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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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A holographic motion picture camera is reported for producing three dimensional images by employing an elliptical optical system. There is provided in one of the beam paths (the object or reference beam path) a motion compensator which enables the camera to photograph faster moving objects.
A few new algorithms for region growing in pictures were developed. These algorithms are a step toward finding a satisfactory solution to the image segmentation problem, and in-depth understanding of the problems of nonsemantic image segmentation. The algorithms utilize a sequential decision approach for region boundaries detection. The sequential decisions are supported by a stochastic algorithm that maintains local statistics of the region near the boundaries as the region grows. A few illustrations of the algorithm's performance are included.
Using NASA facilities in space (OSO-7) and on the ground (Goddard multi-channel spectrophotometer at Sacramento Peak, New Mexico) an active region has been mapped. By combining these ultraviolet, X-ray, and visible data, a physical picture of this structured region was constructed from the photosphere to the corona, corresponding to temperature regimes from 4500 K to 4,000,000 K. The morphology of the active region was studied by comparing grey-shaded images in which fine details stand out more clearly than in the contour plots. One result of the study is that gross similarities persist from the low photosphere up to high in the transition region, while some changes occur in the corona.
This semi-tutorial paper describes the process of using orthogonal transforms for the purposes of encoding TV picture data. Results pertaining to a 6:1 data compression experiment using the Walsh-Hadamard transform are included.
A vehicle geometric definition based upon quadrilateral surface elements to produce realistic pictures of an aerospace vehicle. The PCSYS programs can be used to visually check geometric data input, monitor geometric perturbations, and to visualize the complex spatial inter-relationships between the internal and external vehicle components. PCSYS has two major component programs. The between program, IMAGE, draws a complex aerospace vehicle pictorial representation based on either an approximate but rapid hidden line algorithm or without any hidden line algorithm. The second program, HIDDEN, draws a vehicle representation using an accurate but time consuming hidden line algorithm.
The use of photographs from satellites to assist in census operations is discussed. Principles of selecting the sources of cartographic information are outlined, and the use of LANDSAT pictures in census cartography is examined.
Imaging system uses charge-coupled devices (CCD's) to generate TV-like pictures with high resolution, sensitivity, and signal-to-noise ratio. It combines detectors for five spectral bands as well as processing and control circuitry all on single silicon chip.
We obtained and processed 56 pictures of Io's sodium cloud on 15 nights during the 1976-1977 apparition of Jupiter. These show rapid changes in the appearance of the cloud, but may be consistent with a steady-state cloud whose appearance is controlled by the viewing geometry. The sodium is in a column extending forward from Io, with the axis pointing slightly inside the orbit. The size and shape of the cloud convey information on the anisotropy and velocity of emission and the lifetime of neutral sodium. We find some confirnation for Trafton's findings of north/south asymmetries related to the position of the magnetic field.
The degradation of picture quality in a high-resolution, large-swath SAR mapping system caused by speckle, additive white Gaussian noise and range and azimuthal ambiguities occurring because of the nonfinite antenna pattern produced by a square aperture antenna was studied and simulated. The effect of the azimuth antenna pattern was accounted for by calculating the azimuth ambiguity function. Range ambiguities were accounted for by adding, to each pixel of interest, appropriate pixels at a range separation corresponding to one pulse repetition period, but attenuated by the antenna pattern. It is concluded that azimuth ambiguities do not cause any noticeable degradation (for large time bandwidth product systems, at least) but range ambiguities might.
Results are presented for a detailed study of the peculiar elliptical galaxy NGC 5128 (Cen A), based on computer video analysis of several photographic plates of exceptional quality reduced to the standard UBV system. The picture-processing results and the measured properties of the elliptical and gaseous-disk components of NGC 5128 are examined, along with the distribution, spectral characteristics, and chemical composition of the H II regions in the disk. The data show that NGC 5128 consists of a giant E2 galaxy containing a significant amount of gas and dust situated predominantly in an equatorial disk where vigorous star formation is occurring. Reasons why NGC 5128 is so different from giant ellipticals in clusters are considered.
The program, LACVIN, calculates vegetative indexes numbers on limited area coverage/high resolution picture transmission data for selected IJ grid sections. The IJ grid sections were previously extracted from the full resolution data tapes and stored on disk files.
