Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “televisions”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Design of a composite filter realizable on practical spatial light modulators

Hybrid optical correlator systems use two spatial light modulators (SLM's), one at the input plane and the other at the filter plane. Currently available SLM's such as the deformable mirror device (DMD) and liquid crystal television (LCTV) SLM's exhibit arbitrarily constrained operating characteristics. The pattern recognition filters designed with the assumption that the SLM's have ideal operating characteristic may not behave as expected when implemented on the DMD or LCTV SLM's. Therefore it is necessary to incorporate the SLM constraints in the design of the filters. In this report, an iterative method is developed for the design of an unconstrained minimum average correlation energy (MACE) filter. Then using this algorithm a new approach for the design of a SLM constrained distortion invariant filter in the presence of input SLM is developed. Two different optimization algorithms are used to maximize the objective function during filter synthesis, one based on the simplex method and the other based on the Hooke and Jeeves method. Also, the simulated annealing based filter design algorithm proposed by Khan and Rajan is refined and improved. The performance of the filter is evaluated in terms of its recognition/discrimination capabilities using computer simulations and the results are compared with a simulated annealing optimization based MACE filter. The filters are designed for different LCTV SLM's operating characteristics and the correlation responses are compared. The distortion tolerance and the false class image discrimination qualities of the filter are comparable to those of the simulated annealing based filter but the new filter design takes about 1/6 of the computer time taken by the simulated annealing filter design.

Rajan, P. K.↗
NASA NTRS1993

The proposed HDTV schemes and the NASA network

Results of the simulation of high definition television (HDTV) techniques in the context of their application to transmit HDTV sequences over the NASA network are presented. Various tradeoffs involved in selecting the different services available on the NASA network are discussed. The possibility of transmitting an HDTV-like signal over the CCSDS network is investigated. Some suitable approaches are suggested.

Chen, Y. C.↗
NASA NTRS1992

Periglacial and glacial analogs for Martian landforms

The list of useful terrestrial analogs for Martian landforms has been expanded to include: features developed by desiccation processes; catastrophic flood features associated with boulder-sized materials; and sorted ground developed at a density boundary. Quantitative analytical techniques developed for physical geography have been adapted and applied to planetary studies, including: quantification of the patterns of polygonally fractured ground to describe pattern randomness independent of pattern size, with possible correlation to the mechanism of origin and quantification of the relative area of a geomorphic feature or region in comparison to planetary scale. Information about Martian geomorphology studied in this project was presented at professional meetings world-wide, at seven colleges and universities, in two interactive televised courses, and as part of two books. Overall, this project has expanded the understanding of the range of terrestrial analogs for Martian landforms, including identifying several new analogs. The processes that created these terrestrial features are characterized by both cold temperatures and low humidity, and therefore both freeze-thaw and desiccation processes are important. All these results support the conclusion that water has played a significant role in the geomorphic history of Mars.

Rossbacher, Lisa A.↗
NASA NTRS1994

Error control techniques for satellite and space communications

The unequal error protection capabilities of convolutional and trellis codes are studied. In certain environments, a discrepancy in the amount of error protection placed on different information bits is desirable. Examples of environments which have data of varying importance are a number of speech coding algorithms, packet switched networks, multi-user systems, embedded coding systems, and high definition television. Encoders which provide more than one level of error protection to information bits are called unequal error protection (UEP) codes. In this work, the effective free distance vector, d, is defined as an alternative to the free distance as a primary performance parameter for UEP convolutional and trellis encoders. For a given (n, k), convolutional encoder, G, the effective free distance vector is defined as the k-dimensional vector d = (d(sub 0), d(sub 1), ..., d(sub k-1)), where d(sub j), the j(exp th) effective free distance, is the lowest Hamming weight among all code sequences that are generated by input sequences with at least one '1' in the j(exp th) position. It is shown that, although the free distance for a code is unique to the code and independent of the encoder realization, the effective distance vector is dependent on the encoder realization.

