Voyager spacecraft. Volume V - Alternate designs, subsystems considerations, appendix I
Structural analyses, radiation environment effects, thermodynamics, and video communication system for Voyager spacecraft
THERMODYNAMICS↗
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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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New electron microscope employs new video display technique
Video display system for a scanning electron microscope provides slow scanning rates, a self-generated color gradient technique, and allows leisurely viewing of several hours. It also enables the viewing of areas where selected energy regions contribute relatively few electrons, and the changing of specimen position and magnification without adjustments.
Brookshier, W. K.↗
Technique for improving solid state mosaic images
Method identifies and corrects mosaic image faults in solid state visual displays and opto-electronic presentation systems. Composite video signals containing faults due to defective sensing elements are corrected by a memory unit that contains the stored fault pattern and supplies the appropriate fault word to the blanking circuit.
Saboe, J. M.↗
Means for generating a sync signal in an FM communication system Patent
Circuitry for generating sync signals in FM communication systems including video information
Landauer, F. P.↗
The development of spectro-signature indicators of root disease
The development and testing of airborne sensors that might be effective in discrimination root rot infected trees from healthy ones are outlined. The sensing device is composed of a thermal infrared radiometer and an instant replay video scan system.
Wear, J. F.↗
Investigation of atmospheric effects in image transfer
Investigations have been directed mainly toward: (1) theoretical work oriented toward computations of the effects of atmospheric aerosols on the transfer of images through the atmosphere; (2) measurements of the polarization field in the cloud-free atmosphere as an indicator of the existence and characteristics of atmospheric aerosols; and (3) the design of a video-polarizer system for the detection and display of the polarization field of light utilized in remote sensing of the environment. In addition, a camera system is under development for characterizing the polarization properties of a scene (landscape, city, etc.) by photographic means.
Coulson, K. L.↗
AIROscope stellar acquisition
The acquisition system which operates in conjunction with a balloon-borne TV system, boresighted to a telescope is described. It has two main functions, a star field monitor and an offset star tracker. The design of the system was strongly influenced by the TV camera, which uses the same interlaced scanning system as is employed in commercial television broadcasting. To reduce power and bandwidth requirements, the star field information transmitted in our system consists only of the horizontal and vertical coordinates of each star and its brightness. As a star field monitor the system provides video thresholding, camera blemish suppression, coordinate digitization in 3 axes, circuity to recognize as single star the dispersed video signals resulting from one star overlapping adjacent scanning lines and storage of all signals for readout by the telemetry at appropriate times.
Deboo, G. J.↗
Computerized X-ray reconstruction tomography in stereometric analysis of cardiovascular dynamics
A computerized technique is proposed for obtaining cross-sectional images of the dynamic spatial distribution of X-ray attenuation covering the entire anatomic extent of the thorax and its contents in living dogs with a resolution of 1 mm and at time intervals of 1/60 sec. Use is made of an X-ray imaging chain which is a new high-performance video-fluoroscopic system, unique in its design and construction and called SSDSR for single source dynamic spatial reconstructor. This dynamic spatial reconstruction system is shown to provide the temporally and spatially coherent multiple cross sections required to obtain the full three-dimensional anatomic and simultaneous hemodynamic information necessary for detailed quantitative analyses of regional cardiopulmonary and vascular functions in both basic investigations of animals and clinical diagnostic applications to patients. Numerous photographs supplement the text.
Robb, R. A.↗
Large Area Silicon Sheet by EFG
Displaced die concepts were explored along with some initial work on buckle characterization. Convective impurity redistribution was further studied. Growth from single cartridges was continued to create a quality baseline to allow comparison of the results with those in the upcoming multiple run and to choose the most appropriate die design. Fabrication and assembly work on the actual five ribbon furnace continued. Progress was made toward the development of the video optical system for edge position and meniscus height control. In preparation for a detailed program, designed to explore the buckling problem, ribbon guidance in the machine was improved. Buckle free, full width ribbon was grown under stable conditions without a cold shoe, an achievement essential to finally arrive at quantitative correlations between growth conditions and buckle formation.
Wald, F. V.↗
A real-time satellite data acquisition, analysis and display system - A practical application of the GOES network
A real-time satellite data acquisition, analysis and display system is described which uses analog data transmitted by telephone line over the GOES network. Results are displayed on the system color video monitor as 'thermal' images which originated from infrared surface radiation sensed by the Geostationary Operational Environmental Satellite (GOES).
