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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
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Viewing Phobos and Deimos for navigating Mariner 9.

A new on-board optical navigation data technique has been successfully demonstrated on Mariner 9. Science TV pictures of Phobos and Deimos against star fields were used in the real time navigation process to insert Mariner 9 into orbit about Mars. Real time and post flight evaluation results have shown that the satellite/star data taken by Mariner 9 was more accurate than preflight analysis indicated. In fact the orbital insertion phase of the mission could have been achieved using only optical data to determine encounter parameters. The use of a science TV camera to obtain this data was successfully demonstrated. Stars as dim as 9th magnitude were detected and measurement accuracies of 3 arc sec (1 sigma) were achieved. The success of the optical navigation techniques developed for Mariner 9 has placed a new class of demanding missions (e.g., multiple outer planet, satellite tour, etc) within realized navigation capability.

Duxbury, T. C.↗
NASA NTRS1973

Mariner Mars 1971 television picture catalog: Sequence design and picture coverage, volume 2, addendum 1

This addendum to the Mariner Mars 1971 Television Picture Catalog, Volume 2 (for abstract, see N73-20850) contains data for the Mariner 9 TV pictures taken after Rev 262. Some of the data presented in Volume 2 is brought up to date. The new provisional mapping pole is discussed, and tables provide the latitude and longitude with respect to the new pole, prime meridian, and rotation rate for the centerpoints of all the Mariner 9 TV pictures.

Koskela, P. E.↗
NASA NTRS1973

Relevance of ERTS to the State of Ohio

The author has identified the following significant results. A significant result was the fabrication of an image transfer and comparison device. To avoid problems and high costs encountered in manual drafting methods, Battelle staff members have fabricated an inexpensive, yet effective, technique for transferring ERTS-1 analysis displays from the Spatial Data 32-Color Viewer to maps and/or aircraft imagery. In brief, the image transfer-comparison device consists of a 2-way mirror which functions similar to a zoom transfer scope. However, the device permits multiuser viewing and real time photographic recording (35-mm and Polaroid) of enhanced ERTS-1 imagery superimposed over maps and aircraft photography. Thirty-five mm, 70 mm, and 4 in. x 5 in. photographs are taken of 80% of the TV screen of the Spatial Data Density Slicing Viewer. The resulting black and white and color imagery is then used in transparent overlays, viewgraphs, 35-mm and 70-mm transparencies, and paper prints for reports and publications. Annotations can be added on the TV screen or on the finished product.

Sweet, D. C.↗
NASA NTRS1973

Developments in electronic imaging techniques; Proceedings of the Seminar-in-Depth, San Mateo, Calif., October 16, 17, 1972.

Capabilities and limitations of infrared imaging systems are discussed, and a real-time simulator for image data systems is described. Ultrahigh resolution electronic imaging and storage with the return beam vidicon is treated, and a description is given of an electron-lens for opaque photocathodes. Ground surveillance with an active low light level TV, digital processing of Mariner 9 TV data, image enhancement by holography, and application of data compression techniques to spacecraft imaging systems are given attention. Individual items are announced in this issue.

Zirkind, R.↗
NASA NTRS1973

Robot vision.

The work reported had been undertaken to develop hardware that would guide an automatic vehicle in the exploration of the surface of Mars, recognize objects, and report the findings to earth. Approaches for automatically determining the range and shape of objects are discussed, giving attention to the automatic comparison of one scan line of the left with one scan line of the right TV image. Methods of mapping binocular space into match space are considered together with the use of a model in match space, rules for processing random-dot stereograms, the elimination of spurious matches, random-square stereograms, questions of the processing of a real scene, and aspects of range accuracy. Methods of computation for extracting other features are also discussed along with stereo TV cameras and approaches for reconstructing the appearance of a scene.

