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Sample records for airglow zodiacal light

  1. Cosmic ultraviolet background radiation and zodiacal light

    NASA Technical Reports Server (NTRS)

    Tennyson, P. D.; Henry, R. C.; Feldman, P. D.; Hartig, G. F.

    1988-01-01

    Spectroscopic measurements of the diffuse cosmic UV background in the 1700-2850-A range are presented. In agreement with previous results, the data have resulted in the detection at high Galactic latitude of an intensity of 300 + or - 100 photons/sq cm s sr A at 1800 A without correction for starlight or airglow, a similar intensity over the 1900-2500-A range after correction for measured airglow, and a similar intensity over the 2500-2800-A range after correction for zodiacal light. It is suggested that this radiation may originate partly in line radiation from a Galactic halo and partly from extragalactic sources, perhaps the integrated light of distant galaxies.

  2. Cosmic Infrared Background Fluctuations and Zodiacal Light

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

    2017-01-01

    We performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR (near-infrared)background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution or from IRAC (Infrared Array Camera) observations of high-latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS (Cosmic Evolution Survey) field at low ecliptic latitude where the zodiacal light intensity varies by factors of approximately 2 over the range of solar elongations at which the field can be observed. We find that the white-noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that are evident in the zodiacal light model. At large angular scales (greater than or approximately equal to 100 arcseconds) where excess power above the white noise is observed, we find no correlation of the power with the modeled intensity of the zodiacal light. This test clearly indicates that the large-scale power in the infrared background is not being caused by the zodiacal light.

  3. Cosmic Infrared Background Fluctuations and Zodiacal Light

    NASA Astrophysics Data System (ADS)

    Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

    2016-06-01

    We performed a specific observational test to measure the effect that the zodiacal light can have on measurements of the spatial fluctuations of the near-IR background. Previous estimates of possible fluctuations caused by zodiacal light have often been extrapolated from observations of the thermal emission at longer wavelengths and low angular resolution or from IRAC observations of high-latitude fields where zodiacal light is faint and not strongly varying with time. The new observations analyzed here target the COSMOS field at low ecliptic latitude where the zodiacal light intensity varies by factors of ˜2 over the range of solar elongations at which the field can be observed. We find that the white-noise component of the spatial power spectrum of the background is correlated with the modeled zodiacal light intensity. Roughly half of the measured white noise is correlated with the zodiacal light, but a more detailed interpretation of the white noise is hampered by systematic uncertainties that are evident in the zodiacal light model. At large angular scales (≳100″) where excess power above the white noise is observed, we find no correlation of the power with the modeled intensity of the zodiacal light. This test clearly indicates that the large-scale power in the infrared background is not being caused by the zodiacal light.

  4. A study of zodiacal light models

    NASA Technical Reports Server (NTRS)

    Gary, G. A.; Craven, P. D.

    1973-01-01

    A review is presented of the basic equations used in the analysis of photometric observations of zodiacal light. A survey of the methods used to model the zodiacal light in and out of the ecliptic is given. Results and comparison of various models are presented, as well as recent results by the authors.

  5. Light Phenomena over the ESO Observatories III: Zodiacal Light

    NASA Astrophysics Data System (ADS)

    Horálek, P.; Christensen, L. L.; Nesvorný, D.; Davies, R.

    2016-06-01

    The zodiacal light is often seen at the ESO observatories in the hours after sunset and before sunrise. The origin of the zodiacal light is described and recent research briefly summarised. Some fine images of the zodiacal light from Paranal and La Silla, including the full extent of the night sky are presented.

  6. Transfer of diffuse astronomical light and airglow in scattering Earth atmosphere

    NASA Astrophysics Data System (ADS)

    Hong, S. S.; Kwon, S. M.; Park, Y.-S.; Park, C.

    1998-06-01

    To understand an observed distribution of atmospheric diffuse light (ADL) over an entire meridian, we have solved rigorously, with the quasi-diffusion method, the problem of radiative transfer in an anisotropically scattering spherical atmosphere of the earth. In addition to the integrated starlight and the zodiacal light we placed a narrow layer of airglow emission on top of the scattering earth atmosphere. The calculated distribution of the ADL brightness over zenith distance shows good agreement with the observed one. The agreement can be utilized in deriving the zodiacal light brightness at small solar elongations from the night sky brightness observed at large zenith distances.

  7. IRTS observation of zodiacal light and emission

    NASA Technical Reports Server (NTRS)

    Matsumoto, T.; Murakami, H.; Onaka, T.; Ootsubo, T.; Roellig, T. L.; Chan, K. -W.; Noda, M.

    1998-01-01

    We present the infrared spectrum of the zodiacal light and emission obtained by the Near-Infrared Spectrometer (NIRS) and Mid-Infrared Spectrometer (MIRS) onboard the Infrared Telescope in Space (IRTS). The wavelength coverages and spectral resolutions are 1.4-4.0 microns and 0.12 microns for the NIRS, and 4.5-11.7 microns and 0.23-0.36 microns for the MIRS respectively. Both instruments have the same beam size of 8 arcminutes square. The IRTS observations were made for 1995 March 29 - April 26. Here we present the data of two days, April 19 and April 20.

  8. Rutgers zodiacal light experiment on OSO-6

    NASA Technical Reports Server (NTRS)

    Carroll, B.

    1975-01-01

    A detector was placed in a slowly spinning wheel on OSO-6 whose axis was perpendicular to the line drawn to the sun, to measure the surface brightness and polarization at all elongations from the immediate neighborhood of the sun to the anti-solar point. Different wavelength settings and polarizations were calculated from the known order of magnitude brightness of the zodiacal light. The measuring sequence was arranged to give longer integration times for the regions of lower surface brightness. Three types of analysis to which the data on OSO-6 were subjected are outlined; (1) photometry, (2) colorimetry and (3) polarimetry.

  9. The NGST and the Zodiacal Light in the Solar System

    NASA Technical Reports Server (NTRS)

    Gorkavyi, Nick; Ozernoy, Leonid; Mather, John; Taidakova, Tanya

    1999-01-01

    We develop a physical model of the zodiacal cloud incorporating the real dust sources of asteroidal, cometary, and kuiperoidal origin. Using the inferred distribution of the zodiacal dust, we compute its thermal emission and scattering at several wavelengths (1.25, 5, and 20 micron) as a function of NGST location assumed to be at 1 AU or 3 AU. Areas on the sky with a minimum of zodiacal light are determined.

  10. Zodiacal light as an indicator of interplanetary dust

    NASA Technical Reports Server (NTRS)

    Weinberg, J. L.; Sparrow, J. G.

    1978-01-01

    The most striking feature of the night sky in the tropics is the zodiacal light, which appears as a cone in the west after sunset and in the east before sunrise. It is caused by sunlight scattered or absorbed by particles in the interplanetary medium. The zodiacal light is the only source of information about the integrated properties of the whole ensemble of interplanetary dust. The brightness and polarization in different directions and at different colors can provide information on the optical properties and spatial distribution of the scattering particles. The zodiacal light arises from two independent physical processes related to the scattering of solar continuum radiation by interplanetary dust and to thermal emission which arises from solar radiation that is absorbed by interplanetary dust and reemitted mainly at infrared wavelengths. Attention is given to observational parameters of zodiacal light, the methods of observation, errors and absolute calibration, and the observed characteristics of zodiacal light.

  11. Dynamical Zodiacal Cloud Models Constrained by High Resolution Spectroscopy of the Zodiacal Light.

    NASA Astrophysics Data System (ADS)

    Ipatov, S. I.; Kutyrev, A. S.; Madsen, G. J.; Mather, J. C.; Moseley, S. H.; Reynolds, R. J.

    2004-11-01

    We have developed a set of self-consistent dynamical models of the Zodiacal cloud, following the orbital evolution of dust particles under the gravitational influence of planets, radiation pressure, Poynting-Robertson drag, and solar wind drag (Ipatov et al., Annals of New York Academy of Sciences, 2004, v. 1017, 66-80). Three populations were considered, originating from the Kuiper belt, asteroids and comets. Using the models developed, we investigated how the solar spectrum is changed by scattering by the zodiacal cloud grains. For each particles population different scattering functions were considered. Reynolds, Madsen and Moseley (ApJ, in press) have observed the Zodiacal light spectrum near the solar Mg Iλ 5184 absorption line. For the first time, high resolving power spectra (R=25,000) with high signal to noise ratio provide an opportunity to model the shape of the Fraunhofer line in the Zodiacal spectrum. The line profile depends on the velocity, size, density distribution of particles on the line of sight and their respective scattering properties. We have carried out an initial comparison of our models with the observed spectra. The value of the Doppler shift and the shape of the Fraunhofer line produced by our model is in general agreement with the observations. Unlike results by Clarke et al. (A&A, 1996, 308, 273), our modeled spectra do not exhibit strong asymmetry. Different particles populations produce clearly distinct model spectra of the Zodiacal light. At the same time, the results of modeling are relatively insensitive to the scattering function considered. We believe that with improved and more extensive observations it will be possible to distinguish the sources of dust and impose constraints on the particle size distribution. This should result in a self-consistent 3D model of Zodiacal cloud density and velocity particles distribution. This work was supported by NASA (NAG5-12265) and the NSF through AST-0204973.

  12. Research studies using OSO-6 zodiacal light experiment data

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The results of research studies on the OSO-6 zodiacal light experiment, conducted during the period from May 1976 to October 1977 are described. A discussion is included of the instrument performance and the empirical calibrations developed. Main areas of the research performed, i.e., (1) zodiacal light variation analysis; (2) integrated starlight and diffuse galactic light; and (3) earth/moon libration region counterglow, are covered. Considerable data processing was performed during these studies and it is summarized. Recommendations for future research to complete the interim results are given.

  13. Origin of Interplanetary Dust through Optical Properties of Zodiacal Light

    NASA Astrophysics Data System (ADS)

    Yang, Hongu; Ishiguro, Masateru

    2015-11-01

    This study investigates the origin of interplanetary dust particles (IDPs) through the optical properties, albedo and spectral gradient, of zodiacal light. The optical properties were compared with those of potential parent bodies in the solar system, which include D-type (as analogs of cometary nuclei), C-type, S-type, X-type, and B-type asteroids. We applied Bayesian inference to the mixture model composed of the distribution of these sources, and found that >90% of the IDPs originate from comets (or their spectral analogs, D-type asteroids). Although some classes of asteroids (C-type, X-type, and B-type) may make a moderate contribution, ordinary chondrite-like particles from S-type asteroids occupy a negligible fraction of the interplanetary dust cloud complex. The overall optical properties of the zodiacal light were similar to those of chondritic porous IDPs, supporting the dominance of cometary particles in the zodiacal cloud.

  14. Clementine Star-Tracker Images of the Inner Zodiacal Light

    NASA Astrophysics Data System (ADS)

    Cooper, B. L.; Zook, H. A.; Hahn, J. M.; Potter, A. E.

    2000-10-01

    Excellent photographs of the inner zodiacal light, using the Moon as an occulting disk, have been obtained with the Clementine star-tracker cameras. With exposures that vary from 50 milliseconds to 700 milliseconds, with a dynamic range of 256 for each exposure, and with a 28.9 degree by 43.4 degree field of view, the Clementine cameras have recorded the zodiacal light brightness from 1 degree (the solar F- corona) to in excess of 20 degrees from the Sun. Problems of proper removal of thermal background electrons, of 'streak' removal, and of absolute brightness calibration, have been earlier described and resolved (1). The problem of correcting for the non-uniform response of the star-tracker cameras to a field of uniform brightness is now also largely resolved, and photometrically accurate maps of the inner zodiacal light intensity isophotes are now obtainable. These maps represent a major advance in obtaining zodiacal light brightnesses, in both heliocentric longitude and latitude, over previous studies in this region of the sky. The spatial density of dust grains, as a function of both ecliptic longitude and latitude relative to the Sun, are obtained using well-understood integral inversion procedures. The relation of the symmetry plane of the dust density to the ecliptic plane will be analyzed in terms of gravitational perturbations by Jupiter and the inner planets. (1) Zook et al., LPSC 28, 1635-1636, 1997.

  15. A Near-Infrared Spectrometer to Measure Zodiacal Light Absorption Spectrum

    NASA Technical Reports Server (NTRS)

    Kutyrev, A. S.; Arendt, R.; Dwek, E.; Kimble, R.; Moseley, S. H.; Rapchun, D.; Silverberg, R. F.

    2010-01-01

    We have developed a high throughput infrared spectrometer for zodiacal light fraunhofer lines measurements. The instrument is based on a cryogenic dual silicon Fabry-Perot etalon which is designed to achieve high signal to noise Fraunhofer line profile measurements. Very large aperture silicon Fabry-Perot etalons and fast camera optics make these measurements possible. The results of the absorption line profile measurements will provide a model free measure of the zodiacal Light intensity in the near infrared. The knowledge of the zodiacal light brightness is crucial for accurate subtraction of zodiacal light foreground for accurate measure of the extragalactic background light after the subtraction of zodiacal light foreground. We present the final design of the instrument and the first results of its performance.

  16. Galactic and zodiacal light surface brightness measurements with the Atmosphere Explorer satellites

    NASA Technical Reports Server (NTRS)

    Abreu, V. J.; Hays, P. B.; Yee, J. H.

    1982-01-01

    Galactic and zodiacal light surface maps based on the Atmosphere Explorer-C, -D, and -E satellite data are presented at 7320, 6300, 5577, 5200, and 4278 A. A procedure used to generate these maps, which involves separation of the individual stars and diffuse starlight from the zodiacal light, is described in detail. The maps can be used in atmospheric emission studies to correct for galactic emissions which contaminate satellite as well as ground-based photometric observations. The zodiacal light maps show enhanced features which are important for understanding the nature of interplanetary dust.

  17. Disentangling the main populations of the Zodiacal Cloud from Zodiacal Light observations

    NASA Astrophysics Data System (ADS)

    Dumont, R.; Renard, J. B.; Levasseur-Regourd, A. C.; Weinberg, J. L.

    1998-06-01

    Photometric surveys of the Zodiacal Light (ZL) already allowed to retrieve features of interplanetary dust space distribution and optical behaviour. Of the brightness "gathering" function dZ = D(α)/ m along each line of sight (LOS), (α being the phase angle, m the subsolar distance of the LOS, D) the local scattering coefficient), two approximate values could be derived, based on the constraints provided by the two observed values of its integral Z, when the LOS is in-ecliptic. This "nodes of lesser uncertainty" method (Dumont, Levasseur-Regourd, Renard, 1985 to 1996), however, lowered but did not rule out question marks upon the phase function. To improve this inversion, additional constraints can be found in ZL surveys from deep space probes. We show that both the Pioneer 10 (Toller and Weinberg, 1985) and (despite their lack of in-ecliptic scans) the Helios (Leinert et al., 1982) data imply the phase function to weakly depart from isotropy, at least in the 30°-150° range. The latitudinal dependence f(β⊙, r = cst) of the space density (less well known than the heliocentric, D( r, β⊙ = 0)) can be tracked through the brightness ratio, at the same elongation ɛ, aiming in the helioecliptic meridian, against in the ecliptic. At ɛ = 90°, this ratio 0.3 would lead—in the improper assumption of a single, homogeneous cloud—to fit the latitudinal density drop by a — cos12β⊙ function. The resulting brightness ratio at ɛ < 90°, which should be equal to ∫LOS cos12 β⊙(α)D(α)· dα/∫LOS D(α) dα turns out to be much lower than the ratio observed in the 60° > ɛ > 15° range (again ≃0.3). This contradiction is solved with a steeper exponent (20-22?) for cos/gb⊙, and by assuming the flattened cloud to coexist with another one, spherically symmetrical, which contributes 15-25 S10 at ɛ = 90°, 50-80 S10 at ɛ = 60°, 100-160 S10 at ɛ = 45° and 250-450 S10 at ɛ = 30°.

  18. A SPITZER/IRAC MEASURE OF THE ZODIACAL LIGHT

    SciTech Connect

    Krick, Jessica E.; Glaccum, William J.; Carey, Sean J.; Lowrance, Patrick J.; Surace, Jason A.; Ingalls, James G.; Hora, Joseph L.; Reach, William T.

    2012-07-20

    The dominant non-instrumental background source for space-based infrared observatories is the zodiacal light (ZL). We present Spitzer Infrared Array Camera (IRAC) measurements of the ZL at 3.6, 4.5, 5.8, and 8.0 {mu}m, taken as part of the instrument calibrations. We measure the changing surface brightness levels in approximately weekly IRAC observations near the north ecliptic pole over a period of roughly 8.5 years. This long time baseline is crucial for measuring the annual sinusoidal variation in the signal levels due to the tilt of the dust disk with respect to the ecliptic, which is the true signal of the ZL. This is compared to both Cosmic Background Explorer Diffuse Infrared Background Experiment data and a ZL model based thereon. Our data show a few-percent discrepancy from the Kelsall et al. model including a potential warping of the interplanetary dust disk and a previously detected overdensity in the dust cloud directly behind the Earth in its orbit. Accurate knowledge of the ZL is important for both extragalactic and Galactic astronomy including measurements of the cosmic infrared background, absolute measures of extended sources, and comparison to extrasolar interplanetary dust models. IRAC data can be used to further inform and test future ZL models.

  19. Is the zodiacal light intensity steady. [cloud surface brightness and polarization from OSO-5 data

    NASA Technical Reports Server (NTRS)

    Burnett, G. B.; Sparrow, J. G.; Ney, E. P.

    1974-01-01

    It is pointed out that conclusions reported by Sparrow and Ney (1972, 1973) could be confirmed in an investigation involving the refinement of OSO-5 data on zodiacal light. It had been found by Sparrow and Ney that the absolute value of both the surface brightness and polarization of the zodiacal cloud varied by less than 10% over the 4-yr period from January 1969 to January 1973.

  20. The zodiacal light as observed with the Clementine startracker cameras - Calibration and image analysis procedures

    NASA Astrophysics Data System (ADS)

    Zook, H. A.; Cooper, B. L.; Potter, A. E.

    1997-03-01

    The zodiacal light, due to sunlight reflected off interplanetary dust grains, is a measure of their spatial density as a function of heliocentric distance and latitude. We have developed procedures to photometrically correct the brightness variations in the Clementine Corona and Zodiacal Light (CZL) photographs to true image brightnesses. The processing steps follow generally along the path described by Berry (1994); however, there are additional processing steps involved for the Clementine images. Careful corrections are necessary because of the dimness of the features that we wish to observe.

  1. On the influence of the atmospheric dust on the zodiacal light polarization

    NASA Technical Reports Server (NTRS)

    Divari, N. B.; Krylova, S. N.

    1973-01-01

    Three color observations of the nightglow brightness and polarization were made to determine the brightness of zodiacal light at the ecliptic pole. On the assumption that the degree of polarization of zodiacal light is 0.20 at the ecliptic pole, the corresponding brightnesses are found to be 68, 70, and 96 G2 stars of the 10th magnitude per square deg. at 0.37, 0.53, and 0.58 micron. The large diurnal variations in observed intensity and direction of polarization are attributed to the effects of dust in the earth's atmosphere.

  2. Observations of the Near-infrared Spectrum of the Zodiacal Light with CIBER

    NASA Astrophysics Data System (ADS)

    Tsumura, K.; Battle, J.; Bock, J.; Cooray, A.; Hristov, V.; Keating, B.; Lee, D. H.; Levenson, L. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Wada, T.; Zemcov, M.

    2010-08-01

    Interplanetary dust (IPD) scatters solar radiation which results in the zodiacal light that dominates the celestial diffuse brightness at optical and near-infrared wavelengths. Both asteroid collisions and cometary ejections produce the IPD, but the relative contribution from these two sources is still unknown. The low resolution spectrometer (LRS) onboard the Cosmic Infrared Background ExpeRiment (CIBER) observed the astrophysical sky spectrum between 0.75 and 2.1 μm over a wide range of ecliptic latitude. The resulting zodiacal light spectrum is redder than the solar spectrum, and shows a broad absorption feature, previously unreported, at approximately 0.9 μm, suggesting the existence of silicates in the IPD material. The spectral shape of the zodiacal light is isotropic at all ecliptic latitudes within the measurement error. The zodiacal light spectrum, including the extended wavelength range to 2.5 μm using Infrared Telescope in Space (IRTS) data, is qualitatively similar to the reflectance of S-type asteroids. This result can be explained by the proximity of S-type asteroidal dust to Earth's orbit, and the relatively high albedo of asteroidal dust compared with cometary dust.

  3. OBSERVATIONS OF THE NEAR-INFRARED SPECTRUM OF THE ZODIACAL LIGHT WITH CIBER

    SciTech Connect

    Tsumura, K.; Matsumoto, T.; Matsuura, S.; Wada, T.; Battle, J.; Bock, J.; Zemcov, M.; Cooray, A.; Hristov, V.; Levenson, L. R.; Mason, P.; Sullivan, I.; Keating, B.; Renbarger, T.; Lee, D. H.; Nam, U. W.; Suzuki, K.

    2010-08-10

    Interplanetary dust (IPD) scatters solar radiation which results in the zodiacal light that dominates the celestial diffuse brightness at optical and near-infrared wavelengths. Both asteroid collisions and cometary ejections produce the IPD, but the relative contribution from these two sources is still unknown. The low resolution spectrometer (LRS) onboard the Cosmic Infrared Background ExpeRiment (CIBER) observed the astrophysical sky spectrum between 0.75 and 2.1 {mu}m over a wide range of ecliptic latitude. The resulting zodiacal light spectrum is redder than the solar spectrum, and shows a broad absorption feature, previously unreported, at approximately 0.9 {mu}m, suggesting the existence of silicates in the IPD material. The spectral shape of the zodiacal light is isotropic at all ecliptic latitudes within the measurement error. The zodiacal light spectrum, including the extended wavelength range to 2.5 {mu}m using Infrared Telescope in Space (IRTS) data, is qualitatively similar to the reflectance of S-type asteroids. This result can be explained by the proximity of S-type asteroidal dust to Earth's orbit, and the relatively high albedo of asteroidal dust compared with cometary dust.

  4. Skylab experiment SO73: Gegenschein/zodiacal light. [electrophotometry of surface brightness and polarization

    NASA Technical Reports Server (NTRS)

    Weinberg, J. L.

    1976-01-01

    A 10 color photoelectric polarimeter was used to measure the surface brightness and polarization associated with zodiacal light, background starlight, and spacecraft corona during each of the Skylab missions. Fixed position and sky scanning observations were obtained during Skylab missions SL-2 and SL-3 at 10 wavelenghts between 4000A and 8200A. Initial results from the fixed-position data are presented on the spacecraft corona and on the polarized brightness of the zodiacal light. Included among the fixed position regions that were observed are the north celestial pole, south ecliptic pole, two regions near the north galactic pole, and 90 deg from the sun in the ecliptic. The polarized brightness of the zodiacal light was found to have the color of the sun at each of these positions. Because previous observations found the total brightness to have the color of the sun from the near ultraviolet out to 2.4 micrometers, the degree of polarization of the zodiacal light is independent of wavelength from 4000A to 8200A.

  5. On the line profiles in the spectra of the zodiacal light.

    NASA Astrophysics Data System (ADS)

    Clarke, D.; Matthews, S. A.; Mundell, C. G.; Weir, A. S.

    1996-04-01

    The model proposed by Hong (1985) describing the surface brightness variation with elongation of the Zodiacal Light has been applied to predict the spectral line profiles produced by Doppler effects associated with scattering from interplanetary dust for the simple case of prograde Keplerian orbits. Over the greater elongation range, the predictions are substantially the same as for previous models but with shallower line depths and more pronounced asymmetries. At elongations ~30deg and less, however, Hong's mixture of phase angle scattering functions predicts bifurcation of the lines so providing an alternative explanation to the two dust stream model of Beavers et al. (1980) proposed as the interpretation of their spectra of the F corona. The work also highlights a general problem of using radial velocity correlation masks for investigations of Zodiacal Light spectra.

  6. Calibration of imaging parameters for space-borne airglow photography using city light positions

    NASA Astrophysics Data System (ADS)

    Hozumi, Yuta; Saito, Akinori; Ejiri, Mitsumu K.

    2016-09-01

    A new method for calibrating imaging parameters of photographs taken from the International Space Station (ISS) is presented in this report. Airglow in the mesosphere and the F-region ionosphere was captured on the limb of the Earth with a digital single-lens reflex camera from the ISS by astronauts. To utilize the photographs as scientific data, imaging parameters, such as the angle of view, exact position, and orientation of the camera, should be determined because they are not measured at the time of imaging. A new calibration method using city light positions shown in the photographs was developed to determine these imaging parameters with high accuracy suitable for airglow study. Applying the pinhole camera model, the apparent city light positions on the photograph are matched with the actual city light locations on Earth, which are derived from the global nighttime stable light map data obtained by the Defense Meteorological Satellite Program satellite. The correct imaging parameters are determined in an iterative process by matching the apparent positions on the image with the actual city light locations. We applied this calibration method to photographs taken on August 26, 2014, and confirmed that the result is correct. The precision of the calibration was evaluated by comparing the results from six different photographs with the same imaging parameters. The precisions in determining the camera position and orientation are estimated to be ±2.2 km and ±0.08°, respectively. The 0.08° difference in the orientation yields a 2.9-km difference at a tangential point of 90 km in altitude. The airglow structures in the photographs were mapped to geographical points using the calibrated imaging parameters and compared with a simultaneous observation by the Visible and near-Infrared Spectral Imager of the Ionosphere, Mesosphere, Upper Atmosphere, and Plasmasphere mapping mission installed on the ISS. The comparison shows good agreements and supports the validity

  7. First Light from Triple-Etalon Fabry-Perot Interferometer for Atmospheric OI Airglow (6300 A)

    NASA Astrophysics Data System (ADS)

    Watchorn, S.; Noto, J.; Pedersen, T.; Betremieux, Y.; Migliozzi, M.; Kerr, R. B.

    2006-05-01

    Scientific Solutions, Inc. (SSI) has developed a triple-etalon Fabry-Perot interferometer (FPI) to observe neutral winds in the ionosphere by measuring neutral oxygen (O I) emission at 630.0 nm during the day. This instrument is to be deployed in the SSI airglow building at the Cerro Tololo observatory (30.17S 70.81W) in Chile, in support of the Comm/Nav Outage Forecast System (C/NOFS) project. Post-deployment observation will be made in conjunction with two other Clemson University Fabry-Perots in Peru, creating a longitudinal chain of interferometers for thermospheric observations. These instruments will make autonomous day and night observations of thermospheric dynamics. Instruments of this type can be constructed for a global chain of autonomous airglow observatories. The FPI presented in this talk consists of three independently pressure-controlled etalons, fed collimated light by a front optical train headed by an all-sky lens with a 160-degree field of view. It can be controlled remotely via a web-based service which allows any internet-connected computer to mimic the control computer at the instrument site. In fall 2005, the SSI system was first assembled at the Millstone Hill Observatory in Westford, Massachusetts, and made day and evening observations. It was then moved to the High-frequency Active Auroral Research Project (HAARP) site in Gakona, Alaska, to participate in joint optical/ionospheric heating campaigns. Additionally, natural airglow observations were made, both locally and remotely via the internet from Massachusetts. The Millstone and HAARP observations with two etalons yielded strong 630-nm atmospheric Fraunhofer absorption lines, with some suggestion of the Ring effect. By modeling the atmospheric absorption line as the constant times the corresponding solar absorption -- itself modeled as a Gaussian plus a polynomial -- the absorption feature is subtracted, leaving only the emission feature. Software ring-summing tools developed at the

  8. A CMB foreground study in WMAP data: Extragalactic point sources and zodiacal light emission

    NASA Astrophysics Data System (ADS)

    Chen, Xi

    The Cosmic Microwave Background (CMB) radiation is the remnant heat from the Big Bang. It serves as a primary tool to understand the global properties, content and evolution of the universe. Since 2001, NASA's Wilkinson Microwave Anisotropy Probe (WMAP) satellite has been napping the full sky anisotropy with unprecedented accuracy, precision and reliability. The CMB angular power spectrum calculated from the WMAP full sky maps not only enables accurate testing of cosmological models, but also places significant constraints on model parameters. The CMB signal in the WMAP sky maps is contaminated by microwave emission from the Milky Way and from extragalactic sources. Therefore, in order to use the maps reliably for cosmological studies, the foreground signals must be well understood and removed from the maps. This thesis focuses on the separation of two foreground contaminants from the WMAP maps: extragalactic point sources and zodiacal light emission. Extragalactic point sources constitute the most important foreground on small angular scales. Various methods have been applied to the WMAP single frequency maps to extract sources. However, due to the limited angular resolution of WMAP, it is possible to confuse positive CMB excursions with point sources or miss sources that are embedded in negative CMB fluctuations. We present a novel CMB-free source finding technique that utilizes the spectrum difference of point sources and CMB to form internal linear combinations of multifrequency maps to suppress the CMB and better reveal sources. When applied to the WMAP 41, 64 and 94 GHz maps, this technique has not only enabled detection of sources that are previously cataloged by independent methods, but also allowed disclosure of new sources. Without the noise contribution from the CMB, this method responds rapidly with the integration time. The number of detections varies as 0( t 0.72 in the two-band search and 0( t 0.70 in the three-band search from one year to five years

  9. Passive SWIR airglow illuminated imaging compared with NIR-visible for low-light nighttime observations

    NASA Astrophysics Data System (ADS)

    Dayton, David C.; Allen, Jeffery; Gonglewski, John D.; Nolasco, Rudolph; Myers, Michael; Burns, Dennis; Mons, Ishan; Maia, Francisco

    2011-05-01

    It is well known that luminance from photo-chemical reactions of hydroxyl ions in the upper atmosphere (~85 km altitude) produces a significant amount of night time radiation in the short wave infra-red (SWIR) band with wavelength between 0.9 and 1.7 μm. By examining images in an urban and a rural setting, we investigate the correlation between the appearances of passive dark of night images in the SWIR with NIR- visible. The experimental setup consists of two sensors, a NIR-visible CCD and an InGaAs array sensitive in the SWIR, both colocated on an AZ-EL mount, and both co-boresighted so that different viewing angles of the sky and terrestrial scenes are possible. By making corrections for focal length and pixel size, the visible and SWIR data can be compared. After taking several nights of data in the urban environment of Albuquerque, NM, the entire system was then re-located to a rural location on the island of Kauai in a rural setting with very low ambient light. It is shown that under most conditions the SWIR sensor produces significantly better imagery using the airglow illumination source.

  10. Partially light-controlled imager based on liquid crystal plate and image intensifier for aurora and airglow measurement.

    PubMed

    Tang, Yuanhe; Cao, Xiangang; Liu, Hanchen; Shepherd, G G; Liu, Shulin; Gao, Haiyang; Yang, Xusan; Wu, Yong; Wang, Shuiwei

    2012-04-20

    In order to obtain information both of aurora and airglow in one image by the same detector, a PLCI based on liquid crystal plate LCP and super second-generation image intensifier SSGII is proposed in this research. The detection thresholds of the CCD for aurora and airglow are calculated. For the detectable illumination range of 10(4)-10(-2) lx, the corresponding electron count is 1.57×10(5) - 0.2 for every pixel of CCD. The structure and work principle of the PLCI are described. An LC is introduced in the front of CCD to decrease the intensities of aurora in overexposure areas by means of controlling transmittances pixel by pixel, while an image intensifier is set between the LC and CCD to increase the intensity of the weak airglow. The modulation transfer function MTF of this system is calculated as 0.391 at a Nyquist frequency of 15 lp/mm. The curve of transmittance with regard to gray level for the LC is obtained by calibration experiment. Based on the design principle, the prototype is made and used to take photos of objects under strong light greater than 2×10(5) lx. The clear details of [symbols: see text] presented in the image indicate that the PLCI can greatly improve the imaging quality. The theoretical calculations and experiment results prove that this device can extend the dynamic range and it provides a more effective method for upper atmospheric wind measurement.

  11. Observations from space of the solar corona/inner zodiacal light

    NASA Technical Reports Server (NTRS)

    Macqueen, R. M.; Ross, C. L.; Mattingly, T.

    1973-01-01

    Observations, from the Apollo 16 Spacecraft, in lunar orbit, of the total radiance of the K + F corona, from 3 to 55 solar radii are presented and discussed. The logarithmic slope of the K + F coronal radiance, at distances greater than 20 solar radii, is found to be n equals 1.93, slightly less steep than previous determinations. The photometric axis of the radiance is found to be displaced 3 plus or minus 1 deg north of the ecliptic, at distances greater than 20 solar radii, and this displacement is interpreted as an annual variation due to non-coincidence of the ecliptic and the symmetry axis of the zodiacal cloud.

  12. Astronomical photography. Part A: Gum nebula, galactic cluster, and zodiacal light photography

    NASA Technical Reports Server (NTRS)

    Mercer, R. D.; Dunkelman, L.; Mattingly, T. K.

    1972-01-01

    It is reported that the Apollo 16 command module astronomical photography was performed with the specific objective of capitalizing on the uniqueness of the double umbra as a vantage point to collect astronomical data that are obtainable only near our Moon. For this reason, these data will be compared directly to analogous photography performed from Earth orbit during Project Mercury and the Gemini Program as well as to the Apollo-duplicated photography taken from sites on the Earth surface. Comparison with Earth-based photography should yield direct information on the Earth airglow layer and on atmospheric scattering and extinction.

  13. Skylab experiment performance evaluation manual. Appendix T: Experiment T027/S073 contamination measurement, photometer and Gegenschein/zodiacal light (MSFC)

    NASA Technical Reports Server (NTRS)

    Meyers, J. E.

    1973-01-01

    A series of analyses for Experiment T027/S073, contamination measurement, photometer and gegenschein/zodiacal light (MSFC), to be used for evaluating the performance of the Skylab corollary experiments under preflight, inflight, and post-flight conditons is presented. Experiment contingency plan workaround procedure and malfunction analyses are presented in order to assist in making the experiment operationally successful.

  14. The Origin of the Excess Near-Infrared Diffuse Sky Brightness: Population III Stars or Zodiacal Light?

    NASA Technical Reports Server (NTRS)

    Dwek, Eli

    2006-01-01

    The intensity of the diffuse 1 to 5 micron sky emission from which solar system and Galactic foregrounds have been subtracted is in excess of that expected from energy released by galaxies and stars that formed during the z < 5 redshift interval. The spectral signature of this excess near-infrared background light (NIRBL) component is almost identical to that of reflected sunlight from the interplanetary dust cloud, and could therefore be the result of the incomplete subtraction of this foreground emission component from the diffuse sky maps. Alternatively, this emission component could be extragalactic. Its spectral signature is consistent with that of redshifted continuum and recombination line emission from H-II regions formed by the first generation of very massive stars. In this talk I will present the implications of this excess emission for our understanding of the zodiacal dust cloud, the formation rate of Pop III stars, and the TeV gamma-ray opacity to nearby blazars.

  15. Zodiac II: Debris Disk Imaging Potential

    NASA Technical Reports Server (NTRS)

    Traub Wesley; Bryden, Geoff; Stapelfeldt, Karl; Chen, Pin; Trauger, John

    2011-01-01

    Zodiac II is a proposed coronagraph on a balloon-borne platform, for the purpose of observing debris disks around nearby stars. Zodiac II will have a 1.2-m diameter telescope mounted in a balloon-borne gondola capable of arcsecond quality pointing, and with the capability to make long-duration (several week) flights. Zodiac II will have a coronagraph able to make images of debris disks, meaning that its scattered light speckles will be at or below an average contrast level of about 10(exp -7) in three narrow (7 percent) bands centered on the V band, and one broad (20%) one at I band. We will discuss the potential science to be done with Zodiac II.

  16. Images and Spectra of Artificial Aurora and TMA Releases: Low-Light Level Airglow Observations During the TOMEX Rocket Experiment*

    NASA Astrophysics Data System (ADS)

    Siefring, C. L.; Gelinas, L. J.; Bernhardt, P. A.; Larsen, M. F.; Makela, J. J.; Kelley, M. C.; Hecht, J. H.

    2001-05-01

    We present the first dedicated measurements of Artificial Aurora (AA), a phenomena often observed during rocket-borne TMA releases [cf., Gelinas, et al., 2001]. Previously, only a few images of the Artificial Aurora have been documented and these were obtained using instruments designed and dedicated to tracking TMA trails and their motion. Our observations were made in conjunction with a nighttime E-region study known as the Turbulent Oxygen Mixing EXperiment (TOMEX) that was flown from White Sands Missile Range on Oct. 26, 2000. NRL provided three cameras and a spectrograph solely for observing the AA. The instruments were located at a site almost directly under apogee and all operated successfully during the mission. We will primarily present results from two of these instruments. First, a LLLTV (Low-Light Level Television) camera captured extremely detailed video-rate images of the Artificial Aurora. These video images show significantly more of the structure, dynamics and phenomenology of the Artificial Aurora than previous 'still' images. The aurora appears near 115 km altitude, projected down along the magnetic field line that the rocket is crossing. The LLLTV images show that the aurora becomes visible as the rocket passes through 135 km altitude on the upleg of the trajectory. Second, a compact-grating spectrograph was mated with another LLLTV to attempt to measure the optical spectrum of the AA emissions. The spectrograph was capable of monitoring airglow from about 330nm (limited by atmospheric Blue/NUV scattering and absorption) up to 760 nm. Clear spectra were obtained for the TMA trails, the 're-entry bag' (a bright TMA related emission that occurs as the rocket nears 100 km) and a portion of the AA after the re-entry bag and the AA merged-and-brightened. Preliminary processing of spectra when pointed only at the Artificial Aurora show an increase in the detected emission, but with a low S/N level. Further processing is necessary to extract useful

  17. AIRGLOW OBSERVATIONS AND RESEARCH.

    DTIC Science & Technology

    Huancayo , Peru, and San Juan, Argentina for the years 1957-63. Studies were made of the seasonal diurnal variations for these and other worldwide...stations. Some special analyses were made of the 1965 solar eclipse airglow data from Huancayo , and the variations in airglow intensities during

  18. Functional characteristics of the OGO main body airglow photometer

    NASA Technical Reports Server (NTRS)

    Reed, E. I.; Fowler, W. B.; Blamont, J. E.

    1972-01-01

    The OGO-4 main body airglow photometer used a trialkali cathode photomultiplier to sense light at selected wavelengths between 2500 and 6300A corresponding to important emissions in the aurora and night airglow at emission rates ranging from a few rayleighs to about 200 kilorayleighs. The optical, electronic, and mechanical systems are described in terms of their functional characteristics.

  19. Night airglow in RGB mode

    NASA Astrophysics Data System (ADS)

    Mikhalev, Aleksandr; Podlesny, Stepan; Stoeva, Penka

    2016-09-01

    To study dynamics of the upper atmosphere, we consider results of the night sky photometry, using a color CCD camera and taking into account the night airglow and features of its spectral composition. We use night airglow observations for 2010-2015, which have been obtained at the ISTP SB RAS Geophysical Observatory (52° N, 103° E) by the camera with KODAK KAI-11002 CCD sensor. We estimate the average brightness of the night sky in R, G, B channels of the color camera for eastern Siberia with typical values ranging from ~0.008 to 0.01 erg*cm-2*s-1. Besides, we determine seasonal variations in the night sky luminosities in R, G, B channels of the color camera. In these channels, luminosities decrease in spring, increase in autumn, and have a pronounced summer maximum, which can be explained by scattered light and is associated with the location of the Geophysical Observatory. We consider geophysical phenomena with their optical effects in R, G, B channels of the color camera. For some geophysical phenomena (geomagnetic storms, sudden stratospheric warmings), we demonstrate the possibility of the quantitative relationship between enhanced signals in R and G channels and increases in intensities of discrete 557.7 and 630 nm emissions, which are predominant in the airglow spectrum.

  20. A Chinese Zodiac Mathematical Structure.

    ERIC Educational Resources Information Center

    Lamb, John F., Jr.

    2000-01-01

    Helps students identify the animal that corresponds to the year of their birth according to the Chinese zodiac. Defines the structure of the Chinese zodiac so that the subsets of compatibles and opposites form closed substructures with interesting mathematical properties. (ASK)

  1. Velocities of Zodiacal Dust Particles

    NASA Astrophysics Data System (ADS)

    Ipatov, S. I.; Kutyrev, A. S.; Madsen, G. J.; Mather, J. C.; Moseley, S. H.; Reynolds, R. J.

    2005-09-01

    Ipatov et al. (2005, LPSC, 1266) compared the observational plots of the zodiacal light spectrum near the solar Mg Iλ 5184 absorption line (Reynolds, Madsen and Moseley, ApJ, 2004, 612, 1206-1213) with the spectrum obtained by analyzing computer simulation results of the distribution of dust particles which migrated from different sources (Ipatov et al., Annals of New York Academy of Sciences, 2004, v. 1017, 66-80). Now we compare the rotation curves, i.e., plots of velocities of Mg I line (at zero inclination) versus elongations ǎrepsilon (measured eastward from the Sun). The comparison of the observed rotation curves with the models for dust particles of different sizes (hence for different values of the ratio between the radiation pressure force and gravitational force β ) started from asteroids, comets (2P/Encke, 10P/Tempel 2, 39P/Oterma), and trans-Neptunian objects allowed to make some conclusions about sources of zodiacal dust particles. The rotation curves obtained for different scattering functions were similar for 30<ǎrepsilon<330 deg. For asteroidal dust particles and particles originating from comets 39P and 10P, rotation curves are relatively close to each other at β <0.2. For 2P particles the difference between the rotation curves obtained at different β was considerable in case of the particles produced at aphelion. For asteroidal dust particles modeled rotation curves differed from the observed ones, and for ǎrepsilon<240o modeled velocities were smaller by several km/s; for 10P and 39P particles they were smaller than those for observations at ǎrepsilon<160o and 60<ǎrepsilon<150o, respectively, but for 39P particles the difference was smaller than that for asteroidal and 10P particles. For trans-Neptunian particles the rotation curves were in agreement with the observations at ǎrepsilon<180o, but modeled velocities were smaller than observational velocities at 200<ǎrepsilon<250o. The rotation curves corresponding to particles originating

  2. Thermospheric aurora and airglow

    SciTech Connect

    Meier, R.R.

    1987-04-01

    New information added in the years between 1983 and 1986 to the understanding of the physics and chemistry responsible for the production of aurora and airglow emissions is presented. On auroras, the bulk of new information comes from the information obtained from satellite-based imaging (by DE1) and spectroscopy, rocket-based observations of bremsstrahlung from electrons precipitating in the auroral zone, and measurements of metastable ion species. On airglow, the DE1 photometric experiment has provided the opportunity of studying the geocorona on a global scale. A geotail was detected in the antisolar direction, confirming earlier observations. 123 references.

  3. Sources of zodiacal dust particles

    NASA Astrophysics Data System (ADS)

    Ipatov, S. I.; Mather, J. C.

    2007-08-01

    The orbital evolution of dust particles produced by asteroids, comets, and trans- Neptunian objects was integrated [1-3]. Analysis of results of these integrations testify in favor of a considerable fraction of particles produced by comets among overall zodiacal dust particles, but it does not contradict to >30% of asteroidal dust needed for explanation of formation of dust bands. Fractions of asteroidal particles, particles originating beyond Jupiter's orbit (including trans-Neptunian particles), and cometary particles originating inside of Jupiter's orbit are estimated to be about 1/3 each, with a possible deviation from 1/3 up to 0.1-0.2. Comparison of the plots of the number density vs. the distance R from the Sun obtained for particles produced by different small bodies with the plots based on observations shows that asteroidal and trans- Neptunian particles alone can not explain the observed almost constant number density at R ∼3-18 AU and a lot of particles must be produced by comets at R ∼5-10 AU [2-3]. Comparison of the WHAM (Wisconsin H-Alpha Mapper spectrometer) observations of spectra of zodiacal light with our models showed [4-5] that a significant fraction of particles produced by short-period comets is required to fit the observations of the width and velocity of the Mg I line. Comparison of the observations of the number density inside Jupiter's orbit with the number density of particles produced by different small bodies leads to the same conclusion about a considerable fraction of cometary particles. This comparison does not make limitations on cometary particles produced beyond Jupiter's orbit, but it shows that the fraction of particles produced by Encke-type comets (with eccentricities ∼0.8-0.9) does not exceed 0.15 of the overall population. The estimated fraction of particles produced by long-period and Halley-type comets among zodiacal dust also does not exceed 0.1-0.15. Though trans-Neptunian particles fit different observations of

  4. Inferring Sources in the Interplanetary Dust Cloud, from Observations and Simulations of Zodiacal Light and Thermal Emission

    NASA Technical Reports Server (NTRS)

    Levasseur-Regourd, A. C.; Lasue, J.

    2011-01-01

    Interplanetary dust particles physical properties may be approached through observations of the solar light they scatter, specially its polarization, and of their thermal emission. Results, at least near the ecliptic plane, on polarization phase curves and on the heliocentric dependence of the local spatial density, albedo, polarization and temperature are summarized. As far as interpretations through simulations are concerned, a very good fit of the polarization phase curve near 1.5 AU is obtained for a mixture of silicates and more absorbing organics material, with a significant amount of fluffy aggregates. In the 1.5-0.5 AU solar distance range, the temperature variation suggests the presence of a large amount of absorbing organic compounds, while the decrease of the polarization with decreasing solar distance is indeed compatible with a decrease of the organics towards the Sun. Such results are in favor of the predominance of dust of cometary origin in the interplanetary dust cloud, at least below 1.5 AU. The implication of these results on the delivery of complex organic molecules on Earth during the LHB epoch, when the spatial density of the interplanetary dust cloud was orders of magnitude greater than today, is discussed.

  5. Aurora Australis, Spiked, Sinuous Green Airglow

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This distant view of the Aurora Australis or Southern Lights (location unknown) shows a spiked and sinuous band of green airglow above the Earth Limb. Calculated to be in the 80 - 120 km altitude region, auroral activity is due to exitation of atomic oxygen in the upper atmosphere by radiation from the van Allen Radiation Belts and is most common above the 65 degree north and south latitude range during the spring and fall of the year.

  6. Structure of the Zodiacal Emission by Spitzer Archive Data

    NASA Astrophysics Data System (ADS)

    Verebélyi, Erika

    2015-08-01

    Dust in the Interplanetary Dust Cloud not just reflects the sunlight (known as zodiacal light) but also has its own thermal emission. At the heliocentric distance of Earth the peak of this emission (with particle size 100 μm) is close to 20 μm. In this study we used the data of four programs completed with the MIPS camera of the Spitzer Space Telescope at 24 μm to probe the large scale brightness distribution as well as the small-scale (subarcmin) structure of the Zodiacal Could. The four programs were:1. The Production of Zodiacal Dust by Asteroids and Comets (ID: 2317)2. High Latitude Dust Bands in the Main Asteroid Belt: Fingerprints of Recent Breakup Events (ID: 20539)3. A New Source of Interplanetary Dust: Type II Dust Trails (ID: 30545)4. First Look Survey - Ecliptic Plane Component (ID: 98)We take into account that while the Spitzer Space Telescope carried out the measurements it was orbiting the Sun at an Earth-trailing orbit and looked at different parts of the Zodiacal Cloud, in many cases looking through the same parts of the cloud from different locations. This gives us the chance to investigate the 3D distribution of zodiacal dust in addition to its large and small scale structure.

  7. The symmetry surface of the zodiacal cloud outside the earth's orbit

    NASA Technical Reports Server (NTRS)

    Misconi, Nebil Y.; Rusk, Edwin T.; Weinberg, J. L.

    1990-01-01

    The location in space of the symmetry surface of the zodiacal cloud at elongation angles 110-140 deg from the sun is determined from observations of the zodiacal light taken from the Pioneer 10 space probe, and from the zodiacal light experiment on Skylab. The inclination and ascending node of the symmetry surface from the ecliptic plane are shown to be about 1.2 and 23 deg, respectively, closest to those of the orbital plane of Mars. These results are consistent with those obtained from IRAS at elongation angle of 90 deg from the sun.

  8. Unambiguous evidence of HF pump-enhanced airglow at auroral latitudes

    NASA Astrophysics Data System (ADS)

    Brändström, B. U. E.; Leyser, T. B.; Steen, Å.; Rietveld, M. T.; Gustavsson, B.; Aso, T.; Ejiri, M.

    1999-12-01

    Simultaneous observations by up to three low-light imaging stations belonging to the Auroral Large Imaging System (ALIS) have provided the first strong evidence of high-frequency (HF) pump-enhanced airglow at auroral latitudes. The airglow was enhanced by an ordinary mode 4.04 MHz electromagnetic wave with an effective radiated power (ERP) of about 210 MW that was transmitted from the EISCAT-Heating facility near Tromsø, Norway. While often observed at low or mid-latitudes, and despite numerous earlier experiments, no unambiguous observations of pump-enhanced airglow have been reported at auroral latitudes. On February 16, 1999, the first successful results were obtained, and this paper concentrates on discussing optical data from this event. Triangulated estimations of the altitude and position of the enhanced airglow are also presented. Auroral-latitude observations of HF pump-enhanced airglow are important in order to better understand the underlying excitation mechanisms.

  9. The exo-zodiacal disk mapper

    NASA Technical Reports Server (NTRS)

    Petro, Larry; Bely, P.; Burg, R.; Wade, L.; Beichman, C.; Gay, J.; Baudoz, P.; Rabbia, Y.; Perrin, J. M.

    1998-01-01

    Zodiacal dust around neighboring stars could obscure the signal of terrestrial planets observed with the Terrestrial Planet Finder (TPF) if that dust is similar to that in the Solar System. Unfortunately, little is known about the presence, or frequency of occurrence of zodiacal dust around stars and so the relevance of zodiacal dust to the design of the TPF, or to the TPF mission, is unknown. It is likely that direct observation of zodiacal dust disks will be necessary to confidently determine the characteristics of individual systems. A survey of a large number of stars in the solar neighborhood that could be candidates for observation with TPF should be undertaken. We present a concept for a space mission to undertake a sensitive, large-scale survey capable of characterizing solar-system-like zodiacal dust around 400 stars within 20 pc of the Sun.

  10. WINDII atmospheric wave airglow imaging

    SciTech Connect

    Armstrong, W.T.; Hoppe, U.-P.; Solheim, B.H.; Shepherd, G.G.

    1996-12-31

    Preliminary WINDII nighttime airglow wave-imaging data in the UARS rolldown attitude has been analyzed with the goal to survey gravity waves near the upper boundary of the middle atmosphere. Wave analysis is performed on O[sub 2](0,0) emissions from a selected 1[sup 0] x 1[sup 0] oblique view of the airglow layer at approximately 95 km altitude, which has no direct earth background and only an atmospheric background which is optically thick for the 0[sub 2](0,0) emission. From a small data set, orbital imaging of atmospheric wave structures is demonstrated, with indication of large variations in wave activity across land and sea. Comparison ground-based imagery is discussed with respect to similarity of wave variations across land/sea boundaries and future orbital mosaic image construction.

  11. WINDII atmospheric wave airglow imaging

    NASA Technical Reports Server (NTRS)

    Armstrong, W. T.; Hoppe, U.-P.; Solheim, B. H.; Shepherd, G. G.

    1996-01-01

    Preliminary WINDII nighttime airglow wave-imaging data in the UARS rolldown attitude has been analyzed with the goal to survey gravity waves near the upper boundary of the middle atmosphere. Wave analysis is performed on O[sub 2](0,0) emissions from a selected 1[sup 0] x 1[sup 0] oblique view of the airglow layer at approximately 95 km altitude, which has no direct earth background and only an atmospheric background which is optically thick for the 0[sub 2](0,0) emission. From a small data set, orbital imaging of atmospheric wave structures is demonstrated, with indication of large variations in wave activity across land and sea. Comparison ground-based imagery is discussed with respect to similarity of wave variations across land/sea boundaries and future orbital mosaic image construction.

  12. Aurora Australis, Spiked and Sinuous Red and Green Airglow

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This view of the Aurora Australis or Southern Lights, in the 80 - 120 km altitude region, (location unknown) shows a spiked and sinuous band of red and green airglow above the Earth Limb and a charged plasma glow around the orbiter. Auroral activity is due to exitation of atomic oxygen in the upper atmosphere by the van Allen Radiation Belts and is most common above the 65 degree north and south latitude range during the spring and fall of the year.

  13. Aurora Australis, Spiked and Sinuous Red and Green Airglow

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In This distant view of the Aurora Australis or Southern Lights (location unknown), a spiked and sinuous band of red and green airglow above the Earth Limb is highlighted by moonglow. Auroral activity is due to exitation of atomic oxygen in the upper atmosphere by radiation from the van Allen Radiation Belts and is most common above the 65 degree north and south latitude range during the spring and fall of the year.

  14. Airglow on Titan During Eclipse

    NASA Astrophysics Data System (ADS)

    West, R. A.; Ajello, J. M.; Stevens, M. H.; Strobel, D. F.; Gladstone, R.; Evans, J. S.; Bradley, E. T.

    2012-12-01

    Magnetospheric or cosmic ray charged particle precipitation into Titan's atmosphere is a potential energy source for driving chemistry and may contribute to airglow and energy balance. Estimates of the significance of these processes vary widely and thus far have been only poorly constrained because of the dominance of XUV radiation in stimulating UV airglow. To address these issues we observed Titan when it was deeply embedded in Saturn's shadow in 2009. We obtained EUV and FUV spectra with the Cassini Ultraviolet Imaging Spectrograph (UVIS) and images with the Cassini Imaging Science Subsystem (ISS) at visible wavelengths. For the first time, nitrogen emissions were seen in the spectra in the absence of XUV stimulation, although with insufficient spatial resolution to do limb profiling. The emissions are about a factor of ten smaller than peak dayside emissions observed with UVIS at closer range (from Stevens et al., , J. Geophys. Res., 116, A05304, doi10.1029/2010ja016284). Hydrogen emissions are also observed, consistent with the idea that precipitating protons and oxygen ions are responsible for part of the emission. The visible images from ISS contribute because they resolve the disk well. No auroral structures are seen. Rather, there is a very faint airglow seen on the limb between about 300 and 1000 km and a stronger intensity coming from the region of the haze at 300 km altitude. Although the limb glow is near the noise limit, the radial profile appears to be inconsistent with ionization profiles expected for precipitating electrons, protons, or oxygen ions which are expected to produce strong limb brightening. The stronger glow from the haze region was unexpected. Its origin is not understood but deeply-penetrating cosmic ray ionization and chemiluminescence are candidates that deserve additional scrutiny. . Part of this work was performed by the Jet Propulsion Lab, Cal. Inst. of Tech. under contract with the National Aeronautics and Space Administration.

  15. Planck 2013 results. XIV. Zodiacal emission

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, H. C.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Clements, D. L.; Colley, J.-M.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Mottet, S.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; O'Sullivan, C.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polegre, A. M.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Smoot, G. F.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    The Planck satellite provides a set of all-sky maps at nine frequencies from 30 GHz to 857 GHz. Planets, minor bodies, and diffuse interplanetary dust emission (IPD) are all observed. The IPD can be separated from Galactic and other emissions because Planck views a given point on the celestial sphere multiple times, through different columns of IPD. We use the Planck data to investigate the behaviour of zodiacal emission over the whole sky at sub-millimetre and millimetre wavelengths. We fit the Planck data to find the emissivities of the various components of the COBE zodiacal model - a diffuse cloud, three asteroidal dust bands, a circumsolar ring, and an Earth-trailing feature. The emissivity of the diffuse cloud decreases with increasing wavelength, as expected from earlier analyses. The emissivities of the dust bands, however, decrease less rapidly, indicating that the properties of the grains in the bands are different from those in the diffuse cloud. We fit the small amount of Galactic emission seen through the telescope's far sidelobes, and place limits on possible contamination of the cosmic microwave background (CMB) results from both zodiacal and far-sidelobe emission. When necessary, the results are used in the Planck pipeline to make maps with zodiacal emission and far sidelobes removed. We show that the zodiacal correction to the CMB maps is small compared to the Planck CMB temperature power spectrum and give a list of flux densities for small solar system bodies.

  16. The Dynamic Community of Interest and Its Realization in ZODIAC

    DTIC Science & Technology

    2009-10-01

    the ZODIAC project. ZODIAC is a network architecture that puts security first and foremost, with security broken down into confidentiality, integrity...hosts, a unified solution for MANETs will work for hosts or routers as well. DYNAMIC COMMUNITIES OF INTEREST The basis of the ZODIAC design is a new dis...whether file transfer or real time, is restrict- ed by ZODIAC mechanisms to nodes that have a need to know, and can prove it through posses- sion of

  17. The origin and evolution of the zodiacal dust cloud

    NASA Technical Reports Server (NTRS)

    Dermott, Stanley F.; Durda, Daniel D.; Gustafson, Bo A. S.; Jayaraman, S.; Xu, Y. L.; Gomes, R. S.; Nicholson, P. D.

    1992-01-01

    We have now analyzed a substantial fraction of the IRAS observations of the zodiacal cloud, particularly in the 25 micron waveband. We have developed a gravitational perturbation theory that incorporates the effects of Poynting-Robertson light drag (Gomes and Dermott, 1992). We have also developed a numerical model, the SIMUL mode, that reproduces the exact viewing geometry of the IRAS telescope and calculates the distribution of thermal flux produced by any particular distribution of dust particle orbits (Dermott and Nicholson, 1989). With these tools, and using a distribution of orbits based on those of asteroidal particles with 3.4 micron radii whose orbits decay due to Poynting-Robertson light drag and are perturbed by the planets, we have been able to: (1) account for the inclination and node of the background zodiacal cloud observed by IRAS in the 25 micron waveband; (2) relate the distribution of orbits in the Hirayama asteroid families to the observed shapes of the IRAS solar system dustbands; and (3) show that there is observational evidence in the IRAS data for the transport of asteroidal particles from the main belt to the Earth by Poynting-Robertson light drag.

  18. The origin and evolution of the zodiacal dust cloud

    NASA Astrophysics Data System (ADS)

    Dermott, Stanley F.; Durda, Daniel D.; Gustafson, Bo A. S.; Jayaraman, S.; Xu, Y. L.; Gomes, R. S.; Nicholson, P. D.

    1992-12-01

    We have now analyzed a substantial fraction of the IRAS observations of the zodiacal cloud, particularly in the 25 micron waveband. We have developed a gravitational perturbation theory that incorporates the effects of Poynting-Robertson light drag (Gomes and Dermott, 1992). We have also developed a numerical model, the SIMUL mode, that reproduces the exact viewing geometry of the IRAS telescope and calculates the distribution of thermal flux produced by any particular distribution of dust particle orbits (Dermott and Nicholson, 1989). With these tools, and using a distribution of orbits based on those of asteroidal particles with 3.4 micron radii whose orbits decay due to Poynting-Robertson light drag and are perturbed by the planets, we have been able to: (1) account for the inclination and node of the background zodiacal cloud observed by IRAS in the 25 micron waveband; (2) relate the distribution of orbits in the Hirayama asteroid families to the observed shapes of the IRAS solar system dustbands; and (3) show that there is observational evidence in the IRAS data for the transport of asteroidal particles from the main belt to the Earth by Poynting-Robertson light drag.

  19. A rocket-borne airglow photometer

    NASA Technical Reports Server (NTRS)

    Paarmann, L. D.; Smith, L. G.

    1977-01-01

    The design of a rocket-borne photometer to measure the airglow emission of ionized molecular nitrogen in the 391.4 nm band is presented. This airglow is a well known and often observed phenomenon of auroras, where the principal source of ionization is energetic electrons. It is believed that at some midlatitude locations energetic electrons are also a source of nighttime ionization in the E region of the ionosphere. If this is so, then significant levels of 391.4 nm airglow should be present. The intensity of this airglow will be measured in a rocket payload which also contains instrumentation to measured in a rocket payload which also contains instrumentation to measure energetic electron differential flux and the ambient electron density. An intercomparison of the 3 experiments in a nightime launch will allow a test of the importance of energetic electrons as a nighttime source of ionization in the upper E region.

  20. [Signs of the zodiac and personality].

    PubMed

    Angst, J; Scheidegger, P

    1976-01-01

    3074 young men resident in the canton of Zurich, representing 50% of the 19 year old male population, form the fully representative sample of our large scale investigation. We investigated whether personality traits measured by means of the differentiated "Freiburger personality inventory" (FPI) could in any way be correlated to the signs of the zodiac under which the young men were born. The statistical analysis did not reveal any correlation between signs of the zodiac and personality. The claim made by astrologers that people can be characterized according to their sign of the zodiac (sagitarius, taurus, cancer, scorpion) must be refuted. Of course the astrologically founded description of human personality does not base itself on the position of the sun only, however the latter does form a very essential part of the astrological evaluation of people. This, at any rate has been shown to be without any scientific basis. The fact that astrological evaluation of human personality is so popular nowadays can be explained by the fact that even modern people are inclined towards magical thinking.

  1. Suomi satellite brings to light a unique frontier of nighttime environmental sensing capabilities

    PubMed Central

    Miller, Steven D.; Mills, Stephen P.; Elvidge, Christopher D.; Lindsey, Daniel T.; Lee, Thomas F.; Hawkins, Jeffrey D.

    2012-01-01

    Most environmental satellite radiometers use solar reflectance information when it is available during the day but must resort at night to emission signals from infrared bands, which offer poor sensitivity to low-level clouds and surface features. A few sensors can take advantage of moonlight, but the inconsistent availability of the lunar source limits measurement utility. Here we show that the Day/Night Band (DNB) low-light visible sensor on the recently launched Suomi National Polar-orbiting Partnership (NPP) satellite has the unique ability to image cloud and surface features by way of reflected airglow, starlight, and zodiacal light illumination. Examples collected during new moon reveal not only meteorological and surface features, but also the direct emission of airglow structures in the mesosphere, including expansive regions of diffuse glow and wave patterns forced by tropospheric convection. The ability to leverage diffuse illumination sources for nocturnal environmental sensing applications extends the advantages of visible-light information to moonless nights. PMID:22984179

  2. Measurements and an empirical model of the Zodiacal brightness as observed by the Solar Mass Ejection Imager (SMEI)

    NASA Astrophysics Data System (ADS)

    Buffington, Andrew; Bisi, Mario M.; Clover, John M.; Hick, P. Paul; Jackson, Bernard V.; Kuchar, Thomas A.; Price, Stephan D.

