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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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At least 1,279 records · Page 71
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Use of a raster framebuffer in vision research

For the study of human and animal vision, the video framebuffer is the only technology that is capable of displaying two-dimensional images with precise control of contrast, luminance, and display timing. The video framebuffer also allows precise control of color. However, this device is not designed for precise psychophysical displays, and techniques must be developed to use them in this role. In order to be concrete, an RDS-3000 raster display system (Adage, 1982) is used which is hosted by a PDP-11/73 under the Venix operating system. The principles generalize to other machines. Where it clarifies the issues, the syntax of the software routines involved is shown.

Watson, Andrew B.↗
NASA NTRS1988

Stereoscopic Optical Signal Processor

Optical signal processor produces two-dimensional cross correlation of images from steroscopic video camera in real time. Cross correlation used to identify object, determines distance, or measures movement. Left and right cameras modulate beams from light source for correlation in video detector. Switch in position 1 produces information about range of object viewed by cameras. Position 2 gives information about movement. Position 3 helps to identify object.

Graig, Glenn D.↗
NASA NTRS1987

Space lab system analysis

An analytical analysis of the HOSC Generic Peripheral processing system was conducted. The results are summarized and they indicate that the maximum delay in performing screen change requests should be less than 2.5 sec., occurring for a slow VAX host to video screen I/O rate of 50 KBps. This delay is due to the average I/O rate from the video terminals to their host computer. Software structure of the main computers and the host computers will have greater impact on screen change or refresh response times. The HOSC data system model was updated by a newly coded PASCAL based simulation program which was installed on the HOSC VAX system. This model is described and documented. Suggestions are offered to fine tune the performance of the ETERNET interconnection network. Suggestions for using the Nutcracker by Excelan to trace itinerate packets which appear on the network from time to time were offered in discussions with the HOSC personnel. Several visits to the HOSC facility were to install and demonstrate the simulation model.

Ingels, F. M.↗
NASA NTRS1986

High speed photography, videography, and photonics IV; Proceedings of the Meeting, San Diego, CA, Aug. 19, 20, 1986

Various papers on high-speed photography, videography, and photonics are presented. The general topics addressed include: photooptical and video instrumentation, streak camera data acquisition systems, photooptical instrumentation in wind tunnels, applications of holography and interferometry in wind tunnel research programs, and data analysis for photooptical and video instrumentation.

Ponseggi, B. G.↗
NASA NTRS1987

Remote noncontacting measurements of heat transfer coefficients for detection of boundary layer transition in wind tunnel tests

An infrared measurement system is used that consists of a laser heating source, an infrared camera for data acquisition, and a video recorder for data storage. A laser beam is scanned over an airfoil, heating its surface to a few degrees above ambient. An infrared camera then measures the temperature of the airfoil over a two-dimensional field, and these temperatures are stored as a function of time on a video recorder. The resulting temperature pictures are digitized and an iterative approximation algorithm is used to extract the heat transfer coefficient. The resulting values are normalized to the natural convection condition. The technique has been applied in low-speed wind tunnel tests and compared to well-established hot-film measurements which were made simultaneously to confirm the flow conditions. Heat transfer coefficients were determined using a linear scanning pattern, to indicate the position of natural and of artificially induced transition on an airfoil, at various wind speeds. The technique is shown to be sensitive to transition at low Mach numbers. The advantages of the technique are discussed.

Heath, D. Michele↗
NASA NTRS1988

An airborne system for vortex flow visualization on the F-18 high-alpha research vehicle

A flow visualization system for the F-18 high-alpha research vehicle is described which allows direct observation of the separated vortex flows over a wide range of flight conditions. The system consists of a smoke generator system, on-board photographic and video systems, and instrumentation. In the present concept, smoke is entrained into the low-pressure vortex core, and vortice breakdown is indicated by a rapid diffusion of the smoke. The resulting pattern is observed using photographic and video images and is correlated with measured flight conditions.