Sutro, L. L.↗
NASA NTRS1969

Cathodochromic storage device

A memory and display device has been developed by combing a fast phosphor layer with a cathodochromic layer in a cathode ray tube. Images are stored as patterns of electron beam induced optical density in the cathodo-chromic material. The stored information is recovered by exciting the backing, fast phosphor layer with a constant current electron beam and detecting the emitted radiation which is modulated by absorption in the cathodochromic layer. The storage can be accomplished in one or more TV frames (1/30 sec each). More than 500 TV line resolution and close to 2:1 contrast ratio are possible. The information storage time in a dark environment is approximately 24 hours. A reconstituted (readout) electronic video signal can be generated continuously for times in excess of 10 minutes or periodically for several hours.

Bosomworth, D. R.↗
NASA NTRS1973

Video systems for real-time oil-spill detection

Three airborne television systems are being developed to evaluate techniques for oil-spill surveillance. These include a conventional TV camera, two cameras operating in a subtractive mode, and a field-sequential camera. False-color enhancement and wavelength and polarization filtering are also employed. The first of a series of flight tests indicates that an appropriately filtered conventional TV camera is a relatively inexpensive method of improving contrast between oil and water. False-color enhancement improves the contrast, but the problem caused by sun glint now limits the application to overcast days. Future effort will be aimed toward a one-camera system. Solving the sun-glint problem and developing the field-sequential camera into an operable system offers potential for color 'flagging' oil on water.

Millard, J. P.↗
NASA NTRS1974

Mariner IX optical navigation using Mars lit limb

Optical spacecraft navigation data, i.e., the lit limb TV image of Mars, acquired during the approach phase of the Mariner IX spacecraft to Mars, has been successfully demonstrated to augment the radio spacecraft tracking data. Accurate in-flight calibration of the TV instrument and the scan platform was performed by referencing stars and planets. Simulated real-time processing and the detailed postflight analyses of the onboard optical data have shown that planet limb data is an important data source in a far-encounter period for which other types of onboard optical measurements, e.g., natural satellite(s) of the target planet with star background, may not be available.

Jerath, N.↗
NASA NTRS1973

Some services of the Time and Frequency Division of the National Bureau of Standards

The Time and Frequency Division of the National Bureau of Standards (NBS) provides several services to the general public. The radio broadcasts of WWV, WWVH, and WWVB supply reliable, unambiguous time signals to many users. The NBS telephone time-of-day service attracts several hundreds of thousands of calls each year. Periodically, the NBS provides courses on specific topics relating to time and frequency technology. In addition to numerous technical papers published each year, the NBS has prepared the first volume of a comprehensive monograph on time and frequency. The results of research in the Time and Frequency Division of the NBS have had significant impact. An active TV time system capable of serving most of the U.S. currently awaits a ruling by the FCC on a petition filed last year on behalf of the NBS by the Department of Commerce. Three more recent developments are: (1) a TV frequency comparator (patent applied for); (2) a method to perform an independent (absolute) frequency evaluation of commercial cesium beam oscillators; and (3) a method of removing one source of frequency drift in commercial cesium beam oscillators.

Barnes, J. A.↗
NASA NTRS1973

The color bar phase meter: A simple and economical method for calibrating crystal oscillators

Comparison of crystal oscillators to the rubidium stabilized color burst is made easy and inexpensive by use of the color bar phase meter. Required equipment consists of an unmodified color TV receiver, a color bar synthesizer and a stop watch (a wrist watch or clock with sweep second hand may be used with reduced precision). Measurement precision of 1 x 10 to the minus 10th power can be realized in measurement times of less than two minutes. If the color bar synthesizer were commercially available, user cost should be less than $200.00, exclusive of the TV receiver. Parts cost for the color bar synthesizer which translates the crystal oscillator frequency to 3.579MHz and modulates the received RF signal before it is fed to the receiver antenna terminals is about $25.00. A more sophisticated automated version, with precision of 1 x 10 to the minus 11th power would cost about twice as much.