    2016-07-01

    The Solar Mass Ejection Imager (SMEI) provided near-full-sky broadband visible-light photometric maps for 8.5 years from 2003 to 2011. At a cadence of typically 14 maps per day, these each have an angular resolution of about 0.5º and differential photometric stability of about 1% throughout this time. When individual bright stars are removed from the maps and an empirical sidereal background subtracted, the residue is dominated by the zodiacal light. This sky coverage enables the formation of an empirical zodiacal-light model for observations at 1 AU which summarizes the SMEI data. When this is subtracted, analysis of the ensemble of residual sky maps sets upper limits of typically 1% for potential secular change of the zodiacal light for each of nine chosen ecliptic sky locations. An overall long-term photometric stability of 0.25% is certified by analysis of three stable sidereal objects. Averaging the nine ecliptic results together yields a 1-σ upper limit of 0.3% for zodiacal light change over this 8.5 year period.

  3. Measurements and an Empirical Model of the Zodiacal Brightness as Observed by the Solar Mass Ejection Imager (SMEI)

    NASA Astrophysics Data System (ADS)

    Buffington, A.; Bisi, M. M.; Clover, J. M.; Hick, P. P.; Jackson, B. V.; Kuchar, T. A.; Price, S. D.

    2015-12-01

    The Solar Mass Ejection Imager (SMEI) has provided near-full-sky broadband visible-light photometric maps for 8.5 years from 2003 to 2011. These have an angular resolution of about 0.5º and differential photometric stability of about 1% per map throughout this time. When individual bright stars are removed from the maps and an empirical sidereal background subtracted, the residue is dominated by the zodiacal light. This sky coverage enables the formation of an empirical zodiacal-light model for observations at 1 AU which summarizes the SMEI data. When this is subtracted, analysis of the ensemble of residual sky maps sets upper limits of typically 1% for potential secular change of the zodiacal light for each of nine chosen ecliptic sky locations. An overall long-term photometric stability of 0.25% is certified by analysis of three stable sidereal objects. Averaging the nine ecliptic results together yields a 1-σ upper limit of 0.3% for zodiacal light change over this 8.5 year period.

  4. [[On the change of sex ratio by the Japanese zodiac

    PubMed

    Sakai, H

    1989-04-01

    Changes in the sex ratio in Japan from 1899 to 1986 are analyzed using data from official sources. The emphasis is on differences in the sex ratio according to the signs of the Japanese zodiac. The author notes that although the significance of the zodiac on the sex ratio has been decreasing since the early 1970s, it still has a measurable impact.

  5. A study of extended zodiacal structures

    NASA Technical Reports Server (NTRS)

    Sykes, Mark V.

    1990-01-01

    Observations of cometary dust trails and zodiacal dust bands, discovered by the Infrared Astronomical Satellite (IRAS) were analyzed in a continuing effort to understand their nature and relationship to comets, asteroids, and processes effecting those bodies. A survey of all trails observed by IRAS has been completed, and analysis of this phenomenon continues. A total of 8 trails have been associated with known short-period comets (Churyumov-Gerasimenko, Encke, Gunn, Kopff, Pons-Winnecke, Schwassmann-Wachmann 1, Tempel 1, and Tempel 2), and a few faint trails have been detected which are not associated with any known comet. It is inferred that all short-period comets may have trails, and that the trails detected were seen as a consequence of observational selection effects. Were IRAS launched today, it would likely observe a largely different set of trails. The Tempel 2 trail exhibits a small but significant excess in color temperature relative to a blackbody at the same heliocentric distance. This excess may be due to the presence of a population of small, low-beta particles deriving from large particles within the trail, or a temperature gradient over the surface of large trail particles. Trails represent the very first stage in the formation and evolution of a meteor stream, and may also be the primary mechanism by which comets contribute to the interplanetary dust complex. A mathematical model of the spatial distribution of orbitally evolved collisional debris was developed which reproduces the zodiacal dust band phenomena and was used in the analysis of dust band observations made by IRAS. This has resulted in the principal zodiacal dust bands being firmly related to the principal Hirayama asteroid families. In addition, evidence for the collisional diffusion of the orbital elements of the dust particles has been found in the case of dust generated in the Eos asteroid family.

  6. The Saptarishis Calendar: 'The Indian tropical Zodiac'!

    NASA Astrophysics Data System (ADS)

    Indrasena, Buddhike S. H.

    2015-07-01

    The Saptarishis Calendar of ancient India is based on precession of the equinoxes. It employs the tropical zodiac of the Greeks and the precessional rate of Hipparchus. The Saptarishis era has to be determined by naked eye observation of the sky. Currently, the line of reference goes through the stars Dubhe and Merak in the constellation of Ursa Major, touching both of them, and crosses the ecliptic in the sidereal Purvaphalguni Nakshatra of Simha Rashi at a point close to the star 59 Leonis. The angular difference between this 'Saptarishis pointer' and the vernal equinox gives the tropical lunar mansion in which Saptarishis resides at a given point in time.

  7. The Extra-Zodiacal Explorer (EZE)

    NASA Astrophysics Data System (ADS)

    Greenhouse, Matthew A.; Benson, S. W.; Fixsen, D. J.; Gardner, J. P.; Kruk, J. W.; Thronson, H. A.

    2012-01-01

    We describe a mission architecture study designed to substantially increase the potential science performance of the NASA SMD Astrophysics Explorer Program for all AO offerors working within the near-UV to far-infrared spectrum. We have demonstrated that augmentation of Falcon 9 Explorer launch services with a Solar Electric Propulsion (SEP) stage can deliver a 700 kg science observatory payload to an extra-Zodiacal orbit. This new capability enables up to 10X increased photometric sensitivity and 150X increased observing speed relative to a Sun-Earth L2 or Earth-trailing orbit with no increase in telescope aperture. All enabling SEP stage technologies for this launch service augmentation have reached sufficient readiness (TRL-6) for Explorer Program application in conjunction with the Falcon 9. We demonstrate that enabling Astrophysics Explorers to reach extra-zodiacal orbit will allow this small payload program to rival the science performance of much larger long development time systems; thus, providing a means to realize major science objectives while increasing the SMD Astrophysics portfolio diversity and resiliency to external budget pressure. The SEP technology employed in this study has applicability to SMD Planetary competed missions and aligns with NASA in-space propulsion technology road map objectives and associated flight demonstration planning.

  8. Microwave thermal emission from the zodiacal dust cloud predicted with contemporary meteoroid models

    NASA Astrophysics Data System (ADS)

    Dikarev, Valery V.; Schwarz, Dominik J.

    2015-12-01

    Predictions of the microwave thermal emission from the zodiacal dust cloud are made using several contemporary meteoroid models to construct the distributions of the cross-section area of dust in space, and by applying the Mie light-scattering theory to estimate the temperatures and emissivities of dust particles in a wide range of sizes and heliocentric distances. In particular, the Kelsall model of the zodiacal light emission based on COBE infrared observations is extrapolated to the microwaves with assistance from fits to selected IRAS and Planck data. Furthermore, the five populations of interplanetary meteoroids by Divine and the Interplanetary Meteoroid Engineering Model (IMEM) based on a variety of remote and in situ observations of dust are used in combination with the optical properties of olivine, carbonaceous, and iron spherical particles. The Kelsall model has been accepted by the cosmic microwave background (CMB) community for subtraction of the zodiacal cloud's foreground emission. We show, however, that the Kelsall model predicts microwave emission from interplanetary dust that is remarkably different from the results obtained by applying the meteoroid engineering models. We make maps and spectra of the microwave emission predicted by all three models assuming different compositions of dust particles. The predictions can be used to look for the emission from interplanetary dust in CMB experiments and to plan new observations.

  9. Telescopic Imaging of Heater-Induced Airglow at HAARP

    DTIC Science & Technology

    2007-01-01

    03-01-2007 Final1 10-09-2003 - 10-09-2006 4. TITLE AND SUBTITLE Ba. CONTRACT NUMBER Telescopic Imaging of Heater-Induced Airglow at HAARP N00014-03-1... HAARP to optically measure fine structure in the ionosphere and to study airglow sources. In the presence of aurora and a strong blanketing E layer... HAARP was modulated at intervals of several seconds. For several cycles, small bright airglow spots were observed whenever HAARP was on. These spots

  10. Heater-induced ionization inferred from spectrometric airglow measurements

    NASA Astrophysics Data System (ADS)

    Hysell, D. L.; Miceli, R. J.; Varney, R. H.; Schlatter, N.; Huba, J. D.

    2013-12-01

    Spectrographic airglow measurements were made during an ionospheric modification experiment at HAARP on March 12, 2013. Artificial airglow enhancements at 427.8, 557.7, 630.0, 777.4, and 844.6 nm were observed. On the basis of these emissions and using a methodology based on the method of Backus and Gilbert [1968, 1970], we estimate the suprathermal electron population and the subsequent equilibrium electron density profile, including contributions from electron impact ionization. We find that the airglow is consistent with significant induced ionization in view of the spatial intermittency of the airglow.

  11. Apollo 16 far ultraviolet imagery of the polar auroras, tropical airglow belts, and general airglow

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.; Page, T.

    1976-01-01

    Far-ultraviolet imagery of the earth in the wavelength ranges from 1050 to 1600 A and from 1250 to 1600 A was obtained from the lunar surface during the Apollo 16 mission on Apr. 21, 1972. The images have an angular resolution of about 2 arcmin (230-km linear resolution) and have been quantitatively analyzed to obtain absolute intensities and spatial distributions of the polar auroras (both wavelength ranges), the day and night airglow, and tropical airglow belts (1250-A to 1600-A wavelength range). The observations are consistent with previous results obtained from the OGO-4 spacecraft, but they have also provided details on the spatial distributions of the various emissions over an entire hemisphere at a single time. A general night airglow, at least in the Northern Hemisphere, is indicated.

  12. Brightness contribution of zodiacal dust along the line of sight in and out of the ecliptic plane and in the F-corona

    NASA Astrophysics Data System (ADS)

    Misconi, Nebil Y.; Rusk, Edwin T.

    1987-12-01

    Model calculations are used to determine the location of interplanetary dust particles that contribute most of the brightness of the zodiacal light as seen from earth, in and out of the ecliptic plane and in the F-corona. It is found that, as one observes in increasing ecliptic latitude (beta), the distance to the earth decreases for dust contributing equal fractions to the line-of-sight brightness. This and other results will help in the analysis of: (1) structures in the observed brightness of the zodiacal light, (2) bands such as those observed by IRAS, (3) temporal variations in the brightness of the zodiacal light, (4) observations of the photometric axis, and (5) past and future observations of the F-corona.

  13. The Primeval Zodiac: Its Social, Religious, and Mythological Background

    NASA Astrophysics Data System (ADS)

    Verderame, L.

    2009-08-01

    In this brief paper we try to draw the lines of the possible development of the originary iconographic and symbolic repertoire of the Mesopotamian zodiac, which through the Greeks was adopted in the Western world.

  14. 72. 451 MADISON AVENUE, GRAND STAIR, ZODIAC CLOCK WITH DECORATIVE ...

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

    72. 451 MADISON AVENUE, GRAND STAIR, ZODIAC CLOCK WITH DECORATIVE CARVING BY STANFORD WHITE AND AUGUSTUS SAINT-GAUDENS - Villard Houses, 451-457 Madison Avenue & 24 East Fifty-first Street, New York County, NY

  15. Zodiac II: Debris Disk Science from a Balloon

    NASA Technical Reports Server (NTRS)

    Bryden, Geoffrey; Traub, Wesley; Roberts, Lewis C., Jr.; Bruno, Robin; Unwin, Stephen; Backovsky, Stan; Brugarolas, Paul; Chakrabarti, Supriya; Chen, Pin; Hillenbrand, Lynne; Krist, John; Lillie, Charles; Macintosh, Bruce; Mawet, Dimitri; Mennesson, Bertrand; Moody, Dwight; Rey, Justin; Stapelfeldt, Karl; Stuchlik, David; Trauger, John; Vasisht, Gautam

    2011-01-01

    Zodiac II is a proposed balloon-borne science investigation of debris disks around nearby stars. Debris disks are analogs of the Asteroid Belt (mainly rocky) and Kuiper Belt (mainly icy) in our Solar System. Zodiac II will measure the size, shape, brightness, and color of a statistically significant sample of disks. These measurements will enable us to probe these fundamental questions: what do debris disks tell us about the evolution of planetary systems; how are debris disks produced; how are debris disks shaped by planets; what materials are debris disks made of; how much dust do debris disks make as they grind down; and how long do debris disks live? In addition, Zodiac II will observe hot, young exoplanets as targets of opportunity. The Zodiac II instrument is a 1.1-m diameter SiC (Silicone carbide) telescope and an imaging coronagraph on a gondola carried by a stratospheric balloon. Its data product is a set of images of each targeted debris disk in four broad visible-wavelength bands. Zodiac II will address its science questions by taking high-resolution, multi-wavelength images of the debris disks around tens of nearby stars. Mid-latitude flights are considered: overnight test flights in the US followed by half-global flights in the Southern Hemisphere. These longer flights are required to fully explore the set of known debris disks accessible only to Zodiac II. On these targets, it will be 100 times more sensitive than the Hubble Space Telescope's Advanced Camera for Surveys (HST/ACS); no existing telescope can match the Zodiac II contrast and resolution performance. A second objective of Zodiac II is to use the near-space environment to raise the Technology Readiness Level (TRL) of SiC mirrors, internal coronagraphs, deformable mirrors, and wavefront sensing and control, all potentially needed for a future space-based telescope for high-contrast exoplanet imaging.

  16. Zodiac II: Debris Disk Science from a Balloon

    NASA Technical Reports Server (NTRS)

    Bryden, Geoffrey; Traub, Wesley; Roberts, Lewis C., Jr.; Bruno, Robin; Unwin, Stephen; Backovsky, Stan; Brugarolas, Paul; Chakrabarti, Supriya; Chen, Pin; Hillenbrand, Lynne; Krist, John; Lillie, Charles; Macintosh, Bruce; Mawet, Dimitri; Mennesson, Bertrand; Moody, Dwight; Rahman, Zahidul; Rey, Justin; Stapelfeldt, Karl; Stuchlik, David; Trauger, John; Vasisht, Gautam

    2011-01-01

    Zodiac II is a proposed balloon-borne science investigation of debris disks around nearby stars. Debris disks are analogs of the Asteroid Belt (mainly rocky) and Kuiper Belt (mainly icy) in our Solar System. Zodiac II will measure the size, shape, brightness, and color of a statistically significant sample of disks. These measurements will enable us to probe these fundamental questions: what do debris disks tell us about the evolution of planetary systems; how are debris disks produced; how are debris disks shaped by planets; what materials are debris disks made of; how much dust do debris disks make sa they grind down; and how long do debris disks live? In addition, Zodiac II will observe hot, young exoplanets as targets of opportunity. The Zodiac II instrument is a 1.1-m diameter SiC telescope and an imaging coronagraph on a gondola carried by a stratospheric balloon. Its data product is a set of images of each targeted debris disk in four broad visible wavelength bands. Zodiac II will address its science questions by taking high-resolution, multi-wavelength images of the debris disks around tens of nearby stars. Mid-latitude flights are considered: overnight test flights within the United States followed by half-global flights in the Southern Hemisphere. These longer flights are required to fully explore the set of known debris disks accessible only to Zodiac II. On these targets, it will be 100 times more sensitive than the Hubble Space Telescope's Advanced Camera for Surveys (HST/ACS); no existing telescope can match the Zodiac II contrast and resolution performance. A second objective of Zodiac II is to use the near-space environment to raise the Technology Readiness Level (TRL) of SiC mirrors, internal coronagraphs, deformable mirrors, and wavefront sensing and control, all potentially needed for a future space-based telescope for high-contrast exoplanet imaging.

  17. Berkeley extreme-ultraviolet airglow rocket spectrometer - BEARS

    NASA Technical Reports Server (NTRS)

    Cotton, D. M.; Chakrabarti, S.

    1992-01-01

    The Berkeley EUV airglow rocket spectrometer (BEARS) instrument is described. The instrument was designed in particular to measure the dominant lines of atomic oxygen in the FUV and EUV dayglow at 1356, 1304, 1027, and 989 A, which is the ultimate source of airglow emissions. The optical and mechanical design of the instrument, the detector, electronics, calibration, flight operations, and results are examined.

  18. Lightning induced brightening in the airglow layer

    SciTech Connect

    Boeck, W.L. ); Vaughan, O.H. Jr.; Blakeslee, R. ); Vonnegut, B. ); Brook, M. )

    1992-01-24

    This report describes a transient luminosity observed at the altitude of the airglow layer (about 95 km) in coincidence with a lightning flash in a tropical oceanic thunderstorm directly beneath it. This event provides new evidence of direct coupling between lightning and ionospheric events. This luminous event in the ionosphere was the only one of its kind observed during an examination of several thousand images of lightning recorded under suitable viewing conditions with Space Shuttle cameras. Several possible mechanisms and interpretations are discussed briefly.

  19. Pluto's Far Ultraviolet Spectrum and Airglow Emissions

    NASA Astrophysics Data System (ADS)

    Steffl, A.; Schindhelm, E.; Kammer, J.; Gladstone, R.; Greathouse, T. K.; Parker, J. W.; Strobel, D. F.; Summers, M. E.; Versteeg, M. H.; Ennico Smith, K.; Hinson, D. P.; Linscott, I.; Olkin, C.; Parker, A. H.; Retherford, K. D.; Singer, K. N.; Tsang, C.; Tyler, G. L.; Weaver, H. A., Jr.; Woods, W. W.; Young, L. A.; Stern, A.

    2015-12-01

    The Alice far ultraviolet spectrograph on the New Horizons spacecraft is the second in a family of six instruments in flight on, or under development for, NASA and ESA missions. Here, we present initial results from the Alice observations of Pluto during the historic flyby. Pluto's far ultraviolet spectrum is dominated by sunlight reflected from the surface with absorption by atmospehric constituents. We tentatively identify C2H2 and C2H4 in Pluto's atmosphere. We also present evidence for weak airglow emissions.

  20. The Zodiacal Exoplanets in Time (ZEIT) Survey

    NASA Astrophysics Data System (ADS)

    Mann, Andrew; Gaidos, Eric; Newton, Elisabeth R.; Rizzuto, Aaron C.; Vanderburg, Andrew; Mace, Gregory N.; Kraus, Adam L.

    2017-01-01

    Planets and their host stars evolve with time, and the first few hundred million years are thought to be the most formative. However, the majority of known exoplanets orbit stars older than the timescales of interest (>1 Gyr). We have launched the Zodiacal Exoplanets in Time (ZEIT) survey with the goal of identifying and characterizing young (<1 Gyr) transiting planets. To this end, we have utilized high-precision photometry of nearby young clusters and stellar associations taken as part of the K2 mission. Thus far we have discovered transiting planets in the Hyades and Praesepe clusters (˜800 Myr), and the Upper Scorpius OB association (˜11 Myr), but interestingly none in the Pleiades (˜125 Myr). These discoveries can be used to set limits on the migration timescale, estimate atmosphere loss around young planets, and provide independent tests of pre-main sequence stellar models. Here I overview some key science results from our survey and briefly discuss our plans to identify more young planetary systems.

  1. Mesopause region wind, temperature and airglow irradiance above Eureka, Nunavut

    NASA Astrophysics Data System (ADS)

    Kristoffersen, Samuel; Ward, William E.; Vail, Christopher; Shepherd, Marianna

    2016-07-01

    The PEARL All Sky Imager (PASI, airglow images), the Spectral Airglow Temperature Imager (SATI, airglow irradiance and temperature) and the E-Region Wind Interferometer II (ERWIN2, wind, airglow irradiance and temperature) are co-located at the Polar Environment Atmospheric Research Laboratory (PEARL)in Eureka, Nunavut (80 N, 86 W). These instruments view the wind, temperature and airglow irradiance of hydroxyl (all three) O2 (ERWIN2 and SATI), sodium (PASI), and oxygen green line (PASI and ERWIN2). The viewing locations and specific emissions of the various instruments differ. Nevertheless, the co-location of these instruments provides an excellent opportunity for case studies of specific events and for intercomparison between the different techniques. In this paper we discuss the approach we are using to combine observations from the different instruments. Case studies show that at times the various instruments are in good agreement but at other times they differ. Of particular interest are situations where gravity wave signatures are evident for an extended period of time and one such situation is presented. The discussion includes consideration of the filtering effect of viewing through airglow layers and the extent to which wind, airglow and temperature variations can be associated with the same gravity wave.

  2. Origin and evolution of the zodiacal dust cloud

    NASA Technical Reports Server (NTRS)

    Dermott, S. F.; Durda, D.; Gustafson, B.; Jayaraman, S.; Xu, Y.-L.; Nicholson, P. D.; Gomes, R. S.

    1991-01-01

    The astrophysical importance of the zodiacal cloud became more apparent. The most useful source of information on the structure of the zodiacal cloud is the Infrared Astronomical Satellite (IRAS) observations. A substantial fraction of the extensive IRAS data set was analyzed. Also, a numerical model was developed (SIMUL) that allows to calculate the distribution of night-sky brightness that would be produced by any particular distribution of dust particle orbits. This model includes the effects of orbital perturbations by both the planets and solar radiation, it reproduces the exact viewing geometry of the IRAS telescope, and allows for the eccentricity of the Earth's orbit. SIMUL now is used to model not just the solar system dust bands discovered by IRAS but the whole zodiacal cloud.

  3. Productino of KSR-III Airglow Photometers to Measure MUV Airglows of the Upper Atmosphere Above the Korean Peninsular

    NASA Astrophysics Data System (ADS)

    Oh, T.-H.; Park, K.-C.; Kim, Y.-H.; Yi, Y.; Kim, J.

    2002-12-01

    We have constructed two flight models of airglow photometer system (AGP) to be onboard Korea Sounding Rocket-III (KSR-III) for detection of MUV dayglow above the Korean peninsular. The AGP system is designed to detect dayglow emissions of OI 2972 Å, N_2 VK (0,6) 2780Å, N_2 2PG 3150Å and background 3070Å toward the horizon at altitudes between 100 km and 300 km. The AGP system consists of a photometer body, a baffle, an electronic control unit and a battery unit. The MUV dayglow emissions enter through a narrow band interference filter and focusing lens of the photometer, which contains an ultraviolet sensitive photomultiplier tube. The photometer is equipped with an in-flight calibration light source on a circular plane that will rotate at the rocket's apogee. A baffle tube is installed at the entry of the photometer in order to block strong scattering lights from the lower atmosphere. We have carried out laboratory measurements of sensitivity and in-flight calibration light source for the AGP flight models. Although absolute sensitivities of the AGP flight models could not be determined in the country, relative sensitivities among channels are well measured so that observation data during rocket flight in the future can be analyzed with confidence.

  4. Teeth and numerology from zodiac signs. A correlative study.

    PubMed

    Kudva, S; Bhat, A P

    2000-01-01

    Comparative anatomical descriptions have been time and again mentioned in the literature. Based on these aspects, an attempt is made to correlate the morphological features of the human teeth, the zodiac sun signs and numerology. This unique study (first ever of its kind) is also done with a purpose as to whether a particular 'Zodiac Sunsign' or numerology can predict about an individual dental health, the same way the future predictions are being made. It was quite interesting to note that there are few definite attributable dental morphological traits and health to the specific sun signs and numerology.

  5. Airglow events visible to the naked eye

    NASA Technical Reports Server (NTRS)

    Peterson, A. W.

    1979-01-01

    During IR photographic airglow observations covering several years, three naked-eye events have been recorded. Two of these are moving luminous acoustic-gravity-wave groups of some 10-15-km wavelength, which occur near high lunar tide in the atmosphere. The events appear quickly, endure 0.5-1 h, then fade. Visible photos of two events appear enhanced, while little enhancement is present in the IR photos, although the structures are well correlated. If these events are due to OH, it is suggested that some unrecognized mechanism, perhaps a gravity wave interaction, enhances the visible transitions of the OH over the IR transitions. If the events are due to an unrecognized continuum emitter, perhaps NO, its emission must occur at the same height as the OH. Spectra seem to be the only reasonable approach to solving this problem.

  6. Heater-induced artificial airglow observations at the HAARP facility

    NASA Astrophysics Data System (ADS)

    Gerken, E.

    Since 2002, dedicated artificial airglow campaigns have been conducted each winter at the High Frequency Active Auroral Program (HAARP) in Gakona AK (62.39N, 145.15W). Experiments performed during these optical campaigns have focused on exploring the so-called ``magnetic zenith effect.'' A dramatic enhancement in airglow brightness is observed when the HAARP heater beam is aimed along the geomagnetic field lines (15 degrees from vertical). The artificial airglow campaigns are a collaborative effort with participants from a number of institutions. Cameras with fields of view ranging from ˜1 degree to all-sky are located at HAARP, Poker Flat Research Range, the HIPAS antenna facility, and other Alaskan locations. An array of SEE receivers is set up during the campaigns and the Kodiak SuperDARN radar is run in a dedicated mode. In addition, data is gathered throughout the campaigns by the HAARP diagnostic instruments including a riometer, magnetometer, digisonde, ELF receiver, and TEC tomographic system. Data from all three campaigns will be presented and future plans will be discussed. A very successful artificial airglow campaign was conducted from January 31 to February 19, 2002. 630 nm and/or 557.7 nm artificial airglow was observed on thirteen nights during the campaign. Bright 630 nm (several hundred Rayleighs) and 557.7 nm (over 50 R) airglow was observed simultaneously during F-layer heating. Both structured and non-structured airglow was observed at 630 nm and 557.7 nm. Patchy 557.7 nm airglow was observed to drift through the heated region. Altitude calculations were performed from sideview triangulations at HIPAS and Poker Flat.

  7. On the Onset of HF-Induced Airglow at HAARP

    DTIC Science & Technology

    2007-11-02

    revised 2 December 2003; accepted 19 December 2003; published 13 February 2004. [i] Observations of airglow at 630 nm (red line) and 557.7 nm ( green ...during injections toward magnetic zenith (MZ) the green and red lines gain -5 R within ,-1 s and -20 R within ,-,10 s, respectively. We term this period...observations show that the airglow maximizes Gustavsson et al., 2001, 2002; Kosch et al., 2000, 2002]. during HF injections toward magnetic zenith

  8. AKARI far-infrared maps of the zodiacal dust bands

    NASA Astrophysics Data System (ADS)

    Ootsubo, Takafumi; Doi, Yasuo; Takita, Satoshi; Nakagawa, Takao; Kawada, Mitsunobu; Kitamura, Yoshimi; Matsuura, Shuji; Usui, Fumihiko; Arimatsu, Ko

    2016-06-01

    Zodiacal emission is thermal emission from interplanetary dust. Its contribution to the sky brightness is non-negligible in the region near the ecliptic plane, even in the far-infrared (far-IR) wavelength regime. We analyze zodiacal emission observed by the AKARI far-IR all-sky survey, which covers 97% of the entire sky at arcminute-scale resolution in four photometric bands, with central wavelengths of 65, 90, 140, and 160 μm. AKARI detected small-scale structures in the zodiacal dust cloud, including the asteroidal dust bands and the circumsolar ring, at far-IR wavelengths. Although the smooth component of the zodiacal emission structure in the far-IR sky can be reproduced well by models based on existing far-IR observations, previous zodiacal emission models have discrepancies in the small-scale structures compared with observations. We investigate the geometry of the small-scale dust-band structures in the AKARI far-IR all-sky maps and construct template maps of the asteroidal dust bands and the circumsolar ring components based on the AKARI far-IR maps. In the maps, ± 1.4°, ± 2.1°, and ± 10° asteroidal dust-band structures are detected in the 65 μm and 90 μm bands. A possible ± 17° band may also have been detected. No evident dust-band structures are identified in either the 140 μm or the 160 μm bands. By subtracting the dust-band templates constructed in this paper, we can achieve a similar level of flux calibration of the AKARI far-IR all-sky maps in the |β| < 40° region to that in the region for |β| > 40°.

  9. Understanding airglow signatures of short-period gravity waves

    NASA Astrophysics Data System (ADS)

    Snively, Jonathan; Taylor, Michael J.; Pendleton, William R., Jr.; Pautet, Pierre-Dominique

    Airglow imaging is a primary tool in the study of gravity waves at mesospheric and lower-thermospheric (MLT) altitudes, clearly revealing signatures of small-scale (<100 km) and short-period (<30 min) waves. Short-period waves are in particular able to carry significant momentum into the MLT [e.g., Fritts and Alexander, 2003, Rev. Geophys., 41(1)]. However, quantification of short-period wave fluxes and propagation characteristics is complicated by their susceptibility to refraction by ambient wind and thermal structure at airglow altitudes. These effects lead to vertical wavelengths that vary dramatically with altitude throughout the airglow layers, and reflection and ducting, which can prevent the accurate assessment of ampli-tude and vertical direction of propagation [e.g., Fritts, 2000, JGR, 105(D17), 22,355-22,360]. To investigate airglow signatures of short-period gravity waves, we utilize a two-dimensional nonlinear dynamics model coupled with OH Meinel band and OI 557.7 nm airglow photochem-istry models. Case studies where the ambient atmospheric structure significantly influences wave propagation are presented, for both ducted and reflected waves, and also for waves ap-proaching critical levels. Arising from Doppler shifts to higher and lower intrinsic frequencies, respectively, these effects contribute to significant variation of vertical wavelength throughout the airglow region, and may limit the altitude of propagation. Cancellation effects of vertically-integrated airglow volume emission rate perturbations are discussed, along with observable nonlinear features due to large amplitude [e.g., Huang et al., 2003, JGR, 108(A5), 1173], and effects of partial perturbations to airglow layers by vertically-confined waves [e.g., Snively et al., JGR, In Review, 2010]. In particular, it is demonstrated that high temporal and spatial resolution measurements of airglow intensity and brightness-weighted temperature, combined with detailed descriptions of ambient

  10. Nitrogen airglow sources - Comparison of Triton, Titan, and earth

    NASA Technical Reports Server (NTRS)

    Strobel, Darrell F.; Meier, R. R.; Summers, Michael E.; Strickland, Douglas J.

    1991-01-01

    The individual contributions of direct solar excitation, photoelectron excitation, and magnetospheric electron excitation of Triton and Titan airglow observed by the Voyager Ultraviolet Spectrometer (UVS) are quantified. The principal spectral features of Triton's airglow are shown to be consistent with precipitation of magnetospheric electrons with power dissipation about 500 million W. Solar excitation rates of the dominant N2 and N(+) emission features are factors of 2-7 weaker than magnetospheric electron excitation. On Titan, the calculated disk center and bright limb N(+) 1085 A intensities due to solar excitation agree with observed values, while the 970 A feature is mostly N21 c5 band emission. The calculated LBH intensity by photoelectrons suggests that magnetospheric electrons play a minor role in Titan's UV airglow. On earth, solar/photoelectron excitation explains the observed N(+) 1085 A and LBH intensites and accounts for only 40 percent of the N(+) 916 A intensity.

  11. The Chevroches zodiacal cap and its Burgundy relations

    NASA Astrophysics Data System (ADS)

    Devevey, Frédéric; Vernou, Christian; Rousseau, Aurélie

    2011-06-01

    The excavation of an unexplored secondary agglomeration in Chevroches (France), from 2001 to 2002 has led to the discovery of a bronze dome of a type unknown in the Ancient world. It is inscribed with three lines in Greek transcribing Egyptian and Roman months, and the twelve signs of the Zodiac. This paper presents the first observations and some other finds from similar objects in Burgundy.

  12. Simulations of DE 1 UV airglow images

    NASA Astrophysics Data System (ADS)

    Gladstone, G. Randall

    1994-06-01

    In this paper we present simulations of the UV airglow observed in selected images obtained by the spinscan auroral imager experiment on the Dynamics Explorer 1 satellite. In particular, we present one example each of observed and modeled images for the dayglow and for the nightglow. The model dayglow emissions include the OI 130.4 nm triplet (excited by both photoelectron impact excitation of O atoms and resonant scattering of the solar OI 130.4 nm triplet), the OI 135.6 nm doublet (excited by photoelectron impact excitation of O atoms), and the N2 Lyman-Birge-Hopfield (LBH) molecular bands (excited by photoelectron impact excitation of N2 molecules). The model neglects minor contributions from HI 121.6 nm and NI 149.3 nm dayglow emissions. The model nightglow emissions are comprised of the same OI 130.4 and 135.6 nm features, but on the nightside they are produced through recombination of O+ ions. The model neglects a contribution to the nightglow OI 130.4 nm and 135.6 nm emissions due to recombination of O+ and O- ions. The results presented here demonstrate that the dayglow emissions are well understood and can be simulated with high accuracy. This allows us to determine relative contributions of the various dayglow emission sources over the disk of the Earth. For example, while the OI 130.4 nm emission is very bright and fairly uniform at about 15-20 kR over much of the disk, the optically thin LBH emissions become much larger than the OI 130.4 nm emission at the limb, with a band-integrated maximum brightness of about 35 kR. Although the image simulation code used is fairly CPU intensive, it should prove useful in studying variations in the abundances of O and N2 following geomagnetic storms or in extracting the dayglow contribution from images of the sunlit auroral oval, for instance. The nightglow emissions are not as well fit by the model, indicating that the O+-O- mutual neutralization source is significant and should be included in future simulations

  13. Short period airglow temperature and emission rate oscillations in the high Arctic MLT region during stratospheric warming events

    NASA Astrophysics Data System (ADS)

    Lederman, J. I.

    2015-12-01

    The airglow is a photochemical glow in the upper atmosphere that occurs in thin layers corresponding to different chemical processes. The O2 Atmospheric airglow layer exists at about 94 km altitude and the hydroxyl layer at about 87 km. The intensity of the light gives information about the concentration of atomic oxygen there, while the shape of the spectrum gives accurate values of the temperature. In this investigation, these are measured above Eureka in the Canadian Arctic (80N, 86W) using an instrument called SATI (Spectral Airglow Temperature Imager). The optical data are employed to characterize short period oscillations in rotational temperatures and integral emission rates of OH (6,2) Meinel and O2 (0,1) Atm. bands during a stratospheric warming event from January 2015. In this presentation, SATI observations coupled with wind radiosonde data at Eureka and the ECMWF model are used to compare the January 2015 warming with the major stratospheric warming event of January 2009, thereby providing a window into high frequency atmospheric wave dynamics at play between altitudes of 20 km - 100 km.

  14. Correlated measurements of mesospheric density and near infrared airglow

    NASA Astrophysics Data System (ADS)

    Moreels, G.; Pautet, D.; Faivre, M.; Keckhut, P.; Hauchecorne, A.

    A program aimed at simultaneously measuring the mesospheric density and the evolution with time of the near IR emission at the mesopause level was initiated in July 2000 and July 2001. The atmospheric density is measured along a vertical line using the Rayleigh scattering lidar located at Observatoire de Haute Provence (OHP). The near IR emission, mainly due to OH, is measured along a slant path from the Pic de Château-Renard (Hautes-Alpes, altitude 2989 m). The field of view of the CCD camera encompasses an area located vertically above OHP. Rayleigh scattering by air molecules is much less efficient than fluorescence by alkaline atoms. Therefore, the lidar data could only be retrieved with a one-hour time resolution at altitudes of 65, 70, 72.5 and 75 km. The time resolution for the airglow intensity measurement was equal to three minutes. The temporal evolution over the 5-hour duration of the night appears as opposite in the density up to 75 km and in the near IR airglow. The airglow shows around 23h30 a minimum intensity about 28% lower than its maximum value. During the first part of the night the intensity decreases. During the second part, it increases. The increase during the second part cannot be explained by the evolution of the atmospheric chemical system. Given the variation in opposite phases of the air density and of the emission, it is suggested that the near IR airglow is a semi-direct tracer of the density variations at the mesopause level, the air molecules being effective quenchers of the excited OH radicals. The excitation and quenching rates will therefore be discussed. Two short movie films showing the airglow waves coming across the observation field of view will be presented.

  15. Moon based global field airglow: For Artemis or any common Lunar Lander

    NASA Astrophysics Data System (ADS)

    Kozlowski, R. W. H.; Sprague, A. L.; Sandel, B. R.; Hunten, D. M.; Broadfoot, A. L.

    1994-06-01

    An inexpensive, small mass, airglow experiment consisting of a suite of airglow detectors is planned for one or more lunar landers. Solid state detectors measuring light through narrow band filters or concave gratings can integrate emissions from lunar atmospheric constituents and store the information for relay to earth when convenient. The proposed instrument is a simplified version of the Shuttle-borne Arizona Imager-Spectrograph. These zenith and near horizon viewing detectors may allow us to monitor fluctuations in atomic species of oxygen, calcium, sodium, potassium, argon, and neon and OH, if present. This choice of observations would monitor outgassing from the interior (Ar), meteoritic dust flux (Na, K) solar wind sputtering (O, Ca), and outgassing from the surface (implanted Ne, Na, K). A global network could be inexpensively deployed aboard landers carrying a variety of other selenographic instrumentation. Powered by solar cells such a field network will return data applicable to a wide variety of interplanetary medium and solar-lunar interaction problems.

  16. Observations of the galactic plane by the zodiacal infrared project

    NASA Technical Reports Server (NTRS)

    Rickard, L. J.; Stemwedel, S. W.; Price, S. D.

    1990-01-01

    The two rocket flights of the Zodiacal Infrared Project (ZIP), flown 18 August 1980 and 31 July 1981, were intended to provide data on the near-infrared thermal emission of the interplanetary dust cloud over a broad range of ecliptic coordinates (latitudes -60 to +85 degrees, solar elongation angles 22 to 90 degrees and 140 to 180 degrees). In addition, their multiple crossings of the Galactic plane provided low resolution spectral data (delta lambda/lambda ranging from 1. to 0.1, for effective wavelengths from 3 to 30 microns) for most of the first quadrant (longitudes 30 to 100 degrees). Examples are displayed. Having made a thorough reanalysis of the calibration of the ZIP database, researchers present the salient features of the Galactic plane as observed by ZIP. The binned, in-plane data, corrected for zodiacal emission, generally show an exponential decrease with increasing longitude. The fitted exponential scale-length is 0.038/degree, and can be inverted to derive a radial density profile. Channel ratios are converted to temperatures by using model spectra in which thermal emitters with emissivity approx. 1/lambda are convolved with the filter responses. The results for channels 5 (11 microns) and 12 (21 microns) are shown, along with similarly derived temperatures from Infrared Astronomy Satellite (IRAS) 12 microns and 25 microns data. The ZIP data show little variation with longitude, consistent with IRAS results. A narrow spectral feature at 13 microns appears consistently in data for the plane (uncorrected for zodiacal emission). However, this is strongly contaminated by calibration problems for channel 8. Researchers suggest that residual emission at 13 microns arises from the (NeII) line at 12.8 microns.

  17. Zodiac: A Balloon Facility for Exoplanet Debris Disk Observations

    NASA Astrophysics Data System (ADS)

    Unwin, S.; Traub, W.

    2010-10-01

    Zodiac is a telescope-coronagraph system, operating at visible wavelengths, mounted on a balloon-borne gondola in the stratosphere. The science objective is to image debris disks around nearby stars. Debris disks, usually found in the outer reaches of a planetary system, are significant for exoplanet science because (a) they tell us that planet formation did actually get started around a star, (b) they are a contributing source of potentially obscuring dust to the inner part of the disk where we will someday start searching for terrestrial planets, and (c) for a disk with an inner edge, this feature is a signpost for a shepherding planet and thus a sign that planet formation did indeed proceed to completion around that star. The telescope has a 1-m diameter, clear-aperture primary mirror, designed to operate in the cold stratospheric environment. The coronagraph is designed to suppress starlight, including its diffracted and scattered components, and allow a faint surrounding debris disk to be imaged. We will control the speckle background to be about 7 orders of magnitude fainter than the star, with detection sensitivity about one more order of magnitude fainter, in order to comfortably image the expected brightness of typical debris disks. Zodiac will be designed to make scientifically useful measurements on a conventional overnight balloon flight, but would also be fully compatible with future Ultra Long Duration Balloon flights. Zodiac has a technical objective of advancing the technology levels of future mission components from the lab to near-space flight status. These components include deformable mirrors, wavefront sensors, coronagraph masks, lightweight mirrors, precision pointing, and speckle rejection by wavefront control.

  18. Zodiac: A Balloon Facility for Exoplanet Debris Disk Observations

    NASA Astrophysics Data System (ADS)

    Unwin, Stephen C.; Traub, W.; Bryden, G.

    2011-01-01

    Zodiac is a telescope-coronagraph system, operating at visible wavelengths, mounted on a balloon-borne gondola in the stratosphere. The science objective is to image debris disks around nearby stars. Debris disks, usually found in the outer reaches of a planetary system, are significant for exoplanet science because (a) they tell us that planet formation did actually get started around a star, (b) they are a contributing source of potentially obscuring dust to the inner part of the disk where we will someday start searching for terrestrial planets, and (c) for a disk with an inner edge, this feature is a signpost for a shepherding planet and thus a sign that planet formation did indeed proceed to completion around that star. The telescope has a 1-m diameter, clear-aperture primary mirror, designed to operate in the cold stratospheric environment. The coronagraph is designed to suppress starlight, including its diffracted and scattered components, and allow a faint surrounding debris disk to be imaged. We will control the speckle background to be about 7 orders of magnitude fainter than the star, with detection sensitivity about one more order of magnitude fainter, in order to comfortably image the expected brightness of typical debris disks. Zodiac will be designed to make scientifically useful measurements on a conventional overnight balloon flight, but would also be fully compatible with future Ultra Long Duration Balloon flights. Zodiac has a technical objective of advancing the technology levels of future mission components from the lab to near-space flight status. These components include deformable mirrors, wavefront sensors, coronagraph masks, lightweight mirrors, precision pointing, and speckle rejection by wavefront control. The research described in this talk was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Government sponsorship acknowledged.

  19. Zodiacal dust bands - Their relation to asteroid families

    NASA Technical Reports Server (NTRS)

    Sykes, Mark V.

    1990-01-01

    The zodiacal dust band phenomenon is presently reproduced by a mathematical model of orbitally evolved collisional debris spatial distributions whose torus exhibits particle-density maxima at heliocentric latitudes near its constituent particles' mean proper orbital inclinations, as well as near the loci of the particle orbits' perihelia and aphelia. Models of dust toruses for seven asteroid families are generated and compared with observations of the principal dust bands. Nonequilibrium models of dust band production and evolution furnish a framework within which all dust band observations can be understood.

  20. Zodiacal emission. III - Dust near the asteroid belt

    NASA Technical Reports Server (NTRS)

    Reach, William T.

    1992-01-01

    Properties of the zodiacal dust bands are derived from fits to Infrared Astronomical Satellite profiles of the ecliptic. Three observations lead to the conclusion that the dust-band material is spread over a range of heliocentric distances between the asteroid belt and the sun: parallax, color temperature, and wavelength dependence of the band latitudes. The orientations of the midplanes of the bands are found to be typical of asteroids. A model of 'migrating bands', wherein dust is produced near the asteroid belt and spirals into the sun under the influence of Poynting-Robertson drag, is used to explain the range of heliocentric distances of dust-band material.

  1. Zodiacal emission. III - Dust near the asteroid belt

    NASA Astrophysics Data System (ADS)

    Reach, William T.

    1992-06-01

    Properties of the zodiacal dust bands are derived from fits to Infrared Astronomical Satellite profiles of the ecliptic. Three observations lead to the conclusion that the dust-band material is spread over a range of heliocentric distances between the asteroid belt and the sun: parallax, color temperature, and wavelength dependence of the band latitudes. The orientations of the midplanes of the bands are found to be typical of asteroids. A model of 'migrating bands', wherein dust is produced near the asteroid belt and spirals into the sun under the influence of Poynting-Robertson drag, is used to explain the range of heliocentric distances of dust-band material.

  2. Prehistory of Zodiac Dating: Three Strata of Upper Paleolithic Constellations

    NASA Astrophysics Data System (ADS)

    Gurshtein, Alex A.

    A pattern of archaic proto-constellations is extracted from Aratus' "The Phaenomena" didactic poem list according to a size criterion elaborated earlier, and their symbolism is analyzed. As a result of this approach three celestial symbolical strata are discovered to be probably a reflection of the symbols for the Lower, the Middle and the Upper Worlds; the Under-World creatures have a water character, the Middle World ones are mostly anthropomorphic and flying beings are for the Upper World. The strata excerpted from Aratus' sky seems to be in agreement with the well-known Babylonian division into three god pathways for Ea (Enki), Anu and Enlil. There is a possibility of dating the pattern discovered because of precession's strong influence as far back as 16 thousand years, the result being supported by the comparison of different star group mean sizes. The archaic constellation pattern under consideration is a reasonable background of symbolical meanings for the first Zodiacal generation quartet (7.5 thousand years old) examined by the author previously. The enormous size of the Argo constellation (Ship of Argo and his Argonauts) as well as the large sizes of other southern constellations are explained as due to the existence of an accumulation zone near the South celestial pole. Some extra correlations between the reconstruction proposed and cultural data available are discussed. The paper is the second part of the investigation "On the Origin of the Zodiacal constellations" published in Vistas in Astronomy, vol.36, pp.171-190, 1993.

  3. Magnetic Zenith Enhancement of HF Radio-Induced Airglow Production at HAARP

    DTIC Science & Technology

    2003-02-22

    frequencies and ionospheric conditions. The spot at HAARP appears on average just equatorward of the nominal magnetic field direction, deflects somewhat...earlier airglow observations at HAARP [Pedersen and Carlson, 2001]. Airglow observations over a wide range of transmitter and ionospheric frequencies...P. A., C. A. Tepley, and L. M. Duncan, Airglow enhancements associated with plasma cavities formed during ionospheric heating ex- periments, J

  4. Spatial and temporal evolution of 630. 0 nm airglow enhancement during ionospheric heating experiments

    SciTech Connect

    Bernhardt, P.A.; Duncan, L.M.; Tepley, C.A.; Behnke, R.A.; Sheerin, J.P.

    1986-01-01

    Images of 630.00 nm enhancements have been recorded during the January, 1986 ionospheric heating campaign at Arecibo. The artificial airglow clouds convected eastward, vanished, and then reappeared at the zenith of the HF heater. Occasionally, the airglow patches are bifurcated. The structure and motion of the airglow clouds is an indication of the dynamic behavior of the modified ionosphere. 5 refs., 8 figs.

  5. Measurements of airglow on Maunakea at Gemini Observatory

    NASA Astrophysics Data System (ADS)

    Roth, Katherine C.; Smith, Adam; Stephens, Andrew; Smirnova, Olesja

    2016-07-01

    Gemini Observatory on Maunakea has been collecting optical and infrared science data for almost 15 years. We have begun a program to analyze imaging data from two of the original facility instruments, GMOS and NIRI, in order to measure sky brightness levels in multiple infrared and optical broad-band filters. The present work includes data from mid-2016 back through late-2008. We present measured background levels as a function of several operational quantities (e.g. moon phase, hours from twilight, season). We find that airglow is a significant contributor to background levels in several filters. Gemini is primarily a queue scheduled telescope, with observations being optimally executed in order to provide the most efficient use of telescope time. We find that while most parameters are well-understood, the atmospheric airglow remains challenging to predict. This makes it difficult to schedule observations which require dark skies in these filters, and we suggest improvements to ensure data quality.

  6. Issues in Quantitative Analysis of Ultraviolet Imager (UV) Data: Airglow

    NASA Technical Reports Server (NTRS)

    Germany, G. A.; Richards, P. G.; Spann, J. F.; Brittnacher, M. J.; Parks, G. K.

    1999-01-01

    The GGS Ultraviolet Imager (UVI) has proven to be especially valuable in correlative substorm, auroral morphology, and extended statistical studies of the auroral regions. Such studies are based on knowledge of the location, spatial, and temporal behavior of auroral emissions. More quantitative studies, based on absolute radiometric intensities from UVI images, require a more intimate knowledge of the instrument behavior and data processing requirements and are inherently more difficult than studies based on relative knowledge of the oval location. In this study, UVI airglow observations are analyzed and compared with model predictions to illustrate issues that arise in quantitative analysis of UVI images. These issues include instrument calibration, long term changes in sensitivity, and imager flat field response as well as proper background correction. Airglow emissions are chosen for this study because of their relatively straightforward modeling requirements and because of their implications for thermospheric compositional studies. The analysis issues discussed here, however, are identical to those faced in quantitative auroral studies.

  7. High Resolution Measurements of OH Infrared Airglow Structure.

    DTIC Science & Technology

    1985-01-01

    and Space Science 19:561-566. Rayleigh , Lord ( Strutt , R.J.). 1931. On a Night Sky of Exceptional Brightness, and on the Distinction between the Polar...Air Force apeito isexpressed toD.DrnBkrfor his excellent direction and guidance. Also appreciation is extended to Dr. Kay Baker, Dr. William Pendleton...decades +rom 1930 to 1970, however, failed to recognize the nature o+ the airglow structure phenomenon. Rayleigh E19313 was among the first 3 to recoq

  8. Zodiac: A Comprehensive Depiction of Genetic Interactions in Cancer by Integrating TCGA Data

    SciTech Connect

    Zhu, Yitan; Xu, Yanxun; Helseth, Donald L.; Gulukota, Kamalakar; Yang, Shengjie; Pesce, Lorenzo L.; Mitra, Riten; Muller, Peter; Sengupta, Subhajit; Guo, Wentian; Foster, Ian; Bullock, JaQuel A.

    2015-08-01

    Background: Genetic interactions play a critical role in cancer development. Existing knowledge about cancer genetic interactions is incomplete, especially lacking evidences derived from large-scale cancer genomics data. The Cancer Genome Atlas (TCGA) produces multimodal measurements across genomics and features of thousands of tumors, which provide an unprecedented opportunity to investigate the interplays of genes in cancer. Methods: We introduce Zodiac, a computational tool and resource to integrate existing knowledge about cancer genetic interactions with new information contained in TCGA data. It is an evolution of existing knowledge by treating it as a prior graph, integrating it with a likelihood model derived by Bayesian graphical model based on TCGA data, and producing a posterior graph as updated and data-enhanced knowledge. In short, Zodiac realizes “Prior interaction map + TCGA data → Posterior interaction map.” Results: Zodiac provides molecular interactions for about 200 million pairs of genes. All the results are generated from a big-data analysis and organized into a comprehensive database allowing customized search. In addition, Zodiac provides data processing and analysis tools that allow users to customize the prior networks and update the genetic pathways of their interest. Zodiac is publicly available at www.compgenome.org/ZODIAC. Conclusions: Zodiac recapitulates and extends existing knowledge of molecular interactions in cancer. It can be used to explore novel gene-gene interactions, transcriptional regulation, and other types of molecular interplays in cancer.

  9. Vacuum-ultraviolet instrumentation for solar irradiance and thermospheric airglow

    SciTech Connect

    Woods, T.N.; Rottman, G.J. . High Altitude Observatory); Bailey, S.M.; Solomon, S.C. . Lab. for Atmospheric and Space Physics)

    1994-02-01

    A NASA sounding rocket experiment was developed to study the solar extreme-ultraviolet (EUV) spectral irradiance and its effect on the upper atmosphere. Both the solar flux and the terrestrial molecular nitrogen via the Lyman-Birge-Hopfield bands in the far-ultraviolet (FUV) region were measured remotely from a sounding rocket on October 27, 1992. The rocket experiments also includes EUV instruments from Boston University, but only the National Center for Atmospheric Research's (NCAR)/University of Colorado's (CU) four solar instruments and one airglow instrument are discussed. The primary solar EUV instrument is a 0.25-m Rowland circle EUV spectrograph that has flown on three rockets since 1988 measuring the solar spectral irradiance from 30 to 110 nm with 0.2-nm resolution. Another solar irradiance instrument is an array of six silicon soft x-ray (XUV) photodiodes, each having different metallic filters coated directly on the photodiodes. The other solar irradiance instrument is a silicon avalanche photodiode coupled with pulse height analyzer electronics. The fourth solar instrument is a XUV imager that images the sun at 17.5 nm with a spatial resolution of 20 arc sec. The airglow spectrograph measures the terrestrial FUV airglow emissions along the horizon from 125 to 160 nm with 0.2-nm spectral resolution.

  10. Computing uncertainties in ionosphere-airglow models: II. The Martian airglow

    NASA Astrophysics Data System (ADS)

    Gronoff, Guillaume; Simon Wedlund, Cyril; Mertens, Christopher J.; Barthélemy, Mathieu; Lillis, Robert J.; Witasse, Olivier

    2012-05-01

    One of the objectives of spectrometers onboard space missions is to retrieve atmospheric parameters (notably density, composition and temperature). To fulfill this objective, comparisons between observations and model results are necessary. Knowledge of these model uncertainties is therefore necessary, although usually not considered, to estimate the accuracy in planetary upper atmosphere remote sensing of these parameters. In Part I of this study, “Computing uncertainties in ionosphere-airglow models: I. Electron flux and species production uncertainties for Mars” (Gronoff et al., 2012), we presented the uncertainties in the production of excited states and ionized species from photon and electron impacts, computed with a Monte-Carlo approach, and we applied this technique to the Martian upper atmosphere. In the present paper, we present the results of propagation of these production errors to the main UV emissions and the study of other sources of uncertainties. As an example, we studied several aspects of the model uncertainties in the thermosphere of Mars, and especially the O(1S) green line (557.7 nm, with its equivalent, the trans-auroral line at 297.2 nm), the Cameron bands CO(a3Π), and CO2+(B2Σu+) doublet emissions. We first show that the excited species at the origin of these emissions are mainly produced by electron and photon impact. We demonstrate that it is possible to reduce the computation time by decoupling the different sources of uncertainties; moreover, we show that emission uncertainties can be large (>30%) because of the strong sensitivity to the production uncertainties. Our study demonstrates that uncertainty calculations are a crucial step prior to performing remote sensing in the atmosphere of Mars and the other planets and can be used as a guide to subsequent adjustments of cross sections based on aeronomical observations. Finally, we compare the simulations with observations from the SPICAM spectrometer on the Mars Express

  11. Global temperature distributions from OGO-6 6300 A airglow measurements

    NASA Technical Reports Server (NTRS)

    Blamont, J. E.; Luton, J. M.; Nisbet, J. S.

    1974-01-01

    The OGO-6 6300 A airglow temperature measurements have been used to develop models of the global temperature distributions under solstice and equinox conditions for the altitude region from 240 to 300 km and for times ranging from dawn in this altitude region to shortly after sunset. The distributions are compared with models derived from satellite orbital decay and incoherent scatter sounding. The seasonal variation of the temperature as a function of latitude is shown to be very different from that derived from static diffusion models with constant boundary conditions.

  12. HF-Induced Airglow at Magnetic Zenith: Theoretical Considerations

    DTIC Science & Technology

    2007-11-02

    7.8 MHz. Significantly, green -to-red ratios fgr >0.3 are often ob- For a heater ERP Po= 150 MW and distance R=250 kin, served. Gustavsson et al...and 145.15’W) show that the HF-induced airglow maximizes 557.7nm ( green line) during HF modification experiments during injections toward magnetic...1989; Pedersen and injected frequency f0. Here, Oc=arcsin( fsinx), f, is Carlson, 2001; Gustavsson et al., 2001, 2002; Kosch et al., the electron

  13. Near Infrared Characterization of Hot Exo-Zodiacal Disks around Nearby Stars

    NASA Astrophysics Data System (ADS)

    Mennesson, Bertrand

    Debris disks found around main sequence stars are the remnants of planetary formation. The outer colder parts of these disks, analogous to our solar system Kuiper belt, were first detected via their mid/far infrared excess emission, and then abundantly imaged at visible to sub-millimeter wavelengths. Structures and asymmetries in spatially resolved debris disks have been used to infer the presence of yet unseen planets. The power of this technique was recently demonstrated with the direct imaging of massive planets at the inner edge of warped extended dust disks previously detected around Fomalhaut and beta Pic. Conversely, very little is known about the warmer dust component of debris disks, similar to the zodiacal dust of the inner solar system. A few hot disks have been found by Spitzer around mature stars via excess emission at 24 microns. But surprisingly, the majority of hot debris disk detections has come from the ground, where near infrared interferometric observations have recently revealed small (~1%) resolved excesses around a dozen nearby main sequence stars. The dust grains forming in these bright "exozodi disks" or dust belts are located within a few AU of their parent star. They are thought to be produced by the evaporation of comets or by collisions between larger rocky bodies, as in the solar zodiacal disk. Many of the detected disks are however much hotter (1000-1500K) and more massive than the zodiacal cloud. Their grain populations should be rapidly expelled from the inner planetary system by radiation pressure, which indicates inordinate replenishment rates. In practice, the steady state collisional grinding of a massive asteroid belt cannot be at the origin of these dust populations. They are most likely produced by isolated catastrophic events (e.g., major asteroid collision, break-up of a massive comet), or by major dynamical perturbations such as the Falling Evaporating Bodies (FEB) phenomenon in the beta Pic inner disk or the Late Heavy

  14. Extra-Zodiacal-Cloud Astronomy via Solar Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Benson, Scott W.; Falck, Robert D.; Oleson, Steven R.; Greenhouse, Matthew A.; Kruk, Jeffrey W.; Gardner, Jonathan P.; Thronson, Harley A.; Vaughn, Frank J.; Fixsen, Dale J.

    2011-01-01

    Solar electric propulsion (SEP) is often considered as primary propulsion for robotic planetary missions, providing the opportunity to deliver more payload mass to difficult, high-delta-velocity destinations. However, SEP application to astrophysics has not been well studied. This research identifies and assesses a new application of SEP as primary propulsion for low-cost high-performance robotic astrophysics missions. The performance of an optical/infrared space observatory in Earth orbit or at the Sun-Earth L2 point (SEL2) is limited by background emission from the Zodiacal dust cloud that has a disk morphology along the ecliptic plane. By delivering an observatory to a inclined heliocentric orbit, most of this background emission can be avoided, resulting in a very substantial increase in science performance. This advantage enabled by SEP allows a small-aperture telescope to rival the performance of much larger telescopes located at SEL2. In this paper, we describe a novel mission architecture in which SEP technology is used to enable unprecedented telescope sensitivity performance per unit collecting area. This extra-zodiacal mission architecture will enable a new class of high-performance, short-development time, Explorer missions whose sensitivity and survey speed can rival flagship-class SEL2 facilities, thus providing new programmatic flexibility for NASA's astronomy mission portfolio. A mission concept study was conducted to evaluate this application of SEP. Trajectory analyses determined that a 700 kg-class science payload could be delivered in just over 2 years to a 2 AU mission orbit inclined 15 to the ecliptic using a 13 kW-class NASA's Evolutionary Xenon Thruster (NEXT) SEP system. A mission architecture trade resulted in a SEP stage architecture, in which the science spacecraft separates from the stage after delivery to the mission orbit. The SEP stage and science spacecraft concepts were defined in collaborative engineering environment studies. The

  15. Voyages of the Zodiac, an Impenitent Traveller across Lands and Ages

    NASA Astrophysics Data System (ADS)

    Belmonte, Juan Antonio

    2015-05-01

    The zodiac is one of humankind's oldest astronomical heritages. Indeed, it has a long history and had an impressive cultural influence in the past that could be traced from the steppes of Mesopotamia to the wilderness of the Roman frontiers in Great Britain. In the present essay, we will discuss the origin of the zodiacal constellations in ancient Mesopotamia from their possible prehistoric ancestors in the pre-ceramic context of the 10,000-year-old site of Göbleki Tepe. Later on, we will discuss the role that the zodiac played in the development of the new cult established by King Antiochos I of Commagene in his hierothesion at Nemrud Dag, where a planetary conjunction in Leo has played a role in the clues to understand the enigmas of such an impressive monument. This will be followed by the analysis of its southwards travel to the Valley of the Nile, where we will study the famous Zodiac of Dendera. Then we will travel westwards to discuss the astronomical aspects of a new religion where astronomical eras and the zodiac ought to play a most relevant role, Mithraism. Finally, new ideas for future research in this most interesting topic will briefly be sketched.

  16. Twilight Intensity Variation of the Infrared Hydroxyl Airglow

    NASA Technical Reports Server (NTRS)

    Lowe, R. P.; Gilbert, K. L.; Niciejewski, R. J.

    1984-01-01

    The vibration rotation bands of the hydroxyl radical are the strongest features in the night airglow and are exceeded in intensity in the dayglow only by the infrared atmospheric bands of oxygen. The variation of intensity during evening twilight is discussed. Using a ground-based Fourier Transform Spectrometer (FTS), hydroxyl intensity measurements as early as 3 deg solar depression were made. Models of the twilight behavior show that this should be sufficient to provide measurement of the main portion of the twilight intensity change. The instrument was equipped with a liquid nitrogen-cooled germanium detector whose high sensitivity combined with the efficiency of the FTS technique permits spectra of the region 1.1 to 1.6 microns at high signal-to-noise to be obtained in two minutes. The use of a polarizer at the entrance aperture of the instrument reduces the intensity of scattered sunlight by a factor of at least ten for zenith observations.

