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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 235 records · Page 13

92 GHz dual-polarized integrated horn antennas

A dual-polarized two-dimensional imaging array was designed for millimeter-wave applications. The dual-polarized design consists of two dipoles perpendicular to each other and suspended on the same membrane inside a pyramidal cavity etched in silicon. The dual-polarized antenna is fully monolithic with room available for processing electronics. The IF or video signals are taken out through a novel bias and feeding structure. The measured polarization isolation is better than 20 dB at 92 GHz, and the orthogonal channels show identical far-field patterns. The antenna is well suited for millimeter-wave polarimetric synthetic-aperture radars (SARs) and high-efficiency balanced-mixer receivers.

Ali-Ahmad, Walid Y.↗

Gain, Level, And Exposure Control For A Television Camera

Automatic-level-control/automatic-gain-control (ALC/AGC) system for charge-coupled-device (CCD) color television camera prevents over-loading in bright scenes using technique for measuring brightness of scene from red, green, and blue output signals and processing these into adjustments of video amplifiers and iris on camera lens. System faster, does not distort video brightness signals, and built with smaller components.

Major, Geoffrey J.↗

Huntsville Operations Support Center

Information is given in viewgraph form on the Huntsville Operations Support Center (HOSC). The HOSC is a multi-mission control and support facility designed to provide simultaneous support to several diverse missions, using a common set of processing equipment and facilities. Information is given on the missions supported by the HOSC; facility layout; generic system goals; HOSC existing computer architecture; current mission requirements; currently employed hardware and software; front end processing; central processing; peripheral processors; audio and video communications; and upgrading plans.

Bailey, Darrell G.↗

Particle displacement tracking applied to air flows

Electronic Particle Image Velocimetric (PIV) techniques offer many advantages over conventional photographic PIV methods such as fast turn around times and simplified data reduction. A new all electronic PIV technique was developed which can measure high speed gas velocities. The Particle Displacement Tracking (PDT) technique employs a single CW laser, small seed particles (1 micron), and a single intensified, gated CCD array frame camera to provide a simple and fast method of obtaining two-dimensional velocity vector maps with unambiguous direction determination. Use of a single CCD camera eliminates registration difficulties encountered when multiple cameras are used to obtain velocity magnitude and direction information. An 80386 PC equipped with a large memory buffer frame-grabber board provides all of the data acquisition and data reduction operations. No array processors of other numerical processing hardware are required. Full video resolution (640 x 480 pixel) is maintained in the acquired images, providing high resolution video frames of the recorded particle images. The time between data acquisition to display of the velocity vector map is less than 40 sec. The new electronic PDT technique is demonstrated on an air nozzle flow with velocities less than 150 m/s.

Wernet, Mark P.↗

Probabilistic Extraction Of Vectors In PIV

Probabilistic technique for extraction of velocity vectors in particle-image velocimetry (PIV) implemented with much less computation. Double-exposure photograph of particles in flow illuminated by sheet of light provides data on velocity field of flow. Photograph converted into video image then digitized and processed by computer into velocity-field data. Velocity vectors in interrogation region chosen from magnitude and angle histograms constructed from centroid map of region.

Humphreys, William M., Jr.↗

Medical Imaging

This video shows how satellite data processing techniques (multispectral scanning) can improve disease detection and treatment.

Source record↗

Transport and Chemical Effects on Concurrent and Opposed-Flow Flame Spread at Microgravity

With support from a previous NASA grant, NAG3-161 1, the PI studied the effects of diluent type, the addition of sub-flammability-limit concentrations of combustible gases, and the effects of concurrent buoyant flow on flame spread processes. The results of these studies are reported and directions for the current grant outlined. Most experiments were conducted in a 20 liter combustion chamber. Exactly the same apparatus was used for 1 g and microgravity tests. The effect of inert gases He, Ar, N2, CO2 and SF6 on flame spread were tested since they provide a variety of radiative properties and oxygen Lewis numbers. CO and CH4 were used for the gaseous fuels in partially-premixed atmosphere tests, plus H2, C3H8 and NH3 for 1 g tests only. In most experiments 5 cm wide Kimwipe samples 15 cm long were used and were held by aluminum quenching plates. The samples were ignited by an electrically-heated Kanthal wire. The flame spread process was imaged via three video cameras and a laser shearing interferometer.

Honda, L. K.↗

STS-114: Discovery Post MMT Press Conference

Bruce Buckingham from NASA Public Affairs introduces the panel who consists of: Wayne Hale, Space Shuttle Program Deputy Manager; John Muratore, Manager, Space Shuttle Systems and Integration; and Mike Wetmore, Director of Shuttle Processing. Hale begins with a video presentation of the point sensor box (black box) and discusses the troubleshooting plans that are in place to fix the low level fuel sensor inside the External Tank of the Space Shuttle Discovery. Muratore talks about exploring conditions that may be causing the problem and Wetmore discusses completing scrub securing. Questions from the news media pertaining to solutions to the sensor problem, risks involved, and anomalies are addressed.

Source record↗

Digital data processing of ERTS-1 imagery of Delaware Bay

A user-oriented Earth Resources Data Center is in operation at Bendix Aerospace, which a capable of automatically producing classification imagery and thematic maps from ERTS computer compatible tapes. The ERDC is now being used to process ERTS-1 data under a subcontract from the University of Delaware. ERTS coverage of Delaware Bay has been processed to produce classification imagery of water masses in the bay, and a map of all land-water boundaries along the shoreline including wetlands and inland lakes. Imagery, the user's video monitor color display, the data processing facility, and methodology are described.