Costello, Daniel J., Jr.↗
NASA NTRS1994

Feasibility study of transmission of OTV camera control information in the video vertical blanking interval

The Operational Television system at Kennedy Space Center operates hundreds of video cameras, many remotely controllable, in support of the operations at the center. This study was undertaken to determine if commercial NABTS (North American Basic Teletext System) teletext transmission in the vertical blanking interval of the genlock signals distributed to the cameras could be used to send remote control commands to the cameras and the associated pan and tilt platforms. Wavelength division multiplexed fiberoptic links are being installed in the OTV system to obtain RS-250 short-haul quality. It was demonstrated that the NABTS transmission could be sent over the fiberoptic cable plant without excessive video quality degradation and that video cameras could be controlled using NABTS transmissions over multimode fiberoptic paths as long as 1.2 km.

White, Preston A., III↗
NASA NTRS1994

Live from Antarctica: Then and Now

This real-time educational video series, featuring Camille Jennings from Maryland Public Television, includes information from Antarctic scientists and interactive discussion between the scientists and school children from both Maryland and Hawaii. This is part of a 'Passport to Knowledge Special' series. In this part of the four part Antarctic series, the history of Antarctica from its founding to the present, its mammals, plants, and other life forms are shown and discussed. The importance of Antarctica as a research facility is explained, along with different experiments and research that the facilities there perform.

Source record↗
NASA NTRS1994

Live from Antarctica: the Coldest, Windiest Place on Earth

In this first part of a four part 'Passport to Knowledge Special', hosted by Camille Jennings from Maryland Public Television, children from Maryland and Texas schools had the opportunity to directly interact with and ask questions of scientists and researchers in Antarctica live. The physical characteristics of Antarctica are featured, along with their effects on the human and microbiological organisms living in the region. The reasons behind the clothing worn in the Antarctic and the importance of the meteorological station are featured. Interviews with Professor Ian Dolziel (U of Texas) and Lt. commander John Joseph, NSFA (the head of the Navy Meteorology Center) occur with the school children, along with actual video footage of the surrounding geological features and geography. The 'Weatherops' is located at McMurdo Station, Antarctica.

Source record↗
NASA NTRS1994

Live from Antarctica, Volume 4

In this fourth video of a four part 'Passport to Knowledge Special', hosted by Camille Moody Jennings from Maryland Public Television, children from Maryland and Alaska public schools had the opportunity to directly interact with and ask questions of scientists and researchers from the Antarctic, and learn about the different geological and meteorological research going on in the Antarctic and McMurdo Base at McMurdo Sound. The scientists questioned included: Donal Manahan (biologist from Un. of So. California), who described some of the geological features from Hut Point, the historic hut built by Capt. Scott in 1902; Sridar Anandakrishnan (Penn State Un.) whose research includes ice plate movement of the central ice sheet and earthquakes and how they affect the sheet; and Lt. j.g. Kate McNitt, who spends her winters investigating the trace gases, aerosols, CFC's and ozone levels over the Antarctic area that are affecting the seasonal ozone hole that appears in that region. Historical film footage of Capt. Scott's exploration of the Antarctic is included.

Source record↗
NASA NTRS1993

International Space University

The International Space University (ISU) is described in this video, hosted by Marina Sirtis from the 'Star Trek' television show's Starship Enterprise. A complete explanation of what ISU is, how the university functions, and the benefits that the university provides are described. Included are brief comments from former ISU graduates.

Kassler, Maggie↗
NASA NTRS1995

Production of a long-term global water vapor and liquid water data set using ultra-fast methods to assimilate multi-satellite and radiosonde observations

There is a well-documented requirement for a comprehensive and accurate global moisture data set to assist many important studies in atmospheric science. Currently, atmospheric water vapor measurements are made from a variety of sources including radiosondes, aircraft and surface observations, and in recent years, by various satellite instruments. Creating a global data set from a single measuring system produces results that are useful and accurate only in specific situations and/or areas. Therefore, an accurate global moisture data set has been derived from a combination of these measurement systems. Under a NASA peer-reviewed contract, STC-METSAT produced two 5-yr (1988-1992) global data sets. One is the total column (integrated) water vapor data set and the other, a global layered water vapor data set using a combination of radiosonde observations, Television and Infrared Observation Satellite (TIROS) Operational Satellite (TOVS), and Special Sensor Microwave/Imager (SSM/I) data sets. STC-METSAT also produced a companion, global, integrated liquid water data set. The complete data set (all three products) has been named NVAP, an anachronym for NASA Water Vapor Project. STC-METSAT developed methods to process the data at a daily time scale and 1 x 1 deg spatial resolution.

