical performance in narrow wavelength bands. This paper describes an initial investigation to assess the effect of wavelength on camera calibration parameters for two different camera bodies and the same `C-mount' wide angle lens. Results demonstrate the expected strong influence on principal distance, radial and tangential distortion, and also highlight possible trends in principal point, orthogonality and affinity parameters which are close to the parameter estimation noise level from the strong convergent self-calibrating image networks.

Robson, S.; MacDonald, L.; Kyle, S. A.; Shortis, M. R.

2014-06-01

111

Experience with duplex bearings in narrow angle oscillating applications  

NASA Technical Reports Server (NTRS)

Duplex ball bearings are matched pairs on which the abutting faces of the rings have been accurately ground so that when the rings are clamped together, a controlled amount of interference (preload) exists across the balls. These bearings are vulnerable to radial temperature gradients, blocking in oscillation and increased sensitivity to contamination. These conditions decrease the service life of these bearings. It was decided that an accelerated thermal vacuum life test should be conducted. The test apparatus and results are described and the rationale is presented for reducing a multiyear life test on oil lubricated bearings to less than a year.

Phinney, D. D.; Pollard, C. L.; Hinricks, J. T.

1988-01-01

112

Venus Monitoring Camera for Venus Express  

Microsoft Academic Search

The Venus Express mission will focus on a global investigation of the Venus atmosphere and plasma environment, while additionally measuring some surface properties from orbit. The instruments PFS and SPICAV inherited from the Mars Express mission and VIRTIS from Rosetta form a powerful spectrometric and spectro-imaging payload suite. Venus Monitoring Camera (VMC)—a miniature wide-angle camera with 17.5° field of view—was

W. J. Markiewicz; D. V. Titov; N. Ignatiev; H. U. Keller; D. Crisp; S. S. Limaye; R. Jaumann; R. Moissl; N. Thomas; L. Esposito; S. Watanabe; B. Fiethe; T. Behnke; I. Szemerey; H. Michalik; H. Perplies; M. Wedemeier; I. Sebastian; W. Boogaerts; S. F. Hviid; C. Dierker; B. Osterloh; W. Böker; M. Koch; H. Michaelis; D. Belyaev; A. Dannenberg; M. Tschimmel; P. Russo; T. Roatsch; K. D. Matz

2007-01-01

113

What's Your Angle on Angles?  

ERIC Educational Resources Information Center

Although the nature of the research varies, as do concepts of angle, research in general supports the supposition that angle is a complex idea, best understood from a variety of perspectives. In fact, the concept of angle tends to be threefold, consisting of: (1) the traditional, static notion of two rays meeting at a common vertex; (2) the idea…

Browning, Christine A.; Garza-Kling, Gina; Sundling, Elizabeth Hill

2007-01-01

114

Two-Camera Acquisition and Tracking of a Flying Target  

NASA Technical Reports Server (NTRS)

A method and apparatus have been developed to solve the problem of automated acquisition and tracking, from a location on the ground, of a luminous moving target in the sky. The method involves the use of two electronic cameras: (1) a stationary camera having a wide field of view, positioned and oriented to image the entire sky; and (2) a camera that has a much narrower field of view (a few degrees wide) and is mounted on a two-axis gimbal. The wide-field-of-view stationary camera is used to initially identify the target against the background sky. So that the approximate position of the target can be determined, pixel locations on the image-detector plane in the stationary camera are calibrated with respect to azimuth and elevation. The approximate target position is used to initially aim the gimballed narrow-field-of-view camera in the approximate direction of the target. Next, the narrow-field-of view camera locks onto the target image, and thereafter the gimbals are actuated as needed to maintain lock and thereby track the target with precision greater than that attainable by use of the stationary camera.

Biswas, Abhijit; Assad, Christopher; Kovalik, Joseph M.; Pain, Bedabrata; Wrigley, Chris J.; Twiss, Peter

2008-01-01

115

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

116

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

117

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

118

Disposition of camera parameters in vehicle navigation system  

NASA Astrophysics Data System (ADS)

To resolve the calibration of onboard camera in the vehicle navigation system based on machine vision, a respective method for disposing of intrinsic and extrinsic parameters of the camera is presented. In view of that the intrinsic parameters are basically invariable during the car's moving, they can be firstly calibrated with a planar pattern as soon as the camera is installed. The installation location of onboard camera can be real-time adjusted according to the slope and vanishing point of lane lines in the picture. Then the quantity of such extrinsic parameters as direction angle, incline angle and level translation are adjusted to zero. This respective disposing method for camera parameters is applied to lane departure detection on the structural road, with which camera calibration is simplified and the measuring error due to extrinsic parameters is decreased. The correctness and feasibility of the method is proved by theoretical calculation and practical experiment.

Yu, Houyun; Zhang, Weigong

2010-05-01

119

Making Ceramic Cameras  

ERIC Educational Resources Information Center

This article describes how to make a clay camera. This idea of creating functional cameras from clay allows students to experience ceramics, photography, and painting all in one unit. (Contains 1 resource and 3 online resources.)

Squibb, Matt

2009-01-01

120

Novel fundus camera design  

NASA Astrophysics Data System (ADS)

A fundus camera a complex optical system that makes use of the principle of reflex free indirect ophthalmoscopy to image the retina. Despite being in existence as early as 1900's, little has changed in the design of a fundus camera and there is minimal information about the design principles utilized. Parameters and specifications involved in the design of fundus camera are determined and their affect on system performance are discussed. Fundus cameras incorporating different design methods are modeled and a performance evaluation based on design parameters is used to determine the effectiveness of each design strategy. By determining the design principles involved in the fundus camera, new cameras can be designed to include specific imaging modalities such as optical coherence tomography, imaging spectroscopy and imaging polarimetry to gather additional information about properties and structure of the retina. Design principles utilized to incorporate such modalities into fundus camera systems are discussed. Design, implementation and testing of a snapshot polarimeter fundus camera are demonstrated.

Dehoog, Edward A.

121

Vacuum Camera Cooler  

NASA Technical Reports Server (NTRS)

Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

Laugen, Geoffrey A.

2011-01-01

122

Angle Measurer  

NSDL National Science Digital Library

This Flash applet gives students practice in creating an angle measuring between zero and 180 degrees. Two buttons control the increase or decrease of the opening between two rays. Points are awarded for accuracy.

2011-01-01

123

Right Angle  

NSDL National Science Digital Library

This article gives teachers background information on right angles. It provides geometric and practical examples, a paper folding construction method, and some history of the usage of the term 'right.'

Goldenberg, Paul

2011-06-09

124

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

125

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

126

Omnifocus video camera.  

PubMed

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. PMID:21529037

Iizuka, Keigo

2011-04-01

127

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

128

Folded Catadioptric Cameras  

Microsoft Academic Search

Abstract A framework is developed for the design and analysis of single - viewpoint catadioptric cameras that use two or more mirrors The use of multiple mirrors permits folding of the optics which leads to more compact camera designs than ones that use a single mirror A dictionary of camera designs that use two conic mirrors is presented We show

Shree K. Nayar; Venkata Peri

1999-01-01

129

Prediction of Viking lander camera image quality  

NASA Technical Reports Server (NTRS)

Formulations are presented that permit prediction of image quality as a function of camera performance, surface radiance properties, and lighting and viewing geometry. Predictions made for a wide range of surface radiance properties reveal that image quality depends strongly on proper camera dynamic range command and on favorable lighting and viewing geometry. Proper camera dynamic range commands depend mostly on the surface albedo that will be encountered. Favorable lighting and viewing geometries depend mostly on lander orientation with respect to the diurnal sun path over the landing site, and tend to be independent of surface albedo and illumination scattering function. Side lighting with low sun elevation angles (10 to 30 deg) is generally favorable for imaging spatial details and slopes, whereas high sun elevation angles are favorable for measuring spectral reflectances.

Huck, F. O.; Burcher, E. E.; Jobson, D. J.; Wall, S. D.

1976-01-01

130

10. CONSTRUCTION OF FIXED CAMERA STATION 1100 (BUILDING NO. 42020) ...  

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

10. CONSTRUCTION OF FIXED CAMERA STATION 1100 (BUILDING NO. 42020) LOOKING NORTHEAST SHOWING CONCRETE FOUNDATION, WOOD FORMWORK AND STEEL REINFORCING, March 26, 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Camera Stations, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

131

Project Echo: Boresight Cameras for Recording Antenna Pointing Accuracy  

NASA Technical Reports Server (NTRS)

Motion picture cameras equipped with telephoto lenses were installed on the transmitting and receiving antennas at Holmdel, New Jersey. When the Echo satellite was visible, a camera obtained a photographic record of the pointing accuracy of the antenna. These data were then used to correlate variations of signal strength with deviations in antenna pointing angle.

Warthman, K. L.

1961-01-01

132

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

133

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

134

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

135

Ultra-fast framing camera tube  

DOEpatents

An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.

Kalibjian, Ralph (1051 Batavia Ave., Livermore, CA 94550)

1981-01-01

136

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

137

Mining Technique for Narrow Orebodies.  

National Technical Information Service (NTIS)

The report is a summary of a narrow mining project in Sweden. The purpose of the project was to compile, develop and propose suitable techniques for mining of underground narrow orebodies. The first part of the report presents a summary of present mining ...

M. Olsson H. Thorshag

1987-01-01

138

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

139

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

140

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

141

UV Cameras for Volcanic Monitoring  

NASA Astrophysics Data System (ADS)

Levels of SO2 emission provide valuable information on the activity status of volcanic systems and are routinely used in hazard and risk assessment. A recent development in this field is UV camera technology, an effective and easy to use method for remote monitoring of volcanic emissions, which provides information across the full field of view and real time analysis of equipment set-up and performance. This study, carried out on Stromboli, Italy, in July 2010 sought to explore the range of data available from this technique and improve issues relating to instrument calibration, building on the findings of Kantazas et al (2010) and Kern et al (2010). A 1Hz passive and explosive degassing data set was obtained using a dual camera set-up, filters focused on 310 nm and 330 nm wavelengths, in conjunction with a fixed point USB2000 spectrometer. The cameras were initially calibrated using cells containing known values of SO2. During recording periods the adoption of a new rapid calibration protocol provided enhanced data quality whilst minimising monitoring down time. Data was analysed using an in house built Lab View VI routine (Tamburello et al 2011). The ability to take multi directional plume cross sections improved the accuracy of obliquely angled plume data, whilst enabling within program measurement of plume speed. Explosive masses were also measured with values obtained for both short duration and prolonged release events. In addition to emitted SO2, the visual aspect of data sets enabled measurement and monitoring of ascent velocities, direction of ejection, plume collimation and changes between explosive types. Furthermore, flexibility within post processing set-up permitted concurrent analysis of passive and active degassing behaviours. Time shifting of plume traces to the start times of explosive events allowing interplay between these two behaviours to be directly studied. This work demonstrates that UV cameras are versatile and a valuable contributor to the systematic study of volcanic degassing processes.

Tamburelllo, G.; Swanson, E.

2011-12-01

142

The Dawn Framing Camera  

Microsoft Academic Search

The Framing Camera (FC) is the German contribution to the Dawn mission. The camera will map 4 Vesta and 1 Ceres through a\\u000a clear filter and 7 band-pass filters covering the wavelengths from the visible to the near-IR. The camera will allow the determination\\u000a of the physical parameters of the asteroids, the reconstruction of their global shape as well as

H. Sierks; H. U. Keller; R. Jaumann; H. Michalik; T. Behnke; F. Bubenhagen; I. Büttner; U. Carsenty; U. Christensen; R. Enge; B. Fiethe; P. Gutiérrez Marqués; H. Hartwig; H. Krüger; W. Kühne; T. Maue; S. Mottola; A. Nathues; K.-U. Reiche; M. L. Richards; T. Roatsch; S. E. Schröder; I. Szemerey; M. Tschentscher

2011-01-01

143

Alternative Images for Perpendicular Parking: A Usability Study of a Multi-Camera Parking Assistance System  

Microsoft Academic Search

16. Abstract The parking assistance system evaluated consisted of four outward facing cameras whose images could be presented on a monitor on the center console. The images presented varied in the location of the virtual eye point of the camera (the height above the vehicle and forward depression angle) and the number of camera images (one or multiple) appearing together.

Sean Michael Walls; John Amann; Brian Cullinane; Paul Green; Sujata Gadgil; Rachel Rubin

144

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

145

LSST camera optics design  

NASA Astrophysics Data System (ADS)

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.

Olivier, Scot S.; Riot, Vincent J.; Gilmore, David K.; Bauman, Brian; Pratuch, Steve; Seppala, Lynn; Ku, John; Nordby, Martin; Foss, Mike; Antilogus, Pierre; Morgado, Nazario; Sassolas, Benoit; Flaminio, Raffaele; Michel, Christophe

2012-09-01

146

Improved Tracking of Targets by Cameras on a Mars Rover  

NASA Technical Reports Server (NTRS)

A paper describes a method devised to increase the robustness and accuracy of tracking of targets by means of three stereoscopic pairs of video cameras on a Mars-rover-type exploratory robotic vehicle. Two of the camera pairs are mounted on a mast that can be adjusted in pan and tilt; the third camera pair is mounted on the main vehicle body. Elements of the method include a mast calibration, a camera-pointing algorithm, and a purely geometric technique for handing off tracking between different camera pairs at critical distances as the rover approaches a target of interest. The mast calibration is an extension of camera calibration in which the camera images of calibration targets at known positions are collected at various pan and tilt angles. In the camerapointing algorithm, pan and tilt angles are computed by a closed-form, non-iterative solution of inverse kinematics of the mast combined with mathematical models of the cameras. The purely geometric camera-handoff technique involves the use of stereoscopic views of a target of interest in conjunction with the mast calibration.

Kim, Won; Ansar, Adnan; Steele, Robert

2007-01-01

147

Gamma ray camera  

Microsoft Academic Search

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

1997-01-01

148

Gamma ray camera  

Microsoft Academic Search

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

Victor

1997-01-01

149

Security camera video authentication  

Microsoft Academic Search

The ability to authenticate images captured by a security camera, and localise any tampered areas, will increase the value of these images as evidence in a court of law. This paper outlines the challenges in security camera video authentication, and discusses the reasons why fingerprinting, a robust type of digital signature, provides a solution preferable to semi-fragile watermarking. A fingerprint

D. K. Roberts

2002-01-01

150

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

151

CameraScope  

NSDL National Science Digital Library

CameraScope is an easy to use software application that supports a wide range of digital imaging devices, including the Intel QX3, Canon and Olympus digital cameras, and most commonly available webcams. It is easy to take high-quality still images, digital movies, and time-lapse movies of events too long in duration to fully comprehend.

Innovation, Center F.

152

Sweeping Image Mirror Camera.  

National Technical Information Service (NTIS)

The camera is for photographing high speed events, and is especially useful for the scientific study of nuclear phenomena. The camera housing encloses a system of two curved mirrors for reflecting light. This light emanates or is reflected from an object ...

T. Anderson

1965-01-01

153

Camera Obscura Sun Viewer  

NSDL National Science Digital Library

In this activity, make a simple "camera obscura" so you can stare at the Sun in a safe way. Discover how a very long camera obscura allows you to see something very bright but far away (like the Sun) in a safe way. This activity guide includes a step-by-step instructional video.

Center, Saint L.

2013-01-17

154

LSST Camera Overview.  

National Technical Information Service (NTIS)

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 f...

D. Burke J. Oliver K. Gilmore M. Norby P. OConnor S. Kahn

2007-01-01

155

LSST Camera Optics Design  

Microsoft Academic Search

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

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

2012-01-01

156

The Dawn Framing Camera  

NASA Astrophysics Data System (ADS)

The Framing Camera (FC) is the German contribution to the Dawn mission. The camera will map 4 Vesta and 1 Ceres through a clear filter and 7 band-pass filters covering the wavelengths from the visible to the near-IR. The camera will allow the determination of the physical parameters of the asteroids, the reconstruction of their global shape as well as local topography and surface geomorphology, and provide information on composition via surface reflectance characteristics. The camera will also serve for orbit navigation. The resolution of the Framing Camera will be up to 12 m per pixel in low altitude mapping orbit at Vesta (62 m per pixel at Ceres), at an angular resolution of 93.7 ?rad px-1. The instrument uses a reclosable front door to protect the optical system and a filter-wheel mechanism to select the band-pass for observation. The detector data is read out and processed by a data processing unit. A power converter unit supplies all required power rails for operation and thermal maintenance. For redundancy reasons, two identical cameras were provided, both located side by side on the + Z-deck of the spacecraft. Each camera has a mass of 5.5 kg.

Sierks, H.; Keller, H. U.; Jaumann, R.; Michalik, H.; Behnke, T.; Bubenhagen, F.; Büttner, I.; Carsenty, U.; Christensen, U.; Enge, R.; Fiethe, B.; Gutiérrez Marqués, P.; Hartwig, H.; Krüger, H.; Kühne, W.; Maue, T.; Mottola, S.; Nathues, A.; Reiche, K.-U.; Richards, M. L.; Roatsch, T.; Schröder, S. E.; Szemerey, I.; Tschentscher, M.

2011-12-01

157

Do Speed Cameras Reduce Collisions?  

PubMed Central

We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods – before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions.

Skubic, Jeffrey; Johnson, Steven B.; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

2013-01-01

158

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

159

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

160

Traffic Sign Recognition with Invariance to Lighting in Dual-Focal Active Camera System  

NASA Astrophysics Data System (ADS)

In this paper, we present an automatic vision-based traffic sign recognition system, which can detect and classify traffic signs at long distance under different lighting conditions. To realize this purpose, the traffic sign recognition is developed in an originally proposed dual-focal active camera system. In this system, a telephoto camera is equipped as an assistant of a wide angle camera. The telephoto camera can capture a high accuracy image for an object of interest in the view field of the wide angle camera. The image from the telephoto camera provides enough information for recognition when the accuracy of traffic sign is low from the wide angle camera. In the proposed system, the traffic sign detection and classification are processed separately for different images from the wide angle camera and telephoto camera. Besides, in order to detect traffic sign from complex background in different lighting conditions, we propose a type of color transformation which is invariant to light changing. This color transformation is conducted to highlight the pattern of traffic signs by reducing the complexity of background. Based on the color transformation, a multi-resolution detector with cascade mode is trained and used to locate traffic signs at low resolution in the image from the wide angle camera. After detection, the system actively captures a high accuracy image of each detected traffic sign by controlling the direction and exposure time of the telephoto camera based on the information from the wide angle camera. Moreover, in classification, a hierarchical classifier is constructed and used to recognize the detected traffic signs in the high accuracy image from the telephoto camera. Finally, based on the proposed system, a set of experiments in the domain of traffic sign recognition is presented. The experimental results demonstrate that the proposed system can effectively recognize traffic signs at low resolution in different lighting conditions.

Gu, Yanlei; Panahpour Tehrani, Mehrdad; Yendo, Tomohiro; Fujii, Toshiaki; Tanimoto, Masayuki

161

Angle imaging: Advances and challenges  

PubMed Central

Primary angle closure glaucoma (PACG) is a major form of glaucoma in large populous countries in East and South Asia. The high visual morbidity from PACG is related to the destructive nature of the asymptomatic form of the disease. Early detection of anatomically narrow angles is important and the subsequent prevention of visual loss from PACG depends on an accurate assessment of the anterior chamber angle (ACA). This review paper discusses the advantages and limitations of newer ACA imaging technologies, namely ultrasound biomicroscopy, Scheimpflug photography, anterior segment optical coherence tomography and EyeCam, highlighting the current clinical evidence comparing these devices with each other and with clinical dynamic indentation gonioscopy, the current reference standard.

Quek, Desmond T L; Nongpiur, Monisha E; Perera, Shamira A; Aung, Tin

2011-01-01

162

IR interferometers using modern cameras  

NASA Astrophysics Data System (ADS)

Laser interferometers have been used widely in the optics and disk drive industries. Often the surface of the sample is either too curved to resolve the fringes or too rough to reflect the incident beam back into the interferometer. Illuminating at a graze incident angle effectively increases the equivalent wavelength, and hence the reflectivity, but the image of a circular aperture becomes elliptical. Lasers with a long IR wavelength seem to be the solution. However,the spatial resolution of the vidicon cameras is usually poor, and the image lag is often too long. These limit the accuracy of an IR phase-shifting interferometer. Recently, we have designed tow types of interferometers for 3.39 micrometers and 10.6 micrometers using an InSb array and a micro- bolometer array, respectively. These modern cameras have a high resolution and hence greatly extend the range of measurable material from a blank to a finished optics. Because the refractive index of the optical material at the IR wavelength is usually very high, the anti-reflection coating of the optics at IR is more critical than that at a visible wavelength. The interferometer's design, the resolution, the dependence of the fringe contrast on the sample roughness, and the measurement results of various samples are presented.

Ai, Chiayu

1997-10-01

163

Filter wheel cameras for the NGST  

NASA Astrophysics Data System (ADS)

A near and a mid infrared imaging camera for the NGST are presented, which were studied under ESA contract. Imaging in the 1 to 5 microns domain, possibly extended to 0.6 microns is a strong requirement for the core programs identified for NGST. Our compact near-IR camera design emphasizes simplicity with a single optical train covering a field 6 X 3 arcmin2 with a fixed spatial sampling of 0.03 arcsec/pixel on a 12 k X 6 k detector array. Three filter wheels allow for broad band and narrow band imaging. A mid- IR camera on NGST will be capable of carrying out aspects of many programs in the DRM. In addition to mid-IR is relatively unexplored at the spatial resolution and sensitivity NGST will be capable of, and so there is great potential for serendipitous science. A compact mid-IR camera design is presented covering a field 2.5 X 2.5 arcmin2 in the spectral range from 5 - 28 micrometers with two optical channels and a critical spatial sampling of 0.075 arcsec at 5 micrometers and 0.15 arcsec at 10 micrometers wavelengths.

Posselt, Winfried; Le Fevre, Oliver; Wright, Gillian S.; Lagage, Pierre-Olivier; Cornelisse, Koos W.; Jakobsen, Peter

2000-07-01

164

Copernican craters: Early results from the Lunar Reconnaissance Orbiter Camera  

NASA Astrophysics Data System (ADS)

The youngest (Copernican) craters on the Moon provide the best examples of original crater morphology and a record of the impact flux over the last ~1 Ga in the Earth-Moon system. The LRO Narrow Angle Cameras (NAC) provide 50 cm pixels from an altitude of 50 km. With changing incidence angle, global access, and very high data rates, these cameras provide unprecedented data on lunar craters. Stereo image pairs are being acquired for detailed topographic mapping. These data allow comparisons of relative ages of the larger young craters, some of which are tied to absolute radiometric ages from Apollo-returned samples. These relative ages, the crater populations at small diameters, and details of crater morphology including ejecta and melt morphologies, allow better delineation of recent lunar history and the formation and modification of impact craters. Crater counts may also reveal differences in the formation and preservation of small diameter craters as a function of target material (e.g., unconsolidated regolith versus solid impact melt). One key question: Is the current cratering rate constant or does it fluctuate. We will constrain the very recent cratering rate (at 10-100 m diameter) by comparing LROC images with those taken by Apollo nearly 40 years ago to determine the number of new impact craters. The current cratering rate and an assumption of constant cratering rate over time may or may not correctly predict the number of craters superimposed over radiometrically-dated surfaces such as South Ray, Cone, and North Ray craters, which range from 2-50 Ma and are not saturated by 10-100 m craters. If the prediction fails with realistic consideration of errors, then the present-day cratering rate must be atypical. Secondary craters complicate this analysis, but the resolution and coverage of LROC enables improved recognition of secondary craters. Of particular interest for the youngest Copernican craters is the possibility of self-cratering. LROC is providing the the image quality needed to classify small craters by state of degradation (i.e., relative age); concentrations of craters with uniform size and age indicate secondary formation. Portion of LROC image M103703826LE showing a sparsely-cratered pond of impact melt on the floor of farside Copernican crater Necho (4.95 S, 123.6 E).

McEwen, A. S.; Hiesinger, H.; Thomas, P. C.; Robinson, M. S.; van der Bogert, C.; Ostrach, L.; Plescia, J. B.; Bray, V. J.; Tornabene, L. L.

