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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Research study of droplet sizing technology leading to the development of an advanced droplet sizing system

An instrument to measure the size and velocity of droplets was developed. The instrument uses one of two techniques, as appropriate. In the first technique two small laser beams of one color identify the center of a larger laser beam of a different color. This defines a region of almost uniform intensity where the light scattered by the individual droplets can be related to their size. The first technique uses the visibility of a Doppler burst and validates it against the peak intensity of the signal's pedestal. Results are presented for monodisperse, bimodal, trimodal, and polydisperse sprays produced by the Berglund-Liu droplet generator and a pressure nozzle. Size distributions of a given spray obtained using three different size ranges show excellent self-consistency in the overlapping region. Measurements of sprays of known characteristics exhibit errors in the order of 10%. The principles of operation and design criteria of the instrument are discussed in great detail.

Hess, C. F.↗
NASA NTRS1972

The application of color display techniques for the analysis of Nimbus infrared radiation data

A color enhancement system designed for the Applications Technology Satellite (ATS) spin scan experiment has been adapted for the analysis of Nimbus infrared radiation measurements. For a given scene recorded on magnetic tape by the Nimbus scanning radiometers, a virtually unlimited number of color images can be produced at the ATS Operations Control Center from a color selector paper tape input. Linear image interpolation has produced radiation analyses in which each brightness-color interval has a smooth boundary without any mosaic effects. An annotated latitude-longitude gridding program makes it possible to precisely locate geophysical parameters, which permits accurate interpretation of pertinent meteorological, geological, hydrological, and oceanographic features.

Allison, L. J.↗
NASA NTRS1983

Global multispectral mosaics of the icy Galilean satellites

Multispectral mosaics of the three icy Galilean satellites have been produced from low- to moderate-resolution Voyager images. The digital image data have been calibrated using preflight and in-flight calibration data, and reduced to normal albedos for four-color band passes, centered at 0.35, 0.41, 0.48, and 0.59 microns. The individual images have been geometrically corrected, mosaiked, and presented in a normal cylindrical map projection at a uniform scale of 8 km/pixel. Preliminary analysis of the normal albedo data shows that (1) the darkest terrains on the satellites are the dark regions on Callisto, (2) the brightest regions are bright plains regions on Europa and bright, fresh craters on Ganymede, (3) bright craters on Ganymede and its dark, cratered regions are both significantly brighter than comparable terrains on Callisto, and (4) Europa exhibits several distinct spectral units, with regions on the trailing hemisphere having lower relative ultraviolet spectral reflectance than areas on the leading hemisphere. This is consistent with proposals that Io-related plasma impact on Europa's trailing side has altered its optical properties.

Johnson, T. V.↗
NASA NTRS1987

An imaging study of NGC 1275 and PKS 0745-191 - Vigorous star formation in cooling flow cluster dominant galaxies

Observations of NGC 1275 and PKS 0745-191, obtained at 8290 A (FWHM 1900 A) and 4506 A (FWHM 355 A) using a UV-flooded 800 x 800 CCD detector on the 2.3-m telescope at Steward Observatory on December 9, 1986, are reported along with additional observations of PKS 0745-191 at 7240 A (FWHM 78 A) and 6737 A (FWHM 86 A). The results are presented graphically and analyzed in detail. Both of these cluster-central galaxies are shown to have strong cooling flows, total H-alpha luminosities of 4.8 x 10 to the 42nd erg/s, large color gradients (bluer centers), and a blue excess relative to normal old elliptical galaxies (probably indicating star formation at a few times 10 solar mass/yr).