  17. Calibration of the Berkeley EUV Airglow Rocket Spectrometer

    NASA Technical Reports Server (NTRS)

    Cotton, Daniel M.; Chakrabarti, Supriya; Siegmund, Oswald

    1989-01-01

    The Berkeley Extreme-ultraviolet Airglow Rocket Spectrometer (BEARS), a multiinstrument sounding rocket payload, made comprehensive measurements of the earth's dayglow. The primary instruments consisted of two near-normal Rowland mount spectrometers: one channel to measure several atomic oxygen features at high spectral resolution (about 1.5 A) in the band passes 980-1040 and 1300-1360 A, and the other to measure EUV dayglow and the solar EUV simultaneously in a much broader bandpass (250-1150 A) at moderate resolution (about 10 A). The payload also included a hydrogen Lyman-alpha photometer to monitor the solar irradiance and goecoronal emissions. The instrument was calibrated at the EUV calibration facility at the University of California at Berkeley, and was subsequently launched successfully on September 30, 1988 aboard a four-stage experimental sounding rocket, Black Brant XII flight 12.041 WT. The calibration procedure and resulting data are presented.

  18. A case study on the possible altitude-dependent effects of collisions on sodium airglow emission

    NASA Astrophysics Data System (ADS)

    Sarkhel, S.; Sekar, R.; Chakrabarty, D.; Sridharan, S.

    2010-10-01

    Simultaneous observations of a narrowband sodium (Na) airglow photometer corresponding to the D2 line in conjunction with a Na lidar from Gadanki (13.5°N, 79.2°E), India, reveal episodic enhancements in Na airglow intensity during 1930-0142 Indian standard time (IST; IST = UT + 5.5 h) on 18-19 March 2007. This variation is drastically different from the average Na airglow intensity variation for that duration during that month. Interestingly, the Na airglow intensity variation is found to be well correlated with the Na atom concentration variation only at 93.6 km during the period 2312-0142 IST, a period closer to the measurement of mesospheric ozone by the Sounding of Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. Moreover, the correlation coefficient is not significant at 88.5 km, where the Na concentration is maximum. Estimations of the altitude profiles of the volume emission rate of Na airglow corresponding to the D2 line using measured parameters during local postmidnight hours reveal that the peak of volume emission rate is different from 93.6 km. It is suggested that the altitude variation in collisional quenching is needed to match the peak altitude of emission to the altitude where correlation between the Na atom concentration and Na airglow intensity is maximum. The fact that the measured atmospheric pressure reduces by a factor of ˜2.5 as altitude changes from 88.5 to 93.6 km supports this proposition. The case study brings out the sensitivity of Na airglow intensity to the altitude dependence of the collisional quenching that eventually affects Na airglow emission.

  19. Equatorial Spread F Found in AN Old Airglow Scan Atlas of Dudley Observatory

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Hong, S.; Weinberg, J. L.

    2001-12-01

    We have searched for F-region ionospheric disturbances in the airglow scan atlas of Dudley observatory. The airglow scan observations were made with narrow band filters of OI 5577 A and OI 6300 A for 164 nights at Haleakala, Maui in the period of April 1965 through October 1968. The OI 6300 emissions are produced mostly via recombination of O2+ in the F-region, whereas the OI 5577 emissions are generated both in the E- and F-regions. The Dudley atlas of the airglow scan has unique significance, since it covers more than three years of observations in 1960's when there was no other program to monitor ionospheric airglows. We find disturbances in the OI airglow brightness, from which we constructed projected maps of airglow distributions at the F-region altitude. The projected maps clearly show wavelike disturbances whose crests are mostly aligned along north-south direction. The disturbances were found exclusively in the southern azimuth (toward the equator), implying that they are one of the equatorial ionospheric irregularities, known as equatorial spread F (ESF). The ESF disturbances occurred 19 nights out of total 164 nights of observations with a maximum in September. The disturbances seem to arise regardless of geomagnetic activities. The seasonal variation of the occurrence is consistent with recent analyses of satellite data in which ESF is suggested to be caused by gravity waves from the troposphere where they are generated by strong convection in inter-tropical convergence zone.

  20. Enhanced Airglow by High Frequency Electromagnetic Pumping of the Ionosphere at Auroral Latitudes

    NASA Astrophysics Data System (ADS)

    Leyser, T. B.; Gustavsson, B.; Brändström, B. U. E.; Steen, E.; Honary, F.; Rietveld, M. T.; Aso, T.; Ejiri, M.

    2000-10-01

    A powerful high frequency electromagnetic pump wave transmitted into the ionosphere from the ground may enhance the background airglow. The airglow enhancement is due to an increase in the number of electrons having energies which are an order of magnitude higher than the thermal energy in the ionospheric plasma. The energetic electrons collisionally excite, for example, the meta-stable O(1D) state in atomic oxygen, which radiates at 630 nm as the excited oxygen atom relaxes to its ground state. Airglow enhancement is used to study, for example, the dissipation of the pump-driven plasma turbulence by electron energization. We present experimental results of pumping the ionospheric F region with the EISCAT-Heating facility at auroral latitudes in Norway and detection of the airglow with the multi-station Auroral Large Imaging System (ALIS) in northern Sweden. The experimental results also include simultaneous measurements of background plasma parameter values with the EISCAT-UHF incoherent scatter radar. The multi-station imaging technique enables for the first time tomography-like inversion to estimate the spatial extent of the pumped airglow cloud. Further, the airglow enhancement is correlated with large pump-induced electron temperature enhancements of up to 250

  1. Dynamical Model for the Zodiacal Cloud and Sporadic Meteors

    NASA Astrophysics Data System (ADS)

    Nesvorný, David; Janches, Diego; Vokrouhlický, David; Pokorný, Petr; Bottke, William F.; Jenniskens, Peter

    2011-12-01

    The solar system is dusty, and would become dustier over time as asteroids collide and comets disintegrate, except that small debris particles in interplanetary space do not last long. They can be ejected from the solar system by Jupiter, thermally destroyed near the Sun, or physically disrupted by collisions. Also, some are swept by the Earth (and other planets), producing meteors. Here we develop a dynamical model for the solar system meteoroids and use it to explain meteor radar observations. We find that the Jupiter Family Comets (JFCs) are the main source of the prominent concentrations of meteors arriving at the Earth from the helion and antihelion directions. To match the radiant and orbit distributions, as measured by the Canadian Meteor Orbit Radar (CMOR) and Advanced Meteor Orbit Radar (AMOR), our model implies that comets, and JFCs in particular, must frequently disintegrate when reaching orbits with low perihelion distance. Also, the collisional lifetimes of millimeter particles may be longer (gsim 105 yr at 1 AU) than postulated in the standard collisional models (~104 yr at 1 AU), perhaps because these chondrule-sized meteoroids are stronger than thought before. Using observations of the Infrared Astronomical Satellite to calibrate the model, we find that the total cross section and mass of small meteoroids in the inner solar system are (1.7-3.5) × 1011 km2 and ~4 × 1019 g, respectively, in a good agreement with previous studies. The mass input required to keep the zodiacal cloud in a steady state is estimated to be ~104-105 kg s-1. The input is up to ~10 times larger than found previously, mainly because particles released closer to the Sun have shorter collisional lifetimes and need to be supplied at a faster rate. The total mass accreted by the Earth in particles between diameters D = 5 μm and 1 cm is found to be ~15,000 tons yr-1 (factor of two uncertainty), which is a large share of the accretion flux measured by the Long Term Duration

  2. Dynamical Model for the Zodiacal Cloud and Sporadic Meteors

    NASA Technical Reports Server (NTRS)

    Nesvorny, David; Janches, Diego; Vokrouhlicky, David; Pokorny, Petr; Bottke, William F.; Jenniskens, Peter

    2011-01-01

    The solar system is dusty, and would become dustier over time as asteroids collide and comets disintegrate, except that small debris particles in interplanetary space do not last long. They can be ejected from the solar system by Jupiter, thermally destroyed near the Sun, or physically disrupted by collisions. Also, some are swept by the Earth (and other planets), producing meteors. Here we develop a dynamical model for the solar system meteoroids and use it to explain meteor radar observations. We find that the Jupiter Family Comets (JFCs) are the main source of the prominent concentrations of meteors arriving to the Earth from the helion and antihelion directions. To match the radiant and orbit distributions, as measured by the Canadian Meteor Orbit Radar (CMOR) and Advanced Meteor Orbit Radar (AMOR), our model implies that comets, and JFCs in particular, must frequently disintegrate when reaching orbits with low perihelion distance. Also, the collisional lifetimes of millimeter particles may be longer (approx. > 10(exp 5) yr at 1 AU) than postulated in the standard collisional models (approx 10(exp 4) yr at 1 AU), perhaps because these chondrule-sized meteoroids are stronger than thought before. Using observations of the Infrared Astronomical Satellite (IRAS) to calibrate the model, we find that the total cross section and mass of small meteoroids in the inner solar system are (1.7-3.5) 10(exp 11) sq km and approx. 4 10(exp 19) g, respectively, in a good agreement with previous studies. The mass input required to keep the Zodiacal Cloud (ZC) in a steady state is estimated to be approx. 10(exp 4)-10(exp 5) kg/s. The input is up to approx 10 times larger than found previously, mainly because particles released closer to the Sun have shorter collisional lifetimes, and need to be supplied at a faster rate. The total mass accreted by the Earth in particles between diameters D = 5 micron and 1 cm is found to be approx 15,000 tons/yr (factor of 2 uncertainty), which is

  3. Laboratory studies on the excitation and collisional deactivation of metastable atoms and molecules in the aurora and airglow

    NASA Technical Reports Server (NTRS)

    Zipf, E. C.

    1974-01-01

    The aeronomy group at the University of Pittsburgh is actively engaged in a series of coordinated satellite, sounding rocket, and laboratory studies designed to expand and clarify knowledge of the physics and chemistry of planetary atmospheres. Three major discoveries have been made that will lead ultimately to a complete and dramatic revision of our ideas on the ionospheres of Mars, Venus, and the Earth and on the origin of their vacuum ultraviolet airglows. The results have already suggested a new generation of ionosphere studies which probably can be carried out best by laser heterodyning techniques. Laboratory studies have also identified, for the first time, the physical mechanism responsible for the remarkable nitric oxide buildup observed in some auroral arcs. This development is an important break-through in auroral physics, and has military ramifications of considerable interest to the Department of Defense. This work may also shed some light on related NO and atomic nitrogen problems in the mesosphere.

  4. The influence of the Chinese zodiac on fertility in Hong Kong SAR.

    PubMed

    Yip, Paul S F; Lee, Joseph; Cheung, Y B

    2002-11-01

    The annual total of births in Hong Kong SAR fell substantially in the past 20 years; hence the total fertility rate (TFR) followed the downward trend and dropped to a low of 0.9 below replacement level in 2000. Despite the long-term downward trend, short-run increases in the annual total of births and the TFR were exhibited. Such temporary fertility increases are identified in the Dragon Years of 1988 and 2000. The phenomenon of fertility changes associated with zodiacal animal years is examined in this paper with a view to gaining some insight into whether Chinese cultural preferences and folklore beliefs might have influenced prospective parents' reproductive behaviour. The paper explains the underlying philosophy of the Chinese astrological tradition and discusses how zodiacal preferences affect fertility between 1976 and 2000. The paper also explores why zodiacal influences on Chinese fertility before 1976 did not exist. It is unquestionable that the Dragon Year preference exerts an influence on fertility of modern Chinese populations through zodiacal birth-timing motivations. Birth rate rise in the Dragon Year is due to changes in timing of births that will have little effect on cumulative fertility.

  5. The out-of-plane distribution of zodiacal dust near the earth

    NASA Technical Reports Server (NTRS)

    Clark, F. O.; Torbett, M. V.; Jackson, A. A.; Price, S. D.; Kennealy, J. P.; Noah, P. V.; Glaudell, G. A.; Cobb, M.

    1993-01-01

    Analysis of IRAS data of the thermal zodiacal emission reveals an out-of-plane dust distribution near the Earth which is well-represented by a Lorentzian function. We suggest a possible explanation for the similarity as near-Earth gravitational perturbations of dust grains. Such perturbations are expected to be chaotic and will randomize any residual band structure near the Earth.

  6. Hydroxyl airglow on Venus in comparison with Earth

    NASA Astrophysics Data System (ADS)

    Migliorini, A.; Piccioni, G.; Cardesín Moinelo, A.; Drossart, P.

    2011-08-01

    Hydroxyl nightglow is intensively studied in the Earth atmosphere, due to its coupling to the ozone cycle. Recently, it was detected for the first time also in the Venus atmosphere, thanks to the VIRTIS-Venus Express observations. The main Δ ν=1, 2 emissions in the infrared spectral range, centred, respectively, at 2.81 and 1.46 μm (which correspond to the (1-0) and (2-0) transitions, respectively), were observed in limb geometry ( Piccioni et al., 2008) with a mean emission rate of 880±90 and 100±40 kR (1R=10 6 photon cm -2 s -1 (4 πster) -1), respectively, integrated along the line of sight. In this investigation, the Bates-Nicolet chemical reaction is reported to be the most probable mechanism for OH production on Venus, as in the case of Earth, but HO 2 and O may still be not negligible as mechanism of production for OH, differently than Earth. The nightglow emission from OH provides a method to quantify O 3, HO 2, H and O, and to infer the mechanism of transport of the key species involved in the production. Very recently, an ozone layer was detected in the upper atmosphere of Venus by the SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) instrument onboard Venus Express ( Montmessin et al., 2009); this discovery enhances the importance of ozone to the OH production in the upper atmosphere of Venus through the Bates-Nicolet mechanism. On Venus, OH airglow is observed only in the night side and no evidence has been found whether a similar emission exists also in the day side. On Mars it is expected to exist both on the day and night sides of the planet, because of the presence of ozone, though OH airglow has not yet been detected. In this paper, we review and compare the OH nightglow on Venus and Earth. The case of Mars is also briefly discussed for the sake of completeness. Similarities from a chemical and a dynamical point of view are listed, though visible OH emissions on Earth and IR OH emissions on Venus are

  7. The Calculation of Shoushi Li When the Sun Transited Zodiacal Signs Improved by Xing Yunlu

    NASA Astrophysics Data System (ADS)

    Li, Y.

    2012-01-01

    The book Gujin likao was written by Xing Yunlu, an ancient astronomer in the latter Ming dynasty. In this paper, base on our previous recovery for both calendars of Shoushi Li and Datong Li, we investigate the Xing's practical calculations for the times and locations when the sun transited zodiacal signs, then check and compare his results with our calculations after accepted Xing's parameters and the methods. First, when using the improving Shoushi methods claimed by Xing, we obtain,in the year of Wanli Jihai (1599), the standard error of the time between our calculations and Xing's results when the sun transit each of the zodiacs is 5.93 Ke (=85.39 min), but when ignore the biggest error derived by Zodiacs Xu, the error will decrease to 1.38 Ke (=19.87 min), and at the same time the standard deviation of solar longitude at middle-night just before transit is 0.06 Du (=0.059 °). The second,when employing our recovering methods of Datong Li and comparing with Xing's calculation, we ascertain that in the same year the standard error of the time when the sun transit each of the zodiacs is 1.09 Ke (=15.70 min), and the standard error of solar longitude at middle-night just before transit is 0.005 Du (=0.049 °). So we are sure we have recovered the work declared by Xing. And in fact Xing do not improve the method of Shoushi Li but provide the new values of the tropical year-length, the data of Zhoutian Fen (the degrees of the whole ecliptic or celestial equator), and the range of each zodiac. At the same time, the bigger deviations between both calendars derived by Xing just caused by his new parameters, and this probably leads to Xing approving Shoushi Li and despising Datong Li.

  8. DYNAMICAL MODEL FOR THE ZODIACAL CLOUD AND SPORADIC METEORS

    SciTech Connect

    Nesvorny, David; Vokrouhlicky, David; Pokorny, Petr; Bottke, William F.; Janches, Diego

    2011-12-20

    The solar system is dusty, and would become dustier over time as asteroids collide and comets disintegrate, except that small debris particles in interplanetary space do not last long. They can be ejected from the solar system by Jupiter, thermally destroyed near the Sun, or physically disrupted by collisions. Also, some are swept by the Earth (and other planets), producing meteors. Here we develop a dynamical model for the solar system meteoroids and use it to explain meteor radar observations. We find that the Jupiter Family Comets (JFCs) are the main source of the prominent concentrations of meteors arriving at the Earth from the helion and antihelion directions. To match the radiant and orbit distributions, as measured by the Canadian Meteor Orbit Radar (CMOR) and Advanced Meteor Orbit Radar (AMOR), our model implies that comets, and JFCs in particular, must frequently disintegrate when reaching orbits with low perihelion distance. Also, the collisional lifetimes of millimeter particles may be longer ({approx}> 10{sup 5} yr at 1 AU) than postulated in the standard collisional models ({approx}10{sup 4} yr at 1 AU), perhaps because these chondrule-sized meteoroids are stronger than thought before. Using observations of the Infrared Astronomical Satellite to calibrate the model, we find that the total cross section and mass of small meteoroids in the inner solar system are (1.7-3.5) Multiplication-Sign 10{sup 11} km{sup 2} and {approx}4 Multiplication-Sign 10{sup 19} g, respectively, in a good agreement with previous studies. The mass input required to keep the zodiacal cloud in a steady state is estimated to be {approx}10{sup 4}-10{sup 5} kg s{sup -1}. The input is up to {approx}10 times larger than found previously, mainly because particles released closer to the Sun have shorter collisional lifetimes and need to be supplied at a faster rate. The total mass accreted by the Earth in particles between diameters D = 5 {mu}m and 1 cm is found to be {approx}15

  9. A study of the airglow and the sporadic E layers during stratospheric warming events

    NASA Astrophysics Data System (ADS)

    Mikhalev, Alexander; Ratovsky, Konstantin; Medvedev, Andrey; Medvedeva, Irina; Kurkin, Vladimir; Chernigovskaya, Marina; Kostyleva, Nadegda

    In the present work the events of disturbances of the 557.7 nm and 630 nm airglow and occurrence of sporadic E layer in middle latitudes of Asian region during sudden stratospheric warmings in December 2006 and January-February 2008 are analyzed. Ionosphere data were obtained with the DPS-4 ionosonde located in Irkutsk (52.3N, 104.3E). Airglow measurements were made by the 4-channel zenith photometer and colour CCD imager at ISTP Geophysical observatory located 130 km southwest of Irkutsk. To identify the stratospheric warming events the Berlin Meteorological University data (http://strat-www.met.fu-berlin.de) on stratospheric warming at standard isobaric levels and the atmospheric temperature height profiles measured by the Microwave Limb Sounder (MLS) aboard the EOS Aura spacecraft were used. In some cases we observed correlated diurnal variations of 557.7 nm airglow intensity and Es characteristics. The fact that the correlation between 557.7 nm and Es layer characteristics did not always happen probably can be explained by the different spatial localization of Es layer and emitting layer as well as by the features of their dynamics. During a maximal rise of 557.7 nm airglow its spatial inhomogeneity registered by CCD imager in a continuum was observed. The possible mechanisms of the airglow disturbances and occurrence of sporadic E layers during sudden stratospheric warming are discussed. The work was supported by RAS Presidium Program 16 (Part 3).

  10. Simulations and observations of plasma depletion, ion composition, and airglow emissions in two auroral ionospheric depletion experiments

    NASA Technical Reports Server (NTRS)

    Yau, A. W.; Whalen, B. A.; Harris, F. R.; Gattinger, R. L.; Pongratz, M. B.

    1985-01-01

    Observations of plasma depletion, ion composition modification, and airglow emissions in the Waterhole experiments are presented. The detailed ion chemistry and airglow emission processes related to the ionospheric hole formation in the experiment are examined, and observations are compared with computer simulation results. The latter indicate that the overall depletion rates in different parts of the depletion region are governed by different parameters.

  11. MODELING OF THE ZODIACAL EMISSION FOR THE AKARI/IRC MID-INFRARED ALL-SKY DIFFUSE MAPS

    SciTech Connect

    Kondo, Toru; Ishihara, Daisuke; Kaneda, Hidehiro; Nakamichi, Keichiro; Takaba, Sachi; Kobayashi, Hiroshi; Ootsubo, Takafumi; Pyo, Jeonghyun; Onaka, Takashi E-mail: ishihara@u.phys.nagoya-u.ac.jp

    2016-03-15

    The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our solar system, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. Therefore, we aim to improve the IPD cloud model based on Kelsall et al., using the AKARI 9 and 18 μm all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest that the size of the smooth cloud, a dominant component in the model, is about 10% more compact than previously thought, and that the dust sizes are not large enough to emit blackbody radiation in the mid-IR. Furthermore, we detect a significant isotropically distributed IPD component, owing to an accurate baseline measurement with AKARI.

  12. Modeling of the Zodiacal Emission for the AKARI/IRC Mid-infrared All-sky Diffuse Maps

    NASA Astrophysics Data System (ADS)

    Kondo, Toru; Ishihara, Daisuke; Kaneda, Hidehiro; Nakamichi, Keichiro; Takaba, Sachi; Kobayashi, Hiroshi; Ootsubo, Takafumi; Pyo, Jeonghyun; Onaka, Takashi

    2016-03-01

    The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our solar system, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. Therefore, we aim to improve the IPD cloud model based on Kelsall et al., using the AKARI 9 and 18 μm all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest that the size of the smooth cloud, a dominant component in the model, is about 10% more compact than previously thought, and that the dust sizes are not large enough to emit blackbody radiation in the mid-IR. Furthermore, we detect a significant isotropically distributed IPD component, owing to an accurate baseline measurement with AKARI.

  13. Mid-Infrared Spectrum of the Zodiacal Emission: Detection of Crystalline Silicates in Interplanetary Dust

    NASA Technical Reports Server (NTRS)

    Ootsubo, T.; Onaka, T.; Yamamura, I.; Ishihara, D.; Tanabe, T.; Roellig, T. L.

    2003-01-01

    Within a few astronomical units of the Sun the solar system is filled with interplanetary dust, which is believed to be dust of cometary and asteroidal origin. Spectroscopic observations of the zodiacal emission with moderate resolution provide key information on the composition and size distribution of the dust in the interplanetary space. They can be compared directly to laboratory measurements of candidate materials, meteorites, and dust particles collected in the stratosphere. Recently mid-infrared spectroscopic observations of the zodiacal emission have been made by two instruments on board the Infrared Space Observatory; the camera (ISOCAM) and the spectrophotometer (ISOPHOT-S). A broad excess emission feature in the 9-11 micron range is reported in the ISOCAM spectrum, whereas the ISOPHOT-S spectra in 6-12 microns can be well fitted by a blackbody radiation without spectral features.

  14. World cup soccer players tend to be born with sun and moon in adjacent zodiacal signs

    PubMed Central

    Verhulst, J

    2000-01-01

    The ecliptic elongation of the moon with respect to the sun does not show uniform distribution on the birth dates of the 704 soccer players selected for the 1998 World Cup. However, a uniform distribution is expected on astronomical grounds. The World Cup players show a very pronounced tendency (p = 0.00001) to be born on days when the sun and moon are in adjacent zodiacal signs. Key Words: soccer; World Cup; astrology; moon PMID:11131239

  15. The Zodiacal Emission Spectrum as Determined by COBE and its Implications

    NASA Technical Reports Server (NTRS)

    Fixsen, D. J.; Dwek, Eli; Oliversen, R. (Technical Monitor)

    2002-01-01

    We combine observations from the DIRBE and FIRAS instruments on the COBE satellite to derive an annually-averaged spectrum of the zodiacal cloud in the 10 to 1000 micron wavelength region. The spectrum exhibits a break at approx. 150 microns which indicates a sharp break in the dust size distribution at a radius of about 30 microns The spectrum can be fit with a single blackbody with a lambda(exp -2) emissivity law beyond 150 microns and a temperature of 240 K. We also used a more realistic characterization of the cloud to fit the spectrum, including a distribution of dust temperatures, representing different dust compositions and distances from the sun, as well as a realistic representation of the spatial distribution of the dust. We show that amorphous carbon and silicate dust with respective temperatures of 280 and 274 K at 1 AU, and size distributions with a break at grain radii of 14 and 32 microns, can provide a good fit to the average zodiacal dust spectrum. The total mass of the zodiacal cloud is 2 to 11 Eg (Eg=10(exp 18) g), depending on the grain composition. The lifetime of the cloud, against particle loss by Poynting- Robertson drag and the effects of solar wind, is about 10(exp 5) yr. The required replenishment rate is approx. 10(exp 14) g/yr. If this is provided by asteroid belt alone, the asteroids lifetime would be approx. 3 x 10(exp 10) yr. But comets and Kuiper belt objects may also contribute to the zodiacal cloud.

  16. Wave breaking signatures in OH airglow and sodium densities and temperatures 1. Airglow imaging, Na lidar, and MF radar observations

    NASA Astrophysics Data System (ADS)

    Hecht, J. H.; Walterscheid, R. L.; Fritts, D. C.; Isler, J. R.; Senft, D. C.; Gardner, C. S.; Franke, S. J.

    The Collaborative Observations Regarding the Nightglow (CORN) campaign took place at the Urbana Atmospheric Observatory during September 1992. The instrumentation included, among others, the Aerospace Corporation narrowband nightglow CCD camera, which observes the OH Meinel (6-2) band (hereafter designated OH) and the O2 atmospheric (0-1) band (hereafter designated O2) nightglow emissions; the University of Illinois Na density/temperature lidar; and the University of Illinois MF radar. Here we report on observations of small-scale (below 10-km horizontal wavelength) structures in the OH airglow images obtained with the CCD camera. These small-scale structures were aligned perpendicular to the motion of 30- to 50-km horizontal wavelength waves, which had observed periods of about 10-20 min. The small-scale structures were present for about 20 min and appear to be associated with an overturned or breaking atmospheric gravity wave as observed by the lidar. The breaking wave had a horizontal wavelength of between 500 and 1500 km, a vertical wavelength of about 6 km, and an observed period of between 4 and 6 hours. The motion of this larger-scale wave was in the same direction as the ~30- to 50-km waves. While such small-scale structures have been observed before, and have been previously described as ripple-type wave structures [Taylor and Hapgood, 1990], these observations are the first which can associate their occurrence with independent evidence of wave breaking. The characteristics of the observed small-scale structures are similar to the vortices generated during wave breakdown in three dimensions in simulations described in Part 2 of this study [Fritts et al., this issue]. The results of this study support the idea that ripple type wave structures we observe are these vortices generated by convective instabilities rather than structures generated by dynamical instabilities.

  17. Out-of-the-ecliptic Trajectories to Reduce Zodiacal Dust Interference for Terrestrial Planet Finder

    NASA Astrophysics Data System (ADS)

    Arrell, R.; Gurfil, P.; Kasdin, J.; Seager, S.; Nissanke, S.

    2001-05-01

    Out-of-the-ecliptic trajectories that are beneficial to space observatories such as the Terrestrial Planet Finder and other potential mid-IR missions are introduced. These novel trajectories result in significantly reduced background noise from the zodiacal dust and therefore allow a reduction in the necessary size of the telescope collecting area. The reduced size of the mirrors allows for a considerable reduction in payload mass and manufacturing costs. Two types of optimal trajectories that are energetically feasible were derived using genetic algorithms. These are highly inclined non-Keplerian heliocentric orbits. We use the zodiacal dust model from the COBE data (Kelsall et al. 1998) to determine how well the orbits mitigate the zodi dust interference. The first optimal trajectory can use existing launch technology and yields a maximum decrease of 67% in the zodiacal cloud brightness. The zodi brightness for this trajectory is reduced by at least 50% for 60% of the mission lifetime. The second optimal trajectory requires planned improvement in launch technology but it renders a dramatic 97% maximum noise decrease. The zodi brightness is reduced by at least 70% for 82% of the mission lifetime for this trajectory. Heliocentric orbits at 5 AU have been discussed because the zodi dust concentration is extremely low there. Unfortunately such orbits are exceedingly impractical because of high cost, power source constraints (inability to use solar cells), and a long travel time before science return.

  18. Mesospheric sodium airglow emission: Modeling and first results over a mid-latitude

    NASA Astrophysics Data System (ADS)

    Bag, Tikemani; Krishna, M. V. Sunil; Singh, Vir

    2016-07-01

    Atmospheric sodium plays a very important role in the mesospheric chemistry and dynamics. We have developed a comprehensive model for mesospheric/thermospheric sodium airglow emission by incorporating all the known reaction mechanisms. The latest reaction rate coefficients and the related cross sections are obtained from the theoretical studies and experimental observations. The continuity equations are explicitly solved for the major species. Similarly, the steady-state approximation has been used for the intermediate and short lived minor species. The number densities from in-situ observations, NRLMSISE-00, and IRI-2012 have been successfully implemented to calculate the vertical volume emission rate. The modeled results compared to a good agreement with the measured profiles of Na airglow emission. The mesospheric sodium density shows a large day-to-day variability. The observed variations in the mesospheric sodium layer have been incorporated to obtain the variations in the sodium airglow intensities. The nocturnal variation of sodium airglow emissions are presented over a mid latitude location using this model.

  19. Satellite-based observations of tsunami-induced mesosphere airglow perturbations

    NASA Astrophysics Data System (ADS)

    Yang, Yu-Ming; Verkhoglyadova, Olga; Mlynczak, Martin G.; Mannucci, Anthony J.; Meng, Xing; Langley, Richard B.; Hunt, Linda A.

    2017-01-01

    Tsunami-induced airglow emission perturbations were retrieved by using space-based measurements made by the Sounding of the Atmosphere using Broad-band Emission Radiometry (SABER) instrument on board the Thermosphere-Ionosphere-Mesosphere Energetics Dynamics spacecraft. At and after the time of the Tohoku-Oki earthquake on 11 March 2011, and the Chile earthquake on 16 September 2015, the spacecraft was performing scans over the Pacific Ocean. Significant ( 10% relative to the ambient emission profiles) and coherent nighttime airglow perturbations were observed in the mesosphere following Sounding of the Atmosphere using Broad-band Emission Radiometry limb scans intercepting tsunami-induced atmospheric gravity waves. Simulations of emission variations are consistent with the physical characteristics of the disturbances at the locations of the corresponding SABER scans. Airglow observations and model simulations suggest that atmospheric neutral density and temperature perturbations can lead to the observed amplitude variations and multipeak structures in the emission profiles. This is the first time that airglow emission rate perturbations associated with tsunamis have been detected with space-based measurements.

  20. HF-induced airglow structure as a proxy for ionospheric irregularity detection

    NASA Astrophysics Data System (ADS)

    Kendall, E. A.

    2013-12-01

    The High Frequency Active Auroral Research Program (HAARP) heating facility allows scientists to test current theories of plasma physics to gain a better understanding of the underlying mechanisms at work in the lower ionosphere. One powerful technique for diagnosing radio frequency interactions in the ionosphere is to use ground-based optical instrumentation. High-frequency (HF), heater-induced artificial airglow observations can be used to diagnose electron energies and distributions in the heated region, illuminate natural and/or artificially induced ionospheric irregularities, determine ExB plasma drifts, and measure quenching rates by neutral species. Artificial airglow is caused by HF-accelerated electrons colliding with various atmospheric constituents, which in turn emit a photon. The most common emissions are 630.0 nm O(1D), 557.7 nm O(1S), and 427.8 nm N2+(1NG). Because more photons will be emitted in regions of higher electron energization, it may be possible to use airglow imaging to map artificial field-aligned irregularities at a particular altitude range in the ionosphere. Since fairly wide field-of-view imagers are typically deployed in airglow campaigns, it is not well-known what meter-scale features exist in the artificial airglow emissions. Rocket data show that heater-induced electron density variations, or irregularities, consist of bundles of ~10-m-wide magnetic field-aligned filaments with a mean depletion depth of 6% [Kelley et al., 1995]. These bundles themselves constitute small-scale structures with widths of 1.5 to 6 km. Telescopic imaging provides high resolution spatial coverage of ionospheric irregularities and goes hand in hand with other observing techniques such as GPS scintillation, radar, and ionosonde. Since airglow observations can presumably image ionospheric irregularities (electron density variations), they can be used to determine the spatial scale variation, the fill factor, and the lifetime characteristics of

  1. Airglow Observation with IMAP/ VISI on the International Space Station: Current status and simulation

    NASA Astrophysics Data System (ADS)

    Perwitasari, S.; Sakanoi, T.; Yamazaki, A.; Otsuka, Y.; Akiya, Y.; Saito, A.

    2012-12-01

    The Visible and near-Infrared Spectral Imager (VISI) of the IMAP mission was launched successfully by H-IIB/HTV3 on July 21 2012. At this moment HTV3 is docked onto the International Space Station (ISS), and VISI is scheduled to be installed on the exposed facility within a week. VISI will be operated in the nightside hemisphere in the range of +/- 51 deg. GLAT, and measure the airglow emissions of OI at 630 nm, the OH Meinel band at 730 nm and the O2 atmospheric band (0-0) at 762 nm at an altitude of ~400 km with typical spatial resolution of 16 - 50 km. Since the influence of cloud reflections of moonlight is overlapped with the airglow pattern in the visible wavelength range, the precise subtraction of the cloud influence is a key issue of this mission. Therefore, a simulation work to study on how much the surface albedo on the cloud top will affect the data is critically important. The height profiles of volume emission rates were estimated for O2 and OH airglows with the MSIS models, and then the airglow intensities were integrated along the line-of-sight direction. The cloud pattern was estimated based on the realistic data measured with a geostationary climate satellite. The simulation result shows that for OH Meinel at 730 nm, the moonlight reflection during the first/last quarter will increase the brightness of the airglow by factor of 1.5-2 and ~5 for full moon phase. Meanwhile, for O2 atmospheric band (0-0) at 762 nm, the simulation result shows that there's no significant (structured) background, even during the full moon phase. We will report the quantitative effect of cloud albedo on the airglow pattern, and discuss the physical parameters those expected to be derived from the VISI data. Concerning on the operation of VISI, we will carry out the initial function check by the middle of August, and start nominal observation within a few months. Thus, we will also report the current status and initial result of VISI.

  2. The formation and origin of the IRAS zodiacal dust bands as a consequence of single collisions between asteroids

    NASA Technical Reports Server (NTRS)

    Sykes, M. V.; Greenberg, R.

    1986-01-01

    Debris fom the single collisions between asteroids that are presently suggested as an explanation for zodiacal dust bands discovered by IRAS is distributed about the plane of the ecliptic, as particles undergo differential precession of their ascending nodes because of their semimajor axes' dispersion. On time scales of 100,000 to 1,000,000 yr, two bands are formed on each side of the ecliptic for each collision; the IRAS band pairs are probably due to collisions of aproximately 15-km diameter asteroids which occurred within the last several million yr. The model presented suggests that asteroid collisions suffice as a basis for most of the observed zodiacal emission.

  3. HF-enhanced 4278-Å airglow: evidence of accelerated ionosphere electrons?

    NASA Astrophysics Data System (ADS)

    Fallen, C. T.; Watkins, B. J.

    2013-12-01

    We report calculations from a one-dimensional physics-based self-consistent ionosphere model (SCIM) demonstrating that HF-heating of F-region electrons can produce 4278-Å airglow enhancements comparable in magnitude to those reported during ionosphere HF modification experiments at the High-frequency Active Auroral Research Program (HAARP) observatory in Alaska. These artificial 'blue-line' emissions, also observed at the EISCAT ionosphere heating facility in Norway, have been attributed to arise solely from additional production of N2+ ions through impact ionization of N2 molecules by HF-accelerated electrons. Each N2+ ion produced by impact ionization or photoionization has a probability of being created in the N2+(1N) excited state, resulting in a blue-line emission from the allowed transition to its ground state. The ionization potential of N2 exceeds 18 eV, so enhanced impact ionization of N2 implies that significant electron acceleration processes occur in the HF-modified ionosphere. Further, because of the fast N2+ emission time, measurements of 4278-Å intensity during ionosphere HF modification experiments at HAARP have also been used to estimate artificial ionization rates. To the best of our knowledge, all observations of HF-enhanced blue-line emissions have been made during twilight conditions when resonant scattering of sunlight by N2+ ions is a significant source of 4278-Å airglow. Our model calculations show that F-region electron heating by powerful O-mode HF waves transmitted from HAARP is sufficient to increase N2+ ion densities above the shadow height through temperature-enhanced ambipolar diffusion and temperature-suppressed ion recombination. Resonant scattering from the modified sunlit region can cause a 10-20 R increase in 4278-Å airglow intensity, comparable in magnitude to artificial emissions measured during ionosphere HF-modification experiments. This thermally-induced artificial 4278-Å aurora occurs independently of any artificial

  4. Estimating the electron energy distribution during ionospheric modification from spectrographic airglow measurements

    NASA Astrophysics Data System (ADS)

    Hysell, D. L.; Vlasov, M.; Watkins, B. J.

    2011-12-01

    The electron energy distribution during an F region ionospheric modification experiment is inferred from spectrographic airglow emission data. Emission lines at 630.0, 557.7, and 844.6 nm are considered along with the absence of detectable emissions at 427.8 nm. Estimating the electron energy distribution function from the airglow data is a problem in classical linear inverse theory. We describe an augmented version of the method of Backus and Gilbert which we use to invert the data. The method optimizes the model resolution, the precision of the mapping between the actual electron energy distribution and its estimate. Here, the method has also been augmented so as to limit the model prediction error. Our methodology predicts a heater-induced electron energy spectrum with a peak near 5 eV that decreases by almost three orders of magnitude between 5--30 eV.

  5. Measurement of atomic oxygen and related airglows in the lower thermosphere

    NASA Technical Reports Server (NTRS)

    Thomas, R. J.; Young, R. A.

    1981-01-01

    Instruments on board a sounding rocket were used to make simultaneous observations of atomic oxygen density and airglow emissions between 80 and 120 km. Atomic oxygen was measured with a resonance lamp and was found to have a peak density of 6 x 10 to the 11th at 94 km. Similar structure is seen in the oxygen density profile on both uplegs and downlegs. The following airglow emissions were measured by using vertical-viewing photometers: Herzberg I bands near 300 nm; O(1S) green line at 557.7 nm; background at 566 nm; O2(1 Delta g) bands at 1.27 microns; and OH (X 2 pi) Meinel bands near 1.7 microns.

  6. Ground-based observation of the Venus 1.27-um O2 airglow

    NASA Astrophysics Data System (ADS)

    Ohtsuki, S.; Iwagami, N.; Sagawa, H.; Kasaba, Y.; Ueno, M.; Imamura, T.

    We conducted near-infrared imaging spectroscopy of the nightside of Venus at Okayama Astrophysical Observatory Japan on December 11, 2002. The 1.3-um spectra show 1.27-um O_2 IRA (0,0) airglow feature and thermal emission from the lower atmosphere. The brightest airglow feature of 5MR is found at the anti-solar point, which agrees with the previous studies. The hemispheric distribution of 1.3-um thermal emission shows equatorial depression similar to that of the 2-um region in previous studies. The hemispheric distribution of the rotational temperature shows a hot region at around the anti-solar point overlapping the bright region, and which suggests adiabatic heating due to the downward flow.

  7. Thin film interference optics for imaging the O II 834-A airglow

    NASA Technical Reports Server (NTRS)

    Seely, John F.; Hunter, William R.

    1991-01-01

    Normal incidence thin film interference mirrors and filters have been designed to image the O II 834-A airglow. It is shown that MgF2 is a useful spacer material for this wavelength region. The mirrors consist of thin layers of MgF2 in combination with other materials that are chosen to reflect efficiently in a narrow band centered at 834 A. Peak reflectance of 60 percent can be obtained with a passband 200 A wide. Al/MgF2/Si and Al/MgF2/SiC interference coatings have been designed to reflect 834 A and to absorb the intense H I 1216 A airglow. An In/MgF2/In interference filter is designed to transmit 834 A and attenuate 1216 A radiation. Interference photocathode coatings for rejecting 1216 A radiation are also discussed.

  8. Nature's Late-Night Light Shows

    NASA Astrophysics Data System (ADS)

    Peterson, Carolyn Collins

    2002-09-01

    In addition to stars and planets, there are other interesting lights to be seen in the night sky. The northern and southern lights, called the aurora borealis and aurora australis, are created by charged particles from the Sun reacting in Earth's magnetic field. Night-shining clouds or noctilucent clouds appear at evening twilight as a result of water vapor in the polar mesosphere. Zodiacal light can be seen stretching up from the horizon after sunset or before sunrise.

  9. Mars dayside temperature from airglow limb profiles : comparison with in situ measurements and models

    NASA Astrophysics Data System (ADS)

    Gérard, Jean-Claude; Bougher, Stephen; Montmessin, Franck; Bertaux, Jean-Loup; Stiepen, A.

    The thermal structure of the Mars upper atmosphere is the result of the thermal balance between heating by EUV solar radiation, infrared heating and cooling, conduction and dynamic influences such as gravity waves, planetary waves, and tides. It has been derived from observations performed from different spacecraft. These include in situ measurements of orbital drag whose strength depends on the local gas density. Atmospheric temperatures were determined from the altitude variation of the density measured in situ by the Viking landers and orbital drag measurements. Another method is based on remote sensing measurements of ultraviolet airglow limb profiles obtained over 40 years ago with spectrometers during the Mariner 6 and 7 flybys and from the Mariner 9 orbiter. Comparisons with model calculations indicate that they both reflect the CO_2 scale height from which atmospheric temperatures have been deduced. Upper atmospheric temperatures varying over the wide range 270-445 K, with a mean value of 325 K were deduced from the topside scale height of the airglow vertical profile. We present an analysis of limb profiles of the CO Cameron (a(3) Pi-X(1) Sigma(+) ) and CO_2(+) doublet (B(2) Sigma_u(+) - X(2) PiΠ_g) airglows observed with the SPICAM instrument on board Mars Express. We show that the temperature in the Mars thermosphere is very variable with a mean value of 270 K, but values ranging between 150 and 400 K have been observed. These values are compared to earlier determinations and model predictions. No clear dependence on solar zenith angle, latitude or season is apparent. Similarly, exospheric variations with F10.7 in the SPICAM airglow dataset are small over the solar minimum to moderate conditions sampled by Mars Express since 2005. We conclude that an unidentified process is the cause of the large observed temperature variability, which dominates the other sources of temperature variations.

  10. Propagation of plasma bubbles observed in Brazil from GPS and airglow data

    NASA Astrophysics Data System (ADS)

    Haase, J. S.; Dautermann, T.; Taylor, Michael J.; Chapagain, N.; Calais, E.; Pautet, D.

    2011-05-01

    Equatorial spread-F is a common occurrence in the equatorial ionosphere that is associated with large variations in plasma density that often cause scintillation and interference in communication signals. These events are known to result from Rayleigh-Taylor instability, but the day-to-day variability of their occurrence is not well understood. The triggering mechanism of plasma depletions is still a matter of debate, but may be linked to gravity waves that under favorable conditions propagate to the middle atmosphere. Understanding the triggering of ESF was the focus of the SpreadFEx campaign near Brasilia, Brazil in 2005. The campaign provided co-located airglow and GPS observations to study the onset of plasma depletions and their evolution as they traversed the region. Comparisons between the 630.0 nm airglow data and GPS data demonstrate the ability of the compact dual frequency GPS array to detect the plasma bubbles and retrieve reliable propagation characteristics of the depletions. In this case study, a plasma depletion was detected and moved over the array at velocities of 85-110 m/s, slowing as it moved towards the east. Correlation of consecutive airglow images gives consistent estimates of the eastward drift over the same time period. Mapping the airglow data to the GPS line-of-sight geometry allows direct comparison and reveals a resolvable westward tilt of the plasma depletion that may be due to vertical shear. The uniqueness of this study is the ability to resolve locally the characteristics of the plasma depletion without relying on assumptions about the mapping of the depletion along magnetic field lines to large latitudinal distances. It presents new information for understanding ESF development and the development of depletions strong enough to produce scintillation.

  11. Similarities Between RF- and Lightning-Induced Airglow in the Upper Atmosphere

    NASA Astrophysics Data System (ADS)

    Sentman, D. D.; Wescott, E. M.; Stenbaek-Nielsen, H. C.; Moudry, D. R.; Sao Sabbas, F. T.

    2002-12-01

    Recent experiments in Alaska using the HAARP and HIPAS high power RF transmitters have succeeded in artificially generating oxygen neutral and molecular nitrogen ion emissions, or artificial airglow, in the ionosphere. An apparently different type of transient airglow generated by lightning, in the form of sprites and elves in the mesosphere and lower ionosphere, has been extensively studied in recent years. Despite occurring in vastly different atmospheric regimes, these seemingly disparate forms of optical emissions, one derived from artificial modification of the ionosphere and the other from natural thunderstorm processes, share a common underlying microphysical description based on electron heating by RF and quasi-DC electric fields, respectively, accompanied by impact excitation of ambient neutrals and subsequent optical relaxation and quenching of excited species. The theoretical description of these processes has its roots in work described by Zel'dovich and Raizer on the microphysics of shock waves and high temperature gasses. This work was subsequently adapted by Gurevich, Papadopoulis and coworkers to describe high power microwave interactions with the stratosphere. Extended to include nonlinear plasma interactions, it is the basis for understanding the effects of intense RF waves on the ionosphere, including creation of airglow, from high power transmitters currently operating in Alaska, Sweden and Russia. Pasko and coworkers have successfully adapted these theories to conditions appropriate to lightning impulse interactions with the upper atmosphere to describe the basic breakdown and streamer processes associated with sprite production. Thus, sprites and RF-induced airglow theories share a common set of concepts at the microphysical level and a common theoretical language. This talk outlines areas of especially strong overlap, and describes some possible high power RF ionospheric interaction experiments that could be performed to help study

  12. Imaging mesospheric winds using the Michelson interferometer for airglow dynamics imaging

    NASA Astrophysics Data System (ADS)

    Langille, Jeffery; Ward, William E.

    2016-07-01

    The first ground based images of mesospheric winds in airglow are presented and discussed in this paper. These were obtained with the Michelson Interferometer for Airglow Dynamics Imaging (MIADI)a ground based field widened Michelsoin interferometer designed to obtain two dimensional images of the line of sight Doppler wind and irradiance field in the mesosphere. The purpose of this instrument is to measure perturbations in line-of-sight wind and airglow irradiance associated with gravity waves. In its current configuration, the instrument observes an ~80 km x ~80 km region of the night sky in ~33 minutes using the O(1S) emission at 557.73 nm and the OH (6, 2) P1 (2) emission at 839.918 nm. The instrument was installed and tested at a field site outside Fredericton, NB (45.96 N, 66.65 W) during the summer of 2014. Successful measurements over a six hour period were obtained on July 31, 2014. Variations in the meridional and zonal wind were observed that are consistent with a semi-diurnal tide with an amplitude of ˜ 35 m/s. Small scale variations (< 10 m/s) were also observed that indicate the presence of gravity waves. In this paper, the instrument concept will be presented and the field measurements and their precision and accuracy discussed.

  13. Gravity wave amplitudes changes observed in different airglow emissions: influence of wave breaking and observational selection

    NASA Astrophysics Data System (ADS)

    Schmidt, Carsten; Wüst, Sabine; Hannawald, Patrick; Bittner, Michael

    2016-04-01

    The upper mesosphere lower thermosphere region is well known for enhanced gravity wave breaking. Airglow emissions originating in this height region provide a good possibility for detailed studies of gravity wave behavior in this altitude. Therefore, rotational temperatures and intensities of the OH(3-1), OH(4-2), OH(6-2) and O2b(0-1)-transitions recorded at the NDMC (Network for the Detection of Mesospheric Change) site Oberpfaffenhofen (48.1°N, 10.3°E), Germany are examined. First results indicate, that both significant amplitude growth from the lower (~87km) OH airglow emissions to the higher (~95km) O2 airglow emissions of more than 100% as well as strong damping can be observed. On several occasions OH- and O2-emissions show completely independent behavior - probably related to the complete breakup of a gravity wave. These amplitude changes are set into relation to emission layer height, vertical wavelength, absolute temperature and potential seasonal dependence. Observations from further NDMC sites in France, Germany and Austria are used to discuss the evolution of these waves on horizontal scales from 100km to 1000km.

  14. Airglow-imaging observation of plasma bubble disappearance at geomagnetically conjugate points

    NASA Astrophysics Data System (ADS)

    Shiokawa, Kazuo; Otsuka, Yuichi; Lynn, Kenneth JW; Wilkinson, Philip; Tsugawa, Takuya

    2015-03-01

    We report the first observation of the disappearance of a plasma bubble over geomagnetically conjugate points. It was observed by airglow imagers at Darwin, Australia (magnetic latitude: -22°N) and Sata, Japan (21°N) on 8 August 2002. The plasma bubble was observed in 630-nm airglow images from 1530 (0030 LT) to 1800 UT (0300 LT) and disappeared equatorward at 1800 to 1900 UT (0300 to 0400 LT) in the field of view. The ionograms at Darwin and Yamagawa (20 km north of Sata) show strong spread-F signatures at approximately 16 to 21 UT. At Darwin, the F-layer virtual height suddenly increased from approximately 200 to approximately 260 km at the time of bubble disappearance. However, a similar F-layer height increase was not observed over the conjugate point at Yamagawa, indicating that this F-layer rise was caused not by an eastward electric field but by enhancement of the equatorward thermospheric wind over Darwin. We think that this enhancement of the equatorward neutral wind was caused by an equatorward-propagating large-scale traveling ionospheric disturbance, which was identified in the north-south keogram of 630-nm airglow images. We speculate that polarization electric field associated with this equatorward neutral wind drive plasma drift across the magnetic field line to cause the observed bubble disappearance.

  15. Airglow-imaging observation of plasma bubble disappearance at geomagnetically conjugate points

    NASA Astrophysics Data System (ADS)

    Shiokawa, K.; Otsuka, Y.; Lynn, K. J. W.; Wilkinson, P. W.; Tsugawa, T.

    2014-12-01

    We report the first observation of the disappearance of plasma bubbles overgeomagnetically conjugate points. It was observed by airglow imagers at Darwin,Australia (magnetic latitude: -22N) and Sata, Japan (21N) on 8 August 2002. Theplasma bubble was observed in 630-nm airglow images from 1530 UT (0030 LT) to1800 UT (0300 LT) and disappeared equatorward at 1800-1900 UT (0300-0400 LT) inthe field of view. The ionograms at Darwin and Yamagawa (20 km north of Sata)show strong spread-F signatures at ~16-21 UT. At Darwin, the F-layer virtualheight suddenly increased from ~200 km to ~260 km at the time of bubbledisappearance. However a similar F-layer height increase was not observed overthe conjugate point at Yamagawa, indicating that this F-layer rise was causednot by an eastward electric field but by enhancement of the equatorwardthermospheric wind over Darwin. We think that this enhancement of theequatorward neutral wind was caused by an equatorward-propagating large-scaletraveling ionospheric disturbance, which was identified in the north-southkeogram of 630-nm airglow images. We suggest that either F-region dynamoor polarization electric field associated with this equatorward neutral winddrive plasma drift across the magnetic field line to cause the observed bubbledisappearance.

  16. The evolution of the zodiac in the context of ancient oriental history

    NASA Astrophysics Data System (ADS)

    Gurshtein, Alex A.

    The dates for the second (ca. 2700 B.C. to within 250 years) and the third ecliptical quartets (ca. 1200 B.C. to within 400 years) evaluated earlier are considered in the context of ancient Egyptian history. The origin of the second quartet coincides with the Great Pyramids and the initiation of the Egyptian solar, or so-called "civil" calendar, the first of such a type in the world. The third quartet is concurrent with the solar conversion of Amenhotep IV (Akhenaton) and takes place at the finale of the great Sothic period of 1461 years after the initiation of the solar calendar. It is argued that the Great Pyramids seem to be monuments to the Sun-god built in honor of the Egyptians having reached an understanding of the Sun's track upon the starry background, Akhenaton's conversion being in a direct connection with the original Pyramids' ideology. This paper is the third part of a single investigation. The first two parts "On the Origin of the Zodiacal Constellations" and "Prehistory of Zodiac Dating: Three Strata of Upper Paleolithic Constellations" were published in Vistas in Astronomy in 1993 and 1995.

  17. Radar Detectability Studies of Slow and Small Zodiacal Dust Cloud Particles: II. A Study of Three Radars with Different Sensitivity

    NASA Astrophysics Data System (ADS)

    Janches, D.; Swarnalingam, N.; Plane, J. M. C.; Nesvorný, D.; Feng, W.; Vokrouhlický, D.; Nicolls, M. J.

    2015-07-01

    The sensitivity of radar systems to detect different velocity populations of the incoming micrometeoroid flux is often the first argument considered to explain disagreements between models of the Near-Earth dust environment and observations. Recently, this was argued by Nesvorný et al. to support the main conclusions of a Zodiacal Dust Cloud (ZDC) model which predicts a flux of meteoric material into the Earth’s upper atmosphere mostly composed of small and very slow particles. In this paper, we expand on a new methodology developed by Janches et al. to test the ability of powerful radars to detect the meteoroid populations in question. In our previous work, we focused on Arecibo 430 MHz observations since it is the most sensitive radar that has been used for this type of observation to date. In this paper, we apply our methodology to two other systems, the 440 MHz Poker Flat Incoherent Scatter Radar and the 46.5 Middle and Upper Atmosphere radar. We show that even with the less sensitive radars, the current ZDC model over-predicts radar observations. We discuss our results in light of new measurements by the Planck satellite which suggest that the ZDC particle population may be characterized by smaller sizes than previously believed. We conclude that the solution to finding agreement between the ZDC model and sensitive high power and large aperture meteor observations must be a combination of a re-examination not only of our knowledge of radar detection biases, but also the physical assumptions of the ZDC model itself.

  18. Preliminary Validation of Atmospheric Neutral Density Derived From Ultraviolet Airglow Observations

    NASA Astrophysics Data System (ADS)

    Nicholas, A. C.; Thonnard, S. E.; Picone, J. M.; Dymond, K.; Budzien, S. A.; Knowles, S.; Bennert, E.; McCoy, R.

    2003-12-01

    In the past, orbit determination and prediction for resident space objects relied on climatological models to estimate atmospheric drag. Characteristic of climatology, atmospheric density models have errors that range from 10% to 15%. For Low Earth Orbiting (LEO) satellites, the error due to an imprecise density specification is the most significant contribution to the error ellipse associated with the position of the object. Several techniques to obtain corrections for the atmospheric density models and improve orbit determination are in various stages of research and development. This paper presents ultraviolet airglow derived atmospheric density corrections for the NRLMSISE-00 model during January and February 2001. Observations of the naturally occurring airglow on the Earth's limb were obtained from the Low-Resolution Airglow and Auroral Spectrograph (LORAAS) on the Advanced Research and Global Observation Satellite (ARGOS). Inversion algorithms developed at the Naval Research Laboratory were used to retrieve neutral density profiles from the observations. The result of the inversion process produces four correction coefficients for the NRLMSISE-00 atmospheric model; one for the F10.7 cm solar flux model input parameter, and three scalars for the O, O2 and N2 model output. The proper application of these correction coefficients with NRLMSISE-00 allows for the calculation of a global total density specification. Ultraviolet airglow derived density for January and February of 2001 were first compared to climatology using the Jacchia J70 and NRLMSISE-00 models. Additionally the ultraviolet derived density was compared to global density specification from the High Accuracy Satellite Drag Model (HASDM) developed for the Air Force Battlelab. HASDM determines global atmospheric density by simultaneously evaluating the drag on a reference set of resident space objects. From the Space Surveillance Network (SSN) observations of the HASDM reference objects, in

  19. Comparison of winds measured by MU radar and Fabry-Perot interferometer and effect of OI5577 airglow height variations

    NASA Astrophysics Data System (ADS)

    Fujii, Junsuke; Nakamura, Takuji; Tsuda, Toshitaka; Shiokawa, Kazuo

    2004-04-01

    We have compared wind velocities around mesopause height measured by the middle and upper atmosphere (MU) radar (meteor mode) and OI (5577) airglow observation by an Fabry-Perot Interferometer (FPI), at Shigaraki (34.8°N,136.1°E), Japan, on November 13/14, 1999. When we assume the airglow height is constant throughout the night, it was difficult to find a single height exhibiting small r.m.s. differences between the two methods for both eastward and northward wind velocities. However, in the case we introduce a time variation of the airglow height due to a large-scale gravity wave activity, we have found very small r.m.s. wind difference: The assumptions are of the airglow height variation with an amplitude of 1.5km, a period of 5.7h and a linear trend of -0.19km/h having the average height of 92.8km. Further analysis of time and height variations of the winds and diffusion coefficients measured by the MU radar indicated that a gravity wave with a very similar structure predicted in the above comparison between the FPI and meteor winds has been detected as a dominant wave component. Thus, we conclude that the existence of a gravity wave which can change the airglow height will lead to differences in wind velocities observed with FPI and radar techniques.

  20. Internal Gravity Wave Induced by the Queen Charlotte Event (27 October 2012, Mw 7.8): Airglow Observation and Modeling.

    NASA Astrophysics Data System (ADS)

    Occhipinti, G.; Bablet, A.; Makela, J. J.

    2015-12-01

    The detection of the tsunami related internal gravity waves (IGWtsuna) by airglow camera has been recently validated by observation (Makela et al., 2011) and modeling (Occhipinti et al., 2011) in the case of the Tohoku event (11 March 2011, Mw 9.0). The airglow is measuring the photon emission at 630 nm, indirectly linked to the plasma density of O2+ (Link & Cogger, 1988) and it is commonly used to detect transient event in the ionosphere (Kelley et al., 2002, Makela et al., 2009, Miller et al., 2009). The modeling of the IGWtsuna clearly reproduced the pattern of the airglow measurement observed over Hawaii and the comparison between the observation and the modeling allows to recognize the wave form and allow to explain the IGWtsuna arriving before the tsunami wavefront at the sea level (Occhipinti et al., 2011). Approaching the Hawaiian archipelagos the tsunami propagation is slowed down (reduction of the sea depth), instead, the IGWtsuna, propagating in the atmosphere/ionosphere, conserves its speed. In this work, we present the modeling of the new airglow observation following the Queen Charlotte event (27 October 2012, Mw 7.8) that has been recently detected, proving that the technique can be generalized for smaller events. Additionally, the effect of the wind on the IGWtsuna, already evocated in the past, is included in the modeling to better reproduce the airglow observations. All ref. here @ www.ipgp.fr/~ninto

  1. Within-Sulfonylurea-Class Evaluation of Time to Intensification with Insulin (ZODIAC-43)

    PubMed Central

    Hartog, Laura C.; Kleefstra, Nanne; Groenier, Klaas H.; Landman, Gijs W. D.; Bilo, Henk J. G.

    2016-01-01

    Background Previous studies have shown that many within-class differences exist between sulfonylureas (SUs), however, whether differences exist regarding the time it takes between initiating an SU and the need to intensify treatment with insulin is unclear. The aim of this study was investigate the relationships between the three frequently used sulphonylureas, prescribed as dual therapy next to metformin, and the time needed to treatment intensification with either insulin or oral triple therapy in patients with type 2 diabetes mellitus. Methods Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) is a prospective observational cohort study set in primary care in the Netherlands. Annually collected data on diabetes medication and clinical variables within ZODIAC are used to evaluate the primary outcome, time to insulin and secondary outcome, time to either insulin or triple oral therapy. For statistical analysis a time-dependent cox proportional hazard model was used. Results 3507 patients were included in the analysis, with a mean age of 61 (SD 11.4) and a median HbA1c of 6.8% [IQR 6.4–7.4] (50.8 mmol/mol [IQR 46.4–57.4]).The hazard ratio (HR) for the primary endpoint was 1.10 (95% CI 0.78–1.54) for metformin/glimepiride and 0.93 (95% CI 0.67–1.30) for metformin/tolbutamide with metformin/gliclazide as reference group. The HR for the secondary outcome was 1.04 (95% CI 0.78–1.40) and 0.85 (95% CI 0.64–1.13), respectively. Conclusion In this large Dutch primary care cohort, new users of neither gliclazide, glimepiride nor tolbutamide as dual therapy with metformin, resulted in differences in the time needed for further treatment intensification. PMID:27327605

  2. Mesospheric airglow and ionospheric responses to upward-propagating acoustic and gravity waves above tropospheric sources

    NASA Astrophysics Data System (ADS)

    Snively, J. B.; Zettergren, M. D.

    2013-12-01

    The existence of acoustic waves (periods ~1-5 minutes) and gravity waves (periods >4 minutes) in the ionosphere above active tropospheric convection has been appreciated for more than forty years [e.g., Georges, Rev. Geophys. and Space Phys., 11(3), 1973]. Likewise, gravity waves exhibiting cylindrical symmetry and curvature of phase fronts have been observed via imaging of the mesospheric airglow layers [e.g., Yue et al., JGR, 118(8), 2013], clearly associated with tropospheric convection; gravity wave signatures have also recently been detected above convection in ionospheric total electron content (TEC) measurements [Lay et al., GRL, 40, 2013]. We here investigate the observable features of acoustic waves, and their relationship to upward-propagating gravity waves generated by the same sources, as they arrive in the mesosphere, lower-thermosphere, and ionosphere (MLTI). Numerical simulations using a nonlinear, cylindrically-axisymmetric, compressible atmospheric dynamics model confirm that acoustic waves generated by transient tropospheric sources may produce "concentric ring" signatures in the mesospheric hydroxyl airglow layer that precede the arrival of gravity waves. As amplitudes increase with altitude and decreasing neutral density, the modeled acoustic waves achieve temperature and vertical wind perturbations on the order of ~10s of Kelvin and m/s throughout the E- and F-region. Using a coupled multi-fluid ionospheric model [Zettergren and Semeter, JGR, 117(A6), 2012], extended for low-latitudes using a 2D dipole magnetic field coordinate system, we investigate acoustic wave perturbations to the ionosphere in the meridional direction. Resulting perturbations are predicted to be detectable by ground-based radar and GPS TEC measurements, or via in situ instrumentation. Although transient and short-lived, the acoustic waves' airglow and ionospheric signatures are likely to in some cases be observable, and may provide important insight into the regional

  3. First tomographic estimate of volume distribution of HF-pump enhanced airglow emission

    NASA Astrophysics Data System (ADS)

    Gustavsson, B.; Sergienko, T.; Rietveld, M. T.; Honary, F.; Steen, Å.; Brändström, B. U. E.; Leyser, T. B.; Aruliah, A. L.; Aso, T.; Ejiri, M.; Marple, S.

