SFOF digital television display subassembly
SFOF digital television display subassembly providing continuous television compatible video output
Singleton, F. L.↗
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Development and testing of the television instrument for the Mariner Mars 1971 spacecraft
The Mariner Mars 1971 television instrument is described. It emphasizes those aspects that are different from the Mariner Mars 1969 television subsystem. The various modes of operation are described and functional descriptions of the major elements in the system summarized. An electronic description of the circuits that differ from those of Mariner Mars 1969 is also presented along with a brief description of the calibration and test sequences.
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Analysis of Surveyor 3 television cable after residence on the moon
The Apollo 12 astronauts brought the Surveyor III television camera back from the moon in November 1969. Chemical analyses of a portion of television cable revealed changes in the glass fabric sleeve and in the wire insulation as a result of exposure to the lunar environment. Loss of volatile constituents from the glass fabric and a discoloration of the glass occurred. The Teflon layer on the wire showed a slight discoloration and possibly a slight change in its infrared spectrum. Both the polyimide layer and the Teflon layer of the wire insulation showed changes in tensile strength and elongation.
Gross, F. C.↗
Development of television tubes for the large space telescope
Princeton Observatory has been working for several years under NASA sponsorship to develop television type sensors to use in place of photographic film for space astronomy. The performance of an SEC-vidicon with a 25 mm x 25 mm active area, MgF2 window, and bi-alkali photocathode is discussed. Results from ground based use on the Coude spectrograph of the 200-inch Hale telescope are included. The intended use of this tube in an echelle spectrograph sounding rocket payload and on Stratoscope 2 for direct high resolution imagery is also discussed. The paper also discusses the large space telescope image sensor requirements and the development of a larger television tube for this mission.
Lowrance, J. L.↗
Development of television tubes for the large space telescope.
Princeton Observatory has been working for several years under NASA sponsorship to develop television type sensors to use in place of photographic film for space astronomy. This paper discusses the performance of an SEC-vidicon with a 25 mm x 25 mm active area, MgF2 window, and bi-alkali photocathode. Results from ground based use on the Coude spectrograph of the 200-inch Hale telescope are included. The intended use of this tube in an echelle spectrograph sounding rocket payload and on Stratoscope II for direct high resolution imagery is also discussed. The paper also discusses the Large Space Telescope image sensor requirements and the development of a larger television tube for this mission.
Lowrance, J. L.↗
Digital image processing for the rectification of television camera distortions.
All television systems introduce distortions into the imagery they record which influence the results of quantitative photometric and geometric measurements. Digital computer techniques provide a powerful approach to the calibration and rectification of these systematic effects. Nonlinear as well as linear problems can be attacked with flexibility and precision. Methods which have been developed and applied for the removal of structured system noises and the correction of photometric, geometric, and resolution distortions in vidicon systems are briefly described. Examples are given of results derived primarily from the Mariner Mars 1969 television experiment.
Rindfleisch, T. C.↗
Development and application of color television for Apollo 15 and beyond
The development of the television system used for Apollo 15 mission is discussed. Data cover identification of factors contributing to the high quality of pictures generated on the lunar surface and exploration of several possible present and future uses of the television equipment developed.
Russell, S.↗
Ground-Commanded Television Assembly (GCTA)
A ground-commanded color television assembly (GCTA) was designed for use on lunar explorations associated with NASA manned Apollo missions. The camera system as seen on Apollo 15 provided television coverage in the vicinity of the lunar module (LM) landing site, and was mounted on the lunar roving vehicle (LRV) to provide color coverage of astronaut activity and lunar topography during traverses on the surface. Remote control of the camera from earth was accomplished through the existing real-time Apollo command links. The assembly is illustrated. The configuration satisfied all anticipated requirements of the Apollo 15 mission and was fully responsive to specifications. The technical approach was based on proven designs and offered maximum mission flexibility, potential growth, and capability to withstand environmental extremes encountered on the lunar surface.
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The data-handling problem with television recording of spectra.
A television tube is a useful way to record a many-element picture such as is obtained from an echelle spectrograph. The signal on the tube target is scanned and relayed to the data-processing center where it must be reconstituted into the scene that was present in the focal plane of the spectrograph camera. A typical television frame will contain four million bits of information which must be processed to remove transmission errors and random noise pulses, to remove periodic noise, to correct for optical and electrical distortion, to remove sensitivity variations across the face of the tube, to calibrate from the photoelectrons back to incident energy, and to provide a wavelength scale. Results of a study of these problems is presented.
Underhill, A. B.↗
Multichannel television coupling modulation experiments using a CO2 laser.
Experiments are described in which a carbon dioxide laser oscillating at 28.4 THz has been modulated simultaneously by three commercial television signals with carriers at 54, 66, and 82 MHz. Signal-to-noise degradation in the system was measured to be less than 1 dB, corresponding to modulator drive power of 1 W. This combination of wide bandwidth and low power consumption was made possible by the application of coupling modulation. This technique employs an intracavity electrooptic crystal to which the modulating fields are applied. Despite the fact that the crystal is positioned inside the laser cavity, the maximum bandwidth attainable is independent of both the cavity Q and the laser transition linewidth, and is limited only by modulator characteristics and optical transit time. Rigrod's (1965) method has been adapted to obtain an expression for the power coupled out of the laser. Modulator frequency response and drive power requirements are also summarized. It is seen that the noise bandwidth performance of the system would allow simultaneous modulation by 17 color television channels, or equivalently, more than a 300-megabit/sec capacity.