Romanishin, W.↗
NASA NTRS1990

An experimental study of counter-rotating cores in elliptical galaxies

Recent observational studies (Franx and Illingworth 1987; Jedrzejewski and Schechter 1988; Bender 1988; Illingworth and Franx 1989) have shown that some elliptical galaxies have a small region near the center that rotates in the opposite direction from the outer parts of the galaxy. Often the rotation in the central part is much faster than that in the outer part. A few other galaxies show a small region near the center that rotates in the same direction as the rest of the galaxy, but much faster. Either way, the part near the center that shows a strange pattern of rotation (the 'core') has been interpreted as a distinct dynamical subsystem. Very briefly, the observational data seem to be that anomalies show up in rotation curves near the centers of some elliptical galaxies and that galaxies with these strange rotational properties do not show a photometric signature: there are no noticeable bumps in the brightness profile and no unusual shapes of isophotal contours that would suggest an excess of matter concentrated near the center. No strong color variations have been reported. The puzzle is to learn what we can about elliptical galaxies in general, and about galaxies with strange central regions in particular, from these observational facts. The authors' approach is experimental. They make a guess about the form of the dynamically distinct subsystem, and then build a galaxy model to test experimental consequences such as the amount of matter required to produce observable effects and the length of time over which these effects would remain observable. They sidestep questions about how the galaxy might have gotten to be that way in the first place. That gives them more freedom to explore a variety of suggestions about what kind of dynamical system might give rise to the observed rotational patterns.

Miller, R. H.↗
NASA NTRS1992

The reddening to the galaxy IC 342 from CCD BV photometry of its brightest stars

An attempt was made to estimate the reddening for the galaxy IC 342 on the basis of CCD BV photometry obtained for 117 stars brighter than V = 22.0 mag in a field centered near a spiral arm. At V = 19.4 mag, the plume of the main sequence and slightly evolved blue supergiant stars were detected. The plume is centered at a color of (B-V) = 0.54 mag. A comparison with similar color-magnitude-diagram data for the brightest stars in IC 1613 suggests that these stars in IC 342 are reddened by E(B-V) = 0.79 +/- 0.05 mag (A sub B = 3.32 +/- 0.21 mag).

Madore, Barry F.↗
NASA NTRS1973

Iron-absorption band analysis for the discrimination of iron-rich zones

The author has identified the following significant results. Study has concentrated on the two primary aspects of the project, structural analysis through evaluation of lineaments and circular features and spectral analyses through digital computer-processing techniques. Several previously unrecognized lineaments are mapped which may be the surface manifestations of major fault or fracture zones. Two of these, the Walker Lane and the Midas Trench lineament system, transect the predominantly NNE-NNW-trending moutain ranges for more than 500 km. Correlation of major lineaments with productive mining districts implies a genetic relationship, the 50 circular or elliptical features delineated suggest a related role for Tertiary volcanism. Color-ratio composites have been used to identify limonitic zones and to discriminate mafic and felsic rock by combing diazo color transparencies of three different ratios. EROS Data Center scene identification number for color composite in this report is ER 1 CC 500. Refinement of enhancement procedures for the ratio images is progressing. Fieldwork in coordination with both spectral and structural analyses is underway.

Rowan, L. C.↗
NASA NTRS2014

Calibration Uncertainty in Ocean Color Satellite Sensors and Trends in Long-term Environmental Records

Launched in late 2011, the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (NPP) spacecraft is being evaluated by NASA to determine whether this sensor can continue the ocean color data record established through the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) and the MODerate resolution Imaging Spectroradiometer (MODIS). To this end, Goddard Space Flight Center generated evaluation ocean color data products using calibration techniques and algorithms established by NASA during the SeaWiFS and MODIS missions. The calibration trending was subjected to some initial sensitivity and uncertainty analyses. Here we present an introductory assessment of how the NASA-produced time series of ocean color is influenced by uncertainty in trending instrument response over time. The results help quantify the uncertainty in measuring regional and global biospheric trends in the ocean using satellite remote sensing, which better define the roles of such records in climate research.

environment↗
NASA NTRS1984

Far Infrared Continuum Emission from the Galactic Center

High angular resolution observations of the Galactic center from the Kuiper Airborne Observatory are discussed. The results of multi-wavelength mapping reveal that the 30 micron distribution shows a single peak which lies between two emission lobes seen at the longer wavelengths. The 30 micron emission is known from ground-based measurements to peak at the galactic center. The far-infrared color temperature and luminosity also peak at the position of the galactic center, and the observations show a strong temperature gradient away from the galactic center in all directions. Consideration of these data leads to the conclusion that the dust density decreases inward over the central 3 pc of the Galaxy, and that the central parsec of the Galaxy is remarkably devoid of dust, so that optical and ultraviolet photons may traverse it freely. The inferred total luminosity of the sources that heat the dust radiating the far-infrared emission from the central few pc of the Galaxy is 1 to 3 x to the 7th power L(Sun). It is probable that these same sources are responsible for ionizing the plasma at the galactic center.