2009-12-01

165

Pinhole Camera Model  

NSDL National Science Digital Library

The Pinhole Camera Model demonstrates the operation of a pinhole camera. Light rays leaving the top and bottom on an object of height h pass through a pinhole and strike a flat screen. These rays travel in straight lines accord with the principles of geometric optics. Drag the object and observe the image on the camera screen. Simple geometry shows that the image is inverted and that the ratio of the image to object size (the magnification) is the same as the ratio of the image to object distance. The Pinhole Camera Model was developed using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the jar file will run the program if Java is installed. You can modify this simulation if you have EJS installed by right-clicking within the map and selecting "Open Ejs Model" from the pop-up menu item.

Christian, Wolfgang

2012-04-20

166

Thermal Camera Pictures  

NSDL National Science Digital Library

This page includes pictures taken with an infrared camera. Though the pictures include very little explanation, they do demonstrate some properties of light, including reflection, as well as conduction of heat.

Falstad, Paul

2004-11-28

167

Cameras in the Classroom.  

ERIC Educational Resources Information Center

Describes the following uses for a video camera in the science classroom: video presentations, microscope work, taping and/or monitoring experiments, analyzing everyday phenomena, lesson enhancement, field trip alternative, and classroom management. (PR)

Steinman, Richard C.

1993-01-01

168

LSST camera control system  

NASA Astrophysics Data System (ADS)

The LSST Camera Control System (CCS) will manage the activities of the various camera subsystems and coordinate those activities with the LSST Observatory Control System (OCS). The CCS comprises a set of modules (nominally implemented in software) which are each responsible for managing one camera subsystem. Generally, a control module will be a long lived "server" process running on an embedded computer in the subsystem. Multiple control modules may run on a single computer or a module may be implemented in "firmware" on a subsystem. In any case control modules must exchange messages and status data with a master control module (MCM). The main features of this approach are: (1) control is distributed to the local subsystem level; (2) the systems follow a "Master/Slave" strategy; (3) coordination will be achieved by the exchange of messages through the interfaces between the CCS and its subsystems. The interface between the camera data acquisition system and its downstream clients is also presented.

Marshall, Stuart; Thaler, Jon; Schalk, Terry; Huffer, Michael

2006-07-01

169

Cardboard Box Camera Obscura  

NSDL National Science Digital Library

In this activity, learners construct a device that projects images onto a surface, so they can trace landscapes and other sights. The cardboard box camera captures the images using a mirror, holder, and lens, which work together like a simple camera. Use this activity to introduce learners to concepts related to optics, light, lenses, and mirrors. Note: this activity requires the use of a drill and saw, not included in the cost of materials.

Centers, Oakland D.

2012-01-01

170

Multi-camera systems  

Microsoft Academic Search

In this article, we present some simple and effective techniques for accurately calibrating a multi-camera acquisition system. The proposed methods were proven to be capable of accurate results even when using very simple calibration target sets and low-cost imaging devices, such as standard TV-resolution cameras connected to commercial frame-grabbers. In fact, the performance of our calibration approach yielded results that

F. Pedersini; A. Sarti; S. Tubaro

1999-01-01

171

Spacecraft camera image registration  

NASA Technical Reports Server (NTRS)

A system for achieving spacecraft camera (1, 2) image registration comprises a portion external to the spacecraft and an image motion compensation system (IMCS) portion onboard the spacecraft. Within the IMCS, a computer (38) calculates an image registration compensation signal (60) which is sent to the scan control loops (84, 88, 94, 98) of the onboard cameras (1, 2). At the location external to the spacecraft, the long-term orbital and attitude perturbations on the spacecraft are modeled. Coefficients (K, A) from this model are periodically sent to the onboard computer (38) by means of a command unit (39). The coefficients (K, A) take into account observations of stars and landmarks made by the spacecraft cameras (1, 2) themselves. The computer (38) takes as inputs the updated coefficients (K, A) plus synchronization information indicating the mirror position (AZ, EL) of each of the spacecraft cameras (1, 2), operating mode, and starting and stopping status of the scan lines generated by these cameras (1, 2), and generates in response thereto the image registration compensation signal (60). The sources of periodic thermal errors on the spacecraft are discussed. The system is checked by calculating measurement residuals, the difference between the landmark and star locations predicted at the external location and the landmark and star locations as measured by the spacecraft cameras (1, 2).

Kamel, Ahmed A. (Inventor); Graul, Donald W. (Inventor); Chan, Fred N. T. (Inventor); Gamble, Donald W. (Inventor)

1987-01-01

172

Calibration Procedures in Mid Format Camera Setups  

NASA Astrophysics Data System (ADS)

A growing number of mid-format cameras are used for aerial surveying projects. To achieve a reliable and geometrically precise result also in the photogrammetric workflow, awareness on the sensitive parts is important. The use of direct referencing systems (GPS/IMU), the mounting on a stabilizing camera platform and the specific values of the mid format camera make a professional setup with various calibration and misalignment operations necessary. An important part is to have a proper camera calibration. Using aerial images over a well designed test field with 3D structures and/or different flight altitudes enable the determination of calibration values in Bingo software. It will be demonstrated how such a calibration can be performed. The direct referencing device must be mounted in a solid and reliable way to the camera. Beside the mechanical work especially in mounting the camera beside the IMU, 2 lever arms have to be measured in mm accuracy. Important are the lever arms from the GPS Antenna to the IMU's calibrated centre and also the lever arm from the IMU centre to the Camera projection centre. In fact, the measurement with a total station is not a difficult task but the definition of the right centres and the need for using rotation matrices can cause serious accuracy problems. The benefit of small and medium format cameras is that also smaller aircrafts can be used. Like that, a gyro bases stabilized platform is recommended. This causes, that the IMU must be mounted beside the camera on the stabilizer. The advantage is, that the IMU can be used to control the platform, the problematic thing is, that the IMU to GPS antenna lever arm is floating. In fact we have to deal with an additional data stream, the values of the movement of the stabiliser to correct the floating lever arm distances. If the post-processing of the GPS-IMU data by taking the floating levers into account, delivers an expected result, the lever arms between IMU and camera can be applied. However, there is a misalignment (bore side angle) that must be evaluated by photogrammetric process using advanced tools e.g. in Bingo. Once, all these parameters have been determined, the system is capable for projects without or with only a few ground control points. But which effect has the photogrammetric process when directly applying the achieved direct orientation values compared with an AT based on a proper tiepoint matching? The paper aims to show the steps to be done by potential users and gives a kind of quality estimation about the importance and quality influence of the various calibration and adjustment steps.

Pivnicka, F.; Kemper, G.; Geissler, S.

2012-07-01

173

Seasonal and vertical changes in leaf angle distribution for selected deciduous broadleaf tree species common to Europe  

NASA Astrophysics Data System (ADS)

Leaf inclination angle distribution is a key parameter in determining the transmission and reflection of radiation by vegetation canopies. It has been previously observed that leaf inclination angle might change gradually from more vertical in the upper canopy and in high light habitats to more horizontal in the lower canopy and in low light habitats [1]. Despite its importance, relatively few measurements on actual leaf angle distributions have been reported for different tree species. Even smaller number of studies have dealt with the possible seasonal changes in leaf angle distribution [2]. In this study the variation of leaf inclination angle distributions was examined both temporally throughout the growing season and vertically at different heights of trees. We report on leaf inclination angle distributions for five deciduous broadleaf species found commonly in several parts of Europe: grey alder (Alnus incana), Silver birch (Betula pendula Roth), chestnut (Castanea), Norway maple (Acer platanoides), and aspen (Populus tremula). The angles were measured using the leveled camera method [3], with the data collected at several separate heights and four times during the period of May-September 2013. The results generally indicate the greatest change in leaf inclination angles for spring, with the changes usually being the most pronounced at the top of the canopy. It should also be noted, however, that whereas the temporal variation proved to be rather consistent for different species, the vertical variation differed more between species. The leveled camera method was additionally tested in terms of sensitivity to different users. Ten people were asked to measure the leaf angles for four different species. The results indicate the method is quite robust in providing coinciding distributions irrespective of the user and level of previous experience with the method. However, certain caution must be exercised when measuring long narrow leaves. References [1] G.G. McMillen, and J.H. McClendon, "Leaf angle: an adaptive feature of sun and shade leaves," Botanical Gazette, vol. 140, pp. 437-442, 1979. [2] J. Pisek, O. Sonnentag, A.D. Richardson, and M. Mõttus, "Is the spherical leaf inclination angle distribution a valid assumption for temperate and boreal broadleaf tree species?" Agricultural and Forest Meteorology, vol. 169, pp. 186-194, 2013. [3] Y. Ryu, O. Sonnentag, T. Nilson, R. Vargas, H. Kobayashi, R. Wenk, and D. Baldocchi, "How to quantify tree leaf area index in a heterogenous savanna ecosystem: a multi-instrument and multimodel approach," Agricultural and Forest Meteorology, vol. 150, pp. 63-76, 2010.

Raabe, Kairi; Pisek, Jan; Sonnentag, Oliver; Annuk, Kalju

2014-05-01

174

Auto-converging stereo cameras for 3D robotic tele-operation  

NASA Astrophysics Data System (ADS)

Polaris Sensor Technologies has developed a Stereovision Upgrade Kit for TALON robot to provide enhanced depth perception to the operator. This kit previously required the TALON Operator Control Unit to be equipped with the optional touchscreen interface to allow for operator control of the camera convergence angle adjustment. This adjustment allowed for optimal camera convergence independent of the distance from the camera to the object being viewed. Polaris has recently improved the performance of the stereo camera by implementing an Automatic Convergence algorithm in a field programmable gate array in the camera assembly. This algorithm uses scene content to automatically adjust the camera convergence angle, freeing the operator to focus on the task rather than adjustment of the vision system. The autoconvergence capability has been demonstrated on both visible zoom cameras and longwave infrared microbolometer stereo pairs.

Edmondson, Richard; Aycock, Todd; Chenault, David

2012-05-01

175

Spectral narrowing via quantum coherence  

SciTech Connect

We have studied the transmission through an optically thick {sup 87}Rb vapor that is illuminated by monochromatic and noise-broadened laser fields in {lambda} configuration. The spectral width of the beat signal between the two fields after transmission through the atomic medium is more than 1000 times narrower than the spectral width of this signal before the medium.

Mikhailov, Eugeniy E.; Rostovtsev, Yuri V.; Zhang Aihua; Welch, George R. [Department of Physics and Institute of Quantum Studies, Texas A and M University, College Station, Texas 77843-4242 (United States); Sautenkov, Vladimir A. [Department of Physics and Institute of Quantum Studies, Texas A and M University, College Station, Texas 77843-4242 (United States); P. N. Lebedev Institute of Physics, 119991 Moscow (Russian Federation); Zubairy, M. Suhail [Department of Physics and Institute of Quantum Studies, Texas A and M University, College Station, Texas 77843-4242 (United States); Department of Electronics, Quaid-i-Azam University, Islamabad (Pakistan); Scully, Marlan O. [Department of Physics and Institute of Quantum Studies, Texas A and M University, College Station, Texas 77843-4242 (United States); Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States)

2006-07-15

176

Narrow-band reflecting filters  

Microsoft Academic Search

A narrowing of the band of maximum reflection as compared with the band of a classical quarter-wave multilayer system can be obtained in two ways. One of these is to reduce the difference in refractive index An = nH-n L between the alternate layers [1]. In this case, in order to preserve the large values of reflection coefficients at the

I. N. Shklyarevskii; R. I. Umerov; E. A. Lupashko; I. I. Kalimanova

1970-01-01

177

Image dissector camera system study  

NASA Technical Reports Server (NTRS)

Various aspects of a rendezvous and docking system using an image dissector detector as compared to a GaAs detector were discussed. Investigation into a gimbled scanning system is also covered and the measured video response curves from the image dissector camera are presented. Rendezvous will occur at ranges greater than 100 meters. The maximum range considered was 1000 meters. During docking, the range, range-rate, angle, and angle-rate to each reflector on the satellite must be measured. Docking range will be from 3 to 100 meters. The system consists of a CW laser diode transmitter and an image dissector receiver. The transmitter beam is amplitude modulated with three sine wave tones for ranging. The beam is coaxially combined with the receiver beam. Mechanical deflection of the transmitter beam, + or - 10 degrees in both X and Y, can be accomplished before or after it is combined with the receiver beam. The receiver will have a field-of-view (FOV) of 20 degrees and an instantaneous field-of-view (IFOV) of two milliradians (mrad) and will be electronically scanned in the image dissector. The increase in performance obtained from the GaAs photocathode is not needed to meet the present performance requirements.

Howell, L.

1984-01-01

178

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

179

1-5-um infrared camera of the IAC  

NASA Astrophysics Data System (ADS)

The Instituto de Astrofisica de Canarias (IAC) is undertaking the construction of an IR camera for astronomical use at the 1.5 meter (f/13,8) Carlos Sanchez IR Telescope (CST), sited at the Observatorio del Teide (Tenerife). The camera will employ a 256 X 256 InSb focal plane array, and will be used in the 1 - 5 micron atmospheric windows. The Camera uses an optical reimaging system which maps 0.5 square arcseconds of sky per pixel. The optical system will be diamond turned in aluminum and mounted in such a way that the optical alignment is facilitated. Two filter wheels will accommodate 14 broad and narrow band filters. A SUN SPARCstation will control the camera and allow data handling and displaying of the images. With this configuration we expect to achieve sensitivities of 17 and 12.5 magnitude (3 (sigma) in 10 sec) at the K and L band respectively.

Gonzalez, Juan C.; Acosta, J. D.; Diaz, Jose J.; Fuentes, F. Javier; Fuensalida, Jesus J.; Hammersley, Peter; Joven-Alvarez, Enrique; Mampaso, A.; Manescau, Antonio; Martin, Carlos; Paez, E.; Espinosa, Jose M.; Rodriguez-Mora, A.; Rodriguez-Ramos, Luis F.; Sanchez, Vicente; Selby, M.; Sosa, Nicolas A.

1993-10-01

180

Binocular Camera for cockpit visibility of general aviation aircraft  

NASA Astrophysics Data System (ADS)

A history of cockpit visibility studies and requirements with regard to aircraft safety, human factors, collision avoidance, and accident investigations is presented. The Federal Aviation Administration's development of the Binocular Camera is reviewed, and the technical details of a new and improved camera are discussed. The Binocular Camera uses two 65 mm wide angle F6.8 lenses and covers an 88 1/2 deg field of vision. The camera produces images, representative of what the human eyes see before the brain integrates them into one, thus making it possible to analyze the effect of obstruction to vision. The improvements, applications, and uses of the camera in the research, development, and operations of general aviation aircraft are discussed.

Barile, A. J.

1981-04-01

181

All-sky camera with a concave mirror.  

PubMed

The characteristics of an all-sky camera with a concave mirror are analyzed. A differential equation for a concave aspheric mirror with constant angular magnification is derived for the general dependence of the camera image height on the camera field angle. This equation is solved in parametric form for the case of a concave mirror with a constant angular magnification. The explicit equations for the shape of the aspheric mirror are given for some particular values of the angular magnification. Parametric equations of the surface shape for sevenfold angular magnification are developed into a power series that is used to analyze the imaging performance of such a mirror. The performance of the concave aspheric mirror is compared with that of a spherical mirror. The minimal camera-to-mirror distance is determined as a function of the blur allowed and the camera lens aperture. Some characteristics of convex mirrors are also presented for comparison. PMID:21068991

Andrei?, Z; Radi?, N

1996-01-01

182

3-D Flow Visualization with a Light-field Camera  

NASA Astrophysics Data System (ADS)

Light-field cameras have received attention recently due to their ability to acquire photographs that can be computationally refocused after they have been acquired. In this work, we describe the development of a light-field camera system for 3D visualization of turbulent flows. The camera developed in our lab, also known as a plenoptic camera, uses an array of microlenses mounted next to an image sensor to resolve both the position and angle of light rays incident upon the camera. For flow visualization, the flow field is seeded with small particles that follow the fluid's motion and are imaged using the camera and a pulsed light source. The tomographic MART algorithm is then applied to the light-field data in order to reconstruct a 3D volume of the instantaneous particle field. 3D, 3C velocity vectors are then determined from a pair of 3D particle fields using conventional cross-correlation algorithms. As an illustration of the concept, 3D/3C velocity measurements of a turbulent boundary layer produced on the wall of a conventional wind tunnel are presented. Future experiments are planned to use the camera to study the influence of wall permeability on the 3-D structure of the turbulent boundary layer.Schematic illustrating the concept of a plenoptic camera where each pixel represents both the position and angle of light rays entering the camera. This information can be used to computationally refocus an image after it has been acquired. Instantaneous 3D velocity field of a turbulent boundary layer determined using light-field data captured by a plenoptic camera.

Thurow, B.

2012-12-01

183

What convention is used for the illumination and view angles?  

... Azimuth angles are measured clockwise from the direction of travel to local north. For both the Sun and cameras, azimuth describes the ... to the equator, because of its morning equator crossing time. Additionally, the difference in view and solar azimuth angle will be near ...

2012-07-20

184

Merlin microbolometer camera calibration  

NASA Astrophysics Data System (ADS)

The Low Cost Gun Launched Seeker is a component of the Navy's effort to develop effective weapons for surface fire support missions by enhancing the performance of projectiles like the Extended Range Guided Munitions with low-cost, uncooled infrared (IR) staring focal plane array terminal seekers. IR target images for validating target detection algorithms were collected using a Merlin long wave camera from Indigo Systems. This paper characterizes the camera in order to develop performance parameters for simulating the seeker and to understand features in the imagery. These parameters include temperature response, temporal noise characteristics, fixed pattern noise, and the modulation transfer function.

Green, William J.; Maurer, Donald E.

2001-09-01

185

GROT in NICMOS Cameras  

NASA Astrophysics Data System (ADS)

Grot is exhibited as small areas of reduced sensitivity, most likely due to flecks of antireflective paint scraped off the optical baffles as they were forced against each other. This paper characterizes grot associated with all three cameras. Flat field images taken from March 1997 through January 1999 have been investigated for changes in the grot, including possible wavelength dependency and throughput characteristics. The main products of this analysis are grot masks for each of the cameras which may also contain any new cold or dead pixels not specified in the data quality arrays.

Sosey, M.; Bergeron, E.

1999-09-01

186

Multiframing image converter camera  

NASA Astrophysics Data System (ADS)

In this paper we describe a multiframe camera based on PV-OOl image tube. This tube is very convenient for obtaining short frame exposures due to availability of high-frequency shutter system with the image shift compensation facility, as well as with one pair of high-frequency deflection system. The developed camera provides 164 million frames/s recording speed with minimum time exposure of about 3ns. The frame number is controled between 6 and 16. Dynamic spatial resolution is not less than 5 line pair/ mm.

Frontov, H. N.; Serdyuchenko, Yury N.

1991-04-01

187

MODELING DISTORTION OF SUPER-WIDE-ANGLE LENSES FOR ARCHITECTURAL AND ARCHAEOLOGICAL APPLICATIONS  

Microsoft Academic Search

Mapping of architectural and archaeological objects often encounters limitations in imaging distances (interiors, narrow streets, excavations), usually tackled via large numbers of images or special camera platforms This, however, seriously contradicts the benefits of simple, low-cost photogrammetric procedures. In these cases, furthermore, the use of digital cameras with the currently limited area of sensitive sensors may also be impracticable. In

G. E. Karras; G. Mountrakis; P. Patias; E. Petsa

1998-01-01

188

Spas color camera  

NASA Technical Reports Server (NTRS)

The procedures to be followed in assessing the performance of the MOS color camera are defined. Aspects considered include: horizontal and vertical resolution; value of the video signal; gray scale rendition; environmental (vibration and temperature) tests; signal to noise ratios; and white balance correction.

Toffales, C.

1983-01-01

189

Secure Digital Camera  

Microsoft Academic Search

In this paper, we propose a biometric solution to solve some of the significant problems associated with use of digital camera images as evidence in a court of law. We present a lossless watermarking solution to the problems associated with digital image integrity and the relationship to its chain of custody. The integrity of digital images as evidence rests on

Paul Blythe; Jessica Fridrich

190

Stardust Imaging Camera  

NASA Astrophysics Data System (ADS)

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 as some inherited designs to provide an excellent, low-cost imaging system with a 1024 × 1024 pixel CCD detector and an f/3.5 lens with a 202 mm focal length. These yield a 3.5° × 3.5° field of view and, potentially, 12 arc second resolution. Spacecraft roll combined with a movable mirror permits safe autonomous body tracking. This capability was proven on Annefrank and will be used to acquire the desired data on P/Wild 2, with the spacecraft protected by a dust shield (a Whipple bumper) during that flyby. Details of the instrumental design and problems associated with its use make up the bulk of the paper.

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

2003-10-01

191

LSST Camera Optics.  

National Technical Information Service (NTIS)

The Large Synoptic Survey Telescope (LSST) is a unique, three-mirror, modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary feeding a camera system that includes corrector optics to produce a 3.5 degree field of view with ...

S. S. Olivier L. Seppala K. Gilmore L. Hale W. Whistler

2006-01-01

192

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

193

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 ordinary…

Fisher, Diane K.; Novati, Alexander

2009-01-01

194

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

195

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

196

Image Sensors Enhance Camera Technologies  

NASA Technical Reports Server (NTRS)

In the 1990s, a Jet Propulsion Laboratory team led by Eric Fossum researched ways of improving complementary metal-oxide semiconductor (CMOS) image sensors in order to miniaturize cameras on spacecraft while maintaining scientific image quality. Fossum s team founded a company to commercialize the resulting CMOS active pixel sensor. Now called the Aptina Imaging Corporation, based in San Jose, California, the company has shipped over 1 billion sensors for use in applications such as digital cameras, camera phones, Web cameras, and automotive cameras. Today, one of every three cell phone cameras on the planet feature Aptina s sensor technology.

2010-01-01

197

Do speed cameras reduce collisions?  

PubMed

We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods - before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions. PMID:24406979

Skubic, Jeffrey; Johnson, Steven B; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

2013-01-01

198

Camera motion and mobile imaging  

NASA Astrophysics Data System (ADS)

Due to the demanding size and cost constraints of camera phones, the mobile imaging industry needs to address several key challenges in order to achieve the quality of a digital still camera. Minimizing camera-motion introduced image blur is one of them. Film photographers have long used a rule-of-thumb that a hand held 35mm format film camera should have an exposure in seconds that is not longer than the inverse of the focal length in millimeters. Due to the lack of scientific studies on camera-motion, it is still an open question how to generalize this rule-of-thumb to digital still cameras as well as camera phones. In this paper, we first propose a generalized rule-of-thumb with the original rule-of-thumb as a special case when camera-motion can be approximated by a linear motion at 1.667 °/sec. We then use a gyroscope-based system to measure camera-motion patterns for two camera phones (one held with one hand and the other held in two hands) and one digital still camera. The results show that effective camera-motion function can be approximated very well by a linear function for exposure durations less than 100ms. While the effective camera-motion speed for camera phones (5.95 °/sec and 4.39 °/sec respectively) is significantly higher than that of digital still cameras (2.18 °/sec), it was found that holding a camera phone with two hands while taking pictures does reduce the amount of camera motion. It was also found that camera-motion not only varies significantly across subjects but also across captures for the same subject. Since camera phones have significantly higher motion and longer exposure durations than 35mm format film cameras and most digital still cameras, it is expected that many of the pictures taken by camera phones today will not meet the sharpness criteria used in 35mm film print. The mobile imaging industry is aggressively pursuing a smaller and smaller pixel size in order to meet the digital still camera's performance in terms of total pixels while retaining the small size needed for the mobile industry. This makes it increasingly more important to address the camera-motion challenge associated with smaller pixel size.