Curry, Robert E.↗
NASA NTRS1989

Gray-Scale Processing For Tracking Of Welds

Digital analysis of video-image-processing system contributes to automation of weld-seam tracking. Makes no contact with seam. Small television camera views seam just ahead of point currently being welded. Arc provides illumination. Periodically frame grabber digitizes video image and stores in computer memory as gray-scale values. Seam located by analyzing Hough-transform arrays of derivatives of digitally-filtered image data. Information on location and orientation of seam used as feedback by welding robot to correct deviations of electrode from seam as welding continues.

Gutow, David A.↗
NASA NTRS1987

Ultraviolet spectroscopy of meteoric debris: In situ calibration experiments from earth orbit

It is proposed to carry out slitless spectroscopy at ultraviolet wavelengths from orbit of meteoric debris associated with comets. The Eta Aquarid, Orionid/Halley, and the Persied/1962 862 Swift-Tuttle showers would be principal targets. Low light level, ultraviolet video technique will be used during the night side of the orbit in a wide field, earthward viewing mode. Data will be stored in compact video cassette recorders. The experiment may be configured as a GAS package or in the HITCHHIKER mode. The latter would allow flexible pointing capability beyond that offered by shuttle orientation of the GAS package, and doubling of the data record. The 1100 to 3200 A spectral region should show emissions of atomic, ionic, and molecular species of interest on cometary and solar system studies.

Nuth, Joseph A.↗
NASA NTRS1988

Simulation of water vapor condensation on LOX droplet surface using liquid nitrogen

The formation of ice or water layers on liquid oxygen (LOX) droplets in the Space Shuttle Main Engine (SSME) environment was investigated. Formulation of such ice/water layers is indicated by phase-equilibrium considerations under conditions of high partial pressure of water vapor (steam) and low LOX droplet temperature prevailing in the SSME preburner or main chamber. An experimental investigation was begun using liquid nitrogen as a LOX simulant. A monodisperse liquid nitrogen droplet generator was developed which uses an acoustic driver to force the stream of liquid emerging from a capillary tube to break up into a stream of regularly space uniformly sized spherical droplets. The atmospheric pressure liquid nitrogen in the droplet generator reservoir was cooled below its boiling point to prevent two phase flow from occurring in the capillary tube. An existing steam chamber was modified for injection of liquid nitrogen droplets into atmospheric pressure superheated steam. The droplets were imaged using a stroboscopic video system and a laser shadowgraphy system. Several tests were conducted in which liquid nitrogen droplets were injected into the steam chamber. Under conditions of periodic droplet formation, images of 600 micron diameter liquid nitrogen droplets were obtained with the stroboscopic video systems.

Powell, Eugene A.↗
NASA NTRS1989

NASA ground communications

As part of the Communications Requirements and Constraints, NASA's two major Ground Data Networks were briefly described. The NASA Communication Network, called NASCOM, is the worldwide operational telecommunications system which interconnects as the tracking and telemetry acquisition sites, launch areas, mission and project control centers, data capture facilities, and network control centers in support of space flight. For the Space Station era, NASCOM plans are set for higher data rate service utilizing data packet switched technology. Increased use of fiber optics is expected in a much more diverse network topology. The second major ground network, the Program Support Communications Network (PSCN), interconnects all NASA Centers and NASA contractor locations for intercenter non-operation communications. The primary functions are to transport voice, video, data and facsimile information for intercenter coordination, and to provide user access to space science and applications data bases. For the Space Station era, PSCN plans address the significant increase in forecast requirements for science data distribution and access to the Numerical Aerodynamics Simulator, and increased use of the Video Teleconference System.