Werner, M. W.↗
NASA NTRS1994

A finding list of faint UV-bright stars in the galactic plane, 2

Fifty-three UV-bright stars have been found on three two-color 48-in. Schmidt plates centered on the galactic plane. The sources detected range in U-B color from near U- B = 0 to U - B = -1.5, and in magnitude from m(sub B) approximately = 10 to approximately 21. Some of the more interesting sources are discussed, and finding charts are included for all sources listed. Additionally, follow-up spectroscopic and postitional information is provided for several objects first listed in Paper I of this series. One new cataclysmic variable discovered during the course of this portion of the survey has been published previously and is discussed herein.

Lanning, Howard H.↗
NASA NTRS1994

Preliminary evidence for dust in galactic halos

I use B and I photometry of distant galaxies observed through the halos of two nearby spiral galaxies, NGC 2835 and NGC 3521, to test for the existence of dust in galactic halos out to at least a radius of 60 kpc. B - I colors of background galaxies in fields centered along the nearby galaxy's major axis at a projected separation of 60 kpc are compared to the colors of background galaxies in fields centered at a projected separation of about 220 kpc. Background galaxies in the fields at smaller projected separations have average B - I colors that are 0.067 +/- 0.033 mag redder than those in the outer fields. Such a result will occur by chance less than 2.2% of the time and so is taken as preliminary evidence that galaxy halos contain more dust at galactic radii of 60 than 220 kpc. A model which assumes that the radial dust profile in galactic disks and halos is a single exponential has a corresponding scale length of 31 +/- 8 kpc. I argue on the basis of the Infrared Astronomy Satellite (IRAS) 100 micron flux maps that absorption by Galactic dust is not responsible for this result and briefly discuss connections between this result and other observations of the baryonic component of galaxy halos.

Zaritsky, Dennis↗
NASA NTRS1994

Mineral identification and mapping of hydrothermal alteration zones using high-spectral resolution images (AVIRIS)

High-spectral resolution images (AVIRIS) of the cuprite mining area were used to evaluate atmospheric calibration algorithms and test several mineral mapping techniques. Four scene normalization techniques were used: (1) the flat-field method, (2) the internal average reflectance method, (3) the empirical line method, and (4) the atmospheric absorption removal method (ATREM). The algorithms were evaluated in terms of their spectral interpret- ability and their ability to remove both solar irradiance and atmospheric absorption features, noise, and artifacts. Noise was quantified by calculating the coefficient of variation of the spectra, and spectral interpretability was quantified by calcu- lating a difference spectrum (eg, laboratory spectrum minus pixel spectrum) for areas with known occurrences of clay minerals. These difference spectra were useful in evaluating the degree of removal of atmospheric features. The empirical line method produced the best calibration results. Mineral mapping as done using (1) color-composites of bands on the shoulders and centers of expected absorption features, (2) color-coded spectra, and (3) spectral angle mapping.

Van Der Meer, Freek D.↗
NASA NTRS1989

The 100 and 160 micron maps of the dust reemission from the nucleus and inner-arm regions of NGC 6946