Xiao, Feng; Pincenti, John; John, George; Johnson, Kevin

2007-03-01

199

The Martian Atmosphere as seen by the OSIRIS camera  

NASA Astrophysics Data System (ADS)

Despite the long time that has passed since the observations, only few studies based on the data from the wide- (WAC) and narrow- (NAC) angle camera systems of OSIRIS have been published to date. In this Paper we will present the results on the observations of the Martian Limbs acquired by the OSIRIS [1] instrument on board the ESA mission Rosetta during its swing-by maneuver around February 25th, 2007 on the way to Comet 67P/Churyumov-Gerasimenko, during the onset of the very active dust storm season of Mars year 28 (at Ls ~190). Although OSIRIS did only capture the Planet during a relatively short time interval of several hours, the obtained global view and the spectral coverage, from the UV (245 nm) over the full visible range to the near IR (1000 nm), allow for a valuable global overview over the state of the Martian atmosphere. The image acquisition started a February 24 around 18:00 UTC from a distance of about 260.000 km and continued until 04:51 UTC on February 25 to a distance of 105.000 km. During the Closest Approach to the Planet at 01:54 UTC o February 25 at a distance of 250 km. All images have been manually co-registered with the help of SPICE data, and vertical profiles have been extracted over the limb in intervals of ~0.5 degrees (se Figures 1 and 2). Despite the long time that has passed since the observations, only few studies based on the data from the wide- (WAC) and narrow- (NAC) angle camera systems of OSIRIS have been published to date. In this Paper we will present the results on the observations of the Martian Limbs acquired by the OSIRIS [1] instrument on board the ESA mission Rosetta during its swing-by maneuver around February 25th, 2007 on the way to Comet 67P/Churyumov-Gerasimenko, during the onset of the very active dust storm season of Mars year 28 (at Ls ~190). Although OSIRIS did only capture the Planet during a relatively short time interval of several hours, the obtained global view and the spectral coverage, from the UV (245 nm) over the full visible range to the near IR (1000 nm), allow for a valuable global overview over the state of the Martian atmosphere. The image acquisition started at February 24 around 18:00 UTC from a distance of about 260.000 km and continued until 04:51 UTC on February 25 to a distance of 105.000 km. During the Closest Approach to the Planet at 01:54 UTC on February 25 at a distance of 250 km. All images have been manually co-registered with the help of SPICE data, and vertical profiles have been extracted over the limb in intervals of ~0.5 degrees (see Figures 1 and 2). In this work we will focus on our findings about the vertical structure of the atmosphere over the Martian limbs and report on the observed altitudes and optical densities of dust and (partially detached) clouds and put the findings in context with data from other satellites in orbit around Mars at the same time (e.g. Mars Express). Based on previous datasets (MGS/TES, MOd/THEMIS, MRO/MCS, see, e.g., [2], [3] and [4]) we can expect to observe the waning of the South polar hood and the development of the Northern one. Some remains of the aphelion cloud belt might still be visible near the equator. Detached layers have been recently observed at this season by MEx/SPICAM [5] and MRO/MCS [6].

Moissl, R.; Pajola, M.; Määttänen, A.; Küppers, M.

2013-09-01

200

The underwater camera calibration based on virtual camera lens distortion  

Microsoft Academic Search

The machine view is becoming more and more popular in underwater. It is a challenge to calibrate the camera underwater because of the complicated light ray path in underwater and air environment. In this paper we firstly analyzed characteristic of the camera when light transported from air to water. Then we proposed a new method that takes the high-level camera

Dahui Qin; Ting Mao; Peng Cheng; Zhiliang Zhang

2011-01-01

201

15. ELEVATED CAMERA STAND, SHOWING LINE OF CAMERA STANDS PARALLEL ...  

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

15. ELEVATED CAMERA STAND, SHOWING LINE OF CAMERA STANDS PARALLEL TO SLED TRACK. Looking west southwest down Camera Road. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

202

Computer-controlled stereoscopic camera base used to assess visual depth judgment under orthostereoscopic and nonorthostereoscopic conditions  

NASA Astrophysics Data System (ADS)

A computer controlled stereoscopic camera system that produces precise and rapid changes of camera orientation and lens parameters is described and assessed. The system consists of a pair of cameras, each attached to a lens with a computer controlled zoom, focus and aperture. Cameras, at right angle to each other, are aimed through a half-silvered mirror to acquire the left and right images. Each camera is mounted on a motorized base that controls the camera separation and convergence angle. The computer controls camera separation from zero to 45 cm, with an accuracy of 0.1 cm, and the convergence angle of each camera from +/- 15 degrees off- center, with an accuracy of 0.02 degrees. Subjects viewed 27 conditions on a stereo monitor system where camera and target parameters were changed. There were three levels of convergence angle, camera separation and target intensity creating 27 viewing conditions. The subjects viewed all conditions and made depth judgments between four pairs of point source lights. Depth judgement results indicate that direct and remote views are consistent, subjects produce consistent judgments despite non-orthoscopic intervening camera configurations and judgments are consistent with varying system parameters.

Ikehara, Curtis S.

2001-06-01

203

Streak camera receiver definition study  

NASA Technical Reports Server (NTRS)

Detailed streak camera definition studies were made as a first step toward full flight qualification of a dual channel picosecond resolution streak camera receiver for the Geoscience Laser Altimeter and Ranging System (GLRS). The streak camera receiver requirements are discussed as they pertain specifically to the GLRS system, and estimates of the characteristics of the streak camera are given, based upon existing and near-term technological capabilities. Important problem areas are highlighted, and possible corresponding solutions are discussed.

Johnson, C. B.; Hunkler, L. T., Sr.; Letzring, S. A.; Jaanimagi, P.

1990-01-01

204

Automated Camera Array Fine Calibration  

NASA Technical Reports Server (NTRS)

Using aerial imagery, the JPL FineCalibration (JPL FineCal) software automatically tunes a set of existing CAHVOR camera models for an array of cameras. The software finds matching features in the overlap region between images from adjacent cameras, and uses these features to refine the camera models. It is not necessary to take special imagery of a known target and no surveying is required. JPL FineCal was developed for use with an aerial, persistent surveillance platform.

Clouse, Daniel; Padgett, Curtis; Ansar, Adnan; Cheng, Yang

2008-01-01

205

Design of mct1024×1 short wave infrared thermal camera  

Microsoft Academic Search

A thermal camera consists of 1024-element MCT line wavelength IRFPA with reading electrocircuit made in china. It is presented the composing of this infrared thermal camera and some key question of this thermal camera: 1) nonuniformity correction; 2) Correction of lines and rows. With same axial transmission optics and a 1-D equality angle scanner and 1024X1600 pixels per frame.the scan

Xian Zhong Jian; Su Ying Zhang

2005-01-01

206

The Joys of Digital Cameras.  

ERIC Educational Resources Information Center

Discusses the educational uses of digital cameras and describes a fourth grade project that created a computerized yearbook. Lists available digital cameras, including prices; describes benefits, including speed; and explains negative aspects, including cost of the cameras and computer hardware and software requirements. (LRW)

Lester, Shelley; Mulroney, Erin

1998-01-01

207

Smart Cameras as Embedded Systems  

Microsoft Academic Search

Recent technological advances are enabling a new generation of smart cameras that represent a quantum leap in sophistication. While today's digital cameras capture images, smart cameras capture high-level descriptions of the scene and analyze what they see. These devices could support a wide variety of applications including human and animal detection, surveillance, motion analysis, and facial identification. Video processing has

Wayne Wolf; Burak Ozer; Lv Tiehan

2002-01-01

208

Automatic locking radioisotope camera lock  

Microsoft Academic Search

A radioisotope camera lock for locking the source isotope in a safe, shielded position in the camera when not in use is described. The lock prevents the source isotope from being moved to an operative position outside of the camera, unless intentionally released by a key and reverse movement of source pigtail. A hollow lock casing is secured to and

Rosauer

1976-01-01

209

Camera Calibration Using Neural Networks  

Microsoft Academic Search

This work presents a procedure for camera calibration using artificial neural networks of the type back propagation perceptron. Camera calibration is employed in computer vision for pose determination and it requires a solution of non-linear system of equations. By employing neural network, it becomes unnecessary to know the parameters of the cameras, such as focus, distortions besides the geometry of

Márcio Mendonça; Ivan N. Da Silva; José E. C. Castanho

2002-01-01

210

Differential Methods for Nonmetric Calibration of Camera Lens Distortion  

Microsoft Academic Search

This paper addresses the problem of calibrating camera lens distortion, which can be significant in medium to wide angle lenses. Our approach is based on the analysis of distorted images of straight lines. We derive new distortion measures that can be optimized using non-linear search techniques to find the best distortion parameters that straighten these lines. Unlike other approaches, we

Moumen T. Ahmed; Aly A. Farag

2001-01-01

211

Non-metric calibration of camera lens distortion  

Microsoft Academic Search

This paper addresses the problem of calibrating camera lens distortion, which can be significant in medium to wide angle lenses. Our approach is based on the analysis of distorted images of straight lines. We derive a new distortion measure that can be optimized using nonlinear search techniques to find the best distortion parameters that straighten these lines. Unlike the other

M. Ahmed; A. Farag

2001-01-01

212

Visual Tunnel Analysis for Visibility Prediction and Camera Planning  

Microsoft Academic Search

A sequence of images taken along a camera trajec- tory captures a subset of scene appearance. If visibility space is the space that encapsulates the appearance of the scene at every conceivable pose and viewing angle, then the act of acquiring the image sequence consti- tutes \\

Sing Bing Kang; Peter-pike J. Sloan; Steven M. Seitz

2000-01-01

213

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) [Rolling Hills, CA

1984-02-21

214

The Dark Energy Camera  

NASA Astrophysics Data System (ADS)

The DES Collaboration has completed construction of the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera which is now mounted at the prime focus of the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory. DECam is comprised of 74 250 micron thick fully depleted CCDs: 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. A filter set of u,g,r,i,z, and Y, a hexapod for focus and lateral alignment as well as thermal management of the cage temperature. DECam will be used to perform the Dark Energy Survey with 30% of the telescope time over a 5 year period. During the remainder of the time, and after the survey, DECam will be available as a community instrument. An overview of the DECam design, construction and initial on-sky performance information will be presented.

Flaugher, Brenna; DES Collaboration

2013-01-01

215

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

216

LSST Camera Optics  

SciTech Connect

The Large Synoptic Survey Telescope (LSST) is a unique, three-mirror, modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary feeding a camera system that includes corrector optics to produce a 3.5 degree field of view with excellent image quality (<0.3 arcsecond 80% encircled diffracted energy) over the entire field from blue to near infra-red wavelengths. We describe the design of the LSST camera optics, consisting of three refractive lenses with diameters of 1.6m, 1.0m and 0.7m, along with a set of interchangeable, broad-band, interference filters with diameters of 0.75m. We also describe current plans for fabricating, coating, mounting and testing these lenses and filters.

Olivier, S S; Seppala, L; Gilmore, K; Hale, L; Whistler, W

2006-06-05

217

LSST Camera Electronics  

Microsoft Academic Search

The 3.2 Gpixel LSST camera will be read out by means of 189 highly segmented 4K x 4K CCDs. A total of 3024 video channels will be processed by a modular, in-cryostat electronics package based on two custom multichannel analog ASICs now in development. Performance goals of 5 electrons noise, .01% electronic crosstalk, and 80 mW power dissipation per channel

F. Mitchell Newcomer; S. Bailey; C. L. Britton; N. Felt; J. Geary; K. Hashimi; H. Lebbolo; Z. Ning; P. O'Connor; J. Oliver; V. Radeka; R. Sefri; V. Tocut; R. Van Berg

2009-01-01

218

An Ion Streak Camera  

Microsoft Academic Search

The possibility of detecting fast ions (protons and a particles) using an X-ray-sensitive streak camera with a CsI photocathode is demonstrated. The spatial resolution of the instrument is 70 µm, and its physical time resolution is 7 ps. The yield of secondary electrons from the photocathode irradiated with a particles is 8 electrons\\/particle. The instrument is able to detect single

A. G. Kravchenko; D. N. Litvin; V. P. Lazarchuk; V. M. Murugov; S. I. Petrov; A. V. Senik; I. G. Pryanishnikov

2004-01-01

219

Investigation of unsteady regular and Mach reflection in water using an image converter camera  

Microsoft Academic Search

The oblique collisions of two shock waves in water are investigated by an image converter camera. These two shock waves are produced by the detonation of two plane efficient explosives at angles to each other. The propagating shock wave is confirmed to be pseudo-stationary by framing photographs taken with by the image converter camera. Configurations of the shock wave are

S. Itoh; S. Nagano; O. Suzuki; I. Morita; M. Fujita

1995-01-01

220

Orbiter Camera Payload System  

NASA Technical Reports Server (NTRS)

Components for an orbiting camera payload system (OCPS) include the large format camera (LFC), a gas supply assembly, and ground test, handling, and calibration hardware. The LFC, a high resolution large format photogrammetric camera for use in the cargo bay of the space transport system, is also adaptable to use on an RB-57 aircraft or on a free flyer satellite. Carrying 4000 feet of film, the LFC is usable over the visible to near IR, at V/h rates of from 11 to 41 milliradians per second, overlap of 10, 60, 70 or 80 percent and exposure times of from 4 to 32 milliseconds. With a 12 inch focal length it produces a 9 by 18 inch format (long dimension in line of flight) with full format low contrast resolution of 88 lines per millimeter (AWAR), full format distortion of less than 14 microns and a complement of 45 Reseau marks and 12 fiducial marks. Weight of the OCPS as supplied, fully loaded is 944 pounds and power dissipation is 273 watts average when in operation, 95 watts in standby. The LFC contains an internal exposure sensor, or will respond to external command. It is able to photograph starfields for inflight calibration upon command.

1980-01-01

221

Hemispherical Laue camera  

DOEpatents

A hemispherical Laue camera comprises a crystal sample mount for positioning a sample to be analyzed at the center of sphere of a hemispherical, X-radiation sensitive film cassette, a collimator, a stationary or rotating sample mount and a set of standard spherical projection spheres. X-radiation generated from an external source is directed through the collimator to impinge onto the single crystal sample on the stationary mount. The diffracted beam is recorded on the hemispherical X-radiation sensitive film mounted inside the hemispherical film cassette in either transmission or back-reflection geometry. The distances travelled by X-radiation diffracted from the crystal to the hemispherical film are the same for all crystal planes which satisfy Bragg's Law. The recorded diffraction spots or Laue spots on the film thereby preserve both the symmetry information of the crystal structure and the relative intensities which are directly related to the relative structure factors of the crystal orientations. The diffraction pattern on the exposed film is compared with the known diffraction pattern on one of the standard spherical projection spheres for a specific crystal structure to determine the orientation of the crystal sample. By replacing the stationary sample support with a rotating sample mount, the hemispherical Laue camera can be used for crystal structure determination in a manner previously provided in conventional Debye-Scherrer cameras.

Li, James C. M. (Pittsford, NY); Chu, Sungnee G. (Rochester, NY)

1980-01-01

222

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

223

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

224

The Venus Monitoring Camera  

NASA Astrophysics Data System (ADS)

The Venus Monitoring Camera (VMC) is part of the Venus Express payload. One of the main goals of the Venus Express mission is to study the dynamics of the atmo- sphere. This objective requires global imaging of the planet. The VMC is designed to meet this goal with a wide field of view (FOV 30). The VMC will take images of Venus in six filters from UV to near-IR with spatial resolution from 0.25 km to 30 km depending on the distance from the planet. The full disc of Venus will be in the FOV near the apocentre of the orbit. The camera will complement other instru- ments of Venus Express 1.) by tracking cloud motions at 70 km (cloud tops) and at 50km (main cloud); 2.) by mapping O2 and NO night-glow and its variability that are optical tracers of the thermospheric dynamics (110-150 km); 3.) by mapping the night-side thermal emission from the surface and studying of the lapse rate and H2O content in the lower 6-10 km. In addition the camera will provide imaging context for the whole mission and its movies will be of significant interest for science but also for the public outreach programme. Moreover, the same instrument will be proposed for the Japanese Venus Orbiter.

Markiewicz, W. J.; Keller, H. U.; Kramm, R.; Titov, D.

225

Visual Feedback Stabilization of Balancing Tasks with Camera Misalignment  

NASA Astrophysics Data System (ADS)

In this paper, we consider visual feedback stabilization which tolerates small camera misalignment. Specifically, a balancing task with a cart-pendulum system using camera image is examined. Such a task is known to rely heavily on the detection of the vertical direction and the angle measurement error due to the camera misalignment could be fatal for stabilization. From a mathematical model of the measurement error, the effect of the misalignment is naturally represented by affine perturbation to the coefficient matrix of the output equation. Motivated by this fact, a special type of robust dynamic output feedback stabilization against polytopic uncertainty is investigated. By solving the related BMI, one can design a controller which tolerates the camera misalignment to some extent. The result is verified via experiments.

Hirata, Kentaro; Mizuno, Takashi

226

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

227

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

NASA Technical Reports Server (NTRS)

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. (inventor)

1993-01-01

228

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.

229

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

230

Neutron Imaging Camera  

NASA Technical Reports Server (NTRS)

The Neutron Imaging Camera (NIC) is based on the Three-dimensional Track Imager (3DTI) technology developed at GSFC for gamma-ray astrophysics applications. The 3-DTI, a large volume time-projection chamber, provides accurate, approximately 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 (sup 3)He(n,p) (sup 3)H interactions in the 3-DTI volume. The performance of the NIC from laboratory and accelerator tests is presented.

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

2008-01-01

231

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

232

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...

233

Application of narrow-band television to industrial and commercial communications  

NASA Technical Reports Server (NTRS)

The development of narrow-band systems for use in space systems is presented. Applications of the technology to future spacecraft requirements are discussed along with narrow-band television's influence in stimulating development within the industry. The transferral of the technology into industrial and commercial communications is described. Major areas included are: (1) medicine; (2) education; (3) remote sensing for traffic control; and (5) weather observation. Applications in data processing, image enhancement, and information retrieval are provided by the combination of the TV camera and the computer.

Embrey, B. C., Jr.; Southworth, G. R.

1974-01-01

234

Mars Science Laboratory Engineering Cameras  

NASA Technical Reports Server (NTRS)

NASA's Mars Science Laboratory (MSL) Rover, which launched to Mars in 2011, is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover (MER) cameras, which were sent to Mars in 2003. The engineering cameras weigh less than 300 grams each and use less than 3 W of power. Images returned from the engineering cameras are 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 (Haz - cams) 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 frame-transfer CCD (charge-coupled device) with a 1024x1024 imaging region 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 MSL rover carries 8 Hazcams and 4 Navcams.

Maki, Justin N.; Thiessen, David L.; Pourangi, Ali M.; Kobzeff, Peter A.; Lee, Steven W.; Dingizian, Arsham; Schwochert, Mark A.

2012-01-01

235

The Orbiter camera payload system's large-format camera and attitude reference system  

NASA Technical Reports Server (NTRS)

The Orbiter camera payload system (OCPS) is an integrated photographic system carried into earth orbit as a payload in the Space Transportation System (STS) Orbiter vehicle's cargo bay. The major component of the OCPS is a large-format camera (LFC), a precision wide-angle cartographic instrument capable of producing high-resolution stereophotography of great geometric fidelity in multiple base-to-height ratios. A secondary and supporting system to the LFC is the attitude reference system (ARS), a dual-lens stellar camera array (SCA) and camera support structure. The SCA is a 70 mm film system that is rigidly mounted to the LFC lens support structure and, through the simultaneous acquisition of two star fields with each earth viewing LFC frame, makes it possible to precisely determine the pointing of the LFC optical axis with reference to the earth nadir point. Other components complete the current OCPS configuration as a high-precision cartographic data acquisition system. The primary design objective for the OCPS was to maximize system performance characteristics while maintaining a high level of reliability compatible with rocket launch conditions and the on-orbit environment. The full OCPS configuration was launched on a highly successful maiden voyage aboard the STS Orbiter vehicle Challenger on Oct. 5, 1984, as a major payload aboard the STS-41G mission.

Schardt, B. B.; Mollberg, B. H.

1985-01-01

236

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

237

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

238

Miniaturized fundus camera  

NASA Astrophysics Data System (ADS)

Retinopathy of Prematurity (ROP) denotes a patholgoic development of the retina in prematurely born children. In order to prevent severe permanent damage to the eye and enable a timely treatment, the fundus of the eye in such children has to be examined according to established procedures. By the way of a miniaturized fundus camera it is intended to record digital pictures of the fundus for on-line or off-line examination and diagnosis. Within the framework of a network for telescreening of ROP, this communication is devoted to technical aspects related to the development of a miniaturized, handheld fundus camera that can be used to relate digital images of the fundus covering the entire area of interest to the network. The images can then be examined by a specialist who is, if not available on location, remote from the hospital. Due to the limited amount of space in a neonatology unit, furthermore, electronic racks containing controllers, computers, etc. are not acceptable, i.e., miniaturization and integration of all functions associated with networking is necessary.

Gliss, Christine; Parel, Jean-Marie A.; Flynn, John T.; Pratisto, Hans S.; Niederer, Peter F.

2003-07-01

239

Transmission electron microscope CCD camera  

DOEpatents

In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

Downing, Kenneth H. (Lafayette, CA)

1999-01-01

240

The All Sky Camera Network  

NSDL National Science Digital Library

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. Students involved in the network participate in an authentic, inquiry-based experience by tracking meteor events. This article discusses the past, present, and future of the All Sky Camera Network.

Caldwell, Andy

2005-02-01

241

A novel convergence control method for toed-in stereo camera systems  

NASA Astrophysics Data System (ADS)

In this paper, we present a novel convergence control method for toed-in stereo camera systems. The proposed method automatically computes a convergence angle for both (i.e., left and right) cameras to locate a target object at image center. Unlike other image based auto-convergence algorithms, the proposed method aims at controlling the angle of yaw of stereo camera, and thus makes a disparity of the target object be zero while capturing stereoscopic images. The proposed algorithm is based on the fact that an object at convergence position has a zero-disparity in stereoscopic images under the toed-in camera configuration. As a result, we can avoid the accommodation-convergence conflict while watching the target object in stereoscopic images. Experimental results demonstrate that the proposed method effectively estimates convergence angles for target objects at different distances.

Seo, Ja-Won; Kim, Changick

2012-10-01

242

Gated MCP framing camera system  

NASA Astrophysics Data System (ADS)

A picosecond gated MCP framing camera system is presented. The camera with four parallel microstripline cathode has longer measuring time range and better gain uniformity. The camera is equipped with a pinhole-array adjustment system and other practical accessories for laser plasma experiment. The measured spatial resolution of the camera is 15 lp/mm with 10% modulation and the exposure time ranges from 60 ps to 100 ps with different gain. The whole system was used at the 11# laser facility and got some results of several target type during laser plasma experiment.

Secroun, Aurelia; Mens, Alain; Segre, Jacques; Assous, Franck; Piault, Emmanuel; Rebuffie, Jean-Claude; Zhu, Wenhua; Luo, Yongming; Cheng, Jinxiu; Yang, Cunbang; Wen, Tianshu; Tang, Daoyuan; Wen, Shu Huai; Zheng, Zhijian

1997-05-01

243

Narrow-band radiation wavelength measurement by processing digital photographs in RAW format  

NASA Astrophysics Data System (ADS)

The technique of measuring the mean wavelength of narrow-band radiation in the 455 - 625-nm range using the image of the emitting surface is presented. The data from the camera array unprocessed by the built-in processor (RAW format) are used. The method is applied for determining the parameters of response of holographic sensors. Depending on the wavelength and brightness of the image fragment, the mean square deviation of the wavelength amounts to 0.3 - 3 nm.

Kraiskii, A. V.; Mironova, T. V.; Sultanov, T. T.

2012-12-01

244

Narrow gap electronegative capacitive discharges  

NASA Astrophysics Data System (ADS)

Narrow gap electronegative (EN) capacitive discharges are widely used in industry and have unique features not found in conventional discharges. In this paper, plasma parameters are determined over a range of decreasing gap length L from values for which an electropositive (EP) edge exists (2-region case) to smaller L-values for which the EN region connects directly to the sheath (1-region case). Parametric studies are performed at applied voltage Vrf=500 V for pressures of 10, 25, 50, and 100 mTorr, and additionally at 50 mTorr for 1000 and 2000 V. Numerical results are given for a parallel plate oxygen discharge using a planar 1D3v (1 spatial dimension, 3 velocity components) particle-in-cell (PIC) code. New interesting phenomena are found for the case in which an EP edge does not exist. This 1-region case has not previously been investigated in detail, either numerically or analytically. In particular, attachment in the sheaths is important, and the central electron density ne0 is depressed below the density nesh at the sheath edge. The sheath oscillations also extend into the EN core, creating an edge region lying within the sheath and not characterized by the standard diffusion in an EN plasma. An analytical model is developed using minimal inputs from the PIC results, and compared to the PIC results for a base case at Vrf=500 V and 50 mTorr, showing good agreement. Selected comparisons are made at the other voltages and pressures. A self-consistent model is also developed and compared to the PIC results, giving reasonable agreement.

Kawamura, E.; Lieberman, M. A.; Lichtenberg, A. J.