    2001-12-01

    This report presents the first estimates of the three-dimensional volume emission rate of enhanced O(1D) 6300 Å airglow caused by HF radio wave pumping in the ionosphere. Images of the excitation show how the initially speckled spatial structure of excitation changes to a simpler shape with a smaller region that contains most of the excitation. A region of enhanced airglow was imaged by three stations in the Auroral Large Imaging System (ALIS) in northern Scandinavia. These images allowed for a tomography-like inversion of the volume emission of the airglow. The altitude of maximum emission was found to be around 235+/-5km with typical horizontal and vertical scale sizes of 20 km. The shape of the O(1D) excitation rate varied from flatish to elongated along the magnetic field. The altitude of maximum emission is found to be approximately 10 km below the altitude of the enhanced ion line and 15 km above the altitude of maximum electron temperature. Comparisons of the measured altitude and temporal variations of the 6300 Å emission with modelled emission caused by O(1D) excitation from the high energy tail of a Maxwellian electron distribution show significant deviations. The 6300 Å emission from excitation of the high energy tail is about a factor of 4 too large compared with what is observed. This shows that the source of O(1D) excitation is electrons from a ``sub-thermal'' distribution function, i.e. the electron distribution is Maxwellian at low energies and at energies above 1.96 eV there is a depletion.

  4. Concentric gravity waves over northern China observed by an airglow imager network and satellites

    NASA Astrophysics Data System (ADS)

    Xu, Jiyao; Li, Qinzeng; Yue, Jia; Hoffmann, Lars; Straka, William C.; Wang, Cuimei; Liu, Mohan; Yuan, Wei; Han, Sai; Miller, Steven D.; Sun, Longchang; Liu, Xiao; Liu, Weijun; Yang, Jing; Ning, Baiqi

    2015-11-01

    The first no-gap OH airglow all-sky imager network was established in northern China in February 2012. The network is composed of six all-sky airglow imagers that make observations of OH airglow gravity waves and cover an area of about 2000 km east and west and about 1400 km south and north. An unusual outbreak of Concentric Gravity Wave (CGW) events were observed by the network nearly every night during the first half of August 2013. These events were coincidentally observed by satellite sensors from Fengyun-2 (FY-2), Atmospheric Infrared Sounder (AIRS)/Aqua, and Visible Infrared Imaging Radiometer Suite (VIIRS)/Suomi National Polar-orbiting Partnership (NPP). Combination of the ground imager network with satellites provides multilevel observations of the CGWs from the stratosphere to the mesopause region. In this paper, two representative CGW events in August 2013 are studied in detail: first is the CGW on the night of 13 August 2013, likely launched by a single thunderstorm. The temporal and spatial analyses indicate that the CGW horizontal wavelengths follow freely propagating waves based on a GW dispersion relation within 300 km from the storm center. In contrast, the more distant observed gravity wave field exhibits a smaller horizontal wavelength of ~20 km, and our analysis strongly suggest this wave field represents a ducted wave. A second event, exhibiting multiple CGWs, was induced by two very strong thunderstorms on 9 August 2013. Multiscale waves with horizontal wavelengths ranging from less than 10 km to 200 km were observed.

  5. Comparison of theories for gravity wave induced fluctuations in airglow emissions

    NASA Technical Reports Server (NTRS)

    Walterscheid, R. L.; Schubert, G.; Hickey, M. P.

    1994-01-01

    A comparison is undertaken of theories for the gravity wave induced fluctuations in the intensity of airglow emissions and the associated temperature of the source region. The comparison is made in terms of Krassovsky's ratio eta(sub E) for a vertically extended emission region (eta(sub E) is the ratio of the vertically integrated normalized intensity perturbation to the vertically integrated intensity-weighted temperature perturbation). It is shown that the formulas for eta(sub E) in the works by Tarasick and Hines (1990) and Schubert et al. (1991) are in agreement for the case of an inviscid atmosphere. The calculation of eta(sub E) using the theory of Tarasick and Hines (1990) requires determination of their function chi; we show that chi is simply related to the 'single-level' Krassovsky's ratio eta of Schubert et al. (1991). The general relationship between chi and eta is applied to a simple chemical-dynamical model of the O2 atmospheric airglow and the altitude dependence of these quantities is evaluated for nonsteady state chemistry. Though the Tarasick and Hines (1990) formula for eta(sub E) does not explicitly depend on the scale heights of the minor constituents involved in airglow chemistry, eta(sub E) implicitly depends upon these scale heights through its dependences on chemical production and loss contained in chi. We demonstrate this dependence of eta(sub E) for the OH nightglow on atomic oxygen scale height by direct numerical evaluation of eta(sub E) in this case the dependence originates in the chemical production of perturbed ozone.

  6. Airglow-solar spectrometer instrument (20-700 nm) aboard the San Marco D/L satellite

    NASA Astrophysics Data System (ADS)

    Schmidtke, G.; Seidl, P.; Wita, C.

    1985-10-01

    The ASSI experiment aboard the San Marco D/L aeronomy satellite will monitor the airglow, solar, and interplanetary radiations from the EUV through the visible spectral regions. Four spectrometers with solar pointing control cover this broad region using channels with eighteen overlapping wavelength ranges with spectral resolutions from 0.8 to 3.0 nm, which are adequate for aeronomy. Large dynamic ranges up to 1:10 to the 11th permit the measurement of faint airglow or interplanetary radiation and intense solar emissions with one and the same instrument. Instrumental details such as the special optical design and calibration procedures are presented in detail.

  7. Measurements of the Michigan Airglow Observatory from 1971 to 1973 at Ester Dome Alaska

    NASA Technical Reports Server (NTRS)

    Mcwatters, K. D.; Meriwether, J. W.; Hays, P. B.; Nagy, A. F.

    1973-01-01

    The Michigan Airglow Observatory (MAO) was located at Ester Dome Observatory, College, Alaska (latitude: 64 deg 53'N, longitude: 148 deg 03'W) since October, 1971. The MAO houses a 6-inch Fabry-Perot interferometer, a 2-channel monitoring photometer and a 4-channel tilting filter photometer. The Fabry-Perot interferometer was used extensively during the winter observing seasons of 1971-72 and 1972-73 to measure temperature and mass motions of the neutral atmosphere above approximately 90 kilometers altitude. Neutral wind data from the 1971-72 observing season as measured by observing the Doppler shift of the gamma 6300 A atomic oxygen emission line are presented.

  8. Observations of Atmospheric Gravity Wave damping in the Mesosphere with lidar and airglow

    NASA Astrophysics Data System (ADS)

    Swenson, G. R.; Li, F.; Liu, A.; Thakker, P.

    2002-12-01

    Correlative measurements of temperature and winds by Na lidar and brightness in OH and O2 Atmospheric band airglow have been made at Albuquerque, NM and Maui, HI for a study of high frequency (Period less than 30 minutes) Atmospheric Gravity Waves (AGWs). Waves studies from four nights have been made and the correlative information describes the intrinsic wave properties with altitude, their damping characteristics, and resulting accelerations to the large scale dynamics in the 85-100 km altidude region. Generally, saturated to super-saturated conditions were observed below 95 km. Above this altitude, they became freely propagating.

  9. An atlas of low latitude 6300A (01) night airglow from OGO-4 observations

    NASA Technical Reports Server (NTRS)

    Reed, E. I.; Fowler, W. B.; Blamont, J. E.

    1972-01-01

    The atomic oxygen emission line at 6300 A, measured in the nadir direction by a photometer on the polar orbiting satellite OGO-4, was plotted between 40 deg N and 40 deg S latitude on a series of maps for the moon-free periods between 30 August 1967 and 10 January 1968 The longitudinal and local time variations which occur during the northern fall-winter season are indicated. The northern tropical arc is more widespread while the southern arc is not present at all longitudes. The conditions under which the observations were made are described, and four airglow maps were selected to show the local time variations.

  10. Monitoring Saturn's Upper Atmosphere Density Variations Using Helium 584 Å Airglow

    NASA Astrophysics Data System (ADS)

    Parkinson, Chris

    2016-10-01

    The study of He 584 Å brightness of Saturn is interesting as the EUV planetary airglow have the potential to yield useful information about mixing and other important parameters in its thermosphere. Resonance scattering of sunlight by He atoms is the principal source of the planetary emission of He 585 Å. The helium is embedded in an absorbing atmosphere of H2 and since it is heavier than the background atmosphere, it's concentration falls off rapidly above the homopause. The scattering region (i.e. where the absorption optical depth in H2 is < ~1) generally lies well above the homopause. As the eddy diffusion coefficient, Kzz, increases in the middle atmosphere, relatively more helium is mixed into the scattering region and thus the reflected intensity increases. The principal parameter involved in determining the He 584 Å albedo are the He volume mixing ratio, f, well below the homopause, and Kzz, (which will generally be a function of altitude), the solar He 584 Å flux and line shape, and the atmospheric temperature profile. The main science objective discussed is the estimation of the helium mixing ratio in the lower atmosphere. Specifically, He emissions come from above the homopause where τ =1 in H2 and therefore the interpretation depends mainly on two parameters: He mixing ratio of the lower atmosphere and Kzz. The occultations of Koskinen et al (2015) give Kzz with an accuracy that has never been possible before and the combination of occultations and airglow therefore provide estimates of the mixing ratio in the lower atmosphere. We have made these estimates at several locations that can be reasonably studied with both occultations and airglow and then average the results. Our results point to a greatly improved estimate of the mixing ratio of He in the upper atmosphere and below. The second topic addressed is regarding constraining the dynamics in the atmosphere by using the estimate of the He mixing ratio from the main objective. Once we have an

  11. An observation of polar auroral and airglow from the ISIS-II spacecraft.

    NASA Technical Reports Server (NTRS)

    Shepherd, G. G.; Anger, C. D.; Brace, L. H.; Maier, E. J.; Burrows, J. R.; Heikkila, W. J.; Hoffman, J.; Whitteker, J. H.

    1973-01-01

    This is a preliminary but comprehensive report on coordinated data obtained with the ISIS-II spacecraft, fourth in the ISIS series, launched 1 April 1971, into a near circular 1400 km orbit. The capabilities of the ISIS-I spacecraft have been extended in a number of ways, including the global mapping of the 3914, 5577 and 6300 A emissions. Data obtained during a 30-min pass over the south pole depict the nightside oval and polar cap, as well as mid-latitude airglow effects; these data are described and discussed.

  12. First mesospheric wind images using the Michelson interferometer for airglow dynamics imaging.

    PubMed

    Langille, J A; Ward, W E; Nakamura, T

    2016-12-10

    The Michelson interferometer for airglow dynamics imaging (MIADI) is a ground-based instrument that combines an imaging capability with the Doppler Michelson interferometry in order to remotely detect motions in the mesopause region using spectrally isolated airglow emissions: the O(S1) emission at 557.73 nm and the OH (6, 2) P1 (2) at 839.918 nm. A measurement and analysis approach has been developed that allows simultaneous images of the line-of-sight Doppler wind field and irradiance field to be obtained. A working field instrument was installed and tested at a field site outside Fredericton, NB (45.96 N, 66.65 W) during the summer of 2014. Successful measurements over a 6 h period were obtained on 31 July 2014. This paper describes the MIADI measurement and analysis approach and presents the work that has been done to extract images of the line-of-sight Doppler wind field and irradiances from these observations. The imaging capability is validated by identifying the presence of large-scale and small-scale geophysical perturbations in the images.

  13. Variations in mesospheric gravity waves observed in multiple airglow layers, and filtered temporal spectra studies

    NASA Astrophysics Data System (ADS)

    Mangognia, T.; Swenson, G. R.; Vargas, F.

    2013-12-01

    The Andes Lidar Observatory (ALO) at Cerro Pachon, Chile (Lat= 30.25 S, Long = 70.74 W) is equipped with an all-sky OH and O(1S) airglow imager, OH temperature mapper, OH IR imager, multichannel photometer, meteor radar, and a Na wind/temperature lidar. Spectral analysis of airglow photometry data of OH Meinel (5-1),(6-2); O2 (b) (0,1); and O(1S) emissions reveals varying gravity wave periods over time. Variations in period of high frequency waves are often observed. Studies of frequency variability with the background atmospheric temperature and the effect on the Brunt-Vaisala frequency will be described. Additionally, the vertical separation of the respective layers of a few km offers information regarding wave damping and reflection as the amplitude often changes with altitude. The nature of wave damping is primarily noted to be constant with altitude as a saturated wave spectrum indicates. The correlative nature of the data provides verification of optical methods in characterizing wave attributes. These studies will be described in this presentation.

  14. The EUV Airglow of Titan: Production and Loss of N2 c'4(0) - X

    NASA Technical Reports Server (NTRS)

    Stevens, Michael H.

    2001-01-01

    The N(2) Carroll-Yoshino (CY) c'(4) X (0,0) and (0,1) Rydberg bands between 95 and 99 nm were reported to be the most prominent EUV emission features in Voyager 1 ultraviolet spectrometer (UVS) airglow spectra from Titan's atmosphere. Although c'(4) is strongly excited by photoelectron impact, the (0,0) band is optically thick near peak production, so a multiple-scattering model is employed to calculate (0,v) nadir-viewing intensities. The model accounts for all known loss processes and quantifies the redistribution of photons to (0,v is greater than 0). Results show 7.6 R of (0,1) intensity, in agreement with reported observations (5-10 R), and 0.2 R of (0,0), in spectacular disagreement with reported observations (6-10 R). Nadir-viewing intensities of all other expected NI multiplets and N2 bands in the brightest portion of the EUV airglow spectrum (92.0-101.5 nm) are also calculated using photodissociative ionization of N(2) and photoelectron impact on N(2). It is found that NI multiplets and N(2) bands near (0,0) and unresolved by the UVS combine to produce 8.3 R, consistent with that reported for (0,0) and indicating that it was misidentified in previous analyses. The Ultraviolet Imaging Spectrograph (UVIS) on Cassini should unambiguously distinguish any (0,0) intensity from the brightest features nearby.

  15. Estimating the electron energy distribution during ionospheric modification from spectrographic airglow measurements

    NASA Astrophysics Data System (ADS)

    Hysell, D. L.; Varney, R. H.; Vlasov, M. N.; Nossa, E.; Watkins, B.; Pedersen, T.; Huba, J. D.

    2012-02-01

    The electron energy distribution during an F region ionospheric modification experiment at the HAARP facility near Gakona, Alaska, is inferred from spectrographic airglow emission data. Emission lines at 630.0, 557.7, and 844.6 nm are considered along with the absence of detectable emissions at 427.8 nm. Estimating the electron energy distribution function from the airglow data is a problem in classical linear inverse theory. We describe an augmented version of the method of Backus and Gilbert which we use to invert the data. The method optimizes the model resolution, the precision of the mapping between the actual electron energy distribution and its estimate. Here, the method has also been augmented so as to limit the model prediction error. Model estimates of the suprathermal electron energy distribution versus energy and altitude are incorporated in the inverse problem formulation as representer functions. Our methodology indicates a heater-induced electron energy distribution with a broad peak near 5 eV that decreases approximately exponentially by 30 dB between 5-50 eV.

  16. Cassini UVIS observations of Titan ultraviolet airglow intensity dependence with solar zenith angle

    NASA Astrophysics Data System (ADS)

    Royer, E. M.; Ajello, J. M.; Holsclaw, G. M.; West, R. A.; Esposito, L. W.; Bradley, E. T.

    2017-01-01

    The Cassini Ultraviolet Imaging Spectrometer (UVIS) observed the airglow (dayglow and nightglow) of Titan over a range of solar zenith angles (SZA) from 14 to 150° on five separate observations obtained between 2008 and 2012. The modeling of the solar cycle normalized UVIS observations indicates that a Chapman layer function provides a satisfactory fit to the intensity of the EUV and FUV airglow molecular emissions of the N2 Lyman-Birge-Hopfield band system (LBH a1Πg→X1>∑g+), the Carroll-Yoshino band system (c4'1>∑u+→X1>∑g+), and of several atomic multiplets of nitrogen (NI, II) as a function of SZA. This result shows that the strongest contribution to the Titan dayglow occurs by processes (photoelectrons and photodissociation) involving the solar EUV flux rather than magnetospheric particle precipitation that dominates emission excitation in the nightglow.

  17. Comparison of Airglow from excited O2- and OH-molecules in the global model EMAC compared to SCIAMACHY observations

    NASA Astrophysics Data System (ADS)

    Versick, Stefan; Bender, Stefan; von Savigny, Christian; Sinnhuber, Miriam; Teiser, Georg; Vlasov, Alexey; Zarboo, Amirmahdi

    2016-04-01

    Airglow is a luminous effect mainly in the upper atmosphere (mesosphere and thermosphere). It is caused by various processes. Airglow can be used to derive minor species abundances, to diagnose dynamical phenomena or to derive chemical heating rates (Mlynzcak 1999). Here we concentrate on Airglow from excited O2- and OH-molecules. For the presented study we use the newly developed extended EMAC (3d-CTM) version which includes the thermosphere and reaches upto about 170 km. We extended the chemistry by the relevant processes for airglow. The online-coupled chemistry module MECCA is calculating the different transitions of the excited OH-molecules. In this presentation we weill concentrate on the OH(3-1) transition at a wavelength of 1540 nm. We compare the model results to SCIAMACHY observations during the sudden stratospheric warming in the northern hemisphere winter 2008/09. The model results are qualitatively in good agreement with the observations. EMAC chemistry has also been extended by two excited states of molcular oxygen: O2(1Δ) at 1270 nm and O2(1Σ) at 762 nm. We show first results of the newly developed retrieval for the 762 nm band from SCIAMACHY-observations and compare it to EMAC results.

  18. Brightness Map of the Zodiacal Emission from the AKARI IRC All-Sky Survey

    NASA Astrophysics Data System (ADS)

    Pyo, Jeonghyun; Ueno, Munetaka; Minn Kwon, Suk; Hong, Seung Soo; Ishihara, Daisuke; Ishiguro, Masateru; Usui, Fumihiko; Ootsubo, Takafumi; Mukai, Tadashi

    The Japanese infrared space mission AKARI successfully scanned the whole sky with its two main instruments, Infrared Camera (IRC) and Far-Infrared Surveyor (FIS). The AKARI All-Sky Survey provides us with an invaluable opportunity to examine the zodiacal emission (ZE) over the entire sky in both leading and trailing directions of the Earth's motion. We describe our efforts to reduce the ZE brightness map from AKARI's survey in the 9 µm waveband. The map is compared with the interplanetary dust (IPD) cloud model of Kelsall et al. (1998). From the comparison, we derived the emissivity modification factors at 9 µm for the smooth cloud, the dust bands, and the resonance ring components. The result requires to increase the contribution of the ring component to the ZE brightness by about 20%. The map of residual brightness after subtracting the model from the observation reveals three dust bands and the leading resonance blob, which are not implemented in the model. We paid special attention to the north and south ecliptic pole brightnesses. The symmetry plane's inclination and longitude of ascending node for the smooth cloud are modified from those in Kelsall et al. (1998) to make the best fit to the observed pole brightness difference. The analysis result indicates possible warping of the symmetry plane. We found that the average of the two pole brightnesses does not become the maximum at the Earth's perihelion, which is a probable evidence of the cloud's off-centering.

  19. An assessment of twilight airglow inversion procedures using atmosphere explorer observations

    NASA Technical Reports Server (NTRS)

    Mcdade, I. C.; Sharp, W. E.

    1993-01-01

    The aim of this research project was to test and truth some recently developed methods for recovering thermospheric oxygen atom densities and thermospheric temperatures from ground-based observations of the 7320 A O(+)((sup 2)D - (sup 2)P) twilight air glow emission. The research plan was to use twilight observations made by the Visible Airglow Experiment (VAE) on the Atmosphere Explorer 'E' satellite as proxy ground based twilight observations. These observations were to be processed using the twilight inversion procedures, and the recovered oxygen atom densities and thermospheric temperatures were then to be examined to see how they compared with the densities and temperatures that were measured by the Open Source Mass Spectrometer and the Neutral Atmosphere Temperature Experiment on the satellite.

  20. F region airglow - Are ground-based observations consistent with recent satellite results

    NASA Technical Reports Server (NTRS)

    Cogger, L. L.; Walker, J. C. G.; Meriwether, J. W., Jr.; Burnside, R. G.

    1980-01-01

    The Atmosphere Explorer photochemistry is used to interpret simultaneous observations made at the Arecibo Observatory of the OI (6300 A) and NI (5200 A) airglow surface brightness and electron density and temperature profiles measured by incoherent scatter radar. It was found that the theory and the experiment agree for the 5200-A emission; however, it was not possible to obtain to a complete agreement for the 6300-A nightglow. It is suggested that the source of the discrepancy results from one of the parameters used to calculate the production rate of O(lD); the data show evidence of an asymmetrical behavior of the ionosphere between times when the F layer is descending and when it is ascending, with asymmetry probably reflecting the effects of transport on molecular ion densities in the bottom side of the F region.

  1. Investigation of the night sky airglow near the epicenter of the earthquake

    NASA Astrophysics Data System (ADS)

    Didebulidze, G. G.; Fishkova, L. M.; Pataraya, A. D.; Toroshelidze, T. I.

    1990-08-01

    Some peculiarities of the upper atmosphere airglow variations according to Abastumani (USSR) observations before and after earthquakes (EQs) near the region of a major shock are given. It is shown that peculiarities of the night intensity variation of atomic oxygen OI 557.7 nm and OI 630 nm lines depend both on the EQ amplitude and region of observations. It is assumed that the reason for such variations is dissipation and dissociation of acoustic-gravitational waves in the middle and upper atmosphere, that in its turn is caused by soil shifting and lava like growth of fractures and spalling of rocks. Or the reason may consist in the periodic amplitude modulation of the high frequency seismic noise on a vast area around the center of a next arterial fracture due to an increasing tension. Based on the example of observations after the Spitak (USSR) EQ, the possibility of wind generation after the major shock is indicated.

  2. Localized polar cap precipitation in association with nonstorm time airglow patches

    NASA Astrophysics Data System (ADS)

    Zou, Ying; Nishimura, Yukitoshi; Lyons, Larry R.; Shiokawa, Kazuo

    2017-01-01

    Although airglow patches are traditionally regarded as high-density ionospheric plasma unrelated to local precipitation, past observations were limited to disturbed conditions. Recent nonstorm time observations show patches to be associated with ionospheric flow channels and localized field-aligned currents. We examine whether nonstorm time patches are related also to polar cap precipitation using Fast Auroral Snapshot-imager conjunctions. We have identified localized precipitation that is enhanced within patches in comparison to the weak polar rain outside patches. The precipitation consists of structured or diffuse soft electron fluxes. While the latter resembles polar rain only with higher fluxes, the former consists of discrete fluxes enhanced by 1-2 orders of magnitude from several to several hundred eV. Therefore, patches should be regarded as part of a localized magnetosphere-ionosphere coupling system along open magnetic field lines and their transpolar evolution as a reflection of mesoscale magnetotail lobe processes. The precipitation a minor contributor to patch ionization.

  3. The nonlinear thermodynamics of meteors, noctilucent clouds, enhanced airglow and global atmospheric circulation

    NASA Technical Reports Server (NTRS)

    Rajchl, J.

    1987-01-01

    Two types of fundamental topological junctions of elements are deduced from a nonlinear thermodynamical model. Using this scheme, the possibility of a causal relation between fireballs and faint meteors as nonlinear sources on the one hand, and noctilucent clouds (NC) and Hoffmeister's enhanced airglow (EA) as complementary formative processes in the middle atmosphere and ionosphere, on the other hand, is examined. The principal role of the global atmospheric circulation in this relation is demonstrated. Such circulation in the mesosphere appears to prevent the neutral dust dissipated by fireballs from becoming an efficient agent in NLC generation. In this case, the behavior of ionized material deposited by both the bright and faint meteors is more probably controlled, as shown from the annual variation of the E sub s layer by the darkness of lunar eclipses and the global circulation of the lower thermosphere. The role of fireballs and neutral dust might be more significant as a source of EA phenomenon.

  4. Observations of airglow during injections of exhaust streams of ``Progress'' orbital maneuvering subsystem

    NASA Astrophysics Data System (ADS)

    Beletsky, Alexandr; Mikhalev, Alexander; Khakhinov, Vitaly; Lebedev, Valentin

    Observations of airglow during injections of exhaust streams of “Progress” orbital maneuvering subsystem A. Mikhalev, V. Khakhinov, A. Beletsky, V. Lebedev Institute of Solar-Terrestrial Physics of Siberian Branch of Russian Academy of Sciences (ISTP SB RAS) 664033, Lermontov str. 126a, p/o Box 291, Irkutsk, Russia ABSTRACT The effect of increasing the intensity of airglow emissions associated with spacecraft engines exhaust to the atmosphere is well-known. We carried out the "Radar-Progress" active space experiment for studying the ionosphere on April 17 2013. The exhaust products of orbital maneuvering subsystem engines of transport spacecraft “Progress” were used as a source of ionosphere disturbances. The engines run from 13:24:37 to 13:24:46 UT. The "Progress" orbit altitude was 412 km. We carried out observations of nightglow in the several spectral lines. The all-sky camera was used for obtaining spatial distribution of the 630 nm emission intensity. An increase in the emission intensity in the area of "Progress" track was observed after starting the engines. According to preliminary estimates, the rate of the glow expansion at the orbit altitude during first 60 seconds after the start was ~ 7 km/c along the orbit and ~ 3.5 km/s across the orbit. The observed glow area reached the largest size of ~ 350 km along the orbit and ~ 250 km across the orbit 120-150 s after start. The study has been supported by the grant 13-05-00456-a and 13-02-00957-a of the Russian Foundation for Basic Research and RF President Grant of Public Support for RF Leading Scientific Schools (NSh-2942.2014.5).

  5. Post sunset behavior of the 6300 A atomic oxygen airglow emission

    NASA Technical Reports Server (NTRS)

    Smith, R. E.

    1976-01-01

    A theoretical model of the 6300 A OI airglow emission was developed based on the assumptions that both the charged and neutral portions of the Earth's upper atmosphere are in steady state conditions of diffusive equilibrium. Intensities of 6300 A OI emission line were calculated using electron density true height profiles from a standard C-4 ionosonde and exospheric temperatures derived from Fabry-Perot interferometer measurements of the Doppler broadened 6300 A emission line shape as inputs to the model. Reaction rate coefficient values, production mechanism efficiencies, solar radiation fluxes, absorption cross sections, and models of the neutral atmosphere were varied parametrically to establish a set of acceptable inputs which will consistently predict 6300 A emission intensities that closely agree with intensities observed during the post-sunset twilight period by an airglow observatory consisting of a Fabry-Perot interferometer and a turret photometer. Emission intensities that can only result from the dissociative recombination of molecular oxygen ions were observed during the latter portion of the observational period. Theoretical calculations indicate that contamination of the 6300 A OI emission should be on the order of or less than 3 percent; however, these results are very sensitive to the wavelengths of the individual lines and their intensities relative to the 6300 A OI intensity. This combination of a model atmosphere, production mechanism efficiencies, and quenching coefficient values was used when the dissociative photoexcitation and direct impact excitation processes were contributing to the intensity to establish best estimates of solar radiation fluxes in the Schumann--Runge continuum and associated absorption cross sections. Results show that the Jacchia 1971 model of the upper atmosphere combined with the Ackerman recommended solar radiation fluxes and associated absorption cross sections produces theoretically calculated intensities that more

  6. Computing uncertainties in ionosphere-airglow models: I. Electron flux and species production uncertainties for Mars

    NASA Astrophysics Data System (ADS)

    Gronoff, Guillaume; Simon Wedlund, Cyril; Mertens, Christopher J.; Lillis, Robert J.

    2012-04-01

    The ionization and excitation of atoms and molecules in the upper atmospheres of the Earth and planets are computed by a number of physical models. From these calculations, quantities measurable by dedicated satellite experiments such as airglow and electron fluxes can be derived. It is then possible to compare model and observation to derive more fundamental physical properties of the upper atmospheres, for example, the density as a function of altitude. To ensure the accuracy of these retrieval techniques, it is important to have an estimation of the uncertainty of these models and to have ways to account for these uncertainties. The complexity of kinetic models for computing the secondary production of excited state species (including ions) makes it a difficult evaluation, and studies usually neglect or underestimate it. We present here a Monte-Carlo approach to the computation of model uncertainties. As an example, we studied several aspects of the model uncertainties in the upper atmosphere of Mars, including the computed secondary electron flux and the production of the main ion species. Our simulations show the importance of improving solar flux models, especially on the energy binning and on the photon impact cross sections, which are the main sources of uncertainties on the dayside. The risk of modifying cross sections on the basis of aeronomical observations is highlighted for the case of Mars, while accurate uncertainties are shown to be crucial for the interpretation of data from the particle detectors onboard Mars Global Surveyor. Finally, it shows the importance of AtMoCiad, a public database dedicated to the evaluation of aeronomy cross section uncertainties. A detailed study of the resulting emissions cross sections uncertainties is the focus of a forthcoming paper (Gronoff et al., 2012) in which the outputs discussed in the present paper are used to compute airglow uncertainty, and the overall result is compared with the data from the SPICAM UV

  7. Hemispheric asymmetry in transition from equatorial plasma bubble to blob as deduced from 630.0 nm airglow observations at low latitudes

    NASA Astrophysics Data System (ADS)

    Park, Jaeheung; Martinis, Carlos R.; Lühr, Hermann; Pfaff, Robert F.; Kwak, Young-Sil

    2016-01-01

    Transitions from depletions to enhancements of 630.0 nm nighttime airglow have been observed at Arecibo. Numerical simulations by Krall et al. (2009) predicted that they should occur only in one hemisphere, which has not yet been confirmed observationally. In this study we investigate the hemispheric conjugacy of the depletion-to-enhancement transition using multiple instruments. We focus on one event observed in the American longitude sector on 22 December 2014: 630.0 nm airglow depletions evolved into enhancements in the Northern Hemisphere while the evolution did not occur in the conjugate location in the Southern Hemisphere. Concurrent plasma density measured by low Earth orbit (LEO) satellites and 777.4 nm airglow images support that the depletions and enhancements of 630.0 nm nighttime airglow reflect plasma density decreases and increases (blobs), respectively. Characteristics of the airglow depletions, in the context of the LEO satellite data, further suggest that the plasma density depletion deduced from the airglow data represents equatorial plasma bubbles (EPBs) rather than medium-scale traveling ionospheric disturbances from midlatitudes. Hence, the event in this study can be interpreted as EPB-to-blob transition.

  8. The Zodiacal Cloud Model applied to the Martian atmosphere. Diurnal variations in Meteoric ion layers

    NASA Astrophysics Data System (ADS)

    Diego Carrillo-Sánchez, Juan; Plane, John M. C.; Withers, Paul; Fallows, Kathryn; Nesvorný, David; Pokorný, Petr; Feng, Wuhu

    2016-04-01

    Sporadic metal layers have been detected in the Martian atmosphere by radio occultation measurements using the Mars Express Orbiter and Mars Global Surveyor spacecraft. More recently, metallic ion layers produced by the meteor storm event following the close encounter between Comet Siding Spring (C/2013 A1) and Mars were identified by the Imaging UltraViolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. However, the background metal layers produced by the influx of sporadic meteors have not yet been detected at Mars (contrary to the permanent metal layers identified in the Earth's atmosphere). The Zodiacal Dust Cloud (ZDC) model for particle populations released by asteroids (AST), and dust grains from Jupiter Family Comets (JFC) and Halley-Type Comets (HTC) has been combined with a Monte Carlo sampling method and the Chemical ABlation MODel (CABMOD) to predict the ablation rates of Na, K, Fe, Si, Mg, Ca and Al above 40 km altitude in the Martian atmosphere. CABMOD considers the standard treatment of meteor physics, including the balance of frictional heating by radiative losses and the absorption of heat energy through temperature increases, melting phase transitions and vaporization, as well as sputtering by inelastic collisions with the air molecules. These vertical profiles are input into the Leeds 1-D Mars atmospheric model which includes photo-ionization, and gas-phase ion-molecule and neutral chemistry, in order to explore the evolution of the resulting metallic ions and atoms. We conclude that the formation of the sporadic ion layers observed below 100 km with a plasma density exceeding 104 cm-3 requires the combination of the three different influx sources considered by the ZDC model, with a significant asteroidal contribution. Finally, we explore the changes of the neutral and ionized Mg and Fe layers over a diurnal cycle.

  9. A prospective observational study of quality of diabetes care in a shared care setting: trends and age differences (ZODIAC-19)

    PubMed Central

    van Hateren, Kornelis J J; Drion, Iefke; Kleefstra, Nanne; Groenier, Klaas H; Houweling, Sebastiaan T; van der Meer, Klaas; Bilo, Henk J G

    2012-01-01

    Objective The Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) study was initiated in 1998 to investigate the effects of shared care for patients with type 2 diabetes mellitus (T2DM) in the Netherlands, and to reduce the number of diabetes-related complications. Benchmarking the performance of diabetes care was and is an important aspect of this study. We aimed to investigate trends in diabetes care, within the ZODIAC study for a wide variety of quality indicators during a long follow-up period (1998–2008), with special interest for different age groups. Design Prospective observational cohort study. Setting Primary care, Zwolle, The Netherlands. Participants Patients with T2DM. Methods A dataset of quality measures was collected annually during the patient's visit to the practice nurse or general practitioner. Linear time trends from 1998 to 2008 were estimated using linear mixed models in which we adjusted for age and gender. Age was included in the model as a categorical variable: for each follow-up year all participants were categorised into the categories <60, 60–75 and >75 years. Differences in trends between the age categories were investigated by adding an interaction term to the model. Results The number of patients who were reported to participate increased in the period 1998–2008 from 1622 to 27 438. All quality indicators improved in this study, except for body mass index. The prevalence albuminuria decreased in an 11-year-period from 42% to 21%. No relevant differences between the trends for the three age categories were observed. During all years of follow-up, mean blood pressure and body mass index were the lowest and highest, respectively, in the group of patients <60 years (data not shown). Conclusions Quality of diabetes care within the Dutch ZODIAC study, a shared care project, has considerably improved in the period 1998–2008. There were no relevant differences between trends across various age categories

  10. Light

    NASA Astrophysics Data System (ADS)

    Vernon, C. G.

    2016-09-01

    Preface; 1. Historical; 2. Waves and wave-motion; 3. The behaviour of ripples; 4. The behaviour of light; 5. Refraction through glass blocks and prisms; 6. The imprinting of curvatures; 7. Simple mathematical treatment; 8. More advanced mathematical treatment; 9. The velocity of light; 10. The spectrum and colour; 11. Geometrical optics; 12. The eye and optical instruments; 13. Sources of light; 14. Interference, diffraction and polarisation; 15. Suggestions for class experiments; Index.

  11. The US Naval Observatory Zodiacal Zone Catalog (Douglas and Harrington 1990): Documentation for the machine-readable version

    NASA Technical Reports Server (NTRS)

    Warren, Wayne H., Jr.

    1990-01-01

    The machine readable version of the catalog, as it is currently being distributed from the Astronomical Data Center, is described. The Zodiacal Zone Catalog is a catalog of positions and proper motions for stars in the magnitude range where m sub v is between 4 and 10, lying within 16 deg of the ecliptic and north of declination -30 deg. The catalog contains positions and proper motions, at epoch, for equator and equinox J2000.0, magnitudes and spectral types taken mostly from the Smithsonian Astrophysical Observatory Star Catalog, and reference positions and proper motions for equinox and epoch B1950.0.

  12. Development of low-cost sky-scanning Fabry-Perot interferometers for airglow and auroral studies

    NASA Astrophysics Data System (ADS)

    Shiokawa, K.; Otsuka, Y.; Oyama, S.; Nozawa, S.; Satoh, M.; Katoh, Y.; Hamaguchi, Y.; Yamamoto, Y.; Meriwether, J.

    2012-11-01

    We have developed new Fabry-Perot interferometers (FPIs) that are designed to measure thermospheric winds and temperatures as well as mesospheric winds through the airglow/aurora emissions at wavelengths of 630.0 nm and 557.7 nm, respectively. One FPI (FP01), possessing a large aperture etalon (diameter: 116 mm), was installed at the EISCAT Tromsø site in 2009. The other FPIs, using 70-mm diameter etalons, were installed in Thailand, Indonesia, and Australia in 2010-2011 (FP02-FP04) by the Solar-Terrestrial Environment Laboratory, and in Peru (Nazca and Jicamarca) and Alaska (Poker Flat) by Clemson University. The FPIs with 70-mm etalons are low-cost compact instruments, suitable for multipoint network observations. All of these FPIs use low-noise cooled-CCD detectors with 1024 × 1024 pixels combined with a 4-stage thermoelectric cooling system that can cool the CCD temperature down to -80°C. The large incident angle (maximum: 1.3°-1.4°) to the etalon achieved by the use of multiple orders increases the throughput of the FPIs. The airglow and aurora observations at Tromsø by FP01 show wind velocities with typical random errors ranging from 2 to 13 m s-1 and from 4 to 27 m s-1 for mesosphere (557.7 nm) and thermosphere (630.0 nm) measurements, respectively. The 630.0-nm airglow observations at Shigaraki, Japan, by FP02-FP04 and by the American FPI instruments give thermospheric wind velocities with typical random errors that vary from 2 m s-1 to more than 50 m s-1 depending on airglow intensity.

  13. Mesoscale field-aligned irregularity structures (FAIs) of airglow associated with medium-scale traveling ionospheric disturbances (MSTIDs)

    NASA Astrophysics Data System (ADS)

    Sun, Longchang; Xu, Jiyao; Wang, Wenbin; Yue, Xinan; Yuan, Wei; Ning, Baiqi; Zhang, Donghe; Meneses, F. C.

    2015-11-01

    In this paper, we report the evolution (generation, amplification, and dissipation) of optically observed mesoscale field-aligned irregularity structures (FAIs) (~150 km) associated with a medium-scale traveling ionospheric disturbance (MSTID) event. There have not been observations of mesoscale FAIs of airglow before. The mesoscale FAIs were generated in an airglow-depleted front of southwestward propagating MSTIDs that were simultaneously observed by an all-sky imager, a GPS monitor, and a digisonde around Xinglong (40.4°N, 30.5° magnetic latitude), China, on 17/18 February 2012. A normalized cross-correlation method has been used to obtain the velocities of mesoscale FAIs and MSTIDs. The mesoscale FAIs had an obvious northwestward relative velocity to main-body MSTIDs (about 87.0 m/s on average). The direction of this relative velocity was roughly parallel to the depleted fronts. Furthermore, the evolution of the mesoscale FAIs was mostly controlled by the intensity of the depleted fronts. Occurred in a highly elevated ionosphere that had a total electron content depletion associated with large negative airglow perturbations (-25%), the mesoscale FAIs grew rapidly when they experienced southeastward wind, which had a speed of about 100 m/s and were measured by a Fabry-Perot interferometer. A northeastward polarization electric field within a depleted airglow front can play a controlling role in the development of the mesoscale FAIs. The electric field can significantly elevate the ionosphere and move the mesoscale FAIs northwestward by the E × B drift. The processes for the generation and development of the polarization electric field and the mesoscale FAIs, however, need further study.

  14. Helium 584 Å and H Lyman-α Airglow in Giant Planetary Atmospheres: Modeling, Observations, and Implications

    NASA Astrophysics Data System (ADS)

    Parkinson, Christopher; Esposito, Larry W.

    2016-07-01

    The atmosphere of the outer planets is mainly composed of H2 and neutral atomic helium. The study of He 584 Å and H Lyman-α brightnesses is interesting as the EUV and FUV (Extreme and Far Ultraviolet) planetary airglow have the potential to yield useful information about mixing and other important parameters in their thermospheres. Time variation, asymmetries, and polar enhancement of the airglow are also possible and analysis of the public archived NASA mission data sets (i.e. Voyager and Cassini) can help solve some of the outstanding problems associated with these phenomena. The comparison of observations with results from sophisticated photochemical and radiative transfer models can also help ameliorate unexplained differences in the dynamical processes operating within planetary upper atmospheres. Powerful analysis techniques allow us to extract information on atmospheric mixing, temperatures, and temporal changes due to the solar and seasonal cycles from the variations in distribution and intensity of airglow emissions that result. The presentation will discuss the implications of interpretations from comparison of modeling and observations in giant planetary atmospheres.

  15. Upper atmospheric processes as measured by collocated Lidar, infrasound, radiometer and airglow measurements

    NASA Astrophysics Data System (ADS)

    Le Pichon, A.; Blanc, E.; Assink, J. D.; Ceranna, L.; Pilger, C.; Ross, O.; Keckhut, P.; Hauchecorne, A.; Schmidt, C.; Bittner, M.; Wuest, S.; Rüfenacht, R.; Kaempfer, N.; Smets, P.

    2013-12-01

    To better initialize weather forecasting systems, a key challenge is to understand stratosphere-resolving climate models. The ARISE project (http://arise-project.eu/) aims to design a novel infrastructure integrating different atmospheric observation networks to accurately recover the vertical structure of the wind and temperature from the ground to the mesosphere. This network includes Lidar and mesospheric airglow observations, complemented by continuous infrasound measurements. Together with additional ground-based wind radar system, such complementary techniques help to better describe the interaction between atmospheric layers from the ground to the mesosphere and the influence of large scale waves on the atmospheric dynamics. Systematic comparisons between these observations and the ECMWF upper wind and temperature models (http://www.ecmwf.int/) have been performed at the OHP site (Haute-Provence Observatory, France). The main results are outlined below. - Systematic comparisons between Lidar soundings (NDACC, http://ndacc-lidar.org/) and ECMWF highlight differences increasing with altitude. Below 50 km altitude, differences are as large as 20°K. In average, the temperature appears to be overestimated by ~5 m/s in the stratosphere and underestimated by ~10 m/s in the mesopause. - Comparisons with collocated infrasound measurements provide additional useful integrated information about the structure of the stratospheric waveguide. Below 0.5 Hz, most infrasound signals originate from ocean swells in the North Atlantic region. As expected, since most long-range propagating signals travel in the stratospheric waveguide, improved detection capability occurs downwind. Deviations from this trend are either related to short time-scale variability of the atmosphere (e.g., large-scale planetary waves, stratospheric warming effects), or can be explained by changes in the nature of the source. We investigate possible correlation between unexpected propagation paths and

  16. Global variability of the oxygen airglow as observed by WINDII and predicted with the TIME-GCM

    NASA Astrophysics Data System (ADS)

    Liu, Guiping

    This dissertation reports on the global temporal variations of the oxygen airglow emissions from the analysis of seven years of WINDII (Wind Imaging Interferometer) satellite data. To interpret the emission signatures, the observations are compared with the simulations of NCAR's TIME-GCM general circulation model that includes atmospheric photochemistry and dynamics. The nighttime O(1S), O2( b1S+g ), and OH airglow emissions originate from the recombination of atomic oxygen, which acts as a tracer of atmospheric motions. Variations of these emissions thus provide information on wave activity and on the large-scale circulation in the mesosphere and lower thermosphere (MLT). The study focuses on the seasonal climatology of the emission rate for various latitude regions. In the tropics, a dramatic semi-annual variation exists but only for limited local times. The onset of the variation is consistent with the propagating tidal wave. At mid-latitudes, both semi-annual and annual variations occur. They are subject to local time variations, which again manifest the tidal influence. At higher latitudes, an annual behaviour becomes dominant. It may also result from upward and downward motions associated with the large-scale general circulation. However, a mid-summer peak is superimposed, indicating other influences. Further, the long-term trend variation is examined. The emissions at all latitudes follow the variation of F10.7 flux and are in phase with the solar cycle. They also have a two-year period variation that may be caused by the quasi-biennial oscillation. All these emission variations could be ultimately explained in terms of vertical motion. Vertical motion is observed directly as a universal inverse relationship of the airglow emission rate and emission altitude. Finally, the anomalous WINDII airglow profiles with multiple peaks are investigated. Their occurrences coincide with steep emission rate gradients associated with the diurnal tide. Moreover, the

  17. Localized field-aligned currents in the polar cap associated with airglow patches

    NASA Astrophysics Data System (ADS)

    Zou, Ying; Nishimura, Yukitoshi; Burchill, Johnathan K.; Knudsen, David J.; Lyons, Larry R.; Shiokawa, Kazuo; Buchert, Stephan; Chen, Steve; Nicolls, Michael J.; Ruohoniemi, J. Michael; McWilliams, Kathryn A.; Nishitani, Nozomu

    2016-10-01

    Airglow patches have been recently associated with channels of enhanced antisunward ionospheric flows propagating across the polar cap from the dayside to nightside auroral ovals. However, how these flows maintain their localized nature without diffusing away remains unsolved. We examine whether patches and collocated flows are associated with localized field-aligned currents (FACs) in the polar cap by using coordinated observations of the Swarm spacecraft, a polar cap all-sky imager, and Super Dual Auroral Radar Network (SuperDARN) radars. We commonly (66% of cases) identify substantial FAC enhancements around patches, particularly near the patches' leading edge and center, in contrast to what is seen in the otherwise quiet polar cap. These FACs have densities of 0.1-0.2 μA/m-2 and have a distribution of width peaking at 75 km. They can be approximated as infinite current sheets that are orientated roughly parallel to patches. They usually exhibit a Region 1 sense, i.e., a downward FAC lying eastward of an upward FAC. With the addition of Resolute Bay Incoherent Scatter radar data, we find that the FACs can close through Pedersen currents in the ionosphere, consistent with the locally enhanced dawn-dusk electric field across the patch. Our results suggest that ionospheric polar cap flow channels are imposed by structures in the magnetospheric lobe via FACs, and thus manifest mesoscale magnetosphere-ionosphere coupling embedded in large-scale convection.

  18. Gravity wave characteristics in the mesopause region revealed from OH airglow imager observations over Northern Colorado

    NASA Astrophysics Data System (ADS)

    Tang, Yihuan; Dou, Xiankang; Li, Tao; Nakamura, Takuji; Xue, Xianghui; Huang, Can; Manson, Alan; Meek, Chris; Thorsen, Denise; Avery, Susan

    2014-01-01

    Using 5 years of all-sky OH airglow imager data over Yucca Ridge Field Station, CO (40.7°N, 104.9°W), from September 2003 to September 2008, we extract and deduce quasi-monochromatic gravity wave (GW) characteristics in the mesopause region. The intrinsic periods are clustered between approximately 4 and 10 min, and many of them are unstable and evanescent. GW occurrence frequency exhibits a clear semiannual variation with equinoctial minima, which is likely related to the seasonal variation of background wind. The anomalous propagation direction in January 2006, with strong southward before major warming starting in 21 January and weak southward propagation afterward, was most likely affected by stratospheric sudden warming. The momentum fluxes show strongly anticorrelated with the tides, with ~180° out of phase in the zonal component. While in the meridional component, the easterly maximum occurred approximately 2-6 h after maximum easterly tidal wind. However, the anticorrelations are both weakest during the summer. The dissipating and breaking of small-scale and high-frequency GW's components could have a potential impact on the general circulation in the mesopause region.

  19. A Climatology of Ripple Instabilities in the OH Airglow at Cerro Pachon, Chile

    NASA Astrophysics Data System (ADS)

    Gelinas, L. J.; Hecht, J. H.; Walterscheid, R. L.; Rudy, R. J.

    2015-12-01

    Airglow imaging provides a unique means by which to study many wave-related phenomena in the 80 to 100 km altitude regime. Observations reveal quasi-monochromatic disturbances associated with atmospheric gravity waves (AGWs) as well as small-scale instabilities often called ripples. Ripples are wavelike features that resemble AGWs in appearance, but have short horizontal wavelengths (<15 km) and short lifetimes (a few tens of minutes). The end product of the breakdown of ripples is turbulence, leading to increased eddy diffusion. Thus, ripple observations may help refine our understanding of the occurrence of turbulence in the upper Mesosphere and Lower Thermosphere. The Aerospace Corporation's Nightglow Imager (ANI) is located at the Andes Lidar Observatory near the crest of Cerro Pachon, Chile. ANI observes nighttime OH emission (near 1.6 microns) every 2 seconds over an approximate 73 degree field of view, which allows the study of AGW and ripple features over very short temporal and spatial scales. An automated wave detection algorithm is used to identify ripple and quasi monochromatic wave features in the ANI data. Ripples are characterized by their wavelength, orientation, drift speed and location in the image. Quasi-monochromatic waves are quantified by wavelength, wave period and propagation direction. We present a climatology of ripple instabilities at Chile, including comparisons to the background quasi-monochromatic wave field. Lidar and radar data are used to determine the background wind and temperatures, which allows comparisons between ripple observations and evanescent regions and potentially unstable regions identified by Richardson number.

  20. Solar measurements from the Airglow-Solar Spectrometer Instrument (ASSI) on the San Marco 5 satellite

    NASA Technical Reports Server (NTRS)

    Woods, Thomas N.

    1994-01-01

    The analysis of the solar spectral irradiance from the Airglow-Solar Spectrometer Instrument (ASSI) on the San Marco 5 satellite is the focus for this research grant. A pre-print copy of the paper describing the calibrations of and results from the San Marco ASSI is attached to this report. The calibration of the ASSI included (1) transfer of photometric calibration from a rocket experiment and the Solar Mesosphere Explorer (SME), (2) use of the on-board radioactive calibration sources, (3) validation of the ASSI sensitivity over its field of view, and (4) determining the degradation of the spectrometers. We have determined that the absolute values for the solar irradiance needs adjustment in the current proxy models of the solar UV irradiance, and the amount of solar variability from the proxy models are in reasonable agreement with the ASSI measurements. This research grant also has supported the development of a new solar EUV irradiance proxy model. We expected that the magnetic flux is responsible for most of the heating, via Alfen waves, in the chromosphere, transition region, and corona. From examining time series of solar irradiance data and magnetic fields at different levels, we did indeed find that the chromospheric emissions correlate best with the large magnetic field levels.

  1. Case study of convective instability observed in airglow images over the Northeast of Brazil

    NASA Astrophysics Data System (ADS)

    Carvalho, A. J. A.; Paulino, I.; Medeiros, A. F.; Lima, L. M.; Buriti, R. A.; Paulino, A. R.; Wrasse, C. M.; Takahashi, H.

    2017-02-01

    An intense activity of ripples during the nighttime was observed in airglow images over São João do Cariri (36.5° W, 7.4° S) on 10 October 2004 which lasted for two hours. Those ripples appeared simultaneously with the crossing of a mesospheric front and medium scale gravity waves. The ripples occurred ahead of the mesospheric front and their phase front were almost parallel to the phase of the mesospheric front and were almost perpendicular to the phase front of the gravity wave. Using wind measurements from a meteor radar located at São João do Cariri and simultaneous vertical temperature profiles from the TIMED/SABER satellite, on the night of the events and within the imager field of view, the atmospheric background environment in the mesosphere and lower thermosphere (MLT) was investigated in order to understand the instability process that caused the appearance of the ripples. Dynamic and convective instabilities have been pointed out as responsible for creation of ripples in the MLT. The observed ripples were advected by the neutral wind, they occurred into a region with negative lapse rate of the potential temperature and the Richardson number was negative as well. According to these characteristics, the ripple structures could be generated in the MLT region due to the predominance of convective instability.

  2. New approach of gravity wave detection in mesopause temperatures operating an array of airglow spectrometers

    NASA Astrophysics Data System (ADS)

    Wachter, Paul; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael

    2014-05-01

    GRIPS (Ground based Infrared P-branch Spectrometer) airglow measurements allow the derivation of kinetic temperature in the mesopause region averaged over a field of view of some 10km x 10km. In 2011, three identical GRIPS instruments were setup at Oberpfaffenhofen (11.28°E, 48.09°N), Germany, in a way that their fields of view form an equilateral triangle shape in the mesopause with a horizontal dimension of approximately 70km. Using this setup, GRIPS time series cannot only be analyzed with respect to gravity wave periods, but also spatial wave parameters can be derived. Based on the results of the harmonic analysis the horizontal wavelength, phase speed and the direction of propagation were determined for gravity wave events from February to July 2011. We present distinct relationships between periods, amplitudes, phase speeds and wavelengths, which were identified in this dataset. Further data analysis of the derived wave parameters show preferred directions of propagation and suggest seasonal variations of the wave characteristics. The presentation will be concluded by the introduction of a measurement setup relying on one GRIPS instrument which is equipped with a variably adjustable mirror optic. The capability to scan multiple fields of view during nightly measurements will offer longer-term investigations of mesopause gravity waves.

  3. Analysis of excitation of the 630.0 nm airglow during a heating experiment in Tromsø on February 16, 1999

    NASA Astrophysics Data System (ADS)

    Sergienko, T.; Gustavsson, B.; Steen, Å.; Brändström, U.; Rietveld, M.; Leyser, T. B.; Honary, F.

    During an ionospheric heating experiment in Tromsø during February 1999, artificial 630.0 nm airglow enhancements have been observed by the auroral large imaging system (ALIS). The airglow enhancements took place in the F region of the ionosphere near the heating wave reflection point. Two possible mechanisms are proposed for the explanation of this phenomenon. The first is the excitation of the O(1D) state by the energetic electrons from the tail of the artificially heated thermal electron gas, and the second is the excitation of this state by the plasma instability accelerated electrons. The detailed spatial and temporal characteristics of the red line airglow are obtained from the ALIS measurements. An analysis of these characteristics based on the models of thermal response of the ionosphere and the atmospheric optical emissions allows us to draw conclusions about the mechanism of the interaction between the heating radio wave and the ionospheric plasma.

  4. Concentric Gravity Waves over Northern China Observed by a No-Gap OH Airglow Imager Network and Satellites

    NASA Astrophysics Data System (ADS)

    Xu, J.; Li, Q.; Yue, J.; Hoffmann, L.; Straka, W. C.; Miller, S. D.; Yuan, W.; Liu, X.

    2015-12-01

    The first no-gap OH airglow all-sky imager network in the world was established in northern China in February 2012. The network is composed of 6 all-sky airglow imagers that make observations of OH airglow gravity waves and cover an area of about 2000 km east and west and about 1400 km south and north. A comparison of the observations in 2012, 2013, and 2014 are made, which shows that there were more strong thunderstorms take place in 2013 in the northern China and produce more Concentric Gravity Wave (CGW) events. Especially, a series of CGW events were observed by the network nearly every night during the first half of August 2013. These events were also observed by satellite sensors from FY-2, AIRS/Aqua, and VIIRS/Suomi NPP. Combination of the ground imager network with satellites provides multi-level observations of the CGWs from the stratosphere to the mesopause region. In this talk, two representative CGW events in August 2013 are studied in detail and movies of the two events are displayed. One is the CGW on the night of 13 August 2013, likely launched by a single thunderstorm. The temporal and spatial analyses indicate that the CGW horizontal wavelengths agree with the GW dispersion relation within 300 km from the storm center. A gravity wave with horizontal wavelength of about 20 km propagates horizontally to more than 800 km in the mesopause region, probably due to a ducting layer. Another CGW event was induced by two very strong thunderstorms on 09 August 2013. Multi-scale waves with horizontal wavelengths ranging from less than 10 km to 200 km were observed. Many ripples were found, probably due to the breaking of strong gravity waves with large relative OH intensity perturbations of 10%.

  5. Near infrared spectrometric airglow measurements during the total solar eclipse of 26 February 1979. Final report, 2 February 1972-31 July 1980

    SciTech Connect

    Pendleton, W.R. Jr.; Baker, D.J.; Steed, A.J.

    1981-01-15

    Spectrometric airglow measurements during the solar eclipse of 26 February 1979 have yielded first-of-a-kind residual airglow spectra during the total phase of the eclipse. The temporal variations of the O2 infrared atmospheric features and the He multiplet at 1.083 microns are consistent with current excitation/emission models; however, the OH Meinel emission levels decreased almost monotonically by totality, in contrast with expectations based on most code predictions. Twilight transition, nightglow and auroral data were also acquired to characterize airflow conditions during the general timeframe of the eclipse. The twilight-transition results compare favorably with similar earlier measurement by other investigators.

  6. Characteristics of mesospheric gravity waves measured by an OH airglow imager at Qujing, China

    NASA Astrophysics Data System (ADS)

    Li, Qinzeng; Chen, Jinsong; Yuan, Wei; Yue, Jia; Liu, Xiao; Xu, Jiyao; Liu, Mohan

    An all-sky imager was installed at Qujing (25.6ºN, 103.7ºE) to investigate the characteristics of mesospheric gravity waves over the Yunnan-Guizhou Plateau. Using OH airglow images from November 2011 to October 2013, we detected 332 events of gravity waves. Along with the collocated meteor radar wind measurements and mean temperature data from SABER instrument onboard the TIMED satellite, the propagation condition (freely propagating, ducted, or evanescent) of these gravity waves was estimated. Most gravity waves exhibited ducted and evanescent behavior. About 20% of the events are freely propagating waves. We analyzed the sources in the lower atmosphere for these freely propagating gravity waves using ray tracing analysis. Statistical analysis shows a clear relation between mesospheric gravity wave activity and jet streams around Yunnan-Guizhou-Tibet Plateau. We also investigate the statistical features of all observed gravity waves. The propagation directions of the gravity waves show a strong northeastward preference in summer, while almost all gravity waves propagate southeastward in winter. The gravity waves propagation directions in winter are significantly different from other observations at northern middle latitudes, such as Xinglong(40.2ºN,117.4ºE), Shigaraki(34.9ºN,136.1 ºE), Urbana IL(40ºN, 80ºW). They all found the gravity waves presented southwestward propagation directions in winter. The horizontal wavelengths of observed gravity waves are typically from 10 to 35 km, the vertical wavelengths from 10 to 30 km, the observed periods from 4 to 8 min and the observed horizontal phase speeds of 30 to 90 m/s. The intrinsic periods are mainly in the range of 4-8 min. The intrinsic phase speeds are mainly in the range of 40-100 m/s. The wind filtering in the middle atmosphere plays a role in controlling the propagation directions of the gravity waves.

  7. Spatial gravity wave characteristics obtained from multiple OH(3-1) airglow temperature time series

    NASA Astrophysics Data System (ADS)

    Wachter, Paul; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael

    2015-12-01

    We present a new approach for the detection of gravity waves in OH-airglow observations at the measurement site Oberpfaffenhofen (11.27°E, 48.08°N), Germany. The measurements were performed at the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) during the period from February 4th, 2011 to July 6th, 2011. In this case study the observations were carried out by three identical Ground-based Infrared P-branch Spectrometers (GRIPS). These instruments provide OH(3-1) rotational temperature time series, which enable spatio-temporal investigations of gravity wave characteristics in the mesopause region. The instruments were aligned in such a way that their fields of view (FOV) formed an equilateral triangle in the OH-emission layer at a height of 87 km. The Harmonic Analysis is applied in order to identify joint temperature oscillations in the three individual datasets. Dependent on the specific gravity wave activity in a single night, it is possible to detect up to four different wave patterns with this method. The values obtained for the waves' periods and phases are then used to derive further parameters, such as horizontal wavelength, phase velocity and the direction of propagation. We identify systematic relationships between periods and amplitudes as well as between periods and horizontal wavelengths. A predominant propagation direction towards the East and North-North-East characterizes the waves during the observation period. There are also indications of seasonal effects in the temporal development of the horizontal wavelength and the phase velocity. During late winter and early spring the derived horizontal wavelengths and the phase velocities are smaller than in the subsequent period from early April to July 2011.

  8. Periodic waves in the lower thermosphere observed by OI630 nm airglow images

    NASA Astrophysics Data System (ADS)

    Paulino, I.; Medeiros, A. F.; Vadas, S. L.; Wrasse, C. M.; Takahashi, H.; Buriti, R. A.; Leite, D.; Filgueira, S.; Bageston, J. V.; Sobral, J. H. A.; Gobbi, D.

    2016-02-01

    Periodic wave structures in the thermosphere have been observed at São João do Cariri (geographic coordinates: 36.5° W, 7.4° S; geomagnetic coordinates based on IGRF model to 2015: 35.8° E, 0.48° N) from September 2000 to November 2010 using OI630.0 nm airglow images. During this period, which corresponds to almost one solar cycle, characteristics of 98 waves were studied. Similarities between the characteristics of these events and observations at other places around the world were noted, primarily the spectral parameters. The observed periods were mostly found between 10 and 35 min; horizontal wavelengths ranged from 100 to 200 km, and phase speed from 30 to 180 m s-1. These parameters indicated that some of the waves, presented here, are slightly faster than those observed previously at low and middle latitudes (Indonesia, Carib and Japan), indicating that the characteristics of these waves may change at different places. Most of observed waves have appeared during magnetically quiet nights, and the occurrence of those waves followed the solar activity. Another important characteristic is the quasi-monochromatic periodicity that distinguish them from the single-front medium-scale traveling ionospheric disturbances (MSTIDs) that have been observed previously over the Brazilian region. Moreover, most of the observed waves did not present a phase front parallel to the northeast-southwest direction, which is predicted by the Perkins instability process. It strongly suggests that most of these waves must have had different generation mechanisms from the Perkins instability, which have been pointed out as being a very important mechanism for the generation of MSTIDs in the lower thermosphere.

  9. Lighting

    SciTech Connect

    Audin, L.

    1994-12-31

    EPAct covers a vast territory beyond lighting and, like all legislation, also contains numerous {open_quotes}favors,{close_quotes} compromises, and even some sleight-of-hand. Tucked away under Title XIX, for example, is an increase from 20% to 28% tax on gambling winnings, effective January 1, 1993 - apparently as a way to help pay for new spending listed elsewhere in the bill. Overall, it is a landmark piece of legislation, about a decade overdue. It remains to be seen how the Federal Government will enforce upgrading of state (or even their own) energy codes. There is no mention of funding for {open_quotes}energy police{close_quotes} in EPAct. Merely creating such a national standard, however, provides a target for those who sincerely wish to create an energy-efficient future.