Conrod, A. C.↗

Imaging Invisible Flames Without Additives

Image intensifiers, video cameras, and image-data-processing computers used to study combustion. Possible to view and analyze methane, hydrogen, and other flames dim or invisible to human eye and difficult to image by use of conventional photographic and video cameras.

Weiland, Karen J.↗

Synthesis of Speaker Facial Movement to Match Selected Speech Sequences

A system is described which allows for the synthesis of a video sequence of a realistic-appearing talking human head. A phonic based approach is used to describe facial motion; image processing rather than physical modeling techniques are used to create video frames.

phonics speech synthesis imaging image processing ↗

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.↗

The interactive digital video interface

A frequent complaint in the computer oriented trade journals is that current hardware technology is progressing so quickly that software developers cannot keep up. A example of this phenomenon can be seen in the field of microcomputer graphics. To exploit the advantages of new mechanisms of information storage and retrieval, new approaches must be made towards incorporating existing programs as well as developing entirely new applications. A particular area of need is the correlation of discrete image elements to textural information. The interactive digital video (IDV) interface embodies a new concept in software design which addresses these needs. The IDV interface is a patented device and language independent process for identifying image features on a digital video display and which allows a number of different processes to be keyed to that identification. Its capabilities include the correlation of discrete image elements to relevant text information and the correlation of these image features to other images as well as to program control mechanisms. Sophisticated interrelationships can be set up between images, text, and program control mechanisms.

Doyle, Michael D.↗

Open Source Subtitle Editor Software Study for Section 508 Close Caption Applications

This paper will focus on a specific item within the NASA Electronic Information Accessibility Policy - Multimedia Presentation shall have synchronized caption; thus making information accessible to a person with hearing impairment. This synchronized caption will assist a person with hearing or cognitive disability to access the same information as everyone else. This paper focuses on the research and implementation for CC (subtitle option) support to video multimedia. The goal of this research is identify the best available open-source (free) software to achieve synchronized captions requirement and achieve savings, while meeting the security requirement for Government information integrity and assurance. CC and subtitling are processes that display text within a video to provide additional or interpretive information for those whom may need it or those whom chose it. Closed captions typically show the transcription of the audio portion of a program (video) as it occurs (either verbatim or in its edited form), sometimes including non-speech elements (such as sound effects). The transcript can be provided by a third party source or can be extracted word for word from the video. This feature can be made available for videos in two forms: either Soft-Coded or Hard-Coded. Soft-Coded is the more optional version of CC, where you can chose to turn them on if you want, or you can turn them off. Most of the time, when using the Soft-Coded option, the transcript is also provided to the view along-side the video. This option is subject to compromise, whereas the transcript is merely a text file that can be changed by anyone who has access to it. With this option the integrity of the CC is at the mercy of the user. Hard-Coded CC is a more permanent form of CC. A Hard-Coded CC transcript is embedded within a video, without the option of removal.

Murphy, F. Brandon↗

Simulation of the Effects of Hard Limiting on Image Quality of Synthetic Aperture Radar

Starting with a magnetic tape of a scene viewed by the Landsat satellite, the radar return of reflectors whose average intensity matched that of the picture elements in the scene has been simulated. The returns were processed in three ways: normally or with no quantization, with a procedure simulation IF hard limiting, and with a procedure simulating video (baseband) hard limiting. For each type of processing an image for a one, two, and four-look system has been developed. It was found that IF limiting is slightly better than video limiting, while both can be reasonable trade-offs of image quality for reduced data rates when the number of looks is four or less. These conclusions are supported by photographs representing the different processing techniques.

Lipes, R. G.↗

Electron beam recorder image correction for ERTS

Video data from the Earth Resources Technology Satellite (ERTS) are entered into the initial image generation system and placed on film using an electron beam to correct for both radiometric and geometric errors, a hardware unit called EBRIC was designed, fabricated, and incorporated in the image processing system. It operates under the control of a process control computer, as it varies video signal and the x and y deflection signals of the EBR.

Heffner, P.↗

Some technical considerations on the evolution of the IBIS system

In connection with work related to the use of earth-resources images, it became apparent by 1974, that certain system improvements are necessary for the efficient processing of digital data. To resolve this dilemma, Billingsley and Bryant (1975) proposed the use of image processing technology. Bryant and Zobrist (1976) reported the development of the Image Based Information System (IBIS) as a subset of an overall Video Image Communication and Retrieval (VICAR) image processing system. A description of IBIS is presented, and its employment in connection with advanced applications is discussed. It is concluded that several important lessons have been learned from the development of IBIS. The development of a flexible system such as IBIS is found to rest upon the prior development of a general purpose image processing system, such as VICAR.

Bryant, N. A.↗

Advanced Video Analysis Needs for Human Performance Evaluation

Evaluators of human task performance in space missions make use of video as a primary source of data. Extraction of relevant human performance information from video is often a labor-intensive process requiring a large amount of time on the part of the evaluator. Based on the experiences of several human performance evaluators, needs were defined for advanced tools which could aid in the analysis of video data from space missions. Such tools should increase the efficiency with which useful information is retrieved from large quantities of raw video. They should also provide the evaluator with new analytical functions which are not present in currently used methods. Video analysis tools based on the needs defined by this study would also have uses in U.S. industry and education. Evaluation of human performance from video data can be a valuable technique in many industrial and institutional settings where humans are involved in operational systems and processes.

Campbell, Paul D.↗