2013-10-01

245

Narrow gap electronegative capacitive discharges  

SciTech Connect

Narrow gap electronegative (EN) capacitive discharges are widely used in industry and have unique features not found in conventional discharges. In this paper, plasma parameters are determined over a range of decreasing gap length L from values for which an electropositive (EP) edge exists (2-region case) to smaller L-values for which the EN region connects directly to the sheath (1-region case). Parametric studies are performed at applied voltage V{sub rf}=500 V for pressures of 10, 25, 50, and 100 mTorr, and additionally at 50 mTorr for 1000 and 2000 V. Numerical results are given for a parallel plate oxygen discharge using a planar 1D3v (1 spatial dimension, 3 velocity components) particle-in-cell (PIC) code. New interesting phenomena are found for the case in which an EP edge does not exist. This 1-region case has not previously been investigated in detail, either numerically or analytically. In particular, attachment in the sheaths is important, and the central electron density n{sub e0} is depressed below the density n{sub esh} at the sheath edge. The sheath oscillations also extend into the EN core, creating an edge region lying within the sheath and not characterized by the standard diffusion in an EN plasma. An analytical model is developed using minimal inputs from the PIC results, and compared to the PIC results for a base case at V{sub rf}=500 V and 50 mTorr, showing good agreement. Selected comparisons are made at the other voltages and pressures. A self-consistent model is also developed and compared to the PIC results, giving reasonable agreement.

Kawamura, E.; Lieberman, M. A.; Lichtenberg, A. J. [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States)] [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States)

2013-10-15

246

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

247

A view of the ET camera on STS-112  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. - A view of the camera mounted on the external tank of Space Shuttle Atlantis. The color video camera mounted to the top of Atlantis' external tank will provide a view of the front and belly of the orbiter and a portion of the solid rocket boosters (SRBs) and external tank during the launch of Atlantis on mission STS-112. It will offer the STS-112 team an opportunity to monitor the shuttle's performance from a new angle. The camera will be turned on fifteen minutes prior to launch and will show the orbiter and solid rocket boosters on the launch pad. The video will be downlinked from the external tank during flight to several NASA data-receiving sites and then relayed to the live television broadcast. The camera is expected to operate for about 15 minutes following liftoff. At liftoff, viewers will see the shuttle clearing the launch tower and, at two minutes after liftoff, see the right SRB separate from the external tank. When the external tank separates from Atlantis about eight minutes into the flight, the camera is expected to continue its live feed for about six more minutes although NASA may be unable to pick up the camera's signal because the tank may have moved out of range.

2002-01-01

248

A view of the ET camera on STS-112  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. - A closeup view of the camera mounted on the external tank of Space Shuttle Atlantis. The color video camera mounted to the top of Atlantis' external tank will provide a view of the front and belly of the orbiter and a portion of the solid rocket boosters (SRBs) and external tank during the launch of Atlantis on mission STS-112. It will offer the STS-112 team an opportunity to monitor the shuttle's performance from a new angle. The camera will be turned on fifteen minutes prior to launch and will show the orbiter and solid rocket boosters on the launch pad. The video will be downlinked from the external tank during flight to several NASA data-receiving sites and then relayed to the live television broadcast. The camera is expected to operate for about 15 minutes following liftoff. At liftoff, viewers will see the shuttle clearing the launch tower and, at two minutes after liftoff, see the right SRB separate from the external tank. When the external tank separates from Atlantis about eight minutes into the flight, the camera is expected to continue its live feed for about six more minutes although NASA may be unable to pick up the camera's signal because the tank may have moved out of range.

2002-01-01

249

A Motionless Camera  

NASA Technical Reports Server (NTRS)

Omniview, a motionless, noiseless, exceptionally versatile camera was developed for NASA as a receiving device for guiding space robots. The system can see in one direction and provide as many as four views simultaneously. Developed by Omniview, Inc. (formerly TRI) under a NASA Small Business Innovation Research (SBIR) grant, the system's image transformation electronics produce a real-time image from anywhere within a hemispherical field. Lens distortion is removed, and a corrected "flat" view appears on a monitor. Key elements are a high resolution charge coupled device (CCD), image correction circuitry and a microcomputer for image processing. The system can be adapted to existing installations. Applications include security and surveillance, teleconferencing, imaging, virtual reality, broadcast video and military operations. Omniview technology is now called IPIX. The company was founded in 1986 as TeleRobotics International, became Omniview in 1995, and changed its name to Interactive Pictures Corporation in 1997.

1994-01-01

250

Neutron Imaging Camera  

NASA Technical Reports Server (NTRS)

We describe the Neutron Imaging Camera (NIC) being developed for DTRA applications by NASA/GSFC and NSWC/Carderock. The 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, approximately 0.4 mm resolution. 3-D tracking of charged particles. The incident direction of fast neutrons, E(sub N) > 0.5 MeV. arc reconstructed from the momenta and energies of the proton and triton fragments resulting from 3He(n,p)3H interactions in the 3-DTI volume. We present angular and energy resolution performance of the NIC derived from accelerator tests.

Hunter, Stanley D.; DeNolfo, Georgia; Floyd, Sam; Krizmanic, John; Link, Jason; Son, Seunghee; Guardala, Noel; Skopec, Marlene; Stark, Robert

2008-01-01

251

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

252

In-flight calibration of the Dawn Framing Camera II: Flat fields and stray light correction  

NASA Astrophysics Data System (ADS)

The NASA Dawn spacecraft acquired thousands of images of asteroid Vesta during its year-long orbital tour, and is now on its way to asteroid Ceres. A method for calibrating images acquired by the onboard Framing Camera was described by Schröder et al. (Schröder et al. [2013]. Icarus 226, 1304). However, their method is only valid for point sources. In this paper we extend the calibration to images of extended sources like Vesta. For this, we devise a first-order correction for in-field stray light, which is known to plague images taken through the narrow band filters, and revise the flat fields that were acquired in an integrating sphere before launch. We used calibrated images of the Vesta surface to construct simple photometric models for all filters, that allow us to study how the spectrum changes with increasing phase angle (phase reddening). In combination with these models, our calibration method can be used to create near-seamless mosaics that are radiometrically accurate to a few percent. Such mosaics are provided in JVesta, the Vesta version of the JMARS geographic information system.

Schröder, S. E.; Mottola, S.; Matz, K.-D.; Roatsch, T.

2014-05-01

253

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

254

An Instability in Narrow Planetary Rings  

Microsoft Academic Search

We will present our work investigating the behavior of narrow planetary rings with low dispersion velocities. Such narrow a ring will be initially unstable to self-gravitational collapse. After the collapse, the ring is collisionally very dense. At this stage, it is subject to a new instability. Waves appear on the inner and outer edges of the ring within half of

J. W. Weiss; G. R. Stewart

2003-01-01

255

Narrow Band Gap Amorphous Silicon Semiconductors.  

National Technical Information Service (NTIS)

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...

A. Madan A. H. Mahan

1985-01-01

256

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

257

Infants Experience Perceptual Narrowing for Nonprimate Faces  

ERIC Educational Resources Information Center

Perceptual narrowing--a phenomenon in which perception is broad from birth, but narrows as a function of experience--has previously been tested with primate faces. In the first 6 months of life, infants can discriminate among individual human and monkey faces. Though the ability to discriminate monkey faces is lost after about 9 months, infants…

Simpson, Elizabeth A.; Varga, Krisztina; Frick, Janet E.; Fragaszy, Dorothy

2011-01-01

258

Airborne ballistic camera tracking systems  

NASA Technical Reports Server (NTRS)

An operational airborne ballistic camera tracking system was tested for operational and data reduction feasibility. The acquisition and data processing requirements of the system are discussed. Suggestions for future improvements are also noted. A description of the data reduction mathematics is outlined. Results from a successful reentry test mission are tabulated. The test mission indicated that airborne ballistic camera tracking systems are feasible.

Redish, W. L.

1976-01-01

259

Camera artifacts in IUE spectra  

NASA Technical Reports Server (NTRS)

This study of emission line mimicking features in the IUE cameras has produced an atlas of artifiacts in high-dispersion images with an accompanying table of prominent artifacts and a table of prominent artifacts in the raw images along with a medium image of the sky background for each IUE camera.

Bruegman, O. W.; Crenshaw, D. M.

1994-01-01

260

The Eye of the Camera  

Microsoft Academic Search

This study addresses the effects of security cameras on prosocial behavior. Results from previous studies indicate that the presence of others can trigger helping behavior, arising from the need for approval of others. Extending these findings, the authors propose that security cameras can likewise trigger such approval-seeking behaviors by implying the presence of a watchful eye. Because people vary in

Rompay van Thomas J. L; Dorette J. Vonk; Marieke L. Fransen

2009-01-01

261

Lightweight Video-Camera Head  

NASA Technical Reports Server (NTRS)

Compact, lightweight video camera head constructed by remounting lens and charge-coupled-device image detector from small commercial video camera in separate assembly. Useful in robotics, artificial vision, and vision guidance systems. Designed to be mounted on visor of helmet to monitor motions of eyes in experiments on vestibulo-ocular reflexes.

Proctor, David R.

1988-01-01

262

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

263

High-speed camera synchronization  

NASA Technical Reports Server (NTRS)

Photoelectric sensor enables synchronization of the rotating mirror in a high-speed framing camera with the passage of a very-high-velocity droplet to obtain direct photographic data on droplet breakup. It detects droplet movement across a high intensity light beam and generates a signal triggering the camera.

Rojec, E. A.

1968-01-01

264

High performance SPECT camera design  

Microsoft Academic Search

SPECT is primarily used in the clinic for cardiac applications like myocardial perfusion imaging (MPI). However, for SPECT, sensitivity is impaired due to the need for collimation. System resolution is poor as well (FWHM~1 cm). New SPECT camera designs have emerged with improved sensitivity over the standard gamma cameras currently used in the clinic for estimating myocardial perfusion. Most of

J. Dey

2009-01-01

265

Digital Cameras for Student Use.  

ERIC Educational Resources Information Center

Describes the features, equipment and operations of digital cameras and compares three different digital cameras for use in education. Price, technology requirements, features, transfer software, and accessories for the Kodak DC25, Olympus D-200L and Casio QV-100 are presented in a comparison table. (AEF)

Simpson, Carol

1997-01-01

266

Memory Card Camera and Player.  

National Technical Information Service (NTIS)

A memory card camera which records digital still images on a semiconductor memory card has been developed. The camera contains image data compression LSIs and is capable of recording 12 high-quality frame images on an 18-Mbit SRAM card. In addition, it is...

F. Izawa T. Saga T. Suyama

1991-01-01

267

Multi-camera colour tracking  

Microsoft Academic Search

We propose a colour tracker for use in visual surveillance. The tracker is part of a framework designed to monitor a dynamic scene with more than one camera. Colour tracking complements spatial tracking: it can also be used over large temporal intervals, and between spatially uncalibrated cameras. The colour distributions from objects are modelled, and measures of difference between them

J. Orwell; P. Remagnino; G. A. Jones

1999-01-01

268

Eye typing with common cameras  

Microsoft Academic Search

Low cost eye tracking has received an increased attention due to the rapid developments in tracking hardware (video boards, digital camera and CPU's) [Hansen and Pece 2005; OpenEyes 2005]. We present a gaze typing system based on components that can be bought in most consumer hardware stores around the world. These components are for example cameras and graphics cards that

Dan Witzner Hansen; John Paulin Hansen

2006-01-01

269

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

270

The depth discontinuity occlusion camera  

Microsoft Academic Search

Rendering a scene using a single depth image suffers from disocclusion errors as the view translates away from the reference view. We present the depth discontinuity occlusion camera (DDOC), a non-pinhole camera that samples surfaces which are hidden in the reference view, but are likely to become visible in nearby views. The DDOC reference image alleviates disocclusion errors; since it

Voicu Popescu; Daniel G. Aliaga

2006-01-01

271

Describe Angle Pair Relationships  

NSDL National Science Digital Library

This lesson will explain the types of pairs of angles you will find in Geometry. Note taking time on page 5: Angle Information Now, let's see if you get it: Angle Relationship Quiz (fun) Ok! Now for your assignment, #8 on page 38! Class Zone Geometry Textbook ...

Neubert, Mrs.

2011-09-01

272

What's Your Angle?  

NSDL National Science Digital Library

In this activity, students devise procedures for using a protractor to measure the number of degrees in an angle, and use inductive reasoning to develop "angle sense." Then they describe circumstances and careers that require a working knowledge of angles and their measurements.

2010-01-01

273

IMAX camera (12-IML-1)  

NASA Technical Reports Server (NTRS)

The IMAX camera system is used to record on-orbit activities of interest to the public. Because of the extremely high resolution of the IMAX camera, projector, and audio systems, the audience is afforded a motion picture experience unlike any other. IMAX and OMNIMAX motion picture systems were designed to create motion picture images of superior quality and audience impact. The IMAX camera is a 65 mm, single lens, reflex viewing design with a 15 perforation per frame horizontal pull across. The frame size is 2.06 x 2.77 inches. Film travels through the camera at a rate of 336 feet per minute when the camera is running at the standard 24 frames/sec.

1992-01-01

274

Coherent infrared imaging camera (CIRIC)  

SciTech Connect

New developments in 2-D, wide-bandwidth HgCdTe (MCT) and GaAs quantum-well infrared photodetectors (QWIP) coupled with Monolithic Microwave Integrated Circuit (MMIC) technology are now making focal plane array coherent infrared (IR) cameras viable. Unlike conventional IR cameras which provide only thermal data about a scene or target, a coherent camera based on optical heterodyne interferometry will also provide spectral and range information. Each pixel of the camera, consisting of a single photo-sensitive heterodyne mixer followed by an intermediate frequency amplifier and illuminated by a separate local oscillator beam, constitutes a complete optical heterodyne receiver. Applications of coherent IR cameras are numerous and include target surveillance, range detection, chemical plume evolution, monitoring stack plume emissions, and wind shear detection.

Hutchinson, D.P.; Simpson, M.L.; Bennett, C.A.; Richards, R.K.; Emery, M.S.; Crutcher, R.I.; Sitter, D.N. Jr.; Wachter, E.A.; Huston, M.A.

1995-07-01

275

How are the nine MISR cameras arranged?  

... Ca, and, Da, beginning with the most forward-viewing oblique camera and ending with the most aft-viewing oblique camera. The initial letter (A, B, C, D) denotes the focal length of the camera lens, with the A cameras having the shortest focal length and the D cameras the ...

2013-03-20

276

Calibration Method for Misaligned Catadioptric Camera  

Microsoft Academic Search

This paper proposes a calibration method for catadioptric camera systems consisting of a surface of revolution mir- ror and a perspective camera, such as HyperOmni Vision. The proposed method is based on conventional camera cal- ibration and mirror posture estimation. Many methods for camera calibration have been proposed. During the last decade, methods for catadioptric camera calibration have also been

Tomohiro Mashita; Yoshio Iwai; Masahiko Yachida

2006-01-01

277

Augmented heat transfer in rectangular channels of narrow aspect ratios with rib turbulators  

NASA Technical Reports Server (NTRS)

The effects of the rib angle-of-attack on the distributions of the local heat transfer coefficient and on the friction factors in short rectangular channels of narrow aspect ratios with a pair of opposite rib-roughened walls are determined for Reynolds numbers from 10,000 to 60,000. The channel width-to-height ratios are 2/4 and 1/4; the corresponding rib angles-of-attack are 90, 60, 45, and 30 deg, respectively. The results indicate that the narrow-aspect-ratio channels give better heat transfer performance than the wide-aspect-ratio channels for a constant pumping power. Semiempirical friction and heat transfer correlations are obtained. The results can be used in the design of turbine cooling channels of narrow aspect ratios.

Han, J. C.; Ou, S.; Park, J. S.; Lei, C. K.

1989-01-01

278

Real-Time Person Localization System with an Active Camera  

NASA Astrophysics Data System (ADS)

This paper proposed a method in which location of a person is estimation with one active camera in real-time. The approach taken in this paper is as follows. First, we detect the person region with proposed method which is the region detection method based on short time distribution of the density to avoid the influence of the camera movement. Then we obtain his height and the gravity point. The rotate angle and the distance between the person and the camera are calculated by the information of the height and the gravity point. Experiments were applied with several examples. We obtained that the average error distance is less than 12[cm]. The average error distance is small enough in comparison with shoulder width of the persons. Our method can estimate the location in real-time.

Ooshima, Naoya; Saitoh, Takeshi; Konishi, Ryosuke

279

Saturn's hydrogen aurora: Wide field and planetary camera 2 imaging from the Hubble Space Telescope  

Microsoft Academic Search

Wide field and planetary camera 2\\/Hubble Space Telescope (WFPC2\\/HST) images of Saturn's far ultraviolet aurora reveal emissions confined to a narrow band of latitudes near Saturn's north and south poles. The aurorae are most prominent in the morning sector with patterns that appear fixed in local time. The geographic distribution and vertical extent of the auroral emissions seen in these

John T. Trauger; John T. Clarke; Gilda E. Ballester; Robin W. Evans; Christopher J. Burrows; David Crisp; John S. Gallagher; Richard E. Griffiths; J. Jeff Hester; John G. Hoessel; Jon A. Holtzman; John E. Krist; Jeremy R. Mould; Raghvendra Sahai; Paul A. Scowen; Karl R. Stapelfeldt; Alan M. Watson

1998-01-01

280

Reflectance Calibration Scheme for Airborne Frame Camera Images  

NASA Astrophysics Data System (ADS)

The image quality of photogrammetric images is influenced by various effects from outside the camera. One effect is the scattered light from the atmosphere that lowers contrast in the images and creates a colour shift towards the blue. Another is the changing illumination during the day which results in changing image brightness within an image block. In addition, there is the so-called bidirectional reflectance of the ground (BRDF effects) that is giving rise to a view and sun angle dependent brightness gradient in the image itself. To correct for the first two effects an atmospheric correction with reflectance calibration is chosen. The effects have been corrected successfully for ADS linescan sensor data by using a parametrization of the atmospheric quantities. Following Kaufman et al. the actual atmospheric condition is estimated by the brightness of a dark pixel taken from the image. The BRDF effects are corrected using a semi-empirical modelling of the brightness gradient. Both methods are now extended to frame cameras. Linescan sensors have a viewing geometry that is only dependent from the cross track view zenith angle. The difference for frame cameras now is to include the extra dimension of the view azimuth into the modelling. Since both the atmospheric correction and the BRDF correction require a model inversion with the help of image data, a different image sampling strategy is necessary which includes the azimuth angle dependence. For the atmospheric correction a sixth variable is added to the existing five variables visibility, view zenith angle, sun zenith angle, ground altitude, and flight altitude - thus multiplying the number of modelling input combinations for the offline-inversion. The parametrization has to reflect the view azimuth angle dependence. The BRDF model already contains the view azimuth dependence and is combined with a new sampling strategy.

Beisl, U.

2012-07-01

281

Camera sensitivity study  

NASA Astrophysics Data System (ADS)

As the cost/performance Ratio of vision systems improves with time, new classes of applications become feasible. One such area, automotive applications, is currently being investigated. Applications include occupant detection, collision avoidance and lane tracking. Interest in occupant detection has been spurred by federal automotive safety rules in response to injuries and fatalities caused by deployment of occupant-side air bags. In principle, a vision system could control airbag deployment to prevent this type of mishap. Employing vision technology here, however, presents a variety of challenges, which include controlling costs, inability to control illumination, developing and training a reliable classification system and loss of performance due to production variations due to manufacturing tolerances and customer options. This paper describes the measures that have been developed to evaluate the sensitivity of an occupant detection system to these types of variations. Two procedures are described for evaluating how sensitive the classifier is to camera variations. The first procedure is based on classification accuracy while the second evaluates feature differences.

Schlueter, Jonathan; Murphey, Yi L.; Miller, John W. V.; Shridhar, Malayappan; Luo, Yun; Khairallah, Farid

2004-12-01

282

Focused plenoptic camera and rendering  

NASA Astrophysics Data System (ADS)

Plenoptic cameras, constructed with internal microlens arrays, capture both spatial and angular information, i.e., the full 4-D radiance, of a scene. The design of traditional plenoptic cameras assumes that each microlens image is completely defocused with respect to the image created by the main camera lens. As a result, only a single pixel in the final image is rendered from each microlens image, resulting in disappointingly low resolution. A recently developed alternative approach based on the focused plenoptic camera uses the microlens array as an imaging system focused on the image plane of the main camera lens. The flexible spatioangular trade-off that becomes available with this design enables rendering of final images with significantly higher resolution than those from traditional plenoptic cameras. We analyze the focused plenoptic camera in optical phase space and present basic, blended, and depth-based rendering algorithms for producing high-quality, high-resolution images. We also present our graphics-processing-unit-based implementations of these algorithms, which are able to render full screen refocused images in real time.

Georgiev, Todor; Lumsdaine, Andrew

2010-04-01

283

Optical Systems Study for Advanced Facsimile Camera.  

National Technical Information Service (NTIS)

Slight modifications on the design of the camera lens and other optical components of the Viking Lander Camera are considered. Topics discussed are: (1) alternative techniques for extending the spectral range of the camera lens (by using fiber optics, mir...

W. J. Davis P. J. Jarmuz C. D. Hardesty

1976-01-01

284

Accuracy in fixing ship's positions by camera survey of bearings  

NASA Astrophysics Data System (ADS)

The paper presents the results of research on the possibilities of fixing ship position coordinates based on results of surveying bearings on navigational marks with the use of the CCD camera. Accuracy of the determination of ship position coordinates, expressed in terms of the mean error, was assumed to be the basic criterion of this estimation. The first part of the paper describes the method of the determination of the resolution and the mean error of the angle measurement, taken with a camera, and also the method of the determination of the mean error of position coordinates when two or more bearings were measured. There have been defined three software applications assigned for the development of navigational sea charts with accuracy areas mapped on. The second part contains the results of studying accuracy in fixing ship position coordinates, carried out in the Gulf of Gdansk, with the use of bearings taken obtained with the Rolleiflex and Sony cameras. The results are presented in a form of diagrams of the mean error of angle measurement, also in the form of navigational charts with accuracy fields mapped on. In the final part, basing on results obtained, the applicability of CCD cameras in automation of coastal navigation performance process is discussed.

Naus, Krzysztof; W??, Mariusz

2011-01-01

285

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 to…

Meyn, Jan-Peter

2008-01-01

286

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

287

Vertical ocean reflectance at low altitudes for narrow laser beams  

NASA Astrophysics Data System (ADS)

A narrow-beam laser altimeter was used to measure the reflected signal from the ocean surface as represented by the waters beneath the Golden Gate Bridge. This site allowed precise measurements as a function of angle from the vertical not possible from flying platforms. For short-wavelength water waves superimposed on swell, the signal amplitude probability distribution for the reflected signals showed periods of zero reflection, even for vertical incidence, apparently due to tipping of the water surface. The nonzero signals showed a distribution that could be fitted with an antilog-normal distribution. This is skewed toward higher signals than a normal (Gaussian) distribution. With incidence angle displaced from the vertical, the distribution shape was retained but with more frequent zero reflections. The decrease with angle of the average signal, including the zeroes, is well fitted with a Gram- Charlier distribution, as seen by earlier observers using photographic techniques which masked these details of the structure. For the simpler wave pattern due to a long sustained wind direction, the probability distribution is log-normal with no zero signal periods. At large angles from the vertical the log-normal distribution shifts toward exponential. For surface states intermediate between the above two extremes the distribution is often normal. The larger return signals resulting from the skew toward larger amplitudes from lognormal are more favorable for disposable laser altimeters than previously believed. Also, for an altimeter which may be swinging from a parachute or balloon, the return remains high at angles other than vertical. The presence of occasional zero return signal does somewhat degrade the accuracy of altitude measurement for a descending altimeter, but the signal available assures performance at larger altitudes than previously expected.

Crittenden, Eugene C.; Rodeback, G. W.; Milne, Edmund A.; Cooper, Alfred W.

1991-09-01

288

Analysis of streak-camera measurement errors caused by misorientation of the camera slit with recording direction  

SciTech Connect

Erroneous data are produced when we analyze streak or smear camera records in which the lack of perpendicularity between the camera slit and the recording direction is not considered. Generated velocity errors are either constant or variable, depending upon the orientation strategy used in analyzing the film. The size of these absolute errors is proportional to the slit misorientation angle or to the product of slit misorientation and the square of event velocity. To a first approximation, the relative velocity error, expressed as a decimal fraction, is equal to the slit misorientation angle in radians. When the degree of slit misorientation is unknown, film reading strategies are offered for minimizing absolute and relative errors. Unfortunately, slit misorientation also causes symmetrical phenomena to be recorded asymmetrically. Nevertheless, we can correct all aberrances with a simple function that restores the photographic measurements to their true displacement-time values.

Igel, E.A.