  10. The Mesospheric OH* layer above Spitsbergen: Investigation of polar mesospheric dynamics and temperature trends by means of ground based OH* airglow measurements and model studies

    NASA Astrophysics Data System (ADS)

    Kowalewski, S.; Palm, M.; Notholt, J.

    2012-04-01

    The hydroxyl (OH*) emission layer is one of the dominant features of the mesopause region. It is primarily formed via the reaction of ozone and atomic hydrogen, which results in vibrationally excited OH* radicals. Due to radiative deexcitation, these radicals contribute to the airglow, which we can observe at different emission bands. For low excitation levels (ν≤6) of OH*, its lifetime can be sufficient to become thermalized by collision with the surrounding molecules, hence its emission can serve as a measure of ambient temperature. Because of the remoteness of the mesosphere, this offers a valuable source of information on mesospheric temperatures. While satellite based observations of the OH* layer offer comprehensive data sets on global scales, the spatial as well as the temporal resolution is limited by the corresponding orbits. Ground based measurements can fill this gap and enable us to study mesospheric disturbances at shorter time scales. Particularly the polar mesospheric region can be subject to large variability, which becomes apparent in the brightness and temperature signals from the OH* emission layer. In this poster we present temperatures derived from measurements taken from a Fourier Transform Spectrometer (FTS), which is located at the AWIPEV Arctic Research Base in Ny-Ålesund, Spitsbergen (79°). Measurements are available since 2007 and cover various emission bands of OH* in the spectral region from 5900 cm^-1 to 6500 cm^-1. We illustrate large scale polar mesospheric warming events, which have a striking impact on mesospheric dynamics and the coupling to the lower atmosphere. In addition to satellite based observations that we compare with our data, we illustrate the ability of our instrument to resolve short term perturbations. We discuss how we will combine these observations to model studies, in order to shed more light on the associated polar mesospheric dynamics in an upcoming analyis.

  11. Tidal influence on O(1S) airglow emission rate distributions at the geographic equator as observed by WINDII

    NASA Technical Reports Server (NTRS)

    Shephere, G. G.; Mclandress, C.; Solheim, B. H.

    1995-01-01

    WINDII, the Wind Imaging Interferometer on the Upper Atmosphere Research Satellite, observes winds, temperatures and emission rates in the upper mesosphere and thermosphere. In this paper we report on nighttime observations of the vertical distribution of the O(1S) 557.7 nm emission near the geographic equator for March/April, 1993. The airglow volume emission rate distribution is found to be strongly dependent on local time. Beginning at dusk, an intense airglow emission layer descends from a mean altitude of 95 km, reaching 89 km by midnight after which the emission rapidly decays. Shortly after midnight it reappears weakly at a higher altitude and remains at this level as the emission rate gradually increases towards dawn. This strong local time dependence leads us to conclude that the effect is tidally driven. Comparison with the Forbes (1982a,b) model suggest that total density perturbations and changes in the atomic oxygen mixing ratio may the cause of the changes in emission rate distribution between dusk and midnight. The reappearance of the emission after midnight may be caused by downward winds bringing oxygen-rich air from above.

  12. Atmospheric Gravity Wave Properties for TOMEX as Observed With Na wind/temperature Lidar and Airglow Instrumentation From Albuquerque, NM

    NASA Astrophysics Data System (ADS)

    Li, F.; Tang, J.; Liu, A.; Swenson, G.; Gardner, C.

    2002-12-01

    On the night of October 26, 2000, the TOMEX sounding rocket was launched from White Sands rocket range ~5 hours after sunset. Na lidar, airglow imagers, and a Michelson interferometer observed the perturbations in the mesosphere. In addition, the Na lidar measured the winds which were applied to the observed motion field from which intrinsic wave speeds were resolved. The extracted wave field from combined lidar and airglow observations included waves with periods of 5 hours, 1.5 hours, and 13 minutes present for the period leading to, and during the rocket launch. The vertical structures of the 13-minute and 1.5-hour period waves were determined primarily by the thermal structure, which was characterized by a small Brunt-Vaisala frequency between 90 km and 92 km with a strong gradient above and below. The 5-hour period waves exhibited a standing wave pattern, indicative of strong wave reflection in the mesopause region. In addition to the intrinsic wave parameters, the vertical flux of horizontal momentum and acceleration rate as a function of altitude was calculated for each of the waves. Momentum fluxes and accelerations were dominated by contributions from the 13-minute period waves.

  13. OI 630.0 nm Night Airglow Observations during the Geomagnetic Storm on November 20, 2003 at Kolhapur (P43)

    NASA Astrophysics Data System (ADS)

    Sharma, A. K.; et al.

    2006-11-01

    sharma_ashokkumar@yahoo.com The ground based photometric observations of OI 630 nm emission line have been carried out from Kolhapur station (Geog. Lat.16.8˚N, Geo. Long 74.2˚E), India during the period of the largest geomagnetic storm of the solar cycle 23 which occurred on 20 November 2003, with minimum Dst index 472 nT occurring around mid-night hours. We observed that on 19 November 2003 which was geomagnetically quiet day, the airglow activity of OI 630 nm emission was subdued and it was decreasing monotonically. However, on the night of November 20, 2003 the enhancement is observed during geomagnetic storm due to the increased electron density at the altitude of the F region which is related to the downward transport of electron from the plasmasphere to the F-region. Airglow intensity at OI 630.0 nm showed increase around midnight on November 21, 2003 but comparatively on a smaller scale. On this night the DST index was about 100 nT. This implies that the effect of the geomagnetic storm persisted on that night also. These observations have been explained by the penetration magnetospheric electric field to the low latitude region and the subsequent modulation of meridional wind during the magnetic disturbance at night.

  14. Spatial and Temporal Stability of Airglow Measured in the Meinel Band Window at 1191.3 nm

    NASA Astrophysics Data System (ADS)

    Nguyen, Hien T.; Zemcov, Michael; Battle, John; Bock, James J.; Hristov, Viktor; Korngut, Phillip; Meek, Andrew

    2016-09-01

    We report on the temporal and spatial fluctuations in the atmospheric brightness in the narrow band between Meinel emission lines at 1191.3 nm using a λ/Δλ = 320 near-infrared instrument. We present the instrument design and implementation, followed by a detailed analysis of data taken over the course of a night from Table Mountain Observatory. At low airmasses, the absolute sky brightness at this wavelength is found to be 5330 ± 30 nW m-2 sr-1, consistent with previous measurements of the inter-band airglow at these wavelengths. This amplitude is larger than simple models of the continuum component of the airglow emission at these wavelengths, confirming that an extra emissive or scattering component is required to explain the observations. We perform a detailed investigation of the noise properties of the data and find no evidence for a noise component associated with temporal instability in the inter-line continuum. This result demonstrates that in several hours of ˜100 s integrations the noise performance of the instrument does not appear to significantly degrade from expectations, giving a proof of concept that near-infrared line intensity mapping may be feasible from ground-based sites.

  15. Airglow in the Visible and Infrared Spectral Ranges of the Disturbed Upper Atmosphere under Conditions of High-Velocity Plasma Jet Injection: I. Experimental data

    NASA Astrophysics Data System (ADS)

    Zetzer, J. I.; Kozlov, S. I.; Rybakov, V. A.; Ponomarenko, A. V.; Smirnova, N. V.; Romanovsky, Yu. A.; Meng, C.-I.; Erlandson, R.; Stoyanov, B.

    2002-05-01

    The measurements of infrared emission from an artificial structure, which was generated during the Fluxus experiment with plasma jet injection into the atmosphere, are obtained and discussed for the first time. Additional experimental data on the airglow in the visible spectral band of the disturbed region of the atmosphere are presented. A generalized analysis of the data is given.

  16. High-resolution observations of small-scale gravity waves and turbulence features in the OH airglow layer

    NASA Astrophysics Data System (ADS)

    Sedlak, René; Hannawald, Patrick; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael

    2016-12-01

    A new version of the Fast Airglow Imager (FAIM) for the detection of atmospheric waves in the OH airglow layer has been set up at the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) at Oberpfaffenhofen (48.09° N, 11.28° E), Germany. The spatial resolution of the instrument is 17 m pixel-1 in zenith direction with a field of view (FOV) of 11.1 km × 9.0 km at the OH layer height of ca. 87 km. Since November 2015, the system has been in operation in two different setups (zenith angles 46 and 0°) with a temporal resolution of 2.5 to 2.8 s. In a first case study we present observations of two small wave-like features that might be attributed to gravity wave instabilities. In order to spectrally analyse harmonic structures even on small spatial scales down to 550 m horizontal wavelength, we made use of the maximum entropy method (MEM) since this method exhibits an excellent wavelength resolution. MEM further allows analysing relatively short data series, which considerably helps to reduce problems such as stationarity of the underlying data series from a statistical point of view. We present an observation of the subsequent decay of well-organized wave fronts into eddies, which we tentatively interpret in terms of an indication for the onset of turbulence. Another remarkable event which demonstrates the technical capabilities of the instrument was observed during the night of 4-5 April 2016. It reveals the disintegration of a rather homogenous brightness variation into several filaments moving in different directions and with different speeds. It resembles the formation of a vortex with a horizontal axis of rotation likely related to a vertical wind shear. This case shows a notable similarity to what is expected from theoretical modelling of Kelvin-Helmholtz instabilities (KHIs). The comparatively high spatial resolution of the presented new version of the FAIM provides new insights into the structure of atmospheric wave instability and

  17. Atmospheric entry survival of large micrometeorites: Implications for their sources and for the cometary contribution to the zodiacal cloud

    NASA Technical Reports Server (NTRS)

    Flynn, George J.

    1992-01-01

    Atmospheric entry heating simulations indicate that a large fraction of the micrometeorites larger than 100 microns in diameter which survive atmospheric entry must have entered the Earth's atmosphere with velocities very near the Earth's escape velocity. Thus, these particles must have been captured by Earth from heliocentric orbits with small eccentricities and low inclinations, indicating a main-belt asteroidal source. Space exposure ages measured on these large micrometeorites are also consistent with a main-belt asteroidal source. However, dynamical calculations have previously indicated that particles larger than 100 microns in diameter were likely to be destroyed by catastrophic collisions in the time required for orbital evolution from the main-belt to Earth capture by Poynting-Robertson drag. The absence of a large amount of collisional debris in the less than 50 microns size range indicates these large micrometeorites are not the few, rare survivors of a mostly collisionally disrupted population. The measured space exposure ages, which are about an order of magnitude larger than their calculated catastrophic collision lifetimes, confirm the survival of these large micrometeorites for times much longer than the calculated catastrophic collision lifetimes. Since collisions with cometary dust less than 20 microns in size were expected to be the major contributor to the collisional destruction of these larger particles, the contribution of cometary material to the zodiacal cloud is likely to be much smaller than previously believed.

  18. Atmospheric entry survival of large micrometeorites: Implications for their sources and for the cometary contribution to the zodiacal cloud

    NASA Astrophysics Data System (ADS)

    Flynn, George J.

    1992-12-01

    Atmospheric entry heating simulations indicate that a large fraction of the micrometeorites larger than 100 microns in diameter which survive atmospheric entry must have entered the Earth's atmosphere with velocities very near the Earth's escape velocity. Thus, these particles must have been captured by Earth from heliocentric orbits with small eccentricities and low inclinations, indicating a main-belt asteroidal source. Space exposure ages measured on these large micrometeorites are also consistent with a main-belt asteroidal source. However, dynamical calculations have previously indicated that particles larger than 100 microns in diameter were likely to be destroyed by catastrophic collisions in the time required for orbital evolution from the main-belt to Earth capture by Poynting-Robertson drag. The absence of a large amount of collisional debris in the less than 50 microns size range indicates these large micrometeorites are not the few, rare survivors of a mostly collisionally disrupted population. The measured space exposure ages, which are about an order of magnitude larger than their calculated catastrophic collision lifetimes, confirm the survival of these large micrometeorites for times much longer than the calculated catastrophic collision lifetimes. Since collisions with cometary dust less than 20 microns in size were expected to be the major contributor to the collisional destruction of these larger particles, the contribution of cometary material to the zodiacal cloud is likely to be much smaller than previously believed.

  19. Solar Energy Deposition Rates in the Mesosphere Derived from Airglow Measurements: Implications for the Ozone Model Deficit Problem

    NASA Technical Reports Server (NTRS)

    Mlynczak, Martin G.; Garcia, Rolando R.; Roble, Raymond G.; Hagan, Maura

    2000-01-01

    We derive rates of energy deposition in the mesosphere due to the absorption of solar ultraviolet radiation by ozone. The rates are derived directly from measurements of the 1.27-microns oxygen dayglow emission, independent of knowledge of the ozone abundance, the ozone absorption cross sections, and the ultraviolet solar irradiance in the ozone Hartley band. Fifty-six months of airglow data taken between 1982 and 1986 by the near-infrared spectrometer on the Solar-Mesosphere Explorer satellite are analyzed. The energy deposition rates exhibit altitude-dependent annual and semi-annual variations. We also find a positive correlation between temperatures and energy deposition rates near 90 km at low latitudes. This correlation is largely due to the semiannual oscillation in temperature and ozone and is consistent with model calculations. There is also a suggestion of possible tidal enhancement of this correlation based on recent theoretical and observational analyses. The airglow-derived rates of energy deposition are then compared with those computed by multidimensional numerical models. The observed and modeled deposition rates typically agree to within 20%. This agreement in energy deposition rates implies the same agreement exists between measured and modeled ozone volume mixing ratios in the mesosphere. Only in the upper mesosphere at midlatitudes during winter do we derive energy deposition rates (and hence ozone mixing ratios) consistently and significantly larger than the model calculations. This result is contrary to previous studies that have shown a large model deficit in the ozone abundance throughout the mesosphere. The climatology of solar energy deposition and heating presented in this paper is available to the community at the Middle Atmosphere Energy Budget Project web site at http://heat-budget.gats-inc.com.

  20. Space borne photometry perturbations from solar light scatterd by debris

    NASA Astrophysics Data System (ADS)

    Mandeville, Jean-Claude; Perrin, Jean-Marie; Vuillemin, André

    2001-10-01

    We study the possible impairment of the solar light scattered by small debris, measured by high photometric quality instrument, during space borne observations. We compute the contribution of the fragments released on orbit by the host satellite and of the debris already present in the background. Preliminary results show that these spurious fluxes can reach the level of the collected Zodiacal Light: there are the main components of the noise level which affect the scientific signal. On the future, threats on high sensitivity photometric missions should rise with the increasing launches of satellite constellations if no legislation controls the design of satellites.

  1. Zodiacal Exoplanets in Time (ZEIT). IV. Seven Transiting Planets in the Praesepe Cluster

    NASA Astrophysics Data System (ADS)

    Mann, Andrew W.; Gaidos, Eric; Vanderburg, Andrew; Rizzuto, Aaron C.; Ansdell, Megan; Medina, Jennifer Vanessa; Mace, Gregory N.; Kraus, Adam L.; Sokal, Kimberly R.

    2017-02-01

    Open clusters and young stellar associations are attractive sites to search for planets and to test theories of planet formation, migration, and evolution. We present our search for, and characterization of, transiting planets in the 800 Myr old Praesepe (Beehive, M44) Cluster from K2 light curves. We identify seven planet candidates, six of which we statistically validate to be real planets, the last of which requires more data. For each host star, we obtain high-resolution NIR spectra to measure its projected rotational broadening and radial velocity, the latter of which we use to confirm cluster membership. We combine low-resolution spectra with the known cluster distance and metallicity to provide precise temperatures, masses, radii, and luminosities for the host stars. Combining our measurements of rotational broadening, rotation periods, and our derived stellar radii, we show that all planetary orbits are consistent with alignment to their host star’s rotation. We fit the K2 light curves, including priors on stellar density to put constraints on the planetary eccentricities, all of which are consistent with zero. The difference between the number of planets found in Praesepe and Hyades (8 planets, ≃ 800 Myr) and a similar data set for Pleiades (0 planets, ≃125 Myr) suggests a trend with age, but may be due to incompleteness of current search pipelines for younger, faster-rotating stars. We see increasing evidence that some planets continue to lose atmosphere past 800 Myr, as now two planets at this age have radii significantly larger than their older counterparts from Kepler.

  2. Preliminary observations and simulation of nocturnal variations of airglow temperature and emission rates at Pune (18.5°N), India

    NASA Astrophysics Data System (ADS)

    Fadnavis, S.; Feng, W.; Shepherd, Gordon G.; Plane, J. M. C.; Sonbawne, S.; Roy, Chaitri; Dhomse, S.; Ghude, S. D.

    2016-11-01

    Preliminary observations of the nocturnal variations of the OH(6-2) and O2b(0-1) nighttime airglow in the mesosphere and lower thermosphere are investigated in the context of tidal influence for the tropical latitude station Pune (18.5°N, 73.85°E). This is the only tropical Spectral Airglow Temperature Imager (SATI) station where the tidal variations of mesosphere and lower thermosphere (MLT) temperature have been determined from ground based SATI observations. The SATI observations obtained since October 2012 reveal the influence of the migrating semidiurnal tides during solstice at this tropical station. There is variability in amplitude and phase obtained from SATI observations. In this paper, SATI observations on 10 Dec 2012 and 3 March 2013 are compared with Whole Atmosphere Community Climate Model (WACCM) simulations. The amplitude of semidiurnal tides is 25 K/30 K on 10 Dec 2012 during solstice for OH/O2 temperature. During equinox SATI data indicates existence of semidiurnal tide also. The airglow observations are compared with simulations from the WACCM. The model underestimates the amplitude of the semi diurnal tide during equinox (1.6 K/2.7 K at 87 km/96 km) and solstice ( 3.8 K/4.8 K at 87 km/96 km) for these days. The reason may be related to dampening of tides in the model due to the effect of strong latitudinal shear in zonal wind. The diurnal variation of airglow emission - which the model simulates well - is related to the vertical advection associated with the tides and downward mixing of atomic oxygen.

  3. Spaced sensor measurements of artificial airglow emission at 630 nm of ionosphere caused by ``Sura'' facility radiation in November 2013

    NASA Astrophysics Data System (ADS)

    Nasyrov, Igor; Grach, Savely; Gumerov, Rustam; Shindin, Alexey; Kogogin, Denis; Dementiev, Vladislav

    Some first results on simultaneous observation artificial airglow emission at 630 nm during HF pumping of the ionosphere by “Sura” facility from two spatial situated experimental sites are reported. The measurements of artificial airglow are usually conducted in red and green lines of atomic oxygen (the radiation of levels O((1) D) and O((1) S) under their excitation by electronic impact) with wave lengths of 630 and 557.7 nm and excitation energy of 1.96 and 4.17 eV accordingly. An enhancement of airglow intensity in the red line is related at present to the electron heating by powerful radio waves. The idea of the experiment was to estimate the heated volume three-dimensional structure and drift motion one. The experiment was carried out in November 2013 at the “Sura” radio facility, situated near Nizhny Novgorod, Russia (geographical coordinates 56.13(o) N, 46.10(o) E, geomagnetic field declination and inclination are ˜ 10.0(o) east and ˜ 71.5(o) , respectively). Conditions of ionosphere were checked by means of "Cady" ionosonde during “Sura” runs. According to the ionospheric conditions, on the 7(th) of November the “Sura” facility operated at frequency 4.540 MHz. At this frequency the effective radiated power was about 120MW. The HF beam width at the “Sura” facility is ˜ 12(o) . A square wave pump modulation of 5 min on, 5 min off, was used. Measurements were carried out in the period from 14:40 to 17:30 UTC. Optical imaging was performed on two spatial experimental sites: “Vasilsursk” (situated about 500 m from antenna system of “Sura” facility); “Raifa” (situated about 170 km from “Sura” facility at the Magnetic Observatory of Kazan Federal University, geographical coordinates 55.93(o) N, 48.75(o) E). They both were fitted out Peltier-cooled front-illuminated bare CCD cameras with 16-bit slow-scan read-out (S1C3). On “Vasilsursk” site the images were binned down to 256× 256 pixels in addition to cooling, in order

  4. Climatology of the O+ temperatures over Arecibo for the historical deep solar minimum using Incoherent Scatter Radar and airglow data.

    NASA Astrophysics Data System (ADS)

    Santos, P. T.; Brum, C. G. M.; Kerr, R.; Noto, J.

    2014-12-01

    At Arecibo Observatory (AO) a comprehensive description of the ionosphere and thermosphere environment is achieved by the synergy between the Incoherent Scatter Radar (ISR) and the optical instruments nested on site. An example of this synergy is present in his work where optical and radar techniques were reconciled in order to obtain the O+ temperature variability for 2008 and 2009. During this period, a historical deep solar minimum condition was registered with a remarkable absence of sunspots for a long period (translated into a decreasing in the EUV-UV irradiance). This particular feature implies in an important tool to investigate the variability of O+ temperature, once that any variation can be related to season (modulated by the neutral atmosphere) and/or another modulator different than solar energy input. The OII 7320 Å twilight airglow data used in this work were obtained during new moon periods using a high-spectral resolution Fabry-Perot Interferometer (FPI) with CCD array detection. The FPI was configured with 0.9 cm plate spacing, which produced a free spectral range of 0.298Å and a spectral resolution of 0.03Å, sufficient to sample line width temperatures as low as 500K. A very narrow 3Å Full Width at Half Maximum (FWHM) three-cavity interference filter was also used.

  5. Statistical analysis of nighttime medium-scale traveling ionospheric disturbances using airglow images and GPS observations over central China

    NASA Astrophysics Data System (ADS)

    Huang, Fuqing; Dou, Xiankang; Lei, Jiuhou; Lin, Jian; Ding, Feng; Zhong, Jiahao

    2016-09-01

    Statistical analyses were conducted to investigate the nighttime medium-scale traveling ionospheric disturbances (MSTIDs) for the first time by using airglow images and Global Positioning System (GPS) data over central China during 2013-2015. Our results show that the phase fronts of perturbations are aligned from northwest to southeast direction and propagate toward the southwest direction. The characteristics of the nighttime MSTIDs observed by OI 630.0 nm images are consistent with those of the nighttime MSTIDs obtained from the GPS data. The phase velocity, period, wavelength, and amplitude of nighttime MSTIDs are 50-150 m/s, 0.5-1.5 h, 150-400 km, and 2%-15%, respectively, as measured from 630.0 nm images and GPS data. In addition, we utilized the simultaneous observations from OI 630.0 nm and OI 557.7 nm images to explore the relationship between nighttime MSTIDs and gravity waves (<100 km) in the mesopause. It is found that the nighttime MSTIDs frequently occurred in the summer solstice, which was not consistent with the occurrence of gravity wave observed in the mesopause. Our results indicate that the nighttime MSTIDs may be generated by the coupling of electrodynamic processes rather than be trigged by gravity waves from the lower atmosphere.

  6. Numerical modeling of a multiscale gravity wave event and its airglow signatures over Mount Cook, New Zealand, during the DEEPWAVE campaign

    NASA Astrophysics Data System (ADS)

    Heale, C. J.; Bossert, K.; Snively, J. B.; Fritts, D. C.; Pautet, P.-D.; Taylor, M. J.

    2017-01-01

    A 2-D nonlinear compressible model is used to simulate a large-amplitude, multiscale mountain wave event over Mount Cook, NZ, observed as part of the Deep Propagating Gravity Wave Experiment (DEEPWAVE) campaign and to investigate its observable signatures in the hydroxyl (OH) layer. The campaign observed the presence of a λx=200 km mountain wave as part of the 22nd research flight with amplitudes of >20 K in the upper stratosphere that decayed rapidly at airglow heights. Advanced Mesospheric Temperature Mapper (AMTM) showed the presence of small-scale (25-28 km) waves within the warm phase of the large mountain wave. The simulation results show rapid breaking above 70 km altitude, with the preferential formation of almost-stationary vortical instabilities within the warm phase front of the mountain wave. An OH airglow model is used to identify the presence of small-scale wave-like structures generated in situ by the breaking of the mountain wave that are consistent with those seen in the observations. While it is easy to interpret these feature as waves in OH airglow data, a considerable fraction of the features are in fact instabilities and vortex structures. Simulations suggest that a combination of a large westward perturbation velocity and shear, in combination with strong perturbation temperature gradients, causes both dynamic and convective instability conditions to be met particularly where the wave wind is maximized and the temperature gradient is simultaneously minimized. This leads to the inevitable breaking and subsequent generation of smaller-scale waves and instabilities which appear most prominent within the warm phase front of the mountain wave.

  7. Coordinated airglow observations between IMAP/VISI and a ground-based all-sky imager on concentric gravity wave in the mesopause

    NASA Astrophysics Data System (ADS)

    Perwitasari, S.; Sakanoi, T.; Yamazaki, A.; Otsuka, Y.; Hozumi, Y.; Akiya, Y.; Saito, A.; Shiokawa, K.; Kawamura, S.

    2015-11-01

    We present a study of concentric gravity waves (CGWs) event from the coordinated observation between Ionosphere, Mesosphere, upper Atmosphere, and Plasmasphere mapping (IMAP)/Visible and near-Infrared Spectral Imager (VISI), all-sky camera at Rikubetsu, Multi-functional Transport Satellite (MTSAT), Tropical Rainfall Measuring Mission, and MF radar at Wakkanai combined with Modern-Era Retrospective Analysis for Research and Application data. IMAP/VISI is the first space-based imager that capable of imaging the airglow in the mesosphere and lower thermosphere region in the nadir-looking direction. Therefore, it has a unique ability to observe a great extend of CGWs propagation. Arc-like shaped, part of CGWs pattern was observed around the mesopause (~95 km) in the O2 762 nm airglow emission obtained by IMAP/VISI at 1204 UT on 18 October 2012. Similar patterns were also observed by the all-sky imager at Rikubetsu (43.5°N, 143.8°E) in OI 557.7 nm and OH band airglow emissions from ~1100 to 1200 UT. Horizontal wavelengths of the observed small-scale gravity waves are ~50 km (OH band and OI 557.7 nm) and ~67 km (O2 762 nm). The source is suggested to be a deep convective activity over Honshu Island which likely was an enhanced convective activity related to a typhoon in the south of Japan. The data showed that the CGWs could propagate up to ~1400-1500 km horizontally from the source to the mesopause but not farther away. Using atmospheric temperature profiles obtained by Thermospheric Ionosphere Mesosphere Energetics Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry, we conclude that this long-distance propagation of the waves could be caused by thermal duct in the middle atmosphere. The arc-like shaped instead of full circle pattern points out that the wind filtering effect is significant for the particular direction of wave propagation.

  8. Gravity waves in mesopause region induced by thunderstorms over Northern China observed by a no-gap OH airglow imager network

    NASA Astrophysics Data System (ADS)

    Xu, Jiyao

    2016-07-01

    A no-gap OH airglow all-sky imager network was established in northern China in February 2012. The network is composed of 6 all-sky airglow imagers that make observations of OH airglow gravity waves and cover an area of about 2000 km east and west and about 1400 km south and north. A large number of gravity wave events in the mesopause region induced by thunderstorms were observed by the network during the past 4 years. A comparison of the observations in 2012, 2013, and 2014 are made, which shows that there were more strong thunderstorms take place in 2013 in the northern China and produce more Concentric Gravity Wave (CGW) events. Especially, a series of CGW events were observed by the network nearly every night during the first half of August 2013. These events were also observed by satellite sensors from FY-2, AIRS/Aqua, and VIIRS/Suomi NPP. Combination of the ground imager network with satellites provides multi-level observations of the CGWs from the stratosphere to the mesopause region. In this talk, two representative CGW events in August 2013 are studied in detail and movies of the two events are displayed. One is the CGW on the night of 13 August 2013, likely launched by a single thunderstorm. The temporal and spatial analyses indicate that the CGW horizontal wavelengths agree with the GW dispersion relation within 300 km from the storm center. A gravity wave with horizontal wavelength of about 20 km propagates horizontally to more than 800 km in the mesopause region, probably due to a ducting layer. Another CGW event was induced by two very strong thunderstorms on 09 August 2013. Multi-scale waves with horizontal wavelengths ranging from less than 10 km to 200 km were observed. Many ripples were found, probably due to the breaking of strong gravity waves with large relative OH intensity perturbations of 10%.

  9. An atmospheric radiation model for the Very Large Telescope at Cerro Paranal in Chile

    NASA Astrophysics Data System (ADS)

    Noll, S.; Kausch, W.; Barden, M.; Jones, A. M.; Szyszka, C.; Kimeswenger, S.

    2012-04-01

    The quality of ground-based astronomical observations is strongly affected by scattering, absorption, and radiation processes in the Earth's atmosphere. For effective telescope time management, it is important to accurately estimate the wavelength-dependent contribution of the Earth's atmosphere to the observed flux. For this reason we developed an atmospheric radiation model for the Very Large Telescope of the European Southern Observatory at Cerro Paranal in the Atacama desert. It is comprised of all relevant components, i.e. scattered moonlight, scattered starlight, zodiacal light, molecular radiation and absorption in the lower atmosphere, and airglow line and continuum emission in the upper atmosphere. The model covers the entire wavelength range from the near-UV to the mid-IR. Thermal radiation and absorption in the lower atmosphere are computed applying the LBLRTM radiative transfer code and suitable time-averaged atmospheric profiles for the telescope site. Scattered light from extended sources, such as zodiacal light and airglow, is estimated by 3D single scattering calculations and a multiple scattering correction. The intensity and variability of airglow emission lines and continuum is derived by a semi-empirical model based on more than 1000 high signal-to-noise spectra of the FORS1 instrument taken over six years. A comparison of the resulting combined model with observed data yields an accuracy of about 20 per cent, which is a significant improvement over previous models.

  10. Traveling planetary wave activity from mesopause region airglow temperatures determined by the Network for the Detection of Mesospheric Change (NDMC)

    NASA Astrophysics Data System (ADS)

    Reisin, E. R.; Scheer, J.; Dyrland, M. E.; Sigernes, F.; Deehr, C. S.; Schmidt, C.; Höppner, K.; Bittner, M.; Ammosov, P. P.; Gavrilyeva, G. A.; Stegman, J.; Perminov, V. I.; Semenov, A. I.; Knieling, P.; Koppmann, R.; Shiokawa, K.; Lowe, R. P.; López-González, M. J.; Rodríguez, E.; Zhao, Y.; Taylor, M. J.; Buriti, R. A.; Espy, P. J.; French, W. J. R.; Eichmann, K.-U.; Burrows, J. P.; von Savigny, C.

    2014-11-01

    The global distribution of traveling planetary wave (PW) activity in the mesopause region is estimated for the first time from ground-based airglow measurements. Monthly and total mean climatologies of PW power are determined from rotational temperatures measured at 19 sites from 78° N to 76° S which contribute to the Network for the Detection of Mesospheric Change (NDMC). Wave power is expressed as the standard deviation of nocturnal mean temperature around the seasonal temperature variation. The results from 20° N confirm the SABER traveling PW proxy by Offermann et al. (2009, J. Geophys. Res. 114, D06110) at two altitudes. Most sites between 69° S and 69° N show total mean traveling PW activity of about 6 K, and only some high latitude sites have considerably higher activity levels. At the two tropical sites, there is practically no seasonal variation of PW activity. At 70% of the midlatitude sites, the seasonal variation is moderate for most of the year, but it is quite appreciable at all high latitude sites. Results about traveling PW activity at 87 km and 95 km available from several sites signal similar behavior at both altitudes. The total mean climatological results here obtained have further been used to separate the traveling PW contribution from the superposition of wave types contained in OH rotational temperature fluctuations measured by the SCIAMACHY instrument on Envisat. A narrow equatorial wave activity maximum is probably caused by gravity waves, while a tendency towards greater activity at higher northern latitudes may be due to stationary planetary waves.

  11. The N_2 c_4'-X (0,v") Airglow on Titan: What is Required to fit the UVS Observations?

    NASA Astrophysics Data System (ADS)

    Stevens, M. H.

    1999-09-01

    The N_2 Carroll-Yoshino (CY) c_4'(1Sigma_u ^+-X^1Sigma_g ^+) (0,0) and (0,1) Rydberg bands between 95 and 99 nm were observed to be the most prominent N_2 emission features in Voyager 1 Ultraviolet Spectrometer (UVS) airglow spectra of Titan. In order to study both the observed bright limb peak and the observed variation of CY(0,v") over the sunlit disk, a radiative transfer model is employed which considers both photoelectron excitation and magnetospheric particle precipitation. The resonant (0,0) band is known to be optically thick so multiple scattering and all known loss processes to the CY(0,v") system are included. Results show that only 23-33% of c_4'(0) source excitation appears in (0,0)+(0,1), primarily due to the effects of predissociation compounded over multiple scatterings. Such loss rules out photoelectrons as the only source and requires a flux of 1 keV magnetospheric electrons that is between 0.02-0.04 erg/cm(2) s to fit the disk observations. The relative variation of (0,0)+(0,1) over the sunlit disk can be explained by the variation of solar zenith angle (SZA) specific to each observation. Lower SZAs place photoelectron excitation at lower altitudes where (0,1) optical depths are greater, yielding less emission. The magnitude of the UVS bright limb peak can be accounted for with the same input fluxes, after taking into account the lower incidence angle of precipitating electrons.

  12. Gravity Wave Energetics Determined From Coincident Space-Based and Ground-Based Observations of Airglow Emissions

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Significant progress was made toward the goals of this proposal in a number of areas during the covered period. Section 5.1 contains a copy of the originally proposed schedule. The tasks listed below have been accomplished: (1) Construction of space-based observing geometry gravity wave model. This model has been described in detail in the paper accompanying this report (Section 5.2). It can simulate the observing geometry of both ground-based, and orbital instruments allowing comparisons to be made between them. (2) Comparisons of relative emission intensity, temperatures, and Krassovsky's ratio for space- and ground-based observing geometries. These quantities are used in gravity wave literature to describe the effects of the waves on the airglow. (3) Rejection of Bates [1992], and Copeland [1994] chemistries for gravity wave modeling purposes. Excessive 02(A(sup 13)(Delta)) production led to overproduction of O2(b(sup 1)(Sigma)), the state responsible for the emission of O2. Atmospheric band. Attempts were made to correct for this behavior, but could not adequately compensate for this. (4) Rejection of MSX dataset due to lack of coincident data, and resolution necessary to characterize the waves. A careful search to identify coincident data revealed only four instances, with only one of those providing usable data. Two high latitude overpasses and were contaminated by auroral emissions. Of the remaining two mid-latitude coincidences, one overflight was obscured by cloud, leaving only one ten minute segment of usable data. Aside from the statistical difficulties involved in comparing measurements taken in this short period, the instrument lacks the necessary resolution to determine the vertical wavelength of the gravity wave. This means that the wave cannot be uniquely characterized from space with this dataset. Since no observed wave can be uniquely identified, model comparisons are not possible.

  13. A statistical analysis of equatorial plasma bubble structures based on an all-sky airglow imager network in China

    NASA Astrophysics Data System (ADS)

    Sun, Longchang; Xu, Jiyao; Wang, Wenbin; Yuan, Wei; Li, Qinzeng; Jiang, Chaowei

    2016-11-01

    This paper investigates the statistical features of equatorial plasma bubbles (EPBs) using airglow images from 2012 to 2014 from a ground-based network of four imagers in the equatorial region of China. It is found that (1) EPBs mainly occur during 21:00-00:00 local time (LT) in equinoxes. There is an asymmetry in occurrence rates between March (June) and September equinoxes (December solstices). (2) Most EPBs occur in groups of two to six depletions. The distance between adjacent EPB depletions is 100-700 km, and the average is 200-300 km. The zonal extension of an EPB group is usually less than 1500 km but can reach 3000 km. (3) EPBs usually have a maximum drift velocity near 100 m/s at 21:00-22:00 LT in 9.5° ± 1.5° geomagnetic latitude and then decrease to 50-70 m/s toward sunrise. (4) The averaged westward tilt angle of most EPBs (with respect to the geographic north-south) increased from 5°-10° to 23°-30° with LT between 20:00 and 03:00 LT, then decreasing to 10°-20° toward sunrise. (5) When 90 < F10.7 < 140, the maximum magnetic latitudinal extension (PMLE) is usually lower than 15.0° (apex height 725 km), but it can reach 23.0° (apex height 1330 km) when F10.7 > 140. The maximum PMLE increases by 3.4°-5.5° when F10.7 changes from 90 to 190. (6) The EPB occurrence patterns and zonal drift velocities are significantly different from those at Kolhapur, India, which locates west to our stations by 20.0°-32.0° in longitude.

  14. Seasonal variations of the nighttime O(1S) and OH (8-3) airglow intensity at Adelaide, Australia

    NASA Astrophysics Data System (ADS)

    Reid, Iain M.; Spargo, Andrew J.; Woithe, Jonathan M.

    2014-06-01

    We analyze 15 years of atomic oxygen (OI) 558 nm and hydroxyl (OH) (8-3) 730 nm nightglow emission intensities from heights near 96 and 87 km, respectively, measured using filter photometers at the Buckland Park Field Station (34.6°S, 138.6°E) near Adelaide, Australia. The intensity of both emissions exhibits clear seasonal and interannual periodicities, with annual, semiannual, and quasi-biennial oscillations, as well as a solar cycle influence. In addition, there is a terannual and 4.1 year component in the OI airglow intensity and both a quasi-biennial and quasi-triennial oscillation in the OH intensity. The results are in very good agreement with simultaneous collocated measurements made with an imager, and with global satellite climatologies of OI and OH intensities reported for the Wind Imaging Interferometer instrument. The mean value of the OI annual oscillation intensity is the same as that of the semiannual oscillation at this location to within the experimental uncertainty. The OI annual oscillation maximizes in summer, and the semiannual oscillation maximizes in autumn and spring, with the largest maximum in autumn. The terannual component in the OI nightglow maximizes in early summer, autumn, and spring. The quasi-biennial oscillation in the OI nightglow takes its first maximum value in autumn 1996, and the 4.1 year period in this emission first maximizes in summer 1998. The OH annual and semiannual oscillation intensities also agree to within the experimental uncertainties and are observed to peak in early winter. The quasi-biennial and quasi-triennial oscillations in this emission take their first maximum value in summer 1996.

  15. Studying the Fine Structure and Temporal Variations of the Zodiacal Cloud and Asteroidal Dust Bands Using the 3-Year Near-IR COBE-DIRBE Data

    NASA Technical Reports Server (NTRS)

    Jayaraman, Sumita

    1999-01-01

    The report presents the results of the data analyses of the DIRBE-COBE data set to study the structure of the zodiacal cloud in the near-infrared wavebands at 1.2, 2.2, and 3.4 microns. The cloud has been divided into two components which have been analyzed and studied separately. The annual variation of the flux in the smooth or low frequency component has been measured in all three bands and the presence of any asymmetries due to the Earth's resonant ring have been studied. The high frequency component which primarily consisted of the asteroidal dust bands. Extensive and careful co-addition was done to extract the central bands in all three wavebands. The ten-degree bands are present in the 1.2 and 2.2 microns but not in the 3.4 micron waveband.

  16. James Webb Space Telescope stray light performance status update

    NASA Astrophysics Data System (ADS)

    Lightsey, Paul A.; Wei, Zongying

    2012-09-01

    The James Webb Space Telescope (JWST) is a large space based astronomical telescope that will operate at cryogenic temperatures. The architecture has the telescope exposed to space, with a large sun shield providing thermal isolation and protection from direct illumination from the sun. The instruments will have the capability to observe over a spectral range from 0.6 µm to 28 µm wavelengths. The following paper will present updated stray light analysis results characterizing the stray light getting to the instrument focal planes from the full galactic sky, zodiacal background, bright objects near the line of sight, and scattered earth and moon shine. Included is a discussion of internal alignments of pupils at relevant interface planes to stray light. The amount of self-generated infrared background from the Observatory that reaches the instrument focal planes will be presented including the tolerance to the alignment of the edges of the sun shield membranes relative to each other and the telescope.

  17. THE TRANSIT LIGHT CURVE OF AN EXOZODIACAL DUST CLOUD

    SciTech Connect

    Stark, Christopher C.

    2011-10-15

    Planets embedded within debris disks gravitationally perturb nearby dust and can create clumpy, azimuthally asymmetric circumstellar ring structures that rotate in lock with the planet. The Earth creates one such structure in the solar zodiacal dust cloud. In an edge-on system, the dust 'clumps' periodically pass in front of the star as the planet orbits, occulting and forward-scattering starlight. In this paper, we predict the shape and magnitude of the corresponding transit signal. To do so, we model the dust distributions of collisional, steady-state exozodiacal clouds perturbed by planetary companions. We examine disks with dusty ring structures formed by the planet's resonant trapping of in-spiraling dust for a range of planet masses and semi-major axes, dust properties, and disk masses. We synthesize edge-on images of these models and calculate the transit signatures of the resonant ring structures. The transit light curves created by dusty resonant ring structures typically exhibit two broad transit minima that lead and trail the planetary transit. We find that Jupiter-mass planets embedded within disks hundreds of times denser than our zodiacal cloud can create resonant ring structures with transit depths up to {approx}10{sup -4}, possibly detectable with Kepler. Resonant rings produced by planets more or less massive than Jupiter produce smaller transit depths. Observations of these transit signals may provide upper limits on the degree of asymmetry in exozodiacal clouds.

  18. Primary results from the Berkeley EUV airglow rocket spectrometer: O I and N2 FUV/EUV dayglow in the thermosphere and lower exosphere

    NASA Technical Reports Server (NTRS)

    Cotton, Daniel M.; Chakrabarti, Supriya; Gladstone, G. Randall

    1993-01-01

    The Berkeley extreme-ultraviolet airglow rocket spectrometer (BEARS) made spectroscopic measurements of far and extreme UV, atomic oxygen emissions from a Black Brandt XII (12.041 WT) sounding rocket launched from Wallops Island, Virginia, on September 30, 1988. BEARS' primary instrument, a near-normal Rowland mount spectrometer, measured several atomix oxygen and molecular nitrogen dayglow features at high spectral resolution (1.5 A): O I (989, 1027, 1304, and 1356 A); and N2 Lyman-Birge-Hopfield (4, 0) and (3, 0) bands at 1325 and 1354 A. The instrument collected over 800 s of data spanning altitudes of 150 - 963 km with look directions between 95 deg and 125 deg from zenith. We have analyzed the data using electrons and radiative transport models in a forward modeling approach. The model and data are generally in good agreement. However, there are some discrepancies, which are discussed in terms of remote sensing capabilities and improvements to the models.

  19. Radar detectability studies of slow and small Zodiacal Dust Cloud Particles: I. The case of Arecibo 430 MHz meteor head echo observations

    PubMed Central

    Janches, D.; Plane, J.M.C.; Nesvorný, D.; Feng, W.; Vokrouhlický, D.; Nicolls, M.J.

    2016-01-01

    Recent model development of the Zodiacal Dust Cloud (ZDC) model (Nesvorný et al. 2010, 2011b) argue that the incoming flux of meteoric material into the Earth’s upper atmosphere is mostly undetected by radars because they cannot detect small extraterrestrial particles entering the atmosphere at low velocities due to the relatively small production of electrons. In this paper we present a new methodology utilizing meteor head echo radar observations that aims to constrain the ZDC physical model by ground-based measurements. In particular, for this work, we focus on Arecibo 430 MHz observations since this is the most sensitive radar utilized for this type of observations to date. For this, we integrate and employ existing comprehensive models of meteoroid ablation, ionization and radar detection to enable accurate interpretation of radar observations and show that reasonable agreement in the hourly rates is found between model predictions and Arecibo observations when: 1) we invoke the lower limit of the model predicted flux (~16 t/d) and 2) we estimate the ionization probability of ablating metal atoms using laboratory measurements of the ionization cross sections of high speed metal atom beams, resulting in values up to two orders of magnitude lower than the extensively utilized figure reported by Jones (1997) for low speeds meteors. However, even at this lower limit the model over predicts the slow portion of the Arecibo radial velocity distributions by a factor of 3, suggesting the model requires some revision. PMID:27642186

  20. The properties of large particles in the zodiacal cloud and in the interstellar medium, and their relation to recent IRAS observations

    NASA Astrophysics Data System (ADS)

    Hoyle, F.; Wickramasinghe, N. C.

    1984-12-01

    To explain the scattering of sunlight observed from the F-corona and from the zodiac, the scattering particles must have radii of order 15 microns, and must have an imaginary component of the refractive index that requires the presence of from 5 to 10 percent of free carbon. The particles, therefore, have a composition very like the material of C 1-carbonaceous chondrites and like extraterrestrial particles which have been recovered from the high atmosphere. Such particles absorb sunlight, the absorbed solar energy being reradiated in the infrared with a close approximation to black-body emission, even a far into the infrared as 100 microns, a deduction in good agreement with observations by Hauser et al., (1984) from the IRAS satellite. The IRAS observations at high-ecliptic latitudes require similar particles to be present in large quantity in the interstellar medium, about 10 to the 6th solar masses or more of them. The presence of such a quantity of material with properties very like the material of the C 1-carbonaceous chondrites is a remarkable outcome of the IRAS observations and is likely to have profound implications in many directions.

  1. Radar Detectability Studies of Slow and Small Zodiacal Dust Cloud Particles: I. The Case of Arecibo 430 MHz Meteor Head Echo Observations

    NASA Technical Reports Server (NTRS)

    Janches, D.; Plane, J. M. C.; Nesvorny, D.; Feng, W.; Vokrouhlicky, D.; Nicolls, M. J.

    2014-01-01

    Recent model development of the Zodiacal Dust Cloud (ZDC) model (Nesvorny et al. 2010, 2011b) argue that the incoming flux of meteoric material into the Earth's upper atmosphere is mostly undetected by radars because they cannot detect small extraterrestrial particles entering the atmosphere at low velocities due to the relatively small production of electrons. In this paper we present a new methodology utilizing meteor head echo radar observations that aims to constrain the ZDC physical model by ground-based measurements. In particular, for this work, we focus on Arecibo 430 MHz observations since this is the most sensitive radar utilized for this type of observations to date. For this, we integrate and employ existing comprehensive models of meteoroid ablation, ionization and radar detection to enable accurate interpretation of radar observations and show that reasonable agreement in the hourly rates is found between model predictions and Arecibo observations when: 1) we invoke the lower limit of the model predicted flux (approximately 16 t/d) and 2) we estimate the ionization probability of ablating metal atoms using laboratory measurements of the ionization cross sections of high speed metal atom beams, resulting in values up to two orders of magnitude lower than the extensively utilized figure reported by Jones (1997) for low speeds meteors. However, even at this lower limit the model over predicts the slow portion of the Arecibo radial velocity distributions by a factor of 3, suggesting the model requires some revision.

  2. Radar detectability studies of slow and small Zodiacal Dust Cloud Particles: I. The case of Arecibo 430 MHz meteor head echo observations.

    PubMed

    Janches, D; Plane, J M C; Nesvorný, D; Feng, W; Vokrouhlický, D; Nicolls, M J

    2014-11-20

    Recent model development of the Zodiacal Dust Cloud (ZDC) model (Nesvorný et al. 2010, 2011b) argue that the incoming flux of meteoric material into the Earth's upper atmosphere is mostly undetected by radars because they cannot detect small extraterrestrial particles entering the atmosphere at low velocities due to the relatively small production of electrons. In this paper we present a new methodology utilizing meteor head echo radar observations that aims to constrain the ZDC physical model by ground-based measurements. In particular, for this work, we focus on Arecibo 430 MHz observations since this is the most sensitive radar utilized for this type of observations to date. For this, we integrate and employ existing comprehensive models of meteoroid ablation, ionization and radar detection to enable accurate interpretation of radar observations and show that reasonable agreement in the hourly rates is found between model predictions and Arecibo observations when: 1) we invoke the lower limit of the model predicted flux (~16 t/d) and 2) we estimate the ionization probability of ablating metal atoms using laboratory measurements of the ionization cross sections of high speed metal atom beams, resulting in values up to two orders of magnitude lower than the extensively utilized figure reported by Jones (1997) for low speeds meteors. However, even at this lower limit the model over predicts the slow portion of the Arecibo radial velocity distributions by a factor of 3, suggesting the model requires some revision.

  3. Radar detectability studies of slow and small zodiacal dust cloud particles. I. The case of Arecibo 430 MHz meteor head echo observations

    SciTech Connect

    Janches, D.; Nesvorný, D.; Vokrouhlický, D.; Nicolls, M. J. E-mail: j.m.c.plane@leeds.ac.uk E-mail: davidn@boulder.swri.edu E-mail: Michael.Nicolls@sri.com

    2014-11-20

    Recent model development of the Zodiacal Dust Cloud (ZDC) argues that the incoming flux of meteoric material into the Earth's upper atmosphere is mostly undetected by radars because they cannot detect small extraterrestrial particles entering the atmosphere at low velocities due to the relatively small production of electrons. In this paper, we present a new methodology utilizing meteor head echo radar observations that aims to constrain the ZDC physical model by ground-based measurements. In particular, for this work, we focus on Arecibo 430 MHz observations since this is the most sensitive radar utilized for this type of observations to date. For this, we integrate and employ existing comprehensive models of meteoroid ablation, ionization, and radar detection to enable accurate interpretation of radar observations and show that reasonable agreement in the hourly rates is found between model predictions and Arecibo observations when (1) we invoke the lower limit of the model predicted flux (∼16 t d{sup –1}) and (2) we estimate the ionization probability of ablating metal atoms using laboratory measurements of the ionization cross sections of high-speed metal atom beams, resulting in values up to two orders of magnitude lower than the extensively utilized figure reported by Jones for low-speed meteors. However, even at this lower limit, the model overpredicts the slow portion of the Arecibo radial velocity distributions by a factor of three, suggesting that the model requires some revision.

  4. REANALYSIS OF THE NEAR-INFRARED EXTRAGALACTIC BACKGROUND LIGHT BASED ON THE IRTS OBSERVATIONS

    SciTech Connect

    Matsumoto, T.; Kim, M. G.; Pyo, J.; Tsumura, K.

    2015-07-01

    We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 μm, the result is fairly consistent with the recent observation with AKARI. We also perform the same analysis using a different ZL model by Wright and detect residual isotropic emission that is slightly lower than that based on the original Kelsall model. Both models show residual isotropic emission that is significantly brighter than the integrated light of galaxies.

  5. Zodiacal exoplanets in time (ZEIT) - II. A `super-Earth' orbiting a young K dwarf in the Pleiades Neighbourhood

    NASA Astrophysics Data System (ADS)

    Gaidos, E.; Mann, A. W.; Rizzuto, A.; Nofi, L.; Mace, G.; Vanderburg, A.; Feiden, G.; Narita, N.; Takeda, Y.; Esposito, T. M.; De Rosa, R. J.; Ansdell, M.; Hirano, T.; Graham, J. R.; Kraus, A.; Jaffe, D.

    2017-01-01

    We describe a `super-Earth'-size (2.30 ± 0.16 R⊕) planet transiting an early K-type dwarf star in the Campaign 4 field observed by the K2 mission. The host star, EPIC 210363145, was identified as a candidate member of the approximately 120 Myr-old Pleiades cluster based on its kinematics and photometric distance. It is rotationally variable and exhibits near-ultraviolet emission consistent with a Pleiades age, but its rotational period is ≈20 d and its spectrum contains no Hα emission nor the Li I absorption expected of Pleiades K dwarfs. Instead, the star is probably an interloper that is unaffiliated with the cluster, but younger (≲1.3 Gyr) than the typical field dwarf. We ruled out a false positive transit signal produced by confusion with a background eclipsing binary by adaptive optics imaging and a statistical calculation. Doppler radial velocity measurements limit the companion mass to <2 times that of Jupiter. Screening of the light curves of 1014 potential Pleiades candidate stars uncovered no additional planets. An injection-and-recovery experiment using the K2 Pleiades light curves with simulated planets, assuming a planet population like that in the Kepler prime field, predicts only 0.8-1.8 detections (versus ˜20 in an equivalent Kepler sample). The absence of Pleiades planet detections can be attributed to the much shorter monitoring time of K2 (80 d versus 4 yr), increased measurement noise due to spacecraft motion, and the intrinsic noisiness of the stars.

  6. Modelling UV sky for future UV missions

    NASA Astrophysics Data System (ADS)

    Sreejith, A. G.; Safanova, M.; Mohan, R.; Murthy, Jayant

    Software simulators are now widely used in all areas of science, especially in application to astronomical missions: from instrument design to mission planning, and to data interpretation. We present a simulator to model the diffuse ultraviolet sky, where the different contributors are separately calculated and added together to produce a sky image of the size specified by the instrument requirements. Each of the contributors to the background, instrumental dark current, airglow, zodiacal light and diffuse galactic light, is dependent on various factors. Airglow is dependent on the time of day, zodiacal light on the time of year, angle from the Sun and from the ecliptic, and diffuse UV emission depends on the look direction. To provide a full description of any line of sight, we have also added stars. The diffuse UV background light can dominate in many areas of the sky and severely impact space telescopes viewing directions due to over brightness. The simulator, available as a downloadable package and as a simple web-based tool, can be applied to separate missions and instruments. For demonstration, we present the example used for two UV missions: the UVIT instrument on the Indian ASTROSAT mission to be launched in the next year and a prospective wide-field mission to search for transients in the UV.

  7. Predicting UV sky for future UV missions

    NASA Astrophysics Data System (ADS)

    Safonova, M.; Mohan, R.; Sreejith, A. G.; Murthy, Jayant

    2013-02-01

    Software simulators are now widely used in all areas of science, especially in application to astronomical missions: from instrument design to mission planning, and to data interpretation. We present a simulator to model the diffuse ultraviolet sky, where the different contributors are separately calculated and added together to produce a sky image of the size specified by the instrument requirements. Each of the contributors to the background, instrumental dark current, airglow, zodiacal light and diffuse Galactic light, depends on different factors. Airglow is dependent on the time of day; zodiacal light depends on the time of year, angle from the Sun and from the ecliptic; diffuse UV emission depends on the line of sight. To provide a full description of the sky along any line of sight, we have also added stars. The UV background light can dominate in many areas of the sky and severely limit viewing directions due to overbrightness. The simulator, available as a downloadable package and as a web-based tool, can be applied to preparation of real space missions and instruments. For demonstration, we present the example use for the two near-future UV missions: UVIT instrument on the Indian Astrosat mission and a new proposed wide-field (∼1000 square degrees) transient explorer satellite.

  8. Cassini UVIS Observations of Titan Ultraviolet Airglow Spectra with Laboratory Modeling from Electron- and Proton-Excited N2 Emission Studies

    NASA Astrophysics Data System (ADS)

    Ajello, J. M.; West, R. A.; Malone, C. P.; Gustin, J.; Esposito, L. W.; McClintock, W. E.; Holsclaw, G. M.; Stevens, M. H.

    2011-12-01

    Joseph M. Ajello, Robert A. West, Rao S. Mangina Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 Charles P. Malone Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 & Department of Physics, California State University, Fullerton, CA 92834 Michael H. Stevens Space Science Division, Naval Research Laboratory, Washington, DC 20375 Jacques Gustin Laboratoire de Physique Atmosphérique et Planétaire, Université de Liège, Liège, Belgium A. Ian F. Stewart, Larry W. Esposito, William E. McClintock, Gregory M. Holsclaw Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 E. Todd Bradley Department of Physics, University of Central Florida, Orlando, FL 32816 The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed photon emissions of Titan's day and night limb-airglow and disk-airglow on multiple occasions, including three eclipse observations from 2009 through 2010. The 77 airglow observations analyzed in this paper show EUV (600-1150 Å) and FUV (1150-1900 Å) atomic multiplet lines and band emissions (lifetimes less than ~100 μs), including the Lyman-Birge-Hopfield (LBH) band system, arising from photoelectron induced fluorescence and solar photo-fragmentation of molecular nitrogen (N2). The altitude of peak UV emission on the limb of Titan during daylight occurred inside the thermosphere/ionosphere (near 1000 km altitude). However, at night on the limb, the same emission features, but much weaker in intensity, arise in the lower atmosphere below 1000 km (lower thermosphere, mesosphere, haze layer) extending downwards to near the surface at ~300 km, possibly resulting from proton- and/or heavier ion-induced emissions as well as secondary-electron-induced emissions. The eclipse observations are unique. UV emissions were observed during only one of the three eclipse events, and no Vegard-Kaplan (VK) or LBH emissions were seen. Through regression analysis using

  9. The Light of the Night Sky in EUSO: Duty Cycle and Background

    NASA Technical Reports Server (NTRS)

    Adams, J.; Berat, C.; Lebrun, D.; Montanet, F.

    2003-01-01

    The EUSO detector, which will be installed on the International Space Station, will detect the light produced by the EAS generated by the UHECR when entering the Earth's atmosphere. The EUSO telescope will operate only during dark night. The light background in the EUSO detector is of outmost importance. To determine the detector duty cycle, it is necessary to know the periods in which it will be in the obscurity, taking into account both sun and moon precise ephemerides and the ISS trajectory. For signal to background determination and trigger efficiency study, the photon background has to be evaluated, taking into account the various UV light sources at night: natural sources as airglow, stars and diffuse light of the night sky, and artificial sources.

  10. OH(v=1 to 9) Relative Population Levels Inferred from VIRTIS/Rosetta Airglow Observations in the Earth's Atmosphere (Invited)

    NASA Astrophysics Data System (ADS)

    Migliorini, A.; Gerard, J. C.; Soret, L.; Piccioni, G.; Capaccioni, F.; Filacchione, G.; Snels, M.

    2015-08-01

    On its way to the comet 67P/Churyumov-Gerasimenko, the Rosetta spacecraft performed three flybys with the Earth, in March 2005, November 2007 and November 2009. The last one was quite suitable to observe the nightside of our planet. The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board Rosetta was especially adapted to study the hydroxyl nightglow emissions in the infrared spectral range. The OH v=1,2 sequences were measured simultaneously. We thus investigate the relative population levels of the v=1 to 9 vibrational levels at the same time. Results, obtained using our simple 1-dimension model, are presented for the relative population levels; in particular, the value of level v=1 is derived for the first time, relative to levels up to 9. The vibrational population decreases with increasing vibrational quantum number. Our results are in satisfactorily agreement with previous observations and models developed for mid-latitudes conditions. They favor the models where sudden death deactivation by atomic oxygen is the major process controlling the vibrational population. The observed behavior results to be distinctly different than the OH airglow observations made in the Venus atmosphere with the VIRTIS instrument on board Venus Express, where quenching by CO2 seems to occur with collisional cascades. The authors thank ESA, ASI and all the national space agencies, which support the Rosetta mission (Grants: ASI-INAF I/062/08/0 and ASI-INAF I/050/10/0).

  11. The global characteristics of atmosphere emissions in the lower thermosphere and their aeronomic implications. [OGO-4 airglow photometric observations of oxygen

    NASA Technical Reports Server (NTRS)

    Reed, E. I.; Chandra, S.

    1974-01-01

    The green line of atomic oxygen and the Herzberg bands of molecular oxygen as observed from the OGO-4 airglow photometer are discussed in terms of their spatial and temporal distributions and their relation to the atomic oxygen content in the lower thermosphere. Daily maps of the distribution of emissions show considerable structure (cells, patches, and bands) with appreciable daily changes. When data are averaged over periods of several days in length, the resulting patterns have occasional tendencies to follow geomagnetic parallels. The Seasonal variations are characterized by maxima in both the Northern and Southern Hemispheres in October, with the Northern Hemisphere having substantially higher emission rates. Formulae are derived relating the vertical column emission rates of the green line and the Herzberg bands to the atomic oxygen peak density. Global averages for the time period for these data (August 1967 to January 1968), when converted to maximum atomic oxygen densities near 95 km, have a range of 2.0 x 10 to the 11th power/cu cm 2.7 x 10 to the 11th power/cu cm.

  12. Stray light field dependence for the James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Lightsey, Paul A.

    2016-07-01

    The James Webb Space Telescope (JWST) is a large space based astronomical telescope that will operate at cryogenic temperatures. The architecture has the telescope exposed to space, with a large sun shield providing thermal isolation and protection from direct illumination from the sun. The instruments will have the capability to observe over a spectral range from 0.6 μm to 29 μm wavelengths. Stray light analysis has been performed to characterize the stray light getting to the instrument focal planes from the celestial sky. A Radiance Transfer Function (RTF) is defined for the susceptibility of stray light to sky radiance relative to the observatory frame of reference. The stray light is calculated by overlaying the radiance maps of the celestial sky background (both galactic and zodiacal background) onto the RTF map. The product of the two is summed to obtain the total stray light background at the instrument detectors. The orientation of the observatory for observing a given field location in the sky depends on the direction of the sun, hence the day of the year. The variability of stray light with time of year for observing a given sky locations is determined.

  13. Mystery of Polar Inertia-gravity Waves: An Observational Study Combining Lidar, Radar and Airglow Imager at McMurdo/Scott Base (77.8°S, 166.7°E)

    NASA Astrophysics Data System (ADS)

    Chen, C.; Chu, X.; Fong, W.; McDonald, A.; Pautet, P. D.; Taylor, M. J.