Dust reemission from the Scd galaxy NGC 6946 has been measured at 100 and 160 microns with the 32-channel University of Chicago Far-Infrared Camera. Researchers present fully sampled maps of the nucleus and inner spiral arms at 45 seconds resolution. The far-infrared morphology of the galaxy is a bright peak centered on a diffuse disk, where the peak occurs about 24 seconds NE of the Dressel and Condon optical center. The 100/160 micron color temperature is correlated with the H alpha surface brightness. Assuming the distance from Earth to the galaxy is 10.1 Mpc, researchers determine that Tc is 32 K at the nucleus and at radius 5.4 kpc, where there is a concentration of H II regions. In the intermediate annulus of relatively low H alpha surface brightness, the temperature drops to a local minimum of 25 K at radius 3 kpc. The ratio of reradiated to transmitted stellar luminosity is approx. 3.0 at the nucleus and approx. 0.9 for the disk. The optical depth at 100 micron increases from .0005 at the edges of our map to .0035 at the far infrared radiation (FIR) peak. Combining our observations with a fully sampled map of similar spatial extent in CO(1 greater than 0), researchers determine that the ratio F sub IR/I sub CO at the center of the galaxy is almost twice that for the disk, where the value is more or less constant.

Engargiola, Gregory↗
NASA NTRS1988

The psychology of computer displays in the modern mission control center

Work at NASA's Western Aeronautical Test Range (WATR) has demonstrated the need for increased consideration of psychological factors in the design of computer displays for the WATR mission control center. These factors include color perception, memory load, and cognitive processing abilities. A review of relevant work in the human factors psychology area is provided to demonstrate the need for this awareness. The information provided should be relevant in control room settings where computerized displays are being used.

Granaas, Michael M.↗
NASA NTRS2009

Tiny Devices Project Sharp, Colorful Images

Displaytech Inc., based in Longmont, Colorado and recently acquired by Micron Technology Inc. of Boise, Idaho, first received a Small Business Innovation Research contract in 1993 from Johnson Space Center to develop tiny, electronic, color displays, called microdisplays. Displaytech has since sold over 20 million microdisplays and was ranked one of the fastest growing technology companies by Deloitte and Touche in 2005. Customers currently incorporate the microdisplays in tiny pico-projectors, which weigh only a few ounces and attach to media players, cell phones, and other devices. The projectors can convert a digital image from the typical postage stamp size into a bright, clear, four-foot projection. The company believes sales of this type of pico-projector may exceed $1.1 billion within 5 years.

Source record↗
NASA NTRS1995

Method for determining shear direction using liquid crystal coatings

A method is provided for determining shear direction wherein a beam of white light is directed onto the surface of a liquid crystal coating to cause the white light to be dispersed (reflected) from the surface in a spectrum having bands of different colors in a fixed spatial 2 (angular) sequence. The system is calibrated by locating an observer, e.g., a video and movie camera, such that a particular color band (preferably at or near the center of the reflected spectrum) is observed to thereby provide a reference color band. Because the application of shear causes either clockwise or counterclockwise rotation of the reflected spectrum dependent on the direction of the shear, a determination is then made of the reflected color band observed by the observer when the surface of the liquid crystal is subjected to shear to thereby determine the direction of the shear based on the directional (rotation) relation of the observed color band with respect to the reference color band in the spatial sequence of color bands.

Reda, Daniel C.↗
NASA NTRS1980

The galactic center - 16-30 micron observations and the 18 micron extinction

Within the galactic center, ionized gas, stars, and heated dust are in close proximity to each other. Observations of the galactic center were made during two flight series on NASA aircraft flying at altitudes of more than 12 km. In both series the instrument used was a 10-channel liquid helium cooled grating spectrometer. Three 16-30 micrometers continuum spectra are presented along with two-color scans of the galactic center. No 18.71 micrometers line emission has been detected from Sgr A West. This is consistent with large dust extinction and normal S III/H II abundances. All three 16-30 micrometers continuum spectra show a broad depression centered at about 18 micrometers. This observation is attributed to absorption by cold silicate dust grains. The characteristics of a silicate model are discussed.

Mccarthy, J. F.↗
NASA NTRS1985

Determining The Slope Error Of A Parabolic Reflector

Approximate slope error determined with minimal test equipment. Test Setup for Determining Slope Error for Point-Focusing Dish includes pinhole camera at center of curvature and color-coded target mounted around pinhole. Floodlights illuminate target to minimize exposure time. New procedure provides good approximation of reflector slope error and is excellent tool for comparative analysis of reflectors used as solar collectors for microwave receivers.

Christ, G. R.↗