1982-12-01

289

Mars Orbiter Camera Views the 'Face on Mars' - Best View from Viking  

NASA Technical Reports Server (NTRS)

Shortly after midnight Sunday morning (5 April 1998 12:39 AM PST), the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft successfully acquired a high resolution image of the 'Face on Mars' feature in the Cydonia region. The image was transmitted to Earth on Sunday, and retrieved from the mission computer data base Monday morning (6 April 1998). The image was processed at the Malin Space Science Systems (MSSS) facility 9:15 AM and the raw image immediately transferred to the Jet Propulsion Laboratory (JPL) for release to the Internet. The images shown here were subsequently processed at MSSS.

The picture was acquired 375 seconds after the spacecraft's 220th close approach to Mars. At that time, the 'Face', located at approximately 40.8o N, 9.6o W, was 275 miles (444 km) from the spacecraft. The 'morning' sun was 25o above the horizon. The picture has a resolution of 14.1 feet (4.3 meters) per pixel, making it ten times higher resolution than the best previous image of the feature, which was taken by the Viking Mission in the mid-1970's. The full image covers an area 2.7 miles (4.4 km) wide and 25.7 miles (41.5 km) long.

This Viking Orbiter image is one of the best Viking pictures of the area Cydonia where the 'Face' is located. Marked on the image are the 'footprint' of the high resolution (narrow angle) Mars Orbiter Camera image and the area seen in enlarged views (dashed box). See PIA01440-1442 for these images in raw and processed form.

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

1998-01-01

290

Focal plane metrology for the LSST camera  

NASA Astrophysics Data System (ADS)

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°) field of view. In turn, meeting those imaging requirements necessitates maintaining precise control of the focal plane surface (10 ?m P-V) over the entire field of view (640 mm diameter) at the operating temperature (T ~ -100°C) and over the operational elevation angle range. We briefly describe the heirarchical 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.

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

2006-06-01

291

Compact MWIR camera with x20 zoom optics  

NASA Astrophysics Data System (ADS)

The development of a compact and high performance MWIR zoom camera based on the 320 X 240 staring focal plane array (FPA) is described. The camera has 20 magnification zoom optics with the maximum 40 degree(s) X 30 degree(s) of super wide field of view and 7.6 cycles/mrad of resolving power with the operation of attached microscanning system. In order to correct non-uniformities of detector arrays, we have proposed the multi-point correction method using the defocusing technique of the optics and acquired the highest quality images. The MRTD of our system shows good results below 0.05 degree(s)K at spatial frequency 1 cycles/mrad at narrow field of view.

Kim, Hyun S.; Yu, Wee K.; Park, Young C.; Yoon, Eon S.; Kim, Chang W.; Song, In Seob; Hong, Seok-Min

2001-10-01

292

Narrow-Linewidth Interwell THz Intersubband Emission.  

National Technical Information Service (NTIS)

Narrow-linewidth terahertz spontaneous emission resulting from interwell (or diagonal) intersubband transition from an electrically pumped multiple quantum-well (MQW) structure was observed. The center frequency of the emission peak is at 2.57 THz, and it...

B. Xu B. S. Williams M. Melloch Q. Hu

2000-01-01

293

Electron strings in solids with narrow bands  

Microsoft Academic Search

Electronic phase separation may arise due to electron–phonon interactions. In polar materials with a narrow band this polarization effect may lead to the creation of electron strings, whose length depends on dielectric constants.

F. V. Kusmartsev

2000-01-01

294

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

295

Narrow diameter implant in posterior region  

PubMed Central

Dental implants placement can sometimes be limited due to physical conditions, wherein the horizontal space is limited by adjacent teeth and roots or situations in which there is narrow alveolar ridge, By using a narrow diameter implant (NDI), the need for bone augmentation can be avoided. In situations where there is limited horizontal space, a NDI may be the only option to replace a missing tooth.

Mohamed, Jumshad B.; Alam, Md. Nazish; Salman, Arif; Chandrasekaran, S. C.

2012-01-01

296

National Park Service Web Cameras  

NSDL National Science Digital Library

The National Park Service (NPS) operates digital cameras at many parks in the lower 48 states, Alaska, and Hawaii to help educate the public on air quality issues. These cameras often show the effects of air pollution, especially visibility impairment. Because the cameras are typically located near air quality monitoring sites, their web pages display other information along with the photo, such as current levels of ozone, particulate matter, or sulfur dioxide, visual range, and weather conditions. The digital photos are usually updated every 15 minutes, while air quality data values are revised hourly. Charts of the last ten days of hourly weather, ozone, particulate matter, or sulfur dioxide data are also available. The cameras are accessible by clicking on an interactive map.

297

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

298

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

299

Solid state television camera (CID)  

NASA Technical Reports Server (NTRS)

The design, development and test are described of a charge injection device (CID) camera using a 244x248 element array. A number of video signal processing functions are included which maximize the output video dynamic range while retaining the inherently good resolution response of the CID. Some of the unique features of the camera are: low light level performance, high S/N ratio, antiblooming, geometric distortion, sequential scanning and AGC.

Steele, D. W.; Green, W. T.

1976-01-01

300

Nonholonomic camera-space manipulation  

Microsoft Academic Search

The method of camera-space manipulation is extended to wheeled systems. A minimum of two cameras is required to place points on end-effectors (or objects in their grasp) of n-degree-of-freedom manipulators relative to other bodies where the nonholonomic degrees of freedom on a mobile manipulator base may be included. The target bodies do not have a precisely known location relative to

Steven B. Skaar; Issac Yalda-Mooshabad; William H. Brockman

1992-01-01

301

CAMERA OBJECT TRACKING FAST ALGORITHM  

Microsoft Academic Search

This paper addresses camera real-time object tracking problems. Here we present one camera object tracking solution based on block-matching technique. In our solution object is marked in the first frame, and afterwards its movement is tracked using the block-matching technique in limited area of the picture. The size of limited area depends on predicted object movement between two frames. We

Nikola Teslic; Vladimir Radenkovic; Snezana Crnogorac

302

Reductions in Injury Crashes Associated With Red Light Camera Enforcement in Oxnard, California  

PubMed Central

Objectives. This study estimated the impact of red light camera enforcement on motor vehicle crashes in one of the first US communities to employ such cameras—Oxnard, California. Methods. Crash data were analyzed for Oxnard and for 3 comparison cities. Changes in crash frequencies were compared for Oxnard and control cities and for signalized and nonsignalized intersections by means of a generalized linear regression model. Results. Overall, crashes at signalized intersections throughout Oxnard were reduced by 7% and injury crashes were reduced by 29%. Right-angle crashes, those most associated with red light violations, were reduced by 32%; right-angle crashes involving injuries were reduced by 68%. Conclusions. Because red light cameras can be a permanent component of the transportation infrastructure, crash reductions attributed to camera enforcement should be sustainable. (Am J Public Health. 2002;92:1822–1825)

Retting, Richard A.; Kyrychenko, Sergey Y.

2002-01-01

303

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.

2009-11-01

304

Robust Rotation Angle Estimator  

Microsoft Academic Search

The conventional method of estimating the rotation angle of a pattern using the principal axes is not suitable for circular symmetric patterns since their eigenvalues are similar in both directions. In the paper, a robust method of estimating a rotation angle using the phase information of Zernike moments is presented. The experimental results show that the proposed method estimates the

Whoi-yul Kim; Young-sung Kim

1999-01-01

305

Reading Angles in Maps  

ERIC Educational Resources Information Center

Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections…

Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S.

2014-01-01

306

What's My Angle?  

NSDL National Science Digital Library

This interactive module offers learners the opportunity to check their knowledge of angle measure and estimation, and the use of a protractor. There are ten activities that vary the tasks and the degree of precision. The site is designed for whiteboard demonstration as well, and it includes a tutorial on angle types and protractor use.

2011-01-01

307

Stable Angles of Slopes  

NSDL National Science Digital Library

In this activity, students use a box filled with sand to learn about factors controlling the angle of repose (the stable angle of a slope). They will will see what happens when slopes are oversteepened, and relate the experiment results to general understanding of instability of slopes.

308

Wide Angle Optical Systems.  

National Technical Information Service (NTIS)

A wide angle optical field flattening system for a multispectral scanner is described which provides a large field angles and high resolution at low f-numbers. The system utilizes a basic optical element in the form of a first flat surface of a reflecting...

F. Vicik

1979-01-01

309

Feature-based automatic configuration of semi-stationary multi-camera components  

NASA Astrophysics Data System (ADS)

Autonomously operating semi-stationary multi-camera components are the core modules of ad-hoc multi-view methods. On the one hand a situation recognition system needs overview of an entire scene, as given by a wide-angle camera, and on the other hand a close-up view from e.g. an active pan-tilt-zoom (PTZ) camera of interesting agents is required to further increase the information to e.g. identify those agents. To configure such a system we set the field of view (FOV) of the overview-camera in correspondence to the motor configuration of a PTZ camera. Images are captured from a uniformly moving PTZ camera until the entire field of view of the master camera is covered. Along the way, a lookup table (LUT) of motor coordinates of the PTZ camera and image coordinates in the master camera is generated. To match each pair of images, features (SIFT, SURF, ORB, STAR, FAST, MSER, BRISK, FREAK) are detected, selected by nearest neighbor distance ratio (NNDR), and matched. A homography is estimated to transform the PTZ image to the master image. With that information comprehensive LUTs are calculated via barycentric coordinates and stored for every pixel of the master image. In this paper the robustness, accuracy, and runtime are quantitatively evaluated for different features.

Grosselfinger, Ann-Kristin; Münch, David; Hübner, Wolfgang; Arens, Michael

2013-10-01

310

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

Microsoft Academic Search

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

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

2001-01-01

311

The MC and LFC cameras. [metric camera (MC); large format camera (LFC)  

NASA Technical Reports Server (NTRS)

The characteristics of the shuttle-borne Large Format Camera are listed. The LFC focal plane format was 23 by 46 cm, double the usual size, thereby acquiring approximately double the ground area. Forward motion compensation was employed. With the stable platform (shuttle) it was possible to use the slow exposure, high resolution, Kodak aerial films; 3414 and 3412 black and white, SO-242 color, and SO-131 aerochrome infrared. The camera was designed to maintain stability during varying temperature extremes of space.

Norton, Clarice L.; Schroeder, Manfried; Mollberg, Bernard

1986-01-01

312

Special Angle Pairs Discovery Activity  

NSDL National Science Digital Library

This lesson uses a discovery approach to identify the special angles formed when a set of parallel lines is cut by a transversal. During this lesson students identify the angle pair and the relationship between the angles. Students use this relationship and special angle pairs to make conjectures about which angle pairs are considered special angles.

Henry, Barbara

2012-04-16

313

Autoconfiguration of a Dynamic Nonoverlapping Camera Network  

Microsoft Academic Search

In order to monitor sufficiently large areas of interest for surveillance or any event detection, we need to look beyond stationary cameras and employ an automatically configurable network of nonoverlapping cameras. These cameras need not have an overlapping field of view and should be allowed to move freely in space. Moreover, features like zooming in\\/out, readily available in security cameras

Imran N. Junejo; Xiaochun Cao; Hassan Foroosh

2007-01-01

314

New View Generation with a Bicentric Camera  

Microsoft Academic Search

We propose a novel method for new view generation from a rectified sequence of images. Our new images correspond to a new camera model, which we call a bi-centric camera; in this model the centers of horizontal and vertical projections lie in different locations on the camera's optical axis. This model reduces to the regular pinhole camera when the two

Daphna Weinshall; Mi-suen Lee; Tomás Brodský; Miroslav Trajkovic; Doron Feldman

2002-01-01

315

Tailored slice selection in solid-state MRI by DANTE under magic-echo line narrowing  

NASA Astrophysics Data System (ADS)

We propose a method of slice selection in solid-state MRI by combining DANTE selective excitation with magic-echo (ME) line narrowing. The DANTE RF pulses applied at the ME peaks practically do not interfere with the ME line narrowing in the combined ME DANTE sequence. This allows straightforward tailoring of the slice profile simply by introducing an appropriate modulation, such as a sinc modulation, into the flip angles of the applied DANTE RF pulses. The utility of the method has been demonstrated by preliminary experiments performed on a test sample of adamantane.

Matsui, Shigeru; Masumoto, Hidefumi; Hashimoto, Takeyuki

2007-06-01

316

A narrow-angled corpus analysis of moves and strategies of the genre: ‘Letter of Application’  

Microsoft Academic Search

Nowadays, the term ‘genre’ is thought of as sociolinguistic activity through which members of a discourse community achieve their communicative goals. A genre approach to language teaching attempts to teach learners the main parts, ‘moves’, of a genre and the most common linguistic features associated with the moves. To date, many genre analyses have been carried out in academic and

Alex Henry; Robert L Roseberry

2001-01-01

317

A Narrow-Angled Corpus Analysis of Moves and Strategies of the Genre: "Letter of Application."  

ERIC Educational Resources Information Center

Many genre analyses have been carried out in English for specific purposes settings, but none has made full use of computer analysis to obtain exact linguistic information on the moves and strategies of a genre. This article reports a genre analysis, complemented by the Wordsmith suite of computer programs for corpus analysis, of the moves and…

Henry, Alex; Roseberry, Robert L.

2001-01-01

318

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

319

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

320

Dynamic calibration of pan-tilt-zoom cameras for traffic monitoring.  

PubMed

Pan-tilt-zoom (PTZ) cameras have been widely used in recent years for monitoring and surveillance applications. These cameras provide flexible view selection as well as a wider observation range. This makes them suitable for vision-based traffic monitoring and enforcement systems. To employ PTZ cameras for image measurement applications, one first needs to calibrate the camera to obtain meaningful results. For instance, the accuracy of estimating vehicle speed depends on the accuracy of camera calibration and that of vehicle tracking results. This paper presents a novel calibration method for a PTZ camera overlooking a traffic scene. The proposed approach requires no manual operation to select the positions of special features. It automatically uses a set of parallel lane markings and the lane width to compute the camera parameters, namely, focal length, tilt angle, and pan angle. Image processing procedures have been developed for automatically finding parallel lane markings. Interesting experimental results are presented to validate the robustness and accuracy of the proposed method. PMID:17036815

Song, Kai-Tai; Tai, Jen-Chao

2006-10-01

321

Method of rotation angle measurement in machine vision based on calibration pattern with spot array.  

PubMed

We propose a method of rotation angle measurement with high precision in machine vision. An area scan CCD camera, imaging lens, and calibration pattern with a spot array make up the measurement device for measuring the rotation angle. The calibration pattern with a spot array is installed at the rotation part, and the CCD camera is set at a certain distance from the rotation components. The coordinates of the spots on the calibration pattern is acquired through the vision image of the calibration pattern captured by the CCD camera. At the initial position of the calibration pattern, the camera is calibrated with the spot array; the mathematical model of distortion error of the CCD camera is built. With the equation of coordinate rotation measurement, the rotation angle of the spot array is detected. In the theoretic simulation, noise of different levels is added to the coordinates of the spot array. The experiment results show that the measurement device can measure the rotation angle precisely with a noncontact method. The standard deviation of rotation angle measurement is smaller than 3 arc sec. The measurement device can measure both microangles and large angles. PMID:20174168

Li, Weimin; Jin, Jing; Li, Xiaofeng; Li, Bin

2010-02-20

322

Method of rotation angle measurement in machine vision based on calibration pattern with spot array  

SciTech Connect

We propose a method of rotation angle measurement with high precision in machine vision. An area scan CCD camera, imaging lens, and calibration pattern with a spot array make up the measurement device for measuring the rotation angle. The calibration pattern with a spot array is installed at the rotation part, and the CCD camera is set at a certain distance from the rotation components. The coordinates of the spots on the calibration pattern is acquired through the vision image of the calibration pattern captured by the CCD camera. At the initial position of the calibration pattern, the camera is calibrated with the spot array; the mathematical model of distortion error of the CCD camera is built. With the equation of coordinate rotation measurement, the rotation angle of the spot array is detected. In the theoretic simulation, noise of different levels is added to the coordinates of the spot array. The experiment results show that the measurement device can measure the rotation angle precisely with a noncontact method. The standard deviation of rotation angle measurement is smaller than 3 arc sec. The measurement device can measure both microangles and large angles.

Li Weimin; Jin Jing; Li Xiaofeng; Li Bin

2010-02-20

323

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

324

Wide field camera observations of Baade's Window  

NASA Technical Reports Server (NTRS)

We have observed a field in Baade's Window using the Wide Field Camera (WFC) of the Hubble Space Telescope (HST) and obtain V- and I-band photometry down to V approximately 22.5. These data go several magnitudes fainter than previously obtained from the ground. The location of the break in the luminosity function suggests that there are a significant number of intermediate age (less than 10 Gyr) stars in the Galactic bulge. This conclusion rests on the assumptions that the extinction towards our field is similar to that seen in other parts of Baade's Window, that the distance to the bulge is approximately 8 kpc, and that we can determine fairly accurate zero points for the HST photometry. Changes in any one of these assumptions could increase the inferred age, but a conspiracy of lower reddening, a shorter distance to the bulge, and/or photometric zero-point errors would be needed to imply a population entirely older than 10 Gyr. We infer an initial mass function slope for the main-sequence stars, and find that it is consistent with that measured in the solar neighborhood; unfortunately, the slope is poorly constrained because we sample only a narrow range of stellar mass and because of uncertainties in the observed luminosity function at the faint end.

Holtzman, Jon A.; Light, R. M.; Baum, William A.; Worthey, Guy; Faber, S. M.; Hunter, Deidre A.; O'Neil, Earl J., Jr.; Kreidl, Tobias J.; Groth, E. J.; Westphal, James A.

1993-01-01

325

Effects of narrow-band filters on the output enalytical extension of the Bedrosian-Rice formulation  

NASA Astrophysics Data System (ADS)

The problem of determining the wave-form distortion produced by a (symetrical) narrow-band linear filter when an off-tune, simultaneously amplitude- and angle-modulated carrier is introduced, is analytically solved by an extension of the Bedrosian-Rice approach. Here, both the instantaneous angle and envelope of the resulting narrow-band output are determined. The results provide a basis for numerical calculations and extension to the more complex problem of interference effects produced by multiple inputs of the above type.

Middleton, D.

1985-04-01

326

Cameras for semiconductor process control  

NASA Technical Reports Server (NTRS)

The application of X-ray topography to semiconductor process control is described, considering the novel features of the high speed camera and the difficulties associated with this technique. The most significant results on the effects of material defects on device performance are presented, including results obtained using wafers processed entirely within this institute. Defects were identified using the X-ray camera and correlations made with probe data. Also included are temperature dependent effects of material defects. Recent applications and improvements of X-ray topographs of silicon-on-sapphire and gallium arsenide are presented with a description of a real time TV system prototype and of the most recent vacuum chuck design. Discussion is included of our promotion of the use of the camera by various semiconductor manufacturers.

Porter, W. A.; Parker, D. L.

1977-01-01

327

The GISMO-2 Bolometer Camera  

NASA Technical Reports Server (NTRS)

We present the concept for the GISMO-2 bolometer camera) which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISM0-2 will operate Simultaneously in the 1 mm and 2 mm atmospherical windows. The 1 mm channel uses a 32 x 40 TES-based Backshort Under Grid (BUG) bolometer array, the 2 mm channel operates with a 16 x 16 BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISM0-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera which is successfully operating at the 30m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals.

Staguhn, Johannes G.; Benford, Dominic J.; Fixsen, Dale J.; Hilton, Gene; Irwin, Kent D.; Jhabvala, Christine A.; Kovacs, Attila; Leclercq, Samuel; Maher, Stephen F.; Miller, Timothy M.; Moseley, Samuel H.; Sharp, Elemer H.; Wollack, Edward J.

2012-01-01

328

Geiger-mode ladar cameras  

NASA Astrophysics Data System (ADS)

The performance of Geiger-mode LAser Detection and Ranging (LADAR) cameras is primarily defined by individual pixel attributes, such as dark count rate (DCR), photon detection efficiency (PDE), jitter, and crosstalk. However, for the expanding LADAR imaging applications, other factors, such as image uniformity, component tolerance, manufacturability, reliability, and operational features, have to be considered. Recently we have developed new 32×32 and 32×128 Read-Out Integrated Circuits (ROIC) for LADAR applications. With multiple filter and absorber structures, the 50-?m-pitch arrays demonstrate pixel crosstalk less than 100 ppm level, while maintaining a PDE greater than 40% at 4 V overbias. Besides the improved epitaxial and process uniformity of the APD arrays, the new ROICs implement a Non-uniform Bias (NUB) circuit providing 4-bit bias voltage tunability over a 2.5 V range to individually bias each pixel. All these features greatly increase the performance uniformity of the LADAR camera. Cameras based on these ROICs were integrated with a data acquisition system developed by Boeing DES. The 32×32 version has a range gate of up to 7 ?s and can cover a range window of about 1 km with 14-bit and 0.5 ns timing resolution. The 32×128 camera can be operated at a frame rate of up to 20 kHz with 0.3 ns and 14-bit time resolution through a full CameraLink. The performance of the 32×32 LADAR camera has been demonstrated in a series of field tests on various vehicles.

Yuan, Ping; Sudharsanan, Rengarajan; Bai, Xiaogang; Boisvert, Joseph; McDonald, Paul; Labios, Eduardo; Morris, Bryan; Nicholson, John P.; Stuart, Gary M.; Danny, Harrison; van Duyne, Stephen; Pauls, Greg; Gaalema, Stephen

2011-05-01

329

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

330

The Sydney University PAPA camera  

NASA Astrophysics Data System (ADS)

The Precision Analog Photon Address (PAPA) camera is a photon-counting array detector that uses optical encoding to locate photon events on the output of a microchannel plate image intensifier. The Sydney University camera is a 256x256 pixel detector which can operate at speeds greater than 1 million photons per second and produce individual photon coordinates with a deadtime of only 300 ns. It uses a new Gray coded mask-plate which permits a simplified optical alignment and successfully guards against vignetting artifacts.

Lawson, Peter R.

1994-04-01

331

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.

332

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

333

Narrow-band ELF events observed from South Pole Station  

NASA Astrophysics Data System (ADS)

Extremely Low Frequency (ELF) waves are typically in the range of 3 Hz - 3 kHz and can play a role in acceleration and pitch-angle scattering of energetic particles in the radiation belts. Observations of a not uncommon, but not well studied ELF phenomenon are presented with ground-based data from South Pole Station. The narrow-band waves last approximately one or two minutes maintaining bandwidth over the course of the event, begin around 100 Hz, decrease to about 70 Hz, and typically show a higher frequency harmonic. The waves have only been documented at four locations - Heacock, 1974 (Alaska); Sentman and Ehring, 1994 (California); Wang et al, 2005 and Wang et al, 2011 (Taiwan); and Kim et al, 2006 (South Pole). The waves observed at the South Pole are not detected when the Sun drops below a 10 degree elevation angle, which is not true for the other locations. We extend the study of Kim et al, 2006, and explore possible generation mechanisms including sunlit ionosphere and ion cyclotron wave modes, as well as correspondence with energetic particle precipitation.

Heavisides, J.; Weaver, C.; Lessard, M.; Weatherwax, A. T.

2012-12-01

334

Transition Temperature of Narrow-Band Superconductors  

Microsoft Academic Search

The equation for the vertex part of a Cooper pair is developed in the Wannier representation to highlight the atomic nature of the electrons responsible for superconductivity in narrow energy bands. For a nondegenerate band and a short-range interaction between two electrons at sites n-->1 and n-->2, the transition temperature Tc is determined by a small set of coupled integral

J. Appel; W. Kohn

1971-01-01

335

Narrow-Band Applications of Communications Satellites.  

ERIC Educational Resources Information Center

This paper attempts to describe the advantages of "narrow-band" applications of communications satellites for education. It begins by discussing the general controversy surrounding the use of satellites in education, by placing the concern within the larger context of the general debate over the uses of new technologies in education, and by…

Cowlan, Bert; Horowitz, Andrew

336

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

337

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

338

Attenuation in very narrow photon beams  

Microsoft Academic Search

When one measures the half-value layer (HVL) or the attenuation coefficient (mu) in a high-energy photon beam, it is necessary to use a narrow beam to eliminate the scattered photons produced in the attenuator. However, lateral electron equilibrium will be compromised if the beam is too small. If the HVL and mu are based on measurements of absorbed dose, the

B. E. T. Bjaerngard; J. S. Tsai; R. K. Rice

1989-01-01

339

Method for shaping and aiming narrow beams. [sonar mapping and target identification  

NASA Technical Reports Server (NTRS)

A sonar method and apparatus is discribed which utilizes a linear frequency chirp in a transmitter/receiver having a correlator to synthesize a narrow beamwidth pattern from otherwise broadbeam transducers when there is relative velocity between the transmitter/receiver and the target. The chirp is so produced in a generator in bandwidth, B, and time, T, as to produce a time bandwidth product, TB, that is increased for a narrower angle. A replica of the chirp produced in a generator is time delayed and Doppler shifted for use as a reference in the receiver for correlation of received chirps from targets. This reference is Doppler shifted to select targets preferentially, thereby to not only synthesize a narrow beam but also aim the beam in azimuth and elevation.