    2014-12-01

    Since the start of the McMurdo Fe lidar campaign, large-amplitude (~±30 K), long-period (4 to 9 h) perturbations with upward propagating Inertia Gravity Wave (IGW) signatures are frequently observed in the MLT temperature data. Despite its frequent appearance, such type of wave was neither widely observed, nor well understood in the past, primarily due to a paucity of measurements in Polar Regions. At McMurdo, the simultaneous observations of such waves using lidar, radar and airglow imager can provide their unique 3-D intrinsic wave-propagation properties, which are greatly needed for understanding their sources and potential impacts. This study presents the first coincident observation of IGWs by lidar, radar and airglow imager in the Antarctic mesopause region. On 11 June 2013, coherent wave structures with observed period of ~ 5 h and vertical wavelength of ~20 km were observed in both the Fe lidar temperature and MF radar winds. Derived from hodograph analysis, the wave has a horizontal wavelength of ~1200 km and propagates southward at ~60 m/s. The phase relationship between the temperature and winds is in good agreement with the gravity wave polarization relationship. Similar wave structures were also observed in the airglow keograms. The results of the horizontal propagation information obtained from appropriate filtering and applying a non-linear least-square fit of the keograms are similar to those estimated from the combined lidar-radar hodograph analysis. A Monte Carlo sampling method is used to perform all the non-linear fits of the observations to the linear gravity wave models.

  14. A Comparison of Electron Density Profiles Derived from the Low Resolution Airglow and Aurora Spectrograph (LORAAS) Ultraviolet Measurements: Resolution of the 911 Å Conundrum

    NASA Astrophysics Data System (ADS)

    Dymond, K.; Budzien, S. A.; Coker, C.; Nicholas, A. C.; Stephan, A. W.; Bishop, R. L.; Christensen, A. B.; Hecht, J. H.; Straus, P. R.

    2010-12-01

    Previous measurements of the 911 Å emission made by sounding rockets, at altitude less than 320 km, indicated that the emission was either very weak or non-existent. Newer measurements made by the Remote Atmospheric and Ionospheric Detection System (RAIDS) currently in operation aboard the International Space Station, at an altitude of 340 km, show the same behavior. Yet, satellite-based measurements made at altitudes above 800 km showed the emission to be present and strong enough to be accurately measured and inverted; those inversions were validated against ionosonde measurements and demonstrated the possibility of using the 911 Å emission for daytime ionospheric sensing. So the conundrum is: why do measurements made at lower altitudes (< 350 km) indicate weak or non-existent emission while satellite measurements at higher altitudes (>800 km) show the presence of the emission at the expected level? We present our measurements of the daytime and nighttime electron density derived by analysis of the O I 1356 and O I 911 Å altitude profiles measured by the Low Resolution Airglow and Aurora Spectrograph (LORAAS) instrument launched aboard the Advanced Research and Global Observation Satellite (ARGOS), which operated between mid-May 1999 and April 2002. We compare the retrieved electron density profiles inferred from the limb intensities of the ultraviolet emissions to peak heights and peak densities measured during ionosonde overflights. We show that the 911 Å emission is strongly affected by the height of the ionosphere and show that this is consistent with absorption of the 911 Å by atomic oxygen. Model results are presented showing that the RAIDS and sounding rocket measurements can be explained by this absorption.

  15. Bili lights

    MedlinePlus

    Phototherapy for jaundice; Bilirubin - bili lights; Neonatal care - bili lights; Newborn care - bili lights ... Phototherapy involves shining fluorescent light from the bili lights on bare skin. A specific wavelength of light can break down bilirubin into a form that ...

  16. Polarimetric Studies of Solar Light Scattered by Interplanetary Dust Particles and the Eye-Sat Project

    NASA Astrophysics Data System (ADS)

    Levasseur-Regourd, A. C.; Lasue, J.

    2014-12-01

    Studying intensity and linear polarization of the solar light scattered by interplanetary dust is of interest for various reasons. This so-called zodiacal light constitutes a faint polarized glow that constitutes a changing foreground for observations of faint extended astronomical sources. Besides, analysis of its polarization provides information on properties of the dust particles, such as spatial density, morphology and complex refractive index. Previous observations, mostly from the Earth and with a resolution in the 10° range, have been used to infer that the local polarization at 90° phase angle increases with increasing solar distance. Numerical simulations suggest that, in the inner solar system, interplanetary dust particles consist of a mixture of absorbing and less absorbing materials, and that radial changes originate in a decrease of organic materials with decreasing solar distance under alteration or evaporation processes. To improve the quality of data on zodiacal light polarimetry, Eye-Sat nanosat is being developed in the context of the JANUS CNES cubesats program for students. The project is now in phase C-D, for a piggy-back launch in 2016. Eye-Sat triple cubesat is anticipated to demonstrate the feasibility of a series of new on-board technologies. Moreover, during its one-year mission, zodiacal light intensity and polarization are to be measured, for the first time with a spatial resolution of about 1° over a wide portion of the sky and in four different wavelengths (visible to near-IR), leading to a better assessment of interplanetary dust properties. Finally, a significant fraction of the interplanetary dust is estimated to come from comets, the most pristine objects to be found in the inner solar system. While similarities have indeed been noticed between polarimetric properties of interplanetary and cometary dust particles, the latter being currently extensively documented by the Rosetta mission to comet 67P

  17. Lighting: Green Light.

    ERIC Educational Resources Information Center

    Maniccia, Dorine

    2003-01-01

    Explains that by using sustainable (green) building practices, schools and universities can make their lighting systems more efficient, noting that embracing green design principles can help schools attract students. Discusses lighting-control technologies (occupancy sensing technology, daylighting technology, and scheduling based technologies),…

  18. Spectroscopy of diffuse light in dust clouds. Scattered light and the solar neighbourhood radiation field

    NASA Astrophysics Data System (ADS)

    Lehtinen, K.; Mattila, K.

    2013-01-01

    Context. The optical surface brightness of dark nebulae is mainly due to scattering of integrated starlight by classical dust grains. It contains information on the impinging interstellar radiation field, cloud structure, and grain scattering properties. We have obtained spectra of the scattered light from 3500 to 9000 Å in two globules, the Thumbprint Nebula and DC 303.8-14.2. Aims. We use observations of the scattered light to study the impinging integrated starlight spectrum as well as the scattered Hα and other line emissions from all over the sky. We search also for the presence of other than scattered light in the two globules. Methods. We obtained long-slit spectra encompassing the whole globule plus adjacent sky in a one-slit setting, thus enabling efficient elimination of airglow and other foreground sky components. We calculated synthetic integrated starlight spectra for the solar neighbourhood using HIPPARCOS-based stellar distributions and the spectral library of Pickles. Results. Spectra are presented separately for the bright rims and dark cores of the globules. The continuum spectral energy distributions and absorption line spectra can be well modelled with the synthetic integrated starlight spectra. Emission lines of Hα +[N II], Hβ, and [S II] are detected and are interpreted in terms of scattered light plus an in situ warm ionized medium component behind the globules. We detected an excess of emission over the wavelength range 5200-8000 Å in DC 303.8-14.2 but the nature of this emission remains open. Based on observations collected at the European Southern Observatory, Chile, under programme ESO No. 073.C-0239(A). Appendix A is available in electronic form at http://www.aanda.org.

  19. Results from the intercalibration of optical low light calibration sources 2011

    NASA Astrophysics Data System (ADS)

    Brändström, B. U. E.; Enell, C.-F.; Widell, O.; Hansson, T.; Whiter, D.; Mäkinen, S.; Mikhaylova, D.; Axelsson, K.; Sigernes, F.; Gulbrandsen, N.; Schlatter, N. M.; Gjendem, A. G.; Cai, L.; Reistad, J. P.; Daae, M.; Demissie, T. D.; Andalsvik, Y. L.; Roberts, O.; Poluyanov, S.; Chernouss, S.

    2012-05-01

    Following the 38th Annual European Meeting on Atmospheric Studies by Optical Methods in Siuntio in Finland, an intercalibration workshop for optical low light calibration sources was held in Sodankylä, Finland. The main purpose of this workshop was to provide a comparable scale for absolute measurements of aurora and airglow. All sources brought to the intercalibration workshop were compared to the Fritz Peak reference source using the Lindau Calibration Photometer built by Wilhelm Barke and Hans Lauche in 1984. The results were compared to several earlier intercalibration workshops. It was found that most sources were fairly stable over time, with errors in the range of 5-25%. To further validate the results, two sources were also intercalibrated at UNIS, Longyearbyen, Svalbard. Preliminary analysis indicates agreement with the intercalibration in Sodankylä within about 15-25%.

  20. Results from the intercalibration of optical low-light calibration sources 2011

    NASA Astrophysics Data System (ADS)

    Brändström, B. U. E.; Enell, C.-F.; Widell, O.; Hansson, T.; Whiter, D.; Mäkinen, S.; Mikhaylova, D.; Axelsson, K.; Sigernes, F.; Gulbrandsen, N.; Schlatter, N. M.; Gjendem, A. G.; Cai, L.; Reistad, J. P.; Daae, M.; Demissie, T. D.; Andalsvik, Y. L.; Roberts, O.; Poluyanov, S.; Chernouss, S.

    2011-12-01

    Following the 38th Annual Meeting on Atmospheric studies by Optical methods at Siuntio in Finland, an intercalibration workshop for optical low-light calibration sources was held in Sodankylä, Finland. The main purpose of this workshop was to provide a comparable scale for absolute measurements of aurora and airglow. All sources brought to the intercalibration workshop were compared to an international standard source (Fritz-Peak) using the Lindau Calibration Photometer built by Wilhelm Barke and Hans Lauche in 1984. The international standard source is on loan from Michael Gadsden, Aberdeen. The results were compared to several earlier intercalibration workshops. It was found that most sources were fairly stable over time with errors in the range of 5-20%. To further validate the results, two sources were also intercalibrated at UNIS, Longyearbyen, Svalbard. Preliminary analysis indicate good agreement with the intercalibration in Sodankylä.

  1. Extragalactic background light measurements and applications

    PubMed Central

    Cooray, Asantha

    2016-01-01

    This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar System. The best measurements of COB come from an indirect technique involving γ-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB. PMID:27069645

  2. Extragalactic background light measurements and applications.

    PubMed

    Cooray, Asantha

    2016-03-01

    This review covers the measurements related to the extragalactic background light intensity from γ-rays to radio in the electromagnetic spectrum over 20 decades in wavelength. The cosmic microwave background (CMB) remains the best measured spectrum with an accuracy better than 1%. The measurements related to the cosmic optical background (COB), centred at 1 μm, are impacted by the large zodiacal light associated with interplanetary dust in the inner Solar System. The best measurements of COB come from an indirect technique involving γ-ray spectra of bright blazars with an absorption feature resulting from pair-production off of COB photons. The cosmic infrared background (CIB) peaking at around 100 μm established an energetically important background with an intensity comparable to the optical background. This discovery paved the way for large aperture far-infrared and sub-millimetre observations resulting in the discovery of dusty, starbursting galaxies. Their role in galaxy formation and evolution remains an active area of research in modern-day astrophysics. The extreme UV (EUV) background remains mostly unexplored and will be a challenge to measure due to the high Galactic background and absorption of extragalactic photons by the intergalactic medium at these EUV/soft X-ray energies. We also summarize our understanding of the spatial anisotropies and angular power spectra of intensity fluctuations. We motivate a precise direct measurement of the COB between 0.1 and 5 μm using a small aperture telescope observing either from the outer Solar System, at distances of 5 AU or more, or out of the ecliptic plane. Other future applications include improving our understanding of the background at TeV energies and spectral distortions of CMB and CIB.

  3. Light Duty.

    ERIC Educational Resources Information Center

    Rogers, Jeff

    1996-01-01

    Discusses multipurpose athletic-field lighting specifications to enhance lighting quality and reduce costs. Topics discussed include lamp choice, lighting spillover and glare prevention, luminary assemblies and poles, and the electrical dimming and switching systems. (GR)

  4. Light Pollution

    ERIC Educational Resources Information Center

    Riegel, Kurt W.

    1973-01-01

    Outdoor lighting is light pollution which handicaps certain astronomical programs. Protective measures must be adopted by the government to aid observational astronomy without sacrificing legitimate outdoor lighting needs. (PS)

  5. Lighting Conservation

    ERIC Educational Resources Information Center

    Arnold, Frank D.

    1975-01-01

    With the energy crisis has come an awareness of wasteful consumption practices. One area where research is being done is in lighting conservation. Information in this article is concerned with finding more effective and efficient lighting designs which include daylight utilization, task-oriented lighting, and lighting controls. (MA)

  6. A study into the effects of gravity wave activity on the diurnal tide and airglow emissions in the equatorial mesosphere and lower thermosphere using the Coupled Middle Atmosphere and Thermosphere (CMAT) general circulation model

    NASA Astrophysics Data System (ADS)

    England, S. L.; Dobbin, A.; Harris, M. J.; Arnold, N. F.; Aylward, A. D.

    2006-02-01

    Momentum deposition by gravity wave breaking is known to affect the amplitude and phase of the diurnal tide. Modelling studies of this interaction have produced some conflicting results and as yet, the exact nature of this interaction is not fully understood. In this study, the effects of parameterised gravity wave momentum deposition on the diurnal tide and subsequently on green line airglow from atomic oxygen during equinox are investigated using the Coupled Middle Atmosphere and Thermosphere (CMAT) general circulation model. The effects of gravity wave drag calculated by two different parameterisations, Meyer [1999. Gravity wave interactions with the diurnal propagating tide. Journal of Geophysical Research 104, 4223 4239] and Medvedev and Klaassen [2000. Parameterisation of gravity wave momentum deposition based on non-linear wave interactions: basic formulation and sensitivity tests. Journal of Atmospheric and Terrestrial Physics 62, 1015 1033], are compared in the low latitude MLT region between 70 and 120 km, where the amplitude of the diurnal tide and green line volume emission rates maximise. Results indicate that momentum sources from both gravity wave parameterisations act to reduce the mid-latitude zonal jets and advance the phase of the diurnal tide, such that the peak amplitude at a given height occurs at an earlier time of day. Gravity wave momentum deposition as parameterised by Meyer [1999. Gravity wave interactions with the diurnal propagating tide. Journal of Geophysical Research 104, 4223 4239] results in a reduction of the amplitude of the diurnal tide in the MLT region, whereas the tidal amplitude is increased when the Medvedev and Klaassen [2000. Parameterisation of gravity wave momentum deposition based on non-linear wave interactions: basic formulation and sensitivity tests. Journal of Atmospheric and Terrestrial Physics 62, 1015 1033] parameterisation is used. Both parameterisations affect the local time variability of the simulated

  7. Zodiacal Exoplanets in Time (ZEIT). I. A Neptune-sized Planet Orbiting an M4.5 Dwarf in the Hyades Star Cluster

    NASA Astrophysics Data System (ADS)

    Mann, Andrew W.; Gaidos, Eric; Mace, Gregory N.; Johnson, Marshall C.; Bowler, Brendan P.; LaCourse, Daryll; Jacobs, Thomas L.; Vanderburg, Andrew; Kraus, Adam L.; Kaplan, Kyle F.; Jaffe, Daniel T.

    2016-02-01

    Studying the properties of young planetary systems can shed light on how the dynamics and structure of planets evolve during their most formative years. Recent K2 observations of nearby young clusters (10-800 Myr) have facilitated the discovery of such planetary systems. Here we report the discovery of a Neptune-sized planet transiting an M4.5 dwarf (K2-25) in the Hyades cluster (650-800 Myr). The light curve shows a strong periodic signal at 1.88 days, which we attribute to spot coverage and rotation. We confirm that the planet host is a member of the Hyades by measuring the radial velocity of the system with the high-resolution near-infrared spectrograph Immersion Grating Infrared Spectrometer. This enables us to calculate a distance based on K2-25's kinematics and membership to the Hyades, which in turn provides a stellar radius and mass to ≃5%-10%, better than what is currently possible for most Kepler M dwarfs (12%-20%). We use the derived stellar density as a prior on fitting the K2 transit photometry, which provides weak constraints on eccentricity. Utilizing a combination of adaptive optics imaging and high-resolution spectra, we rule out the possibility that the signal is due to a bound or background eclipsing binary, confirming the transits’ planetary origin. K2-25b has a radius ({3.43}-0.31+0.95 R⊕) much larger than older Kepler planets with similar orbital periods (3.485 days) and host-star masses (0.29 M⊙). This suggests that close-in planets lose some of their atmospheres past the first few hundred million years. Additional transiting planets around the Hyades, Pleiades, and Praesepe clusters from K2 will help confirm whether this planet is atypical or representative of other close-in planets of similar age.

  8. Light Visor

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Seasonal Affective Disorder is a form of depression brought on by reduced light. For some people, this can lead to clinical depression. NASA has conducted research in light therapy and employs it to help astronauts adjust internal rhythms during orbital flight. Dr. George Brainard, a medical researcher and NASA consultant, has developed a portable light therapy device, which is commercially available. The Light Visor allows continuous light therapy and can be powered by either batteries or electricity. Dr. Brainard continues to research various aspects of light therapy.

  9. Light Motives.

    ERIC Educational Resources Information Center

    Filler, Martin

    1979-01-01

    The new energy consciousness has led to a thorough reevaluation of how artificial lighting can be used wisely, while other researchers have explored the potential of daylighting as an alternative interior light source. (Author/MLF)

  10. Light Reflector

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Ultra Sales, Inc.'s fluorescent lighting fixture gets a boost in reflectivity through installation of Lightdriver, a thin tough thermoplastic film plated with aluminum, capable of reflecting 95 percent of visible light striking it. Lightdriver increases brightness without adding bulbs, and allows energy savings by removing some bulbs because the mirrorlike surface cuts light loss generally occasioned by conventional low reflectivity white painted surface above the bulbs in many fluorescent fixtures. Forty-five percent reduction in lighting electricity is attainable.

  11. SCHOOL LIGHTING

    ERIC Educational Resources Information Center

    1965

    SEVERAL ARTICLES ON SCHOOL LIGHTING ARE CONTAINED IN THIS JOURNAL. THE TITLES AND AUTHORS INCLUDED ARE AS FOLLOWS--(1) "TODAY'S CONCEPTS IN SCHOOL LIGHTING" BY CHARLES D. GIBSON, (2) "CHALLENGE OF TOMMORROW'S LIGHTING" BY S.K. GUTH AND E.H. WITTE, (3) "PEEK PREVIEW OF THE WINDOWLESS SCHOOL" BY JAMES J. MORISSEAU, (4) "MAINTENANCE BEGINS BEFORE…

  12. Implementation of a High-Altitude Balloon Payload to Study Thermospheric Wind Speeds through Redline Airglow Emissions of Atomic Oxygen at 630 nm via a Split-field Etalon Doppler Imager Utilizing a Fabry-Perot Interferometer.

    NASA Astrophysics Data System (ADS)

    Terry, L. B.; Fullmer, R.; Swenson, C.; Marchant, A.; Hooser, P.; Victors, J.; Muchmore, K.; Yin, L.

    2015-12-01

    Little data exists on the wind velocity characteristics of the upper atmosphere. The Red Line Air Glow Experiment is designed to measure the relative density and velocity of the thermosphere at altitudes approximately ranging between 250 and 350 km. To accomplish this, a Split-Field Etalon Imager will make doppler shift interferometry measurements of the oxygen redline at 630 nm wavelength airglow a using a high altitude balloon platform floating at 36 km. The imager collects up to 10 images per hour. Velocity resolution is within a 5 m/s. The Etalon is thermally controlled to within 1 deg C to achieve this goal. The pointing direction of the sensor is determined post-filght using GPS, IMU and three sun imaging sensors. An experimental star camera is included with a potential pointing accuracy of under 5 arc-min. The instrument first flew from Fort Sumner N,M., on August 26, 2014. Due to the short duration (3.5 hours) of the data collection period on this flight, a second flight was requested and awarded, to take place around September 10, 2015. This flight will allow for data collection over a 24 hour period. Both flight results will be included in the final presentation. This project was designed and built by an undergraduate team including students from physics, aerospace, electrical and mechanical engineering and management at both Utah State University and the University of Maryland Eastern Shores as a NASA's Undergraduate Student Instrument Project (USIP).

  13. Implementation of a High-Altitude Balloon Payload to Study Thermospheric Wind Speeds through Redline Airglow Emissions of Atomic Oxygen at 630 nm via a Split-field Etalon Doppler Imager Utilizing a Fabry-Perot Interferometer.

    NASA Astrophysics Data System (ADS)

    Terry, L. B.; Hooser, P.; Victors, J.; Muchmore, K.; Yin, L.; Fullmer, R.; Marchant, A.; Mogavero, M.; Dingwell, B.; Tuttle, J.; Swenson, C.; Polidan, J.; English, M.

    2014-12-01

    Little data exists on the wind velocity characteristics of the upper atmosphere. The Red Line Air Glow Experiment is designed to measure the relative density and velocity of the thermosphere at altitudes approximately ranging between 250 and 350 km. To accomplish this, a Split-Field Etalon Imager will make doppler shift interferometry measurements of the oxygen redline at 630 nm wavelength airglow a using a high altitude balloon platform floating at 36 km. The imager collects up to 10 images per hour. Velocity resolution is within a 5 m/s. The Etalon is thermally controlled to within 1 deg C to achieve this goal. The pointing direction of the sensor is determined post-filght using GPS, IMU and three sun imaging sensors. An experimental star camera is included with a potential pointing accuracy of under 5 arc-min. The instrument is currently scheduled for flight from Fort Sumner N,M., on August 15, 2014. Flight results will be included in the final presentation. This project was designed and built by an undergraduate team including students from physics, aerospace, electrical and mechanical engineering and management at both Utah State University and the University of Maryland Eastern Shores as a NASA's Undergraduate Student Instrument Project (USIP). .

  14. Light Source

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Research on food growth for long duration spacecraft has resulted in a light source for growing plants indoors known as Qbeam, a solid state light source consisting of a control unit and lamp. The light source, manufactured by Quantum Devices, Inc., is not very hot, although it generates high intensity radiation. When Ron Ignatius, an industrial partner of WCSAR, realized that terrestrial plant research lighting was not energy efficient enough for space use, he and WCSAR began to experiment with light emitting diodes. A line of LED products was developed, and QDI was formed to market the technology. An LED-based cancer treatment device is currently under development.

  15. WOW: light print, light propel, light point

    NASA Astrophysics Data System (ADS)

    Glückstad, Jesper; Bañas, Andrew; Aabo, Thomas; Palima, Darwin

    2012-10-01

    We are presenting so-called Wave-guided Optical Waveguides (WOWs) fabricated by two-photon polymerization and capable of being optically manipulated into any arbitrary orientation. By integrating optical waveguides into the structures we have created freestanding waveguides which can be positioned anywhere in a sample at any orientation using real-time 3D optical micromanipulation with six degrees of freedom. One of the key aspects of our demonstrated WOWs is the change in direction of in-coupled light and the marked increase in numerical aperture of the out-coupled light. Hence, each light propelled WOW can tap from a relatively broad incident beam and generate a much more tightly confined light at its tip. The presentation contains both numerical simulations related to the propagation of light through a WOW and preliminary experimental demonstrations on our BioPhotonics Workstation. In a broader context, this research shows that optically trapped micro-fabricated structures can potentially help bridge the diffraction barrier. This structure-mediated paradigm may be carried forward to open new possibilities for exploiting beams from far-field optics down to the sub-wavelength domain.

  16. Emergency Lighting

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A lighting system originally developed for NASA's Apollo and Skylab manned spacecraft resulted in a industrial spinoff and creation of a whole new company to produce and market the product line. The company is UDEC Corp., Waltham, Mass. UDEC's "Multi-Mode" electronic lighting systems are designed for plant emergency and supplemental use, such as night lighting, "always-on" stairwell lights and illuminated exit signs. Their advantages stem from the qualities demanded for spacecraft installation: extremely high fight output with very low energy drain, compactness, light weight, and high reliability. The Multi-Mode system includes long-life fluorescent lamps operated by electronic circuitry, a sealed battery that needs no maintenance for 10 years, and a solid-state battery charger. A typical emergency installation consists of a master module with battery and an eight watt lamp, together with four remote "Satellight" modules powered by the master's battery. As a night lighting system for maintenance or I security, UDEC fixtures can bypass the battery and 1 operate on normal current at a fraction of the energy 1 demand of conventional night lighting. Industrial customers have realized savings of better than ninety percent with UDEC night lights. UDEC started as a basement industry in 1972 but the company has already sold more than 1,000 lighting systems to building operators.

  17. On applicability of the photochemical-equilibrium approach for retrieval of O and H mesospheric distributions from the satellite-based measurements of the airglow emission and ozone concentration

    NASA Astrophysics Data System (ADS)

    Feigin, Alexander; Belikovich, Mikhail; Kulikov, Mikhail

    2016-04-01

    Atomic oxygen and hydrogen are known to be among key components for the photochemistry and energy balance of the Earth's atmosphere between approximately 80 and 100 km altitude (mesopause region). Therefore, obtaining information about the vertical distributions of O and H concentrations is an important task in studies of this region. Solving of this problem is rather difficult due to the absence of regular methods which allow one to direct measurements of distributions of these components in mesosphere. However, indirect methods used to retrieve O and H distributions from the satellite-based measurements of the OH and O2(1D) airglow emission, as well as the data of IR and microwave O3 measurements have a sufficiently long development history. These methods are rooted in the use of the condition of photochemical equilibrium of ozone density in the range of altitudes from 50 to 100 km. A significant factor is that an insufficient volume of such measurement data forces researchers to use approximate ("truncated") photochemical-equilibrium conditions. In particular, it is assumed that in the daytime the ozone production reaction is perfectly balanced by ozone photodissociation, whereas during the night the only ozone sink is the reaction of ozone with atomic hydrogen, which, in its turn, leads to formation of excited OH and airglow emission of the latter. The presentation analyzes applicability of the photochemical-equilibrium conditions both in the total and truncated forms for description of the spatio-temporal evolution of mesospheric ozone during a year. The analysis is based on year-long time series generated by a 3D chemical transport model, which reproduces correctly various types of atmosphere dynamics in the range of altitudes from 50 to 100 km. These data are used to determine statistics of the ratio between the correct (calculated dynamically) distributions of the O3 density and its uncontracted and truncated equilibrium values for the conditions of the

  18. EDITORIAL: Slow light Slow light

    NASA Astrophysics Data System (ADS)

    Boyd, Robert; Hess, Ortwin; Denz, Cornelia; Paspalakis, Emmanuel

    2010-10-01

    Research into slow light began theoretically in 1880 with the paper [1] of H A Lorentz, who is best known for his work on relativity and the speed of light. Experimental work started some 60 years later with the work of S L McCall and E L Hahn [2] who explored non-linear self-induced transparency in ruby. This field of research has burgeoned in the last 10 years, starting with the work of L Vestergaard Hau and coworkers on slow light via electromagnetically induced transparency in a Bose-Einstein condensate [3]. Many groups are now able to slow light down to a few metres per second or even stop the motion of light entirely [4]. Today, slow light - or more often `slow and fast light' - has become its own vibrant field with a strongly increasing number of publications. In broad scope, slow light research can be categorized in terms of the sort of physical mechanism used to slow down the light. One sort of slow light makes use of material dispersion. This dispersion can be the natural dispersion of the ordinary refractive index or can be the frequency dependence of some nonlinear optical process, such as electromagnetically induced transparency, coherent population oscillations, stimulated light scattering, or four-wave mixing processes. The second sort of slow light makes use of the wavelength dependence of artificially structured materials, such as photonic crystals, optical waveguides, and collections of microresonators. Material systems in which slow light has been observed include metal vapours, rare-earth-doped materials, Raman and Brillioun gain media, photonic crystals, microresonators and, more recently, metamaterials. A common feature of all of these schemes is the presence of a sharp single resonance or multiple resonances produced by an atomic transition, a resonance in a photonic structure, or in a nonlinear optical process. Current applications of slow light include a series of attractive topics in optical information processing, such as optical data

  19. IRAS observations of extended zodiacal structures

    NASA Technical Reports Server (NTRS)

    Sykes, Mark V.

    1988-01-01

    In 1983, the Infrared Astronomical Satellite discovered two pairs of dust bands, straddling the ecliptic plane and located in the asteroid belt. New analysis of the IRAS data has resulted in the detection of as many as eight additional bands, spread over more than 40 deg of ecliptic latitude. Dust band morphology is found to vary between different band pairs, having a typical apparent width of a few degrees. This limits the total number of bands which can be distinguished to near the number observed. The Tempel 2 and Encke dust trails are observed to extend over much more of their orbits than had been previously reported, and a new type of dust trail is found which has a relatively large angular width and no imbedded cometary source.

  20. Animals of the Chinese Zodiac. [Lesson Plan].

    ERIC Educational Resources Information Center

    2002

    The Chinese lunar calendar dates back to the second millennium BC. Unlike the western calendar, which numbers the years progressively from the birth of Jesus Christ, the Chinese calendar is cyclical. Each cycle is made up of 12 years--after the 12th year, the cycle is repeated. The Chinese associate each year of a 12-year cycle with an animal, and…

  1. Light Learning.

    ERIC Educational Resources Information Center

    Cutshall, Sandy

    2002-01-01

    Describes a career and technical education program on photonics, the study, research, and development of equipment and concepts used in the transmission of information through light, including fiber optics and experimental laser technologies. (JOW)

  2. Light touch

    NASA Astrophysics Data System (ADS)

    Baskaran, G.

    2014-09-01

    Light sustains life. It enlightens. Over centuries it has illuminated our path to understanding our physical universe. Efforts to understand black body radiation gave birth to quantum mechanics. Same light revealed the secret of space-time through special theory of relativity. Light is a visible manifestation of quantum mechanics. Laser is a macroscopic quantum state available even at room temperatures. Following a general introduction I discuss quantum coherence, common in macroscopic quantum phenomena such as laser, superfluidity, superconductivity and superradiance. I raise a question, can we transfer macroscopic quantum coherence from a laser to a metal and induce superconductivity at room temperatures?. In certain recent experiments, femtosecond laser light is claimed to create transient superconductivity at room temperatures, in the pseudo gap metallic phase of certain cuprates. This has been discussed in terms of superradiant superconductivity, a new quantum coherence transfer mechanism we have suggested recently.

  3. Light's twist

    PubMed Central

    Padgett, Miles

    2014-01-01

    That light travels in straight lines is a statement of the obvious. However, the energy and momentum flow within light beams can twist to form vortices such as eddies in a stream. These twists carry angular momentum, which can make microscopic objects spin, be used to encode extra information in communication systems, enable the design of novel imaging systems and allow new tests of quantum mechanics. PMID:25484612

  4. Synchrotron light

    SciTech Connect

    Craievich, A. )

    1990-01-01

    Several developed countries such as the USA, URSS, England, France, Italy, Sweden and Japan have one or more of these synchrotron light facilities operating or under construction. Some developing countries have constructed (China) or are building (Taiwan, India, Korea, Brazil) synchrotron light facilities. The construction of the Brazilian synchrotron source began in June, 1987. After two years of activities, the injector linac for the electron storage ring is in its final stage of construction. These Proceedings contain the Invited Lectures presented at the Workshop by specialists working on synchrotron light applications and related instrumentation and by members of LNLS regarding technical details of the Brazilian project. The II Workshop Synchrotron Light: Applications and Related Instrumentation was dedicated to oral presentations about applications of synchrotron light, most of which were not covered during the I Workshop, organized by LNLS in 1988, and the Proceedings of which were published by World Scientific. The II Workshop included discussions on the application possibilities for the newly designed LNLS 1.15 GeV storage ring, and on the modifications which would eventually be necessary for the work-station and instrumentation projects currently in progress at LNLS and at various external user laboratories.

  5. Lighting installations

    NASA Technical Reports Server (NTRS)

    Schurer, Kees

    1994-01-01

    Model computations that give the lay-out of a lighting installation have to be implemented in the real world. There, deviations from the ideal performance of just about every element of the installation will be felt. A list of possible sources of non-ideal behavior, based on practical experience, are: lamps, ballasts, reflectors, mounting position, sagging of lamps, and soiling. It is clear that with all possible deviations from the ideal the homogeneity of a real lighting installation can never be as good as the one computed. The only way to make sure it is nearly as good is by measurement of the actual light distribution. Then, an occasional adjustment or replacement may often yield a satisfactory result. This measurement should really be part of the installation contract.

  6. Light's Darkness

    ScienceCinema

    Padgett, Miles [University of Glasgow, Glasgow, Scotland

    2016-07-12

    Optical vortices and orbital angular momentum are currently topical subjects in the optics literature. Although seemingly esoteric, they are, in fact, the generic state of light and arise whenever three or more plane waves interfere. To be observed by eye the light must be monochromatic. Laser speckle is one such example, where the optical energy circulates around each black spot, giving a local orbital angular momentum. This talk with report three on-going studies. First, when considering a volume of interfering waves, the laser specs map out threads of complete darkness embedded in the light. Do these threads form loops? Links? Or even knots? Second, when looking through a rapidly spinning window, the image of the world on the other side is rotated: true or false? Finally, the entanglement of orbital angular momentum states means measuring how the angular position of one photons sets the angular momentum of another: is this an angular version of the EPR (Einstein, Podolsky, and Rosen) paradox?

  7. Innovative Techniques to Predict Atmospheric Effects on Sensor Performance

    DTIC Science & Technology

    2009-10-15

    MODTRAN• 7 5. Solar Mass Ejection Imager (SMEI) 7 5.1. Celestial Background Scene Descriptor Zodiacal 8 Emission (CBZODY-7) 6. Diffuse...the SMEI zodiacal analysis is to use SMEI to refine and validate the current visible light predictions of the Celestial Background Scene Descriptor... Zodiacal Emission (CBZODY) model. The most efficient way to do this is fit the model to the zodiacal variations observed at the north and south

  8. School Lighting.

    ERIC Educational Resources Information Center

    Rennhackkamp, W. M. H.

    Research gathered by the Functional Efficiency Division of the National Building Research Institute, South Africa, is aimed at providing lighting conditions under which the school child can produce his maximum effort with the least strain and fatigue. These favorable conditions are outlined along with specific examples of their realization in…

  9. No-Light Light Bulbs

    ERIC Educational Resources Information Center

    Modern Schools, 1976

    1976-01-01

    A thumbnail sketch of some of the light bulbs manufactured for a purpose other than seeing. These "dark" lamps perform varied tasks including keeping food fresh, detecting and preventing disease, spurring plant growth, heating, and copying printed material. (Author/MLF)

  10. Light Sources and Lighting Circuits

    NASA Astrophysics Data System (ADS)

    Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

    According to the Machinery Statistics of the Ministry of Economy, Trade and Industry, the production of incandescent lamps in Japan in 2007 was 990 million units (90.0% of the previous year's total), in which the production of incandescent lamps for general lighting was 110 million units (90.0% of the previous year's total) and of tungsten-halogen lamps was 44 million units (96.6% of the previous year's total). The production of fluorescent lamps was 927 million units (93.9% of the previous year's total), in which general fluorescent lamps, excluding those for LCD back lighting, was 320 million units (87.2% of the previous year's total). Also, the production of HID lamps was 10 million units (101.5% of the previous year's total). On the other hand, when the numbers of sales are compared with the sales of the previous year, incandescent lamps for general use was 99.8%, tungsten-halogen lamps was 96.9%, fluorescent lamps was 95.9%, and HID lamps was 98.9%. Self-ballasted fluorescent lamps alone showed an increase in sales as strong as 29 million units, or 121.7% of the previous year's sales. It is considered that the switchover of incandescent lamps to HID lamps was promoted for energy conservation and carbon dioxide reduction with the problem of global warming in the background. In regard to exhibitions, Lighting Fair 2007 was held in Tokyo in March, and LIGHTFAIR INTERNATIONAL 2007 was held in New York in May. Regarding academic conferences, LS:11 (the 11th International Symposium on the Science & Technology of Light Sources) was held in Shanghai in May, and the First International Conference on White LEDs and Solid State Lighting was held in Tokyo in November. Both conferences suggested that there are strong needs and concerns now about energy conservation, saving natural resources, and restrictions of hazardous materials. In regard to incandescent lamps, the development of products aiming at higher efficacy, electric power savings, and longer life was advanced by

  11. Glareless light-emitting diode lighting tube

    NASA Astrophysics Data System (ADS)

    Chang, Rong-Seng; Li, Tung-Yen; Jwo, Ko-Wen; Wang, Sha-Wei; Tsai, Jang-Zern

    2012-03-01

    We develop a novel light bar waveguide design to produce a glareless light-emitting diode (LED) lighting tube. We design optimal parameters, such as the gap y between the tube and the reflective surface, the relative distance x between the lens and the LED, and so on. Using these parameters, we fabricate an illumination system consisting of LED light bulb installed at both ends of lighting tube. The lighting tube is shaped the same as a traditional fluorescent lighting tube in order to replace traditional lighting tubes without the modification of the lighting stand. The LED lighting tube is glareless to the observer from the side view.

  12. Cosmic Infrared Background ExpeRiment (CIBER): A probe of Extragalactic Background Light from reionization

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha; Bock, Jamie; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hee; Levenson, Louis; Matsumoto, Toshio; Matsuura, Shuji; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Zemcov, Michael

    2012-08-01

    The Cosmic Infrared Background ExpeRiment (CIBER) is a rocket-borne absolute photometry imaging and spectroscopy experiment optimized to detect signatures of first-light galaxies present during reionization in the unresolved IR background. CIBER-I consists of a wide-field two-color camera for fluctuation measurements, a low-resolution absolute spectrometer for absolute EBL measurements, and a narrow-band imaging spectrometer to measure and correct scattered emission from the foreground zodiacal cloud. CIBER-I was successfully flown in February 2009 and July 2010 and four more flights are planned by 2014, including an upgrade (CIBER-II). We propose, after several additional flights of CIBER-I, an improved CIBER-II camera consisting of a wide-field 30 cm imager operating in 4 bands between 0.5 and 2.1 microns. It is designed for a high significance detection of unresolved IR background fluctuations at the minimum level necessary for reionization. With a FOV 50 to 2000 times larger than existing IR instruments on satellites, CIBER-II will carry out the definitive study to establish the surface density of sources responsible for reionization.

  13. Cosmic Infrared Background Experiment (CIBER): A Probe of Extragalactic Background Light from Reionization

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha; Bock, Jamie; Kawada, Mitsunobu; Keating, Brian; Lee, Dae-Hee; Levenson, Louis; Matsumoto, Toshio; Matsuura, Shuji; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Zemcov, Michael

    2010-11-01

    The Cosmic Infrared Background ExpeRiment (CIBER) is a rocket-borne absolute photometry imaging and spectroscopy experiment optimized to detect signatures of first-light galaxies present during reionization in the unresolved IR background. CIBER-I consists of a wide-field two-color camera for fluctuation measurements, a low-resolution absolute spectrometer for EBL measurements, and a narrow-band imaging spectrometer to measure and correct scattered emission from the foreground zodiacal cloud. CIBER-I was successfully flown on February 25th, 2009 and is expected to be flown three more times over the next two years at six month intervals. CIBER-II is a wide-field 30 cm imager operating in 4 bands between 0.5 and 2.1 microns. It is designed for a high sigma detection of unresolved IR background fluctuations at the minimum level necessary for reionization. With an etendue (a figure-of-merit for survey studies) a factor of 50 to 500 larger than existing IR instruments on satellites, CIBER-II will carry out the definitive study to establish the surface density of sources responsible for reionization.

  14. Cosmic Infrared Background ExpeRiment (CIBER): A Probe of Extragalactic Background Light from Reionization

    NASA Astrophysics Data System (ADS)

    Cooray, A.; Bock, J.; Kawada, M.; Keating, B.; Lange, A.; Lee, D.-H.; Levenson, L.; Matsumoto, T.; Matsuura, S.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2009-12-01

    The Cosmic Infrared Background ExpeRiment (CIBER) is a rocket-borne absolute photometry imaging and spectroscopy experiment optimized to detect signatures of first-light galaxies present during reionization in the unresolved IR background. CIBER-I consists of a wide-field two-color camera for fluctuation measurements, a low-resolution absolute spectrometer for absolute EBL measurements, and a narrow-band imaging spectrometer to measure and correct scattered emission from the foreground zodiacal cloud. CIBER-I was successfully flown on February 25th, 2009 and has one more planned flight in early 2010. We propose, after several additional flights of CIBER-I an improved CIBER-II camera consisting of a wide-field 30 cm imager operating in 4 bands between 0.5 and 2.1 microns. It is designed for a high significance detection of unresolved IR background fluctuations at the minimum level necessary for reionization. With a FOV 50 to 2000 times larger than existing IR instruments on satellites, CIBER-II will carry out the definitive study to establish the surface density of sources responsible for reionization.

  15. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): A SOUNDING ROCKET PAYLOAD TO STUDY THE NEAR INFRARED EXTRAGALACTIC BACKGROUND LIGHT

    SciTech Connect

    Zemcov, M.; Bock, J.; Hristov, V.; Levenson, L. R.; Mason, P.; Arai, T.; Matsumoto, T.; Matsuura, S.; Tsumura, K.; Wada, T.; Battle, J.; Cooray, A.; Keating, B.; Renbarger, T.; Kim, M. G.; Lee, D. H.; Nam, U. W.; Sullivan, I.; Suzuki, K.

    2013-08-15

    The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.

  16. The Cosmic Infrared Background Experiment (CIBER): A Sounding Rocket Payload to Study the near Infrared Extragalactic Background Light

    NASA Astrophysics Data System (ADS)

    Zemcov, M.; Arai, T.; Battle, J.; Bock, J.; Cooray, A.; Hristov, V.; Keating, B.; Kim, M. G.; Lee, D. H.; Levenson, L. R.; Mason, P.; Matsumoto, T.; Matsuura, S.; Nam, U. W.; Renbarger, T.; Sullivan, I.; Suzuki, K.; Tsumura, K.; Wada, T.

    2013-08-01

    The Cosmic Infrared Background Experiment (CIBER) is a suite of four instruments designed to study the near infrared (IR) background light from above the Earth's atmosphere. The instrument package comprises two imaging telescopes designed to characterize spatial anisotropy in the extragalactic IR background caused by cosmological structure during the epoch of reionization, a low resolution spectrometer to measure the absolute spectrum of the extragalactic IR background, and a narrow band spectrometer optimized to measure the absolute brightness of the zodiacal light foreground. In this paper we describe the design and characterization of the CIBER payload. The detailed mechanical, cryogenic, and electrical design of the system are presented, including all system components common to the four instruments. We present the methods and equipment used to characterize the instruments before and after flight, and give a detailed description of CIBER's flight profile and configurations. CIBER is designed to be recoverable and has flown four times, with modifications to the payload having been informed by analysis of the first flight data. All four instruments performed to specifications during the subsequent flights, and the scientific data from these flights are currently being analyzed.

  17. Airglow and Auroral Emission from Ganymede

    NASA Astrophysics Data System (ADS)

    Cessateur, Gaël; Barthelemy, Mathieu

    2014-05-01

    In term of space environment Ganymede is a unique object in the solar system. Its own magnetic field in the jovian magnetosphere gives rise to particles precipitation. Although these object have a very faint atmosphere, their exosphere can show some emissions features due to both solar UV flux and precipitating particles. We recently calculated the effects of the solar UV flux (Cessateur et al 2012). However, in the case of the polar region of Ganymede the precipitating electrons play an important role in the emission features as measured by Hall et al. (1997) and Feldman (2000) for the O 130 nm triplet. To calculate these emissions, we use the atmospheric model produced by Marconi (2007). We use a simple primary ionization calculation. This is justified by the fact that the atmosphere is essentially non collisional except at very low altitudes and latitudes. By comparison between the data of Feldman et al., we constrained the electrons fluxes precipitating in the atmosphere of Ganymede. These calculations give strong information on the processes involved in the Ganymede environment. In particular, we will be able to produce constraints on the electrons spectrum precipitating in Ganymede atmosphere.

  18. Multi-Color Anisotropy Measurements of the Cosmic Near-Infrared Extragalactic Background Light with CIBER2

    NASA Astrophysics Data System (ADS)

    Bock, James

    We propose to carry out a program of observations with the Cosmic Infrared Background Experiment (CIBER-2), a sounding rocket instrument designed to measure anisotropy in the extragalactic background light in multiple optical to near-infrared spectral bands. Scientifically, CIBER-2 follows on the results of CIBER-1, which has detected near-infrared background anisotropy. CIBER-1 has also produced leading results on the absolute brightness of the background, the spectrum of diffuse galactic light, the spectrum of Zodiacal light, and constraints on the Zodiacal light foreground from Fraunhofer line observations. CIBER-2 builds on the measurement techniques developed and successfully demonstrated by CIBER-1. With high-sensitivity, multi-color anisotropy measurements, CIBER-2 will elucidate the history of interhalo light production and carry out a deep search for extragalactic background fluctuations associated with the epoch of reionization. A plausible interpretation of the infrared background anisotropy detected by CIBER-1, Spitzer and AKARI is interhalo light from stars tidally stripped from their parent galaxies during galaxy mergers. Based on the rms amplitude of the anisotropy, interhalo light produces approximately half of the background, representing a major branch of light production. Probing the history of interhalo light through improved anisotropy measurements using multiple bands and correlating with tracers of large-scale structure is essential to understand its role in the cosmic history of star formation. The first generation of stars and their remnants are likely responsible for the reionization of the intergalactic medium, observed to be ionized out to distant quasars at a redshift of 6. The total luminosity produced by first stars is uncertain, but a lower limit can be placed assuming a minimal number of photons to produce and sustain reionization. This 'minimal' extragalactic background component associated with reionization is detectable in

  19. Lighting the Learning Environment.

    ERIC Educational Resources Information Center

    Fielding, Randall

    2000-01-01

    Explores the benefits and pitfalls of day lighting, indirect light, and full-spectrum lamps for general illumination and accent lighting in classrooms. Discussions include lighting considerations in areas where computers are used and fixture cost factors versus efficiency. (GR)

  20. Light and Libraries.

    ERIC Educational Resources Information Center

    Scherer, Jeffrey

    1999-01-01

    Addresses how to integrate various types of light within the context of library design. Discusses light basics; the light spectrum; light measurement; reflectance; glare and brightness ratio; daylighting; electric lighting; and computer screens and lighting. Includes a checklist for plan review. (Author/LRW)

  1. Observations of the White Light Corona from Solar Orbiter and Solar Probe Plus

    NASA Astrophysics Data System (ADS)

    Howard, R. A.; Thernisien, A. F.; Vourlidas, A.; Plunkett, S. P.; Korendyke, C. M.; Sheeley, N. R.; Morrill, J. S.; Socker, D. G.; Linton, M. G.; Liewer, P. C.; De Jong, E. M.; Velli, M. M.; Mikic, Z.; Bothmer, V.; Lamy, P. L.

    2011-12-01

    The SoloHI instrument on Solar Orbiter and the WISPR instrument on Solar Probe+ will make white light coronagraphic images of the corona as the two spacecraft orbit the Sun. The minimum perihelia for Solar Orbiter is about 60 Rsun and for SP+ is 9.5 Rsun. The wide field of view of the WISPR instrument (about 105 degrees radially) corresponds to viewing the corona from 2.2 Rsun to 20 Rsun. Thus the entire Thomson hemisphere is contained within the telescope's field and we need to think of the instrument as being a traditional remote sensing instrument and then transitioning to a local in-situ instrument. The local behavior derives from the fact that the maximum Thomson scattering will favor the electron plasma close to the spacecraft - exactly what the in-situ instruments will be sampling. SoloHI and WISPR will also observe scattered light from dust in the inner heliosphere, which will be an entirely new spatial regime for dust observations from a coronagraph, which we assume to arise from dust in the general neighborhood of about half way between the observer and the Sun. As the dust grains approach the Sun, they evaporate and do not contribute to the scattering. A dust free zone has been postulated to exist somewhere inside of 5 Rsun where all dust is evaporated, but this has never been observed. The radial position where the evaporation occurs will depend on the precise molecular composition of the individual grains. The orbital plane of Solar Orbiter will gradually increase up to about 35 degrees, enabling a very different view through the zodiacal dust cloud to test the models generated from in-ecliptic observations. In this paper we will explore some of the issues associated with the observation of the dust and will present a simple model to explore the sensitivity of the instrument to observe such evaporations.

  2. Probing Reionization through Near-Infrared Background Fluctuations with CIBER

    NASA Astrophysics Data System (ADS)

    Sullivan, Ian S.

    2010-01-01

    The Cosmic Infrared Background Experiment (CIBER) is a NASA sounding rocket payload that was first launched in February 2009. CIBER consists of four co-aligned instruments designed with foreground subtraction and control of systematics in mind. In addition, the platform of a sounding rocket enables observations of the NIRB outside of narrow atmospheric windows that are uncontaminated by airglow. We will present preliminary results from the first flight. CIBER seeks to measure the absolute brightness spectrum of the extragalactic NIRB, and has two spectrometers dedicated to that purpose. One, a high-resolution Fabry-Perot spectometer, is tuned to the 8545 nm Ca II line of the solar spectrum, and is designed to measure the absolute brightness of the Zodiacal Light directly, which is the source of greatest uncertainty in the NIRB spectrum. The second spectrometer measures the NIRB spectrum from 700nm to 1800nm, which spans the wavelength range where a Lyman cutoff feature from Reionization could appear. CIBER also houses two Infrared imaging telescopes, which have identical optics that give 2º x 2º field of views with 7 arcsec pixels, but have different band defining filters. The first imager has a wide band centered at 1600nm, and images the background at the expected peak of the spectrum. The imagers’ wide field of view allows them to measure the distinctive power spectrum peaking at 10 arcminutes. The second imager has a wide band centered at 1000nm that is intended to image at wavelengths shorter than the Lyman cutoff, and provides a powerful systematic test for any detection made at 1600 nm. First-light fluctuations should have a distinctive spatial power spectrum with very red 1600nm / 1000nm color, distinctly redder than the approximately solar color of any residual fluctuations arising from Zodiacal light, Galactic starlight, or low-redshift galaxies.

  3. Light up My Life

    ERIC Educational Resources Information Center

    Kellett, Sarah

    2015-01-01

    Simply stated, light is nature's way of transferring energy through space. Discussions of light usually refer to visible light, which is perceived by the human eye and is responsible for the sense of sight. We see however, only a small part of the light spectrum. Light connects us as we sit and tell yarns around camp fires. Yet, one in every four…

  4. Mobile lighting apparatus

    DOEpatents

    Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

    2013-05-14

    A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

  5. Image and Processing Models for Satellite Detection in Images Acquired by Space-based Surveillance-of-Space Sensors

    DTIC Science & Technology

    2010-09-01

    external sources ‘L1’ like zodiacal light (or diffuse nebula ) or stray light ‘L2’ and these components change with the telescope pointing. Bk (T,t...Astronomical scene background (zodiacal light, diffuse nebulae , etc.). L2(P A(tk), t): Image background component caused by stray light. MS

  6. Optics for natural lighting

    NASA Technical Reports Server (NTRS)

    Edwards, H. B.

    1978-01-01

    Energy-saving optics utilize sky and sun for lighting. Innovative optical arrangements for transmitting outdoor light into building interiors are decribed using flat white and mirrored surfaces for converging and diverging light pipes.

  7. Light 'Em Up.

    ERIC Educational Resources Information Center

    Wiese, Paul J.; Lindstrom, Chuck

    1998-01-01

    Provides advice on designing sports-field lighting that can help balance design with cost and lighting-system performance. Areas addressed include system installation, pole placement, light-spillage control, and maintenance. (GR)

  8. PFP Emergency Lighting Study

    SciTech Connect

    BUSCH, M.S.

    2000-02-02

    NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergency Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently or for significant lengths of time will need one or two Backup lights to provide general illumination of the egress points. (2) Complexity of the egress routes. Office spaces with a standard hallway/room configuration will not require Backup Lights while a large room with several subdivisions or irregularly placed rooms, doors, and equipment will require Backup Lights to make egress safer. (3) Reasonable balance between the safety benefits of additional lighting and the man-hours/exposure required for periodic light maintenance. In some plant areas such as building 236-Z, the additional maintenance time and risk of contamination do not warrant having Backup Lights installed in all rooms

  9. Lighting in Schools.

    ERIC Educational Resources Information Center

    Department of Education and Science, London (England).

    The application of good lighting principles to school design is discussed. Part 1 of the study is concerned with the general principles of light and vision as they affect lighting in schools. Parts 2 and 3 deal with the application of these principles to daylighting and artificial lighting. Part 4 discusses the circumstances in which the…

  10. Pedestrian Friendly Outdoor Lighting

    SciTech Connect

    Miller, N. J.; Koltai, R. N.; McGowan, T. K.

    2013-12-01

    The GATEWAY program followed two pedestrian-scale lighting projects that required multiple mockups – one at Stanford University in California and the other at Chautauqua Institution in upstate New York. The report provides insight into pedestrian lighting criteria, how they differ from street and area lighting criteria, and how solid-state lighting can be better applied in pedestrian applications.

  11. Environmental Outdoor Lighting

    NASA Astrophysics Data System (ADS)

    Nelson, D.

    2004-05-01

    Lighting for the outdoor environment presents challenges not usually found in interior lighting. Outdoors, the universal standard is the daytime sun, yet nighttime electric lighting falls far short of daylight. This presentation provides guidance in dealing with these shortcomings, allowing electric lighting systems to solve multiple needs while being responsive to the need for quality exterior lighting. Main aspects include visual issues, ordinances, sources, energy conservation, structure, softscape and hardscape, roadways and walkways, retail and parking lots, sports, and outdoor hospitality lighting. We will review many of the present recommendations for such lighting applications, ones designed to minimize any adverse effects.

  12. Concept of white light in stage lighting

    NASA Astrophysics Data System (ADS)

    Rinaldi, Mauricio R.

    2002-06-01

    In perceiving objects, generally we see them in a white light situation. But, actually, there is not an absolute white, in such a manner that the different light sources have a determined kind of white, what it is known as color temperature. Even the white light may be of different kinds (different color temperature), the individual mind tends to perceive it as the same kind of white, that is to say, there is in our mind a psychological function by which we operate an integration in the perception in order to do the object perceptually invariable. On the other hand, it is a common practice in stage lighting to use color light sources. It is a well known phenomenon that a color of light produces a change in the object color perception. However, when we go to theater, we see the objects as having their real color, even if the lighting is not white. In this paper the concept of white light in stage lighting is presented, showing its possibilities of aesthetical expression.

  13. Lights illuminate surfaces superluminally

    NASA Astrophysics Data System (ADS)

    Nemiroff, Robert J.; Zhong, Qi; Lilleskov, Elias

    2016-07-01

    When a light bulb is turned on, light moves away from it at speed c, by definition. When light from this bulb illuminates a surface, however, this illumination front is not constrained to move at speed c. A simple proof is given that this illumination front always moves faster than c. Generalized, when any compact light source itself varies, this information spreads across all of the surfaces it illuminates at speeds faster than light.

  14. Quality studies of the data taking conditions for the Auger fluorescence detector

    SciTech Connect

    Caruso, R.; Fonte, R.; Insolia, A.; Petrera, S.; Rodriquez Martino, J.; /Rome U.,Tor Vergata

    2005-07-01

    As more than half of the Fluorescence Detector (FD) of the Auger Observatory is completed, data taking is becoming a routine job. It is then necessary to follow strict procedures to assure the quality of the data. An overview of the data taking methods is given. The nature of the FD background signal is due to the night sky brightness (stars and planet faint light, moonlight, twilight, airglow, zodiacal and artificial light) and to the electronic background (photomultiplier and electronic noise). The analysis of the fluctuations in the FADC signal (variance analysis), directly proportional to the background mean light level, performed for each night of data taking is used to monitor the FD background signal. The data quality is analyzed using different techniques, described in detail. Examples of trigger rates, number of stereo events, dead time due to moonlight, weather or hardware problems are given. The analysis comprises several months of data taking, giving an overview of the FD capabilities, performance and allowing a systematic study of data and their correlation with the environment.

  15. The Properties of Light

    NASA Astrophysics Data System (ADS)

    Haglund, Richard F.

    The mystery of light has formed the core of creation stories in every culture, and attracted the earnest attentions of philosophers since at least the fifth century BCE. Their questions have ranged from how and what we see, to the interaction of light with material bodies, and finally to the nature of light itself. This chapter begins with a brief intellectual history of light from ancient Greece to the end of the 19th century. After introducing the physical parameterization of light in terms of standard units, three concepts of light are introduced: light as a wave, light as a quantum particle, and light as a quantum field. After highlighting the distinctive characteristics of light beams from various sources - thermal radiation, luminescence from atoms and molecules, and synchrotron light sources - the distinctive physical characteristics of light beams are examined in some detail. The chapter concludes with a survey of the statistical and quantum-mechanical properties of light beams. In the appropriate limits, this treatment not only recovers the classical description of light waves and the semiclassical view of light as a stream of quanta, but also forms a consistent description of quantum phenomena - such as interference phenomena generated by single photons - that have no classical analogs.

  16. Measurements of Extragalactic Background Light from the Far UV to the Far IR from Deep Ground- and Space-based Galaxy Counts

    NASA Astrophysics Data System (ADS)

    Driver, Simon P.; Andrews, Stephen K.; Davies, Luke J.; Robotham, Aaron S. G.; Wright, Angus H.; Windhorst, Rogier A.; Cohen, Seth; Emig, Kim; Jansen, Rolf A.; Dunne, Loretta

    2016-08-01

    We combine wide and deep galaxy number-count data from the Galaxy And Mass Assembly, COSMOS/G10, Hubble Space Telescope (HST) Early Release Science, HST UVUDF, and various near-, mid-, and far-IR data sets from ESO, Spitzer, and Herschel. The combined data range from the far UV (0.15 μm) to far-IR (500 μm), and in all cases the contribution to the integrated galaxy light (IGL) of successively fainter galaxies converges. Using a simple spline fit, we derive the IGL and the extrapolated IGL in all bands. We argue that undetected low-surface-brightness galaxies and intracluster/group light are modest, and that our extrapolated-IGL measurements are an accurate representation of the extragalactic background light (EBL). Our data agree with most earlier IGL estimates and with direct measurements in the far IR, but disagree strongly with direct estimates in the optical. Close agreement between our results and recent very high-energy experiments (H.E.S.S. and MAGIC) suggests that there may be an additional foreground affecting the direct estimates. The most likely culprit could be the adopted model of zodiacal light. Finally we use a modified version of the two-component model to integrate the EBL and obtain measurements of the cosmic optical background (COB) and cosmic infrared background of {24}-4+4 nW m-2 sr-1 and {26}-5+5 nW m-2 sr-1 respectively (48%:52%). Over the next decade, upcoming space missions such as Euclid and the Wide Field Infrared Space Telescope will have the capacity to reduce the COB error to <1%, at which point comparisons to the very high-energy data could have the potential to provide a direct detection and measurement of the reionization field.

  17. FEASIBILITY OF HELIOSPHERIC IMAGING FROM NEAR EARTH

    SciTech Connect

    DeForest, C. E.; Howard, T. A.

    2015-05-10

    Imaging solar wind structures via Thomson scattered sunlight has proved important to understanding the inner heliosphere. The principal challenge of heliospheric imaging is background subtraction: typical solar wind features are fainter than the zodiacal light and starfield by 2-3 orders of magnitude. Careful post-processing is required to separate the solar wind signal from the static background. Remnant background, and not photon noise, is the dominant noise source in current STEREO data. We demonstrate that 10× shorter exposure times would not strongly affect the noise level in these data. Further, we demonstrate that current processing techniques are sufficient to separate not only the existing background of the STEREO images but also diffuse variable backgrounds such as are expected to be seen from low Earth orbit. We report on a hare-and-hounds style study, demonstrating blind signal extraction from STEREO/HI-2 data that have been degraded by the addition of large-scale, time-dependent artifacts to simulate viewing through airglow or high-altitude aurora. We demonstrate removal of these effects via image processing, with little degradation compared to the original. Even with as few as three highly degraded source images over 48 hr, it is possible to detect and track large coronal mass ejections more than 40° from the Sun. This implies that neither the high altitude aurora discovered by Coriolis/SMEI, nor airglow effects seen from low Earth orbit, are impediments to a hypothetical next-generation heliospheric imager in low Earth orbit; and also that post-processing is as important to heliospheric image qualitiy as are optical contamination effects.

  18. Feasibility of Heliospheric Imaging from Near Earth

    NASA Astrophysics Data System (ADS)

    DeForest, C. E.; Howard, T. A.

    2015-05-01

    Imaging solar wind structures via Thomson scattered sunlight has proved important to understanding the inner heliosphere. The principal challenge of heliospheric imaging is background subtraction: typical solar wind features are fainter than the zodiacal light and starfield by 2-3 orders of magnitude. Careful post-processing is required to separate the solar wind signal from the static background. Remnant background, and not photon noise, is the dominant noise source in current STEREO data. We demonstrate that 10× shorter exposure times would not strongly affect the noise level in these data. Further, we demonstrate that current processing techniques are sufficient to separate not only the existing background of the STEREO images but also diffuse variable backgrounds such as are expected to be seen from low Earth orbit. We report on a hare-and-hounds style study, demonstrating blind signal extraction from STEREO/HI-2 data that have been degraded by the addition of large-scale, time-dependent artifacts to simulate viewing through airglow or high-altitude aurora. We demonstrate removal of these effects via image processing, with little degradation compared to the original. Even with as few as three highly degraded source images over 48 hr, it is possible to detect and track large coronal mass ejections more than 40° from the Sun. This implies that neither the high altitude aurora discovered by Coriolis/SMEI, nor airglow effects seen from low Earth orbit, are impediments to a hypothetical next-generation heliospheric imager in low Earth orbit; and also that post-processing is as important to heliospheric image qualitiy as are optical contamination effects.

  19. Plant Light Measurement & Calculations.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1991-01-01

    The differences between measuring light intensity for the human eye and for plant photosynthesis are discussed. Conversion factors needed to convert various units of light are provided. Photosynthetic efficiency and the electricity costs for plants to undergo photosynthesis using interior lighting are described. (KR)

  20. Seeing the Light

    ERIC Educational Resources Information Center

    Sportel, Samuel; Bruxvoort, Crystal; Jadrich, James

    2009-01-01

    Conceptually, students are typically introduced to light as a type of wave. However, children struggle to understand this model because it is highly abstract. Light can be represented more concretely using the photon model. According to this scientific model, light emanates from sources as tiny "packets" of energy (called "photons") that move in…

  1. Architectural Physics: Lighting.

    ERIC Educational Resources Information Center

    Hopkinson, R. G.