Using the data obtained from the IMS North American magnetometer network stations at high latitudes, a motion picture was made by a computer technique, describing time changes of Pc5 and Pi3 magnetic pulsation vectors. Examples of pulsation characteristics derived from this presentation are regional polarization changes including shifts of polarization demarcation lines, changes in the extent of an active region and its movement with time.
The importance of ice sheet flow as part of the process of concentrating meteorites in Antarctica is discussed. Ford and Tabor were the first to surmise that some type of ice sheet transport of Antarctic meteorites was likely considering that the Thiel Mountains pallasite was found on glacier ice without evidence of impact. It was found that meteorites were carried by the ice to regions of high ablation where they were periodically uncovered. Three models of concentration have been proposed to explain the phenomena of meteorite accumulations on blue ice fields. Model 1, is a general picture relating meteorite fall and accumulation to the entire Antarctic continent. Model 2 is based upon the petrographic examination of an 8m ice core from the Allan Hills Icefield and suggests a local origin of ice from the catchment basin. The third model is presented by Whillans and Cassidy who infer, by using conventional ice flow concepts, a path length as long as 1,000km from the sites of fall to recovery for Allan Hills specimens. Despite achievement of these working hypotheses, a number of questions must be resolved before a comprehensive model can be presented.
SHADE computer program generates realistic color-shaded pictures from computer-defined arbitrary shapes. Objects defined for computer representation displayed as smooth, color-shaded surfaces, including varying degrees of transparency. Results also used for presentation of computational results. By performing color mapping, SHADE colors model surface to display analysis results as pressures, stresses, and temperatures. NASA has used SHADE extensively in sign and analysis of high-performance aircraft. Industry should find applications for SHADE in computer-aided design and computer-aided manufacturing. SHADE written in VAX FORTRAN and MACRO Assembler for either interactive or batch execution.
Over the last few years, discoveries in astronomy, geochemistry, and atmospheric chemistry have resulted in a new picture of how our planet and its atmosphere formed. The traditional view held that the early atmosphere was composed of methane, ammonia, and molecular hydrogen, but the actual composition may have been nitrogen, carbon dioxide, and water vapor. The history leading to the present understanding is discussed and topics covered include: chemical evolution, origin of the atmosphere, atmospheric evolution on earth, Venus, and Mars, and prebiological atmospheric oxygen and the early sun.
The past 25 years of space travel and exploration have generated an unprecedented quantity of data from planetary systems. Data gathered at close range, and from above the distorting effects of Earth's atmosphere, produce images far more detailed than pictures taken by even the largest Earth-bound telescopes. The techniques used to acquire and process these images are discussed briefly.
In MAP observations, it was found that: (1) gravity waves in selected or filtered portions of data are fit for monochromatic structures, whereas (2) those in fully continuous and resolved observations take universal continuous spectra. It is possible to explain (2) by dispersion of quasi-monochromatic (or slowly varying) wave packets observed locally as (1), since the medium atmosphere is unsteady and nonuniform. Complete verification of the wave-mean flow interactions by tracking individual wave packets seems hopeless, because the wave induced flow cannot be distinguished from the basic flow independent of the waves. Instead, the primitive picture is looked at before MAP, that is, the atmosphere is just like an entertainment stage illuminated by cocktail lights of quasi-monochromatic gravity waves. The wave parameters are regarded as functions of time and spatial coordinates. The observational evidences (1) and (2) suggest that the wave parameter field is rather homogeneous, which can be explained by interference of quasi-monochromatic wave packets.
Subjective reports of American astronauts and their Soviet counterparts suggest that homogeneous, often symmetrical, spacecraft interiors can contribute to motion sickness during the earliest phase of a mission and can also engender boredom. Two studies investigated the functional aspects of Space Station interior aesthetics. One experiment examined differential color brightnesses as body orientation cues; the other involved a large survey of photographs and paintings that might enhance the interior aesthetics of the proposed International Space Station. Ninety male and female college students reclining on their backs in the dark were disoriented by a rotating platform and inserted under a slowly rotating disk that filled their entire visual field. The entire disk was painted the same color but one half had a brightness value that was about 69 percent higher than the other. The effects of red, blue, and yellow were examined. Subjects wearing frosted goggles opened their eyes to view the rotating, illuminated disk, which was stopped when they felt that they were right-side up. For all three colors, significant numbers of subjects said they felt right-side up when the brighter side of the disk filled their upper visual field. These results suggest that color brightness could provide Space Station crew members with body orientation cues as they move about. It was found that subjects preferred photographs and paintings with the greatest depths of field, irrespective of picture topic.