Vonderhaar, Thomas H.↗
NASA NTRS1994

Global temperature monitoring from space

Global and regional temperature variations in the lower troposphere and lower stratosphere are examined for the period 1979-92 from Microwave Sounder Unit (MSU) data obtained by the Television Infrared Observation Satellite (TIROS)-N series of National Oceanic and Atmospheric Administration (NOAA) operational satellites. In the lower troposphere, globally-averaged temperature variations appear to be dominated by tropical El Nino (warm) and La Nina (cool) events and volcanic eruptions. The Pinatubo volcanic eruption in June 1991 appears to have initiated a cooling trend which persisted through the most recent data analyzed (July, 1992), and largely overwhelmed the warming from the 1991-92 El Nino. The cooling has been stronger in the Northern Hemisphere than in the Southern Hemisphere. The temperature trend over the 13.5 year satellite record is small (+0.03 C) compared to the year-to-year variability (0.2-0.4 C), making detection of any global warming signal fruitless to date. However, the future global warming trend, currently predicted to be around 0.3 C/decade, will be much easier to discern should it develop. The lower stratospheric temperature record is dominated by warm episodes from the Pinatubo eruption and the March 1982 eruption of El Chichon volcano.

Spencer, R. W.↗
NASA NTRS1994

ATLAS-1 and middle atmosphere global change

To understand the extent and trends of middle atmosphere change, it is necessary to establish the baseline of atmospheric behavior and its response to changes in solar irradiance over at least a solar cycle. An element in NASA's global change program is the ATLAS shuttle series. The international payload includes several instruments intended to make precise, absolute measurements of solar irradiance, each being calibrated before and after each shuttle flight. These instruments, in addition to obtaining an 11-year database, will also intercalibrate solar instruments on the Earth Radiation Budget (ERB) and Upper Atmosphere Research (UARS) satellites. Other instruments will measure the atmospheric composition and temperature, also intercalibrating instruments on Television and Infrared Observation Satellite (TIROS)-N and UARS. Some have flown on shuttle missions dating back to 1983 and it is hoped that the ATLAS series will provide a capability until the turn of the century. This paper reviews the early results of the ATLAS-1 mission, which flew between March 24 and April 2, 1992.

Torr, Marsha R.↗
NASA NTRS1993

Opinion polls and the U.S. civil space program

The conclusions that can be drawn from public opinion polls depend a great deal on what usually does not appear on the newspaper page or television screen. Subtle biases can result from the population interviewed, the time of day individuals were called, how a particular question was asked, or how the answer was interpreted. Examples are the 1961 Gallop Poll, the survey done for Rockwell International by the firm of Yankelovich, Skelly and White/Clancy Shulman, and the one done by Jon D. Miller of the International Center for the Advancement of Scientific Literacy. There is more to learn from opinion polls than that a good proportion of adult Americans support the space program. We can learn that social and economic security are not competing goals with space, but interdependent goals. If we want to increase public support for space, we must increase the number of Americans who have the economic freedom to take an interest in something besides getting by, day after day. We can also learn that the majority of those who support the space program can distinguish between the bread and circuses of space travel. They are content to experience extraordinary adventures in the movie theaters; for their tax dollars they want real return in expended scientific knowledge and understanding. Finally, we can learn that we need to increase that return, not just for scientific careers, but for the ordinary people who pay our bills and for their children, our children. Ultimately, the space program is for them, as all investments in the future must be.

