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At least 631 records · Page 35

Color surface-flow visualization of fin-generated shock wave boundary-layer interactions

Kerosene-lampblack mixtures with addition of a ground colored chalk were used in an experiment on visualizing surface flows of swept shock boundary-layer interactions. The results show that contrasting colors intensify the visualization of different regions of the interaction surface, and help the eye in following the fine streaks to locate the upstream influence. The study confirms observations of the separation occurring at shock strength below accepted values. The superiority of the reported technique over the previous monochrome technique is demonstrated.

Lu, F. K.↗

Radiometric considerations for ocean color remote sensors

A methodology for determination of the effects of radiometric noise on the performance of ocean color sensors is developed and applied to the Coastal Zone Color Scanner on Nimbus 7 and the Moderate Resolution Imaging Spectrometer planned for the Earth Observing System.

Gordon, Howard R.↗

Albedo and color maps of the Saturnian satellites

The paper discusses the production of maps of the albedos and colors of Mimas, Enceladus, Tethys, Dione, and Rhea over the full range of their imaged surfaces. Voyager images were used to prepare maps of the normal reflectances and color ratios (0.58/0.41 micron) of these satelites.

Buratti, Bonnie J.↗

Color and chemistry on Triton

The surface of Triton is very bright but shows subtle yellow to peach hues which probably arise from the production of colored organic compounds from CH4 + N2 and other simple species. In order to investigate possible relationships between chemical processes and the observed surface distribution of chromophores, the surface units are classified according to color/albedo properties, the rates of production of organic chromophores by the action of ultraviolet light and high-energy charged particles is estimated, and rates, spectral properties, and expected seasonal redistribution processes are compared to suggest possible origins of the colors seen on Triton's surface.

Thompson, W. Reid↗

Color composite processing of multi-wavelength, multi-polarization airborne radar imagery

Multiwavelength, multipolarization radar image data can be processed to allow the clear depiction of most information in color composite displays. The first principal component, depicted as variations in image intensity, captures the dominant variation in the data and reduces noise without degradation of spatial detail. Other principal components, depicted primarily as variations in image chromaticity, are derived from spatially filtered data so that image colors can be attributed to significant wavelength and polarization contrasts, and not to speckle. Processing paths can be designed to emphasize wavelength contrasts, polarization contrasts, or overall discrimination of surface features.

Crippen, Robert E.↗

Oberon - Color photometry from Voyager and its geological implications

The surface of the Uranian satellite Oberon is characterized on the basis of ground-based and Voyager photometric observations. Disk-integrated phase-curve and disk-resolved data are presented in extensive tables, graphs, maps, and black-and-white and false-color images and discussed in terms of fits to the Hapke (1986) parameters, local variations in albedo and color, and their possible geological significance. It is found that most of the leading hemisphere is covered with dark materials like those in the crater floors, while the trailing hemisphere has patches of the dark material on a surface with a higher proportion of icy materials which are spectrally neutral.

Helfenstein, Paul↗

Color maps of Arp 146

Four color maps of Arp 146 are given. The structure and color of the ring galaxy and its companion show evidence of a bridge of material between the companion and the remnant nucleus of the original galaxy now forming the ring. Broad band spatial coverage clearly defines regions of starburst occurrence.

Schultz, A. B.↗

Color-coded global topographic map of Mars

A Digital Terrain Model (DTM) was derived with both Mercator and Sinusoidal Equal-area projections from the global topographic map of Mars at a scale of 1:15 million and a contour interval of 1 km. Elevations on the map are referred to the Mars topographic datum that is defined by the gravity field at a 6.1-millibar pressure surface with respect to the center of mass of Mars. The DTM has a resolution at the equator of 1/59.226 degrees (exactly 1 km) per pixel. By using the DTM, color-coded global maps of Mars' topography were generated in both the Mercator projection and the Sinusoidal Equal-Area projection. On both maps, colors indicate 1 km increments of height. From the equal-are dataset, the positive and negative elevation distributions are calculated to be 67 and 33 percent, respectively.

Wu, Sherman S. C.↗

SeaWiFS technical report series. Volume 1: An overview of SeaWiFS and ocean color

The purpose of this series of technical reports is to provide current documentation of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Project activities, instrument performance, algorithms, and operations. This documentation is necessary to ensure that critical information related to the quality and calibration of the satellite data is available to the scientific community. SeaWiFS will bring to the ocean community a welcomed and improved renewal of the ocean color remote sensing capability lost when the Nimbus-7 Coastal Zone Color Scanner (CZCS) ceased operating in 1986. The goal of SeaWiFS, scheduled to be launched in August 1993, is to examine oceanic factors that affect global change. Because of the role of phytoplankton in the global carbon cycle, data obtained from SeaWiFS will be used to assess the ocean's role in this cycle, as well as other biogeochemical cycles. SeaWiFS data will be used to help elucidate the magnitude and variability of the annual cycle of primary production by marine phytoplankton and to determine the distribution and timing of spring blooms. The observations will help to visualize the dynamics of ocean and costal currents, the physics of mixing, and the relationships between ocean physics and large-scale patterns of productivity. The data will help fill the gap in ocean biological observations between those of the CZCS and the upcoming Moderate Resolution Imaging Spectrometer (MODIS) on the Earth Observing System-A (EOS-A) satellite.

Hooker, Stanford B.↗

The effect of a redundant color code on an overlearned identification task

The possibility of finding redundancy gains with overlearned tasks was examined using a paradigm varying familiarity with the stimulus set. Redundant coding in a multidimensional stimulus was demonstrated to result in increased identification accuracy and decreased latency of identification when compared to stimuli varying on only one dimension. The advantages attributable to redundant coding are referred to as redundancy gain and were found for a variety of stimulus dimension combinations, including the use of hue or color as one of the dimensions. Factors that have affected redundancy gain include the discriminability of the levels of one stimulus dimension and the level of stimulus-to-response association. The results demonstrated that response time is in part a function of familiarity, but no effect of redundant color coding was demonstrated. Implications of research on coding in identification tasks for display design are discussed.