Heyser, R. C. (inventor)

1981-01-01

340

Narrow Components in Hot Star Winds  

NASA Astrophysics Data System (ADS)

It has been known for some time that the non-saturated P Cygni profiles in hot stars often show sharp absorption components superposed on the broad absorption feature, but there is little understanding of their nature. Similar components of a highly variable nature are seen in many Be stars, and Henrichs, et at. (1982) have argued that it is due to episodic mass loss and is a common phenomenon in all early-type stars. However, it is not clear that we are seeing the same thing in the Be stars and the O stars. Lamers, Gathier and Snow (1982) found these narrow components in 17 of 25 O and B type stars observed with Copernicus. The velocities of the narrow absorption is approximately three-quarters of the terminal velocity in all the stars, implying that they are not variable in velocity. From a larger sample of IUE -data, Garmany (1982) has found that the strength of the narrow components is independent of the star's position in the HR diagram, which implies time variability. We propose to make use of archive data on a large number of O-type stars as well as additional observations to answer the following questions: do the narrow components occur in all O-type stars and are they variable in appearance and time? Are they really uncorrelated with the star's position in the H-R diagram? Can these narrow components be formed in the same manner as those in Be stars? In answering these questions, we hope to discover their mechanism of formation and how they are related to stellar winds in general.

Garmany, Catharine D.

341

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

342

Directing Performers for the Cameras.  

ERIC Educational Resources Information Center

An excellent way for an undergraduate, novice director of television and film to pick up background experience in directing performers for cameras is by participating in nonbroadcast-film activities, such as theatre, dance, and variety acts, both as performer and as director. This document describes the varieties of activities, including creative,…

Wilson, George P., Jr.

343

Fall detection using multiple cameras  

Microsoft Academic Search

Today, different ways are suggested to help elderly people in case of emergency. Our aim here is to propose a novel method, without any wearable device, to detect falls on the floor with a multiple cameras system. This proposal uses image analysis to localise people and reconstruct their 3D shape and position. The particularity of this contribution is the use

Edouard Auvinet; Lionel Reveret; Alain St-Arnaud; Jacqueline Rousseau; Jean Meunier

2008-01-01

344

Gamma-ray camera flyby  

ScienceCinema

Animation based on an actual classroom demonstration of the prototype CCI-2 gamma-ray camera's ability to image a hidden radioactive source, a cesium-137 line source, in three dimensions. For more information see http://newscenter.lbl.gov/feature-stories/2010/06/02/applied-nuclear-physics/.

345

Gamma-ray camera flyby  

SciTech Connect

Animation based on an actual classroom demonstration of the prototype CCI-2 gamma-ray camera's ability to image a hidden radioactive source, a cesium-137 line source, in three dimensions. For more information see http://newscenter.lbl.gov/feature-stories/2010/06/02/applied-nuclear-physics/.

None

2010-01-01

346

The Advanced Camera for Surveys  

Microsoft Academic Search

The Advanced Camera for Surveys (ACS) will be installed in the Hubble Space Telescope during the fourth servicing mission (SM-3B), which is scheduled for February 2002. All thermal-vacuum tests and alignment tests have been completed; the ACS meets the performance goals that were set at the beginning of the program. By the time of the AAS meeting the ACS should

H. C. Ford

2001-01-01

347

Camera lens adapter magnifies image  

NASA Technical Reports Server (NTRS)

Polaroid Land camera with an illuminated 7-power magnifier adapted to the lens, photographs weld flaws. The flaws are located by inspection with a 10-power magnifying glass and then photographed with this device, thus providing immediate pictorial data for use in remedial procedures.

Moffitt, F. L.

1967-01-01

348

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

349

The Soft Shadow Occlusion Camera  

Microsoft Academic Search

A fundamental challenge for existing shadow map based algorithms is dealing with partially illuminated surfaces. A conventional shadow map built with a pinhole camera only provides a binary visibility sorting of the scene, and this all-or-nothing approach to visibility does not capture penu m- bral regions. We present an interactive soft shadow algorithm based on a variant of the depth

Qi Mo; Voicu Popescu; Chris Wyman

2007-01-01

350

Virtual Camera Planning: A Survey  

Microsoft Academic Search

Modelling, animation and rendering has dominated research computer graphics yielding increasingly rich and realistic virtual worlds. The complexity, richness and quality of the virtual worlds are viewed through a single media that is a virtual camera. In order to properly convey information, whether related to the characters in a scene, the aesthetics of the composition or the emotional impact of

Marc Christie; Rumesh Machap; Jean-marie Normand; Patrick Olivier; Jonathan Pickering

2005-01-01

351

Optically trapped atomic resonant devices for narrow linewidth spectral imaging  

NASA Astrophysics Data System (ADS)

This thesis focuses on the development of atomic resonant devices for spectroscopic applications. The primary emphasis is on the imaging properties of optically thick atomic resonant fluorescent filters and their applications. In addition, this thesis presents a new concept for producing very narrow linewidth light as from an atomic vapor lamp pumped by a nanosecond pulse system. This research was motivated by application for missile warning system, and presents an innovative approach to a wide angle, ultra narrow linewidth imaging filter using a potassium vapor cell. The approach is to image onto and collect the fluorescent photons emitted from the surface of an optically thick potassium vapor cell, generating a 2 GHz pass-band imaging filter. This linewidth is narrow enough to fall within a Fraunhefer dark zone in the solar spectrum, thus make the detection solar blind. Experiments are conducted to measure the absorption line shape of the potassium resonant filter, the quantum efficiency of the fluorescent behavior, and the resolution of the fluorescent image. Fluorescent images with different spatial frequency components are analyzed by using a discrete Fourier transform, and the imaging capability of the fluorescent filter is described by its Modulation Transfer Function. For the detection of radiation that is spectrally broader than the linewidth of the potassium imaging filter, the fluorescent image is seen to be blurred by diffuse fluorescence from the slightly off resonant photons. To correct this, an ultra-thin potassium imaging filter is developed and characterized. The imaging property of the ultra-thin potassium imaging cell is tested with a potassium seeded flame, yielding a resolution image of ˜ 20 lines per mm. The physics behind the atomic resonant fluorescent filter is radiation trapping. The diffusion process of the resonant photons trapped in the atomic vapor is theoretically described in this thesis. A Monte Carlo method is used to simulate the absorption and fluorescence. The optimum resolution of the fluorescent image is predicted by simulation. Radiation trapping is also shown to be useful for the generation of ultra-narrow linewidth light from an atomic vapor flash lamp. A 2 nanosecond, high voltage pulse is used to excite low pressure mercury vapor mixed with noble gases, producing high intensity emission at the mercury resonant line at 253.7 nm. With a nanosecond pumping time and high electrical current, the radiation intensity of the mercury discharge is increased significantly compared to a normal glow discharge lamp, while simultaneously suppressing the formation of an arc discharge. By avoiding the arc discharge, discrete spectral lines of mercury were kept at narrow bandwidth. Due to radiation trapping, the emission linewidth from the nanosecond mercury lamp decreases with time and produces ultra-narrow linewidth emission 100 ns after of the excitation, this linewidth is verified by absorption measurements through low pressure mercury absorption filter. The lamp is used along with mercury absorption filters for spectroscopic applications, including Filtered Rayleigh Scattering with different CO2 pressures and Raman scattering from methanol.

Qian, Lipeng

352

Estimating physical camera parameters based on multisprite motion estimation  

NASA Astrophysics Data System (ADS)

Global-motion estimation algorithms as they are employed in the MPEG-4 or H.264 video coding standards describe motion with a set of abstract parameters. These parameters model the camera motion, but they cannot be directly related to a physical meaning like rotation angles or the focal-length. We present a two step algorithm to factorize these abstract parameters into physically meaningful operations. The first step applies a fast linear estimation method. In an optional second step, these parameters can be refined with a non-linear optimization algorithm. The attractivity of our algorithm is its combination with the multi-sprite concept that allows for unrestricted rotational camera motion, including varying of focal-lengths. We present results for several sequences, including the well-known stefan sequence, which can only be processed with the multi-sprite approach.

Farin, Dirk; de With, Peter H. N.

2005-03-01

353

Directional reflectance of vegetation measured by a calibrated digital camera  

NASA Astrophysics Data System (ADS)

Obtaining directional reflectance information for vegetation canopies is often an expensive and time-consuming process. We present here a simple approach based on the use of an inexpensive digital camera equipped with a wide-angle lens. By the imaging of a large homogeneous area, a single image captures multiple views of a vegetation canopy. This gives a directional reflectance distribution fully sampled for view direction and free of variations in Sun elevation and azimuth. We determined the radiometric response of the camera sensor CCD s at the focal point and then extended this calibration to the full CCD array by using averaged images of clear blue sky. We evaluated the utility of the system by obtaining directional reflectance distributions of two vegetation targets, grass ( Lolium spp) and pine forest ( Pinus radiata ), for red visible light. The precision of the derived biangular pattern of reflectance was 7 .

Dymond, John R.; Trotter, Craig M.

1997-06-01

354

A cubic gamma camera with an active collimator.  

PubMed

Mechanical collimation with photon absorption and electronic collimation using Compton scattering are combined to form a cubic gamma camera with an active collimator. The collimator is made active by constructing it with a uniformly redundant array of patterned Bi4Ge3O12 (BGO) scintillators, which not only attenuates incident radiations but also detects scattered radiation, in a gamma-camera consisting of and five planar CsI(Na) scintillators. The entire module forms a cubic structure that generates images on the basis of radiation interactions from every direction. The coverage angle for detecting scattered radiation is 2? with a detection efficiency approximately 17 times higher than previous systems that comprised only one pair of detectors. PMID:24709608

Lee, Taewoong; Lee, Wonho

2014-08-01

355

Search for atmospheric holes with the Viking cameras  

SciTech Connect

Images taken with the two ultraviolet cameras on board the Viking spacecraft were examined for evidence of transient decreases of Earth's ultraviolet dayglow. Comparison of near-limb observations of dayglow intensities with those at smaller angles to the nadir with the camera sensitive to OI 130.4 nm emissions supports the existence of transient decreases in the near-nadir dayglow. However, the amount of near-nadir imaging is severely limited and only several significant events are found. More decisive confirmation of the existence of such transient decreases must await a larger survey from another spacecraft. The diameters of these regions as detected with Viking are {approximately}50 to 100 km. Occurrence frequencies, intensity decreases, and dimensions for these clusters of darkened pixels are similar to those previously reported for such events, or atmospheric holes, as seen in images of the ultraviolet dayglow with Dynamics Explorer 1.

Frank, L.A.; Sigwarth, J.B.; Craven, J.D. (Univ. of Iowa, Iowa City (USA))

1989-12-01

356

G-APDs in Cherenkov astronomy: The FACT camera  

NASA Astrophysics Data System (ADS)

Geiger-mode avalanche photodiodes (G-APD, SiPM) are a much discussed alternative to photomultiplier tubes in Cherenkov astronomy. The First G-APD Cherenkov Telescope (FACT) collaboration builds a camera based on a hexagonal array of 1440 G-APDs and has now finalized its construction phase. A light-collecting solid PMMA cone is glued to each G-APD to eliminate dead space between the G-APDs by increasing the active area, and to restrict the light collection angle of the sensor to the reflector area in order to reduce the amount of background light. The processing of the signals is integrated in the camera and includes the digitization using the domino ring sampling chip DRS4.

Krähenbühl, T.; Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, V.; Djambazov, L.; Dorner, D.; Farnier, C.; Gendotti, A.; Grimm, O.; von Gunten, H.; Hildebrand, D.; Horisberger, U.; Huber, B.; Kim, K.-S.; Köhne, J.-H.; Krumm, B.; Lee, M.; Lenain, J.-P.; Lorenz, E.; Lustermann, W.; Lyard, E.; Mannheim, K.; Meharga, M.; Neise, D.; Nessi-Tedaldi, F.; Overkemping, A.-K.; Pauss, F.; Renker, D.; Rhode, W.; Ribordy, M.; Rohlfs, R.; Röser, U.; Stucki, J.-P.; Schneider, J.; Thaele, J.; Tibolla, O.; Viertel, G.; Vogler, P.; Walter, R.; Warda, K.; Weitzel, Q.

2012-12-01

357

What Is the Angle?  

NSDL National Science Digital Library

This activity will help students understand how the angle of the Sun affects temperatures around the globe. After experimenting with a heat lamp and thermometers at differing angles, students apply what they learned to explain temperature variations on Earth. The printable six-page handout includes a series of inquiry-based questions to get students thinking about what they already know about temperature patterns, detailed experiment directions, and a worksheet that will help students use the experiment results to gain a deeper understanding of seasonal temperature changes and why Antarctica is always so cold. The students will explore all the angles of sunlight with a few thermometers and a heat lamp and understand why there is such a dramatic temperature change between the equator and the South Pole.

358

Using Inscribed Angles and Polygons  

NSDL National Science Digital Library

This unit will teach you about inscribed angles, intercepted arcs, their measures, inscribed polygons, and their associated theorems. OK, time for notes! Define Inscribed Angles, using the following website (Only define the inscribed angle from this site): Inscribed Angle Definition Using this new idea, you can use the following activity to figure out the formula for the measure of an inscribed angle: Inscribed Angle Formula Discovery The whole lesson depends upon this definition. Define Intercepted Arc, Inscribed polygons, ...

Neubert, Mrs.

2011-03-10

359

What's the Angle?  

NSDL National Science Digital Library

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

360

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

361

The role of contact angle on unstable flow formation during infiltration and drainage in wettable porous media  

NASA Astrophysics Data System (ADS)

The impact of contact angle on 2-D spatial and temporal water-content distribution during infiltration and drainage was experimentally studied. The 0.3-0.5 mm fraction of a quartz dune sand was treated and turned subcritically repellent (contact angle of 33°, 48°, 56°, and 75° for S33, S48, S56, and S75, respectively). The media were packed uniformly in transparent flow chambers and water was supplied to the surface as a point source at different rates (1-20 ml/min). A sequence of gray-value images was taken by CCD camera during infiltration and subsequent drainage; gray values were converted to volumetric water content by water volume balance. Narrow and long plumes with water accumulation behind the downward moving wetting front (tip) and negative water gradient above it (tail) developed in the S56 and S75 media during infiltration at lower water application rates. The plumes became bulbous with spatially uniform water-content distribution as water application rates increased. All plumes in these media propagated downward at a constant rate during infiltration and did not change their shape during drainage. In contrast, regular plume shapes were observed in the S33 and S48 media at all flow rates, and drainage profiles were nonmonotonic with a transition plane at the depth that water reached during infiltration. Given that the studied media have similar pore-size distributions, the conclusion is that imbibition hindered by the nonzero contact angle induced pressure buildup at the wetting front (dynamic water-entry value) that controlled the plume shape and internal water-content distribution during infiltration and drainage.

Wallach, Rony; Margolis, Michal; Graber, Ellen R.

2013-10-01

362

21 CFR 892.1110 - Positron camera.  

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1110 Positron camera. (a) Identification. A positron camera is a...

2014-04-01

363

21 CFR 892.1110 - Positron camera.  

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1110 Positron camera. (a) Identification. A positron camera is a...

2011-04-01

364

21 CFR 892.1110 - Positron camera.  

Code of Federal Regulations, 2012 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1110 Positron camera. (a) Identification. A positron camera is a...

2012-04-01

365

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

366

Automatic Focusing Devices for Photographic Cameras.  

National Technical Information Service (NTIS)

Automatic focusing systems for either still or movie cameras are defined. System requirements, depending on camera characteristics (aperture), lighting conditions or the use of high-speed color film, are identified. Passive and active systems are consider...

K. Birgmeier A. Hell

1980-01-01

367

Automatic Focussing Devices for Photographic Cameras.  

National Technical Information Service (NTIS)

High-aperture cameras and photography under poor light conditions make focussing with conventional methods very difficult. Hence, the need for autofocussing systems. Initial requirements for autofocussing systems for both still and cine cameras were defin...

K. Birgmeir A. Hell

1983-01-01

368

21 CFR 892.1110 - Positron camera.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1110 Positron camera. (a) Identification. A positron camera is a...

2013-04-01

369

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

370

Narrow-Line Seyfert 1 Galaxies  

NASA Astrophysics Data System (ADS)

The primary work during this year has been the analysis and interpretation of our HST spectra from two extreme Narrow-line Seyfert 1 galaxies (NLS1s) Infrared Astronomy Satellite (IRAS) 13224-3809 and 1H 0707-495. This work has been presented as an invited talk at the workshop entitled "Observational and theoretical progress in the Study of Narrow-line Seyfert 1 Galaxies" held in Bad Honnef, Germany December 8-11, as a contributed talk at the January 2000 AAS meeting in Atlanta, Georgia, and as a contributed talk at the workshop "Probing the Physics of Active Galactic Nuclei by Multiwavelength Monitoring" held at Goddard Space Flight Center June 20-22, 2000.

Leighly, Karen M.

2000-09-01

371

Narrow linewidth single frequency microfiber laser.  

PubMed

A compact 2 kHz linewidth single frequency microfiber ring laser is demonstrated. Microfiber, with a diameter of 1.88 ?m, which is drawn from an Er(3+)/Yb(3+) co-doped phosphate glass fiber, serves as the gain medium. By using this microfiber, a double-knot resonator with a total length of 1.75 mm is constructed. Based on this resonator, a narrow linewidth single frequency laser with output power higher than 0.95 ?W is obtained at the wavelength of 1536.1 nm. The linewidth of this microfiber laser is as narrow as 2 kHz, and the side-mode-suppression ratio is higher than 38 dB. PMID:23073450

Fan, Wei; Gan, Jiulin; Zhang, Zhishen; Wei, Xiaoming; Xu, Shanhui; Yang, Zhongmin

2012-10-15

372

Narrow-Line Seyfert 1 Galaxies  

NASA Technical Reports Server (NTRS)

The primary work during this year has been the analysis and interpretation of our HST spectra from two extreme Narrow-line Seyfert 1 galaxies (NLS1s) Infrared Astronomy Satellite (IRAS) 13224-3809 and 1H 0707-495. This work has been presented as an invited talk at the workshop entitled "Observational and theoretical progress in the Study of Narrow-line Seyfert 1 Galaxies" held in Bad Honnef, Germany December 8-11, as a contributed talk at the January 2000 AAS meeting in Atlanta, Georgia, and as a contributed talk at the workshop "Probing the Physics of Active Galactic Nuclei by Multiwavelength Monitoring" held at Goddard Space Flight Center June 20-22, 2000.

Leighly, Karen M.

2000-01-01

373

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

374

Mass enhancement in narrow-band systems  

Microsoft Academic Search

A perturbative study of the Holstein molecular crystal model which accounts for lattice structure and dimensionality effects is presented. Anti-adiabatic conditions peculiar to narrow-band materials and an intermediate-to-strong electron-phonon coupling are assumed. The polaron effective mass depends crucially in all dimensions on the intermolecular coupling strengths which also affect the size of the lattice deformation associated with the small-polaron formation.

Marco Zoli

2000-01-01

375

Decay Modes of Narrow Molecular Resonances  

SciTech Connect

The heavy-ion radiative capture reactions 12C(12C,{gamma})24Mg and 12C(16O,{gamma})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. [IPHC, UMR-7178, ULP(Strasbourg1) and CNRS/IN2P3, F-67037 Strasbourg Cedex 2 (France); Jenkins, D. G.; Glover, R. G.; Kent, P. E. [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Hutcheon, D.; Davis, C.; Pearson, J. E. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Lister, C. J. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2006-08-14

376

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

377

A CCD photometric camera for satellite observation  

NASA Astrophysics Data System (ADS)

A CCD camera for photometric measurement of satellites has been built, tested, and has been integrated into the Experimental Test System (ETS). This report describes the camera, the computer system and programs used to collect data, the camera's sensitivity parameters, the sensitivity of the camera on the ETS 31-inch Telescope, and its projected sensitivity on Ground-Based Electro-Optical Deep Space Surveillance System (GEODSS) main telescope.

Mayer, G. J.; MacDonald, M. J.; Pong, N. G. S.

1983-11-01

378

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

379

Metal fluxes in the Mersey Narrows  

NASA Astrophysics Data System (ADS)

Surveys of the Mersey estuary in north-west England were undertaken near the mouth of the estuary in the region known as the Mersey Narrows. Tidal fluxes of suspended and dissolved matter, particularly heavy metals, through the Mersey Narrows were investigated. This paper gives results of conducting four intensive cross-sectional surveys of the Narrows, during which currents, salinities, turbidity and water samples were obtained systematically at numerous positions, throughout selected tidal cycles. Over 300 water samples per survey were analysed to yield suspended and dissolved concentrations of the elements As, Cd, Cr, Cu, Hg, Ni, Pb and Zn, at all states of the tide. Suspended solids, concentrations and salinities were also measured. Suspended particulates account for the majority of each element present, except for cadmium, which was present in roughly equal dissolved and suspended fractions. From the tidal current and water quality data, calculations were made of hour-by-hour fluxes of each component, to show the detailed ebb and flow of heavy metals and the net tidal transport of each component. Although some differences between landward transport on the flood tide and seaward transport on the ebb were not significant, the more definite results consistently showed a seawards net transport. For spring tides of high tidal range, there was an indication of an opposite tendency, reducing the seawards transport or even reversing it, for certain suspended components.

Cole, J. A.; Whitelaw, K.

380

Yaw Angle Demonstration  

NASA Technical Reports Server (NTRS)

The Large Angle Magnetic Suspension Test Fixture (LAMSTF) is a 5 degree-of -freedom repulsive force magnetic suspension system designed to study the control of objects over large magnetic gaps. A digital control algorithm uses 6 sets of laser-sheet sensors and 5 control coils to position a cylinder 3' above the plane of electromagnetics

1994-01-01

381

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.

382

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

383

Silicone Contamination Camera for Developed for Shuttle Payloads  

NASA Technical Reports Server (NTRS)

On many shuttle missions, silicone contamination from unknown sources from within or external to the shuttle payload bay has been a chronic problem plaguing experiment payloads. There is currently a wide range of silicone usage on the shuttle. Silicones are used to coat the shuttle tiles to enhance their ability to shed rain, and over 100 kg of RTV 560 silicone is used to seal white tiles to the shuttle surfaces. Silicones are also used in electronic components, potting compounds, and thermal control blankets. Efforts to date to identify and eliminate the sources of silicone contamination have not been highly successful and have created much controversy. To identify the sources of silicone contamination on the space shuttle, the NASA Lewis Research Center developed a contamination camera. This specially designed pinhole camera utilizes low-Earth-orbit atomic oxygen to develop a picture that identifies sources of silicone contamination on shuttle-launched payloads. The volatile silicone species travel through the aperture of the pinhole camera, and since volatile silicone species lose their hydrocarbon functionalities under atomic oxygen attack, the silicone adheres to the substrate as SiO_x. This glassy deposit should be spatially arranged in the image of the sources of silicone contamination. To view the contamination image, one can use ultrasensitive thickness measurement techniques, such as scanning variable-angle ellipsometry, to map the surface topography of the camera's substrate. The demonstration of a functional contamination camera would resolve the controversial debate concerning the amount and location of contamination sources, would allow corrective actions to be taken, and would demonstrate a useful tool for contamination documentation on future shuttle payloads, with near negligible effect on cost and weight.

1996-01-01

384

Scheduling an active camera to observe people  

Microsoft Academic Search

Remote identification of people is an important capability for security systems. Automatically controlling a pan-tilt-zoom camera is an effective way to collect high resolution video or images of people in an unconstrained environment. Often there will be more people in an area than cameras available. The cameras must then divide their time among the people in order to view everyone.

Cash J. Costello; Christopher P. Diehl; Amit Banerjee; Hesky Fisher

2004-01-01

385

Introducing the Single Camera VTR System.  