    The author coordinates the many diverse branches of knowledge which have dealt with the field of lighting--physiology, psychology, engineering, physics, and architectural design. Part I, "The Elements of Architectural Physics", discusses the physiological aspects of lighting, visual performance, lighting design, calculations and measurements of…

  2. Light in man's environment

    PubMed Central

    Marshall, J

    2016-01-01

    Light in the form of solar radiation influenced early civilisations and resulted in the independent development of a number of sun-worshipping dieties. These were of particular importance as hunter gatherers transformed into settled agricultural societies. All artificial light sources were synonymous with fire, and early civilisations began to expand their visual day by burning brands, oil, and candles. Fire-based light sources extended for thousands of years and were still present in the era of gas lighting. Light meant fire risk. The advent of incandescent bulbs and the era of electric lighting really only expanded in the early part of the twentieth century. Fluorescent lighting became available in the 1940s, and today the drive for low energy has resulted in a plethora of novel light sources—in particular, light-emitting diodes (LEDs). Evolution governed the development of the eye in relation to roughly 12 h of light gradually changing to 12 h of darkness. Today almost daylight levels can be achieved abruptly at the flick of a switch. Many studies have demonstrated the spectral dependence of eye health, with the retinal hazard zone associated with wavelengths in the blue, peaking at 441 nm— many of today's low-energy sources peak in this region. Given the increased longevity and artificial light sources emitting at biologically unfriendly wavelengths, attention has to be directed towards light in man's environment as a risk factor in age-related ocular diseases. PMID:26742864

  3. Light metals 1989

    SciTech Connect

    Campbell, P.G.

    1989-01-01

    This volume contains a cross section of the most important developments in the light metals field. The papers detail the latest solutions to problems in alumina and bauxite; carbon technology; cast shop technology; reduction technology; and reactive metals. Nearly every important company and research facility in the aluminum industry is represented. Light Metals 1989 is a reference for anyone in light metals technology.

  4. Light in man's environment.

    PubMed

    Marshall, J

    2016-02-01

    Light in the form of solar radiation influenced early civilisations and resulted in the independent development of a number of sun-worshipping dieties. These were of particular importance as hunter gatherers transformed into settled agricultural societies. All artificial light sources were synonymous with fire, and early civilisations began to expand their visual day by burning brands, oil, and candles. Fire-based light sources extended for thousands of years and were still present in the era of gas lighting. Light meant fire risk. The advent of incandescent bulbs and the era of electric lighting really only expanded in the early part of the twentieth century. Fluorescent lighting became available in the 1940s, and today the drive for low energy has resulted in a plethora of novel light sources-in particular, light-emitting diodes (LEDs). Evolution governed the development of the eye in relation to roughly 12 h of light gradually changing to 12 h of darkness. Today almost daylight levels can be achieved abruptly at the flick of a switch. Many studies have demonstrated the spectral dependence of eye health, with the retinal hazard zone associated with wavelengths in the blue, peaking at 441 nm- many of today's low-energy sources peak in this region. Given the increased longevity and artificial light sources emitting at biologically unfriendly wavelengths, attention has to be directed towards light in man's environment as a risk factor in age-related ocular diseases.

  5. CSM/LM Lighting

    NASA Technical Reports Server (NTRS)

    Interbartolo, Michael

    2009-01-01

    Objectives include: a)Identify the types and uses of the various lighting components: Interior (CM, LM), Exterior (CSM, LM); b) Explain the purpose and locations of electroluminescent (EL) and radioluminescent (RL)lighting techniques; c) Understand the use of various D&C lighting components; and d) Understand in-flight anomalies.

  6. Simulating Supernova Light Curves

    SciTech Connect

    Even, Wesley Paul; Dolence, Joshua C.

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  7. Emergency lighting gets 'smarter'.

    PubMed

    Daniels, Alan

    2012-10-01

    Alan Daniels, business development director of emergency lighting specialist, P4, describes the latest trends in, and requirements for, emergency lighting, a vital part of the building services footprint in hospitals and other healthcare premises. He also explains how those responsible for the safe operation of emergency lighting system can ensure they comply with their obligations under the law.

  8. Light On the Behavior of Light Bulbs.

    ERIC Educational Resources Information Center

    Armstrong, H. L.

    1985-01-01

    Discusses a problem (on page 523 of "College Physics," by Sears, Zemansky, and Young, published by Addison-Wesley, 1980) concerning light bulbs and resistance. Shows why the assumption of constant resistance is unrealistic and provides guidelines for revision. (DH)

  9. High Intensity Lights

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Xenon arc lamps developed during the Apollo program by Streamlight, Inc. are the basis for commercial flashlights and emergency handlights. These are some of the brightest portable lights made. They throw a light some 50 times brighter than automobile high beams and are primarily used by police and military. The light penetrates fog and smoke and returns less back-scatter light. They are operated on portable power packs as boat and auto batteries. An infrared model produces totally invisible light for covert surveillance.

  10. Astronomy and Sodium Lighting,

    DTIC Science & Technology

    1984-02-01

    o-... 0 -23- rincreased Oxygen Atoms , Soodum Oxygen Atoms Peckg trom LPS Ligh t Level Limit Motel Br-ue Green...Yellow Orcrge Red Fig. 5 - San Jose 1979 with bPS street lights New Sodium Peaks frome Oxyge.n Atom’s HPS Oxygen Atoms Full Growth Light Level- 1990...Light LevelI 1979 Light Level I L Light Level - 0 Lmt Broad Specr ,,m Excess Li;hl SVoel Blue Gpen Yelloo Oro-’e Red Fig. 6 -- Sarn Jose with 11PS street

  11. Roadmap on structured light

    NASA Astrophysics Data System (ADS)

    Rubinsztein-Dunlop, Halina; Forbes, Andrew; Berry, M. V.; Dennis, M. R.; Andrews, David L.; Mansuripur, Masud; Denz, Cornelia; Alpmann, Christina; Banzer, Peter; Bauer, Thomas; Karimi, Ebrahim; Marrucci, Lorenzo; Padgett, Miles; Ritsch-Marte, Monika; Litchinitser, Natalia M.; Bigelow, Nicholas P.; Rosales-Guzmán, C.; Belmonte, A.; Torres, J. P.; Neely, Tyler W.; Baker, Mark; Gordon, Reuven; Stilgoe, Alexander B.; Romero, Jacquiline; White, Andrew G.; Fickler, Robert; Willner, Alan E.; Xie, Guodong; McMorran, Benjamin; Weiner, Andrew M.

    2017-01-01

    Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized.

  12. Light-storing photocatalyst

    SciTech Connect

    Zhang Junying; Pan Feng; Hao Weichang; Ge Qi; Wang Tianmian

    2004-12-06

    Light-storing photocatalyst was prepared by coating light-storing phosphor and TiO{sub 2} photocatalyst in sequence on ceramic. The light-storing photocatalyst can store light irradiation and emit slowly. Consequently, the photocatalyst remains active when the irradiation source is cut off. Rhodamine B (RhB) can be decomposed efficiently by this photocatalyst in the dark after it absorbs light irradiation. This photocatalyst is photoreactive in an outdoor environment or can save energy by supplying irradiation intermittently for the photocatalyst.

  13. Light Emitting Diode (LED)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique called photodynamic therapy, requires the surgeon to use tiny pinhead-size Light Emitting Diodes (LEDs) (a source releasing long wavelengths of light) to activate light-sensitive, tumor-treating drugs. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can also be used for hours at a time while still remaining cool to the touch. The LED probe consists of 144 tiny pinhead-size diodes, is 9-inches long, and about one-half-inch in diameter. The small balloon aids in even distribution of the light source. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The probe was developed for photodynamic cancer therapy by the Marshall Space Flight Center under a NASA Small Business Innovative Research program grant.

  14. Deep IRAC Imaging Lensing Galaxy Clusters for JWST 'First Light' Search

    NASA Astrophysics Data System (ADS)

    Yan, Haojing; Conselice, Christopher; Windhorst, Rogier; Cohen, Seth; Alpaslan, Mehmet; Zitrin, Adi; Broadhurst, Tom; Frye, Brenda; Driver, Simon; Robotham, Aaron; Hopkins, Andrew; Wyithe, Staurt; Jansen, Rolf; Hathi, Nimish; Mechtley, Matthew; Ryan, Russell; Rutkowski, Michael; Finkelstein, Steven; Koekemoer, Anton

    2016-08-01

    JWST has a key goal to search for First Light objects beyond z>10. Our 110-hr JWST GTO program, 'Webb Medium-Deep Fields' (WMDF), will target both blank and lensed fields to probe both the bright and the faint ends of the galaxy luminosity function at z > 10. While a number of well studied lensing clusters exist, not all of them are optimal for the JWST search of First Light objects, either because of their low Ecliptic latitudes (and hence high Zodiacal background) or because of their strong intra-cluster light (ICL) at the critical curve regions corresponding to the redshifts of interest. For this reason, our WMDF candidate lensing targets will include some recently discovered, high-mass (log[M/Msun] ~ 15) galaxy clusters, which we choose either because of their high Ecliptic latitude (beta > 40 deg) or because of their extreme compactness that minimizes the impact of the ICL. As part of our effort to collect ancillary data for these new systems to finalize the target list, we propose IRAC observations for 13 of them that are lacking sufficient data. These 3.6/4.5um data will be critical for our guaranteed JWST program: (1) they will greatly facilitate the modeling of the straylight that JWST will suffer in 1--5 um (the key range to search for z>10--20 objects), a problem that has recently been identified. If left untreated, such straylight components would severely hamper the detection of faint sources in a lensing field. The JWST observations alone would be difficult to separate the ICL from the straylight at the level needed. (2) the new 3.6/4.5um data will best match our deep optical imaging and spectroscopy at HST, Gemini, LBT and MMT. We will derive accurate photometric redshifts for any lensed background galaxies (at z<6) and most member galaxies in the outskirts, which will be critical in refining the mass profile through strong/weak lensing analysis. Finally, we note that these data will be highly valuable for the study of these clusters themselves

  15. Photonic crystal light source

    DOEpatents

    Fleming, James G.; Lin, Shawn-Yu; Bur, James A.

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  16. Development of Data Analysis Techniques to Provide Photometric Images for a Heliospheric Imager

    DTIC Science & Technology

    2008-10-31

    signed / / signed / JANET C. JOHNSTON...ejections Heliospheric plasma 3D tomography Zodiacal light Spaceborne optical instrument Janet C. Johnston UNCL UNCL UNCL...waves. The instrument evolved from the heliospheric imaging capability demonstrated by the zodiacal light photometers of the Helios spacecraft. A near

  17. Navigation lights color study

    NASA Astrophysics Data System (ADS)

    Barbosa, Jose G.; Alberg, Matthew T.

    2015-05-01

    The chromaticity of navigation lights are defined by areas on the International Commission on Illumination (CIE) 1931 chromaticity diagram. The corner coordinates for these areas are specified in the International Regulations for Prevention of Collisions at Sea, 1972 (72 COLREGS). The navigation light's color of white, red, green, and yellow are bounded by these areas. The chromaticity values specified by the COLREGS for navigation lights were intended for the human visual system (HVS). The HVS can determine the colors of these lights easily under various conditions. For digital color camera imaging systems the colors of these lights are dependent on the camera's color spectral sensitivity, settings, and color correction. At night the color of these lights are used to quickly determine the relative course of vessels. If these lights are incorrectly identified or there is a delay in identifying them this could be a potential safety of ship concern. Vessels that use camera imaging systems exclusively for sight, at night, need to detect, identify, and discriminate navigation lights for navigation and collision avoidance. The introduction of light emitting diode (LED) lights and lights with different spectral signatures have the potential to be imaged very differently with an RGB color filter array (CFA) color camera than with the human eye. It has been found that some green navigation lights' images appear blue verse green. This has an impact on vessels that use camera imaging systems exclusively for navigation. This paper will characterize color cameras ability to properly reproducing navigation lights' color and survey a set of navigation light to determine if they conform to the COLREGS.

  18. Studying Light Color using White LED Lighting

    NASA Astrophysics Data System (ADS)

    Yamagishi, Misako; Yamaba, Kazuo; Nagata, Manori; Kubo, Chiho; Nokura, Kunihiro

    Recently, white Light Emitting Diodes (LEDs) are receiving attention worldwide as new lighting devices. This study examined effects of a lighting application on performance using white LEDs. The light color—the correlated color temperature (CCT) —was assessed. It affected to psychological states and physiological conditions. Three CCT conditions were respectively set for the experiment: 2500 K, 5000 K, and 8200 K. In all, 20 younger subjects (20-30 years old), 15 middle-aged to elderly subjects (45-60 years old) and 12 elderly subjects (over 65 years-old) participated. They were presented a Numerical Verification (NV) task for performance measurement. The psychological states on performance were evaluated using the lighting assessment questionnaire. The physiological conditions were recorded using an electrocardiograph. Results show that the effects of CCT differ among age groups. Especially, the performance of younger subjects might differ from CCT conditions; elderly subjects are affected by CCT condition because of their visual acuity or response to contrast of objects.

  19. Light Emitting Diodes (LEDs)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique, called Photodynamic Therapy, requires the surgeon to use tiny, pinhead-size Light Emitting Diodes (LEDs) (a source that releases long wavelengths of light ) to activate light-sensitive, tumor-treating drugs. 'A young woman operated on in May 1999 has fully recovered with no complications and no evidence of the tumor coming back,' said Dr. Harry Whelan, a pediatric neurologist at the Medical Hospital of Wisconsin in Milwaukee. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can be used for hours at a time while still remaining cool to the touch. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The LEDs, developed and managed by NASA's Marshall Space Flight Center, have been used on seven Space Shuttle flights inside the Microgravity Astroculture Facility. This technology has also been successfully used to further commercial research in crop growth.

  20. Light metal production

    DOEpatents

    Fan, Qinbai

    2016-04-19

    An electrochemical process for the production of light metals, particularly aluminum. Such a process involves contacting a light metal source material with an inorganic acid to form a solution containing the light metal ions in high concentration. The solution is fed to an electrochemical reactor assembly having an anode side containing an anode and a cathode side containing a cathode, with anode side and the cathode side separated by a bipolar membrane, with the solution being fed to the anode side. Light metal ions are electrochemically transferred through the bipolar membrane to the cathode side. The process further involves reducing the light metal ions to light metal powder. An associated processing system is also provided.

  1. National Synchrotron Light Source

    ScienceCinema

    BNL

    2016-07-12

    A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

  2. Berkeley Lighting Cone

    SciTech Connect

    Lask, Kathleen; Gadgil, Ashok

    2016-10-24

    A lighting cone is a simple metal cone placed on the fuel bed of a stove during ignition to act as a chimney, increasing the draft through the fuel bed. Many stoves tend to be difficult to light due to poor draft through the fuel bed, so lighting cones are used in various parts of the world as an inexpensive accessory to help with ignition.

  3. High efficiency incandescent lighting

    SciTech Connect

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

  4. Dissecting a Light Echo

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for audio animation

    This animation illustrates how a light echo works, and how an optical illusion of material moving outward is created.

    A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one.

    The animation starts by showing the explosion of a star, which results in a flash of light that moves outward in all directions. The direction of our line of sight from Earth is indicated by the blue arrow.

    When the light flash reaches surrounding dust, shown here as three dark clouds, the dust is heated up, creating infrared light that begins to travel toward Earth (indicated by the red arrows). Dust closest to the explosion lights up first, while the explosion's shock wave takes longer to reach more distant material. This results in light from different parts of the cloud reaching Earth at different times, creating the illusion of motion over time.

    As the animation shows, the inclination of the cloud toward our line of sight can result in the material seeming to move both away from and toward the central star.

  5. Photovoltaic lighting system performance

    SciTech Connect

    Harrington, S.R.; Hund, T.D.

    1996-06-01

    The performance of 21 PV-powered low pressure sodium lighting systems on a multi-use has been documented in this paper. Specific areas for evaluation include the vandal resistant PV modules, constant voltage and on/off PV charge controllers, flooded deep-cycle lead-antimony and valve regulated lead-acid (VLRA) gel batteries, and low pressure sodium ballasts and lights. The PV lighting system maintenance intervals and lessons learned have been documented over the past 2.5 years. The above performance data has shown that with careful hardware selection, installation, and maintenance intervals the PV lighting systems will operate reliably.

  6. Theodolite Ring Lights

    NASA Technical Reports Server (NTRS)

    Clark, David

    2006-01-01

    Theodolite ring lights have been invented to ease a difficulty encountered in the well-established optical-metrology practice of using highly reflective spherical tooling balls as position references. A theodolite ring light produces a more easily visible reflection and eliminates the need for an autocollimating device. A theodolite ring light is a very bright light source that is well centered on the optical axis of the instrument. It can be fabricated, easily and inexpensively, for use on a theodolite or telescope of any diameter.

  7. Natural light illumination system.

    PubMed

    Whang, Allen Jong-Woei; Chen, Yi-Yung; Yang, Shu-Hua; Pan, Po-Hsuan; Chou, Kao-Hsu; Lee, Yu-Chi; Lee, Zong-Yi; Chen, Chi-An; Chen, Cheng-Nan

    2010-12-10

    In recent years, green energy has undergone a lot of development and has been the subject of many applications. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting. Natural light illumination systems have collecting, transmitting, and lighting elements. Today, most daylight collectors use dynamic concentrators; these include Sun tracking systems. However, this design is too expensive to be cost effective. To create a low-cost collector that can be easily installed on a large building, we have designed a static concentrator, which is prismatic and cascadable, to collect sunlight for indoor illumination. The transmission component uses a large number of optical fibers. Because optical fibers are expensive, this means that most of the cost for the system will be related to transmission. In this paper, we also use a prismatic structure to design an optical coupler for coupling n to 1. With the n-to-1 coupler, the number of optical fibers necessary can be greatly reduced. Although this new natural light illumination system can effectively guide collected sunlight and send it to the basement or to other indoor places for healthy lighting, previously there has been no way to manage the collected sunlight when lighting was not desired. To solve this problem, we have designed an optical switch and a beam splitter to control and separate the transmitted light. When replacing traditional sources, the lighting should have similar characteristics, such as intensity distribution and geometric parameters, to those of traditional artificial sources. We have designed, simulated, and optimized an illumination lightpipe with a dot pattern to redistribute the collected sunlight from the natural light illumination system such that it equals the qualities of a traditional lighting system. We also provide an active lighting module that provides lighting from the natural light illumination system or LED auxiliary

  8. The Traffic Light Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2014-01-01

    Traffic lights are an important part of the transportation infrastructure, regulating traffic flow and maintaining safety when crossing busy streets. When they go awry or become nonfunctional, a great deal of havoc and danger can be present. During power outages, the street lights go out all over the affected area. It would be good to be able to…

  9. Demand-controlled lighting

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1977-01-01

    Automatic lighting is controlled by photocell that measures intensity of available light. Photocell drives motor which operates mercury switches controlling indoor illumination sources. Device effects increase in indoor illumination intensity when illumination input to cell is insufficient. Reverse is true if input is too great.

  10. OBSTRUCTION LIGHT SYSTEM.

    DTIC Science & Technology

    The report describes the design, development and fabrication of a prototype high intensity obstruction lighting system. A detailed light source ... study was made which indicated a newly developed lamp consisting of a quartz-iodide lamp sealed in a parabolic envelope, was the most advantageous type

  11. Semiconductor Spatial Light Modulators.

    DTIC Science & Technology

    1982-06-01

    16 8 Experimental transmission coefficient in sample garnet ........ ........................ ... 17 9 Typical energy states...laser beam. Carrier lifetime is 4.0 microseconds ............ .... 45 15 Silicon energy band diagram with allowed optical transitions, a) Interband...silicon as a function of 1.06nm light energy ..... ................... .... 62 24 Calculated absorption coefficient in silicon as a function of 1.06n light

  12. Light intensity compressor

    DOEpatents

    Rushford, Michael C.

    1990-01-01

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  13. Light-Emitting Pickles

    ERIC Educational Resources Information Center

    Vollmer, M.; Mollmann, K-P.

    2015-01-01

    We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

  14. Light intensity compressor

    DOEpatents

    Rushford, Michael C.

    1990-02-06

    In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.

  15. Lighting in Architectural Design.

    ERIC Educational Resources Information Center

    Phillips, Derek

    The primary function of this book is to treat the topic of lighting design in such a manner as to bridge the gap between architects and illuminating engineers. The work is divided into three parts: Part I, Principles of Design, offers information and analysis of how natural and artificial lighting affects building design, how illumination levels…

  16. Splayed mirror light pipes

    SciTech Connect

    Swift, P.D.

    2010-02-15

    An expression is given for the transmission of the rectangular-section mirror light pipe. The expression is used to model throughputs for simulated solar conditions over a calender year. It is found that the splaying of a mirror light pipe results in a significant increase in throughputs particularly in winter months. (author)

  17. Shedding Some Light.

    ERIC Educational Resources Information Center

    Whitney, Tim

    1998-01-01

    Discusses the basics of designing natural and artificial light in an indoor athletic facility. Also examines individual lighting requirements of typical rooms such as weight and fitness rooms, aerobics and multipurpose rooms, gymnasiums, field houses, pools, and racquetball and squash courts. (GR)

  18. Handrail Lighting Module

    NASA Technical Reports Server (NTRS)

    Mattei, John P.

    1988-01-01

    Lightweight, space-saving combined handrail-and-flourescent-light unit serves decorative or safety functions. Fluorescent lamp mounted inside clear tubular plastic housing shaped to form handrail. Designed for either temporary or permanent installation or part of emergency lighting system.

  19. Lighting for Schools.

    ERIC Educational Resources Information Center

    Benya, James R.

    This publication highlights some of the benefits of proper daylighting design in educational facilities, discusses energy efficient electric lighting choices schools can make that are long lasting and require little maintenance, and offers six steps for designing lighting systems that use half the energy of earlier conventional designs. Several…

  20. Light-emitting Diodes

    PubMed Central

    Opel, Daniel R.; Hagstrom, Erika; Pace, Aaron K.; Sisto, Krisanne; Hirano-Ali, Stefanie A.; Desai, Shraddha

    2015-01-01

    Background: In the early 1990s, the biological significance of light-emitting diodes was realized. Since this discovery, various light sources have been investigated for their cutaneous effects. Study design: A Medline search was performed on light-emitting diode lights and their therapeutic effects between 1996 and 2010. Additionally, an open-label, investigator-blinded study was performed using a yellow light-emitting diode device to treat acne, rosacea, photoaging, alopecia areata, and androgenetic alopecia. Results: The authors identified several case-based reports, small case series, and a few randomized controlled trials evaluating the use of four different wavelengths of light-emitting diodes. These devices were classified as red, blue, yellow, or infrared, and covered a wide range of clinical applications. The 21 patients the authors treated had mixed results regarding patient satisfaction and pre- and post-treatment evaluation of improvement in clinical appearance. Conclusion: Review of the literature revealed that differing wavelengths of light-emitting diode devices have many beneficial effects, including wound healing, acne treatment, sunburn prevention, phototherapy for facial rhytides, and skin rejuvenation. The authors’ clinical experience with a specific yellow light-emitting diode device was mixed, depending on the condition being treated, and was likely influenced by the device parameters. PMID:26155326

  1. Explosively pumped laser light

    DOEpatents

    Piltch, Martin S.; Michelotti, Roy A.

    1991-01-01

    A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.

  2. Incoherent Light Sources

    NASA Astrophysics Data System (ADS)

    Bertram, Dietrich; Born, Matthias; Jüstel, Thomas

    Since the invention and industrialization of incandescent lamps at the end radiation of the 19th century electrical lighting has become a commodity in our daily life. Today, incoherent light sources are used for numerous application areas. Major improvements have been achieved over the past decades with respect to lamp efficiency (Fig. 10.1), lifetime and color properties.

  3. Incoherent Light Sources

    NASA Astrophysics Data System (ADS)

    Bertram, Dietrich; Born, Matthias; Jüstel, Thomas

    Since the invention and industrialization of incandescent lamps at the end of the 19th century electrical lighting has become a commodity in our daily life. Today, incoherent light sources are used for numerous application areas. Major improvements have been achieved over the past decades with respect to lamp efficiency Fig. 10.1, lifetime and color properties.

  4. Lighting for Education.

    ERIC Educational Resources Information Center

    Ontario Ministry of Colleges and Universities, Toronto.

    Some of the qualities and quantities that must be juggled to produce good lighting for educational facilities are analyzed with photographs, tables, and drawings. The three categories of lamps used for school lighting (incandescent, fluorescent, and high intensity discharge) are described; a lamp selection guide gives the design characteristics of…

  5. Shedding Light on Learning.

    ERIC Educational Resources Information Center

    Graves, Ben E.

    1985-01-01

    Summarizes findings of an Alberta light/color study that looked at mood, noise levels, IQ test scores, blood pressure, and absences under fluorescent or full-spectrum light in two color schemes in four elementary schools with 700 students. (MLF)

  6. Enriching lighting design.

    PubMed

    Brawley, Elizabeth C

    2009-01-01

    Good lighting is perhaps the most important and least understood element in designing healthcare environments. Both physically and mentally challenged individuals become more vulnerable and dependent on their environment to compensate for sensory impairments, including dimming eyesight, which interferes to some degree with daily activities as well as social and leisure activities - the things that provide emotional and social well-being. Too few building designs today result in lighting that meets the needs of these individuals, regardless of age. Typical lighting in most care environments is inadequate to meet lighting needs affecting both vision and the photobiological (non-visual) needs of synchronization of circadian rhythm, which impacts sleep and depression. Well-designed lighting is one of the most important design elements that will support an individual's ability to perform normal daily activities and decrease the level of disability associated with these impairments. Daylight contains the spectrum to which the circadian clock is most sensitive and provides higher light levels during the day. Easily accessible outdoor gardens encourage individuals outside, providing the necessary regular exposure to direct bright light that sunlight provides. The combination good interior lighting and regular daylight exposure contributes to regaining and maintaining an active and fulfilling lifestyle - greatly improving quality of life.

  7. The light ion trough.

    NASA Technical Reports Server (NTRS)

    Taylor, H. A., Jr.

    1972-01-01

    A distinct feature of the ion composition results from the OGO-2, 4 and 6 satellites is the light ion trough, wherein the mid-latitude concentrations of H+ and He+ decrease sharply with latitude. In contrast to the 'main trough' in electron density observed primarily as a nightside phenomenon, the light ion trough persists during both day and night. For daytime winter hemisphere conditions and for all seasons during night, the mid-latitude light ion concentration decrease is a pronounced feature. In the dayside summer and equinox hemispheres, the rate of light ion decrease with latitude is comparatively gradual, and the trough boundary is less well defined, particularly for quiet magnetic conditions. In response to magnetic storms, the light ion trough minimum moves equatorward, and deepens, consistent with earlier evidence of the contraction of the plasmasphere in response to storm time enhancements in magnetospheric plasma convection.

  8. Stray Light Analysis

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Based on a Small Business Innovation Research contract from the Jet Propulsion Laboratory, TracePro is state-of-the-art interactive software created by Lambda Research Corporation to detect stray light in optical systems. An image can be ruined by incidental light in an optical system. To maintain image excellence from an optical system, stray light must be detected and eliminated. TracePro accounts for absorption, specular reflection and refraction, scattering and aperture diffraction of light. Output from the software consists of spatial irradiance plots and angular radiance plots. Results can be viewed as contour maps or as ray histories in tabular form. TracePro is adept at modeling solids such as lenses, baffles, light pipes, integrating spheres, non-imaging concentrators, and complete illumination systems. The firm's customer base includes Lockheed Martin, Samsung Electronics and other manufacturing, optical, aerospace, and educational companies worldwide.

  9. Sources of Interplanetary Dust and the Zodiacal Cloud (Invited)

    NASA Astrophysics Data System (ADS)

    Flynn, G. J.

    2013-12-01

    Every Solar System object is a potential source of interplanetary dust (IDPs) produced by impact cratering, disruption, or emission. Two major sources were identified by infrared observation of dust trails - asteroids and comets, and modeling shows collisions in the Kuiper Belt could also contribute significantly (Flynn, 1996). Gravitational focusing substantially enhances the flux into the Earth's atmosphere of particles in near-circular orbits, e.g. asteroidal dust, over dust in eccentric orbits (Flynn, 1989). Modeling by Kortenkamp et al. (1998) indicates that the asteroid families contribute a large fraction of the dust accreted by the Earth and fewer than 25% of accreted IDPs come from comets. The most significant constraint on the source(s) of the ~5 to 20 micron diameter IDPs comes from the survival of the larger, 100 to 10,000 micron, micrometeorites. Space exposure ages of micrometeorites, inferred from spallogenic Ne and radiogenic nuclides, range from ~10^5 to 2x10^7 years (Olinger et al., 1990; Raisbeck and Yiou, 1989; Nishiizumi et al., 1991), consistent with the timescale for orbital evolution of these micrometeorites from the asteroid belt to Earth under Poynting-Robertson drag. The elemental and mineralogical compositions of micrometeorites show strong similarities to ordinary chondrites, the dominant objects of the main belt. Relative abundances of the radionuclides demonstrate that micrometeorites were irradiated in space as small objects (<1 cm), so they are not material released from meteorites either during atmospheric entry or in space shortly before Earth encounter. Further, Nishiizumi et al. (1991) concluded that the exposure took place in the inner solar system, not in highly eccentric orbits, suggesting the micrometeorites were generated by collisions in the asteroid belt and evolved to Earth-crossing orbits by Poynting-Robertson drag. However, numerous calculations of the catastrophic disruption lifetimes of 100 to 10,000 micron particles in the inner solar system (Dohnanyi, 1978; Leinert et al., 1983; Grun et al., 1985; Steel and Elford, 1986) are one to three orders-of-magnitude lower than the observed space exposures of these particles. The possibility that only rare survivors from the micrometeorite population reach Earth is can be ruled out, because disruption of most micrometeorites, which are at the peak of the mass influx to Earth, during orbital evolution to the Earth encounter would produce numerous 5 to 20 micron fragments. But the 5 to 20 micron IDPs collected from the stratosphere are carbon-rich (Schramm et al., 1989) while the micrometeorites are low-carbon ordinary chondrites. The disruption lifetime calculations for micrometeorites are based in the assumption that the observed flux of IDPs, the particles that disrupt the micrometeorites, are in elliptical, or comet-like, orbits. If the IDPs are in nearly circular orbits, as would be expected for particles generated in the asteroid belt and spiraling inwards under Poynting-Robertson drag, the collision probability is greatly reduced. The survival of main-belt asteroidal micrometeorites indicates that much of the flux of 5 to 20 micron IDPs must originate either from a main belt asteroidal source of from cometary sources that have had their orbits nearly completely circularized by planetary gravitational perturbations.

  10. The Impact of Zodiac Signs on Human Nature and Fate

    NASA Astrophysics Data System (ADS)

    Gasparyan, Naira

    2015-07-01

    Horoscope signs have unavoidable impact on human behaviour and interests, health and even fate. Moreover, intermingled with the impact of planets they become a powerful force able to bring about unbelievable changes. The investigation reveals that horoscopes have existed in the Armenian reality since ancient times. The most striking fact about their eistence is that in order to have and use zodiak signs in one's national culture, the nation should first of all have sufficient knowledge in Astrological Sciences since the system of zodiak signs has a direct reference to the cognitive processes and scientific knowledge of the universe, astrological issues and sometimes even there is a hint on hidden signs and messages. Anania Shirakatsi, one of the learned Armenians, had to display much diplomacy with the Armenian Church and religion when discussing the topic in his manuscripts. His observations are still of much importance and vitality even today.

  11. American Zodiac: Astronomical signs in Dickinson, Melville, and Poe

    NASA Astrophysics Data System (ADS)

    Ricca, Bradley James

    2003-11-01

    Science and literature, two means of inquiry now thought in opposition (if not posed as outright contradiction) emerged for a moment in the nineteenth century as provocatively complimentary in their methods of reading. In America, astronomy in particular provided a rich, complex subject for writers of the imagination to think about in terms of content and methodology. The purpose of my study is to uncover these unacknowledged astronomical referents in the works of Emily Dickinson, Herman Melville, and Edgar Allan Poe, and engage them as interpretive contexts in new readings of their most esoteric projects; specifically, Dickinson's solstice and circumference poetry, the Plinlimmon pamphlet in Melville's Pierre, and Poe's Eureka. After providing historical context through the shared public experience of the 1833 Leonid Meteor Storm, I uncover several astronomical and scientific sources for these writers: Denison Olmsted for Dickinson; Gauss and Plotinus for Melville; and Kepler and Alexander von Humboldt for Poe, among others. Exploring these sources in close readings of their works, I find that these authors employ astronomical facts in very different, metaphorical ways in response to the larger challenge of navigating their own poetics between the emerging new laws of science and the immeasurability of human feeling evoked by the unknown Universe.

  12. [Xenon light therapy].

    PubMed

    Kanai, Akifumi

    2012-07-01

    The xenon light, generated by high-intensity electrical stimulation of xenon gas, is used to sterilize wounds, aid tissue repair, and relieve pain as a low-level light therapy. The light produced consists of non-coherent beams of multiple wavelengths in the ultraviolet to infrared spectrum. This broad-band light can be emitted in a continuous wave or pulsed mode, with the wave band chosen and the energy distribution controlled for the purpose. Specifically, wavelengths in the 500-700 nm range are suitable for treating superficial tissue, and wavelengths between 800 and 1,000 nm are suitable for deeper-seated tissues, due to longer optical penetration distances through tissue. One of the most common benefits in the xenon light therapy is considered to be the wide and deep irradiation of optimal rays to living tissue. Research into the use of xenon light for tissue repair and pain reduction is restricted within open-label studies and case reports. The present review expounded the effects of xenon light therapy on the basis of the available evidence in vitro and in vivo studies using a laser beam of single wavelength.

  13. 3. View from former light tower to Cape Elizabeth Light ...

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

    3. View from former light tower to Cape Elizabeth Light Tower, view northeast, southwest side of Cape Elizabeth Tower - Cape Elizabeth Light Station, Near Two Lights State Park at end of Two Lights Road, off State Highway 77, Cape Elizabeth, Cumberland County, ME

  14. City Lights of Europe

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Growth in 'mega-cities' is altering the landscape and the atmosphere in such a way as to curtail normal photosynthesis. By using data from The Defense Meteorological Satellite Program's Operational Linescan System, researchers have been able to look at urban sprawl by monitoring the emission of light from cities at night. By overlaying these 'light maps' onto other data such as soil and vegetation maps, the research shows that urbanization can have a variable but measurable impact on photosynthetic productivity. For more information, read Bright Lights, Big City Image by the NASA GSFC Scientific Visualization Studio

  15. Light harvesting dendrimers.

    PubMed

    Nantalaksakul, Arpornrat; Reddy, D Raghunath; Bardeen, Christopher J; Thayumanavan, S

    2006-01-01

    Tree-like dendrimers with decreasing number of chromophores from periphery to core is an attractive candidate for light-harvesting applications. Numerous dendritic designs with different kinds of light-collecting chromophores at periphery and an energy-sink at the core have been demonstrated with high energy transfer efficiency. These building blocks are now being developed for several applications such as light-emitting diodes, frequency converters and other photonic devices. This review outlines the efforts that are based on both conjugated and non-conjugated dendrimers.

  16. Green Light Pulse Oximeter

    DOEpatents

    Scharf, John Edward

    1998-11-03

    A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

  17. Light-weight plastination.

    PubMed

    Steinke, Hanno; Rabi, Suganthy; Saito, Toshiyuki; Sawutti, Alimjan; Miyaki, Takayoshi; Itoh, Masahiro; Spanel-Borowski, Katharina

    2008-11-20

    Plastination is an excellent technique which helps to keep the anatomical specimens in a dry, odourless state. Since the invention of plastination technique by von Hagens, research has been done to improve the quality of plastinated specimens. In this paper, we have described a method of producing light-weight plastinated specimens using xylene along with silicone and in the final step, substitute xylene with air. The finished plastinated specimens were light-weight, dry, odourless and robust. This method requires less use of resin thus making the plastination technique more cost-effective. The light-weight specimens are easy to carry and can easily be used for teaching.

  18. Differentiating spatial light modulator

    NASA Astrophysics Data System (ADS)

    Armitage, D.

    1985-04-01

    A differentiating spatial light modulator device in which a photoreceptor and an electro-optic crystal are isolated by a dielectric mirror is discussed. The electro-optic crystal is configured to have low or zero longitudinal response, yet is sensitive to transverse electric fields. The fringe field generated by the photoreceptor (photodiode) modulates the crystal birefringence. Readout via a polarizing beamsplitter gives an output light related to the spatial gradient of the input light. In a liquid crystal embodiment of the invention, reversal of the applied voltage gives a driven off state which speeds the erasure. Storage is possible in the smectic liquid crystal phase.

  19. Light multinary computing

    NASA Astrophysics Data System (ADS)

    Arago, Jaime

    2012-11-01

    Next-generation optical communication and optical computing imply an evolution from binary to multinary computing. Light multinary computing encodes data using pulses of light components in higher orders than binary and processes it using truth tables larger than Boolean ones. This results in lesser encoded data that can be processed at faster speeds. We use a general-purpose optical transistor as the building block to develop the main computing units for counting, distributing, storing, and logically operating the arithmetic addition of two bytes of base-10 data. Currently available optical switching technologies can be used to physically implement light multinary computing to achieve ultra-high speed communication and computing.

  20. White light velocity interferometer

    DOEpatents

    Erskine, D.J.

    1999-06-08

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

  1. White light velocity interferometer

    DOEpatents

    Erskine, D.J.

    1997-06-24

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.

  2. White light velocity interferometer

    DOEpatents

    Erskine, David J.

    1999-01-01

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

  3. White light velocity interferometer

    DOEpatents

    Erskine, David J.

    1997-01-01

    The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s.

  4. AUTOMATIC LIGHT CONTROL

    DOEpatents

    Artzt, M.

    1957-08-27

    A control system for a projection kinescope used in a facsimile scanning system and, in particular, meams for maintaining substantially constant the light emanating from the flying spot on the face of the kinescope are described. In general, the invention provides a feeler member disposed in such a position with respect to a projecting lens as to intercept a portion of the light striking the lens. Suitable circuitry in conjunction with a photomultiplier tube provides a signal proportional to the light intensity of the flying spot. The grid bias on the kinescope is controlled by this signal to maintain the intensity of the spot substantially constant.

  5. Shining a Light on Electronics

    ERIC Educational Resources Information Center

    Statler, James D.

    2009-01-01

    While they produced a limited amount of light when first introduced, light-emitting diode (LED) lights offered the benefit of rarely burning out. As a result, they were initially used primarily as indicator lights. Advances in the technology have made available LEDs that produce far brighter light, and one application that has come to market is…

  6. 10. LIGHT TOWER, VIEW NORTHEAST FROM LIGHT PLATFORM, SOUTHWEST SIDE ...

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

    10. LIGHT TOWER, VIEW NORTHEAST FROM LIGHT PLATFORM, SOUTHWEST SIDE OF BOAT HOUSE AND KEEPER'S HOUSE, WITH DETAIL OF RAILING IN FOREGROUND - Grindle Point Light Station, Western end of Ferry Road on Grindle Point, Islesboro, Waldo County, ME

  7. Exotic Light Nuclei

    ERIC Educational Resources Information Center

    Cerny, Joseph; Poskanzer, Arthur M.

    1978-01-01

    Among the light elements, nuclei with unequal numbers of protons and neutrons are highly unstable. Some survive just long enough to be detected and exhibit unusual regimes of radioactive decay. ( Autor/MA)

  8. Magic of Light

    NASA Astrophysics Data System (ADS)

    Curticapean, Dan

    2010-08-01

    This paper focuses on the concept of the website "Magic of Light", an internet platform that offers podcasts, slides, pictures, Flash animations and educational materials to allow a better understanding in optics and photonics.

  9. Light on curved backgrounds

    NASA Astrophysics Data System (ADS)

    Batic, D.; Nelson, S.; Nowakowski, M.

    2015-05-01

    We consider the motion of light on different spacetime manifolds by calculating the deflection angle, lensing properties and by probing into the possibility of bound states. The metrics in which we examine the light motion include, among other items, a general relativistic dark matter metric, a dirty black hole, and a worm hole metric, the last two inspired by noncommutative geometry. The lensing in a holographic screen metric is discussed in detail. We study also the bending of light around naked singularities like, e.g., the Janis-Newman-Winicour metric and include other cases. A generic property of light behavior in these exotic metrics is pointed out. For the standard metric like the Schwarzschild and Schwarzschild-de Sitter cases, we improve the accuracy of the lensing results for the weak and strong regimes.

  10. Cauldron of Light

    NASA Video Gallery

    In this animation, a seething cauldron of light appears to bubble and ooze around the remains of a giant star that astronomers have been watching tear itself apart for the last 300 years. This movi...

  11. Polarized Light Corridor Demonstrations.

    ERIC Educational Resources Information Center

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  12. National Synchrotron Light Source

    ScienceCinema

    None

    2016-07-12

    A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

  13. Ferroelectric Light Control Device

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon (Inventor); Choi, Sang H. (Inventor); King, Glen C. (Inventor); Kim, Jae-Woo (Inventor); Elliott, Jr., James R. (Inventor)

    2008-01-01

    A light control device is formed by ferroelectric material and N electrodes positioned adjacent thereto to define an N-sided regular polygonal region or circular region there between where N is a multiple of four.

  14. Dark light Higgs bosons.

    SciTech Connect

    Draper, P.; Liu, T.; Wagner, C. E. M.; Wang, L.-T.; Zhang, H.

    2011-03-24

    We study a limit of the nearly Peccei-Quinn-symmetric next-to-minimal supersymmetric standard model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally coexist three light singletlike particles: a scalar, a pseudoscalar, and a singlinolike DM candidate, all with masses of order 0.1-10 GeV. The decay of a standard model-like Higgs boson to pairs of the light scalars or pseudoscalars is generically suppressed, avoiding constraints from collider searches for these channels. For a certain parameter window annihilation into the light pseudoscalar and exchange of the light scalar with nucleons allow the singlino to achieve the correct relic density and a large direct-detection cross section consistent with the DM direct-detection experiments, CoGeNT and DAMA/LIBRA, preferred region simultaneously. This parameter space is consistent with experimental constraints from LEP, the Tevatron, ?, and flavor physics.

  15. National Synchrotron Light Source

    SciTech Connect

    2009-03-10

    A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

  16. Light Duty Vehicle Program

    EPA Pesticide Factsheets

    View a fact sheet on how the Final Endangerment Finding will allow EPA to finalize the first greenhouse gas standards for new light-duty vehicles as part of the joint rulemaking with the Department of Transportation.

  17. Shedding Light on Nanomedicine

    PubMed Central

    Tong, Rong

    2012-01-01

    Light is electromagnetic radiation that can convert its energy into different forms (e.g., heat, chemical energy, and acoustic waves). This property has been exploited in phototherapy (e.g., photothermal therapy and photodynamic therapy) and optical imaging (e.g., fluorescence imaging) for therapeutic and diagnostic purposes. Light-controlled therapies can provide minimally or non-invasive spatiotemporal control as well as deep tissue penetration. Nanotechnology provides a numerous advantages, including selective targeting of tissues, prolongation of therapeutic effect, protection of active payloads, and improved therapeutic indices. This review explores the advances that nanotechnology can bring to light-based therapies and diagnostics, and vice versa, including photo-triggered systems, nanoparticles containing photoactive molecules, and nanoparticles that are themselves photoactive. Limitations of light-based therapies such as photic injury and phototoxicity will be discussed. PMID:22887840

  18. Ocular hazards of light

    NASA Technical Reports Server (NTRS)

    Sliney, David H.

    1994-01-01

    The eye is protected against bright light by the natural aversion response to viewing bright light sources. The aversion response normally protects the eye against injury from viewing bright light sources such as the sun, arc lamps and welding arcs, since this aversion limits the duration of exposure to a fraction of a second (about 0.25 s). The principal retinal hazard resulting from viewing bright light sources is photoretinitis, e.g., solar retinitis with an accompanying scotoma which results from staring at the sun. Solar retinitis was once referred to as 'eclipse blindness' and associated 'retinal burn'. Only in recent years has it become clear that photoretinitis results from a photochemical injury mechanism following exposure of the retina to shorter wavelengths in the visible spectrum, i.e., violet and blue light. Prior to conclusive animal experiments at that time, it was thought to be a thermal injury mechanism. However, it has been shown conclusively that an intense exposure to short-wavelength light (hereafter referred to as 'blue light') can cause retinal injury. The product of the dose-rate and the exposure duration always must result in the same exposure dose (in joules-per-square centimeter at the retina) to produce a threshold injury. Blue-light retinal injury (photoretinitis) can result from viewing either an extremely bright light for a short time, or a less bright light for longer exposure periods. This characteristic of photochemical injury mechanisms is termed reciprocity and helps to distinguish these effects from thermal burns, where heat conduction requires a very intense exposure within seconds to cause a retinal coagulation otherwise, surrounding tissue conducts the heat away from the retinal image. Injury thresholds for acute injury in experimental animals for both corneal and retinal effects have been corroborated for the human eye from accident data. Occupational safety limits for exposure to UVR and bright light are based upon this

  19. Indoor Lighting Facilities

    NASA Astrophysics Data System (ADS)

    Matsushima, Koji; Saito, Yoshinori; Ichikawa, Shigenori; Kawauchi, Takao; Tanaka, Tsuneo; Hirano, Rika; Tazuke, Fuyuki

    According to the statistics by the Ministry of Land, Infrastructure and Transport, the total floor space of all building construction started was 188.87 million m2 (1.5% increase y/y), marking the fourth straight year of increase. Many large-scale buildings under construction in central Tokyo become fully occupied by tenants before completion. As for office buildings, it is required to develop comfortable and functional office spaces as working styles are becoming more and more diversified, and lighting is also an element of such functionalities. The total floor space of construction started for exhibition pavilions, multipurpose halls, conference halls and religious architectures decreased 11.1% against the previous year. This marked a decline for 10 consecutive years and the downward trend continues. In exhibition pavilions, the light radiation is measured and adjusted throughout the year so as not to damage the artworks by lighting. Hospitals, while providing higher quality medical services and enhancing the dwelling environment of patients, are expected to meet various restrictions and requirements, including the respect for privacy. Meanwhile, lighting designs for school classrooms tend to be homogeneous, yet new ideas are being promoted to strike a balance between the economical and functional aspects. The severe economic environment continues to be hampering the growth of theaters and halls in both the private and public sectors. Contrary to the downsizing trend of such facilities, additional installations of lighting equipment were conspicuous, and the adoption of high efficacy lighting appliances and intelligent function control circuits are becoming popular. In the category of stores/commercial facilities, the construction of complex facilities is a continuing trend. Indirect lighting, high luminance discharge lamps with excellent color rendition and LEDs are being effectively used in these facilities, together with the introduction of lighting designs

  20. Simple Schlieren Light Meter

    NASA Technical Reports Server (NTRS)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1992-01-01

    Simple light-meter circuit used to position knife edge of schlieren optical system to block exactly half light. Enables operator to check quickly position of knife edge between tunnel runs to ascertain whether or not in alignment. Permanent measuring system made part of each schlieren system. If placed in unused area of image plane, or in monitoring beam from mirror knife edge, provides real-time assessment of alignment of schlieren system.

  1. Cauldron of Light

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image to view the animation

    In this animation, a seething cauldron of light appears to bubble and ooze around the remains of a giant star that astronomers have been watching tear itself apart for the last 300 years. This movie flips quickly between different observations taken over three years by NASA's Spitzer Space Telescope.

    Beginning in the center, the well-studied Cassiopeia A supernova remnant is shown. Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died.

    Panning outward, 'light echoes' create the illusion of motion in the clouds, as different areas of the material are lit up in succession by the light flash of the supernova. A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light.

    In reality, the clouds are stationary, at least in the brief time over which these observations were taken. The inclination of the clouds cause some light echoes to appear to expand away from the supernova remnant, while others move towards it or boil in many directions with seeming turbulence.

  2. Solid state lighting component

    SciTech Connect

    Yuan, Thomas; Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald

    2010-10-26

    An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.

  3. Solid state lighting component

    SciTech Connect

    Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald; Yuan, Thomas

    2012-07-10

    An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.

  4. Fingerprints in the Light

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1

    This graph, or spectrum, shows the light from a dusty, distant galaxy located 11 billion light-years away. The galaxy is invisible to optical telescopes, but NASA's Spitzer Space Telescope was able to capture the light from it and dozens of other similar galaxies using heat-seeking infrared eyes.

    Spectra are created when an instrument called a spectrograph spreads light out into its basic parts, like a prism turning sunlight into a rainbow. They contain the signatures, or 'fingerprints,' of molecules that contribute to an object's light.

    In this case, the galaxy's spectrum reveals the fingerprint for silicate dust (large dip at right), a planetary building block like sand, only smaller. This particular fingerprint is important because it helped astronomers determine how far away the galaxy lies, or more specifically, how much the galaxy's light had stretched, or 'redshifted,' during its journey to Spitzer's eyes. Because the universe is expanding, a galaxy's light will shift toward reddish wavelengths as it moves away from us. This galaxy was found to have a redshift of 1.95, which means that its light took about 11 billion years to get here.

    The presence of the silicate fingerprint is also significant because it implies that galaxies were ripe for planetary formation 11 billion years ago - back to a time when the universe was 3 billion years old. The universe is currently believed to be 13.5 billion years old. This is the furthest back in time that silicate dust has been detected around a galaxy.

    These data were taken by Spitzer's infrared spectrograph in July, 2004.

  5. Conversion of orange light into blue light.

    PubMed

    Rai, Nirupama; Jha, Y; Kamal, K P; Kumar, S; Rai, V K

    2010-08-01

    Frequency upconversion in triply ionized praseodymium doped glass with composition TeO(2)-Na(2)O (TNO) system under the excitation with a laser light from a dye laser has been reported and the covalency, bonding parameter, nephalauxetic effect which provides the information about the nature of bonding between the lanthanide ions and the surrounding oxygens for the present glassy material calculated. The energy transfer route followed by the two excited praseodymium ions is observed to be the leading process for the upconversion emission.

  6. Earth's City Lights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Earth's city lights was created with data from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS). Originally designed to view clouds by moonlight, the OLS is also used to map the locations of permanent lights on the Earth's surface. The brightest areas of the Earth are the most urbanized, but not necessarily the most populated. (Compare western Europe with China and India.) Cities tend to grow along coastlines and transportation networks. Even without the underlying map, the outlines of many continents would still be visible. The United States interstate highway system appears as a lattice connecting the brighter dots of city centers. In Russia, the Trans-Siberian railroad is a thin line stretching from Moscow through the center of Asia to Vladivostok. The Nile River, from the Aswan Dam to the Mediterranean Sea, is another bright thread through an otherwise dark region. Even more than 100 years after the invention of the electric light, some regions remain thinly populated and unlit. Antarctica is entirely dark. The interior jungles of Africa and South America are mostly dark, but lights are beginning to appear there. Deserts in Africa, Arabia, Australia, Mongolia, and the United States are poorly lit as well (except along the coast), along with the boreal forests of Canada and Russia, and the great mountains of the Himalaya. The Earth Observatory article Bright Lights, Big City describes how NASA scientists use city light data to map urbanization. Image by Craig Mayhew and Robert Simmon, NASA GSFC, based on DMSP data

  7. Light Sources 2007

    NASA Astrophysics Data System (ADS)

    Liu, M. Q.; Devonshire, R.

    2007-04-01

    This volume contains the proceedings of the 11th International Symposium on the Science and Technology of Light Sources (LS:11) held in Fudan University, Shanghai, China in the period May 20th to 24th, 2007. In the 32 years since the first symposium was held in Loughborough, UK, the LS series has established itself as the major international event which brings together on a regular basis the world's leading scientists and engineers involved in the research and development of light source technologies. The participants come from the R&D laboratories of the world’s leading light source manufacturing companies and from research groups in universities, government laboratories and research institutes. The highly multi-disciplinary nature of the field results in a unique mix of physicists, chemists, chemical physicists, materials scientists and electrical, electronic and mechanical engineers attending the symposia. The more than 250 papers in these LS:11 proceedings provide an excellent overview of the current status of light source science and technology. The energy efficiency and light emission characteristics of existing technologies continue to be improved, solid state technologies are advancing rapidly and innovation flourishes generally. Audience Professional scientists and engineers involved in light source related R&D. Postgraduate-level students in the physical sciences, applied mathematics, materials science, and electrical and electronic engineering. The contents will also be of interest to anyone with a background in science and engineering wishing to gain an overview of current activity in this important global industry and research field.

  8. [Bright light therapy].

    PubMed

    Poirrier, R; Cambron, L

    2007-01-01

    Bright light therapy is a treatment that emerged in the eighties of the last century. It can be used in different pathologies such as seasonal affective disorders, major depressions, and many disorders of the wake-sleep rhythm, whether they are of primary or secondary origin. Important progress made at the basic neuroscience levels, allows today a sound understanding of the bright light mode of action. Moreover, the main indications are now the subject of consensus reports and meta-analyses which show good levels of evidence-based medicine. Bright light therapy constitutes a first choice indication in seasonal affective disorder. It is also perfectly possible to prescribe bright light therapy in the major depression disorders. It has been demonstrated that the effect size is the same as with antidepressants of reference. It is admitted nowadays that bright light therapy may be at least, an adjunct to pharmacotherapy, in order to accelerate the antidepressant effect onset, or to prolong this effect after withdrawal of the drug. Bright light therapy can also be viewed as an alternative to the pharmacological approach especially when this one is impossible, not tolerated or not accepted by the patient. The contraindications are rare.

  9. Fifth generation light sources

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2016-12-01

    Coherent light sources are one of the most fundamental research tools in biology, technology and in other areas. Synchrotron light source consists of a few basic parts: energy source - which is an electron beam accelerator, energy converter between electron and photon beams - which is an undulator, and photon user experimental lines. Each of these parts is separately a complex system, which is currently a subject to fast technological development. Future light sources of the fifth generation are based on completely new solutions of these fundamental parts, in comparison with the sources of the previous generations. Energy source is a new generation laser - plasma accelerator with electrical field in the area of multiple GV/m. A miniature undulator is tested in the MEMS technology from new materials. Classical light beam lines, vacuum, and difficult for management and beam distribution, change their meaning in the case of availability of miniature undulators positioned immediately at or even inside the experimental stations. After an introduction concerning the light sources of the previous generations, the article shows current research efforts on the mentioned key components of the fifth generation light sources. In some cases this is a continuation and modernization of the previous technologies, in the majority it is a brave endeavour to apply completely new technologies, like laser - plasma acceleration.

  10. Light Pollution and Wildlife

    NASA Astrophysics Data System (ADS)

    Duffek, J.

    2008-12-01

    for Educational Program IYA Dark Skies Education Session Fall American Geophysical Union San Francisco, December 15-19, 2008 Light Pollution and Wildlife This is a very exciting time to be a part of the mission to keep the nighttime skies natural. The International Year of Astronomy (IYA) 2009 is developing programs for all areas of Dark Skies Awareness. For many years the issue of light pollution focused on the impact to the astronomy industry. While this is an important area, research has shown that light pollution negatively impacts wildlife, their habitat, human health, and is a significant waste of energy. Since the message and impact of the effects of light pollution are much broader now, the message conveyed to the public must also be broader. Education programs directed at youth are a new frontier to reach out to a new audience about the adverse effects of too much artificial light at night. The International Dark-Sky Association (IDA) has developed educational presentations using the National Science Teachers Association Education Standards. These programs focus on youth between the ages of 5 to 17exploring new territory in the education of light pollution. The IDA education programs are broken down into three age groups; ages 5-9, 8-13, 12 and older. The presentations come complete with PowerPoint slides, discussion notes for each slide, and workbooks including age appropriate games to keep young audiences involved. A new presentation reflects the growing area of interest regarding the effects of too much artificial light at night on wildlife. This presentation outlines the known problems for ecosystems caused by artificial light at night. Insects are attracted to artificial lights and may stay near that light all night. This attraction interferes with their ability to migrate, mate, and look for food. Such behavior leads to smaller insect populations. Fewer insects in turn affect birds and bats, because they rely on insects as a food source. The IDA

  11. Nonclassical light in interferometric measurements

    NASA Technical Reports Server (NTRS)

    Ansari, N. A.; Difiore, L.; Romano, R.; Solimeno, S.; Zaccaria, F.; Manko, Margarita A.; Manko, Vladimir I.

    1995-01-01

    It is shown that the even and odd coherent light and other nonclassical states of light like superposition of coherent states with different phases may replace the squeezed light in an interferometric gravitational wave detector to increase its sensitivity.

  12. Light diffusing fiber optic chamber

    DOEpatents

    Maitland, Duncan J.

    2002-01-01

    A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

  13. Light pipe - design for efficiency

    SciTech Connect

    Hockey, S.N.

    1985-08-01

    The high cost and availability of materials which are clear enough to transmit light without absorption has limited the idea of piping large-scale quantities of light. The light pipe uses the principle of Total Internal Reflection, with the light guided by very accurate prisms. The transmission of light directed into the end of a Light Pipe at an angle of less than 27.6 degrees is theoretically 100% efficient. The author describes its uses and advantages for lighting offices, cold storage areas, difficult access and hazardous areas, and for solar lighting. Future directions will be to improve the economics and accuracy of the technology. 4 references, 2 figures.

  14. Biomaterials in light amplification

    NASA Astrophysics Data System (ADS)

    Mysliwiec, Jaroslaw; Cyprych, Konrad; Sznitko, Lech; Miniewicz, Andrzej

    2017-03-01

    Biologically produced or inspired materials can serve as optical gain media, i.e. they can exhibit the phenomenon of light amplification. Some of these materials, under suitable dye-doping and optical pumping conditions, show lasing phenomena. The emerging branch of research focused on obtaining lasing action in highly disordered and highly light scattering materials, i.e. research on random lasing, is perfectly suited for biological materials. The use of biomaterials in light amplification has been extensively reported in the literature. In this review we attempt to report on progress in the development of biologically derived systems able to show the phenomena of light amplification and random lasing together with the contribution of our group to this field. The rich world of biopolymers modified with molecular aggregates and nanocrystals, and self-organized at the nanoscale, offers a multitude of possibilities for tailoring luminescent and light scattering properties that are not easily replicated in conventional organic or inorganic materials. Of particular importance and interest are light amplification and lasing, or random lasing studies in biological cells and tissues. In this review we will describe nucleic acids and their complexes employed as gain media due to their favorable optical properties and ease of manipulation. We will report on research conducted on various biomaterials showing structural analogy to nucleic acids such as fluorescent proteins, gelatins in which the first distributed feedback laser was realized, and also amyloids or silks, which, due to their dye-doped fiber-like structure, allow for light amplification. Other materials that were investigated in that respect include polysaccharides, like starch exhibiting favorable photostability in comparison to other biomaterials, and chitosan, which forms photonic crystals or cellulose. Light amplification and random lasing was not only observed in processed biomaterials but also in living

  15. Indoor Lighting Facilities

    NASA Astrophysics Data System (ADS)

    Matsushima, Koji; Saito, Yoshinori; Ichikawa, Shigenori; Kawauchi, Takao; Tanaka, Tsuneo; Hirano, Rika; Tazuke, Fuyuki

    According to the statistics on building construction floor area from the Ministry of Land, Infrastructure, Transport and Tourism, the total floor area of building construction started in Japan in 2007 was 160,991 thousand square meters, or 14.8% less than the area of the previous year, and the reduction was the first reduction in the past five years. The office markets in Tokyo and Nagoya were active, as represented by the supplies of skyscrapers, and energy saving measures, such as the adoption of high efficiency lighting equipment, the control for initial stage illuminance, daylight harvesting, and the use of occupancy sensors, were well established. In the field of public construction, including museums, multi-purpose halls, and religious buildings, the total area of the new construction was 10.8% less than the total for the previous year, and this reduction was a continuation of an eleven-year trend. In spaces with high ceiling, the innovation for easy replacement of light sources used with reflection mirror systems and optical fibers was noted. Hospitals adapted to the expectation for improved services in their selection of lighting facilities to improve the residential environment for patients while taking into consideration the needs of the aging population, by their use of devices in corridors to help maintain a continuity of light. In libraries, a pendant system was developed to illuminate both ceilings and book shelves. In the field of theaters and halls, the time limit for repairing existing systems had come for the large facilities that were opened during the theater and hall construction boom of the 1960s through 1980s, and around 26 renovations were done. Almost all the renovations were conversions to intelligent dimming systems and lighting control desks. In the field of stores and commercial facilities, the atmosphere and glitter of the selling floor was produced by new light sources, such as ceramic metal halide lamps and LEDs, which have high

  16. Laser light scattering review

    NASA Technical Reports Server (NTRS)

    Schaetzel, Klaus

    1989-01-01

    Since the development of laser light sources and fast digital electronics for signal processing, the classical discipline of light scattering on liquid systems experienced a strong revival plus an enormous expansion, mainly due to new dynamic light scattering techniques. While a large number of liquid systems can be investigated, ranging from pure liquids to multicomponent microemulsions, this review is largely restricted to applications on Brownian particles, typically in the submicron range. Static light scattering, the careful recording of the angular dependence of scattered light, is a valuable tool for the analysis of particle size and shape, or of their spatial ordering due to mutual interactions. Dynamic techniques, most notably photon correlation spectroscopy, give direct access to particle motion. This may be Brownian motion, which allows the determination of particle size, or some collective motion, e.g., electrophoresis, which yields particle mobility data. Suitable optical systems as well as the necessary data processing schemes are presented in some detail. Special attention is devoted to topics of current interest, like correlation over very large lag time ranges or multiple scattering.