Obrien, Kevin↗

The X-ray spectra of galaxies. I - Spectral fits of individual galaxies and X-ray colors

The X-ray spectra of normal galaxies is investigated systematically by using the Imaging Proportional Counter (IPC) data in the Einstein data bank. In addition to the standard model fitting technique, X-ray colors are introduced in order to extract spectral information from the fainter X-ray sources. Spectral parameters for 43 galaxies and X-ray colors for 127 galaxies are presented.

Kim, D.-W.↗

Extraordinary colors of asteroidal object (5145) 1992 AD

The colors of the recently discovered 1992 AD indicate a heretofore unknown spectral class, with colors that are far redder than those of any asteroids and comets thus far studied. It is suggested that the redness may be due to the exposure of organic substances that are purer than those associated with C, P, and D asteroids and comets, and therefore more likely to exhibit diagnostic spectral features in the IR.

Mueller, Beatrice E. A.↗

A method of making a single layer multi-color luminescent display

The invention is a method of forming a multi-color luminescent display including the steps of depositing on an insulator substrate a smooth single layer of host material which itself may be a phosphor with the properties to host varying quantities of different impurities and introducing one or more of said different impurities into selected areas of the single layer of host material via an appropriately positioned mask as by thermal diffusion or ion-implantation to form a pattern of phosphors of different colors in the single layer of host material such that the top surface of the host layer remains smooth. Red phosphors are formed by adding impurities selected from the group consisting of Sm, SmF3, Eu, EuF3, and ZnS:MnTbF3 to a ZnS host; green phosphors by adding impurities selected from the group consisting of Tb and TbF3 to a ZnS host; and blue phosphors by adding impurities selected from the group consisting of Tm, Al, Ag, and Mg to a ZnS host.

Robertson, James B.↗

Color and population gradients in globular clusters

We present preliminary results from a survey for color and population gradients in globular cluster cores. Color gradients, in the sense of becoming bluer inwards, are always found in post-core-collapse clusters. They seem to be caused by the demise of red giants, and possibly an increased number of blue stragglers. This may be a consequence of stellar interactions during and after the core collapse. No gradients are seen in clusters with King-model morphology.

Djorgovski, S.↗

In-simulator assessment of trade-offs arising from mixture of color cuing and monocular, binoptic, and stereopsis cuing information

The use of monochrome Helmet Mounted Display (HMD) systems is becoming prevalent in today's complex flight mission environment. These HMD systems can provide stereopsis cueing as an almost natural byproduct for binocular helmet systems of an additional image generation source is provided. The addition of color cueing capability is much more difficult. The application of stereopsis cueing to advanced HMD and heads-down flight display concepts has demonstrated gains in pilot situation awareness and improved task performance. To provide stereopsis, binocular HMD systems must trade some of the total field-of-view (FOV) available from their two monocular fields to obtain a partial overlap region. The visual field then provides a mixture of cues, with monocular regions on both peripheries, and, in the overlapped center, a binoptic (the same image to both eyes) or, if lateral disparity is introduced to produce two images, a stereo region. The goal of this research was to assess the trade-offs arising from the mixture of color cueing and monocular, biocular, and stereopsis cueing information in peripheral monitoring displays as encountered in HMD systems. The accompanying effect of stereopsis cueing in the foveal display of tracking information was also assessed.

Williams, Steven P.↗

Streaks Of Colored Water Indicate Surface Airflows

Response faster and contamination less than in oil-flow technique. Flowing colored water provides accurate and clean way to reveal flows of air on surfaces of models in wind tunnels. Colored water flows from small orifices in model, forming streak lines under influence of air streaming over surface of model.

Wilcox, Floyd J., Jr.↗

Two color holographic interferometry for microgravity application

Holographic interferometry is a primary candidate for the measurement of temperature and concentration in various crystal growth experiments destined for space. The method measures refractive index changes in the experiment test cell. A refractive index change can be caused by concentration changes, temperature changes, or a combination of temperature and concentration changes. If the refractive index changes are caused by temperature and concentration changes occurring simultaneously in the experiment test cell, the contributions by the two effects cannot be separated by conventional measurement methods. By using two wavelengths, two independent interferograms can be produced from the reconstruction of the hologram. The two interferograms will be different due to dispersion properties of fluid materials. These differences provide the additional information that allows the separation of simultaneously occurring temperature and concentration gradients. There is no other technique available that can provide this type of information. The primary objectives of this effort are to experimentally verify the mathematical theory of two color holographic interferometry and to determine the practical value of this technique for space application. To achieve these objectives, the accuracy and sensitivity of the technique must be determined for geometry's and materials that are relevant to the Materials Processing in the Space program of NASA. This will be achieved through the use of a specially designed two-color holographic interferometry breadboard optical system. In addition to experiments to achieve the primary goals, the breadboard will also provide inputs to the design of an optimum space flight system.

Trolinger, James D.↗

State-of-the-art for large area high resolution gray scale and full color AC plasma flat panel displays

A development status evaluation is presented for gas plasma display technology, noting how tradeoffs among the parameters of size, resolution, speed, portability, color, and image quality can yield cost-effective solutions for medical imaging, CAD, teleconferencing, multimedia, and both civil and military applications. Attention is given to plasma-based large-area displays' suitability for radar, sonar, and IR, due to their lack of EM susceptibility. Both monochrome and color displays are available.

Stoller, Ray A.↗