Roeder, John↗
NASA NTRS1989

A VLSI chip set for real time vector quantization of image sequences

The architecture and implementation of a VLSI chip set that vector quantizes (VQ) image sequences in real time is described. The chip set forms a programmable Single-Instruction, Multiple-Data (SIMD) machine which can implement various vector quantization encoding structures. Its VQ codebook may contain unlimited number of codevectors, N, having dimension up to K = 64. Under a weighted least squared error criterion, the engine locates at video rates the best code vector in full-searched or large tree searched VQ codebooks. The ability to manipulate tree structured codebooks, coupled with parallelism and pipelining, permits searches in as short as O (log N) cycles. A full codebook search results in O(N) performance, compared to O(KN) for a Single-Instruction, Single-Data (SISD) machine. With this VLSI chip set, an entire video code can be built on a single board that permits realtime experimentation with very large codebooks.

Baker, Richard L.↗
NASA NTRS1989

International standards activities in image data compression

Integrated Services Digital Network (ISDN); coding for color TV, video conferencing, video conferencing/telephone, and still color images; ISO color image coding standard; and ISO still picture standard are briefly discussed. This presentation is represented by viewgraphs only.

Haskell, Barry↗
NASA NTRS1988

Telescience space life sciences test bed

This paper discusses the life sciences test bed project to evaluate the methodology for conducting a life sciences experiment over real physical distance with voice, video, and data interaction between the experiment and the remotely located investigators. The project was planned to identify the requirements for the Space Station Information System for life sciences experiments. The experiment design is presented, including video, data, and voice links. The ground based principal investigator workstation and the telescience operations are examined.

Nijhawan, Vinit↗
NASA NTRS1988

The recovery and utilization of space suit range-of-motion data

A technique for recovering data for the range of motion of a subject wearing a space suit is described along with the validation of this technique on an EVA space suit. Digitized data are automatically acquired from video images of the subject; three-dimensional trajectories are recovered from these data, and can be displayed using three-dimensional computer graphics. Target locations are recovered using a unique video processor and close-range photogrammetry. It is concluded that such data can be used in such applications as the animation of anthropometric computer models.

Reinhardt, AL↗
NASA NTRS1989

Joint-transform correlator systems using deformable-mirror spatial light modulators

Two joint-transform correlator systems based on deformable-mirror-device (DMD) spatial light modulators and CCD video cameras are described. The system designs provide for real-time correlation between video-formatted input scenes and stored reference images. The DMD light modulators are used exclusively for inputting data in the optical stages of these systems, and the CCD cameras are used to provide the critical square-law detection required in joint-transform achitectures. Experimental verification of the functionality of these DMD/CCD joint-transform systems is also presented.

Florence, James M.↗
NASA NTRS1990

Borescope Aids Welding In Confined Spaces

Welding torch holds video borescope to give operator view of workpiece in enclosed space. Operator sees clear, magnified image on video monitor and manipulates torch accordingly, despite visual obstruction presented by enclosure. Tinted shield tilted up while torch being positioned, then down to block excess light during welding. Reduces welding time by 50 percent, and increases quality of weld substantially.

Carrasco, Eddie↗
NASA NTRS1990

Monitoring Both Sides Of A Weld In Progress

Proposed remote vision system provides simultaneous viewing of front and back of workpiece while being welded. Enables human or automatic controller to monitor both weld pool on front and weld penetration on back. Nitrogen laser generates ultraviolet light, distributed to both sides of workpiece through two optical fiber cables. Image-intensifier tubes convert reflected ultraviolet light to visible light. Video cameras equipped with high-resolution charge-coupled devices convert visible outputs of image intensifiers into images for viewing on video monitors.

Dickinson, C. B.↗
NASA NTRS1990

Monitoring Coating Thickness During Plasma Spraying

High-resolution video measures thickness accurately without interfering with process. Camera views cylindrical part through filter during plasma spraying. Lamp blacklights part, creating high-contrast silhouette on video monitor. Width analyzer counts number of lines in image of part after each pass of spray gun. Layer-by-layer measurements ensure adequate coat built up without danger of exceeding required thickness.

Miller, Robert A.↗