  17. Light emitting ceramic device

    DOEpatents

    Valentine, Paul; Edwards, Doreen D.; Walker, Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard

    2010-05-18

    A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, is herein claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.

  18. High Intensity Lighting

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Nightime illumination is an important part of round-the-clock pre-launch preparations because NASA uses TV and film cameras to monitor each step of the preliminaries and at times to identify the cause of malfunction during countdown. Generating a one billion candlepower beam visible 50 miles away, the lamps developed by Duro-Test Corporation provide daylight quality light that eliminates color distortion in film and TV coverage. The lighting system was first used at Kennedy Space Center in 1968 for the launch of Apollo 8. Modified versions are available in wide range of applications, such as the battery of spotlights with colored filters that light up Niagara Falls, as well as the lamps used in the projectors for the Smithsonian's IMAX Theatre, indoor theatres with supersized screens and outdoor projection systems.

  19. 3D light robotics

    NASA Astrophysics Data System (ADS)

    Glückstad, Jesper; Palima, Darwin; Villangca, Mark; Banas, Andrew

    2016-04-01

    As celebrated by the Nobel Prize 2014 in Chemistry light-based technologies can now overcome the diffraction barrier for imaging with nanoscopic resolution by so-called super-resolution microscopy1. However, interactive investigations coupled with advanced imaging modalities at these small scale domains gradually demand the development of a new generation of disruptive tools, not only for passively observing at nanoscopic scales, but also for actively reaching into and effectively handling constituents in this size domain. This intriguing mindset has recently led to the emergence of a novel research discipline that could potentially be able to offer the full packet needed for true "active nanoscopy" by use of so-called light-driven micro-robotics or Light Robotics in short.

  20. Sneaky light stop

    DOE PAGES

    Eifert, Till; Nachman, Benjamin

    2015-02-20

    A light supersymmetric top quark partner (stop) with a mass nearly degenerate with that of the standard model (SM) top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been suggested to give a handle for this ‘stealth stop’ scenario. We present an estimate of the potential impact a light stop may have on top quark mass measurements. The results indicate that certain light stop models may induce a bias of up to a few GeV, and that this effect can hide the shift in, and hence sensitivity from, cross-section measurements. Duemore » to the different initial states, the size of the bias is slightly different between the LHC and the Tevatron. The studies make some simplifying assumptions for the top quark measurement technique, and are based on truth-level samples.« less

  1. Sneaky light stop

    SciTech Connect

    Eifert, Till; Nachman, Benjamin

    2015-04-01

    A light supersymmetric top quark partner (stop) with a mass nearly degenerate with that of the standard model (SM) top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been suggested to give a handle for this ‘stealth stop’ scenario. We present an estimate of the potential impact a light stop may have on top quark mass measurements. The results indicate that certain light stop models may induce a bias of up to a few GeV, and that this effect can hide the shift in, and hence sensitivity from, cross-section measurements. Due to the different initial states, the size of the bias is slightly different between the LHC and the Tevatron. The studies make some simplifying assumptions for the top quark measurement technique, and are based on truth-level samples.

  2. Sneaky light stop

    SciTech Connect

    Eifert, Till; Nachman, Benjamin

    2015-02-20

    A light supersymmetric top quark partner (stop) with a mass nearly degenerate with that of the standard model (SM) top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been suggested to give a handle for this ‘stealth stop’ scenario. We present an estimate of the potential impact a light stop may have on top quark mass measurements. The results indicate that certain light stop models may induce a bias of up to a few GeV, and that this effect can hide the shift in, and hence sensitivity from, cross-section measurements. Due to the different initial states, the size of the bias is slightly different between the LHC and the Tevatron. The studies make some simplifying assumptions for the top quark measurement technique, and are based on truth-level samples.

  3. Light echoes - Novae

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.

    1988-01-01

    The sudden brilliance of a nova eruption will be reflected on surrounding dust grains to create a phantom nebula. Previous searches for these light echoes have used relatively short exposures with photograhic detectors. This paper reports on a search around eight recent novae with long exposures using a CCD camera. Despite an increase of sensitivity by over an order of magnitude, no light echoes were detected. It is found that the average grain density must be less than about 10 to the -9th per cu cm for distances from 0.1 pc to 1000 pc from the novae. The light echo around Nova Persei 1901 was caused by reflection off clouds with grain densities of several times 10 to the -9th per cu cm which are at distances between 0.1 pc and 10 pc. Echoes from dust in a circumstellar shell or ejected during a previous eruption will be effectively unobservable.

  4. Encouragement for lighting victims

    NASA Astrophysics Data System (ADS)

    Mizon, R.

    2001-02-01

    Much of the correspondence I receive (and there's a lot of it) is from people, both astronomers and non-astronomers, who suffer from neighbours' security lighting, and feel that there is nothing that they can do about it, since there is as yet no legislation on light as a nuisance. In some cases, people's quality of life is affected to the extent that they have had to change living patterns, jobs, or even move house. The law of nuisance states that one is entitled to the 'enjoyment of one's property', which includes legitimate pursuits undertaken on that property. Light is not yet(!) a statutory nuisance, but note the use of the word in the judgment below. Here is the story of someone who did do something about it.

  5. Pupillary efficient lighting system

    DOEpatents

    Berman, Samuel M.; Jewett, Don L.

    1991-01-01

    A lighting system having at least two independent lighting subsystems each with a different ratio of scotopic illumination to photopic illumination. The radiant energy in the visible region of the spectrum of the lighting subsystems can be adjusted relative to each other so that the total scotopic illumination of the combined system and the total photopic illumination of the combined system can be varied independently. The dilation or contraction of the pupil of an eye is controlled by the level of scotopic illumination and because the scotopic and photopic illumination can be separately controlled, the system allows the pupil size to be varied independently of the level of photopic illumination. Hence, the vision process can be improved for a given level of photopic illumination.

  6. MEMS Incandescent Light Source

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret; King, Kevin; Kim, Lynn; Hansler, Richard; Jones, Eric; George, Thomas

    2001-01-01

    A MEMS-based, low-power, incandescent light source is being developed. This light source is fabricated using three bonded chips. The bottom chip consists of a reflector on Silicon, the middle chip contains a Tungsten filament bonded to silicon and the top layer is a transparent window. A 25-micrometer-thick spiral filament is fabricated in Tungsten using lithography and wet-etching. A proof-of-concept device has been fabricated and tested in a vacuum chamber. Results indicate that the filament is electrically heated to approximately 2650 K. The power required to drive the proof-of-concept spiral filament to incandescence is 1.25 W. The emitted optical power is expected to be approximately 1.0 W with the spectral peak at 1.1 microns. The micromachining techniques used to fabricate this light source can be applied to other MEMS devices.

  7. White light emitting diodes

    NASA Astrophysics Data System (ADS)

    Baur, J.; Schlotter, P.; Schneider, J.

    Using blue-emitting GaN LEDs on SiC substrate chips as primary light sources, we have fabricated green, yellow, red and white light emitting diodes (LUCOLEDs). The generation of mixed colors, as turquoise and magenta, is also demonstrated. The underlying physical principle is that of luminescence downconversion (Stokes shift), as typical for organic dye molecules and many inorganic phosphors. For white light generation via the LUCOLED principle, the phosphor Y3Al5O12:Ce3+(4f1) is ideally suited. The optical characteristics of Ce3+(4f1) in Y3Al5O12(YAG) are discussed in detail. Possibilities to "tune" the white color by various substitutions in the garnet lattice are shortly outlined.

  8. Radioluminescent lighting technology

    SciTech Connect

    Not Available

    1990-01-01

    The glow-in-the-dark stereotype that characterizes the popular image of nuclear materials is not accidental. When the French scientist, Henri Becquerel, first discovered radioactivity in 1896, he was interested in luminescence. Radioluminescence, the production of light from a mixture of energetic and passive materials, is probably the oldest practical application of the unstable nucleus. Tritium-based radioluminescent lighting, in spite of the biologically favorable character of the gaseous tritium isotope, was included in the general tightening of environmental and safety regulations. Tritium light manufacturers would have to meet two fundamental conditions: (1) The benefit clearly outweighed the risk, to the extent that even the perceived risk of a skeptical public would be overcome. (2) The need was significant enough that the customer/user would be willing and able to afford the cost of regulation that was imposed both in the manufacture, use and eventual disposal of nuclear materials. In 1981, researchers at Oak Ridge National Laboratory were investigating larger radioluminescent applications using byproduct nuclear material such as krypton-85, as well as tritium. By 1982, it appeared that large source, (100 Curies or more) tritium gas tube, lights might be useful for marking runways and drop zones for military operations and perhaps even special civilian aviation applications. The successful development of this idea depended on making the light bright enough and demonstrating that large gas tube sources could be used and maintained safely in the environment. This successful DOE program is now in the process of being completed and closed-out. Working closely with the tritium light industry, State governments and other Federal agencies, the basic program goals have been achieved. This is a detailed report of what they have learned, proven, and discovered. 91 refs., 29 figs., 5 tabs. (JF)

  9. Neuroendocrine effects of light

    NASA Astrophysics Data System (ADS)

    Reiter, Russel J.

    1991-09-01

    The light/dark cycle to which animals, and possibly humans, are exposed has a major impact on their physiology. The mechanisms whereby specific tissues respond to the light/dark cycle involve the pineal hormone melatonin. The pineal gland, an end organ of the visual system in mammals, produces the hormone melatonin only at night, at which time it is released into the blood. The duration of elevated nightly melatonin provides every tissue with information about the time of day and time of year (in animals that are kept under naturally changing photoperiods). Besides its release in a circadian mode, melatonin is also discharged in a pulsatile manner; the physiological significance, if any, of pulsatile melatonin release remains unknown. The exposure of animals including man to light at night rapidly depresses pineal melatonin synthesis and, therefore, blood melatonin levels drop precipitously. The brightness of light at night required to depress melatonin production is highly species specific. In general, the pineal gland of nocturnally active mammals, which possess rod-dominated retinas, is more sensitive to inhibition by light than is the pineal gland of diurnally active animals (with cone-dominated retinas). Because of the ability of the light/dark cycle to determine melatonin production, the photoperiod is capable of influencing the function of a variety of endocrine and non-endocrine organs. Indeed, melatonin is a ubiquitously acting pineal hormone with its effects on the neuroendocrine system having been most thoroughly investigated. Thus, in nonhuman photoperiodic mammals melatonin regulates seasonal reproduction; in humans also, the indole has been implicated in the control of reproductive physiology.

  10. Nonimaging optics in lighting to reduce light pollution

    NASA Astrophysics Data System (ADS)

    Ricketts, Melissa; Ferry, Jon; Jiang, Lun; Winston, Roland

    2016-09-01

    Light pollution has become a prominent issue, specifically in National Parks such as Yosemite, where visitors go to enjoy the natural `night sky'. In an effort to reduce light pollution, a particularly obtrusive light source has been selected for retrofit. Using nonimaging optics and light emitting diodes (LEDs), light can be controlled to achieve a desired prescribed illumination distribution. This distribution possesses a sharp cut-off such that light leakage is minimal. Nonimaging optical designs are 3D printed, retrofitted into the candidate fixture, and tested in Yosemite National Park. The end goal is to drastically reduce and even eliminate the excess light from sources around the park.

  11. Light and Color

    NASA Astrophysics Data System (ADS)

    Overheim, R. Daniel; Wagner, David L.

    1982-08-01

    Equally valuable as a semester course for non-majors or an introduction for general readers, this text uses only a minimum of science and mathematical background to explain the physical principles of light. It emphasizes color: the properties of light and materials that give rise to it, how it is described and analyzed, how it is produced in nature, and how the eye sees it. Also discusses topics such as geometrical and wave optics and color phenomena, such as rainbows, that appear in nature. Learning aids include problems and exercises at the end of each chapter.

  12. Light-bending nanoparticles.

    PubMed

    Mirin, Nikolay A; Halas, Naomi J

    2009-03-01

    Metallic nanostructures with their geometry-dependent optical resonances are a topic of intense current interest due to their ability to manipulate light in ways not possible with conventional optical materials. A particularly fascinating aspect of these systems is the recently realized possibility of creating optical frequency "magnetic plasmon" responses of comparable magnitude to the "electric plasmon" response. Here we show that Au nanocups at their magnetoinductive resonance have the unique ability to redirect scattered light in a direction dependent on cup orientation, as a true three-dimensional nanoantenna.

  13. Light metals 1996

    SciTech Connect

    Hale, W.

    1996-10-01

    Light Metals 1996 presents the proceedings of the technical sessions of the TMS Light Metals Committee at the 125th TMS Annual Meeting held in Anaheim, California, February 4--8, 1996. Developments and innovation in the aluminum and reactive metals industries were covered including basic studies as well as their use and fabrication. The topics encompassed ore and its processing, aluminum reduction, carbon technology, casting technology, recycling, reactive metals, separation processes and waste processing. A number of papers involved mathematical modeling while others were about equipment and applications. One hundred and seventy nine papers were processed separately for inclusion on the data base.

  14. Lighting and Astronomy

    DTIC Science & Technology

    2009-12-01

    ago. Bright light is becoming a form of advertising. Figure 1. The sky over Mauna Kea , Hawaii, is affected by outdoor lighting in communit ies from...8217 chris Luginbuhl is an astronomer at the US Naval observatory Flagstaff station in Arizona. connie walker is an associate scientist and education...specialist " tf," N"iio".iOpalut-nraronomy Observatory in Arizona and director of both the lnternational Year of Astrono.my , ;il;;;;i; n*ui"n"rt

  15. Spatial Light Amplifier Modulators

    NASA Technical Reports Server (NTRS)

    Eng, Sverre T.; Olsson, N. Anders

    1992-01-01

    Spatial light amplifier modulators (SLAM's) are conceptual devices that effect two-dimensional spatial modulation in optical computing and communication systems. Unlike current spatial light modulators, these provide gain. Optical processors incorporating SLAM's designed to operate in reflection or transmission mode. Each element of planar SLAM array is optical amplifier - surface-emitting diode laser. Array addressed electrically with ac modulating signals superimposed on dc bias currents supplied to lasers. SLAM device provides both desired modulation and enough optical gain to enable splitting of output signal into many optical fibers without excessive loss of power.

  16. Light sheet microscopy.

    PubMed

    Weber, Michael; Mickoleit, Michaela; Huisken, Jan

    2014-01-01

    This chapter introduces the concept of light sheet microscopy along with practical advice on how to design and build such an instrument. Selective plane illumination microscopy is presented as an alternative to confocal microscopy due to several superior features such as high-speed full-frame acquisition, minimal phototoxicity, and multiview sample rotation. Based on our experience over the last 10 years, we summarize the key concepts in light sheet microscopy, typical implementations, and successful applications. In particular, sample mounting for long time-lapse imaging and the resulting challenges in data processing are discussed in detail.

  17. The SAGA Light Source

    SciTech Connect

    Yoshida, K.; Iwasaki, Y.; Koda, S.; Okajima, S.; Setoyama, H.; Takabayashi, Y.; Tomimasu, T.; Yoshimura, D.; Ohgaki, H.

    2007-01-19

    Saga prefectural government operates a synchrotron light facility mainly for industrial applications of the synchrotron light. The facility comprises a 1.4 GeV storage ring, a 250 MeV linac as an electron injector and beamlines. The lattice of the storage ring is designed to perform as small emittance as 25 nm-radian and has long straight sections of 2.9 m length for installing insertion devices. Three beam lines have been prepared by Saga prefectural government and one by Saga University.

  18. [Light and Medicine].

    PubMed

    Lemmer, Björn

    2016-12-01

    There would be no life without light. The rotation of the earth around its axis has introduced the development of biological clocks in all living subjects regulating all functions of the body. The rhythms best described are the 24-hour/circadian and the seasonal rhythms. The rhythmic composition around the body clock has great impact on health and disease, both in diagnostics and treatment. Nowadays, bright light, e.g. in seasonal affective disorder, can be regarded as a drug, being even more effective than selective serotonin reuptake inhibitors.

  19. Tempel Alive with Light

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This spectacular image of comet Tempel 1 was taken 67 seconds after it obliterated Deep Impact's impactor spacecraft. The image was taken by the high-resolution camera on the mission's flyby craft. Scattered light from the collision saturated the camera's detector, creating the bright splash seen here. Linear spokes of light radiate away from the impact site, while reflected sunlight illuminates most of the comet surface. The image reveals topographic features, including ridges, scalloped edges and possibly impact craters formed long ago.

  20. Get More from Your Lighting.

    ERIC Educational Resources Information Center

    Bachner, John Philip

    1999-01-01

    Explains how improved lighting can pay for installation of a new system or upgrading existing lighting in an educational facility. Examples explore the use of high-benefit lighting to enhance other activities and reduce crime and security patrolling costs. Also discussed is the upgrading of one school's sports arena lighting that produced…

  1. Short Course in Highway Lighting.

    ERIC Educational Resources Information Center

    Federal Highway Administration (DOT), Washington, DC.

    This course guide in highway lighting includes an overview of trends in highway lighting, illustrated information on three light sources for today's luminaires, a reference guide to lamp classification, specifications for highway lighting equipment, and instructions for calculating appropriate use. Maintenance notes on highway illumination and…

  2. High Brightness OLED Lighting

    SciTech Connect

    Spindler, Jeffrey; Kondakova, Marina; Boroson, Michael; Hamer, John

    2016-05-25

    In this work we describe the technology developments behind our current and future generations of high brightness OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.

  3. Photoacoustics with coherent light

    PubMed Central

    Bossy, Emmanuel; Gigan, Sylvain

    2016-01-01

    Since its introduction in the mid-nineties, photoacoustic imaging of biological tissue has been one of the fastest growing biomedical imaging modality, and its basic principles are now considered as well established. In particular, light propagation in photoacoustic imaging is generally considered from the perspective of transport theory. However, recent breakthroughs in optics have shown that coherent light propagating through optically scattering medium could be manipulated towards novel imaging approaches. In this article, we first provide an introduction to the relevant concepts in the field, and then review the recent works showing that it is possible to exploit the coherence of light in conjunction with photoacoustics. We illustrate how the photoacoustic effect can be used as a powerful feedback mechanism for optical wavefront shaping in complex media, and conversely show how the coherence of light can be exploited to enhance photoacoustic imaging, for instance in terms of spatial resolution or for designing minimally invasive endoscopic devices. Finally, we discuss the current challenges and perspectives down the road towards practical applications in the field of photoacoustic imaging. PMID:27069874

  4. Windows and lighting program

    SciTech Connect

    Not Available

    1990-06-01

    More than 30% of all energy use in buildings is attributable to two sources: windows and lighting. Together they account for annual consumer energy expenditures of more than $50 billion. Each affects not only energy use by other major building systems, but also comfort and productivity -- factors that influence building economics far more than does direct energy consumption alone. Windows play a unique role in the building envelope, physically separating the conditioned space from the world outside without sacrificing vital visual contact. Throughout the indoor environment, lighting systems facilitate a variety of tasks associated with a wide range of visual requirements while defining the luminous qualities of the indoor environment. Windows and lighting are thus essential components of any comprehensive building science program. Despite important achievements in reducing building energy consumption over the past decade, significant additional savings are still possible. These will come from two complementary strategies: (1) improve building designs so that they effectively apply existing technologies and extend the market penetration of these technologies; and (2) develop advanced technologies that increase the savings potential of each application. Both the Windows and Daylighting Group and the Lighting System Research Group have made substantial contributions in each of these areas, and continue to do so through the ongoing research summarized here. 23 refs., 16 figs.

  5. Polarized Light: Three Demonstrations.

    ERIC Educational Resources Information Center

    Goehmann, Ruth; Welty, Scott

    1984-01-01

    Describes three demonstrations used in the Chicago Museum of Science and Industry polarized light show. The procedures employed are suitable for the classroom by using smaller polarizers and an overhead projector. Topic areas include properties of cellophane tape, nondisappearing arrows, and rope through a picket fence. (JN)

  6. Lights and Larvae

    ERIC Educational Resources Information Center

    TItlow, Josh; Anderson, Heidi; Cooper, Robin

    2014-01-01

    Switching genes between organisms and controlling an animal's brain using lasers may seem like science fiction, but with advancements in a technique called optogenetics, such experiments are now common in neuroscience research. Optogenetics combines recombinant DNA technology with a controlled light source to help researchers address…

  7. Conceptualization of Light Refraction

    ERIC Educational Resources Information Center

    Sokolowski, Andrzej

    2013-01-01

    There have been a number of papers dealing quantitatively with light refraction. Yet the conceptualization of the phenomenon that sets the foundation for a more rigorous math analysis is minimized. The purpose of this paper is to fill that gap. (Contains 3 figures.)

  8. Light microscopy digital imaging.

    PubMed

    Joubert, James; Sharma, Deepak

    2011-10-01

    This unit presents an overview of digital imaging hardware used in light microscopy. CMOS, CCD, and EMCCDs are the primary sensors used. The strengths and weaknesses of each define the primary applications for these sensors. Sensor architecture and formats are also reviewed. Color camera design strategies and sensor window cleaning are also described in the unit.

  9. Fluorescence and Light Scattering

    ERIC Educational Resources Information Center

    Clarke, Ronald J.; Oprysa, Anna

    2004-01-01

    The aim of the mentioned experiment is to aid students in developing tactics for distinguishing between signals originating from fluorescence and light scattering. Also, the experiment provides students with a deeper understanding of the physicochemical bases of each phenomenon and shows that the techniques are actually related.

  10. Bringing Light onto Shadows

    ERIC Educational Resources Information Center

    Barrow, Lloyd H.

    2007-01-01

    "What starts out long but gets shorter then longer each day?" Shadows! This student's clever riddle was an opportunity to investigate how the Sun's daily position in the sky influences shadow length. Thus began a mini-lesson which was created to help third-grade students understand that a shadow occurs when an opaque object blocks light (Shapiro…

  11. Solid State Lighting

    SciTech Connect

    Hastbacka, Mildred; Dieckmann, John; Bouza, Antonio

    2013-03-30

    The article discusses solid state lighting technologies. This topic was covered in two previous ASHRAE Journal columns (2010). This article covers advancements in technologies and the associated efficacies. The life-cycle, energy savings and market potential of these technologies are addressed as well.

  12. Lighting the Way

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2007-01-01

    In recent years, more education administrators and designers have embraced the potential benefits of daylighting. They have been persuaded that using natural light to illuminate facilities enables schools and universities to conserve energy and provide a learning environment in which students perform better. For daylighting advocates, the…

  13. Lights, Camera, Chemistry!

    ERIC Educational Resources Information Center

    Lamb, William G.

    1984-01-01

    Recommends using dramatic demonstrations on the energy in chemical systems as an audiovisual adjunct to lectures and laboratory sessions. Lists materials needed and provides procedures including safety tips for various experiments to produce chemical light, heat, and electricity; and concludes with hints for preparation/rehearsal. (JM)

  14. The Bright Lights

    ERIC Educational Resources Information Center

    Progressive Architecture, 1976

    1976-01-01

    High intensity discharge lighting sources share the compactness and beam controllability of incandescent sources, but are far more efficient and longer-lived. They share the efficiency and long life of fluorescent sources, but are compact and optically controllable, and are available in higher wattages. (Author/MLF)

  15. Light and Cool

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2010-01-01

    When the subject of buildings and daylighting arises, most people's thoughts will turn first to windows. To the uninitiated, it seems a simple formula: more windows, more daylight; fewer windows, less daylight. But designers know that effective use of daylighting in a building design involves more than just letting in light to otherwise darkened…

  16. Lighting up Savings.

    ERIC Educational Resources Information Center

    Ryerson, Charles

    1996-01-01

    Suggests group relamping in educational facilities as a more efficient method than spot replacement of failed lamps. It can reduce operating costs, improve lighting quality, and help with federal and state regulations compliance. The implementation of group relamping is discussed in terms of planning, energy savings, and environmental issues. (RE)

  17. Radioluminescent polymer lights

    SciTech Connect

    Jensen, G.A.; Nelson, D.A.; Molton, P.M.

    1990-09-01

    The preparation of radioluminescent light sources where the tritium is located on the aryl-ring in a polymer has been demonstrated with deuterium/tritium substitution. This report discusses tests, results, and future applications of radioluminescent polymers. 10 refs. (FI)

  18. Lighting for Our Schools.

    ERIC Educational Resources Information Center

    Rankin, John C.

    In this speech, the author traces the history of lighting in schools, discusses the variables affecting the amount of illuminance needed, and provides a table of illuminances recommended for Ontario schools. Other factors that affect vision--glare, veiling reflection, color, and brightness balance--are outlined. Planners are admonished to…

  19. Light-created chemiluminescence

    NASA Astrophysics Data System (ADS)

    Vasil'ev, Rostislav F.; Tsaplev, Yuri B.

    2006-11-01

    The results of studies of light-created chemiluminescence are described systematically. Conditions for the transformation of a dark chemical reaction into a chemiluminescence reaction are considered. Examples of photosensitised and photoinduced processes as well as of analytical applications are given.

  20. Light water reactor program

    SciTech Connect

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  1. Light Exotic Mesons

    NASA Astrophysics Data System (ADS)

    Eugenio, Paul

    2016-03-01

    tudies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenological models for QCD such as the constituent quark model. However, QCD allows for a much richer spectrum of meson states which include extra states such as hybrids, exotics, multi-quarks, and glueballs. Within the past two decades a number of experiments have put forth tantalizing evidence for the existence of light quark exotic hybrid mesons in the mass range below 2 GeV . Recent Lattice QCD calculations of the light-quark meson spectrum indicate a constituent gluon-like excitation contributing an additional JPC =1+- and mass 1 - 1 . 5 GeV resulting in the lightest hybrid nonets with masses near 2 . 0 GeV . High statistical yields from recent experiments along with new advances in analysis techniques have shed a new light towards the understanding the latest experimental exotic candidates. Recent results from hadro-production and photo-production will be presented followed by an overview of ongoing and future efforts to search for light exotic mesons.

  2. Volumetric Light-Field Excitation

    PubMed Central

    Schedl, David C.; Bimber, Oliver

    2016-01-01

    We explain how to concentrate light simultaneously at multiple selected volumetric positions by means of a 4D illumination light field. First, to select target objects, a 4D imaging light field is captured. A light field mask is then computed automatically for this selection to avoid illumination of the remaining areas. With one-photon illumination, simultaneous generation of complex volumetric light patterns becomes possible. As a full light-field can be captured and projected simultaneously at the desired exposure and excitation times, short readout and lighting durations are supported. PMID:27363565

  3. Green light in photomorphogenic development

    NASA Astrophysics Data System (ADS)

    Maruhnich, Stefanie Anne

    Light quality, quantity, and duration provide essential environmental cues that shape plant growth and development. Over the last century, researchers have worked to discover how plants sense, integrate, and respond to red, blue, and far-red light. Green light is often considered a “benign” wavelength with little to no effect in plant development. However, sparse experiments in the literature demonstrate that green effects are often counterintuitive to normal light responses and oppose red- and blue-light-induced responses. Green light effects on plant growth and development are described here through the use of custom, tunable LED, light-emitting diode, chambers. These light sources allow for specific light qualities and quantities to be administered. The effects of green wavebands were assessed when red and blue photomorphogenic systems were active to answer the question: Are the effects of an inhibitor (green light) more evident in the presence of inducers (red and blue light)? In seedlings, supplemental green light increased hypocotyl elongation opposite to classical inhibition of hypocotyl elongation associated with growth in light and induced by red and blue wavebands. Results indicate that added green light induced a reversion of light-grown phenotypes. In mature plants, supplemental green light induced phenotypes typical of the shade-avoidance syndrome, including elongated petioles, smaller leaf areas, and leaf hyponasty. These responses are typical of lower-light conditions or far-red enriched environments. Contrary to far-red-light-induced shade-avoidance, data indicate green delays flowering. In Arabidopsis and strawberry plants, anthocyanin levels also decreased when green light was added to red and blue light treatments, which is again opposite to normal light-induced phenotypes. Photoreceptor mutants were tested and indicate green light effects in early development are cryptochromedependent. However, green-light-induced shade-avoidance responses

  4. NASA Lighting Research, Test, & Analysis

    NASA Technical Reports Server (NTRS)

    Clark, Toni

    2015-01-01

    The Habitability and Human Factors Branch, at Johnson Space Center, in Houston, TX, provides technical guidance for the development of spaceflight lighting requirements, verification of light system performance, analysis of integrated environmental lighting systems, and research of lighting-related human performance issues. The Habitability & Human Factors Lighting Team maintains two physical facilities that are integrated to provide support. The Lighting Environment Test Facility (LETF) provides a controlled darkroom environment for physical verification of lighting systems with photometric and spetrographic measurement systems. The Graphics Research & Analysis Facility (GRAF) maintains the capability for computer-based analysis of operational lighting environments. The combined capabilities of the Lighting Team at Johnson Space Center have been used for a wide range of lighting-related issues.

  5. Radioluminescent lighting technology

    NASA Astrophysics Data System (ADS)

    The glow-in-the-dark stereotype that characterizes the popular image of nuclear materials is not accidental. When the French scientist, Henri Becquerel, first discovered radioactivity in 1896, he was interested in luminescence. Radioluminescence, the production of light from a mixture of energetic and passive materials, is probably the oldest practical application of the unstable nucleus. Tritium based radioluminescent lighting, in spite of the biologically favorable character of the gaseous tritium isotope, was included in the general tightening of environmental and safety regulations. Tritium light manufacturers would have to meet two fundamental conditions: (1) The benefit clearly outweighed the risk, to the extent that even the perceived risk of a skeptical public would be overcome; and (2) The need was significant enough that the customer/user would be willing and able to afford the cost of regulation that was imposed both in the manufacture, use, and eventual disposal of nuclear materials. In 1981, researchers at Oak Ridge National Laboratory were investigating larger radioluminescent applications using byproduct nuclear material such as krypton-85, as well as tritium. By 1982, it appeared that large source, (100 Curies or more) tritium gas tube, lights might be useful for marking runways and drop zones for military operations and perhaps even special civilian aviation applications. The successful development of this idea depended on making the light bright enough and demonstrating that large gas tube sources could be used and maintained safely in the environment. The basic program goals were achieved. This is a detailed report of what they have learned, proven, and discovered.

  6. CIBER : a near-infrared probe of the epoch of reionization

    NASA Astrophysics Data System (ADS)

    Sullivan, Ian Sorensen

    The Cosmic Infrared Background Experiment (CIBER) is a NASA sounding rocket payload that was first launched in February 2009. CIBER consists of four co-aligned instruments designed to study the near-Infrared background by measuring fluctuations and the absolute spectrum. The platform of a sounding rocket enables observations of the near-Infrared background outside of narrow atmospheric windows that are uncontaminated by airglow. CIBER uses two spectrometers to measure the absolute brightness spectrum of the extragalactic near-Infrared background. One, a high-resolution Fabry-Perot spectometer, is tuned to the 854.5 nm CaII line of the solar spectrum, and is designed to measure the absolute brightness of the Zodiacal Light directly, which is the source of greatest uncertainty in the near-Infrared background spectrum. The second spectrometer measures the near-Infrared background spectrum from 700 nm to 1800 nm, spanning the wavelength range where a Lyman limit cutoff feature from reionization could appear. CIBER also houses two Infrared imaging telescopes, which have identical optics that give 2 x 2 degree field of views with 7 arcsecond pixels, but have different band defining filters. The first imager has a wide band centered at 1600 nm, and images the background at the expected peak of the spectrum. The imagers?~@~Y wide field of view allows them to measure the distinctive power spectrum of first-light galaxy fluctuations peaking at 10 arcminutes. The second imager has a wide band centered at 1000 nm that is intended to image at wavelengths shorter than the Lyman cutoff, and provides a powerful systematic test for any detection made at 1600 nm. First-light fluctuations should have a distinctive spatial power spectrum with very red 1600 nm / 1000 nm color, distinctly redder than the approximately solar color of any residual fluctuations arising from Zodiacal light, Galactic starlight, or moderate-redshift galaxies. This work describes the design and

  7. Analysis of light regime in continuous light distributions in photobioreactors.

    PubMed

    Brindley, Celeste; Fernández, F G Acién; Fernández-Sevilla, J M

    2011-02-01

    Maximum photobioreactor (PBR) efficiency is a must in applications such as the obtention of microalgae-derived fuels. Improving PBR performance requires a better understanding of the "light regime", the varying irradiance that microalgal cells moving in a dense culture are exposed to. We propose a definition of light regime that can be used consistently to describe the continuously varying light patterns in PBRs as well as in light/dark cycles. Equivalent continuous and light/dark regimes have been experimentally compared and the results show that continuous variations are not well represented by light/dark cycles, as had been widely accepted. It has been shown that a correct light regime allows obtaining photosynthetic rates higher than the corresponding to continuous light, the so-called "flashing light effect" and that this is possible in commercial PBRs. A correct PBR operation could result in photosynthetic efficiency close to the optimum eight quanta per O(2).

  8. The International Year of Light and Light-based Technologies

    NASA Astrophysics Data System (ADS)

    Pendrill, Ann-Marie

    2015-05-01

    I report on the opening ceremony of the International Year of Light and Light-based Technologies 2015 (IYL2015), which took place at the UNESCO headquarters in Paris, France, on 19-20 January 2015. Over the two days, more than 1000 participants from all over the world learned more about the fundamental properties of light and advanced photonics applications, the history of optics and its applications through the centuries, light poverty and light pollution, and light for everyday life, health and research.

  9. Experimental demonstration of light sensor-based visible light communications using time shift light intensity modulation

    NASA Astrophysics Data System (ADS)

    Kim, Yong-hyeon; Chung, Yeon-ho

    2016-09-01

    An experimental light sensor-based indoor visible light communication (VLC) is presented. Light-emitting diodes (LEDs) primarily used for illumination are employed to transmit wireless optical data over a short distance, while a smartphone's light sensor is used to receive the data. The light sensor in a smartphone is originally installed to function as a power saving method by adjusting the brightness of the smartphone screen. We propose an efficient and easy-to-use short range VLC based on this light sensor. To compensate for the inherent low sampling rate of the light sensor and also to avoid LED (transmitter) flickering, we propose time shift light intensity modulation. To verify the proposed light sensor VLC, experiments were conducted. The results demonstrate that the data can reliably be transmitted over the VLC link between the LEDs and the smartphone light sensor.

  10. First-Light Galaxies or Intrahalo Stars: Multi-Wavelength Measurements of the Infrared Background Anisotropies

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha

    explained with DGL. The proposed research supports Goal 2 of the NASA 2011 Strategic Plan to Expand scientific understanding of the Earth and the universe which we live, specifically to address the sub-goal 2.4 to discover how the universe works and explore how it began and evolved. The proposal is relevant to NASA's 2007 Science Plan in addressing the Science Question How do planets, stars, galaxies, and cosmic structure come into being?. The training of next-generation astrophysicists in the form of undergraduate students, graduate students, and postdoctoral fellows leading to experience and background in the analysis and interpretation of space-based astronomical data support the Goal 6 of the NASA 2011 Strategic Plan to Share NASA with the public, educators, and students to provide opportunities to participate in our Mission, foster innovation, and contribute to a strong national economy. The PI's efforts to involve undergraduates in his research programs will specifically improve retention of students in STEM disciplines by providing opportunities and activities along the full length of the education pipeline (subgoal 6.1). The IR fluctuation study supports JWST, Euclid, and WFIRST since we study the ensemble properties of the faint emission buried in existing deep and wide space-based IR data. We expect some fraction of the fluctuations to be from first-light galaxies that JWST seeks to detect and characterize individually. Euclid and WFIRST can make very deep and wide multi-band fluctuation measurements, depending on the final choice of bands (WFIRST) and observation/deep-field strategy (Euclid and WFIRST). This work could also motivate a small instrument for space-borne measurement of the absolute sky brightness from 5 AU, where the Zodiacal foreground is expected to be 100 times fainter than at 1.

  11. Semi-imaging light pipe for collecting weakly scattered light

    NASA Astrophysics Data System (ADS)

    Hopkins, George W.; Simons, Tad D.

    1998-09-01

    A simple reflective light pipe, formed from a cylindrical tube with an external reflective coating and a small central aperture, can be a highly efficient optical element for collecting light from molecular scattering processes along the path of a laser beam. When the laser beam is co-linear with the axis of the light pipe, scattered light from any location along the interaction region (near the pipe axis) re-images repeatedly to another location along the axis of the pipe. This semi-imaging property of the light pipe permits a large fraction of the total scattered light to re- image along the entire length of the interaction region. If one observes through the small central aperture, scattered light from the single segment of the laser beam in view appears to come from all the locations along the interaction length, as well as from the single segment. In this manner, one can have the advantage of collecting scattered light from a small segment (and thus onto a small detector), while observing an effective interaction length that is many times longer than the segment. Measurements from practical light pipes confirm effective gains of about 10X with light pipes a few centimeters long (Effective gain is defined as the ratio of light collected with the light pipe divided by the light collected from a direct image of the beam using the collection optics).

  12. Sun light European Project

    NASA Astrophysics Data System (ADS)

    Soubielle, Marie-Laure

    2015-04-01

    2015 has been declared the year of light. Sunlight plays a major role in the world. From the sunbeams that heat our planet and feed our plants to the optical analysis of the sun or the modern use of sun particles in technologies, sunlight is everywhere and it is vital. This project aims to understand better the light of the Sun in a variety of fields. The experiments are carried out by students aged 15 to 20 in order to share their discoveries with Italian students from primary and secondary schools. The experiments will also be presented to a group of Danish students visiting our school in January. All experiments are carried out in English and involve teams of teachers. This project is 3 folds: part 1: Biological project = what are the mechanisms of photosynthesis? part 2: Optical project= what are the components of sunlight and how to use it? part 3: Technical project= how to use the energy of sunlight for modern devices? Photosynthesis project Biology and English Context:Photosynthesis is a process used by plants and other organisms to convert light energy, normally from the Sun, into chemical energy that can later fuel the organisms' activities. This chemical energy is stored in molecules which are synthesized from carbon dioxide and water. In most cases, oxygen is released as a waste product. Most plants perform photosynthesis. Photosynthesis maintains atmospheric oxygen levels and supplies all of the organic compounds and most of the energy necessary for life on Earth. Outcome: Our project consists in understanding the various steps of photosynthesis. Students will shoot a DVD of the experiments presenting the equipments required, the steps of the experiments and the results they have obtained for a better understanding of photosynthesis Digital pen project Electricity, Optics and English Context: Sunlight is a complex source of light based on white light that can be decomposed to explain light radiations or colours. This light is a precious source to create

  13. Mapping nanoscale light fields

    NASA Astrophysics Data System (ADS)

    Rotenberg, N.; Kuipers, L.

    2014-12-01

    The control of light fields on subwavelength scales in nanophotonic structures has become ubiquitous, driven by both curiosity and a multitude of applications in fields ranging from biosensing to quantum optics. Mapping these fields in detail is crucial, as theoretical modelling is far from trivial and highly dependent on nanoscale geometry. Recent developments of nanoscale field mapping, particularly with near-field microscopy, have not only led to a vastly increased resolution, but have also resulted in increased functionality. The phase and amplitude of different vector components of both the electric and magnetic fields are now accessible, as is the ultrafast temporal or spectral evolution of propagating pulses in nanostructures. In this Review we assess the current state-of-the-art of subwavelength light mapping, highlighting the new science and nanostructures that have subsequently become accessible.

  14. [LED lights in dermatology].

    PubMed

    Noé, C; Pelletier-Aouizerate, M; Cartier, H

    2017-04-01

    The use in dermatology of light-emitting diodes (LEDs) continues to be surrounded by controversy. This is due mainly to poor knowledge of the physicochemical phases of a wide range of devices that are difficult to compare to one another, and also to divergences between irrefutable published evidence either at the level of in vitro studies or at the cellular level, and discordant clinical results in a variety of different indications: rejuvenation, acne, wound healing, leg ulcers, and cutaneous inflammatory or autoimmune processes. Therapeutic LEDs can emit wavelengths ranging from the ultraviolet, through visible light, to the near infrared (247-1300 nm), but only certain bands have so far demonstrated any real value. We feel certain that if this article remains factual, then readers will have a different, or at least more nuanced, opinion concerning the use of such LED devices in dermatology.

  15. Fusion pumped light source

    DOEpatents

    Pappas, Daniel S.

    1989-01-01

    Apparatus is provided for generating energy in the form of light radiation. A fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The neutron flux is coupled directly with the lasing medium. The lasing medium includes a first component selected from Group O of the periodic table of the elements and having a high inelastic scattering cross section. Gamma radiation from the inelastic scattering reactions interacts with the first component to excite the first component, which decays by photon emission at a first output wavelength. The first output wavelength may be shifted to a second output wavelength using a second liquid component responsive to the first output wavelength. The light outputs may be converted to a coherent laser output by incorporating conventional optics adjacent the laser medium.

  16. EDITORIAL: LED light sources (light for the future) LED light sources (light for the future)

    NASA Astrophysics Data System (ADS)

    Grandjean, N.

    2010-09-01

    Generating white light from electricity with maximum efficacy has been a long quest since the first incandescent lamp was invented by Edison at the end of the 19th century. Nowadays, semiconductors are making reality the holy grail of converting electrons into photons with 100% efficiency and with colours that can be mixed for white light illumination. The revolution in solid-state lighting (SSL) dates to 1994 when Nakamura reported the first high-brightness blue LED based on GaN semiconductors. Then, white light was produced by simply combining a blue dye with a yellow phosphor. After more than a decade of intensive research the performance of white LEDs is quite impressive, beating by far the luminous efficacy of compact fluorescent lamps. We are likely close to replacing our current lighting devices by SSL lamps. However, there are still technological and fabrication cost issues that could delay large market penetration of white LEDs. Interestingly, SSL may create novel ways of using light that could potentially limit electricity saving. Whatever the impact of SSL, it will be significant on our daily life. The purpose of this special cluster issue is to produce a snapshot of the current situation of SSL from different viewing angles. In an introductory paper, Tsao and co-workers from Sandia National Laboratories, present an energy-economics perspective of SSL considering societal changes and SSL technology evolution. In a second article, Narukawa et al working at Nichia Corporation—the pioneer and still the leading company in SSL—describe the state of the art of current research products. They demonstrate record performance with white LEDs exhibiting luminous efficacy of 183 lm W-1 at high-current injection. Then, a series of topical papers discuss in detail various aspects of the physics and technology of white LEDs Carrier localization in InGaN quantum wells has been considered the key to white LEDs' success despite the huge density of defects. A

  17. Light Localisation and Lasing

    NASA Astrophysics Data System (ADS)

    Ghulinyan, Mher; Pavesi, Lorenzo

    2014-12-01

    List of contributors; Preface; 1. Light propagation and emission in complex photonic media W. L. Vos, A. Lagendijk and A. P. Mosk; 2. Transport of localized waves via modes and channels A. Genack and Z. Shi; 3. Modes structure and interaction in random lasers M. Leonetti and C. Lopez; 4. Ordered and disordered light transport in couple microring resonators S. Mookherjea; 5. One-dimensional photonic quasicrystals M. Ghulinyan; 6. 2D pseudo-random and deterministic aperiodic lasers H. Cao, H. Noh and L. Dal Negro; 7. 3D photonic quasicrystal and deterministic aperiodic structures A. Ledermann, M. Renner and G. von Freymann; 8. Cavity quantum electrodynamics with three-dimensional photonic bandgap crystals W. L. Vos and L. A. Woldering; References; Index.

  18. Dichroic ultraviolet light filters

    NASA Astrophysics Data System (ADS)

    Kocher, Christoph; Weder, Christoph; Smith, Paul

    2003-10-01

    With the intention to produce dichroic filters for use in photoluminescent systems that rely on polarized UV light, we synthesized a number of linear, dichroic dyes, which absorb mainly in the near-UV range of the electromagnetic spectrum. These dyes were designed for compatibility with common thermoplastic polymers such as linear low-density poly(ethylene), poly(ethylene terephthalate), and polyamide-12. Films of these host polymers that consisted of 0.2% by weight of various dichroic UV dyes were produced by common melt-processing schemes. Uniaxial drawing of these films yielded highly dichroic UV filters with dichroic ratios in absorption that in some cases exceeded 100. The fact that these free-standing films display little or no coloration and are environmentally stable makes them useful for various applications that involve generation of polarized UV light.

  19. Parametric light generation.

    PubMed

    Ebrahimzadeh, M

    2003-12-15

    Since its invention more than 40 years ago, the laser has become an indispensable optical tool, capable of transforming light from its naturally incoherent state to a highly coherent state in space and time. Yet, due to fundamental limitations, operation of the laser remains confined to restricted spectral and temporal regions. Nonlinear optics can overcome this limitation by allowing access to new spectral and temporal regimes through the exploitation of suitable dielectric materials in combination with the laser. In particular, optical parametric oscillators are versatile coherent light sources with unique flexibility that can provide optical radiation across an entire spectral range from the ultraviolet to the far-infrared and over all temporal scales from continuous wave to the ultrafast femtosecond domain.

  20. Braiding light quanta

    NASA Astrophysics Data System (ADS)

    Iadecola, Thomas; Schuster, Thomas; Chamon, Claudio

    The possibility that anyons -- quantum particles other than fermions or bosons -- can emerge in condensed matter systems has motivated generations of physicists. In addition to being of fundamental scientific importance, so-called non-Abelian anyons are particularly sought-after for potential applications to quantum computing. However, experimental evidence of anyons in electronic systems remains inconclusive. We propose to demonstrate non-Abelian braiding by injecting coherent states of light into ``topological guided modes'' in specially-fabricated photonic waveguide arrays. These modes are photonic analogues of topological zero modes in electronic systems. Light traveling inside spatially well-separated topological guided modes can be braided, leading to the accumulation of non-Abelian phases. We propose an optical interference experiment to probe this non-Abelian braiding directly. T.I. is supported by a National Science Foundation Graduate Research Fellowship under Grant No. DGE-1247312.

  1. OLEDS FOR GENERAL LIGHTING

    SciTech Connect

    Anil Duggal; Don Foust; Chris Heller; Bill Nealon; Larry Turner; Joe Shiang; Nick Baynes; Tim Butler; Nalin Patel

    2004-02-29

    The goal of this program was to reduce the long term technical risks that were keeping the lighting industry from embracing and developing organic light-emitting diode (OLED) technology for general illumination. The specific goal was to develop OLEDs for lighting to the point where it was possible to demonstrate a large area white light panel with brightness and light quality comparable to a fluorescence source and with an efficacy comparable to that of an incandescent source. it was recognized that achieving this would require significant advances in three area: (1) the improvement of white light quality for illumination, (2) the improvement of OLED energy efficiency at high brightness, and (3) the development of cost-effective large area fabrication techniques. The program was organized such that, each year, a ''deliverable'' device would be fabricated which demonstrated progress in one or more of the three critical research areas. In the first year (2001), effort concentrated on developing an OLED capable of generating high illumination-quality white light. Ultimately, a down-conversion method where a blue OLED was coupled with various down-conversion layers was chosen. Various color and scattering models were developed to aid in material development and device optimization. The first year utilized this approach to deliver a 1 inch x 1 inch OLED with higher illumination-quality than available fluorescent sources. A picture of this device is shown and performance metrics are listed. To their knowledge, this was the first demonstration of true illumination-quality light from an OLED. During the second year, effort concentrated on developing a scalable approach to large area devices. A novel device architecture consisting of dividing the device area into smaller elements that are monolithically connected in series was developed. In the course of this development, it was realized that, in addition to being scalable, this approach made the device tolerant to the most

  2. Light cone matrix product

    SciTech Connect

    Hastings, Matthew B

    2009-01-01

    We show how to combine the light-cone and matrix product algorithms to simulate quantum systems far from equilibrium for long times. For the case of the XXZ spin chain at {Delta} = 0.5, we simulate to a time of {approx} 22.5. While part of the long simulation time is due to the use of the light-cone method, we also describe a modification of the infinite time-evolving bond decimation algorithm with improved numerical stability, and we describe how to incorporate symmetry into this algorithm. While statistical sampling error means that we are not yet able to make a definite statement, the behavior of the simulation at long times indicates the appearance of either 'revivals' in the order parameter as predicted by Hastings and Levitov (e-print arXiv:0806.4283) or of a distinct shoulder in the decay of the order parameter.

  3. Light from cosmic strings

    SciTech Connect

    Steer, Daniele A.; Vachaspati, Tanmay

    2011-02-15

    The time-dependent metric of a cosmic string leads to an effective interaction between the string and photons--the ''gravitational Aharonov-Bohm'' effect--and causes cosmic strings to emit light. We evaluate the radiation of pairs of photons from cosmic strings and find that the emission from cusps, kinks and kink-kink collisions occurs with a flat spectrum at all frequencies up to the string scale. Further, cusps emit a beam of photons, kinks emit along a curve, and the emission at a kink-kink collision is in all directions. The emission of light from cosmic strings could provide an important new observational signature of cosmic strings that is within reach of current experiments for a range of string tensions.

  4. Scattering Of Light Nuclei

    SciTech Connect

    Quaglioni, S; Navratil, P; Roth, R

    2009-12-15

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.

  5. Fundamentals of Polarized Light

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael

    2003-01-01

    The analytical and numerical basis for describing scattering properties of media composed of small discrete particles is formed by the classical electromagnetic theory. Although there are several excellent textbooks outlining the fundamentals of this theory, it is convenient for our purposes to begin with a summary of those concepts and equations that are central to the subject of this book and will be used extensively in the following chapters. We start by formulating Maxwell's equations and constitutive relations for time- harmonic macroscopic electromagnetic fields and derive the simplest plane-wave solution that underlies the basic optical idea of a monochromatic parallel beam of light. This solution naturally leads to the introduction of such fundamental quantities as the refractive index and the Stokes parameters. Finally, we define the concept of a quasi-monochromatic beam of light and discuss its implications.

  6. Light Dust Devil Tracks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    14 October 2004 Many Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images exhibit wild patterns of dark streaks thought to have formed by the passage of many dust devils. The dust devils disrupt the dust coating the martian surface, leaving behind a streak. However, not all dust devils make streaks, and not all dust devil streaks are dark. Some are light---it simply depends upon which is darker, the substrate or the dust that the spinning vortex disrupts. The example of light-toned dust devil streaks shown here is located in southern Schiaparelli Basin near 5.3oS, 343.3oW. The image covers an area about 3 km (1.9 mi) across; sunlight illuminates the scene from the left/upper left.

  7. Radioluminescent lighting program description

    SciTech Connect

    1987-11-01

    For more than 30 years the Department of Energy (DOE) and its predecessor agencies have conducted research and development aimed at beneficial uses of products derived from its nuclear activities. An important and promising element of radiation technology is the Program for Radioluminescent (RL) development. For years simple RL devices, such as aircraft exit signs, have served necessary functions in society. Electrons exciting phosphors and producing light is a fundamental concept to which the layman can immediately relate, while gaining a balanced perspective concerning risk and safety. DOE`s RL lighting development program has advanced the technology with infrared RL markers for helipads which are not detectable without the aid of special viewers. These devices were used to aid in the evacuation of wounded from Grenada. Visible RL airfield lighting has been used to promote aviation safety in remote Eskimo communities in Alaska, and non-electric taxiway signs and markers in the corrosive saline soils of Florida airports. The current plan is to consolidate past accomplishments and develop RL devices and systems using advanced technology for new applications. The potential for improved performance that solid-matrix RL techniques offer has stimulated interest in a variety of innovative applications for which electric lighting has long been the only practical alternative. The program described in this document is intended to provide for an optimum development and application of RL technology while supporting the transfer of this technology to the private sector and providing an institutional perspective from which the longer range applications and ramifications of this technology can be anticipated.

  8. Nuclear light bulb

    NASA Technical Reports Server (NTRS)

    Latham, Tom

    1991-01-01

    The nuclear light bulb engine is a closed cycle concept. The nuclear light bulb concept provides containment by keeping the nuclear fuel fluid mechanically suspended in a cylindrical geometry. Thermal heat passes through an internally cooled, fused-silica, transparent wall and heats hydrogen propellant. The seeded hydrogen propellant absorbs radiant energy and is expanded through a nozzle. Internal moderation was used in the configuration which resulted in a reduced critical density requirement. This result was supported by criticality experiments. A reference engine was designed that had seven cells and was sized to fit in what was then predicted to be the shuttle bay mass and volume limitations. There were studies done of nozzle throat cooling schemes to remove the radiant heat. Elements of the nuclear light bulb program included closed loop critical assembly tests done at Los Alamos with UF6 confined by argon buffer gas. It was shown that the fuel region could be seeded with constituents that would block UV radiation from the uranium plasma. A combination of calculations and experiments showed that internal moderation produced a critical mass reduction. Other aspects of the research are presented.

  9. Polymorphous light eruption.

    PubMed

    Hölzle, E; Plewig, G; von Kries, R; Lehmann, P

    1987-03-01

    Polymorphous light eruption (PLE) is a common photodermatosis of unknown etiology. It afflicts mainly fair-skinned patients, with a preponderance of young females. There is, however, no absolute restriction as to age, sex, or race. Clinical variants include the papular, vesiculo-bullous, and hemorrhagic variety, as well as plaque, erythema multiforme-like, and insect bite (strophulus)-like types. Skin lesions appear only in certain exposed areas hours or a few days after intense sunshine, and are nearly always monomorphous in the same patient. The rash subsides spontaneously within several days without leaving scars. The histopathologic picture is characteristic and shows a perivascular lymphocytic infiltrate in the upper and middle corium with subepidermal edema, vacuolization of basal cells, and spongiosis in the lower epidermis. The most important differential diagnoses are solar urticaria, photosensitive erythema multiforme, and lupus erythematosus. The action spectrum of PLE is under debate. Reproduction of skin lesions has been reported with UVB, UVA, and, rarely, visible light, with UVA probably being the most effective part of the spectrum. More important than treatment of PLE is prophylaxis. UVA- and UVB-effective sunscreens are of some help. Phototherapy and especially photochemotherapy (psoralen + UVA; PUVA) offer effective ways to decrease light sensitivity. Systemic treatment with chloroquine or beta-carotene has been disappointing.

  10. SWIR Hemispherical Air-Glow Plotting System SHAPS: Postprint

    DTIC Science & Technology

    2010-06-01

    atmosphere, as modeled using the van Rhijn method (4). 60.-~-----~--~- -- 200 10 °07--0~5~~--~15~~-725~ .-3 15 4.5 T.mo (hour!.) Ttm ~ (hou’!!.) a...temporal variations in the irradiance, both short and long term, can be used to validate and calibrate physical models of atmospheric chemistry and...spatio- temporal variations in the irradiance. both short and long term. can be used to validate and calibrate physical models of atmospheric

  11. Allsky Airglow Imagery from Albuquerque, NM; TOMEX 2000

    NASA Astrophysics Data System (ADS)

    Swenson, G. R.

    2001-12-01

    Allsky imager of OH Meinel and O2 Atmospheric emission bands were observed for the TOMEX rocket campaign from Albuquerque, NM, along with the Na/wind temperature lidar. Motion analysis of imagery describes a main wave propagating from the NW but other secondary waves appear from the NE to present a quasi chaotic wave field. The main wave had a typical horizontal wavelength of a several 10s of km and a period of less than15 minutes. The instrinsic wave parameters of the high frequency waves will be presented.

  12. Infrared Radiance Structure of the Aurora and Airglow,

    DTIC Science & Technology

    1982-06-30

    and 130 km. The presence of protons was initially recognized from the doppler-shifted hydrogen atom line emissions in auroral spectra, which are...that do not involve direct production of N2D by electron impact. Clearly, assuming that N + 02 is the rate-limiting step gives a lower limit to the time...auroral altitudes. (The rms horizontal !ad from upward- directed 4.3 w photons originating from a it source at 90 km is of the order of 10 km, and

  13. High-Resolution Measurement of OH Infrared Airglow Structure.

    DTIC Science & Technology

    1985-10-18

    Interaction of off-axis rays In a conventional Michelson interferometer ESteed 197832................. 11 1-3. Isocon camera system spectral range...had proven effective in the past. The detector selected was an RCA Ltd., solid state germanium device with a self - contained preamplifier and load

  14. Airglow and aurora in the atmospheres of Venus and Mars

    NASA Astrophysics Data System (ADS)

    Fox, J. L.

    Measurements and models of the luminosity that originates in the Martian and Venusian atmospheres, including dayglow, nightglow and aurora, are compared. Most of the emission features considered appear in the UV and visible regions of the spectrum and arise from electronic transitions of thermospheric species. Spatially and temporally variable intensities of the oxygen 1304 and 1356 A lines have been observed on the nightside of Venus and have been labeled 'auroral', that is, ascribed to electron precipitation. Only a future aeronomy mission to Mars could unequivocally determine whether such emissions are present on the nightside of Mars.

  15. Large storms: Airglow and related measurements. VLF observations, volume 4

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The data presented show the typical values and range of ionospheric and magnetospheric characteristics, as viewed from 1400 km with the ISIS 2 instruments. The definition of each data set depends partly on geophysical parameters and partly on satellite operating mode. Preceding the data set is a description of the organizational parameters and a review of the objectives and general characteristics of the data set. The data are shown as a selection from 12 different data formats. Each data set has a different selection of formats, but uniformity of a given format selection is preserved throughout each data set. Each data set consists of a selected number of passes, each comprising a format combination that is most appropriae for the particular data set. Description of ISIS 2 instruments are provided.

  16. Observations of thunderstorm-related 630 nm airglow depletions

    NASA Astrophysics Data System (ADS)

    Kendall, E. A.; Bhatt, A.

    2015-12-01

    The Midlatitude All-sky imaging Network for Geophysical Observations (MANGO) is an NSF-funded network of 630 nm all-sky imagers in the continental United States. MANGO will be used to observe the generation, propagation, and dissipation of medium and large-scale wave activity in the subauroral, mid and low-latitude thermosphere. This network is actively being deployed and will ultimately consist of nine all-sky imagers. These imagers form a network providing continuous coverage over the western United States, including California, Oregon, Washington, Utah, Arizona and Texas extending south into Mexico. This network sees high levels of both medium and large scale wave activity. Apart from the widely reported northeast to southwest propagating wave fronts resulting from the so called Perkins mechanism, this network observes wave fronts propagating to the west, north and northeast. At least three of these anomalous events have been associated with thunderstorm activity. Imager data has been correlated with both GPS data and data from the AIRS (Atmospheric Infrared Sounder) instrument on board NASA's Earth Observing System Aqua satellite. We will present a comprehensive analysis of these events and discuss the potential thunderstorm source mechanism.

  17. Airglow and star photographs in the daytime from a rocket.

    PubMed

    Evans, D C; Dunkelman, L

    1969-06-20

    Photographs of the constellation Cygnus taken in the daytime from altitudes above 100 kilometers indicate that the day sky brightness in the wave-length region from 3600 to 7000 angstroms is only slightly brighter than the night sky viewed from the ground. No diffuse cloud of particles was apparent in the vicinity of the rocket payload, but discrete particles must be considered in the design of instruments for rockets and satellites. The resultant data and reports of star sightings from manned spacecraft indicate similar optical environments for both types of vehicles, that is, discrete particles and relatively low levels of background brightness, only slightly brighter than the night sky as an upper limit.

  18. Advanced mesospheric temperature mapper for high-latitude airglow studies.

    PubMed

    Pautet, P-D; Taylor, M J; Pendleton, W R; Zhao, Y; Yuan, T; Esplin, R; McLain, D

    2014-09-10

    Over the past 60 years, ground-based remote sensing measurements of the Earth's mesospheric temperature have been performed using the nighttime hydroxyl (OH) emission, which originates at an altitude of ∼87  km. Several types of instruments have been employed to date: spectrometers, Fabry-Perot or Michelson interferometers, scanning-radiometers, and more recently temperature mappers. Most of them measure the mesospheric temperature in a few sample directions and/or with a limited temporal resolution, restricting their research capabilities to the investigation of larger-scale perturbations such as inertial waves, tides, or planetary waves. The Advanced Mesospheric Temperature Mapper (AMTM) is a novel infrared digital imaging system that measures selected emission lines in the mesospheric OH (3,1) band (at ∼1.5  μm) to create intensity and temperature maps of the mesosphere around 87 km. The data are obtained with an unprecedented spatial (∼0.5  km) and temporal (typically 30″) resolution over a large 120° field of view, allowing detailed measurements of wave propagation and dissipation at the ∼87  km level, even in the presence of strong aurora or under full moon conditions. This paper describes the AMTM characteristics, compares measured temperatures with values obtained by a collocated Na lidar instrument, and presents several examples of temperature maps and nightly keogram representations to illustrate the excellent capabilities of this new instrument.

  19. Interplanetary dust and debris, as observed from the Moon

    NASA Astrophysics Data System (ADS)

    Levasseur-Regourd, A. Chantal

    1994-06-01

    The visible trace of the interplanetary dust cloud, so-called the zodiacal light, has already been photographed from the Moon, more than twenty years ago (part 1). The interplanetary dust grains do not only scatter solar light; they produce a thermal emission in the near infrared domain; also they may impact the Earth and Moon system as they spiral towards the Sun (part 2). The main problems which can be anticipated for Moon based observations of faint astronomical sources are likely to be due to zodiacal light and zodiacal emission; the induced contamination would however be reduced by appropriate choices in the periods of observation (part 3).

  20. 30. BEDROOM #3 INTERIOR SHOWING 1 LIGHT OVER 1 LIGHT ...

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

    30. BEDROOM #3 INTERIOR SHOWING 1 LIGHT OVER 1 LIGHT WINDOW ON EAST WALL AND PARTIALLY OPENED DOOR TO WINDOWED CLOSET. VIEW TO EAST. - Big Creek Hydroelectric System, Powerhouse 8, Operator Cottage, Big Creek, Big Creek, Fresno County, CA