Sutherland, R. A.↗
Communication architecture for large geostationary platforms
Large platforms have been proposed for supporting multipurpose communication payloads to exploit economy of scale, reduce congestion in the geostationary orbit, provide interconnectivity between diverse earth stations, and obtain significant frequency reuse with large multibeam antennas. This paper addresses a specific system design, starting with traffic projections in the next two decades and discussing tradeoffs and design approaches for major components including: antennas, transponders, and switches. Other issues explored are selection of frequency bands, modulation, multiple access, switching methods, and techniques for servicing areas with nonuniform traffic demands. Three-major services are considered: a high-volume trunking system, a direct-to-user system, and a broadcast system for video distribution and similar functions. Estimates of payload weight and d.c. power requirements are presented. Other subjects treated are: considerations of equipment layout for servicing by an orbit transfer vehicle, mechanical stability requirements for the large antennas, and reliability aspects of the large number of transponders employed.
Bond, F. E.↗
Image-based information, communication, and retrieval
IBIS/VICAR system combines video image processing and information management. Flexible programs require user to supply only parameters specific to particular application. Special-purpose input/output routines transfer image data with reduced memory requirements. New application programs are easily incorporated. Program is written in FORTRAN IV, Assembler, and OS JCL for batch execution and has been implemented on IBM 360.
Bryant, N. A.↗
Three-dimensional visualization and display technologies; Proceedings of the Meeting, Los Angeles, CA, Jan. 18-20, 1989
Special attention was given to problems of stereoscopic display devices, such as CAD for enhancement of the design process in visual arts, stereo-TV improvement of remote manipulator performance, a voice-controlled stereographic video camera system, and head-mounted displays and their low-cost design alternatives. Also discussed was a novel approach to chromostereoscopic microscopy, computer-generated barrier-strip autostereography and lenticular stereograms, and parallax barrier three-dimensional TV. Additional topics include processing and user interface isssues and visualization applications, including automated analysis and fliud flow topology, optical tomographic measusrements of mixing fluids, visualization of complex data, visualization environments, and visualization management systems.
Robbins, Woodrow E.↗
Characteristics of return stroke electric fields produced by lightning flashes at distances of 1 to 15 kilometers
Electric field derivative signals from single and multiple lightning strokes are presented. For about 25 pct. of all acquired waveforms, produced by return strokes, stepped leaders or intracloud discharges, type and distance of the signal source are known from the observations by an all sky video camera system. The analysis of the electric field derivative waveforms in the time domain shows a significant difference in the impulse width between return stroke signals and those of stepped leaders and intracloud discharges. In addition, the computed amplitude density spectrum of return stroke waveforms lies by a factor of 10 above that of stepped leaders and intracloud discharges in the frequency range from 50 to 500 kHz.
Hopf, CH.↗
Aerodynamic heating in hypersonic flows
Aerodynamic heating in hypersonic space vehicles is an important factor to be considered in their design. Therefore the designers of such vehicles need reliable heat transfer data in this respect for a successful design. Such data is usually produced by testing the models of hypersonic surfaces in wind tunnels. Most of the hypersonic test facilities at present are conventional blow-down tunnels whose run times are of the order of several seconds. The surface temperatures on such models are obtained using standard techniques such as thin-film resistance gages, thin-skin transient calorimeter gages and coaxial thermocouple or video acquisition systems such as phosphor thermography and infrared thermography. The data are usually reduced assuming that the model behaves like a semi-infinite solid (SIS) with constant properties and that heat transfer is by one-dimensional conduction only. This simplifying assumption may be valid in cases where models are thick, run-times short, and thermal diffusivities small. In many instances, however, when these conditions are not met, the assumption may lead to significant errors in the heat transfer results. The purpose of the present paper is to investigate this aspect. Specifically, the objectives are as follows: (1) to determine the limiting conditions under which a model can be considered a semi-infinite body; (2) to estimate the extent of errors involved in the reduction of the data if the models violate the assumption; and (3) to come up with correlation factors which when multiplied by the results obtained under the SIS assumption will provide the results under the actual conditions.
Reddy, C. Subba↗
Root gravitropism in maize and Arabidopsis
Research during the period 1 March 1992 to 30 November 1993 focused on improvements in a video digitizer system designed to automate the recording of surface extension in plants responding to gravistimulation. The improvements included modification of software to allow detailed analysis of localized extension patterns in roots of Arabidopsis. We used the system to analyze the role of the postmitotic isodiametric growth zone (a region between the meristem and the elongation zone) in the response of maize roots to auxin, calcium, touch and gravity. We also used the system to analyze short-term auxin and gravitropic responses in mutants of Arabidopsis with reduced auxin sensitivity. In a related project, we studied the relationship between growth rate and surface electrical currents in roots by examining the effects of gravity and thigmostimulation on surface potentials in maize roots.
Evans, Michael L.↗
Exobiology and Solar System Exploration
The exploration of the solar system through video animation is shown. Actual footage of the Earth's water and land surface is included.
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