Kraemer, Sylvia K.↗
NASA NTRS1995

Variability of moisture in the upper troposphere as inferred from TOVS satellite observations and the ECMWF model analyses in 1989

Large-scale variability of moisture in the upper troposphere is examined using TIROS (Television Infrared Observation Satellite) Operational Vertical Sounder (TOVS) satellite observations and European Centre for Medium-Range Weather Forecasts (ECMWF) model analyses from 1989 in the latitude band from 40 deg N to 40 S. To compare these dissimilar datasets, upwelling radiances were computed for the 6-7 micrometer water vapor band from the ECMWF temperature and moisture analyses, and these computed radiances were compared to the corresponding TOVS satellite observations. The ECMWF-based radiances reproduce the general locations and seasonal cycle of the TOVS-observed moisture features, particularly after an improved convective parameterization scheme was adopted by ECMWF in May 1989. However, the ECMWF analysis scheme still results in much milder lateral moisture gradients and seasonal contrasts than indicated by the TOVS observations. Seasonally, the upper troposphere in each hemisphere dries in winter and moistens in summer, but there are regions in each hemisphere that run counter to this seasonal trend, apparently depending on continental- and monsoon-scale dynamics. Dynamically, the TOVS-observed regions of significant subtropical dryness are correlated with persistent subsidence indicated by ECMWF 300-mb vertical velocity analyses. The TOVS radiance observations indicate large variations in space and time of the upper-tropospheric moisture field, which are not fully captured by the ECMWF analyses.

Salathe, Eric P., Jr.↗
NASA NTRS1995

Preliminary results from the Sprites94 aircraft campaign: 1. Red sprites

The dual jet aircraft Sprites94 campaign yielded the first color imagery and unambiguously triangulated physical dimensions and heights of upper atmospheric optical emissions associated with thunderstorm systems. Low light level television images, in both color and in black and white (B/W), obtained during the campaign show that there are at least two distinctively different types of optical emissions spanning part or all of the distance between the anvil tops and the ionosphere. The first of these emissions, dubbed 'sprites' after their elusive nature, are luminous structures of brief (less than 16 ms) duration with a red main body that typically spans the latitude range 50-90 km, and possessing lateral dimensions of 5-30 km. Faint bluish tendrils often extend downward from the main body of sprites, occasionally appearing to reach cloud tops near 20 km. In this paper the principal characteristics of red sprites as observed during the Sprites94 campaign are described. The second distinctive type of emissions, 'blue jets,' are described in a companion paper (Wescott et al., this issue).

Sentman, D. D.↗
NASA NTRS1995

Enhancing Images By Nonlinear Extrapolation In Frequency

Improved method of enchancing edges in image involves nonlinear filter operation creating image-intensity components having spatial frequencies higher than those present in input image and locked in phase to lower-frequency input components. In comparison with other edge-enhancement methods involving mostly strengthening of higher-frequency components already present in input, this method computationally simpler and yields better results. Better suited to real-time applications like high-definition television and compression of image data.

Anderson, Charles H.↗
NASA NTRS1991

STS-48 Mission Highlights Resource Tape. Part 2 of 2

In this second part of a two part mission highlights tape for the STS-48 Mission, television interviewer, Larry King, hosts a live, satellite-link interview with the flight crew of the STS-48 Mission. Listeners called in and the astronauts answered questions about their flight and space travel in general. The flight crew consisted of: Cmdr. J. O. Creighton; Pilot Rick Hauck, and Mission Specialists Sam Gemar, Jim Buchli, and Mark Brown.

Source record↗
NASA NTRS1995

STS-69 Flight Day 5 Video File

Awakening to the theme song of the television show 'Rin Tin Tin', the astronauts, Cmdr. Dave Walker, Pilot Ken Cockrell, and Mission Specialists Jim Voss, Jim Newman, and Mike Gernhardt, of the STS-69 mission began their fifth day in orbit. The deployment of the Wake Shield Facility (WSF) was accomplished successfully, although it was delayed several hours due to communication problems between the satellite and its carrier platform located in the shuttle's cargo bay. The WSF satellite's main purpose was to grow up to seven layers of semiconductor films in a vacuum-like state while orbiting behind the space shuttle. The shuttle's Global Positioning System and Satellite Tracking System were both given checkout tests.

Source record↗