ERIC Educational Resources Information Center

This basic manual designed to introduce helical scan videotape recording is written in nontechnical style. The operating principles of videotape recording are explained, and practical standards for selecting basic equipment for a single camera system are suggested. This includes cameras, camera supports, lenses, cables, tape recorders, monitors,…

Mattingly, Grayson; Smith, Welby

386

A New Concept of Security Camera Monitoring  

Microsoft Academic Search

We present a novel framework for encoding images obtained by a security monitoring camera with protecting the privacy of moving objects in the images. We are motivated by the fact that although secu- rity monitoring cameras can deter crimes, they may infringe the privacy of those who and objects which are recorded by the cameras. Moving objects, whose privacy should

Kenichi YABUTA; Hitoshi KITAZAWA; Toshihisa TANAKA

387

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

388

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

389

An Effective Surveillance System Using Thermal Camera  

Microsoft Academic Search

Thermography, or thermal visualization is a type of infrared visualization. Thermographic cameras are used in many heavy factories like metal recycling factories, wafer production factories and etc for monitoring the temperature conditions of the machines. Besides, thermographic camera can be used to detect trespassers in environment with poor lighting condition, whereby, the conventional digital cameras are less applicable in. In

Wai Kit Wong; Poi Ngee Tan; Chu Kiong Loo

2009-01-01

390

Intelligent Camera Control in a Virtual Environment  

Microsoft Academic Search

This paper describes a framework for exploring intelligent camera controls in a 3D virtual environment. It presents a methodology for designing the underlying camera controls based on an analysis of what tasks are to be required in a specific environment. Once an underlying camera framework is built, a variety of interfaces can be connected to the framework. A virtual museum

Steven M. Drucker; David Zeltzer

1994-01-01

391

TRENDS FOR DIGITAL AERIAL MAPPING CAMERAS  

Microsoft Academic Search

More and more analogue cameras are replaced by digital aerial cameras, which is a ma jor change for the industry in various aspects. Organizations tendering out aerial photo flight projects will need information about new sensors on the market and their characteristics. There are big differences in accuracy, image quality and data format. Camera buyers have the challenge to select

Klaus J. Neumann

392

Recording of essential ballistic data with a new generation of digital ballistic range camera  

NASA Astrophysics Data System (ADS)

Scientists and Engineers still require to record essential parameters during the design and testing of new (or refined) munitions. This essential data, such as velocities, spin, pitch and yaw angles, sabot discards, impact angles, target penetrations, behind target effects and post impact delays, need to be recorded during dynamic, high velocity, and dangerous firings. Traditionally these parameters have been recorded on high-speed film cameras. With the demise of film as a recording media a new generation of electronic digital recording cameras has come to be accepted method of allowing these parameters to be recorded and analysed. Their obvious advantage over film is their instant access to records and their ability for almost instant analysis of records. This paper will detail results obtained using a new specially designed Ballistic Range Camera manufactured by Specialised Imaging Ltd.

Haddleton, Graham P.; Honour, Jo

2007-01-01

393

Nonmetric calibration of camera lens distortion: differential methods and robust estimation  

Microsoft Academic Search

This paper addresses the problem of calibrating camera lens distortion, which can be significant in medium to wide angle lenses. Our approach is based on the analysis of distorted images of straight lines. We derive new distortion measures that can be optimized using nonlinear search techniques to find the best distortion parameters that straighten these lines. Unlike the other existing

Moumen Ahmed; Aly A. Farag

2005-01-01

394

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

395

Automated digital camera sensor characterization  

NASA Astrophysics Data System (ADS)

The color characterization of professional imaging devices typically involves the capture of a reference color target under the scene-specific lighting conditions and the use of dedicated profiling software. However, the limited set of color patches on the target may not adequately represent the reflection spectra found in the scene. We present a solution developed in collaboration with a camera manufacturer for the automatic color characterization of the sensors without the need of a physical color target. The optimal color transforms are computed based on the individually measured sensor spectral sensitivities, computer generated sets of color spectra forming a virtual characterization target and a mathematical model of the camera. The use of a virtual target enables the optimization of the color transform for specific image capturing situations by selective generation of the reflection spectra.

Normand, C.; Fornaro, P.; Gschwind, R.

2007-03-01

396

Electronographic cameras for space astronomy.  

NASA Technical Reports Server (NTRS)

Magnetically-focused electronographic cameras have been under development at the Naval Research Laboratory for use in far-ultraviolet imagery and spectrography, primarily in astronomical and optical-geophysical observations from sounding rockets and space vehicles. Most of this work has been with cameras incorporating internal optics of the Schmidt or wide-field all-reflecting types. More recently, we have begun development of electronographic spectrographs incorporating an internal concave grating, operating at normal or grazing incidence. We also are developing electronographic image tubes of the conventional end-window-photo-cathode type, for far-ultraviolet imagery at the focus of a large space telescope, with image formats up to 120 mm in diameter.

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

1972-01-01

397

Wideband comet camera lens design  

NASA Technical Reports Server (NTRS)

A quarter-meter diameter, modified Ritchey-Chretien camera is described for spacecraft-based observation of Halley's Comet. The system will operate over an unusually broad spectral region, from 0.1216 micron (the hydrogen Lyman-alpha line) to 1.1 microns using reflective primary and secondary mirror optics and a thin UV-grade lithium fluoride refractive element as a field corrector near the image plane. The f/12, 3000 mm focal length camera has a 0.4 deg full field of view for operation with a 15 x 15 mm charge-coupled device detector array. The UV-enhanced silicon CCD detector is a 1000 x 1000 array of 15 micron pixels which establishes the system resolution requirement. The optical design and performance are discussed, with an emphasis on the image analysis with respect to pixel resolution elements used for viewing extended objects such as comets.

Huber, E. D.

1981-01-01

398

Development of Nikon Space Camera  

NASA Astrophysics Data System (ADS)

After Soviet cosmonaut Gagarin succeeded as the first human to orbit the Earth in 1961, American astronaut Glenn succeeded in a similar mission the following year, 1962, aboard the Friendship 7 spacecraft for the Mercury-Atlas 6 mission. Since before this event, the National Aeronautics and Space Administration (NASA) has used a large amount of imaging equipment to successfully record major astronomical phenomena and acquire analysis data. Nikon has made significant contributions to the American space program since the Apollo Program by continuously providing NASA with space cameras that meet their strict demands in terms of reliability, quality and durability under the most extreme conditions. The following details our achievements and specifics regarding modifications necessary for use in space, and also touches on space cameras provided by manufacturers other than Nikon, for which information may be quite limited.

Goto, Tetsuro

399

Rotating-prism scanning system to equip an NFOV camera lens  

Microsoft Academic Search

This paper presents the results given by the nominal design and tolerance analysis of a narrow-field-of-view camera lens equipped with a rotating prism scanning system. The first aspects taken into consideration have been the compensation of the chromatic aberration, distortion reduction, and the correlation between depth-of-field and lens resolution. Then, a rigorous approach to determine the relationship between the field-of-regard

Eugene O. Curatu; Paul C. Chevrette; Daniel St-Germain

1999-01-01

400

ISO camera array development status  

NASA Astrophysics Data System (ADS)

A short outline is given of the Infrared Space Observatory Camera (ISOCAM), one of the 4 instruments onboard the Infrared Space Observatory (ISO), with the current status of its two 32x32 arrays, an InSb charge injection device (CID) and a Si:Ga direct read-out (DRO), and the results of the in orbit radiation simulation with gamma ray sources. A tentative technique for the evaluation of the flat fielding accuracy is also proposed.

Sibille, F.; Cesarsky, C.; Agnese, P.; Rouan, D.

1989-10-01

401

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

2008-12-01

402

ISO camera array development status  

NASA Technical Reports Server (NTRS)

A short outline is given of the Infrared Space Observatory Camera (ISOCAM), one of the 4 instruments onboard the Infrared Space Observatory (ISO), with the current status of its two 32x32 arrays, an InSb charge injection device (CID) and a Si:Ga direct read-out (DRO), and the results of the in orbit radiation simulation with gamma ray sources. A tentative technique for the evaluation of the flat fielding accuracy is also proposed.

Sibille, F.; Cesarsky, C.; Agnese, P.; Rouan, D.

1989-01-01

403

Vista IR Camera: Conceptual Design  

Microsoft Academic Search

This paper describes the conceptual design for a near infrared camera for the Visible and Infrared Survey Telescope for Astronomy (VISTA). VISTA is a 4m class survey telescope that is being designed to perform pre-planned, ground-based astronomical surveys of the Southern sky from ESO's Cerro Paranal Observatory in Chile. The IR Surveys will be carried out in the J, H

Ian Egan; Eli Atad-Ettedgui; Mark M. Casali; Simon C. Craig; Maureen A. Ellis; Peter R. Hastings; David M. Henry; Ken Laidlaw; John Murray; Malcom Stewart; Will Sutherland

2002-01-01

404

Human-camera interaction: an exploratory study on people's emotions and attitude towards cameras  

Microsoft Academic Search

Motivation -- Cameras are increasingly dominating our life, but do these influence our behaviour as well? What are people's emotions and attitude towards camera surveillance? Research approach -- In an exploratory study (n=23) people's emotional reactions to (visible and hidden) cameras were observed. Next, a survey studied people's attitude towards camera surveillance at different places (n=102). Findings\\/Design -- Results suggest

Manon van der Sar; Ingrid Mulder

2010-01-01

405

Automatic tracking sensor camera system  

NASA Astrophysics Data System (ADS)

We are developing a sensor camera system for automatically tracking and determining the positions of subjects moving in three-dimensions. The system is intended to operate even within areas as large as soccer fields. The system measures the 3D coordinates of the object while driving the pan and tilt movements of camera heads, and the degree of zoom of the lenses. Its principal feature is that it automatically zooms in as the object moves farther away and out as the object moves closer. This maintains the area of the object as a fixed position of the image. This feature makes stable detection by the image processing possible. We are planning to use the system to detect the position of a soccer ball during a soccer game. In this paper, we describe the configuration of the developing automatic tracking sensor camera system. We then give an analysis of the movements of the ball within images of games, the results of experiments on method of image processing used to detect the ball, and the results of other experiments to verify the accuracy of an experimental system. These results show that the system is sufficiently accurate in terms of obtaining positions in three-dimensions.

Tsuda, Takao; Kato, Daiichiro; Ishikawa, Akio; Inoue, Seiki

2001-04-01

406

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

407

Camera calibration for color research  

NASA Astrophysics Data System (ADS)

In this paper we introduce a new method for determining the relationship between signal spectra and camera RGB which is required for many applications in color. We work with the standard camera model, which assumes that the response is linear. We also provide an example of how the fitting procedure can be augmented to include fitting for a previously estimated non-linearity. The basic idea of our method is to minimize squared error subject to linear constraints, which enforce positivity and range of the result. It is also possible to constrain the smoothness, but we have found that it is better to add a regularization expression to the objective function to promote smoothness. With this method, smoothness and error can be traded against each other without being restricted by arbitrary bounds. The method is easily implemented as it is an example of a quadratic programming problem, for which there are many software solutions available. In this paper we provide the results using this method and others to calibrate a Sony DXC-930 CCD color video camera. We find that the method gives low error, while delivering sensors which are smooth and physically realizable. Thus we find the method superior to methods which ignore any of these considerations.

Barnard, Kobus; Funt, Brian V.

1999-05-01

408

Bio-inspired hemispherical compound eye camera  

NASA Astrophysics Data System (ADS)

Compound eyes in arthropods demonstrate distinct imaging characteristics from human eyes, with wide angle field of view, low aberrations, high acuity to motion and infinite depth of field. Artificial imaging systems with similar geometries and properties are of great interest for many applications. However, the challenges in building such systems with hemispherical, compound apposition layouts cannot be met through established planar sensor technologies and conventional optics. We present our recent progress in combining optics, materials, mechanics and integration schemes to build fully functional artificial compound eye cameras. Nearly full hemispherical shapes (about 160 degrees) with densely packed artificial ommatidia were realized. The number of ommatidia (180) is comparable to those of the eyes of fire ants and bark beetles. The devices combine elastomeric compound optical elements with deformable arrays of thin silicon photodetectors, which were fabricated in the planar geometries and then integrated and elastically transformed to hemispherical shapes. 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).

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

2014-03-01

409

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

410

Collaborative real-time scheduling of multiple PTZ cameras for multiple object tracking in video surveillance  

NASA Astrophysics Data System (ADS)

This paper proposes a multi-PTZ-camera control mechanism to acquire close-up imagery of human objects in a surveillance system. The control algorithm is based on the output of multi-camera, multi-target tracking. Three main concerns of the algorithm are (1) the imagery of human object's face for biometric purposes, (2) the optimal video quality of the human objects, and (3) minimum hand-off time. Here, we define an objective function based on the expected capture conditions such as the camera-subject distance, pan tile angles of capture, face visibility and others. Such objective function serves to effectively balance the number of captures per subject and quality of captures. In the experiments, we demonstrate the performance of the system which operates in real-time under real world conditions on three PTZ cameras.

Liu, Yu-Che; Huang, Chung-Lin

2013-03-01

411

Attitude and Interlock Angle Estimation Using Split-Field-of-View Star Tracker1  

Microsoft Academic Search

An efficient Kalman filter based algorithm has been proposed for the spacecraft attitude estimation problem using a novel split-field-of-view star camera and three-axis rate gyros. The conventional spacecraft attitude algorithm has been modified for on-orbit estimation of interlock angles between the two fields of view of star camera, gyro axis, and the spacecraft body frame. Real time estimation of the

Puneet Singla; D. Todd Griffith; Anup Katake; John L. Junkins

412

A Different Angle on Perspective  

ERIC Educational Resources Information Center

When a plane figure is photographed from different viewpoints, lengths and angles appear distorted. Hence it is often assumed that lengths, angles, protractors, and compasses have no place in projective geometry. Here we describe a sense in which certain angles are preserved by projective transformations. These angles can be constructed with…

Frantz, Marc

2012-01-01

413

Passive Millimeter Wave Camera (PMMWC) at TRW  

NASA Technical Reports Server (NTRS)

Engineers at TRW, Redondo Beach, California, inspect the Passive Millimeter Wave Camera, a weather-piercing camera designed to 'see' through fog, clouds, smoke and dust. Operating in the millimeter wave portion of the electromagnetic spectrum, the camera creates visual-like video images of objects, people, runways, obstacles and the horizon. A demonstration camera (shown in photo) has been completed and is scheduled for checkout tests and flight demonstration. Engineer (left) holds a compact, lightweight circuit board containing 40 complete radiometers, including antenna, monolithic millimeter wave integrated circuit (MMIC) receivers and signal processing and readout electronics that forms the basis for the camera's 1040-element focal plane array.

1997-01-01

414

Passive Millimeter Wave Camera (PMMWC) at TRW  

NASA Technical Reports Server (NTRS)

Engineers at TRW, Redondo Beach, California, inspect the Passive Millimeter Wave Camera, a weather-piercing camera designed to see through fog, clouds, smoke and dust. Operating in the millimeter wave portion of the electromagnetic spectrum, the camera creates visual-like video images of objects, people, runways, obstacles and the horizon. A demonstration camera (shown in photo) has been completed and is scheduled for checkout tests and flight demonstration. Engineer (left) holds a compact, lightweight circuit board containing 40 complete radiometers, including antenna, monolithic millimeter wave integrated circuit (MMIC) receivers and signal processing and readout electronics that forms the basis for the camera's 1040-element focal plane array.

1997-01-01

415

Rover mast calibration, exact camera pointing, and camara handoff for visual target tracking  

NASA Technical Reports Server (NTRS)

This paper presents three technical elements that we have developed to improve the accuracy of the visual target tracking for single-sol approach-and-instrument placement in future Mars rover missions. An accurate, straightforward method of rover mast calibration is achieved by using a total station, a camera calibration target, and four prism targets mounted on the rover. The method was applied to Rocky8 rover mast calibration and yielded a 1.1-pixel rms residual error. Camera pointing requires inverse kinematic solutions for mast pan and tilt angles such that the target image appears right at the center of the camera image. Two issues were raised. Mast camera frames are in general not parallel to the masthead base frame. Further, the optical axis of the camera model in general does not pass through the center of the image. Despite these issues, we managed to derive non-iterative closed-form exact solutions, which were verified with Matlab routines. Actual camera pointing experiments aver 50 random target image paints yielded less than 1.3-pixel rms pointing error. Finally, a purely geometric method for camera handoff using stereo views of the target has been developed. Experimental test runs show less than 2.5 pixels error on high-resolution Navcam for Pancam-to-Navcam handoff, and less than 4 pixels error on lower-resolution Hazcam for Navcam-to-Hazcam handoff.

Kim, Won S.; Ansar, Adnan I.; Steele, Robert D.

2005-01-01

416

Imaging and radiometric performance simulation for a new high-performance dual-band airborne reconnaissance camera  

NASA Astrophysics Data System (ADS)

In recent years, high performance visible and IR cameras have been used widely for tactical airborne reconnaissance. The process improvement for efficient discrimination and analysis of complex target information from active battlefields requires for simultaneous multi-band measurement from airborne platforms at various altitudes. We report a new dual band airborne camera designed for simultaneous registration of both visible and IR imagery from mid-altitude ranges. The camera design uses a common front end optical telescope of around 0.3m in entrance aperture and several relay optical sub-systems capable of delivering both high spatial resolution visible and IR images to the detectors. The camera design is benefited from the use of several optical channels packaged in a compact space and the associated freedom to choose between wide (~3 degrees) and narrow (~1 degree) field of view. In order to investigate both imaging and radiometric performances of the camera, we generated an array of target scenes with optical properties such as reflection, refraction, scattering, transmission and emission. We then combined the target scenes and the camera optical system into the integrated ray tracing simulation environment utilizing Monte Carlo computation technique. Taking realistic atmospheric radiative transfer characteristics into account, both imaging and radiometric performances were then investigated. The simulation results demonstrate successfully that the camera design satisfies NIIRS 7 detection criterion. The camera concept, details of performance simulation computation, the resulting performances are discussed together with future development plan.

Seong, Sehyun; Yu, Jinhee; Ryu, Dongok; Hong, Jinsuk; Yoon, Jee-Yeon; Kim, Sug-Whan; Lee, Jun-Ho; Shin, Myung-Jin

2009-05-01

417

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

418

Initial laboratory evaluation of color video cameras  

NASA Astrophysics Data System (ADS)

Sandia National Laboratories has considerable experience with monochrome video cameras used in alarm assessment video systems. Most of these systems, used for perimeter protection, were designed to classify rather than identify an intruder. Monochrome cameras are adequate for that application and were selected over color cameras because of their greater sensitivity and resolution. There is a growing interest in the identification function of security video systems for both access control and insider protection. Color information is useful for identification purposes, and color camera technology is rapidly changing. Thus, Sandia National Laboratories established an ongoing program to evaluate color solid-state cameras. Phase one resulted in the publishing of a report titled, 'Initial Laboratory Evaluation of Color Video Cameras (SAND--91-2579).' It gave a brief discussion of imager chips and color cameras and monitors, described the camera selection, detailed traditional test parameters and procedures, and gave the results of the evaluation of twelve cameras. In phase two, six additional cameras were tested by the traditional methods and all eighteen cameras were tested by newly developed methods. This report details both the traditional and newly developed test parameters and procedures, and gives the results of both evaluations.

Terry, P. L.

1991-12-01

419

Gamma cameras--state of the art.  

PubMed

The growth of nuclear medicine has paralleled the development and acceptance of gamma cameras, which are stationary instruments that produce an image of an isotope distribution. The most successful gamma camera is based on a large, single crystal of the scintillator sodium iodide coupled to an array of photomultiplier tubes and electronic networks to determine the location of a gamma ray. Current cameras are capable of spatial resolution of 4.0 mm or better. Other types of gamma cameras have been developed, including the multi-crystal camera and a limited number of instruments using gas detectors and semiconductor detectors. The scintillation type of gamma camera will continue to be the dominant camera for the next 5 to 10 years, and will continue to gradually improve. Most significant improvements will result from application of digital electronics to position circuits. PMID:440176

Zimmerman, R E

1979-01-01

420

Mini gamma camera, camera system and method of use  

DOEpatents

A gamma camera comprising essentially and in order from the front outer or gamma ray impinging surface: 1) a collimator, 2) a scintillator layer, 3) a light guide, 4) an array of position sensitive, high resolution photomultiplier tubes, and 5) printed circuitry for receipt of the output of the photomultipliers. There is also described, a system wherein the output supplied by the high resolution, position sensitive photomultipiler tubes is communicated to: a) a digitizer and b) a computer where it is processed using advanced image processing techniques and a specific algorithm to calculate the center of gravity of any abnormality observed during imaging, and c) optional image display and telecommunications ports.

Majewski, Stanislaw (Grafton, VA); Weisenberger, Andrew G. (Grafton, VA); Wojcik, Randolph F. (Yorktown, VA)

2001-01-01

421

Laser angle sensor  

NASA Technical Reports Server (NTRS)

A laser angle measurement system was designed and fabricated for NASA Langley Research Center. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the model. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. This report includes optical and electrical schematics, system maintenance and operation procedures.

Pond, C. R.; Texeira, P. D.

1985-01-01

422

Surface nanobubble contact angles  

Microsoft Academic Search

Previous AFM experiments on surface nanobubbles have suggested an anomalously large contact angle theta of the bubbles (typically ˜160,o measured through the water) and a possible size dependence theta(R). Here we determine theta(R) for nanobubbles on smooth highly orientated pyrolytic graphite (HOPG) with a variety of different cantilevers. It is found that theta(R) is constant within the experimental error, down

Bram Borkent; Sissi de Beer; Frieder Mugele; Detlef Lohse

2009-01-01

423

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

424

Ejs Brewsterâs Angle Model  

NSDL National Science Digital Library

The Ejs Brewsterâs Angle model displays the electric field of an electromagnetic wave incident on a change of index of refraction. The simulation allows an arbitrarily linearly (in parallel and perpendicular components) polarized wave to encounter the change of index of refraction. The initial electric field and incidence angle change of index of refraction can all be changed via sliders. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting âOpen Ejs Modelâ from the pop-up menu item. Ejs Brewsterâs Angle model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_ehu_waves_brewster.jar file will run the program if Java is installed. Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional Ejs models for wave optics are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.

Aguirregabiria, Juan

2008-08-20

425

f-band narrowing in uranium intermetallics  

SciTech Connect

Although the discovery of heavy fermion behavior in uranium compounds has attracted a great deal of attention, relatively little work has been done which is sufficiently systematic to allow an assessment of the relationship of such behavior to more common phenomena, such as mixed valence, narrow-band effects, etc. In this paper we report bulk property measurements for a number of alloys which form a part of such a systematic study. The approach has been to take relatively simple and well-understood materials and alter their behavior by alloying to produce heavy fermion or Kondo behavior in a controlled way.

Dunlap, B.D.; Litterst, F.J.; Malik, S.K.; Kierstead, H.A.; Crabtree, G.W.; Kwok, W.; Lam, D.J.; Mitchell, A.W.

1987-01-01

426

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

427

LDEF yaw and pitch angle estimates  

NASA Technical Reports Server (NTRS)

Quantification of the LDEF yaw and pitch misorientations is crucial to the knowledge of atomic oxygen exposure of samples placed on LDEF. Video camera documentation of the LDEF spacecraft prior to grapple attachment, atomic oxygen shadows on experiment trays and longerons, and a pinhole atomic oxygen camera placed on LDEF provided sources of documentation of the yaw and pitch misorientation. Based on uncertainty-weighted averaging of data, the LDEF yaw offset was found to be 8.1 plus or minus 0.6 degrees, allowing higher atomic oxygen exposure of row 12 than initially anticipated. The LDEF pitch angle offset was found to be 0.8 plus or minus 0.4 degrees, such that the space end was tipped forward toward the direction of travel. The resulting consequences of the yaw and pitch misorientation of LDEF on the atomic oxygen fluence is a factor of 2.16 increase for samples located on row 12, and a factor of 1.18 increase for samples located on the space end compared to that which would be expected for perfect orientation.