Hall, D. R.↗
Ground-Commanded Television Assembly (GCTA)
The characteristics of the Ground-Commanded Television Assembly (GCTA) are discussed. The equipment was used to provide television coverage of lunar surface explorations during Apollo 15, 16, and 17 missions. The subjects include the following; (1) yoke/faceplate qualification data, (2) elevation drive improvement program, (3) Apollo 17 thermal data, (4) equipment status, and (5) drawing status. Illustrations of the components of the assembly are provided. Tables of data are developed to show the performance of the components.
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An exploratory flight investigation of helicopter sling-load placements using a closed-circuit television as a pilot aid
Helicopter sling load operations have been limited during pick up and delivery of external cargo by the lack of precision achieved by the combination of pilot, helicopter, and sling load. Use of a closed circuit television as a pilot aid during sling load delivery and placement was documented along with additional cases representing procedures currently employed by military and commercial operators. Although an increase in pilot workload was noted when the television system was used, the results indicated a comparable level of performance for each test case.
Dicarlo, D. J.↗
Atlas of Surveyor 5 television data
This atlas is a compendium of the Surveyor 5 television mosaics. It it divided into two main sections. The first consists of improved mosaics of panoramas and basic cartographic data used in investigating surface detail, and the second contains individual frame data, including photoindex mosaics and tabulations in which individual frames are identified. A short section containing a set of special-purpose mosaics assembled by the staff of the Jet Propulsion Laboratory is also included. For more details about the Surveyor 5 mission, television data, or science results, a brief bibliography is included.
Batson, R. M.↗
Mariner Mars 1971 television picture catalog. Volume 1: Experiment design and picture data
A compilation of Mariner 9 television data is presented for the study of the planet Mars and of its two satellites, Phobos and Deimos. The concept of the basic mission, camera characteristics, and various processing techniques of the raw television data recovered from the spacecraft are discussed. Data are arranged into the following disciplines; (1) mapping and geology, (2) polar studies, (3) geodesy, (4) variable surface features, (5) atmospheric phenomena, and (6) satellites. Reproduction and arrangements of approximately 3000 individual pictures and photomosaics are provided.
Cutts, J. A.↗
Investigation of television transmission using adaptive delta modulation principles
The results are presented of a study on the use of the delta modulator as a digital encoder of television signals. The computer simulation of different delta modulators was studied in order to find a satisfactory delta modulator. After finding a suitable delta modulator algorithm via computer simulation, the results were analyzed and then implemented in hardware to study its ability to encode real time motion pictures from an NTSC format television camera. The effects of channel errors on the delta modulated video signal were tested along with several error correction algorithms via computer simulation. A very high speed delta modulator was built (out of ECL logic), incorporating the most promising of the correction schemes, so that it could be tested on real time motion pictures. Delta modulators were investigated which could achieve significant bandwidth reduction without regard to complexity or speed. The first scheme investigated was a real time frame to frame encoding scheme which required the assembly of fourteen, 131,000 bit long shift registers as well as a high speed delta modulator. The other schemes involved the computer simulation of two dimensional delta modulator algorithms.
Schilling, D. L.↗
ATS-6 - Satellite Instructional Television Experiment
The Satellite Instructional Television Experiment (SITE) is scheduled for the second year of satellite operation. Applications Technology Satellite (ATS-6) will receive C-band video signals from Ahmedabad and Delhi, India, and will retransmitt the video and two audio subcarriers at 860 MHz to 6 clusters of 400 direct-receive stations for a total of 2400 direct-receive stations. Morning programs of 1.5 hours per day are designed for classroom use, and evening programs of 2.5 hours duration are designed for village adult education. Indian production antennas and television sets have been tested and found to meet specifications, and a successful experiment is anticipated.
Miller, J. E.↗
Digital television system design study
The use of digital techniques for transmission of pictorial data is discussed for multi-frame images (television). Video signals are processed in a manner which includes quantization and coding such that they are separable from the noise introduced into the channel. The performance of digital television systems is determined by the nature of the processing techniques (i.e., whether the video signal itself or, instead, something related to the video signal is quantized and coded) and to the quantization and coding schemes employed.
Huth, G. K.↗
Design of a digital compression technique for shuttle television
The determination of the performance and hardware complexity of data compression algorithms applicable to color television signals, were studied to assess the feasibility of digital compression techniques for shuttle communications applications. For return link communications, it is shown that a nonadaptive two dimensional DPCM technique compresses the bandwidth of field-sequential color TV to about 13 MBPS and requires less than 60 watts of secondary power. For forward link communications, a facsimile coding technique is recommended which provides high resolution slow scan television on a 144 KBPS channel. The onboard decoder requires about 19 watts of secondary power.
Habibi, A.↗