Davis, D. D.↗
NASA NTRS1974

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.↗
NASA NTRS1975

Recent developments in CID imaging

Readout of CID imaging arrays was first performed by injecting and detecting the signal charge from each sensing site in sequence. A new readout method, termed parallel injection, has been developed in which the functions of signal charge detection and injection have been separated. The level of signal charge at each sensing site is detected during a line scan, and during the line retrace interval, all charge in the selected line is injected. The parallel injection technique is well adapted to TV scan formats in that the signal is read out at high speed, line by line. A 244 line by 248 element TV compatible imager, employing this technique and including an on chip preamplifier, has been constructed and operation demonstrated.

Michon, G. J.↗
NASA NTRS1975

The MVM imaging system and its spacecraft interactions

The present work describes the main considerations and steps taken in determining the functional design of the imaging system of the Mariner Venus/Mercury (MVM) spacecraft and gives examples of some of the interactions between the spacecraft and the imaging instrument during the design and testing phases. Stringent cost and scheduling constraints dictated the use of the previous Mariner 9 dual-camera TV system. The TV parameters laid the groundwork for the imaging definition. Based on the flyby distances from Venus and Mercury and the goal of surface resolution better than 500 meters per sample pair, calculation was performed on focal length, format size, planetary coverage, and data rates. Some problems encountered in initial mechanical operation and as a result of spacecraft drift during the mission are also discussed.

Vescelus, F. E.↗
NASA NTRS1975

A novel technique for estimating relative motion

A potential method for determining the information needed for a successful docking between two vehicles, for example, an orbit-to-orbit shuttle and a malfunctioning satellite, is described. The method involves a single TV, used to obtain all the necessary information for docking and stationkeeping. Four passive reflectors, designed so that the electronically scanned images are distinguishable, are mounted on the satellite to provide the only means of cooperation required between the satellite and the shuttle. The relations for obtaining range and rate data from TV data are set forth.

Larson, V.↗
NASA NTRS1976

Shear dampers for deflections of micro-inch magnitudes

The rotation of the TV camera on the Mariner Jupiter/Saturn 1977 (MJS77) spacecraft will excite the long magnetometer and heavy RTG booms which are slightly damped perturbances that have long settling times. To ensure clear TV pictures additional damping was required over micro-inch displacements and at low frequencies. The solution incorporated elastomeric shear dampers at the base of these booms which possessed high loss tangent values in the expected frequency and temperature ranges. Presented are the shear damper design, results of full scale horizontal boom tests and relative effects of damper sizing and temperature. Boom instrumentation and excitation used for the full scale tests are also discussed.

Otth, D.↗
NASA NTRS1977

Observing and recording instantaneous images on ATM television monitors

A persistent image-converter device was utilized to make visible to the astronaut solar images that were isolated, instantaneous flashes on the ATM TV monitors. In addition, these instantaneous images, as well as normal TV images, were recorded with a Polaroid SX-70 camera for study by the astronauts.

Patterson, N. P.↗
NASA NTRS1979

Apparatus for measuring an aircraft's speed and height

An apparatus for measuring aircraft horizontal speed and height above ground without the need for airborne cooperative devices is presented. Two ground level TV cameras separated by a measured distance and pointed at zenith are placed in line with the projection of the expected path of the aircraft. Speed is determined by measuring the time that it takes the aircraft to travel between the fields of view of the two TV cameras using zenith crossings as the reference points. Height is determined by correlating the speed with the time required to cross the field of view of either of the two cameras.

Young, W. R.↗
NASA NTRS1978

Shuttle Orbiter solid-state television camera

The Shuttle closed-circuit TV system incorporates a mix of monochrome TV cameras (in the payload bay for operations support purposes) and color cameras (in the crew cabin for crew activity monitoring purposes). These cameras currently employ glass enclosed, vacuum processed image sensors. A camera that uses a solid-state image sensor offers many extremely attractive advantages. This paper presents the current status of development of solid-state television cameras - monochrome and NTSC color - for use in various aspects of the Space Shuttle program. Results of in depth design and testing programs are discussed as well as the plans for employing these cameras in the Shuttle program.

Embrey, B. C., Jr.↗