Banks, Bruce A.; Gebauer, Linda

1992-01-01

428

Arrival Angles of Mid-latitude Mesospheric Hf Echoes  

NASA Astrophysics Data System (ADS)

Mesospheric HF sounding is performed at SURA facility of Radiophisical Research Institute since 1994 using HF SURA radar operated in 4.5­9.3 MHz frequency range. Together with measurements of amplitudes and Doppler velocities of mesospheric echoes their arrival angles were measured as well using spaced along magnetic merid- ian sub-arrays of SURA facility antenna array. Distribution of arrival angles is dif- ferent for different types of echoes. Below approximately 80 km where echoes are observed sporadically it is narrow with angular width of about 1­2 degrees usually centered at vertical direction. Sometimes declination to several degrees from vertical occured while angular distribution remains narrow. Echoes from meteor tracks are also narrow with the same angular width often showing dependence of arrival angle on altitude. Most permanent and intense echoes are observed from mesopause region and usually show different angular distribution. It is much wider, up to more than 10 degrees, and has fast (few seconds) temporal variations. This feature can be explained supposing turbulent scattering as a nature of echoes from those altitudes when sev- eral sources of scattered signal of comparable amplitudes are distributed across the antenna main lobe. Another evidence of turbulent scattering is a weak correlation of signal amplitudes received by spaced antennas. Described work was supported by RFBR through the Grant 99­05­64483.

Karashtin, A. N.; Shlyugaev, Yu. V.; Bychkov, V. V.; Komrakov, G. P.; Malikeev, A. L.

429

Vision-based vehicle body slip angle estimation with multi-rate Kalman filter considering time delay  

Microsoft Academic Search

Body slip angle is one of the most important information for vehicle motion control; as specific sensors for body slip angle measurement are expensive, it is necessary to investigate estimation methods using existing popular sensors such as gyro sensor, encoder, camera, etc. For EV (electric vehicle), in particular, the motor response is several milliseconds which enables high performance control with

Yafei Wang; Binh Minh Nguyen; Hiroshi Fujimoto; Yoichi Hori

2012-01-01

430

The Advanced Camera for the Hubble Space Telescope  

Microsoft Academic Search

The Advanced Camera for the Hubble Space Telescope has three cameras. The first, the Wide Field Camera, will be a high- throughput, wide field, 4096 X 4096 pixel CCD optical and I-band camera that is half-critically sampled at 500 nm. The second, the High Resolution Camera (HRC), is a 1024 X 1024 pixel CCD camera that is critically sampled at

G. D. Illingworth; Paul D. Feldman; David A. Golimowski; Zlatan Tsvetanov; Christopher J. Burrows; James H. Crocker; Pierre Y. Bely; George F. Hartig; Randy A. Kimble; Michael P. Lesser; Richard L. White; Tom Broadhurst; William B. Sparks; Robert A. Woodruff; Pamela Sullivan; Carolyn A. Krebs; Douglas B. Leviton; William Burmester; Sherri Fike; Rich Johnson; Robert B. Slusher; Paul Volmer

1997-01-01

431

Radiometric calibration for MWIR cameras  

NASA Astrophysics Data System (ADS)

Korean Multi-purpose Satellite-3A (KOMPSAT-3A), which weighing about 1,000 kg is scheduled to be launched in 2013 and will be located at a sun-synchronous orbit (SSO) of 530 km in altitude. This is Korea's rst satellite to orbit with a mid-wave infrared (MWIR) image sensor, which is currently being developed at Korea Aerospace Research Institute (KARI). The missions envisioned include forest re surveillance, measurement of the ocean surface temperature, national defense and crop harvest estimate. In this paper, we shall explain the MWIR scene generation software and atmospheric compensation techniques for the infrared (IR) camera that we are currently developing. The MWIR scene generation software we have developed taking into account sky thermal emission, path emission, target emission, sky solar scattering and ground re ection based on MODTRAN data. Here, this software will be used for generating the radiation image in the satellite camera which requires an atmospheric compensation algorithm and the validation of the accuracy of the temperature which is obtained in our result. Image visibility restoration algorithm is a method for removing the eect of atmosphere between the camera and an object. This algorithm works between the satellite and the Earth, to predict object temperature noised with the Earth's atmosphere and solar radiation. Commonly, to compensate for the atmospheric eect, some softwares like MODTRAN is used for modeling the atmosphere. Our algorithm doesn't require an additional software to obtain the surface temperature. However, it needs to adjust visibility restoration parameters and the precision of the result still should be studied.

Yang, Hyunjin; Chun, Joohwan; Seo, Doo Chun; Yang, Jiyeon

2012-05-01

432

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

433

Magnetoacoustic transport in narrow electron channels  

NASA Astrophysics Data System (ADS)

We develop a theory of the effect due to a small perpendicular magnetic field on the quantized acoustoelectric current induced by a surface acoustic wave (SAW) in a narrow electron channel. The quasi one-dimensional channel is formed in a piezoelectric GaAs/AlGaAs semiconductor structure by a split gate technique with the gate voltage beyond pinch-off. The current is the result of the trapping of electrons in the SAW induced moving quantum dots and the transfer of electrons residing in these dots through the channel. It has been observed recently (J. Cunningham, et al., Phys. Rev.B, 1999) that in small magnetic fields the acoustoelectric current oscillates as a function of magnetic field. Based on a simple model for the quantized acoustoelecric transport in a narrow channel (G. Gumbs et al., Phys. Rev.B, Rapid Commun., 60, N20, R13954, 1999) we develop a theory for these oscillations. The case when one electron is captured in the dot is considered, and the period, the amplitude, and the phase of the current oscillations as a function of the system's parameters are obtained and analyzed.

Aizin, Gregory; Gumbs, Godfrey; Pepper, M.

2000-03-01

434

Studies of narrow autoionizing resonances in gadolinium  

SciTech Connect

The autoionization (AI) spectrum of gadolinium between the first and second limits has been investigated by triple-resonance excitation with high-resolution cw lasers. A large number of narrow AI resonances have been observed and assigned total angular momentum J values. The resonances are further divided into members of AI Rydberg series converging to the second limit or other ''interloping'' levels. Fine structure in the Rydberg series has been identified and interpreted in terms of Jc j coupling. A number of detailed studies have been performed on the interloping resonances: These include lifetime determination by lineshape analysis, isotope shifts, hyperfine structure, and photoionization saturation parameters. The electronic structure of the interloping levels is discussed in terms of these studies. Linewidths generally decrease with increasing total angular momentum and the J = 7 resonances are extremely narrow with Lorentzian widths ranging from < 1 MHz up to 157 MHz. The strongest resonances are found to have cross-sections of {approx}10-12 cm{sup 2} and photoionization can be saturated with powers available from cw diode lasers.

Bushaw, Bruce A.; Nortershauser, W.; Blaum, K.; Wendt, Klaus

2003-06-30

435

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

436

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

437

First results from the Faint Object Camera - SN 1987A  

NASA Technical Reports Server (NTRS)

The first images of SN 1987A taken on day 1278 after outburst with the Faint Object Camera on board the Hubble Space Telescope are presented. The supernova is well detected and resolved spatially in three broadband ultraviolet exposures spanning the 1500-3800 A range and in a narrow-band image centered on the forbidden O III 5007 line. Simple uniform disk fits to the profiles of SN 1987A yield an average angular diameter of 170 + or - 30 mas, corresponding to an average expansion velocity of 6000 km/s. The derived broadband ultraviolet fluxes, when corrected for interstellar absorption, indicate a blue ultraviolet spectrum corresponding to a color temperature near 13,000 K.

Jakobsen, P.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.

1991-01-01

438

Narrow Iron K? Lines in Active Galactic Nuclei: Evolving Populations?  

NASA Astrophysics Data System (ADS)

We assemble a sample consisting of 66 active galactic nuclei (AGNs) from the literature and from the XMM-Newton archive in order to investigate the origin of the 6.4 keV narrow iron K? line (NIKAL). The X-ray Baldwin effect of the NIKAL is confirmed in this sample. We find that the equivalent width (EW) of the NIKAL is more strongly inversely correlated with the Eddington ratio (E) than with the 2-10 keV X-ray luminosity. Our sample favors the dusty torus origin, with the X-ray Baldwin effect being caused by the changing opening angle of the dusty torus. The EW-E relation can be derived from a toy model of the dusty torus. If the unification scheme is valid in all AGNs, we can derive the Baldwin effect from the ratio of type II AGNs to the total population given by Chandra and Hubble Space Telescope deep surveys. Thus, the evolution of populations could be reflected in the NIKAL's Baldwin effect.

Zhou, Xin-Lin; Wang, Jian-Min

2005-01-01

439

Optimising camera traps for monitoring small mammals.  

PubMed

Practical techniques are required to monitor invasive animals, which are often cryptic and occur at low density. Camera traps have potential for this purpose, but may have problems detecting and identifying small species. A further challenge is how to standardise the size of each camera's field of view so capture rates are comparable between different places and times. We investigated the optimal specifications for a low-cost camera trap for small mammals. The factors tested were 1) trigger speed, 2) passive infrared vs. microwave sensor, 3) white vs. infrared flash, and 4) still photographs vs. video. We also tested a new approach to standardise each camera's field of view. We compared the success rates of four camera trap designs in detecting and taking recognisable photographs of captive stoats (Mustelaerminea), feral cats (Felis catus) and hedgehogs (Erinaceuseuropaeus). Trigger speeds of 0.2-2.1 s captured photographs of all three target species unless the animal was running at high speed. The camera with a microwave sensor was prone to false triggers, and often failed to trigger when an animal moved in front of it. A white flash produced photographs that were more readily identified to species than those obtained under infrared light. However, a white flash may be more likely to frighten target animals, potentially affecting detection probabilities. Video footage achieved similar success rates to still cameras but required more processing time and computer memory. Placing two camera traps side by side achieved a higher success rate than using a single camera. Camera traps show considerable promise for monitoring invasive mammal control operations. Further research should address how best to standardise the size of each camera's field of view, maximise the probability that an animal encountering a camera trap will be detected, and eliminate visible or audible cues emitted by camera traps. PMID:23840790

Glen, Alistair S; Cockburn, Stuart; Nichols, Margaret; Ekanayake, Jagath; Warburton, Bruce

2013-01-01

440

CCD Camera Lens Interface for Real-Time Theodolite Alignment  

NASA Technical Reports Server (NTRS)

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

Wake, Shane; Scott, V. Stanley, III

2012-01-01

441

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

442

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

443

Laser angle measurement system  

NASA Technical Reports Server (NTRS)

The design and fabrication of a laser angle measurement system is described. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the mode. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. Optical and electrical schematics, system maintenance and operation procedures are included, and the results of a demonstration test are given.

Pond, C. R.; Texeira, P. D.; Wilbert, R. E.

1980-01-01

444

Measuring Non-spherical Airborne Dust with Space-based MISR Multi-angle Imaging.  

NASA Astrophysics Data System (ADS)

Some of the world's largest dust plumes emanate from Northern Eurasian deserts and are expected to increasingly affect Asian ergonomics. Together with field experiments, satellite observations of dust outbreaks, placed into the context of large-scale dust transport modeling, can help understand the impact of mineral dust aerosols on past and present climate and climate predictions in North and Central Asia. Multi-angle instruments such as the Multi-angle Imaging SpectroRadiometer (MISR) provide independent constraints on aerosol properties based on sensitivity to the shape of the scattering phase function. We present an analysis of the Multi-angle Imaging SpectroRadiometer (MISR) Standard Aerosol Retrieval algorithm, updated with new non-spherical dust models (Version 16 and higher). We compare the MISR products with coincident AERONET surface sun-photometer observations taken during the passage of dust fronts. Our analysis shows that during such events MISR retrieves Angstrom exponents characteristic of large particles, having little spectral variation in extinction over the MISR wavelength range (442, 550, 672 and 866 nm channels), as expected. Also, the retrieved fraction of non-spherical particles is very high. This quantity is not retrieved by satellite instruments having only nadir-viewing cameras. We assess whether MISR aerosol optical thickness (AOT) acquired at about 10:30 AM local time, can be used to represent daily mean AOT in dust climate forcing studies, by comparing MISR-retrieved aerosol optical thickness (AOT) with AERONET daily-mean values. We also compare the effect of particle shape on MISR and MODIS dust retrievals, using co-located MISR, MODIS, and AERONET AOTs and Angstrom exponents. In most cases obtained for this study, MODIS had no retrievals due to sun-glint when MISR's narrower swath observed AERONET sties on islands surrounded by dark water. For the few coincident MISR-MODIS-AERONET dark-water, dusty condition retrievals we obtained, the MISR retrievals were in better agreement with AERONET than those from MODIS. Over bright desert sites, MODIS AOTs at visible wavelengths was systematically higher than those of AERONET and MISR. MISR-derived aerosol type mixtures for these cases included non-spherical dust components with high frequency in retrievals over dark water, and slightly lower frequency over land. The frequency with which non-spherical dust models were selected by the algorithm also decreased in dusty regions affected by pollution. Both MISR and MODIS retrievals have a high fail rate over optically thick dust plumes.

Kalashnikova, O. V.; Diner, D. J.; Abdou, W.; Kahn, R.; Gaitley, B. J.; Gasso, S.

2004-12-01

445

Study on the Line Scan CCD Camera Calibration of Vehicle-Borne 3d Data Acquisition System  

NASA Astrophysics Data System (ADS)

Based on the characters of the line scan CCD camera and the Vehicle-borne 3D data acquisition system, it presented a novel method to calibrate the line Scan Camera (LSC) based on the laser scanner. Using the angle information in the original laser scanner data, combing the principle of the line scan camera, it built a calibration model for LSC and designed some experiment methods to implement that. Using the new model and the special experiment methods it computed out high precision LSC calibration parameters, which provides basis for the fusion of image and point cloud data and gives references to the similar sensors calibration.

Han, Y.; Yang, B.; Zhang, F.

2012-07-01

446

Feasibility study for the application of the large format camera as a payload for the Orbiter program  

NASA Technical Reports Server (NTRS)

The large format camera (LFC) designed as a 30 cm focal length cartographic camera system that employs forward motion compensation in order to achieve the full image resolution provided by its 80 degree field angle lens is described. The feasibility of application of the current LFC design to deployment in the orbiter program as the Orbiter Camera Payload System was assessed and the changes that are necessary to meet such a requirement are discussed. Current design and any proposed design changes were evaluated relative to possible future deployment of the LFC on a free flyer vehicle or in a WB-57F. Preliminary mission interface requirements for the LFC are given.

1978-01-01

447

Calibration of smooth camera models.  

PubMed

Generic imaging models can be used to represent any camera. Current generic models are discrete and define a mapping between each pixel in the image and a straight line in 3D space. This paper presents a modification of the generic camera model that allows the simplification of the calibration procedure. The only requirement is that the coordinates of the 3D projecting lines are related by functions that vary smoothly across space. Such a model is obtained by modifying the general imaging model using radial basis functions (RBFs) to interpolate image coordinates and 3D lines, thereby allowing both an increase in resolution (due to their continuous nature) and a more compact representation. Using this variation of the general imaging model, we also develop a calibration procedure. This procedure only requires that a 3D point be matched to each pixel. In addition, not all the pixels need to be calibrated. As a result, the complexity of the procedure is significantly decreased. Normalization is applied to the coordinates of both image and 3D points, which increases the accuracy of the calibration. Results with both synthetic and real datasets show that the model and calibration procedure are easily applicable and provide accurate calibration results. PMID:23868772

Miraldo, Pedro; Araujo, Helder

2013-09-01

448

Fruit Detectability Analysis for Different Camera Positions in Sweet-Pepper †  

PubMed Central

For robotic harvesting of sweet-pepper fruits in greenhouses a sensor system is required to detect and localize the fruits on the plants. Due to the complex structure of the plant, most fruits are (partially) occluded when an image is taken from one viewpoint only. In this research the effect of multiple camera positions and viewing angles on fruit visibility and detectability was investigated. A recording device was built which allowed to place the camera under different azimuth and zenith angles and to move the camera horizontally along the crop row. Fourteen camera positions were chosen and the fruit visibility in the recorded images was manually determined for each position. For images taken from one position only with the criterion of maximum 50% occlusion per fruit, the fruit detectability (FD) was in no case higher than 69%. The best single positions were the front views and looking with a zenith angle of 60° upwards. The FD increased when a combination was made of multiple viewpoint positions. With a combination of five favourite positions the maximum FD was 90%.

Hemming, Jochen; Ruizendaal, Jos; Hofstee, Jan Willem; van Henten, Eldert J.

2014-01-01

449

Integrated calibration between digital camera and laser scanner from mobile mapping system for land vehicles  

NASA Astrophysics Data System (ADS)

The paper presents the concept of lever arm and boresight angle, the design requirements of calibration sites and the integrated calibration method of boresight angles of digital camera or laser scanner. Taking test data collected by Applanix's LandMark system as an example, the camera calibration method is introduced to be piling three consecutive stereo images and OTF-Calibration method using ground control points. The laser calibration of boresight angle is proposed to use a manual and automatic method with ground control points. Integrated calibration between digital camera and laser scanner is introduced to improve the systemic precision of two sensors. By analyzing the measurement value between ground control points and its corresponding image points in sequence images, a conclusion is that position objects between camera and images are within about 15cm in relative errors and 20cm in absolute errors. By comparing the difference value between ground control points and its corresponding laser point clouds, the errors is less than 20cm. From achieved results of these experiments in analysis, mobile mapping system is efficient and reliable system for generating high-accuracy and high-density road spatial data more rapidly.

Zhao, Guihua; Chen, Hong; Li, Xingquan; Zou, Xiaoliang

450

High Speed Digital Camera Technology Review  

NASA Technical Reports Server (NTRS)

A High Speed Digital Camera Technology Review (HSD Review) is being conducted to evaluate the state-of-the-shelf in this rapidly progressing industry. Five HSD cameras supplied by four camera manufacturers participated in a Field Test during the Space Shuttle Discovery STS-128 launch. Each camera was also subjected to Bench Tests in the ASRC Imaging Development Laboratory. Evaluation of the data from the Field and Bench Tests is underway. Representatives from the imaging communities at NASA / KSC and the Optical Systems Group are participating as reviewers. A High Speed Digital Video Camera Draft Specification was updated to address Shuttle engineering imagery requirements based on findings from this HSD Review. This draft specification will serve as the template for a High Speed Digital Video Camera Specification to be developed for the wider OSG imaging community under OSG Task OS-33.

Clements, Sandra D.

2009-01-01

451

Television camera video level control system  

NASA Technical Reports Server (NTRS)

A video level control system is provided which generates a normalized video signal for a camera processing circuit. The video level control system includes a lens iris which provides a controlled light signal to a camera tube. The camera tube converts the light signal provided by the lens iris into electrical signals. A feedback circuit in response to the electrical signals generated by the camera tube, provides feedback signals to the lens iris and the camera tube. This assures that a normalized video signal is provided in a first illumination range. An automatic gain control loop, which is also responsive to the electrical signals generated by the camera tube 4, operates in tandem with the feedback circuit. This assures that the normalized video signal is maintained in a second illumination range.

Kravitz, M.; Freedman, L. A.; Fredd, E. H.; Denef, D. E. (inventors)

1985-01-01

452

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

453

A Note on Angle Construction  

ERIC Educational Resources Information Center

The author investigates the construction of angles (using Euclidean tools) through a numerical approach. He calls attention to the surprising impossibility of constructing the conventional units of angle measure--the degree, minute, second, radian, and mil. (MN)

Francis, Richard L.

1978-01-01

454

Wide field and diffraction limited array camera for SIRTF  

NASA Technical Reports Server (NTRS)

The Infrared Array Camera for the space Infrared Telescope Facility (SIRTF/IRAC) is capable of two-dimensional photometry in either a wide field or diffraction-limited mode over the wavelength interval from 2 to 30 microns. Three different two-dimensional direct readout (DRO) array detectors will be used: Band 1-InSb or Si:In (2-5 microns) 128 x 128 pixels, Band 2-Si:Ga (5-18 microns) 64 x 64 pixels, and Band 3-Si:Sb (18-30 microns) 64 x 64 pixels. The hybrid DRO readout architecture has the advantages of low read noise, random pixel access with individual readout rates, and nondestructive readout. The scientific goals of IRAC are discussed, which are the basis for several important requirements and capabilities of the array camera: (1) diffraction-limited resolution from 2-30 microns, (2) use of the maximum unvignetted field of view of SIRTF, (3) simultaneous observations within the three infrared spectral bands, and (4) the capability for broad and narrow bandwidth spectral resolution. A strategy has been developed to minimize the total electronic and environmental noise sources to satisfy the scientific requirements.

Fazio, G. G.; Koch, D. G.; Melnick, G. J.; Tresch-Fienberg, R. M.; Willner, S. P.; Gezari, D. Y.; Lamb, G.; Shu, P.; Chin, G.; Mccreight, C. R.

1986-01-01

455

Wide field and diffraction limited array camera for SIRTF  

NASA Astrophysics Data System (ADS)

The Infrared Array Camera for the Space Infrared Telescope Facility (SIRTF/IRAC) is capable of two-dimensional photometry in either a wide field or diffraction-limited mode over the wavelength interval from 2 to 30 microns. Three different two-dimensional direct readout (DRO) array detectors are being considered: Band 1-InSb or Si:In (2-5 microns) 128 x 128 pixels, Band 2-Si:Ga (5-18 microns) 64 x 64 pixels, and Band 3-Si:Sb (18-30 microns) 64 x 64 pixels. The hybrid DRO readout architecture has the advantages of low read noise, random pixel access with individual readout rates, and nondestructive readout. The scientific goals of IRAC are discussed, which are the basis for several important requirements and capabilities of the array camera: (1) diffraction-limited resolution from 2-30 microns, (2) use of the maximum unvignetted field of view of SIRTF, (3) simultaneous observations within the three infrared spectral bands, and (4) the capability for broad and narrow bandwidth spectral resolution. A strategy has been developed to minimize the total electronic and environmental noise sources to satisfy the scientific requirements.

Fazio, G. G.; Koch, D. G.; Melnick, G. J.; Tresch-Fienberg, R. M.; Willner, S. P.; Gezari, D. Y.; Lamb, G.; Shu, P.; Chin, G.; McCreight, C. R.

1986-01-01

456

Wide field and diffraction limited array camera for SIRTF  

NASA Astrophysics Data System (ADS)

The Infrared Array Camera for the space Infrared Telescope Facility (SIRTF/IRAC) is capable of two-dimensional photometry in either a wide field or diffraction-limited mode over the wavelength interval from 2 to 30 microns. Three different two-dimensional direct readout (DRO) array detectors will be used: Band 1-InSb or Si:In (2-5 microns) 128 x 128 pixels, Band 2-Si:Ga (5-18 microns) 64 x 64 pixels, and Band 3-Si:Sb (18-30 microns) 64 x 64 pixels. The hybrid DRO readout architecture has the advantages of low read noise, random pixel access with individual readout rates, and nondestructive readout. The scientific goals of IRAC are discussed, which are the basis for several important requirements and capabilities of the array camera: (1) diffraction-limited resolution from 2-30 microns, (2) use of the maximum unvignetted field of view of SIRTF, (3) simultaneous observations within the three infrared spectral bands, and (4) the capability for broad and narrow bandwidth spectral resolution. A strategy has been developed to minimize the total electronic and environmental noise sources to satisfy the scientific requirements.

Fazio, G. G.; Koch, D. G.; Melnick, G. J.; Tresch-Fienberg, R. M.; Willner, S. P.; Gezari, D. Y.; Lamb, G.; Shu, P.; Chin, G.; McCreight, C. R.

457

The VEN?S super-spectral camera  

NASA Astrophysics Data System (ADS)

A 5m GSD satellite camera with 12 narrow spectral bands in the VNIR region is being developed by El-Op, Israel, for a cooperative project between CNES (France) and the Israel Space Agency. The satellite, called "VEN?S" (Vegetation and Environment monitoring on a New Micro-Satellite) will enable evaluation of the use of high-resolution, high repetitivity, super-spectral imaging data for vegetation and environmental monitoring. The camera will image a limited number of selected sites around the globe with a two-day revisit interval. Highly demanding requirements for signal-to-noise ratio, radiometric accuracy, band-to-band registration and precise location on the ground will ensure the validity of the data. It will also help to define the optimal set of bands and the image processing algorithms of future instruments in the framework of the GMES program. The satellite bus will be built by Israel Aircraft Industries and will also carry an experimental ion propulsion system developed by Rafael (Israel).

Topaz, Jeremy; Tinto, Francesc; Hagolle, Olivier

2006-10-01

458

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

459

Place Recognition Using Multiple Wearable Cameras  

Microsoft Academic Search

Recognizing a user’s location is the most challenging problem for providing intelligent location-based services. In this paper,\\u000a we presented a real-time camera-based system for the place recognition problem. This system takes streams of scene images\\u000a of a learned environment from user-worn cameras and produces the class label of the current place as an output. Multiple cameras\\u000a are used to collect

Kyungmin Min; Seonghun Lee; Kee-eung Kim; Jin Hyung Kim

2007-01-01

460

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